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中文
Table of Content
24 June 1994, Volume 15 Issue 6
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Articles
Immobilization and Characterization of Porphyrin and Study of Its CatalyticCapability
WANG Xing-Qiao, GAO Shuang, LIU Yu-Wen, YU Lian-Xiang, LIU Yang, CAO Xi-Zhang, WU Zhi-Yun, CUI Yue-Yong
1994, 15(6): 789-793.
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Astepwish synthesis method was used to encapsulate tetrahalogen-tetramethyl porphyrins in the supercages of NaCoXmolecular sieve, The resulting samples were washed with DMFin a Soxhiet extractor untill the porphyrin which deposited on the external surface of molecular sieve was removed completely.Charaterization of TCTMPand TBTMPwas made by the methods of UV-Vis, IR, SEM, DTAand absorption.Catalytic capabilities of porphyrin, molecular sieve and NaCoXmolecular sieve with supercage structure in which porphyrin was entrapped were compared.
Synthesis and Characterization of N,N'-Bis(2-hydroxybenzylidene)-2-hydroxyphenymethanediamine and N,N'-Bis-(2-hydroxybenzyl)-2-hydroxyphenylmethanediamine complexes with transition metals
WANG Yong-Wei, ZHANG Hua-Lin
1994, 15(6): 794-798.
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Binuclear and trinuclear complexes of a Schiff base ligand, N, N'-bis(2-hydroxy-benzylidene)-2-hydroxyphenylmethanediamine(SB), with divalent transition metals Ni, Cu and Zn, have been synthesized in THF.Also, the hydrogenated product of the Schiff base ligand(HSB)and its copper complex liave been prepared in ethanol.These complexes were characterized by elemental analysis, thermogravimetric analysis, molar conductance, and UVand IRspectra.Cu
3
(SB)
2
·1.5THFis a trinulear complex with tetrahedral Cu
1
, Cu
2
and square-pyramidal Cu
3
coordination configurations.Ni
2
(SB)Ac
2
·THFand Zn
2
(SB)(Ac)
2
·THFare binuclear complexes, each metal ion is coordinated in a square-pyramidal configuration by 1N, 1O of SB, two carboxylate oxygen of acetate and oxygen of THF.Binuclear Cu
2
(HSB)(Ac)
2
is similar to Zn(Ni)-SBcomplexes, but metal ions are coordinated in a square-planar configuration.The metal ions in these polynuclear complexes are bridged by ligand SBor HSB.
Synthesis and Characterization of(NH
4
)n[LaSb
9
W
21
O
86
M
3
]·xH
2
OHeteropoly Complexes
LIU Jing-Fu, WANG Wei-Qing, LIU Shu-Xia, ZHAO Ben-Liang, GUO Yi-Hang, ZHAN Xiao-Peng, LIU Ya
1994, 15(6): 799-802.
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Ammonium salts of seven new heteropolytungstates, [LaSb
9
W
21
O
86
M
3
]
10-,7-
(M=Mn, Co, Ni, Cu, Zn, Cr, Fe)were prepared from[LaSb
9
W
21
O
86
M
3
]
16-
and characterized by elemental analysis, visible spectroscopy and electrochemistry.Based on
183
W NMRspectroscopy of the lanthanum complex, the lanthanide cations occupy the central site in the structure previously demonstrated for the sodium derivative, and the possible binding sites for transition metal cations are discussed.
Studies on Synthesis and Sensing Characteristics of Nanocrystalline La
1-x
Sr
x
FeO
3
WU Feng-Qing, XU Bao-Kun, LI Xi, SUO Hui, YANG Hua, ZHAO Mu-Yu
1994, 15(6): 803-806.
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Using citrate method, a series of nanocrystalline materials of composite oxides La
1-x
Sr
x
FeO
3
(x=0, 0.1, 0.2, 0.3, 0.4)were synthesized.These samples were characterized by XRD, IR, TGand DTA.The crystal structure is of perovskite-ype;The grain size is about 10-25 nm, The experimental results show that the grain sizes are related to the composition, calcination temperature and time, and nanocrystalline materials La
1-x
Sr
x
FeO
3
(x=0, 0.1)possess a high selectivity to ethanol, the order of selectivity is La
0.9
Sr
0.1
FeO
3
>LaFeO
3
(23nm)>LaFeO
3
(110nm).
