最小费用k度限制树对策

本在Glover—Klingman算法及最小费用支撑树对策的基础上，讨论了最小费用k度限制树对策问题．利用威胁、旁支付理论制订了两种规则，并利用优超、策略等价理论分别给出了在这两种规则下最小费用k度限制树对策核心中的解，从而证明了在这两种规则下其核心非空．     

醇盐法制备稀土化合物超微粉末

稀土元素具有广泛的用途,在大多数的应用中其效果都与原料的纯度、粒度、粒经分布范围等因素有关。由于超微粉末的比表面积大、化学活性高,因此可以预料,若将稀土化合物制成超微粉末,会使它的催化性能及在各种材料中的性能有明显的改变,也可使稀土有新的、更高的应用价值。     

Microemulsion-mediated solvothermal synthesis of SrCO3 nanostructures

The controlled synthesis of SrCO3 nanostructures with different morphologies, such as rodlike, whiskerlike, ellipsoidlike, and spherelike, were successfully achieved by the cationic surfactant-CTAB-microemulsion-mediated solvothermal method. Various comparison experiments showed that fundamental experimental parameters, such as the molar ratio of H2O to CTAB and the concentration of reactants, played important roles in the morphological control of SrCO3 nanostructures. A lower molar ratio of H2O to CTAB favors rodlike products, whereas a higher molar ratio generally leads to the formation of spherical products. A rational mechanism based on fusion, aggregate, and coalescence of microemulsion droplets is proposed for the selective formation of various morphologies. X-ray powder diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and field-emission scanning electron microscope (FE-SEM) were used to characterize the products.     

Pt粒大小对PtNaY/HY体系氢溢出效应的影响

负载型金属催化剂的表面溢出效应(Spillover)是指吸附在金属上的物种可沿固体表面转移到担体上去的现象,是金属活性组分与担体相互作用的一个重要方面。近年来随着金属与担体之间强相互作用(SMSI)研究的逐渐深入,人们注意到溢出效应在SMSI中的重要作用。虽然提出溢出效应已有20多年的历史,并且人们采用不同的实验方法对此进行了广泛的研究,但对以分子筛为担体的负载型金属催化剂体系溢出效应的研究仍比较少。影     

Carboxylic acid functionalization of nylon 6 by radiation grafting and conversion to zinc salts: Effects on physical properties

 Functionalization of polymers by grafting monomeric species on to the backbone of molecular chains with the use of γ-radiation has been used extensively. In this work methacrylic acid was grafted onto a commercial grade of polycaproamide (Nylon 6) by preirradiating the polymer granules to 15 kGy at a rate of 1.0 kGy per hour and subsequently immersing these in a 10% aqueous solution of methacrylic acid in the presence of small quantities of FeSO₄ as homopolymerization inhibitor. The polymer was subsequently neutralized by mixing it with zinc acetylacetonate in a laboratory scale melt mixing device. The acid-grafting polymer modification resulted in an increase in glass transition temperature, while the addition of zinc acetylacetonate gave rise to two transitions: The lower transition corresponds to a miscible mixture of free polyamide and acid-grafted polymer, both plasticized with undecomposed zinc compound, while the upper transition corresponds to the zinc salt of the acid grafted polyamide. Through rheological measurements it was shown that both the acid-grafted polymer and the derived zinc salt have a branched structure, possibly containing also some crosslinked domains. Large improvements in solvent resistance were observed for both type of polymer modifications. Received: 13 December 1996 Accepted: 10 February 1997     

Formation and Crystal Structure of Stable Five‐coordinate Diorgano Cobalt(III) Complexes

The mer‐octahedral complexes(2‐carbonyl)(4‐Me)(6‐tBu)phenolato[C,O]hydridotris(trimethylphosphine)cobalt(III) ( 1 ) or ‐(1‐carbonyl)(2‐oxo)(1,2‐diphenylethene)[C,O]hydridotris(trimethylphosphine)cobalt(III) ( 2 ) via formal insertion of propynoic acid ethyl ester into Co‐H functions afford pentacoordinate vinylcobalt(III) 3 and 4 , respectively, that are diamagnetic and attain a square pyramidal structure as exemplified by an X‐ray diffraction analysis of 3 .     

过敏性哮喘患者血清中10种必需微量元素水平的研究

３４例过敏性哮喘患者血清中铁，锌、铜，锰硒铬，钴镍，钡，钼的含量水平与对照组比较，揭示：（１）铁，铜，铬的含量升高；（２）硒，镍，钴、钒的钼的含量降低；（３）锌和锰的含量差异无显著性，Ｐ〉０．０５。     

Simultaneous determination of chlorpheniramine and pseudoephedrine in human plasma by liquid chromatography-tandem mass spectrometry

A sensitive and specific procedure for simultaneous quantitation of chlorpheniramine and pseudoephedrine in human plasma has been developed and validated. Analytes were extracted from plasma samples by liquid-liquid extraction, separated on a Diamonsil C18 column (250 x 4.6 mm i.d.) and detected by tandem mass spectrometry with an atmospheric pressure chemical ionization interface. Diphenhydramine was used as the internal standard. The method has a lower limit of quantitation of 0.2 and 2.0 ng/mL for chlorpheniramine and pseudoephedrine, respectively. The intra- and inter-day relative standard deviation, calculated from quality control (QC) samples were below 4.3% for chlorpheniramine and below 9.5% for pseudoephedrine. The inter-day relative error as determined from QC samples was within 4.7% for each analyte. The overall extraction recoveries of chlorpheniramine and pseudoephedrine were 77 and 61% on average, respectively. The method was successfully applied to pharmaockinetic study of chlorpheniramine and pseudoephedrine in volunteers receiving formulations containing 4 mg of chlorpheniramine maleate and 60 mg of pseudoephedrine hydrochloride.