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Lighthouse Desktop

· 0 checks — Desktop Lighthouse audit -- Performance, Accessibility, Best Practices, and SEO category breakdown.
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Detailed Report

Audit breakdown by category with detailed findings.

48

Performance

Insights

Remove large, duplicate JavaScript modules from bundles to reduce unnecessary bytes consumed by network activity.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Polyfills and transforms enable older browsers to use new JavaScript features. However, many aren't necessary for modern browsers. Consider modifying your JavaScript build process to not transpile Baseline features, unless you know you must support older browsers. Learn why most sites can deploy ES6+ code without transpiling

Why this matters

Performance issues directly impact user engagement and conversion rates.

3rd party code can significantly impact load performance. Reduce and defer loading of 3rd party code to prioritize your page's content.

Why this matters

Performance issues directly impact user engagement and conversion rates.

A long cache lifetime can speed up repeat visits to your page. Learn more about caching.

Why this matters

Performance issues directly impact user engagement and conversion rates.

RequestCache TTLTransfer Size
www.cas.cn/gd/202603/W020260320367237873144_ORIGIN.jpg0.0 ms622.6 KiB
www.cas.cn/gd/202603/W020260304562615519478_ORIGIN.jpg0.0 ms456.8 KiB
www.cas.cn/yx/202603/W020260324417741201243.png0.0 ms454.2 KiB
www.cas.cn/images/topbgimg_20251217.png0.0 ms441.8 KiB
www.cas.cn/gd/202603/W020260320373519199299_ORIGIN.jpg0.0 ms387.9 KiB
www.cas.cn/gd/202603/W020260305339535003381_ORIGIN.jpg0.0 ms366.7 KiB
www.cas.cn/gj/202604/W020260421522038092312.png0.0 ms350.4 KiB
www.cas.cn/cm/202604/W020260421385309959198.png0.0 ms280.4 KiB
www.cas.cn/newmedia/dsp/202604/W020260420329652831168.png0.0 ms269.6 KiB
www.cas.cn/sygz/202604/W020260416563069960778.png0.0 ms267.7 KiB
www.cas.cn/gd/202603/W020260304562615738276_ORIGIN.jpg0.0 ms266.8 KiB
www.cas.cn/gd/202603/W020260305339535231140_ORIGIN.jpg0.0 ms233.6 KiB
www.cas.cn/gd/202601/W020260128305083603703_ORIGIN.jpg0.0 ms230.0 KiB
www.cas.cn/spx/202604/W020260420379180266731_ORIGIN.jpg0.0 ms217.0 KiB
www.cas.cn/images/z19_ewm3.jpg0.0 ms215.4 KiB
www.cas.cn/gd/202603/W020260303457407403045_ORIGIN.jpg0.0 ms212.4 KiB
www.cas.cn/images/z19_foot.png0.0 ms208.7 KiB
www.cas.cn/spx/202604/W020260417530461254188_ORIGIN.jpg0.0 ms206.3 KiB
www.cas.cn/yw/202604/W020260414668107692283_ORIGIN.jpg0.0 ms192.9 KiB
www.cas.cn/images/20260309_navkjqk.png0.0 ms187.3 KiB
www.cas.cn/newmedia/dsp/202604/W020260421546988627746.png0.0 ms167.1 KiB
www.cas.cn/syky/202604/W020260421315832007785_ORIGIN.jpg0.0 ms141.8 KiB
www.cas.cn/images/20230731zcjd.jpg0.0 ms129.0 KiB
www.cas.cn/gd/202601/W020260121576547305038_ORIGIN.jpg0.0 ms123.3 KiB
www.cas.cn/images/z19_foot_m.jpg0.0 ms122.8 KiB
www.cas.cn/gd/202601/W020260121572218060263_ORIGIN.jpg0.0 ms121.2 KiB
www.cas.cn/gd/202603/W020260303457407615596_ORIGIN.jpg0.0 ms120.0 KiB
www.cas.cn/gd/202601/W020260128305083857947_ORIGIN.jpg0.0 ms118.4 KiB
www.cas.cn/lib/css/hover.css0.0 ms116.2 KiB
www.cas.cn/spx/202604/W020260418314827276324_ORIGIN.jpg0.0 ms115.0 KiB
www.cas.cn/lib/js/plugin/wza/esdtoolsinit.js0.0 ms100.9 KiB
www.cas.cn/lib/js/jquery.min.js0.0 ms95.1 KiB
www.cas.cn/zt1/202604/W020260401410085460301.jpg0.0 ms94.8 KiB
www.cas.cn/images/swiper.min.js0.0 ms94.4 KiB
www.cas.cn/zt1/202603/W020260320378579484579.jpg0.0 ms88.3 KiB
www.cas.cn/images/zjzkymob_202303.jpg0.0 ms86.4 KiB
www.cas.cn/zt1/202604/W020260401410081532588.jpg0.0 ms82.5 KiB
www.cas.cn/zz/yld/201605/W020190929739561066807.jpg0.0 ms81.1 KiB
www.cas.cn/kxyj/202512/W020251218633030399800.jpg0.0 ms75.0 KiB
www.cas.cn/zz/yld/201704/W020190929738332637068.jpg0.0 ms73.3 KiB
www.cas.cn/kxyj/202512/W020251218541107090958_ORIGIN.jpg0.0 ms71.2 KiB
www.cas.cn/images/zjxbmob_202303.jpg0.0 ms70.6 KiB
www.cas.cn/images/z19_kxyj_img2.jpg0.0 ms69.7 KiB
www.cas.cn/syzc/202312/W020231229530488598921_ORIGIN.jpg0.0 ms56.4 KiB
www.cas.cn/images/z19_tj_img1.jpg0.0 ms53.2 KiB
www.cas.cn/zz/yld/201803/W020191125383560116474.jpg0.0 ms49.3 KiB
www.cas.cn/images/zjzkypc_202303.jpg0.0 ms47.3 KiB
www.cas.cn/lib/js/plugin/swiper/idangerous.swiper.min.js0.0 ms44.4 KiB
www.cas.cn/kx/202404/W020240510574946875857_ORIGIN.jpg0.0 ms43.9 KiB
www.cas.cn/zz/yld/202504/W020250416559005659783_ORIGIN.jpg0.0 ms40.3 KiB
www.cas.cn/images/zkyzsmob_202303.jpg0.0 ms38.8 KiB
www.cas.cn/images/z2025_dqgz1.jpg0.0 ms37.9 KiB
www.cas.cn/images/z19_dqgz2.jpg0.0 ms37.4 KiB
www.cas.cn/images/zkyzspc_202303.jpg0.0 ms36.9 KiB
www.cas.cn/zz/yld/202308/W020240329553856002424_ORIGIN.jpg0.0 ms36.5 KiB
www.cas.cn/zz/yld/202409/W020240912524118761361_ORIGIN.jpg0.0 ms36.2 KiB
www.cas.cn/images/dsb02_20251217.png0.0 ms36.0 KiB
www.cas.cn/zz/yld/202404/W020240407367171999355_ORIGIN.jpg0.0 ms34.7 KiB
www.cas.cn/images/zjxbpc_202303.jpg0.0 ms34.5 KiB
www.cas.cn/zz/yld/202504/W020250406365313605807_ORIGIN.jpg0.0 ms34.0 KiB
www.cas.cn/zz/yld/202311/W020231122659760924736.jpg0.0 ms33.6 KiB
www.cas.cn/zz/yld/202504/W020250406366075798999_ORIGIN.jpg0.0 ms31.3 KiB
www.cas.cn/zz/yld/201909/W020201118270525579945.jpg0.0 ms30.5 KiB
www.cas.cn/kx/202404/W020240510575174145626_ORIGIN.jpg0.0 ms29.0 KiB
www.cas.cn/images/z19_public.css?v=202512180.0 ms24.6 KiB
www.cas.cn/newmedia/dsp/202604/W020260421276040437486.jpg0.0 ms23.5 KiB
www.cas.cn/images/20220826kejitop.jpg0.0 ms23.3 KiB
www.cas.cn/cg/112072/images/P020190929620050824644.jpg0.0 ms22.8 KiB
www.cas.cn/images/yjzxgl_202203826.jpg0.0 ms21.4 KiB
www.cas.cn/lib/js/plugin/swiper/swiper.min.css0.0 ms19.5 KiB
www.cas.cn/images/dsb01_20251217.png0.0 ms18.2 KiB
www.cas.cn/images/z19_logo.png0.0 ms16.3 KiB
www.cas.cn/images/z19_tj_img3.jpg0.0 ms15.2 KiB
www.cas.cn/images/z19_school_bar1.jpg0.0 ms13.8 KiB
www.cas.cn/images/z19_index.css?v=202512250.0 ms13.2 KiB
www.cas.cn/images/z19_main.js?v=1.00.0 ms13.0 KiB
www.cas.cn/images/z19_school_bar3.jpg0.0 ms12.3 KiB
www.cas.cn/images/z19_stylePad.css0.0 ms12.1 KiB
www.cas.cn/images/z19_school_bar2.jpg0.0 ms11.7 KiB
www.cas.cn/images/z19_school3.jpg0.0 ms10.3 KiB
www.cas.cn/images/z19_school2.jpg0.0 ms9.5 KiB
www.cas.cn/images/z19_school1.jpg0.0 ms8.0 KiB
www.cas.cn/images/z19_close.png0.0 ms6.3 KiB
www.cas.cn/images/z22_jl_xfqd.png0.0 ms5.3 KiB
www.cas.cn/images/z19_jl_icon4.png0.0 ms5.2 KiB
www.cas.cn/images/z19_index_yw2.png0.0 ms4.6 KiB
www.cas.cn/images/z19_jl_icon2.png0.0 ms4.6 KiB
www.cas.cn/images/z19_gopc.png0.0 ms4.4 KiB
www.cas.cn/images/jiucuo.png0.0 ms4.1 KiB
www.cas.cn/images/z19_jl_icon5.png0.0 ms3.7 KiB
www.cas.cn/images/wza_2024.png0.0 ms3.3 KiB
www.cas.cn/lib/js/plugin/jquery.cookie.js0.0 ms3.3 KiB
www.cas.cn/images/z19_scroll_wb.png0.0 ms3.2 KiB
www.cas.cn/images/z19_return_m.png0.0 ms3.0 KiB
www.cas.cn/images/z19_scroll_wx.png0.0 ms2.6 KiB
www.cas.cn/images/blue.png0.0 ms2.5 KiB
www.cas.cn/images/z19_yw_2025tab2.png0.0 ms2.4 KiB
www.cas.cn/images/z19_search_m.png0.0 ms2.4 KiB
www.cas.cn/images/z19_index_yw1.png0.0 ms2.2 KiB
www.cas.cn/images/z19_pc_m.png0.0 ms2.2 KiB
www.cas.cn/images/z19_index_xk1.png0.0 ms2.0 KiB
www.cas.cn/images/z19_h5.js0.0 ms2.0 KiB
www.cas.cn/images/z19_video_play.png0.0 ms1.9 KiB
www.cas.cn/images/z19_jl_bg.jpg0.0 ms1.7 KiB
www.cas.cn/images/z19_en_m.png0.0 ms1.7 KiB
www.cas.cn/images/z19_index_tz2.png0.0 ms1.7 KiB
www.cas.cn/images/foot_jgawb.png0.0 ms1.6 KiB
www.cas.cn/images/z19_index_tj.png0.0 ms1.6 KiB
www.cas.cn/images/z19_nav_up.png0.0 ms1.4 KiB
www.cas.cn/images/z19_index_xk2.png0.0 ms1.4 KiB
www.cas.cn/lib/js/plugin/topSide.min.js0.0 ms1.4 KiB
www.cas.cn/images/z19_focus_left.png0.0 ms1.3 KiB
www.cas.cn/images/z19_focus_right.png0.0 ms1.3 KiB
www.cas.cn/images/z19_resize.js0.0 ms1.3 KiB
www.cas.cn/images/z19_xk_tab_pad.png0.0 ms1.3 KiB
www.cas.cn/images/z19_index_tz1.png0.0 ms1.2 KiB
www.cas.cn/images/z19_bg_blue2.png0.0 ms1.2 KiB
www.cas.cn/images/z19_index_ky1.png0.0 ms1.2 KiB
www.cas.cn/images/z19_scroll_top.png0.0 ms1.1 KiB
www.cas.cn/images/z19_index_ft1.png0.0 ms1.0 KiB
www.cas.cn/images/z19_index_video1.png0.0 ms1.0 KiB
www.cas.cn/images/z19_index_video2.png0.0 ms1020 B
www.cas.cn/images/z19_jl_img.png0.0 ms919 B
www.cas.cn/images/z19_index_zt1.png0.0 ms877 B
www.cas.cn/images/z19_index_ky2.png0.0 ms750 B
www.cas.cn/images/z19_index_ft2.png0.0 ms750 B
www.cas.cn/images/z19_index_gz2.png0.0 ms727 B
www.cas.cn/images/z19_index_gz1.png0.0 ms689 B
www.cas.cn/images/z19_search.png0.0 ms647 B
www.cas.cn/images/z19_news_list.png0.0 ms597 B
www.cas.cn/images/z19_bg_blue.png0.0 ms539 B
www.cas.cn/images/z19_xk_tab.png0.0 ms485 B
www.cas.cn/images/z19_xk_list.png0.0 ms318 B