Synthesis and Characterization of Zincphosphate from Non-aqueous System
SONG Tian-You, XU Jia-Ning, XU Ru-Ren, YUE Yong
1994, 15(6): 807-808.
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Two types of zincphosphate crystals were synthesized from non-aqueous system with ethylene glycol as the solvent and ZnPO/MEA-1 with HOCH
2
CH
2
NH
2
and ZnPO/EA-1 with CH
3
CN
2
NH
2
as the templating agent respectively.Their structures were investigated by means of XRDand SEM.
Studies on the Atomization Mechanism of Sanmarium on the Graphite Probe Surface in the Graphite Furnace
GAO Yun-Geng, DENG Bo
1994, 15(6): 809-812.
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In this paper, atomization mechanism of Sm(NO
3
)
3
and Sm
2
O
3
on the graphite probe surface in the graphite furnace was investigated experimentally using X-ray diffraction spectrometry.X-ray photoelectron spectroscopy and Auger electron spectroscopy.It showed that in the course of atomization, the samarium samples firstly decomposed into Sm
2
O
3
then converted into SmOand samarium carbide, the atomization of samarium originated from the thermal decomposition of SmO, the formation of refractory carbide accounted for the severe memory effect of determination.
The Study of Normal Dual Pulse Superimposed Four Potential Step Differential Voltammetry─Theory of Quasi-Reversible Electrode Processes andExperimental Verifications
PANG Yu-ZH, LIU Xin-Yu, TONG Wei, JIN Li-Tong
1994, 15(6): 813-818.
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The mathematical expression of current functions of the new pulsed volatmmetric technique:normal dual pulse superimposed four potential step differential voltammetry, proposed by the authors, for quasi-reversible electrode processes have been deduced and verified by experiments, The effects of parameters, such as scan increment(E
s
), pulse height(△E), transfer coefficient(α), on the peak current function(ψ
p
), peak current(i
p
), peak potential(E
p
)and half-width(W
1/2
)have been discussed.According to theoretical, vs -lgks and Simplex Optimization caculations, the kinetic parameters, k
s
, αfor/Fe-KCl system at glassy carbon electrode and Zn(Ⅱ)/Zn(Hg)-NaNO
3
system at static mercury electrode have been determined.The results are in agreement with the literature values.
Kinetic-Catalytic Simultaneous Determination of Tungsten(Ⅵ)and Molybdenum(Ⅵ)in Mixtures with Multivariate Calibration Method
NI Yong-Nian, XIE Su-Wen
1994, 15(6): 819-823.
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Tungsten(Ⅵ)and molybdenum(Ⅵ)have similar catalytic behavior and they all have catalytic effects on the oxidation of iodide by hydrogen peroxide in acidic medium.There is, however, different inhibition in the catalytic activity of each catalyst in the presence of suitable organic reagents.In this paper, two equal sets of standard mixtures of tungsten(Ⅵ)and molybdenum(Ⅵ)were used as the catalysts in the experiments with and without the presence of Organic reagents, respectively.The reaction rate was measured potential by an iodic ion selective t3lectrode.Two multivariate calibration models, linear and nonlinear, were then developed.The catalytic behavior of tungsten(Ⅵ)and molybdenum(Ⅵ)in the presence of different organic acids(citric, tartaric, oxalic and malonic)was investigated.The two calibration models were successfully applied to the prediction of unknown samplesof trace tungsten(Ⅵ)and molybdenum(Ⅵ)in the range of 0.012-0.20μg/mL.
Microscope Fluorescence-Hadamard Transform Three-Dimensional Image Analysis
MEI Er-Wen, ZENG Xiao-Bin, CHEN Guan-Quan, ZENG Yun-E
1994, 15(6): 824-826.
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This research combines Hadamard transform multiplexed image technique with fluorescence microscopy.By this method, a Hadamard transform microscope cell fluorescence image was obtained with one detector(PMT)for the first time.The image shows a lot of useful information including the appearance ofcell, the content and the distribution of some species in a cell at same time.The result shows the possibility of using Hadamard multiplexed image technique to obtain a cell fluorescence image with one detector.
