1982～2003年间中国科技人员重心动态变化特征分析

应用区域重心的概念和模型计算中国1982～2003年间科技人员重心位置.计算结果表明,中国科技人员重心始终偏离于几何中心,且呈现先向东移动,1989年后持续向西南方向移动的特征.与同时期不同产业GDP重心比较,反映出科技人员重心移动轨迹与工业重心移动轨迹趋同的特征,而与农业重心、第三产业重心移动轨迹无明显关联,表明改革开放以来中国工业对科技人员的吸引力最大,科技人员对GDP增长的贡献也以工业为主,农业及第三产业对科技人员的吸引和利用较弱.     

中国城市郊区化问题研究综述

近年来中国城市郊区化问题突出,相关研究日益增多.对中国城市郊区化问题的研究现状总结后,认为中国目前以人口郊区化和工业郊区化为主,驱动力为市场经济的推动作用和城市社会问题的外部拉动作用;通过对国内外城市郊区化的比较,中国城市郊区化现阶段处于不发达时期,属于被动式外迁;最后指出了未来研究应该注意的问题和需加强的研究领域.     

山东泰山地区湖北海棠唐群间变异的研究

在对山东泰山地区湖北海棠居群进行详细调查的基础上，依据花、果性状对该地区的4个湖北海棠居群间的形态变异进行了系统研究．结果表明，湖北海棠花、果性状在所选取的4个居群间出现了一定程度的分化，但这种分化是一个连续的变异过程，居群间的分化与居群生境的异质性有很大的关系；湖北海棠花、果的整体性状在4个居群间表现出一种海拔梯度变异，即随着分布海拔的升高，萼齿长、萼筒长、花柄长、果长、果径均有逐渐变小的趋势；并对泰山湖北海棠变种区别于模式变种的形态特征进行了补充描述．     

新疆沙冬青(Ammopiptanthus nanus）的开花物候与环境的关系

 对自然生境与迁地保护条件下开花物候的比较观察结果表明：新疆沙冬青每年开一次花,具有相同的开花频率;自然种群的始花期及进入开花高峰期的时间比迁地保护种群晚,开花持续时间长,二者在始花日期(F=764.23, P<0.001 )及持续时间(F=46.50, P<0.01)上存在极显著和显著差异;自然种群每花序的开花数比迁地保护种群多,开放持续时间长,二者均存在极显著差异（F=80.10, P<0.001和F=84.06, P<0.001);花序开放持续时间的频率分布明显不同,迁地保护种群较自然种群更为集中;花序上花的开放顺序基本相似,均从花序近基部向两端开放;单花寿命较稳定;花序开花振幅明显不同,自然种群呈双峰不规则间断开花式样,迁地保护种群呈单峰集中开花式样;花序的开花时间、开花数、座果数间均存在一定程度的相关性,但在不同生境下其相关性的表现有所不同。在上述开花参数中,种群的开花频率以及花序的开花顺序和单花开放持续时间在不同的环境条件下表现一致,而个体与种群的开花时间和开花持续时间、花序的开花数与持续时间及开花振幅则表现不同,说明其与生长的环境条件存在密切的联系。     

