Chemical Research in Chinese Universities

A Novel 5-Fluorouracil Salt of 12-Silicatungstic Acid: Synthesis, Structure Characterization and Antitumor Activity

LI Juan, WU Xin-yu, LI Jing, WANG Hong-fang, QI Yan-fei, YU Xi-he, SUN Zhi-wei, WANG En-bo

2005, 21(2): 127-130.

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A novel 5-fluorouracil salt of 12-silicatungstic acid was synthesized and characterized by means of elemental analysis, IR, ¹H NMR and ¹⁸³W NMR spectra.The antitumor activity and toxicity of the complex have been evaluated both in vitro and in vivo.

Mesoporous Silica MCM-48 Membrane Synthesized on a Coarse-pore α-Al₂O₃ Ceramic Tube

LIU Chun-yan, WANG Jin-qu

2005, 21(2): 131-133.

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A mesoporous MCM-48 membrane was synthesized on a coarse-pore a-alumina ceramic tube by hydrothermal treatment by using a cationic surfactant as the structure-directing agent under basic conditions.The products were characterized by small-angle X-ray diffraction, SEM measurements and N₂ adsorption experiments.The X-ray diffraction(XRD) results show that the membrane possesses a periodic mesostructure,which is typical for an MCM-48 material.The results of the SEM measurements indicate that MCM-48 grew in the pores of the support and formed a continuous membrane.The N₂ adsorption and desorption isotherms also show that the membrane is a typical mesoporous material with pore channel size of about 2.74 nm.

Synthesis of Copper Oxalate Nanorods by a Simple One-step Solid-state Chemical Reaction Method

CAO Ya-li, JIA Dian-zeng, LIU Lang, XIAO Ding-quan, XIN Xin-quan

2005, 21(2): 134-136.

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Copper oxalate nanorods were successfully prepared by means of a simple one-step solid-state reaction method with the assistance of a suitable surfactant, polyethylene glycol 400.The product with uniform rodlike morphology was characterized by XRD, TEM and SEM.The formational mechanism of the rod-like structure was also preliminary discussed.

High Resistive ZnO/Diamond/Si Films Grown via Metal-organic Chemical Vapour Deposition

YANG Hong-jun, ZHAO Bai-jun, FANG Xiu-jun, DU Guo-tong, LIU Da-li, GAO Chun-xiao, LIU Xi-zhe

2005, 21(2): 137-140.

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Piezoelectric ZnO layers with high resistivity for surface acoustic wave applications were prepared on polycrystalline diamond/Si substrates with (111) orientation via metal-organic chemical vapour deposition.The characteristics of the films were optimized through different growth methods.The comparative study of the X-ray diffraction spectra and scanning electron microscopic images showed that the final-prepared ZnO films were dominantly c-axis oriented.Zn and O elements in the final prepared ZnO films were investigated through X-ray photoelectron spectroscopy.According to the statistical results, the n(Zn)/n(O) ratio is near 1.The Raman scattering was also performed in back scattering configuration.E2 mode was observed for the final films, which indicated that the better quality ZnO films had been obtained.The resistivity of the films was also enhanced via the modification of the growth methods.

Determination of 6-Mercaptopurine in Rat Blood by Microdialysis Coupled with High Performance Liquid Chromatography on a Functionalized Multi-wall Carbon Nanotubes Modified Electrode

LIN Li, QIU Pei-hong, XIE Xia-feng, CAO Xu-ni, JIN Li-tong

2005, 21(2): 141-144.

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A new chemically modified electrode(CME) immobilized on the surface of multi-wall carbon nanotubes functionalized with carboxylic groups was fabricated.The results indicate that the CME exhibits efficiently electrocatalytic oxidation of 6-mercaptopurine(6-MP).The CME can be used as the working electrode in the liquid chromatography for the determination of 6-MP.The peak current of 6-MP is linearly changed with its concentration ranging from 4.0×10^-7 to 1.0×10^-4 mol/L with the calculated detection limit (S/N=3) of 2.0×10^-7 mol/L.Coupled with microdialysis sampling, the method has been successfully applied to assessing the content of 6-MP in rat blood.

Studies on the Recognition Interaction of Rhodamine B and DNA by Voltammetry

JIAO Kui, LI Qing-jun, SUN Wei, WANG Zhen-yong

2005, 21(2): 145-148.

