Inventory Model with Supply Disruption Risk and Service Level Constraint

We. develop a newsvender model with service level constraint for one- product, and multi-supplier system, where the supplies are susceptible to disruption risks. We prove the convexity of the programming problem,and provide the neces- sary and sufficient conditions for the optimal order quantities. Through analysis or numerical experiments we observe the effects of the disrupt risk and the service level constraint on the optimal policy. We propose some managerial insights in managing the multi-source supply chain with disruption risks.     

全球变暖背景下温室效应的光谱能量分布分析

利用一维辐射传递方程及LBLRTM逐线积分模式建立计算模型,对工业革命前与目前大气构成情况下温室效应的能量分布及其光谱吸收机理进行分析,在保持温室气体浓度为当前水平的基础上,研究温室效应能量分布与地表温度之间的相互耦合机理.结果表明:工业革命前地球的温暖环境主要来自于大气温室气体的(100~370)cm^-1、(640~710)cm^-1以及(1370~2000)cm^-1三个强吸收带对于地球长波辐射的吸收,而地球当前的变暖则源自于大气的(370~640)cm^-1和(710~1370)cm^-1两个弱吸收带的作用,其对工业革命以来所额外增加的温室效应贡献分别达到了25%和55%;地表温度升高,温室效应在全波段范围内也会随之增强,但不同谱带处的温室效应贡献以地球平均温度所对应的辐射峰值波数为界线,峰值波数右侧的温室效应贡献将会增加,在其左侧的贡献比例则会减小.     

The Periodic Wave Solutions for Two Nonlinear Evolution Equations

By using the F-expansion method proposed recently, the periodic wave solutions expressed by Jacobi elliptic functions for two nonlinear evolution equations are derived. In the limit cases, the solitary wave solutions and the other type of traveling wave solutions for the system are obtained.     

锂离子电池正极材料Li[Li_(0.167)Mn_(0.583)Ni_(0.25)]O_2的合成与性能研究

应用低热固相法制备镍锰复合正极材料Li[Li0.167Mn0.583Ni0.25]O2.XRD、FESEM和恒电流充放电测试表明,该材料结晶良好,可标定为α-NaFeO2型结构(空间群R3-m),颗粒粒径约为60~100 nm,粒度均匀细小.在2.5~4.4 V之间以0.5 C(100 mA/g)做充放电循环时,可逆比容量在120 mAh/g以上,循环性能非常稳定.如将截止电压升高到4.6 V,则比容量大大提高,最高可达234 mAh/g.上述充放电测试都出现了比容量随循环次数上升的现象.主要原因可归结为材料中Mn(Ⅳ)向Mn(Ⅲ)的转变,但在不同的电压范围内导致该转变的起因并不相同.     

Syntheses, Structures and Luminescent Properties of Two Zinc Complexes Containing N-P-Acetamidobenzenesulfonyl-glycine Acid Ligand

Using N-P-acetamidobenzenesulfonyl-glycine acid （abbreviated as abglyH2） as a ligand, two zinc（II） complexes [Zn（abglyH）2（bipy）2（H2O）2], （1） and {[Znz（abgly）2（bipy）2（H2O）2]. 2（H2O）}n （2） （bipy = 4,4＇-bipyridine） have been synthesized under mild conditions and characterized by IR, elemental analysis and X-ray diffraction analysis. Complex 1 is a monomeric compound, which is further assembled by intermolecular hydrogen bonds and π-π interactions into a 3-D supramolecular network. Complex 2 adopts a one-dimensional double chain structure and is further linked by hydrogen bonds to form a 2-D structure. Fluorescent analysis shows that complex 1 has an emissive maximum at 337 nm and complex 2 exhibits an emissive maximum at 339 nm in the solution state at room temperature.     

Determination of thermodynamic properties of aqueous mixtures of RbCl and Rb2SO4 by the EMF method at T=298.15 K

The thermodynamic properties, including activity coefficients, osmotic coefficients and excess Gibbs free energy for RbCl and Rb₂SO₄ aqueous mixtures at T=298.15 K and in 0.01 mol · kg⁻¹ to 5 mol · kg⁻¹ ionic strength, were determined by emf measurements. The Rb–ISE and Ag–AgCl electrodes used in this work were prepared in our laboratory and had a reasonably good Nernst response. The experimental data were fitted by using the Harned rule and Pitzer model. The Harned coefficients and the Pitzer binary and ternary interaction parameters for the system have been evaluated. The experimental results obey the Harned rule. The Pitzer model can be used to describe this aqueous system satisfactorily.     

A study on waviness induced vibration of ball bearings based on signal coherence theory

This paper focuses on the effects of waviness on vibration of ball bearings. An experimental analysis method is developed by adopting signal coherence theory of multiple-inputs/single-output (MISO) system. The inputs are waviness excitations of the inner and outer races, and the output is vibration response of the outer ring. Waviness excitation signals are first derived from the manufacturing deviations, and found to be strongly coherent in low frequency range. Virtual input signals are then introduced by the method of orthogonalization. In both cases of vibration acceleration and speed responses, the cumulated virtual input–output coherence function verifies that the first peak region of vibration spectrum is mainly induced by the waviness excitations. In order to distinguish the contributions of the inner and outer races, coherence functions of the virtual inputs with real inputs are calculated, and the results indicate that the outer race waviness contributes more to vibration than the inner race waviness does in the example. Further, a multi-body dynamic model is constructed and employed to frequency response analyses. It is discovered that the waviness induced spectral peak frequency is close to the natural frequency of bearing.     

Liquid–vapour equilibria of the methyl esters of alkanoic acids: vapour pressures as a function of temperature and standard thermodynamic function changes

The vapour pressures as a function of temperature of the methyl esters of alkanoic acids from butanoic to eicosanoic acid, have been measured using two different techniques: the static diaphragm and spinning rotor manometry and the combined torsion mass-loss effusion. Combined with data available from literature, the new data have been processed using the thermodynamic regression equation proposed by Clarke and Glew. The results of this research are reliable vapour pressures and the thermodynamic properties of vaporisation.     

橄榄苦甙的NMR数据解析

对橄榄苦甙进行了¹H和¹³C MNR检测, 通过DEPT和¹H-¹H COSY、HMQC、HMBC、NO ESY等2D NMR对其¹H和¹³C NMR数据进行了全归属和较详细的解析, 并指出其NMR数据特征.     

半球封闭圆柱体表面绕射声场研究

基于一致性几何绕射理论,对半球封闭圆柱体上半球表面的高频绕射声场进行了数值计算与分析。获得了单个点声源作用下,半球表面声场的声压分布图,其中包括一些干涉条纹,干涉条纹的区域及形状与点声源的位置和频率有关;在多个点声源作用下,发现在接近半球顶点的附近,多个声波经多途传播后在该区域的叠加声压由衰减转为增强的现象。