查询词典 nine point finite difference scheme

In this paper, the 3-D finite element relocating mesh method is used to calculate the temperature field and the thermal creep stress field of spillway dam and mid level outlet dam in certain roller compacted concrete gravity dam, sensitivity analysis have been down with different parameters, such as placing temperature, the location of cooling pipe, cooling temperature, time for water supply, ascended-layer of concrete, intermissive time and different placing time, and the commendatory construction scheme have been put forward in such analysis; according by the test result on the two scheme of concrete aggregate combination (basalt as coarse aggregate and limestone as fine aggregate, basalt as coarse aggregate and basalt as fine aggregate), simulation analysis on temperature field and thermal creep stress field of the commendatory construction scheme have been down, and analysis have also been down on temperature field and thermal stress field of the two different aggregate combination, the result indicates that the spillway dam and mid level outlet dam which adopted these two aggregate combination can both satisfy the require of design crack resistance in concrete, furthermore limestone as fine is better than basalt as fine aggregate; the effect of summer water storage and winter water storage on the temperature field and thermal stress field have been analyzed, comparing with winter water storage, in summer water storage scheme the maximum tensile stress at abnormal concrete in upstream fill is decreased by 0.1～0.3MPa and there are no evidence change of the maximum tensile stress at other parts, which indicate that summer water storage is avail for the crack resistance of upstream fill; according to the simulation calculating result and comparing temperature simulation calculating results and temperature controlling measures of some similarity projects both completed and construction, synthesis appraise have been carried to the design temperature controlling measures of dam, and the temperature controlling measures of this project have been brought forward, all these have great reference value on the design of temperature controlling measures and the optimization of the construction scheme.

本文采用三维有限元浮动网格法仿真计算程序，对某碾压混凝土重力坝的溢流坝段和中孔坝段分别进行了三维有限元温度场和温度徐变应力仿真计算分析，对浇筑温度、冷却水管的布置方式、冷却水温、通水时间、浇筑升程和间歇时间、不同开始浇筑日期等参数进行了敏感性分析，在此基础上提出了推荐的施工方案；根据两种骨料方案(玄武岩粗骨料+灰岩细骨料方案；玄武岩粗骨料+玄武岩细骨料方案)的混凝土性能试验研究成果，对推荐的施工方案进行了温度场和温度徐变应力仿真计算，并对比分析了两种不同骨料情况下的温度场和温度应力，结果表明溢流坝段及中孔坝段采用上述两种骨料均能满足混凝土的抗裂设计要求，且灰岩细骨料优于玄武岩细骨料；计算分析了夏季蓄水和冬季蓄水对坝体温度场和温度应力的影响，夏季蓄水方案与冬季蓄水方案相比，坝体上游变态混凝土区域最大拉应力小0.1～0.3MPa，其他部位最大拉应力无明显变化，夏季蓄水对坝体上游面混凝土的抗裂有利；根据仿真计算成果并通过比较国内一些已建和在建的类似工程的温度仿真计算成果及采取的温控措施，对大坝的设计温控措施进行了综合评价，并提出了该工程的温控措施，对温控设计和优化施工方案具有重要参考价值。

Equidistance point and difference theory in theory of function approximation are studied. Meanwhile, the relation among difference, difference quotient and derivate is revealed. By drawing Lagrange's and Cauchy's theorem of mean on difference and Taylor's formula into difference function, four theorems, such as Lagrange's theorem of mean on difference, are concluded in simple way. On the basis of these conclusions, the asymptotic property of middle point is studied, a series of new conclusions are drawn and the discussions on the asymptotic property of middle point in differential mid-value are summarized.

对函数逼近论中等距节点和差分理论进行了研究，揭示了差分、差商与导数之间的联系；将Lagrange中值定理、Cauchy中值定理、Taylor公式引入到差分函数中，简明地推导出Lagrange差分中值定理等4个定理，并在此基础上对"中间点"的渐近性进行了研究，得出了一系列"中间点"的渐近性的结果，概括了有关文献对微分中值公式的"中间点"的渐近性的讨论；给出的引理改进了函数逼近论的证明方法，精简了函数逼近论中的一些内容。

Equidistance point and difference theory in theory of function approximation are studied. Meanwhile, the relation among difference, difference quotient and derivate is revealed. By drawing Lagrange's and Cauchy's theorem of mean on difference and Taylor's formula into difference function, four theorems, such as Lagrange's theorem of mean on difference, are concluded in simple way. On the basis of these conclusions, the asymptotic property of middle point is studied, a series of new conclusions are drawn and the discussions on the asymptotic property of middle point in differential mid-value are summarized.

