The use of water-soluble phthalocyanines as textile dyes in nylon/elastane fabric: fastness and antibacterial effectiveness

This work reports on dyeing of nylon/elastane fabric with water-soluble phthalocyanines ( 1-4 ) bearing quinoline 5-sulfonic acid substituents on the peripheral or nonperipheral positions and determining the antibacterial efficiency of the phthalocyanine compounds and the dyed nylon/elastane fabrics. The light, washing, water, perspiration, and rubbing fastness properties of nylon/elastane fabrics dyed with phthalocyanines were also determined. The results showed that all dyed fabrics showed very good wet fastness values. The lightfastness value of the nylon/elastane fabric dyed with phthalocyanine dye ( 1 ) showed a much better value than the others. Also, the antibacterial efficiencies of the dyed nylon fabrics and the dye compounds were investigated against a gram-negative ( Escherichia coli ) and a grampositive ( Staphylococcus aureus ) bacteria by using disc diffusion method. The results showed that the dyed nylon/elastane fabrics and the compounds exhibited antibacterial activities against both bacteria.     

利用无桥式技术提供更高效率的功率因数修正器

国际整流器公司交流转直流应用部门的Ron Brown与Marco Soldano,利用周期控制技术(one-cycle control)来实现更高效率的无桥式功率因数修正器的设计. 最近,无桥式升压型功率因数修正器线路,获得了很多关注的焦点.借助移除传统转换器其输入级的桥式整流器,切换损失可以降低,而使设计者设计出更高的效率.尤有甚者,无桥式的方法可以避免因导通损,而降低效率,这种现象特别是出现在低的输入电压,其根本的原因是二极管整流器的顺向导通压降.最后,无桥式设计具有先天上更简单,需要更少器件的优点.     

SOME CENTRAL LIMIT THEOREMS FOR SUPER BROWNIAN MOTION

The author proves a central limit theorem for the critical super Brownian motion, which leads to a Gaussian random field. In the transient case the limitingfield is the same as that obtained by Dawson (1977). In the recurrent case it is aspatially uniform field. The author also give a central limit theorem for the weightedoccupation time of the super Brownian motion with underlying dimension numberd 3, completing the results of Iscoe (1986).     

独居石微晶玻璃中玻璃相含量的红外光谱定量测定

独居石微晶玻璃由偏磷酸盐玻璃和独居石两相组成。玻璃和独居石的红外吸收谱带彼此不相重叠,且1275和616cm~(-1)谱带的吸收强度随玻璃相的含量变化而变化。两谱带的对数吸光度比值与玻璃相含量(w％)的相关系数r=0.9975,其回归方程为y=48.356 25.93x。合成独居石的IR谱中952和616cm~(-1)谱带的吸光度比值也随不同的Ce_2O_3/La_2O_3比值规律变化。其r=0.9917,回归方程为y=0.2211exp(0.0221x)。高的相关性表明IR技术可在磷酸盐微晶玻璃物相定量分析中得到实际应用。     

空芯光纤输出能量分布及其应用的研究

空芯光纤纤芯内场强分布一直是研究热点，在某些限定条件下可通过光纤输出能量分布近似。提出了一种空芯传能光纤输出能量分布的简便测量方法，通过试验测量结果分析了输出能量分布在光纤模式纯度估算和光纤耦合状态检测两方面的应用，最后通过实验讨论了输出光束腰问题，对不同全内反射(ATR)空芯光纤所得结果进行了比较。     

手持应用上的CLASS D放大器开关良好的混合信号系统需要对转换器的详细规格进行深入了解

CLASS D放大器现在在大多数的音响应用上已经被强烈的认为是种可行的替代方案。理论上,CLASS D放大器具有100%效率、无失真、在音频上无噪音产生等特性,使得它们在手持应用、家庭剧院这些特别重视功率消耗的场合特别有吸引力。然而实际上,若没有妥善的设计,CLASS D放大器不一定会达到它们最大的效率;并且像其它的电路一样,会产生失真与噪音。因为它们的操作原理是如此的与传统线性放大器不同,工程师需要熟悉一整套新的电路设计技巧,来极佳化效能。虽然有些设计技巧,可以靠聪明的原件选择来增进,其它的则与CLASS D天生的架构有关。…     

采用低损耗IGBT为次级2.5kW逆变器应用提升开关性能

传统的lGBT(绝缘栅极型功率管)通常应用在要求高电压和高电流等级,以及相对缓慢的开关频率的场合.当开关频率低时,IGBT固有的低传导损耗源自IGBT中少数载流子工作产生的低VCE(on)(集电极-发射极饱和电压),其在价值上已经超过了它贫乏的开关性能,使获得高的整体操作效率成为可能.     

THE PREPARATION AND STABILITY OF COLLOIDAL METAL DISPERSIONS PREPARED BY A TWO-PHASE NON-AQUEOUS ROUTE

Stable suspensions of small metal Au, Ru, PI, Pd, Rh, Co and Nl particles dispersed in n-heptane and n-dodecane have been prepared using a novel two-phase system, Involving the formation of the particles In a methanolic phase and subsequent phase transfer of the panicles to the alkane medium. The dispersions consisted of small particles having diameters In the range of 8-30 nm (the gold sols were very polydlsperse having average diameters of ca.34 nm). The phase transfer of the particles and their subsequent colloid stability were effected by the presence of dissolved dispersant in the hydrocarbon phase (either Oloa 1200 or Hypermer LP 8). In the case of Oloa 1200, a widely-used polylsobutylene succinimide automotive engine dispersant, It Is proposed that the amlne groups adsorb strongly to the acidic surface o1 the particles, and the 70-carbon polyisobutylene chains extend Into the hydrocarbon medium sufficiently to maintain the separation of adjacent particles by steric and possibly also by electrical repulsion.