Momentum transport of wave zero during March: A possible predictor for the Indian summer monsoon

Analysis of monthly momentum transport of zonal waves at 850 hPa for the period 1979 to 1993, between ‡S and ‡N for January to April, using zonal (u) and meridional (v) components of wind taken from the ECMWF reanalysis field, shows a positive correlation (.1% level of significance) between the Indian summer monsoon rainfall (June through September) and the momentum transport of wave zero TM(0) over latitudinal belt between 25‡S and 5‡N (LB) during March. Northward (Southward) TM(0) observed in March over LB subsequently leads to a good (drought) monsoon season over India which is found to be true even when the year is marked with the El-Nino event. Similarly a strong westerly zone in the Indian Ocean during March, indicates a good monsoon season for the country, even if the year is marked with El-Nino. The study thus suggests two predictors, TM(0) over LB and the strength of westerly zone in the Indian Ocean during March.     

华北近十年来水平运动动态与地震活动危险区的讨论

根据华北地区1999年和2001年两期高精度GPS观测结果，通过与1992，1995，1996年和1999年这几期资料的比较，发现近两年的运动与前有所不同，主要表现为：（1）阴山单元和鄂尔多斯单元之间显示为压性运动的性质，但比较微弱，它们之间的边界带上似乎有左旋走滑运动，但从整体上看并不显著。（2）晋冀鲁单元和燕山单元的整体活动性不如以前，各单元内部存在着较明显的差异运动，并山单元和晋冀鲁单元的北部存在着比较显著的东西向挤压，北京地区则表现为南北向挤压。（3）晋冀鲁单元南部与胶辽鲁苏单元的南部的趋势活动呈张性，优势运动方向为东南，这样的结果可能表明，华北目前存在着应力扰动行为，大同与天津之间的区域是受其影响最大的地区，该区有可能成为未来几年中强地震活动的一个主体地区。     

Simulation of individual particle movement in a gravel streambed

A two‐dimensional simulation model of travel distances of individual particles in a gravel‐bed river is presented. The model is based on a number of rules, which include particle size, entrainment, trajectory, distance of movement and entrapment. Particle interactions are controlled by resistance fields defined about each obstacle and critical elevation defined in the model. Resistance fields, particle dropping and critical elevation rules control particle interactions. The interaction rules cause the particles to develop pebble clusters, stone cells and transverse structures (transverse ribs). The simulated travel distances of individual particles are consistent with reported field results. Individual particle travel distances were simulated using two different models; one without interactions between the individual particles and the stationary bed and one with interactions. The case without interactions demonstrates the random nature of sediment transport, and narrow ranges of travel distances. Wider ranges of travel distances, similar to those for natural situations, were obtained for the cases with interactions. The more intense the interaction between the mobile stones and the stationary ones, the wider the range of distances of travel for a given particle size. Modelling the mean travel distance yielded a result similar to that published previously, which was based on empirical data. Well developed bed‐surface structures were obtained for relatively poorly sorted sediment with intense interactions between particles. Transverse structures developed when relatively large particles were allowed to move. Copyright © 2002 John Wiley & Sons, Ltd.     

On crustal movement in Mt. Qomolangma area

Mt. Qomolangma lies in the collision zone between the fringe of Eurasia plate and Indian plate. The crustal movement there is still very active so far. In the past three decades China carried out five geodetic campaigns in Mt. Qomolangma and its north vicinal area, independently or cooperatively with other countries, including triangulation, leveling, GPS positioning, atmospheric, astronomical and gravity measurements. On the basis of the observation results achieved in the campaigns the crustal movements in the area were studied and explored. A non-stationary phenomenon both in time and space of the crustal vertical movement in the area is found. There seems to be some relevance between the phenomenon of non-stationary in time and seismic episode in China. The phenomenon of non-stationary in space is possibly relevant to the no-homo- geneity of crustal medium and non-uniform absorption of terrestrial stress. The horizontal crustal movement in the area is in the direction of NEE at a speed of 6–7 cm per year, and the trend of strike slip movement is manifested evidently in the collision fringe of Indian plate and Qinghai-Xizang block.     

跨国公司地区总部职能与亚洲地区总部的区位研究

跨国公司建立地区总部制度是跨国公司应对经营“全球化”和“本地化”的要求而进行的一项组织变革。由于跨国公司地区总部承担着制定区域性经营战略和协调区域内众多子公司生产、销售、物流、研究与开发、资金筹供、人力资源培养等经营活动的职能，它的区位对东道国及其所在城市经济带来广泛影响。本文从跨国公司和地区总部职能特点入手，分析了该职能的区位因素，并探讨了跨国公司亚洲地区总部的区位特点，最后对中国大陆的国际商务职能建设提出了若干建议。     

Silenced Rivers: The Ecology and Politics of Large Dams.

Patrick McCully. New York: Blackwell Publishing, 2001. ill and 416 pp., diags., notes, apps., and index. $69.95 cloth (ISBN 1856499014), $25.00 paper (ISBN 1856499022). Reviewed by Patrick H. Buckley, Department of Environmental Studies, Policy, Planning, Education, and Geography, Western Washington University, Bellingham, WA.     

黔西南地甲病重病区与环境地球化学关系研究

贵州是我国碘缺乏病严重地区之一，特别是黔西南地区。本根据含碘量的调查，编制了贵州露头地层、地表土壤和地表水中含碘量分布图，并与地甲病患病率分布图进行对比研究。研究表明，地甲病患病率与露头地层中碘含量关系不明显，地表土壤中碘含量与地甲病患病率有一定关系，而地表水中碘含量与地甲病患病率关系较为密切，地表水中含碘量高的地区，地甲病患病率就低，反之则地甲病患病率高。     

过去5000年西太平洋副热带高压活动的泥炭纤维素碳同位素记录

文章以金川和红原两组泥炭纤维素Δδ¹³C时间序列值的反向变化来指示西太平洋副热带高压活动变化.结果表明,在过去5000年中,西太平洋副热带高压的活动可分为4个阶段,即西太平洋副热带高压位置在2800～2200B.C.期间持续偏北,2200～600B.C.期间持续偏南,600B.C.～1200A.D.期间在北进与南移之间频繁波动,以及1200～1900A.D.期间再次持续偏北,它们导致降雨量在中国大陆上不同的分布.从约1900A.D.起西太平洋副热带高压的活动似乎又开始一个新的偏南阶段,值得进一步加强研究.     

豫西南铅锌银矿集区深部构造与成矿作用

豫西南地区是我国中部重要的多金属成矿远景区，找矿前景巨大。本文中利用重力、航磁和深部地球物理剖面资料，解析研究区三维岩石圈结构，揭示深部构造特征，进而探讨深部成矿作用。结果表明，研究区莫霍面顶面形态基本上呈东高西低，地壳厚度由东向西增大。壳-幔结构的不均一性制约着成矿系统物质和能量的交换。矿集区位于幔向斜内，其地壳增厚处、莫霍面的梯度变化处或变形部位成矿强度大。幔背斜与幔向斜之间过渡带有走向超壳型深大断裂(如栾川断裂和朱阳关断裂)，其与次级断裂的交汇处，岩浆、变质与成矿作用十分强烈，深部通道为成矿物质来源提供了较好的成矿条件，因此是形成大型、超大型矿床的有利地段。     

论全吉运动

全吉运动发生于柴北缘地区的全吉山一带，除角度不整合的自然现象外，接触面上下岩层之岩性载然不同、变质程度迥异，同位素测试值显示，是一次强烈的区域动力变质构造运动。