Layout shifts occur when elements move absent any user interaction. Investigate the causes of layout shifts, such as elements being added, removed, or their fonts changing as the page loads.

Why this matters

Performance issues directly impact user engagement and conversion rates.

headings: [map[key:node label:Element subItemsHeading:map[key:extra] valueType:node] map[granularity:0.001 key:score label:Layout shift score subItemsHeading:map[key:cause valueType:text] valueType:numeric]]
items: [map[node:map[type:text value:Total] score:0.626579] map[node:map[boundingRect:map[bottom:2292 height:1321 left:48 right:1302 top:971 width:1254] lhId:page-33-DIV nodeLabel:要闻播报 院内要闻 更多院内要闻 + 中央第十三巡视组巡视中国科学院党组工作动员会召开 2026年04月14日 中央第十三巡视组巡视中国科学院党组工作动员会召… path:1,HTML,1,BODY,14,DIV,6,DIV selector:body > div.container > div.row snippet:<div class="row clearfix"> type:node] score:0.362307 subItems:map[items:[map[cause:Unsized image element extra:map[boundingRect:map[bottom:1009 height:30 left:68 right:98 top:979 width:30] lhId:page-50-IMG nodeLabel:ul.tab_title > li.tab_title_yw1 > a > img path:1,HTML,1,BODY,14,DIV,6,DIV,1,DIV,1,DIV,0,UL,0,LI,0,A,0,IMG selector:ul.tab_title > li.tab_title_yw1 > a > img snippet:<img src="//www.cas.cn/images/z19_index_yw1.png"> type:node]]] type:subitems]] map[node:map[boundingRect:map[bottom:2292 height:1321 left:48 right:1302 top:971 width:1254] lhId:page-33-DIV nodeLabel:要闻播报 院内要闻 更多院内要闻 + 中央第十三巡视组巡视中国科学院党组工作动员会召开 2026年04月14日 中央第十三巡视组巡视中国科学院党组工作动员会召… path:1,HTML,1,BODY,14,DIV,6,DIV selector:body > div.container > div.row snippet:<div class="row clearfix"> type:node] score:0.160445 subItems:map[items:[map[cause:Unsized image element extra:map[boundingRect:map[bottom:1009 height:30 left:68 right:98 top:979 width:30] lhId:page-50-IMG nodeLabel:ul.tab_title > li.tab_title_yw1 > a > img path:1,HTML,1,BODY,14,DIV,6,DIV,1,DIV,1,DIV,0,UL,0,LI,0,A,0,IMG selector:ul.tab_title > li.tab_title_yw1 > a > img snippet:<img src="//www.cas.cn/images/z19_index_yw1.png"> type:node]]] type:subitems]] map[node:map[boundingRect:map[bottom:2432 height:2122 left:48 right:1302 top:310 width:1254] lhId:page-29-DIV nodeLabel:习近平同莫桑比克总统查波举行会谈 中科院之声 专题：改革创新发展这五年 中国科学院深入开展树立和践行正确政绩观学习教育 科学家发现野生稻多年生生活习性关键… path:1,HTML,1,BODY,14,DIV selector:body > div.container snippet:<div class="container boxcenter main index_add2025"> type:node] score:0.097845 subItems:map[items:[map[cause:Unsized image element extra:map[boundingRect:map[bottom:134 height:60 left:48 right:308 top:74 width:260] lhId:page-25-IMG nodeLabel:div.top2 > div.container > a.xsdlogotop > img.logo path:1,HTML,1,BODY,5,DIV,0,DIV,0,A,0,IMG selector:div.top2 > div.container > a.xsdlogotop > img.logo snippet:<img src="//www.cas.cn/images/z19_logo.png" class="logo fl_all"> type:node]]] type:subitems]] map[node:map[boundingRect:map[bottom:1181 height:146 left:48 right:264 top:1035 width:216] lhId:page-7-IMG nodeLabel:div.tab_con > div.yw_img > a > img.hvr-grow path:1,HTML,1,BODY,14,DIV,6,DIV,1,DIV,1,DIV,1,DIV,4,DIV,1,DIV,0,A,0,IMG selector:div.tab_con > div.yw_img > a > img.hvr-grow snippet:<img src="./yw/202604/W020260414668107692283_ORIGIN.jpg" class="hvr-grow"> type:node] score:0.005899 subItems:map[items:[map[cause:Unsized image element extra:map[boundingRect:map[bottom:1466 height:28 left:62 right:90 top:1438 width:28] lhId:page-49-IMG nodeLabel:ul.tab_title > li.now > a > img path:1,HTML,1,BODY,14,DIV,6,DIV,1,DIV,4,DIV,0,UL,0,LI,0,A,0,IMG selector:ul.tab_title > li.now > a > img snippet:<img src="//www.cas.cn/images/z19_index_ky1.png"> type:node]]] type:subitems]] map[node:map[boundingRect:map[bottom:1462 height:20 left:174 right:178 top:1442 width:4] lhId:page-32-SPAN nodeLabel:| path:1,HTML,1,BODY,14,DIV,6,DIV,1,DIV,4,DIV,0,UL,0,LI,0,A,2,SPAN selector:ul.tab_title > li.now > a > span snippet:<span> type:node] score:8.3e-05 subItems:map[items:[map[cause:Unsized image element extra:map[boundingRect:map[bottom:1466 height:28 left:62 right:90 top:1438 width:28] lhId:page-49-IMG nodeLabel:ul.tab_title > li.now > a > img path:1,HTML,1,BODY,14,DIV,6,DIV,1,DIV,4,DIV,0,UL,0,LI,0,A,0,IMG selector:ul.tab_title > li.now > a > img snippet:<img src="//www.cas.cn/images/z19_index_ky1.png"> type:node]]] type:subitems]]]
headings: [map[key:node label:Element subItemsHeading:map[key:extra] valueType:node] map[granularity:0.001 key:score label:Layout shift score subItemsHeading:map[key:cause valueType:text] valueType:numeric]]
items: [map[node:map[type:text value:Total] score:0.214815] map[node:map[boundingRect:map[bottom:2432 height:2122 left:48 right:1302 top:310 width:1254] lhId:page-29-DIV nodeLabel:习近平同莫桑比克总统查波举行会谈 中科院之声 专题：改革创新发展这五年 中国科学院深入开展树立和践行正确政绩观学习教育 科学家发现野生稻多年生生活习性关键… path:1,HTML,1,BODY,14,DIV selector:body > div.container snippet:<div class="container boxcenter main index_add2025"> type:node] score:0.214815]]
headings: [map[key:node label:Element subItemsHeading:map[key:extra] valueType:node] map[granularity:0.001 key:score label:Layout shift score subItemsHeading:map[key:cause valueType:text] valueType:numeric]]
items: [map[node:map[type:text value:Total] score:0.115954] map[node:map[boundingRect:map[bottom:921 height:511 left:-2460 right:-1206 top:410 width:1254] lhId:page-44-LI nodeLabel:科学家发现野生稻多年生生活习性关键基因 path:1,HTML,1,BODY,14,DIV,2,DIV,0,DIV,0,UL,2,LI selector:div.m_index_focus > div#swiper_container_top_Focus > ul.swiper-wrapper > li.swiper-slide snippet:<li class="swiper-slide" style="width: 1254px; height: 511px;"> type:node] score:0.115954 subItems:map[items:[map[cause:Unsized image element extra:map[boundingRect:map[bottom:1009 height:30 left:68 right:98 top:979 width:30] lhId:page-50-IMG nodeLabel:ul.tab_title > li.tab_title_yw1 > a > img path:1,HTML,1,BODY,14,DIV,6,DIV,1,DIV,1,DIV,0,UL,0,LI,0,A,0,IMG selector:ul.tab_title > li.tab_title_yw1 > a > img snippet:<img src="//www.cas.cn/images/z19_index_yw1.png"> type:node]]] type:subitems]]]
headings: [map[key:node label:Element subItemsHeading:map[key:extra] valueType:node] map[granularity:0.001 key:score label:Layout shift score subItemsHeading:map[key:cause valueType:text] valueType:numeric]]
items: [map[node:map[type:text value:Total] score:4e-06] map[node:map[boundingRect:map[bottom:900 height:14 left:1178 right:1192 top:886 width:14] lhId:page-48-SPAN nodeLabel:div.container > div.m_index_focus > div.pagination > span.swiper-pagination-switch path:1,HTML,1,BODY,14,DIV,2,DIV,1,DIV,2,SPAN selector:div.container > div.m_index_focus > div.pagination > span.swiper-pagination-switch snippet:<span class="swiper-pagination-switch"> type:node] score:4e-06 subItems:map[items:[map[cause:Unsized image element extra:map[boundingRect:map[bottom:885 height:475 left:3810 right:5064 top:410 width:1254] lhId:page-1-IMG nodeLabel:ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc path:1,HTML,1,BODY,14,DIV,2,DIV,0,DIV,0,UL,7,LI,0,A,0,IMG selector:ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc snippet:<img src="./gd/202603/W020260304562615519478_ORIGIN.jpg" class="focus_img_pc"> type:node]]] type:subitems]]]

