变频器的常见故障分析

本文阐述了变频器的常见故障，并针对常见故障提出了解决措施。     

元刊杂剧特指式反问句

详细描写了元刊杂剧特指式反问句的结构及意义，指出反问句用疑问句的形式表达与语表形式相反的“言外之意”，其基本语用意义是评价，特指式的反问意义是在具体的语言环境中形成的。     

高坝风险分析的事件树法

新世纪一批高坝将要在我国开工建设,这对我国的水电能源及国民经济的发展有着不可估量的作用,而高坝建设中,安全性是需要首先保证的。目前对高坝的风险分析方法有主观概率法、客观概率法等。从系统工程的角度出发,采用事件树方法对高坝的风险进行了探索研究,并给出了算例以说明该方法的有效性和实用性。     

Novel blood-compatible waterborne polyurethane using chitosan as an extender

A series of novel block polymers of polyurethane (PU) and chitosan have been prepared in two steps. The first step is the preparation of PU prepolymer, obtained from polytetramethylene oxide glycol (PTMO, M_n = 1000), isophrone diisocyanate (IPDI), and 2,2′-dimethylol propionic acid (DMPA), followed by ionizing PU prepolymer with triethylamine (TEA). The second step involves PU chain-extended by water-soluble chitosan of low molecular weight (M_n = 5000) by self-emulsion polymerization method. The sizes of the latex particles, morphology, and copolymer architecture have been characterized by dynamic light scattering (DLS), general tensile test, infrared spectroscopy (IR), surface contact angle measurement, and transmission electron microscopy (TEM). Furthermore, it shows that the addition of chitosan remarkably increases anticoagulative property of PU elastomers confirmed by the recalcification time. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

首届文博会向创意产业迈进

创意产业为期5天的首届“中国北京国际文化创意产业博览会”12月10日至14日在北京国际展览中心举行，首届北京文博会包括展览展示，论坛峰会，推介交易，创意活动，文艺演出等五大系列的第十场活动，境外共有5个国际性组织和40多个国家和地区的400多位嘉宾应邀参会参展，[第一段]     

c-BN color change with bonded water added into the h-BN–Mg system

Cubic boron nitride (c-BN) crystals were synthesized in conditions of high temperature and high pressure (HTHP) when different kinds of bonded water were respectively added into the system of h-BN–Mg. All bonded water used in this work could reduce the temperature of growing c-BN compared to that in the system of h-BN–Mg. The c-BN color could change from black to yellow when certain amounts of bonded water, such as NiSO₄·6H₂O and CuSO₄·5H₂O, Mg(OH)_2, were added. However, c-BN color remained black no matter how much bonded water, such as NiCl₂·6H₂O, CuCl₂·2H₂O, and SnCl₂·2H₂O, was added. The bonded water can be classified into Chlorine-containing bonded water (Cl-BW) and Chlorine-free bonded water (ClF-BW) according to their different characters and effects on the synthesized c-BN color.     

基于免疫算法的Hopfield神经网络多用户检测器

提出的基于免疫算法的Hopfield神经网络多用户检测器，将扰乱的Hopfield神经网络多用户检测器的输出作为免疫算法的初始种群，利用了免疫算法的全局收敛的特点，从而克服了Hopfield易收敛到局部能量最小点的缺点。理论分析和仿真结果表明：该检测器具有良好的抗多址干扰和抗远近效应的能力。     

硬质合金与铁基复合材料热等静压扩散连接

以烧结结态硬质合金和粉末态铁基复合材料为连接对象，研究了两种材料的热等静压扩攻连接工艺，获得了直接连接接头和加镍作中间过渡层的间接连接接头，考察了接头的结合界面形貌，界面的元素扩散和界面结合强度。     

Optically tuned superconductive-dielectric resonators with whispering-gallery modes

An analytical method is presented for calculating the resonant frequency andQ-factor of a superconducting dielectric disk resonator operating in millimeter-wave regime with whispering-gallery mode. Resonant frequency shift due to the optical generation of quasi-particles in superconducting film is investigated as a function of photon flux. An optically tunable resonant frequency of about 500 MHz is estimated, and good agreement is found between numerical results and experimental ones.