Investigation on Carbon fiber Microelectrodes(ⅩⅧ)─The Determination of Hemoglobin at a Methylene Blue/Nafion Modified Carbon Fiber Microcylinder Electrode
JU Huang-Xian, XUN Yi-Gang, CHEN Hong-Yuan
1994, 15(6): 827-831.
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The methylene blue/Nafion modified carbon fiber microcylinder electrode is manufactured.The state and constitution of the modified electrode surface is observed by scanning electron microscope.The stability is very good in either events scaned with cyclic voltmmetry or immersed in the buffer solution of pH=7.2.The electrode shows significantly electrocatalytic activity to the oxidation of hemoglobin in the system of weak acid, it can be used for the determination of hemoglobin in the range of 5×10
-6
-5×10
-5
mol/L.The variation coefficient of peak current is 3.5%determining continuously 6×10
-6
mol/L HBfor 6 times.The catalytic mechanism is discussed.
CL-ELISA Determination of DNA Antibody in Serum
ZHANG Zhu-Jun, ZOU Ke-Wei, FENG Man-Liang
1994, 15(6): 832-835.
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Amethod for determination of the DNAantibody in serum was established based on chemiluminescence enzyme-linked immunosorbant assay(CL-ELISA).The DNAantigen is immobilized on the inner surface of polystyrene cup, then reacts with DNAantibody in serum sample, only specific antibody binds to antigen to form Ag-Ab HRPlabeled anti-HuIgGreacts with DNAantibody molecules in the complex to form second Ag-Ab, finally determine the label with p-IPenhanced luminol-H
2
O
2
-HRPchemiluminescence system.The clinical applications show that present method has a good correlation with ELISA.The correlation coefficient is 0.958.It is more sensitive, convenient and economical than ELISA.
Fluorescence Energy Transfer Used for Designing a More Sensitive Pieric Acid Optrode Membrane
WANG Ke-Min, ZENG Hui-Hui, YU Ru-Qin
1994, 15(6): 836-837.
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Anew type of picric acid optrode membrane is described based on fluorescence energy transfer from fluoranthene(FA, donor)to fluorescein octadecyl ester(FODE, acceptor).When FAand FODEare incorporated in plasticized poly(vinyl chloride)polymer membrane, the two fluorophore system is strongly quenched, with a 3-fold increase in the Stern-Volmer quenching constant as compared to the quenching of FAor FODEalone.This phenomenon is mainly due to that donor-acceptor pair fluorescence is quenched with a much big efficiency by picric acid.The new optrode membrane offers a more sensitive method for the determination of picric acid over the existing picric acid sensors.
High Efficient Stationary Phases of HPLC for the Separation of Fullerenes
CHEN De-PU, YU Jian-Yuan, LIAO Mu-Zhen, HUANG He-Sheng, LIU Feng-Ying, LIU Meng-Lin
1994, 15(6): 838-839.
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Aseries of high efficient stationary phases of HPLC, FUL-1, FUL-2, FUL-3 and FUL-4, with different separation function groups for the separation of C
60
and C
70
were prepared on the basis of analysis of relationship between intermolecular forces and molecular structures.FUL-1, FUL-2 and FUL-3 can be successfully used to separate C
60
and C
70
from each other with benzene, toluene and o-xylene as mobile phase, respectively.The action force between FUL-4 and C
60
or C
70
is so strong that no solution has been found to elute C
60
or C
70
from FUL-4 column, Of all these stationary phases, FUL-3 is the best because of the highest solubilities of Fullerenes in o-xylene and the highest separation factors of Fullerenes in this system.
Research on the Autoxidation Oscillating Reaction of Aldehydes
SONG Xue-Yu, ZHANG Yi-Xue, JIAO Nian-Xin, CUI Jian-Xia, YANG Xiao-Ping, SHANG Zhen-Feng, MA Ke-Qin, ZHAO Hong-Xi, ZANG Ya-Ru, ZHAO Xue-Zuang
1994, 15(6): 840-844.
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The autoxidation oscillating reaction of aldehydes in the mixed solvent of acetic acid and water(V/V=9:1)with the catalyts of Co
2+
and Br
-
as been studied.We found that the autoxidation of some substituted benzaldehydes and many aliphatic aldehydes could oscillate under proper conditions.We studied the effect of kinetic constraints of benzaldehyde, butyraldehyde and acetaldehyde on the period of oscillation in detail.The relativemechanism involving 14elementary reactions, is proposed as shown in Table 2.According to this model, the oscillating periods calculated by Gear's method are in the main accordance with the experimental results.
