Loading...

Table of Content

    24 February 1985, Volume 6 Issue 2
    Articles
    A Thermodynamic Analysis and Experimental Study on the Reactions of the Source Zones in a Growth System of GaN
    Meng Guangyao, Peng Dingkun
    1985, 6(2):  97-102. 
    Asbtract ( )   PDF (588KB) ( )  
    Related Articles | Metrics
    The paper reports the results of thermodynamic analysis and experimental studies on the reactions in the source zones of the Ga-HCl-NH3-carrier gas system for depositing GaNthin fimls.It ispredicted theoretically that at higher temperatures and in an usual partial pressure range of input HCl hydrogen chloride transforms completely into chlorides among which GaCl is the dominant species transporting toward deposition zone.Experimental study showed that the reactions in Ga source zone did not reach equilibrium and a significant influence of gas flow condition and temperature on the transformation of HCl was found.In the deposition temperature range (1173-1323K) and NH3 initial partial pressure range (0.2 - 0.4atm) the thermal decomposition of NH3 was not considerable that NH3 would essentially be the species containing Nand reacting with GaCl in deposition zone.
    Structural and Electron Paramagnetic Resonance Studies of (η5-C5H5)2Nb[CH2Si(CH3)3]2
    Liu Juzheng, Peterson J. I.
    1985, 6(2):  103-108. 
    Asbtract ( )   PDF (453KB) ( )  
    Related Articles | Metrics
    5-C5H5)2Nb[CH2Si(CH3)3]2 has been prepared and characterized by X-ray diffraction method and solution and frozen-glass EPR.The compound crystallizes in a monoclinic space group P21/Cwith lattice par ameters a=13.29lÅ, b=12.406Å, c=13.90lÅ, β=115.40° V = 2070Å3 and Z = 4.Full-matrix least-squares refinement of the diffractometry data led to final discrepancy indices of R(F0) - 0.043, R(F02) = 0.057, RB(F02) = 0.071.From computer simulation of the frozen-glass spectrum of the compound, the principal components of the g and Ttensors are gx = 1.9840, gy =2.0075, gx=2.0020, Tx = -89.2G, Ty = -136.9G, Tz = -50.0G.
    The Study of Extraction of Tl+ from Sulfuric Acid Solution with Di2 Ethylhexyldithiophoric Acid (D2EHDTPA)
    Song Yulin, Tian Runqi
    1985, 6(2):  109-111. 
    Asbtract ( )   PDF (218KB) ( )  
    Related Articles | Metrics
    The extraction of Tl+ from sulfuric acid solution withdi-2-ethylhexyldithiophoric acid (D2EHDTPA) has been studied.The experimental conditions of the effect of the solution acidity and the lime needes on attaining equilibrium have been found.The composition of the extracted complex has been determined by the methods of saturation and molecular ratio.The structure of the extracted complex has been discussed on the basis of iis IR and NMR.The extracting reaction is process of thecation exchange.
    Determination of Stability Constants of Complexes of Rare Earths with 2,3,5,6-Tetrahydro-6-Phenylimidazo(2,1-b) Thiazole by pH Method
    Zhang Aiyou, Zhang Jianmin, Liao Hongmin, Yang Bingyu, Li Chengshen, Zhang Ran
    1985, 6(2):  112-114. 
    Asbtract ( )   PDF (204KB) ( )  
    Related Articles | Metrics
    The stability of complex compounds formed by 2, 3, 5, 6-tetrahydro-6-phenylimidazo (2, 1-b) thiazole with La3+, Pr3+, Nd3+, Sm3+,Eu3+, Gd3+ and Yb3+ has been determined by pHmethod.The logarithm of the first consecutive stability constants (β1) of LaL3+, PrL3+, NdL3+, SmL3+ and EuL3+ could be expressed as linear function of the reciprocal of their ion radius (1/r).
    The Uses of Masking Agents in Chelometry(Ⅻ)——The Investigation of Masking Ti with Benzilic Acid
    Chen Yongzhao, Qiu Ruolan, Chen Huanguang
    1985, 6(2):  115-119. 
    Asbtract ( )   PDF (407KB) ( )  
    Related Articles | Metrics
    Benzilic acid was found to be a specific masking agent for Ti at pH 58-5.5.When DCTAis used as the titrant, the so-called "DCTA-Benzilic acid masking method" should be used to titrate the Ti.The selectivity is very high, over 33 metal ions, such as Zr, Th, Bi, Fe, Al, La, Hg, Cu, Ni etc, will not interfere.This method can be used to determine the Ti in titanium ores, bauxites and silicates with rapidity and accuracy.
