乳液聚合法制备聚合物与十二醇复合乳胶粒

通过乳液聚合法, 以苯乙烯、丙烯酸丁酯为主要单体, 以甲基丙烯酸为功能性单体, 以二乙烯基苯或二甲基丙烯酸乙二醇酯为交联剂, 制备了包覆有十二醇的聚合物复合颗粒. 通过动态光散射粒径仪和透射电镜观测乳胶粒粒径和形态, 气相色谱法测试了十二醇的包覆率, 并探讨了聚合过程中十二醇包覆率的变化情况. 结果表明十二醇的包覆率和十二醇与单体的质量比及单体转化率显著相关, 并且在聚合过程中包覆率存在先升后降的趋势. 实验发现十二醇包覆率的先升后降是由聚合物和十二醇的相容性不好引起的.     

Multiple-task and multiple-agent models: Incentive contracts and an application to point pollution control

Two types of linear-quadratic principal-agent models will be considered: one in which a single agent has to perform several tasks and one in which several agents have to perform a certain task. For both models, we derive optimal contractual principal-agent relations. It turns out that under certain conditions (concerning risk-aversion and the correlation of the agents' outcome) the multiple-agent problem reduces to a multiple-task one-agent problem. Our results will be discussed within the framework of (multiple-) point pollution to which, in addition, also the results of the standard principal-agent model will be applied.     

市场经济下政府对国有企业经营的调控管理方法

本文针对国有企业改革中，实现公有制与市场经济兼容时遇到的企业独立自主经营和政府履行管理与控制责任之间的矛盾统一性的问题，提出了实现两方面统一的调控管理方法。     

In vitro biological performances of phosphorylcholine-grafted ePTFE prostheses through RFGD plasma techniques

Arterial prostheses made of microporous Teflon (ePTFE) are currently used in vascular surgery as bypasses for small and medium vessels. However, several clinical complications, such as thrombosis, frequently occur in these prostheses when implanted in humans. In this work, an original strategy was developed to improve the hemocompatibility of ePTFE prostheses, based on glow-discharge surface modification followed by chemical grafting of phosphorylcholine, known for its hemocompatible properties. This procedure leads to a covalent attachment of the molecules, therefore preventing their removal by shear stress induced by blood flow at the implant wall. The improvement of the blood compatibility properties of the modified ePTFE arterial prostheses have been investigated by in vitro tests such as thromboelastography, neutrophil adsorption, platelet aggregation, and cell cultures. These in vitro tests put in evidence that thrombogenicity index, platelet aggregation, and neutrophil adhesion were decreased by the molecule grafted on the prostheses. Moreover, the cell growth on the surface of the PRC-grafted prostheses was greatly enhanced in comparison to the virgin prosthesis. Based on these results, it could be concluded that PRC grafting on ePTFE prostheses permit to improve in vitro hemocompatibility and biocompatibility in comparison with their virgin counterpart.     

Application of the finite-element method to improve the quasi-exact reinforcement theory of fibrous polymeric composites

In the paper, the WL quasi-exact reinforcement theory of fibrous polymeric composites is improved. An optimum compatibility condition related to the transverse shear problem for a unit cell, which brings solutions closest to reality, is derived. This condition is formulated in the form of a linear combination of maximum radial and circumferential displacements. Optimum coefficients of this combination are determined by comparing analytical and numerical solutions for a test specimen in the form of a rectangular thin plate, which is in a plane strain state and is subject to selected loading schemes. The analytic solutions are obtained for a homogenized material by using the WL reinforcement theory. The numerical solutions are found for an actual heterogeneous composite material by using the finite-element method, and they verify the WL reinforcement theory, in particular, the admissibility of Hills assumption. An analysis performed for two composite materials shows that the improved WL reinforcement theory gives adequate displacement fields.Russian translation published in Mekhanika Kompozitnykh Materialov, Vol. 41, No. 1, pp. 79–92, January–Febrauary, 2005.     

Scheduling on a Batch Processing Machine with Split Compatibility Graphs

We consider the problem of minimizing the makespan on a batch processing machine, in which jobs are not all compatible. Only compatible jobs can be included into the same batch. This relation of compatibility is represented by a split graph. All jobs are available at the same date. The capacity of the batch processing machine is finite or infinite. The processing time of a batch is given by the processing time of the longest job in the batch. We establish the NP-hardness of the general problem and present polynomial algorithms for several special cases.     

Compression Bases in Unital Groups

We introduce and launch a study of compression bases in unital groups. The family of all compressions on a compressible group and the family of all direct compressions on a unital group are examples of compression bases. In this article we show that the properties of the compatibility relation in a compressible group generalize to unital groups with compression bases. PACS Classification Primary 03.65.Fd. Secondary 02.30 Tb. AMS Classification: Primary 06F20. Secondary 47A20.     

Organotin wood preservatives: Their compatibility with synthetic pyrethroid insecticides

The stability of three synthetic pyrethroids (cypermethrin, deltamethrin and permethrin) to selected tributyltin compounds, Bu₃SnX [where X = OSnBu₃, Cl, O₂CC₆H₅, O₂C(naphthenyl), OSO₂C₂H₅], (Bu₃SnO)₃PO and (Bu₄N) (Bu₃SnCl₂), in toluene solution was investigated by infrared spectroscopy over a 24-week period. It was found that only (Bu₃Sn)₂O reacted with the pyrethroids and that their order of reactivity was cypermethrin>deltamethrin>permethrin. An attempt was made to elucidate the reaction mechanism(s) occurring between (Bu₃Sn)₂O and the pyrethroids by studying mixtures of this tributyltin fungicide with simple model compounds, R¹CO₂R² where R¹=CH₃; R²=CH₂C₆H₅ and R¹=cyclo-C₃H₅ and R²=CH₂C₆H₅.     

聚丙烯改性及应用的最新进展

本文综述了1990年以来聚丙烯（PP）的氧化、卤化、硼化、辐射接枝及其它末端功能化改性、其粘接能力、相容性的改善及在工程材料作为相容剂的应用的最新进展．