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31.
ENVIRONMENTAL SUSTAINABILITY AND SCENARIOS OF URBANIZATION IN ARID AREA——A Case Study in Wuwei City of Gansu Province 总被引:1,自引:0,他引:1
YOUFei LIYu DONGSuo-cheng 《中国地理科学(英文版)》2005,15(2):120-130
1IN T R O D U C T IO N The western China isfacinggrowing problems of eco- logicaland economic development. The disparitiebse- tween the socio-economy of the western and eastern China were enlarging, and the major ecologicalprob- lems stilelvolve as past(H… 相似文献
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A highly automated moving object detection package 总被引:1,自引:0,他引:1
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隧道工程地质评价的内容和方法 总被引:2,自引:0,他引:2
结合工程隧道实际,首先阐述了隧道工程的基本地质环境和工程地质条件,然后针对隧道工程可能出现的不良地质现象和可采取的工程措施,从大气降水、围岩稳定、围岩压力、洞口稳定、隧道比选等角度探讨隧道工程地质评价的主要方法和一般内容,进行隧道工程地质评价,为隧道施工、支护提供了依据. 相似文献
36.
薛建康 《成都信息工程学院学报》1990,(1)
本文针对冬半年高原低涡几个不同源地的低涡生成背景,着重分析500hpa环流场,指出:地形对低涡生成是非常重要的条件,但一定范围内有利的环境流场也是低涡生成不可缺少的外部条件。并给出了不同涡源区有利于低涡发生,发展的500hpa环流形势。 相似文献
37.
Majid T. Manzari 《国际地质力学数值与分析法杂志》2004,28(10):1011-1032
A micropolar elastoplastic model for soils is formulated and a series of finite element analyses are employed to demonstrate the use of a micropolar continuum in overcoming the numerical difficulties encountered in application of finite element method in standard Cauchy–Boltzmann continuum. Three examples of failure analysis involving a deep excavation, shallow foundation, and a retaining wall are presented. In all these cases, it is observed that the length scale introduced in the polar continuum regularizes the incremental boundary value problem and allows the numerical simulation to be continued until a clear collapse mechanism is achieved. The issue of grain size effect is also discussed. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
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Characteristics of Spatial and Temporal Variations of Monthly Mean Surface Air Temperature over Qinghai-Tibet Plateau 总被引:1,自引:0,他引:1
ZHANG Qianggong KANG Shichang YAN Yuping 《中国地理科学(英文版)》2006,16(4):351-358
1 Introduction The Qinghai-Tibet Plateau, known as the highest plateau with the most complex topography in the world, covers an area of more than 200km2, with a mean elevation of more than 4000m a.s.l. (Ye and Gao, 1979). Surrounded by the Earth’s highest mountains, such as the Himalayas, Pamir, Kunlun Mountains, the plateau plays a significant role in climate change in China even in the world, thus attracted great attention of researchers. Up to now, many achievements have been gained by… 相似文献
40.
In the first paper of this series, we presented EBAS – Eclipsing Binary Automated Solver, a new fully automated algorithm to analyse the light curves of eclipsing binaries, based on the ebop code. Here, we apply the new algorithm to the whole sample of 2580 binaries found in the Optical Gravitational Lensing Experiment (OGLE) Large Magellanic Cloud (LMC) photometric survey and derive the orbital elements for 1931 systems. To obtain the statistical properties of the short-period binaries of the LMC, we construct a well-defined subsample of 938 eclipsing binaries with main-sequence B-type primaries. Correcting for observational selection effects, we derive the distributions of the fractional radii of the two components and their sum, the brightness ratios and the periods of the short-period binaries. Somewhat surprisingly, the results are consistent with a flat distribution in log P between 2 and 10 d. We also estimate the total number of binaries in the LMC with the same characteristics, and not only the eclipsing binaries, to be about 5000. This figure leads us to suggest that (0.7 ± 0.4) per cent of the main-sequence B-type stars in the LMC are found in binaries with periods shorter than 10 d. This frequency is substantially smaller than the fraction of binaries found by small Galactic radial-velocity surveys of B stars. On the other hand, the binary frequency found by Hubble Space Telescope ( HST ) photometric searches within the late main-sequence stars of 47 Tuc is only slightly higher and still consistent with the frequency we deduced for the B stars in the LMC. 相似文献