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rare Metals 2011年第6期30卷 644-649页

作者： WANG ping LU Wei WANG Yuehui LIU Jianhua ZHANG ruijun State Key Laboratory of Metastable Materials Science and Technology Yanshan University Qinhuangdao 066004 China college of Civil engineering andMechanics Yanshan University Qinhuangdao 066004 China Tangshan Vocational Technology college Tangshan 063000 China college of physics ＆ chemistry Hebei Normal University of Science ＆ Technology Qinhuangdao 066004 China

The thermal diffusion coefficient, heat capacity, thermal conductivity, and thermal expansion coefficient of Cu76.12Al23.88 alloy before and after cryogenic treatment in the heating temperature range of 25℃ to 600℃ were measured by thermal constant tester and thermal expansion instrument. The effects of cryogenic treatment on the thermal physical properties of CU76,12A123,88 alloy were investigated by comparing the variation of the thermal parameters before and after cryogenic treatment. The results show that the variation trend of the thermal diffusion coefficient, heat capacity, thermal conductivity, and thermal expansion coefficient of CU76.12Al23.88 alloy after cryogenic treatment was the same as before. The cryogenic treatment can increase the thermal diffusion coefficient, thermal conductivity, and thermal expansion coeffi- cient of Cu76.12Al23.88 alloy and decrease its heat capacity. The maximum difference in the thermal diffusion coefficient between the before and after cryogenic treatment appeared at 400℃. Similarly, thermal conductivity was observed at 200℃.

关键词： Cu76.12Al23,88 alloy cryogenic treatment thermal diffusion coefficient thermal expansion coefficient

Theoretical study on the hydrolysis mechanism of N,N-dimethyl-N′-(2′,3′-dideoxy-3′-thiacytidine)formamidine

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Science china chemistry 2008年第10期51卷 911-917页

作者： ZHANG Chang1 & XUE Ying2? 1 college of chemistry and environment protection engineering, Southwest university for Nationalities, Chengdu 610041, china 2 college of chemistry, Sichuan university, Chengdu 610064, china 1. college of chemistry and environment protection engineering Southwest University for Nationalities Chengdu 610041 China 2. college of chemistry Sichuan University Chengdu 610064 China

The hydrolysis mechanisms of N,N-dimethyl-N′-(2′,3′-dideoxy-3′-thiacytidine)formamidine (FA-3TC) in the gas phase and in aqueous solution were studied by use of the density functional theory B3LYp/6-31+G(d, p) method. Two possible reaction pathways in the title reaction were considered. In one pathway water attacks the C=N double bond first (path A) while in the other water attacks the C—N single bond first (path B). The calculated results indicate that the first step in both pathways is the rate-limiting process and path A is more favorable than path B in the gas phase. The effect of solvent water on the title reaction was assessed at the B3LYp/6-31+G(d, p) level of theory based on the po-larizable continuum model (CpCM). In water the first mechanism (path A) is also favored.

关键词： N N-dimethyl-N′-(2′ 3′-dideoxy-3′-thiacytidine)formamidine hydrolysis solvent effect B3LYp polarizable continuum model

preparation of nanometer perovskite-type oxide La_(0.8)Sr_(0.2)MnO_3 by organic solvent sol-gel method and capability testing

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rare Metals 2008年第2期27卷 131-133页

作者： HU Jie SHAO Guangjie HUANG Hao XING Guangzhong State Key Laboratory of Metastable Materials Science ＆ Technology Yanshan University Qinhuangdao 066004 China Department of environment and chemistry Yanshan University Qinhuangdao 066004 China

A perovskite-type oxide, La0.8Sr0.2MnO3, was synthesized by the organic solvent sol-gel method. The desired metal cations were chelated in a solution by using citric acid as the chelating agent and absolute ethanol as the solvent. The thermal decomposition of the metal carboxylate precursor gels was studied by thermogravimetric/differential thermal analyzer （TG/DTA） and the products derived from calcining the gels were characterized by X-ray diffraction （XrD） and transmission electronic microscope （TEM）. The polarization curves were acquired on an electrochemical workstation （LK98） and the discharge curves were acquired on a testing instrument of batteries （DC-5）, with a constant current discharge, less than 120 mA/cm^2. The results revealed that the nanometer perovskite-type powder with lesser particle size could be achieved with an organic solvent and had a better catalytic activity.

