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61.
The dechlorination of aqueous polychlorinated biphenyls (PCBs) using the ultrasound-assisted chemical process (UACP), which is a combination of ultrasonic irradiation and radical generations using di-tert-butyl peroxide as a radical initiator and ferrous ion as a catalyst at moderate temperature in alkaline 2-propanol, was demonstrated with a high reduction of PCBs. A commercial PCB-containing compound, Aroclor 1260, was also decomposed with the removal efficiency of 97 % achieved within 3 h of UACP. The gas chromatograph was used as a quantitative method to measure the decomposition rate of PCBs. The competitive elimination among the ortho (2-position), meta (3-position), and para (4-position) chlorine atoms of PCB was also identified.  相似文献   
62.
济青高速公路大雾天气气候特征及其影响   总被引:30,自引:3,他引:30       下载免费PDF全文
张飒  冯建设 《气象》2005,31(2):70-73
利用济青高速公路沿线13个气象站1971~2000年的地面观测资料,分析了济青高速公路沿线大雾天气的天气气候特征,发现:济青高速公路沿线大雾天气不仅具有明显的年际变化,而且具有明显季节、昼夜和地域差异,并在此基础上将不同路段大雾服务划分为特别关键期、关键期、次关键期。结合实际交通气象服务的需要,将大雾天气对于高速公路的影响划分为4个等级,并提出了未来开展高速公路大雾服务的设想。  相似文献   
63.
The crosslinking reaction caused by blending different biopolymers and/or adding a crosslinking agent to biopolymers was studied. The rate of crosslinking reaction was estimated with weight swelling ratio (WSR), viscosity, and biodegradability. The crosslinked material from blending two biopolymers or mixing a crosslinking agent with a mixture of two biopolymers showed a polymeric volume change, a high microbial resistance even after 80 days, and a viscosity increased because of chemical functional groups to form extensive intra- and interpenetrating polymer networks (IPNs). The organized IPN is a base block in building a three-dimensional (3-D) crosslinked biopolymer structure. This 3-D structure can be utilized in the environmental and geotechnical applications such as an environmental barrier or containment to encapsulate and treat hazardous materials against toxic flow in a subsurface engineering system.  相似文献   
64.
Contourlet变换和Tsallis熵的多源遥感图像匹配   总被引:1,自引:0,他引:1  
吴一全  陈飒 《遥感学报》2010,14(5):899-910
提出了一种利用Contourlet变换、Tsallis熵和改进粒子群优化的多源遥感图像匹配算法。在分别对参考图像和目标图像进行Contourlet分解的基础上,以基于Tsallis熵的互信息量作为相似性度量准则,利用改进的带极值扰动的简化粒子群优化算法对低分辨率的遥感图像进行匹配操作,逐级上推,最终实现全分辨率情况下多源遥感图像的匹配。实验结果表明,与常用的遥感图像匹配算法相比,该算法匹配精度高,稳健性好,且运算量大幅减少。  相似文献   
65.
This article develops a methodology using a Geographical Information System (GIS) to evaluate the best location to stop a high speed passenger train when faced with an undesired event. The proposed method is based on multicriteria decision‐making where different stretches of line which could be chosen as the stopping point are ranked depending on the characteristics of the line, the surrounding area and its accessibility for equipment. The method was integrated into the GIS to develop an expert support system for decision makers faced with different kinds of undesired events. It has been applied to a case study on the high speed line between Valladolid and Madrid (Spain). The proposed method is new and has not previously been applied to high speed railway networks and could be adapted to other case studies. The speed of the algorithm provides an almost instantaneous reply within seconds of an emergency situation occurring. The method can therefore be part of an overall support system for decision making in undesired rail events.  相似文献   
66.
以系统热噪声、时空基线、季节性变化和多普勒质心频率作为影响因子,建立主图像选取函数,根据生成相干系数矩阵预测最佳主图像,并利用拉斯维加斯地区的数据实际处理结果对该方法的预测结果进行验证.结果表明该方法能够准确地预测PSInSAR数据处理中不相干图像个数以及图像之间的相干系数,为最佳主图像的选取提供可靠的参考依据.  相似文献   
67.
地测信息系统及其应用   总被引:1,自引:0,他引:1  
介绍了一个专门为地测部门设计和开发的软件系统——地质、测量信息系统(MSGIS)的应用范围、主要功能,并以系统的具体操作为主线阐述了系统的用户界面、输入输出接口、图形生成、地测图形的自动处理和3D地测模型。  相似文献   
68.
The need for a thorough knowledge of boundary conditions over the vast oceanic surfaces makes remote sensing appear as the most suitable tool for future development. Remote sensing techniques require calibration data and consequently in-situ experiments to yield those data. Over the sea, aircraft seem to be the most convenient means of conducting validation experiments because they allow exploration of a large range of scales (from local measurements to measurements of pixel scale). This paper reports on some in-situ atmospheric aircraft measurements that were conducted as part of the TOSCANE-T experiment organized by the European Space Agency to calibrate the scatterometer for launch on ERS-1 in the early 1990's for global ocean wind measurement.The data analysed are the thermodynamic and turbulent variables measured by an instrumented aircraft, the Hurel Dubois, flying at a constant level of 50 m over the sea surface. Special attention was drawn to the variability of the boundary conditions within areas of 25 × 30 km. In fact, the two-dimensional fields of fluxes and thermodynamic parameters were inhomogeneous with some rather strong wind distortion.The eddy fluxes were parameterized with the aid of bulk aerodynamic formulations at a basic scale of 30 km samples, which corresponds to the aircraft flux computation legs. The bulk aerodynamic coefficients for momentum and heat were found to remain independent of windspeed (for wind velocities less than 12 m/s). Fluxes and thermodynamic parameters were also investigated at two other scales: the integration scale was either reduced to small areas of which size always remains larger than several characteristic lengths of turbulent transfer, or extended to a large area of 25 × 30km. The results of the bulk aerodynamic relationships appeared to be scale invariant, which would therefore justify the application of average values, within the range of scales under study.  相似文献   
69.
文章通过一段气象节目制作的实例,浅析了气象影视节目制作中各种主要设备的综合使用及切换台和非线性编辑系统的主要工作原理.  相似文献   
70.
对加强地震政府网站地震突发事件信息保障工作的思考   总被引:1,自引:0,他引:1  
地震政府网站是地震行业面向社会宣传防震减灾工作、服务公众的重要窗口.汶川、玉树地震后,地震工作越来越受到社会的关注,地震政府网站已成为社会公众和主流媒体、网站获取地震信息的重要平台,在抗震救灾中发挥着越来越重要的作用.本文通过地震政府网站在汶川、玉树等地震突发事件中信息保障工作的实践,从网站应急制度建设、编制网站应急预...  相似文献   
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