发展旅游业要避免的陷阱--"柠檬问题"   总被引：9，自引：0，他引：9  

张辉 《地域研究与开发》2003,22(1):80-83

文章首先介绍了旅游业的一些基本情况,然后着重分析了在产品信息不对称的情况下,市场上出现“柠檬问题”的内在机制,通过对旅游业的特性分析,文章认为旅游业中存在发生“柠檬问题”的可能性,并从理论和实践的角度论证了如何规避旅游业中的“柠檬问题”,最后,文章阐说了解决“柠檬问题”对地区旅游以及区域经济发展的意义。  相似文献   

Subspace methods for large inverse problems with multiple parameter classes   总被引：6，自引：0，他引：6  

B. L. N. Kennett  M. S. Sambridge  P. R. Williamson 《Geophysical Journal International》1988,94(2):237-247

  相似文献   

BOOK REVIEWS     

《The Professional geographer》1984,36(4):498-530

Book reviewed is the article: Small-State Security in the Balkans . Aurel Braun. South American Development: A Geographical Introduction . Rosemary D. F. Bromley and Ray Bromley. Interregional Migration, National Policy and Social Justice . Gordon L. Clark. Marketing Architectural and Engineering Services . Weld Coxe. A Geography of the Third World . J. P. Dickenson, C. G. Clarke, W. T. S. Gould, R. M. Prothero, D. J. Siddle, C. T. Smith, E. M. Thomas-Hope, and A. G. Hodgkiss. Wildlife and Man in Texas: Environmental Change and Conservation . Robin W. Doughty. At the Sea's Edge . William T. Fox. Englewood Cliffs Geography and Ecology . I. P. Gerasimov. Urbanization in Contemporary Latin America. Critical Approaches to the Analysis of Urban Issues . Alan Gilbert in association with Jorge E. Hardoy and Ronaldo Ramírez, eds. The Coming of the Transactional City . Jean Gottmann. College Park Visions of City and Country: Prints and Photographs of Nineteenth-Century France . Bonnie L. Grad and Timothy A. Riggs. Worcester Soviet Geography Today: Physical Geography . N. A. Gvozdetskiy, ed. Adaptive Responses of Native Amazonians . Raymond B. Hames and William T. Vickers, eds. Urban and Regional Industrial Research: The Changing UK Data Base . Michael Healey, ed. Cuando se Acaban los Montes . Stanley Heckadon Moreno. A Panama Forest and Shore: Natural History and Amerindian Culture in Bocas del Toro . Burton L. Gordon. Pacific Grove Mozambique: From Colonialism to Revolution, 1900–1982 . Allen Isaacman and Barbara Isaacman. Soviet Natural Resources in the World Economy . Robert G. Jensen, Theodore Shabad, and Arthur W. Wright, eds. The Changing Geography of the United Kingdom . R. J. Johnston and J. C. Doornkamp, eds. Pluralism and Political Geography—People, Territory and State . Nurit Kliot and Stanley Waterman, eds. Landmarks Preservation and the Property Tax . David Listokin. Irrigation Horticulture in Highland Guatemala: The Tablón System of Panajachel . Kent Mathewson. Her Space, Her Place: A Geography of Women . Mary Ellen Mazey and David R. Lee. Man, A Geomorphological Agent . Dov Nir. Dordrecht The Book of America: Inside the 50 States Today . Neal R. Peirce and Jerry Hagstrom. Rivers . Geoffrey E. Petts. Proceedings, United States/Australia Workshop on Design and Implementation of Computer-Based Geographic Information Systems . Donna Peuquet and John O'Callaghan, eds. Outdoor Recreational and Resource Management . John Pigram. Remaking the City: Social Science Perspectives on Urban Design . John S. Pipkin, Mark La Gory and Judith R. Blau, eds. The Crust of Our Earth: An Armchair Traveler's Guide to the New Geology . Chet Raymo. Englewood Cliffs Concepts and Themes in the Regional Geography of Canada J. Lewis Robinson. Vancouver Secondary Cities in Developing Countries: Policies for Diffusing Urbanization . Dennis A. Rondinelli. Beverly Hills Legal Foundations of Environmental Planning , Vol 1. J. G. Rose. Can We Delay a Greenhouse Warming? Stephen Seidel and Dale Keyes. Mobilizing Human Resources in the Arab World . R. Paul Shaw. Prairie Mosaic: An Ethnic Atlas of Rural North Dakota . William C. Sherman. The Future of Conflict in the 1980s . William J. Taylor, Jr. and Steven A. Maaranen, eds. The Visual Display of Quantitative Information . Edward R. Tufte. U.S. 40 Today: Thirty Years of landscape Change in America . Thomas R. Vale and Geraldine R. Vale. Madison Silent Violence: Food, Famine and Peasantry in Northern Nigeria . Michael Watts. Readings in Historic Preservation: Why? What? How? Norman Williams Jr., Edmund Kellogg and Frank Gilbert, eds.  相似文献   

Symmetric Periodic Orbits in the Anisotropic Schwarzschild-Type Problem     

Vasile Mioc  Mira-Cristiana Anisiu  Michael Barbosu 《Celestial Mechanics and Dynamical Astronomy》2005,91(3-4):269-285

