IR2110的功能及其在高频感应加热电源中的应用

对功率MOSFET的几种基本驱动电路与由IR2110构成的驱动电路进行了分析比较,详尽地分析和研究了IR2110的工作原理、功能及在高频感应加热电源中的应用技术。还通过实验结果说明了IR2110在高频感应加热电源中用作电力半导体开关器件功率MOSFET的驱动器,既可以满足其驱动要求,又极大筒化硬件,提高工作可靠性并弥补其它驱动电路的不足,具有良好的应用前景。     

Sterilization of mycete attached on the unearthed silk fabrics by an atmospheric pressure plasma jet

The sterilization of the simulated unearthed silk fabrics using an atmospheric pressure plasma jet(APPJ) system employing Ar/O_2 or He/O_2 plasma to inactivate the mycete attached on the silk fabrics is reported. The effects of the APPJ characteristics(particularly the gas type and discharge power) on the fabric strength, physical-chemical structures,and sterilizing efficiency were investigated. Experimental results showed that the Ar/O_2 APPJ plasma can inactivate the mycete completely within 4.0 min under a discharge power of 50.0 W. Such an APPJ treatment had negligible impact on the mechanical strength of the fabric and the surface chemical characteristics. Moreover, the Ar ions, O and OH radicals were shown to play important roles on the sterilization of the mycete attached on the unearthed silk fabrics.     

多功能高效灭虫器的设计与制作

基于对＂四害＂生活习性等的深入研究,研制出＂多功能高效灭虫器＂的实物模型。此款模型能够更有效、简单的解决＂四害＂。本文详细的介绍了此款灭虫器的设计、制作及使用方法。     

直接进样-冷原子吸收分光光度法测定大气颗粒物中汞的含量

<正>大气中汞的来源主要有自然源和人为源,自然源包括土壤、水体、植被、森林火灾、火山爆发等,人为源包括化石燃料燃烧、金属冶炼、水泥制造等^[1-2]。据统计,全球每年向大气中排放汞的总量为5 000 t, 其中4 000 t来自人为排放。大气中的汞可以通过皮肤和呼吸进入人体,并且对神经系统造成危害^[3]。大气中的汞按照物理化学特性分类,一般可被分为气态元素汞、活性气态汞和颗粒态汞3种形态。     

强次指数分布族S*(γ)的μ积分尾分布的卷积等价性

在Klüppelberg提出强次指数分布族并研究其积分尾分布的次指数性的基础上,推广Foss等关于强次指数分布族S*的μ积分尾分布的次指数性结果,得到S*(γ)的μ积分尾分布的卷积等价性.     

Effect of pulsed bias on the properties of ZrN/TiZrN films deposited by a cathodic vacuum arc

ZrN/TiZrN multilayers are deposited by using the cathodic vacuum arc method with different substrate bias(from 0 to 800 V),using Ti and Zr plasma flows in residual N 2 atmosphere,combined with ion bombardment of sample surfaces.The effect of pulsed bias on the structure and properties of films is investigated.Microstructure of the coating is analyzed by X-ray diffraction(XRD),and scanning electron microscopy(SEM).In addition,nanohardness,Young’s modulus,and scratch tests are performed.The experimental results show that the films exhibit a nanoscale multilayer structure consisting of TiZrN and ZrN phases.Solid solutions are formed for component TiZrN films.The dominant preferred orientation of TiZrN films is(111) and(220).At a pulsed bias of 200 V,the nanohardness and the adhesion strength of the ZrN/TiZrN multilayer reach a maximum of 38 GPa,and 78 N,respectively.The ZrN/TiZrN multilayer demonstrates an enhanced nanohardness compared with binary TiN and ZrN films deposited under equivalent conditions.     

Lowering plasma frequency by enhancing the effective mass of electrons： A route to deep sub-wavelength metamaterials

Deep sub-wavelength metamaterials are the key to the further development of practical metamaterials with small volumes and broadband properties. We propose to reduce the electrical sizes of metamaterials down to more sub-wavelength scales by lowering the plasma frequencies of metallic wires. The theoretical model is firstly established by analyzing the plasma frequency of continuous thin wires. By introducing more inductance elements, the effective electron mass can be enhanced drastically, leading to significantly lowered plasma frequencies. Based on this theory, we demonstrate that both the electric and the magnetic plasma frequencies of metamaterials can be lowered significantly and thus the electrical sizes of metamaterials can be reduced to more sub-wavelength scales. This provides an efficient route to deep sub-wavelength metamaterials and will give rigorous impetus for the further development of practical metamaterials.     

卷积等价分布簇的推广及其分布卷积的封闭性

给出卷积等价分布簇S（γ）的一种扩张,并研究它们的性质,发现新簇也具有卷积的封闭性等性质。     

土工布对砂质土渗透特性影响规律的试验研究

设计了由马氏瓶和渗透仪组成的常水头渗透试验系统,展开了不设置土工布与设置土工布的对照试验,分别研究了土工布放置位置和层数对土体渗透性能的影响规律;土工布上部荷载对土工布自身渗透系数的影响．试验结果表明:土工布可以有效减小土体的渗透系数,增大其临界渗透破坏水头高度,从而提升土体的渗透稳定性．但土工布上部荷载的增加,会导致土工布自身渗透系数的变大．通过对试验数据的处理,发现渗透系数随着土工布位置的增高与土工布层数的增多而减小,临界渗透破坏水头高度随着土工布层数的增多而增大;在设置单层土工布的情况下,土工布放置于土体中间位置处时,临界渗透破坏水头高度达到最大,土体的渗流稳定性最好．使用本文所推导的公式,可以较好地计算土体内土工布设置的埋深与土体渗透系数的对应关系．