气候变化对全新世以来中国东部政治、经济和社会发展影响的初步研究   总被引：6，自引：3，他引：3  

任美锷 《地球科学进展》2004,19(5):695-698

将社会科学(文史考古研究)与自然科学(气候变化)结合,分析了黄土高原社会经济发展较长江三角洲地区为早的原因,提出这可能是由于全新世大暖期的气候变化对不同地理区域产生不同的影响,最后并分析了中国历史上的3次移民潮的原因及其对长江三角洲社会经济发展的影响。  相似文献   

Research on Water-Taking Characteristics of Huanghua Power Plant Reach     

Tong Zhongshan  Ying Xingya  Qian Bingfa Engineer 《中国海洋工程》1998,(1)

In this paper the water-taking characteristics of the first,the second and the third stage of theHuanghua Power Plant are studied by numerical model and physical model.The results show that the pres-ent inlet channel only satisfies the supply need of the first stage of the power plant.If the riverbed of the in-let reach is properly dredged,the need of water supply for the third stage of the power plant could be met.  相似文献   

Numerical Modeling on Suspended Sediment Transportation in the Hangzhou Bay   总被引：4，自引：0，他引：4  

Zhang Jinshan  Lu Peidong  Xu Ming Senior Engineer 《中国海洋工程》1998,(1)

In this paper the characteristics of tidal flow and seasonal variation of seidment content in theHangzhou Bay and their affecting factors are studied.Field investigations and data analysis indicate thatthe sediment movement is mainly influenced by the Yangtze estuary and the sediment of the Yangtze estua-ry is induced by wind wave and tidal flow.Owing to the variation of dynamic conditions,the instanta-neous sediment content is controlled by tidal flow,wind wave,depth of water and tidal range synthetically.A sediment content relationship formula is established with related factors.A non-equilibrium2-dimensional numerical model of suspended sediment transportation is set up,and the finite element meth-od is applied.The computation results of the model is in accordance with field data.  相似文献   

Study on Coastal Protection Engineering in the Area of Abandoned Yellow River Mouth     

ZHANG Yifan  YU Guohua  SHENG Zhaoci  XU Ming Senior Engineer  River  Harbour Department  Nanjing Hydraulic Research Institute 《中国海洋工程》1998,(2)

This paper reviews the history of coast evolution and coastal protection in the area of theabandoned Yellow River mouth in Jiangsu Province,analyzes the erosion characteristics and dynamic en-vironment,evaluates the efficiency of coastal protection engineering works and designs the dimensions ofthe main seadike and offshore submerged dam.A gerneral scheme of shore protection for this area is pro-posed.  相似文献   

Chronostratigraphic Subdivision and Correlation of the Permian in China   总被引：11，自引：0，他引：11  

JIN Yugan  SHANG Qinghau  WANG Xiangdong  WANG Yue  SHENG Jinzhang Nanjing Institute of Geology & Palaeontology  Chinese Academy of Sciences  Nanjing 《《地质学报》英文版》1999,73(2):127-138

Since the principle of multiple stratigraphic classification has been widely accepted by Chinese stratigraphers, various new Permian chronostratigraphic units have been proposed in China, and they need to be redefined. The establishment of a new global chronostratigraphic scheme of the Permian, compilation of Permian lithostratigraphic units and updating of Permian biostratigraphic sequences of China makes it possible to present a revised regional chronostratigraphic succession for the Permian System in China. This succession consists of three series and eight stages. The Chuanshanian Series includes two stages, the Zisongian and the Longlinian; the Yanghsinian (Yangxinian) Series is subdivided into the Chihsian (Qixiaan) and the Maokouan Subseries, of which the former comprises the Luodianian and the Xiangboan Stage, and the latter the Kufengian (Gufengian) and the Lengwuan Stage; the Lopingian (Lepingian) Series includes the Wuchiapingian (Wujiapingian) and the Changhsingian (Changxingian) Stage.  相似文献   

边坡监测信息可视化查询分析系统及其应用   总被引：9，自引：0，他引：9  

袁宝远  吕建红  刘大安 《工程地质学报》1999,7(4):355-360

大型边坡监测系统数据庞大,项目及测点繁多。传统的数据库管理系统很难直观地查询分析监测数据。作者用在Window 系统下面向对象的程序设计语言VisualBasic和面向对象的数据库管理开发系统Access 开发了具有可视化查询分析特征的监测信息分析管理系统。本文以五强溪水电站左岸船闸边坡为例,介绍了系统的设计和程序功能。  相似文献   