    Study of the Color Reaction of Tribromoarsenazo with Rare Earths (Ⅰ)——Determination of Trace Rare Earth in Human Hair
    Cai Ruxiu, Wang Lisha, Yu Ximao
    1985, 6(2):  120-122. 
    Asbtract ( )   PDF (231KB) ( )  
    Related Articles | Metrics
    In this paper, the color reaction of 2-(2-arsonophonylaze)-7-(2,4,6-tribromoa-rsenazo)-1.8-dihydrexy-3, 6-disulionic acid (TBA) with total amount of rare earth and lignter rare earths (La-Ho, Y) has been studied.If combined with extraction of PMBP, it can be used to determine trace rare earth in human hair.
    Determination of Ascorbic Acid Using Plasma Polymerized Vinylferrocene Film Electrode
    Zou Mingzhu, Yang Haiquan, Li Hongyang
    1985, 6(2):  123-125. 
    Asbtract ( )   PDF (235KB) ( )  
    Related Articles | Metrics
    The electrocataiytic oxidation of ascorbic acid using argon plasma polymerized vinylferrocene film electrode of glassy carbon was described.The method has been applied successfully to the analysis of ascorbic acid in fruits and vegetables.
    Electrochemical Studies of Noble Elements(Ⅱ)——Determination of Micro-Rhodium in the Macro Amount of Iridium by ASV
    Zhang Yuxiang, Wang Chunmin, Wang Ping, Fan Maihu
    1985, 6(2):  126-128. 
    Asbtract ( )   PDF (236KB) ( )  
    Related Articles | Metrics
    In this paper, the methods of separation macro-lridium and determination of micro-rhodium have been studied.By using home-made 15% of tri-(6,7,8)alkyl-phosphine oxide-benzene solution for extracting in 4N HCl, we have been successively separated the macro-lridum apart from micro-rhodium.The extraction rate for once lies in the range 97-99%.We have also found the optimum electrolytic system of 0.1N HCl-0.02Nethylene diamine-2.5×10-6M HgCl2(pH= 1.4) for determination of micro amount of rhodium (Ⅲ) by anodic stripping voltammatry (ASV) on glass carbon electrode.The limit of detection as low as to 10 ppb may be achieved.
    Studies on the Active Principles of Royal Jelly (Ⅰ)——Isolation and Identification of (E)-10-hydroxy-2-decylenic Acid.
    Huang Xiaofeng, Li Zhonglin
    1985, 6(2):  129-130. 
    Asbtract ( )   PDF (233KB) ( )  
    Related Articles | Metrics
    Awhite crystal has been isolated from the Royal Jelly.Its structure was identified as (E)-10-hydroxy-2-decylenic acid by the spectral methods and chemical methods.It was found to have an abvious anti-radiation activity in animal tests.
    Study on Protonation Constants of Meso-Substituted Octaethylporphyrins
    Gong Liangchu
    1985, 6(2):  131-134. 
    Asbtract ( )   PDF (310KB) ( )  
    Related Articles | Metrics
    The protonation constants (K3 and K4) of 15 porphyrins were determined by Aronoff method, being in the range of 4.3-6.61gKvalues.When the difference between 1gK3 and 1gK4 is larger than l,no double protonated cation (PH42+) is formed before the simple protonated cation(PH3+) has been completely formed; otherwise the formation processes of PH3+ and PH42+ mix up to some extent.Strong electron with drawing meso-nitro groups make protonation constants decrease through inductive effect while meso-chlorine atoms increase the constants due to the steric effect.
    Synthesis and Spectral Studies of (μ-Phenylthio)(μ-Alkylthio) Hexacarbonyldiiron Complexes
    Song Licheng, Hu Qingmei, Liu Xiangyang, Wang Jitao
    1985, 6(2):  135-140. 
    Asbtract ( )   PDF (612KB) ( )  
    Related Articles | Metrics
    Through reductive addition of phLi to μ-S2Fe2(CO)6 and nucleophilic substitution between RXand (μ-PhS)(μ-LiS)Fe2(CO)6 nine clusters of (μ-PhS)(μ-RS)Fe2(CO)6 series (Ⅰ) -(Ⅸ) have been synthesized successfully.It is shown that yields of clusters (Ⅰ) -(Ⅸ) and reactivities of RXin nucleophilic reactions depend on both structures of Rand nature of X.And according to chemical shift and integrated values of related signals of 1HNMRpossible isomers and isomcr ratios of some clusters have been determined.In addition, it is suggested that diamagnetic aniso-tropic effects of C = Oand orientations of unshared electron pairs are likely responsible for systematic variations in δ CH3-Sand δ CH2-Sof cluster isomers.
