1996 Volume 12 Issue 9

Study of Organic Silicon Protection Film by Magnetic-Controlling Plasma Polymerization on the Y-Ba-Cu-O Superconductor
Wang Rui , Jin Xin-Yu , Cheng Kang-Sheng , Liang Su-Zhen
1996, 12(09): 769-772  doi: 10.3866/PKU.WHXB19960901
[Abstract](3073) [FullText HTML] [PDF 741KB](2167)
Abstract:

A new method of deposition of organic silicon film by magnetic-controlling plasma polymerization was used to protect Y-Ba-Cu-O superconductor from corrosion. The deposition rate of plasma polymer film with magnetic-controlling is 20 times over that without magnetic-controlling. The relation between the deposition rate of film and the process factors of magnetic-controlling plasma were studied. The Y-Ba-Cu-O superconductor covered with organic silicon film was formed by magnetic-controlling plasma polymerization had been protected from corrosion in water over 48 hours.

Adsorption and Diffusion of Hydrogen Atom on Pd Loe Index Surfaces
Zhang Ji-Shu , Zhang Wen-Xia , Wang Ze-Xin
1996, 12(09): 773-779  doi: 10.3866/PKU.WHXB19960902
[Abstract](3299) [FullText HTML] [PDF 1146KB](2298)
Abstract:

The 5-parameter-Morse potential of interaction between hydrogen and palladium was constructed, the adsorption and diffusion of hydrogen atom on Pd(100),Pd(111),Pd(110) low index surfaces were studied by means of the classical pair potential methods. The data of the adsorption sites, adsorption geometry, binding energy and eigenvibration etc were obtained for a hydrogen atom on Pd surfaces, they are in od agreement with the experimental results. Meanwhile, the construction of adsoption diffusion potential energy surface was systematically studied for three systems.

Study of the Intramolecular Electron Transfer of Diphenyl-2-pyrazoline Compounds
Guo Jian-Xin , Zhang qi-Yuan
1996, 12(09): 780-785  doi: 10.3866/PKU.WHXB19960903
[Abstract](2970) [FullText HTML] [PDF 1127KB](2242)
Abstract:

The molecular geometry and the electronic structure of 2-pyrazoline(PZL),1,3-biphenyl-2-pyrazoline (DPP) and their nitro derivatives are calculated. The results show that atoms in PZL ring in ground state are not located in a common plane because of the existence of the lone electron-pair at atom N1, and the benzene rings at 1-position and 3-position deviate off the plane of PZL ring. For the excited states of 1,o-DPP and 3,o-DPP, the corresponding benzene rings are perpendicular to the PZL ring, and the electrons are transfered from N1 to the corresponding benzene rings. For the excited states of other cases, the benzene rings are nearly in the same plane as that of PZL ring, and the electron are transfered from N1 to the position between N2-C3.

Diode Laser Probing of NH3ν2 Vibrational Mode Excited by Relaxation of Highly Vibrational Exited NO2
Cai Ji-Ye , Liu Yi , Li Ya-Dong , Cheng Guo-Sheng , Zhang Wei , Zhang Bing , Zhou Shi-Kang , Gao Jun-Yi , ng Zhi-Ben
1996, 12(09): 786-795  doi: 10.3866/PKU.WHXB19960904
[Abstract](3173) [FullText HTML] [PDF 1537KB](1995)
Abstract:

IR diode laser probing technique has been used to detect the vibrational energy transfer of NH3(ν2) excited by the relaxation of high energy NO2 molecule. NO2 was pumped by YAG 532nm laser. The time resolved absorption spectra of NH3(ν2) ro-vibronic levels were detected by diode laser. When the pressure ratios of NO2:NH3 were 1:5, 1:1, 2:1 and 5:1, the excited rate constants of NH3(0100;7,k) are 9.28×10-1, 6.42×10-1, 5.05×10-1,3.65×10-1 ms-1•Pa-1 respectively. The amount of energy transferred from excited NO2 to the ν2 mode of NH3 was found to be 6% of the original excitation energy. Most of the excitation energy was transferred to rotational and translational energy of NH3. The mechanism of vibrational excitation was discussed.

