作为电催化剂的炭在电化学能转化中的应用

一、引言各种炭,如乙炔炭黑、石墨及活性炭被应用于许多电化学能转化体系。在Zn/MnO_2体系中,给阳极加入石墨以提高其电导率;在初级锂—卤氧化物电池中,阳极的主要成分是乙炔炭黑,它起催化剂和集电器双重作用;在燃料电池或活泼金属—空气电池中(如Zn—空气     

市场综述

CPU:市场保持平稳本月以来,CPU市场的总体走势比较平稳,AMD方面,除了极个别的型号价格有比较大的变化外,其他大部分都基本保持价格稳定,价格波动比较厉害的是三年盒装的XP2800+,这款基于BARTON核心的ATHLON XP,上个月价格还在1650元左右摆动,而在本月初就突然降到1350元,降幅之大实在令人难以置信,不过,由于同样是BARTON核心的三年盒装XP2600+现在才卖920元,因此就算XP2800+已经降到1350元的,价格依然还是明显     

信息荟萃

本刊 2 0 0 0年度编委会年会召开　　本刊讯　 2 0 0 0年 1 2月 2 7日 ,本刊 2 0 0 0年度编委会年会在长沙召开。中国工程院院士、国防科技大学计算机学院院长、《计算机工程与科学》杂志社社长卢锡城教授 ,国防科技大学计算机学院副院长、副社长兼编委会副主任王志英教授 ,在长的部分顾问和编委会委员以及编辑部全体工作人员出席了年会。会议由王志英副社长主持。会议听取了陈怀义主编代表编辑部所作的《计算机工程与科学》杂志编辑部 2 0 0 0年工作汇报。他说 ,今年是《计算机工程与科学》杂志变更为双月刊后试运行的第二年 ,是改为大 1 6…     

水电开发成为助力凉山发展的“引擎”

金沙江流经青、藏、滇、川、贵五省区,石鼓以上河段为上游,石鼓至攀枝花为中游,攀枝花至宜宾为下游。沿江流域生活着汉、藏、彝、纳西、白等民族。千百年来,各民族在此生息、繁衍、融合,创造了丰富、灿烂、迥异的民族文化。2002年,本报记者曾"春走金沙江",一方面为金沙江雄奇、瑰丽的自然风光和绚丽多姿的民族文化所折服,另一方面,却不得不感叹金沙江沿岸的干旱与贫瘠。金沙江区域虽然水能资源丰富,矿产资源富集,但山高路陡,江势惊险,交通闭塞,信息不畅。千百年来,一江春     

The Remote Product Check and Acceptance Technology Based on Web

1 Introduction The remote product check and acceptanceis ani mportant part of the e-purchase ,andthelast essential linkto a successfully e-purchase .By tri mming and opti mizing the traditional purchase process and the automation ofrepetitive work,the e-purchase systembased on Internet technology greatly raises the efficiency of bothsides ofthe business ,reduces the cost and the cycle of order form disposal as well as the items on stock of both sideswhich eventuallyleads tothe falling of the p…     

Flume Experiment on Stream Blockage by the Debris Flow From Tributary

Stream blockage by the debris flow from tributary valleys is a common phenomenon in mountainous area,which takes place when large quantities of sediment transported by debris flow reaches a river channel causing its complete or partial blockage.The dam formed by debris flow may causes upstream and downstream flooding,and presents great threat to people and property.Because of the catastrophic influence on people and property,debris-flow dam has attracted many attentions from the researchers and local administration.But,lit- tle attention has been given to the quantitative interrelationships of the potential influential factors.In this pa- per,the interrelationships of important influential factors caused the stream blockage by debris flow were ana- lyzed through flume experiment,and a model to predict the blockage was presented.     

The effect of pitch and collimation on radiation dose in spiral CT

1 Introduction Spiral computed tomography (CT) was intro- duced in clinical practice in 1980s. Its distinctive characteristic is continuous data acquisition and con- tinuous tube rotation with high speed while simulta- neously translating the patient through the gantry.[1] Owing to these functions the spiral CT possesses the ability to scan an entire organ volume within a single breathhold. Thus, the anatomical section is contiguous and therefore the reliable demonstration of small le- sions…     

行走在山野——MAGGEAR(麦格尔)TAD快速背包

优秀设计的传承与提升MAGGEAR(麦格尔)一贯信奉质量优先的原则,在针对休闲、户外、运动、军警装备的相关市场上,对于特殊用途的装备,在质量和创意要求上更为苛刻。每一件贴有MAGGEAR商标的户外装备都是为了各行精英的需要而特别设计的,每一处细节所包含的特点和用途都是为了避免产品实际使用中存在的不适和瑕疵,在原材料及周边辅料的选用和制造生产工艺上MAGGEAR也要求精益求精。     

A Stability Theory in Nonlinear Programming

1　ＩｎｔｒｏｄｕｃｔｉｏｎＡｃｏｎｓｔｒａｉｎｅｄｎｏｎｌｉｎｅａｒ ｐｒｏｇｒａｍｍｉｎｇｃａｎｂｅｔｒａｎｓｆｏｒｍｅｄａｎｄｓｏｌｖｅｄｂｙＯｒｄｉｎａｒｙＤｉｆｆｅｒｅｎｔｉａｌＥ ｑｕａｔｉｏｎｓ (ＯＤＥ) [4～5] [8～ 1 2 ] .Ｔｈｉｓｐａｐｅｒｕｓｅｓａｓｔａ ｂｉｌｉｔｙｔｈｅｏｒｙｏｆＯＤＥｓｙｓｔｅｍｓｔｏａｎａｌｙｓｅｔｈｅａｓｙｍｐ ｔｏｔｉｃｐｒｏｐｅｒｔｉｅｓｏｆｔｈｅｄｉｆｆｅｒｅｎｔｉａｌｅｑｕａｔｉｏｎｓｗｈｉｃｈａｒｅｄｅｒｉｖｅｄｆｒｏｍａｇｉｖｅｎｃｏｎｓｔｒａｉ…