检索结果-南通市图书馆

THE FUNCTION OF La（III） ON ＂ION－GATE＂ OF THE GLUTATHIONE MONOLAYER GOLD ELECTRODE

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 1995年第6期6卷 513-516页

作者： Zi Wei JIANG Wen Kuan XIN Xiao Xia GAO(Department of chemistry,peking university,{2.) peking Univ Dept Chem Beijing 100871 Peoples R China

The regulative function of La3+ on the self-assembled glutathione(GSH)monolayer An electrode for the ion-gate response was studied in aqueous Fe(CN)6 solution at PH 5.6 and compared with the function of Ca2. It was fo... 详细信息

关键词： FUNCTION OF THE III ELECTRODE La

Triethylamine or diethylenetriamine as dynamic modifier for suppressing basic protein adsorption in capillary electrophoresis

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 1999年第3期10卷 227-230页

作者： Ying Hua QIU Al Jin HUANG Yi Liang SUN(Department of chemistry. peking university. {2.) peking Univ Dept Chem Beijing 100871 Peoples R China

Either triethylamine or diethylenetriamine can be conveniently used as a dynamic modifier to suppress the adsorption of basic proteins in capillary zone electrophoresis. Sufficiently high column efficiencies (> 2.10(5) plates/m for cytochrome C) were obtained with either of them along with the improvement of the peak shapes and repeatability of migration time. The relationship between the adsorption suppression effect of the modifier and its structure was discussed.

关键词： capillary zone electrophoresis basic proteins dynamic modifier triethylamne diethylenetriamine

NEW OPTICALLY ACTIVE AROMATIC POLYIMIDES Ⅱ: SYNTHESIS AND PROPERTIES OF OPTICALLY ACTIVE AROMATIC POLYIMIDE BASED ON (R)-(+)-2. 2.-BIS (2.TRIFLUORO-4-AMINOPHENOXY)-1, 1′-BINAPHTHYL

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 1999年第1期17卷 87-90页

作者： Qi-ding Mi Yu Ma Lian-xun Gao Meng-xian Ding Changchun Institute of Applied chemistry, Chinese Academy of Sciences Changchun 13002., china Department of chemistry, peking university, beijing 100871 中科院长春应用化学所吉林长春 130022 中科院长春应用化学所吉林长春

Optically active (R)-(+)-2. 2. -bis(2.-trifluoro-4 -aminophenoxy)- 1, 1' -binaphthyl was prepared from1, 1'-bi-2.naphthol. The optically active aromatic polyimide was also successfully synthesized. This newpolymer has good solubility, thermal stability etc. Its specific rotation was found to be +174°, and itschiroptical property was also studied.

关键词： Optical activity 1, 1′-Bi-2.naphthol, Polyimide

A submillimeter observation and study of star-forming regions

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2002年第1期47卷 16-21页

作者： JIANG Linhua, WU Yuefang & M. MillerDepartment of Astronomy, peking university, beijing 100871, {2. Chinese Academy of Sciences-peking university Joint beijing Astrophysics center, beijing 100871, {2. I. Physikalisches Institut, Zulpicher Str Department of Astronomy Peking University Beijing China Chinese Academy of Sciences-peking university Joint beijing Astrophysics {2. Beijing China I. Physikalisches Institut Koeln 41 Germany

Using the 3-m radio telescope of KOSMA, we mapped 12.O (J = 3-2. lines for three molecular clouds, B35, S146 and TMC-2.. High-velocity molecular outflows are found in all these regions. The physical and dynamical pa-rameters of the outflows are derived, and their shapes and driving sources are analyzed. Contour maps of center veloci-ties show that the large scale systematic gradients exist in the three clouds. These observed motions are best explained by rotation after excluding the cause of outflows. Furthermore, in the core region of TMC-2. there is a velocity gradient in opposite direction from that of the large scale. It may be caused by magnetic braking. Finally, angular velocities of the clouds are calculated, and the effects of rotation against gravity and lowering the star-formation rate are also ana-lyzed.

关键词： dynamics of interstellar medium jets and outflows star formation.

Application of an Organophosphorus Compound-DEPBT as Coupling Reagent in Liquid Phase Peptide Synthesis

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 1997年第9期8卷 749-750页

作者： Yan Nei HE Yao LIN(Department of chemistry. beijing {2.. beijing 100871) beijing UNIV DEPT CHEMBEIJING 100871PEOPLES R CHINA

DEPBT, a novel coupling reagent containing phosphorus, was used in synthesis of pentapeptide Boc-Ile-Asn-Met-Trp(For)-*** by solution method.

