榍石LA-ICP-MS U-Pb定年中元素分馏的影响及校正研究

同位素地质年代学是探索地质体时空演化及地球动力学等问题的基础学科,应用最为广泛的当属含铀副矿物的U-Pb定年技术。榍石具有相对较低的U-Pb体系封闭温度,并广泛发育于岩浆岩、各类变质岩、热液成因岩石以及少量沉积岩中,是一种理想的中高温地质事件定年矿物。利用电感耦合等离子体质谱法(ICP-MS)测定榍石U-Pb年龄时,不可避免地要解决高普通铅以及元素分馏效应对测试的影响。本文对榍石LA-ICP-MS实验过程中的元素分馏行为进行研究,采用相同基体的标准样品与未知样品对比,发现了榍石不同颗粒之间元素分馏行为不一致的现象;同时采用不同的元素分馏校正方法,分别应用于锆石、独居石和榍石进行对比研究,认为分馏行为一致的副矿物定年可以采用"指数法"和"均值法"对数据进行校正,但是对于榍石这种分馏行为不一致的副矿物,定年时只有采用"截距法"对数据进行校正才可以获得正确的年龄。进而将此结论应用于秦岭造山带老牛山地区岩浆成因榍石样品,得到的结果与锆石年龄一致,表明"截距法"可以避免分馏行为不一致导致的校正不准确的问题。本研究成果为榍石LA-ICP-MS U-Pb定年方法的完善提供了一种思路。     

Development in modeling cyclic loading of sands based on kinematic hardening

In this paper, there is presented an elastoplastic constitutive model to predict sandy soils behavior under monotonic and cyclic loadings. This model is based on an existing model (Cambou‐Jafari‐Sidoroff) that takes into account deviatoric and isotropic mechanisms of plasticity. The flow rule used in the deviatoric mechanism is non‐associated and a mixed hardening law controls the evolution of the yield surface. In this research the critical state surface and history surface, which separates the virgin and cyclic states in stress space, are defined. Kinematic hardening modulus and stress–dilatancy law for monotonic and cyclic loadings are effectively modified. With taking hardening modulus as a function of deviatoric and volumetric plastic strain and with defining the history surface and stress reversal, the model has the ability to predict the sandy soils' behavior. All of the model parameters have clear physical meanings and can be determined from usual laboratory tests. In order to validate the model, the results of homogeneous tests on Hostun and Toyoura sands are used. The results of validation show a good capability of the proposed model. Copyright © 2009 John Wiley & Sons, Ltd.     

地理环境与时空行为对主观幸福感的影响研究进展

主观幸福感是目前国内外研究热点,与提升居民生活质量和建设宜居城市密切相关。已有大部分文献侧重单一空间尺度的研究,分析社会经济属性和地理环境要素(包括建成环境、社会环境、环境污染)对主观幸福感的影响;也有部分研究关注居民日常出行属性和活动特征对主观幸福感的作用机制,探讨长期幸福感与短期幸福感的内在关系。论文对上述研究进行较为系统的梳理与评价,综合考虑地理环境、时空行为与主观幸福感的复杂关系,构建主观幸福感的理论研究框架,总结时空行为视角下多尺度、多维度地理环境要素对主观幸福感的影响机制以及作用路径,并探讨主观幸福感的时空动态规律以及微观行为机制,为改善城市人居环境、优化居民行为模式提供科学依据和政策建议。     

宅基地流转农户行为影响因素的实证研究——基于广东省19个县市34个行政村的抽样调查

宅基地流转是提高农村宅基地资源有效配置的途径之一.以广东省为例,在对19个县(市、区)34个行政村544户农户抽样调查的基础上,运用 Logistic 回归模型,定量分析广东省不同区域类别下农户宅基地流转的主要影响因素及其影响程度.研究表明:广东省省域59.33%的农户发生宅基地流转,而珠江三角洲地区和粤东地区的比例分别高达67.42%和62.5%,粤西地区和粤北地区的比例分别为59.26%和43.04%;不同区域类别下农户宅基地流转的主要影响因素有明显差异;农户家庭年纯收入和宅基地面积因子是影响广东省宅基地流转的最重要因素.针对研究结果,提出了相应促进宅基地资源更有效配置的政策建议     

