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2.0} photometry and age estimation of the globular clusters in the outer halo of M31

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Research in Astronomy and Astrophysics 2012年第2期12卷 115-126页

作者： Jun Ma 1,2. National Astronomical Observatories,chinese academy of Sciences,{2. 100012.china 2.Key Laboratory of Optical Astronomy,National Astronomical Observatories,chinese academy of Sciences,{2. 100012.china National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China

We present the first photometric results in J, H and Ks from 2.0} （Two Micron All Sky Survey） imaging of 10 classical globular clusters （GCs） in the far outer regions of M31. Combined with the V and I photometric data from previous literature, we constructed a color-color diagram between J - Ks and V - Ⅰ. By comparing the integrated photometric measurements with evolutionary models, we estimate the ages of these clusters. The results showed that all of these clusters are older than 3 × 109 yr, and among them four are older than 10 Gyr and the other six have intermediate ages between 3 - 8 Gyr. The masses for these outer-halo GCs are from 7.0 × 104 M to 1.02.× 10^6 M. We argued that GC2.and GC3, whose ages, metallicities and distance moduli are almost the same, were accreted from the same satellite galaxy, if they did not form in situ. The statistical results show that the ages and metallicities of these 10 M31 outer-halo GCs do not vary with projected radial position, and a relationship between age and metallicity does not exist.

关键词： galaxies: halos - galaxies: individual (M31) - star clusters: general

Disposable Electrochemical Biosensor for Amperometric Measurement of β-hydroxybutyrate and Total Cholesterol

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稀有金属材料与工程 2006年第S3期 305-308页

作者： Huaqing Li~(1,2. Li Wang~1 Nenggao Rao~1 Dafu Cui~1 Xinxia Cai~(1,2. (1.State Key Laboratory of Transducer Technology,institute of Electronics,chinese {2. of Sciences,beijing 100080,china) (2.Graduate School of chinese {2. of Science,beijing 100080,china)

A new type of disposable thin-film amperometric biosensor has been developed for measurement ofβ-hydroxybutyrate and total cholesterol in *** biosensor consists of two plain gold electrodes mounted on a Polyethylene terephthalate （PET） *** reagent solution contains bienzymes （cholesterol oxidase and cholesterol esterase for total cholesterol,β-hydroxybutyrate dehydrogenase and diaphorase forβ-hydroxybutyrate respectively） with mediator （ferricyanide） were absorption at the surface of electrodes coated by electrodepositing platinum *** presence of the mediator lowers the applied potential and eliminates the interference from other oxidizable species enhancing the sensitivity and selectivity of the biosensor without modifying the dynamic parameters of the *** enzymes stably retains in the matrices of platinum black film improving the performance of the mediated *** linearity is observed in the concentration range from 1.0×10-4to 1.0×10-2.M and 1.0×10-4mM to 4.99×10-3mM with sensitivity of 1.958μA/mM and 2.447μA/mM *** optimized biosensor exhibits excellent reproducibility and stability retaining more than 90% of its original activity over a period of one *** simple operation of the biosensor mass-produced at low cost is expected to find clinical application and homecare.

关键词： amperometric β-Hydroxybutyrate total cholesterol ferricyanide platinum black

Progress and review of the studies on the end-Triassic mass extinction event

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Science china Earth Sciences 2005年第12期48卷 2049-2060页

作者： DENG Shenghui1,2. LU Yuanzheng1,2.3 & XU Daoyi4 1. Research institute of Petroleum Exploration and Development, beijing 100083,{2. 2. Key Laboratory of Oil and Gas Reservoir of Petrochina, beijing 100083,{2. 3.{2. University of Geosciences, beijing 100083,{2. 4. institute of Geology,{2. Earthquake Administration, beijing 10002.,{2. 1. Research institute of Petroleum Exploration and Development 100083 Beijing China 2. Key Laboratory of Oil and Gas Reservoir of Petrochina 100083 Beijing China 3. china University of Geosciences 100083 Beijing China 4. institute of Geology China Earthquake Administration 100029 Beijing China

