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Near-Infrared Imaging Observations of the Orion A-W Star Forming Region

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chinese Journal of Astronomy and Astrophysics 2002年第3期2卷 260-265页

作者： Jun-Jie WangNational Astronomical Observatories, chinese academy of {2., beijing 100012.0} academy of {2.-Peking university Joint beijing Astrophysics Center, beijing100871 National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 Chinese Academy of Sciences-Peking University Joint Beijing Astrophysics Center Beijing 100871

We carried out near-infrared imaging observations of the Ori A-W region using the Italian 1.5 m TIRGO infrared telescope at Gornergrat. A group of infrared objects is visible on the K band image, including an IRAS source (IRS 1). From its IRAS flux density the IRAS luminosity is derived to be 4.L⊙, which shows that IRS 1 is a low-mass protostar. By superimposing the position of the VLA H2. maser on the K image, we can identify the less evolved object IRS 1 as the excitation source of the H2. maser, within a projected distance of 4.0AU. This would be evidence that the maser effect is associated with the youngest phase of stellar evolution. The first probable HH object candidate in the Ori A-W region is discovered from the H2.(1)1-0 observation. Comparing the position of the H2. maser with the direction of the molecular hydrogen emission in the region, we suggest that the observed H2. maser could be tracing the circumstellar disk of IRS 1.

关键词： Stars: formation - ISM: jets and outflows

Plus cupping degrees do not form an ideal

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Science in China(Series F) 2004年第5期47卷 635-654页

作者： LI Angsheng1,2.& ZHAO Yicheng1 1. Institute of Software,chinese academy of {2.,beijing 100080,China 2. School of Information {2.,beijing Normal university,beijing 100871,China 1. Institute of Software Chinese Academy of Sciences 100080 Beijing China 2. School of Information sciences Beijing Normal University 100871 Beijing China

A computably enumerable (c.e.,for short)degree a is called plus cupping,if every c.e. degree x with 0 详细信息

A computably enumerable (c.e.,for short)degree a is called plus cupping,if every c.e. degree x with 0

关键词： computably enumerable set Turing degree definability.

Geomorphologic evidence of phased uplift of the northeastern Qinghai-Tibet Plateau since 14.million years ago

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Science China Earth sciences 2004年第9期47卷 822-833页

作者： LU Huayu1, WANG Xiaoyong1, AN Zhisheng1, MIAO Xiaodong1, ZHU Rixiang3, MA Haizhou2. LI Zhen4. TAN Hongbing2.& WANG Xianyan1 1. State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, chinese {2. of {2., Xi’an 710075 China 2. Qinghai Institute of Salt Lakes, chinese {2. of {2.. Xining 810008, China 3. Institute of Geology and Geophysics, chinese {2. of {2., beijing 10002., China 4. Department of Geography, Qinghai Normal {12., Xining 810008, China chinese Acad Sci Inst Earth Environm State Key Lab Loess & Quaternary Geol Xian 710075 Peoples R China chinese Acad Sci Qinghai Inst Salt Lakes Xining 810008 Peoples R China chinese Acad Sci Inst Geol & Geophys Beijing 100029 Peoples R China Qinghai Normal Univ Dept Geog Xining 810008 Peoples R China

