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自１９９２年４月１２日至１２月３０日对中山站附近内拉峡湾冰下水柱中浮游植物生物量以及环境因子的季节变化进行了测定。水中叶绿素ａ含量在０．０３－２１．４０ｍｇ／ｍ３之间波动，在覆冰期间，生物量基本上随深度的增加而下降；５－９月份各层次的生物量普遍低于０．５ｍｇ／ｍ３，８－９月份低于０．１ｍｇ／ｍ３。各层次中以水表含量的季节变化最为明显，成冰后在９月份形成低谷，于１２月中旬紧接着冰底水华的消失而形成单一峰值。生物量中微型浮游植物（＜２０μｍ）的比重在４－９月份的多数层次占有一半以上，１０月份后随着生物量的上升而下降，在水华期水表的比重最低，仅占总量的３．２％。其柱总生物量基本上与冰中生物量处于同一数量级，在冰藻水华期其量值甚至低于冰中生物量。营养盐（μｍｏｌ／Ｌ）的波动范围为ＰＯ４－Ｐ：０．３２－０．７９，ＳｉＯ３－Ｓｉ：２６．４７－６９．９２，ＮＯ３－Ｎ：１．４１－３１．７５，尽管水华期水表营养盐含量降至观测期间的最低点，但仍能满足冰下浮游植物的生长所需。光辐照度由于在冰水界面的量值仅为冰表入射光的不足５．３％至低于１％，成为水中产量最为可能的限制因子。 相似文献
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青藏高原4月—10月光合有效量子值的气候学计算 总被引：4，自引：0，他引：4
根据１９９４年４月～１０月青藏高原太阳分光辐射的实测资料，计算出太阳总辐射中，光合有效辐射（ＰＡＲ）所占比例η＝０．４３９±０．００９，ＰＡＲ每１Ｊ的能量含有４．４３μｍｏｌ的量子。在青藏高原的气候学计算中，可用下式估算旬平均的ＰＡＲ能量日总量ＨＰＡＲ（ＭＪ·ｍ－２ｄ－１）和量子日总量ＵＰＡＲ（ｍｏｌ·ｍ－２ｄ－１）：ＨＰＡＲ＝（０．３９９＋０．０３６ｌｇＥ＊）ＨＵＰＡＲ＝（１．７６８＋０．１５９ｌｇＥ＊）Ｈ式中Ｈ（ＭＪ·ｍ－２ｄ－１）为总辐射旬平均日总量，Ｅ＊＝Ｅ·Ｐ０／Ｐ，Ｐ０（ｈｐａ）为标准大气压，Ｐ（ｈｐａ）为测点大气压，Ｅ（ｈｐａ）为地面水汽压。 相似文献
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用锂离子选择电极和经典Ａｇ－ＡｇＣｌ电极测定了２９８．１５Ｋ下ＬｉＣｌ－Ｌｉ２Ｂ４Ｏ７－Ｈ２Ｏ体系中离子强度范围为０．０１～２．５０ｍｏｌ．ｋｇ＾－１,不同Ｌｉ２Ｂ４Ｏ７离子强度分数的ＬｉＣｌ的平均活度系数。由实验数据,用迭代法及多元线性回归法,求取了Ｌｉ２Ｂ４Ｏ７的化学计量离解平均常数Ｋｍ,热力学离解平衡常数Ｋ及Ｐｉ－ｔｚｅｒ离子作用参数,并与实验值比较标准偏差为０．０５００,同时该实验结果在０ 相似文献
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塔克拉玛干沙漠的起沙风速 总被引：53，自引：1，他引：53
起沙风速根据观测高度、风速时距以及流体或冲击起动性质分别确定。本文建立了塔克拉玛干沙漠腹地肖塘地区不同高度、不同时距的流体起动与冲击起动风速的相关方程。结果表明：该地天然沙的瞬时冲击起动风速（２ｍ高度）５．０ｍ／ｓ，流体起动风速６．０ｍ／ｓ；１分钟平均流体起动与冲击起动风速为５．２ｍ／ｓ和４．３ｍ／ｓ。气象站观测高度（１１．４ｍ）瞬时流体起动和冲击起动风速为７．８ｍ／ｓ和６．６ｍ／ｓ；１０分钟平均值为７．４ｍ／ｓ和５．９７（≈６．０）ｍ／ｓ。 相似文献
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黄淮海平面原沙地不同治理利用措施下土壤性质的差异 总被引：2，自引：0，他引：2
延津站经过７－８ａ改造后,试区的０农业用地,果园地用,封育沙垄地较试区未封育裸露沙垄地,粉粒含量增加９－１６．６４倍,物理性粘粒含量增加１．１７－３．６７倍,土壤有机质含量增加８．４－１２．６倍,全Ｎ含量增加３．６－５．２５倍,全Ｐ含量增加１．５２－２．１９倍。 相似文献
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设计了小流量流通池，制备了低阻锂离子选择电极，模拟在线监测核反应堆一回路含铵水质中的氢氧化锂，９：１体积比混合液样和ＰＨ５．５的Ａｘ１０＾－２ｍｏｌ／ＬＮＨ４Ａｃ－ＨＡｃ离子强度调节缓冲剂，泵入由聚醚三（二环己酰胺）ＰＶＣ膜锂电极和Ａｇ／ＡｇＣｌ参比电级构成的流通池，电位法测定，锂含量大于２×１０＾－５ｍｏｌ／Ｌ时，误差在５％以内。 相似文献
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《The Professional geographer》1988,40(4):471-499
Books reviewed in this article: USA, Eine Geographische Landeskunde , Vol. I, Der Grossraum in Strukturellem, Wandel, 3rd Ed. Helmut Blume . Introduction to Remote Sensing . James B. Campbell . The Sounds of People and Places: Readings in the Geography of American Folk and Popular Music . George O. Carney , ED. Development and Underdevelopment . John Cole . Mobility and Employment in Urban Southeast Asia: Example from Indonesia and the Philippines . Michael A. Costello , Thomas R. Leinbach , AND Richard Ulack . Soviet Asia: Economic Development and National Policy Choices . Leslie Dienes . The Third World City . David Drakakis -Smith . Scholars' Guide to Washington, DC for Cartography and Remote Sensing Imagery (maps, charts, aerial photographs, satellite images, cartographic literature and geographic information systems). Ralph E. Ehrenberg . Population and Development in the Third World . Allan AND Anne Findlay . The Early Mapping of Hawaii . Gary L. Fitzpatrick . Energetics of Physical Environment: Energetic Approaches to Physical Geography . K. J. Gregory , ED. Wildland Recreation: Ecology and Management . William E. Hammitt and David N. Cole . Agricultural Commercialization and Government Policy in Africa . J. Hinderink AND J. J. Sterkenburg . The Dynamics of American Housing . James W. Hughes AND George Sternlieb . Thailand: Buddhist