Structure Identification of Inflasaponin Ⅲ and Inflasaponin Ⅴ
ZOU Kun, CAI Li-Ning, ZHANG Ru-Yi
1994, 15(6): 845-848.
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Two new saponins, Inflasaponin Ⅲ and Inflasaponin Ⅴ were obtained from 10% EtOHextracts of Glycyrrhiza inflata Bat.through HPLCisolation and purification.On the basis of chemical and spectroscopic evidences, their structures were identified as Liouiritic acid-3-O-β-D-6"-n-butyl-gluctironopyranosyl-(1→2).-β-D-6'-ethyl-glucuronopyranoside, Liquiritic acid-3-O-β-D-6"-n-butyl-glucuronopyranosyl-(1→2)-β-D-6'-n-butyl-glucuronopy-ranoside, The
13
C NMRdata of metliyl-liquiritic ester were reassigned.
Syntheses and Properties of Di-tertiary Alkylphosphinic Acids
HU Wen-Xiang
1994, 15(6): 849-853.
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Di-t-butyl, di-t-pentyl, di-t-octyl phosphinic acids were synthesized by the reaction of Grignard reagents with phosphorus trichloride, followed by oxidation with 30 percent hydrogen peroxide.The preparation of Grignard reagent from tertalkylchlorides is easier than that from tertalkylbromides, The structural identification and stereochemical analysis were also studied by pK
a
values, MSand 1H,
13
C,
31
P NMR.
Reaction of Lithium Diphenylphosphide with Fulvenes─Syntheses and Characterization of Substituted Ferrocene Derivatives
WANG Jia-Xi, HE Zheng-Jie, CHEN Shou-Shan, WANG Xu-Kun, WANG Hong-Gen
1994, 15(6): 854-858.
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Lithium diphenylphosphide reacted with 6, 6-dimethylfulvene to give addition product, phosphino-substituted cyclopentadienyl anion(I), which complexed with FeCl
2
, to form 1, 1′-bis[1-diphenylphosphino-isopropyl) ferrocene(Ⅱ).Compound Ⅱ reacted with PdCl
2
, (PhCN)
2
, to give heteronuclear metal complex(Ⅲ).The single crystal of Ⅱ is monoclinic, space group P2
1
/c with a= 1.3382(5) nm, b=0.8550(1)nm, c=1.7309(4)nm, β-109.16(2)°.V=1.87082 nms, D
x
=1.272 g/cm
3
.μ=5.16 cm
-1
, F(000)=378, Z=2. The study on
31
p NMRshowed complex(Ⅱ)was a fluxional molecule with η
5
η
3
η
1
.
Rubicunoside A─a New Acetylated Triterpenoid Saponin from Silene Rubicunda
TAN Ning-Hua, ZHOU Shou-Xun, ZHOU Jun, CHENG Chang-Xiang, WANG De-Zu, HE Yi-Neng
1994, 15(6): 859-860.
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Anew acetylated triterpenoid saponin, rubicunoside A(1), was isolated from the roots of Silene rubicunda.On the basis of extensive chemical, enzymic, and spectral methods the structure was elucidated as 3-O-β-D-galactopyranosyl-(1-2)-[β-D-xylopyranosyl-(1→3)]-β-D-glucuronopyranosyl quillaic acid 28-O-β-D-xylopyranosyl-(1-3)-β-D-xylopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→3)-[2'-OAc]-β-D-fucopyranosyl-(1-2)-[3'-OAc]-β-D-fucopyranoside(1).The enzymic cleavage method with glyrrhizinic acid hydrolase providing selectively 3-oligosaccharides and 28-O-glucosides, and partial methanolysis providing selectively 28-oligosaccharides from 3, 28-O-bisglucosides were effective for the structure elucidation.
DITERPENOIDS FROM Euphorbia Micractina
SHI Jian-Gong, JIA Zhong-Jian, YANG Li
1994, 15(6): 861-863.
