过冷沸腾非均相汽泡界面特性分析

本文针对过冷沸腾中汽泡顶部射流现象进行分析与模拟。建立汽泡界面模型,考虑蒸发凝结以及Marangoni效应。利用CFD软件Fluent6.0对模型进行计算分析,成功模拟得到泡顶射流流场。模拟结果无论是流场结构,还是流场强度,都与实验一致吻合,充分证明泡顶射流由Marangoni效应引起。     

Tunable All-Optical Microwave Filters Based on Fiber Loop and Chirped Fiber Bragg Gratings

All-optical microwave filters are important parts of fiber-optic microwave/millimeter wave processing systems. In this paper, two novel passive tunable all-optical microwave filters based on fiber loop and chirped fiber Bragg gratings (CFBGs) are demonstrated, where the frequency response of the both filters can be continuously tuned by adjusting the wavelength of the input light. The required free spectral range (FSR) of the filters can be obtained by carefully controlling the length of fiber loop and the positions of the CFBGs in the fiber loop. Experimental results prove the feasibility of the proposed filtering structures.     

基于支持向量机的中国工业增加值预测研究

工业增加值是衡量一个国家工业发展水平的重要指标。由于其受多种因素影响，对其预测相对困难。本文提出运用时间序列预测方法对其预测，并利用支持向量机和微分进化算法（differential evolution，DE）相结合的方法对中国工业增加值数据进行预测。数据仿真显示该模型比核主成分分析的最小二乘支持向量机（KPCA-LS-SVM）以及岭回归（ridge regression，RR）具有更高的预测精度。     

LC–MS–MS Study of the Pharmacokinetics of a 9-β-Dihydro-9,10-O-acetal Derivative of Docetaxel in Rats and Beagle Dogs

SHR110008 is a representative 9-β-dihydro-9,10-O-acetal taxane with greater anticancer activity and less toxicity than docetaxel. To support a preclinical study of its pharmacokinetics and to predict the effect of 9-β-dihydro-9,10-O-acetal modification on its pharmacokinetic properties, we have developed a sensitive and rapid liquid chromatographic–tandem mass spectrometric method for quantitative analysis of SHR110008 in rat and dog plasma. Plasma was extracted with ethyl acetate. The analytes were separated on a 150 × 4.6 mm i.d., 5 μm particle, reversed-phase C₁₈ column with 90:10 (v/v) methanol–0.1% formic acid as mobile phase at a flow rate of 0.3 mL min⁻¹. Detection was performed by triple-quadrupole tandem mass spectrometry in selected reaction monitoring (SRM) mode with an electrospray ionization source. The precursor-to-product ion transition m/z 933 → 142 was used. The method was validated for accuracy and precision, and linearity in the two matrices was good. Lower limits of quantification (LLOQ) in rat and dog plasma were 5 and 2 ng mL⁻¹, respectively. There were no stability-related problems in the procedure for analysis of SHR110008. The method was successfully used in a preclinical study of the pharmacokinetics of SHR110008 in rats and beagle dogs. The pharmacokinetics of SHR110008 were non-linear in rats and dogs. The elimination half-life ranged from 5.18 to 7.32 h for the rats and from 6.42 to 8.42 h for the dogs.

     

城市交通管理中的出租车规划模型

最佳数量的确定和价格的制定是城市出租车规划中的两个核心问题.对影响出行强度的市区人口和建成区面积分析建立了出行总量预测模型,再通过分析出租车最佳数量与出租车运营里程的关系,得出出租车最佳数量的预测模型.在出租车最佳数量模型的基础上,分析出租车数量的差异和差异产生的原因,给出了出租车定价判断模型,为出租车定价机制的调整指明了方向.最后以长沙市为例进行了实证分析.     

Synthesis and characterization of a series of 2‐aminopyridine nickel(II) complexes and their catalytic properties toward ethylene polymerization

A series of 2‐aminopyridine Ni(II) complexes bearing different substituent groups {(2‐PyCH₂NAr)NiBr, Ar = 2,4,6‐trimethylphenyl ( 3a) , 2,6‐dichlorophenyl ( 3b ), 2,6‐dimethylphenyl ( 3c) , 2,6‐diisopropylphenyl ( 3d ), 2,6‐difluorophenyl ( 3e ); (2‐PyCH₂NHAr)₂NiBr₂, Ar = 2,6‐diisopropylphenyl ( 4a )} have been synthesized and investigated as precatalysts for ethylene polymerization in the presence of methylaluminoxane (MAO). High molecular weight branched polymers as well as short‐chain oligomers were simultaneously produced with these complexes. Enhancing the steric bulk of the ortho‐aryl‐substituents of the catalyst resulted in higher ratio of solid polymer to oligomer and higher molecular weight of the polymer. With ortho‐haloid‐substitution, the catalysts afforded a product with low polymer/oligomer ratio ( 3b ) and even only oligomers ( 3e ) in which C₁₄H₂₈ had the maximum content. Compared with complex 3d containing ionic ligand, complex 4a containing neutral ligand exhibited obviously low catalytic activity for ethylene polymerization. The molecular weight, molecular weight distribution, and microstructure of the resulted polymer were characterized by gel permeation chromatography and ¹³C NMR spectrogram. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1618–1628, 2008     

Schiff碱作为桥配体的双核钌化合物的合成与性质

合成并表征了3个Schiff碱配体及由其桥联的3个双核钌配合物,并通过核磁共振谱、红外光谱、质谱及元素分析等测试手段对配体及化合物进行了表征.电化学测试结果表明,在3个双核配合物中存在着分子内的金属-金属间相互作用,且连接两个金属的桥配体是影响金属间相互作用强弱的关键因素.