Comparative study on Chinese urban agglomeration districts   总被引：2，自引：1，他引：1  

李诚固  黄岩君  王祁春 《中国地理科学(英文版)》1998,8(2):136-143

ＣＯＭＰＡＲＡＴＩＶＥＳＴＵＤＹＯＮＣＨＩＮＥＳＥＵＲＢＡＮＡＧＧＬＯＭＥＲＡＴＩＯＮＤＩＳＴＲＩＣＴＳＬｉＣｈｅｎｇｇｕ（李诚固）ＨｕａｎｇＹａｎｊｕｎ（黄岩君）ＵｒｂａｎａｎｄＥｎｖｉｒｏｎｍｅｎｔＳｃｉｅｎｃｅＳｃｈｏｌ,ＮｏｒｔｈｅａｓｔＮｏ...  相似文献   

板桥凹陷古流体势与油气运移聚集史研究   总被引：5，自引：0，他引：5  

李延钧  于志海 《沉积学报》1996,14(4):94-101

本文从板桥凹陷出发，以古流体势动态地描述了油气运移聚集史。建立和讨论了断层在古流体势数值模拟恢复中的处理方法，对有利油气勘探区进行了级别划分，并指出自生自储油气常分布于高势区域。阐明类似板桥凹陷的年青盆地具沉积压实离心流的特点，水流方向与各期流体势方向基本一致。最后作者预测出板桥凹陷一批有利的勘探区。  相似文献   

南岭两类不同成因花岗岩中的磷灰石特征          下载免费PDF全文

高善继  高艳君  翟丽娜  应兰 《岩石矿物学杂志》1988,7(3):265-272

本文对南岭地区燕山期两类不同成因花岗岩(改造型及同熔型)共5个岩体23个人工重砂样品中磷灰石作了较详细的矿物学工作,包括矿物的物理性质、化学成分、稀土元素地球化学特征、红外吸收光谱以及锶同位素特征等。研究结果表明,所研究的两类不同成因花岗岩中的磷灰石标型特征有较明显区别:改造型花岗岩磷灰石为不够完整的六方柱状晶形,相对密度、硬度、红外光谱吸收带某些特征值及其初始~(87)Sr/~(86)Sr比值均稍大(强)于同熔型花岗岩的磷灰石;改造型花岗岩的磷灰石中较富含Mn、REE及F,同熔型磷灰石中较富含Cu、Pb和Cl。文中探讨了磷灰石标型特征的控制因素和形成规律,为其母岩的成因、物质来源提供了矿物学标志和信息。  相似文献   

Experimental Study of Synthesis Processing System for Rock Acoustical Measurement     

Wang Gaizheng  Cheng Leping  Xie Qing  Luo Xiao  Yang Yanjun  LiBaohua  Chai Zhongli  Liu Ke 《岩土力学》1985,6(1):85-92

The system consists of SYC rock acoustical measurement instrument, microcomputer and single board computer. It is a building block system used in both laboratory and field testing to measure rock acoustical data. In this paper the main performances, the fundamental configuration, the interface technique and software design methods are presented, and measurement result analysis is made. An idea was proposed of the automatic acquisition and processing of test data by means of micro-computer control over the test device.  相似文献   

边坡工程加固需求度评价及其应用   总被引：8，自引：6，他引：8  

杨志法张路青  尚彦军李丽慧 《工程地质学报》2004,12(1):12-20

稳定程度不足的边坡通常都需要进行加固。但在加固系统设计时工程师们必须搞清边坡的哪些部位应进行重点加固 ,哪些部位只需要一般加固 ,甚至不需要加固 ,以便合理地布置加固措施。在工程地质力学综合集成方法论 (EGMS)的基础上 ,作者提出了边坡工程加固需求度 (DRD)的概念及其应用方法。  相似文献   

A quick cooling event of the East Asian monsoon responding to Heinrich Event 1: Evidence from stalagmite δ18O records   总被引：2，自引：0，他引：2  

WANG Yongjin  WU Jiangying  LIU Dianbing  WU Jinquan  CAI Yanjun  CHENG Hai 《中国科学D辑(英文版)》2002,45(1)

Based on TIMS U-series dating results and annual band counting method, an annual-resolution time scale from 17450 to 14420 aBP has been established for a stalagmite from the Hulu Cave at Tangshan, Nanjing. A high-resolution oxygen isotopic record reveals decadral-centural oscillations in air temperature in the East Asian monsoon climate area during the last glacial maximum. The most conspicuous feature in the oxygen isotopic record in the period is the particular cold event synchronized with the last Heinrich event (H1) in the northern Atlantic deep-sea records. This particular cold event, beginning at 16140 ( 100 aBP, shows a rapid cooling down with a magnitude of 7-8℃ in air temperature within 36 years. Furthermore, (6)18O record demonstrates that the event lasted 790 years with gradually warming tendency (10 cycles of air temperature oscillations) after the remarkable cooling down. We believed that this unique pattern of event recorded in the stalagmite ? 8O might be controlled by various factors including changes of insolation at mid-latitude Northern Hemisphere, the southern extend of the last ice-rafted event in the North Atlantic and changes of the Equatorial Pacific sea surface temperature.  相似文献   