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From the acetone extract of the whole plants of Euphorbia micractina(Euphorbiaceae), two new diterpenoids 15β-O-benzoyl-5α-hydroxyl-isolathyrol, 20-O-acetyl-in-genol-3-O-(2'E, 4'Z)-decadienoate, and one known compound, jolkinol Bwere obtained.Their structures were elucidated on the basis of spectrometric methods, including
2
D NMRtechniques(
1
H-
1
H COSY,
1
H-
13
C COSY, and
1
H-
1
H NOESY).
Rectification of the Product Structure of the Reaction of Phenylmethylenepropanedinitriles and Phloroglucinol
LU Kuan-Ke, TAN Zhen, LI Yu-Lin
1994, 15(6): 864-866.
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The conclusion of the paper on synthesis of flavanone(see Chem.J.ChineseUniv.1987, 8(10):914)was tested to be uncorrect.Phloroglucinol reacted with p-hydrox-y-phenemethylenepropanedinitrile and phenylmetliylenepropanedinitrile respectively to give 3, 4-dihydro-5, 7-dihydroxy-4-(p-hydroxyphenyl)-coumarin(Ⅲ)and 3, 4-dihydro-5, 7-dihy-droxy-4-phenylcoumarin(Ⅳ), but not to give Naringenin and Pinocembrin.
Hyperspherical Analysis and Energy Calculation of the Ground-State for Three-Electron Atom
WANG Yi-Xuan, DENG Cong-Hao
1994, 15(6): 867-872.
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The Schrodinger equation of many-electron atom is expressed in terms of hyperspherical ccordinates.Bsaed on the total wave function satisfying the Pauli principle, the coupled hyperradial differential equation is derived, which is similar to that of He atom.Symmetric basis functions are constructed for irreducible representation of S
3
permiitation group by applying the standard Young projection operator on nine-dimensional hyperspherical harmonics.We generdlize the HHGLmethod proposed by C.H.Deng to Li atom, and calculate firstly the ground-state eigenvalue, which qualitatively approaches to the experimental one.Morever, the slow convergence of the method for eigen energy is discussded.
Studies on SO
4
2-
/TiO
2
and SO
4
2-
/Fe
2
O
3
Solid Superacid Systems
GAO Zi, CHEN Jian-Min
1994, 15(6): 873-877.
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The crystallization, phase transition, dehydration and desulfuration of amorphous TiO
2
and Fe
2
O
3
impregnated with H
2
SO
4
during calcination were studied by using XRD, TG-DTG, SEMand chemical analysis methods.Comparing the experimental results with that of SO
4
2-
/ZrO
2
, it was concluded that the regularity of formation of all types of SO
4
2-
/M
x
O
y
superacids is similar.The superacidity of the SO
4
2-
/TiO
2
and/Fe
2
O
3
sampleswas charac terized by IRspectroscopy and n-pentane isomerization reaction at ambient temperature.Their acid site structure is the same as that of SO
4
2-
/ZrO
2
.For the dehydrated samples the main acid sites are Lewis type acid sites, which may be transformed into Bronsted type acid sites when the samples are partially hydrated.The superacidity of SO
4
2-
/TiO
2
and SO
4
2-
/Fe
2
O
3
is weaker than that of SO
4
2-
/ZrO
2
, their acid strength H
0
is estimated in the range of -13─ -14.
Theoretical Study on the Cycloaddition of-CN Substituted Propadiene with Ethylene
ZHANG Shao-Wen, FU Xiao-Yuan
1994, 15(6): 878-881.
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Semi-empirical MOtheory AM1 method has been used to investigate the[2+2]cycloaddition of-CNsubstituted propadiene with ethylene.The results show that this reaction can proceed through three possible paths:(1)ethylene reacts with the central carbon of-CNsubstituted propadiene;(2)ethylene reacts with the terminal carbon attached and(3)not attached with-CNgroup. Path(1)has a relatively lower activation barrier than that of(2)and(3).The activation barrier of(1)is lower than that of the cycloaddition of ethylene with-NH
2
substituted propadiene, The three paths all involve intermediate radicals.
Pattern Recognition Optimization(PRO)Method for Multiple Targets and Its Application to V-PTC Materials Design
LU Wen-Cong, ZHU Xing-Wen, LIU Hong-Lin, CNEN Nian-Yi
1994, 15(6): 882-885.