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The recognition interaction of Rhodamine B(RB) with DNA was studied in a Britton-Robinson (B-R)buffer solution with pH=7.5 at a glassy carbon electrode by electrochemical techniques.RB shows an irreversible oxidation peak at +0.92 V(vs.SCE).After the addition of DNA inthe RB solution, the peak current of RB decreased apparently without the shift of the peak potential.The electrochemical parameters such as the charge transfer coefficient a and the electrode reaction rate constant k^s of the interaction system were carefully studied.The parameters did not change before and after the addition of DNA, which indicated that an electrochemical non-active complex had been formed, so the concentration of RB in the solution decreased and the peak current decreased correspondingly.The binding ratio of RB to DNA was 2:1 with a binding constant of 2.66×10⁹.

Electrochemical and Spectroscopic Studies on Interaction between Complex of Copper(Ⅱ) with Schiff Base Ligand and DNA

NIU Shu-yan, JIE Gui-fen, ZHANG Shu-sheng, LI Ying, YANG Fan

2005, 21(2): 149-153.

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The crystal structure of ([CuL(H₂O)₂](ClO₄)₂·2H₂O, CuL) (L＝N-(5-sulfosalicylidene)-4'-bromoaniline) was determined by means of X-ray crystallography.The interaction between CuL and salmon sperm DNA in a 0.1 mol/L HOAc-NaOAc buffer solution (pH 5.10) was investigated by cyclic voltammetry and UV-Vis spectroscopy.A couple of redox peaks of CuL in the cyclic voltammograms(CV) can be seen at the glassy carbon electrode.It was found that the peak current of CuL decreased significantly with a negative shift of the peak potential in the presence of DNA compared with that in the absence of DNA.In addition,the decreased absorbance of CuL was observed with increasing the concentration of DNA; the absorption spectrum of an ethidium bromide(EB)-DNA system inthe presence of CuL confirms that the binding mode of CuL to DNA is different from the intercalation of EB with DNA.All the experimental results indicate that CuL can bind to DNA by electrostatic binding and form a 1:1 association complex with a binding constant of 2.72×10⁴ L/mol.

Toxicity Effects of 1,4-Dinitrobenzene on Oryzias Latipes

XU Jing-bo, JING Ti-song, LIANG Lin, SHENG Lian-xi

2005, 21(2): 154-157.

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1,4-Dinitrobenzene(1,4-DNB) is one of the preferential toxicants stipulated by OECD and EPA of USA.With Oryzias latipes, which were chosen as the acceptors according to the international standard, the acute,subacute and accumulative toxicity experiments were conducted.The threshold mass concentration of O.latipes was 1.360 mg/L.The subacute experiment showed that O.latipes were hardly affected when the mass concentration of 1,4-DNB was 0.0292 mg/L, but were significantly affected when the mass concentration of 1,4-DNB was 0.0420, 0.0608 or 0.0875 mg/L in contrast to the control sample(P＜0.05).The accumulative rate(K) was 1.21.This shows that there are significant accumulative actions of 1,4-DNB in fish.When the mass concentration of 1,4-DNB is in the range of 0.032-0.320 mg/L, the higher the 1,4-DNB concentration, the more strongly the Na⁺/K⁺-ATPase is inhibited.The calculated IC50 values in gill, kidney and liver of O.latipes are 0.128, 0.132 and 0.428 mg/L, respectively.

Syntheses and Application of New Room Temperature Ionic Liquids Based on Hexaalkylguanidinium Salts

LI Sheng-hai, LIN Ying-jie, CAO Jun-gang, DUAN Hai-feng, CAI Wu-jie, XU Jia-ning

2005, 21(2): 158-162.

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A new series of guanidinium cation-based room temperature ionic liquids (RTILS) was prepared by treating tetraalkylguanidine with an alkylating agent in the presence of an alkaline reagent and a phase transfer catalyst(PTC).Good results were obtained when GPF6 was used as the reaction medium for the selective oxidation of benzyl alcohol with sodium hypochlorite as the oxidant.

Synthesis and Crystal Structure of O-Ethyl-N (2,3,4-tri-O-acetyl-β-D-xylopyranosyl )-thiocarbamate

YANG Bo, ZHANG Shu-sheng, WANG Yan-fang, LI Xue-mei, JIAO Kui

2005, 21(2): 163-165.

