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Selective Oxidation of Methane to Methanol Using Molecular Oxygen on MoOx/(LaCoO3.Co3.4)Catalysts

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Chinese Chemical Letters 2003年第10期14卷 1066-1069页

作者： Xin ZHANG, De Hua HE, Qi Jiang ZHANG, Bo Qing XU, Qi Ming ZHUState Key Laboratory of C1 Chemistry and Technology, department of Chemistry, Tsinghua university, beijing 100084 State Laboratory of C1 Chemistry and Technology Department of Chemistry Tsinghua University

Comparatively high CH3.H selectivity (60.0%) and yield (6.7%) were obtained on MoOx/(LaCoO3.Co3.4) catalysts in selective oxidation of methane to methanol using molecular oxygen as oxidant. The interaction between MoOx and La-Co-oxide modified the molecular structure of molybdenum oxide and the ratio of O7O ' on the catalyst surface, which controlled the catalytic performance of MoOx/(LaCoO3.Co3.4) catalysts.

关键词： Methane selective oxidation methanol molybdenum oxide species O-/O2- ratio.

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泥石流风险评价中若干问题的探讨

山地学报 2000年第4期18卷 341-345页

作者：刘希林北京大学城市与环境学系!北京100871中国科学院、水利部成都山地灾害与环境研究所四川成都610041

介绍了自然灾害风险评价的一般模式及泥石流危险性和泥石流区域易损性的评价方法。探讨了危险度的指标选择及其量值表达 ,以及风险度和易损度的异同。论述了风险评价和环境评价的关系 ,并对有关文献中的危险性和易损性评价问题进行了讨论

关键词：危险性易损性风险评价泥石流

Interaction between N-Phospho-Amino Acids and Nucleoside in Aqueous Medium

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Chinese Chemical Letters 2000年第5期11卷 407-408页

作者： Yu Fen ZHAO Jian Jun HU Yong JU (State Laboratory of Bioorganic Phosphorus Chemistry. department of Chemislry. School of Life Science and Engineering. Tsinghua university. beijing 100084) Tsing Hua Univ Sch Life Sci & Engn Dept Chem State Lab Bioorgan Phosphorus Chem Beijing 100084 Peoples R China

Nucleosides were phosphorylated with different N- (O, O-diisopropyl) phosphoryl amino acids to give nucleoside mono phosphates in aqueous solution. 2', 3., and 5'-isomers had been confirmed by comparison with authentic samples on the basis of HPLC analysis. The conversion percentage of nucleoside indicated that N- (O, O-diisopropyl) phosphoryl aspartic acid reacted with adenosine and guanosine at a much higher rate than other kinds of N- phosphoryl amino acids. while phosphorylation of cytidine and uridine was relatively easy by using N- (O, O-diisopropyl) phosphoryl threonine. The result could give some clue to the prebiotic code origin of nucleic acid and protein.

关键词： N-phospho-amino acids nucleoside mono phosphate phosphorylation uridylyl uridine (UpU) origin chemical evolution

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Quantum and Classical Coincidence Imaging in Spontaneous Parametric Down-conversion

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Quantum and Classical Coincidence Imaging in Spontaneous Par...

第十一届全国量子光学学术会议

作者： WANG Kaige CAO Dezhong (department of Physics,Applied Optics beijing Area Major Laboratory beijing Normal {3.,beijing 100875,china)

＜正＞Two-photon coincidence imaging （It is also called quantum or ghost imaging） can be carried out by an entangled two-photon quantum *** a recent experiment （***,et al,***.89, （2002） 113.01） shows that this e...

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Landuse/landcover changes in Zhangye oasis of Hexi Corridor

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Journal of Geographical sciences 2003年第1期13卷 71-75页

作者： MENG Jijun,WU Xiuqin,LI Zhengguo(department of Urban and Environmental Scien ce, peking university, Laboratory of Analysis and Simulation of Earth Surface P rocesses, the Ministry of Education, beijing 100871,{3.) department of Urban and Environmental Science Peking University Laboratory of Analysis and Simulation of Earth Surface Processes the Ministry of Education Beijing China