Kingdom as Modern Nation State . Charles F. Keyes . Resolving Locational Conflict . Robert W. Lake , ED. Lands at Risk in the Third World: Local-level Perspectives . Peter D. Little and Michael M. Horowitz , EDS. Nathaniel Southgate Shaler and the Culture of American Science . David N. Livingstone . Regions: The Economics and Politics of Territory . Ann R. Markusen . Wetlands . William J. Mitsch and James G. Gosselink . Historical Geography: Progress and Prospect . Michael Pacione , ED. Loess and Periglacial Phenomena . Marton P$eacsi and Hugh M. French , EDS. Regional Management of Metropolitan Floodplains, Experience in the United States and Abroad . Rutherford H. Platt , ED. Human Cartography: Mapping the World of Man . Janos Szegö . Atlas of Great Lakes Indian History . Helen H. Tanner , ED. The Botany of Mangroves . P. B. Tomlinson . Urban Spatial Traffic Patterns . Rodney Vaughan . The Night After … Climatic and Biological Consequences of a Nuclear War . Yevgeni Velikhov , ED. Industrial Geography . H. D. Watts . Dictionary of Quotations in Geography . James O. Wheeler and Francis M. Sibley . Vermont Townscape . Norman Wiliams , Jr. , Edmund K. Kellogg and Peter M. Lavigne . 相似文献
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《The Professional geographer》2013,65(4):488-489
Book Reviewed in this article: Main Street: Northeastern Oregon: The Founding and Development of Small Towns. Barbara Ruth Bailey. Food Politics: The Regional Conflict. David N. Balaam and Michael J. Carey, eds. The International Economy and Industrial Development: Trade and Investment in the Third World. R. Ballance, J. Ansari and H. Singer. Neighborhoods in Urban America. Ronald H. Bayor, ed. The English Heartland. By Robert Beckinsale and Monica Beckinsale. Regional Dimensions of Industrial Policy. Michael E. Bell and Paul S. Lande, eds. Tension Areas of the World. D. Gordon Bennett, ed. Latin America: an Introductory Survey. B. W. Blouet and O. M. Blouet, eds. Integration and Division: Geographical Perspectives on the Northern Ireland Problem. Frederick W. Boal and J. Neville H. Douglas, eds. Energy and Land Use. Robert W. Burchell and David Listokin, eds. Slopes and Weathering. Michael Clarke and John Small. Alaska's Rural Development. Peter G. Cornwall and Gerald McBeath, eds. The Politics of Park Design: A History of Urban Parks in America. Galen Cranz. World Congress on Land Policy, 1980, Proceedings. Matthew Cullen and Sharon Woolery, eds. Oregon Divided: A Regional Geography. Samuel N. Dicken and Emily F. Dicken. Urban Food Marketing and Third World Rural Development. T. Scarlett Epstein. South Africa: Spatial Frameworks for Development. T. J. D. Fair. Institutions and Geographical Patterns. Robin Flowerdew, ed. Industrialization of U.S. Agriculture, An Interpretive Atlas. Howard F. Gregor. Planning Theory: Prospects for the 1980s. Patsy Healy, Glen McDougall and Michael J. Thomas, eds. Neighborhood Mobilization: Redevelopment and Response. Jeffrey R. Henig. The American Urban System: A Geographical Perspective. R. J. Johnston. Climate, History and the Modern World. Hubert H. Lamb. Climate and History: Studies in Past Climates and Their Impact on Man. T. M. L. Wigley, M. J. Ingram and G. Farmer. China: Railways and Agricultural Development, 1875–1935. Ernest P. Liang. A Desirable Energy Future—A National Perspective. Robert