BOOK REVIEWS

Book Reviewed in this article: Unfairly Structured Cities . Blair Badcock Religion and Rural Revolt . Janos M. Bak and Gerhard Benecke The Industrial Geography of Canada . Anthony Blackbourn and Robert G. Putnam The Cuban-American Experience, Culture, Images, and Perspectives. Thomas D. Boswell and James R. Curtis Quaternary Paleoclimatology . R. S. Bradley Development and Crisis in Brazil, 1930–1983 . Luiz Bresser Pereiras Centres of Origin in Biogeography . John C. Briggs Analytical Urban Geography . Martin Cadwallader Geomorphology . Richard J. Chorley , Stanley A. Schumm, and David E. Sugden South Africa: The Impact of Past Geographies . A. J. Christopher The Geography of Underdevelopment. A Critical Survey . D. K. Forbes Health Care in Developing Countries . Wilbert M. Gesler Place to Grow Old: The Meaning of Environment in Old Age . Stephen M. Golant The Emerging Marine Economy of the Pacific . Chennat Gopalakrishnan An Introduction to Agricultural Geography . David B. Grigg The Soviet Union: A Geographical Study . G. Melvyn Howe Geographical Aspects of Health: Essays in Honour of Andrew Learmonth . N. D. Mc Glashan and J. R. Blunden Physical Geography: A Landscape Appreciation . Tom L. Mc Knight Mountain Experience. The Psychology and Sociology of Adventure. Richard G. Mitchell Jr . Systematic and Regional Biogeography. Stanley A. Morain The Economic Transformation of American Cities. T. J. Noyelle and T. M. Stanback , Jr . Normal Accidents: Living With High-Risk Technologies. Charles Perrow Vanishing Farmland: A Legal Solution for the States. Sarah E. Redfield Applied Methods of Regional Analysis: The Spatial Dimensions of Development Policy. Dennis A. Rondinelli Urbanization in Romania. A Geography of Social and Economic Change Since Independence. Per Ronnas Statistical Techniques in Geographical Analysis. Gareth Shaw and Dennis Wheeler The Granite Garden: Urban Nature and Human Design. Anne Whiston Spirn Political Geography: Recent Advances and Future Directions. Peter Taylor and John House Geographia y Medio Ambiente. Manuel Valenzuela -Rubío Nãgara and Commandery: Origins of the Southeast Asian Urban Traditions. Paul Wheatley The Common Fisheries Policy of the European Community. Mark Wise Geography and Gender. Women and Geography Study Group of the IBG Technological Hazards. D. J. Zeigler , J. H. Johnson , S. D. Brunn     

陕西蟒岭地区宽坪群的构造演化

本文将宽坪群的构造演化序列分为两大阶段,即海西一印支运动及其以前的以褶皱为主的变形;燕山运动以来的以断裂为主的变形。两个阶段所形成的构造均沿着北西西和北东两个方向延伸,显然它们是北西西和北东两个方向的构造波系在蟒岭地区活动的表现,并由此形成了该区的斜向构造格局。     

基于激光扫描点云的隧道断面提取方法

传统断面测量方法存在效率低、精度差等特点,为优化断面测量方法,提出利用地面激光点云提取断面的方法。其主要包括:中轴线拟合、点云分割、断面提取三步骤。在基于点云双向投影确定初始中轴线的基础上,运用弦高偏移算法,提取骨架特征拐点,对中轴线分段再次拟合,获取二次中轴线;点云分割是基于隧道中轴线进行的,对隧道的点云数据进行连续分割,对截取的断面进行椭圆拟合。实验表明,通过此方法快速提取中轴线上任意位置的断面。     

论徐连经济带建设

通过对徐连经济带在全省，淮海经济区中经济地位的分析，与省内宁镇扬，苏锡常两区的比较，找出本带经济中存在的问题及原因，提出加快其经济发展所拥有的优势区位，优越的自然条件和重要意义，并就点轴开理论本带建设布局中的应用进行了探讨。     

华北板块北缘东段上三叠统的若干特征

位于华北板块与古蒙古洋板块的交接处、金银别河至白水滩一带的一套变质的陆相碎屑岩,前人命名为白水滩组,时代归属早侏罗世。80年代末笔者在此进行1∶5万区域地质调查,在该地层中采到了Neoclamites sp.,Cycadocarpiclium sp.,Uniohuang bogouensis(?)等重要分子,同时发现其被二长花岗岩(U—Pb 192.7Ma)侵入,暂与小营子组对比,将其时代归属为晚三叠世。该套地层分为上下两段,即下部砾岩段和上部砂岩段;地层褶皱形态复杂,断裂构造发育,新老地质体相互推覆掩盖,构成独特的地质景观。     

Numerical and Experimental Study of the 3D Effect on Connecting Arm of Vertical Axis Tidal Current Turbine

Vertical axis tidal current turbine is a promising device to extract energy from ocean current. One of the important components of the turbine is the connecting arm, which can bring about a significant effect on the pressure distribution along the span of the turbine blade, herein we call it 3D effect. However, so far the effect is rarely reported in the research, moreover, in numerical simulation. In the present study, a 3D numerical model of the turbine with the connecting arm was developed by using FLUENT software compiling the UDF (User Defined Function) command. The simulation results show that the pressure distribution along the span of blade with the connecting arm model is significantly different from those without the connecting arm. To facilitate the validation of numerical model, the laboratory experiment has been carried out by using three different types of NACA aerofoil connecting arm and circle section connecting arm. And results show that the turbine with NACA0012 connecting arm has the best start-up performance which is 0.346 m/s and the peak point of power conversion coefficient is around 0.33. A further study has been performed and a conclusion is drawn that the aerofoil and thickness of connecting arm are the most important factors on the power conversion coefficient of the vertical axis tidal current turbine.     