Your first network request is the most important. Reduce its latency by avoiding redirects, ensuring a fast server response, and enabling text compression.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Reducing the download time of images can improve the perceived load time of the page and LCP. Learn more about optimizing image size

Why this matters

Performance issues directly impact user engagement and conversion rates.

URLResource SizeEst Savings
ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc
www.cas.cn/gd/202603/W020260320367237873144_ORIGIN.jpg622.4 KiB525.5 KiB
ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc
www.cas.cn/gd/202603/W020260304562615519478_ORIGIN.jpg456.6 KiB359.7 KiB
body > div.top2 > div.container body > div.top2 > div.container
www.cas.cn/images/topbgimg_20251217.png441.6 KiB354.9 KiB
ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc
www.cas.cn/gd/202603/W020260305339535003381_ORIGIN.jpg366.5 KiB269.5 KiB
div.tab_con > div.ky_img > a > img.hvr-grow div.tab_con > div.ky_img > a > img.hvr-grow
www.cas.cn/sygz/202604/W020260416563069960778.png267.5 KiB263.9 KiB
ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_m ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_m
www.cas.cn/gd/202603/W020260304562615738276_ORIGIN.jpg266.6 KiB210.9 KiB
div.tab_con > div.video_left > a > img div.tab_con > div.video_left > a > img
www.cas.cn/spx/202604/W020260420379180266731_ORIGIN.jpg216.8 KiB209.2 KiB
div.tab_con > div.yw_img > a > img.hvr-grow div.tab_con > div.yw_img > a > img.hvr-grow
www.cas.cn/yw/202604/W020260414668107692283_ORIGIN.jpg192.7 KiB173.4 KiB
© 1996 - 2026 中国科学院 版权所有　京ICP备05002857号-1　京公网安备110402500047号　网站标识码bm48000002 地… body > div.foot
www.cas.cn/images/z19_foot.png208.5 KiB165.7 KiB
div.tab_con > div.ky_img > a > img.hvr-grow div.tab_con > div.ky_img > a > img.hvr-grow
www.cas.cn/syky/202604/W020260421315832007785_ORIGIN.jpg141.6 KiB138.0 KiB
ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc
www.cas.cn/gd/202601/W020260128305083603703_ORIGIN.jpg229.8 KiB132.9 KiB
ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc
www.cas.cn/gd/202603/W020260303457407403045_ORIGIN.jpg212.2 KiB115.2 KiB
div.divBox > div.zt > a > img.hvr-grow div.divBox > div.zt > a > img.hvr-grow
www.cas.cn/zt1/202604/W020260401410085460301.jpg94.6 KiB90.7 KiB
div.divBox > div.zt > a.mar0 > img.hvr-grow div.divBox > div.zt > a.mar0 > img.hvr-grow
www.cas.cn/zt1/202603/W020260320378579484579.jpg88.1 KiB84.1 KiB
div.divBox > div.zt > a > img.hvr-grow div.divBox > div.zt > a > img.hvr-grow
www.cas.cn/zt1/202604/W020260401410081532588.jpg82.2 KiB78.3 KiB
ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_m ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_m
www.cas.cn/gd/202601/W020260121572218060263_ORIGIN.jpg121.0 KiB65.4 KiB
ul.tj_list > li.hvr-grow-img > a > img ul.tj_list > li.hvr-grow-img > a > img
www.cas.cn/images/z19_tj_img1.jpg52.9 KiB51.7 KiB
ul.videoBox > li.hvr-grow-img > a > img.hvr-grow ul.videoBox > li.hvr-grow-img > a > img.hvr-grow
www.cas.cn/images/zjzkypc_202303.jpg47.1 KiB43.5 KiB
中科院之声 div.container > div.topTitle > a > div.img_video
www.cas.cn/images/zkyzspc_202303.jpg36.7 KiB31.5 KiB
ul.videoBox > li.hvr-grow-img > a > img.hvr-grow ul.videoBox > li.hvr-grow-img > a > img.hvr-grow
www.cas.cn/images/zjxbpc_202303.jpg34.3 KiB30.7 KiB
div.clearfix > div.videopad > a > img div.clearfix > div.videopad > a > img
www.cas.cn/syzc/202312/W020231229530488598921_ORIGIN.jpg56.1 KiB26.4 KiB
ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc
www.cas.cn/gd/202601/W020260121576547305038_ORIGIN.jpg123.1 KiB26.1 KiB
div.top2 > div.container > div.xsdadd-2025 > img.xsdimg01 div.top2 > div.container > div.xsdadd-2025 > img.xsdimg01
www.cas.cn/images/dsb02_20251217.png35.8 KiB20.5 KiB
ul.tj_list > li.hvr-grow-img > a > img ul.tj_list > li.hvr-grow-img > a > img
www.cas.cn/images/yjzxgl_202203826.jpg21.2 KiB19.9 KiB
ul.tj_list > li.hvr-grow-img > a > img ul.tj_list > li.hvr-grow-img > a > img
www.cas.cn/images/z19_tj_img3.jpg15.0 KiB13.7 KiB
div.top2 > div.container > a.xsdlogotop > img.logo div.top2 > div.container > a.xsdlogotop > img.logo
www.cas.cn/images/z19_logo.png16.0 KiB13.5 KiB
div.top2 > div.container > a.xsdlogotop > img.logobtmxsd div.top2 > div.container > a.xsdlogotop > img.logobtmxsd
www.cas.cn/images/dsb01_20251217.png18.0 KiB12.5 KiB
ul.tab_title > li.now > a > img ul.tab_title > li.now > a > img
www.cas.cn/images/z19_index_yw2.png4.4 KiB4.3 KiB

Each subpart has specific improvement strategies. Ideally, most of the LCP time should be spent on loading the resources, not within delays.

Why this matters

Performance issues directly impact user engagement and conversion rates.

headings: [map[key:label label:Subpart valueType:text] map[key:duration label:Duration valueType:ms]]
items: [map[duration:2198.0220009765626 label:Time to first byte subpart:timeToFirstByte] map[duration:271.4619990234375 label:Resource load delay subpart:resourceLoadDelay] map[duration:9444.342 label:Resource load duration subpart:resourceLoadDuration] map[duration:16.958 label:Element render delay subpart:elementRenderDelay]]
lhId: page-28-IMG
nodeLabel: ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc
path: 1,HTML,1,BODY,14,DIV,2,DIV,0,DIV,0,UL,1,LI,0,A,0,IMG
selector: ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc
snippet: <img src="./gd/202603/W020260304562615519478_ORIGIN.jpg" class="focus_img_pc">

Optimize LCP by making the LCP image discoverable from the HTML immediately, and avoiding lazy-loading

Why this matters

Performance issues directly impact user engagement and conversion rates.

lhId: page-28-IMG
nodeLabel: ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc
path: 1,HTML,1,BODY,14,DIV,2,DIV,0,DIV,0,UL,1,LI,0,A,0,IMG
selector: ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc
snippet: <img src="./gd/202603/W020260304562615519478_ORIGIN.jpg" class="focus_img_pc">

HTTP/2 and HTTP/3 offer many benefits over HTTP/1.1, such as multiplexing. Learn more about using modern HTTP.

Why this matters

Performance issues directly impact user engagement and conversion rates.

