铝酸盐系长余辉发光粉的表面包覆研究

采用正硅酸乙酯对铝酸盐系长余辉发光粉进行表面包覆。经耐水性、耐酸性和发光性以及扫描电镜的测试表明:发光粉的包覆效果良好,其耐水性和耐酸性得到明显提高。包覆后,发光粉的发光性未发生明显改变。     

考虑任务不确定性的片上网络鲁棒性应用映射问题研究

标准应用映射问题中,每个任务的通信量是确定值,而实际应用中任务通信具有突发性和时变特征,因此将任务通信量建模为不确定值具有现实意义。该文利用区间流法对任务不确定性进行描述,基于保守因子对鲁棒性应用映射问题建模,提出了求解问题的改进禁忌搜索算法(Tabu-RAM),通过5个Benchmark案例对本文模型和算法进行了验证。实验结果表明Tabu-RAM能够求解传统应用映射问题,且优于现有文献中给出的算法。此外,与传统禁忌搜索算法相比,Tabu-RAM算法在求解鲁棒性应用映射问题时具有更好的性能和稳定性。     

建立企业食品安全体系的联合监管作用研究

通过博弈分析,研究了食品安全风险为高低两类的情况下,公共政策法规对生产企业建立食品安全体系的监管作用,并进一步研究了引入供应链中零售商对生产企业进行联合监管的作用。结果表明,无论食品污染的风险是什么类型,公共政策法规绝对强制性地监管会促使生产企业自愿地建立食品安全体系。当食品污染风险较低的行业,食品供应链中零售商的联合监管作用,更会迫使生产企业自愿实施食品安全措施。     

履带运输车差速转向仿真研究

利用MATLAB/Simulink软件平台建立履带运输车差速转向仿真模型,分别从转向负载变化、液压系统及动力源3个方面研究运输车的差速转向过程,对比分析了仿真结果与试验数据,证明所建模型的合理性。并利用该仿真模型分析输入变量对该履带运输车转向半径、发动机扭矩消耗及液压系统工作压差的影响。     

Preparation and characterization of a modified montmorillonite/sulfonated polyphenylether sulfone/PTFE composite membrane

Organically modified montmorillonites are valuable materials that have been used to improve the permeability, water retention, and proton conductivity of proton exchange membrane for fuel cells. A sulfonated montmorillonite/sulfonated poly (biphenyl ether sulfone)/Polytetrafluoroethylene (SMMT/SPSU-BP/PTFE) composite membrane was prepared for fuel cells. The thermal stability of the SMMT was tested by the thermogravimetry-mass spectrometry (TGA-MS) and its structure in the composite membrane was characterized by X-ray diffraction (XRD). It was found that SMMT was stable up to 205 °C and the interlayer distance of the nanoclay expanded from 1.43 nm to 1.76 nm after the organic sulfonic modification. The SMMT was completely exfoliated in the composite membranes. The properties of ion-exchange capacity, water uptake, swelling ratio, proton conductivity, and mechanical strength of the composite membranes were investigated as well. The good water retention of SMMT made the SMMT/SPSU-BP and SMMT/SPSU-BP/PTFE composite membranes have about 20% more bound water than the SPSU-BP membrane. Due to the reinforce effect of the PTFE porous film, the SMMT/SPSU-BP/PTFE composite membrane presented low swelling even at elevated temperature and high stress strength. All of the properties indicate that the SMMT/SPSU-BP/PTFE composite membrane is very promising as the PEM for medium temperature PEMFCs.     

Optimal design of fossil-solar hybrid thermal desalination for saline agricultural drainage water reuse

Ultra-high recovery solar thermal desalination of agricultural drainage water is presented as one solution to the historic extreme drought and long-standing salt accumulation problems facing California's fertile Central Valley region. Building on the results obtained from a recent pilot demonstration of a novel solar thermal desalination system, a techno-economic analysis is presented using an existing agricultural region as a case study. Three strategies are considered: continue retiring farmland as crop productivity wanes in future years, desalinate saline drainage water with a novel distillation process using natural gas as the fuel source, and desalinate using natural gas and solar as a hybrid energy source. The study is cast as a parametric optimization problem taking into account natural gas costs and water purchase contract pricing. The results show that with projections of the long-term effects and cost of salt accumulation in the region, solar thermal desalination is economically favorable over both the alternative of doing nothing (retire farmland) as well as implementing conventional (non-renewable) thermal desalination. Most importantly, the results indicate that solar thermal desalination is an economically-viable solution that can increase the sustainability of farming in the region and create a new, sustainable, scalable source of additional freshwater.     

PEMFC用Ce-MCM-41/SPEES复合膜的研究

室温下,通过非水热合成法制备了Ce-MCM-41淬灭剂,通过XRF、FT-IR、XRD等表征显示了Ce4+很好地插入到MCM-41骨架中,TEM表征了Ce-MCM-41的多孔结构,利用二甲基亚砜(DMSO)作为捕获剂通过UV-VIS光谱方法表征了Ce-MCM-41淬灭剂捕获自由基的能力.为了降低燃料电池条件下自由基(HO·)对膜的降解制备了Ce-MCM-41/SPEES复合膜,通过离线Fenton实验和在线加速开路降解实验观察了膜的稳定性,结果显示了Ce-MCM-41/SPEES复合膜的稳定性得到了提高.     

自控闭环控制在化工设备中的应用

合成橡胶业在20世纪初开始生产，从20世纪40年代起得到了迅速的发展。合成橡胶具有高弹性、绝缘性、气密性、耐油、耐高温或低温等性能，因而广泛应用于工农业、国防、交通及日常生活中。近年来，合成橡胶产业的发展态势让人欣喜。随着生产规模的不断扩大，合成橡胶产业将在我国产业经济中将占据更加重要的地位。通过几年的发展，国内合成橡胶产业取得了长足的进步。无论是年产量和消费量，都已经挤入世界前列。合成橡胶设备是化工行业必不可少的生产装置，由于生产过程连续、产量大，如何减少人力成本，降低单位产量损耗就是一个重要的课题。     

An Improved Angle Polishing Method for Measuring Subsurface Damage in Silicon Wafers

提出了一种改进的角度抛光方法来测量硅片的亚表面损伤.其原理是:经过研磨和化学机械抛光后,起保护作用的陪片靠近胶黏剂的一端形成一个无损伤的、完整的劈尖,劈尖的棱边作为测量亚表面损伤的基准;角度抛光的倾斜角可通过劈尖上面产生的干涉条纹准确地测量得到.采用这种方法可以方便、准确地测量硅片由切割、研磨和磨削引起的亚表面损伤,其能够测量的最小损伤深度为几百纳米.     

硅酸盐型LED荧光粉的表面处理及其性能

采用硅溶胶对Sr2–xBaxSiO4∶Eu2+LED荧光粉进行表面处理,以改善其稳定性、在树脂中的分散性及封装应用的老化效果。考察了硅溶胶用量、处理温度和时间对荧光粉性能影响,分析了表面处理对荧光粉的晶体形貌和发光性能的影响,并对其应用老化性能进行了研究。结果表明,表面处理使硅酸盐荧光粉的初始发光强度提高约2%,可靠性也有所提高,可使封装后的LED的光衰减少6%。