基于营运资金信息匹配平台的供应链金融动态折扣决策研究

当前逐渐受到实业界关注的一种新型供应链金融模式是基于营运资金信息匹配平台的动态折扣。本文针对两级供应链的动态折扣决策问题进行建模,揭示了动态折扣的应用对于改善供应链参与方现金流的影响机理。首先通过考虑供需双方动态折扣的独立决策,得出日折扣率的边界条件、双方效用最大时的日折扣率、买方混合还款方式下营运资金的最优准备方案和最低边界值;其次考虑供需双方动态折扣的最优决策,推导出在不同折扣率和利率关系下的最优还款策略,研究表明动态折扣可以明显提升供需双方的利润情况。     

重金属污泥高温处理磨细粉对改性硫氧镁水泥基材料性能的影响

为探究重金属污泥高值资源化利用途径, 研究了含重金属污泥高温处理渣料磨细粉(简称磨细粉)对改性硫氧镁(MMOS)水泥基材料的工作性能、力学性能、早期自由收缩变形及其重金属浸出行为的影响. 结果表明: 随着磨细粉掺量的增加, MMOS水泥基材料的净浆流动度呈现逐渐增大趋势; 早期(3d)力学性能则呈现明显的降低趋势, 90d后磨细粉掺量对MMOS水泥基材料的力学性能的影响程度降低; 磨细粉可以显著降低MMOS水泥基材料早期的自由收缩变形值, 其中含10%磨细粉的MMOS水泥基材料早期的自由收缩变形比未掺加磨细粉MMOS水泥基材料的自由收缩变形值降低了57.1%. 微观分析结果表明: 掺加30%磨细粉后MMOS水泥基材料中水化产物5Mg(OH)2?MgSO4?7H2O(517相)的相对含量降低, MMOS水泥基材料硬化体的平均孔径提高了31.0%, 表明磨细粉降低了MMOS水泥基材料的力学性能. 当磨细粉掺量增加至40%时MMOS水泥基材料硬化体中重金属Ni、Cr、Zn和Cu的浸出浓度指标均能满足GB 30760-2014的浸出要求.     

XANES characteristics of tribofilms generated by dithiophosphate additive in water at different test temperatures and durations

Water‐based lubricants and metal‐working fluids are becoming more and more popular in modern manufacturing due to environmental concerns. Owing to the poor lubricating properties offered by pure water, additives are generally needed to improve the antiwear and extreme pressure properties. In the present work, the tribological behaviors of synthesized additives in water‐based lubricants are studied for different durations and temperatures by a four‐ball machine, and the worn surfaces were analyzed by scanning electron microscopy (SEM) and X‐ray absorption near‐edge structure (XANES) spectroscopy. It was found that the tribological properties changed with the duration and temperature, and the tribofilms mainly consisted of an adsorbed layer and a tribochemical layer. The compositions of tribofilms also changed with duration and temperature, and the different compositions of tribofilms would result in different tribological properties accordingly. Copyright © 2009 John Wiley & Sons, Ltd.     

带有部分工作休假和休假中断的M/M/c排队

考虑了一个带有部分工作休假和休假中断的多服务台M/M/c排队.在休假期,d(d相似文献   

带有负顾客且具有Bernoulli反馈的M/M/1工作休假排队

本文研究带反馈的具有正、负两类顾客的M/M/1工作休假排队模型.工作休假策略为空竭服务多重工作休假.负顾客一对一抵消队尾的正顾客(若有),若系统中无正顾客时,到达的负顾客自动消失,负顾客不接受服务.完成服务的正顾客以概率p(0相似文献   

Voltammetric determination of electronic structure of quantum dots

Electronic structure plays an important role in determining the physiochemical properties of semiconductor quantum dots (QDs). Fabrication of high-performance QD devices relies on the reliable determination of electronic structure of QDs. Voltammetry enables the easily accessible detection on the energy levels of QDs. Herein, the fundamentals of voltammetric detection are first reviewed and discussed. Since the common ways used for tailoring electronic structure of QDs include tuning size, surface engineering, and varying composition, we next summarize the recent research on using voltammetry for probing the energy levels when studying these three effects.     

Clinoptilolite‐based Conductometric Sensors for Detection of Ammonium in Aqueous Solutions

New clinoptilolite‐based conductometric sensors were developed and optimized for selective detection of ammonium in the buffered aqueous solutions. The sensors’ selective elements were prepared by subsequent drop‐casting of zeolite and Nafion on the gold electrode surface. Electrochemical impedance spectroscopy and differential conductometry were used to investigate the sensor performance. As determined in the phosphate buffer solution, the detection limit of the sensors was 30 μM and the linear range 0–1.5 mM. The developed sensors were featured with a simple preparation procedure, high selectivity to , and storage stability for not less than 126 days.     

Identification of micro-scale calorimetric devices

An improved accuracy is researched in flat and silicon based nano-calorimeters related to fluid reaction via drop-to-drop 'reaction' or via a steady state in continuous injection of two reactants inside a working chamber. Two types of the experimental aspects of the sensitivity changes, related to 3-D effects, are described: drop effects and volume rate effects. To increase the accuracy, well-controlled joule measurements are dissipated in the manufacturer resistance and in several resistances in carefully controlled experiments. The shape factor (SF) values reduce the manufacturer's joule sensitivity up to fifty per cent. a working methodology is proposed: the results are compared with the standard TRIS reaction. The results suggest that the systematic error can be reduced to ±5%. This revised version was published online in July 2006 with corrections to the Cover Date.     

Active layer of the oxygen cathode in a fuel cell with Nafion and platinum: The role played by the diffusion and ohmic restrictions and the selection of the working thickness of the active layer

The basic parameters that characterize the operation of the active layer of a cathode with Nafion are the effective coefficient of the diffusion of oxygen, the effective ionic conductance, and the thickness of the active layer. One of the deficiencies intrinsic to the fuel cells containing Nafion is their extreme sensitivity to the heat and moisture exchange. Nafion demands an optimum degree of humidification. Upon thoroughly draining the active layer of a cathode with Nafion, its effective ionic conductance substantially lowers, and large diffusion restrictions arise following the flooding of pores in the active layer. The goal of this work is to perform a comparison of values of some dimensional characteristics pertaining to the flooded and thoroughly drained active layers of a cathode with similar indicators of an active layer in its optimum (normal) state. It is demonstrated how one should perform the selection of the working thickness of an active layer that would provide for the efficiency of its functioning.     

Negative‐working photoresist of methacrylate polymers based on the transesterification of the 2‐hydroxyethyl group in the presence of an acid

This article reports a novel crosslinking functionality of the 2‐hydroxyethyl methacrylate unit (HEMA) in the presence of an acid. The polymeric compositions, consisting of a polymer containing the HEMA unit and a photoacid generator, were insolubilized in an aqueous base developer on exposure to UV light and a successive baking process to provide a negative‐working photoresist. A series of poly(benzyl methacrylate‐co‐methacrylic acid‐co‐2‐hydroxyethyl methacrylate) terpolymers with various contents of HEMA were prepared to elucidate the photopolymeric characteristics. The polymer behavior in films was examined by a comparison of the photosensitivity and IR spectroscopic method. Experiments with a model compound were also carried out. On the basis of the results, we found that the resist was insolubilized by crosslinking through the transesterification of HEMA segments due to acid generated from the photoacid generator and subsequent heating. The advantage of using the 2‐hydroxyethyl group is that in the terpolymer, the HEMA unit is transparent at a short‐wavelength region and is a promising crosslinking unit for ArF lithographic photoresists. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1858–1867, 2002