关键词： Application of an Organophosphorus Compound-DEPBT as Coupling Reagent in Liquid Phase Peptide Synthesis Met

Steady-state kinetics and osillation phenomena for complete oxidation of benzene over Pt/Al_2._3 catalyst

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 1990年第2期2卷 41-50页

作者： Yu Qiquan, Jin Yun and Shi FajunDepartment of chemistry,peking university,{2.,china.

The steady-state kinetics for complete oxidation of benzene over has been investigated by the external recycling reactor. The kinetics equation was described by the L-H model of adsorption of benzene and oxygen with the inhibition of carbon dioxide. The parameters of the kinetics model were estimated by the method of orthogonal design. The heats of adsorption of benzene, oxygen and carbon dioxide were determined by the method of gas-adsorption chromatography. The details of oscillations of complete oxidation of benzene were investigated.

关键词： steady-state kinetics complete oxidation benzene Pt/Al2.3.

Closed and endoreversible chemical oscillation

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of chemistry 1994年第3期12卷 199-205页

作者： LI, Ru-ShengDepartment of chemistry, Tsinghua university, {2. 100084, china Department of chemistry Tsinghua University Beijing 100084 China

Based on a simple nonideal chemical reaction model, the closed system with reversible nonideal reactions and illumination is shown to be able to exhibit sustained oscillation. The essential points in the occurrence of such oscillations are the nonideality of reacting media, which gives rise to multiple chemical equilibria, and the energy flow through illumination and heat conduction, which gives rise to spontaneous transitions repeatedly between the multiple equilibrium states. During the oscillation, reacting media undergo only reversible chemical transformation and all irreversibilities are restricted to the coupling of the system to external world. This oscillation provides an example of the so-called endoreversible machine and a possible way to convert radiation energy of the light directly into mechanical energy.

关键词： Chemical oscillation closed system nonideality endoreversible machine illumination.

DOUBLE　SUBSTITUTE　CALIBRATION　FOR　THE　ISOTOPIC　RATIO　MEASUREMENT　AMONG　RARE　EARTH　ELEMENTS

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 1996年第5期7卷 499-502页

作者： Teing Lien CHANG (Department of chemistry, peking university, {2.)Dun Min ZHAO (Institute of Geology, Academy of Geological Sciences. beijing 100037) Department of chemistry Peking University Beijing 100871 Institute of Geology Academy of Geological Sciences Beijing 100037

Abstract: Through the application of the method of double substitute calibration using the true isotopic ratios of cerium and europium of our laboratory standards, the atomic weight of ytterbium has been determined a... 详细信息

关键词： RATIO CALIBRATION DOUBLE EARTH ELEMENTS FOR ISOTOPIC MEASUREMENT RARE AMONG

Adjoint method for the optimum planning of industrial pollutant sources

在线全文

学校读者我要写书评

暂无评论

Science china Earth Sciences 2005年第8期48卷 1270-1279页

作者： LIU Feng1,2. HU Fei2.& ZHU Jiang2.1. College of Environmental Sciences, peking university, beijing 100871, {2. 2. LAPC, Institute of Atmospheric Physics, Chinese Academy of Sciences, beijing 10002., {2. 1. College of Environmental Sciences Peking University 100871 Beijing China 2. LAPC Institute of Atmospheric Physics Chinese Academy of Sciences 100029 Beijing China

The optimum planning of industrial pollutant sources, which optimizes the economic object without violating environmental constraints, is an important and hard task to be conquered. In this paper, an adjoint method is developed to solve the problem. The penalty function is in-troduced to deal with the environmental inequality constraints, and Lagrange function is con-structed to derive the adjoint equation and the gradient of the object function. In this means, the gradient of the object function can be calculated by solving the adjoint equation, and the infor-mation from the gradient is used to make the object function descend and approach to an optimal solution after some iterations. A two-dimensional, simplified model is used for numerical experi-ments. The theoretical derivations are verified by the results of the experiments. Furthermore, the adjoint method is shown to be of excellent convergence and efficiency, which is adaptive to the fast development of air quality numerical models and super computers.

关键词： optimum planning, industrial pollutant sources, adjoint equation, penalty function, gradient.