Dynamic Behaviour of a Caisson Quaywall Under Strong Earthquake     

LIU Hanlong  DAI Huichao  Susumu IAI Professor  Geotechnical Engineering Research Institute  Hohai University  Nanjing  China. Senior Engineer  China Yangtze Three Gorges Project Development Corporation  Yichang  China. Doctor  Port  Harbour Research Institute  Ministry of Transport  Nagase  Japan. 《中国海洋工程》1999,(1)

—Effective stress analysis is performed to evaluate the residual displacement of a caissonquaywall during 1994 Hokkaido-Toho-Oki Earthquake and 1993 Kushiro-Oki Earthquake.Theconstitutive model used in this study is a multiple shear mechanism type defined in strain space and cantake into account the effect of rotation of principal stress axis.The earthquake accelerations recorded atthe outcropping rock during the earthquake are used as input bedrock motion.The results of finite ele-ment analysis are in good agreement with the observed behaviour of the quaywall.The analysis also indi-cates that liquefaction and high excess pore water pressure have a significant effect on the deformation ofthe caisson.Soil improvement is speculated as the most reliable measures against liquefaction.The influ-ence of soil improvement and the reasonable improved area are discussed in the paper.  相似文献   

Mechanics of a Grip System of Three-Key-Board Hydraulic Tongs Developed for Offshore Oil Pipe Lines     

ZHAO Junyou  GUO Aiju  DING Keqin  LIU Chuntu Lecturer  Petroleum University of China  Shangdong  P. R. China. Engineer  Zhongyuan Petrochemical Corporation  Henan  P. R. China. Postdoctoral Fellow 《中国海洋工程》1999,(1)

-This paper carries out the analysis of mechanics of a grip system of three-key-board hydraulictongs developed for offshore oil pipe lines which has been successfully used in oil fields in China.The mainimprovement of this system is that a lever frame structure is used in the structural design,which reducesgreatly the stresses of the major components of the oil pipe tongs.Theoretical analysis and numerical calcu-lation based on thirteen basic equations developed show that the teeth board of the tongs is not easy to slipas frequently happens to other systems and is of higher reliability.  相似文献   

南极乔治王岛阿德默勒尔蒂湾火山活动时空演化          下载免费PDF全文

邢光福  王德滋  金庆民  沈渭洲  陶奎元 《极地研究》2002,14(1):22-34

在乔治王岛中部的阿德默勒尔蒂湾 ,凯勒半岛、于尔曼山嘴和埃内坎角是第三纪火山岩集中分布区。野外地质调查和同位素年代学研究表明 ,凯勒半岛发生了三期火山喷发 (三个火山喷发旋回 ) ,同时伴随着火山活动中心的不断北移 ;在第二期火山喷发之后 ,火口塌陷 ,形成破火山 ,之后在半岛北部又发生火山喷发 ,并向东迁移到于尔曼山嘴。因此凯勒半岛是一复活破火山 ,火山活动具有随时间迁移的特性。埃内坎角火山活动虽与上述两地区大致同时 ,但化学成分上不存在明显演化关系 ,应属另一相对独立的火山活动中心  相似文献   

The Bivalve Yangtzedonta is not the Brachiopod Xianfengella   总被引：2，自引：0，他引：2  

YU Wen Nanjing Institute of Geology  Palaeontology  Chinese Academy of Sciences  Nanjing  Jiangsu  China 《《地质学报》英文版》2005,79(6):770-776

Abstract The alleged ＂holotype＂of the bivalve Yangtzedonta primitiva Yu.1985 figured by Qian （2001） is a broken and distorted specimen of the brachiopod Xianfengella prima He and Yang, 1982 and not the holotype of Y. primitiva. Qian contends that the oldest recognized monoplacophoran, Maikhanella pristinis （Jiang, 1980）, is neither a monoplacophoran nor the oldest molluscan fossil in the Meishucunian Stage of China. Furthermore, he considers that the oldest bivalve Xianfengoconcha eUiptica Zhang, 1980 is an inarticulate brachiopod, not a mollusc. WatsoneUa yunnanensis （He and Yang, 1982）, is associated with Yangtzedonta primitiva Yu but indicates no evolutionary relationship between the Classes Rostroconchia and Bivalvia in the Lower Cambrian Zhongyicun Member of the Yuhucun Formation. Qian＇s confusion in using non-molluscan fossils to discuss the early evolution of shelled molluscs also confuses the basic concepts of the respective groups.  相似文献