冠醚/离子液体体系对锂离子萃取动力学的研究（英文）

本文通过恒界面池法研究了以4’—乙酰基苯并—15—冠—5作为萃取剂和1—丁基—3—甲基咪唑双[(三氟甲基)磺酰基]酰亚胺作为协萃剂的萃取体系从高浓度水溶液中提取锂的动力学。研究了搅拌速度、平衡时间、温度、界面面积和传质阻力区对锂离子传质速率的影响。结果表明,界面膜的厚度在1 600 rpm～2 000 rpm转速范围内是逐渐变薄的,并且在1 800 rmp～2 000 rmp转速范围内是没有变化的,说明锂离子传质速率1 800 rmp～2 000 rmp转速范围内是不变的;在锂离子的萃取平衡时间为40 min;萃取过程的传质阻力主要来自有机相;该萃取过程是混合控制的动力学过程;在两相界面上发生的萃取反应。通过研究锂离子、冠醚离子液体的浓度,锂离子的动力学方程可表达为:ν_(Li,0)=10~(-3.843±0.001)·[Li~+]~( 0.907 1)·[[BMIm]~+]~(0.832 8)·[AcB15C5]~(0.855 5)。通过两相界面处形成锂离子最终配合物的传质速率步骤推导出锂的提取机理,这与实验结果一致。     

球形MnO2·0.5H2O提锂性能及其机理研究

考察了形貌对尖晶石型锂离子筛吸附剂MnO₂·0.5H₂O吸附性能的影响。实验证明,反应物Mn₂O₃的形貌在很大程度上决定了前驱体及其吸附剂的形貌。采用XRD、SEM、TEM、FT-IR、XPS和N₂吸附—解吸等温线等对样品进行了表征。表征和吸附实验结果表明,与立方形锂离子筛相比,球形锂离子筛具有较高的吸附容量(42.46 mg/g),同时对溶液中的Li⁺具有较高的选择性。表面脱质子和离子交换过程的共同作用增强了离子筛型吸附剂的提锂Li⁺性能。此外,本文对Li1.6Mn1.6O₄与MnO₂·0.5H₂O的吸附—解吸机理进行了解释。     

Li+的水合结构和近似饱和水合层:基于密度泛函理论的研究

结合密度泛函理论,运用B3LYP/aug-cc-pVDZ方法对[Li(H₂O)_n]⁺(n=1~10)水合团簇的结构进行了研究。研究结果表明,在气相和液相中,四配位结构的[Li(H₂O)_n]⁺水合团簇比其五配位的异构体稳定,即在水溶液中Li⁺易形成四配位的四面体结构。随着同时水分子数的增加,Li-O键长增大,Li⁺上的电荷密度减小。但是当水分子数大于4时,Li-O键长和Li⁺上的电荷密度变化很小。[Li(H₂O)_n]⁺水合团簇中每个水分子的结合能计算结果表明,7个水分子已足以形成Li⁺的近似饱和水合层。另外红外光谱显示[Li(H₂O)_n]⁺水合团簇中O-H伸缩振动随着水分子数的增加发生蓝移,而~3 600 cm-1和~3 500 cm-1处的吸收峰是第二水合层与第一水合层、第三水合层和第二水合层的水分子形成氢键引起的。     

Li+,Na+,K+/Cl-,SO2-4-H2O五元体系25 ℃相图及其应用

Li⁺,Na⁺,K⁺/Cl-,SO2-₄-H₂O五元体系相图对于硫酸钠亚型富锂卤水分离提取锂盐、锂辉石加工利用和锂盐产品的开发利用工艺制定都有指导作用。20世纪50年代曾有人研究过这一体系25 ℃时的相图,限于当时的科研水平,液相组成确定不准确,对平衡固相的判断,后来诸多研究结果证明也有错误。50多年来再没有人研究这一五元体系相图。利用我们提出的Li⁺,Na⁺,K⁺/Cl^-,SO^2-₄-H₂O六元体系热力学模型,对该五元体系的平衡溶液组成和正确的平衡固相进行理论预测,给出了该体系的完整相图。结合硫酸锂混盐分离、加工实例阐述了该五元体系相图的应用。     

