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Speciation of the elements and compositions on the surfaces of dust storm particles:The evidence for the coupling of iron with sulfur in aerosol during the long-range transport

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chinese science Bulletin 2005年第8期50卷 738-744页

作者： ZHANG Xingying1,2, ZHUANG Guoshun1,2,3. CHEN Jianmin2 & XUE Huaxin2 1. center for Atmospheric Environment Study, Department of Chemistry, beijing Normal University, beijing 100875, China 2. center for Atmospheric Chemistry Study, Department of Environ- mental {4. and Engineering, Fudan University, Shanghai 2004.0}, China 3. LAPC/NZC, Institute of Atmospheric physics, NZC/LAPC, chinese academy of sciences, beijing 100029, China center for Atmospheric Environment Study Department of Chemistry Beijing Normal University Beijing 100875 China center for Atmospheric Chemistry Study Department of Environmental Science and Engineering Fudan University Shanghai 200433 China LAPC/NZC Institute of Atmospheric Physics NZC/LAPC Chinese Academy of Sciences Beijing 100029 China

The speciation of the elements on the surface of the particles collected during dust storm and non-dust storm in beijing and Inner Mongolia was studied by XPS. The ma- jor species of iron on the surface were oxides, sulfate, silicate, FeOOH and minor part sorbed on SiO2/Al2O3. Sulfate is the dominant species of sulfur on the surface. SiO2 and Al2O3.are the main components of Si and Al on the surface respectively. One of the most important findings was that the Fe(II) (FeS and FeSO4. produced could account for up to 4..3. and 4..6% of the total Fe on the surface in the aerosol sample collected at that night and next day of the “peak” time of the dust storm occurring on March 20, 2002, while Fe2(SO4.3. one of the Fe(III) species on the surface decreased from 67.1% to 4..5% and 4..0% respectively. Both S and Fe en- riched on the surface of aerosol particles. Fe(II) accounted for 1.3.?5.3. of total Fe in bulk aerosol samples during dust storm. These results provided strong evidence to sup- port the hypothesis of the coupling between iron and sulfur in aerosols during the long-range transport, which would have important impact on the global biogeochemical cycle.

关键词：物种形成原理 XPS 大气悬浮物 Fe-S结合粒子集合

Stereocomplex Formation of Atactic Poly(methyl mcthacrylate)

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chinese Chemical Letters 2000年第5期11卷 405-406页

作者： Qun GU De Yan SHEN (Polymer physics Laboratory, center for Molecular science, Institute of Chemistry, {3., Bet.jing 100080) Polymer physics Laboratory Center for Molecular Science Chinese Academy of Sciences Beijing 100080 China

Stereocomplexes formed in atactic poly(methyl methacrylatc) (α-PMMA) films cast form different solvents were studied by means of Fourier transform infrared spectroscopy (FTIR). and differential scanning calorimetry (... 详细信息

关键词： Atactic poly(methyl methacrylate) stereocomplex annealing.

Collision dynamics of He@C_(60)+He@C_(60) at low energies

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science China(physics,Mechanics & Astronomy) 2008年第7期51卷 765-772页

作者： ZHAO Qiang1,2, ZHANG FengShou1,2,3.& ZHOU HongYu1,2 1 Key Laboratory of Beam Technology and Material Modification of Ministry of Education, Institute of Low Energy Nuclear physics, beijing Normal University, beijing 100875, China 2 beijing Radiation {4., beijing 100875, China 3.{4. of theoretical Nuclear physics, National Laboratory of Heavy Ion Accelerator of Lanzhou, Lanzhou 73.000, China Key Laboratory of Beam Technology and Material Modification of Ministry of Education Institute of Low Energy Nuclear Physics Beijing Normal University Beijing China beijing Radiation center Beijing China center of theoretical Nuclear physics National Laboratory of Heavy Ion Accelerator of Lanzhou Lanzhou China

A semi-empirical molecular dynamics model is developed. The central collisions of C60+C60 and He@C60+He@C60 at different incident energies are investigated based on this model. It is found that the dimer structures have been produced at proper incident energies and these fullerene dimers could be formed by a self-assembly of C60 fullerene and He@C60. The He atom has a significant effect at higher incident energy and this embedded He atom can enhance the stability of the dimer structure.