URLProtocol
www.cas.cn/http/1.1
www.cas.cn/lib/js/plugin/swiper/swiper.min.csshttp/1.1
www.cas.cn/lib/css/hover.csshttp/1.1
www.cas.cn/images/z19_public.css?v=20251218http/1.1
www.cas.cn/images/z19_index.css?v=20251225http/1.1
www.cas.cn/images/z19_stylePad.csshttp/1.1
www.cas.cn/images/z19_logo.pnghttp/1.1
www.cas.cn/images/dsb01_20251217.pnghttp/1.1
www.cas.cn/images/dsb02_20251217.pnghttp/1.1
www.cas.cn/images/z19_pc_m.pnghttp/1.1
www.cas.cn/images/z19_en_m.pnghttp/1.1
www.cas.cn/images/wza_2024.pnghttp/1.1
www.cas.cn/images/z19_search_m.pnghttp/1.1
www.cas.cn/images/z19_close.pnghttp/1.1
www.cas.cn/zz/yld/201803/W020191125383560116474.jpghttp/1.1
www.cas.cn/zz/yld/202404/W020240407367171999355_ORIGIN.jpghttp/1.1
www.cas.cn/zz/yld/201704/W020190929738332637068.jpghttp/1.1
www.cas.cn/zz/yld/201909/W020201118270525579945.jpghttp/1.1
www.cas.cn/zz/yld/201605/W020190929739561066807.jpghttp/1.1
www.cas.cn/zz/yld/202308/W020240329553856002424_ORIGIN.jpghttp/1.1
www.cas.cn/zz/yld/202409/W020240912524118761361_ORIGIN.jpghttp/1.1
www.cas.cn/zz/yld/202311/W020231122659760924736.jpghttp/1.1
www.cas.cn/zz/yld/202504/W020250406365313605807_ORIGIN.jpghttp/1.1
www.cas.cn/zz/yld/202504/W020250406366075798999_ORIGIN.jpghttp/1.1
www.cas.cn/zz/yld/202504/W020250416559005659783_ORIGIN.jpghttp/1.1
www.cas.cn/kxyj/202512/W020251218541107090958_ORIGIN.jpghttp/1.1
www.cas.cn/kxyj/202512/W020251218633030399800.jpghttp/1.1
www.cas.cn/images/z19_kxyj_img2.jpghttp/1.1
www.cas.cn/images/20260309_navkjqk.pnghttp/1.1
www.cas.cn/images/20220826kejitop.jpghttp/1.1
www.cas.cn/cg/112072/images/P020190929620050824644.jpghttp/1.1
www.cas.cn/images/z19_school1.jpghttp/1.1
www.cas.cn/images/z19_school2.jpghttp/1.1
www.cas.cn/images/z19_school3.jpghttp/1.1
www.cas.cn/images/z19_school_bar1.jpghttp/1.1
www.cas.cn/images/z19_school_bar2.jpghttp/1.1
www.cas.cn/images/z19_school_bar3.jpghttp/1.1
www.cas.cn/kx/202404/W020240510574946875857_ORIGIN.jpghttp/1.1
www.cas.cn/kx/202404/W020240510575174145626_ORIGIN.jpghttp/1.1
www.cas.cn/images/z2025_dqgz1.jpghttp/1.1
www.cas.cn/images/z19_dqgz2.jpghttp/1.1
www.cas.cn/gd/202603/W020260304562615519478_ORIGIN.jpghttp/1.1
www.cas.cn/gd/202603/W020260304562615738276_ORIGIN.jpghttp/1.1
www.cas.cn/gd/202603/W020260320367237873144_ORIGIN.jpghttp/1.1
www.cas.cn/gd/202603/W020260320373519199299_ORIGIN.jpghttp/1.1
www.cas.cn/gd/202603/W020260303457407403045_ORIGIN.jpghttp/1.1
www.cas.cn/gd/202603/W020260303457407615596_ORIGIN.jpghttp/1.1
www.cas.cn/gd/202603/W020260305339535003381_ORIGIN.jpghttp/1.1
www.cas.cn/gd/202603/W020260305339535231140_ORIGIN.jpghttp/1.1
www.cas.cn/gd/202601/W020260128305083603703_ORIGIN.jpghttp/1.1
www.cas.cn/gd/202601/W020260128305083857947_ORIGIN.jpghttp/1.1
www.cas.cn/gd/202601/W020260121576547305038_ORIGIN.jpghttp/1.1
www.cas.cn/gd/202601/W020260121572218060263_ORIGIN.jpghttp/1.1
www.cas.cn/syzc/202312/W020231229530488598921_ORIGIN.jpghttp/1.1
www.cas.cn/images/z19_index_yw1.pnghttp/1.1
www.cas.cn/images/z19_index_yw2.pnghttp/1.1
www.cas.cn/gj/202604/W020260421522038092312.pnghttp/1.1
www.cas.cn/yw/202604/W020260414668107692283_ORIGIN.jpghttp/1.1
www.cas.cn/images/z19_index_ky1.pnghttp/1.1
www.cas.cn/images/z19_index_ky2.pnghttp/1.1
www.cas.cn/syky/202604/W020260421315832007785_ORIGIN.jpghttp/1.1
www.cas.cn/cm/202604/W020260421385309959198.pnghttp/1.1
www.cas.cn/images/z19_index_gz1.pnghttp/1.1
www.cas.cn/images/z19_index_gz2.pnghttp/1.1
www.cas.cn/sygz/202604/W020260416563069960778.pnghttp/1.1
www.cas.cn/yx/202603/W020260324417741201243.pnghttp/1.1
www.cas.cn/images/z19_index_zt1.pnghttp/1.1
www.cas.cn/zt1/202604/W020260401410085460301.jpghttp/1.1
www.cas.cn/zt1/202604/W020260401410081532588.jpghttp/1.1
www.cas.cn/zt1/202603/W020260320378579484579.jpghttp/1.1
www.cas.cn/images/z19_jl_img.pnghttp/1.1
www.cas.cn/images/zjzkypc_202303.jpghttp/1.1
www.cas.cn/images/zjzkymob_202303.jpghttp/1.1
www.cas.cn/images/zjxbpc_202303.jpghttp/1.1
www.cas.cn/images/zjxbmob_202303.jpghttp/1.1
www.cas.cn/images/zkyzsmob_202303.jpghttp/1.1
www.cas.cn/images/z19_index_tz1.pnghttp/1.1
www.cas.cn/images/z19_index_tz2.pnghttp/1.1
www.cas.cn/images/z19_index_video1.pnghttp/1.1
www.cas.cn/images/z19_index_video2.pnghttp/1.1
www.cas.cn/spx/202604/W020260420379180266731_ORIGIN.jpghttp/1.1
www.cas.cn/images/z19_video_play.pnghttp/1.1
www.cas.cn/spx/202604/W020260418314827276324_ORIGIN.jpghttp/1.1
www.cas.cn/spx/202604/W020260417530461254188_ORIGIN.jpghttp/1.1
www.cas.cn/newmedia/dsp/202604/W020260421276040437486.jpghttp/1.1
www.cas.cn/newmedia/dsp/202604/W020260420329652831168.pnghttp/1.1
www.cas.cn/newmedia/dsp/202604/W020260421546988627746.pnghttp/1.1
www.cas.cn/images/z19_index_xk2.pnghttp/1.1
www.cas.cn/images/z19_index_xk1.pnghttp/1.1
www.cas.cn/images/z19_index_ft1.pnghttp/1.1
www.cas.cn/images/z19_index_ft2.pnghttp/1.1
www.cas.cn/images/20230731zcjd.jpghttp/1.1
www.cas.cn/images/swiper.min.jshttp/1.1
www.cas.cn/images/z19_jl_icon2.pnghttp/1.1
www.cas.cn/images/z19_jl_icon4.pnghttp/1.1
www.cas.cn/images/z19_jl_icon5.pnghttp/1.1
www.cas.cn/images/z22_jl_xfqd.pnghttp/1.1
www.cas.cn/images/z19_index_tj.pnghttp/1.1
www.cas.cn/images/z19_tj_img3.jpghttp/1.1
www.cas.cn/images/z19_tj_img1.jpghttp/1.1
www.cas.cn/images/yjzxgl_202203826.jpghttp/1.1
www.cas.cn/images/z19_scroll_wb.pnghttp/1.1
www.cas.cn/images/z19_scroll_wx.pnghttp/1.1
www.cas.cn/images/z19_ewm3.jpghttp/1.1
www.cas.cn/images/z19_scroll_top.pnghttp/1.1
www.cas.cn/images/z19_return_m.pnghttp/1.1
www.cas.cn/images/foot_jgawb.pnghttp/1.1
www.cas.cn/images/jiucuo.pnghttp/1.1
www.cas.cn/images/blue.pnghttp/1.1
www.cas.cn/images/z19_gopc.pnghttp/1.1
www.cas.cn/lib/js/jquery.min.jshttp/1.1
www.cas.cn/images/z19_h5.jshttp/1.1
www.cas.cn/lib/js/plugin/swiper/idangerous.swiper.min.jshttp/1.1
www.cas.cn/lib/js/plugin/jquery.cookie.jshttp/1.1
www.cas.cn/images/z19_main.js?v=1.0http/1.1
www.cas.cn/images/z19_resize.jshttp/1.1
www.cas.cn/lib/js/plugin/wza/esdtoolsinit.jshttp/1.1
www.cas.cn/lib/js/plugin/topSide.min.jshttp/1.1
www.cas.cn/images/z19_search.pnghttp/1.1
www.cas.cn/images/topbgimg_20251217.pnghttp/1.1
www.cas.cn/images/z19_nav_up.pnghttp/1.1
www.cas.cn/images/z19_focus_right.pnghttp/1.1
www.cas.cn/images/z19_focus_left.pnghttp/1.1
www.cas.cn/images/z19_yw_2025tab2.pnghttp/1.1
www.cas.cn/images/z19_news_list.pnghttp/1.1
www.cas.cn/images/z19_xk_list.pnghttp/1.1
www.cas.cn/images/z19_bg_blue.pnghttp/1.1
www.cas.cn/images/z19_xk_tab_pad.pnghttp/1.1
www.cas.cn/images/z19_bg_blue2.pnghttp/1.1
www.cas.cn/images/z19_jl_bg.jpghttp/1.1
www.cas.cn/images/z19_foot_m.jpghttp/1.1
www.cas.cn/images/zkyzspc_202303.jpghttp/1.1
www.cas.cn/images/z19_xk_tab.pnghttp/1.1
www.cas.cn/images/z19_foot.pnghttp/1.1
www.cas.cn/lib/images/favicon.icohttp/1.1

Avoid chaining critical requests by reducing the length of chains, reducing the download size of resources, or deferring the download of unnecessary resources to improve page load.