T-BAMBP/磺化煤油萃取体系从盐湖卤水中萃取铷的动力学研究

采用上升单液滴法研究从盐湖卤水中萃取铷的动力学,主要考察了比界面积、水相铷浓度和油相(t-BAMBP/磺化煤油)浓度对萃取速率的影响,通过比界面积的研究发现t-BAMBP萃取铷的过程由界面化学反应和相内化学反应共同控制;通过对实验数据的非线性拟合得到了萃取体系的动力学方程,R=9.936×10_-7[Rb+]_1.134[t-BAMBP]_2.190,萃取速率对铷的反应级数为a=1.134,对t-BAMBP反应级数b=2.190,实验值和计算值的均方根误差为1.735 %。     

纳滤法用于铝锂分离的初步研究

本文探讨了纳滤分离Al³⁺和Li⁺的可行性,研究了含盐量和铝锂比对分离效率的影响,提出了从锂云母浸出液中分离回收锂的新方法。实验结果表明,纳滤膜对Al³⁺和Li⁺的截留率随含盐量的升高而降低,其中Li⁺始终呈现负浓度梯度扩散的趋势,而Al³⁺的截留率始终稳定在99%以上。当含盐量为45 g/L时,铝锂分离因子最高可达248.33,膜面相应Zeta电位的绝对值达到最大。随着溶液中铝锂比的变化,Al³⁺和Li⁺的截留率分别在不同铝锂比的条件下出现拐点,溶液的pH呈现先下降后上升最后下降的复杂趋势。本实验研究发现,DK膜能够在酸性环境下实现高效的铝锂分离和锂的浓缩,从而为锂云母浸出液中锂的提取提供新的思路。     

新型复合生物质锂吸附剂的制备及吸附性能研究

以KMnO₄、苯胺、LiOH和生物质碳气凝胶(BCA)为原料,通过水热沉积法得到了锰酸锂(LMO)负载的生物质碳气凝胶(BCA@LMO),并用HCl酸洗后得到了BCA@HMO复合锂吸附剂。利用IR、XRD、XPS、SEM、EDS、Mapping、BET等手段对其结构进行了表征。考察了pH值、离子强度、初始浓度、温度和吸附时间对锂吸附的影响。结果表明,复合吸附剂为介孔结构,其孔道内和表面具有丰富的锰酸锂颗粒,Li⁺的最大平衡吸附量在pH=12时为4.07 mmol·g-1,吸附过程符合Langmuir等温线和准二阶动力学模型,升高温度和碱性环境利于Li⁺的吸附。吸附机理为H⁺与Li⁺的离子交换。复合吸附剂较好地改善了锰系锂吸附剂固液分离困难的问题,该吸附剂在实际南翼山盐田和东台吉乃尔盐田卤水(2.92 mmol·g-1)中具有良好的吸附性能。因此,该吸附剂在卤水锂的分离中具有良好的应用价值和潜力。     

基于盐湖尾卤溶液结构变化的镁锂分离研究

盐湖卤水提锂工艺的难点之一在于卤水中镁锂比过高。采用红外光谱对非平衡动态降温过程中溶液结构变化进行分析,测定不同类型单盐溶液和卤水的结构变化,并基于此规律强化盐湖尾卤的镁锂分离。结果表明,MgSO4 溶液在40 ℃及以上时, 984 cm-1 处的特征峰显示可能出现接触式离子对结构(Mg²⁺-SO₄2-);1 280 cm-1处出现溶剂共享型离子对结构( Mg²⁺-H₂O-SO₄2-);Li₂SO₄溶液中出现溶剂共享型离子对结构的可能性低,镁锂之间会出现结构差异。基于如上溶液结构的变化,通过非平衡动态降温过程,实现盐湖尾卤中的镁锂分离,镁锂质量比值可由最初的40降至20左右,Mg²⁺以MgSO₄·nH₂O型混合结晶产品的形式从卤水中析出,而液相中Li⁺的损失率可低至5.01%以下,以此达到了脱镁及锂富集的效果。     

四苯硼钠—季铵盐质量滴定法分析钾含量研究

依据四苯硼钠—季铵盐容量法滴定K⁺离子的原理,采用质量滴定法,考察了滴定速度、松节油加入量对四苯硼钠与季铵盐反应的影响及共存离子(包括Li⁺、Mg²⁺、Ca²⁺、SO2-₄、B₄O2-₇、CO2-₃)对K⁺含量测定结果的影响。当测定K⁺离子含量在5～15 mg范围内,松节油最佳加入量为25滴,分析误差< 0.3%。     

