域名系统的研究和改进

文中分析了目前ＤＮＳ的解析过程,并针对在解析“准同域”类的查询请求时所存在的不足,提出一种改进的ＡＤＶ－ＤＮＳ设计模型。它在当前ＤＮＳ的基础上,增加了ＡＤＶ广播信息,本级名字服务器将它知道的所有上级名字服务器的地址／域名对以及自身的地址／域名时一起定向它相邻的下级名字服务器广播下去,从而使“准同域”类的查询请求在一个相对小的域内得以解决,并且可以减轻国际信道的负担。     

氯化丁基再生胶生产摩托车丁基内胎工艺探讨

<正>2009,受国际金融风暴的影响,国内力车胎为之配套的自行车、摩托车产量和出口量都有较大幅度下降。年初,力车胎行业生产曾大幅度下降,1月份降幅达到34.87%。之后在国家四万亿投资刺激经济计划     

基于可回收能力的空间行波管高效率研究

效率是行波管设计的重要指标之一。对于空间行波管,效率的提高可以立即转化为经济效益。本文通过对注波互作用电路参数的优化设计,得到便于收集的“作用完了”的电子注。通常具有高电子效率的电子注,能量分散较大,不利于收集。通过设定电子效率大于25%这个限制条件,来保证了具有高可回收能力的电子注,同时具有较高的输出功率。在遗传算法中调用3 维MTSS,用来计算注波互作用后的输出能量和电子能谱图。并对一支Ku 波段的螺旋线行波管进行优化设计,从数值计算结果来看,可回收效率提高到了89%,且具有26.9%的电子效率。     

钢丝绳芯传输胶带的电磁无损检测方法与装置研究

基于电磁无损检测理论,分析了钢丝绳传输胶带（以下简称胶带）检测的本质,比较了几种电磁检测方法的优劣。然后确定了以漏磁检测为基础的胶带检测实验方法,同时设计了可以对胶带的无损检测进行多因素、多角度变量研究的实验检测装置,文章还具体介绍了装置的关键部件。最后对胶带的电磁检测发展前景进行了讨论。     

Dynamics of liquid dispersion in a rotating packed bed with single-layer wire mesh

The improvement of liquid dispersion by rotating wire mesh is one of the major causes for the mass transfer and micromixing intensification in rotating packed beds (RPBs). In particular, the initial dispersion region has been proved to have the greatest mass transfer and micromixing efficiency. However, the dispersion mechanism has not been revealed. This study investigated the dynamics of liquid dispersion in an RPB with single-layer wire mesh. The liquid dispersion behaviors were obtained by high-speed photography and numerical simulation. The liquid was found to stretch into ligaments and break into the main droplet and several satellite droplets. A new theoretical model was established to reveal the dispersion mechanism of these two stages. The stretching stage depends on the liquid initial momentum and acquired impulse, while the breakup stage was determined by the competition of ligaments recoil and pinch-off behaviors. The model was validated in good agreement with the experimental and simulation results of the dispersion characteristics.     

Normal State Properties and Upper Critical Magnetic Field in Three-dimensional Polycrystalline Niobium Films

Journal of Superconductivity and Novel Magnetism - Three-dimensional (3D) niobium (Nb) films have been deposited on quartz substrates by changing substrate temperature or film thickness. The...     

多功能外围芯片CH451原理及其应用

CH451是一个整合了数码管理显示驱动和键盘扫描控制以及μP监控的多功能外围芯片，并详细介绍了它的应用电路和单片机接口程序。     

增韧Al2O3结构陶瓷氧化反应裂纹愈合动力学研究(Ⅰ) 理论模型

氧化反应引起裂纹愈合是结构陶瓷提高强度的一个重要途径．针对目前研究中缺乏定量性这一不足之处，本文从热力学和动力学角度研究了氧化反应与裂纹愈合、强度提高之间的定量关系．建立了裂纹愈合模型，并进行了动力学研究，分析了高温加热时间、温度、裂纹尺寸对裂纹愈合及材料强度的影响．以期为裂纹愈合与强度恢复的定量或半定量的研究，实现人为精确控制裂纹愈合的程度提供一定的理论依据．     

结构陶瓷氧化反应裂纹愈合动力学研究(Ⅲ)模型验证与修正: Al2O3-SiC W陶瓷裂纹愈合动力学研究

Al2O3-SiCw材料通过在高温下发生氧化反应,生成物所引起的体积膨胀对裂纹处的填充迁移,使裂纹产生愈合现象．动力学分析表明, Al2O3-SiCw材料裂纹愈合速度为 ,强度恢复由下式计算 ,与 Al2O3-TiCp材料相比,增加了一个填充项F,从物理意义上分析,F是除裂纹面外对裂纹愈合有利的填充面积当量,就Al2O3-SiCw材料而言,F与裂纹面上晶须桥联及晶须露头面积及裂纹周边反应物能够对裂纹处进行填充的面积有关． 1200℃保温时F值约为9．94×10-8m2．     

Hot corrosion behavior and mechanism of FGH96 P/M superalloy in molten NaCl–Na_2SO_4 salts

Hot corrosion behavior of FGH96 powder metallurgy(P/M) superalloy in 25 % NaCl + 75 % Na_2SO_4 molten salts at 650, 700, and 750 ℃ was investigated in this paper. The methods of mass loss measurement, X-ray diffraction(XRD), scanning electron microscopy(SEM),and energy-dispersive spectroscopy(EDS) were used here.The experimental results show that hot corrosion kinetics follows a square power law at 650 ℃, while a linear one at 700 and 750 ℃. The corrosion layer is detected to be composed of Cr_2O_3, NiO, and Ni2S_3 at each temperature.The cross-sectional morphologies and corresponding elemental maps indicate that the corrosion layer is a stratified structure of oxide and sulfide. The results and analyses confirm that the hot corrosion mechanism of FGH96 P/M superalloy is a cooperate process of oxidation and sulfidation. Furthermore, the relatively higher concentrations of Cr, Co, and Ti provide better corrosion resistance to the attack of S and Cl~-.