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The crystal and molecular structures of O-ethyl-N-(2,3, 4-tri-O-acetyl-β-D-xylopyranosyl)-thiocarbamate were determined by X-ray crystallography.It crystallizes in the orthorhombic system with space group P2(1)2 (1) 2 (1), lattice parameters a =0.90636 (18) nm, b =0.94716 (19) nm, c =2.1855 (4) nm, V =1.8762(7) nm³, and Z=4.All the substituents are in equatorial positions.There are four intramolecular interactions , each forming a five-membered ring.The molecules are linked by interactions to form three-dimensional framework.Atoms O6 and O8 show positional disorder.

Synthesis of Poly[(3-octanoylpyrrole-2,5-diyl)-p-(N, N-dimethylamino) benzylidene] and Its Properties by Nitrogen Ion Implantation

ZHANG Zhi-gang, WU Hong-cai, LIU Xiao-zeng, YI Wen-hui

2005, 21(2): 166-168.

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A novel soluble π-conjugated polymer, poly[(3-octanoylpyrrole-2,5-diyl)-p-(N,N-dimethylamino)benz ylidene] (POPDMABE), was synthesized firstly by the condensation of 3-octanoylpyrrole with paradimethylaminobenzaldehyde.The chemical structure of the polymer was characterized by FTIR and ¹H NMR spectrometries.The polymer is a potential nonlinear optical(NLO) material.According to the function of optical forbidden band gap(E_g) and photon energy(hv), the optical forbidden band gaps of the polymer before and after ion implantation were calculated.The resonant third-order nonlinear optical properties of POPDMABE before and after ion implantation were also studied by using the degenerate four-wave mixing (DFWM) technique at 532 nm.When the energy is 25 keV and the dose is 2.2×10¹⁷ ions/cm², the polymer's optical forbidden band gap is about 1.63 eV which is smaller than that of the non-implanted sample (1.98eV) and the resonant third-order NLO susceptibility of POPDMABE is about 4.3×10^-7 esu, 1 order of magnitude higher than that of the non-implanted sample(4.1×10^-8 esu).The results show that nitrogen ion implantation is an effective method to improve the resonant third-order NLO property of the polymer.

A Convenient Method for Chlorination in Allylic Position

WANG Xin-yan, SHI Hong-chang, CHEN Gang, HONG Xiao-yin, XU Shou-yi

2005, 21(2): 169-171.

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A convenient method for the chlorination in allylic position was developed by using the aqueous solution of sodium hypochlorite(2%_5% active chlorine) and an acid as chlorination reagent in a diphase system.The method has the advantage of cheap reagents, mild reaction conditions and good yields.The quantity and the feeding rate of the chlorination reagent can be controlled easily.The method is particularly suitable for the chlorination in laboratories.

Synthesis of N-Aryl-2-(1', 6'-dihydro-6'-pyridazinone-3'-carbonyl) Thiosemicarbazides and Their Related Heterocyclic Compounds

WANG Duo-zhi, CAO Ling-hua

2005, 21(2): 172-176.

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1,6-Dihydro-3-hydrozinocarbonyl-6-pyridazinone(compound 2) were prepared from α-ketoglutaric acid and hydrazine hydrate.A series of N-aryl-2-(1',6'-dihydro-6'-pyridazinone-3'-earbonyl) thiosemicarbazides 3a-3f were synthesized from the reaction of aryl isothiocyanates with compound 2.The terminal compounds 1,3, 4-thiadiazole, 1,3,4-oxadiazole and 1,2, 4-triazol-5-thione derivatives were cyclized from compounds 3a_3f.Their structures were confirmed by IR, ¹H NMR, MS and elemental analyses.

Synthesis and Antibacterial Activities of Erythromycin Derivatives

FENG Run-liang, GONG Ping, FANG Lin, HONG Wei

2005, 21(2): 177-182.

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Ten new erythromycin antibacterial agents containing amidino group were designed and synthesized from erythromycin via oximation, reduction and condensation.Their structures were confirmed by MS and ¹³C NMR; the synthetic condition(reaction medium)was explored; and their in vtiro antibacterial activities were tested.Compound HMA-3 showed antibacterial activity against staphylococcus aureus, which is equivalent to that of erythromycin A.Compounds HMA-8 and HMA-4 also showed an antibacterial activitiy.But no compound showed bactericidal activity.

Activation of G551D-CFTR by Bicyclooctane Compounds Is cAMP-dependent and Exhibits Low Sensitivity to Thiazolidinone CFTR Inhibitor CFTRinh-172

WANG Ying, ZHAO Lu, HE Cheng-yan, XU Li-na, YANG Hong

2005, 21(2): 183-186.

