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41.
仝坤  王琦 《特种油气藏》2006,13(2):98-100
针对辽河油区超稠油采油污水的特点,采用Fenton试剂催化氧化,对采油污水处理进行研究。实验研究及现场应用结果表明,此方法对污水的CODCr具有良好的去除效果。处理后污水经过简单生化,进一步降解污染物,能够实现稳定迭标排放,且具有能耗低、运行成本低和操作简单等特点。  相似文献   
42.
论文比较详细地阐述了涉密网主机系统所面临的安全隐患,提出了涉密网主机安全防护所要解决的几个技术问题,并就可能实现的技术方法进行了探讨和比较。  相似文献   
43.
根据不同剥蚀量恢复方法的特点和松辽盆地滨北地区实际地质情况,采用不同的方法对滨北地区T5和T4不整合面进行剥蚀量恢复。利用镜质体反射率法和体积平衡-沉积速率法相结合对T5不整合面进行剥蚀量恢复;应用镜质体反射率法、地层趋势分析法和沉积速率法相结合对T4不整合面进行剥蚀量恢复。研究结果表明T5不整合面因经历较长时间的剥蚀,剥蚀量较大,剥蚀量在700~2800m之间;T4不整合面剥蚀量多在200~1000m,在经历剥蚀时间较长的地区和靠近断陷盆地边缘的地区剥蚀量大。  相似文献   
44.
A numerical technique for modeling fatigue crack propagation of multiple coplanar cracks is presented. The proposed method couples the extended finite element method (X-FEM) [Int. J. Numer. Meth. Engng. 48 (11) (2000) 1549] to the fast marching method (FMM) [Level Set Methods & Fast Marching Methods: Evolving Interfaces in Computational Geometry, Fluid Mechanics, Computer Vision, and Materials Science, Cambridge University Press, Cambridge, UK, 1999]. The entire crack geometry, including one or more cracks, is represented by a single signed distance (level set) function. Merging of distinct cracks is handled naturally by the FMM with no collision detection or mesh reconstruction required. The FMM in conjunction with the Paris crack growth law is used to advance the crack front. In the X-FEM, a discontinuous function and the two-dimensional asymptotic crack-tip displacement fields are added to the finite element approximation to account for the crack using the notion of partition of unity [Comput. Meth. Appl. Mech. Engng. 139 (1996) 289]. This enables the domain to be modeled by a single fixed finite element mesh with no explicit meshing of the crack surfaces. In an earlier study [Engng. Fract. Mech. 70 (1) (2003) 29], the methodology, algorithm, and implementation for three-dimensional crack propagation of single cracks was introduced. In this paper, simulations for multiple planar cracks are presented, with crack merging and fatigue growth carried out without any user-intervention or remeshing.  相似文献   
45.
Maria Ziolek   《Catalysis Today》2003,78(1-4):47-64
This review article is devoted to the materials containing niobium, which have been discovered or developed in the past few years and exhibit the potential application in heterogeneous catalysis. Niobium oxides and mixed oxides as well as sulfides, nitrides (oxynitrides), carbides (oxycarbides), and phosphates are considered. Among the catalytic processes in which Nb-containing materials were tested, liquid and gas phase oxidation is described in details, and the role of niobium in the prevention of the catalyst from SO2 poisoning is mentioned.  相似文献   
46.
针对川西新场气田JS12气藏开展了多参数的综合评价研究,多参数包括储层参数、裂缝参数、储层分类厚度参数。首先,开展了储层参数及裂缝参数的计算,以岩心分析结果为依据,建立了孔隙度、渗透率、含水饱和度计算模型。利用铸体薄片进行了微裂缝识别,对样品的裂缝参数和测井曲线进行相关分析,建立了测井计算裂缝参数的数学模型;其次,对储层进行聚类分析,通过聚类将储层分为三类;最后,将计算的裂缝参数、储层分类中的Ⅰ类储层厚度、孔渗饱等参数进行正态化处理,拟和测试的无阻流量与这些参数建立多元回归计算模型,即综合含气指标的数学计算模型。以综合含气指标为主要依据,进行储层综合分类和评价,指出了有利的含气区域和可供挖潜井的建议。该方法在指导气藏开发中获得了良好效果。  相似文献   
47.
面阵凝视型成像空间应用技术   总被引:7,自引:6,他引:1       下载免费PDF全文
介绍了凝视型成像技术的特点、优势、现状和发展趋势,论述了凝视型成像技术应用于遥感领域发展的重要性,总结了面阵凝视型成像技术作为空间应用所涵盖的关键技术,将为我国空间凝视型成像技术的进一步发展提供参考。  相似文献   
48.
