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Relative importance of water, energy, and heterogeneity in determining regional pteridophyte and seed plant richness in china

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Journal of Systematics and Evolution 2011年第2期49卷 95-107页

作者： 1,2.3 Sheng-Bin CHEN § 1 Gao-Ming JIANG 3 Zhi-Yun OUYANG 3 Wei-Hua XU 3 Yi XIAO 1 (State key laboratory of Vegetation and Environmental Change, {2. of Botany, chinese academy of sciences, beijing 100093, china) 2.(Graduate University of the chinese academy of sciences, beijing 100049, china) 3 (State key laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental sciences, chinese academy of sciences, beijing 100085, china) (State key laboratory of Vegetation and Environmental Change Institute of Botany Chinese Academy of Sciences Beijing 100093 China) (Graduate University of the chinese academy of sciences Beijing 100049 China) (State key laboratory of Urban and Regional Ecology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China)

Environmental variables, such as ambient energy, water availability, and environmental heterogeneity have been frequently proposed to account for species diversity gradients. How taxon-specific functional traits define large-scale richness gradients is a fundamental issue in understanding spatial patterns of species diversity, but has not been well documented. Using a large dataset on the regional flora from china, we examine the contrast spatial patterns and environmental determinants between pteridophytes and seed plants which differ in dispersal capacity and environmental requirements. Pteridophyte richness shows more pronounced spatial variation and stronger environmental associations than seed plant richness. Water availability generally accounts for more spatial variance in species richness of pteridophytes and seed plants than energy and heterogeneity do, especially for pteridophytes which have high dependence on moist and shady environments. Thus, pteridophyte richness is disproportionally affected by water-related variables; this in turn results in a higher proportion of pteridophytes in regional vascular plant floras (pteridophyte proportion) in wet regions. Most of the variance in seed plant richness, pteridophyte richness, and pteridophyte proportion explained by energy is included in variation that water and heterogeneity account for, indicating the redundancy of energy in the study extent. However, heterogeneity is more important for determining seed plant distributions. Pteridophyte and seed plant richness is strongly correlated, even after the environmental effects have been removed, implying functional linkages between them. Our study highlights the importance of incorporating biological traits of different taxonomic groups into the studies of macroecology and global change biology.

关键词： habitat heterogeneity pteridophytes seed plants species richness water-energy hypothesis.

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Light collection of the POLAR detector

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Science china(Physics,Mechanics & astronomy) 2010年第S1期53卷 43-46页

作者： DONG YongWei,LI YanGuo,WU BoBing,ZHANG YongJie & ZHANG ShuangNan key laboratory of {2. astrophysics,institute of high energy Physics,chinese academy of sciences,beijing 100049,{12. key laboratory of {2. astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing China

POLAR is a compact polarimeter dedicated to measuring the polarization of GRBs between 50-350 *** light collection of 2.0 mm×6 mm×6 mm plastic bars has been simulated and optimized in order to get uniform response to X-rays at different points along one single *** to the Monte Carlo results,the amplitude uniformity strongly depends on the level of polishing of the scintillator surface and the covering.A uniformity of 89% is achieved with a prototype constructed by a non position-sensitive PMT and an array of 4×4 bars.

关键词： plastic scintillator light collection gamma-ray burst polarimeter

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Study on the atmospheric photochemical reaction of CF_3 radicals using ultraviolet photoelectron and photoionization mass spectrometer

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Science china Chemistry 2008年第4期51卷 316-321页

作者： YAO Li1,2. DU Lin1,2. YIN Shi1,2.& GE MaoFa1 1 beijing National laboratory for Molecular {2. (BNLMS), State key laboratory for Structural Chemistry of Unstable and Stable Species, institute of Chemistry, chinese academy of sciences, beijing 100080, china 2.Graduate University of chinese academy of sciences, beijing 100080, china beijing National laboratory for Molecular {2. (BNLMS) State Key Laboratory for Structural Chemistry of Unstable and Stable Species Institute of Chemistry Chinese Academy of Sciences Beijing China Graduate University of chinese academy of sciences Beijing China

A study of the atmospheric photochemical reaction of CF3 radical with CO and O2.was performed by using a homemade ultraviolet photoelectron spectrometer-photoionization mass spectrometer (PES- PIMS). The electronic structures and mechanism of ionization and dissociation of CF3OC(O)OOC(O)- OCF3 were investigated. It was indicated that the two bands on the photoelectron spectrum of CF3OC(O)OOC(O)OCF3 are the result of ionization of an electron from a lone pair of oxygen and a fluo- rine lone pair of CF3 group. The outermost electrons reside in the oxygen lone pair. The experimental and theoretical first vertical ionization energy is 13.2. and 13.178 eV, respectively, with the PES and OVGF method. They are in good agreement. The photo ionization and dissociation processes were discussed with the help of theoretical calculations and PES-PIMS experiment. After ionization, the parent ions prefer the dissociation of the C-O bond and giving the fragments CF3OCO+ and CF3+. It demonstrated that the ultraviolet photoelectron and photoionization mass spectrometer could be ap- plied widely in the study of atmospheric photochemical reaction.

