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Description of Mechanism Function about Dehydration of Cobalt Oxalate Dihydrate by Multiple Rates Isotemperature Method

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wuhan university Journal of Natural {2. 2004年第2期9卷 239-246页

作者： LiLi-qing ChenDong-hua collegeofchemistryand{2.sciences SouthCentralUniversityforNationalitiesWuhan430074HubeiChina

A new method of the multiple rates isotemperature is proposed to define the most probable mechanismg(α) of thermal anlaysis; the iterative isoconversional procedure has been employed to estimate apparent activation energyE; the pre-exponential factorA is obtained on the basis ofE andg(α). By this new method, the thermal analysis kinetics triplet of dehydration of cobalt oxalate dihydrate is determined, apparent activation energyE is 99.84 kJ·mol?1; pre-exponential factorA is 3.42.×109–3.872.109 s?1 and the most probable mechanism belongs to nucleation and growth,A m model, the range ofm is from 1.50 to 1.70. Key words multiple rates isotemperature method - isoconversional method - cobalt oxalate dihydrate - accomodation function - differential scanning calorimetry (DSC) CLC number O 636.1 Foundation item: Supported by the Key Foundation of the Science and Technology Committee of Hubei Province (2.01ABA009)Biography: Li Li-qing (1977-), female, Master candidate, research direction: material synthesize and thermal analysis kinetics.

关键词： multiple rates isotemperature method isoconversional method cobalt oxalate dihydrate accomodation function differential scanning calorimetry (DSC)

MCM-41 Prepared with Ionic Liquid and Cethytrimethylammonium Bromide as Co-templates

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Journal of wuhan university of Technology(Materials Science) 2009年第1期24卷 25-29页

作者：张光旭 School of Chemical Engineering Wuhan University of Technology college of chemistry and Molecular {2. Wuhan University

The mesoporous molecular sieves MCM-41 were prepared using room tempera-ture ionic liquid （RTIL） synthesized in laboratory and cethytrimethylammonium bromide （CTAB） as compound templates for the first time. They were prepared under low aging temperature and short aging time. Via characterizing by XRD and nitrogen adsorption instrument, MCM-41 synthesized by this new method exhibited good crystal structure and narrow pore distribution. The following pre-paratory conditions was optimal： the molar ratio of RTIL to CTAB was 1.0∶1.0, aging at 80 ℃, for 40 h and calcined at 540 ℃. It is found that the acidified MCM-41 improves its activity as catalyst over the unmodified ones.

关键词： mesoporous molecular sieve hydrothermal crystallization co-templates ionicliquid MCM-41

Preparation and Characterization of Chitosan/Carboxymethylated Konjac Glucomannan Blend Films

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wuhan university Journal of Natural {2. 2002年第1期7卷 107-112页

作者： Zheng Hua 1 , Du Yu-min 2.1. Department of Chemical Engineering, wuhan university of Technology, wuhan 430070, Hubei, china 2. college of chemistry and Molecular sciences, wuhan university, wuhan 430072. Hubei, china wuhan university of Technology Department of Chemical Engineering Wuhan Hubei China (GRID:grid.162110.5) (ISNI:***) wuhan university College of Chemistry and Molecular Sciences Wuhan Hubei China (GRID:grid.49470.3e) (ISNI:***)

In order to improve the mechanical and water swelling properties of the chitosan (CS) film, a series of transparent films were prepared by blending 2.(weight) chitosan acetic acid solution with 1.5%(weight) carboxymethylated konjac glucomannan (CMKGM) aqueous solution according to predetermined ratio and drying at 30°C. The morphological structure, miscibility, thermal stability, mechanical properies, and swelling capacity of the blend films were studied by infrared (IR), X-ray diffraction (XRD), differential thermal analysis (DTA), scanning electron micrograph (SEM), and measurements of the mechanical properties and swelling properties. The results demonstrated that there was strong interaction and good miscibility between CS and CMKGM resulted from intermolecular hydrogen bonding and electrostatic force. The mechanical properties in dry state and wet state, thermostability, and water swelling properties of the blend films were obviously improved. The best values of the tensile strength in the dry and wet state achieved 89 MPa and 49 MPa, respectively, when the CMKGM content was 30%(weight). The CS/ CMKGM blend films provided promising biomedical applications.

