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1.
对基于网络的远程考试系统进行了分析,对系统功能和特点进行了描述,对系统体系结构和数据库结构进行了设计,给出了本系统开发和运行环境,对部分子模块的实现进行了描述。  相似文献   

2.
针对坪江电站工程的电气部分进行了较为祥细的设计研究,对主要的接线方案给出了比较方案,并进行了技术经济比较,电气设备部分进行了选型,对电气保护进行了系统设计。  相似文献   

3.
对开环数控进给系统进行圆弧插补时产生误差的原因进行了分析,针对圆弧插补误差建立了数学模型并进行了圆弧插补单位线性误差值的计算,通过在数控装置上对整圆进行切削实验,标定误差值,对模型计算值和实验值进行了检验.  相似文献   

4.
本论文对刀具调度系统进行了初步的概述,对系统进行了方案设计,建立了刀具数据库,并对系统的各功能模块进行了简述.  相似文献   

5.
本文在对ugs公司的PLM系统Teamcenter Engineering进行了分析介绍,对其客户端核心Portal Kernel进行了分析,并就在该系统中进行产品数据管理进行了研究,进行二次开发,研制了一个基于Teamcenter Engineering的产品数据管理的原型。  相似文献   

6.
周为  李宏伟 《科技促进发展》2010,(6):184-184,189
本文对工业循环冷却水系统的水质现状进行了分析,并介绍了其的腐蚀原理,并综述了工业循环冷却水系统的防腐措施以及其进展,并对这些方法进行了说明,着重对添加缓蚀剂的方法进行了讨论。最后对该系统的防腐技术发展进行了展望。  相似文献   

7.
对太行山地区铁矿进行了研究,分析了矽卡岩型铁矿的成因,并对矽卡岩型铁矿尾矿矿物组成及成分进行了分析,指出了此类尾矿的特殊性.还对其应用前景进行了简单的探讨,其中对尾矿还进行了几个方面的工业应用研究.  相似文献   

8.
应用有限元电磁场分析方法对发光二极管(LED)芯片的光学传播进行模拟.对光子晶体结构的外量子效率进行了计算.特别的是,对光源的处理上,使用了点光源球面波来进行分析并且考虑了光源的相干性.由于计算的复杂程度,对模型进行了简化处理.把光子晶体结构的实验数据与仿真结果进行了对比,验证了模型的正确性.  相似文献   

9.
“11.15”火灾的系统与风险分析   总被引:1,自引:1,他引:0  
针对上海11.15重特大火灾事故,对事故进行了系统分析,利用故障树对事故原因和风险进行了分解,对火灾的主要原因进行总结归类,对火灾进行了突变分析,探讨了本次火灾事故中凸显的一些特别的经验教训.  相似文献   

10.
杨腾 《太原科技》2014,(12):41-43
采用ANSYS/LS-DYNA进行了前处理建模,分析了聚能射流药型罩的材料属性,对网格进行了划分,加载了约束和初始条件定义,并对求解参数进行了设置,通过LS-DYNA输出K文件的生成和修改,对结果进行后处理,得出了聚能射流仿真的结果。  相似文献   

11.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

12.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

13.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

14.
Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with  相似文献   

15.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

16.
17.
The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.  相似文献   

18.
R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).  相似文献   

19.
The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.  相似文献   

20.
Advances in wireless technologies and positioning technologies and spread of wireless devices, an interest in LBS (Location Based Service) is arising. To provide location based service, tracking data should have been stored in moving object database management system (called MODBMS) with proper policies and managed efficiently. So the methods which acquire the location information at regular time intervals then, store and manage have been studied. In this paper, we suggest tracking data management techniques using topology that is corresponding to the moving path of moving object. In our techniques, we update the MODBMS when moving object arrived at a street intersection or a curved road which is represented as the node in topology and predict the location at past and future with attribute of topology and linear function. In this technique, location data that are corresponding to the node in topology are stored, thus reduce the number of update and amount of data. Also in case predicting the location,because topology are used as well as existing location information, accuracy for prediction is increased than applying linear function or spline function.  相似文献   

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