关键词： nanometer-materials perovskite organic solvent catalytic activity

photoresponsive organogel and organized nanostructures of cholesterol imide derivatives with azobenzene substituent groups

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progress in Natural Science:Materials International 2012年第1期22卷 64-70页

作者： Tifeng Jiao a,b,c,Yujin Wang a,Fengqing Gao a,Jingxin Zhou a,Faming Gao a a hebei Key Laboratory of Applied chemistry,college of environmental and Chemical engineering,yanshan university,qinhuangdao 066004,china b college of chemistry & Materials engineering,Wenzhou university,Wenzhou 325027,china c State Key Laboratory of Solid Lubrication,Lanzhou Institute of Chemical physics,Chinese Academy of Sciences,Lanzhou 730000,china [a] hebei Key Laboratory of Applied chemistry College of Environmental and Chemical Engineering Yanshan University Qinhuangdao 066004 China [b] college of chemistry & Materials engineering Wenzhou University Wenzhou 325027 China [c] State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical Physics Chinese Academy of Sciences Lanzhou 730000 China

Two new cholesterol imide derivatives with azobenzene substituent groups have been *** compounds possess headgroups of hydrogen or methyl units,*** gelation test revealed that a subtle change in the headgroup of azobenzene segment produced a dramatic change in the gelation behavior of both *** compound with headgroups of hydrogen units only gelated N,N-Dimethylformamide(DMF),while the other compound with headgroups of methyl units cannot gelate any solvent tested *** DMF gel and solution of the gelator,the reversible photoisomerization transitions by irradiation with ultraviolet(UV) and visible light are investigated by UV-vis absorption spectra,Fourier transform infrared spectrometer,scanning electron microscope,atomic force microscope,and X-ray diffraction *** UV irradiation of the gel,trans-cis photoisomerization of the azobenzene groups occurs,the change in molecular polarity leads to the breaking of van der Waals interactions,resulting in the gel-sol *** gel can be recovered by the reverse cis-trans photoisomerization after exposure to visible *** and spectral studies reveal that the gelator molecules selfassemble into one-dimensional fibers,which further crossed-linked to form regular *** results afford useful information for the development of new versatile low molecular mass gelators and soft matter.

关键词： Organogel Cholesterol Azobenzene photoisomerization Soft material

Inhibitory effect of picroside Ⅱ on hepatocyte apoptosis

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Acta pharmacologica Sinica 2005年第6期26卷 729-736页

作者： Hua GAO, Ya-wei ZHOU~2 college of chemistry and Molecular engineering, peking university, Beijing 100871, china college of chemistry and Molecular engineering Peking University Beijing China

Aim: To investigate the influence of picroside on hepatocyte apoptosis and its mechanism. Methods: Morphological changes and quantification of apoptotic cells were determined under transmission electron microscopy and flow cytometry respectively. DNA fragmentation was visualized by agarose gel electrophoresis. Semi-quantitative reverse transcription-pCr (rT-pCr) was used to analyze the expression of bcl-2 and bax genes. The content of manganese-superoxide dismutase (SOD) in liver mitochondria was detected by the Marland method. The content of malonic aldehyde (MDA) and the protein level in liver tissue were determined by thiobarbituric acid colorimetry and Lowry method. results: picroside decreased the levels of alanine aminotransferase and aspartate aminotransferase in the serum resulting from acute-liver injured mice induced with D-GalN and LpS; it also reduced the content of MDA, and thus, enhanced the activity of SOD. picroside 0 mg/kg was found to protect hepatocytes against apoptosis in a dose-dependent manner; it up-regulated the expression of bcl-2 genes, thus increased the bcl-2/bax ratio. Conclusion: picroside 鈪an protect hepatocytes against injury and prevent hepatocytes from apoptosis. It might by upregulating the bcl-2 gene expression and antioxidation.

关键词： picroside Ⅱ hepatocytes apoptosis oxidative stress bcl-2 genes bax genes

Density functional theory study of the magnetic properties of rare earth complexes:the magnetic coupling mechanism in Y~Ⅲ and Gd~Ⅲ complexes with nitronyl nitroxide

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Science china chemistry 2009年第11期52卷 1961-1968页

作者： rEN Jie1,2,WANG BingWu1 & CHEN ZhiDa1 1 Beijing National Laboratory for Molecular Sciences,State Key Laboratory of rare Earth Materials chemistry and Applications,college of chemistry and Molecular engineering,peking university,Beijing 100871,china 2 college of Science,hebei university of Science and Technology,Shijiazhuang 050018,china 1. Beijing National Laboratory for Molecular Sciences State Key Laboratory of Rare Earth Materials Chemistry and Applications College of Chemistry and Molecular Engineering Peking University Beijing 100871 China 2. college of Science Hebei University of Science and Technology Shijiazhuang 050018 China

The magnetic coupling interactions of the nitronyl nitroxide radicals bound to diamagnetic(YⅢ) and paramagnetic(GdⅢ) rare earth ions in two model magnetic systems based on novel rare earth organic radical complexes Ln(hfac)3(NITphOCH3)2(Ln=YⅢ 1,GdⅢ 2;hafc = hexafluoroacetylacetonate;NIT-phOCH3 = 4'-methoxyo-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) have been investigated by density functional theory(DFT).The magnetic coupling mechanisms were also explored from the viewpoint of molecular orbital and spin density *** calculations show that the empty 4d-orbitals of YⅢ and 5d-orbitals of GdⅢ play an important role in the antiferromagnetic coupling between the two nitronyl nitroxide radical ligands,and that the ferromagnetic coupling between the GdⅢ ion and the radical magnetic centers can be attributed to the nearly complete localization of the isotropic 4f-shell and singly occupied magnetic orbital(π) of the nitronyl nitroxide.