关键词： C60 He@C60 collision molecular dynamics

Hard X-ray lags of Cygnus X-1 on short timescales

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science China(physics,Mechanics & Astronomy) 2010年第S1期53卷 150-152页

作者： JIN Jing1,LU Yu2,3.QU JinLu2 & LI TiPei1,2 1 Department of Engineering physics & center for Astrophysics,Tsinghua University,{3. 100084.China 2 Key Laboratory of Particle Astrophysics,Institute of High Energy physics,chinese academy of sciences,{3. 10004.,China 3.Graduate University of chinese academy of sciences,{3. 10004.,China Department of Engineering physics & center for Astrophysics Tsinghua University Beijing China Key Laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing China Graduate University of chinese academy of sciences Beijing China

Calculating the time lags over different timescales using the cross-correlation technique may lead to a biased estimate of small *** a timescale for lightcurve binning,we propose to subtract the local average instead of the global average during the cross-correlation,in order to filter variations on timescales larger than the bin *** new method allows us to make an unbiased estimate of the time lags using RXTE/PCA data on timescales as small as-5 ms,where the Fourier technique becomes *** calculate the time lag spectra of Cygnus X-1 at different spectral states with the new method,and find that the source appears to have similar X-ray lags on small timescales independent of its spectral states.

关键词： spectral lags Cygnus X-1 data analysis

A systematic investigation of high harmonic generation using mid-infrared driving laser pulses

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science China(physics,Mechanics & Astronomy) 2010年第6期53卷 1054-1059页

作者： YAO JinPing 1,2 ,XIONG Hui 1 ,XU Han 1 ,FU YuXi 1,2 ,ZENG Bin 1,2 ,CHU Wei 1,2 ,CHENG Ya 1 ,XU ZhiZhan 1 ,LIU XiaoJun 3.& CHEN Jing 4.5 1 State Key Laboratory of High Field Laser physics,Shanghai Institute of Optics and Fine Mechanics,chinese academy of sciences,Shanghai 201800,China 2 Graduate University of chinese academy of sciences,{3. 10004.,China 3.State Key Laboratory of Magnetic Resonance and Atomic and Molecular physics,Wuhan Institute of physics and Mathematics,chinese academy of sciences,Wuhan 4.0}071,China 4.Institute of Applied physics and Computational Mathematics,{3. 100088,China 5 center for Applied physics and Technology,Peking University,{3. 100084.China State Key Laboratory of High Field Laser physics Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences Shanghai China Graduate University of chinese academy of sciences Beijing China State Key Laboratory of Magnetic Resonance and Atomic and Molecular physics Wuhan Institute of Physics and Mathematics Chinese Academy of Sciences Wuhan China Institute of Applied physics and Computational Mathematics Beijing China center for Applied physics and Technology Peking University Beijing China

We report on a systematic investigation of the influences of gas pressure,focal position and focusing geometry on high harmonic generation by use of mid-infrared femtosecond laser pulses. We also discuss the spatial characteristics of harmonics under different focusing conditions. By optimizing the parameters,we experimentally observed the generation of 1 kHz,low divergence coherent X-ray beams in the water-window region.

关键词： mid-infrared laser pulses high harmonic generation water window

Some evidence of drying trend over northern China from 1951 to 2004

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chinese science Bulletin 2006年第23期51卷 2913-2925页

作者： MA Zhuguo1,2 & FU Congbin1,2 1. Key Laboratory of Regional Climate-Environment for Temperate East Asia, chinese academy of sciences, beijing 100029, China 2. START Regional center for Temperate East Asia, Institute of Atmos-pheric {3., chinese academy of sciences, beijing 100029, China Key Laboratory of Regional Climate-Environment for Temperate East Asia Chinese Academy of Sciences Beijing 100029 China START Regional center for Temperate East Asia Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

The surface wetness index, Palmer drought sererity index and the retrieval of soil moisture over China were calculated using monthly precipitation and monthly mean surface air temperature. Based on the contrast analysis of the variation of the above three indices and precipitation, the dry/wet spatio-temporal pattern of northern China in the last 54.years was revealed, and the evidence of drying trend over northern China was analyzed, especially. The results show the following four facts: (1) The drying trend is the main characteristic of the eastern part of Northwest China and the central part of North China since the 1980s and it was enhanced in the last 15 years mainly due to the precipitation decrease and the temperature increase; (2) During the last 54.years, there was only one dry/wet shift at the interdecadal scale occurring in the eastern part of Northwest China and the central part of North China in the late 1970s, which was related to 1977/1978 global abrupt change, whereas there were three shifts in Northeast China, one was in the mid 1990s and the other two were in 1965 and 1983. respectively; (3. Unlike the variation trend of other subregions of northern China, the western part of Northwest China is currently located in a relatively wetting period, which is weak-ened due to the temperature increase; (4. The extreme drought frequency is obviously increasing in the eastern part of Northwest China, the central part of North China and Northeast China since the 1980s, which is closely related to the precipitation decrease and temperature increase in these subregions.

