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Formation of complexes of Rubisco-Rubisco activase from La^3., Ce^3. treatment spinach

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science china Chemistry 2005年第1期48卷 67-74页

作者： HONG Fashui1, LIU Chao1, ZHENG Lei1, WANG Xuefeng1, WU Kang1, SONG Weiping1, Lü Shipeng1, TAO Ye2.& ZHAO Guiwen3.1. College of Life sciences, Suzhou Universty, Suzhou 2.5006,{3. {2., institute of high Energy physics, the chinese academy of science, beijing 10003.,{3. 3. Chemical Department, University of science and Technology of{3., Hefei 2.002.,{3. 1. College of Life sciences Suzhou Universty 215006 Suzhou China 2. synchrotron radiation laboratory Institute of High Energy Physics The Chinese Academy of Science 100039 Beijing China 3. Chemical Department University of Science and Technology of China 230026 Hefei China

The complex of Rubisco and Rubisco activase from LaCl3., CeCl3. treated spinach in vivo is induced. SDS-PAGE result shows that the purified proteins from LaCl3., CeCl3. treated spinach have not only large and small subunits (55 kD, 14.4 kD) of Rubisco, but also two large subunits of 45 kD and 41 kD near the large subunits of Rubisco. Native-PAGE shows that the purified proteins from LaCl3., CeCl3. treated spinach have not only a band of Rubisco (560 kD), but also a band of about 1100 kD, about twice distant from Rubisco, which might be a complex of Rubisco and Rubisco activase. The purified enzyme activities from LaCl3., CeCl3.treated spinach are 1.8 and 2.8 times that of the control,the intensities of absorption and fluorescence are sig- nificantly higher than that of the purified Rubisco from the control, and the total sulfhydryl groups and available sulfhydryl groups are 3.—3. –SH per mol enzyme, 14—2. –SH per mol enzyme more than those of the purified Rubisco from the control, respectively. The CD spectra show that the secondary structure of the purified enzyme from LaCl3., CeCl3.-treated spinach is very dif- ferent from the control. The enzyme activities from LaCl3., CeCl3. treated spinach in vivo are 1.5 and 1.9 times those of the control.

关键词： La3., Ce3., spinach, Rubisco, complex of Rubisco and Rubisco acitivase, spectral characteristics.

Studies on BEPC upgrade from pretzel to double-ring

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science china({2.,Mechanics & Astronomy) 2010年第11期53卷 2084-2089页

作者： ZHANG Chuang institute of high Energy {2.,{3. academy of sciences,beijing 100049,china 1. institute of high Energy {2. Chinese Academy of Sciences Beijing 100049 China

physics opportunity in the charm and τ energy region calls for higher luminosity of the {2. Electron-Positron Collider (BEPC).The BEPC has experienced continuous improvement since its completion in ***,as a major upgrading project of the BEPC,aims at enhancing its luminosity of factor 3.–100,following the principle of "one machine,two purposes" as adopted in BEPC,so that both high energy physics and synchrotron radiation experiments can be carried out with *** the BEPC to BEPCII,the double-ring scheme with multi-bunch e +-e-collision in the large crossing angle was studied in comparison with the single-ring pretzel *** the dedicated synchrotron radiation operation,artful "bridges" are designed to connect two halves of the outer ring in both the southern and the northern crossing *** paper reviews the studies on the BEPC upgrade from pretzel to double-ring structure of BEPCII.

关键词： collider storage ring high energy physics synchrotron radiation

Structure Relaxation of Mg_(65)Cu_(2.)Gd_(10) Metallic Glass and Its Effect on Strength

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Journal of Wuhan University of Technology(Materials science) 2009年第2期24卷 210-213页

作者：李国强 School of Materials science & Engineering Beijing University of Aeronautics and Astronautics china Perfect Machinery Industry Corp. Ltd

To identify the re-arrangement of constituent atoms of an amorphous Mg65Cu2.Gd10 alloy happened with annealing, structure relaxation of the alloy was investigated as a function of an- nealing time at 3.3.K through extended X-ray absorption fine structure （EXAFS） analysis procedures. To understand the effect of structure relaxation on strength, compression tests were conducted for both the as-cast and the annealed Mg65Cu2.Gd10 samples. It is found that short range order around Cu and Gd atoms exhibits different variation trends with increasing annealing time at 3.3.K, though the structure of the alloy still remains to be amorphous. Based on the fact that the strength of the alloy first exhibits a reduction and then a recovery with annealing time, it is suggested that the enhancement of short range order around Cu should be responsible for the strength reduction, while the enhancement of short range order around Gd should be responsible for the strength recovery.

