Interaction of water with poly(vinyl methyl ether) in aqueous solution

Near-infrared, viscometric, and calorimetric measurements were made on aqueous poly(vinyl methyl ether) (PVME) solutions at temperatures between 15 and 43°C. We found a hydrogen-bonded structure of water around the polymer chain (a polymer-water complex), which is characterized by two distinct hydration numbers (i.e., 2.7 and 5.0 water molecules on each monomer unit of the chain) by analyzing the concentration dependence of endothermic enthalpies at a cloud point temperature, ca. 35°C. In particular, the 2.7 water-polymer complex has been suggested to be cooperatively formed by using data of the near-infrared (nir) absorption spectrum around 1930 nm. Furthermore, the peak-wavelength of the nir spectrum has been observed to change drastically at the cloud point when the temperature is raised. This can be interpreted as a cooperative collapse of the hydrogen-bonded water structure to free water, resulting in the aggregation of the polymer chains due to the exposure of their hydrophobic groups at the cloud point. © 1994 John Wiley & Sons, Inc.     

Optimization of a minimal-storage strategy for cloud amount data

A strategy is proposed which reduces the storage requirements for cloud amount information by up to 50%. Archiving only the mean cloud amount, μ, is recommended. Retrieval of most of the original data is possible if observations are made at high resolution ( 1 km) and the processing system gives rise to predominantly binary (i.e. cloud or no-cloud) information. The strategy is applicable to cloud amount at any level and to total cloud cover. One year's global cloud data can be stored on 2.5 computer magnetic tapes in contrast to the 13 tapes suggested by GARP/JOC (1980) and ISCCP (1982). The resultant new cloud archive will have the advantage of being equally useful for all scientific users (e.g. remote sensing and climate modelling groups) and each group's post-processing time will be greatly reduced.     

Cosolvency effects on copolymer solutions at high pressure

Cloud-point data to 180°C and 2800 bar are presented for polyethylene, poly(methyl acrylate), and two poly(ethylene-co-methyl acrylate) copolymers (10 and 31 mol % methyl acrylate) in propane and chlorodifluoromethane with two cosolvents, acetone and ethanol. The addition of small amounts of either cosolvent to the copolymer–solvent mixtures shifts the cloud-point curve to lower pressures and temperatures, as both cosolvents provide favorable polar interactions with the acrylate group in the backbone of the copolymer. Ethanol has a larger effect than acetone since ethanol hydrogen bonds to the acrylate group. However, if the concentration of ethanol is increased above ca. 10 wt %, it self-associates and reverts to antisolvent behavior, forcing the copolymer out of solution. For nonpolar polyethylene–propane mixtures, the polar cosolvents behave as traditional an-tisolvents. In poly(methyl acrylate)–chlorodifluoromethane mixtures, both polar cosolvents enlarge the single-phase region. The cloud-point curves for the (co)polymer–propane–acetone mixtures are modeled reasonably well using the Sanchez–Lacombe equation of state with two adjustable mixture parameters. No attempt is made to model the mixtures that exhibit hydrogen bonding. © 1993 John Wiley & Sons, Inc.     

基于云计算的动漫产业协作模型

云计算作为一种计算模式可以通过志愿技术将用户的计算资源整合起来,动态组成虚拟化的资源提供给用户使用.云计算可以将动漫企业的软硬件资源进行集中化与标准化,提高资源的利用效率.首先分析动漫产业的发展现状和动漫产业在规模、投入及资源共享方面存在的问题,然后基于云计算的特点研究云计算可以为动漫企业带来的优势,建立一种基于云计算的动漫产业协作模型,通过动漫企业之间的协作实现资源共享和利益共享.对动漫产业建立云计算平台的途径提出对策和建议,主要集中在解决动漫产业的企业规模偏小、资金比较紧张、资源共享及资源有效利用率低等问题.     

分形迭代算法在云彩生成的研究与应用

本文针对可变形气流场中不规则云彩扩散的计算机仿真问题,利用分形迭代理论进行深入研究。从云彩的局部相似性和随机性扩散特征出发,介绍了分形仿真中比较常用的IFS和分形插值技术,提出了基于分形迭代的云彩生成算法,给出了部分仿真结果。     

基于云平台的软件服务流引擎技术研究

传统的工作流自动化处理大多是针对固定的较为简单的执行单元,不能适应复杂的SaaS服务要求。为同时向大规模访问用户提供可靠实时的云计算服务,文章设计了软件服务流,高效、实时、稳定的调度算法是软件服务流成功实施的关键。通过服务抽象过程把复杂的用户自定制请求匹配成云平台的可执行单元后,软件服务流引擎利用文中提出的EOE实时调度算法处理用户请求,交付下层执行,监控执行进程、系统状态,实现软件服务流的自动化高效运行。最后,给出了在海洋环境信息云服务体系框架下的实现。     

洛阳智慧交通系统的设计与实现

科技使城市更智慧,让城市学会思考和自我控制来保障社会集约型和可持续快速发展.论述了建设洛阳智慧交通系统的意义,分析了系统的体系结构,重点讨论了洛阳智慧交通系统的总体框架、系统功能、数据库结构和最佳路径分析方法.洛阳智能交通系统的建设,将很大程度上满足人们出行的需要,节约人们的时间资源和城市的道路资源,保障城市交通的畅通,提高政府对控制突发事件的应急能力.     

云计算环境下高校图书馆发展策略研究

介绍了云计算的定义和优势,阐述了云计算在国内外图书馆的应用现状,分析了云计算对高校图书馆发展的影响,提出了高校图书馆面对云计算的发展策略。     

“数字校园”智能化的探讨

本文介绍了校园物联网及数字校园的概念和特征,从多个方面阐述了数字校园建设的内涵和目标。在数字校园建设和智能化的研究基础上,运用人工智能和云计算的理论,提出了构建校园智能系统的研究理念,以促进数字校园向全面智能化发展。