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Applications of 14.-AMS in biomedical sciences (Bio-14.-AMS)

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Science Bulletin 2001年第7期46卷 537-543页

作者： WANG Haifang, SUN Hongfang & LIU Yuanfangdepartment of technical physics,{3.,{4.,ChinaCorrespondence should be addressed to Liu Yuangfang (e-mail: yliu@***) department of technical physics Peking University Beijing China

Accelerator mass spectrometry (AMS) is an ultrasensitive measure for tracing 14. labeled molecules in vivo or detecting the biomarker for assessment of carcino-genesis. In this review, basic principles, wide applications and new progresses of 14.-bio-AMS are presented. It has been a new advanced tool for measuring the adduction of biologcial molecules with xenobiotics, including carcinogens, drugs, agrochemicals, nicotine, etc. The successful applications have proven the effectiveness of AMS to assessing cancer risk, screening drug toxicity and studying nutrients uptake. In particular, AMS is characterized by measuring xenobiotics at very low dose levels relevant to human environmental exposure. It is sensitive and precise to an attomole (10~18 mole) or less of 14. per mg carbon. Although it has some shortcomings, undoubtedly, AMS possesses an evident merit of high sensitivity and will have widespread applications in the biomedical sciences.

关键词： accelerator mass spectrometry (AMS) DNA adduction protein adduction biomarker for carcinogenesis tracer of xenobiot-ics.

Energy transfer of n-hexane-tributyl phosphate(TBP)binary system:Using TBP as a probe for the detection of excited states of n-hexane

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化学学报(英文版) 1985年第1期3卷 14-20页

作者： YUAN Rong-Yao PAN Xian-Ming WU Ji-Lan technical physics department,{3. {4.,beijing technical physics department Peking University Beijing

In this paper TBP labeled with 3.p was used as a probe for detecting the excited speciesof *** γ irradiation of n-hexane-TBP binary system,it was found that TBP was sen-sitized by excited n-hexane molecules and a G value of 1.05 was found for the excited state of *** energy transfer mechanism was proposed,and kinetic equation of sensitization was *** calculation is in agreement with experimental results.

关键词： hexane excited ketone irradiation detecting benzene labeled sensitized transferred solute

Use of Dispersion Relations in ππ and K■ Coupled-Channel System

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Communications in Theoretical physics 2007年第10期 685-694页

作者： XIAO Zhi-Guang ZHENG Han-Qing department of physics,peking {3.,{4. 100871,China department of physics Peking University Beijing 100871 China

Systematic and careful studies are made on the properties of the IJ=00 ππ and KK coupled-channelsystem,using newly derived dispersion relations between the phase shifts and poles and *** effects of nearbybranch poin... 详细信息

关键词： ππ scattering

Regularity of Solutions of Certain Parabolic System with Nonstandard Growth Condition

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Acta Mathematica Sinica,English Series 1998年第2期14卷 145-160页

作者： You Jiangsheng (department of Mathematics and Institute of Heavy Ion physics peking university,{3. {4.,China) department of Mathematics and Institute of Heavy Ion physics peking university 100871 Beijing China

By the use of Moser iteration and Campanato space estimate,the L~∞ and C~α regularity gradient of solutions of nonlinear parabolic system (u^2)/(t)-▽(g|▽u|▽u^2)=0 with nonstandard growth conditions are obtained u... 详细信息

关键词： Nonstandard growth condition Degenerate and singular Equations Moser iteration Campanato space estimate

STUDIES ON THE ASYMMETRIC DECOMPOSITION OF D,L-LEUCINE INDUCED BY ^(60)Co γ-IRRADIATION

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Chinese Chemical Letters 1993年第4期4卷 363-365页

作者： Wen Qing WANG Jian JIANG Yu Rong ZHOU Ji Lan WU department of technical physics,{3. {4.,beijing 100871

Sublimed D-,L-,and DL-leucine under vacuum were subjected to ^(60)Co γ-irradiation with different *** enantiomeric compositions of samples were determined by chirasil- val capillary column gas chromatography,and the relative yields of radiolytic products(H_2, CO_2 and NH_3.were measured by packed column gas *** obtained data showed the peak area ratios D/L of DL-leucine after different absorbed doses of irradiation are all the same as that of samples with no irradiation,within the limit of *** are the ratios for the separately irradiated D-and *** suggests that no asymmetric decom- position was *** relative yields D/L of radiolytic products(H_2,CO_2 and NH_3.are very close to 1.00,indicating that the D-leucine cleavage rate was the same with that of the *** the view of dissipative structure,an explanation for the result was presented.