    Study of SNAr Reaction Between Para-substituted Nitrobenzenes with Phenylacetonitrile
    Hua Mei, Bai Tao, Li Qimin, Guan Zuowu
    1985, 6(2):  141-142. 
    Asbtract ( )   PDF (158KB) ( )  
    Related Articles | Metrics
    We have found that in reactions of para-chloro-, bromo-, Iodo- and carboxy-nitrobenzenes with phenylacetonitrile in the presence of EtOHand NaOHthe 5-substilulcd-3-phenyl-2,1 -isoxazoles arc obtained.However, there occur only SNAr reaction in the position para to nitrogroup for p-fluoro- and nitro-benzenes under various conditions.
    The Effect of Substituents on the Infrared Spectra of Some 1,4-Bis[β-(4-Substituted Phenyl)Ethenyl] Benzene Compounds
    Xue Jiayou, Zhang Yufan, Wang Xiaolan
    1985, 6(2):  143-145. 
    Asbtract ( )   PDF (224KB) ( )  
    Related Articles | Metrics
    In this paper, the effects of substituents on the infrared spectra of some 1,4-bis[β-(4-substituted phenyl) ethenyl] benzene compounds have been discussed.It was found that there is a relationship of homologous linearity between the out-of-plane C-Hbending vibration frequency of olefinic bond and the substituent constants σp σpo, or, σp+.
    Carbon13 Chemical Shifts in Transition Metal Complexes
    You Xiaozeng, R. F. Fenske, D. G. Freier
    1985, 6(2):  146-150. 
    Asbtract ( )   PDF (311KB) ( )  
    Related Articles | Metrics
    The results for the first overlaping sphere Xa-SWchemical shift calculation are shown to reproduce the trends in13C NMRexperiments for the CO, C9, CNand C5H5 ligands in transition metal complexes Ni(CO)4, Cr(CO)5CSand Fe(CBH5)(CO)2CN.The relationship between the chemical shifts with the electronic structure and bonding have been discussed.
    Study on the Chemical Behavior of Solid Phase Reaction of WO3 and Me2CO3 by the Method of Thermal Analysis
    Sun Shiqing
    1985, 6(2):  151-155. 
    Asbtract ( )   PDF (366KB) ( )  
    Related Articles | Metrics
    The reaction of WO3 and Me3CO (Me = Li, Na, K, Rb, Cs) series in solid phase has been studied by using the MOMtype-Derivatograph.The chemical behavior of reaction process was indicated by TGand DTAcurves.The kinetic parameters, activation energy (E), reaction order (n), frequency factor (A) and reaction velocity constant (K) were evaluated by treating TGcurves with Coats-Redfern method.For the system of WO3+Na2CO3, the Evalue calculated by Coats-Redfern method (347.8 KJ/mol) is consistent with the value (372.9 KJ/mol) obtained by Kissinger method.
    Study on Electrocatalytic Oxidation of Trace Carbon Monoxide (Ⅰ)——The Kinetics of Reaction on Pt/C Catalyst
    Zhang Huixin, Xu Xingzhong, Li Zuojun
    1985, 6(2):  156-160. 
    Asbtract ( )   PDF (383KB) ( )  
    Related Articles | Metrics
    Under the condition that the effect of mass transfer and IRdrop are negligible, we have determined experimentally the influences of COand H3O+ concentration and temperature on the rates of electro-oxidation of trace carbon monoxide on the Pt/Ccatalyst in aqueous sulphuric acid.
    The Relationship Between the Structures and the Magnetic Properties for Mo-Fe-S Cluster Compounds
    Tang Aoqing, Li Shuqian
    1985, 6(2):  161-162. 
    Asbtract ( )   PDF (117KB) ( )  
    Related Articles | Metrics
    By means of the data of structural analysis for Mo-Fe-Scluster compounds and the structural rule of metallic cluster compounds, a formula which describes the relationship between the structures and the magnetic properties for the compounds is proposed.The theoretical values of highest spin are in accordance with experiment facts.The relationship mentioned above can be interpreted by the results of the EHMOquantum chemistry calculations.
    The Modified Huckel Molecular Orbital Method(V)——MHMO Calculations on Some Hyperconjugative Systems
    Sun Juchang, Ren Dehou, Lin Huixin, Zhang Di
    1985, 6(2):  163-165. 
    Asbtract ( )   PDF (216KB) ( )  
    Related Articles | Metrics
    In this paper, we have proposed a new model--hyperconjugative one ofmethyl group.Some hyperconjugative system have been treated by this new model.No matter whether on the calculated pi-energies or pi-charge densities of methyl group and pi-bond orders, all calculted results are reasonable and better come close to practical situation.
