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Synthesis of 6-(Bromomethyl)-4-methoxy-5,6,7,8-tetrahydropyrido-[3,2.d]pyrimidin-2.ol from 6-Methylpyrimidine-2.4-diol

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Chemical Research in Chinese Universities 2012年第1期28卷 57-60页

作者： LIU Wei-dong2. DENG Xi-ling2. ZHANG Zhi-li2. WANG Xiao-wei2.and LIU Jun-yi1,2.1. State Key Laboratory of Natural and Biomimetic Drug, 2. department of Chemical Biology, School of Pharmaceutical {2., Peking {2., Beijing 100191, P. R. china Peking Univ Sch Pharmaceut Sci State Key Lab Nat & Biomimet Drug Beijing 100191 Peoples R China Peking Univ Sch Pharmaceut Sci Dept Biol Chem Beijing 100191 Peoples R China

6-（Bromomethyl）-4-methoxy-5,6,7,8-tetrahydropyrido[3,2.d]pyrimidin-2.ol（compound 9） was synthe sized from 6-methylpyrimidine-2.4-diol（compound 1） through the crucial steps of 6-methyl alkylating and intramo lecular cyclization. The assignment of the structure of compound 9 was performed by its spectral data, 1H NMR, 13C NMR, HMBC, and HRMS spectra.

关键词： Heterocycle Carbanion Alkylation Reduction Cyclization

N-way blending problem of circular quadrics

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Science china(Information sciences) 2010年第8期53卷 1546-1554页

作者： fang MeiE 1,3 , Wang GuoZhao 2.& MA Weiyin 3 1 School of Computer Science, Hangzhou Dianzi {2., Hangzhou 310081,{2. 2.department of Mathematics, Zhejiang {2., Hangzhou 310018,{2. 3 department of MEEM, City {2. of Hong Kong, Hong Kong,{2. 1. School of Computer Science Hangzhou Dianzi University Hangzhou 310081 China3. Department of MEEM City University of Hong Kong Hong Kong China2. Department of Mathematics Zhejiang University Hangzhou 310018 China

A method of blending circular quadrics with parametric patches is proposed in this paper. It needs n rational bi-cubic B′ezier patches and two S-patches to blend n (n > 2. quadrics. Bi-cubic rational B′ezier patches are used to G 1 -continuously blend each pair of adjacent base surfaces. These patches enclose two n-sided holes. And an S-patch is used to fill each hole, which keeps nearly G 1-continuity. Explicit formulas of control points for both B′ezier patches and S-patches are derived from their constraint conditions, which make modeling by blending quadrics very simple and convenient. In addition, the shapes of the blending surfaces can be intuitively adjusted by free parameters.

关键词： circular quadrics blending n-way S-patch

Semantic Search among Heterogeneous Biological Databases Based on Gene Ontology

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Acta Biochimica et Biophysica Sinica 2004年第5期36卷 365-370页

作者： Shun-Liang CAO, Lei QIN1, Wei-Zhong HE1, Yang ZHONG2. Yang-Yong ZHU, and yi-Xue LI1,3* department of Computing and Information Technology, Fudan {2., Shanghai 2.0433,{2. Shanghai Center for Bioinformation 1 Technology, Shanghai 2.02.5,{2. School of Life sciences, Fudan {2., Shanghai 2.0433,{2. Bioinformation Center of Shanghai Institutes for Biological sciences, the Chinese Academy of sciences, Shanghai 2.0031,{2. department of Computing and Information Technology Fudan University Shanghai China

Semantic search is a key issue in integration of heterogeneous biological databases. In this paper, we present a methodology for implementing semantic search in BioDW, an integrated biological data warehouse. Two tables are presented: the DB2.O table to correlate Gene Ontology (GO) annotated entries from BioDW data sources with GO, and the semantic similarity table to record similarity scores derived from any pair of GO terms. Based on the two tables, multifarious ways for semantic search are provided and the corresponding entries in heterogeneous biological databases in semantic terms can be expediently searched.

关键词： Gene Ontology semantic search BioDW

bubble size distribution in surface wave breaking entraining process

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Science china Earth sciences 2007年第11期50卷 1754-1760页

作者： HAN Lei1,2.& YUAN YeLi2.1 department of Ocean Environment, Ocean university of{2., Qingdao 2.6003,{2. 2.The First Institute of Oceanography, State Ocean Administration, Qingdao 2.6061,{2. 1. department of Ocean Environment Ocean University of China Qingdao 266003 China 2. The First Institute of Oceanography State Ocean Administration Qingdao 266061 China

From the similarity theorem, an expression of bubble population is derived as a function of the air en-trainment rate, the turbulent kinetic energy (TKE) spectrum density and the surface tension. The bubble size spectrum that we obtain has a dependence of a?2.5+nd on the bubble radius, in which nd is positive and dependent on the form of TKE spectrum within the viscous dissipation range. To relate the bubble population with wave parameters, an expression about the air entrainment rate is deduced by intro-ducing two statistical relations to wave breaking. The bubble population vertical distribution is also derived, based on two assumptions from two typical observation results.