皂化二-(2-乙基己基)磷酸萃取锂的动力学研究

采用恒界面池法研究了钠皂二-(2-乙基己基)磷酸(P204)萃取锂的动力学,考察了搅拌强度、界面面积、反应温度和反应物浓度等因素对锂萃取速率影响。通过搅拌强度、界面积和温度对萃取速率影响规律判别该萃取过程为扩散和界面化学反应共同控制,萃取过程表观活化能为19.95 kJ·mol-1。基于反应物浓度对萃取速率影响,确定初始萃取速率方程为[RLi, init= (0.0048±0.0007)?nLi+?nNaA],Li+与A-(P204阴离子)在界面处生成LiA的反应为萃取锂过程的决速步骤。     

BOOK REVIEWS

Book Reviewed in this article: Development and Environment in Peninsular Malaysia . S. Robert Aiken, Colin H. Leigh, Thomas R. Leinbach, Michael R. Moss. The Rural-Urban Fringe: Canadian Perspectives . Ken B. Beesley and Lorne H. Russwurm, eds. Women and Development . Lourdes Benería, ed. The Border that Joins: Mexican Migrants and U.S. Responsibility . Peter G. Brown and Henry Shue, eds. Cities of the World: World Regional Urban Development . Stanley D. Brunn and Jack L. Williams, eds. Time Resources, Society, and Ecology: On the Capacity for Human Interaction in Space and Time (Vol. I, Preindustrial Societies). Tommy Carlstein. Urban Geography . David Clark. Spanish City Planning in North America . Dora P. Crouch, Daniel J. Garr, and Axel I. Mundigo. Not On Our Street: Community Attitudes to Mental Health Care . M. J. Dear and S. M. Taylor Unequal growth: Urban and Regional Employment Change in the U.K. Stephen Fothergill and Graham Gudgin. Agricultural Land in an Urban Society . Owen J. Furuseth and John T. Pierce. The Petroleum Industry in Oil-Importing Developing Countries . Fariborz Ghadar. Historical Understanding in Geography, An Idealist Approach . Leonard Guelke. Regional Planning in Europe . R. Hudson and J. R. Lewis, eds. Remote Sensing for Resource Management . Chris J. Johannsen and James L. Sanders, eds. Geography and The State . R. J. Johnston. Texas Graveyards: a Cultural Legacy . Tlrry G. Jordan. The Politics of Location: An Introduction . Andrew Kirby. A Social Geography of the City . David Ley. Energy and the Future . Douglas MacLean and Peter Brown, eds. The Natural Environment of Newfoundland Past and Present . A. G. Macpherson and J. B. Macpherson, eds. Tourism: Economic, Physical and Social Impacts . Alister Mathieson and Geoffrey Wall. Railroads and Land Grant Policy: A Study in Government Intervention . Lloyd J. Mercer. Progress in Rural Geography . Michael Pacione, ed. Progress in Urban Geography . Michael Pacione, ed. Models of Spatial Inequality: Settlement Patterns in Historical Archaeology . Robert Paynter. Natural Hazard Risk Assessment and Public Policy, Anticipating the Unexpected . William J. Petak and Arthur A. Atkisson. The Nature of Geomorphology . Alistair F. Pitty. Regional Conflict and National Policy . Kent A. Price Women and Spatial Change: Learning Resources for Social Science Courses . Arlene C. Rengert and Janice J. Monk, eds. Urban and Regional Analysis for Development Planning . Richard Rhoda. Rivers: Form and Process in Alluvial Channels . Keith Richards. This Remarkable Continent: An Atlas of United States and Canadian Society and Culture . John F. Rooney, Jr., Wilbur Zelinsky, and Dean R. Louder, gen. eds. The Origins of Open-Field Agriculture . Trevor Rowley, ed. Residential Location Determinants of the Older Population . Gundars Rudzitis. Borderland Sourcebook: A Guide to the Literature on Northern Mexico and the American Southwest . Ellwyn R. Stoddard, Richard L. Nostrand, and Jonathan P. West, eds. Arctic and Antarctic . David Sugden. Tall Timbers Ecology and Management Conference, February 22–24, 1979, Proceedings No. 16 . Graphic Communication and Design in Contemporary Cartography (Progress in Contemporary Cartography , Vol. II). D. R. Fraser Taylor, ed. Living with Energy Shortfall: A Future for American Towns and Cities . Jon Van Til. The United States: Habitation of Hope . J. Wreford Watson. Air Photo Interpretation for Archaeologists . D. R. Wilson. Urban and Rural Change in West Germany . Trevor Wild, ed. Population and Resources . Harry Robinson.     

