Optimal control of price and production in an assemble-to-order system

We study the optimal control of an assembly system that produces one assembled-to-order final product with multiple made-to-stock components and sells it at variable price. It is shown that a threshold control on component production, product price, and product orders maximizes total discounted profit over an infinite horizon.     

Solution to the Cosmological Constant Problem by Gauge Theory of Gravity

Based on geometry picture of gravitational gauge theory, the cosmological constant is determined theoreti-cally. The cosmological constant is related to the average energy density of gravitational gauge field. Because the energydensity of gravitational gauge field is negative, the cosmological constant is positive, which generates repulsive force onstars to make the expansion rate of the Universe accelerated. A rough estimation of it gives out its magnitude of theorder of about 10-52m-2, which is well consistent with experimental results.     

酞菁锌掺杂二氧化硅凝胶基质的光谱学特征

利用溶胶凝胶技术将四磺化酞菁锌 (ZnPcS4)成功地引入到了二氧化硅凝胶基质中 ,制备了均匀掺杂的有机 /无机复合干凝胶。研究ZnPcS4分子在溶胶凝胶过程中紫外可见吸收光谱的变化规律以探索其在复合体系中的存在状态。实验表明 ,在溶胶阶段 ,随着时间的延长 ,紫外可见吸收光谱中单体的吸收峰强度增大 ,说明凝胶中酞菁单体的浓度增大 ;而形成凝胶后 ,随着时间的延长 ,紫外可见吸收光谱中单体的吸收峰强度减小 ,二聚体的吸收峰强度增大 ,说明由于体系结构和微化学环境的变化 ,酞菁分子趋向于聚合。     

Preparation and characterizations of novel zwitterionic membranes

A novel route was proposed for preparation of zwitterionic membranes, and it comprises (1) free radical polymerization between glycidylmethacrylate (GMA) and acrylic acid (AA) monomers and (2) subsequent ring-opening of epoxide and quaternary amination with trimethylamine hydrochloride. The reaction products were confirmed by FTIR spectra. The cation-exchange capacities (CIECs) and anion-exchange capacities (AIECs) of these zwitterionic membranes are within the range of (5.4–9.3) × 10⁻² and (30.6–11.1) × 10⁻² mmol g⁻¹, respectively. In addition, the CIEC increases as AA content increases, but the AIEC generally decreases. TGA and DrTGA measurements reveal that their thermal stabilities can arrive at as high as 380 °C. The water uptake is independent of pH. As for membrane potential and streaming potential, they both suggest that these membranes possess the characteristics of anion-exchange membranes and no IEP is observed. Permeation experiments of mixed KCl and glucose solution indicate that the transport behavior of ions is dependent on the membrane’s charge density.     

Study on the effect of mechanical alloying on properties of Zn-Sb alloy

The effect of mechanical alloying on Zn-Sb alloy system is investigated with X-ray diffraction (XRD), laser grain size analysis and differential scanning calorimetry (DSC) respectively. The results of laser particle size analysis shows that the particle size decreases with increasing of the grinding time between 0 and 24 h. XRD and DSC results indicate that longer the grinding time of Zn-Sb is, the more content of Zn₄Sb₃ become in the product in this process.     

亚纯函数导数的亏量和

设ｆ（ｚ）是开平面Ｃ内的亚纯函数，Ｅ．Ｍｕｅｓ证明了对任何自然数ｋ有杨乐推广以上不等式，证明了本文推广了以上结果，证明了以下定理：设ｆ（ｚ）为亚纯函数，则对任何自然数ｋ有例子显示此不等式是精确的。     

The Degradation of Beam Quality in Large-Core Optical Fiber

The degradation of beam quality in large-core fiber is investigated experimentally. It is found that the output beam quality factor M2 is a compound tanh function ofthe fiber lengths and misalignment launch results that the beam quality degraded faster.     

RIBLL1终端实验装置

描述了一套HIRFL的放射性核次级束流引起反应测量的实验装置,它由RIB鉴别、测量系统、次级靶控制系统和次级反应产物鉴别、测量系统组成.高增益分组延迟线读出、重心定位PPAC,横向场IC,椭球面镜聚焦、PMT读出、闪烁薄膜时间拾取器,双叠层纵向场阳极分条读出IC,PMT矩阵读出x—y位置灵敏Phoswich闪烁探测器,康普顿抑制HpGeγ探测器等单元是这套装置的基本部件.目前,该装置已安装在兰州重离子加速器RIBLL1终端.性能测试和实验研究正在进行.     

基于等效衰减矢方法的非均匀光波导色散方程

利用转换矩阵理论和等效衰减矢的概念，以此为根据分析了任意折射率分布平板波导的模式传输特性，导出了意义明确的非均匀平板波导的色散方程的严格的解析解，并指出了ＷＫＢ法的局限性，数值计算的结果表明本文所得公式的结果和严格的数值解非常接近，表明本文所得的公式是严格的。     

矩阵酉扩张的刻划

本文用奇异值刻划了具有指定阶酉扩张的矩阵类，同时讨论了矩阵的正规扩张问题