积极准备小型燃气热电联产系统应用

小型燃气热电联产具有发电效率高、能源能充分利用、良好的环保、投资成本低、建设时间短及运行简单等优点,可作为今后发展热电联产的首选。根据用户对热力产品的需求不同,联产系统可以有不同的组合形式。但在推广燃气热电联产时必须要有必要的技术准备以及相应的政策。     

依靠科技促进发展加快发展诚邀合作

上海于2003年获得园林城市称号.新一轮的城市绿化将按照建设现代化国际大都市的目标,以2010年上海承办世博会为契机,创造良好的生态环境,实现"城市,让生活更美好"的办会主题,为此,上海绿化管理局诚邀国内外专家参与上海的新一轮绿化科研工作.     

城市规划的先导作用--青浦的探索

文章讨论城市规划对城市发展建设的影响，从政府与市场的关系开始讨论，一直谈到规划的作用与政府角色，以上海市青浦区的实践为例，论述城市开发操作过程中的政府角色问题，得出政府与市场合作的创新理论与三种模式。     

稳步发展的新疆建材工业

一发展中显现出的几个特点1、基数小,底子薄,高速度发展但绝对量仍不大新疆和平解放后,新疆建材工业开始艰难起步,改革开放以来,建材工业取得了快速的发展,自1979年以来工业总产值和主要产品水泥的产量,年均增幅都在10%以上。但由于新疆基础薄弱,虽经多年高速发展,各项经济指标     

宝山:规划建设中的现代化滨江新区

1区域性质、规模和发展目标1.1区域性质上海北翼连接长江三角洲沿江城市发展带上的重要门户;世界级精品钢制造以及物流等相关产业集聚辐射区;上海国际航运中心的重要组成部分;生态、生活、     

Optimization and Mechanical Accuracy Reliability of a New Type of Forging Manipulator

Researches on forging manipulator have enormous influence on the development of the forging industry and national economy.Clamp device and lifting mechanism are the core parts of forging manipulator,and have been studied for longer time.However,the optimization and mechanical accuracy reliability of them are less analyzed.Based on General Function(G_F)set and parallel mechanism theory,proper configuration of 10t forging manipulator is selected firstly.A new type of forging manipulator driven by cylinders is proposed.After solved mechanical analysis of manipulator’s core mechanisms,expressions of force of cylinders are carried out.In order to achieve smaller force afforded by cylinders and better mechanical characteristics,some particular sizes of core mechanisms are optimized intuitively through the combined use of the genetic algorithms(GA)and GUI interface in MATLAB.Comparing with the original mechanisms,optimized clamp saves at least 8 percent efforts and optimized lifting mechanism 20 percent under maximum working condition.Finally,considering the existed manufacture error of components,mechanical accuracy reliability of optimized clamp,lifting mechanism and whole manipulator are demonstrated respectively based on fuzzy reliability theory.Obtained results show that the accuracy reliability of optimized clamp is bigger than 0.991 and that of optimized lifting mechanism is 0.995.To the whole manipulator under maximum working condition,that value exceeds 0.986 4,which means that optimized manipulator has high motion accuracy and is reliable.A new intuitive method is created to optimize forging manipulator sizes efficiently and more practical theory is utilized to analyze mechanical accuracy reliability of forging manipulator precisely.     

Exploring the deep biosphere

Over the past two decades, scientific drilling into sediments and rocks in the ocean and the continent has revealed the presence of physiologically and phylogenetically complex microbial life in the deep subsurface. Microorganisms, most of which have no cultured or known relatives in the surface biosphere, have been discovered in sediments and rock at depth as deep as 1 km below the seafloor and more than 3 km deep in the continent. The deep biosphere probably represents the most voluminous part of the glob...     

Two types of changes in apparent resistivity in earthquake prediction

Two types of changes in apparent resistivity (AR) have been linked to earthquake occurrences. This paper studies the changes and their causes, in detail with the ultimate purpose of developing and assessing a method of earthquake (EQ) prediction. The AR changes of the first type (CFT) are considered to be precursors related to earthquakes (EQs); these appear mostly in the medium-term period before EQs and in the short-term period preceding EQs. The changes of the second type (CST) are characterized by a tur...     

Stress arch bunch and its formation mechanism in blocky stratified rock masses

Stress arch is a common phenomenon occurring in continuous materials and has also been proved to have great influences on the self-stabilization of soils or rock masses after excavation.In this paper,based on UDEC simulation,stress redistribution after excavation is investigated for a kind of special discontinuous material,i.e.blocky stratified rock mass.A layered stress arch system is observed with each stress arch lying over another.This special phenomenon is defined herein as "stress arch bunch".Effects of dip angle of bedding plane,lateral pressure and joint offset on this stress arch bunch are studied.Its formation mechanism is also discussed based on voussoir beam theory.     

Effect of Solidifcation Rate on Grain Structure Evolution During Directional Solidifcation of a Ni-based Superalloy

The effect of solidification rate on grain structure evolution during directional solidification(DS) of a Ni-based superalloy was explored.It was found that a high solidification rate led to sharper <001> texture and smaller grain size in the DS samples.One of the most important findings in this work was that such result was not in accordance with the general concept,and the sharper <001> texture was accompanied by the larger grain size.To explain the contradiction,the modeling samples with five grains were produced and the effect of solidification rate on the evolution of grain texture was illustrated based on the modeling samples.