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Applications of URANS on predicting unsteady turbulent separated flows

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Acta Mechanica Sinica 2009年第3期25卷 319-324页

作者： Jinglei Xu Huiyang Ma Department of Physics, graduate university of the chinese academy of {4., 10004. Beijing, china Department of Physics Graduate University of the Chinese Academy of Sciences Beijing China

Accurate prediction of unsteady separated turbulent flows remains one of the toughest tasks and a practi cal challenge for turbulence modeling. In this paper, a 2D flow past a circular cylinder at Reynolds number 3,900 is numerically investigated by using the technique of unsteady RANS （URANS）. Some typical linear and nonlinear eddy viscosity turbulence models （LEVM and NLEVM） and a quadratic explicit algebraic stress model （EASM） are evaluated. Numerical results have shown that a high-performance cubic NLEVM, such as CLS, are superior to the others in simulating turbulent separated flows with unsteady vortex shedding.

关键词： URANS Nonlinear eddy viscosity turbulencemodel ,Separated flows Circular cylinder

Compositions of heavy minerals in Northeastern china sandlands and provenance analysis

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Science china Earth sciences 2007年第11期50卷 1715-1723页

作者： XIE Jing1,2 & DING ZhongLi1 1 Institute of Geology and Geophysics, chinese academy of sciences, Beijing 100029, china {4., Beijing 10004., china Institute of Geology and Geophysics Chinese Academy of Sciences Beijing China graduate university of chinese academy of {4. Beijing China

Sand samples deposited since the Last Glacial Maximum (LGM) from the Hulun Buir, Horqin and Otin-dag sandlands were measured for their assemblages of heavy minerals and chemical compositions of detrital garnets and tourmalines. Heavy mineral assemblages of these three sandlands consist mainly of garnet, ilmenite, epidote and minor amphibole and magnetite. Garnets consist mainly of high Mg type-A ones (58% on average), and minor type-B ones. Toumalines are mainly composed of Mg-rich and minor Fe-rich ones. Compared with those of central-southern Mongolia and central Tarim, these three sandlands are derived from the Phanerozoic rocks of the Central Asian Orogenic Belt and the Archean and Paleoprotorozoic basement rocks of the North china Craton. Our results provide direct evidence that the present-day sands may be reworked from LGM ones. Differences of heavy mineral composi-tions occur between the samples of the three sandlands and Taklimakan Desert, indicating that the material of the western arid regions contributes little to the eastern sandlands.

关键词： heavy minerals,provenance,Northeastern china,garnet,tourmaline

A new class of symmetric periodic solutions of the spatial elliptic restricted three-body problem

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Science china(Physics,Mechanics & Astronomy) 2009年第9期52卷 1404-1413页

作者： XU XingBo1,2 & FU YanNing1 1 Purple Mountain Observatory, chinese academy of sciences, Nanjing 210008, china {4., Beijing 100039, china Purple Mountain Observatory Chinese Academy of Sciences Nanjing China graduate university of chinese academy of {4. Beijing China

We show that there exists a new class of symmetric periodic solutions of the spatial elliptic restricted three-body problem. In such a solution, the infinitesimal body is confined to the vicinity of a primary and moves on a nearly circular orbit. This orbit is almost perpendicular to the orbital plane of the primaries, where the line of symmetry of the orbit lies. The existence is shown by applying a corollary of Arenstorf's fixed point theorem to a periodicity equation system of the problem. And this existence doesn't require any restriction on the mass ratio of the primaries, nor on the eccentricity of their relative elliptic orbit. Potential relevance of this new class of periodic solutions to real celestial body systems and the follow-up studies in this respect are also discussed.

关键词： periodic orbits spatial restricted three-body problem symmetric orbits averaging

Isotopic feature and uranium dating of the volcanic rocks in the Okinawa Trough

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中国科学：地球科学英文版 2006年第4期49卷 375-383页

作者： HUANG Peng1,2, LI Anchun1, HU Ningjing2,3, FU Yongtao1& MA Zhibang4.1. Institute of Oceanology, chinese academy of sciences, Qingdao 266071, china 2. {4. School of the chinese academy of sciences, Beijing 100039, china 3. Institute of Soil Science, chinese academy of sciences, Nanjing 210008, china 4. Institute of Geology and Geophysics, chinese academy of sciences, Beijing 100029, china Institute of Oceanology Chinese Academy of Sciences Qingdao China graduate School of the chinese academy of sciences Beijing China Institute of Soil Science Chinese Academy of Sciences Nanjing China Institute of Geology and Geophysics Chinese Academy of Sciences Beijing China

Volcanic rocks from the northern and middle Okinawa Trough were dated by ura- nium-series dating method. Differential fractions using magnetic procedure were designed to separate samples. New report on the ages and isotopic data of rocks in the northern trough (especially black pumice) was discussed. Based on the uranium dates and Sr-Nd isotopic ratio, magmatic evolution process of the Okinawa Trough was noted. Firstly, there have been wide silicic volcanic activities in the Okinawa Trough from late Pleistocene to present, and the volcanic rocks can be divided into three subgroups. Secondly, magma generally came from PREMA source area under the Okinawa Trough. Magmatic evolution in the northern trough was similar to the middle, but different to the south. Finally, volcanic activities indicated that opening of the southern Okinawa Trough did not happen due to the collision between Luson Arc and Eurasian Plate until the early Pleistocene.

