BOOK REVIEWS     

《The Professional geographer》1987,39(3):363-386

Book Reviewed in this article: Hillslope Processes. Binghamton Symposia in Geomorphology International Series: 16. Athol D. Abrahams , ed. The Atlas of Central America and the Caribbean. The Diagram Group . The Cultural Atlas of Islam. Isma'il R. al Faruqi and Lois Lamaya'al Faruqi . Atlas of Israel Contemporary Africa: Development, Culture and the State. Morag Bell . Fundamentals of Physical Geography. David Briggs and Peter Smithson . The Bicentennial Census: New Directions for Methodology in 1990. Constance F. Citro and Michael L. Cohen , eds . World Patterns of Modern Urban Change: Essays in Honor of Chauncy D. Harris. Michael P. Conzen , ed . New Directions for Agriculture and Agricultural Research: Neglected Dimensions and Emerging Alternatives. Kenneth A. Dahlberg , ed . Water Resources Atlas of Florida. E.A. Fernald and D.J. Patton , eds . Landscape Ecology. R.T.T. Forman and M. Godron . The Myth of the North American City: Continentalism Challenged. Michael Goldberg and John Mercer . The Permafrost Environment. Stuart A. Harris . Climate and Circulation of the Tropics. Stefan Hastenrath . The Island of South Georgia. Robert Headland . The Making of Urban Europe, 1000-1950. Paul M. Hohenberg and Lynn Hollen Lees . Bombay in Transition: The Growth and Social Ecology of a Colonial City, 1889–1980. Meera Kosambi . Plant Closings; Public or Private Choices? Richard B. McKenzie , ed . Malaysia: Tradition, Modernity and Islam. R.S. Milne and Diane K. Mauzy . Technology on the Frontier: Mining in Old Ontario. Dianne Newell . The Maritime Political Boundaries of the World. J.R.V. Prescott . Tall Office Buildings in the United States. James W. Pygman and Richard Kateley (Real Estate Research Corporation). Technology, Regions, and Policy. John Rees , ed . The United States and the Regional Organization of Asia and the Pacific: 1965-1985. W.W. Rostow . Renewable Energy: Progress, Prospects. Stephen W. Sawyer Wisconsin Foundations. Gwen Schultz . Dwelling, Place and Environment: Towards a Phenomenology of Person and World. David Seamon and Robert Mugerauer , eds . Power and Place: Canadian Urban Development in the North American Context. Gilbert A. Stelter and Alan F.J. Artibise , eds . Small Firms in Regional Economic Development: Britain, Ireland and the United States. D. J. Storey , ed . Mathematical Methods in Human Geography and Planning. A. G. Wilson and R. J. Bennett . El Niño North: Niño Effects on the Eastern Subarctic Pacific Ocean. W. S. Wooster and D. L. Fluharty , eds . The Soviet Iron and Steel Industry. Craig ZumBrunnen and Jeffrey Osleeb .  相似文献   

测量平差中的最优化方法     

李家权 《地球科学与环境学报》1987,(2)

本文应用最优化方法分析平差问题,指出无论是古典平差或是秩亏自由网平差,实际上都是求矛盾方程组BX-L=0的极小最小二乘解。以此为基础,本文采用Cram-Schmidt矩阵直交化方法,提出一种对古典平差和秩亏自由网平差都适用的计算方法。  相似文献   

Placement Optimization Method of FPSO Gas Detectors Based on Leakage Risk     

KANG Jichuan  SUN Chongwen  JIN Peng  YAN Fasuo  SUN Liping 《中国海洋大学学报(英文版)》2022,21(1):49-61

As the first step of the fire/gas-detection systems of floating production storage and offloading(FPSO)units is to iden-tify leakage accidents,gas detectors play an important role in controlling the leakage risk.To improve the leakage scenario detection rate and reduce the cumulative risk value,this paper presents an optimization method of the gas detector placement.The probability density distribution and cumulative probability density distribution of the leakage source variables and environmental variables were calculated based on the Offshore Reliability Data and the statistical data of the relevant leakage variables.A potential leakage sce-nario set was constructed using Latin hypercube sampling.The typical FPSO leakage scenarios were analyzed through computational fluid dynamics(CFD),and the impacts of different parameters on the leakage were addressed.A series of detectors was deployed according to the simulation results.The minimization of the product of effective detection time and gas leakage volume was the risk optimization objective,and the location and number of detectors were taken as decision variables.A greedy extraction heuristic algo-rithm was used to solve the optimization problem.The results show that the optimized placement had a better monitoring effect on the leakage scenario.  相似文献   

植草沟滞蓄城市道路雨水的试验及模拟   总被引：1，自引：0，他引：1       下载免费PDF全文

孟莹莹  陈茂福  张书函 《水科学进展》2018,29(5):636-644

为定量分析植草沟的水文性能,优化其设计参数取值,通过植草沟滞蓄城市道路雨水的试验设施开展模拟径流试验,验证了SWMM （storm water management model）模型模拟植草沟滞蓄效果的可行性,通过模型情景分析提出了设施的优化设计参数,评估了设施对提高道路排水标准和长期径流削减的影响。研究结果表明:SWMM模型对模拟植草沟水文性能具有较好的精度,对较小的降雨重现期和边坡比,较大的滞蓄深度、植被覆盖率和面积负荷比,植草沟的滞蓄能力更强,建议其设计降雨重现期不超过10年,滞蓄深度为10 cm以上,边坡比至少为3,植被覆盖率为0.5以上,面积负荷比为5%以上。模拟北京某城市道路采用植草沟设施后,可将3年、5年、10年的排水标准分别提高到15年、20年、30年,在长达64年的运行中,植草沟几乎可消纳自身及汇水区域内所有径流,可为道路植草沟的设计和应用提供参考。  相似文献   