Why this matters

Performance issues directly impact user engagement and conversion rates.

description: [preconnect](https://developer.chrome.com/docs/lighthouse/performance/uses-rel-preconnect/) hints help the browser establish a connection earlier in the page load, saving time when the first request for that origin is made. The following are the origins that the page preconnected to.
title: Preconnected origins
value: no origins were preconnected
description: Add [preconnect](https://developer.chrome.com/docs/lighthouse/performance/uses-rel-preconnect/) hints to your most important origins, but try to use no more than 4.
title: Preconnect candidates
value: No additional origins are good candidates for preconnecting

Requests are blocking the page's initial render, which may delay LCP. Deferring or inlining can move these network requests out of the critical path.

Why this matters

Performance issues directly impact user engagement and conversion rates.

URLTransfer SizeDuration
www.cas.cn/images/z19_public.css?v=2025121824.6 KiB205 ms
www.cas.cn/lib/css/hover.css116.2 KiB325 ms
www.cas.cn/images/z19_stylePad.css12.1 KiB165 ms
www.cas.cn/images/z19_index.css?v=2025122513.2 KiB165 ms
www.cas.cn/lib/js/plugin/swiper/swiper.min.css19.5 KiB85 ms

These insights are also available in the Chrome DevTools Performance Panel - record a trace to view more detailed information.

Redirects introduce additional delays before the page can be loaded. Learn how to avoid page redirects.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Estimated savings: 399 ms
URLTime Spent
cas.cn/209 ms
www.cas.cn/190 ms
www.cas.cn/0.0 ms

These are the largest layout shifts observed on the page. Each table item represents a single layout shift, and shows the element that shifted the most. Below each item are possible root causes that led to the layout shift. Some of these layout shifts may not be included in the CLS metric value due to windowing. Learn how to improve CLS

Why this matters

Performance issues directly impact user engagement and conversion rates.

ElementLayout shift score
要闻播报 院内要闻 更多院内要闻 + 中央第十三巡视组巡视中国科学院党组工作动员会召开 2026年04月14日 中央第十三巡视组巡视中国科学院党组工作动员会召… body > div.container > div.row
0.362
习近平同莫桑比克总统查波举行会谈 中科院之声 专题：改革创新发展这五年 中国科学院深入开展树立和践行正确政绩观学习教育 科学家发现野生稻多年生生活习性关键… body > div.container
0.215
要闻播报 院内要闻 更多院内要闻 + 中央第十三巡视组巡视中国科学院党组工作动员会召开 2026年04月14日 中央第十三巡视组巡视中国科学院党组工作动员会召… body > div.container > div.row
0.160
科学家发现野生稻多年生生活习性关键基因 div.m_index_focus > div#swiper_container_top_Focus > ul.swiper-wrapper > li.swiper-slide
0.116
习近平同莫桑比克总统查波举行会谈 中科院之声 专题：改革创新发展这五年 中国科学院深入开展树立和践行正确政绩观学习教育 科学家发现野生稻多年生生活习性关键… body > div.container
0.098
div.tab_con > div.yw_img > a > img.hvr-grow div.tab_con > div.yw_img > a > img.hvr-grow
0.006
| ul.tab_title > li.now > a > span
0.000
div.container > div.m_index_focus > div.pagination > span.swiper-pagination-switch div.container > div.m_index_focus > div.pagination > span.swiper-pagination-switch
0.000

Time to Interactive is the amount of time it takes for the page to become fully interactive. Learn more about the Time to Interactive metric.

Why this matters

Performance issues directly impact user engagement and conversion rates.

TTI

Diagnostics

Minifying CSS files can reduce network payload sizes. Learn how to minify CSS.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Estimated savings: 20 ms 21.8 KiB
URLTransfer SizeEst Savings
www.cas.cn/lib/css/hover.css116.2 KiB18.8 KiB
www.cas.cn/images/z19_public.css?v=2025121824.6 KiB3.0 KiB

Reduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. Learn how to reduce unused CSS.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Estimated savings: 110 ms 152.3 KiB
URLTransfer SizeEst Savings
www.cas.cn/lib/css/hover.css116.0 KiB115.7 KiB
www.cas.cn/images/z19_public.css?v=2025121824.4 KiB19.0 KiB
www.cas.cn/lib/js/plugin/swiper/swiper.min.css19.3 KiB17.6 KiB

Reduce unused JavaScript and defer loading scripts until they are required to decrease bytes consumed by network activity. Learn how to reduce unused JavaScript.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Estimated savings: 80 ms 110.7 KiB
URLTransfer SizeEst Savings
www.cas.cn/images/swiper.min.js94.2 KiB58.6 KiB
www.cas.cn/lib/js/jquery.min.js94.9 KiB52.1 KiB

Minifying JavaScript files can reduce payload sizes and script parse time. Learn how to minify JavaScript.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Estimated savings: 0.0 ms 2.5 KiB
URLTransfer SizeEst Savings
www.cas.cn/images/z19_main.js?v=1.012.8 KiB2.5 KiB

Large network payloads cost users real money and are highly correlated with long load times. Learn how to reduce payload sizes.

Why this matters

Performance issues directly impact user engagement and conversion rates.

URLTransfer Size
www.cas.cn/gd/202603/W020260320367237873144_ORIGIN.jpg622.6 KiB
www.cas.cn/gd/202603/W020260304562615519478_ORIGIN.jpg456.8 KiB
www.cas.cn/yx/202603/W020260324417741201243.png454.2 KiB
www.cas.cn/images/topbgimg_20251217.png441.8 KiB
www.cas.cn/gd/202603/W020260320373519199299_ORIGIN.jpg387.9 KiB
www.cas.cn/gd/202603/W020260305339535003381_ORIGIN.jpg366.7 KiB
www.cas.cn/gj/202604/W020260421522038092312.png350.4 KiB
www.cas.cn/cm/202604/W020260421385309959198.png280.4 KiB
www.cas.cn/newmedia/dsp/202604/W020260420329652831168.png269.6 KiB
www.cas.cn/sygz/202604/W020260416563069960778.png267.7 KiB

Set an explicit width and height on image elements to reduce layout shifts and improve CLS. Learn how to set image dimensions

Why this matters

Performance issues directly impact user engagement and conversion rates.

URL
ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc
www.cas.cn/gd/202601/W020260121576547305038_ORIGIN.jpg
ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc
www.cas.cn/gd/202603/W020260304562615519478_ORIGIN.jpg
ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc
www.cas.cn/gd/202603/W020260320367237873144_ORIGIN.jpg
ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc
www.cas.cn/gd/202603/W020260303457407403045_ORIGIN.jpg
ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc
www.cas.cn/gd/202603/W020260305339535003381_ORIGIN.jpg
ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc
www.cas.cn/gd/202601/W020260128305083603703_ORIGIN.jpg
ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc
www.cas.cn/gd/202601/W020260121576547305038_ORIGIN.jpg
ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc
www.cas.cn/gd/202603/W020260304562615519478_ORIGIN.jpg
div.tab_con > div.ky_img > a > img.hvr-grow div.tab_con > div.ky_img > a > img.hvr-grow
www.cas.cn/syky/202604/W020260421315832007785_ORIGIN.jpg
div.tab_con > div.ky_img > a > img.hvr-grow div.tab_con > div.ky_img > a > img.hvr-grow
www.cas.cn/sygz/202604/W020260416563069960778.png
div.top2 > div.container > div.xsdadd-2025 > img.xsdimg01 div.top2 > div.container > div.xsdadd-2025 > img.xsdimg01
www.cas.cn/images/dsb02_20251217.png
div.divBox > div.zt > a > img.hvr-grow div.divBox > div.zt > a > img.hvr-grow
www.cas.cn/zt1/202604/W020260401410085460301.jpg
div.divBox > div.zt > a > img.hvr-grow div.divBox > div.zt > a > img.hvr-grow
www.cas.cn/zt1/202604/W020260401410081532588.jpg
div.divBox > div.zt > a.mar0 > img.hvr-grow div.divBox > div.zt > a.mar0 > img.hvr-grow
www.cas.cn/zt1/202603/W020260320378579484579.jpg
ul.tj_list > li.hvr-grow-img > a > img ul.tj_list > li.hvr-grow-img > a > img
www.cas.cn/images/z19_tj_img3.jpg
ul.tj_list > li.hvr-grow-img > a > img ul.tj_list > li.hvr-grow-img > a > img
www.cas.cn/images/z19_tj_img1.jpg
ul.tj_list > li.hvr-grow-img > a > img ul.tj_list > li.hvr-grow-img > a > img
www.cas.cn/images/yjzxgl_202203826.jpg
div.top2 > div.container > a.xsdlogotop > img.logobtmxsd div.top2 > div.container > a.xsdlogotop > img.logobtmxsd
www.cas.cn/images/dsb01_20251217.png
div.top2 > div.container > a.xsdlogotop > img.logo div.top2 > div.container > a.xsdlogotop > img.logo
www.cas.cn/images/z19_logo.png
ul.tab_title > li.tab_title_yw1 > a > img ul.tab_title > li.tab_title_yw1 > a > img
www.cas.cn/images/z19_index_yw1.png
ul.tab_title > li.now > a > img ul.tab_title > li.now > a > img
www.cas.cn/images/z19_index_yw2.png
li > span#_ideConac > a > img#imgConac li > span#_ideConac > a > img#imgConac
www.cas.cn/images/blue.png
div.Rightfixed > div.RF_box > a > img div.Rightfixed > div.RF_box > a > img
www.cas.cn/images/z19_scroll_wb.png
div.container > div.Rightfixed > div.RF_box > img div.container > div.Rightfixed > div.RF_box > img
www.cas.cn/images/z19_scroll_wx.png
li > span#_span_jiucuo > a > img li > span#_span_jiucuo > a > img
www.cas.cn/images/jiucuo.png
ul.tab_title > li.now > a > img ul.tab_title > li.now > a > img
www.cas.cn/images/z19_index_ky1.png
ul.tab_title > li > a > img ul.tab_title > li > a > img
www.cas.cn/images/z19_index_ky2.png
ul.tab_title > li.now > a > img ul.tab_title > li.now > a > img
www.cas.cn/images/z19_index_gz1.png
ul.tab_title > li > a > img ul.tab_title > li > a > img
www.cas.cn/images/z19_index_gz2.png
div.divBox > div.div_title > p > img div.divBox > div.div_title > p > img
www.cas.cn/images/z19_index_zt1.png
div.divBox > div.jl > div.jl_left > img div.divBox > div.jl > div.jl_left > img
www.cas.cn/images/z19_jl_img.png
ul.tab_title > li.now > a > img ul.tab_title > li.now > a > img
www.cas.cn/images/z19_index_tz1.png
ul.tab_title > li > a > img ul.tab_title > li > a > img
www.cas.cn/images/z19_index_tz2.png
ul.tab_title > li.now > a > img ul.tab_title > li.now > a > img
www.cas.cn/images/z19_index_video1.png
ul.tab_title > li > a > img ul.tab_title > li > a > img
www.cas.cn/images/z19_index_video2.png
ul.tab_title > li.now > a > img ul.tab_title > li.now > a > img
www.cas.cn/images/z19_index_xk2.png
ul.tab_title > li > a > img ul.tab_title > li > a > img
www.cas.cn/images/z19_index_xk1.png
ul.tab_title > li.now > a > img ul.tab_title > li.now > a > img
www.cas.cn/images/z19_index_ft1.png
ul.tab_title > li > a > img ul.tab_title > li > a > img
www.cas.cn/images/z19_index_ft2.png
div.tj > div.div_title > p > img div.tj > div.div_title > p > img
www.cas.cn/images/z19_index_tj.png
div.boxcenter > div.foot_txt > p > img div.boxcenter > div.foot_txt > p > img
www.cas.cn/images/foot_jgawb.png

