Studies on the properties of flow-induced oscillation and sound radiation in streamlined protuberant special cavities

I.IntroductionAsanuidpassingthroughthecavityatcertainflowrate,themediuminthemouthandthccavityisoscillatingandsoundisradiated.Noton1ystochasticturbu1encenoiscispossi-blyproducedbutsinglefrequencysoundofspecia1lydesignatedpitchisalsoproduced.Andthusthespcctrumofthcradiatedsoundisshownascontinuousspectrumandcharacteristiclinespcctrum.Inthiscascwcmaycallitflow-inducedosci1lation.Flow-inducedoscillationandsoundradiationcanbeproducedasafluid(waterorgas)passingthroughthecavitybysinkingcavityunderint…     

球约束凸二次规划的一个新算法

首先利用Lagrange对偶 ,将球约束凸二次规划问题转化为无约束优化问题 ,然后运用单纯形法求解无约束优化问题 ,从而获得原问题的最优解     

搜索三个目标

本文通过建立简洁而有效的搜索方法 ,证明了对于无穷多个n来说 ,三个目标的最优搜索问题的最小试验次数等于信息论下界 .同时也研究了上述问题的修正情形 ,证明了对于所有整数n来说 ,对应的最小试验次数或者等于信息论下界或者超过信息论下界 1次并且对于无穷多个区间 ,信息论下界均是可以达到的 .     

紧交换半群上概率测度卷积序列的极限性质

本文用“部分群化”的方法研究紧交换半群上概率测度的极限性质.§3讨论 i.i.d 的情形,将紧群上的 Kawada-It(?)型结果以相应的形式建立到紧交换半群上.§4讨论独立非同分布的情形,建立了紧交换半群上的强 Kloss 收敛准则,它曾由苏联学者 Maksimov先后在有限群([1])与紧群上([2])得到.     

On a Boolean-valued Model of the Strict Implication System(Continuous)

The reference [4] proved the consistency of S1 and S2 among Lewis' five strict implication systems in the modal logic by using the method of the Boolean-valued model. But, in this method, the consistency of S3, S4 and S5 in Lewis' five strict implication systems is not decided. This paper makes use of the properties: (1) the equivalence of the modal systems S3 and P3, S4 and P4; (2) the modal systems P3 and P4 all contained the modal axiom T(□p → p); (3) the modal axiom T is correspondence to the reflexive property in VB. Hence, the paper proves: (a) ‖As31‖ = 1; (b) ‖AS41‖ = 1; (c) ‖AS5l‖ = 1 in the model (where B is a complete Boolean algebra, R is reflexive property in VB). Therefore, the paper finally proves that the Boolean-valued model VB of the ZFC axiom system in set theory is also a Boolean-valued model of Lewis' the strict implication system S3, S4 and S5.     

The Spaces b~p with 0 < p < 1

Let 0 < p < 1. In this paper we prove that the Bergman norm on the p-th Bergman space bp(H) is equivalent to certain "normal direction norm" as well as certain "tangential direction norm", where H = Rn-1 × R is the upper half space. As an application, we get the boundedness of harmonic conjugation operators on bp(H).     

集值映射的切导数与向量优化问题的最优性条件

利用集值映射切导数与半可微概念，给出了无约束与具约束的集值向量优化问题局部真有效解与局部强有效解的最优性条件。     

Click chemistry in materials synthesis. III. Metal‐adhesive polymers from Cu(I)‐catalyzed azide–alkyne cycloaddition

1,2,3‐Triazole‐based polymers generated from the Cu(I)‐catalyzed cycloaddition between multivalent azides and acetylenes are effective adhesive materials for metal surfaces. The adhesive capacities of candidate mixtures of azide and alkyne components were measured by a modified peel test, using a customized adhesive tester. A particularly effective tetravalent alkyne and trivalent azide combination was identified, giving exceptional strength that matches or exceeds the best commercial formulations. The addition of Cu catalyst was found to be important for the synthesis of stronger adhesive polymers when cured at room temperature. Heating also accelerated curing rates, but the maximum adhesive strengths achieved at both room temperature and high temperature were the same, suggesting that crosslinking reaches the same advanced point in all cases. Polytriazoles also form adhesives to aluminum, but copper is bound more effectively, presumably because active Cu(I) ions may be leached from the surface to promote crosslinking and adhesion. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5182–5189, 2007     

虚拟技术在实验教学中的应用

介绍了虚拟技术在实验教学改革中的作用与意义，探讨了电子信息系统实验教学改革的新思路与实现措施，并总结了实验教学改革的初步成果．     

Study on Inhibitors of Methionine Synthase Ⅷ: Synthesis of 2,5-Diamino-4-oxo-6- (3-butenyl) pyrimidine

Cobalamin-dependent methionine synthase plays a crucial role in folate metabolism and such would appear to be an excellent target for rational antifolate drug design. However, to date, no anticancer agents directed at this enzyme are available, but the enzyme is efficiently and specifically inhibited by N2O and this has proven invaluable for evaluating the biochemical consequence of enzyme inhibition and for mechanistic studies. [1,2] 2,5-Diamino-4-oxo-6-(3-butenyl) pyrimidine, a key intermediate in synthetic inhibitors of methionine synthase, was first synthesized using γbutenyl-β-ketoester and guanidine carbonate (Scheme 1). [3]