北京地区中尺度非静力数值预报产品释用技术研究   总被引：9，自引：2，他引：9       下载免费PDF全文

王迎在  刘凤辉等 《应用气象学报》2002,13(3):312-321

在国家气象中心与北京市气象局联合开发的“北京地区中尺度数值预报业务系统”基础上，充分利用高分辨率中尺度数值预报产品和地面加密气象观测资料，分别使用统计和动力释用方法进行局地温度、风和北京市区空气污染状况的预报。试预报结果表明，用卡尔曼滤波方法建立的温度和风的预报效果高于中尺度数值预报直接输出结果；使用中尺度数值预报结果作为一个简单的污染预报动力模式的气象背景场，进行了污染预报试验，结果表明该预报方法具有一定的预报能力，其中SO₂、NO₂、CO浓度的预报准确率在夏、秋、冬三季中均可达到65%以上。上述研究成果已用于业务预报。  相似文献   

Variation of fluxes of water vapor, sensible heat and carbon dioxide above winter wheat and maize canopies     

ZHANG Yongqiang  SHEN Yanjun  YU Qiang  LIU Changming  A. Kondoh  TANG Changyuan  SUN Hongyong  JIA Jinsheng 《地理学报》2002,12(3):295-300

Surface energy fluxes were measured using Bowen-Ratio Energy Balance technique (BREB) and eddy correlation system at Luancheng of Hebei Province, on the North China Plain from 1999 to 2001. Average diurnal variation of surface energy fluxes and CO2 flux for maize showed the inverse "U" type. The average peak fluxes did not appear at noon, but after noon. The average peak CO2 flux was about 1.65 mg m-2 s-1. Crop water use efficiency (WUE) increased quickly in the morning, stabilized after 10:00 and decreased quickly after 15:00 with no evident peak value. The ratio of latent heat flux (λE) to net solar radiation (Rn) was always higher than 70% during winter wheat and maize seasons. The seasonal average ratio of sensible heat flux (H) divided by Rn stayed at about 15% above the field surface; the seasonal average ratio of conductive heat flux (G) divided by Rn varied between 5% and 13%, and the average G/Rn from the wheat canopy was evidently higher than that from the maize canopy. The evaporative fraction (EF) is correlated to the Bowen ratio in a reverse function. EF for winter wheat increased quickly during that revival stage, after the stage, it gradually stabilized to 1.0, and fluctuated around 1.0. EF for maize also fluctuated around 1.0 before the later grain filling stage, and decreased after that stage.  相似文献   

GIS技术在景观视觉分析中的应用   总被引：6，自引：0，他引：6  

张艳军  曾咺 《地理空间信息》2008,6(4):87-89

探索应用地理信息系统空间分析技术,通过三维数字高程模型修正模拟规划在建大型建筑群的“地形”表面,并对观察点和目标点之间视觉的通视、可视域分析,采用定性和定量相结合的方法,形象直观分析评价未来重庆科技馆的景观视觉效果,  相似文献   

基于水环境改善的城市湖泊群河湖连通方案研究   总被引：3，自引：0，他引：3  

杨卫  张利平  李宗礼  张艳军  肖宜  夏军 《地理学报》2018,73(1):115-128

河湖水系连通作为水资源调配、水生态修复与改善的重要手段,已成为江河湖泊治理工作的重点之一。河湖水系连通方案的选择和连通效应的评估直接关系到连通工程对湖泊水动力和水环境的改善效果,但目前缺乏对水系连通后河湖水动力和水质的综合评估体系。以汤逊湖湖泊群为研究对象,构建二维水动力水质数学模型,选取NH₃-N、TN和TP作为水质指标,模拟不同连通方案下汤逊湖湖泊群的流场及水质变化情况,结合水动力、水质和经济社会三个方面的评价指标建立综合评价体系,对各连通方案下湖泊群的改善效果进行评估。研究结果表明：引水后湖泊水体流动性有了很大的改善,河湖连通工程能够在短时间内达到改善湖泊水质的目的,但随着引水时间的增长,改善率逐渐减小。通过对比五种连通方案发现,方案五对水动力和水质的改善都取得了最显著的效果,且能够带来最大的引水效益。  相似文献