The mass extinction at the end-Triassic is one of the five biggest in the Phanerozoic. However,it is the least well understood among these five events, and only till last decade it became a great academic interesting subject to geologists. The evidences for this event come obviously from bivalves, brachiopods, ammonites, corals, radiolaria, ostracods and foraminifera of marine habitats, and plants and tetrapods of terrestrial realm. By contrast, for some of other groups, such as marine gastropods and marine vertebrates, no mass extinction has been recog-nized yet. The extinction event is strongly marked at specific level but shown a complicated situa-tion at generic and family levels. Dramatic changing of the environment, such as the temperature raise due to the greenhouse effect, the marine anoxic habitats caused by a sudden transgression after the regression at the end of Triassic, has been claimed to be the main cause of the extinction. Many hypotheses have been suggested to demonstrate the mechanisms of the environment changing, among which two popular ones are the bolide impact and volcanic eruption. The Triassic-Jurassic (Tr-J) boundary mass extinction event is still poorly understood because no enough data have been obtained from the Tr-J boundary successional sections of both marine and terrestrial sediments, and most of these studies were regionally restricted. The basic aspects of the event and its associated environmental conditions remain poorly characterized and the causal mechanism or mechanisms are equivocal. Some authors even doubt its occurrence. china has many successionally developed terrestrial and marine Tr-J sections. Detailed studies of these sections may be important and significant for well understanding of the event.

关键词： progress, review, end-Triassic, mass extinction, mechanism, Tr-J boundary.

Transport　of　atmospheric　trace　elements　and　dust－soil　to　the　Western　Pacific　Ocean

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Journal of Environmental Sciences 1996年第4期8卷 460-465页

作者： Yang Shaojin Chen Bingru Yang Yinan(institute of High Energy Physics,chinese {2. of Sciences,beijing 100080,china) institute of High Energy Physics Chinese Academy of Sciences Beijing 100080 China

Atmospheric aerosol and rainwater samples collected in the different Western Pacific area were analyzed by instrumental neutron activation and proton induced X-ray emission to (1) determine the atmospheric concentrations of trace elements over the Western Pacific and (2. to esti mate the atmospheric deposition of trace elements and dust-soil material to this region. High abundance of pollutant and crustal elements relative to oceanic sources was observed. Some characteristics of marine atmosphere relating to long-range transport of crustal and anthropogenic elements from continent to the remote ocean are discussed. The total dust-soil particle mass is estimated to be 0. 066-1.2.μg/m￣3 over the Western Pacific Ocean areas. Atmospheric inputs of dust-soil particles control the marine particle concentrations of crustal elements. In addition, the characteristics of marine rain water are discussed.

关键词： dust-soil marine rain-water atmospheric trace elements.

Characteristics of air particulate matter and their sources in urban and rural area of beijing, china

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Journal of Environmental Sciences 2000年第4期12卷 402-409页

作者： YANG Shao jin, DONG Jin quan, CHENG Bing ru (institute of High Energy Physics, chinese {2. of Sciences, beijing 100080, china) institute of High Energy Physics Chinese Academy of Sciences Beijing 100080 China

During October 1993 and March 1996, the samples of fine and coarse air particulate matter have been collected at representative urban and rural site of beijing with the Gent Stacked Filter Unit Sampler. Instrumental neutron activation analysis (INAA) and proton induced X ray emission (PIXE) method were used to determine the elemental composition of the particulate matter. Average elemental concentrations and enrichment factors were calculated for the fine and coarse size fractions. Based on the particulate matter data obtained at urban and rural site together with the chemical constituents of the aerosol from the different sources are discussed. The results show that the relative particulate mass and elemental concentrations of crustal and pollutant elements in the air particulate matter collected over the urban are higher than rural and winter heating period are higher than in ordinary season. beijing atmosphere is polluted by aerosols from regional and faraway sources. It was noticed that the toxic or harmful elements such as As, Sb, Pb, Cu, Ni, S and Zn were mainly enriched in fine particles with diameter less than 2.μm. A receptor model was used to assess the relative contribution of major air pollution sources at receptor sites in beijing. Trace elements were used as the markers for the above assessment. Factor analysis method was used to identify possible emission sources of air particles. The major sources of dust soil, coal burning, motor vehicle emission, industry emission and refuse incineration were identified.