A typical sequence of fluvial terraces and aeolian deposits overlying these ter- races were multidisciplinary investigated. New evidences for uplift process of the northeastern Qinghai-Tibetan Plateau in the past 14.million years were obtained. At least 11 river terraces along Huangshui, the first-class tributary of Yellow River, at the Xining-Huzhu region are identi- fied. While the first one (T1) is classified as an accumulation terrace, the others are all basement river terraces, which consist of the Tertiary sandstone and siltstone bedrock, fluvial gravel and pebbles and the overlying aeolian loess-Red Clay deposit. Samples from the aeolian deposits were examined for paleomagnetic stratigraphic reconstruction (1030 samples), luminescence dating (16 samples), magnetic susceptibility and grain-size distribution (more than 4.00 sam- ples). The luminescence dating and stratigraphic correlation suggest that terraces of Tll, T10, T8, T7, T3, T2. T1 were formed at 14. 11.3, 1.55, 1.2. 0.15, 0.07 and 0.01 million years ago, re- spectively. Sedimentological analysis and geomorphological observation indicate that formation and evolution of these terraces were mainly driven by tectonic uplift. Therefore, the terrace se- quence provides an ideal geological record, of the uplift process of the northeastern during the past 14.million years, and the timings of the terraces formation are regarded as the timings of tectonic uplift. The significant uplifting events took place at 14. 11.3, 1.2.and 0.15 mil- lion years ago, respectively. The fluvial incision at the Xining-Huzhu region is less than 100 m during a period of ~12.million years in the Miocene era (between the Tll and T9), while the Huangshui River had incised 4.2.m during the past 1.2.million years (from T7 to the present floodplain). The river incision process clearly demonstrates that accelerated rising of the north- eastern Qinghai-Tibet Plateau during the late Cenozoic, and provides new evidence of previous thoughts

关键词： river terrace, tectonic uplift, loess-Red Clay, the past 14 million years, northeastern Qinghai-Tibet Plateau.

Time of impact of fragment P2.of comet SL 9 on Jupiter

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chinese Science Bulletin 1997年第5期42卷 396-398页

作者： ZHOU Hongnan,QIAN Bochen, HUANG Keliang and LI Qibin1. Department of Astronomy, Nanjing university, Nanjing 2.0093, China 2. Shanghai Observatory, chinese {2. of sciences, Shanghai 2.0030, China 3. Physics Department, Nanjing Normal university, Nanjing 2.0097, China 4. beijing Astronomical Observatory, chinese {2. of sciences, beijing 100080, China Department of Astronomy Nanjing University Nanjing China Shanghai Observatory Chinese Academy of Sciences Shanghai China Physics Department Nanjing Normal University Nanjing China beijing Astronomical Observatory Chinese Academy of Sciences Behijing China

FROM 1994.07-16 to 1994.07-2., 2. fragments of comet SL 9 impacted against Jupiter in succession. During the impact period the impact of fragments D, E, K, N, P2.and S was observed in China. We used a 1.56-m telescope with the CCD camera of Shanghai Observatory to monitor Jupiter and its Galilean Satellites, obtaining 1000 high-quality images at B, V, I wave bands. Our data on optical wave bands are rather complete and valuable in the world. Specially, we got some images of Jupiter, Io and Europa in the impact time of fragment P2.impacting against Jupiter. This will help us understand the precise time, position, depth and energy of the P2.s collision. In this note, we report the impact time of fragment P2.of comet SL 9 and Jupiter. Since the impact of comet SL 9 was expected to take place on the side of Jupiter

关键词： comet comet Shoemaker-Levy 9 impacting against Jupiter impact time.

Estimating forest aboveground biomass using HJ-1 Satellite CCD and ICESat GLAS waveform data

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Science China Earth sciences 2010年第S1期53卷 16-25页

作者： GUO ZhiFeng1,CHI Hong1,2.& SUN GuoQing1,3 1State Key Laboratory of Remote Sensing Science,Jointly Sponsored by the Institute of Remote Sensing Applications of chinese academy of {2. and beijing Normal {4.,Institute of Remote Sensing Applications,chinese academy of {2.,beijing 100101,China 2.9} {4. of chinese academy of {2.,beijing 10004.,China 3Department of Geography {4. of Maryland,College Park,MD 2.74.,USA 1. State Key Laboratory of Remote Sensing Science Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University Institute of Remote Sensing Applications Chinese Academy of Sciences Beijing 100101 China2. Graduate University of Chinese Academy of Sciences Beijing 100049 China3. Department of Geography University of Maryland College Park MD 20742 USA

