EKMAN PUMPING OVER MOUNTAINS     

Wu Rongsheng  Gu Wei 《Acta Meteorologica Sinica》1991,5(4):482-488

The analytical results of the previous paper(Wu,1989)are used to study the properties of vertical veloc-ity distribution at the top of the boundary layer.The relative position of a jet like geostrophic flow and el-lipse-shaped orography will affect the characteristic feature of vertical motion at the top of the boundary layerwhen the contributions of friction and orography are taken into consideration simultaneously.  相似文献   

浙江诸暨地区陈蔡群主要地质特征及其构造演化探讨     

孔祥生  包超民  顾明光 《浙江国土资源》1994,(1)

陈蔡群原岩的主体形成于大洋岛弧环境，由拉斑玄武岩和同源辉长岩，碳酸盐岩和浊流沉积的泥砂质碎屑岩组成；经受了中压角闪岩相区域动力—热流变质作用和多期褶皱变形；岩石地球化学和同位素年代资料表明，中国东南的威尔逊旋回在中元古晚期便已开始，即那时于扬子古陆与华夏地块之间存在一大洋盆地，洋壳上可能存在拉张期残留的花岗质陆壳碎块。中元古晚期开始了洋壳消减作用及其有关的火山—沉积作用，新元古晚期陈蔡大洋岛弧地体与双溪坞陆弧地体拼贴、碰撞，壳体间的聚合作用触发了陈蔡群岩石的变质、变形。  相似文献   

我国沿海近岸带水域的悬沙分布特征   总被引：4，自引：1，他引：3  

谷国传  胡方西 《地理研究》1989,8(2):1-15

本文根据实测悬沙资料,阐述了我国沿海近岸带水域的悬沙浓度由黄河口和长江口-杭州湾为中心,分别向南、北递减,高低相间,构成波状起伏的分布特征,同时分析了径流输沙、潮流、波浪、海岸类型诸要素在悬沙浓度时空变化中的不同作用.  相似文献   

试论铀矿勘查工作阶段的划分     

辜骏如 《华东地质学院学报》1993,16(1):46-49

  相似文献   

F07164+5301: an ESB source with WR features     

Jiehao Huang  Qiusheng Gu  Hongjun Su  Zhaohui Shang 《Astrophysics and Space Science》1996,235(1):109-116

We report on a new ESB source, as defined by Allenet al. (1991), with Wolf-Rayet (WR) bands in its optical spectrum. The WR bump at 4605-4686 is detected. The bump consists of broad HeII 4686, NV4605-4619, NIII4634-41, and possibly, CIII4647-52 emission. The narrow nebular lines are clearly discernable on our spectrum. The number of WR stars derived from the luminosity of HeII4686 is about 8100. The oxygen abundance is about 9.06×10^–4, greater than the solar value.  相似文献   

Transport properties and microstructural characteristics of a thermally cracked mylonite     

M. Le Ravalec  M. Darot  T. Reuschlé  Y. Guéguen 《Pure and Applied Geophysics》1996,146(2):207-227

An experimental study was carried out on a granitic mylonite (La Bresse, France) to analyze the influence of pore microstructure on transport properties. Different crack networks were obtained by a controlled thermal treatment. Microstructures were analyzed by means of gas adsorption and mercury porosimetry. Transport properties have been investigated by measuring gas permeability and electrical conductivity. The dependence of permeability on confining pressure shows an exponential decrease, characteristic of a porosity made of cracks. Correlations between measured parameters have been analyzed by comparing them with relations deduced from theoretical models. Linking the formation factor to the porosity leads to a rather low tortuosity value (about 2.4), characterizing a medium with a well connected porosity. Correlation between permeabilityk and formation factorF leads to a power-law relationk F ^–n wheren2.9, which is consistent with a crack model describing the behavior of the thermally treated rock.  相似文献   

The distribution characteristics of short period geomagnetic variations in Shaanxi region     

GUO HUA FAN TONG QI YAO KE LI HAN KE JIA ZHU ZUO WEN GU Institute of Geophysics  China Seismological Bureau  Beijing  China 《地震学报(英文版)》1998,11(6):719-727

ｎｔｒｏｄｕｃｔｉｏｎＴｈｅｖａｒｉａｔｉｏｎｍａｇｎｅｔｉｃｆｉｅｌｄｏｆｔｈｅＥａｒｔｈｃｏｎｔａｉｎｓａｂｕｎｄａｎｔｉｎｆｏｒｍａｔｉｏｎ,ｓｕｃｈａｓｔｈｅｉｎｆｏｒｍａｔｉｏｎｒｅｌａｔｉｖｅｔｏｓｏｌａｒａｃｔｉｖｉｔｙ,ｓｏｌａｒｔｅ...  相似文献   

Grey characteristics of microbanding of stalagmite in Shihua Cave, Beijing and its climatic signification(I)   总被引：2，自引：0，他引：2  

Xiaoguang Qin  Dongsheng Liu  Ming Tan  Tieying Li  Jinpo Lü  Zhaoyan Gu  Houyuan Lü  Zhongli Ding  Zhengtang Guo  Jiaqi Liu  Gaozhong Nie 《中国科学D辑(英文版)》1998,41(2):151-157

Grey microstructure of microbanding in thin sections of stalagmite T9501 from Shihua Cave, Beijing was studied. The types of grey and the morphologic features of organic material were classified. The signification of microbanding and annual layer was discussed. The standard distinguishing the false annual layer and the multi-year layer is set up, which provides the theoretic fundaments for paleoclimatic study. Project supported by the National Natural Science Foundation of China (Grant No. 49672134).  相似文献   

Comments on “a Practical Method for Relating Scalar Concentrations to Source Distributions in Vegetation Canopies” by M. R. Raupach     

Lianhong Gu 《Boundary-Layer Meteorology》1998,87(3):515-524

This paper considers a modification to the localized near-field (LNF) theory for predicting scalar concentrations from source distributions in plant canopies. It is argued that the non-diffusive, near-field part of the transition probability P_n, and thus the near-field contribution of the scalar concentration C_n, in the original theory are simply errors. The (approximate) equality of the sum of C_n and the diffusive, far-field contribution C_f with the total scalar concentration C is not guaranteed in general by this theory. A revision is suggested.  相似文献   

气候变化对西藏环境经济的可能影响   总被引：4，自引：3，他引：1       下载免费PDF全文

缪启龙  向毓意 《应用气象学报》1998,9(2):225-230

依据西藏一江两河（雅鲁藏布江、拉萨河、年楚河）地区40年的气象资料,分析了该地区的气候变化,指出一江两河地区气温有升高趋势,降水有减少趋势。同时还分析了气候变化对该地区农、牧业生产、水资源及环境的影响,探讨了为适应气候变化可采取的一些策略措施。  相似文献