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The computer-aid design of V-PTCmaterials was investigated by pattern recognition optimization(PRO)method for multiple targets.The relationships between the properties and their features of V-PTCmaterials were studied through the principal component analysis.The classification diagrams with the targets including ρ
r
, ρ
0
/ρ
n
and ρ
m
/ρ
n
were obtained and used to explore the technical conditions and compositions of the samples with better properties.Based on the information provided by PROmethod, a few optimal samples of V-PTCwere synthesized in our laborotary.
Molecular Dynamics Simulation for the Geometry of Water Molecule in Liquid
GU Jian-De, TIAN An-Min, YAN Guo-Sen
1994, 15(6): 886-890.
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Amolecular dynamics simulation for liquid water with the ab initio potential of water(MCYL)was applied to the investigation of the effects of the long and short-range interactions and of the liquid structure on the geometry of water molecule.The effective interaction ranges which influences the changes of the geometry of water molecule were also in vestigated.The simulated pair radial distribution functions of liquid water and the changes of the bond length and the bond angle of water molecule were compared well with those from experiments.The study shows that besides the effects of H-bond, the geometry of water molecule in liquid is greatly influenced by the order structure of the liquid.The changes in the bond angle of water molecule are very sensitive to the order structure of the liquid, while the changes in the bond length are not so.The second-nearest neighbors of a water molecule seem to play an important role in the changes of the bond angle.
The Stucture of Mgo and Its Catalytic Properties for Oxidation Coupling of Methane
ZHEN Kai-Ji, LI Sen-Zi, BI Ying-Li, WEI Quan, YANG Xiang-Guang
1994, 15(6): 891-894.
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Aseries of MgO catalysts prepared by different methods for the catalytic oxidation coupling of methane were investigated.The specific surface area, XRDand XPSmeasurement results reveal that the catalysts with larger specific surface area, larger lattice distortion, Iess crystal dimension and higher amount of surface unsaturated coordinated oxygen can give higher catalytic activity for the reaction mentioned above at lower temperatures.
Role of Ceria in Non-precious Metal Oxide Catalysts(Ⅴ)─The Effect of Environmental Temperature on the Properties of Cu-Mn-Ce-O catalyst
LU Guan-Zhong, WANG Xing-Yi, WNAG Ren, WU Shan-Liang
1994, 15(6): 895-898.
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In this paper, the effects of an environmental temperature on the surface area, solid structures, oxygen properties and catalytic actlvities of Cu-Mn-Ce-Osupported on alumina have been studied.The results indicate that as a promoter, CeO
2
can not inhibit the reduction of surface area of the supporter at high temperature, but can inhibit the crystal growth of CuMn
2
O
4
spinel in the catalyst and avoid the sinter of the amorphus active solidcompounds in catalysts, and increase the thermostability of the catalysts.In particular, over temperature 800℃ the promoting effect of CeO
2
in the catalyst is more obvious, in which the atom ratio of Ce/Cu is 0.38-0.44.
The Treatment of Big Basis Sets in Valence Bond Method
MO Yi-Rong, WU Wei, ZHANG Qian-Er
1994, 15(6): 899-902.
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Ageneralized multi-bonded tableau self-consistent field program(MBTSCF)is framed.The program can optimize the expansion coefficients of single-electron orbitals as well as those of bonded tableaus simultaneously.Though the expansion space of a singleelectron orbital can be defined arbitrarily, we suggest to adopt the form of a hybrid orbital whose expansion space is the basis functions of an unique atom.Test calculations to H
2
, Li
2
and HLi are performed with different basis sets.The results show that the total energies resulted from 3BTSCF, where 3BT's correspond to resonance structures A-B, A
+
-B
-
and A
-
-B
+
for a diatomic molecule AB, are rather near to those resulted from MP
2
calcula tions.Moreover, our method can be used to discuss the covalence and ionicity of a true molecular bond very intuitively.
Quantum-Chemical Calculation Studies on Model Oxyheme(Ⅰ)─Oxygen Geometry and Hydrogen Bond
LIN Da-Wei, WANG Zhi-Zhong
1994, 15(6): 903-906.