S. Livingston, T. D. Anderson, T. M. Besmann, M. Olszewski, A. M. Perry, and C. D. West. Topothesia: Essays Presented to T. S. Ó Máille. B. S. Mac Aodha, ed. Transportation for the Poor: Research in Rural Mobility. Hal S. Maggied. Land Uses in American Cities. Harold M. Mayer and Charles R. Haves. Industrial Organisation and Location. Philip McDermott and Michael Taylor. Human Adaptability: an Introduction to Ecological Anthropology. Emilio F. Moran. Regional Analysis and the New International Division of Labor. Frank Moulaert and Patricia W. Salinas, eds. The Nuclear War Atlas. Victoriaville, Quebec, Canada: Urbanization and Environmental Quality. Isao Orishimo. The Garden of Eden: The Botanic Garden and the Re-Creation of Paradise. John Prest. Earthfire, The Eruption of Mount St. Helens. Charles Rosenfeld and Robert Cooke. Contest for the South China Sea. Marwyn S. Samuels. The Future of the Wetlands: Assessing Visual-Cultural Values. Richard C. Smardon, ed. Tucson: the Life and Times of An American City. C. L. Sonnichsen. The Geography of Multinationals. Michael Taylor and Nigel Thrift, eds. Impact of Marine Pollution on Society. Virginia Tippie and Dana Kester. Reviving the Industrial City: the Politics of Urban Renewal in Lyon and Birmingham. Jerry A. Webman. Andean Reflections: Letters from Carl O. Sauer While on a South American Trip under a Grant from the Rockefeller Foundation, 1942. Robert C. West, ed. Cartographic Drawing with Computers. P. Yoeli. 相似文献
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《The Professional geographer》1983,35(4):488-524
Book Reviewed in this article: Main Street: Northeastern Oregon: The Founding and Development of Small Towns . Barbara Ruth Bailey . Food Politics: The Regional Conflict . David N. Balaam and Michael J. Carey , eds. The International Economy and Industrial Development: Trade and Investment in the Third World . R. Ballance , J. Ansari and H. Singer . Neighborhoods in Urban America . Ronald H. Bayor , ed. The English Heartland . By Robert Beckinsale and Monica Beckinsale . Regional Dimensions of Industrial Policy . Michael E. Bell and Paul S. Lande , eds. Tension Areas of the World . D. Gordon Bennett , ed. Latin America: an Introductory Survey . B. W. Blouet and O. M. Blouet , eds. Integration and Division: Geographical Perspectives on the Northern Ireland Problem . Frederick W. Boal and J. Neville H. Douglas , eds. Energy and Land Use . Robert W. Burchell and David Listokin , eds. Slopes and Weathering . Michael Clarke and John Small . Alaska's Rural Development . Peter G. Cornwall and Gerald Mc Beath , eds. The Politics of Park Design: A History of Urban Parks in America . Galen Cranz . World Congress on Land Policy, 1980, Proceedings . Matthew Cullen and Sharon Woolery , eds. Oregon Divided: A Regional Geography . Samuel N. Dicken and Emily F. Dicken . Urban Food Marketing and Third World Rural Development . T. Scarlett Epstein . South Africa: Spatial Frameworks for Development . T. J. D. Fair . Institutions and Geographical Patterns . Robin Flowerdew , ed. Industrialization of U.S. Agriculture, An Interpretive Atlas . Howard F. Gregor . Planning Theory: Prospects for the 1980s . Patsy Healy , Glen Mc Dougall and Michael J. Thomas , eds. Neighborhood Mobilization: Redevelopment and Response . Jeffrey R. Henig . The American Urban System: A Geographical Perspective . R. J. Johnston . Climate, History and the Modern World . Hubert H. Lamb . Climate and History: Studies in Past Climates and Their Impact on Man . T. M. L. Wigley , M. J. Ingram and G. Farmer . China: Railways and Agricultural Development, 1875–1935 . Ernest P. Liang . A Desirable Energy Future—A National Perspective . Robert S. Livingston , T. D. Anderson , T. M. Besmann , M. Olszewski , A. M. Perry , and C. D. West . Topothesia: Essays Presented to T. S. Ó Máille . B. S. Mac Aodha , ed. Transportation for the Poor: Research in Rural Mobility . Hal S. Maggied . Land Uses in American Cities . Harold M. Mayer and Charles R. Haves . Industrial Organisation and Location . Philip Mc Dermott and Michael Taylor . Human Adaptability: an Introduction to Ecological Anthropology . Emilio F. Moran . Regional Analysis and the New International Division of Labor . Frank Moulaert and Patricia W. Salinas , eds. The Nuclear War Atlas. Victoriaville, Quebec, Canada : Urbanization and Environmental Quality . Isao Orishimo . The Garden of Eden: The Botanic Garden and the Re-Creation of Paradise . John Prest . Earthfire, The Eruption of Mount St. Helens . Charles Rosenfeld and Robert Cooke . Contest for the South China Sea . Marwyn S. Samuels . The Future of the Wetlands: Assessing Visual-Cultural Values . Richard C. Smardon , ed. Tucson: the Life and Times of An American City. C. L. Sonnichsen . The Geography of Multinationals . Michael Taylor and Nigel Thrift , eds. Impact of Marine Pollution on Society . Virginia Tippie and Dana Kester . Reviving the Industrial City: the Politics of Urban Renewal in Lyon and Birmingham . Jerry A. Webman . Andean Reflections: Letters from Carl O. Sauer While on a South American Trip under a Grant from the Rockefeller Foundation, 1942 . Robert C. West , ed. Cartographic Drawing with Computers . P. Yoeli . 相似文献
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《寒旱区科学》2014,(4):I0001-I0001
Permafrost engineering has been developing rapidly in recent years. Many projects have been undertaken with the latest technologies and show their importance in supporting regional social and economical development. For example, the Qinghai-Tibet Railway has been a milestone project in permafrost engineering. However, when designing and building infrastructures in cold regions, 相似文献
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HAYASHI Hiroaki 《资源与生态学报(英文版)》2014,5(4):395-397
<正>1 Characteristics of Kunisaki GIAS and aims of this research Kunisaki GIAHS in the Kunisaki peninsula and Usa area,Oita,Japan,is a system where forestry,agricultural production,and fisheries are sustained by the strong connection between Sawtooth Oak forest,multiple interlinked irriga tion ponds,and Seto Inland Sea(Vafadari 2013a;2013b;Hayashi 2013).This area receive around 1,500 mm of annual precipitation with a 相似文献
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P. Guilizzoni A. Marchetto A. Lami N. G. Cameron P. G. Appleby N. L. Rose Ø. A. Schnell C. A. Belis A. Giorgis L. Guzzi 《Journal of Paleolimnology》1996,15(3):245-264
