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排序方式: 共有183条查询结果,搜索用时 961 毫秒
111.
韦祖林 《广东海洋大学学报》2003,23(5):104-109
无单放货频频发生 ,导致对承运人提出的索赔案件不断发生。文章拟从无单放货的表现形式入手 ,分析每一种形式中无单放货人的法律责任 相似文献
112.
THE BALANCE BETWEEN SUPPLY AND DEMAND OF WATER RESOURCES AND THE WATER—SAVING POTENTIAL FOR AGRICULTURE IN THE HEXI CORRIDOR 总被引:5,自引:0,他引:5
The Hexi Corridor is an important base of agriculture development in Northwest China. According to recent statistics, there
are 65.94×108m3 of water resources available in the Hexi Corridor. At present, net consumption in development and utilization is 43.33×108m3. Water supply and demand reach a balance on the recent level of production, but loss of evaporation and evapotranspiration
is as much as 25.69×108m3. So net use efficiency of water resources is 59%. Based on analyzing balance between water and land considering ecological
environment at present, there exists the serious water shortage in the Shiyang River system where irrigation lands have overloaded.
There is a comparative balance between supply and demand of water resource in the Heihe River system; and the Sule River system
has some surplus water to extend irrigation land. Use of agriculture water accounts for 83.3% and ecological forest and grass
for 6.9%. The Hexi Corridor still has a great potential for water saving in agriculture production. Water-saving efficiency
of irrigation is about 10% by using such traditional technologies as furrow and border-dike irrigation and small check irrigation,
and water-saving with plastic film cover and techniques of advanced sprinkler and drip/micro irrigation etc. cansave more
than 60% of irrigated water. Incremental irrigation area for water-saving potential in the Hexi Corridor has been estimated
as 56% – 197% to original irrigation area. So the second water sources can be developed from water saving agriculture in the
Hexi Corridor under Development of the Western Part of China in large scale. This potential can be realized step by step through
developing the water-saving measures, improving the ecological condition of oasis agriculture, and optimizing allocation of
water resources in three river systems.
Foundation item: Under the auspices of the Key innovation Project Engineering of Chinese Academy of Sciences (KZcx-1-10-03)
Biography: GAO Qian-zhao (1942 –), male, a native of Changzhou, Jiangsu, Professor and supervisor of Ph. D students. His research
interests include hydrology and rational utilization of water resources in the arid zone. 相似文献
113.
南京大学太阳塔CCD成像光谱观测系统和初步观测结果 总被引:1,自引:0,他引:1
本文介绍南京大学太阳塔的CCD成像光谱观测系统的结构,工作方式,给出了该系统的一些性能测试结果,作为应用该系统的实例,文中给出了根据该系统观测的二维光谱资料,经处理得到的一个Ha耀斑在线心和不同偏带处单色像的变化过程,该耀斑的亮度场轮廓图和速度场轮廓图。 相似文献
114.
晚三叠世留山盆地沉积特征与构造环境分析 总被引:1,自引:0,他引:1
本文在实测剖面的基础上,通过薄片观察、粒度分析和阴极发光测试等手段,以沉积相的研究为切入点,将沉积作用和构造作用紧密联系,分析了留山盆地的沉积特征和构造性质。研究表明,留山盆地上三叠统沉积相主要为扇三角洲相,经历了早期的退积作用和晚期的进积作用。沉积相的演化和源区分析综合表现出,留山盆地是一个孤立的陆相盆地,沉积物来源主要为盆地周围的造山带物质。盆地演化经历了盆地形成阶段、平稳沉降阶段、快速沉降阶段和快速充填阶段,其构造动力与盆地周缘的构造作用强度相呼应。盆地性质可能为压坳性盆地,进而推测留山盆地是华北与扬子板块在晚三叠世碰撞期间向南大规模推覆而产生的背驼式盆地。 相似文献
115.
以大量的野外工作为基础,辅以地球化学研究,确定了西峡盆地和夏馆盆地普遍存在着古地震事件的物质记录。同沉积期古地震事件主要表现为同沉积小断裂、同沉积角砾岩层等,且同沉积地震事件对于河流侵蚀作用的产生具有重要的影响;成岩期古地震事件主要表现为沿断裂上盘砾岩的"涂抹"和成岩期形成的方解石擦磨晶体,以及由断裂(裂隙)所围限的不同于周侧岩性的块体。古地震事件的研究不仅可以为恐龙蛋的埋藏作用提供信息,也可以为研究古地理和古构造背景提供信息。 相似文献
116.