对函数逼近论中等距节点和差分理论进行了研究，揭示了差分、差商与导数之间的联系；将Lagrange中值定理、Cauchy中值定理、Taylor公式引入到差分函数中，简明地推导出Lagrange差分中值定理等4个定理，并在此基础上对&中间点&的渐近性进行了研究，得出了一系列&中间点&的渐近性的结果，概括了有关文献对微分中值公式的&中间点&的渐近性的讨论；给出的引理改进了函数逼近论的证明方法，精简了函数逼近论中的一些内容。

First, from the point of view of production and management, the importance for developing TTU is pointed out.the status in quo of technology,The direction of progress,The demand of practical and fundamentality in Distribution Automation are analyzed for Transformer Terminal Unit. The function of equipment and technical specification which meet demand of practical duty are indicated; Second, the scheme of synchronous sampling,quasi-synchronous sampling,non-integer cycle sampling,nonsynchronous sampling and algorithm are analyzed in detail. Then,the scheme of nonsynchronous sampling and multi-chunnel is ascertained. Moreover, the method of disposal sampling data for increasing precision which calculate the number of sampling per cycle dramatic by searching zero is introduced. The technique for analyzing data,stating data,storage data for Electrical Power Quality and control scheme for compensation capacitor are explained also. Finally, The scheme and structure of hardware,key circuitry using 80C196 singlechip,the scheme and ideology of software and flow chart of part software is introduced simply.

文中首先从电力生产、管理角度出发，指出了研制配变监测终端的重要意义，分析了配变监测终端的技术现状、发展趋势、现场需求以及在配网自动化中的基础地位，提出了满足实际运行要求的装置功能、技术要求；然后对目前常用的同步采样、准同步采样、非整周期采样、非同步采样的方案和算法进行了详细的分析、比较、筛选，确定了非同步采样和顺序采样的方案，并提出了一种寻找过零点从而动态计算每周采样点数的提高精度的采样数据处理方法，文中对装置中电能质量分析、统计、存储的方法以及补偿电容器的控制方案和投切原则也做了重点说明；最后，对应用80C196单片机系统研制的装置的硬件方案、结构以及关键电路和软件设计思路、方案、部分主要软件模块的流程图做了介绍。

The main contents of this course include: the construction, convergence, compatibility and stability of finite difference scheme of elliptic equation, parabolic equation and hyperbolic equation, the construction method and computation format of finite difference scheme of a system of partial differential equations.

本课程主要内容有：椭圆型方程的有限差分格式的构造，有限差分格式的收敛性，相容性及稳定性、抛物型方程的有限差分格式的构造，有限差分格式的收敛性，相容性及稳定性、双曲型方程的有限差分格式的构造，有限差分格式的收敛性，相容性及稳定性、偏微分方程组的有限差分格式的构造方法及有关的计算格式。

Cast :, Kevin Allison as Various( twenty-nine episodes, 1993-1995), Michael Ian Black as Various( twenty-nine episodes, 1993-1995), Robert Ben Garant as Various( twenty-nine episodes, 1993-1995), Todd Holoubek as Various( twenty-nine episodes, 1993-1995), Michael Patrick Jann as Various twenty-nine episodes,..

演员：（系列演员[11]），凯文艾利森各种（29集，1993-1995年），迈克尔伊恩布莱克各种（29集，1993-1995），罗伯特本格兰特各种（29集，1993-1995），托德各种（29集，1993-1995年），迈克尔帕特里克詹恩各种（29集，。。霍劳贝克。

Magnetotelluric field finite difference migration tomography Found on the researches of Zhdanov etc. in MT finite difference migration tomography, we analyze and summarize both fruits and limitation of foregone peoples' achievements. So more precise finite difference extrapolation equation can be deduced, and it can be easily applied into the migration tomography. New equation reserved the derivative terms of wave number both at vertical and horizontal direction, so that more exquisite geoelectric diversification can still be accommodated, that is the very requirement of practical data interpolation.

大地电磁有限差分偏移成像技术：在Zhdanov等人建立的有限差分偏移成像研究的基础上，总结分析了前人在 MT成像技术方面的研究成果和存在问题；推导更精确的有限差分波场延拓方程，采用改进的有限差分法进行大地电磁场偏移成像，差分延拓方程保留波数对水平方向和垂直方向的一阶导数项而提高求解精度，可适应电性纵横方向变化剧烈的地电构造，使成像分辨率得到增强。

The coordinate transformation and numerical integration was executed on the discretized tetrahedral elements based on which the 3-D MT vector-finite element method was implemented. A whole computation framework for 3-D vector-finite element method with unstructured mesh was given. Based on this some typical models were tested which has demonstrated that our algorithm could distinctively avoid problems caused by the fake solution and both the accuracy and efficiency were enhanced which made our algorithm has a bright future for further application.3. According to theory of Sobolev vector space and the discretization of Helmholtz space, the error estimate which was suitable for 3-D MT vector-finite element modeling was deduced by which the procedure of adaptive technique was guaranteed.4. Based on the fully unstructured tetrahedralization and optical strategy, the 3-D magnetotelluric h-adaptive vector-finite element method was presented through combining the error estimate. With this work, the accuracy and creditableness for 3-D MT complicatedly modeling was guaranteed.5. The 3-D magnetotelluric h-adaptive vector-finite element algorithm with unstructured mesh was implemented.

