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Flow-injection chemiluminescence determination of tryptophan using galangin-potassium permanganate-polyphosphoric acid system

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Chinese Chemical Letters 2008年第2期19卷 203-206页

作者： hui chen li li Min Zhou Yong Jun Ma College of Chemistry and Chemical Engineering Gansu Key Laboratory of Polymer Materials Northwest Normal University Lanzhou 730070 China

A high sensitive flow-injection chemiluminescence （FI-CL） method for the determination of tryptophan has been developed. The method is based on the chemiluminescence reaction of galangin-potassium permanganate-tryptophan in polyphosphoric acid （PPA） media. Under the optimized conditions, tryptophan was determined in the range 0.05-10 μg/mL with the detection limit （3tr） of 5.0 × 10^-3 μg/mL. The relative standard deviation （RSD） was 1.0% for 11 replicate determinations of 1.0 μg/mL tryptophan. Three synthetic samples were determined selectively with recoveries in the range from 99.6% to 102.0% in the presence of other amino acids.

关键词： Chemiluminescence Flow-injection Galangin Potassium permanganate Tryptophan

One pot synthesis of bis-silicon-bridged stilbene derivatives

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Chinese Chemical Letters 2007年第12期18卷 1436-1438页

作者： chen hui li Hua Yu Qiu Cai Hong Xu Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education Hangzhou Teachers College Hangzhou 310012 China Institute of Chemistry Chinese Academy of Sciences Beijing 100080 China

Bis-silicon-bridged stilbene derivatives were synthesized in a modified procedure that combined the preparation of bis[2- （silyl）phenyl]acetylene and its intramolecular reductive cyclization in one pot. The results indicated that the one pot approach produced target products in a comparable yield to that of the two-step method reported previously.

关键词： Bis-silicon-bridged stilbene Reductive cyclization One pot synthesis

Identification and evolution-ary implication of four novel box H/ACA snoRNAs from Giardia lamblia

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Chinese Science Bulletin 2006年第20期51卷 2451-2456页

作者： LUO Jun ZHOU hui chen Chongjian li Yan chen Yueqin QU lianghu Key Laboratory of Gene Engineering of the Ministry of Education StateKey Laboratory for Biocontrol Zhongshan University Guangzhou510275 China

From a specialized cDNA library, four novel box H/ACA snoRNAs, named GLsR22, GLsR23, GLsR24 and GLsR25, were identified from the primitive eukaryote, Giardia lamblia. Bioinformat- ics analyses indicated that all of them can be poten- tially folded into double hairpins, the typical secon- dary structures of box H/ACA snoRNAs. GLsR24 and GLsR25 are predicted to guide the site-specific pseudouridylation at U1753 and U2396 on 23S rRNA, respectively, while GLsR22 and GLsR23 belong to the family of “orphan” snoRNAs. All of the four novel snoRNAs are encoded by single copy genes and located in small intergenic regions. Interestingly, compared with the counterparts previously reported in Archaea and other unicellular protozoan, the box H/ACA snoRNAs identified from G. lamblia have unique structural features, implying that snoRNAs evolved from prokaryotes to eukaryotes in different ways.

关键词：贾第虫兰氏鞭毛虫基因工程核糖核酸

Abnormal breakdown of Stokes–Einstein relation in liquid aluminium

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Chinese Physics B 2017年第1期26卷 333-343页

作者： chen-hui li Xiu-Jun Han Ying-Wei Luan Jian-Guo li Laboratory of Advanced Materials Solidification School of Materials Science and Engineering Shanghai Jiao Tong University Shanghai 200240 China

