盐城市2003年梅雨期暴雨洪水分析

2003年6月20日～7月21日，江苏省盐城市全境发生了新中国成立以来仅次于1991年的第二大暴雨洪水。分析了该次暴雨洪水的雨量、暴雨特性、洪峰流量、洪量、洪水特性及重现期，有助于掌握和了解该地区的暴雨洪水特性，为防灾减灾工作提供科学依据。     

右江流域"2001.7"暴雨洪水分析

2001年7月2～9日，右江流域连降暴雨，致使该流域发生了有水文资料记载以来的最大洪水，为历史所罕见。对右江流域本次暴雨的成因、暴雨时空分布、洪水形成及洪水特性进行了分析，以掌握该流域暴雨洪水特性变化规律。     

陕南"2002·6"暴雨洪水分析

2002年6月8-9日，陕西省南部突降特大暴雨，致使子午河、旬河发生了特大洪水。分析了本次特大暴雨洪水的特性及洪灾成因，提出了关于防御局地暴雨洪水的几点建议。     

湘江流域2002年汛期暴雨洪水分析

2002年汛期，湘江流域发生了7场暴雨洪水，为历史所罕见。通过对暴雨产生原因、暴雨时空分布特点以及洪水的形成、组合情况的分析，以揭示特殊雨水情形戍的原因及特点。     

新疆乌苏市"2001·7"暴雨洪水分析

2001年7月上旬，新疆乌苏市大部分地区发生了暴雨洪水，对这次暴雨、洪水的特征进行了分析。本次暴雨的特征是笼罩面积大、雨量集中和强度大；洪水特征是来势凶猛、陡涨陡落、峰高量大。对于干旱地区暴雨洪水特征的认识和防洪战灾等，具有一定的参考作用。     

广东省中部"97·5"特大暴雨洪水分析

分析了1997年5月8日发生在广东省中部的特大暴雨的成因以及本次暴雨、洪水的特性，有助于人们对该地区突发性暴雨、洪水的认识，对该地区的经济建设具有借鉴作用。     

浑河流域“95.7”暴雨洪水简析

浑河流域“９５·７”暴雨洪水简析乐嘉祥王光生水利部水利信息中心９９５年７月下旬，浑河流域发生了一场特大暴雨洪水。暴雨强度之大历史罕见。洪水峰高量大，上游大伙房水库入库洪水的洪峰流量为１８８８年以来最大值，洪量值接近水库千年一遇设计洪水的洪量值，中下游...     

云南德宏"2004·720"暴雨洪水分析

2004年7月15～20日，伊洛瓦底江流域大盈江、瑞丽江上游等地区连续普降暴雨，最大3日降雨量428．3mm。本次特大暴雨导致大盈江、龙川江流域水位暴涨。并在德宏州支那、盏西、芒章乡引发了滑坡、泥石流、山洪等洪涝灾害。分析该次暴雨洪水的成因、暴雨特性及洪水特性，有助于掌握和了解该流域暴雨、洪水形成条件和变化规律，为防洪减灾工作提供依据。     

基于随机暴雨移置方法的城市设计暴雨分析

城市地区暴雨洪灾发生频繁，合理计算设计暴雨是解决城市洪涝的重要前提。采用随机暴雨移置方法（Stochastic Storm Transposition，SST），设定暴雨移置区并提取出暴雨目录，通过区域性概率重采样与暴雨空间变换相结合的方式进行降雨频率分析，估计本地化的极端暴雨频率。以上海地区为例，研究发现暴雨移置区内暴雨分布具有空间异质性，暴雨随机移置概率不均，计算得到的设计暴雨方案包含了降雨时空分布信息，在不同重现期下设计暴雨的时空结构存在变异性，说明传统方法中采用的简化雨型和均一化空间分布假设会增加设计暴雨的不确定性。     

基于随机暴雨移置方法的城市设计暴雨分析

城市地区暴雨洪灾发生频繁，合理计算设计暴雨是解决城市洪涝的重要前提。采用随机暴雨移置方法（Stochastic Storm Transposition，SST），设定暴雨移置区并提取出暴雨目录，通过区域性概率重采样与暴雨空间变换相结合的方式进行降雨频率分析，估计本地化的极端暴雨频率。以上海地区为例，研究发现暴雨移置区内暴雨分布具有空间异质性，暴雨随机移置概率不均，计算得到的设计暴雨方案包含了降雨时空分布信息，在不同重现期下设计暴雨的时空结构存在变异性，说明传统方法中采用的简化雨型和均一化空间分布假设会增加设计暴雨的不确定性。     

基于PKI的电子商务安全技术与协议分析

随着互联网技术和电子商务的飞速发展,电子商务的安全问题日益引起关注。确保电子商务交易安全的可靠性、保密性、完整性、不可否认性及身份认证,已成为信息安全与电子商务领域中的研究热点。PKI技术作为安全的基础设施,可以为电子商务应用提供一系列的安全保证。在对电子商务安全问题进行了分析的基础上,对基于PKI的电子商务安全技术以及PKI安全体系进行了探讨,说明了PKI在电子商务安全中的作用及应用特点,并重点分析了基于PKI的安全协议的组成及作用。     

Theoritical and Experimental Studies on the Phase Equilibria and Phase Diagrams on the Salt-Water Systems

