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中文
Table of Content
24 September 1993, Volume 14 Issue 9
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Articles
Studies on the Exchange Kinetics of Metal loporphyrin with a Series of Imidazoles by NMR Method
ZHU Zhi-Ang, GUO Fu-Chun, RUAN Wen-Juan, CHEN Rong-Ti
1993, 14(9): 1185-1189.
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The exchange rates of axially coordinated imidazoles in mono-ligated iron (Ⅲ) and manganese(Ⅲ) complexes of synthetic porphyrins such as tetraphenylporphyrin (TPP) and te-tramesitylporphyrin(TMP) were measured by NMRmethod.The exchange rate constants and activated parameters were obtained.Two exchange reaction mechanisms were proposed.The influences of metallic ions and temperature on the exchange rates were compared.These results were explained reasonably.The linear relationship of the kinetic parameters was verified.
Studies on Siliceous Zeolite ZSM-5 Filled Silicone Rubber Membrane (Ⅱ) ——Influence Factors on Pervaporation Properties
CHEN Xin, PING Zheng-Hua, FU Shou-Kuan, LONG Ying-Cai
1993, 14(9): 1190-1194.
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In this paper, the influence factors, such as the treated methods of zeolite, the composition of feed and the change of hydrogen bond in feed have been studied on silicalite-Ifilled PDMSmembranes.The results show that pretreating zeolite under steam and weakening the intensity of hydrogen bond in alcohol-water mixture by adding electrolytes such as salt and acid can improve the separation properties of the membranes signifcantly.
Crystal Structure and Luminescence Spectra of Binuclear Europium m-Methylbenzoate Ternary Complex with 1,10-phenanthroline, [Eu(m-MBA)
3
PHEN](H
2
O)
2
JIN Lin-Pei, WANG Rui-Fen, WANG Ming-Zhao, CAI Guan-Liang, LIU Shi-Xiong, HUANG Jin-Ling
1993, 14(9): 1195-1200.
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The crystal structure of the title compound has been solved by the heavy-atom, direct method, and by using the three dimensional Patterson-Fourier synthesis.The crystallographic data are:M=1511.22, space group Cc, a=l.5955(6) nm, b=1.8508(6) nm, c=2.2595(9) nm, β = 97.79(4)°, V = 6.610(4) nm
3
, Z = 4, F(000) = 3040, D
x
=1.52 g/cm
3
, μ=19.47 cm
-1
, and R = 0.043 for 7316 observed reflections.Both europium ions in the binuclear complex are octa-coordinated with six oxygen atoms of m-methylbenzoates and two nitrogen atoms of 1, 10-phenathroline, to give the square antiprisms with C
1
site symmetry for the Eu(Ⅲ) ions.The high resolution excitation spectrum at 77Kindicates that only one Eu(Ⅲ) site exists in the complex.
5
D
0
→
7
F
J
(J=0-2)
transition fluorescence spectra confirm the C
1
symmetry of the Eu(Ⅲ) site.
Phase Diagram of LiCl-HOAc and LiCl-HOAc-H
2
O(at
25
℃) Systems
RAN Xin-Quan, QIN Fan, YUAN Min-Zheng
1993, 14(9): 1201-1203.
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The solubilities of saturated solutions of the title systems have been investigated and the corresponding equilibrium phase diagrams were constructed.As shown in the phase diagram of LiCl-HOAc, there are two solid phases:LiCl and the solvate compound LiCl · (l/2)HOAc, which is soluble incongruently.No LiCl · HOAc and LiCl · 5HOAc have been found.There are three solid phases:LiCl · H
2
O, LiCl and LiCl ·(1/2)HOAc in the phase diagram of LiCl-HOAc-H
2
Osystem at 25℃.The changes of the phase LiCl · H
2
O·LiCl·LiCl · (1/2)HOAc were observed and shows saltingin, anhydration and solvate action of HOAc.Based on the phase diagram of LiCl-HOAc-H
2
Oternary system, a new method for preparing anhydrous LiCl may be suggested.
Study on the Performance of Microwave Induced Plasma Atomic Absorption Spectrometry with Electrothermal Sample-introduced Device
DUAN Yi-Xiang, LI Xing-You, HOU Ming-Yi, JIN Qin-Han
1993, 14(9): 1204-1206.