We present the results of systematic molecular dynamics simulations of pure aluminium melt with a well-accepted embedded atom potential. The structure and dynamics were calculated over a wide temperature range, and the calculated results（including the pair correlation function, self-diffusion coefficient, and viscosity） agree well with the available experimental observations. The calculated data were used to examine the Stokes–Einstein relation（SER）. The results indicate that the SER begins to break down at a temperature Tx（-1090 K） which is well above the equilibrium melting point（912.5 K）.This high-temperature breakdown is confirmed by the evolution of dynamics heterogeneity, which is characterised by the non-Gaussian parameter α2（t）. The maximum value of α 2（t）, α（2,max）, increases at an accelerating rate as the temperature falls below Tx. The development of α（2,max） was found to be related to the liquid structure change evidenced by local fivefold symmetry. Accordingly, we suggest that this high-temperature breakdown of SER has a structural origin. The results of this study are expected to make researchers reconsider the applicability of SER and promote greater understanding of the relationship between dynamics and structure.

关键词： diffusion viscosity dynamics heterogeneity local five-fold symmetry

Determination of risperidone in human plasma by HPLC-MS/MS and its application to a pharmacokinetic study in Chinese volunteers

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2008年第2期9卷 114-120页

作者： Ming-zhu HUANG Jian-zhong SHENTU Jun-chun chen Jian liU hui-li ZHOU Research Center of Clinical Pharmaceutical Science the First Affiliated Hospital School of Medicine Zhejiang University Hangzhou 310003 China

This study presents a rapid, specific and sensitive liquid chromatography/tandem mass spectrometry (LC-MS/MS) assay for determination of risperidone (RIS) in human serum using paroxetine as an internal standard (IS). An Alltima-C18 column (2.1 mm×100 mm, 3 μm) and a mobile phase consisting of 0.1% formic acid-acetonitrile (40:60, v/v) were used for separation. The analysis was performed by selected reaction monitoring (SRM) method, and the peak area of the m/z 411.3→191.1 transition for RIS was measured versus that of the m/z 330.1→192.1 transition for IS to generate the standard curves. The assay linearity of RIS was confirmed over the range 0.25～50.00 ng/ml and the limit of quantitation was 0.05 ng/ml. The linear range corresponds well with the serum concentrations of the analytes obtained in clinical pharmacokinetic studies. Intraday and interday relative standard deviations were 1.85%～9.09% and 1.56%～4.38%, respectively. The recovery of RIS from serum was in the range of 70.20%～84.50%. The method was successfully applied to investigate the bioequivalence between two kinds of tablets (test versus reference products) in 18 healthy male Chinese volunteers. The result suggests that two formulations are bioequivalent.

关键词： Risperidone High performance liquid chromatography-mass spectrometry (HPLC-MS) Pharmacokinetics

Microwave-assisted ring-opening copolymerization of ε-caprolactone and 2-Phenyl-5,5-bis(oxymethyl) trimethylene carbonate

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Chinese Science Bulletin 2009年第18期54卷 3237-3243页

作者： LU Ke YAN GuoPing chen hui li liang AI ChaoWu YU XiangHua School of Material Science and Engineering Wuhan Institute of Technology Wuhan 430074 China

A series of polycarbonate copolymers were synthesized by microwave-assisted ring-opening polymerization of ε-caprolactone (CL) and 2-phenyl-5,5-bis(oxymethyl) trimethylene carbonate (PTC) with Tin (II) 2-ethylhexanoate as a catalyst. These copolymers obtained were detected by 1H NMR, FT-IR, UV, gel permeation chromatography (GPC), differential scanning calorimetry (DSC) and automatic contact angle meter. The influences of the feed molar ratio of monomers, catalyst concentration, reaction time and reaction temperature, as well as microwave irradiation power on the copolymerization process were also studied. In vitro degradation tests indicated that these polycarbonate copolymers possess the slow degradation rates and strong hydrophobicity. In vitro release profiles of 5-Fu from copolymers showed that copolymers have the steady drug release rates and good controlled release properties.

