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Teleconnection between the Indian summer monsoon onset and the Meiyu over the Yangtze River Valley

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Science china Earth sciences 2008年第7期51卷 1021-1035页

作者： LIU YunYun1,2,3 & DING YiHui2 1 chinese academy of Meteorological sciences, beijing 100081, china 2 National Climate Center, beijing 100081, china 3 graduate university of chinese academy of sciences, beijing 100049, china chinese academy of Meteorological sciences Beijing China National Climate Center Beijing China graduate university of chinese academy of sciences Beijing China

Based on the Indian and chinese precipitation data and the NCEP-NCAR reanalysis circulation data, the relationship between the Indian summer monsoon (ISM) onset and the Meiyu over the Yangtze River Valley has been discussed by the methods of correlation analysis and composite analysis. The results show that the date of ISM onset over Kerala in the southwestern coast of the Indian Peninsula is about two weeks earlier than the beginning of the Meiyu over the Yangtze River Valley. After the outbreak of ISM, the teleconnection mode sets up from the western coast of India via the Bay of Bengal (BOB) to the Yangtze River Valley and southern Japan. It is different both in time and space from the telecon- nection mode which is from the northwest of India via the Tibetan Plateau to northern china. The for- mer mode is defined as the "south" teleconnection of the Asian summer monsoon, forming in the pe- riod of ISM onset; while the latter mode is called the "north" teleconnection, mainly occurring in the Asian monsoon culminant period. During the process of the "south" teleconnection’s formation, the Asian monsoon circulation has experienced a series of important changes: ISM onset, the northward movement of the south Asia high (SAH), the onset vortex occurrence, the eastward extension of the stronger tropical westerly belt, and the northeastward jump of the western Pacific subtropical high (WPSH), etc. Consequently, since ISM sets up over Kerala, the whole Asian continent is covered by the upper SAH after about two weeks, while in the mid- and lower troposphere, a strong wind belt forms from the Arabian Sea via the southern India, BOB and the South china Sea (SCS), then along the western flank of WPSH, to the Yangtze River Valley and southern Japan. With the northward moving of the subtropical jet streams, the upper westerly jet stream and the low level jet have been coupled ver- tically over east Asia, while the Yangtze River Valley happens to locate in the ascending motion

关键词： Indian summer monsoon (ISM) the Meiyu over the Yangtze River Valley teleconnection mode

Effects of various solar indices on accuracy of Earth’s thermospheric neutral density models

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Science china(Physics,Mechanics & Astronomy) 2009年第7期52卷 1120-1128页

作者： WANG HongBo1,2 & ZHAO ChangYin1 1 Purple Mountain Observatory, chinese academy of sciences, Nanjing 210008, china 2 graduate university of chinese academy of sciences, beijing 100049, china Purple Mountain Observatory Chinese Academy of Sciences Nanjing China graduate university of chinese academy of sciences Beijing China

Four kinds of solar indices F10.7, E10.7, S10, Mg10 and four thermospheric neutral density models, i.e., CIRA72, DTM94, NRLMSISE00 and JB2006, are discussed. The CHAMP accelerometer data are used to calculate thermospheric total mass density. Based on the comparison of the model densities with CHAMP observations, the effects of various indices on the model accuracy are detected. It is found that under quiet and moderate solar conditions (F10.7200) the error’s standard deviation using E10.7 increases quickly and causes the models’ accuracy to fall down. With regard to S10, Mg10, their effects under quiet solar conditions are inconspicuous. If under active solar conditions, they can reduce the model error’s standard deviation by 5%-10%, implying that S10, Mg10 make the model error more stable. The JB2006 model, which was constructed by multi-solar-index (F10.7, S10, Mg10), is compared with DTM94 and NRLMSISE00 based on single-solar-index. It is found that JB2006’s accuracy is better than DTM94’s, and is close to NRLMSISE00 under the quiet solar condition. During the solar burst occurring on October 26, 2003, JB2006 has been in best agreement with CHAMP observations. All in all, the new indices may improve thermospheric density models’ accuracy under some special conditions. Concretely, E10.7 may reduce the average error of models and S10, Mg10 may prevent the error’s divergence.

关键词： solar radiation index CHAMP accelerometer data neutrals density model

A NUMERICAL STUDY ON A SIMPLIFIED TAIL MODEL FOR TURNING FISH IN C-START

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Journal of Hydrodynamics 2006年第2期18卷 135-142页

作者： YANG Yan TONG Bing-gang The Laboratory for Biomechanics of Animal Locomotion Graduate University of Chinese Academy of SciencesBeijing 100049 China Department of Mechanics and Mechanical Engineering University of Science and Technology of China Hefei230026 China

Most freshwater fish are good at turning manoeuvres. A simulated fish tail model was numerically investigated and discussed in detail. This study deals with unsteady forces and moment exerted on the fish tail-fin in an initial sideways stroke and a subsequent return stroke motion, and visualizes the flow fields and vortex structures, in order to explore the flow control mechanism of the typical turning motion of fish. Further discussion on fluid dynamic consequences corresponding to two different bending forms of fish tail-fins in its C-start is given. The two-dimensional unsteady incompressible Navier-Stokes equations are solved with a developed pseudo-compressibility method to simulate the flow around the fish tail-fin. The computed results and the comparison with experiments indicate that （1） fish performs a turning motion of its body using the impulsive moment produced by the to-and-fro stroke, and each stage of the process exhibits its specific hydrodynamic characteristic, （2） fishes adopt two forms of tail-tip bend （single bend and double bend） to accomplish a C-start turning manoeuvre, in dependence of their physical situations and natural environments, （3） fish can control its turning motion by modulating some key kinematic parameters.

