检索结果-南通市图书馆

The Blocking Effect of Phenolic Acid on N-Nitrosomorpholine Formation in vitro

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Biomedical and Environmental sciences 1994年第1期7卷 68-78页

作者： LI PlNG WANG HUAI-ZHOU WANG XU-QING AND WU YONG-NING(institute of Nutrition and Food Hygiene, chinese academy of PreventiveMedicine, 29 Nanwei Road, beijing 100050, china)( Present address: institute of Environmental Health and Engineering, chinese Acad institute of Nutrition and Food Hygiene Chinese Academy of Preventive Medicine Beijing.

Phenolic acids (PAs) are widely found in many daily consumed vegetables and *** inhibitory effects of PAs on Nnitrosomorpholine (NMOR) formation in vitro undersimulated gastric juice condition were studied. The results showed that the inhibjtoryIX)tency of thirteen varieties of PAs differed greatly, which may be related to theirchemical structures; the blocking rate (BR) of different killds of PAs were as follows:caf feic acid, 92.5%; tannic acid, 90.0%; gallic acid, 86.8%; sinaPinic acid, 86.2%; ferulicacid, 8l.l%; chlorogenic acid, 69.4%; gentisic acid, 69.2%; syringic acid, 62.1%; protocatechuic acid, 56.0%; p-coumaric acid, 52.5%; vannilic acid, 35.4%; moreover,p-hydroxybenzoic acid and m-coumaric acid had the least blocking effect or even slightcatalyzing effect. The results also demonstrated that amounts of NMOR formed werenegatively correlated with molar ratio of PAs to nitrite and that the optimum pH forinhibition was between 2 and 3.

关键词： The Blocking Effect of Phenolic Acid on N-Nitrosomorpholine Formation in vitro

Palinspastic Reconstruction for Tectonics of Northeast china and Its Vicinity

在线全文

学校读者我要写书评

暂无评论

Journal of Earth Science 1998年第3期17卷 20-30页

作者： Liu Xianwen Meng Xiangang institute of Geomechanics, chinese academy of Geological sciences, beijing 100081 Tamaki Kensaku Ocean Research institute, University of Tokyo, Tokyo, Japan Shen Ninghua Ge Xiaohong Department of Earth sciences, Cha

Collision and amalgamation of continent and microcontinent block were recognized as one of the major processes for building up a continent. The pre Jurassic structure of Northeast china and its adjacent region (including south of Russia Far East, north of North Korea and inner part of southwest Japan) is characterized by collision and amalgamation of microcontinent blocks, such as the North china block (NCB), Northeast china block (NECB), Khanka block and Hida *** central Jilin belt and Yanbian Grodekovsk belt that juxtapose and amalgamate these blocks in between in Northeast china and its vicinity were formed by a series of rock assemblages that are typical for Paleozoic active continental margin island arcs. The dominant Permian marine sequences in Yanbian (Yanbian Grodekovsk) belt, which are known for bearing transitional marine fauna, include turbidite olistostrome sediments of a slope facies, and limestones, sandstones as well as siltstones of a neritic littoral facies sediments along with predominant acidic to intermediate volcanic materials. The Maizuru belt in southwest Japan is supposed to be the equivalent of Yanbian Grodekovsk belt. The central Jilin belt consists of a well developed sedimentary sequence and volcanics of Paleozoic. The Bamiantong Gudonghe Fuerhe Chongjin suture complex in Northeast china and the equivalent Sangun Akiyoshi belt in southwest Japan serve as a major suture zone among these microcontinental blocks and belts.

关键词： orogenic belt suture zone melange complex tectonic reconstruction Northeast china.

A New Two-Parameter Formula for Rotational Spectra

在线全文

学校读者我要写书评

暂无评论

chinese journal of nuclear physics 1995年第4期17卷 322-327页

作者： Zeng Guo-mo1,2 Liu Wei1 Zhao En-guang21 Department of Physics, Jilin University, Changchun 1300232 institute of Theoretical Physics, the chinese academy of sciences, P. O. Box 2735, beijing 100080 吉林大学物理系吉林长春中科院理论物理所北京

A new two-parameter formula for the rotational spectra of well deformed nuclei isproposed. The formula is deduced from experimental level systematics and alternatively fromnuclear hydrodynamics. Comparisons with a great number of rotational spectra of even-even nu-clei in rare-earth and actinides region show that the formula is the best one among all two-pa-rameter formulas. It is pointed out that this formula can be applied to the spin assignment forsuperdeformed band.

关键词： Two-parameter formula Rotational spectra Nuclear hydrodynamics

Synthesis of 2S-Hydroxymethyl-3R, 4R-dihydroxypyrrolidine

在线全文

学校读者我要写书评

暂无评论

chinese Chemical Letters 1999年第8期10卷 651-652页

作者： Zhen CHEN Ren Yun WANG Li Lian ZHU Xiao Tian LIANG (institute of Materia Medica. Peking Union Medical College) (The chinese academy of Medical sciences, Bejing 100050) chinese Acad Med Sci Inst Mat Med Peking Union Med Coll Beijing 100050 Peoples R China

The sythesis of 2S-hydroxymethyl-3R, 4R-dihydroxypyrrolidine from D-arabinose was described in this paper.