关键词： Key words chitosan carboxymethylated konjac glucomannan blend films structure characterization

Approach to the Relation of Mutual-Feed Joint-Variation in Groundwater Management Model

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Journal of Earth Science 2012年第3期23卷 349-358页

作者：李平卢文喜靳孟贵杨青春 college of chemistry and Materials South-Central University for Nationalities School of Environmental Studies China University of Geosciences college of Environment and Resources Jilin University

In groundwater management,the exchanges between groundwater and other water such as surface water and spring water need to be *** exchange is dependent on the ground-water level,which is called *** pumping rate,groundwater level,and covariate interact and the relation of mutual-feed joint-variation is used to describe their *** article presents a new approach of dealing with the relation in groundwater management *** mathematical for-mulation of the relation,as an additional equality constraint in the optimization model,is developed using response matrix *** the groundwater management model with covariate is set *** code for the simulation and management of groundwater system with covariate is programmed with Fortran 90,and the optimal pumping rate,groundwater level,and covariate are *** approach is verified with a hypothetical ***,the approach is applied to the groundwater management of Qianguo（前郭） area in western Jilin（吉林） *** results indicate that the ap-proach is *** provides a universal solution for various covariates and reduces the computational complexity compared to iteration *** approach is proven to be very efficient to solve ground-water management problem with covariate.

关键词： covariate relation of mutual-feed joint-variation groundwater management response matrix

Synthesis and purification of trialkyl compounds of gallium and indium

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Rare Metals 2002年第1期21卷 1-6页

作者： SHU Wangen, ZHOU Zhongcheng and LI Xiong chemistry and Chemical Engineering college, {2. south university, Changsha 410083, china chemistry and chemistry Engineering {2. Central South University Changsha 410083 chemistry and Chemical Engineering college Central South University Changsha 410083

The The research progress in trialkyl compounds of gallium andindium was discussed from two aspect, one was the chemical synthesisof the compounds and the other was the purification of them. Thereare three synthesis routes be- ing reported in the first aspect, *** route staring form pure metal, the route starting from the puremetal trihalides, and the electrochemical route. In the secondaspect, the purifying methods of decomposition-distillation and zonerefining were reviewed.

关键词： trialkyl compounds gallium nd indium synthesis purification

Silylated and acetylated β-cyclodextrins for gas chromatographic stationary phases

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Journal of central south {2. of Technology 2001年第4期8卷 239-243页

作者： TANG Ke wen 1,2.,YI Jian ming 2.ZHOU Chun shan 1,ZHONG Shi an 1 (1. college of chemistry and Chemical Engineering, {2. south university, Changsha 410083, china 2. college of chemistry and Chemical Engineering, Yueyang Normal university 1. college of chemistry and Chemical Engineering Central South University 410083 Changsha China 2. college of chemistry and Chemical Engineering Yueyang Normal University 414000 Yueyang China

Two new chiral stationary phases, 2.3 di O acetyl 6 O trimethylsilyl β cyclodextrin (DATBCD) and 2.6 di O trimethylsilyl 3 O acetyl β cyclodextrin(DTABCD), were synthesized, their structures were identified by means of infrared and NMR spectra. Capillary columns were coated with the two stationary phases by dynamic method. The chromatographic properties, and enantiomers separation, such as ketone, esters, alcohols and olefines, were investigated on the silylated and acetylated β cyclodextrin stationary phases. The experimental results show that the silylated and acetylated β cyclodextrins are suitable to be used as capillary gas chromatographic stationary phases, the relative polarity of DATBCD and DTABCD stationary phases is respectively 4143 and 392., the column efficiencies are respectively 3084 and 4198, and DATBCD is of stronger enantioselectivity than DTABCD, capacity factor of the first eluted enantiomer ( k 1) and separation factor(α)of α phenylethanol on DATBCD stationary phase are respectively 8.2. and 1.019.

关键词： capillary gas chromatography silylated and acetylated β-cyclodextrins enantiomeric separation

Arginine bi-directional translocation and breakdown into ornithine along the arbuscular mycorrhizal mycelium

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Science china(life {2.) 2009年第4期52卷 381-389页

作者： JIN HaiRu college of chemistry and {2. sciences, Zhejiang Normal university, Jinhua 32.004, china college of chemistry and {2. sciences Zhejiang Normal University Jinhua 321004 China