BOOK REVIEWS

Book Reviewed in this article: Rabat: Urban Apartheid in Morocco . Janet Abu -Lughod . Marketplaces in a Developing Country: The Case of Western Nigeria . Isaac Ayinde Adalemo . Farming Development and Space: A World Agricultural Geography . Bernd Andreae . Section and Party: A Political Geography of American Presidential Elections, from Andrew Jackson to Ronald Reagan . J. Clark Archer and Peter J. Taylor . Women and Space: Ground Rules and Social Maps . Shirley Ardener , ed. European Progress in Spatial Analysis . R. J. Bennett , ed. The Origins of Academic Geography in the United States . Brian W. Blouet Geographic Perspectives on Global Problems . Ronald Reed Boyce . Seasonal Dimensions to Rural Poverty . Robert Chambers , Richard Longhurst and Arnold Pacey eds. The New Nationalism and the Use of Common Spaces: Issues in Marine Pollution and the Exploitation of Antarctica . Jonathan I. Charney , ed. Communications Tomorrow: The Coming of the Information Society . Edward Cornish , ed. The Design of Suburbia . Arthur Edwards . Explorer on the Northern Plains: Lieutenant Gouverneur K. Warren's Preliminary Report of Explorations in Nebraska and Dakota in the Years 1855–56–57. With an Introduction by Frank N. Schubert . The Changing Climate: Responses of the Natural Flora and Fauna . Michael J. Ford . Essentials of Physical Geography . Robert E. Gabler , Robert J. Sager , Sheila Brazier , and Daniel L. Wise. The Road to Jaramillo . William Glen . Valued Environments . John R. Gold and Jacquelin Burgess , eds. Proximity and Preference: Problems in the Multidimensional Analysis of Large Data Sets . Reginald G. Golledge and John N. Rayner , eds. A Search for Common Ground . Peter Gould and Gunnar Olsson , eds. Geography: Its History and Concepts . Arild Holt -Jensen . A Population Geography . Huw R. Jones . The Human Mosaic: A Thematic Introduction to Cultural Geography, 3rd ed. Terry G. Jordan and Lester Rowntree . Urban Social Geography: An Introduction . Paul Knox . The Anatomy of Job Loss: The How, Why and Where of Employment Decline . Doreen Massey and Richard Meegan . The Information Society as Post-Industial Society . Yoneji Masuda . Map Librarianship, 2nd ed. Harold Nichols . India: Cultural Patterns and Processes . Allen G. Noble and Ashok K. Dutt , eds. The God that Limps: Science and Technology in the Eighties . Colin Norman . Geography: An Introductory Perspective . Robert E. Norris , Keith D. Harries and John D. Vitek . The Politics of Technology Assessment . David M. O'Brien and Donald A. Marchand . Ethnic Segregation in Cities . Ceri Peach , Vaughan Robinson and Susan Smith , eds. Churches and Church Membership in the United States, 1980 . Bernard Quinn , Herman Anderson , Martin Bradley , Paul Goetting and Peggy Shriver . Energy in Australia: Politics and Economics . Hugh Saddler . Development from Above or Below? The Dialectics of Regional Planning in Developing Countries . Walter B. Stóuhr and D. R. Fraser Taylor , eds. Human Impact on the Ecosystem . Joy Tivy and Greg O'Hare . Plants and People: Vegetation Change in North America . Thomas R. Vale . The Mapmakers: The Story of the Great Pioneers in Cartography from Antiquity to the Space Age . John Noble Wilford .     

RURAL POPULATION LOSS AND CROPLAND CHANGE IN THE SOUTHERN PLAINS: IMPLICATIONS FOR CROPLAND RETIREMENT POLICY*

Given steadily increasing federal expenditures to manage surplus crop production, it would seem to make economic and environmental sense to concentrate production on the best acreage and to retire marginal crop acreage to alternate uses. A major obstacle constraining adoption and implementation of cropland retirement programs in the past has been the fear that cropland retirement threatens the viability of rural communities. Regression of change in population and retail establishments on changes in farm structure, nonfarm employment, and agricultural land-use in the rural Southern Plains between 1930 and 1970 provides only weak evidence to support this fear. In fact, short-term cropland idling under post-1960 price-support programs appears to pose more of a threat to rural communities than does cropland retirement.     

