Modification of polysulfide sealant with polysulfide polythio‐urethane‐urea

With a small amount of isocyanate‐terminated polysulfide (NCO‐PSF‐NCO) as additive, the commercial polysulfide‐based sealant had significant improvement in mechanical properties. The test results showed that 5% of NCO‐PSF‐NCO could help to rise 50% in the tensile strength and 27% in the ultimate elongation of the polysulfide sealant. The adhesive strength to substrates such as steel, epoxy‐coated or polyurethane‐coated surface also increased significantly. Dynamic mechanical thermal analysis and differential scanning calorimetry analysis revealed that formed polysulfide polythio‐urethane‐urea (polysulfide‐urea) contributed to a slight increase in the T_g of the polysulfide sealant. It might be due to the domains of polysulfide‐urea, which had effects of physical crosslinking and chain‐extending on the polysulfide sealant. However, the introduction of polysulfide‐urea structures had no appreciable influence on oil resistance of the polysulfide sealant. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

高分子材料的微孔发泡方法

介绍了微孔发泡高分子材料的成型方法 ,成型原理和成型工艺及设备。     

Synthesis of polymeric prodrugs of chlorphenesin with saccharide branches by chemo-enzymatic regioselective strategy

A facile and regioselective enzymatic synthesis approach to prepare polymerizable lipophilic chlorphenesin vinyl esters was developed in this research. The influence of different organic solvents, enzyme sources, reaction time and the acylation reagent on the synthesis of chlorphenesin vinyl esters was investigated. Then the polymerizable monomers 1-O-vinylsuccinyl-chlorphenesin (OVSC) and 1-O-vinyladipoyl-chlorphenesin (OVAC) were homopolymerized using AIBN as the initiator. The obtained polymeric prodrugs were characterized with IR, NMR and GPC analyzes. The poly-OVSC has M_n of 1.35 × 10⁴ and M_w/M_n of 1.95, and the poly-OVAC has M_n of 2.37 × 10⁴ and M_w/M_n of 4.30. Moreover, 6-O-vinyladipoyl-d-glucose (OVAG), a biocompatible monomer, was copolymerized with OVSC and OVAC. Polymeric prodrugs of chlorphenesin with saccharide branches were successfully obtained with high molecular weight.     

小型连锁超市优惠券管理系统的开发

本系统适用于小型连锁超市,主要是从总体上对其优惠券进行管理。本系统具有优惠券类别管理、优惠券规则定义、优惠券发放管理、优惠券使用管理、优惠券查询、优惠券统计、会员优惠券管理等功能。本系统界面友好、直观,操作简便,系统中的多级权限管理等也可以保证数据的安全可靠。     

基于ExtJS+SSH架构的民政服务信息系统设计与实现

针对传统民政办公系统结构复杂,不易维护和不易扩展的情况,提出了一种基于Ext JS+SSH(Struts2、Spring和Hibernate)架构的民政服务信息系统。按照Java EE的分层思想,通过Struts2框架实现了MVC模式,将用户界面、业务处理和数据访问三者分离,利用Spring框架统一管理系统对象以降低系统的耦合性,采用Hibernate框架实现业务数据的持久化以降低开发难度。实验结果表明,基于Ext JS和SSH架构的系统具有易维护、可扩展和运行稳定的特性。     

Science in the Cloud: Allocation and Execution of Data-Intensive Scientific Workflows