关键词： photochemical reaction CF3 radical ultraviolet photoelectron and photoionization mass spectroscopy transient species

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A puzzle of the radio-quiet quasar PG 1407+2.5:Are optical and X-ray emissions produced from a relativistic jet?

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Science china(Physics,Mechanics & astronomy) 2011年第1期54卷 183-186页

作者： CHEN Liang 1,2.3 & BAI JinMing 1,2.1 National astronomical Observatories/Yunnan Observatory,chinese {2. of sciences,Kunming 650011,china 2.key laboratory for the Structure and Evolution of Celestial Objects,chinese {2. of sciences,Kunming 650011,china 3 Graduate University of chinese academy of sciences,{12. 100049,china National astronomical Observatories/Yunnan Observatory Chinese Academy of Sciences Kunming China key laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming China Graduate University of chinese academy of sciences Beijing China

PG 1407+2.5 is a radio quiet quasar that has a relativistic *** this report,we show some peculiar properties of its optical and X-ray emissions,which indicate possible non-thermal origins produced from the *** use a simple synchrotron + synchrotron self Compton (SSC) model to fit the emissions with different ratios of energy densities between the magnetic field and electrons (η≡U B/U e),which predicts a different γ-ray *** First LAT AGN Catalog (1LAC) did not include PG 1407+2.5,which indicates an upper limit of γ-ray *** upper limit constrains the ratio to be unreasonably large (η≥10 4-5).This inversely indicates that the optical and X-ray emissions may not be produced from the beaming *** discuss the physical implications of these results.

关键词： active galactic nuclei jet non-thermal emission PG 1407+2.5

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A study on the sharp knee and fine structures of cosmic ray spectra

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Science china(Physics,Mechanics & astronomy) 2010年第5期53卷 842-847页

作者： WANG Bo1,YUAN Qiang1,FAN Chao1,2.ZHANG JianLi1,HU HongBo1 & BI XiaoJun1 1 key laboratory of {2. astrophysics,institute of high energy Physics,chinese academy of sciences,beijing 100049,{12. 2.Department of Physics,Shandong University,Jinan 2.0100,{12. key laboratory of {2. astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing China Department of Physics Shandong University Jinan China

The paper investigates the overall and detailed features of cosmic ray(CR) spectra in the knee region using the scenario of nuclei-photon interactions around the acceleration *** supernova remnants can be the physical realities of such kind of CR acceleration *** results show that the model can well explain the following problems simultaneously with one set of source parameters:the knee of CR spectra and the sharpness of the knee,the detailed irregular structures of CR spectra,the so-called"component B"of Galactic CRs,and the electron/positron excesses reported by recent *** coherent explanation serves as evidence that at least a portion of CRs might be accelerated at the sources similar to young supernova remnants,and one set of source parameters indicates that this portion mainly comes from standard sources or from a single source.

关键词： cosmic ray knee fine structures e+e-excesses "component B" single source

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SVOM gamma ray monitor

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Science china(Physics,Mechanics & astronomy) 2010年第S1期53卷 40-42页

作者： DONG YongWei,WU BoBing,LI YanGuo,ZHANG YongJie & ZHANG ShuangNan key laboratory of {2. astrophysics,institute of high energy Physics,chinese academy of sciences,beijing 100049,{12. key laboratory of {2. astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing China

The space-based multi-band astronomical Variable Object Monitor(SVOM) mission is dedicated to the detection,localization and broad-band study of gamma-ray bursts(GRBs) and other high-{2. transient *** gamma ray monitor(GRM) onboard is designed to observe GRBs up to 5 *** this instrument,one of the key GRB parameters,Epeak,can be easily measured in the hard X-ray *** can achieve a detection rate of 100 GRBs per year which ensures the scientific output of SVOM.