More information about the performance of your application. These numbers don't directly affect the Performance score.

●Optimize DOM size
●Font display
●Forced reflow
●Optimize viewport for mobile
●Max Potential First Input Delay 20 ms
●JavaScript execution time 0.0 s
●Minimizes main-thread work 0.8 s
●Page didn't prevent back/forward cache restoration
●Network Requests
●Network Round Trip Times 270 ms
●Server Backend Latencies 10 ms
●Tasks
●Diagnostics
●Metrics
●Screenshot Thumbnails
●Final Screenshot
●Script Treemap Data
●Resources Summary
●Initial server response time was short Root document took 280 ms
○INP breakdown
○User Timing marks and measures
○Avoid long main-thread tasks
○Avoid non-composited animations
55

Accessibility

These checks highlight opportunities to improve the accessibility of your web app. Automatic detection can only detect a subset of issues and does not guarantee the accessibility of your web app, so manual testing is also encouraged.

Contrast

Low-contrast text is difficult or impossible for many users to read. Learn how to provide sufficient color contrast.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
English / 联系我们 / 网站地图 /邮箱 /无障碍 /关怀版 div.top1 > div.container > div.top_r > div.top_link
English div.container > div.top_r > div.top_link > a
2026年04月14日 div.tab_con > div.yw_img > div.date > span
2026年02月11日 div.tab_con > ul.tzgg > li > p
2026年04月20日 div.tab_con > ul.tzgg > li > p

These are opportunities to improve the legibility of your content.

Internationalization and localization

If a page doesn't specify a `lang` attribute, a screen reader assumes that the page is in the default language that the user chose when setting up the screen reader. If the page isn't actually in the default language, then the screen reader might not announce the page's text correctly. Learn more about the `lang` attribute.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
html html

These are opportunities to improve the interpretation of your content by users in different locales.

Names and labels

Informative elements should aim for short, descriptive alternate text. Decorative elements can be ignored with an empty alt attribute. Learn more about the `alt` attribute.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
div.top2 > div.container > a.xsdlogotop > img.logo div.top2 > div.container > a.xsdlogotop > img.logo
div.top2 > div.container > a.xsdlogotop > img.logobtmxsd div.top2 > div.container > a.xsdlogotop > img.logobtmxsd
div.top2 > div.container > div.xsdadd-2025 > img.xsdimg01 div.top2 > div.container > div.xsdadd-2025 > img.xsdimg01
ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc
ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc
ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc
ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc
ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc
ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc
ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc
ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc
ul.tab_title > li.tab_title_yw1 > a > img ul.tab_title > li.tab_title_yw1 > a > img
ul.tab_title > li.now > a > img ul.tab_title > li.now > a > img
div.tab_con > div.yw_img > a > img.hvr-grow div.tab_con > div.yw_img > a > img.hvr-grow
ul.tab_title > li.now > a > img ul.tab_title > li.now > a > img
ul.tab_title > li > a > img ul.tab_title > li > a > img
div.tab_con > div.ky_img > a > img.hvr-grow div.tab_con > div.ky_img > a > img.hvr-grow
ul.tab_title > li.now > a > img ul.tab_title > li.now > a > img
ul.tab_title > li > a > img ul.tab_title > li > a > img
div.tab_con > div.ky_img > a > img.hvr-grow div.tab_con > div.ky_img > a > img.hvr-grow
div.divBox > div.div_title > p > img div.divBox > div.div_title > p > img
div.divBox > div.zt > a > img.hvr-grow div.divBox > div.zt > a > img.hvr-grow
div.divBox > div.zt > a > img.hvr-grow div.divBox > div.zt > a > img.hvr-grow
div.divBox > div.zt > a.mar0 > img.hvr-grow div.divBox > div.zt > a.mar0 > img.hvr-grow
div.divBox > div.jl > div.jl_left > img div.divBox > div.jl > div.jl_left > img
ul.videoBox > li.hvr-grow-img > a > img ul.videoBox > li.hvr-grow-img > a > img
ul.videoBox > li.hvr-grow-img > a > img.hvr-grow ul.videoBox > li.hvr-grow-img > a > img.hvr-grow
ul.videoBox > li.hvr-grow-img > a > img.hvr-grow ul.videoBox > li.hvr-grow-img > a > img.hvr-grow
ul.tab_title > li.now > a > img ul.tab_title > li.now > a > img
ul.tab_title > li > a > img ul.tab_title > li > a > img
ul.tab_title > li.now > a > img ul.tab_title > li.now > a > img
ul.tab_title > li > a > img ul.tab_title > li > a > img
div.tab_con > div.video_left > a > img div.tab_con > div.video_left > a > img
div.tab_con > div.video_left > a > img.video_play2 div.tab_con > div.video_left > a > img.video_play2
div.video_right > div.video_img > a > img div.video_right > div.video_img > a > img
div.video_right > div.video_img > a > img.video_play2 div.video_right > div.video_img > a > img.video_play2
div.video_right > div.video_img > a > img div.video_right > div.video_img > a > img
div.video_right > div.video_img > a > img.video_play2 div.video_right > div.video_img > a > img.video_play2
ul.tab_title > li.now > a > img ul.tab_title > li.now > a > img
ul.tab_title > li > a > img ul.tab_title > li > a > img
ul.tab_title > li.now > a > img ul.tab_title > li.now > a > img
ul.tab_title > li > a > img ul.tab_title > li > a > img
div.tj > div.div_title > p > img div.tj > div.div_title > p > img
ul.tj_list > li.hvr-grow-img > a > img ul.tj_list > li.hvr-grow-img > a > img
ul.tj_list > li.hvr-grow-img > a > img ul.tj_list > li.hvr-grow-img > a > img
ul.tj_list > li.hvr-grow-img > a > img ul.tj_list > li.hvr-grow-img > a > img
div.Rightfixed > div.RF_box > a > img div.Rightfixed > div.RF_box > a > img
div.container > div.Rightfixed > div.RF_box > img div.container > div.Rightfixed > div.RF_box > img
div.boxcenter > div.foot_txt > p > img div.boxcenter > div.foot_txt > p > img
li > span#_span_jiucuo > a > img li > span#_span_jiucuo > a > img
li > span#_ideConac > a > img#imgConac li > span#_ideConac > a > img#imgConac

Adding discernable and accessible text to input buttons may help screen reader users understand the purpose of the input button. Learn more about input buttons.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
div.container > div.top_r > div.search > input#sub-pc div.container > div.top_r > div.search > input#sub-pc

Form elements without effective labels can create frustrating experiences for screen reader users. Learn more about the `select` element.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
新闻媒体 人民网 新华网 光明网 央视网 中国经济网 中国网 新浪网 搜狐网 科学网 body > div.container > div.row > select
政府机构和组织 中国政府网 国家发展改革委 教育部 科技部 工业和信息化部 财政部 中国工程院 国家自然科学基金委 中国科协 body > div.container > div.row > select
国内院校 清华大学 北京大学 中国科学技术大学 中国科学院大学 浙江大学 上海交通大学 南京大学 复旦大学 中山大学 华中科技大学 武汉大学 上海科技大学 body > div.container > div.row > select.mar0_pad
国内科研机构 林科院 地科院 水科院 农科院 医科院 铁科院 军科院 body > div.container > div.row > select
国际科研机构 美国国家科学院 美国国家科学基金委 德国马普学会 德国洪堡基金会 德国弗朗霍夫学会 德意志研究联合会 法国国家科研中心 法国原子能总署 法兰西科… body > div.container > div.row > select
国际组织 联合国教科文组织 “一带一路”国际科学组织联盟 联合国培训和研究机构 世界知识产权组织 世界银行经济发展论坛 亚太经合组织 世界卫生组织 世界粮食计… body > div.container > div.row > select.mar0