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In this paper, a method of MIP-AASwith electrothermal sample-introduced device is described.An L-shaped discharge-absorption tube was used as the atomization cell.The experimental parameters were optimized and the analytical figures of merit are discussed.The recommended method has been successfully applied to the analysis of several practical samples.
Study of Voltammetric Behaviour at Water/ο-Nitroanisole Interface and Ion Selective Electrode for Succinylcholine Ion
FAN Rui-Xi, ZHOU Ming-Geng, CUI Tao, DI Jun-Wei
1993, 14(9): 1207-1209.
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In the system of 1 mol/L MgCl
2
(w)-0.01 mol/L TBATPB(NA), the “potential window” of the polarized interface was shifted about 200 mVto the anodic potential as compared with nitrobenzene used as oil phase.For succinylcholine ion, the characteristics of semi-integral and semi-differential cyclic voltammograms were similar to those of normal neopolarograms.Δ
w
o
φ
1/2
.Nernst slope, n and D
Sch
w
2+
are 110 mV, 28.2 mV, 2 and 2.3×10
-6
cm
2
/s, respectively.The properties of ISEfor succinylcholine ion prepared from Sch(TPB)
2
and the solvent mixed ο-nitroanisole and dibutylphthalate are the same as those of ITIESof succinylcholine ion.These results prove that the boundary potential difference of the electrode is due to the diffusion and transfer of succinylcholine ion at PVCinterface.The linear range is from 4.0×10
-6
to 1.0×10
-3
mol/Land the detection limit is 2.0× 10
-6
mol/L.
Pyruvate Oxidase Biosensor for the Determination of GPT Based on the Glassy Carbon Electrode Modified with Nafion and Methyl Viologen
JIN Li-Tong YE Jian-Shan, FANG Yu-Zhi
1993, 14(9): 1210-1213.
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Pyruvate oxidase biosensor has been constructed by using bovine serum albumin and glutaraldehyde as cross linker to immobilize pyruvate oxidase on glassy carbon electrode modified with Nafion and methyl viologen(MV).Glutamic pyruvic transaminase is determined by its effect on pyruvate production of reaction of the alanine with α-ketoglutarate.The linear range is 0 -110 U/L, and the response time is 50 s, and this biosensor has high selectivity and sensitivity.
Cholesterol Oxidase Sensor Based on Cobalt Protoporphyrin Modified Electrode
DENG Qing, DONG Shao-Jun
1993, 14(9): 1214-1217.
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Anew amperometric sensor for free cholesterol has been fabricated based on a high electrocatalytic activity of cobalt protoporphyrin to the oxidation of H
2
O
2
.Alayer of cobalt pro-toporphyrin was absorbed on the glassy carbon electrode, the enzyme film consisting of bovine serum albumin and cholesterol oxidase was put on it, then a layer of poly(ο-phenylenediamine) film was electropolymerized out of the enzyme film to avoid interference and fouling.The linear range of concentration was 0.1 mmol/L -2 mmol/L.The response time was less than 30 s.The electrode was used for 150 times assays without loss of any enzymatic activity.
On-Line Column Preconcentration and Determination of Trace Elements with T(4-TAP)P as the Derivation Agent by Flow Injection ICP-AES
PENG Xue-Jun, ZHANG Ye-Xu, JIANG Zu-Cheng, ZENG Yun-E
1993, 14(9): 1218-1221.
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Meso-tetrakis(4-aminophenyl)porphyrin[T(4-TAP)P] used as a suitable chelating reagent was loaded on the mixture of active carbon-silica gel.Experimental parameters such as carrier flow-rate, sampling volume and eluent acidity were optimized.In the buffer solution of NH
3
· H
2
O-NH
4
C
1
at pH9.24, Cu
2+
, Mn
2+
, Pb
2+
, Fe
2+
, Cd
2+
, Ni
2+
could be preconcen-trated.and then determined by ICP-AES.Its enrichment factors were 6-57.8 with the detection limits of ng/mLlevel, the sampling frequency was 6 times/h.The method has been applied to the analysis of NBSstandard sample of pig kidney with satisfactory results.
Studies of Voltammetric Behaviour on Cobalt(Ⅱ, Ⅲ) Complexes of meso-Tetra(p-sulfonatophenyl)porphyrin in Aqueous Solution
HOU Jian-Min, GAO Xiao-Xia
1993, 14(9): 1222-1226.