Investigation on Characteristics of Interaction and Bonding Nature in C60 Cage of Endohedral Complexes X@C60
Zhu Chuan-Bao , Yan Ji-Min
1996, 12(09): 796-803  doi: 10.3866/PKU.WHXB19960905
[Abstract](3495) [FullText HTML] [PDF 1345KB](2467)
Abstract:

 The energy variation during the formation of the titled endohedral complexes X@C60 (X=atoms of the Group IA or the Group VIIA), and the bonding nature and the variation character of the interaction in C60 cage all have been investigated from the viewpoint of intramolecular interaction. The results demonstrated that: ①the force field in C60 cage is of nearly spherical symmetry; ②the total interaction and its components vary regularly with the atomic numbers or redii, of X; ③all concerned endohedral atoms except for I, contribute considerably to the stabilities of X@C60 by way of the interaction between C60 cage and them; ④each X has a special energy minimum location in the cage, at or off the cage center, and this location is due to the resultant effect from the various interactions, but not to the formation of chemical bond between X and C60 cage; ⑤in essence, the interaction in C60 cage is of typical non-bonding characteristics, with ~90%electrostatic interaction and 10% repulsive and dispersive interactions. 

A Zinc(II) Complex of Tripyridylamine(TPA) as a Model for Carbonic Anhydrase
Kou Fu-Ping , Lin Hua-Kuan , Zhu Shou-Rong , Chen Rong-Ti
1996, 12(09): 804-808  doi: 10.3866/PKU.WHXB19960906
[Abstract](3058) [FullText HTML] [PDF 844KB](2161)
Abstract:

The protonation constant of TPA and, in its 1:2 (Zn(II):L) complex, the deprotonation constant of H2O coordinated to Zn(II) have been determined by pH titration at 25±0.1℃, I=0.1 mol•dm-3 KNO3. They are 4.29 and 7.8, respectively. It is worthy to be noted that the H2O bound to Zn(II) could deprotonate easily near physiology pH. A kinetic study of 4-nitrophenyl acetate(NA) hydrolysis by Zn(II)(TPA)2•H2O complex in 10%(v/v) CH3CN at 25±0.1℃, I=0.1 mol•dm-3 NaClO4, and pH range 6~9(20mmol•dm-3 Tris buffer),has been carried out. The maximum value of second-order rate constant k((mol•dm-3)-1•s-1) obtained is 3.32×10-2. Thus, Our present model study shows that, like the Zn(II)-enzymes, the Zn(II)-bound OH- in complex can act as a od nucleophile agent to the carbonyl carbons, the Zn(II) complex of TPA is a od model for carbonic anhydrase.

ANN-Atomic Parameter Method Applied to Prediction of Crystal-type and Lattice Constants of Alloy Phases
Yao Shu-Wen , Guo Jin , Wang Xue-Ye , Chen Nian-Yi
1996, 12(09): 809-811  doi: 10.3866/PKU.WHXB19960907
[Abstract](2660) [FullText HTML] [PDF 500KB](2276)
Abstract:

 Artificial neural network method has been applied to the computerized prediction of the crystal type and lattice constants of binary alloy phases by using atomic parameters of the constituent elements, the results obtained are satisfactory.

Preparation of Fine Particles of Polyaniline in O/W Microemulsion
Song Gen-Ping , , Yan Peng-Quan
1996, 12(09): 812-815  doi: 10.3866/PKU.WHXB19960908
[Abstract](3441) [FullText HTML] [PDF 853KB](2088)
Abstract:

Fine particles of polyaniline were prepared in (An+O/W microemulsion) two phase system in which the An phase was used as a monomer source and the O/W microemulsion phase for polymerization. The particle size of polyaniline was less than 10nm and the particles were spherical and well distributed. The measurements of conductivity of polyaniline in DMF showed that polyaniline prepared in microemulsion system had od conductivity. And the measurements of light spectrum of Polyaniline in organic solvents showed λmax=580 nm which was similar to that given in the reference.

