排序方式: 共有31条查询结果,搜索用时 15 毫秒
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黑龙江省粮食产量结构与影响产量的气象因子分析 总被引:6,自引:0,他引:6
通过黑龙江省1949~2006年粮食产量结构分析及近30年的粮食单产与5~9月气象要素相关分析,得出黑龙江省粮食总产的波动主要取决于粮食作物平均单产波动及作物种植结构的调整.1949年以来,在粮食作物中,玉米和大豆所占比例变化不大,水稻呈逐年增加的趋势,春小麦在20世纪90年代以前呈逐步增加的趋势,而90年代以后则急速下降;水稻的单产最高,其次是玉米,再次是春小麦,大豆单产最低;从单产的增减趋势来看,各种粮食作物单产基本呈逐步增长的趋势.影响黑龙江省粮食产量丰歉的主要气象因子为6月平均温度、9月降水量、5月和6月日照时数. 相似文献
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琼东南盆地中央坳陷带拆离断层及其控盆作用 总被引:4,自引:1,他引:3
Using regional geological, newly acquired 2D and 3D seismic, drilling and well log data, especially 2D long cable seismic profiles, the structure and stratigraphy in the deep-water area of Qiongdongnan Basin are interpreted. The geometry of No.2 fault system is also re-defined, which is an important fault in the central depression belt of the deep-water area in the Qiongdongnan Basin by employing the quantitative analysis techniques of fault activity and backstripping. Furthermore, the dynamical evolution of the No.2 fault sys-tem and its controls on the central depression belt are analyzed. This study indicates that the Qiongdongnan Basin was strongly influenced by the NW-trending tensile stress field during the Late Eocene. At this time, No.2 fault system initiated and was characterized by several discontinuous fault segments, which controlled a series small NE-trending fault basins. During the Oligocene, the regional extensional stress field changed from NW-SE to SN with the oceanic spreading of South China Sea, the early small faults started to grow along their strikes, eventually connected and merged as the listric shape of the No.2 fault system as ob-served today. No.2 fault detaches along the crustal Moho surface in the deep domain of the seismic profiles as a large-scale detachment fault. A large-scale rollover anticline formed in hanging wall of the detachment fault. There are a series of small fault basins in both limbs of the rollover anticline, showing that the early small basins were involved into fold deformation of the rollover anticline. Structurally, from west to east, the central depression belt is characterized by alternatively arranged graben and half-graben. The central depression belt of the Qiongdongnan Basin lies at the extension zone of the tip of the V-shaped northwest-ern ocean sub-basin of the South China Sea, its activity period is the same as the development period of the northwestern ocean sub-basin, furthermore the emplacement and eruption of magma that originated from the mantle b 相似文献
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影响地电场观测数据干扰因素分析 总被引:1,自引:1,他引:0
地电场观测是地震电磁前兆观测方法之一,由于观测物理量的原因,所受到的干扰因素比较多。为了正确鉴别震前异常信息,对临汾中心地震台影响地电场观测数据的各种干扰因素做了详细的研究,并对典型干扰事件进行了举例说明。 相似文献
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生态与农业气象基础数据查询系统 总被引:1,自引:0,他引:1
1引言生态与农业气象数据作为基础性、公益性数据是国家资源的重要组成部分,对国家宏观决策、防灾减灾、可持续发展和经济建设具有重要的技术支撑作用。如果实现资料共享,将有效发挥数据资源的潜在价值,提高数据资源的使用效益,带动其他领域资料的开放和共享,加速部门信息化和现代化进程,最大限度发挥系统资料的支撑能力。该系统就是立足于生态与农业气象业务、服务的实际需要,在深入分析、整理生态与农业气候资源数据的基础上,以计算机技术和软件为支撑,开发统一数据存储平台,为从事相关工作的人员提供统一标准的数据服务。 相似文献
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《南极研究》与广大读者见面了.我怀着十分高兴的心情为它的创刊致以热烈的祝贺!我国的南极考察工作起步较晚,但发展较快,尤其是近几年,建成了南极长城站,已在长城站地区进行了三次较大规模的多学科考察,初步取得了可喜的成果.我国已经具备了独立开展南极考察的能力,并取得了一些经验.这些成绩是在党中央、国务院的关怀和支持下取得的, 相似文献
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