正1 Introduction Salt lakes are widely distributed in the world,and salt lakes in China are mainly located in the area of the Qinghai-Xizang(Tibet),and the Autonomous Regions of Xinjiang and Inner Mongolia.There are more than 700salt lakes,each with an area larger than 1 km2,in the     

中、美两国铀矿钻探工作量的对比分析

钻探进尺、数量、终孔深度、单位进尺的费用等参数是铀矿勘探中的重要实物工作量和可量化指标。以＂红皮书＂和美国能源信息署等公布的数据为依据,对比分析了中、美两国近两年铀矿钻探统计参数,以及与铀矿勘查之间的关系。     

从榴辉岩与围岩的关系论苏鲁榴辉岩的形成与折返

位于华北和扬子两板块碰撞带中的苏鲁榴辉岩形成的温压条件不但是超高压，而且是高温。榴辉岩的PTt轨迹表明其为陆-陆磁撞俯冲带的产物。榴辉岩的区域性围岩花岗质片麻岩为新元古代同碰撞期花岗岩，榴辉岩及其他直接围岩皆呈包体存在于其中，并见新元古代花岗岩呈脉状侵入榴辉岩包体中。区域性围岩新元古代花岗岩的锆石中发现有柯石英、绿辉石等包裹体，表明新元古代花岗岩的组成物质也经受过超高压变质作用，且榴辉岩与围岩新元古代花岗岩的锆石U-Pb体系同位素年龄基本相同。但新元古代花岗岩所记录的变质作用和变形作用期次（或阶段）却少于榴辉岩。椐上述可得如下推断：超高压榴辉岩与新元古代花岗岩岩浆是同时在碰撞带底部（俯冲板块前部）形成的；榴辉岩的第一折返阶段是由新元古代花岗岩岩浆携带上升的，其第二折返阶段是和新元古代花岗岩一起由逆冲及区域性隆起而上升，遭受剥蚀。     

General regularities in the distribution of seismic events on the Earth and on the Moon

Doklady Earth Sciences -     

Non-linear diffusion: Bison on the hoof and on the rail in the United States

This paper puts forth a non-linear, post-structural conception of geographical diffusion by utilizing the example of American bison. In doing so, this approach stands in contrast to canonical theories of diffusion (notably neoclassical economics and political economy), which portray diffusion as a steady progression of development. In reviewing the history of bison diffusion during the 20th century, the impact of several factors is evident. These include environmental, cultural, economic, governmental, health and material factors. Each of these variables has taken several distinct forms, thereby enlarging the number of actors involved in the species’ redistribution. The impact of each variable has waxed and waned over the years. Consequently, a series of heterogeneous networks has formed, which have simultaneously undercut the importance of certain variables and formed the basis for new channels of bison diffusion. The non-linear nature of diffusion emerges from the different temporalities of these networks. In an alternating fashion, this process of network-building has guided bison onto public, private, and tribal lands.     

潮汐摩擦对月球轨道与地球自转影响的研究综述

潮汐摩擦导致月球轨道和地球自转产生长期变化,精密确定这些参数对了解地月系统的演化至关重要.阐述了求解这些参数的理论方法,回顾并对比了利用天文观测、近地卫星、数值潮汐模型和月球激光测距等资料的分析结果,发现近地卫星和月球激光测距数据比天文观测资料精度高,但可提供数据跨度较短.随观测资料的积累,可提供更可靠的月球轨道和地球自转的长期变化信息,提高对地月空间环境变化的认知.     

Physical and biological controls on the formation of carbonate and siliciclastic bedforms on the north-east Brazilian shelf

The continental shelf of the State of Rio Grande do Norte, Brazil, is an open shelf area located 5°S and 35°W. It is influenced by strong oceanic and wind-driven currents, fair weather, 1·5-m-high waves and a mesotidal regime. This work focuses on the character and the controls on the development of suites of carbonate and siliciclastic bedforms, based on Landsat TM image analysis and extensive ground-truth (diving) investigations. Large-scale bedforms consist of: (i) bioclastic (mainly coralline algae and Halimeda) sand ribbons (5–10 km long, 50–600 m wide) parallel to the shoreline; and (ii) very large transverse siliciclastic dunes (3·4 km long on average, 840 m spacing and 3–8 m high), with troughs that grade rapidly into carbonate sands and gravels. Wave ripples are superposed on all large-scale bedforms, and indicate an onshore shelf sediment transport normal to the main sediment transport direction. The occurrence of these large-scale bedforms is primarily determined by the north-westerly flowing residual oceanic and tidal currents, resulting mainly in coast-parallel transport. Models of shelf bedform formation predict sand ribbons to occur in higher energy settings rather than in large dunes. However, in the study area, sand ribbons occur in an area of coarse, low-density and easily transportable bioclastic sands and gravels compared with the very large transverse dunes in an offshore area that is composed of denser medium-grained siliciclastic sands. It suggests that the availability of different sediment types is likely to exert an influence on the nature of the bedforms generated. The offshore sand supply is time limited and originates from sea floor erosion of sandstones of former sea-level lowstands. The trough areas of both sand ribbons and very large transverse dunes comprise coarse calcareous algal gravels that support benthic communities of variable maturity. Diverse mature communities result in sediment stabilization through branching algal growth and binding that is thought to modify the morphology of dunes and sand ribbons. The occurrence and the nature of the bedforms is controlled by their hydrodynamic setting, by grain composition that reflects the geological history of the area and by the carbonate-producing benthic marine communities that inhabit the trough areas.