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The high density, 1.4 grams per cubic centimeter, reported for anomalous water suggests that high pressures should be conducive to the formation of anomalous water. Six attempts at 60 kilobars in which water was cooled from about 600 degrees C in nickel or platinum tubes, with or without the presence of silica, did not produce any detectable amounts of anomalous water.  相似文献   

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《Science (New York, N.Y.)》2008,320(5875):466-467
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国内外设施农业发展的比较   总被引:3,自引:0,他引:3  
设施农业在现代农业中占有重要地位。作为世界上设施农业第一大国,必须重视有关施设农业的科学研究,必须促进设施农业的可持续发展。从对国内外设施农业的比较研究入手,剖析中国与发达国家设施农业系统构成、特征以及支持政策等方面的区别,并进一步分析现阶段中国设施农业发展中存在的问题,最后提出中国发展设施农业的几点对策。  相似文献   

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Schneier B 《Science (New York, N.Y.)》2012,336(6088):1527-1529
The problem of securing biological research data is a difficult and complicated one. Our ability to secure data on computers is not robust enough to ensure the security of existing data sets. Lessons from cryptography illustrate that neither secrecy measures, such as deleting technical details, nor national solutions, such as export controls, will work.  相似文献   

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An increasing body of research indicates that carbon can exist in a number of polymorphic "carbyne" forms. It is proposed that these forms occur because of a shift to triple bonding in the carbon system as temperature increases above 2600 K. It is also proposed that graphite can dissociate into triple-bonded molecules by a simple mechanism.  相似文献   

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