页岩气调查黔地4井钻探技术   总被引：1，自引：1，他引：0       下载免费PDF全文

王宗友  陈刚  乔生贵 《探矿工程》2018,45(2):1-6

黔地4井是部署在渝东南凹陷褶皱带濯河坝向斜南段的一口页岩气地质调查井,全井取心,设计井深2400 m,完钻井深2258 m。项目通过钻探设备、钻具（钻头）选择和井身结构优化设计等,使钻头最高寿命达466 m、钻效提高10%以上。全井平均机械钻速1.78 m/h,钻月效率535 m,其中二开钻月效率704 m,达到了快速、安全钻探目的。  相似文献   

航空摄影测量生产作业流程优化方法     

袁敏 《测绘与空间地理信息》2015,(3):89-91

传统的航空摄影测量生产作业流程存在着内业、外业相对独立,采编与图库相互分离等许多缺点。这样,导致较长的生产周期难以提供实时的测量结果,在经济发展快的地区表现得更加严重。本文通过新技术的应用和工作经验总结,进行了生产作业流程优化方法的关键技术讨论,实现了缩短生产周期,提高了生产作业效率。最后,结合应用实例进行效果评价。  相似文献   

一种优化的自由网平差及其在变形监测中的应用研究     

奉延龙  王建雄 《测绘与空间地理信息》2015,(5):170-172

主要介绍使用序贯平差与秩亏自由网平差联合的方法对自由网平差进行优化,此优化方法能集合自由网平差无控制点约束的特点和序贯平差处理大数据量的高效率特点.最后通过工程实例具体阐述了将该优化的自由网平差方法应用于变形监测中.  相似文献   

山区土地流转对缓解耕地撂荒的作用   总被引：24，自引：6，他引：18  

邵景安  张仕超  李秀彬 《地理学报》2015,(4):636-649

耕地撂荒是目前山区发展较快的一种土地利用变化,耕地流转能否缓解这一过程,促进土地资源有效配置,以避免耕地资源浪费,是一个值得探讨的课题。借助前期研究成果,使用多视角两因素散点分析和单因素相关分析方法,旨在查明山区耕地流转对缓解耕地撂荒的作用,结果表明:1在村级尺度上,样区耕地流转与耕地撂荒间呈现显著负相关关系,流转率高的村庄,撂荒率低,尤其在优等耕作条件的耕地中表现更为突出,说明耕地流转可以减少优等耕作条件的耕地撂荒;2在地块尺度上,优等耕作条件的耕地撂荒率显著低于劣等耕作条件,样区耕地的撂荒主要由Ⅳ等耕作条件的耕地所贡献;3在村级尺度上,样区耕作条件对耕地撂荒率的作用较弱,村样本间耕作条件对撂荒率差异的解释能力不强,优等耕作条件的耕地撂荒仍然存在,说明以耕地流转率代表的土地租赁市场尚不发育;4但是,样区耕地流转率高的村庄,优等耕作条件的耕地撂荒率低,说明耕地撂荒仍然受到土地租赁市场的完善程度所左右,且土地租赁市场在优化耕地资源利用方面的作用已有一定程度的显现;5进一步完善土地租赁的市场化程度,有助于减少或降低耕地撂荒现象的发生,可以避免优等耕作条件的耕地浪费。  相似文献   

重庆丘陵地区农村居民点空间布局优化——以长寿区海棠镇为例   总被引：2，自引：0，他引：2  

樊天相  杨庆媛  何建  潘菲  邓永旺 《地理研究》2015,34(5)

以农村居民点斑块为研究单元,在分析海棠镇农村居民点斑块综合影响力的基础上,基于不同地貌,制定差异化的空间布局优化策略,并应用加权Voronoi图指导居民点斑块的迁移方向。结果表明:1海棠镇村级影响力居民点斑块面积183.57 hm2(183个);社级影响力居民点斑块面积206.86 hm2(391个);零星居民点斑块面积31.49 hm2(118个),影响力较大的居民点斑块主要分布在海棠镇中东部地势较平缓的区域;2通过布局优化,全镇农村居民点斑块总面积从优化前的421.92 hm2减少到优化后的353.73 hm2,减少了16.16%;居民点斑块密度由优化前的14.74个/km2降低到8.94个/km2,降低幅度达39.35%;居民点斑块平均面积从优化前的0.61 hm2增大到0.84 hm2,增加了37.70%。海棠镇农村居民点"小散乱"的空间分布现状得到较大改善。  相似文献   

Inversion of 3D density interface with PSO-BP method     

《世界地质(英文版)》2016,(1):33-40

BP( Back Propagation) neural network and PSO( Particle Swarm Optimization) are two main heuristic optimization methods,and are usually used as nonlinear inversion methods in geophysics. The authors applied BP neural network and BP neural network optimized with PSO into the inversion of 3D density interface respectively,and a comparison was drawn to demonstrate the inversion results. To start with,a synthetic density interface model was created and we used the proceeding inversion methods to test their effectiveness. And then two methods were applied into the inversion of the depth of Moho interface. According to the results,it is clear to find that the application effect of PSO-BP is better than that of BP network. The BP network structures used in both synthetic and field data are consistent in order to obtain preferable inversion results. The applications in synthetic and field tests demonstrate that PSO-BP is a fast and effective method in the inversion of 3D density interface and the optimization effect is evident compared with BP neural network merely,and thus,this method has practical value.  相似文献