浅析一种书写燃料电池负极反应式的新方法

提出了一种配平燃料电池负极反应式的新方法——零价法。即将燃料电池的燃料物质看成零价,根据负极发生失电子的氧化反应,计算出单位燃料参与负极反应时所失去的净电子数,确定燃料物质与电子数之比,再依据守恒原理快速、准确地书写燃料电池的负极反应式。     

三相ZVS逆变器磁链轨迹

ZVS（zero voltage switching） PWM（pulse width modulation） inverters have attracted much attention recently. The basic idea is to use ZVS circuit as the main circuit of inverter resonance at the beginning of every carrier period so that each power device can commutate when voltage of the main circuit＇s DC bus line is zero. To ensure the resonant circuit to operate properly, sawtooth with alternate slope （positive or negative） is used as carrier. But the time of zero voltage vectors with such PWM pattern is greatly different from traditional hard-switching PWM pattern. This paper discusses the locus of flux linkage under soft-switching PWM pattern by using space voltage vector. It is pointed out that, under the hard-switching PWM pattern, speed of flux linkage is adjusted by zero space voltage vector. When soft-switching PWM pattern is used, however, effective time of space voltage vector varies considerably, sometimes even without zero space voltage vector. Therefore non-zero space voltage vector has been used to make the speed of flux linkage locus equal to that of hard-switching PWM pattern. The cause of current distortion in soft-switching PWM inverters is also discussed. Based on the flux linkage locus circle, corresponding compensation methods are proposed. Experimental results show that the described method can effectively improve output current waveform of inverter.     

Bear根的几种新的刻划

本文引入了环R的近似平方为零的理想,近似T幂零理想,以及环R的弱m序列,次强幂零元的概念,并由此给出了环R的Bear根的几种新的刻划。     

基于天线选择对混合空时编码进行优化的研究

针对结合空时分组码（STBC）及分层空时码（V-BLAST）的混合空时编码结构，提出了一种新型的发送编码方案．该方案首先对发送天线以接收端反馈信息为基础进行分组．选取信道情况较差的天线进行分组编码．其余的作为分层码发射信号的天线：介绍了分层空时编码（V-BLAST）、分组空时编码（STBC）和混合空时编码，以及通过天线选择在混合空时编码中的应用。     

浅谈高校体育教学环境

任何工作的开展,都离不开环境条件,体育教学工作同样如此,它包括时间环境、地点环境、方法环境,只有科学充分地利用教学环境,对学生进行思想品德教育,才能切实提高教育教学质量。     

几类非线性常微分方程解稳定性的判据

本文讨论几类非线性微分系统零解的稳定性,分别根据非线性项的不同情况给出了相应的稳定性判据,最后用几个例子说明本文结果的有效性。     

零曲率芬斯拉空间的共形映射

探讨两个零曲率芬斯拉空间构成共形映射的条件.     

三国长坂究竟在何处?

数百年来,人们把三国时期著名的长坂之战的长坂定位当阳玉阳镇,并在那里造碑纪念,几十年前还为之修造了一座“长坂坡公园”,给人凭吊与缅怀。其实,经考证,大量史料说明,三国长坂不在今当阳而在今荆门的响岭岗、掇刀一带     

关于N(2,2,0)代数的弱幂零元的若干结果(英文)

引入了N(2,2,0)代数的弱幂元的概念,讨论了其弱幂元的若干性质.