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The formation and electrochemical behavior of cobalt (Ⅱ,Ⅲ) complexes of meso-te-tra(p-sulfonatophenyl)porphyrin(TPPS) in aqueous solution have been investigated.It has been shown that Co(Ⅱ)-TPPSmay produce a polarographic catalytic hydrogen wave in HAc-NaAc buffer, pH 3.5.In ammoniacal buffer solution (pH 9.0) a absorptive complex wave of Co(Ⅱ)-TPPSwas observed, which is attributed to the reduction of both Co(Ⅱ) and TPPS π-ring in the complex.The formation of Co(Ⅲ)-TPPScomplex and the effect of dissolved oxygen in solution comparing with that of Mn (Ⅲ)-TPPScomplex were discussed.It is considered that oxygen plays an important role in the valence of central metal atom and the rate of electron transfer in metalloporphyrins.The reductive wave of Co(Ⅱ)-TPPSin ammoniacal buffer solution (pH 10.7) can be used to determine trace cobalt in the range of 2.0×10
-7
mol/Lto 6.0×10
-6
mol/ Lwith a detection limit of 1.0×10
-7
mol/L.
ECSTM in-situ Study of the Electropolymerized Mechanism of Pyrrole on HOPG
LI Jing, WANG Er-Kang
1993, 14(9): 1227-1228.
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Electrochemical scanning tunnelling microscope (ECSTM) has been used in situ to follow the progress of pyrrole electropolymerized on HOPG.ECSTMexperiments show that the initial state in the formation of films is polypyrrole chains on the electrode surface, and provide an evidence that the growth of polypyrrole films resembles that of metal film on HOPG.
The Effect of the Buffer pH in Capillary Zone Electrophoresis
LIN Bing-Cheng, SHI Wei, HU Liu-Jiang, YANG Guo-Liang, HUANG Jian-Fu, ZHANG Nai-Qian
1993, 14(9): 1229-1231.
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The effect of buffer pHon the migration time of both peptides and proteins was studied in the range from pH 2.5 to 111 the dependence of the elute order and resolution of the components on the pHis very sensitive and should be optimized.Special attention was also paied to it's effect on the absorption of the wall on the proteins at the basic condition.It is one of the ways to inhibit the absorption, but the pHvalues should be chosen very carefully.
Computerized Digital Alternating Current Voltammetry
YU Jun-Sheng, ZHANG Zu-Xun
1993, 14(9): 1232-1234.
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Digital alternating current voltammetry of computerized electrochemical instrumentation is described.It is found that the frequency of digital sine wave may reach to 1400 Hz.All available information of electrochemical experiments is memorized by instrument on-line, multi-current signal can simultaneously be detected in an experiment.This technique is applicable to electrochemical investigation and determination.
Studies on the Synthesis of Analogues of Pseudoisocytidine
DONG Ling-Jiao, ZHANG Dong, OU YANG-Jun, WANG Yu, MA Ling-Tai, ZHANG Li-He
1993, 14(9): 1235-1238.
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Aseries of analogues of pseudoisocytidine were synthesized via Witting reaction.We successfully raised the yields of the key-intermediates(Ⅵ) by improving the experimental procedure, and also investigated profoundly the condensing condition of Ⅵ with some sorts of guani-dines and amidines.
Syntheses and Characterization of a Series of 4-(Methoxy Substituted-Benzoyl)-PMP and the Extraction of U(Ⅵ) with the Compounds
DONG Xue-Chang, LU Wen, ZHANG Shu-Gui, PENG Li, ZHENG Quan
1993, 14(9): 1239-1243.
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In this paper, o,m,p- 4-(methoxy-benzoyl)-PMP (compounds 2
a
, 2
b
, 2
c
) have been synthesized by introducing methoxy to benzene ring of 4-benzoyl of PMBP.The keto and enol forms of these compounds have been prepared by the method of solvent crystallization and characterized by elemental analysis, IR, UVand
1
H NMR.The keto-enol tautomerism of these compounds in different solvents and the influence of introducing methoxy to benzene ring of benzoyl of PMBPhave been studied.The pK
a
values of compounds (2
a
, 2
b
, 2
c
) have been determined.The extraction of U(Ⅵ) with these compounds(HA) have been studied in contrast to PMBPby slop method.The compositions of the complexes, the pH
1/2
, the logarithm of the extraction e-quilibrium constants lgK
cx
and the pK
a
.