The ecosystem in northeastern China and the Russian Far East is a hotspot of scientific research into the global carbon *** aboveground biomass(AGB) is an important component in the land surface carbon *** this study,using forest inventory data and forest distribution data,the AGB was estimated for forest in Daxinganlin in northeastern China by combining charge-coupled device(CCD) data from the Small Satellite for Disaster and Environment Monitoring and Forecast(HJ-1) and Geoscience Laser Altimeter System(GLAS) waveform data from the Ice,Cloud and land Elevation Satellite(ICESat).The forest AGB prediction models were separately developed for different forest types in the research area at GLAS footprint level from GLAS waveform parameters and field survey plot biomass in the Changqing(CQ) Forest Center,which was calculated from forest inventory *** resulted statistical regression models have a R2.0.68 for conifer and R2.0.71 for broadleaf *** models were used to estimate biomass for all GLAS footprints of forest located in the study *** GLAS footprint biomass coupled with various spectral reflectivity parameters and vegetation indices derived from HJ-1 satellite CCD data were used in multiple regression analyses to establish biomass prediction models(R2.0.55 and R2.0.52.for needle and broadleaf respectively).Then the models were used to produce a forest AGB map for the whole study area using the HJ-1 *** data obtained from forest inventory data of the Zhuanglin(ZL) Forest Center were used as independent field measurements to validate the AGB estimated from HJ-1 CCD data(R2.0.71).About 80% of biomass samples had an error less than 2. t ha-1,and the mean error of all validation samples is 5.74.t *** pixel-level biomass map was then stratified into different biomass levels to illustrate the AGB spatial distribution pattern in this *** was found that HJ-1 wide-swath data and GLAS waveform data can be combined to estim

关键词： Disaster and Environment Monitoring and Forecast Satellite ICESat GLAS waveform boreal forest forest aboveground biomass multiple linear regression

Strengthening of the boreal winter Hadley circulation and its connection with ENSO

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Progress in Natural Science:Materials International 2007年第11期17卷 1327-1333页

作者： Ma Jie1,2.and Li Jianping2.1. College of Atmospheric sciences, Lanzhou university, Lanzhou 730000, China 2. LASG, Institute of Atmospheric Physics, {2. academy of sciences, beijing 10002., China) College of Atmospheric sciences Lanzhou University Lanzhou 730000 China LASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

Empirical orthogonal function (EOF) analysis is carried out for the year-to-year variability of the boreal winter (DJF) mass stream function of the mean meridional circulation (MMC) during the period 194.—2.05. The results demonstrate that it is dominated by the equatorially asymmetric and symmetric modes. Further analysis shows that the former mode is linked with the boreal winter Hadley cell mainly on the decadal time-scale, and the latter on the interannual time-scale. The asymmetric mode index (AMI) with a clear upward trend contributes to the decadal strengthening of the boreal Hadley circulation, and is closely correlated with the tropical SST warming, especially in the region of Indo-west Pacific warm pool (INWP). Furthermore, the AMI also contributes to the abrupt change of the correlation coefficient between the boreal Hadley circulation and ENSO after 1976. The symmetric mode index (SMI) with robust and stable linkage with ENSO shows a significant interannual variability, suggesting that the variability of the Hadley circulation is mainly associated with ENSO on the interannual time-scale.

关键词： the Hadley circulation interannual time-scale decadal time-scale

Polyphyly of the fern family Tectariaceae sensu Ching:Insights from cpDNA sequence data

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Science China(Life sciences) 2007年第6期50卷 789-798页

作者： LIU HongMei1,2. ZHANG XianChun1, CHEN ZhiDuan1, DONG ShiYong3 & QIU YinLong4.1 State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, chinese {2. of {2., beijing 100093, China 2.{4. university of chinese {2. of {2., beijing 100039, China 3 South China Botanical Garden, chinese {2. of {2., Guangzhou 510650, China 4.Department of Ecology and Evolutionary Biology, university of Michigan, Ann Arbor, MI 4.109-104., USA State Key Laboratory of Systematic Evolutionary Botany Institute of Botany Chinese Academy of Sciences Beijing 100093 China graduate university of {2. academy of {4. Beijing 100039 China South China Botanical Garden Chinese Academy of Sciences Guangzhou 510650 China Department of Ecology Evolutionary Biology University of Michigan Ann Arbor MI 48109-1048 USA