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The G551D-CFTR mutation causing cystic fibrosis (CF) results from a missense mutation at codon 551(G551D) in the gene encoding of the cystic fibrosis transmembrane conductance regulator (CFTR).The G551D mutation in CFTR results in a reduced functional channel but G551D-CFTR is appropriately inserted in the apical membrane.In previous studies we discovered a class of high-affinity bicyclooctane (BCO)G551D-CFTR activators(G551D_BCOs) with K_d down to 1μmol/L.In this study, we analyzed the pharmacological activation of G551D-CFTR by the G551D_BCOs by means of short circuit current analysis and cell-based fluorescence quenching assay.The G551D_BCOs-induced G551D-CFTR activation is cAMP-dependent and is less sensitive to thiazolidinone CFTR inhibitor CFTRinh-172.These data suggest that (1) the phosphorylation of G551D-CFTR by protein kinase A is required for the activation by G551D_BCOs; (2) G551D_BCOs and CFTRinh-172 may act at the same site on the G551D-CFTR molecule.

Studies on Pharmacokinetics of Porcine Somatotropin Liposomes

XU Chuan-lai, JI Cheng, HAO Kai, LI Xiang-qian, YAO Hui-yuan

2005, 21(2): 187-190.

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This paper focuses on the pharmacokinetics in fattening pigs as well as the change of serum resulting from the use of porcine somatotropin(PST) and its liposomes.A slow-release model was determined to be relevant to following an examination of all dynamic parameters.The results indicate that the slow-release effect of PST liposomes was significant, with an extended release time of over 7 d.

Screening of scFvs against cTnI from Phage Display Antibody Library and Their Expression in E.coli Rosetta

WEI Jing-yan, LI Shan-yu, MU Ying, ZHU Xue-jun, LIU Lei, GAO Li-zeng, SONG Da-qian, SUN Zhi-wei, YAN Gang-lin, ZHANG Han-qi, JIN Qin-han, LI Wei, LUO Gui-min

2005, 21(2): 191-195.

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The single chain variable fragments of antibodies(scFvs) against eTnI were screened from the phage display antibody library by using cTnI as the target antigen.After four rounds of panning, four clones(H2, G5,A9, B9) from the phage display antibody library were verified to show higher binding affinity for cTnI by ELISA and to contain the variable region genes of the light and heavy chains of scFvs by sequencing.The variable region genes of scFvs H2 and G5 were successfully amplified by polymerase chain reactions (PCR)and cloned into expression vector pPELB and expressed as a soluble protein in E.coli Rosetta, whose expression yield was about 2% of total proteins.The expressed proteins were purified by nickel(Ni) affinity chromatography and a single band is shown in the position of 28 kDa on SDS-PAGE.The western blot analysis result verifies that the expressed scFv proteins are capable of binding with monoclonal antibodies against hexa-histidine, indicating that they are hexa-histidin-tagged aim proteins.The immunoassay demonstrates that the expressed scFv proteins are able to specifically react with cTnI molecules.The association constant (K_A)values range from 1.2×10⁴ to 1.7×10⁵ L/mol that are correspondent to the affinities of polyclonal antibodies against cTnI from rabbits.These antibodies can be valuable reagents for the immunoassay of cTnI.

Effect of Nano-anatase TiO₂ on Spectral Characterization of Photosystem Ⅱ Particles from Spinach

HONG Fa-shui, YANG Ping, GAO Feng-qing, LIU Chao, ZHENG Lei, ZHOU Juan

2005, 21(2): 196-200.

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The photosystem I (PS Ⅱ) particles were purified by means of nano-anatase TiO₂ treatment of spinach and studied by spectroscopy.The results show that the electron transport and the oxygen-evolving rate of PS I are accelerated after it has been treated with nano-anatase TiO₂; the UV-Vis absorption spectrum of PS I particles is increased; the red shift of fluorescence emission peak of PS I is 2 nm; the peak intensity is decreased; the PS Ⅱ signal I s of low temperature electron paramagnetic resonanace(EPR) spectrum is intensified under light, and the PS I circular dichroism(CD) spectrum is similar to that of control.It is suggested that nano-anatase TiO₂ might bind to the PS I reaction center complex and intensify the function of the PS I electron donor, however, nano-anatase TiO₂ treatment does not change the configuration of the PS Ⅱ reaction center complex.