Bi-directional translocation and degradation of Arginine (Arg) along the arbuscular mycorrhizal (AM) fungal mycelium were testified through 15N and/or 13C isotopic labeling. In vitro mycorrhizas of Glomus intraradices and Ri T-DNA-transformed carrot roots were grown in dual compartment Petri dishes. [15N- and/or13C]Arg was supplied to either the fungal compartment or the mycorrhizal compartment or separate dishes containing the uncolonized roots. The levels and labeling of free amino acids (AAs) in the mycorrhizal roots and in the extraradical mycelia(ERM) were measured by gas chromatogra- phy/mass spectrometry (GC-MS) and high-performance liquid chromatography (HPLC). The ERM of AM fungi exposed in either NH4+ or urea as sole external nitrogen source had much higher 15N enrichment of Arg, compared with those in nitrate or exogenous Arg; however, glycerol supplied as an external car- bon source to the ERM had no significant effect on the level of Arg in the ERM. Meanwhile, Arg bio- synthesized in the ERM could be translocated intact to the mycorrhizal roots and thereby the level of Arg in the mycorrhizal roots increased to about 2.% after culture of ERM in 4 mmol/L NH4+ for 6 weeks. Also Arg was found to be bi-directionally transported along the AM fungal mycelium through [U-13C]Arg labeling either in the mycorrhizal compartment or in the fungal compartment. Once Arg was translo- cated to the potential N-limited sites, it would be further degraded into ornithine (Orn) and urea since either [U-13C] or [U-15N/U-13C]Orn was apparently shown up in the mycorrhizal root tissues when [U-13C] or [U-15N/U-13C]Arg was labeled in the fungal compartment, respectively. Evidently Orn formation indi- cated the ongoing activities of Arg translocation and degradation through the urea cycle in AM fungal mycelium.

关键词： arbuscular mycorrhiza arginine in vitro culture 15N labeling ornithine urea cycle

Theoretical study on the hydrolysis mechanism of N,N-dimethyl-N′-(2.,3′-dideoxy-3′-thiacytidine)formamidine

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Science china chemistry 2008年第10期51卷 911-917页

作者： ZHANG Chang1 & XUE Ying2. 1 college of chemistry and Environment Protection Engineering, {2.west university for nationalities, Chengdu 610041, china 2.college of chemistry, Sichuan university, Chengdu 610064, china 1. college of chemistry and Environment Protection Engineering Southwest University for Nationalities Chengdu 610041 China 2. college of chemistry Sichuan University Chengdu 610064 China

The hydrolysis mechanisms of N,N-dimethyl-N′-(2.,3′-dideoxy-3′-thiacytidine)formamidine (FA-3TC) in the gas phase and in aqueous solution were studied by use of the density functional theory B3LYP/6-31+G(d, p) method. Two possible reaction pathways in the title reaction were considered. In one pathway water attacks the C=N double bond first (path A) while in the other water attacks the C—N single bond first (path B). The calculated results indicate that the first step in both pathways is the rate-limiting process and path A is more favorable than path B in the gas phase. The effect of solvent water on the title reaction was assessed at the B3LYP/6-31+G(d, p) level of theory based on the po-larizable continuum model (CPCM). In water the first mechanism (path A) is also favored.

关键词： N N-dimethyl-N′-(2. 3′-dideoxy-3′-thiacytidine)formamidine hydrolysis solvent effect B3LYP polarizable continuum model

Resolution of α-cyclohexyl-mandelic acid enantiomers by two-phase (O/W) recognition chiral extraction

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Science china chemistry 2007年第6期50卷 764-769页

作者： TANG KeWen1,2. ZHANG GuoLi2. HUANG KeLong2. LI Yuanjian3 & YI JianMin1,2.1 Department of chemistry and Chemical Engineering, Hunan Institute of Science and Technology, Yueyang 414000, china 2.{2. of chemistry and Chemical Engineering, central south university, Changsha 410083, china 3 {2. of Pharmaceutical Science, central south university, Changsha 410078, china Department of chemistry and Chemical Engineering Hunan Institute of Science and TechnologyYueyang 414000China college of chemistry and Chemical Engineering Central South UniversityChangsha 410083China

This paper presents a new chiral separation technology:two-phase(O/W)recognition chiral *** behavior of alpha-cyclohexyl-mandelic acid enantiomers was studied in the extraction system with D(L)-isobutyl tartrate in 1,2.dichloroethane organic phase and beta-CD derivatives in aqueous phase,and the influence of the kind and concentration of extractant and pH on extraction performance was *** experimental results indicate that two-phase(O/W)recognition chiral extraction is of strong chiral separation ***-^-CD,HE-beta-CD and Me-beta-CD have higher recognition ability for S-CHMA than that for R-CHMA,among which HP-beta-CD has the strongest ability;whereas,D-isobutyl tartrate has reversed recognition ability for *** the extraction system containing HP-beta-CD and D-isobutyl tartrate,e.e.% of S-CHMA in aqueous phase reached 2..6% by one stage extraction,and the distribution ratio for R-CHMA(k_R)and for S-CHMA(k_S)and separation factor(alpha)are 2.44,0.89 and 2.49,***,pH and concentration of extractant have great effects on chiral separation ***-phase(O/W)recognition chiral extraction has great significance for preparative separation of racemic compounds.

关键词： two-phase(W/0)recognition chiral extraction alpha-cyclohexyl-mandelic acid enantiomers