Reliability analysis of a two-unit cold standby system with a replaceable repair facility

This paper considers a two-dissimilar-unit cold standby system where the repair facility is subject to failure and can be replaced by a new one after it fails. By using Markov renewal theory, we obtain some reliability quantities of the system and the repair facility, respectively.     

Deformation measurements using mutual information: principle and applications

The paper presents a new method applied to measure displacement fields using mutual information concept. Based on analysis of digital image sequences, we propose the formulation derived from the mutual information between subsets in the un-deformed and deformed image. The quantity of the mutual information between two subsets establishes a criterion of their mutual dependence based on the notion of information connection between them. We can obtain the integer pixel displacement for the corresponding subset. And the accurate displacement field is obtained by using sub-pixel technique. In the experiments, the method is validated and the resulting solution can show accuracy to 0.02 pixels. This method was also applied successfully to determine the displacement fields of laminated composites of AS4/PEEK[0/±45/90]_7s under uniaxial compression.     

Simultaneous Determination of Twelve Saponins in Radix et Rhizoma Notoginseng by Rapid Resolution LC-ESI-TOF-MS

Rapid resolution liquid chromatography coupled with electrospray ionization time-of-flight mass spectrometry was developed for simultaneous determination of twelve saponins in Radix et Rhizoma Notoginseng (RRN) with macranthoidine A as internal standard. All calibration curves showed good linear regression (r ² > 0.9935) within test range. The limits of detection of the twelve compounds were in the range of 1.53–5.08 ng mL⁻¹. This method was successfully applied to analyze the saponins in fifteen samples of RRN.

     

Synthesis,characterization, and properties of copolymer of acrylamide and complex pseudorotaxane monomer consisting of cucurbit[6]uril with butyl ammonium methacrylate

The novel copolymers of acrylamide (AM) with complex pseudorotaxane monomer (BAMACB) of butyl ammonium methacrylate (BAMA) and cucurbit[6]uril (CB[6]) were prepared via free‐radical polymerization in aqueous solution. The copolymers containing pseudorotaxane (PAM/BAMACB) were characterized by ¹H‐NMR, FTIR, elemental analysis, TGA, and DSC. The glass transition temperature (T_g) of the copolymer PAM/BAMACB are higher than that of the copolymer of acrylamide and butyl ammonium methacrylate (PAM/BAMA) because of the enhanced rigidity and the bulky steric hindrance of BAMACB side chain in PAM/BAMACB. The molecular weights of copolymer PAM/BAMACB were obtained via static light scattering. The hydrodynamic radii of coils or aggregates were investigated by dynamic light scattering. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5999–6008, 2008     

Solutions for the prescribing mean curvature equation

By variational methods, for a kind of Yamabe problem whose scalar curvature vanishes in the unit ball BN and on the boundary S^N-1 the mean curvature is prescribed, we construct multi-peak solutions whose maxima are located on the boundary as the parameter tends to 0^＋ under certain assumptions. We also obtain the asymptotic behaviors of the solutions.     

Preparation and properties of antiperovskite-type nitrides: InNNi3 and InNCo3

Two antiperovskite-type ternary nitrides of InNM₃ (M=Ni, Co) have been synthesized from In₂O₃ and Ni or Co powders under NH₃ atmosphere at 600 °C. InNCo₃ is a new ternary nitride whereas InNNi₃ was previously reported as InN_0.5Ni₃ with different nitrogen content. The lattice parameters refined by Rietveld method are 3.8445(1) Å for InNNi₃ and 3.8541(7) Å for InNCo₃, respectively. Both nitrides show metallic behaviors and below 70 K the T² temperature dependence of resistivity was observed indicative of a Fermi liquid behavior. The temperature dependence of the field-cooling (FC) and zero-field-cooling (ZFC) magnetization and time decay of thermoremanent magnetization indicate the spin-glass-like behavior in InNM₃ (M=Ni, Co). The freezing temperatures for this behavior, T_f, are about 300 K for InNNi₃ and 10 K for InNCo₃, respectively.     

DEAD-(cat)ZnBr2 an efficient system for the oxidation of alcohols to carbonyl compounds

The combination of diethyl azodicarboxylate (DEAD) and a catalytic amount of ZnBr₂ is an efficient system for the dehydrogenation of alcohols to the corresponding carbonyl compounds. The scope and limitations of this process have been studied.     

采用可运营的IP接入网构建宽带网络

首先介绍了IP接入网的定义，然后指出了传统以太网接入方案存在的问题，最后具体介绍了IP接入网的解决方案及实际应用例子。     

浙江电视发射台自动控制系统的实践和完善

由于全固态电视发射机所具有的诸多优点 ,目前正陆续被一些有经济实力的发射台所采用 ,同时老式的电子管发射机渐渐地淡出了电视发射市场 ,这也是电视发送设备发展的潮流和方向。我们台也一样 ,在 1997年购买了两套美国哈里斯的 10 k W米波、一套德国 R燉S公司的 10 k W分米波共三套全固态发射机。1998年 12月正式投入使用以来 ,不仅工作稳定 ,而且技术指标优良 ,并且就电视发射机的实时控制方面也做了一些工作。现将有关的情况作一简要的介绍。1购置发射机时的考虑和要求对于全固态电视发射机的考察 ,我们在 1995年就已着手进行。在了解…     

Control of the microstructure of polymer network and effects of the microstructures on light scattering properties of UV‐cured polymer‐dispersed liquid crystal films

Polymer‐dispersed liquid crystals (PDLC) films were prepared from ultraviolet (UV) irradiation‐induced polymerization of the photopolymerizable monomers in photopolymerizable monomers/nematic liquid crystal (LC) mixtures. The effects of the composition of the mixtures, the curing temperature, and the UV light intensity on the microstructure of the polymer network in the PDLC films were investigated. Furthermore, the effects of the microstructures on the light scattering properties of the PDLC films in the wavelength region of 300–2500 nm were studied experimentally and theoretically based on the combination of three kinds of classical light scattering theories: the Rayleigh‐Gans (RG) approach, the anomalous diffraction (AD) approach, and the geometrical optics (GO) approach. It was found that the sizes of LC domain in PDLC films increased with the increase of the LC content as well as the decrease of the UV curing intensity, while increased at first and then decreased with the increase of the curing temperature. Moreover, smaller LC domain sizes could exhibit strong scattering properties in a smaller VIS wavelength region and the transmittance in NIR region (especially in the wavelength range of 1300–2500 nm) obviously decreased with the increasing sizes of LC domain. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 2090–2099, 2008