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In this paper the CNDO/2 method was used to investigate the bonding between dioxygen and Fe-porphyrin in oxyheme.Optimized Fe-O
2
complexing geometry is in good agreement with experimental results.At the same time, the hydrogen bond between oxymyoglobin and distal histidine E7 is studied and the liydrogen bond energy 10.5kJ/mol is obtained.For comparison the Fe-COcomplexing geometry is also studied and the result is coincided with experimental measurement.
Ab Initio Molecular Orbital Study of Bonding Trends in
4
m
System(X=H,He,Li,Be, O,F,Ne,Na,Mg,S,Cl,Ar;m=0,±4)
ZHAO Yong-Fang, YU Wen
1994, 15(6): 907-911.
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Bonding trends in SiX
4
m
system are studied using the methods of ab initio molecular orbital at HF/STO-3G, HP/3-21Gand HF/6-31Glevels.The calculated results indicate that all species considered except SiLi
4
have local minima.Comparing with experimentally known molecules SiH
4
, SiF
4
and SiCl
4
, the species SiHe
4
4+
, SiNe
4
4+
, and SiAr
4
4+
containing rare gas, isoelectronic structure with previous molecules, respectively, have larger probability of bonding trends than species containing alkali metals Li and Na, alkali-earth metal Be and Mg.It could be expected that SiHe
4
4+
, SiNe
4
4+
and SiAr
4
4+
could be candidates of probably stable new molecules.
The Relationship Between the Formation of C
60
and the Lattice Plane of Graphite(Ⅱ)
XIE Zhao-Xiong, LIU Zhao-Yang, WANG Chun-Ru, LIN Feng-Chen, ZHENG Lan-Sun
1994, 15(6): 912-913.
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The(0001)plane of the high oriented pyrolytic graphite(HOPG)was directly ablated by pulsed laser, and the products were recorded by mass spectrometry in situ.It is found that the relative abundances of C
60
, C
70
and other larger fullerenes were related to the ablating time─the regularity of the HOPGstirface, which was imaged by scanning tunneling microscopy (STM).At the beginning of laser ablation, the(0001)plane contained enough six-membered rings, which mainly produced C
60
and C
70
.After laser ablation, many exposed platforms with no enough six-memberted rings, like amorphous carbon and aromatic compounds, were formed, which tended to form larger fullerenes.
Studies on the Properties of Hydrogen Storage Alloy LaNi
3.8
Co
0.5
Mn
0.4
Al
0.3
Coated with Chemically Plated Nickel
ZHANG Yun-Shi, CHEN Jun
1994, 15(6): 914-916.
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The effect of chemical plating with Ni of hydrogen storage alloy LaNi
3.8
Co
0.5
Mn
0.4
Al
0.3
on the properties is studied.The results show that the alloy crushing as been greatly improved after the processing of chemical plating with Ni.The alloy elec rode property is good.It can be used in nickel-metal hydride battery.
Synthesis and Photophysical Properties of Substituted Zinc Phthalocyanines
ZNANG Xian-Fu, XU Hui-Jun
1994, 15(6): 917-919.
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Synthesis and photophysicai properties of some substituted zinc phthalocyanines are described in this paper.It was shown that strong electron-withdrawing(or electron-do-nating)substituents decrease the lifetime and quantum yield of both excited singlet state and excited triplet state owing to the intramolecular ground state charge transfer and photoinduced electron transfer process.Halogen substituents on benzene ring of phthalocyanines lead to the decrease of lifetimes of singlet state and triplet state owing to the heavy atom eftect.
The Phase Morphology and Electro-optical Properties of UV Cured PDLC Film
PAN Yi, ZHANG Hong-Dong, YANG Yu-Liang, LI Li
1994, 15(6): 920-924.
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In this paper, PDLC(polymer dispersed liquid crystal)film, a new kind of potential solid display device, has been prepared by using the method of UVlight initiated polymerization induced phase separation and its electro-optical properties have been studied.We have investigated the morphology of UVcured PDLCby SEM.The correlations between phase morphology and electro-optical properties have also been discussed.
Sol-Gel Distribution of A
a
-B
b
,C
c
Polycondensation with Intramolecular Cyclization
BA Xin-Wu, PAN Shou-Fu
1994, 15(6): 925-927.
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By means of polymeric statistics, the sol-gel distribution of A
a
-B
b
,C
c
type polycondensation reaction involving intramolecular cyclization is studied in detail to give to solgel distribution formulae explicitly.Furthermore, the gelation condition for this type is obtained.
