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Reconstruction of temperature series in China for the last 5000 years

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Progress in Natural Science:Materials International 2006年第8期16卷 838-845页

作者： GE Quansheng, WANG Shunbing and ZHENG Jingyun (Institute of Geographical sciences and Natural Resources Research, chinese academy of sciences, beijing 100101, China graduate school of the chinese academy of sciences, beijing 10003., China) [a]chinese academy of sciences Institute of Geographical Sciences and Natural Resources Research Beijing China [b]graduate school of the chinese {3. of sciences Beijing China

A temperature series with a 100 year resolution for the last 5000 years in China has been reconstructed by using 3. longterm temperature proxy series selected from recent publications in the last 20 years. The proxy records include pollens, stalagmites, lake-sediments, peat, ice cores and historical documents. The result reveals that in the millennial scale temperature variation it was warm in 3.50-250 BC and it was cold in 250 BC-1950 AD. In the above two periods there were many stages of sub-scale temperature fluctuations. The result also shows an obvious temperature discrepancy on the century to multi-century scale between the Eastern Monsoon Region, the Qinghai-Tibet Region and the Northwestern Region in 2850 BC, 23.0 BC, 13.0 BC, 950-3.0 BC, 50-250 AD, and 550 AD. A comparison between the reconstructed series of this paper and some North Hemisphere temperature series indicates that in the longterm scale change, the temperature change in China is in phrase with that of the Northern Hemisphere during the last 5000 years, while on the century to multi-century scale there are differences at the beginning and end times, which may imply that temperature change does not occur simultaneously in different regions.

关键词： temperature series the last 5000 years China.

Observation results of relativistic electrons detected by Fengyun-1 satellite and analysis of relativistic electron enhancement (REE) events

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Science China(Physics,Mechanics & Astronomy) 2008年第12期51卷 1947-1956页

作者： YANG XiaoChao1,2↑ & WANG ShiJin1 1 Center for Space Science and Applied Research, chinese academy of sciences, {3., China 2 graduate University of chinese academy of sciences, beijing 100049, China 1. Center for Space Science and Applied Research Chinese Academy of Sciences Beijing 100190 China 2. graduate University of chinese academy of {3. Beijing 100049 China

The space particle component detector on Fengyun-1 satellite which works at the sun-synchronous orbit of about 870 km altitude has detected relativistic electrons for a long time. In comparison with the SAMPEX satellite observations during 1999–2004, the relativistic electron data from Fengyun-1 satellite from June 1999 to 2005 are used to analyze the relativistic electron enhancement (REE) events at the low earth orbit, and the possible correlation among REE events at the low earth orbit, high-speed solar wind and geomagnetic storms is discussed. The statistical result presents that 45 REE events are found in total during this time period, and the strong REE events with the maximum daily average flux > 400 cm?2·srt-1·s?1 occur mostly during the transition period from solar maximum to solar minimum. Among these 45 REE events, four strong REE events last a longer time period from 26-to 51-day and correlate closely with high speed solar wind and strong geomagnetic storms. Meanwhile, several strong geomagnetic storms occur continuously before these REE events, and these continuous geomagnetic storms would be an important factor causing these long-lasting strong REE events. The correlation analysis for overall 45 events indicates that the strength of the REE events correlates with the solar wind speed and the strength of the geomagnetic storm, and the correlation for strong REE events is much stronger than that for weak REE events.

