沙漠砂抗剪强度特征及其与静力触探指标间的关系

通过室内系列化的直剪试验和静力触探模拟试验,对沙漠砂的抗剪强度特征取得了规律性的认识,并建立了砂土内摩擦角与锥尖阻力之间的经验关系,为今后在沙漠地基勘察评价中用静力触探方法估计砂土内摩擦角创造了条件。     

成矿流体运动系统与金质来源和富集机制讨论

以 山东地区大型、超大型金矿为例,从运动学和动力学角度,系统研究其成矿作用的起点（岩石－岩浆－流体间的物理化学作用）和终点（矿富集于断裂复合处或交汇部位）,以及成矿流体在运动中的渗透、振荡、气－液态交替、流速的突变及多层次循环流体的萃取、沟通等多方面的共同作用。结果表明,巨量金质来源和富集的关键取决于各层次流体循环笼统间的沟通,地幔富Ｃ－Ｈ－Ｏ流体循环系统、中－下部地壳富硅流体循环系统、浅－表部（     

福建省同安湾叶绿素的含量

根据1998年2月、5月、8月、11月对同安湾叶绿素a含量的调查,分析了同安湾叶绿素a的季节分布,并估算了初级生产力C的含量,调查结果表明春季的叶绿素a含量为全年最高,范围为2.68 μg/L～16.24 μg/L,平均值为7.22 μg/L,初级生产力C平均为4286.4mg/m2.d;夏季叶绿素a含量为1.03μg/L～5.40 μg/L,平均值为.3.34 μg/L;秋季叶绿素a含量为0.36 μg/L～1.50 μg/L,平均值为0.87μg/L,初级生产力C平均为32.84mg/mg.d;冬季叶绿素a含量为1.11μg/L～2.21μg/L,平均值为1.56 μg/L.本文还将此次调查结果与历史资料作了比较.     

拉萨城市用地变化分析

根据１９９９年８～８月实地调查和以往文献资料、４期航片和地形在信息,动用遥感信息解译和ＧＩＳ软件分析及ＧＰＳ定位核查,准确地展现了过去５０年中拉萨城市用地变化进程,重点分析了城市用地变化产生的生态与环境和问题。主要结论如下：①拉萨城区拓展迅速,从１９５１年始到１９９９年,城区扩大了１０．３１倍,城市建设面积扩大了近１９倍。城区发展分为：城市扩建初期（１９５２～１９６５年）、高速发展时期（１９６６～     

海洋对全球变暖的响应及南海观测证据

回顾了世界各大洋和若干区域海洋的海平面、热含量、温盐结构及珊瑚变化等方面的主要成果,并对中国南海温盐结构的长期变化趋势进行了初步分析。结果表明,对全球增暖的响应,南海中层水盐度的长期变化表现出一定的淡化趋势。     

Current and thermohaline characteristics of the Arabian Sea during January 1998

Based on a ship survey during January 1998, the characteristics of the flow, the thermohaline properties and the volume transport of the Arabian Sea are discussed. A strong westward flow exists between 10.5?N and 11?N, part of which turns to the south as the Somali current near the coast at about 10?N and the rest turns north. At the passage between the African continent and the So- cotra Island, the northern branch separates into two flows: the left one enters the passage and the right one flows eastward along the southern slope of the island. Off the island the flow separates once more, most of it meandering northeast and a small fraction flow- ing southeast. Volume transport calculation suggests that the tidal transport is one or two orders of magnitude smaller than the total transport in this region and it becomes more important near the coast. The average velocity of the flow in the upper layer (0-150 m) is about 20 cm s-1, with a maximum of 53 cm s-1 appearing east of the Socotra Island, and the subsurface layer (200-800 m) has an aver- age velocity of 8.6 cm s-1; the velocity becomes smaller at greater depths. The depth of the seasonal thermocline is about 100 m, above which there is a layer with well mixed temperature and dissolved oxygen. High-salinity and oxygen-rich water appears near the surface of the northern Arabian Sea; a salinity maximum and oxygen minimum at 100 m depth along 8?N testifies the subduction of surface water from the northern Arabian Sea. Waters from the Red Sea and the Persian Gulf also influence the salinity of the area.     

An estimation of internal soliton forces on a pile in the ocean

Internal soliton forces on oil-platform piles in the ocean are estimated with the Morison Formula. Different from sur- face wave forces, which change only in magnitude along a pile, internal soliton forces can be distributed over the entire pile in the water and they change not only in magnitude but also in direction with depth. Our calculations show that the maximum total force caused by a soliton with its associated current of 2.1 m s-1 is nearly equal to the maximum total force exerted by a surface wave with a wavelength of 300 m and a wave-height of 18 m. The total internal soliton force is large enough to affect the operations of marine oil platforms and other facilities. Therefore, the influence of internal solitons should not be neglected in the design of oil platforms.     

基于USB的远程控制系统实现地震灾害救助

基于USB的远程控制系统初步研究设计建立了一种救助模型。与传统生命探测仪的救助系统不同,USB的远程控制系统具有远程实时监控功能。系统的硬件主要由单片机控制电路、USB接口电路、无线收发模块构成。系统利用Internet与计算机互联,通过USB接口电路与单片机的连接,对多个目标检测和控制,实现在地震灾害中的呼叫救助。     

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Agriculture development-induced surface albedo changes and climatic implications across northeastern China

To improve the understandings on regional climatic effects of past human-induced land cover changes,the surface albedo changes caused by conversions from natural vegetation to cropland were estimated across northeastern China over the last 300 years,and its climatic effects were simulated by using the Weather Research and Forecasting (WRF) model.Essential natural vegetation records compiled from historical documents and regional optimal surface albedo dataset were used.The results show that the surface albedo decreased by 0.01-0.03 due to conversions from grassland to cropland in the Northeast China Plain and it increased by 0.005-0.015 due to conversions from forests to cropland in the surrounding mountains.As a consequence,in the Northeast China Plain,the surface net radiation increased by 4-8 W/m 2,2-5 W/m 2,and 1-3 W/m 2,and the climate was therefore warmed by 0.1℃-0.2℃、0.1℃-0.2℃、 0.1℃-0.3 ℃ in the spring,autumn and winter,respectively.In the surrounding mountain area,the net radiation decreased by less than 1.5 W/m 2,and the climate was therefore cooled too slight to be detected.In summer,effects of surface albedo changes on climate were closely associated with moisture dynamics,such as evapotranspiration and cloud,instead of being merely determined by surface radiation budget.The simulated summer climatic effects have large uncertainties.These findings demonstrate that surface albedo changes resulted in warming climate effects in the non-rainy seasons in Northeast China Plain through surface radiation processes while the climatic effects in summer could hardly be concluded so far.