关键词： polydroxylated pyrrolidine 2S-hydroxymethyl-3R 4R-dihydroxypyrrolidine D-arabinose

Secular variations in δ34S and δ13C values of late Neoproterozoic carbonates from southern china

在线全文

学校读者我要写书评

暂无评论

Secular variations in δ34S and δ13C values of late Neoprot...

激光烧蚀Al热原子与CF_4反应中C_2的形成及其发光光谱研究

中国科学院地质与地球物理研究所2003学术年会

作者： X.CHU~(1,2),Q.ZHANG~1,T.ZHANG~1 AND L.FENG~1 1 institute of geology & geophysics,chinese academy of sciences,beijing 100029,china 2 Max-Planck Institut f.Chemie,Postfach 3060,Mainz, 55020,Germany

Carbonate rocks of Sinian age,deposited on the Yangtze Platform,southern china,wee studied in order to document secular variations in δS and δC of late Neoproterozoic *** Sinian,equivalent to NeoproterozoicⅢ,has been confined between ca.600 and 544 Ma according to the ages of Barfod et al.(2002) and Jenkins et al.(2002). Stratigraphic units include in ascending order the Doushantuo and Dengying formations.

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

物理学报 2003年第5期52卷 1297-1301页

作者：张树东李海洋中国科学院安徽光学精密机械研究所环境光谱学实验室

脉冲激光烧蚀金属平面铝靶产生的热原子与气相CF4碰撞反应中 ,在 40 0— 60 0nm之间观测到激发态C2 分子的发光光谱 ,它们可归属为Swan带的d3Πg-a3Πu 跃迁中Δv=2 ,1,0 ,- 1,- 2五个振动序列 (v’≤ 6) .光谱强度分析表明 ,C2 激发态... 详细信息

脉冲激光烧蚀金属平面铝靶产生的热原子与气相CF4碰撞反应中 ,在 40 0— 60 0nm之间观测到激发态C2 分子的发光光谱 ,它们可归属为Swan带的d3Πg-a3Πu 跃迁中Δv=2 ,1,0 ,- 1,- 2五个振动序列 (v’≤ 6) .光谱强度分析表明 ,C2 激发态的振动温度达 63 40K左右 .与激光烧蚀Al+O2 反应生成AlO的实验结果以及激光烧蚀Cu +CF4的光谱比较 ,对比Al( 2 P1 2 - 2 S1 2 ,3 94 4nm)和C2 的d—a跃迁 ( 0— 0 )带带头 ( 5 16 5nm)的飞行时间轮廓 ,认为激发态的Al( 2 S1 2 )原子通过电子态传能可能是C2

关键词：激光烧蚀 C2 CF4 Al 热原子铝靶四氟化碳碰撞反应发光光谱激发态能级跃迁等离子体谱线碳分子

Boundary Exact Controllability for Naghdi’s Models

在线全文

学校读者我要写书评

暂无评论

Boundary Exact Controllability for Naghdi’s Models

IDENTIFICATION OF A METABOLITE OF BIPHENYLDIMETHYLDICARBOXYLE IN HUMAN URINE

第十九届中国控制会议

作者： Peng-Fei Yao institute of Systems Science, academy of Mathematics and Systems Science, The chinese academy of sciences, beijing 100080, china.

＜正＞We consider some observability inequalities for the Naghdi shell from boundary. An estimate is established by the geometric multiplier method in the case that no boundary conditions are imposed. Then the estimate yields continuously observability inequalities for two kinds of boundary conditions which have a physical meaning with an explicit observability time;hence, by duality, exact controllability results. All the observability inequalities are subject to curvature conditions of the middle surface of the shell which are easy to check.

关键词： the Naghdi model the Bochner technique observability inequality

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

chinese Chemical Letters 1996年第4期7卷 345-346页

作者： Ya Wei LI Xiu Yuan ZHU(institute of Materia Medica, chinese academy of Medical sciencesbeijing 100050) institute of Materia Medica Chinese Academy of Medical Sciences Beijing 100050

The metabolism of biphenyldimethyldicarboxylate (BDD), an antihepatitis drug, was studied in human urine by deuterium labeled compound and GC-MS. It was found that the metabolite is mono-O-demethylated BDD, which conf...

关键词：

Automatic generalization of metro maps based on dynamic segmentation

在线全文

学校读者我要写书评

暂无评论

Science china(Technological sciences) 2010年第S1期53卷 158-165页

作者： DONG WeiHua 1,TIAN Yuan 2 & ZHANG Yi 2 1 institute of Geography and Remote Sensing,beijing Normal University,beijing 100875,china 2 institute of Remote Sensing and Geographic Information System,Peking University,beijing 100871,china 1. institute of Geography and Remote Sensing Beijing Normal University Beijing 100875 China 2. institute of Remote Sensing and Geographic Information System Peking University Beijing 100871 China

A metro map is usually optimized for the readability of connections and transportation networks *** order to assure good readability and meet aesthetic considerations,a set of principles for good metro map layout are *** to these principles,a new methodology based on dynamic segmentation is presented to produce the metro maps ***,routes are constructed according to the line attribute similarity and geometry *** a set of cartographic generalization methods about the shape,angle,length,and topology are presented for these *** method is validated by beijing metro plan *** the experiment results,it can be concluded that this new method is more effective than the static segmentation method to produce metro maps with better readability for route plans.

关键词： metro maps generalization dynamic segmentation visualization