BOOK REVIEWS

Book Reviewed in this article: Geography and the Third World. International Seminar, 14–18 May 1980, Kuala Lumpur, Malaysia . Ishmail Ahmad and Jamaluddin Md Jahi, eds. The Growth Dilemma: Residents' Views and Local Population Change in the United States . Mark Baldassare. Sport and Place: A Geography of Sport in England, Scotland & Wales . John Bale. The Deindustrialization of America: Plant Closings, Community Abandonment, and the Dismantling of Basic Industry . Barry Bluestone and Bennett Harrison. Selected Essays 1963–1975: Carl O. Sauer . Bob Callahen, ed. Housing and Planning in the Countryside . G. Clark. Conflict, Politics and the Urban Scene . Kevin R. Cox and R. J. Johnston, eds. Thematic Maps: Their Design and Production . David J. Cuff and Mark T. Mattson. Wine: A Geographic Appreciation . Harm Jan de Blij. USSR in Maps . J. C. Dewdney. Political Geography: A Contemporary Perspective . Ramesh D. Dikshit. Rethinking Human Adaptation . Rada Dyson-Hudson and Michael A. Little, eds. Sacred Sands: The Struggle for Community in the indiana Dunes . J. Ronald Engel. Geography of the Biosphere . A. Furley and Walter W. Newey. Disaster and Reconstruction . Robert Geipel. Glasgow: The Making of a City . Andrew Gibb. Design for Arid Regions . Giden S. Golany, ed. Urbanization and Cancer Mortality: The United States Experience, 1950–1975 . Michael R. Greenberg. Geology in the Nineteenth Century: Changing Views of a Changing World . Mott T. Greene. Colonización y Destrucción de Bosques en Panamá . Stanley Heckadon Moreno and Alberto McKay, eds. Urban Geography: A First Approach . David T. Herbert and Colin J. Thomas. The Visual and Spatial Structure of Landscapes . Tadahiko Higuchi. Climate from Tree Rings . M. K. Hughes, P. M. Kelly, J. R. Pilcher, and V. C. LaMarche, Jr., eds. The structure of Nineteenth Century Cities . James H. Johnson and Colin G. Pooley, eds. The American Planner: Biographies and Recollections . Donald A. Krueckeberg, ed. Urban Land Policy For the 1980s, the Message for State and Local Government . George Lefcoe, ed. Regional Planning: Evolution, Crisis and Prospects . Gill C. Lim, ed. Relevance and Ethics In Geography . Bruce Mitchell and Dianne Draper. China: The Geography of Development and Modernization . Clifton W. Pannell and Laurence J. C. MA. The Urban Retailing System . Robert B. Potter. Hants. Nonconventional Energy Resources . Philip R. Pryde. Caribbean Migrants: Environment and Human Survival on St. Kitts and Nevis . Bonham C. Richardson. Population and Resources . Harry Robinson. East Los Angeles: History of A Barrio . Ricardo Romo. Integrated Impact Assessment . Frederick A. Rossini and Alan L. Porter, eds. Environmental Aesthetics: Essays in Interpretation . Barry Sadler and Allen Carlson, eds. Earthwatch . Charles Sheffield. Field Techniques and Research Methods in Geography . Robert H. Stoddard. Haiti: Land of Poverty . Robert J. Tata. Weathering and Erosion: Sources and Methods in Geography . Stephen T. Trudgill. Once Beneath the Forest. Prehistoric Terracing in the Río Bec Region of the Maya Lowlands . B. L. Turner, II. The Historical Geography of Scotland since 1707 . David Turnock.     

PRODUCTIVITY OF AMERICAN PH.D.-GRANTING DEPARTMENTS OF GEOGRAPHY

Reviews of geographic software in this article:

DEMO-GRAPHICS: WORLD POPULATIONS AND PROJECTIONS.

ESP

GAUSS.

CEMODEL S. Damus

LIMDEP. William H. Greene

MICROSTAT 4.1

OTIS

PCIPS. (Personal Computer Image Processing System). H.J. Meyers and R. Bernstein.

REGRESSION ANALYSIS OF TIME SERIES (RATS)

SPSS/PC+

URBAN DATA MANAGEMENT SOFTWARE (UDMS)     

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 .     