Synthesis and Structure of 3,4-Diphenyl-1,3,4-diazaphospholidin-2-thione-4-oxides(sulfides)
FENG Ke-Sheng, CHEN Ru-Yu, WANG Hong-Gen, WANG Ru-Ji
1993, 14(9): 1244-1249.
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The mannich-type reactions of phenylthiourea with phenyl dichlorophosphine and aldehydes (ketones) are investigated.Besides the expected products, 3,4-diphenyl-1,3,4-diaza-phospholidin-2-thione-4-oxides, small amounts of new products, the corresponding 4-sulfides were isolated and characterized.Some structure information of the products are disclosed.Amechanism involving addition of P-Hto the imine derivatives is proposed for the reactions.
Studies on Synthesis and Spectroscopy of 1-Ferrocenoyl-4-aryl Thiosemicarbazides
WANG Ji-Tao, ZHANG Yun-Wen, XU Yu-Ming, GAO Sheng-Hua, YUAN Yao-Feng
1993, 14(9): 1250-1253.
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Aseries of 1-ferrocenoyl-4-aryl thiosemicarbazides(FATSC), Fc-C(O)-NHNH-C(S)-NH-Ar [where' Ar are C
6
H
5
-(1), p-CH
3
C
6
H
4
- (2), m-CH
3
C
6
H
4
- (3), ο-CH
3
C
6
H
4
-(4), p-ClC
6
H
4
-(5), m-ClC
6
H
4
-(6), ο-ClC
6
H
4
-(7), m-BrC
6
H
4
-(8), p-CH
3
OC
6
H
4
-(9), ο-CH
3
OC
6
H
4
-(10), a-C
10
H
7
-(11)] were synthesized by the addition reaction of ferrocenecarboxyl hydrazide with several arylisothiocyanates.All the products were characterized by elemental analysis, IRand
1
H NMR.FATSCcan be represented by four tautomeric forms, thioketo-keto (a); thioketo-enol (b); thioenol-enol (c) and thioenol-keto (d).
A Study of 1,2,4-Triazines (XX) ——Study on Structures of Products from a Series of Substituted Benzene Sulfonation of 3-Methylthio-5-hydroxy-1,2,4-triazine by Spectrum Analysis
HAN Mei, SHI Xu-Ling, YANG Zhen-Jun, CAI Meng-Shen, CHENG Tie-Ming
1993, 14(9): 1254-1256.
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This paper reported the reaction between 3-methylthio-5-hydroxy-1,2,4-triazine (1) and subsitituted benzene sulfochlorides (p-CH
3
, p-Br, m-NO
2
).The structures of the products were identified as 3-methylthio-4-subsituted benzene sulfonyl-5-oxo-6-hydroxy-1, 4, 5, 6-te-trahydro-1,2,4-triazine by
1
H NMRand
13
C NMRas well as UV.The analysis results show the compounds proceeded both a substituted benzene monosulfonation to N4 position (not to N2 or C
5
-OH) and addition of one molecule H
2
Oto-N
1
= C
6
- double bond in which the hydroxy group was connected to C
6
position.
Studies on Sintering Kinetics of ZrO
2
WU Wen-Fang, GE Qi-Lu, LI Gui-Zhi, LU Zhan-Mang, WU Wei-Hang
1993, 14(9): 1257-1260.
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In this paper, the sintering kinetic of ZrO
2
was investigated, and the activation energies were also measured.It is found that the mechanism controlled by boundary diffusion is dominant during the densification of ZrO
2
. The finer the powder is, the faster the densification process is, but the final relative density ramains constant.The critical relative density for grain growth is 85%, and the effect of the second phase on the grain finement can only be shown when the grain boundaries move.The sintering activation energy of ZrO
2
is 595 ± 65 kJ/mol, and may be obviously increased owing to the presence of the second phase.The activation energy of 700±50 kJ/mol is estimated in ZrO
2
+ 10 vol%Al
2
O
3
. However, it is not affected by Y
2
O
3
content, but the densification process is clearly accelerated.There is an optinum content of Y
2
O
3
which can influence the final density of ZrO
2
.