An important challenge for the adoption of cloud computing in the scientific community remains the efficient allocation and execution of data-intensive scientific workflows to reduce execution time and the size of transferred data. The transferred data overhead is becoming significant with emerging scientific workflows that have input/output files and intermediate data products ranging in the hundreds of gigabytes. The allocation of scientific workflows on public clouds can be described through a variety of perspectives and parameters, and has been proved to be NP-complete. This paper proposes an evolutionary approach for task allocation on public clouds considering data transfer and execution time. In our framework, a solution is represented using an allocation chromosome that encodes the allocation of tasks to nodes, and an ordering chromosome that defines the execution order according to the scientific workflow representation. We propose a multi-objective optimization that relies on a cloud cost model and employs tailored evolution operators. Starting from a population of possible solutions, we employ crossover and mutation operators on both chromosomes aiming at optimizing the data transferred between nodes as well as the total workflow runtime. The crossover operators combine parts of solutions to reduce data overhead, whereas the mutation operators swamp between parts of the same chromosome according to pre-defined rules. Our experimental study compares between the proposed approach and current state-of-the art approaches using synthetic and real-life workflows. Our algorithm performs similarly to existing heuristics for small workflows and shows up to 80 % improvements for larger synthetic workflows. To further validate our approach we compare between the allocation and scheduling obtained by our approach with that obtained by popular scientific workflow managers, when real workflows with hundreds of tasks are executed on a public cloud. The results show a 10 % improvement in runtime over existing schedulers, caused by a 80 % reduction in transferred data and optimized allocation and ordering of tasks. This improved data locality has greater impact as it can be employed to improve and study data provenance and facilitate data persistence for scientific workflows.     

怒江漆油中高级脂肪酸成分

对云南怒江漆油 (漆树籽油 )进行皂化得到了漆油的总脂肪酸 ,将总脂肪酸甲酯化得到总脂肪酸甲酯 ,用GC MS联用仪测定了所含高级脂肪酸的成分 ,结果表明云南怒江漆树油中高级脂肪酸分别为棕榈酸、油酸、硬脂酸、花生酸、二十烷二酸。其中 ,棕榈酸的质量分数高达 76.9%。     

溶剂萃取法回收与处理含DMAc废水的研究

本文研究了用低沸点萃取剂处理和回收含二甲基乙酰胺（DMAc)废水的可行性及工艺条件，经研究表明，在常温20－35℃时，用氯仿萃取二甲基乙酰胺，当溶剂与水相体积比为2：1时，经六级逆流萃取，可将废水中20％（w/w)的二甲基乙酰胺含量降至300mg/L以下。废水的pH值对萃取效率有明显的影响，当废水的pH值较大，即偏碱性对萃取有利。     

Study on esterification of acrylic phenolic resin by maleic anhydride and photocrosslinking properties of the alkali‐soluble product

An alkali‐soluble, photocrosslinkable polymer was synthesized by esterification of OH groups of acrylic phenolic resin with maleic anhydride. The OH groups were formed by the ring‐opening reaction of epoxy groups of epoxy phenolic resin with acrylic acid. The esterification conditions were studied. The results showed that it is better to use tetramethyl ammonium bromide as catalyst than N,N‐dimethylbenzylamine. The conversion of maleic anhydride in acetone can reach about 80% at 56°C for 4 h. The purified product was characterized by IR, DSC, and TGA. The product containing acrylate and maleic acid monoester groups, above a certain content, can be dissolved in 1% Na₂CO₃ solution. The photocrosslinkable properties of the product were investigated through selection of photoinitiator, accelarator, crosslinkable diluent monomer, etc. The acrylate and maleic acid monoester group‐containing phenolic resin exhibited very good photocrosslinking behavior, since it contains double bonds from both acrylate groups and maleic acid monoester groups. The activity of photoinitiator decreases in the order: isopropylthioanthraquinone > benzoin ethyl ether (BE) > anthraquinone (AQ) > benzophenone > Michel ketone (MK) > 2,2‐diethoxyacetophenone. The combination of some photoinitiators showed synergistic effects. The order of increasing activity for the accelerator is as follows: MK > ethyl p‐(dimethylamino)benzoate > N,N‐dimethylaniline > triethanolamine. The optimum diluent monomer is trimethylolpropane trimethacrylate. The gel content of the mixture of the resin and trimethylolpropane trimethacrylate could reach 85% using the combined photoinitiators of BE and AQ under UV exposure for 120 s. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1607–1614, 2005