A palaeoecological study of an oligotrophic alpine lake, Paione Superiore (Italy), provided a record of historical changes in water quality. Historical trends in lake acidification were reconstructed by means of calibration and regression equations from diatoms, chrysophycean scales and pigment ratios. The historical pH was inferred by using two different diatom calibration data sets, one specific to the alpine region. These pH trends, together with the record of sedimentary carbonaceous particles and chironomid remains, indicate a recent acidification of this low alkalinity lake.Concentration of total organic matter, organic carbon, nitrogen, biogenic silica (BSiO2), chlorophyll derivatives (CD), fucoxanthin, diatom cell concentration and number of chironomid head capsules increased during the last 2–3 decades. When expressed as accumulation rates, most of these parameters tended to decrease from the past century to c. 1950, then all except P increased to the present day. A marked increase in sedimentary nitrogen may be related to atmospheric pollution and to the general increases in output of N in Europe. High C/N ratios indicate a prevailing allochthonous source of organic matter.Finally, the increase in measured air temperature from the mid-1800's appeared to be related to lake water pH before industrialization: cold periods generally led to lower pH and vice-versa. The more recent phenomenon of anthropogenic acidification has apparently decoupled this climatic-water chemistry relationship. 相似文献
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K. F. Walker I. G. Dunn D. Edwards T. Petr H. Z. Yang 《International Journal of Salt Lake Research》1995,4(3):169-222
Quinghai Hu is a large, high-altitude, saline lake in north-western China, and supports a fishery based on an endemic species of naked carp (snow trout). The fish take seven years to attain maturity and a marketable weight of 300 g, and have a lifespan of 14–21 years under the present fishery regime. They seasonally migrate from the lake to spawn over the gravel beds of inflowing rivers, but these areas have been reduced by weirs and irrigation diversions and recruitment may have declined. The population may have been affected also by a 1.85-m fall in the lake level over the past 30 years, and by associated changes in salinity. The fishery was opened to large-scale exploitation in 1958. Yields declined sharply (max. 28,523 tonnes, 1960) as the larger, older fish were removed, and then more slowly (min. 2523 tonnes, 1983). Since 1987 the fish factory has been limited to an annual quota of 1200 tonnes, taken by a fleet of four pair trawlers. Another 800 tonnes are taken by licensed fishermen, mainly using gill nets, and perhaps 1000 tonnes are taken illegally. The estimated total catch in 1992 was 3000 tonnes. New trawlers introduced in 1989–90 substantially increased the factory's catch per unit effort, and in 1990 the quota was virtually filled in one month in a zone within 20 km of the factory. Although this could suggest that the stocks will be conserved if the quota is retained, at least half of the catch in 1989–92 consisted of immature individuals. Trawling operations recently were suspended following a further decline in the catch after 1992. While the new trawlers are capable of a major increase in effort, neither the changing environment, the fish stocks or the present markets favour intensified pressure. Gillnets may provide better control over the minimum size limit and may cause less damage than trawling. Other options to improve the viability and profitability of the fishery include improvements in handling, processing and marketing. Failure to develop the fishery may encourage attempts to introduce exotic fish, at some risk to survival of the local species. 相似文献