基于降水微物理特征测量仪的雨滴形状观测与分析

利用自主研制的降水微物理特征测量仪开展降水观测试验,得到了大量的雨滴图像。研究了异常雨滴图像的形成原因和处理方法,以此为基础重点研究了在极坐标下基于Akima插值的数字雨滴图像矢量化方法,得到了雨滴平均形状特征和轴比分布特征。结果表明,直径小于1 mm的雨滴以圆形为主,在1.0~3.0 mm的雨滴以椭圆形为主,大于3.0 mm的雨滴逐渐呈现顶部凸起,底部偏平的形状;雨滴的平均轴比分布与经验分布一致,相互之间差异在±0.04 mm范围以内;雨滴的平均轴比与经验模型的差值在粒径3.4~3.8 mm出现峰值,该范围内的雨滴较经验关系具有更圆的形状特性。     

Second-order ridge axis discontinuities in the south Atlantic: Morphology,structure, and evolution

Continuous along-axis Sea Beam coverage of the slow-intermediate spreading (34–38 mm yr⁻¹ full rate) southern Mid-Atlantic Ridge (25°–27°30′S and 31°–38° S) shows that the ridge axis is segmented by both rigid and non-rigid discontinuities. Following the model of Macdonald et al. (1988b), a hierarchy of four orders is proposed for ridge axis discontinuities based on a continuum of relative age and distance offset across the discontinuites. This paper discusses the characteristics associated with five second-order discontinuities found in the areas surveyed. First-order discontinuities represent rigid offsets, transform faults, whereas non-rigid discontinuities fall into the second, third and fourth orders. Like transform fault boundaries, second-order discontinuities have distinctive morphologic signatures both on and off-axis-discordant zones — and therefore are better defined than third- or fourth-order discontinuities. Second-order discontinuities are offsets that range in distance from less than 10 km to approximately 30 km and vary in age offset from 0.5 to approximately 2.0 m.y. The variable morphotectonic geometries associated with these discontinuities indicate that horizontal shear strains are accommodated by both extensional and strike-slip tectonism and that the geometries are unstable in time. Three characteristic geometries are recognized: (1)en echelon jog in the plate boundary where ridge axis tips overlap slightly, (2)en echelon jog in the plate boundary where ridge axes are separated by an extensional basin whose long axis is oriented parallel to the strike of the adjoining ridge axes, and (3) oblique offset characterized by a large extensional basin that is oriented approximately 45° to the strike of the ridge axes. In the case of the third type, evidence for short strands of strike-slip tectonism that link an obliquely oriented extensional basin flanking ridge tips is often apparent. Analysis of the detailed bathymetric and magnetic data collected over the second-order discontinuities and their off axis terrain out to 5–7 m.y. documents that second-order discontinuities can follow several evolutionary paths: they can evolve from transform fault boundaries through prolonged asymmetric spreading, they may migrate along strike leaving a V-shaped wake, and they may remain in approximately the same position but oscillate slightly back and forth. In addition, a small change in the pole of relative motion occurring 4–5 Ma is thought to have resulted in the initiation of at least one second-order discontinuity in the survey area. A geologic model is proposed which involves the interplay of lithospheric thickness, asymmetric spreading, temporal and spatial variability of along-axis magmatic input and changes in the poles of relative motion to explain the origin, morphology and evolution of second-order ridge axis discontinuities.     

Estimating the Kuroshio Axis South of Japan Using Combination of Satellite Altimetry and Drifting Buoys

By tracking the locally strongest part of the sea-surface velocity field, which was obtained by integrating data of satellite altimeters and surface drifting buoys, we extracted the Kuroshio axis south of Japan every 10 days from October 1992 to December 2000. The obtained axes clearly express the effect of the bottom topography; three modes were observed when the Kuroshio ran over the Izu Ridge. The axis was very stable to the south of ‘Tosa-bae,’ off the Kii Channel. Mean current speed at the Kuroshio axis gradually increased from 0.65 m/s south of Kyushu to 1.45 m/s off Enshu-nada. This revised version was published online in July 2006 with corrections to the Cover Date.     

节理统计锥体单元法的探讨

本文提出在投影球内建立锥体单元统计系统,直接计算以产状表示的单元轴线与节理法线的夹角,统计该夹角小于单元锥角半角的数目。统计结果更合理、可靠。