{"id":21176,"date":"2011-09-29T21:33:50","date_gmt":"2011-09-29T18:33:50","guid":{"rendered":"http:\/\/www.fyysika.ee\/uudised\/?p=21176"},"modified":"2011-09-30T11:18:15","modified_gmt":"2011-09-30T08:18:15","slug":"21176","status":"publish","type":"post","link":"https:\/\/www.fyysika.ee\/?p=21176","title":{"rendered":"Kilogramm ja amper saavad tulevikus uued etalonid"},"content":{"rendered":"<p><strong>Tavaelus h\u00e4sti tuntud SI (Syst\u00e8me Internationale d&#8217;unit\u00e9s, loe <a href=\"http:\/\/et.wikipedia.org\/wiki\/SI-s%C3%BCsteemi_%C3%BChikud\">siit<\/a>) standardsuurused kilogramm ja amper on l\u00e4bimas uuenduskuuri. Teadlaste ammune soov on olnud siduda SI standardid f\u00fc\u00fcsikaliste konstantidega. Kilogrammi etaloniks on praeguse seisuga Prantsusmaal S\u00e8vres hoitav plaatina-iriidium silinder. Amper on defineeritud kahe juhtme vahel m\u00f5juva j\u00f5u kaudu. Uues vormingus oleks kilogramm seotud Plancki konstandiga (loe <a href=\"http:\/\/et.wikipedia.org\/wiki\/Plancki_konstant\">siit<\/a>) ja amper elektroni laenguga (loe <a href=\"http:\/\/et.wikipedia.org\/wiki\/Elementaarlaeng\">siit<\/a>).<\/strong><\/p>\n<div id=\"attachment_21177\" style=\"width: 244px\" class=\"wp-caption alignleft\"><a href=\"http:\/\/www.fyysika.ee\/uudised\/wp-content\/uploads\/2011\/09\/234px-Denmark\u2019s_K48_Kilogram.jpg\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-21177\" class=\"size-full wp-image-21177\" src=\"http:\/\/www.fyysika.ee\/uudised\/wp-content\/uploads\/2011\/09\/234px-Denmark\u2019s_K48_Kilogram.jpg\" alt=\"\" width=\"234\" height=\"269\" \/><\/a><p id=\"caption-attachment-21177\" class=\"wp-caption-text\">Eksemplar K48 on etalonkilogrammi teise seeria koopia, mille tellis Taani riik. Valmistaja poolt garanteeriti t\u00e4psus 1 kg +\/- 81 \u00b5g (mikrogramm, 10-6 kg). Vaakumkuplite all oleva metallsilindri v\u00f5ib varsti muuseumiriiulile asetada.<\/p><\/div>\n<p>Uute seoste loomiseks ei ole teadlased konstantide universaalsuses piisavalt kindlad olnud. Ameerika NPL (National Physical Laboratory) laboratooriumi ja rahvusvahelise teadlaste t\u00f6\u00f6r\u00fchmade koost\u00f6\u00f6na suudeti senisest t\u00e4pseimalt m\u00f5\u00f5ta grafeenis elektroni laengut ja Plancki konstanti siduva f\u00fc\u00fcsikalise n\u00e4htuse kvant-Halli (<a href=\"http:\/\/en.wikipedia.org\/wiki\/Quantum_Hall_effect\">quantum Hall effect<\/a>) efekti. SI p\u00f5hi\u00fchikuid pole s\u00fcsteemi 50 aastase ajaloo jooksul veel n\u00f5nda p\u00f5hjalikult \u00fcle vaadatud.<\/p>\n<p>Kvant-Halli efekt arvati grafeeni avastamiseni olevat seotud vaid v\u00e4heste pooljuhtidega. Grafeen on unikaalsete omadustega kahem\u00f5\u00f5tmeline s\u00fcsinikup\u00f5hine materjal, mille avastamise eest anti Andre Geimile and Konstantin Novoselovile 2010. aastal Nobeli f\u00fc\u00fcsika preemia. Teadust\u00f6\u00f6 raames v\u00f5rreldi pooljuhtmaterjalidelt ja grafeenilt saadud tulemusi. Leiti, et efekt on s\u00f5ltumata materjalist universaalne. NPL laboris m\u00f5\u00f5deti kvant-Halli efekti m\u00e4\u00e4ramatusega 86 ppt (parts per trillion, loe <a href=\"http:\/\/en.wikipedia.org\/wiki\/Parts_per_trillion\">siit<\/a>). T\u00e4psus on teadlaste s\u00f5nul kilogrammi ja ampri m\u00e4\u00e4ratlemiseks piisav.<\/p>\n<p>\u201dPaljud maailma metroloogialaboratooriumid on \u00fcritanud seda eksperimenti l\u00e4bi viia, ent tulutult. NPL ja koost\u00f6\u00f6lised sai sellega hakkama. Tuleb v\u00e4lja, et tegelikkuses on grafeenis kvant-Halli efekti v\u00e4ga lihtne m\u00f5\u00f5ta,\u201d s\u00f5nab JT Janssen, NPL teadlane. Teadusmaailma \u00fcks mainekamaid ajakirjasid Nature hindas t\u00e4pset m\u00f5\u00f5tmist v\u00e4ga oluliseks saavutuseks.<\/p>\n<p>Allikas: <a href=\"http:\/\/www.physorg.com\/news\/2011-09-redefining-kilogram-ampere.html\">PhysOrg<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Tavaelus h\u00e4sti tuntud SI (Syst\u00e8me Internationale d&#8217;unit\u00e9s, loe siit) standardsuurused kilogramm ja amper on l\u00e4bimas uuenduskuuri. Teadlaste ammune soov on olnud siduda SI standardid f\u00fc\u00fcsikaliste konstantidega. Kilogrammi etaloniks on praeguse seisuga Prantsusmaal S\u00e8vres hoitav plaatina-iriidium silinder. Amper on defineeritud kahe juhtme vahel m\u00f5juva j\u00f5u kaudu. Uues vormingus oleks kilogramm seotud Plancki konstandiga (loe siit) ja [&hellip;]<\/p>\n","protected":false},"author":449,"featured_media":21177,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_genesis_hide_title":false,"_genesis_hide_breadcrumbs":false,"_genesis_hide_singular_image":false,"_genesis_hide_footer_widgets":false,"_genesis_custom_body_class":"","_genesis_custom_post_class":"","_genesis_layout":"","footnotes":""},"categories":[16],"tags":[],"class_list":{"0":"post-21176","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-teadusuudis","8":"entry"},"_links":{"self":[{"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=\/wp\/v2\/posts\/21176","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=\/wp\/v2\/users\/449"}],"replies":[{"embeddable":true,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=21176"}],"version-history":[{"count":0,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=\/wp\/v2\/posts\/21176\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=\/wp\/v2\/media\/21177"}],"wp:attachment":[{"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=21176"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=21176"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=21176"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}