针对非结构化的四面体单元，采用坐标变换和数值积分方法，实现了MT三维矢量有限单元分析，建立起基于非结构化网格的三维MT矢量有限元计算流程，并对典型模型和国际标准电磁模型进行了数值模拟，结果对比和分析表明，基于非结构化网格的三维MT矢量有限元不仅消除了节点型有限元的伪解，而且具有很高的计算精度和速度，有广阔的应用前景。3、根据Sobolev函数的向量空间和Hemlholtz空间的分解，推导出基于残差的三维大地电磁矢量有限元后验误差估计公式，为三维大地电磁自适应矢量有限元数值模拟的实现奠定了基础。4、在完全非结构化四面体单元剖分及优化基础上，结合三维大地电磁矢量有限元后验误差估计公式，提出了基于非结构化网格的三维大地电磁h-型自适应矢量有限元计算策略，保证了对复杂大地电磁模型数值计算的精度和可靠性。5、实现了基于非结构化网格的三维大地电磁h-型自适应矢量有限元计算流程，对典型模型和国际标准电磁模型进行了数值模拟。

In this paper, the space-time finite element theory and its application technologies are studied and discussed. Furthermore the space-time finite element method is used to analyze the transient characteristics of electromagnetism equipments. The work is important to develop the numerical method for the transient electromagnetic field. The detailed work is as follow.In the basis theory of finite element method used in the transient engineering problem, the functional theory and the finite element theory are applied to studied the existence condition of a generalized variation principle, which is the basis of the space-time finite element method.

本文在完善时空有限元法的基础理论和应用技术并将该方法应用于解决电磁装置的瞬态过程分析等相关方面进行了深入的研究与探讨，该工作对于发展瞬变电磁场问题的数值计算方法具有重要的意义，为此进行了如下几方面的工作：在工程瞬变问题的有限元方法的基础理论方面，本文应用泛函理论和有限元理论，系统讨论了一般工程瞬变问题的变分定理的存在条件及对应的变分定理。

Firstly, the paper introduced the working principle and device of the two-pass grate-rotary kiln and had an analysis method of mechanics of the tyre. We have put forward the finite element analysis of the contact stress of the tyre-roller based on the whole construction mode of shell-kiln liner-large gear-tyre-roller of the rotary kiln and obtained the strength and distributing rule of the tyre's contact stress. The research shows that within one week the contact stress mainly lies in two leading peak value and catastrophe which appear at the contact zone of the tyre and supporting roller. Then we regarded the tyre's stress as the test of unknown plane stress of principal stress. Utilizing mature and modern testing technology, we raised the testing principle and scheme of tyre stress and then had a on-the-spot test of the stress. Comparing the analysis result of the test with the one calculated from the finite element analysis, it proofed the rationality of finite element analysis method of integral modeling and the correctness of the contact stress result of the tyre and roller. Finally, for two-pass of similar rotary kilns, using the ANSYS APDL re-development technology, carried on the re-development about the overall finite element analytic method of thecontact stress of tyre-roller.

首先，本文介绍了2档回转窑的工作原理和装置，对滚圈的力学行为进行了分析，提出了基于筒体-滚圈-托轮的回转窑整体建模的有限元分析法，来对滚圈-托轮的接触应力进行有限元分析与计算，得到了滚圈接触应力的大小和分布规律，并求得滚圈外中内圈节点的主应力；其次，把滚圈的受力看成是主应力未知的平面应力的测试，利用现代测试技术，提出了滚圈主应力测试的原理和方案，并对滚圈的主应力进行了现场测试，现场测试分析结果与有限元分析计算出的主应力相比较，证明了整体法建模的有限元分析方法的合理性和滚圈-托轮接触应力结果的正确性；最后，利用ANSYS的APDL的二次开发技术，针对2档同类回转窑，就滚圈-托轮接触应力的整体有限元分析法进行了二次开发。

So it was last week in Selma , alabama.

上星期在亚拉巴马州塞尔马市发生的事件也是这样一个转折点。

The group also spearheads various social programs in China.

该组织还带头参与中国的各种社会活动。