关键词： Mg-based metallic glass structure relaxation strength annealing

high-pressure synthesis and properties of CeO_2.ZrO_2.solid solution

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chinese science Bulletin 2001年第10期46卷 801-806页

作者： XU Dapeng, WANG Quanyong, LU Zhe, LIU Zhiguo, ZHANG Gongmu & SU Wenhui1. Department of physics, Jilin University, Changchun 13.02. china 2. International Center for Materials physics, chinese academy of sciences, Shenyang 110015, china 3. Center for Condensed Matter and radiation physics, china Center of Advanced science and Technology (World {13.), {12. 100080, china Department of physics Jilin University Changchun China International Center for Materials physics Chinese Academy of Sciences Shenyang China Center for Condensed Matter and radiation physics China Center of Advanced Science and Technology (World Laboratory) Beijing China

Using nanoparticles of CeO2.and ZrO2.prepared by the chemical precipitation method as starting materials, the single-phase cubic Ce0.5Zr0.5O2.solid solution (c-Ce0.5Z0.5O2. has been synthesized under 3.1 GPa at 1073.K for the first time. The structure of the c-Ce0.5Zr0.5O2.has not been changed before and after annealing at 773.K for 1 h. Only an unknown EPR signal (g =1.990) has been observed in the c-Ce0.5Zr0.5O2.and not varied after annealing at 773.K for 1 h, which exhibited that there exists no Ce3. in the c-Ce0.5Zr0.5O2.and the Ce4+ has not been reduced into Ce3. after annealing. The transport mechanism is ionic for the c-Ce0.5Zr0.5O2. The bulk conductivity (a =1.2.10-5 S/cm at 82. K, σ=2.1 ×10-3.S/cm at 112. K) is the same as that of CeO2. but smaller than that of Y2.3.stabilized ZrO2. A marked curvature at T = 82. K has been observed in the Arrhenius plot of the bulk conductivity. The activation energy below 82. K is lower than that above 82. K, and the reason has been discussed.

关键词： CeO2.ZrO2 nanocrystalline high-pressure and -temperature solid-state reaction solid solution.

Enhancement of magnetism of Zn0.95Co0.05O films by p-type Cu+ doping

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Progress in Natural science:Materials International 2011年第1期21卷 31-35页

作者： Wei-chang HAO~(1,5),Jian-jun LI~2.Huai-zhe XU~3.Jia-ou WANG~4,Tian-min WANG~1 1.Center of Materials physics and Chemistry,Beihang University,beijing 100083.{2. 2.Department of Materials science and Engineering, Anhui University of science and Technology,Huainan 2.2.01,{2. 3.Department of physics,Beihang University,beijing 100083.{2. 4.beijing synchrotron radiation Facility,{12. of high Energy physics, chinese academy of sciences,100049,{2. 5.Key {23. of Micro-nano Measurement,Manipulation and physics, Ministry of Education,Beihang University,beijing 100191,{2. [a] Center of Materials physics and Chemistry Beihang University Beijing 100083 China [b] Department of Materials science and Engineering Anhui University of Science and Technology Huainan 232001 China [c] Department of physics Beihang University Beijing 100083 China [d] beijing synchrotron {2. Facility Institute of High Energy Physics Chinese Academy of Sciences 100049 China [e] Key laboratory of Micro-nano Measurement Manipulation and Physics Ministry of Education Beihang University Beijing 100191 China

Zn0.95Co0.05O and Zn0.91Co0.05Cu0.04O thin films were fabricated on Si（111） substrate by the reactive magnetron sputtering method at different O-Ar *** characterizations by X-ray diffractometry（XRD）,X-ray photo-electronic spectrum（XPS）, and electron paramagnetic resonance（EPR） indicate that the doped Cu ions substitute the Zn2.ions in the ZnO *** doped Cu ions are in Cu+and Cu2.mixture valence *** ferromagnetism of the Zn0.91Co0.05Cu0.04O film increases gradually the increasing Cu+ions *** results indicate that the increase of ferromagnetism is not owing to the magnetic contribution of Cu+ions themselves,but owing to the enhancement of magnetic interaction between Co ions,which suggests that p-type doping of Cu+ions plays an important role in mediating the ferromagnetic coupling between Co ions.