An Integrated Moral Obligation Model for Landowner Conservation Norms

This study applies an integrated moral obligation model to examine the role of environmental and cultural values, and beliefs in the activation of landowner conservation norms. Data for this study were collected through a self-administered survey of riparian landowners in two Minnesota watersheds: Sand Creek and Vermillion River watersheds. Study findings suggest that collectivistic and biospheric–altruistic values form the bases for the activation of personal norms. Further, beliefs about local responsibility and ability to act influence personal norms to protect water resources. Findings suggest that landowners’ personal norms of water conservation are more likely to be activated by conservation strategies that appeal to biospheric–altruistic and collectivistic values, emphasize adverse consequences of water pollution, highlight water resource protection as a local responsibility, and provide the resources needed to protect water resources.     

BOOK REVIEWS

Books reviewed in this article: Aerial Photography and Remote Sensing. Terrain Analysis and Remote Sensing . JOHN R. G. TOWNSHEND , ed. Environmental Data Use in Computer-assisted Data Handling Systems: The Results of a Survey of Applications in the Pacific Northwest States . KENNETH E. GORDON . Applied Land Use: A Spatial Approach . JOHN F. LOUNSBURY , LAWRENCE M. SOMMERS , AND EDWARD A. FERNALD , eds. The Second Battle of New Orleans: A History of the Vieux Carre Riverfront-Expressway Controversy . RICHARD O. BAUMBACH , JR. AND WILLIAM E. BORAH . Cultural Environmental Archaeology . MYRA SHACKLEY . The Immoral landscape: Female Prostitution in Western Societies . RICHARD SYMANSKI . life Among the Poor in Cairo . UNNI WIKAN , translated by Ann Henning. Women, Work and Property in Northwest India . URSULA SHARMA . The Domestication of Women: Discrimination in Developing Societies . BARBARA ROGERS Economic Optimization in Locational and Transport Analysis . A. G. WILSON , J. D. COELHO , S. M. MACGILL , H. C. W. L. WILLIAMS . New Tools for Economic Development: The Enterprise Zone, Development Bank, and RFC . GEORGE STERNLIEB AND DAVID LISTOKIN , eds. Regional Wage Inflation . R. L. MARTIN , ed. Finding A Place For Energy-Siting Coal Conversion Facilities . FRANK J. CALZONETTI WITH MARK S. ECKERT . Environmental Management, Resources, and Systems Environmentalism. Second Edition . T. O'RIORDAN . Countryside Conservation . BRYN GREEN . Medical Spatial Diffusion: An Historical Geography of Epidemics in an Island Community . A. D. CLIFF , P. HAGGETT , J. K. ORD , AND G. R. VERSEY . Philosophy and Geographic Thought Order and Skepticism: Human Geography and the Dialectic of Science . RICHARD SZYMANSKI AND JOHN A. AGNEW . Measurement of Subjective Phenomena . D. F. JOHNSTON , ed. Conceptions of Space in Social Thought: A Geographic Perspective . ROBERT DAVID SACK . The Association of American Geographers: The First Seventy-five Years: 1904-1979 . PRESTON E. JAMES AND GEOFFREY J. MARTIN . The Life and Thought of Isaiah Bowman . GEOFFREY J. MARTIN . Physical River Basin Planning: Theory and Practice . SURANJIT K. SAHA AND CHRISTOPHER J. BARROW , eds. Soils and landforms: An Integration of Ceomorphology and Pedology . A. I. GERRARD Climatic Change and Society. Consequences of Increasing Atmospheric Carbon Dioxide . WILLIAM W. KELLOGG AND ROBERT SCHWARE . Political Political Redistrictings and Geographic Theory . RICHARD L. MORRILL . Population Studies in Spanish American Population History: Dell Plain Latin American Studies NO. 8 . DAVID J. ROBINSON , ed. Population Redistribution in the Midwest . CURTIS C. ROSEMAN , ANDREW J. SOFRANKO , AND JAMES D. WILLIAMS , eds. Geographical Perspectives on the Elderly . A. M. WARNES , ed. Regional Perspective On the American South . MERLE BLACK AND JOHN SHELTON REED , eds. The Prairies and Plains: Prospects for the 80s . JOHN R. ROGGE , ed. Rural Rural Settlement in an Urban World . MICHAEL BUNCE . Social Accident at Three Mile Island: The Human Dimensions . DAVID L. SILLS , C. P. WOLF , AND VIVIEN B. SHELANSKI , eds. The American Small Town: Twentieth-Century Place Images . JOHN JAKLE . Urban A House of My Own . SUSAN LOBO . The City: Patterns and Processes in the Urban Ecosystem . CHRISTOPHER H. EXLINE , GARY L. PETERS , AND ROBERT P. LARKIN . Movement in Cities . P. W. DANIELS AND A. M. WARNES . Urbanization and Urban Planning in Capitalist Society . MICHAEL DEAR AND ALLEN J. SCOT , eds.     

