Seismic stratigraphy records the deglacial history of Jakobshavn Isbræ, West Greenland

Jakobshavn Isbræ is one of the largest ice streams in the Greenland Ice Sheet, presently draining c. 6.5% of the Inland Ice. Here we present high‐resolution Chirp and Sparker sub‐bottom profiles from a seismic survey conducted just outside of the Jakobshavn Isfjord, which provides detailed insight into the glacimarine sedimentary history of the Jakobshavn ice stream during the Holocene. We observe acoustically stratified and homogeneous sediments that drape an irregular substratum and were deposited between ～10 and c. 7.6k cal a BP. The stratified lower units are interpreted as the product of ice‐proximal glacimarine sedimentation deposited rapidly when the grounded ice margin was located close to depositional basins on topographic highs. The upper acoustically homogenous units reflect suspension settling of fine‐grained material and gravitational flows that were extruded from an increasingly unstable ice margin as the ice retreated into the fjord. Proximity to the ice margin and bedrock topography were the dominant controls on sediment accumulation during deglaciation although the 8.2‐ka cooling event probably influenced the position of the ice margin at the fjord mouth. The post‐glacial sedimentary record is characterized by glacimarine and hemipelagic rainout with an increased ice‐rafted detritus fraction that records sedimentation following ice stream retreat into Jakobshavn Isfjord sometime after c. 7.8k cal a BP. Copyright
69; 2011 John Wiley & Sons, Ltd.     

.NET框架下IPv6和IPv4双协议兼容的测试用例实现

在.NET框架下,利用VC＋＋编程语言开发在Windows平台上检测IPv6网络互联情况的测试用例程序,程序对IPv4同样兼容。主要介绍了适用于双协议的Socket API函数和Socket通信原理,给出在双协议下客户机/服务器通信的应用程序及实现思路,为双协议下的其它网络应用程序开发打基础。     

基于IPv6组播的聊天系统的实现

聊天系统实现了在IPv6环境中组播技术的一个具体实例,并根据项目需要搭建了一个小规模的IPv6实验网,经测试可以稳定地运行在IPv6网络环境中,基本实现了IPv6组播应用.     

石家庄山区水热条件遥感调查研究

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Performance of the stereoscopic system of the HEGRA imaging air erenkov telescopes: Monte Carlo simulations and observations

Based on the Monte Carlo simulations we have studied the performance of the HEGRA system of imaging air 6TJ1-3WV9GV8-1-1/0?wchp=dGLzVzb-zSkWA" alt="Image" title="Image" style="vertical-align:bottom" border="0" height=15 width="11"/> erenkov telescopes (IACTs) in its present configuration of 4 IACTs as well as in its future final configuration of 5 IACTs. Here we present the results on the basic characteristics of the IACT system which are used in the standard data analysis procedure, i.e., the collection areas, the detection rates, the angular resolution, the energy resolution, and the γ/hadron-separation efficiency. By comparing several key Monte Carlo predictions with experimental results it is possible to check the accuracy of the simulations. The Monte Carlo results concerning hadron-nuclear showers are tested with the recorded cosmic ray events and the results concerning photon-induced showers are tested with a large data sample of γ-rays observed from BL Lac object Mkn 501 during its high flaring activity in 1997. Summarizing the simulations and current observations we give the basic recommendations of using the instrument and the major values of its sensitivity.     

DCS－偶氮胂光度法测定钛酸锶烧结物中游离的氧化锶

ＤＣＳ－偶氮胂光度法测定钛酸锶烧结物中游离的氧化锶胡浩，周宏实江苏海安磷肥厂２２６６００ＤＣＳ－偶氮肿［２－（２－胂酸基苯偶氮）－７－（２，６－二氯－４－磺酸基苯偶氮）－１，８－二羟基－３，６－二磺酸萘］属双偶氮变色酸类显色剂，主要用于稀土元素的高灵...     

Membrane Ozonation in Wastewater Treatment

The utilization of porous membranes in mass transfer processes of gaseous ozone to water was investigated. With this approach a direct control of the interface between gas and liquid is possible. Furthermore it prevents foam formation in the presence of surfactant pollution, which constitutes a problem in conventional ozonation methods. Different organic and inorganic membrane materials and geometrical arrangements were utilized and ozone transfer under varied experimental conditions was determined. Typical transfer rates obtained in the experiments were 10 g ozone per membrane square meter and hour, but under optimized conditions higher values were possible. A theoretical model was successfully applied to the results obtained. A peculiarity of the method is its inherent ozone dose control in relation to the volume flow of water.     

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V6-A电磁系统山区水源勘测中的应用

本文介绍V6-A电磁系统的设备原理、特点,控源音频大地电磁法,野外数据采集的方法;结合实例说明了V6-A电磁系统在山区找水中的应用效果.