云制造平台加工能力分享调度优化研究

云制造平台加工能力分享的调度优化是云制造模式的核心运营问题。为提高云制造平台对参与能力分享企业资源的利用率,解决实际云制造需求环境下企业级制造资源调度问题,达到云制造平台动态实时的要求,以最小化工期和成本为目标函数,构建了基于平台并面向分享的云加工能力调度模型。为快速求解多个云任务订单的最优调度序列,引入任务简易编码和随机权重,设计了改进的二阶粒子群算法,并提出可分享加工能力时间窗的更新策略。最后,通过算例验证云制造平台加工能力调度机制的可行性和有效性。     

A semidefinite programming approach to the hypergraph minimum bisection problem

The hypergraph minimum bisection (HMB) problem is the problem of partitioning the vertices of a hypergraph into two sets of equal size so that the total weight of hyperedges crossing the sets is minimized. HMB is an NP-hard problem that arises in numerous applications – for example, in digital circuit design. Although many heuristics have been proposed for HMB, there has been no known mathematical program that is equivalent to HMB. As a means of shedding light on HMB, we study the equivalent, complement problem of HMB (called CHMB), which attempts to maximize the total weight of non-crossing hyperedges. We formulate CHMB as a quadratically constrained quadratic program, considering its semidefinite programming relaxation and providing computational results on digital circuit partitioning benchmark problems. We also provide results towards an approximation guarantee for CHMB.     

Realization of superposition and entanglement of coherent and squeezed states in circuit quantum electrodynamics

We propose a new scheme for generating the superposition and entanglement of the coherent states and squeezed states by considering N superconducting charge qubits (or artificial two-level atoms) interacting with photons in a high finesse cavity on a chip, assisted by a strong driving field. By virtue of the parameters of this system, we can generate novel quantum states, for example, multiparty entangled states and Schro¨dinger cat states among the superconducting qubits, coherent states and squeezed state...     

Further bounds for waiting time distributions and their means in the case ρ<1

In the paper exponential bounds for the instationary and stationary waiting time d.f.'s in GI/GI/1/∞, derived by several authors partly using martingale theory arguments, are improved with the help of monotonicity properties. Further it is shown that Ne?eptjrenko's bound for the rate of convergence of the mean waiting time in single server queues Is also valid for many server queues with ρ < 1.     

不同磁路下微型ECR中和器电子引出的模拟研究

电子回旋共振(ECR)中和器是微型ECR离子推力器的重要组成部分,其引出的电子用于中和ECR离子源的离子束流,避免了航天器表面电荷堆积,并且电子引出性能对推力器的整体性能起着重要作用.为了分析影响微型ECR中和器电子引出的因素,本文建立了二维轴对称PIC/MCC计算模型,通过数值模拟研究不同磁路结构对中和器的电子引出,及不同腔体长度对壁面电流损失的影响.计算结果表明, ECR区位置和引出孔附近磁场构型对中和器的电子引出性能至关重要.当ECR区位于天线上游,电子在迁移扩散中易损失,并且电子跨过引出孔前电势阱所需的能量更高.如果更多磁力线平行通过引出孔,中和器引出相同电子电流所需电压较小.当ECR区被天线切割或位于下游时,电子更易沿磁力线迁移到引出孔附近,从而降低了收集板电压.研究了同一磁路结构下不同腔体长度对电子引出的影响,发现增加腔体长度,使得更多平行轴线的磁力线通过引出孔从而避免电子损失在引出板表面,增加了引出电子电流.研究结果有助于设计合理的中和器磁路和腔体尺寸.     

The side chain effects on TPD-based copolymers: the linear chain leads to a higher jsc

Abstract

Alkyl substituents appended to polymers play the determining role on self-assembly and film-forming properties, and on device performance. In this work, we highlight the effects of the linear and branched flexible chains appended to the acceptor moiety (A) in D-A type copolymers. Two thieno[3,4-c]-pyrrole-4,6-dione (TPD) based copolymers PT1 and PT2 with different alkyl chains, were designed and synthesized. By comparison their UV-vis absorptions, HOMO/LUMO energy levels, as well as the characters in polymer solar cells, the influences of alkyl chains were investigated. Both copolymers showed molecular weights of 21?kDa and similar optical properties with a medium band gap of 1.93?eV, while PT2 with the branched chain exhibited a lower HOMO than that of PT1 (?5.43 vs???5.37?eV). In bulk heterojunction (BHJ) solar cells, PT1 with a linear chain presented a short circuit current (J_sc) of 6.76?mA cm^?2, open circuit voltage (V_oc) of 0.89?V and power conversion efficiency (PCE) of 2.92%. To the contrary, PT2 showed a J_sc of 3.53?mA cm^?2, V_oc of 0.99?V, delivering a relatively lower PCE of 2.05%. The result indicates that appending a linear alkyl chain to the TPD unit could sufficient enhance the J_sc value of the related polymer.     

基于FCS的海水痕量元素的通用测定平台

为了对海水痕量营养盐与重金属进行测定,基于FCS的设计思想,采用流动注射分光光度法研制了具有自适应外界设备、快速组建多种仪器及全数字化通信等特点的软硬件一体化的通用测定平台。平台以ARM(S3C2416)处理器为核心,Linux为操作系统,LCD作为人机交互显示,触摸屏或者USB鼠标完成输入控制,构成完整的嵌入式工控机系统;采用CAN总线并制定CAN应用层协议管理设备,提高了系统的可靠性及抗干扰能力。实际测试和应用证明,该平台自动化程度高,通用性、重用性及可扩展性均较强,可组建成亚硝氮、硝氮、氨氮、活性磷、铁等多种痕量元素的实验室、船载和原位分析系统,检测限为nmol/L级别。平台对样品的测试准确度与商品专用仪器无显著性差异。     

基于单片机和光电开关的通用计数器设计

At presrent, the photoelectric switch is more and more widely used in the industrial automation equipment.It can be finished counting industrial products by using the characteristic of the photoelectric switch which can detect the objects without touching them. This design uses the modular design method,including power-supply module, The photoelectric conversion module, optocoupler isolation circuit module, power off protection module, matrix keyboard module, counting module and The display module. It mainly uses 51 single-chip microcomputer to control the system,uses the keilC51 software to design program,uses the Proteus software to complete the simulation. Through the experiment, it proves the design is feasible.     

基于LVDT的新型信号调理电路的设计研究

LVDT线性可变差动变压器,其输出信号为两个线圈的差动电压信号,能够实时的、高准确性的将机械位移信号转化成电信号。传统LVDT信号调理电路存在不易散热、检测修复困难、性价比低、适用范围窄等问题,本文设计了一种新型LVDT信号调理电路,该信号调理电路由驱动电路、整流归一化电路和滤波放大电路组成,测试结果能够匹配LVDT的输出信号特性,达到LVDT信号调理的各项指标要求,实验结果表明本设计具有一定的可行性。     

化学综合测试平台在化学创新型人才培养中的作用

科研平台在创新型人才培养中有重要的支撑和保障作用,通过课程建设、平台资源整合和开放共享、技术培训、学生直接参与科研活动等方式,探索了测试平台为学院本科创新型人才培养发挥更多作用的路径。充分利用测试平台的资源优势,为人才培养发挥更多作用,对于提升学生观察、分析和解决问题的能力,以及培养学生的科研思维具有重要的促进作用。