Densities of CO2-Ethanol,CO2-Acetone,CO2-Heptane Binary Mixtures and Partial Molar Volumes of the Solutes
Zhong Ming-Hong , Ke Jie , Han Bu-Xing , Yan Hai-Ke
1996, 12(09): 816-824  doi: 10.3866/PKU.WHXB19960909
[Abstract](3740) [FullText HTML] [PDF 1343KB](2117)
Abstract:

 The densities of CO2-ethanol, CO2-acetonc and CO2-n-heptane binary mixtures were measured at 308. 15 K and 318.15 K and under pressures ranging from 80 to 170 bar. The concentrations of the solutes (alcohol, acetone, and n-heptane) were form 0 to 1.3 mol•L-1. The partial molar volumes of the solutes at 318.15k were calculated based on the relationship between the densities of the mixtures and the concentrations of the solutes. It was observed that the partial molar volumes of all the three solutes are negative and the absolute value decreases with the pressure and the concentration of the solute.

Mechanism of the Bi-base2223 Superconducting Phase Formation and its Single Phase Bulk Material Preparation
Gao Xiao-Hui , Gao De , Jiang Shu-Fen
1996, 12(09): 825-829  doi: 10.3866/PKU.WHXB19960910
[Abstract](3628) [FullText HTML] [PDF 904KB](2159)
Abstract:

Based on kinetic considerations, it is pointed out that 2201 phase can interact with CaO, CuO to form 2212 phase, subsequently, 2223 phase can be produced by interaction between 2212 and CaO, CuO. Meanwhile, it is proved by chemical kinetics that CaO plane entering unit cell of 2212 phase is the controlling step of 2223 phase formation. In addition, divided step method as well as seed additive techniqe have been adopted to Prepare the 2223-single phase bulk material.

Theoretical Study on Decarbonylation Reaction of Acrolein and Its Derivatives in Their Electronic Ground States
Shao Guo-Quan , Fang Wei-Hai , Chen Guang-Ju , Liu Ruo-Zhuang
1996, 12(09): 830-835  doi: 10.3866/PKU.WHXB19960911
[Abstract](2964) [FullText HTML] [PDF 1057KB](2038)
Abstract:

In this paper, decarbonylation reaction of acrolein and its derivatives in their electronic ground states were investigated by restricted Hartree-Fock SCF method with energy gradient technique at the level of 3-21G basis set. Electron correlation was considered at the second-order perturbation level. It has been found that decarbonylation reaction of acrolein is a simple reaction involving a three-centered transiton state which has been ascertained by frequency analysis. The potential barrier of decarbonylation reaction of acrolein is 435.1kJ•mol-1, the substituting groups have a little influence on the potential barrier of reaction. The decarbonylation reactions of acrolein and its derivatives in their electronic ground states are difficult to take place, but the ground-state decarbonylation probably plays an important role in the mechanisms of the photo-decarbonylation of acrolein.

Studies on Azimuthal Orientation of Hemicyanine Molecules in LB Films
Xu Yong-Sheng , Han Kui , Xu Jian-Hua , Zhou Guang-Peng , Lu Xing-Ze
1996, 12(09): 836-840  doi: 10.3866/PKU.WHXB19960912
[Abstract](3016) [FullText HTML] [PDF 857KB](1954)
Abstract:

Polarized UV-visible absorption spectroscopy was used to investigate the inplane orientation of the hemicyanine molecules in Y-type Langmuir-Blodgett(LB) multilayers. We demonstrated for the first time that the dipping-induced molecular alignment was enhanced significantly with increasing the layer number due to the interlayer interactions. Polarized UV nanosecond pulses were used to control the photoinduced reorientation of the hemicyanine molecules. Thermal-isotropic process was accompaniedd by dissocition of the H-aggregate in hemicyanine LB multilayers.

Surface Enhanced Raman Scattering(SERS) from H2TSPP and Ag(II)TSPP Adsorbed on Uniform Fe3O4 Colloids
Mou Chun-Bo , He Tian-Jing , Wang Xiu-Yan , Liu Fan-Zhen , Jiang Ji-Sen , Chen Long-Wu
1996, 12(09): 841-844  doi: 10.3866/PKU.WHXB19960913
[Abstract](3530) [FullText HTML] [PDF 598KB](2323)
Abstract:

Surface Enhanced Raman Scattering (SERS) of tetrasodium meso-tetrakis (4-sulfonatophenyl) porphine (H2TSPP) and silver tetraphenylporphyrin (Ag(Ⅱ)TSPP) adsorbed spontaneously on uniform Fe3O4 colloids are recorded. The enhancement of Raman bands is approximately 30. An analysis of the SERS spectrum shows that on the Fe3O4 surface H2TSPP takes its diacid form H42+TSPP.

