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展望2009年,随自着全球对可再生、清洁和安全能源需求的日益提升,薄膜技术等新技术的创新和成本逐步降低,中国太阳能电池产业将会在产业链结构上出现局部调整,薄膜太阳能电池、太阳能移动电源等新的应用也将涌现市场。 相似文献
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12月草业科学大事记——国际篇 总被引:1,自引:0,他引:1
4日 美国生物量研发与开发局发布报告,评估农场和森林生物燃料生产满足国家生物能源需求、减少汽油消费的经济可行性,指出立足于新技术的研究与开发是实现国家目标、发展可持续生物能源产业的关键。根据2007年制定的能源法案可更新燃料标准,到2022年全国需要生物燃料360亿加仑。 相似文献
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GUAN Hai-hong XU Qi-you ZHI Bing-jie KUANG You-yi XU Wei YIN Jia-sheng 《中国农业科学(英文版)》2010,9(2):286-293
With the technology of morphology, histology and nutrition, the characteristics of organ development and the source and demand of nutritional at different stages in post-embryonic (water temperature 3-14℃) of Hucho taimen were discussed. The results showed that the membrane of H. taimen fertilized ovum was ruptured in 30 d, the prototype of U-type stomach was formed, the mouth could open and close freely, and nutrition was supplied from its yolk sac. The membrane ruptured after 8 d, teeth formed, and anus communicated with outsiders. The oropharyngeal cavity, esophagus, U-type stomach, intestine, and anus initially formed in the digestive tube, which nutrition was supplied from the huge yolk sac. The membrane ruptured after 16 d, pancreas and pyloric caeca appeared, larvae could intake and digest exogenous food, fish mixed nutrition, which was from yolk sac and outsiders, mainly depended on endogenous. The membrane ruptured after 24 d, the fish began floating and intaking actively, the fish mixed nutrition which mainly depended on exogenous. The membrane ruptured after 30 d, the yolk sac was completely absorbed, the function and structure of each digestive organs developed consummately, fish was from mixed nutrition into the stage of exogenous nutrition, the nutritional need of juveniles was below 10% fat, level of the optimal protein was 50%. 相似文献
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市场瞬息万变,全球拖拉机市场都在经历着变革和进步,并成为非公路机械产业循环周期较少的部分。"这种趋势是由农业产品价格、对粮食和能源需求的增长导致的。农业机械领域必须面对前所未有的挑战:到2050年粮食产量需要满足90亿人口的需求。为了能达到这种需求,一个主要的途径就是在全球范围内提高农业机械的生产效率,因此在耕种过程中需要更有效率的机械化作业。简单的说, 相似文献