Christine Floss Frank J. Stadermann Zu Rong Dai Giles Graham 《Geochimica et cosmochimica acta》2006,70(9):2371-2399
We have carried out a comprehensive survey of the isotopic compositions (H, B, C, N, O, and S) of a suite of interplanetary dust particles (IDPs), including both cluster and individual particles. Isotopic imaging with the NanoSIMS shows the presence of numerous discrete hotspots that are strongly enriched in 15N, up to ∼1300‰. A number of the IDPs also contain larger regions with more modest enrichments in 15N, leading to average bulk N isotopic compositions that are 15N-enriched in these IDPs. Although C isotopic compositions are normal in most of the IDPs, two 15N-rich hotspots have correlated 13C anomalies. CN−/C− ratios suggest that most of the 15N-rich hotspots are associated with relatively N-poor carbonaceous matter, although specific carriers have not been determined. H isotopic distributions are similar to those of N: D anomalies are present both as distinct D-rich hotspots and as larger regions with more modest enrichments. Nevertheless, H and N isotopic anomalies are not directly correlated, consistent with results from previous studies. Oxygen isotopic imaging shows the presence of abundant presolar silicate grains in some of the IDPs. The O isotopic compositions of the grains are similar to those of presolar oxide and silicate grains from primitive meteorites. Most of the silicate grains in the IDPs have isotopic ratios consistent with meteoritic Group 1 oxide grains, indicating origins in oxygen-rich red giant and asymptotic giant branch stars, but several presolar silicates exhibit the 17O and 18O enrichments of Group 4 oxide grains, whose origin is less well understood. Based on their N isotopic compositions, the IDPs studied here can be divided into two groups. One group is characterized as being “isotopically primitive” and consists of those IDPs that have anomalous bulk N isotopic compositions. These particles typically also contain numerous 15N-rich hotspots, occasional C isotopic anomalies, and abundant presolar silicate grains. In contrast, the other “isotopically normal” IDPs have normal bulk N isotopic compositions and, although some contain 15N-rich hotspots, none exhibit C isotopic anomalies and none contain presolar silicate or oxide grains. Thus, isotopically interesting IDPs can be identified and selected on the basis of their bulk N isotopic compositions for further study. However, this distinction does not appear to extend to H isotopic compositions. Although both H and N anomalies are frequently attributed to the survival of molecular cloud material in IDPs and, thus, should be more common in IDPs with anomalous bulk N compositions, D anomalies are as common in normal IDPs as they are in those characterized as isotopically primitive, based on their N isotopes. 相似文献
117.
It is impractical to install sensors on every floor of a tall building to measure the full state vector because of the large number of degrees of freedom. This makes it necessary to introduce reduced‐order control. A kind of system reduction scheme (dynamic condensation method) is proposed in this paper. This method is iterative and Guyan condensation is looked upon as an initial approximation of the iteration. Since the reduced‐order system is updated repeatedly until a desired one is obtained, the accuracy of the reduced‐order system resulting from the proposed method is much higher than that obtained from the Guyan condensation method. Another advantage of the method is that the reduced‐order system is defined in the subspace of the original physical space, which makes the state vectors have physical meaning. An eigenvalue shifting technique is applied to accelerate the convergence of iteration and to make the reduced system retain all the dynamic characteristics of the full system within a given frequency range. Two schemes to establish the reduced‐order system by using the proposed method are also presented and discussed in this paper. The results for a tall building with active tuned mass damper show that the proposed method is efficient for the reduced‐order modelling and the accuracy is very close to exact only after two iterations. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
118.
阿克苏位于新疆南部 ,天山南麓塔里木盆地北缘 ,东西长约 51 3km,南北宽约 386km,总面积为 1 3.2万 km2 ,1 999年年末全地区统计总人口为 2 0 1 .35万人。全地区辖八县一市 ,现有大小市镇 2 0多个 ,阿克苏市是全地区政治、经济、科技的中心 ,市区现有人口近 2 0万人。阿克苏地区在地理位置上是新疆的重要交通枢纽 ,是塔里木油田及西气东输的基地。随着别铁里口岸的开通 ,往日封闭落后的阿克苏 ,将成为改革开放的前沿阵地。近年来 ,阿克苏城镇建设突飞猛进 ,开发西部 ,支援边疆建设的人们从四面八方来到阿克苏 ,农村人口逐渐迁往城镇。目前 ,… 相似文献
119.
报道了天然气水合物专题研讨会的概况,介绍了天然气水合物及其地理化学特征,并就开发天然气水合物对分析测试技术的要求做了简单介绍。 相似文献
120.