Studying the two-body problem associated to an anisotropic Schwarzschild-type field, Mioc et al. (2003) did not succeed in proving the existence or non-existence of periodic orbits. Here we answer this question in the affirmative. To do this, we start from two basic facts: (1) the potential generates a strong force in Gordon’s sense; (2) the vector field of the problem exhibits the symmetries S _i , , which form, along with the identity, an Abelian group of order 8 with three generators of order 2. Resorting to S ₂ and S ₃, in connection with variational methods (particularly the classical lower-semicontinuity method), we prove the existence of infinitely many S ₂- or S ₃-symmetric periodic solutions. The symmetries S ₂ and S ₃ constitute an indicator of the robustness of the classical isotropic Schwarzschild-type system to perturbations (as the anisotropy may be considered).  相似文献   

Inversion of geophysical data using an approximate inverse mapping   总被引：2，自引：0，他引：2  

D. W. Oldenburg  R. G. Ellis 《Geophysical Journal International》1991,105(2):325-353

  相似文献   

BOOK REVIEWS     

《The Professional geographer》1985,37(3):357-389

Book Reviewed in this article: Redundant Spaces in Cities and Regions? Studies in Industrial Decline and Social Change . J. Anderson, S. Duncan and R. Hudson. eds. The Social Consequences and Challenges of New Agricultural Technologies . Gigi M. Berardi and Charles C. Geisler, eds. Determinants of Fertility in Developing Countries, Vol. I, Supply and Demand for Children . Rodolfo A. Bultao and Ronald D. Lee, eds. Computer Mapping: Progress in the‘80s . James R. Carter. Washington: Colonial Africa . A. J. Christopher. Geography of the Soviet Union . J. P. Cole. Chicago Mapmakers, Essays on the Rise of the City's Map Trade . Michael P. Conzen, ed. Changes in the Land: Indians, Colonists and the Ecology of New England . William Cronon. Mizner's Florida: American Resort Architecture . Donald W. Curl. Geographical Studies on the Soviet Union: Essays in Honor of Chauncy D. Harris . George Demko and Roland J. Fuchs, eds. Fluvial Hydrology . S. Lawrence Dingman. Pueblo Indian Water Rights: Struggle For a Precious Resource . Charles T. DuMars, Marilyn O'Leary and Albert E. Utton. Women in the Cities of Asia: Migration and Urban Adaptation . James T. Fawcett, Siew-Ean Khoo, and Peter C. Smith, eds. America's National Parks and Their Keepers . Ronald A. Foresta. Neighborhood Revitalization and the Postindustrial City . Dennis E. Gale. China in Canada: A Dialogue on Resources and Development . R. Louis Gentilcore, ed. China: The 80s Era . Norton Ginsburg and Bernard A. Lalor, eds. Boulder, CO: Global Resources: Challenges of Interdependence . Martin I. Glassner, ed. River Networks . Texas: A Geography . Terry G. Jordan with John L. Bean, Jr. and William M. Holmes. The American Frontier: An Archaeological Study of Settlement Pattern and Process . Kenneth E. Lewis. Water Resources, Geography and Law . Olen Paul Matthews. A Field Guide to American Houses . Virginia and Lee McAlester. Population: Patterns, Dynamics, and Prospects . James L. Newman and Gordon E. Matzke. Wood, Brick, and Stone, The North American Settlement Landscape, Vol. 1: Houses . Allen G. Noble. Historical Analysis in Geography . William Norton. The Displaced Worker and Community Response: Case Study of Portsmouth, Scioto County, Ohio . H. Milton Patton and Janet W. Patton. Disaster Management: Warning Response and Community Relocation . Ronald W. Perry and Alvin H. Muskatel. The Anthropology of Space: Explorations into the Natural Philosophy and Semantics of the Navajo . Rik Pinxten, Ingrid van Dooren, and Frank Harvey. What STYLE Is It? A Guide To American Architecture . John C. Poppeliers, S. Allen Chambers, Jr., and Nancy B. Schwartz. Appalachia: A Regional Geography—Land, People and Development . Karl Raitz and Richard Ulack. An Introduction to Urban Geography . John R. Short. Ford, A Village in the West Highlands of Scotland: A Case Study of Repopulation and Social Change in a Small Community . John B. Stephenson. Income and Jobs: USA Diagnosing the Reality . George Sternlieb and James W. Hughes. Weather and Climate of the Antarctic . W. Schwerdtfeger. History and Ecology: Studies of the Grassland, James C. Malin . Robert P. Swierenga, ed. Optimal Control of Spatial Systems . K. C. Tan and R. J. Bennett. Social Science and Revolutions . Stan Taylor. The Global Textile Industry . Brian Toyne, Jeffrey S. Arpan, David A. Ricks, Terence A. Shimp and Andy Barnett. Integrated Water Development: Water Use and Conservation Practice in Western Colorado . James L. Wescoat, Jr. Proceedings of the First International Symposium on Maps and Graphics for the Visually Handicapped . Joseph W. Wiedel, ed.  相似文献   