Taking two f alse color composite Landsat 5 TM (Thematic Mapper) images of band 4,3.2 taken in 1995 and 2000 as data resources, this paper carried out study on LUCC of Zhan gye oasis in recent five years by interpretation according to land reso urces classification system of 1:100,000 Resources and Environmental Data base of the Chinese Academy of sciences. The results show that great changes have taken place in landuse/landcover in Zhangye oasis since 1 995: (1) Changes of landuse structure show that cropland and land for urban c onstruction and built-up area increased, on the contrary, water area an d grassland decreased. These changes reflect the deterioration of eco-e nvironment and the acceleration of urbanization, and also indicate the problems existing in the arrangement of water and land resources betw een the upper and lower reaches of the Heihe River. (2) Regional diff erences of landuse/landcover are evident, characterized by following asp ects: in Sunan County located in Qilian Mountain area, unused land an d grassland decreased, but cropland and land for urban construction an d built-up area increased. In Minle and Shandan counties located in f oothills, unused land, water area and cropland decreased, but grassland and land for urban construction and built-up area increased. In Zhan gye City, Linze County and Gaotai County located in plain area of th e middle reaches of the Heihe River, unused land, water area and gra ssland decreased, while woodland, cropland and land for urban construction and built-up area increased.

关键词： landuse/landcover changes (LUCC) Zhangye oasi s Hexi Corridor

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Plasticity of upper limbs motor maps after modified anatomical hemisphereomy:A study with fMRI

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Plasticity of upper limbs motor maps after modified anatomic...

中华医学会神经外科学分会第九次学术会议

作者： Yuan Liu Yu-lun Xu~* department of Neurosurgery,beijing Tiantan Hospital,Capital Medical university,beijing 100050,china

Objective To locate motor functional area of patients who undergone modified anatomical hemispherectomy in order to analysis the plasticity of upper limbs motor. Methods The patients who undergone modified anatomical ... 详细信息

关键词： modified anatomical hemispherectomy fMRI Plasticity

Exact Solutions for a Higher-Order Nonlinear Schrdinger Equation in atmospheric Dynamics

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Communications in Theoretical Physics 2006年第3期 573-576页

作者： HUANG Fei TANG Xiao-Yan LOU Sen-Yue department of Physics,Shanghai Jiao Tong university,Shanghai 20003.,chinaHUANG Fei department of Marine Meteorology,Ocean university of china,Qingdao 266003.chinaLOU Sen-Yue department of Physics,Ningbo university,Ningbo 3.5211,china department of Physics，Shanghai Jiao Tong university，Shanghai 20003.，china department of Marine Meteorology，Ocean university of china，Qingdao 266003.{3. department of Physics，Shanghai Jiao Tong university，Shanghai 20003.，china department of Physics，Shanghai Jiao Tong university，Shanghai 20003.，china department of Physics，Ningbo university，Ningbo 3.5211，china

By giving prior assumptions on the form of the solutions,we succeed to find several exact solutions for ahigher-order nonlinear Schr(o|¨)dinger equation derived from one important model in the study of atmospheric and oceandynamical *** analytical solutions include bright and dark solitary waves,and periodical solutions,which canbe used to explain atmospheric phenomena.

关键词： higher-order nonlinear Schr(o|¨)dinger equation atmospheric dynamics bright solitary wave dark solitary wave

Plasma ghrelin concentrations in patients with coronary artery dsisease correlates with heart function and prognosis

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Plasma ghrelin concentrations in patients with coronary arte...

第十三次全国心血管病学术会议

作者： CHU Song-yun,DING Wen-hui,LI Gui-zhong, PANG Yong-zheng,TANG Chao-shu *department of Cardiology,The First Hospital,peking university,{3. 10003.,china

Objective To explore plasma ghrelin concentrations in patients with coronary artery disease and analysis the relationships with heart function and *** Eighty-three patients with coronary artery disease that admitted in our center were recruited in the study,including 3. cases of ST-segment elevation myocardial infarction(STEMI),3. cases of

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A Few Problems on Variations in Discrete Mechanics and Field Theory

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A Few Problems on Variations in Discrete Mechanics and Field...

CCAST“场论、引力与多辛结构”研讨会

作者： Han-Ying Quo Institute of Theoretical Physics, Chinese Academia of sciences, P. O. Box 273., beijing 100080, china KeWu {3. of Mathematics, Capital Normal university, beijing 10003., china Institute of Theoretical Physics, Chinese Academia of sciences, P.O. Box 273., beijing 100080, china

In this paper,it is proposed the difference variational approach with vari—able step—length to discrete mechanics and field theories on right—angle *** upon Hamilton’s principle for the vertical variations and the double op—erations of the vertical exterior differential on action,it is shown that for bothcases there should exist the nontrivial Euler—Lagrange cohomology in general

关键词： Hamiltonian A Few Problems on Variations in Discrete Mechanics and Field Theory Lagrange