六盘山弧形构造带铜多金属矿床的成矿环境

六盘山弧形构造带位于青藏高原东北缘,自震旦-寒武纪以来,经历了“威尔逊旋回“构造演化。在陆内裂谷和板块俯冲阶段,成矿类型主要为海底火山块状硫化物型和与韧性剪切作用有关的构造蚀变岩型,而在碰撞造山和陆内造山阶段,成矿类型演变为与大型推覆体构造有关的似层状热液型,显示出不同构造演化阶段所反映的成矿环境不同。     

Toxic contaminants and their biological effects in coastal waters of Xiamen,China. II. Biomarkers and embryo malformation rates as indicators of pollution stress in fish

Baseline information is presented on embryo malformation rate and biomarkers in fish as indicators of sub-lethal stress caused by pollution in coastal waters of Xiamen, PR China. Fish and eggs were sampled from several areas in Xiamen coastal waters (Xiamen Harbour, Maluan and Tongan Bays and East Channel), where varying levels of pollutant input have been documented. Comparative sampling was done at a "cleaner" reference site at Dongshan Island. Embryonic malformation rates, which indicate general water quality, varied with location and species of fish, and exceeded background levels for unpolluted waters (assumed approximately 5%) by up to eightfold at some sites. Generally, sites around Xiamen Harbour show signs of poor water quality having highest mean levels of embryo deformity (20-30%) and these decreased towards open waters (Tongan Bay, Eastern Channel) where abnormalities approached background levels. An indication that toxic contaminants may be having a localised effect in the region, particularly in the harbour was reinforced by the biomarker assays. However, activities of the biomarkers ethoxyresorufin O-deethylase (EROD) and glutathione S-transferase in fish livers indicate no clear pattern, and there is no evidence that fish from the four sampling areas have been more or less exposed to PAHs and other compounds that induce these biomarkers. Antioxidant biomarkers (glutathione peroxidase, catalase, superoxide dismutase, and reduced glutathione) suggest that exposure to xenobiotics appears to be lowest in Dongshan and Maluan and highest in the harbour and Tongan. Inhibition of acetylcholinesterase in fish muscle indicated possible effects by organophosphate and carbamate pesticides in Xiamen waters and these effects may be greatest in the area of the harbour.     

高精度国际时间比对的进展

在过去的４５ｙｒ中原子频标的性能大约每７ｙｒ提高一个数量级,从国际标准时间和各国高精度守时的需要出发,远距离的高精度时间频率传递比对技术也有与之相适应的很大的发展。ＧＰＳ卫星在近２０ｙｒ中不仅成为导航定位不可缺少的工具,在时间、频率的方面也发挥出巨大威力;近年来多通道“全视接收”技术的发展钎时频传输比对的稳定性有了重大改善;ＧＬＯＮＡＳＳ卫星系统在高精度时间比对方面正在成为ＧＰＳ系统的重要补充手段     

半拉格朗日、半隐式欧拉方程组大气数值模式研究

介绍了一个具有较高时间积分效率的三维弹性大气数值模式。其中,控制方程为能够描述大气非静力及可压缩性的欧拉方程组,时间积分采用了高效率的“半拉格朗日、半隐式”方案。通过引用一个简化的“云物理过程”参数化方案,针对大气中深厚湿对流过程的若干问题进行了数值试验,结果表明,模式能够对该过程中的一些基本和复杂现象进行有效地模拟。试验结果还表明,动力学框架具有很好的稳定性,能够实现高效率的时间积分,它还具有较好的频散特性,保证了空间计算的精度,从而完好地描述了风暴的形态。     

川滇地区地震活动单键群分析

利用单键群（即ＳＬＣ）分析方法,通过有关ＳＬＣ特征参量的时间滑移分析,结合１９７０年以来的区域地震活动和构造环境,分析了川滇西部地区的地震活动。较之７０年代和８０年代,９０年代的地震活动在总体上是处于中等强度的活动水平。文章认为,ＳＬＣ方法考虑了地震事件的时空关联性,可以用来分析地震活动趋势,是研究地震活动性的有用工具。     