巩义市非煤矿产资源存在的问题与对策浅议     

吴松钦  郝朝红 《河南国土资源》2001,(4)

巩义市是郑州的矿业大市 ,非煤矿产资源丰富。随着市场经济的逐步深入 ,非煤矿产资源勘查与开发的逐步升级 ,存在的问题也日益显现。如何解决这些问题 ,推动非煤矿业健康发展 ,是一个十分重要的课题。该文简要概述了巩义市辖区内非煤矿产资源概况 ,阐述了非煤矿产资源存在的问题 ,并归纳为五个重点 ,针对五个重点问题提出一些改进的相应对策  相似文献   

BOOK REVIEWS     

《The Professional geographer》1986,38(4):430-457

Book Reviewed in this article: Latin America: Case Studies . Richard G. Boehm and Sent Visser Locality and Rurality: Economy and Society in Rural Regions . Tony Bradley And Philip Lowe The City and the Grassroots . Manuel Castells Geopolitics and Conflict in South America. Quarrels among Neighbors . Jack Child Post-Industrial America: A Geographical Perspective . David Clark Coastal Research: UK Perspectives . Malcolm W. Clark A Rural Policy for the EEC? Hugh Clout Peasant Agriculture in Assam: A Structural Analysis . M. M. Das . Environmental Change and Tropical Geomorphology . I. Douglas and T. Spencer Advances in Abandoned Settlement Analysis: Application to Prehistoric Anthrosols in Colombia, South America . Robert C. Eidt Measuring Culture . Jonathan L. Gross and Steve Rayner North America: A Human Geography . Paul Guinness and Michael Bradshaw A Geographical Bibliography for American Libraries . Chauncy D. Harris et al. Geography and the Urban Environment: Progress in Research and Applications, Vol. VI . D. T. Herbert and R. J. Johnston Changes in Global Climate: A Study of the Effect of Radiation and Other Factors During the Present Century . K. Ya . Kondrat'ev . Rural Development and the State: Contradictions and Dilemmas in Developing Countries . David A. M. Lea and D. P. Chaudhri The Martial Metropolis: U.S. Cities in War and Peace . Roger W. Lotchin The Climate of the Earth . Paul E. Lydolph . Weather and Climate . Paul E. Lydolph . Spatial Divisions of Labor: Social Structures and the Geography of Production . Doreen Massey . Panorama of the Soviet Union . N. Mikhailov . Soviet Armenia . K. S. Demirchian . USSR: Geography of the Eleventh Five-Year Plan Period . K. Spidchenko . Planung und Verwirklichung der Wiener Ringstrassenzone (Planning and Materialization of the Ringstrasse-Zone of Vienna). Kurt Mollik , Hermann Reining , Rudolf Wurzer . The American West Transformed: The Impact of the Second World War Gerald D. Nash . An Overview of the Survey of Income and Program Participation . Dawn Nelson , David Mc Millen, and Daniel Kasprzyk . Phenomenology, Science and Geography: Spatiality and the Human Sciences . John Pickles . Biological Diversification in the Tropics . Ghillean T. Prance Die Wanderviehwirtschaft im gebirgigen Westen der U.S.A. und ihre Auswirkungen im Naturraum . Gisbert Rinschede . Social and Economic Aspects of Radioactive Waste Disposal: Considerations for Institutional Management . World-Wide Weather . K. Takahashi Coastal Geomorphology in Australia . B. G. Thom Settlement System in Rural India: A Case Study of the Lower Ganga-Yamuna Doab . Ram Chandra Tiwari . Computer Programming for Geographers . David J. Unwin and John A. Dawson . Late Quaternary Environments of the Soviet Union . A. A. Velichko, ed . H. E. Wright , Jr. and C. W. Barnosky Ethics in Planning . Martin Wachs  相似文献   

Identification of soil erosion and fluvial sediment problems     

W. T. Dickinson  R. P. Rudra  G. J. Wall 《水文研究》1986,1(1):111-124

A computer model has been used to estimate soil loss and sediment yield from irregular field-size units of small watersheds. Input to the model includes spring data (i.e. relating to February through May) for the independent variables of the Universal Soil Loss Equation, and for factors such as surface roughness, an index of overland runoff, and proximity to the stream. Output from the model includes maps of seasonal estimates of potential soil losses, field sediment delivery ratios, and expected sediment yields. On the basis of selected erosion and sediment yield tolerances, the output information has been analysed to identify watershed areas which (1) exhibit both erosion and sediment yield problems; (2) exhibit only erosion problems; (3) exhibit only sediment yield problems; and (4) exhibit neither erosion nor sediment yield problems. The percentage of the watershed area in each category and the percentage of the watershed soil loss and sediment loads contributed by each category are also identified. Application of the procedure for planning remedial control programs for five watersheds is discussed.  相似文献   

Granites and granitic magmas: strange phenomena and new perspectives on some old problems   总被引：1，自引：0，他引：1  

J.D. Clemens 《Proceedings of the Geologists' Association. Geologists' Association》2005,116(1):9-16

  相似文献