Electrons Transfer Between Mercaptoacetic Acid and ZnO Nanocrystal Thin Film

SHAN Gui-ye, LÜ Qiang, AN Li-min, WANG Xin, BAI Yu-bai, LI Tie-jin, KONG Xiang-gui, LIU Yi-chun, SUN Jia-zhong

2005, 21(2): 201-204.

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ZnO nanoorystals thin film were prepared by means of the self-assembly mothed.The complex films of mercaptoacetic acid(MPA)and ZnO nanocrystals(ZNCs) were prepared by means of the self-assembly technique.The interaction between the MPA and ZnO within the MPA and ZnO nanocrystal thin film decreases the photoluminescence intensity of the ZnO.The interaction was manifested by the X-ray photoelectron spectra.The intensity change of the photoluminescence of the ZnO is discussed on the basis of taking into account the process of electron transfer on the interface between the ZnO and MPA.The electron transfer of ZnO depends on the distance between the ZnO and MPA.

A Corresponding-state Model for Predicting Surface Tension

WANG Feng-kun, WU Jiang-tao, LIU Zhi-gang

2005, 21(2): 205-208.

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A generalized corresponding-state model based on two reference fluids was developed for the prediction of surface tensions for non-polar and weakly polar pure fluids and their binary mixtures.Four parameters,p_c, T_c, V_c and ω, were used in this model, and the acentric factor ω was used as a scaling parameter.This model has been tested for 69 pure substances and 20 binary mixtures;the average absolute deviations are 0.28 and 0.20 mN/m, respectively.The results indicate that the predictions by means of this model were in good agreement with experimental data.In addition, the calculated deviation would increase with the excess surface tension rising, and if the excess surface tension is less than 3 mN/m, the prediction will be good and credible.

Extension of Huron-Vidal-type Mixing Rule to Three-parameter Harmens-Knapp Cubic Equation of State

HAN Xiao-hong, WANG Qin, CHEN Guang-ming, CUI Xiao-long

2005, 21(2): 209-212.

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In this paper was extended the HV-type mixing rules to Harmens-Knapp cubic equation state (HK CEOS).The new HV-type mixing rule with HK CEOS was tested for Vapor-liquid equilibrium(VLE) of different polar and nonpolar systems.The tested results are in good agreement with existing experimental data within a wide range of temperatures and pressures.In comparison with the VDW mixing rule, the new mixing rule gives much better predictions for the VLE of nonpolar and polar systems.

Metathesis of Butylene-2 and Ethylene to Propylene over 3.0Mo/(Hβ+γ-Al₂O₃) Catalysts with Different γ-Al₂O₃ Contents

LIU Sheng-lin, HUANG Sheng-jun, XIN Wen-Jie, BAI Jie, XIE Su-juan, XU Long-ya

2005, 21(2): 213-216.

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A series of 3.0Mo/(Hβ+γ-Al₂O₃) samples with γ-Al₂O₃ contents in the range of 0-100% (mass fraction) was studied by means of XRD, NH₃-TPD, TPR and BET determinations for characterizing their structures.The Hβ zeolite structure in the 3.0Mo/Hβ sample can be effectively stabilized by adding some γ-Al₂O₃to Hβ zeolite.γ-Al₂O₃ mainly favors the formation of polymolybdate or multilayered Mo oxide, while Hβmainly forms the Al₂(MoO₄)3 species, as evaluated by the TPR technique.When used as the catalyst for the metathesis of butylene-2 and ethylene to propylene, there exists a close correlation between the specific surface area and stability of the catalyst.The specific surface area of the catalyst shows the maximum when (Hβ+ γ-Al₂O₃) contains 30%γ-Al₂O₃, which is in agreement with that of the time needed for the reaction stablization.In the case of maximum surface area, the rate of coke deposition is the minimum.

Effects of Anions and Cations on π-Complexation Between Olefin and Metal Halide

ZHOU Jin-xia, ZHANG Yong-chun, GUO Xin-wen

2005, 21(2): 217-219.