Link text (and alternate text for images, when used as links) that is discernible, unique, and focusable improves the navigation experience for screen reader users. Learn how to make links accessible.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
body > div.top2 > div.container > a.xsdlogotop body > div.top2 > div.container > a.xsdlogotop
div#swiper_container_top_Focus > ul.swiper-wrapper > li.swiper-slide > a div#swiper_container_top_Focus > ul.swiper-wrapper > li.swiper-slide > a
div#swiper_container_top_Focus > ul.swiper-wrapper > li.swiper-slide > a div#swiper_container_top_Focus > ul.swiper-wrapper > li.swiper-slide > a
div#swiper_container_top_Focus > ul.swiper-wrapper > li.swiper-slide > a div#swiper_container_top_Focus > ul.swiper-wrapper > li.swiper-slide > a
div#swiper_container_top_Focus > ul.swiper-wrapper > li.swiper-slide > a div#swiper_container_top_Focus > ul.swiper-wrapper > li.swiper-slide > a
div#swiper_container_top_Focus > ul.swiper-wrapper > li.swiper-slide > a div#swiper_container_top_Focus > ul.swiper-wrapper > li.swiper-slide > a
div#swiper_container_top_Focus > ul.swiper-wrapper > li.swiper-slide > a div#swiper_container_top_Focus > ul.swiper-wrapper > li.swiper-slide > a
div#swiper_container_top_Focus > ul.swiper-wrapper > li.swiper-slide > a div#swiper_container_top_Focus > ul.swiper-wrapper > li.swiper-slide > a
div#swiper_container_top_Focus > ul.swiper-wrapper > li.swiper-slide > a div#swiper_container_top_Focus > ul.swiper-wrapper > li.swiper-slide > a
div#swiper_container_top_Focus > ul.swiper-wrapper > li.swiper-slide > a div#swiper_container_top_Focus > ul.swiper-wrapper > li.swiper-slide > a
div#swiper_container_top_Focus > ul.swiper-wrapper > li.swiper-slide > a div#swiper_container_top_Focus > ul.swiper-wrapper > li.swiper-slide > a
div#swiper_container_top_Focus > ul.swiper-wrapper > li.swiper-slide > a div#swiper_container_top_Focus > ul.swiper-wrapper > li.swiper-slide > a
div#swiper_container_top_Focus > ul.swiper-wrapper > li.swiper-slide > a div#swiper_container_top_Focus > ul.swiper-wrapper > li.swiper-slide > a
div#swiper_container_top_Focus > ul.swiper-wrapper > li.swiper-slide > a div#swiper_container_top_Focus > ul.swiper-wrapper > li.swiper-slide > a
div#swiper_container_top_Focus > ul.swiper-wrapper > li.swiper-slide > a div#swiper_container_top_Focus > ul.swiper-wrapper > li.swiper-slide > a
div#swiper_container_top_Focus > ul.swiper-wrapper > li.swiper-slide > a div#swiper_container_top_Focus > ul.swiper-wrapper > li.swiper-slide > a
div#swiper_container_top_Focus > ul.swiper-wrapper > li.swiper-slide > a div#swiper_container_top_Focus > ul.swiper-wrapper > li.swiper-slide > a
div.row_left > div.divBox > div.zt > a div.row_left > div.divBox > div.zt > a
div.row_left > div.divBox > div.zt > a div.row_left > div.divBox > div.zt > a
div.row_left > div.divBox > div.zt > a.mar0 div.row_left > div.divBox > div.zt > a.mar0
div.row_right > ul.videoBox > li.hvr-grow-img > a div.row_right > ul.videoBox > li.hvr-grow-img > a
div.container > div.Rightfixed > div.RF_box > a div.container > div.Rightfixed > div.RF_box > a
div.foot_img > li > span#_span_jiucuo > a div.foot_img > li > span#_span_jiucuo > a
div.foot_img > li > span#_ideConac > a div.foot_img > li > span#_ideConac > a

These are opportunities to improve the semantics of the controls in your application. This may enhance the experience for users of assistive technology, like a screen reader.

Tables and lists

Screen readers require list items (`<li>`) to be contained within a parent `<ul>`, `<ol>` or `<menu>` to be announced properly. Learn more about proper list structure.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
div.foot > div.boxcenter > div.foot_img > li div.foot > div.boxcenter > div.foot_img > li
div.foot > div.boxcenter > div.foot_img > li div.foot > div.boxcenter > div.foot_img > li

These are opportunities to improve the experience of reading tabular or list data using assistive technology, like a screen reader.

Best practices

Disabling zooming is problematic for users with low vision who rely on screen magnification to properly see the contents of a web page. Learn more about the viewport meta tag.

Why this matters

Informational: a Permissions-Policy directive showing feature -> allowed origins.

Source: MDN Permissions-Policy

Failing Elements
body > meta body > meta

One main landmark helps screen reader users navigate a web page. Learn more about landmarks.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
html html

These items highlight common accessibility best practices.

Navigation

A value greater than 0 implies an explicit navigation ordering. Although technically valid, this often creates frustrating experiences for users who rely on assistive technologies. Learn more about the `tabindex` attribute.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
按回车键在新窗口打开无障碍说明页面,按Ctrl+~键打开导盲模式。 body > a#esdTipLink1

These are opportunities to improve keyboard navigation in your application.

○Interactive controls are keyboard focusable
○Interactive elements indicate their purpose and state
○The page has a logical tab order
○Visual order on the page follows DOM order
○User focus is not accidentally trapped in a region
○The user's focus is directed to new content added to the page
○HTML5 landmark elements are used to improve navigation
○Offscreen content is hidden from assistive technology
○Custom controls have associated labels
○Custom controls have ARIA roles
●`[aria-*]` attributes match their roles
●`[aria-hidden="true"]` is not present on the document `<body>`
●`[aria-*]` attributes have valid values
●`[aria-*]` attributes are valid and not misspelled
●Form elements have associated labels
●ARIA attributes are used as specified for the element's role
●Elements use only permitted ARIA attributes
●Document has a `<title>` element
●Links are distinguishable without relying on color.
●Lists contain only `<li>` elements and script supporting elements (`<script>` and `<template>`).
●Touch targets have sufficient size and spacing.
●Heading elements appear in a sequentially-descending order
○`[accesskey]` values are unique
○`button`, `link`, and `menuitem` elements have accessible names
○Deprecated ARIA roles were not used
○Elements with `role="dialog"` or `role="alertdialog"` have accessible names.
○`[aria-hidden="true"]` elements do not contain focusable descendents
○ARIA input fields have accessible names
○ARIA `meter` elements have accessible names
○ARIA `progressbar` elements have accessible names
○`[role]`s have all required `[aria-*]` attributes
○Elements with an ARIA `[role]` that require children to contain a specific `[role]` have all required children.
○`[role]`s are contained by their required parent element
○`[role]` values are valid
○Elements with the `role=text` attribute do not have focusable descendents.
○ARIA toggle fields have accessible names
○ARIA `tooltip` elements have accessible names
○ARIA `treeitem` elements have accessible names
○Buttons have an accessible name
○The page contains a heading, skip link, or landmark region
○`<dl>`'s contain only properly-ordered `<dt>` and `<dd>` groups, `<script>`, `<template>` or `<div>` elements.
○Definition list items are wrapped in `<dl>` elements
○ARIA IDs are unique
○No form fields have multiple labels
○`<frame>` or `<iframe>` elements have a title
○`<html>` element has a valid value for its `[lang]` attribute
○`<html>` element has an `[xml:lang]` attribute with the same base language as the `[lang]` attribute.
○`<input type="image">` elements have `[alt]` text
○The document does not use `<meta http-equiv="refresh">`
○`<object>` elements have alternate text
○Skip links are focusable.
○Cells in a `<table>` element that use the `[headers]` attribute refer to table cells within the same table.
○`<th>` elements and elements with `[role="columnheader"/"rowheader"]` have data cells they describe.
○`[lang]` attributes have a valid value
○`<video>` elements contain a `<track>` element with `[kind="captions"]`
○Tables have different content in the summary attribute and `<caption>`.
○All heading elements contain content.
○Uses ARIA roles only on compatible elements
○Image elements do not have `[alt]` attributes that are redundant text.
○Identical links have the same purpose.
○Elements with visible text labels have matching accessible names.
○Tables use `<caption>` instead of cells with the `[colspan]` attribute to indicate a caption.
○`<td>` elements in a large `<table>` have one or more table headers.
58

Best Practices

Trust and Safety

All sites should be protected with HTTPS, even ones that don't handle sensitive data. This includes avoiding mixed content, where some resources are loaded over HTTP despite the initial request being served over HTTPS. HTTPS prevents intruders from tampering with or passively listening in on the communications between your app and your users, and is a prerequisite for HTTP/2 and many new web platform APIs. Learn more about HTTPS.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Insecure URLRequest Resolution
www.cas.cn/Allowed

User Experience

Image display dimensions should match natural aspect ratio. Learn more about image aspect ratio.

Why this matters

Performance issues directly impact user engagement and conversion rates.