Reaction Mechanism of Li-CuO Cell (Ⅰ) ——Investigation of the Cathode Intercalation Reaction by Photoelectrochemical Method
ZU Yan-Bing, DONG Qing-Hua
1993, 14(9): 1261-1264.
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The cathode intercalation reaction of Li-CuOcell was studied in-situ by photoelec-trochemical method.The changes of photocurrent of CuOelectrode reflected the intercalation process directly.It is found that Li
+
ions start inserting into CuOlattice at 2.5 V(vs.Li/Li
+
) and act as the donor impurities, changing the semiconductor property of the cathode.Some succeeding reactions may take place at lower potential, leading to the formation of Cu
2
O.
Hydroformylation of Styrene Catalyzed by Chelate Rhodium Complexes
CHEN Wan-Zhi, XU Yun, LIAO Shi-Jian
1993, 14(9): 1265-1269.
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Rhodium(Ⅰ) complexes prepared from the reaction between Rh
2
(CO)
4
Cl
2
and the salts of aminophenol, 8-hydroxyquinoline and leucine respectively can catalyze the hydroformylation of styrene at 0.1 MPa and 60℃.The results show that the kind of phosphine ligands plays a crucial role in determining the catalyst activity and regioselectivity.Diphosphine ligands can induce a higher catalyst activity and regioselectivity to the branched aldehyde than PPh3.Triph-enylphosphite promotes the formation of normal aldehyde.Increasing the P/Rh ratio leads to a decrease of initial activity, nevertheless, the higher conversion can be obtained in the case of higher P/Rh ratio.The variation of P/Rh ratio does not affect the regioselectivity apparently.Dicarbonyl leucinatorhodium combined with diphosphines offers a high selectivity to 2-phenyl-propanal, furthermore, it can also be used as an asymmetric catalyst for the hydroformylation of styrene.The optical yield is 9.5% in the presence of Ph
2
P(CH
2
)
3
PPh
2
at a P/Rh ratio of 5.
Fragmentations of Some Doubly Charged Ions in the Gas Phase
ZHAN Dong-Liang, ZHU Yu-Fen, LIU Shu-Ying, XIN Bao-Min, JIA Wei-Ping, ZHANG Fa-Yi, HUANG Cheng-Yi, SUN Hong-Wei
1993, 14(9): 1270-1274.
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The unimolecular fragmentation and collision-induced dissociation (CID) of doubly charged ions generated by electron impact (EI) were studied by mass analyzed ion kinetic energy spectrometry(MIKES) and tandem mass spectrometry(MS/MS).The factors leading to the differences between the experimental results from above two methods mainly include ion kinetic energy and analyzer types.In addition, the intercharge distances of doubly charged ions at the moment of fragmentation were approximately calculated on the basis of the kinetic energy releases given by MIKESfor charge separation reactions, which can be used to distinguish the transition structures of doubly charged ions fragmenting in different charge separaton ways.
Theoretical Prediction for the Reaction Rates in Salt-Aqueous Binary and Salt-Aqueous-Nonaqueous Ternary Systems
WANG Feng-Yun, YU Bo-Heng, CHEN Min-Sheng, YE Jing-Xian, JIN Jia-Jun
1993, 14(9): 1275-1279.
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Considering the contributions from the cavity formation, non-electrostatic (induction and dispersion), electrostatic (i.e.ion-ion, ion-dipole, dipole-dipole), repulsion (hard-sphere and electrostatic) and the hydrogen bond interactions between the solute and the solvent particles, this paper is a prediction of the rate constants for alkaline hydrolysis reaction of ethyl-acetate in a series of H
2
O-NaCl, H
2
O-KCl, H
2
O-BaCl
2
, H
2
O-SrCl
2
systems, and for solvolysis reaction of t-BuCl in some compositions of H
2
O-DMSO-MX, H
2
O-Me
2
CO-MX, H
2
O-MeOH-MX, H
2
O-EtOH-MXsystems (where MX = NaCl, NaNO
3
, LiClO
4
).For most of the systems, the calculated results are in good agreement with those from literatures.Adiscussion on the formula used, the results obtained and the contributions from each interactions is given at the end briefly.
