The study on the conductivity of styrene-maleic anhydride copolymer electrolytes based on poly(ethylene glycol)400 and LiClO4

Polyelectrolytes, in this study were synthesized from styrene-maleic anhydride (SMA) copolymer, poly(ethylene glycol)400 (PEG400), and lithium perchlorate (LiClO₄). Fourier transform infrared spectroscopy (FTIR), and com/content/image/1-s2.0-S001346860400180X-si3.gif"> magic angle spinning (MAS) solid-state NMR were used to monitor the interaction between Li⁺ ions and polymer. The results of FTIR and com/content/image/1-s2.0-S001346860400180X-si4.gif"> MAS solid-state NMR indicate the Li⁺ ions are preferentially coordinated to the ether oxygen of PEG. The T_g of the PEG segments in polyelectrolyte increases with LiClO₄ concentration, as determined by differential scanning calorimetry (DSC), indicating that solubility of the Li⁺ ions in the host polymer increases with the PEG content. Impedance spectroscopy (IS) shows that the bulk conductivity of polyelectrolytes and the conductivity behavior obeys the Vogel-Tamman-Fulcher (VTF) equation.     

电子信息科技英语的教学实践

为培养复合型人才,科技英语教学的重要性日益显现。分析了目前电子信息类专业中科技英语教学存在的问题,并围绕教学内容改革、教学过程管理等介绍了该课程的教学实践。同时,本文还指出未来科技英语教学的发展趋势。     

An LMI approach to synthesis subject to almost asymptotic regulation constraints

A multi-objective controller synthesis problem is considered in which an output is to be regulated approximately by assuring a bound on the steady-state peak amplification in response to an infinite-energy disturbance, while also guaranteeing a desired level of performance measured in terms of the worst-case energy gain from a finite-energy input to a performance output. Relying on a characterization of the controllers with which almost asymptotic regulation is accomplished, the problem of guaranteeing the desired level of performance is reduced to solving a system of linear matrix inequalities subject to a set of linear equality constraints. Based on the solution of this system, a procedure is outlined for the construction of a suitable controller whose order is equal to the order of the plant plus the order of the exogenous system.     

基于Fnrce．com平台的SaaS应用的设计与实现

该文针对企业的传统业务流程,设计了基于Force．com平台的软件即服务（Software—as—a—Service,SaaS）解决方案,定制开发相关SaaS应用该方案依托Force．com平台可以实现应用的快速配置。Forcc．com平台提供了较好的平台配置和应用定制功能．企业用户可以专注于业务,为类似的系统需求提供了一种解决思路。     

Controller synthesis with guaranteed closed-loop phase constraints

In this paper, we present an analysis and synthesis approach for guaranteeing that the phase of a single-input, single-output closed-loop transfer function is contained in the interval [−α,α] for a given α>0 at all frequencies. Specifically, we first derive a sufficient condition involving a frequency domain inequality for guaranteeing a given phase constraint. Next, we use the Kalman–Yakubovich–Popov theorem to derive an equivalent time domain condition. In the case where com/cache/MiamiImageURL/B6V21-4TVJ07S-1-26/0?wchp=dGLbVlW-zSkzk" alt="View the MathML source" title="View the MathML source" align="absbottom" border="0" height=16 width="39"/>, we show that frequency and time domain sufficient conditions specialize to the positivity theorem. Furthermore, using linear matrix inequalities, we develop a controller synthesis approach for guaranteeing a phase constraint on the closed-loop transfer function. Finally, we extend this synthesis approach to address mixed gain and phase constraints on the closed-loop transfer function.     

A reactive GRASP and path relinking for a combined production–distribution problem

An NP-hard production–distribution problem for one product over a multi-period horizon is investigated. The aim is to minimize total cost taking production setups, inventory levels and distribution into account. An integer linear model is proposed as a compact problem specification but it cannot be solved to optimality for large instances. Instead of using a classical two-phase approach (production planning and then route construction for each day), metaheuristics that simultaneously tackle production and routing decisions are developed: a GRASP (greedy randomized adaptive search procedure) and two improved versions using either a reactive mechanism or a path-relinking process. These algorithms are evaluated on 90 randomly generated instances with 50, 100 and 200 customers and 20 periods. The results confirm the interest of integrating production and distribution decisions, compared to classical two-phase methods. Moreover, reaction and path-relinking give better results than the GRASP alone.     

成熟玉米果穗脱皮装置的研究

为了提高玉米果穗苞叶脱皮环节的苞叶脱净率,通过脱皮辊作业时果穗的受力分析,解析了果穗与苞叶被分离以及果穗未被拧取的作业条件,建模并进行数理分析。结果表明：分离辊拽拉玉米苞叶作用力大于拽拉玉米苞叶所需作用力或拧取角减小到最佳值n满足上述两个基本条件时,本研究装置苞叶脱净率可达97%。     

基于TCP/IP协议的分布式供热远程监控系统开发

本文介绍了一种基于TCP，IP协议的远程配置与监控系统．分析了该系统功能、特点以及软、硬件实现方法，讨论了一对一多通信的实施结构。以分布式供暖系统为例，建立了基于C/S模式的远程工作参数配置及工况监控系统，实施效果安全可靠。     

复合式减温技术在35 t/h 电站锅炉减温器改造上的应用

主汽超温是中小容量电站锅炉经常出现的问题，通过理论计算分析和冷态试验，提出了一种应用复合式减温技术对35 t/h 电站锅炉减温器进行改造的新方法，成功解决了主汽超温问题。此方法不仅简单易行，而且效果显著，为解决中小容量电站锅炉主汽超温问题提供了有益的参考。