关键词： relativistic electron enhancement low earth orbit high-speed solar wind geomagnetic storm

An efficient chiral synthesis of (R)-N-[3.acetyl-4-(2-hydroxy-3.isopropylamino-propoxy)phenyl]-butanamide with high enantioselectivity

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Science China Chemistry 2009年第8期52卷 1216-1219页

作者： WANG NaiXing1,2 & TANG XinLiang1,3.1 Technical Institute of Physics and Chemistry,chinese academy of sciences,{3. 100080,China 2 College of Chemistry and Chemical Engineering,graduate University of chinese academy of sciences,{3. 100049,China 3.school of Chemical Engineering and Environment,{3. Institute of Technology,{3. 100081,China 1. Technical Institute of Physics and Chemistry Chinese Academy of Sciences Beijing 100080 China 2. College of Chemistry and Chemical Engineering Graduate University of Chinese Academy of Sciences Beijing 100049 China 3. school of Chemical Engineering and Environment Beijing Institute of Technology Beijing 100081 China

R-Enantiomer of the β-receptor antagonist N-[3.acetyl-4-(2-hydroxy-3.isopropylamino-propoxy)phenyl] butanamide with high enantioselectivity was synthesized from cheap starting materials and enantiopure chiral reagent through an efficient,convenient and practical synthetic *** product was detected by 1H NMR,13. NMR,and MS,and the enatiomeric excess was determined by chiral HPLC analysis using a chiracel AD-H column.

关键词： chiral synthesis enantioselectivity enatiomeric excess chiral HPLC analysis

Inertial theory of the mean Hadley circulation under the condition of nonstatic equilibrium

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Science China Earth sciences 2006年第5期49卷 546-553页

作者： CHAO Jiping1 & LIU Fei2,3.1. National Marine Environmental Forecasting Center, beijing 100081, China 2. Key Laboratory Regional Climate-Environment for Temperate East Asia, Institute of Atmospheric Physics, chinese academy of {3., beijing 100029, China 3. graduate University of chinese academy of {3., beijing 100049, China 1. National Marine Environmental Forecasting Center Beijing 100081 China 2. Key Laboratory Regional Climate-Environment for Temperate East Asia Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China 3. graduate University of chinese academy of {3. Beijing 100049 China

Tropical atmosphere is divided into two layers, the layer near the ground is the planet boundary layer, where the motion is linear, if the radiation equilibrium temperature is given at the top of the boundary layer, the vertical motion there can be obtained. It is the non-viscous ideal atmos- pheric layer above the boundary one, where the motion is nonlinear. After getting the conservation laws of angular momentum, potential temperature and potential vortex, the inertial theory of the Hadley circulation driven by the vertical motion of the boundary layer is established, followed by sev- eral examples of its application.

关键词： Hadley circulation, inertial theory, conservation laws of angular momentum, potential temperature and potential vortex.

A Test on Different Types of the Time Curve of Hardness Ratio of Gamma-Ray Bursts based on the Curvature Effect

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chinese Journal of Astronomy and Astrophysics 2008年第4期8卷 451-464页

作者： Lan-Wei Jia National Astronomical Observatories/Yunnan Observatory,chinese academy of sciences,Kunming 650011,China {3. school of chinese academy of sciences,beijing 100049,China National Astronomical Observatories/ Yunnan Observatory Chinese Academy of Sciences Kunming 650011 China and graduate school of chinese {3. of sciences Beijing 100049 China

We analyzed a sample of 66 gamma-ray bursts （GRBs） and statistically confirmed the prediction on the time curve of the hardness ratio of GRBs made by Qin et al. based on the curvature effect. In their analysis, GRB pulses are divided into three types according to the shape of their raw hardness ratio （RHR） time curves, defined as to include the background counts to the signal counts, so as to make use of counts within small time intervals. Of the three types, very hard sources exhibit a perfect pulse-like profile （type 1）, hard bursts possess a pulse-like profile with a dip in the decay phase （type 2）, and soft bursts show no pulse-like profile but have only a dipped profile （type 3.. In terms of the conventional hardness ratio, type 3.sources are indeed generally softer than those of type 1 and type 2, in agreement with the prediction. We found that the minimum value of RHR is sensitive in distinguishing the different types. We propose that GRB pulses can be classified according to the minimum value of RHR and that the different type sources may be connected with different strengths of the shock or/and the magnetic field.