Studies on Photochromic Liquid Crystalline Polymers(Ⅰ)─Liquid Crystalline Behaviour or Side-Chain Polysiloxane Containing Cholesteric Mesogens and Its Monomer
ZHANG Qi-Zhen, WANG Yan
1994, 15(6): 928-931.
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The liquid crystalline properties of polysiloxane with cholesteric mesogens in sidechain and its monomer were characterized by polarized microscopy with a hot stage, DSCand x-ray diffraction.Cholesteric texture with oily streaks and spirals, monotropic smectic with fan-shaped and solid-solid transition were observed in monomer while only the smectic phase was exhibited by polysiloxane fan-shaped texture.
Synthesis and Drug Release Property of Biodegradable Polyphosphate Esters
LUO Yi, ZHUO Ren-Xi, FAN Chang-Lie
1994, 15(6): 932-934.
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Polyphosphate esters were synthesized by the catalytic solution polycondensation of biphenols with dichlorophosphoric acid ethyl ester, dichlorophosphonoformic acid ethyl ester or dichlorophosphonoacetic acid ethyl ester, respectively.The polypliosphate esters obtained were characterized by IR,
1
H NMRand elementary analysis.The in vitro drug release of 5-fluorouracil was studied in pH7.4 phosphate buffer solution at 37℃.
Photoluminescence and Electroluminescence Doped PVK Thin Film
MA YU-Guang, TANG Jian-Guo, SNEN Jia-Cong, LIU Shi-Yong
1994, 15(6): 935-936.
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The spin-coating thin films of Alq
3
doped PVKwere prepared.The electroluminescet devices using Alq
3
/PVKas emitting element have been fabricated.The photoluminescence of the film and electroluminescence of the devicewere investigated.The photoluminescence films may find potential application in wavelength transformer for solar cell.The ELdevice can be driven to produce a blue green emission(490 nm)at dc voltage 30 V.The lifetime of the device is up to 3 hours.
Permeability and Permselectivity of HQDEA-BASED and BPADA-based Polyetherimides and HQDEsA-ODA
LI Yue-Sheng, DING Meng-Xian, XU Ji-Ping
1994, 15(6): 937-939.
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Aseries of aromatic polyimides from 3 kinds of dianhydrides containing ether bond and ester bond were prepared byconventional procedure.Gas permeabilities for 6 kinds of polymers to H
2
, O
2
and N
2
have been measured at the temperature from ambient up to 150℃.There is a very large difference in the permeability coefficients of the polyimides accompanied the difference in polymer structure.BPADA-based polyetherimides with the largest free volume have the highest permeability, while polyesterimide(HQDEsA-ODA)with the smallest free volume has the lowest permeability, being favorable barrier polymer.
Environmental Stability of Periodic Structure of Arachidic Acid LB Films
HE Ping-Sheng, GUAN Shui-Yun, LI Chun-E
1994, 15(6): 940-942.
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The periodic structure of arachidic acid salt LBfilms measured by low angle X-ray diffraction will be datnaged by treating LBfilms with vapor of ammonia and hydrogen chloride solution.However, the peaks of the LBfilms, whose diffraction peaks had already disappeared due to the treatment with acid(or base), will be appeared more or less if being treated with base(or acid)again.
Structure/Permeability Rdlationship of BPDA-based Polyimides
LI Yue-Sheng, DING Meng-Xian, XU Ji-Ping
1994, 15(6): 943-945.
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Aseries of BPDA-based polyimldes from 4, 4'-oxyl dianiline and 4, 4'-methane dianiline derivatives was prepared by a conventional procedure.Gas permeabilities and permselectivitis of 7 homoand copolyimides for gas pairs H
2
/N
2
and O
2
/N
2
have been measured at the temperature from ambient up to 150℃.The permeability and permselectivity of BPDA-based polyimides are dominantly controlled by free volume. BPDA-DMMDAand BPDA-TMMDAhave higher permselectivity compared with BPDA-3MPDA/ODAand BPDA-4MPDA/ODA.BPDA-DMMDAand BPDA-TMMDAwith higher permeability and permselectivity are favorablegas separation membrane materials.
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