    A Study on the Kinetics and Mechanism of Nucleophilic Substitution Reaction of μ-Allylthio-μ-Phenylthio-Bis (Tricarbonyliron)
    Chen Rongti, Zhang Qiyan, Song Lichen, Zhu Chengyue
    1985, 6(2):  166-168. 
    Asbtract ( )   PDF (227KB) ( )  
    Related Articles | Metrics
    The kinetics of nucleophilic substitution reaction of Fe2(CO)6(μ-SCH3CH=CH2)-(μ-SPh) with PPh3 and PPh2Et has been studied.The results showed that.PPh3 could displace one carbonyl of the complex while with PPh3Et as substi-tuent a two step substitution could exist in the complex.The reaction followed a two-term rale law.One term implied SN2 substitution and the other implied isomerization.The rate constants for these reactions and their corresponding activation parameters have been determined, Amechanism for this reaction has been proposed.
    Measurement of Electrical Properties for BLM with pH Meter
    Hua Shijin
    1985, 6(2):  169-171. 
    Asbtract ( )   PDF (222KB) ( )  
    Related Articles | Metrics
    Amethod and principle for the measurement of the electrical properties of BLMwith pHmeter are recommend, and the electrical resistance and capacitance of four artificial planar bilayer membranes are tested.The structural effect of solvents is apparent.Resistance of membrane increases with increase of the number of carbon atoms in the chain of normal alkane "molecules.It implies that the differences in resistance are relevant to the thickness of BLM.
    The Kinetic Studies of Nitrogenase from A. Vinelandii-230
    Shui Dexin, Jiang Yongming, Yang Shichen, Zhao Ying, Tao Weisun
    1985, 6(2):  172-176. 
    Asbtract ( )   PDF (327KB) ( )  
    Related Articles | Metrics
    We have studied the kinetics of the nitrogenase from A.vinelandii-230 and found that the nitrogenase is an allosteric enzyme.ATPis a positive effector for the nitrogenase while ADPa negative effector for the nitrogenase.ATPbinding sites are regulatory sites in the nitrogenase and the acetylene reduction active sites are catalytic sites in the nitrogenase.Between Av1 molecules and Av2 molecules, there are two or more than two binding sites among which possesses a positive cooperative effect, namely the effect between the Avl-Av2 binding sites and the acetylene reduction active sites.
    Synthesis and Structural Investigation of BisA-DCDPS-HQ Copolymer
    Ding Youjun, Wang Xilie
    1985, 6(2):  177-182. 
    Asbtract ( )   PDF (461KB) ( )  
    Related Articles | Metrics
    BisA-DCDPS-HQcopolymer has been synthesized.The copolymer has been demonstrated by solubility characteristies, IR, NMR, and dynamic mechanical behavior.It is interesting that BisA-DCDPS-HQcopolymer has higher glass transition temperatures (Tg) than BisA-PSF.The range of glass transition temperatures of these copolymers is between 191℃(Tg of pure BisA-PSF) and 227℃ (Tg of pure HQ-PSF).As seen in table 2 and figure 4 the glass transition temperatures of these copolymers increases monotonically as a function of HQcontents in these copolymers.The copolymers has better solvent resistance properties than BisA-PSF.
    The Determination of the Degree of Hydrolysis for Hydrolyzed Polyacrylamide by Using the Technique of Thermogravimetric Analysis
    Fang Daobin, Chen Fang
    1985, 6(2):  183-186. 
    Asbtract ( )   PDF (305KB) ( )  
    Related Articles | Metrics
    In the present paper, the determination of the degree of hydrolysis for hydrolyzed polyacrylamide has been studied by using the technique of thermogravimetric analysis (TGA).The values measured by TGAwas compared with that obtained from Kjeldabl method for nitrogen content and from potentiometer titration.It is found that the technique of TGAis more accurate, simple and convenient than others.
    Dynamic Torsional Vibration Method and Its Application to the Study of the Curing Processes of Epoxy Resin
    He Piagsheng, Li Chun'e, Xu Weimin
    1985, 6(2):  187-189. 
    Asbtract ( )   PDF (306KB) ( )  
    Related Articles | Metrics
    The LH-1 rubber vuikameter has been improved by using the moulds of half-spherical type instead of that of cylindercal type and by reducing the torsional vibration angle below 1°.By using this improved apparatus the isothermal curing processes of the bisphenol Aepoxy resin E51 cured by imidazole at various temperatures were measured and the curing curve were obtained.The apparent activation energy of the curing processes were estimated.The apparent kinetic analysis of the curing of E51-triethanolamine system has also been made.