Studies on the Determination of Infinite Dilution Activity Coefficients of Acetone-Cycloalkane Systems by Gas Stripping Method
BAO Jian-Bin, HANG Lai-Lai, LING Yue-Ping, CHEN Geng-Hua, HAN Shi-Jun
1993, 14(9): 1280-1283.
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Apre-saturator would be added for the gas stripping method to maintain the amounts of the solvent if it was a high-volatile substance.The infinite dilution activity coefficients of three acetone-cycloalkane systems:acetone-methyl cyclopentane, acetone-cyclohexane, acetone-methyl cyclohexane have been determined in the 298.2-318.2 Ktemperature region.Linear dependence of Inγ
∞
on
1
/Tis found for all systems, and the temperature parameters are in the order:cyclohexane<methyl cyclopentane<methyl cyclohexane.Furthermore, the experimental results are used to predict the whole range VLE.The results show that Wilson equation gives the best fit to literature data.
Studies on Internal and External Surface Acid Pore Size and Shape-Selective Properties of HZSM-5 Zeolite
PAN Lu-Rang, LI He-Xuan
1993, 14(9): 1284-1288.
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Internal and external surface acid amount and their distribution on HZSM-5 (SiO
2
/ Al
2
O
3
= 38) zeolite were measured by the TPDmethod with pyridine, 2,4-dimethylquinoline and ammonia adsorption.The pore size of zeolite is characterized by the adsorption rate of cyclohex-ane.Ethylbenzene disproportionation and para-diethylbenzene isomerization were used as the test reactions for examining the shape-selectivity of catalysts.The result shows that the external surface acid is twenty percent total acid approximately.Both internal and external acids contain strong and weak acid sites.The strong acid is the active site for creaking para-diethylbenzene and ethylbenzene and it has little effect on p-isomer selectivity of disproportionation and isomerization.The m-diethylbenzene is produced mainly on the internal surface acid site, but not by isomerization of p-diethylbenzene on the external surface.The increase of para-selectivity is in a good relation to the decrease of adsorption rate of cyclohexane, but poor to the acid amount variance.Thus, the major factor which affects the selectivity of ethylbenzene disproportionation to p-isomer is the pore size of HZSM-5 zeolite, but is not the strong acid site or the isomerization of p/>-diethylbenzene on the external surface acid.
Studies on Structures of Electrodeposited Ni-Fe Alloys by Using Mossbauer Spectroscopy and X-ray Diffraction
GE Fu-Yun, YAO Shi-Bing, CHEN Rong-Qin, CHEN Bing-Yi, XU Shu-Kai, ZHOU Shao-Min
1993, 14(9): 1289-1292.
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Electrodeposited Ni-Fe alloys with different Fe contents have been studied by means of Mossbauer spectroscopy and X-ray diffraction technique.Those deposits containing less than 46 at% Fe, were identified as γ-phase, those containing 46 at%-63 at% Fe as α+γ phases, and those containing more than 63 at% Fe as γ-phase.Partially ordered Ni
3
Fe was found to exist in deposits containing about 25 at% Fe and Fe-rich phase in the range of 35 at%-46 at% Fe.In general, the lattice parameters of γ-phase increase with Fe content increasing.However, in the deposits containing about 25 at% Fe(20 at%-30 at%) the lattice parameters decrease slightly with the increasing of Fe content, which is due to the presence of partially ordered Ni
3
Fe in the deposits.The lattice parameter is almost constant in deposits with Fe content from 46 at% to 63 at%.
Structural Elucidation and
1
H Spectral Assignments of Complex Natural Organic Compounds by
2
D-HOHAHA and ROESY Methods
YANG Yan-Wu, HE Bing-Lin, XU Xiao-Long, QIU Jian-Qing, WANG De-Hua, QIAN Bao-Gong
1993, 14(9): 1293-1297.