Tectariaceae are a pantropical fern family of about 2. genera, among which 8 are distributed in China. The morphological distinctiveness of the family is widely recognized, yet relatively little systematic research has been conducted on members of Tectariaceae. Phylogenetic analyses of chloroplast DNA sequence data (rbcL; atpB) from 15 species representing all 8 genera in China were carried out under parsimony criteria; Bayesian inference. The phylogenetic reconstructions indicated that the fern family Tectariaceae as traditionally circumscribed are polyphyletic. Ctenitis, Dryopsis, Lastreopsis clustered with; should be included within the newly-defined Dryopteridaceae,; Pleocnemia is also tentatively assigned to it. A narrowly monophyletic Tectariaceae is identified, which includes Ctenitopsis, Hemigramma, Pteridrys, Quercifilix,; Tectaria. In the single rbcL analysis, Arthropteris clustered with the above-mentioned monophyletic Tectariaceae. Although further investigations are still needed to identify infrafamilial relationships within the monophyletic Tectariaceae; to redefine several problematic genera, we propose a working concept here that better reflects the inferred evolutionary history of this group.

关键词： Tectariaceae, polyphyly, rbcL, atpB

Quantitative analysis of soil pores under natural vegetation successions on the Loess Plateau

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Science China Earth sciences 2010年第4期53卷 617-625页

作者： ZHAO ShiWei1,ZHAO YongGang1,2.& WU JinShui3 1 State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,Institute of Soil and Water Conservation,Northwest Agriculture & Forestry university,Yangling 712.00,China 2.graduate university of chinese {4. of sciences,beijing 10004.,China 3 Institute of Subtropical Agriculture,chinese {4. of sciences,Changsha 4.012.,China 1. State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water Conservation Northwest Agriculture & Forestry University Yangling 712100 China2. Graduate University of Chinese Academy of Sciences Beijing 100049 China3. Institute of Subtropical Agriculture Chinese Academy of Sciences Changsha 410125 China

Soil pore is a key attribute of the soil structure that affects soil reservoir under natural vegetation recovery on the Loess *** study is to quantitatively analyze soil pore parameters,measured with Computed Tomography(CT) at 15-57 mm depths under five different vegetation succession stages using a concept of substituting "space" for "time" in the Ziwuling Forest Region of the Loess *** results showed that the soil pore parameters,such as pore number,porosity,circularity,and fractal dimension,increased significantly under the natural vegetation successions and varied with the pattern climax community stage>pioneering arbor community stage>scrub community stage>herbaceous community stage>abandoned farmland stage,indicating that natural vegetation recovery could remarkably improve soil pore *** the vegetation succession,this positive effect will be strengthened gradually,which means that the soil pore parameters may appear to be best at the climax community *** organic matter content increased linearly with the soil pore parameters(P<0.001).Increased organic matter accumulation was one of the major reasons for the changes in soil pore characteristics in natural vegetation succession.

关键词： Computed Tomography Loess Plateau natural vegetation succession soil pore soil organic matter

Relationship between surface subsidence factor and mining depth of strip pillar mining

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中国有色金属学会会刊：英文版 2011年第S3期21卷 594-598页

作者： GUO Wen-bing1, 2. HOU Quan-lin 1, ZOU You-feng2.1. College of Earth Science, graduate university of {2. academy of {4., beijing 10004., China 2. School of Energy Science and Engineering, Henan Polytechnic university, Jiaozuo 4.4.00, China chinese Acad Sci Coll Earth Sci Grad Univ Beijing 100049 Peoples R China Henan Polytech Univ Sch Energy Sci & Engn Jiaozuo 454000 Peoples R China

Strip pillar mining is one of the most important technical measures to control mining subsidence in China. Mining depth is one of the most important factors that can affect the mining subsidence in strip pillar mining. Six numerical simulation models were set up to simulate the surface subsidence of strip pillar mining in different mining depths. The mining depth in these six models ranges from 300 to 800 m. The simulated results were compared and analyzed. The formula was established based on the simulated results. It demonstrated that the subsidence of strip pillar mining method is related to mining depth. While the other conditions are the same, the subsidence of strip pillar mining increases with the increase of mining depth by logarithmic relationship.

关键词： subsidence factor strip pillar mining mining depth numerical simulation