面向并行设计的局部特征识别技术研究

为支持在并行设计过程中设计特征模型到加工特征模型的逐步转换，提出了局部特征识别的方法．在并行设计中，设计特征模型和加工特征模型通过面名历史图共享零件的实体模型，设计特征的变动通过局部特征识别自动地转换为相应的加工特征．局部特征识别是由基于最小条件子图特征识别方法改进来的，它以零件的局部区域为识别对象，通过搜索匹配局部区域构成的边界模式，识别出该局部区域中所包含的加工特征．局部特征识别方法的特点是只对设计中发生变动的区域进行识别．     

Effective central potentials for molecular fluids

A recent suggestion by Lebowitz and Percus that the median intermolecular potential may serve as a simple temperature-independent effective central potential is tested against virial inversion data for the site-site Lennard-Jones potential obtained by Smith and Tindell. Excellent agreement is found even when the anisotropy in the potential is large. Second virial coefficients computed from the effective potential reproduce the true values to a high degree of accuracy.     

Simultaneous gas chromatographic analysis for the four commonly used antiepileptic drugs in serum.

We describe a simple, sensitive method for the determination of phenobarbital, diphenylhydantoin, carbamazepine and primidone in serum, by use of gas-liquid chromatography with temperature programming. The methylated derivatives of these anticonvulsants were well resolved, as was 5-(p-methylphenyl)-5-phenylhydantoin, the internal standard. In this procedure we used an ion-exchange resin for separation of the drug from the serum. The proposed procedure requires only 1.0 ml of serum and can be done in less than 1 h. The lower limit of detection for each of the drugs is 0.5 mg/1. Analytical recoveries of drug from serum were excellent and peak height and concentration were linearly related up to twice the toxic concentration for serum.     

Further electrochemical investigations of the oxidation of 1-phenylpyrazolidin-3-ones at high pH

The oxidation mechanism at pH 14 for a number of 1-phenylpyrazolidin-3-ones substituted in the 4 position of the heterocyclic ring has been investigated with electrochemical techniques. A general oxidation mechanism, resulting in the formation of a radical species and short-lived pyrazolinone tautomers has been postulated.     

Coordination chemistry of 4-methyl-2,6,7-trioxa-1-phosphabicyclo[2,2,1]heptane: preparation and characterization of Ru(II) complexes

The complexes TpRu[P(OCH(2))(2)(OCCH(3)](PPh(3))Cl (2) [Tp = hydridotris(pyrazolyl)borate; P(OCH(2))(2)(OCCH(3)) (1) = (4-methyl-2,6,7-trioxa-1-phosphabicyclo[2,2,1]heptane] and TpRu(L)(PPh(3))Cl [L = P(OCH(2))(3)CEt (3), PMe(3) (4) or P(OMe)(3) (5)], (η(6)-C(6)H(6))Ru(L)Cl(2) [L = PPh(3) (6), P(OMe)(3) (7), PMe(3) (8), P(OCH(2))(3)CEt (9), CO (10) or P(OCH(2))(2)(OCCH(3)) (11)] and (η(6)-p-cymene)Ru(L)Cl(2) [L = P(OCH(2))(3)CEt (12), P(OCH(2))(2)(OCCH(3))P(OCH(2))(2)(OCCH(3)) (13), P(OMe)(3) (14) or PPh(3) (15)] have been synthesized, isolated, and characterized by NMR spectroscopy, cyclic voltammetry, mass spectrometry, and, for some complexes, single crystal X-ray diffraction. Data from cyclic voltammetry and solid-state structures have been used to compare the properties of (1) with other phosphorus-based ligands as well as carbon monoxide. Data from the solid-state structures of Ru(II) complexes show that P(OCH(2))(2)(OCCH(3)) has a cone angle of 104°. Cyclic voltammetry data reveal that the Ru(II) complexes bearing P(OCH(2))(2)(OCCH(3)) have more positive Ru(III/II) redox potentials than analogous complexes with the other phosphorus ligands; however, the Ru(III/II) potential for (η(6)-C(6)H(6))Ru[P(OCH(2))(2)(OCCH(3))]Cl(2) is more negative compared to the Ru(III/II) potential for the CO complex (η(6)-C(6)H(6))Ru(CO)Cl(2). For the Ru(II) complexes studied herein, these data are consistent with the overall donor ability of 1 being less than other common phosphines (e.g., PMe(3) or PPh(3)) or phosphites [e.g., P(OCH(2))(3)CEt or P(OMe)(3)] but greater than carbon monoxide.