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Because of the serious spectral overlap in several regions of the
1
Hspectrum, the 1Hchemical shifts of an ocotillol-type saponin, which was first isolated from the leaves of panax Quinquetolium L., are completely assigned by recently developed two dimensional homonuclear Hartmann-Hahn spectroscopy (2D-HOHAHa) and rotating frame nuclear Overhauser effect spectroscopy (ROESY).The 2D-HOHAHAexperiment is able to obtain the phase sensitive two dimensional spectrum with all peaks in the near absorption mode, and the cross peaks multiplets are nearly in-phase.So the high detection resolution and sensitivity of 2D-HOHAHAexperiment make it possible to observe the cross peaks overlapped such as H13-H17 and H23a-H23e, and that covered by diagonal peaks with high strength in COSYspectrum, such as H2a-H2e.On the other hand, during the spin locking period of 2D-HOHAHAexperiment, relayed magnetization transfer will occurs.For shorter mixing period (shorter than 20 ms) little RELAY signals can be observed, but for longer mixing times single-RELAY and multiple-RELAY effects become significant.Through the RELAY cross peaks appeared in 2D-HOHAHA spectrum of OTS, the accurate
1
Hchemical shifts of some proton signals in severe spectral overlap regions are assigned, such as, the
1
Hchemical shifts of H22a, H22e, Hla, H1e and H9 proton are 1.592, 1.857, 1.026, 1.640 and 1.586 ppm respectively.The spin-locking NOEexperiment is used to provide through-space connectivity between the various coupling networks of protons.The linking position of glucosyl with aglycone in OTSand the chemical shift assignments of methyl protons which are easily distinguished but difficultly assigned are determined by ROESYspectrum.
On the Magnetic Properties of Compounds Y
1-x
Pr
x
Co
5
and Y
1-x
Sm
x
Co
5
HUANG Xu-Ri, LI Ze-Sheng, LI Bo-Fu, JIN Han-Min, SUN Jia-Zhong
1993, 14(9): 1298-1301.
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The magnetization M(H), the spontaneous magnetization M(T), and the cone angle θ
c
(T) between the easy direction of magnetization and the c axis of rare earth compounds Y
1-x
Pr
x
Co
5
and Y
1-x
Sm
x
Co
5
are studied by means of the improved Hamiltonian.The calculated results are in agreement with the experimental M(H),M(T) and θ
c
(T), and the calculated result of second order crystal field parameter A
2
0
for the compounds Y
1-x
Pr
x
Co
5
is improved.
Effects of Interfacial Electron Acceptor Molecules on the Optical Properties of CdS Nanoparticulates
ZOU Bing-Sou, TANG Guo-Qing, SHANG Xiao-Ming, WANG Bin, ZHANG Gui-Lan, CHEN Wen-Ju
1993, 14(9): 1302-1304.
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In this paper, we reported the variances of optical properties of CdSnanoparticulates in reverse micelle as the size and interfacial chemical condition were changed.TCNQ(7,7,8,8-tetracyanoquinodimethane) molecules on the surface of CdSnanoparticulates could induce the acceptor bound excitonic states, increasing the binding energy between electron and hole, which was in relation to the red-shift of optical absorption band edge and the well-discrete optical absorption and photoluminescence structures.This composite system would find applications in optical memory, optical nonlinearity, electron localization and so on.
Studies on Structure-Activity Relationship of Fentanyl Derivatives by EHMO and Pattern Recognition Method
LU Wen-Cong, YAN Li-Cheng, ZHU You-Cheng, CHEN Kai-Xian, CHEN Nian-Yi
1993, 14(9): 1305-1307.
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In this paper, the properties of the fentanyl derivatives were calculated by using EHMOmethod.Then, the correlation between the properties and biological activities of a series of fentanyl derivatives was calculated and analyzed by pattern recognition method.Two new compounds expected to possess higher biological activities have been designed on the basis of mathematical model.
The Synthesis and Study for New Aromatic Pol yaryl ether Ketone
WANG Jun-Zuo, ZHENG Yu-Bin, ZHANG Wan-Jin, WU Zhong-Wen
1993, 14(9): 1308-1311.
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The New aromatic polyarylether ketone is synthesized by new monomers, the general properties are studied by IR, DSC, WAXD.The results indicate that the new aromatic polyaryl ether ketones have the same crystal structure as PEEK.The glass transition point and the melting temperature get higher with the increasing of the ketone content of polyarylether ketone
Synthesis and Characterization of Emulsifier-free Self-cross Linked Polystyrene Latex in the Presence of β-Hydroxy Propyl Acrylate
DAI Li-Zong, ZOU You-Si, SONG Ai-Qun, PAN Rong-Hua
1993, 14(9): 1312-1316.