Deserts and Aeolian Desertification in China: Book review and some thoughts

Desertification is a global phenomenon that affects about two billion people. It occurs in arid zones where the annual precipitation is below 400 mm, partic- ularly in the marginal areas of the world＇s largest deserts. It is a result of water and wind erosion, over- grazing, global warm-ing, improper soil cultivation, and increased pressure ot population growth, and it causes degradation of soil and natural and agricultural vegetation. The direct result is less food for people and livestock, which influences pop- ulation and animal husbandry fluctuations. Despite ef- forts to combat and reduce desertification, the affected areas are annually increasing.     

BOOK REVIEWS

Book Reviewed in this article: The Rice Economy of Asia . Randolph Barker and Robert W. Herdt with Beth Rose. Using Microcomputers: A Guidebook for Writers, Teachers, and Researchers in the Social Sciences . Blaine A. Erie—the Lake that Survived . Noel M. Burns. Geology and Society . Donald R. Coates. Caves and Karst of Kentucky . Percy H. Dougherty, ed. Altered Harvest: Agriculture, Genetics, and the Fate of the World's Food Supply . Jack Doyle. The Middle East and North Africa, A Political Geography . Alasdair Drysdale and Gerald H. Blake. Clamor at the Gates. The New American Immigration . Nathan Glazer, ed. Development and the Landowner: An analysis of the British experience . Robin Goodchild and Richard Munton. Discovering Landscape in England and Wales . Andrew Goudie and Rita Gardner. The Modern Plantation in the Third World . Edgar Graham and Ingrid Floering. Social Relations and Spatial Structures . Derek Gregory and John Urry, eds. The World Food Problem 1950–1980 . David Grigg. Costa Rica: A Geographical Interpretation in Historical Perspective . Carolyn Hall. The Urbanization of Capital: Studies in the History and Theory of Capitalist Urbanization . David Harvey Consciousness and the Urban Experience: Studies in the History and Theory of Capitalist Urbanization . David Harvey. Reviving Main Street . Deryck Holdsworth, ed. Rural Roads and Poverty Alleviation . John Howe and Peter Richards, eds. Uneven Development in Southern Europe: Studies of Accumulation, Class, Migration and the State . Ray Hudson and Jim Lewis, eds. Karst Geomorphology . J. N. Jennings. The Geomorphology of North-west England . R. H. Johnson, ed. Climate Impact Assessment: Studies of the Interaction of Climate and Society . Robert Kates, Jesse Ausubel, Mimi Berberian, eds. Public Service Provision and Urban Development . Andrew Kirby, Paul Knox, and Steven Pinch, ed. State and Market: The Politics of the Public and the Private . Jan-Erik Lane, ed. Living Cities . Twentieth Century Fund Task Force on Urban Preservation Policies. World Climatic Systems . John G. Lockwood. Urban Ethnicity in the United States. New Immigrants and Old Minorities . Lionel Maldonaldo and Joan Moore, eds. Culture and Conservation: The Human Dimension in Environmental Planning . Jeffrey A. McNeely and David Pitt, eds. The Andean Past. Land, Societies, and Conflicts . Magnus Mörner. Gaia: An Atlas of Planet Management . Norman Myers, ed. Progress in Industrial Geography . Michael Pacione, ed. Progress in Political Geography . Michael Pacione, ed. Rivers and Landscape . Geoff Petts and Ian Foster. Urbanization and Planning in the 3rd World: Spatial Perceptions and Public Participation . Robert B. Potter. One Island, Two Nations? A Political Geographical Analysis of the National Conflict in Ireland . D. G. Pringle. Circulation in Third World Countries . R. Mansell Prothero and Murray Chapman. The Ozarks Outdoors: A Guide for Fishermen, Hunters, and Tourists . Milton D. Rafferty. Suburban Burglary: A Time and a Place for Everything . George Rengert and John Wasilchick. Geomorphology and Soils . K.S. Richards, R.R. Arnett, and S. Ellis, eds. The Homes and Homeless of Post-War Britain . Frederick Shaw. Indochinese Refugees in America . Paul J. Strand and Woodrow Jones, Jr. Wild Horses and Sacred Cows . Richard Symanski. Forever Wild: Environmental Aesthetics and the Adirondack Forest Preserve . Philip G. Terrie. The Regional Economic Impact of Technological Change . A.T. Thwaites and R.P. Oakey, eds. The Good Life . Yi-Fu Tuan.     

THE MOST PERFECT EXAMPLE OF AN ALIEN ECOLOGY EVER CONSTRUCTED

Much science-fiction literature is based upon the creation and exploration of alternative environments. Stanley G. Weinbaum's short story, “Parasite Planet,”introduces an unusual environment that may be wrong in the light of recent evidence on Venus but still stimulates the geographical imagination.     