关键词： Zn0.95Co0.05O films Zn0.91Co0.05Cu0.04O films magnetic semiconductors magnetic coupling co-doping

INVESTIGATION ON THE VALENCE STATE OF Ce ATOMIN BULK AND NANOCRYSTAL CeO_2.BY X-RAY ABSORPTION ANDPHOTOEMISSION

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Acta Metallurgica Sinica(English Letters) 2001年第6期14卷 511-516页

作者： K. Ibrahim, Z.Y. Wu, J. Zhang, M.I. Abbas, F.Q. Liu and H.J. Qian (beijing synchrotron {2. {3., institute of high Energy physics, the chinese academy of sciences, P.O. Box 918, beijing 10003., china) beijing synchrotron Radiat. Lab. Inst. of High Energy Phys. Chinese Acad. of Sci. P.O. Box 918 Beijing 100039 China

Valence band photoemission spectra (PES) for both bulk and nanocrystal CeO2.have been measured on and off resonance of Ce 4d-4f absorption edge. The PES show that the bulk and nanocrystal CeO2.of diameter ranging from 8nm to 50nm exhibit a peak near Fermi edge with binding energy of about 1.8eV. The 1.8eV peak shows a strong dependence on excitation energy, although it looks like the contribution of Ce3. ion following the data reported in literatures. However, according to the results of resonance photoemission and X-ray absorption spectra at 1s edge, this electronic structure may be associated to the intermediate state charge transfer effects.

关键词： rare earth oxide photoemission electronic structure photoabsorption

EXAFS Studies on Local Atomic Structure in the Amorphous Mg_(65)Cu_(2.)Gd_(10) Alloy

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Journal of Wuhan University of Technology(Materials science) 2011年第1期26卷 98-101页

作者：李国强 Business Development Department China Perfect Machinery Industry Corp. Ltd

Local atomic structures of an amorphous Mg65Cu2.Gd10 alloy and the structural changes by thermal annealing have been studied by extended X-ray absorption fine structure （EXAFS）. The correlation between structural changes and mechanical properties for the Mg65Cu2.Gd10 alloy has also been discussed. Results showed that Cu atoms around Gd in Mg65Cu2.Gd10 lost rapidly during annealing , resulting in the segregation of Cu atoms. The coordination number NGd-Mg of Mg65Cu2.Gd10 annealed at 3.3.K first diminished and then augmented with the increase of annealing time. The formation of polyhedral short-range order unit with coordination number of nearly 12.around Gd atoms is in favor of the improvement of mechanical properties. The chemical short-range order, not topological short-range order in the amorphous Mg65Cu2.Gd10 alloy had obvious changes during annealing.

关键词： magnesium alloy amorphous alloy short-range EXAFS mechanical properties annealing

RESONANT PHOTOEMISSION OF BULK CeO_(2. AND NANO-CeO_(2. FILMS

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Acta Metallurgica Sinica(English Letters) 2001年第6期14卷 539-543页

作者： M.I. Abbas, K. Ibrahim, Z.Y. Wu, J. Zhang, F.Q. Liu and H.J. Qian (beijing synchrotron {2. {3., institute of high Energy physics, the chinese academy of sciences, P.O. Box 918, beijing 10003., china) beijing synchrotron Radiat. Lab. Inst. of High Energy Phys. Chinese Acad. of Sci. P.O. Box 918 Beijing 100039 China

Photoemission behaviors of nano-CeO2.films with particle sizes ranging from 8 nm to 50 nm and bulk CeO2.in Ce 4 d-4 f absorption region have been investigated. Resonant enhancements of Ce 4 f valance band and Ce 5 p bands for nano film and bulk material have been observed. The variation of electron density of states in valance bands of nano and bulk structures of CeO2.is discussed in terms of Ce 4 d-4 f resonance.

关键词： Nanostructured materials Optical films Oxides Photoemission Resonance

Structural stability of infinite-layer CaCuO_2.under high pressure

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chinese science Bulletin 2003年第12期48卷 1201-1203页

作者： QIN Xiaomei1,2. HONG Ming1,2. ZHANG Gongmu1,2. MAI Wenjie1,2. LI Fengying1,2. YU Richeng1,2. LIU Jing2.3.& JIN Changqing1,2.1. institute of physics, {2. academy of sciences, {13. 100080, china 2. {13. high Pressure Research Center, {13. 100080, china 3. institute of high Energy physics, {2. academy of sciences, beijing 10003., china Correspondence should be addressed to Jin Changqing (e-mail: cqjin@ ***) institute of physics Chinese Academy of Sciences Beijing 100080 China beijing high Pressure Research Center Beijing 100080 China institute of high Energy {2. Chinese Academy of Sciences Beijing 100039 China

In situ high-pressure energy dispersive X-ray diffraction measurements on polycrystalline powder Ca-CuO2.with an infinite layer structure (IL CaCuO2. have been performed by using diamond anvil cell (DAC) instrument with {3. {2.. The results suggest that the crystal structure of IL CaCuO2.is stable under pressure up to 3. GPa at room temperature. According to Birch-Murn- aghan equation of state, assuming pressure derivative 4,=0Bthe bulk modulus B0=181 ?9 GPa is obtained.

关键词： infinite-layer CaCuO2 synchrotron radiation high pressure energy dispersive X-ray diffraction.