关键词： gamma-rays burst -- gamma-rays observations - methods statistical

Multi-channel SAR imaging based on distributed compressive sensing

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Science China(Information sciences) 2012年第2期55卷 245-259页

作者： LIN YueGuan1,2,3.ZHANG BingChen1,2,JIANG Hai1,2,3.HONG Wen1,2 & WU YiRong1,2 1National Key Laboratory of Science and Technology on Microwave Imaging,beijing 100190,China 2Institute of Electronics,chinese academy of {3.,beijing 100190,China 3.5} University of chinese academy of {3.,beijing 100049,China 1. National Key Laboratory of Science and Technology on Microwave Imaging Beijing 100190 China2. Institute of Electronics Chinese Academy of Sciences Beijing 100190 China3. Graduate University of Chinese Academy of Sciences Beijing 100049 China

The rapid development of compressive sensing(CS)shows that it is possible to recover a sparse signal from very limited *** aperture radar(SAR)imaging based on CS can reconstruct the target scene with a reduced number of collected samples by solving an optimization *** multi-channel SAR imaging based on CS,each channel requires sufficient samples for separate imaging and the total number of samples could still be *** propose an imaging algorithm based on distributed compressive sensing(DCS)that reconstructs scenes jointly under multiple ***-channel SAR imaging based on DCS not only exploits the sparsity of the target scene,but also exploits the correlation among *** requires significantly fewer samples than multi-channel SAR imaging based on *** multiple channels offer different sampling rates,DCS joint processing can reconstruct target scenes with a much more flexible allocation of the number of measurements offered by each channel than that used in separate CS processing.

关键词： synthetic aperture radar multi-channel synthetic aperture radar compressive sensing distributed compressive sensing

Spatial heterogeneity of the driving forces of cropland change in China

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Science China Earth sciences 2005年第12期48卷 2231-2240页

作者： LIU Xuhua1,2, WANG Jinfeng1, LIU Mingliang4,1 & MENG Bin1,2,3.1. Institute of Geographic sciences and Natural Resources Research, chinese academy of sciences, beijing 100101, China 2. graduate school of the chinese academy of sciences, beijing 10003., China 3. College of Arts and sciences of beijing Union University, beijing 100083. China 4. school of Forestry and Wildlife sciences, Auburn University, Auburn, Alabama, AL3.849, USA 1. Institute of Geographic sciences and Natural Resources Research Chinese Academy of Sciences 100101 Beijing China 2. graduate school of the chinese {3. of sciences 100039 Beijing China 3. school of Forestry and Wildlife sciences Auburn University Auburn AL36849 Alabama USA 4. College of Arts and sciences of beijing Union University 100083 Beijing China

By using digital satellite remote sensing data acquired in 1987―1989 and 1999―2000 and GIS combined with the natural and socio-economic data, this paper drew an integrated zonation of the cropland change and its driving forces in China. The results indicated that the cropland change in the study period was constrained by geographical factors and driven by cli-mate change as well as socio-economic system. Moreover, the regional differences of the drivers for cropland change were significant. In the midwest of China, natural condition changes and geographical background were the main constraints and drivers, while in Eastern China, social and economic changes and economic policies were the main driving forces. The cropland loss was nationwide. The dominant factors to cause this decrease included buildup of developing area to attract foreign capital and technologies, changes of industry structure due to urban in-fluence, the change of employment notions thanks to living standard improvement, rapid ur-banization due to the expansion of cities and towns, the diminished farming net income partly because of the global warming effects, and the rapid economic growth stimulated by the con-venient transportation system. These factors interact and interdepend with each other to cause the cropland loss in China recently. The reasons for the increase of cropland were primarily the cultivation and deforestation by the farmers who want to increase income. This study on the mechnism of LUCC relied on the cropland change integrated classification considering the natural or human factors both inside and outside the region, which provides a new approach to study the integrated regionalization and LUCC mechanism.

