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Nickolai SHADRIN 《《地质学报》英文版》2014,88(Z1):434-435
正Modern hydrobiology,mainly,is based on conception,which may be named Conception of unicity of ecosystem stable state(CUESS):Mature ecosystems are stable and in dynamic equilibrium.Ecosystem state fluctuates around 相似文献
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山东长岛特色旅游资源研究 总被引:5,自引:0,他引:5
文章从海岛角度出发 ,在分析山东长岛旅游资源条件及开发现状的基础上 ,提出了该岛发展特色旅游应坚持独特性、时代性和系统性的原则及若干建议。 相似文献
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本文简述了铜岩山矿床地质概况,分析了矿区内蚀变带和主要矿体特征,综合研究本矿区剥蚀程度地球化学判别指标。利用累乘晕比值方法,建立5组累乘元素比值公式,求得各组剥蚀系数,以显示矿区内矿体矿化序列和剥蚀程度。发现本矿区内高温成矿元素分布在矿体上方,中低温成矿元素聚集在矿体下部之矿化反序列现象。 相似文献
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KAMEL KHANCHOUL MARGARETA B. JANSSON 《Geografiska Annaler: Series A, Physical Geography》2008,90(3):227-236
The focus of the present study was to estimate suspended sediment load from the Mellah catchment (550 km2 ) during storms. Suspended sediment rating curves were developed on data from a 23-year period. The regression technique of this paper involves a division of data into discharge-based classes, the mean concentrations and discharges of which are used to develop power regressions through log-transformation. Sediment rating curves were also developed on means of data grouped into seasons and stages. Sediment loads estimated by rating curves uncorrected for bias involved underestimations of down to 9% compared with loads from measured concentrations. Correction for bias reduced underestimations to a range from 0.79 to 3%. Rating curves divided into rising and falling stages had the lowest underestimation and were used to estimate load during periods without concentration measurements. During the 23-year study period, the mean annual suspended sediment yield was 373 TI km2 .
Sediment transport is dominated by winter storms accounting for 61% of the annual load. A high exponent 'b' of the power regression equations during the winter season confirms the intense geomorphic work by winter season storms caused by high intensity rainfall, low vegetation cover, and heavy machine activity in the fields. 相似文献
Sediment transport is dominated by winter storms accounting for 61% of the annual load. A high exponent 'b' of the power regression equations during the winter season confirms the intense geomorphic work by winter season storms caused by high intensity rainfall, low vegetation cover, and heavy machine activity in the fields. 相似文献
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利用位移观测数据区分不同形变趋势块体一般分三步进行:基准检测、块体范围区分和各块体内异常形变检测.本文提出用拟准检定法来实现这三步.前两步初选拟准观测是关键.对于基准检测,按形变位移量大小;对于块体范围区分,则按形变方向.最后,通过一个模拟算例,简单介绍了每一步的实施步骤,并比较了拟准检定法与抗差估计(Huber)法、假设检验法的检测效果.结果表明,拟准检定法可以将上述三步成功实现,而抗差估计法只能检测出块体内的异常形变,对稳定基准检测和块体范围划分是失败的;假设检验法在该三步检测中均为失败.从而验证了拟准检定法具有粗差定位准确、崩溃污染率高的优越性. 相似文献
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正20141899Guo Lianjie(Lanzhou Center for Oil and Gas Resources,Institute of Geology and Geophysics,CAS,Lanzhou 730000,China);Ye Danian Origin and Development Anniversary Commemoration of Geology in China:The100th for the Geological Survey of China(Chinese Journal of Geology,ISSN0563-5020,CN11-1937/P,48(4),2013,p.945-969,4 相似文献
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Jeffrey S. Smith 《The Professional geographer》2003,55(1):18-30
As of the year 2000, the Cultural Geography Specialty Group of the Association of American Geographers had 465 members and ranked fourth overall in total membership within the association. Furthermore, cultural geographers had the second fastest growing specialty group between 1993 and 1998, after the Geographic Perspectives on Women specialty group. In spite of this demonstrated overwhelming appeal among geographers, to date, no one has systematically analyzed the subdiscipline of cultural geography to determine such things as its links to other aspects of the discipline, its major scholarly contributions, its most highly regarded publication outlets, its notable practitioners, and its most recognized departments. As the ranks of cultural geographers have swelled, the subdiscipline has become multifaceted. This article contextualizes and interprets the results of a survey sent to members of the 1998–1999 Cultural Geography Specialty Group. Outcomes include Louisiana State University and the University of Texas at Austin listed as offering the strongest cultural geography departments, Wilbur Zelinsky being deemed the subfield's most outstanding living practitioner, and the Annals of the Association of American Geographers named the journal that best meets cultural geographers’ needs. 相似文献
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