首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   4篇
  免费   4篇
化学   4篇
物理学   4篇
  2012年   2篇
  2008年   2篇
  1992年   1篇
  1991年   1篇
  1988年   1篇
  1987年   1篇
排序方式: 共有8条查询结果,搜索用时 109 毫秒
1
1.
2.
Miaodao Islands, lying across the Bohai Gulf between Jiaodong Peninsula and Liaodong Peninsula.are also called Changshan Islands. They consist of eighteen big and small islands, aligned in NNEdirection. The largest of them is the South Changshan Island, which lies at the southernmost end. Thedistance between South Changshan Island and Penglai County is 7 km, and Miaodao Islands have anarea of 12.75 km~2. Because of the fall of the sea level, Miaodao Islands formed a land bridge linkingJiaodong Peninsula and Liaodong Peninsula during the Quaternary period, thus playing an importantrole in the development of mankind and exchange of culture (Fig. 1). Miaodao Islands have been in a structural uplift for a long time, and their outlines are controlledby structural lines in NE, NNE, NW and EW directions. Most of the islands are composed of quartzite of Sinian Age. The coast of each island is bordered with cliffs. The quartzite gravels, fine in textureand multicoloured, on the beach are well rounded. The height  相似文献   
3.
In this paper, the morphology, sedimentary structure, bioherm--building mollusk assem-blages and their growing and piling-up models of modern oyster bioherms in the estuariesof the Zimaigou and Xiaoqing Rivers are described and expounded, the environmentalconditions for the development of oyster bioherms, such as the dynamical geomorphicbackground, water depth, hydrodynamic factors and ecological conditions in the estuaries,are analyzed, the relationship of the successively seaward migrating of oyster biohermswith average annual sea-level changes and the erosion--accretion processes in the estuariesare probed and explained, and the geological significance of oyster bioherms in the studyof Quaternary marine environmental evolution is presented.  相似文献   
4.
鲁公儒  李祥  李培英 《物理学报》2008,57(2):778-783
在LHC上,最小超对称标准模型中R-宇称破缺相互作用使LHC上tt对的产生有两种过程,一种是交换slepton粒子的t道的dRdRtLtL过程,一种是交换squark粒子的u道的dRdRtRt 关键词: 最小超对称标准模型 R-宇称破缺相互作用 top夸克极化  相似文献   
5.
现代牡蛎礁发育与生态特征及古环境意义   总被引:3,自引:0,他引:3  
本文以淄脉沟、小清河等河口牡蛎礁为例,阐述了现代牡蛎礁的形态、结构、造礁生物组合及其堆积、生长方式,分析了牡蛎礁发育的环境条件——地貌背景、水深、动力和生态环境条件,探讨了牡蛎礁不断外移与河口蚀淤、平均海面升降变化的关系,论述了牡蛎礁的古环境指示意义。  相似文献   
6.
山东庙岛群岛的黄土   总被引:26,自引:0,他引:26  
本文论述了庙岛黄土的成因,黄土物质来源有二:一为西北气流自亚洲内陆搬运来的物质;另一物源由地方风系吹物海底沉积物就地降落,两者混合而成。本群岛的黄土堆积与冰期气候控制的低海面时期相吻合。第四纪期间,随着海面的升降,这些岛屿曾多次成为沟通胶辽的渤海陆桥。  相似文献   
7.
在LHC上,最小超对称标准模型中R-宇称破缺相互作用使LHC上tt对的产生有两种过程,一种是交换slepton粒子的t道的dRdRtLtL过程,一种是交换squark粒子的u道的dRdRtRt  相似文献   
8.
We experimentally report on the evolution from singly-dressed to doubly-dressed four-wave mixing (FWM) process by controlling the powers of the probe, the pump and the dressing fields respectively. The differences in the enhancement and the suppression of FWM signal between the two-level and cascade three-level atomic systems are observed and explained by the multi-dressed effect theoretically. Both the x direction and the y direction spatial splittings of the degenerate-FWM (DWFM) beams are obtained. We also investigate the switch between the enhancement and the suppression of the DWFM signals and between its spatial splittings in x direction and y direction. The spatial splittings in x direction and y direction can be controlled by the relative position and the intensity of the involved laser beams. Such a study can be useful for optimizing the efficiency of the FWM process and providing potential applications in spatial signal processing.  相似文献   
1
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号