急性颈椎损伤的CT诊断

本文目的是分析急性颈椎损伤（ＡＣＴ）的ＣＴ征象,评价ＣＴ在ＡＣＴ诊断中的价值及限度。方法：７８例颈椎外伤患者行平片、薄层ＣＴ检查及三维重建,并做对照分析。结果经影像学诊断６０例ＡＣＴ,ＣＴ诊断５９例,１例ＣＴ阴性而由平片确诊 １例。平片与ＣＴ的骨折检出率分别为 ５３． ３％和 ９８．３％。结论：ＣＴ比Ｘ线平片可发现更多的骨折,并能明确骨折块与椎管的关系。这对临床处理严重颈椎损伤起到指导作用。     

黑河流域"96·8"洪水分析

1996年8月22日,甘肃省黑河发生了大洪水.分析了造成这场洪水的降水特点和洪水的形成及发展规律,得出了"96·8"洪水的暴雨中心和洪水形成均在上游山区,黑河流域的降水特性和地貌特点决定了洪水发展的基本规律.     

A bed‐load transport model for rough turbulent open‐channel flows on plane beds

Data from flume studies are used to develop a model for predicting bed‐load transport rates in rough turbulent two‐dimensional open‐channel flows moving well sorted non‐cohesive sediments over plane mobile beds. The object is not to predict transport rates in natural channel flows but rather to provide a standard against which measured bed‐load transport rates influenced by factors such as bed forms, bed armouring, or limited sediment availability may be compared in order to assess the impact of these factors on bed‐load transport rates. The model is based on a revised version of Bagnold's basic energy equation i_bs_b = e_bω, where i_b is the immersed bed‐load transport rate, ω is flow power per unit area, e_b is the efficiency coefficient, and s_b is the stress coefficient defined as the ratio of the tangential bed shear stress caused by grain collisions and fluid drag to the immersed weight of the bed load. Expressions are developed for s_b and e_b in terms of G, a normalized measure of sediment transport stage, and these expressions are substituted into the revised energy equation to obtain the bed‐load transport equation i_b = ω G ^3·4. This equation applies regardless of the mode of bed‐load transport (i.e. saltation or sheet flow) and reduces to i_b = ω where G approaches 1 in the sheet‐flow regime. That i_b = ω does not mean that all the available power is dissipated in transporting the bed load. Rather, it reflects the fact that i_b is a transport rate that must be multiplied by s_b to become a work rate before it can be compared with ω. It follows that the proportion of ω that is dissipated in the transport of bed load is i_bs_b/ω, which is approximately 0·6 when i_b = ω. It is suggested that this remarkably high transport efficiency is achieved in sheet flow (1) because the ratio of grain‐to‐grain to grain‐to‐bed collisions increases with bed shear stress, and (2) because on average much more momentum is lost in a grain‐to‐bed collision than in a grain‐to‐grain one. Copyright © 2006 John Wiley & Sons, Ltd.     

陆相坳陷盆地层序地层格架下岩性地层圈闭/油藏类型与分布规律——以松辽盆地白垩系泉头组—嫩江组为例

本文在圈闭组成和形成条件分析的基础上对坳陷盆地层序地层格架下岩性地层圈闭/油藏类型与分布规律进行了初步分析和总结,探讨了层序地层格架下不同体系域中圈闭/油藏类型的纵向分布、盆地中不同构造部位圈闭/油藏类型的横向分布规律。系统解剖了松辽坳陷盆地白垩系二级层序格架内低位、湖侵和高位体系域中圈闭/油藏类型的纵向分布和变化特征;对比分析了坳陷盆地从凹陷带(近凹中心)、过渡带(凹陷边缘)到斜坡带(环凹斜坡)圈闭/油藏类型的横向分布和变化规律。圈闭/油藏类型的纵、横向分布和变化规律表明:岩性地层圈闭/油藏的形成及类型具有纵向“层控”、横向“相控”的规律性,即纵向上受控于层序格架(体系域),横向上受控于一定构造背景下特定的沉积相带。     

利用高分辨率影像建立三维虚拟校园——以"数字成都理工大学"为例

以数字化校园工程———“数字成都理工大学”为例,探讨利用航空影像和数字摄影测量技术,获取基础空间地理信息的方法及途径。并采用三维建模软件Cyber C ity对建筑物进行三维建模。而对于复杂地物,采用三维地理信息系统IMAGIS软件建立单个模型,从而实现了成都理工大学校区的三维可视化虚拟重建和漫游。实践证明,利用数字摄影测量技术和遥感影像,能够有效地获取大范围区域地表地物的三维信息,并快速地建立地面模型和三维景观。