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101.
新世纪的科技和岩土工程发展 总被引:4,自引:1,他引:4
从科技的发展谈论了人才的需求;以三峡工程、青藏铁路、西气东输、南水北调典型工程为例,论述了现代岩土工程与发展;并就21世纪岩土工程研究热点发表了自己的看法。 相似文献
102.
徐羹慧 《沙漠与绿洲气象(新疆气象)》2003,26(3):1-3,10
气象台预报位于天气预报服务第一线,加快发展气象台业务预报技术显得十分重要。本文着重分析省、地气象台预报技术发展的进展和现状,利用新一代业务技术体制专题研究报告和国外考察报告及近年国内发表的技术文献,作二次分析研究,评估技术发展现状,试图理清气象台预报技术今后发展的环境、发展前景的基本图像和某些规律,并就某些重要技术工作展开讨论。 相似文献
103.
目的 医学核磁共振与地面核磁共振找水是核磁共振技术应用的不同领域。本文通过对二者在方法原理、技术、应用等方面的对比研究,提出了地面核磁共振找水工作建议。 相似文献
104.
隧道GPS网对横向贯通误差的影响 总被引:4,自引:0,他引:4
本文在阐述隧道工程独立坐标系和隧道GPS网数据处理方法的基础上推导出GPS网对横向贯通误差影响的通用计算公式,分析了隧道GPS网基准数据位置对横向贯通误差的影响。 相似文献
105.
主要介绍在北京地区开展气球携带碘化银焰弹雨雪作业的作业技术,经济效益等问题。通过各种增雨雪技术比较,认敢球携带碘化银焰弹增雨雪作业在北方干旱地区的抗旱工作中或作为收音机增雨雪作业的补充手段具有应用价值 相似文献
106.
第14届世界无损检测大会工业CT的层析成像技术 总被引:2,自引:0,他引:2
介绍了新近14届世界无损检测大会有关情况,并对工业CT的发展动态进行了简要的分析。 相似文献
107.
A new numerical method to solve the system of equations describing two phase flow in a Hele-Shaw cell is presented. It combines
a mixed finite element method, the method of subtraction of the singularity and a front tracking grid in a single computational
strategy. This choice of discretization techniques is well motivated by the difficulties present in the system of equations
and the physics of the problem. The new method was tested against analytical solutions and also by solving the Saffman–Taylor
viscous fingering problem for finite and infinite mobility ratios. In both cases convergence under mesh refinement is achieved
for the fingers developed from an initial sinusoidal interface. Finger splitting is observed for low values of the surface
tension and high mobility ratio. Different explanations, based in our results, are provided for this phenomenon.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
108.
Recent attention given to the concept of vertical integration and disintegration of production processes has identified the existence of a continuum, with small, flexibly specialized producers at one end and large, mass production units at the other end. Firms along the continuum constantly strive for the optimum combination of economies of scale and scope. This paper attempts to identify the organizational characteristics of high technology firms in one industrial complex of the U.S. Manufacturing Belt. A principal components analysis is performed on a number of theoretically relevant variables for a sample of high technology establishments in Northeast Ohio. The results indicate that the region contains a variety of organizational forms ranging from isolated workshops to large, vertically integrated assembly plants. These findings conform to expectations derived from recent conceptualizations in the literature. Additional empirical research will further enhance understanding of the processes that shape the organization of production in territorial complexes. 相似文献
109.
Frédérick Delay Hélène Housset-Resche Gilles Porel Ghislain de Marsily 《Mathematical Geology》1996,28(1):45-71
A new method for solving the transport equation based on the management of a large numbe of particles in a discretized 2-D domain is presented. The method uses numerical variables to represent the number of particles in a given mesh and is more complex than the 1-D problem. The first part of the paper focuses on the specific management of particles in a 2-D problem. The method also would be valid for three dimensions as long as the medium can be modeled similar to a layered system. As the particles are no longer tracked individually, the algorithm is fast and does not depend on the number of particles present. The numerical tests show that the method is nearly numerical dispersion free and permits accurate calculations even for simulations of low-concentration transport. Because each mesh is considered as a closed system between two successive time steps, it is easy to add adsorption phenomenon without any problem of numerical stability. The model is tested under conditions that are extremely demanding for its operating mode and gives a good fit to analytical solutions. The conditions in which it can be used to best advantage are discussed. 相似文献
110.