关键词： land use change, driving force, integrated classification, spatial statistics, cropland, China.

A study of spaceborne SAR raw data compression error based on a statistical model of quantization interval transfer probability

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Science China(Information sciences) 2010年第11期53卷 2352-2362页

作者： LI Xin1,2,3., QI HaiMing1,2*, HUA Bin1,2,3. LEI Hong1 & YU WeiDong1 1Institute of Electronics, chinese academy of sciences, {3., China 2The National Key Laboratory of Microwave Imaging Technology, {3., China 3.5} University, chinese academy of sciences, beijing 10003., China 1. Institute of Electronics Chinese Academy of Sciences Beijing 100190 China2. The National Key Laboratory of Microwave Imaging Technology Beijing 100190 China3. Chinese Academy of Sciences Graduate University Beijing 100039 China

SAR raw data signal to noise ratio (SNR) after compression is of great importance since the choice of compression ratio is dependent on it during SAR system design and application analysis. The signal to quantization noise ratio (SQNR) generally used may not precisely indicate the relationship between signal and noise. Considering the thermal noise, a statistical model of quantization interval transfer probability is proposed in this paper. SNR mapping between SAR raw data before analog to digital converter (ADC) and after block adaptive quantization (BAQ) over the whole set of saturation degree is obtained using this model. When the power of echo is small with low SNR, after 1, 2, 3.or 4 bits BAQ compression, SNR has tiny difference among the four compression levels. When the power of the echo is medium with higher SNR, the SNR degradation after BAQ is about 5 dB with each bit decreasing from 4 bits. If voltage of the echo is higher than the clipping point of ADC, SNR after ADC and BAQ degrades stepwise. The higher the saturation degree of SAR raw data, the worse the SNR is. Simulated Gaussian data and real SAR raw data are used to verify the theoretical results, which are useful in the choice of BAQ compression ratio and further application analysis.

关键词： SAR raw data compression SNR saturation

IL-8-induced L-selectin shedding regulates its binding kinetics to PSGL-1

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chinese Science Bulletin 2009年第16期54卷 2786-2793页

作者： JIA XiaoLing1,2,3. CHEN Juan1,2 & LONG Mian1,2 1 National Microgravity Laboratory, Institute of Mechanics, chinese academy of sciences, {3., China 2 Center of Biomechanics and Bioengineering, Institute of Mechanics, chinese academy of sciences, {3., China 3.school of Biological Science and Medical Engineering, Beihang University, beijing 100083. China National Microgravity Laboratory Institute of Mechanics Chinese Academy of Sciences Beijing 100190 China Center of Biomechanics and Bioengineering Institute of Mechanics Chinese Academy of Sciences Beijing 100190 China school of Biological Science and Medical Engineering Beihang University Beijing 100083 China

L-selectin plays a crucial role in inflammation cascade by initiating the tethering and rolling of leukocytes on endothelium wall. While many L-selectin molecules are rapidly shed from the cell surface upon activation, the remaining membrane-anchored L-selectin may still play an important role in regulating leukocyte rolling and adhesion with different binding kinetics. Here we developed an in vitro model to activate Jurkat cells via interlukin-8 (IL-8) and quantified the two-dimensional (2D) binding kinetics, using a micropipette aspiration assay, of membrane-anchored L-selectin to P-selectin glycoprotein ligand 1 (PSGL-1) ligand coupled onto human red blood cells (RBCs). The data indicated that L-selectin shedding reduced the amount of membrane-anchored L-selectin and lowered both its reverse and forward rates. These results suggested that the rolling dynamics of activated leukocytes was determined by two opposite impacts: reducing the surface presentation would enhance the rolling but lowering the kinetic rates would decrease the rolling. This finding provides a new insight into under-standing how L-selectin shedding regulates leukocyte rolling and adhesion.

关键词：结合动力学选择素配体白细胞介素8 Jurkat细胞诱导细胞表面微管吸吮