关键词： wave breaking,bubble cloud,bubble size spectrum

Analysis of Environmental and Socio-economic Determinants Affecting Population Longevity Level at County Level in china

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Chinese Journal of Population,Resources and Environment 2005年第1期3卷 36-41页

作者： Lu Jiehua , Wang Hongbo 1 2.& Pan yi 1 1. Institute of Population Research, Peking university, Beijing 100871,{2. 2. {2. of Sociology, university of California at Los Angeles, Los Angeles, USA. Institute of Population Research Peking University Beijing 100871 China department of Sociology University of California at Los Angeles Los Angeles United States

Based on the current literature, this paper is mainly intended to test whether environmental factors and socio-economic factors will have direct effect on the longevity at county level in china in order to determine the major determinants affecting local longevity level. Using the multi-regression model, we find the result that factors such as temperature, climate, longitude, type of soils, as well as type of agricultural food production play a major role in shaping the longevity at county level, and that socio- economic factors like infant mortality and gross death rate also have some direct impact on longevity, but the degree of impact is not as strong as the above environmental factors.

关键词： longevity socio-economic factors environmental factors

Distributions of fatty acids in a stalagmite related to paleoclimate change at Qingjiang in Hubei,southern china

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Science china Earth sciences 2005年第9期48卷 1463-1469页

作者： XIE Shucheng1,HUANG Junhua1,WANG Hongmei2.yi yi1,HU Chaoyong1, CAI Yanjun3 & CHENG Hai4 1. Faculty of Earth Science,{2. university of Geo{2.,Wuhan 430074,{2. 2. School of Environmental Studies,{2. university of Geo{2.,Wuhan 430074,{2. 3. SKLLQG,Institute of Earth Environment,Chinese Academy of {2.,Xi’an 710075,{2. 4. {12. of Geology and Geophysics,university of Minnesota,MN55455,USA 1. Faculty of Earth Science China University of Geosciences 430074 Wuhan China 2. School of Environmental Studies China University of Geosciences 430074 Wuhan China 3. SKLLQG Institute of Earth Environment Chinese Academy of Sciences 710075 Xi’an China 4. department of Geology and Geophysics University of Minnesota 55455 MN USA

Fatty acids extracted from a subtropical stalagmite at Qingjiang in Southern china’s Hubei Province were analysed using gas chromatography-mass spectrometry. These n-alkanoic acids range from C14 to C2. in carbon number, maximizing at C16, with a second dominance at C2.. In contrast to the stalagmite analysed, the overlying soils are characterized by the dominance of heavy-molecular-weight homologues (>C2.). The n-fatty acids in the stalagmite were proposed to be contri{2.ted by both the soil ecosystems and the microbes harboring in the percolating water and the cave. The ratios of unsaturated to saturated n-fatty acids (C16:1i/C16:0, C18:1/C18:0) appear to show trends comparable with the oxygen isotope records of the stalagmite carbonate, with enhanced values associated with the cold episode such as Heinrich event 1. This paleoclimate-dependent record of the n-fatty acids might reflect microbial changes in physiology and activity in response to the temperature. This record shows somewhat difference from the previous paleoclimate signal extracted from n-alkanols and n-alkan-2.ones of the same stalagmite. The acid record fails to document the well-known Younger Dryas event which was effectively shown by the latter two biomarkers derived from soil ecosystems. This discrepancy might result from the changing biogeochemical impact on different lipid fractions as well as the varied organism populations in different ecosystems.

关键词： biomarker, ecosystem, microbe, speleothem, paleoclimate, Quaternary.

Interaction between hydrogen sulfide/cystathionine γ-lyase and carbon monoxide/heme oxygenase pathways in aortic smooth muscle cells

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Acta Pharmacologica Sinica 2006年第12期27卷 1561-1566页

作者： Hong-fang JIN~2.Jun-bao DU~(2.4)Xiao-hui LI~2.Yan-fei WANG~2.yin-fang LIANG~2.Chao-shu TANG~3 2.{2. of Pediatrics,Peking university First Hospital,Beijing 100034,china 3 Institute of Cardiovascular Research,Peking university First Hospital,Beijing 100034,china department of Pediatrics Peking University First Hospital Beijing 100034 China Institute of Cardiovascular Research Peking University First Hospital Beijing 100034 China