Molecular Similarity and Prediction of pKa for Substituted Phenols
Zhang Xiang-Dong
1996, 12(09): 845-848  doi: 10.3866/PKU.WHXB19960914
[Abstract](3126) [FullText HTML] [PDF 618KB](2141)
Abstract:

 A procedure is presented for the prediction of physical property of organic compound and QSAR/QSPR analysis based on the similarity indices using a back-propagation neural network. The similarity indices were calculated on a chosen set of structural descriptors by equation 1 and used to quantify the similarity or dissimilarity of organic compound. The similarity indices were also used as an input parameter of neural network. The pKa values of the 69 substituted phenols were predicted by using 32 compounds as a training set and all 69 compounds as a predicting set. The results obtained were satisfying.

Microcalorimetric Study on Induced Differentiation of Tumour Cells by Drug
Tan An-Min , Xu Bo , Qu Song-Sheng
1996, 12(09): 849-851  doi: 10.3866/PKU.WHXB19960915
[Abstract](2856) [FullText HTML] [PDF 508KB](2337)
Abstract:

Sp-Octyl-(8-Chloroadenosine)-3',5'-Cyclophosphate (OCC), a newlysynthesized cAMP analog, strongly induces growth inhibition and differentiation in human promyelocytic leukemia HL-60 cells. The effect of OCC is dose-time dependent. By using the LKB2277 Bioactivity Monitor, we determined the heat production rate of HL-60 cells treated by OCC at different concentrations. It was found that the heat production rate of HL-60 cell treated by OCC gradually decreased to that of normal human neutrophiles.

Calculation of the Magnetic Properties and the Susceptibility Characters of Fullerenes
Jiang Zong-Fu
1996, 12(09): 852-855  doi: 10.3866/PKU.WHXB19960916
[Abstract](2838) [FullText HTML] [PDF 738KB](2041)
Abstract:

Ring current theory and the gauge invariant molecule orbital theory were applied to study the magnetic susceptibility of fullerenes. The results show that the diamagnetic susceptibility has anisotropy character. And it was pointed that c60 is of ambiguous aromatic character with anomalous magnetic properties but with the reactivity of a continuous aromatic molecule.

SERS and Quantum Chemistry Studies of Adsorption of Thiourea and Ethylthiourea on Silver Electrode
Yu Jia-Kang , Dong Jun-Hua , Cao Chu-Nan , Lin Hai-Chao
1996, 12(09): 856-860  doi: 10.3866/PKU.WHXB19960917
[Abstract](3490) [FullText HTML] [PDF 809KB](2263)
Abstract:

Adsorption of thiourea (TU) and ethylthiourea(ETU) on roughened silver electrode was investigated using in- situ surface enhanced Raman spectroscopy(SERS). Using quantum chemistry and HSAB theories, the influences of electrode potential and the different substituent groups on SERS were discussed. TU is chemisorbed perpendicularly by Ag-S bond on silver at E=-0.3 V and adsorption of TU turns into a parallel orientation at E=-0.9 V. ETU is always chemisorbed at an angle from Ag. The adsorption of ETU is through C=C and C=O groups at E=-0.3 V, and mainly through C=C at E=-0.9V.

Preparation of La-Mo Series Complex Oxide Ultrafine Particle Catalysts by Sol-gel Method
Kuang Wen-Xing , Fan Yi-Ning , Chen Kai-Dong , Chen Yi
1996, 12(09): 861-863  doi: 10.3866/PKU.WHXB19960918
[Abstract](3449) [FullText HTML] [PDF 583KB](2305)
Abstract:

La-Mo series complex oxide ultrafine particles have been prepared successfully by the sol-gel method at low temperature. The influence of preparation conditions and thermal treatment conditions on the morphology and the structure of the oxide particles has been studied by using XRD, DTA-TG, TEM, FT-IR and BET surface area measurement methods. For the preparation of the well-distributed La-Mo series complex oxide ultrafine particles with the size in the range of 40-80nm, the optimum conditions are:
ncitrie/nLa+Mo=0.3, pH≤1.5, t≤500℃.

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