农户行为视角下的乡村生产空间系统运行机制及重构启示

农户行为转变是乡村生产空间系统量变或从量变到质变的重要驱动力,乡村生产空间系统的运行实质上是农户行为作用的外在表现,厘清农户行为可为诠释乡村生产空间系统的运行机制提供平台。本文在剖析农户行为转变与乡村生产空间系统运行响应的理论框架基础上,从农户行为转变和乡村生产空间系统响应入手构建指标体系,建立模糊综合评价量化模型,并以重庆市江津区恒和村作为实证,诠释乡村生产空间系统运行机制。主要研究结论为：不同农户行为对乡村生产空间系统运行的影响程度各异,大体为生产大户>合作社农户>传统农户;不同农户行为对系统运行响应结果的作用差异明显,生产大户行为主要影响乡村生产空间的利用效率,合作社农户行为对提升生产空间系统经济效益作用明显,传统农户行为对生产空间系统环境改善的贡献作用最小。并从经济、社会、空间重构视角提出发展多种形式的适度规模化经营、培育新型农业经营主体和职业农民、合理引导农户技术和资本投入等建议,以实现乡村生产空间系统协调与均衡发展。     

农业技术扩散中的农户采用行为研究:国外进展与国内趋势

农户是我国农区的微观经济单元,是农业技术采用的行为主体。以农户为对象的农业技术扩散采用行为的研究对于诱导农户行为、提高农业技术的采用效率、促进农区发展具有重要的理论和应用价值。从研究视角、研究方法、研究内容3个方面对国内外相关研究成果进行较为系统的梳理,总结评述最新进展和特点,并在此基础上对农户技术采用行为的研究趋势进行展望,希冀有助于推进国内对农户技术采用行为的深入研究,进而为促进农业技术扩散与推广、提高农业科技成果转化率提供参考。     

基于不同主体的城镇人居环境要素需求特征——以广州市新塘镇为例

从城镇人居环境特点及不同主体的需求出发,构建了一套包括5个综合指标项和32个要素的城镇人居环境指标体系。以广州市新塘镇为例,通过问卷调查和非参数检验分析,揭示了不同主体人居环境要素需求特征;运用相关分析、聚类分析探讨了城镇人居环境要素需求差异性影响因素及不同群体要素需求的空间差异。结果表明:受访者对闲暇活动等10个要素的需求表现出差异性,对生活能源等22个要素的需求表现出共性;居住时间和经济状况对不同主体人居环境要素需求的差异性影响最大。同时结合4个类群主体的差异性环境要素需求和空间分布特征,提出了新塘镇未来人居环境优化应该重点建设的内容。     

北京大型居住区居民通勤行为对比研究——以望京居住区和天通苑居住区为例

郊区化的过程中,居住-就业均衡性存在解体和重构的过程。以北京郊区两个大型居住区——望京居住区和天通苑居住区作为研究对象,通过问卷调查的方式获取了居民居住、就业以及通勤等方面的相关数据。研究表明:通勤时间较长是近郊大型居住区居民的共性,但由于大型居住区功能定位的差异以及所在区位和道路体系的差异,单一型居住区和混合型居住区也存在高峰通勤出行时间、通勤工具选择和通勤流向等通勤行为的差异。对这些主要影响因素加以合理规划,对解决郊区化过程造成的制住分离加剧问题具有重要作用。