关键词：中国北方干燥趋向干旱索引气候背景

Adjoint method for the optimum planning of industrial pollutant sources

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science China Earth sciences 2005年第8期48卷 1270-1279页

作者： LIU Feng1,2, HU Fei2 & ZHU Jiang2 1. College of Environmental sciences, Peking University, beijing 100871, China 2. LAPC, Institute of Atmospheric physics, {3., beijing 100029, China College of Environmental sciences Peking University Beijing China LAPC Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China

The optimum planning of industrial pollutant sources, which optimizes the economic object without violating environmental constraints, is an important and hard task to be conquered. In this paper, an adjoint method is developed to solve the problem. The penalty function is in-troduced to deal with the environmental inequality constraints, and Lagrange function is con-structed to derive the adjoint equation and the gradient of the object function. In this means, the gradient of the object function can be calculated by solving the adjoint equation, and the infor-mation from the gradient is used to make the object function descend and approach to an optimal solution after some iterations. A two-dimensional, simplified model is used for numerical experi-ments. The theoretical derivations are verified by the results of the experiments. Furthermore, the adjoint method is shown to be of excellent convergence and efficiency, which is adaptive to the fast development of air quality numerical models and super computers.

关键词： optimum planning, industrial pollutant sources, adjoint equation, penalty function, gradient.

The relationship between the canonical ENSO and the phase transition of the Antarctic oscillation at the quasi-quadrennial timescale

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Acta Oceanologica Sinica 2010年第6期29卷 26-34页

作者： LIU Changzheng XUE Feng National Climate center Beijing 100081 China LASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

A correlation analysis is performed to investigate the relationship between El Nino-Southern Oscillation （ENSO） and the Antarctic oscillation （AAO） at the quasi-quadrennial （QQ） *** is found that the cold tongue index （CTI） and the AAO index （AAOI） are negatively correlated with about a 7-month lead-time,while they are positively correlated with about a 15-month *** further explore this relationship,complex empirical orthogonal function analysis is employed in the QQ sea level pressure （SLP） anomalies from 1951 to *** results indicate that,during the ENSO cycle,there exists one kind of global tropical wave of wavenumber 1 （GTW1） propagating *** the traveling of GTW1,the tropical SLP anomaly tends to intrude into the southern ***,three strong signals travel synchronously along the circumSouth-Pacific path,and a relatively weak signal extends eastward and poleward over the South Ocean in the Atlantic-Indian Ocean *** the propagation of these signals,the AAO phase tends to be reversed *** a result,there exists an evident lead-lag correlation between CTI and *** can be concluded that ENSO plays a key role in the phase transition of AAO at the QQ *** is also noticed that this regular relationship is only evident in the canonical ENSO events,for which sea surface temperature （SST） anomalies extend westward from the tropical eastern *** the other hand,the similar relationships are not found among those atypical ENSO events for which SST anomalies spread eastward from the central Pacific,such as the 1982-1983.ENSO event.

关键词： ENSO Antarctic oscillation the quasi-quadrennial timescale the global tropical wave of wavenumber 1

A 3.9 V polyanion-type cathode material for Li-ion batteries

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Progress in Natural science:Materials International 2011年第3期21卷 211-215页

作者： Lei LIU,Bin ZHANG,Xue-jie HUANG beijing National Laboratory for Condensed Matter physics, Institute of physics,{3.,beijing,100190,China beijing National Laboratory for Condensed Matter physics Institute of Physics Chinese Academy of Sciences

Monoclinic phase LiFeSO4. was synthesized by a simple fast solid state reaction from the mixture of FeSO4.7H2O and LiF pulverized by high energy ball milling.m-LiFeSO4. was confirmed by GITT measurement to be a 3.9 V polyanion-type cathode materials for Li-ion *** electrochemical activity can be enhanced by addition of carbon.A discharge capacity of 105 mA·h/g (70%of theoretical value) was achieved for a m-LiFeSO4./CNT *** separation behavior during lithium extraction and insertion was observed by ex-situ XRD test.

关键词： LiFeSO4. polyanion cathode Li-ion battery