关键词： Co STUDIES ON THE ASYMMETRIC DECOMPOSITION OF D,L-LEUCINE INDUCED BY IRRADIATION

Shape phase transitions in nuclei:Effective order parameters and trajectories

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Science China(physics,Mechanics & Astronomy) 2011年第S1期54卷 88-97页

作者： ZHANG Yu1,2, HOU ZhanFeng2 & LIU YuXin2,3.1department of physics, Liaoning Normal university, Dalian 116029, China 2department of physics and the State Key Laboratory of Nuclear physics and Technology, peking university, beijing 100871, China 3.enter of Theoretical Nuclear physics, National Laboratory of Heavy Ion Accelerator, Lanzhou 720000, China 1. department of physics Liaoning Normal University Dalian 116029 China2. Department of Physics and the State Key Laboratory of Nuclear Physics and Technology Peking University Beijing 100871 China3. Center of Theoretical Nuclear Physics National Laboratory of Heavy Ion Accelerator Lanzhou 720000 China

We analyze systematically the effective order parameters in nuclear shape phase transition both in experiments and in the interacting boson model. We find that energy ratios and B(E2) ratios can distinguish the first from the second-order phase transition in theory above a certain boson number N (about 50), but in experiments, only those quantities, such as E(L1+)/E(02+) and B(E2; (L+2)1 → L1)/B(E2; 21 → 01), etc., of which the monotonous transitional behavior in the second-order phase transition is broken in the first order phase transition independent of N, are qualified as the effective order parameters. By implementing the originally proposed effective order parameters and the new ones, we find that the isotones with neutron number Nn = 62 are a trajectory of the second order phase transition. In addition, we predict that the transitional behavior of isomer shifts of Xe, Ba isotopes and Nn = 62 isotones is approximately monotonous due to the finiteness of nuclear system.

关键词： nuclear shape phase transition interacting boson model effective order parameter finite particle number effect transition trajectory

Studies on Phosphate Effect of Cytosine and Its Novel Photoproduct

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Chemical Research in Chinese Universities 1998年第4期14卷 17-21页

作者： LIN Feng(department of Chemistry, Hangzhou university, Hangzhou, 3.0028) WANG Wen qing and WU Ji lan (department of {3. {4., peking university, beijing, 100871) Hangzhou Univ Dept Chem Hangzhou 310028 Peoples R China peking Univ Dept Tech Phys Beijing 100871 Peoples R China

Under the irradiation of a middle pressure mercury lamp(MPML), we found that the photo lyses of nucleobases, nucleosides and nucleotides were strongly enhanced by phosphates (termed phosphate effect). In order to explain this phenomenon, the photolytic systems of cytosine in phosphate solutions were selected and studied. Experimental results indicated that the UV irradiation (190-220 nm) in the emission spectra of MPML is responsible for the phosphate effect. Phosphates absorbing the UV (190-220 nm) energy are converted to phosphate radical anions, which react with cytosine, leading to a novel photoproduct with phosphate group (C 4. 6N 3. 5P). It has been isolated, purified and characterized by means of elementary analysis, UV, IR, EI MS, 1H NMR, 13. C NMR and 3. P NMR. The phosphate effect and its formation mechanism have been discussed.

关键词： Phosphate effect Photolysis of cytosine Photoproduct 6 phosphocytosine

Frontal genesis of moisture atmosphere during the early 2008 persistent freezing-rain event in southern China

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Science China Earth Sciences 2010年第3期53卷 454-464页

作者： QIAN WeiHong1 & FU JiaoLan1,2 1 department of Atmospheric Sciences, School of physics, peking university,{3., China 2 National Meteorological Center of CMA, {4., 100081, China 1. department of Atmospheric Sciences School of Physics Peking University Beijing 100871 China2. National Meteorological Center of CMA Beijing 100081 China

From January 10 to February 2, 2008, a severe and persistent freezing-rain event occurred in southern and southwestern China. Here we use an observational analysis to compare the persistent freezing-rain event in the early 2008 with the winter precipita- tion in the late 2007 over south of the Yangtze River (Jiangnan). The persistent freezing-rain event was directly linked to the activity of quasi-stationary front. The gradient of equivalent temperature (ET) can well indicate the frontal genesis of moist atmosphere (moisture front) and its activity as well as its relationship with precipitation belt. The precipitation types (snow and freezing rains) are related to the vertical structure of moisture front. The inversion profile of ET vertical distribution is a typical synoptic condition that caused the freezing-rain event. The horizontal gradient of ET with a criterion of 10℃ / 100 km, which reflects the accumulation and release of atmospheric energy, can be applied to predict the precipitation 5-10 days in advance.

关键词： freezing-rain event frontal genesis extended-range weather forecast winter Jiangnan

Synergic extraction of uranyl perchlorate by the ternary system of AAC species composed of HTTA-HPMBP-（C6H5）4.sC1

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Chinese Journal of Chemistry 1987年第3期5卷 226-230页

作者： WANG Wen-Qing* YI Min DING Yu-Wen, department of technical physics,{3., {4. department of technical physics Peking University Beijing

A new ternary synergic extract system composed of two chelate extract ligands and oneion association ligand, namely AAC species, was studied. Uranyl perchlorate was extracted by thebinary system of thenoyltrifluoroacetone （HTTA） and of 1-phenyl-3.methyl-4.benzoylpyrazol.-5-one（HPMBP） with tetraphenylarsonium chloride [（C6H-5）4.sCl] in chloroform solution. It was foundthat synergic effect occurred during the extraction of uranyl perchlorate with the chloroform solutionof a mixture of HTTA, HPMBP and （C6H5）4.sCl and the principle of minimum density of electriccharge plays an important role. The formation of a ternary complex （C6H5）4.sUO2（ClO4.(TTA)-（PMBP） was confirmed by the slope method, and the perchlorate was determined by the methyleneblue spectrophotometric method. The equilibrium constant was calculated to be log/βA1A2O= 5.52.

关键词： As Synergic extraction of uranyl perchlorate by the ternary system of AAC species composed of HTTA-HPMBP AAC