关键词： atmospheric particulate matter urban rural source aerosol

Liquid propellant analogy technique in dynamic modeling of launch vehicle

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Science china(Technological Sciences) 2010年第8期53卷 2102-2110页

作者： PAN ZhongWen 1,2.,XING YuFeng 1 ,ZHU LiWen 2.,DONG Kai 2.&SUN Mu 2.1Solid Mechanics Research Center,beijing University of Aeronautics and Astronautics,beijing 100191,china 2.beijing Astronautics Systems Engineering institute,beijing 100076,china 1. Solid Mechanics Research Center Beijing University of Aeronautics and Astronautics Beijing 100191 China2. Beijing Astronautics Systems Engineering Institute Beijing 100076 China

The coupling effects among lateral mode,longitudinal mode and torsional mode of a launch vehicle cannot be taken into account in traditional dynamic analysis using lateral beam model and longitudinal spring-mass model *** deal with the problem,propellant analogy methods based on beam model are proposed and coupled mass-matrix of liquid propellant is constructed through additional mass in the present *** an integrated model of launch vehicle for free vibration analysis is established,by which research on the interactions between longitudinal and lateral modes,longitudinal and torsional modes of the launch vehicle can be *** examples for tandem tanks validate the present method and its necessity.

关键词： dynamic characteristics coupled mass integrative modeling propellant analogy

Determination of 2. β_2.agonists and 5 β-blockers in animal muscle by high performance liquid chromatography-linear ion trap mass spectrometry

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Science china chemistry 2010年第4期53卷 832-840页

作者： WU YongNing1,2. MIAO Hong1, FAN Sai1,2.& ZHAO YunFeng1,2.1 institute of Nutrition and Food Safety, chinese Centre for Disease Control and Prevention, {2. 10002., china 2.College of Veterinary Medicine, china Agricultural University, {2. 100193, china 1. institute of Nutrition and Food Safety Chinese Centre for Disease Control and Prevention Beijing 100021 China2. College of Veterinary Medicine China Agricultural University Beijing 100193 China

A high performance liquid chromatography-linear ion trap mass spectrometry method using isotope dilution technique has been developed for the simultaneous determination of 2. β2.agonists and 5 β-blockers in animal muscle tissues. Pork and chicken muscle samples were acid hydrolyzed and extracted with 5% trichloracetic acid in water, and then cleaned up using MCX solid phase extraction (SPE) cartridge. Methanol and 0.1% formic acid were used as mobile phases for gradient elution. A Waters AtlantisT3 column was used for separation. ESI positive ion scan mode was used with selective reaction monitoring. 9 β2.Agonists labeled by the deuterium isotope were used as internal standards for quantification. The linear ranges of 2. β2.agonists and 5 β-blockers were 5-2.0 μg/L, the coefficient of correlation was not less than 0.995, and the limit of detection for each compound in the muscle tissue was below 0.2.μg/kg. The recoveries of each compound in the spiked samples at three levels 5, 10, 2. μg/kg were in the range of 47.3%-12..7%, and the relative standard deviations were in the range of 3.2.-2..7%. The developed method is sensitive and specific for the determination of β2.agonists and β-blockers in pork and chicken muscle samples.