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An ab initio molecular orbital study was performed to determine the effects of anions and cations on the π-complexation of C2H4 on MX(M=Ag, Cu; X=F, Cl).The calculated results show the following order of adsorption strength: F^-＞Cl^- for anions; Cu⁺＞Ag⁺ for cations.The results can be explained by the detailed analysis of atomic charge, orbital energy and orbital population by using the natural bond orbital(NBO) theory: (1) anions with stronger electronegativity can attract more electrons from the s orbital of M, while at the same time it does not obviously weaken the d orbital occupation of M, thus the nearly vacant s orbital and the sufficiently filled d orbitals of M help with forming σ-donation and d-π^* backdonation with the π orbital and the π* orbital of olefin, respectively; (2) a smaller energy gap of symmetry-adapted orbitals between olefin and a cation can favor the electron transfer, that is why Cu⁺ forms stronger adsorption with olefin than Ag⁺ does.

Synthesis of Poly [(3-octanoylpyrrole-2,5-diyl)-p-nitrobenzylidene] and Its Third-order Nonlinear Optical Property

ZHANG Zhi-gang, WU Hong-cai, YI Wen-hui

2005, 21(2): 220-223.

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A novel soluble π-conjugated polymer, poly[(3-octanoylpyrrole-2,5-diyl)-p-nitrobenzylidene](POPNBE), was synthesized by a five-step reaction.As a result of introducing a long aeyl to pyrrole at 3-position, the polymer can be easily solved in polar solvents and be processed into films.The chemical structures of the intermediates and POPNBE were characterized by FTIR, ¹H NMR, and UV-Vis-NIR spectrometries.The absorption band in the range of 400-600 nm in the UV-Vis-NIR spectrum is due to the π-π^* band gap transition.The optical band gap of POPNBE obtained from the optical absorption is about 1.72eV.The resonant third-order nonlinear optical property of POPNBE at 532 nm was studied by using the degenerate fourwave mixing (DFWM) technique.The resonant third-order nonlinear optical susceptibility of POPNBE is about 3.42×10^-8 esu.

Polymerization of n-Hexyl Isocyanate Initiated by Novel Rare Earth Tris (2,6-di-tert-butyl-4-methylphenolate)

XU Xiao-yan, NI Xu-feng, XU Hong, SHEN Zhi-quan

2005, 21(2): 224-226.

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The polymerization of n-hexyl isocyanate(HNCO) was carried out in the presence of a novel single initiator, rare earth tris (2,6-di-tert-butyl-4-methylphenolate) [Ln (OAr)₃].The influences of reaction conditions such as the monomer concentration, the polymerization temperature and time, and the types of solvents on the polymerization of HNCO were studied.Polymerizations of phenyl, i-propyl, p-tolyl, n-butyl and n-octyl isocyanates with La(OAr)₃ were also examined.

Determination and Temperature Dependence of Plateau Modulus for Polymerization of Propylene to Isotactic Polypropylene with Ultra-high Molecular Weight under Catalysis of Ziegler-Natta Catalyst

DING Jian, DING Xue-jia, XU Ri-wei, YU Ding-sheng

2005, 21(2): 227-231.

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The viscoelastic behavior of isotactic polypropylene with ultra-high molecular weight (UHPPH) and broad molecular weight distribution(MWD), produced in the presence of Ziegler-Natta catalyst, was investigated by means of oscillatory rheometry at 180 and 200 ℃, whose loss modulus(G") plots at 180 and 200 ℃ versus the natural logarithm of angular frequency(ω) present a pronounced maximum at 34.35 and 69.21 rad/s, respectively, and do not show a maximum peak at 0.01-100 rad/s for Ziegler-Natta catalyzing ethylenepropylene random copolymerization (PPR) with a conventional molecular weight and broad MWD.The fact indicates that the high molecular weight is responsible for a maximum peak of G"(ω) vs.lnω curves for UHPPH.This makes it possible to determine the plateau modulus (G_N⁰) of UHPPH from a certain experimental temperature G"(ω) curve directly.For UHPPH, the G_N⁰ determined to be 4.28×10⁵ and 3.62×10⁵ Pa at 180 and 200 ℃, respectively, decreases with the increase of temperature and is independent of the molecular weight, which directly confirms reputation theoretical prediction that the G_N⁰ has no relation to the molecular weight.

Synthesis of Calix[4]resorcinarene Schiff Bases

YAN Chao-guo, GE Yun

2005, 21(2): 232-235.

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Preparation and Characterization of CuInS₂ Thin Films for Solar Cells by Chemical Bath Deposition

TANG Hui-xiang, YAN Mi, ZHANG Hui, MA Xiang-yang, WANG Lei, YANG De-ren

2005, 21(2): 236-239.

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