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71.
基于蚁群算法的城市可持续发展综合评价 总被引:1,自引:0,他引:1
在可持续发展体系分类的基础上,应用蚁群算法对可持续发展各分类指数公式和综合指数公式进行优化,建立可持续发展评价模型。将该模型应用于乌鲁木齐市可持续发展水平评价,评价结果与现状分析一敛。结果表明该模型简单适用、有良好的通用性。 相似文献
72.
73.
This paper proposes a multi‐level parallelized substructuring–frontal combined algorithm for the analysis of the problem of thermo/hydraulic/mechanical behaviour of unsaturated soil. Temperature, displacement, pore water pressure and pore air pressure are treated as the primary variables in a non‐linear analysis. Details are given firstly of the substructuring–frontal combined approach. The incorporation of the algorithm in a multi‐level parallel strategy is then discussed. The parallel processing can thus be carried out at different substructural levels. The method thus developed impacts, in a positive way, on both computer storage requirement and execution time. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
74.
应用GPS观测青藏高原东北缘应力场变化 总被引:2,自引:0,他引:2
采用各向同性弹性地球模型推导了地面位移场速率与地壳内任意点应力场变化的边界积分关系,同时利用青藏高原东北缘1999~2001年观测的GPS资料对观测区地壳深度为5 km和25 km的主应力和最大剪应力进行了计算分析.结果表明,青藏高原东北缘的主应力变化主要集中在祁连山断裂、海原断裂等,在1920~1954年间历史上发生过多次震级为7.0~8.5级强震的断裂附近,并具有主应力变化沿断层走向分布、最大剪应力沿断层走向交替变化等特征. 相似文献
75.
本文综述了ASCA ,RXTE ,BeppoSAX和XMM -NEWTON对TeV耀变体 (Blazar)X射线研究的最新进展。主要集中在X射线资料的时间和光谱分析的最重要的方面 ,包括功率谱密度 ,结构函数 ,带间时间延迟 ,同步峰值能量的漂移和谱演化。对这些新结果的物理意义也进行了简要讨论。 相似文献
76.
JIANGDong WANGNai-bin YANGXIao-huan WANGJi-hua 《中国地理科学(英文版)》2003,13(1):62-65
Daily and ten-day Normalized Difference Vegetation Index(NDVI) of crops were retrieved from meteorological statellite NOAA AVHRR images ,The temporal variations of the NDVI were analyzed during the whole growing season,and thus the principle of the interaction between NDIV profile and the growing status of crops was discussed,As a case in point,the relationship between integral NDVI and winter wheat yield of Henan Province in 1999 had been analyzed.By putting integral NDVI values of 60 sample counties into the winter wheat yield-integral NDVI coordination,scattering map was plotted. It demonstrated that integral NDVI had a close relation with winter wheat yield.These relation could be described with linear,cubic polynomial ,and exponential regression,and the cubic polynomial regression was the best way,In general ,NDVI reflects growing status of green vegetation ,so crop monitoring and crop yield estimation could be realized by using remote sensing technique on the basis of time serial NDVI data together with agriculture calendars. 相似文献
77.
YANGYong-liang SHITong-guang JLANGLU-guang LIYue 《中国地理科学(英文版)》2003,13(2):130-133
In recent years, many coal-producing countries have paid great attention to the land subsidence causedby coal cutting. In China, because of the dense population in coalfield areas, the land subsidence hazard is more seri-ous. After a brief analysis on the mechanism of land subsidence, this paper gives a comprehensive and systematical ac-count on all kinds of hazards caused by the land subsidence in China. The study shows that land subsidence has endan-gered land, buildings, traffic and communication lines, dykes and dams. It also causes damage to ecological and socialenvironment. In order to lessen the hazard of land subsidence, preventive measures should be taken to reduce the col-lapse amount, such as extraction with stowing, banded mining system, succession and coordination mining system, orhigh-pressure mudflow between rock strata. Measures of reinforcing or moving certain buildings should also be taken toreduce the destructive degree. In order to harness the subsidence land and bring them under control for fanning, mea-sures should be taken such as filling with spoil or fine breeze, excavating the deeper and covering the shallower land. 相似文献
78.
INTRODUCTIONTriploidanimalsareusefulbecausetheyaresterile ,characterizedbypositivegrowthinthere productiveseason ,usefulfortesting ,forintroductionofnon nativespecies ,andforprotectionofde velopedstrains.Theinductionoftriploidyhadbeenreportedinmanyaquaculturespecies .Triploidshavebeensuccessfullyinducedinshrimpusingtemperatureshockorchemicalshock (CB ,6 DMAP)in 4species :Sicyoniaingentis (Xiangetal.,1 991 ) ,Fenneropenaeuschinensis (Xiangetal.,1 992 ;Daietal.,1 993;Baoetal.,1 993;Li… 相似文献
79.
1INTRODUCTIONWiththerecentmodernizationandurbanizationofChi-na,urbanareashavegreatlyincreased, andgiantbuild-ings,especiallythosetallerthan100m,havebeendomi-nantincities,whichhave resultedinthegreatincreaseintheproportionofbuilding'sexternalsurfacetototalurbanarea.Thedifferencesofthermalpropertiesmain-lyinducedbysolarradiationbetweenbuilding'sexter-nalsurfacesareobviousfordifferentexposures,whichcaninevitablyinfluencethedistributionsofairtempera-turenearby,eventheverticaldistributionsofurb… 相似文献
80.
Kunde Yang Yuanliang Ma Chao Sun Miller J.H. Potty G.R. 《Oceanic Engineering, IEEE Journal of》2004,29(4):964-972
This paper discusses the results of geoacoustic inversion carried out using explosive charge data from the Asian Seas International Acoustic Experiment (ASIAEX) East China Sea (ECS) Experiment. A multifrequency incoherent matched-field inversion processor and a genetic algorithm (GA) are used for the inversion. A multistep matched field inversion approach is presented, which makes use of the varying sensitivities of wave fields at various frequencies to reduce the inversion problem into a sequence of smaller inversions with fewer unknowns to estimate at each stage. Different parameters are estimated using data at different frequencies according to their sensitivities. Inversion results for different areas in the ECS region are summarized and compared with core data. 相似文献