Metals and models: Diagenic modelling in freshwater lacustrine sediments

This review aims to distill and synthesize the existing information on the use of models to describe and predict the distribution and movement of metals in lacustrine sediments. As such it examines the causes of metal diagenesis, the origin and form of the equations that govern these phenomena, and the predictability or measurability of the parameters that appear in the models. The paper concludes by highlighting some seminal results from modelling studies, including the determination of the factors controlling the formation of surficial Mn-Fe-enriched zone or layers, the substantial contribution possible from metal reduction to organic matter regeneration, the calculation of mixing-corrected metal input histories to lakes, and the prediction of growth rates and morphologies for both deep-sea and lacustrine ferromanganese nodules.     

Guidelines to Authors

正1.Aims and scope Sciences in Cold and Arid Regions(SCAR)is a bimonthly journal that publishes in English the latest research achievements in processes and the patterns of the Earth surface system in cold and arid regions.Researches in cold regions emphasize particularly on the cold-region-characterized physical,chemical and biological processes and their interactions,and on the response of cryosphere to global change and human activities as well as their effects on environment and the acclimatizable strategies;focus on the objects of glacier,snow,river,lake,sea ice,permafrost and seasonal frozen ground,and periglacial geomorphology,etc.;and think much of cold regions     

BOOK REVIEWS

Book Reviewed in this article: Portable Utopia: Glasgow and the United States 1820–1920. Bernard Aspinwall. Studies in Russian Historical Geography. James H. Bater and R. A. French, eds. Water and Sanitation: Economic and Sociological Perspectives. Peter G. Bourne, ed. Green Politics. Fritjof Capra and Charlene Spretnak. The Southern Cone: Realities of the Authoritarian State. César N. Caviedes. Women in Third World Development. Sue Ellen Charlton. Land Management: New Directions. David Chiddick and Alan Millington, eds. Geography and Ethnic Pluralism. Colin Clarke, David Ley, Ceri Peach, eds. Geomorphological Hazards in Los Angeles. R. U. Cooke. Regional Impacts of United States-Mexico Economic Relations. Alfonso Corona and Lay James Gibson. eds. Patterns of Jobs and Geographic Mobility. Torvald Gerger. Cities and Sickness: Health Care in Urban America. Ann Lennarson Greer and Scott Greer, eds. Neighborhoods: Their Place in Urban Life. Howard W. Hallman. Development and the Rural-Urban Divide. John Harriss and Mick Moore, eds. Patterns of Undocumented Migration: Mexico and the United States. Richard C. Jones, ed. Central Place Theory. Leslie J. King. The Geography of Western Europe: A Socio-economic Survey. Paul L. Knox. Regions and Resources: Strategies for Development. David T. Krisge, Daniel A. Seiver, Oliver S. Goldsmith and Michael J. Scott. Geography of Crowding and Human Response. A Study of Ahmedabad City. K. M. Kulkarni. Haciendo Pueblo. The Development of a Guadalajaran Suburb. Kathleen Logan. The Imperial Lion: Human Dimensions of Wildlife Management in Central Africa. Stewart A. Marks. Water in the Hispanic Southwest: A Social and Legal History, 1550–1850. Michael C. Meyer. Imlil: A Moroccan Mountain Community in Change. James A. Miller. Tourism in Canada: Selected Issues and Options. Peter E. Murphy, ed. David Harvey's Geography. John L. Paterson. Raster Scanning, Processing and Plotting of Cartographic Documents. Donna J. Peuquet and A. Raymond Boyle. The USSR and the Muslim World: Issues in Domestic and Foreign Policy. Yaacov Ro'i, ed. Environmental Perception and Behavior: An Inventory and Prospect. Thomas F. Saarinen, David Seamon, and James L. Sell. Incised channels, Morphology, Dynamics, and Control. Stanley A. Schumm, Michael D. Harvey, and Chester C. Watson. The Gap Between Rich and Poor: Contending Perspectives on the Political Economy of Development. Mitchell A. Seligson, ed. Twentieth-Century Richmond. Planning, Politics and Race. Christopher Silver. Land Conservation and Development: Examples of Land-Use Planning Projects and Programs. F. R. Steiner and H. N. van Lier, eds. Biogeography: Recent Advances and Future Directions. J. A. Taylor, ed. Late Quaternary Environments of the Soviet Union. A. A. Velichko, ed. H. E. Wright, Jr. and C. W. Barnosky, eds.