不同供应链决策模式下的交货时间问题

在一个经典供应链模型基础上,分析了同一行业背景下的3种不同决策模式下的供应链企业交货时间,得出3种决策模式下的最优交货时间,它们不受决策模式的影响.通过对最优交货时间的研究,给出企业在供应链决策中和选择上应注意的问题.     

考虑质量水平影响的供应链利润模型

引入前人提出的质量预防水平和质量检测水平的概念,确立了质量损失与质量水平的函数关系,从而建立了由一个制造商和一个销售商构成的二级供应链的利润模型.研究发现制造商承担内部损失、销售商承担外部损失的策略不能同时满足各成员的利润分别达到最大和供应链的总利润达到最大,从而设计出分摊策略,使各成员的局部最优目标和供应链的全局最优目标达成一致.最后,通过算例说明了这一结论.     

聚氨酯/环氧梯度互穿网络聚合物微观形貌及力学性能研究

设计了一种新的梯度组分分布数学模型,采用梯度因子和梯度层数控制梯度组分的分布,并采用逐层浇铸的方法制备了聚氨酯(PU)/环氧(EP)梯度互穿网络聚合物(IPNs)材料,研究了其微观形貌和力学性能.研究结果表明,随着梯度组分舍量沿梯度方向的变化,不同梯度单层的相结构和断裂特性也呈现相应的变化,逐渐由分散相向连续相转变.从中心层到表面层,梯度单层的弯曲模量逐层降低,挠度逐层增大,梯度IPNs的弯曲强度和模量低于普通IPNs,抗冲击性能高于普通IPNs.     

低强度激光辐照对蝗虫活性的影响

为研究低强度激光辐照对蝗虫活动能力的影响,以减少农药的使用量和降低农药的浓度,选择大功率连续型近红外半导体二极管激光器,针对3龄至4龄期东亚飞蝗蝻虫头部位置,在距离激光发光面4cm处,进行2s和4s的辐照试验,分别观察比较辐照前后蝗虫的活性和活性降低程度．试验结果表明,辐照前,蝗虫具有较高的活性,辐照后蝗虫的活性降低,并逐渐趋于一致性;辐照时间越长,蝗虫的活性降低程度越高。说明低强度近红外激光辐照蝗虫头部位置能明显抑制其活动能力。     

A Theoretical Investigation of Slot Waveguide Bragg Gratings

Bragg grating, structures based on dielectric slot waveguide, are investigated theoretically for potential applications as optical resonators and filters. Important device performance parameters, such as the reflection spectrum, the peak reflectivity, and the field confinement factor, are examined as functions of key waveguide and grating design parameters.     

Phase characterisation of metalenses

Metalenses have emerged as a new optical element or system in recent years, showing superior performance and abundant applications. However, the phase distribut...     

黄河某水电站库区泥石流特征及工程影响研究

黄河某水电站库区泥石流沟道发育,对该水电站运行安全带来不利影响。结合国内外有关研究成果,根据库区内泥石流的具体特征,以杏儿沟、官亭沟和喇家沟为重点研究对象,分析研究了这几条沟泥石流的形成条件及运动特征,包括泥石流的流速、流量等,并将泥石流对工程的危害作出评价。研究成果对水电站建设具有重要指导意义。     

中深层油藏注CO2吞吐可行性模拟研究

针对冀东油田中深层油藏地质特征和流体性质,应用数值模拟技术,对比分析影响中深层油藏注CO₂吞吐效果的油藏特征参数,提出了中深层油藏注CO₂吞吐的适宜条件。研究表明,对比浅层油藏,中深层表现出渗透率低、地层压力高,原油气油比高、饱和压力高、黏度低的特点;中深层油藏注CO₂吞吐的适宜条件应满足：地层压力适度高于泡点压力,但不高于混相压力,应采取适度非混相吞吐;剩余油饱和度不低于40%;渗透率高,有利于进行CO₂吞吐。     

腐蚀的电化学研究现状

基于电化学原理发展起来的电化学测试技术,如极化曲线分析法,交流阻抗分析法,电化学噪声分析法和Kelvin探针技术等,是研究腐蚀的重要手段,近些年有了很大的进展。掌握这些技术的原理及应用领域的进步,将有助于对腐蚀与防护技术的深入研究和开发。     

A viral system algorithm to optimize the car dispatching in elevator group control systems of tall buildings

Nowadays is very common the presence of tall buildings in the business centres of the main cities of the world. Such buildings require the installation of numerous lifts that are coordinated and managed under a unique control system. Population working in the buildings follows a similar traffic pattern generating situations of traffic congestion. The problem arises when a passenger makes a hall call wishing to travel to another floor of the building. The dispatching of the most suitable car is the optimization problem we are tackling in this paper. We develop a viral system algorithm which is based on a bio-inspired virus infection analogy to deal with it. The viral system algorithm is compared to genetic algorithms, and tabu search approaches that have proven efficiency in the vertical transportation literature. The experiments undertaken in tall buildings from 10 to 24 floors, and several car configurations from 2 to 6 cars, provide valuable results and show how viral system outperforms such soft computing algorithms.