通过本科生研究计划培养大学生创新能力的几点思考   总被引:12,自引:0,他引:12  
上海交通大学“本科生研究计划(PRP)”于2001年启动以来,立足于培养学生创新意识和科研能力。目前。PRP工作已作为完整的本科教育的一部分纳入到常规的教学工作之中,教学效果显著。由于PRP针对的主要是大学二、三年级的学生。大部分学生都是首次参加此类活动,如何以PRP为依托,最大限度地培养大学生的创新能力,为大学生以后的毕业设计甚至研究生的进一步学习打下坚实的基础,是一个值得探讨的课题。笔者通过参与指导了多期PRP项目。从选题、指导等方面讨论了PRP实践应注意的问题。  相似文献   
49.
Quality of service (QoS) support for multimedia services in the IEEE 802.11 wireless LAN is an important issue for such WLANs to become a viable wireless access to the Internet. In this paper, we endeavor to propose a practical scheme to achieve this goal without changing the channel access mechanism. To this end, a novel call admission and rate control (CARC) scheme is proposed. The key idea of this scheme is to regulate the arriving traffic of the WLAN such that the network can work at an optimal point. We first show that the channel busyness ratio is a good indicator of the network status in the sense that it is easy to obtain and can accurately and timely represent channel utilization. Then we propose two algorithms based on the channel busyness ratio. The call admission control algorithm is used to regulate the admission of real-time or streaming traffic and the rate control algorithm to control the transmission rate of best effort traffic. As a result, the real-time or streaming traffic is supported with statistical QoS guarantees and the best effort traffic can fully utilize the residual channel capacity left by the real-time and streaming traffic. In addition, the rate control algorithm itself provides a solution that could be used above the media access mechanism to approach the maximal theoretical channel utilization. A comprehensive simulation study in ns-2 has verified the performance of our proposed CARC scheme, showing that the original 802.11 DCF protocol can statically support strict QoS requirements, such as those required by voice over IP or streaming video, and at the same time, achieve a high channel utilization. Hongqiang Zhai received the B.E. and M.E. degrees in electrical engineering from Tsinghua University, Beijing, China, in July 1999 and January 2002 respectively. He worked as a research intern in Bell Labs Research China from June 2001 to December 2001, and in Microsoft Research Asia from January 2002 to July 2002. Currently he is pursuing the PhD degree in the Department of Electrical and Computer Engineering, University of Florida. He is a student member of IEEE. Xiang Chen received the B.E. and M.E. degrees in electrical engineering from Shanghai Jiao Tong University, Shanghai, China, in 1997 and 2000, respectively, and the Ph.D. degree in electrical and computer engineering from the University of Florida, Gainesville, in 2005. He is currently a Senior Research Engineer at Motorola Labs, Arlington Heights, IL. His research interests include resource management, medium access control, and quality of service (QoS) in wireless networks. He is a Member of Tau Beta Pi and a student member of IEEE. Yuguang Fang received a Ph.D degree in Systems and Control Engineering from Case Western Reserve University in January 1994, and a Ph.D degree in Electrical Engineering from Boston University in May 1997. From June 1997 to July 1998, he was a Visiting Assistant Professor in Department of Electrical Engineering at the University of Texas at Dallas. From July 1998 to May 2000, he was an Assistant Professor in the Department of Electrical and Computer Engineering at New Jersey Institute of Technology. In May 2000, he joined the Department of Electrical and Computer Engineering at University of Florida where he got the early promotion with tenure in August 2003 and has been an Associate Professor since then. He has published over one hundred (100) papers in refereed professional journals and conferences. He received the National Science Foundation Faculty Early Career Award in 2001 and the Office of Naval Research Young Investigator Award in 2002. He is currently serving as an Editor for many journals including IEEE Transactions on Communications, IEEE Transactions on Wireless Communications, IEEE Transactions on Mobile Computing, and ACM Wireless Networks. He is also actively participating in conference organization such as the Program Vice-Chair for IEEE INFOCOM’2005, Program Co-Chair for the Global Internet and Next Generation Networks Symposium in IEEE Globecom’2004 and the Program Vice Chair for 2000 IEEE Wireless Communications and Networking Conference (WCNC’2000).  相似文献   
50.
作者应用地质统计学原理与方法,在山东簸箕李引黄灌区开展大尺度区域水土特性参数时空变异性的研究,描述农田排水、地下水、表层土壤中含盐量的空间与时间变化分布趋势和特征,分析其间存在的相关关系。结果表明,在一个完整的水文循环年内,研究区域的水土特性参数之间具有相近的空间变异分布状态和特点,但却表现出不同的时间变异分布趋势与特征。农田排水和表层土壤的含盐量随季节变化的分布状态在灌区上、下游相对稳定,在中游却变化明显;地下水的盐分浓度在整个灌区的分布状况没有呈现出明显的时间变异性。在春季至初夏时段内,农田排水中含盐量的增加似乎对地下水水质的影响较小,而对表层土壤积盐状况影响较大。研究成果为灌区制定合理的水资源利用与农田水土管理策略提供了理论依据。  相似文献   
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