室温固相反应一步合成N-亚水杨基-4-氨基安替比林

4-氨基安替比林与水杨酬醛通过室温固相反应合成N-亚水杨基-4-氨基安替比 林，反应无溶剂，15 min即可完成，产率达95%，用元素分析，IR，~1H NMR，X射 线粉末衍射和X射线单晶衍射对产物进行了表征。     

Fully aromatic thermotropic liquid crystalline polyesters of substituted 4,4′-biphenols. IV. Homopolyesters with terephthalic acid and copolyesters with terephthalic acid and 4-hydroxybenzoic acid

A series of fully aromatic thermotropic polyesters based on mono-, di-, and tetra-substituted biphenols was prepared by the melt polycondensation method and examined for their thermotropic behavior by a variety of experimental techniques. The homopolyesters obtained from substituted biphenols containing either one phenyl or two phenyl groups as substituent(s) and TA formed nematic melts, but the homopolymers of the substituted biphenols containing either four sec-butyl groups or two tert-butyl groups with TA had melting transitions, T_m, above 400°C. Thus, it was not possible to determine whether they formed nematic melts. On copolymerization with 30 mol % HBA most of the resulting copolyesters had much lower T_m values, compared to those of respective homopolyesters, and the copolymers of the biphenol monomer containing the tert-butyl groups formed a nematic melt at an observable temperature. However, the copolymer of the biphenol with sec-butyl groups still had a T_m above 400°C. © 1993 John Wiley & Sons, Inc.     

On the Integration by Parts and Characterization of a Fractional Diffusion Process北大核心CSCD

本文研究分数扩散过程和其分部积分公式的关系.首先利用Bismut方法给出拉回公式,进而得到分数扩散过程的分部积分公式。反过来,证明了分数扩散过程可由其分部积分公式唯一刻画.     

A new approach to agglomeration problems

In this paper, we study a location problem with positive externalities. We define a new transferable utility game, considering there is no restriction on the transfer of benefits between firms. We prove that the core of this game is non-empty, provide an expression for it, and an axiomatic characterization. We also study several core allocations, selected by means of a certain bankruptcy problem.     

Normalized Dynamic Characterization and Application of Multiple Heat Storage Materials Based on Standard Thermal Resistance北大核心CSCD

基于标准热阻和能量流法,推导出储热材料与换热流体的瞬态换热热阻,通过类比电路分析法,获得了储热-换热过程的瞬态热量流模型及动态响应时间常数。进一步引入节点温度,重新定义换热热阻,获得了储热与换热过程耦合的三阶电路瞬态热量流模型,求解得到了加热、储热和释热三类时间常数,可用于协同表征储热材料中储热与释热的快慢程度,从而实现了多类储热材料的归一化动态表征。通过数值模拟验证与应用对比分析,发现基于多时间常数的归一化动态模型用于表征储热材料的动态特性是可行的,可直接对不同换热、储热材料进行对比分析。案例分析发现与固体储热材料换热时,液态金属的动态换热能力优于熔融盐,而相比于水蒸气和CO₂,空气与陶瓷材料换热能更快达到稳态。     

配合物聚合反应研究──Ⅱ．以二氨基磺磷酸盐配合物合成聚脲

以二氨基磺酸盐配合物合成了一系列主链上合金属元素（Ｃａ，Ｎｉ，Ｃｏ，Ｃｕ）的聚脲聚合物．用ＩＲ和１ＨＮＭＲ对其结构进行了表征，以ＴＧ－ＤＴＡ研究了其热性能，并讨论了金属元素种类及其含量对聚脲聚合物溶液粘度的影响．     

Necessary conditions for characterization of laws via mixed sums

SupposeX andY are independent and identically distributed, and independent ofU which satisfies 0U1. Recent work has centered on finding the lawsL(X) for whichX U(X+Y) where denotes equality in law. We show that this equation corresponds to a certain projective invariance property under random rotations. Implicitly or explicitly, it has been assumed that the characteristic function ofX has an expansion property near the origin. We show that solutions may be admitted in the absence of this condition when –logU has a lattice law. A continuous version of the basic problem replaces sums with a Lévy process. Instead we consider self-similar processes, showing that a solution exists only whenU is constant, and then all processes of a given order are admitted.This research was in part supported by NSERC grant A-8466.     

HRGC of wine free amino acids as a tool for elementary wine characterization

In this paper we show that wine free amino acids derivatized as isopropyl N-heptafluorobutyryl esters can be used as a tool for wine characterization. Elementary wines of eight Vitis vinifera varieties were studied during a seven year period. The characteristic wine amino acids for each variety were assessed by means of pattern recognition techniques. A “star symbol plot” was used for graphic representation.     

Preparation of amphiphilic polyisobutylenes-b-polyethylenamines by mannich reaction. I. Synthesis and characterization of α-phenololigoisobutylenes

The cationic polymerization of isobutylene initiated by 4-(2-hydroxy-2-propyl)phenol/BCl₃ system results mainly in α-phenol-ω-chlorooligoisobutylene; however p-(2-chloro-2,4-dimethyl-4-pentyl)phenol is present in all cases. α-Methyl-ω-chlorooligoisobutylene is formed only when the temperature is below?50°C; it results from initiation by the phenol/BCl₃ system. Thermal dehydrochlorination of α-phenol-ω-chlorooligoisobutylene is quantitative and leads to a mixture of isomeric ω-unsaturated oligoisobutylenes. α-Methyl-ω-phenololigoisobutylene is prepared by the Friedel—Crafts reaction between industrial unsaturated oligoisobutylene and phenol in the presence of SnCl₄ at ?30°C; the reaction is quantitative between ?50 and ?30°C degradation takes place. © 1993 John Wiley & Sons, Inc.     

Multi-element Saha–Boltzmann and Boltzmann plots in laser-induced plasmas

A multi-element Saha–Boltzmann plot method is proposed for the determination of the temperature and the relative number density in laser-induced plasmas, assuming local thermodynamic equilibrium and stoichiometry conservation. The method has been applied to the characterization of a plasma generated with a Cu–Fe–Ni–Mn alloy, using a Nd:YAG laser in air at atmospheric pressure. Spectra of the local emissivity have been obtained by spatial deconvolution of the intensity spectra, obtained with spatial resolution. Saha–Boltzmann plots obtained from the emissivities of 58 spectral lines of Fe I, Fe II, Ni I, Ni II, Mn I and Mn II have been fitted to linear behavior with high correlation, which shows the validity of the equation proposed. Radial distributions of the temperature and number densities of neutral atoms and ions have been determined. The results obtained reinforce the initial considerations of local thermodynamic equilibrium and conservation of stoichiometry. The proposed equation can also be applied to only one ionization species (multi-element Boltzmann plot). Spatially-integrated measurements of the plasma emission have also been performed to show that, in this case, the application of the method to the line intensities provides the two different apparent temperatures for neutral atoms and ions.