关键词： β2.agonists β-blockers muscle determination HPLC-ITMS

Prediction of Dynamic Wellbore Pressure in Gasified Fluid Drilling

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Petroleum Science 2007年第4期4卷 66-73页

作者： Wang Zhiming1,Ping Liqiu2.and Zou Ke2.(1. School of Petroleum Engineering,Petroleum University of china,beijing 102.49,{2.) (2. institute of Drilling Engineering Technology,CNPC,beijing 100097,{2.) Petr Univ china Sch Petr Engn Beijing 102249 Peoples R China CNPC Inst Drilling Engn Technol Beijing 100097 Peoples R China

The basis of designing gasified drilling is to understand the behavior of gas/liquid two-phase flow in the wellbore. The equations of mass and momentum conservation and equation of fluid flow in porous media were used to establish a dynamic model to predict wellbore pressure according to the study results of Ansari and Beggs-Brill on gas-liquid two-phase flow. The dynamic model was solved by the finite difference approach combined with the mechanistic steady state model. The mechanistic dynamic model was numerically implemented into a FORTRAN 90 computer program and could simulate the coupled flow of fluid in wellbore and reservoir. The dynamic model revealed the effects of wellhead back pressure and injection rate of gas/liquid on bottomhole pressure. The model was validated against full-scale experimental data,and its 5.0% of average relative error could satisfy the accuracy requirements in engineering design.

关键词： Gasified fluid drilling dynamic model pressure prediction model validation

β-delayed proton decays near the proton drip line

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Science china(Physics,Mechanics & Astronomy) 2005年第3期48卷 257-267页

作者： XU Shuwei 1 , LI Zhankui 1 , XIE Yuanxiang 1 , HUANG Wenxue 1 , SHU Nengchuan 2., CHEN Yongshou 2., XU Furong 3 , WANG Kun 4 , PAN Qiangyan 1 , WANG Xudong 1 , YU Yong 1 & XING Yebing 1 1. institute of Modern Physics, chinese {2. of Sciences, Lanzhou 730000, china 2. Nuclear Physics Department, china institute of Atomic Energy, beijing 102.13, china 3. Department of Technical Physics, Peking University, beijing 100871, china 4. Shanghai institute for Nuclear Research, Shanghai 2.1800, china 1. institute of Modern Physics Chinese Academy of Sciences 730000 Lanzhou China 2. Nuclear Physics Department China Institute of Atomic Energy 102413 Beijing China 3. Department of Technical Physics Peking University 100871 Beijing China 4. Shanghai institute for Nuclear Research 201800 Shanghai China

We briefly reviewed the experimental study on a-delayed proton decays near the proton drip line published by our group during the period of 1996―2.04, namely the first observation of the a-delayed proton decays of 9 new nuclides in the rare-earth region and the new measurements of a-delayed proton decays of 5 nuclides in the mass ～90 region near the N = Z line with the aid of the “p-?” coincidence in combination with a He-jet tape transport system. In the meantime some important experimental technique details were supplemented. The experimental results, including the half -lives, spins, parities, deformations and production reaction cross sections for the 14 nuclei were summarized and compared with the current nuclear-model predictions, and then the following points were represented. (1) The experimental half-lives for 85Mo and 92.h as well as the predicted “waiting point” nuclei 89Ru and 93Pd are 5―10 times longer than the theoretical predictions given by M?ller et al. using a macroscopic-microscopic model. It considerably influences the predictions of the abundances of the nuclides produced in the rp-process. (2. The current-model predictions are not consistent with the experimental assignments of the spins and parities for the proton drip-line nuclei 142.o and 12.Pm. However, the nuclear potential energy surface (PES) calculated by using a Woods- Saxon-Strutinsky method reproduced the experimental results. (3) The Alice code overestimated the production reaction cross sections of the studied 9 rare-earth nuclei by one order of magnitude or two, while HIVAP code overestimated them by one order of magnitude approximately.

关键词： proton drip line, β-delayed proton decay, He-jet tape transport system, "p-γ" coincidence, spin, parity, deformation, production reaction cross section.