EXISTENCE AND DECAY OF WEAK SOLUTIONS TO DEGENERATE DAVEY-STEWARTSON EQUATIONS

In this paper, the authors consider a system of degenerate Davey-Stewartson equations. They prove the global existence of weak solutions in some weighted function spaces and the decay of weak solutions in some anisotropic spaces for appropriate initial data.     

ON THE DISTRIBUTION OF VALUES AND DEFICIENT FUNCTION OF A GENERAL RANDOM INTEGRAL FUNCTION

We consider the random power serie8aoIw(z) = ZX.(w)z", (1)n =Owhere {Xn} is a 8equence of complex random variables in a probability spare (Q, F, P).Lemma 1 Supose that {Xn) is independent ai1d that there exists a positive coustallt crsuch thatVn 2 l, o'a: = a'ElXn l' S E'lX.l < oo. (2)Then for w e n, there exists a natural nunther N(w) a.s. such that for n > N(w)IXn(w)l 5 nrrn. (3)If {X.* } is any subsequence Of {X.}, thenP (ltL(lXn*l 2;rru*) = l. (4)Proof When ny = 0,X. = 0 a.s. …     

Optimal paths for a light-driven engine with a linear phenomenological heat transfer law

An irreversible light-driven engine is described in this paper, in which the heat transfer between the working fluid and the environment obeys a linear phenomenological heat transfer law [ q ∝Δ(T -1)], with a working fluid composed of the bimolecular reacting system 2SO 3 F■S 2 O 6 F2. Piston trajectories maximizing work output and minimizing entropy generation are determined for such an engine with rate-dependent loss mechanisms of friction and heat leakage. The optimal control theory is applied to determi...     

Synthesis and characterization of six-arm star-shaped liquid crystalline cyclotriphosphazenes

<正>The synthesis and mesomorphic properties of a new class of liquid crystalline cyclotriphosphazenes with rigid cyanostilbene groups and flexible alkoxy groups are reported.The thermal behaviors of cyclotriphosphazene derivatives 5a-5d are studied by the means of differential scanning calorimetry,polarizing optical microscopy.Nematic phases were observed in compounds 5a-5d both on heating and cooling.The clear temperatures of compounds 5a-5d slightly increased with increasing length of terminal alkyl chain.Compounds 5a-5d showed different mesogenic region from minimum 5℃to maximum 142℃.     

电热蒸发ICP-AES法直接测定人血清中微量元素

建立了悬浮体制样电热蒸发电感耦合等离子体原子发射光谱法(ETVICPAES)直接测定人血清中微量元素(Cu,Cr,Fe)的方法。采用聚四氟乙烯(PTFE)悬浮体为化学改进剂,以促进待测物的蒸发,改善方法的分析性能。研究了影响待测元素信号强度的主要因素。在优化实验条件下,方法的检出限为14ng·mL-1(Cu)和29ng·mL-1(Fe),相对标准偏差小于60%。     

关于岩石水力模型

本文对近几年来岩石水力模型、试验及工程应用情况进行了分析和讨论。      

DCS——偶氮胂与稀土元素显色反应及其在水分析中的应用

本文研究了DCS——偶氮胂与稀土的显色反应,在测定水中稀土时,用PMBP萃淋树脂分离干扰元素。用计算机处理实验数据,相关系数r=0.9992,分析结果令人满意。     

具有鲁棒性的矩形窄带滤光片的自动设计

分析了用于WDM光纤通信系统的全介质多腔窄带滤光片的膜系结构特点及其所必须具备的光学特性,提出了一种利用最优化方法的原理,通过计算机寻优来自动完成其膜系设计的方法;构造了合理的评价函数,编制了可自动搜索既满足设计目标、又具有鲁棒性的最优化膜系的计算机程序;使用本程序所设计出的多腔窄带滤光片具有较小的纹波系数和较好的矩形度,可满足WDM光纤通信系统对其分波/复波器的要求.     

配位交换色谱在α-氨基酸光学拆分上的应用

对以不对称配位树脂为固定相,利用配位变换色谱拆分DL-氨基酸的国内外进展,进行了扼要的综述。     

Conformation and dynamics of polyoxyethylene lauryl ether (Brij-35) chains in aqueous micellar solution studied by 2D NOESY and 1H NMR relaxation

Spin-lattice relaxation time, spin-spin relaxation time and two-dimensional nuclear Overhauser enhancement spectroscopy (2D NOESY) experiments of polyoxyethylene lauryl ether (Brij-35) micelles in aqueous solutions at a concentration of 100 times the critical micellar concentration (cmc) give direct evidence that the hydrophilic polyoxyethylene chains, staying in the exterior of the micellar core, are coiled, bent and aligned around the micellar core with a certain number of water molecules included. This hydrophilic layer is in contact with the solvent, water, keeping the micellar solution stable. 1H NMR relaxation time measurements show that the first oxyethylene group next to the alkyl chain participates in the formation of the surface area of the micellar core. The motion of the hydrophilic polyoxyethylene chains is less restricted as compared with the hy-drophobic alkyl chains.