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Emulsifier-free emulsion polymerization of styrene in the presence of β-hydroxy propyl acrylate was studied.Monomer conversion is higher than 90% when [St], [β-HPA], [KPS] is 2.66, 0.228, and 5.8×10
-3
mol/Lrespectively under 80℃ for 5 h.The mono-dispersed latex particle diameter and colloidal particle concentration were given as D=0.23 μm, N=3.13× 10
13
/cm
3
by TEManalyse.The factors of influencing latex stability were discussed.The copoly-mer was characterized by IRand dissolution experiment.The self-cross linked mechanism was also discussed.The apparent activation energy of polymerization and polymerization rate constant were obtained to be 78.7 kJ/mol and 514.3 L/mol · s respectively.
Synthesis of PS Microgel with Iniferter and Star-Like Polystyrene
YANG Wen-Jim, WU Qi-Ye, ZHOU Li-Ling, LI Zeng-Ji, SHEN Jia-Cong
1993, 14(9): 1317-1319.
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By the ultrasonic oscillation dispersion method, the soluble microgel of PSwith chloromethylene was formed during copolymerization of styrene-divinylbenzene-p-chloro-methyl-styrene.When chlorine atoms in microgel were replaced by sodium N,N-diethyldithiocarbamate, the active microgel with iniferter function was obtained and it can be used to prepare the Star-Like PSinitiated by ultraviolet radiation.Iniferter functional groups remained in Star-Like polymer.
Studies on Solution Properties of Acidic Heteropolysaccharide of Auricularia Auricula-Judae
ZHANG Li-Na, CHEN He-Sheng
1993, 14(9): 1320-1325.
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Aacidic heteropolysaccharide (F Ⅱ), which is composed of D-mannose, D-xylose, D-glucose and glucuronic acid, was isolated from the fruiting body of Auricularia auricula-judae, and separated into 8 fractions by reprecipitation.The weight average molecular weights M
w
, number average molecular weights M
n
and second viriai coefficients A
2
of fractions and unfrac-tioned samples in 0.5 mol/L NaCl/10%cadoxen (C) were measured by low angle laser light scattering and membrane osmometry.The values of M
w
and M
n
of the acidic heteropolysaccharide were obtained to be:5.88×10
5
and 1.43 ×10
5
.Intrinsic viscosities [η] were investigated on fractioned samples in aqueous 0.5 mol/L NaCl (A), 0.2 mol/L Na
2
SO
4
/0.01 mol/Lphosphate buffer (B) and (C) at 30℃.The Mark-Houwink equations were established as [η] = 0.235 M
w
0.48
(A), [η] = 7.61×10
-2
M
w
0.57
(B) and [η] = 6.44×10
-2
M
w
0.59
(C).The unperturbed dimensions〈S
2
0
and K
θ
are respectively 12.1 ×10
-18
cm
2
mol g
-1
and 0.175 cm
3
g
-1
.We conclude that the acidic heteropolysaccharide behaves as a slightly stiffened random coil chain in aqueous solution.
Studies on β Phase Crystallization of Poly (Vinyl idene Fluoride)
CHEN Ye, YANG De-Cai, SONG Dan-Dan
1993, 14(9): 1326-1329.
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FTIRand TEMhave been used to study the effect of quenching, melt-drawing and blends component on β phase crystallization of PVF2.Low quenching temperature (30℃) induce β phase formation of PVF
2
directly from the melt.The melt drawn films of PVF
2
consist of highly oriented lamellar structure.Adding a given amount of polymethacrylates (PMAs), especially PMMA, into PVF2 results in formation of fibrillar crystals and β phase.The contents of fibrillar crystals and β phase increases with the increase of the molecular weight of PMAs.
The Polymerization of Ethyl and Butyl Acrylates with Rare Earth Coordination Catalyst
FANG Jiang-Hua, ZHANG Yi-Feng, SHEN Zhi-Quan
1993, 14(9): 1330-1332.
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The polymerizations of ethyl and butyl acrylates with coordination catalyst:Nd(naph)
3
-Al(i-Bu)
3
were studied.Kinetic studies indicated that both ethyl acrylate polymerization and butyl acrylate polymerization reaction are first order wtih respect to monomer concentration and 0.5 order to catalyst concentration.The apparent activation energies of EAand BApolymerzation reactions are 17.8 kJ/mol and 33.3 kJ/mol respectively.
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