{"id":688414,"date":"2026-04-21T04:36:04","date_gmt":"2026-04-21T04:36:04","guid":{"rendered":"https:\/\/microscopemedia.com\/?p=688414"},"modified":"2026-04-21T04:36:04","modified_gmt":"2026-04-21T04:36:04","slug":"mineralul-care-sfida-stiinta-de-200-de-ani-secretul-dolomitei-in-sfarsit-descifrat","status":"publish","type":"post","link":"https:\/\/microscopemedia.com\/?p=688414","title":{"rendered":"Mineralul care sfida \u0219tiin\u021ba de 200 de ani. Secretul dolomitei, \u00een sf\u00e2r\u0219it descifrat"},"content":{"rendered":"
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Dolomita este un mineral<\/a> r\u0103sp\u00e2ndit, prezent \u00een loca\u021bii emblematice: Mun\u021bii Dolomiti din Italia, Cascada Niagara sau Hoodoos din Utah. Este abundent\u0103 \u00een roci mai vechi de 100 de milioane de ani, dar se formeaz\u0103 rar \u00een medii mai recente. Tocmai aceast\u0103 contradic\u021bie a intrigat genera\u021bii de cercet\u0103tori.<\/p>\n

De ce nu \u201ecre\u0219tea\u201d dolomita \u00een laborator<\/h2>\n

Cercet\u0103tori de la Universitatea din Michigan \u0219i Universitatea Hokkaido din Japonia au identificat sursa problemei, potrivit Science Daily<\/a>.<\/p>\n

Structura dolomitei este format\u0103 din straturi alternante de calciu \u0219i magneziu. Pe m\u0103sur\u0103 ce cristalul cre\u0219te, cei doi atomi se ata\u0219eaz\u0103 adesea aleatoriu, \u00een loc s\u0103 se alinieze corect. Apar astfel defecte structurale care blocheaz\u0103 orice cre\u0219tere ulterioar\u0103. Viteza procesului devine extrem de mic\u0103. La acest ritm, formarea unui singur strat bine ordonat ar putea dura p\u00e2n\u0103 la 10 milioane de ani.<\/p>\n

Cum rezolv\u0103 natura problema<\/h2>\n

Cercet\u0103torii au realizat c\u0103 defectele nu sunt permanente. Atomii afla\u021bi \u00een pozi\u021bii gre\u0219ite sunt mai pu\u021bin stabili \u0219i se dizolv\u0103 mai u\u0219or \u00een contact cu apa. \u00cen natur\u0103, cicluri repetate \u2013 precipita\u021bii, maree, inunda\u021bii urmate de uscare \u2013 spal\u0103 \u00een mod regulat zonele defectuoase. Suprafa\u021ba cristalului se cur\u0103\u021b\u0103, iar straturi noi, corect aranjate, pot s\u0103 apar\u0103. Pe perioade geologice lungi, procesul duce la depozitele mari din rocile antice.<\/p>\n

Simul\u0103ri atomice \u0219i un experiment decisiv<\/h2>\n

Pentru a-\u0219i testa teoria, echipa a simulat cre\u0219terea dolomitei la nivel atomic. Un software dezvoltat la Centrul PRISMS al Universit\u0103\u021bii din Michigan a f\u0103cut posibil calculul. \u201eFiecare etap\u0103 atomic\u0103 ar dura \u00een mod normal peste 5.000 de ore pe un supercomputer\u201d, a explicat Joonsoo Kim, primul autor al studiului.<\/p>\n

\u201eAcum putem efectua acela\u0219i calcul \u00een 2 milisecunde pe un computer de birou\u201d.<\/p>\n

Confirmarea experimental\u0103 a venit din Japonia. Cercet\u0103torii de la Universitatea Hokkaido au plasat un mic cristal de dolomit\u0103 \u00eentr-o solu\u021bie cu calciu \u0219i magneziu. Apoi au pulsat un fascicul de electroni de 4.000 de ori \u00een dou\u0103 ore, dizolv\u00e2nd repetat defectele pe m\u0103sur\u0103 ce ap\u0103reau. Cristalul a crescut p\u00e2n\u0103 la aproximativ 100 de nanometri \u2013 echivalentul a circa 300 de straturi de dolomit\u0103. Experimente anterioare nu produseser\u0103 niciodat\u0103 mai mult de cinci straturi.<\/p>\n

Ce \u00eenseamn\u0103 asta pentru tehnologie<\/h2>\n

Descoperirea dep\u0103\u0219e\u0219te sfera geologiei. \u201eTeoria noastr\u0103 arat\u0103 c\u0103 se pot cre\u0219te rapid materiale f\u0103r\u0103 defecte, dac\u0103 se dizolv\u0103 periodic defectele \u00een timpul cre\u0219terii\u201d, a spus Wenhao Sun, profesorul coordonator al studiului. Principiul ar putea fi aplicat \u00een produc\u021bia de semiconductori, panouri solare sau baterii de \u00eenalt\u0103 performan\u021b\u0103.<\/p>\n","protected":false},"excerpt":{"rendered":"

Dolomita este un mineral r\u0103sp\u00e2ndit, prezent \u00een loca\u021bii emblematice: Mun\u021bii Dolomiti din Italia, Cascada Niagara sau Hoodoos din Utah. Este abundent\u0103 \u00een roci mai vechi de 100 de milioane de … Read More<\/a><\/p>\n","protected":false},"author":1,"featured_media":688415,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"Default","format":"standard","meta":[],"categories":[1],"tags":[],"_links":{"self":[{"href":"https:\/\/microscopemedia.com\/index.php?rest_route=\/wp\/v2\/posts\/688414"}],"collection":[{"href":"https:\/\/microscopemedia.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/microscopemedia.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/microscopemedia.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/microscopemedia.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=688414"}],"version-history":[{"count":0,"href":"https:\/\/microscopemedia.com\/index.php?rest_route=\/wp\/v2\/posts\/688414\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/microscopemedia.com\/index.php?rest_route=\/wp\/v2\/media\/688415"}],"wp:attachment":[{"href":"https:\/\/microscopemedia.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=688414"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/microscopemedia.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=688414"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/microscopemedia.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=688414"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}