关键词： magnetic coupling density functional theory rare earth ion gadolinium(Ⅲ) complexes yttrium(Ⅲ) complexes

Hydroisomerization of n-heptane over bimetal-bearing H_3pW_(12)O_(40) catalysts supported on dealuminated USY zeolite

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Science china chemistry 2008年第2期51卷 120-127页

作者： WEI ruiping1,2, GU YanBo1 & WANG Jun1 1 State Key Laboratory of Materials-Oriented Chemical engineering, college of chemistry and Chemical engineering, Nanjing Uni- versity of Technology, Nanjing 210009, china 2 college of chemistry and Chemical engineering, Southeast university, Nanjing 211189, china State Key Laboratory of Materials-Oriented Chemical engineering College of Chemistry and Chemical EngineeringNanjing University of TechnologyNanjing 210009China college of chemistry and Chemical engineering Southeast UniversityNanjing 211189China

The bimetal-bearing (Cept or Lapt) 12-tungstophosphoric acid (H3pW12O40 (pW)) catalysts supported on dealuminated USY zeolite (DUSY) were prepared by impregnation and characterized by XrD, BET, Ir, and H2-chemisorption. Their catalytic activities were tested in the hydroisomerization of n-heptane with a continuous atmospheric fixed-bed reactor. After the steam treatment combined with the acid leaching, as well as the supporting with pW and the bimetals, the DUSY support retains the Y zeolite porosity and the pW well keeps its Keggin structure in catalysts. The doping of Ce into the catalysts enhances the dispersion of pt on the catalyst surface. The pt-bearing pW catalysts doped with Ce or La, especially Ce, exhibit much higher catalytic activity and selectivity than the catalysts without dopants at lowered reaction temperatures. At the optimal reaction conditions, i.e., the reaction temperature of 250℃ and WHSV of 1.4 h1, the catalyst with a pt loading of 0.4%, pW loading of 10% and a molar ratio of Ce to pt of 15:1 shows a conversion of n-heptane of 70.3% with a high selectivity for isomerization products of 94.1%.

关键词： hydroisomerization of n-heptane bimetal catalyst heteropoly acid USY platinum

Influence of MnO_2 on the photocatalytic activity of p-25 TiO_2 in the degradation of methyl orange

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中国科学：化学英文版 2008年第2期51卷 179-185页

作者： LI ShunJun1, MA ZiChuan1,2, WANG Lin1 & LIU JingZe2 1 college of chemistry and Material Sciences, hebei Normal university, Shijiazhuang 050016, china 2 college of Life Science, hebei Normal university, Shijiazhuang 050016, china college of chemistry and Material Sciences Hebej Normal UniversityShijiazhuang 050016China college of Life Science Hebei Normal UniversityShijiazhuang 050016China

Influences of α-MnO2, β-MnO2, and δ-MnO2 on the photocatalytic activity of Degussa p-25 TiO2 have been investigated through the photocatalytic degradation of methyl orange. The TiO2 photocatalyst, before and after being contaminated by MnO2, was characterized by UV-visible diffuse reflectance spectroscopy (UV-vis DrS), photoluminescence (pL), and X-ray photoelectron spectroscopy (XpS). The results showed that photocatalytic activity of TiO2 could be inhibited significantly or completely deactivated due to the presence of even a small amount of MnO2 particles. It was found that the poisoning effect varied with the crystal phases of MnO2 and the effect was in the order δ-MnO2 >α-MnO2 >β-MnO2. The poisoning effect was attributed to the formation of heterojunctions between MnO2 and TiO2 particles. The heterojunctions changed the chemical state of Ti4+ and O2 sites in the crystalline phase of TiO2. MnO2 in contact with TiO2 particles also broadens the band-gap of TiO2, which decreases UV absorption of TiO2. It can also create some deep impurity energy levels serving as photoelec-tron-photohole recombination center, which accelerates the electron-hole recombination.

关键词： TiO2 MnO2 deactivation photocatalysis methyl orange

Virtual Instrument Based on GpIB Interface Bus

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微计算机信息 2004年第6期 88-89页

作者： Xiao,Ying Qi,Hanhong(college of Electrical engineering,yanshan university,qinhuangdao hebei,p.r.china.066004)

In this paper, we introduced the technique of GpIB bus interface. Through the controlling of the GpIB interface board, the computer controlled the current source and the voltmeter, both of which have GpIB bus interface, and a virtual instrument testing system for I~V curve was composed. The virtual instrument front panel and the background graphical control program in Labview environment accomplish virtual instrument testing task along with the hardware system.

关键词： GpIB Labview Virtual Instrument