北京平原区中更新世以来的孢粉组合及其古气候意义

通过对北京平原区3个孔（顺义高丽营GZK1孔、昌平马池口CHZK1孔及大兴DZK1孔）的孢粉资料进行研究和对比,分析了北京平原区中更新世以来的气候变化,并将其划分为8个阶段：第1阶段气候较寒冷干旱,第2阶段气候温暖湿润,第3阶段气候温凉较湿,第4阶段气候温暖较干旱,第5阶段气候较寒冷干旱,第6阶段气候特征为早期暖湿,晚期温凉干旱,第7阶段气候较寒冷干旱,第8阶段气候温和湿润。     

北京西山侏罗纪煤田矿震与地质灾害的关系

北京西山侏罗纪煤田开采中常产生强烈的破坏性冲击地压，是各煤矿生产中严重的井下安全隐患，成为本市十大工业灾害之一。本文作者在多年的地质灾害调查和对京西煤炭开采历史进行分析的基础上，结合西山地质构造特点提出，冲击地压发生时常伴随明显的矿震，矿震的强度受煤质和煤层顶底板性质、地质构造和区域应力场、煤田开采技术和开采深度等因素制约。破坏性矿震除直接对矿山安全生产和矿工生命造成直接的危害外，还常与采矿有关的矿山塌陷等地质灾害相伴发生，对地面居民地建筑物和居民的生命财产安全构成威胁，认为各井田以保安煤柱（或煤带）为采掘对象的生产活动是促发矿震的主要人为扰动因素，建议在有计划的搬迁地表居民地后规划开采，否则应立即强令禁止。     

北京PM10重污染预警预报关键因子研究

利用CART方法对造成北京PM10重污染的气象条件分析结果表明:适当的湿度条件和前期的污染状况是造成北京PM10重污染的必要条件,其他条件,如大气稳定度、边界层高度、持续性小风以及气压,是造成PM10重污染的重要条件。特别值得指出的是,湿度作为必要条件的出现,可能蕴涵着重要的物理化学过程,对其开展深入研究将对北京大气污染的控制和预报有所裨益。     

高密度电法数值模拟及其在寻找北京人头盖骨化石中的应用

为寻找埋藏在地下两米以内深度装有文物的木箱,采用高密度电阻率方法进行了探测.在完成三维正演与二维反演数值模拟的基础上进行了野外数据的反演解释工作,利用三维局部异常体的正演响应特征及二维反演结构与真实模型的对应关系,对实际的数据进行了认识解释,得到了目的层的异常体可能是地道而不是木箱的初步结论.实际表明,利用高密度电法来进行浅层的探测是可行的.     

快速城市化背景下城乡结合部发展特征与机制 ——以北京海淀区为例

通过对北京海淀区城乡结合部的实地调查,探讨了快速城市化背景下城乡结合部的发展特征及其形成机制。发现:海淀区城乡结合部居民构成复杂且就业、收入不稳定,社会保障水平偏低的弱势群体集中;外来人口规模庞大且具有乡镇集聚指向特点,其生产、生活方式与状态对城乡结合部发展影响深远;土地产权复杂交错,土地征用和土地流转存在诸多矛盾;农村经济的长期影响和居民消费能力等制约了城乡结合部的产业发展层次,新兴产业区的高新技术产业、现代化服务业难以与当地传统、低端产业对接,辐射带动能力非常有限;基础设施总体欠账严重,其建设主体多元化、交叉化,投资能力存在差异。独特的地域特点、复杂的历史背景,以及制度、规划与政策的缺失是影响城乡结合部发展的主要因素,未来发展应注重体制、规划与决策的创新。     

Basic features and trends of the economic base of Beijing

In China, systematic studies on economic base of a single city are very weak. Based on the 1990 census and relevant statistics during 1990 – 1994, a comparative study is conducted on Beijing, Shanghai and Tianjin. The major conclusions are as follows: (1) Beijing is not only the national political and cultural center, but also the national economic center, viz the commercial service center and the low water-consuming, light polluting, external economy-typed and knowledge-intensive manufacturing industrial center, which is appropriate for Beijing’s comparative advantage. (2) The high water-consuming, heavy polluting and regional market-oriented industry is overdeveloped as far as Beijing’s scarce water and other natural resources are concerned. (3) Beijing’s industrial base is smaller, more regional market-based, and the service base is more diverse, larger and more national market-based than Shanghai’s and Tianjin’s. (4) With the development of socialist market economy and implement of sustainable development strategy, the external economy-typed and knowledge-intensive manufacturing industry with lower input of water and less environmental pollution, and information-intensive service industries will centralize further, and the industry with higher input of water and/or severe environmental pollution will decentralize.     

北京地区岩溶地下水资源勘察工作探讨

地下水是北京市主要的供水水源。岩溶水作为北京市地下水资源的重要组成部分,对保障目前和今后一个时期首都的供水安全,发挥着至关重要的作用。本文阐述了北京地区岩溶地下水资源的分布状况,介绍了岩溶地下水的勘探开发历史,分析了当前岩溶水勘察工作中存在的主要问题,提出了近期北京地区岩溶水的勘察工作思路和工作重点。     

Numerical Study on Vortices in the Middle Layer of Flow around a Large Mountain under Rotating Stratified Conditions

Generation of cyclonic vortices in the middle layer of flow around a large mountain like Tibet and Rocky was investigated by means of a 3-D nonhydrostatic meteorological prognostic model. Special attention was paid to the effects of the earth’s rotation and stratification on the vortices detached successively from the slope of a high and large horizontal scale mountain. It was found the successive formation and detachment of such ‘von Karman-like vortices’ occurred in the flow regime at high Rossby numbers Ro and low Froude numbers Fr. It was successfully divided by the criterion of baroclinic instability. This means that if the condition is unstable baroclinically, a lee vortex is destabilized into a three-dimensional one, while under baroclinically stable conditions the lee vortex with vertical axis retains its standing structure and remains long lasting in the middle layer.     

The heterogeneous characteristics of crust-mantle structures and the seismic activities in the northwest Beijing region

Introduction Zhangjiakou-Bohai seismic zone is a major active seismic zone that passes through the north-ern part of North China. Zhangjiakou-Beijing area, the northwest part of North China, is located at the intersection position of Yanshan, Taihangshan uplift, and Shanxi down-faulted zone, and the geological structures in this area are extremely complicated. Many researchers in the geoscience circle always pay close attention to this region because Yanqing-Huailai region is located in th…     

自动临近预报系统及其在北京奥运期间的应用

该文介绍了对流风暴自动临近预报系统(BJ-ANC)及其在2008年北京奥运会期间的应用。BJ-ANC是在技术引进基础上,通过本地化改进和拓展研发而形成的适合于在京津冀地区使用的对流风暴自动临近预报系统。BJ-ANC系统通过对风暴进行分析,利用临近预报算法和模糊逻辑集成技术,生成反映风暴发生、发展和消亡的分析及预报产品。系统考虑了京津冀地区边界层辐合线及地形与风暴生消发展之间的密切关系。通过对2008年实时预报结果的检验表明:系统对风暴单体在1 h内的外推预报与实际观测的风暴单体中心的距离偏差较小;系统的1 h定量降水预报和自动站的降水观测接近;系统对风暴回波的总体预报性能明显优于持续性外推方法。通过对2008年奥运期间对流风暴个例的实际应用分析表明:系统对风暴的临近预报具有指导意义,边界层辐合线对风暴的局地新生和快速演变具有明显的正面预报效果。另外,系统反演得到的对流层低层热动力三维特征提供了风暴生消、发展预报的重要判据。