NUMERICAL SIMULATIONS OF SCOUR AND DEPOSITION IN A CHANNEL NETWORK

1 INTRODUCTION Evolution of the river bed in alluvial channels has been studied by many researchers using analytical and numerical approaches. The use of analytical approach alone is insufficient for solving natural river engineering problems. With rapid growth in computer technology, numerical models have become a popular means for the study of mobile bed hydraulics. During the past decade, several numerical models have been developed. Most of the computer codes, such as HEC2SR (Si…     

关于长期天气预报的一些意见

本文简要地陈述了若干长期天气过程的特征及表征长期天气过程并用之于长期天气预报的方法。     

1954年2月11日甘肃省山丹县的地震

緒言 1954年2月11日地方时間8时80分山丹（北緯38°47′东經101°13′）地震。震中在城东北龙首山中。倒塌房屋3,804間,窑59孔,損坏房屋3,473間,压死47人,伤332人。地方政府及企業单位当即分別組队前往調查。三月間,中国科学院地球物理研究所及地質研究所在地方政府领导下,由一些企業单位的工作人員配合,进行了宏观     

100毫巴低纬度环流季节变化的初步分析

低纬度100毫巴流场的季节变化东半球比西半球明显。在东半球低纬度冬季为绕极西风,而到夏季为强东风气流,并在亚非高空产生强大的副热带大陆高压。流场变化过程与东亚季节转换有一定程度的联系,作者建议这种现象可称为“大型季风”。沿30°N波数为1的振幅与位相的变化可作为大型季风转换的一个表征。     

10-12月低纬度东南亚和西太平洋上空流场特征

根据1958—1959年资料,初冬西太平洋低纬度流场可分为两种流型,即浅薄副热带高压型与深厚副热带高压型。前者在高纬度为低西风指数型,副热带急流的配置与平均情况一致在近赤道地区对流层下层有不剧烈发展的东风波。后者在高纬为高西风指数型,副热带急流的配置与平均情况反位相,近赤道地区对流层下层有赤道西风,在赤道辐合带上井有台风发生,两者间有一个月上下的准周期变化。     

中国夏半年几种降水天气系统的分析研究

本文是一年来从事夏季降水天气初步普查的简单报告。第一节首先指出所用分析方法与一般国内所通用者,稍有不同。高空等压面分析,取20米作为等高缐间隔,2℃作为等温缐间隔。代替40米及5℃的间隔,以适应夏半年较弱的温度场与气压形势场,在剖面分析中以等假相当位温缐代替位温缐,与等温缐配合以适应降水天气的凝结降水过程。 第二节讨论了五种夏半年基本降水天气系统,即冷锋、阻塞高压与冷涡、季风热低压、 暖锋及有风的结构,并简单地叙述了演变过程。 第三节对某些天气概念提供一些批判性的讨论。根据现已增加的观测材料,论证季风与梅雨是多样性的,决定于大规模的温度场与流场特性,以高空湿度大小区分赤道气团与热带海洋气团,证明是不适当的,因为中国赤道锋降水区域以南,即在所谓南南季风的赤道气团中,中层大气仍是干燥的。降水区域内,中层对流层的大量水份,是由于辐合或抬升的作用,使潜势的对流不稳定性成为现实的不稳定性,而由下层空气上升带上去的。文中还论证了所谓西北槽槽缐前倾是将两个系统混作—个系统的不正确桔果。最后还讨论了切交缐及一般模型在天气分析预报中的应用与限制。     

An Outline of the Geological Structure of the Western Hills of Peiping

As a pioneer worker in almost every phase of the Chinese geology,the late Dr. V. K. Ting was also a pioneer and enthusiastic worker inthe geology of the Western Hills. It was due to his noble effort andsupervision that the first systematic investigation of 1916 was carried out     

STRATIGRAPHY OF SOUTHEASTERN HUPEI

The geology, of the southeastern part or Hupei has been studied by Mr. Seijirro Noda of the Japanese Geographical Society in 1912. A geological map in the scale of 1:400,000 was prepared by him, covering the districts Ta Yeh, Yang Sing, O Cheng and Wu Chang. Mr. Noda classified the sedimentary rocks into the following series:     

ON LOPINITE,A NEW TYPE OF COAL IN CHINA

To the east of Nanchang,the capital of Kiangsi Province,there cropsout a continuous belt of Permian coal series~1 trending approximately in thedirection from N.E.to S.W.Broadly speaking,this coal belt forms a synclinal     

THINNED POLISHED SECTION OF COAL,A NEW TECHNIQUE IN COAL PETROGRAPHY

Opinions often differ among coal petrographers as to the relative ad-vantages of the thin sections and the polished sections.In reality both of themare useful and they should be used simultaneously in order to get a clear and