A decade of variation of COD in the Changjiang River （Yangtze River） and its variation trend analysis

The average annual value of COD (chemical oxygen demand) fluxes of the Changjiang River (Yangtze River) and its main tributaries in the past decade (i.e., 1991–2000), has been evaluated. Based on the data from the Datong Hydrological Station (DHS), it was found that the Dongting Lake drainage basin contributed the greatest water discharge (35.8%) and COD flux (48.3%) among the main tributary drainage basins, followed by the Poyang Lake drainage basin with the contributions of 15.4% and 19.3%,respectively. By the end of the year of 2000, COD flux in the Changjiang River rose by almost 45% relative to that in the year of 1991, reaching about 1941000 ton/a at DHS. Statistical analysis revealed that industrial wastewater discharge, as well as COD in it, was found decreasing in the same period, due to the gradual reinforcement of environmental management. Moreover, correlation analysis indicated that non-point pollution from agriculture and increasing discharge of domestic sewages caused by rapid growth of population along the Changjiang River drainage valley should be responsible for the high COD. Furthermore, with the current trend of population growth and agricultural development in this basin, water quality of the Changjiang River, in terms of COD level, is going to deteriorate in the near future. Thus, the rational applications of fertilizers and pesticides in agriculture and the proper treatment of domestic sewages before they are discharged would be the most concerned controlling parameters.     

Population at risk: using areal interpolation and Twitter messages to create population models for burglaries and robberies

Population at risk of crime varies due to the characteristics of a population as well as the crime generator and attractor places where crime is located. This establishes different crime opportunities for different crimes. However, there are very few efforts of modeling structures that derive spatiotemporal population models to allow accurate assessment of population exposure to crime. This study develops population models to depict the spatial distribution of people who have a heightened crime risk for burglaries and robberies. The data used in the study include: Census data as source data for the existing population, Twitter geo-located data, and locations of schools as ancillary data to redistribute the source data more accurately in the space, and finally gridded population and crime data to evaluate the derived population models. To create the models, a density-weighted areal interpolation technique was used that disaggregates the source data in smaller spatial units considering the spatial distribution of the ancillary data. The models were evaluated with validation data that assess the interpolation error and spatial statistics that examine their relationship with the crime types. Our approach derived population models of a finer resolution that can assist in more precise spatial crime analyses and also provide accurate information about crime rates to the public.     

京津冀地区再现三河-平谷8.0级地震的人员伤亡分析

京津冀地区1679年曾发生三河－平谷8.0级大地震,造成了严重的人员伤亡,严重影响当时的社会经济。本文对三河－平谷8.0级地震进行原地再现,分析所造成的人员伤亡。首先,基于最新的建筑物竣工面积统计资料更新建筑物公里网格数据,基于普查数据对人口公里网格进行了更新,并采用热力图对人口的时空流动进行了预测,得到了符合当地特征的承灾体的数量和分布。在此基础上,采用分区分类地震易损性模型和人员伤亡评估模型,对京津冀地区遭受三河－平谷8.0级设定地震的人员伤亡进行了分析。分析结果表明:京津冀地区现今的人口数量相对于1679年成百倍增加,但人员伤亡率大幅降低     

Fluid systems and fracture development during syn-depositional fold growth: An example from the Pico del Aguila anticline,Sierras Exteriores,southern Pyrenees,Spain

This paper reports an integrated, spatio-temporal analysis of the fracture-controlled paleo-fluid system in the Pico del Aguila anticline, a N–S trending fold located in the Sierras Exteriores, the southern front of the Spanish Pyrenees. Eight fracture sets (joints or faults) are recognized throughout the fold and are separated into a fracture sequence that is defined using field relationships and the remarkable temporal constraints offered by the syn-tectonic sedimentary deposits. This fracture sequence records a complex Paleocene to Early Oligocene structural evolution, including map-view, clockwise rotation and tilting of the fold axis. The geochemical analysis of calcite cements from the different mineralized fracture/vein sets reveals a compartmentalized fluid system during most of fold development. This initial paleofluid system was later perturbed when bending-related fractures associated with foreland flexure and outer arc extension triggered small-scale, vertical fluid migration. Fractures developed in shallow strata facilitated downward migration of surficial fluids that controlled the paleo-fluid system in the Late Priabonian/Stampian continental deposits. The study of the Pico del Aguila anticline depicts for the first time the evolution of a fluid system in a shallow, syn-depositional compressional setting, and results further strengthen the statement that fluids migrate vertically across stratigraphic boundaries take place during fold hinge-related deformation.