关键词： Okinawa Trough, black pumice, uranium-series dating, Sr-Nd isotopic ratio, magmatic evolution.

Simulations for terrestrial planets formation

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Science china(Physics,Mechanics & Astronomy) 2009年第5期52卷 794-803页

作者： ZHANG Niu 1,2 &JI JiangHui 2,3 1graduate university of chinese academy of {4.,Beijing 10004.,china 2Purple Mountain Observatory,chinese academy of {4.,Nanjing 210008,china 3 National Astronomical Observatories,chinese academy of {4.,Beijing 100012,china graduate university of chinese academy of {4. Beijing China Purple Mountain Observatory Chinese Academy of Sciences Nanjing China National Astronomical Observatories Chinese Academy of Sciences Beijing China

In this paper,the formation of terrestrial planets in the late stage of planetary formation is investigated using the two-planet *** that time,the protostar formed for about 3 Ma and the gas disk *** the model,the perturbations from Jupiter and Saturn are *** of the mass of outer planet,and the initial eccentricities and inclinations of embryos and planetesimals are also *** results show that,terrestrial planets are formed in 50 Ma,and the accretion rate is about 60%-80%.In each simulation,3-4.terrestrial planets are formed inside"Jupiter"with masses of 0.15 -3.6M⊕.In the 0.5-4.AU,when the eccentricities of planetesimals are excited,planetesimals are able to accrete material from wide radial *** plenty of water material of the terrestrial planet in the Habitable Zone may be transferred from the farther places by this *** could also happen a few times between two major planets only if the outer planet has a moderate mass and the small terrestrial planet could survive at some resonances over time scale of 10 8 *** one of our simulations,commensurability of the orbital periods of planets is very ***,a librating-circulating 3:2 configuration of mean motion resonance is found.

关键词： astrophysics exoplanet planetary formation n-body simulation

Evaluation of 10 plant barcodes in Bryophyta (Mosses)

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Journal of Systematics and Evolution 2010年第1期48卷 36-46页

作者： 1,2 Yan LIU 3 Hai-Fei YAN 4.Tong CAO 3 Xue-Jun GE 1(Institute of Applied Ecology, chinese academy of sciences, Shenyang 110016, china) 2({4. university of the chinese academy of sciences, Beijing 10004., china) 3(Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South china Botanical Garden, chinese academy of sciences, Guangzhou 510650, china) 4.College of Life & Environment sciences, Shanghai Normal university, Shanghai 200234. china) (Institute of Applied Ecology Chinese Academy of Sciences Shenyang 110016 China) (graduate university of the chinese academy of {4. Beijing 100049 China) (Key Laboratory of Plant Resources Conservation and Sustainable Utilization South China Botanical Garden Chinese Academy of Sciences Guangzhou 510650 China) (College of Life & Environment sciences Shanghai Normal University Shanghai 200234 China)

DNA barcoding is a molecular tool that uses a standardized DNA region to identify *** preliminary study reported here is the first attempt to specifically focus on universality and attributes of candidate barcodes across a wide systematic range of *** tested eight previously proposed plant barcoding regions(atpF-atpH, ITS2, matK, psbK-psbI, rbcL, rpoB, rpoC1, and trnH-psbA) and two popular phylogenetic markers(rps4.and trnL-trnF of cpDNA) in 4. moss species and 9 liverwort species, representing half of the orders in moss *** ITS2, rbcL, rpoC1, rps4. trnH-psbA and trnL-trnF regions showed good universality, and therefore the efficacy of these loci as DNA barcodes was further evaluated in 36 mosses and 2 liverworts, each of which included two to three individuals per *** five loci, ***, rpoC1, rps4. trnH-psbA and trnL-trnF, were easy to amplify and sequence and showed significant inter-specific genetic variability, making them potentially useful DNA barcodes for *** best performing single loci were the rbcL and rpoC1 coding *** loci showed equivalent performance and combinations of them did not greatly increase their discrimination *** addition, phylogenies generated from each of the separate regions and multi-locus combinations by using best-fit and Kimura 2-parameter models were compared, but no significant difference was found.

关键词： Bryophyta DNA barcoding rbcL rpoC1 rps4 trnH-psbA trnL-trnF.

