排序方式: 共有29条查询结果,搜索用时 15 毫秒
1.
长竹蛏人工育苗技术的初步研究 总被引:4,自引:0,他引:4
本文对长竹蛏繁殖习性、胚胎发育和人工育苗技术关键进行研究.结果表明亲贝经暂养可促进性成熟;幼虫对温、盐度的适应较广;变态附着采用缩光培育,未经缩光的附着时间延长,存活率降低;幼虫长至约240μm变态附着,附着量在(0.6~10)×106个/m 相似文献
2.
程裕淇院士是我国著名的变质岩石学家、矿床学家和前寒武纪地质学家。中国科学院学部委员(院士),中国人民政治协商会议第四届、第五届全国委员会委员,第六届、第七届全国政协常务委员会委员。程裕淇先生开拓了我国变质岩研究领域,提出了矿床成矿系列理论,发展了我国前寒武纪地质学。他在管理上积极推进地质行业的对外开放,促进国际合作交流,为建立中央直属的野战军队伍建言献策;在政协多次提案,推动了我国矿产资源法的立法和实施。 相似文献
3.
LBM钻井液是一种低粘度低失水量的高效造浆材料,通过在绳索取心中应用,证明了LBM钻井液具有良好的抑制水敏性地层膨胀与分散的能力.可有效防止粘附卡钻事故及解决钻杆内壁结垢问题.是绳索取心钻进较理想的钻井液材料。 相似文献
4.
Both direct and indirect effects of freezing drizzle on ice accretion were analyzed for ten freezing drizzle events during a comprehensive ice thickness, fog, and precipitation observation campaign carried out during the winter of 2008 and 2009 at Enshi Radar Station (3017'N, 10916'E), Hubei Province, China. The growth rate of ice thickness was 0.85 mm h-1 during the freezing drizzle period, while the rate was only 0.4 mm h-1 without sleet and freezing drizzle. The rain intensity, liquid water content (LWC), and diameter of freezing drizzle stayed at low values. The development of microphysical properties of fog was suppressed in the freezing drizzle period. A threshold diameter (Dc) was proposed to estimate the inuence of freezing drizzle on different size ranges of fog droplets. Fog droplets with a diameter less thanDc would be affected slightly by freezing drizzle, while larger fog droplets would be affected signicantly. Dc had a correlation with the average rain intensity, with a correlation coefficient of 0.78. The relationships among the microphysical properties of fog droplets were all positive when the effect of freezing drizzle was weak, while they became poor positive correlations, or even negative correlations during freezing drizzle period. The direct contribution of freezing drizzle to ice thickness was about 14.5%. Considering both the direct and indirect effects, we suggest that freezing drizzle could act as a catalyst causing serious icing conditions. 相似文献
5.
以科学发展观为指导,积极应对气候变化 总被引:1,自引:1,他引:0
气候变化已经对全球生态、环境、经济和社会可持续发展以及外交和国家安全产生极大影响,引起各国政府、公众和学术界的极大关注。气候变化关系人类的生存和发展,应对气候变化实现可持续发展具有重要性和紧迫性。我们要以科学发展观为指导,把握好共同但有区别的责任,积极应对气候变化。 相似文献
6.
7.
8.
George W. Housner 《地震工程与工程振动(英文版)》2008,7(2):I0001-I0001
Destructive earthquakes have caused great damage in China and the United States and collapsing buildings havecaused many deaths and injuries. The field of earthquake engineering studies earthquake hazards, the occurrence ofearthquakes of various magnitudes, the nature of the ground shaking during an earthquake, the vibration of structuresduring earthquakes, the strengthening of existing structures and the design of new structures to be earthquake resistant,and finally, how to cope with earthquake damage and restore a city to normal functioning. Such efforts are in progressin both countries, but unfortunately, the language barrier interferes with the free flow of information between China andthe Untied States. It would be mutually beneficial if some means could be developed to promote the exchangeof information across the Pacific Ocean. This new journal has been established for this purpose and its success willbe an important step in promoting earthquake engineering in China and the United States. 相似文献
9.
卢氏县是河南省28个国家级贫困县之一。作者在调查和研究的基础上,阐述了卢氏县的贫困原因及该县区域经济发展的优势和潜力,针对性地提出了该县“烟牧果富民、矿工农兴村和壮工强县的发展思路,促使其尽快脱贫致富。 相似文献
10.