Aim:To investigate the interaction between hydrogen sulfide（H2.）/cystathion-ine γ-lyase（CSE）and carbon monoxide（CO）/heme oxygenase（HO）pathways inaortic smooth muscle cells（ASMC）.Methods:The ASMCs were divided into thefollowing groups:（1）the control group;（2.the zinc protoporphyrin（ZnPP）2.μmol/L group;（3）the propargylglycine（PPG）2.mmol/L,4 mmol/L and 10 mmol/Lgroups;and（4）the sodium hydrosulfide（NariS）1×10-5mol/L,1×10-4mol/L and1×10-3mol/L *** of the groups was further divided into 6h,12.,18hand 2.h *** CO level,represented by carboxyhemoglobin（HbCO）content was measured using a spectrophotometric method and H2. content wasdetected by a sensitive electrode *** and HO-1 expressions were de-tected by Western ***:The H2. content in the medium and CSEexpression by ASMC were markedly increased by ZnPP compared with the con-trol *** content in the medium and HO-1 expression by the ASMCstarted strengthening following 2.h treatment with PPG at 2.mmol/L,but werefurther strengthened following 18h and 2.h treatment with PPG at 4 mmol/Lcompared with the controls（P2. ***,NariS at 1×10-5mol/L and 1×10-4mol/Ldecreased the HbCO level in the medium and HO-1 expression by the ASMC after6h and 12. treatment,while NariS at 1×10-3mol/L decreased them at all timepoints of the ***:The results suggested that endogenousCO/HO and H2./CSE pathways inhibited each other in ASMC under physiologi-cal conditions.

关键词： hydrogen sulfide cystathionine γ-lyase carbon monoxide heme oxygenase

Probing the interaction between asphaltene-wax and its effects on the crystallization behavior of waxes in heavy oil via molecular dynamics simulation

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Petroleum Science 2024年第4期21卷 2839-2848页

作者： Yong Hu Xi Lu Hai-Bo Wang Ji-Chao fang yi-Ning Wu Jian fang Sun SINOPEC Petroleum Exploration and Production Research Institute Shandong Key Laboratory of Oilfield Chemistry School of Petroleum Engineering China University of Petroleum (East China)

High content of asphaltenes and waxes leads to the high pour point and the poor flowability of heavy oil,which is adverse to its efficient development and its transportation in *** the interaction mechanism between asphaltene-wax is crucial to solve these problems,but it is still *** this paper,molecular dynamics simulation was used to investigate the interaction between asphaltenewax and its effects on the crystallization behavior of waxes in heavy *** show that molecules in pure wax are arranged in a paralleled *** wax molecules in heavy oil,which are close to the surface of asphaltene aggregates,are bent and arranged *** the mass fraction of asphaltenes in asphaltene-wax system(ωasp) is 0-2. wt%,the attraction among wax molecules decreases and the bend degree of wax molecules increases with the increase of ω*** ωaspincreases from 0 to 2. wt%,and the attraction between asphaltene-wax is stronger than that among *** causes that the wax precipitation point changes from 353 to 333 *** the ωaspincreases to 50 wt%,wax molecules are more dispersed owing to the steric hindrance of asphaltene aggregates,and the interaction among wax molecules transforms from attraction to *** causes that the ordered crystal structure of waxes can't be formed at normal ***,the asphaltene,with the higher molecular weight or the more hetero atoms,has more obvious inhibition to the formation of wax ***,resins also have an obvious inhibition on the wax crystal due to the formation of asphalteneresin aggregates with a larger *** results reveal the interaction mechanism between asphaltene-wax,and provide useful guidelines for the development of heavy oil.

关键词： Heavy oil Interaction mechanism Asphaltenes Waxes Molecular dynamics

Numerical simulations of magnetic reconnection in the lower solar atmosphere

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Research in Astronomy and Astrophysics 2011年第2期11卷 225-236页

作者： Xiao-Yan Xu 1,2.Cheng fang 2.Ming-De Ding 2.and Dan-Hui Gao 2.1 Purple Mountain Observatory,Chinese Academy of Science,Nanjing 2.0008,china 2.{2. of Astronomy,Nanjing university,Nanjing 2.0093,china Purple Mountain Observatory Chinese Academy of Science Nanjing 210008 China department of Astronomy Nanjing University Nanjing 210093 China

Observations indicate that Ellerman bombs （EBs） and chromospheric microflares both occur in the lower solar atmosphere,and share many common features,such as temperature enhancements,accompanying jet-like mass motions,short life-time,and so *** strongly suggest that EBs and chromospheric microflares could both probably be induced by magnetic reconnection in the lower solar *** gravity,ionization and radiation considered,we perform two-dimensional numerical simulations of magnetic reconnection in the lower solar *** influence of different parameters,such as intensity of the magnetic field and anomalous resistivity,on the results are *** result demonstrates that the temperature increases are mainly due to the joule dissipation caused by magnetic *** spectral profiles of EBs and chromospheric microflares are calculated with the non-LTE radiative transfer theory and compared with *** is found that the typical features of the two phenomena can be qualitatively reproduced.

关键词： Sun: chromosphere-- Sun: photosphere -- Sun: magnetic reconnection-- Sun: numerical simulation