Infrared Galaxies in the Nearby Universe

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chinese Journal of Astronomy and Astrophysics 2008年第6期8卷 643-652页

作者： Jian-Ling Wang 1 National Astronomical Observatories,chinese academy of sciences,Beijing 100012,china 2 {4. School of chinese academy of sciences,Beijing 10004.,china National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China graduate School of chinese academy of sciences Beijing 100049 China

We used the Sloan Digital Sky Survey （SDSS） Data Release 5 （DR5） to study the morphological properties of 1137 nearby infrared （IR） galaxies, most of which are brighter than 15.9 mag in r-band. This sample was drawn from a cross-correlation of the Infra-Red Astronomical Satellite （IRAS） point source catalog redshift survey with DR5 at z ≤ 0.08. Based on this IR galaxy sample, we constructed five volume-limited sub-samples with IR luminosity ranging from 10^9.5 L⊙ to 10^12L⊙. By deriving the IR luminosity functions （LF） for different morphological types, we found that normal spiral galaxies are the dominant population below LIR ~ 8 ~ 10^10 L⊙; while the fraction of barred spiral galaxies increases with increasing IR luminosity and becomes dominant in spiral galaxies beyond LIR ≈ 5 × 10^10L⊙. As the IR luminosity decreases, the IR galaxies become more compact and have lower stellar masses. The analysis also shows that normal spiral galaxies give the dominant contribution to the total comoving IR energy density in the nearby universe, while, in contrast, the contribution from peculiar galaxies is only 39%.

关键词： galaxies evolution galaxies interactions galaxies starburst infrared galaxies galaxies luminosity function

Narrow line Seyfert 1 galaxies: where are the broad line regions?

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Science china(Physics,Mechanics & Astronomy) 2010年第12期53卷 2307-2311,2339-2343页

作者： MAO WeiMing 1,2,3 , HU Chen 2 , WANG JianMin 2 , BIAN WeiHao 4., ZHANG Shu 2 & ZHAO Gang 1 1 Key Laboratory of Optical Astronomy, National Astronomical Observatories, chinese academy of sciences, Beijing 100012, china 2 Key Laboratory for Particle Astrophysics, Institute of High Energy Physics, chinese academy of sciences, Beijing 10004., china 3 graduate university of the chinese academy of sciences, Beijing 10004., china 4.Department of Physics, Nanjing Normal university, Nanjing 210011, china Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences Beijing China Key Laboratory for Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing China graduate university of the chinese academy of {4. Beijing China Department of Physics Nanjing Normal University Nanjing China

A sample consisting of 211 narrow line Seyfert 1 galaxies (NLS1s) with high quality spectra from the Sloan Digital Sky Survey (SDSS) is selected to explore where broad line regions are in these objects. We find that the Hβ profile can be fitted well by three (narrow, intermediate and broad) Gaussian components, and the FWHM ratios of the broad to the intermediate components hold a constant of 3.0 roughly for the entire sample. If the broad components originate from the region scaled by the well-determined Hβ reverberation mapping relation, we find that the intermediate components originate from the inner edge of the torus, which is scaled by dust K-band reverberation. We find that the IC and the BC are strongly linked dynamically, but the relation of their covering factors is much more relaxed, implying that both regions are clumpy.

关键词： black hole physics galaxies: evolution quasars: general

Expression and purification of lipoprotein-associated phospholipase A2,a key enzyme involved in atherosclerosis

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Acta Pharmacologica Sinica 2006年第6期27卷 679-684页

作者： Fu-jun ZHANG~(2,4.Mao-jun CAI~3 Jing-kang SHEN~3 Yi-ping WANG~(2,5)2 State Key Laboratory of Drug Research.3 Department of Medicinal Chemistry,Shanghai Institute of Materia Medica,Shanghai Institutes for Biological sciences,chinese academy of sciences.Shanghai 201203,{4. 4.graduate School of the chinese academy of sciences.chinese academy of sciences,Shanghai 201203.{4. State Key Laboratory of Drug Research Chinese Academy of Sciences Shanghai China graduate School of the chinese academy of sciences Chinese Academy of Sciences Shanghai China Department of Medicinal Chemistry Shanghai Institute of Materia Medica Shanghai Institutes for Biological Sciences Chinese Academy of Sciences Shanghai China

Aim:To express and purify lipoprotein-associated phospholipase A2（Lp-PLA2）,and to establish a screening model for Lp-PLA2inhibitors using the expressed Lp-PLA2,Methods:We cloned the full-length cDNA of Lp-PLA2 from differentiatedTHP-I cells,and subcloned the cDNA into the baculovirus transfer *** addition,we introduced an N-terminal Kozak sequence for high-level translation initiation and a C-terminal sequence of 6 histidine residues forpurification,The fusion enzyme was expressed in Sf9 insect cells and purified byNi2+affinity *** Lp-PLA2activity was measured us-ing[3H]PAF as a substrate,and we examined the enzyme activity of recombinantLp-PLA2pretreated with the known Lp-PLA2inhibitor ***:Wesuccessfully cloned the full-length Lp-PLA2gene from differentiated THP-1 *** fusion enzyme was expressed in Sf9 insect cells at a high level and purifiedefficiently through a 2-step *** recombinant Lp-PLA2activity wasmeasured using[3H]PAF as a substrate,and proved to be enzymatically ***-PLA2inhibitor SB4.54.5 produced a good inhibition curve for inhibition ofrecombinant Lp-PLA2with an IC50of 57±1μmol/***:We expressed andpurified Lp-PLA2at a high level in insect cell-baculovirus expression *** ratio was much greater than that obtained from human plasma and we estab-lished a screening model for Lp-PLA2inhibitors using the expressed Lp-PLA2.

关键词： lipoprotein-associated phospholipase A2 atherosclerosis coronary heart diseases cloning baculovirus purification