关键词：聚碳酸酯微波辅助己内酯丙二醇开环共聚苯基催化剂浓度凝胶渗透色谱

Spatial data modeling for coalfield geological environment

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Journal of Coal Science & Engineering(China) 2010年第3期16卷 300-305页

作者： JIA Bei SU Qiao-mei liU chen li hui-juan College of Mining Engineering Taiyuan University of Technology Taiyuan 030024 China

Presented a study on the design and implementation of spatial data modelingand application in the spatial data organization and management of a coalfield geologicalenvironment *** on analysis of a number of existing data models and takinginto account the unique data structure and characteristic, methodology and key techniquesin the object-oriented spatial data modeling were proposed for the coalfield geological *** model building process was developed using object-oriented technologyand the Unified Modeling Language (UML) on the platform of ESRI geodatabase datamodels.A case study of spatial data modeling in UML was presented with successful implementationin the spatial database of the coalfield geological *** modelbuilding and implementation provided an effective way of representing the complexity andspecificity of coalfield geological environment spatial data and an integrated managementof spatial and property data.

关键词： spatial data model object-oriented Unified Modeling Language (UML) coal- field geological environment

Preparation of porous Si_(3)N_(4) ceramics via tailoring solid loading of Si_(3)N_(4) slurry and Si_(3)N_(4) poly‐hollow microsphere content

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Journal of Advanced Ceramics 2015年第4期4卷 260-266页

作者： Jia-Min WU Xiao-Yan ZHANG Jie XU Ke GAN Jia-Lu li chen-hui li Jin-Long YANG Yu-Sheng SHI State Key Laboratory of Materials Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China State Key Laboratory of New Ceramic and Fine Processing School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China

Porous Si_(3)N_(4) ceramics were prepared by aqueous gelcasting using Si_(3)N_(4) poly-hollow microspheres(PHMs)as pore-forming *** effects of solid loading of Si_(3)N_(4) slurry and Si_(3)N_(4) PHM content on the properties of porous Si_(3)N_(4) ceramics were ***β-Si_(3)N_(4) phase is observed in porous Si_(3)N_(4) ceramics,and Si_(3)N_(4) PHMs distribute uniformly both in Si_(3)N_(4) green samples and porous Si_(3)N_(4) *** show that solid loading of Si_(3)N_(4) slurry and Si_(3)N_(4) PHM content could considerably influence the properties of porous Si_(3)N_(4) *** the increase of solid loading of Si_(3)N_(4) slurry(decrease of Si_(3)N_(4) PHM content),the distributing state of Si_(3)N_(4) PHMs changes from contacting with each other to just embedding in the matrix,thus their porosity decreases,while their shrinkage,flexural strength,and fracture toughness increase.

关键词： porous Si_(3)N_(4)ceramics Si_(3)N_(4)poly-hollow microspheres(PHMs) solid loading aqueous gelcasting mechanical properties

Monthly variation in litterfall and the amount of nutrients in an Aleurites montana plantation

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Forestry Studies in China 2012年第1期14卷 30-35页

作者： liN Han HONG Tao WU cheng-zhen chen hui chen Can li Jian liN Yong-ming FAN Hai-lan Fujian Agriculture and Forestry University Fujian Forest Ecological System Process and Management Key Laboratory Fuzhou350002 P. R. China

In this study, the dynamics of monthly variation in litterfall and the amount of nutrients, i.e., organic C, N, P and K, in an Aleurites montana plantation were analyzed, based on a field study and experiments over one year. The results show that the litterfall mass of A. montana collected generally presents an ascending trend with maximum defoliation occurring in the autumn and winter （October-December）, accounting for 75.67% of the total amount of annual litterfalk The sequence in the amount of nutrients in A. montana litter was as follows： organic C 〉 N 〉 K 〉 P; their monthly amounts show various dynamic curves. Similar to the dynamics of the mass of monthly litterfall, the monthly returns of C, N, P and K generally show an ascending trend with their peak values all occurring in December. The mass of A. montana litterfall and the dynamics of its monthly nutrient return provide, to a certain degree, a scientific reference for planting and fertilizing A. montana.

关键词： Aleurites montana litterfall monthly variation nutrient amounts