关键词： gamma-ray burst Epeak triple phoswich

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Testing local realism in P → VV decays

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Science china(Physics,Mechanics & astronomy) 2010年第5期53卷 870-875页

作者： LI JunLi1 & QIAO CongFeng1,2.1Department of Physics,Graduate University of chinese academy of sciences,beijing {2.,china 2.heoretical Physics Center for Science Facilities(TPCSF),chinese academy of sciences,beijing {2.,china Department of Physics Graduate University of Chinese Academy of Sciences Beijing China Theoretical Physics Center for Science Facilities (TPCSF) Chinese Academy of Sciences Beijing China

It was found that the vector meson pair from the pseudoscalar decays can form an entangled *** this work we give out detailed explanations on the polarization correlation of the two entangled vector *** is demonstrated that an experimental test of the Clauser-Horne inequality can be carried out through measuring the azimuthal distribution of four pseudoscalars in the cascade decay ηc→ VV →(PP)(PP),and the measurement of this process is feasible with the current running experiments in tau-charm ***,a brief discussion on the polarization correlation of the two vector mesons from B → VV decays is also presented.

关键词： nonlocality test high energy experiment meson decays

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Effects of cosmological constant on motion of UHECR particles

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Science china(Physics,Mechanics & astronomy) 2005年第1期48卷 44-56页

作者： CHEN Shaoxia & CHANG Zhe institute of high {2. Physics, chinese academy of sciences, beijing 100039, china Graduate School of chinese academy of sciences, beijing 100039, china institute of high {2. Physics Chinese Academy of Sciences Beijing 100039 China Graduate School Chinese Academy of Sciences Beijing 100039 China

Recent astronomical observations manifest that about two-thirds of the whole energy in the Universe is contributed by a small positive cosmological constant A (> 0). Then, an asymptotically de Sitter spacetime is premised naturally. However, physics in the de Sitter spacetime is very different from that in the Minkowski spacetime. As the first step, a covariant formalism of the kinematics in the de Sitter spacetime is presented here. By solving exactly the equations of motion for a field, we obtain the dispersion relation of a free {2.. It is noticed that the dispersion relation is dependent on the degree of freedom of angular momentum of the {2.. We show the threshold anomaly of the ultra high energy cosmic ray disappears naturally in the framework of the de Sitter kinematics.

关键词： ultrahigh energy cosmic ray, cosmological constant, curved spacetime.

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Effects of diatoms on reproduction and growth of marine copepods

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Progress in Natural Science:Materials International 2004年第10期14卷 1-7页

作者： ZHANG Guangtao 1,2. and SUN Song 1 (1.key laboratory of Marine Ecology&Environment {2.,institute of Oceanology,chinese academy of {2.,Qingdao2.6071,china 2.Graduate School,chinese academy of {2.,beijing100039,china) Lab. of Marine Ecology Inst. of Oceanology Chinese Acad. of Sci. Qingdao 266071 China Graduate Sch. Chinese Acad. of Sci. Beijing 100039 China

Two hot spots in marine ecology,deleterious effects of diatoms and feeding selectivity of copepods,as well as new progress on these two issues achieved in the recent ten years,are *** two issues are considered correlated *** and their metabolites can induce deleterious effects on growth,reproduction and development of copepods,including increase of mortality and decrease of egg production,hatching and growth *** negative effects,resulting from either chemical toxin or nutritional defi-ciency,can be conquered in natural environments by diverse *** is therefore concluded that deleterious effects of diatoms observed in laboratory or during blooming period are only a special case that accommodation of feeding strategy of copepods is *** under-stand their feeding strategy in natural environments is a prerequisite to explaining the mechanisms of deleterious effects caused by diatoms,and makes it possible to re-evaluate the energy flow in marine ecosystems.

关键词： diatoms copepod feeding strategy reproduction deleterious effects

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The rms-flux relation of Cyg X-2.in the horizontal branch

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中国科学：物理学、力学、天文学英文版 2010年第S1期53卷 86-90页

作者： LI ZhiBing,LEI YaJuan,QU JinLu,ZHANG Shu & SONG LiMing key laboratory for {2. astrophysics,institute of high energy Physics,chinese academy of sciences(CAS),beijing 100049,{12. key laboratory for {2. astrophysics Institute of High Energy Physics Chinese Academy of Sciences (CAS) Beijing China

We have investigated the relation between the root mean square(rms) variability and the X-ray flux(rms-flux relation) of the Z source Cyg X-2.and as well the energy dependence based on the Rossi X-ray Timing Explorer(RXTE) *** currently focus on the horizontal branch(HB),due to the negative correlation in flux of the soft and the hard *** rms-flux correlation has energy dependence as follows:positive at hard X-rays(above 10 keV) but negative at soft X-rays(below 10 keV).This provides a feature different from the previous one,and may be suggestive of different origins of X-rays below and above 10 ***,the overall spectrum can be well fitted with a model consisting of a blackbody and Comptonization components,but the fitting results do not reveal any features around 10 keV that could account for such a change in the rms-flux relation.

关键词： accretion accretion disk—binaries:close-stars:individual(Cygnus X-2.-X-rays:binaries

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