URLAspect Ratio (Displayed)Aspect Ratio (Actual)
div.tab_con > div.yw_img > a > img.hvr-grow div.tab_con > div.yw_img > a > img.hvr-grow
www.cas.cn/yw/202604/W020260414668107692283_ORIGIN.jpg216 x 146 (1.48)600 x 400 (1.50)
ul.tzgg > li > a > img ul.tzgg > li > a > img
www.cas.cn/images/20230731zcjd.jpg100 x 200 (0.50)700 x 200 (3.50)
div.model_box > div.model_top > a > img div.model_box > div.model_top > a > img
www.cas.cn/cg/112072/images/P020190929620050824644.jpg100 x 85 (1.18)1220 x 85 (14.35)

General

Deprecated APIs will eventually be removed from the browser. Learn more about deprecated APIs.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Deprecation / WarningSource
Specifying overflow: visible on img, video and canvas tags may cause them to produce visual content outside of the element bounds. See https://github.com/WICG/shared-element-transitions/blob/main/debugging_overflow_on_images.md.
www.cas.cn/
●Avoids third-party cookies
●Allows users to paste into input fields
●Avoids requesting the geolocation permission on page load
●Avoids requesting the notification permission on page load
●Serves images with appropriate resolution
●Page has the HTML doctype
●Properly defines charset
●No browser errors logged to the console
●No issues in the `Issues` panel in Chrome Devtools
●Ensure CSP is effective against XSS attacks
●Use a strong HSTS policy
●Ensure proper origin isolation with COOP
●Mitigate clickjacking with XFO or CSP
●Mitigate DOM-based XSS with Trusted Types
●Detected JavaScript libraries
●Page has valid source maps
○Redirects HTTP traffic to HTTPS
73

SEO

These checks ensure that your page is following basic search engine optimization advice. There are many additional factors Lighthouse does not score here that may affect your search ranking, including performance on Core Web Vitals. Learn more about Google Search Essentials.

Content Best Practices

Meta descriptions may be included in search results to concisely summarize page content. Learn more about the meta description.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Informative elements should aim for short, descriptive alternate text. Decorative elements can be ignored with an empty alt attribute. Learn more about the `alt` attribute.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
div.top2 > div.container > a.xsdlogotop > img.logo div.top2 > div.container > a.xsdlogotop > img.logo
div.top2 > div.container > a.xsdlogotop > img.logobtmxsd div.top2 > div.container > a.xsdlogotop > img.logobtmxsd
div.top2 > div.container > div.xsdadd-2025 > img.xsdimg01 div.top2 > div.container > div.xsdadd-2025 > img.xsdimg01
ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc
ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc
ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc
ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc
ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc
ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc
ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc
ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc ul.swiper-wrapper > li.swiper-slide > a > img.focus_img_pc
ul.tab_title > li.tab_title_yw1 > a > img ul.tab_title > li.tab_title_yw1 > a > img
ul.tab_title > li.now > a > img ul.tab_title > li.now > a > img
div.tab_con > div.yw_img > a > img.hvr-grow div.tab_con > div.yw_img > a > img.hvr-grow
ul.tab_title > li.now > a > img ul.tab_title > li.now > a > img
ul.tab_title > li > a > img ul.tab_title > li > a > img
div.tab_con > div.ky_img > a > img.hvr-grow div.tab_con > div.ky_img > a > img.hvr-grow
ul.tab_title > li.now > a > img ul.tab_title > li.now > a > img
ul.tab_title > li > a > img ul.tab_title > li > a > img
div.tab_con > div.ky_img > a > img.hvr-grow div.tab_con > div.ky_img > a > img.hvr-grow
div.divBox > div.div_title > p > img div.divBox > div.div_title > p > img
div.divBox > div.zt > a > img.hvr-grow div.divBox > div.zt > a > img.hvr-grow
div.divBox > div.zt > a > img.hvr-grow div.divBox > div.zt > a > img.hvr-grow
div.divBox > div.zt > a.mar0 > img.hvr-grow div.divBox > div.zt > a.mar0 > img.hvr-grow
div.divBox > div.jl > div.jl_left > img div.divBox > div.jl > div.jl_left > img
ul.videoBox > li.hvr-grow-img > a > img ul.videoBox > li.hvr-grow-img > a > img
ul.videoBox > li.hvr-grow-img > a > img.hvr-grow ul.videoBox > li.hvr-grow-img > a > img.hvr-grow
ul.videoBox > li.hvr-grow-img > a > img.hvr-grow ul.videoBox > li.hvr-grow-img > a > img.hvr-grow
ul.tab_title > li.now > a > img ul.tab_title > li.now > a > img
ul.tab_title > li > a > img ul.tab_title > li > a > img
ul.tab_title > li.now > a > img ul.tab_title > li.now > a > img
ul.tab_title > li > a > img ul.tab_title > li > a > img
div.tab_con > div.video_left > a > img div.tab_con > div.video_left > a > img
div.tab_con > div.video_left > a > img.video_play2 div.tab_con > div.video_left > a > img.video_play2
div.video_right > div.video_img > a > img div.video_right > div.video_img > a > img
div.video_right > div.video_img > a > img.video_play2 div.video_right > div.video_img > a > img.video_play2
div.video_right > div.video_img > a > img div.video_right > div.video_img > a > img
div.video_right > div.video_img > a > img.video_play2 div.video_right > div.video_img > a > img.video_play2
ul.tab_title > li.now > a > img ul.tab_title > li.now > a > img
ul.tab_title > li > a > img ul.tab_title > li > a > img
ul.tab_title > li.now > a > img ul.tab_title > li.now > a > img
ul.tab_title > li > a > img ul.tab_title > li > a > img
div.tj > div.div_title > p > img div.tj > div.div_title > p > img
ul.tj_list > li.hvr-grow-img > a > img ul.tj_list > li.hvr-grow-img > a > img
ul.tj_list > li.hvr-grow-img > a > img ul.tj_list > li.hvr-grow-img > a > img
ul.tj_list > li.hvr-grow-img > a > img ul.tj_list > li.hvr-grow-img > a > img
div.Rightfixed > div.RF_box > a > img div.Rightfixed > div.RF_box > a > img
div.container > div.Rightfixed > div.RF_box > img div.container > div.Rightfixed > div.RF_box > img
div.boxcenter > div.foot_txt > p > img div.boxcenter > div.foot_txt > p > img
li > span#_span_jiucuo > a > img li > span#_span_jiucuo > a > img
li > span#_ideConac > a > img#imgConac li > span#_ideConac > a > img#imgConac

Format your HTML in a way that enables crawlers to better understand your app’s content.

Crawling and Indexing

Search engines may use `href` attributes on links to crawl websites. Ensure that the `href` attribute of anchor elements links to an appropriate destination, so more pages of the site can be discovered. Learn how to make links crawlable

Why this matters

Performance issues directly impact user engagement and conversion rates.

Uncrawlable Link
无障碍 div.container > div.top_r > div.top_link > a#toolbarSwitch
div.top2 > div.container > div.top_link_m > a#toolbarSwitchmob div.top2 > div.container > div.top_link_m > a#toolbarSwitchmob
按回车键在新窗口打开无障碍说明页面,按Ctrl+~键打开导盲模式。 body > a#esdTipLink1
.cls-1{fill:#fff;} div.cy_toolbar_bg_table > ul > li#cy_refrash > a#toolbar_refresh
.st0{fill:none;stroke:#FFFFFF;stroke-width:1.3;stroke-linecap:round;stroke-line… div.cy_toolbar_bg_table > ul > li#cy_playSpeech > a#toolbar_speakVolume
.cls-1{fill:#fff;} div.cy_toolbar_bg_table > ul > li#cy_pointerRead > a#toolbar_speakSpeed
.cls-1{fill:#fff;} div.cy_toolbar_bg_table > ul > li#cy_pointerRead > a#toolbar_readChange
.cls-1{fill:#fff;} div.cy_toolbar_bg_table > ul > li#cy_color > a#toolbar_colorChange
.cls-1{fill:#fff;} div.cy_toolbar_bg_table > ul > li#cy_bigword > a#toolbar_pageZoomIc
.cls-1{fill:#fff;} div.cy_toolbar_bg_table > ul > li#cy_smallword > a#toolbar_pageZoomDc
.cls-1{fill:#fff;} div.cy_toolbar_bg_table > ul > li#cy_arrow > a#toolbar_refresh1
.cls-1{fill:#fff;} div.cy_toolbar_bg_table > ul > li#cy_ruler > a#toolbar_guides
.cls-1{fill:#fff;} div.cy_toolbar_bg_table > ul > li#cy_displayScreen > a#toolbar_magnifier
.st0{fill:none;stroke:#FFFFFF;stroke-width:1.3;stroke-linecap:round;stroke-line… div.cy_toolbar_bg_table > ul > li#cy_pinned > a#toolbar_pinned
.cls-1{fill:#fff;} div.cy_toolbar_bg_table > ul > li#cy_more > a#toolbar_more
.cls-1{fill:#fff;} div.cy_toolbar_bg_table > ul > li#cy_move > a#toNav
.cls-1{fill:#fff;} div.cy_toolbar_bg_table > ul > li#cy_close > a#toolbar_exit
.st0{fill:none;stroke:#FFFFFF;stroke-width:1.3;stroke-linecap:round;stroke-line… div#toolbarPage2content > div#otherBtns > div#cy_playSpeech_2 > a#toolbar_speakOnOff
.cls-1{fill:#fff;} div#toolbarPage2content > div#otherBtns > div.readDiv > a#toolbar_help_move
.cls-1{fill:#fff;} div#toolbarPage2content > div#otherBtns > div.readDiv > a#toolbar_magnifier_2
.cls-1{fill:#fff;} div#toolbarPage2content > div#otherBtns > div.readDiv > a#toFirstPage
.cls-1{fill:#fff;} div#toolbarPage2content > div#otherBtns > div.readDiv > a#toolbar_exit2

To appear in search results, crawlers need access to your app.

○Structured data is valid
●Page isn’t blocked from indexing
●Document has a `<title>` element
●Page has successful HTTP status code
●Links have descriptive text
●Document has a valid `hreflang`
○robots.txt is valid
○Document has a valid `rel=canonical`

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