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排序方式: 共有843条查询结果,搜索用时 15 毫秒
1.
日本韩国的水环境治理 总被引:3,自引:0,他引:3
北京市水利局水环境治理考察团 《北京水务》2003,(4):30-32
2002年底,北京市水利局组团赴日韩考察。考察主要目的是通过与同行技术交流及参观日韩河道、湖泊环保治理工程实例,学习借鉴发达国家在水资源管理和水环境治理中的先进经验,特别是生物生态技术在水污染治理中的应用,提高北京地区水库、河湖水资源管理和水环境治理水平。考察团走访了许多工程管理和研究机构,实地参观了不少工程项目。我们感到此次考察确有许多东西值得借鉴,对我们找出差距、更新观念、调整思路大有裨益。 相似文献
2.
Ph. D. Candidate:Chen Xue-fengState Key Laboratory of Offshore Coastal Engineering Dalian University of Technology Dalian China e-mail: cxfeng @ student dlut. edu.cn 《水动力学研究与进展(B辑)》2003,15(6)
The reflection coefficient of perforated caissons and the total horizontal forces acting on them were experimentally and numerically analyzed and discussed when wave propagates normally. To consider the viscosity effect of fluid and nonlinear action of waves on structures, the VOF (Volume Of Fluid) method combined with the k-ε turbulence model was used to simulate the interaction between waves and structures. Governing equations were solved with the finite difference method. Through 2D experimental study in the wave flume, the empirical relationship between the reflection coefficient of perforated caissons and the main affecting factors were obtained from the experimental data using the least square method. Also the correlation between the ratio of the total horizontal force acting on perforated caisson and the force acting on solid caisson and the main affecting factors were regressed from the experimental data. 相似文献
3.
On April th over participants among them business leaders IT engineers the enterprise representatives some standardization experts scholars from all over the world gathered in Beijing to attend the International Seminar on "WTO: Intellectual Property Right Issues In Standardization"…… 《中国标准化(英文版)》2007,(3):36-37
On April 17th 2007, over 200participants, among them business leaders, IT engineers, the enterprise representatives and some standardization experts and scholars from all over the world gathered in Beijing to attend the International Seminar on "WTO: Intellectual Property Right Issues In Standardization" 相似文献
4.
本刊讯:年香港公开模型大赛年月日至日在上环文娱中心举办.香港公开模型大赛始于年 至今已举办届.此项赛事是香港地区颇具规模的模型比赛 其影响力已辐射至内地 不时有内地模友赴港参赛并取得佳绩.…… 《模型世界》2007,(2):46-47
本刊讯:2006年香港公开模型大赛2006年12月2日至3日在上环文娱中心举办.香港公开模型大赛始于1998年,至今已举办10届.此项赛事是香港地区颇具规模的模型比赛,其影响力已辐射至内地,不时有内地模友赴港参赛并取得佳绩. 相似文献
5.
北京实现水资源可持续利用的对策 总被引:3,自引:0,他引:3
北京市城市节约用水办公室 《节能与环保》2002,(3):25-27
北京市多年平均可利用水资源总量41.33亿立方米,其中:地表水约15亿立方米,地下水26.33亿立方米.人均占有水资源量约400立方米(如包含流动人口在内,不足300立方米),只有全国的1/8,世界的1/30. 相似文献
6.
Chen Bao-ming Zhang Li-qiangDepartment of Air-conditioning Refrigeration Engineering Shandong Institute of Architecture andEngineering Jinan China e-mail:chenbm @ sdai.edu.cnWang Bu-xuanDepartment of Thermal Engineering Tsinghua University Beijing China 《水动力学研究与进展(B辑)》2003,15(6)
The influences of Soret effect and Dufour effect on the natural convection and heat and mass transfer for a porous enclosure were investigated by means of the penalty finite element method. Numerical results indicate that the Soret and Dufour effects have significant influences on heat and mass transfer in the presence of large temperature gradient and concentration gradient. 相似文献
7.
. Introduction Lost Foam Casting has been introduced into China for two decades it is getting more popularity in foundry industry.In China there are two associations responsible for the LFC industry academic exchanges: Chinese Lost Foam Casting Society 《中国铸造》2007,4(3):240-242
1. Introduction
Lost Foam Casting has been introduced into China for two decades, and it is getting more popularity in foundry industry.In China there are two associations responsible for the LFC industry and academic exchanges: Chinese Lost Foam Casting Society (CLFCS) and Chinese Association of Full Mold Casting. 相似文献
8.
1.~nonNUInericalmodellingbythefiniteelement(FE)methodhasbecomeaneffectiveandeconomyicmeansforsimulatingmetalfoeingprocesses.However,accuratemodellingdemandsthecorrectdefinitionandinputsofthedataforthethermalandphysicalpIDPertiesoftheworkpieceandtoolmaterials,theboUndaryconditionsattheworkpiece--toolinterfaceandinotherareas,inadditiontoappropriatemeshgenerationandnumericalsolutions.Althoughmostofthematerialdataareavailable,thedataforinterfacialheattransferandfrictionconditions,Whichhavesubst… 相似文献
9.
JIN Nengyun Shanghai Jiaotong University Jin Nengyun Department of Materials Science Shanghai Jiaotong University Shanghai China.Present address:Max-Planck-Institut für Metallforschung Institut für Physik Stuttgart FRG 《金属学报(英文版)》1989,2(2):93-99
A dislocation interaction model has been proposed for cyclic deformation of fcc crystals.Ac-cording to this model,cyclic stress-strain responses and saturation dislocation structures of acrystal are associated with the modes and intensities of dislocation interactions between slipsystems active in the crystal; and,hence,may be predicted by the location of its tensile axis inthe crystallographic triangle.This model has successfully explained the different behaviours ofdouble-slip crystals and multi-slip behaviours of some crystals with orientations usually con-sidered as single-slip ones. 相似文献
10.
HUANG Zheng Institute of Physics Academia Sinica Beijing ChinaYAO Mei Harbin Institute of Technology Harbin China Correspondent:HUANG Zheng Post-doctorial Assistant Institute of Physics Academia Sinica Beijing China 《金属学报(英文版)》1990,3(4):282-286
In the light of analysis of the features of cleavage fractographs of low carbon steel,the stresscriterion for cleavage crack propagation across ferrite grain boundary was established on thesupposition that resistance to the propagation results from an arbitrary mutual orientation ofthe cleavage plans in the neighbouring grains.On the basis of concept of statistical distribu-tion of cleavage plane in space,the probabilistic characteristic of cleavage process was ex-pounded,and the fracture stress of the cracked specimen over temperature range in whichfracture is initiated by cleavage mechanism was calculated by means of finite element analysisprogram and the calculated result was found to be in agreement with that measured. 相似文献