关键词： fish swimming turning manoeuvre C-start,tail fin locomotion 2D Navier-Stokes equations CFD physical mechanism optimal control

Conceptual design and simulation analysis of thermal behaviors of TGR blast furnace and oxygen blast furnace

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Science china(Technological sciences) 2010年第1期53卷 85-92页

作者： ZHANG Hui1,2,LI HuiQuan1,TANG Qing1 & BAO WeiJun1 1 National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology,Institute of Process Engineering,chinese academy of sciences,beijing 100190,china 2 graduate university of chinese academy of sciences,beijing 100049,china National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology Institute of Process Engineering Chinese Academy of Sciences Beijing China graduate university of chinese academy of sciences Beijing China

Extensive use of carbon based fuel is the main inducement for global warming and more extreme *** carbon dioxide emission and enhancing energy use is a common subject in steel *** the integrated steel plant,decreasing carbon dioxide emission must consider energy balance in the whole iron and steel works,and secondary energy must be actively *** promising blast-furnaces,top gas recovery blast furnace(TGR-BF) and oxygen blast furnace have been *** this paper,conceptual TGR blast furnace and oxygen blast furnace are *** on the idea of blast furnace gas de-CO2 circulating as reducing agent and the idea of pure oxygen blast decreasing the thermal reserve zone temperature,process modeling is conducted with ASPEN *** is shown that the developed model reasonably describes the energy balance and mass balance feature of the furnace,and provides basic thermodynamic condition for *** effects of changes in different operation conditions are studied by sensitivity analysis and reference data from simulation.

关键词： TGR blast-furnace thermal behavior simulation analysis CO2 emission decreasing

Modeling and verifying Web services driven by requirements:An ontology-based approach

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Science in china(Series F) 2006年第6期49卷 792-820页

作者： HOU Lishan1,3,JIN ZHi1,2 & WU Budan1,4 1. academy of Mathematics and Systems Science, chinese academy of sciences, beijing 100080, china 2. Institute of Computing Technology, chinese academy of sciences, beijing 100080, china 3. Institute of Software, chinese academy of sciences, beijing 100080, china 4. graduate university of chinese academy of sciences, beijing 100049, china academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing China Institute of Software Chinese Academy of Sciences Beijing China Institute of Computing Technology Chinese Academy of Sciences Bejing China graduate university of chinese academy of sciences Beijing China

Automatic discovery and composition of Web services is an important research area in Web service technology, in which the specification of Web services is a key issue. This paper presents a Web service capability description framework based on the environment ontology. This framework depicts Web services capability in two aspects： the operable environment and the environment changes resulting from behaviors of the Web service. On the basis of the framework, a requirement-driven Web service composition model has been constructed. This paper brings forward the formalization of Web service interactions with π calculus. And an automatic mechanism converting conceptual capability description to the formal process expression has been built. This kind of formal specification assists in verifying whether the composite Web service model matches the requirement.

关键词： Web service environment ontology automatic composition π calculus formal verification.

The influence of moderate ENSO on summer rainfall in eastern china and its comparison with strong ENSO

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chinese Science Bulletin 2008年第5期53卷 791-800页

作者： XUE Feng1 & LIU ChangZheng1,2 1 Institute of Atmospheric Physics, chinese academy of sciences, beijing 100029, china 2 graduate university of chinese academy of sciences, beijing 100049, china Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China graduate university of chinese academy of sciences Beijing China

The 6 major ENSO events since 1979 are classified into the strong and moderate ENSO based on in-tensity. The composite analysis is performed to reveal the influence of ENSO on East Asian summer monsoon (EASM) and summer rainfall in eastern china. It is shown that the influence is changed with the seasonal cycle in summer, with a weaker influence in June and a stronger influence in August, in-dicating a long lagged effect of ENSO on EASM. Besides, the circulation and rainfall anomalies caused by the strong ENSO are also stronger with an earlier starting time, while the influence of the moderate ENSO is evident in August. The composite summer rainfall in eastern china for the moderate ENSO exhibits a northern rainfall pattern, which is totally different from the classical ENSO-type rainfall pat-tern. Based on the composite analysis, two moderate ENSO years with a similar intensity (i.e., 1995 and 2003) are compared. The result shows that, the response of EASM to the moderate ENSO during June and July is, to a certain degree, modulated by the circulation systems in mid-high latitudes of Eurasia and in the Southern Hemisphere, thereby inducing a different rainfall distribution in eastern china. In comparison with the strong ENSO in 1983, it is further revealed that, the strong ENSO plays a dominant role in summer rainfall anomalies in eastern china as well as in controlling the influence of the other factors on EASM. The strong ENSO is therefore different with the moderate ENSO.

关键词：中国东部海洋气象学厄尔尼诺现象东亚季风降雨

Terrestrial transect study on driving mechanism of vegetation changes

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Science china Earth sciences 2008年第7期51卷 984-991页

作者： ZHANG YuJin1,2 & ZHOU GuangSheng1 1 State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, chinese academy of sciences, beijing 100093, china 2 graduate university of chinese academy of sciences, beijing 100049, china State Key Laboratory of Vegetation and Environmental Change Institute of Botany Chinese Academy of Sciences Beijing China graduate university of chinese academy of sciences Beijing China

In terms of chinese climate-vegetation model based on the classification of plant functional types, to- gether with climatic data from 1951 to 1980 and two future climatic scenarios (SRES-A2 and SRES-B2) in china from the highest and the lowest emission scenarios of greenhouse gases, the distribution patterns of vegetation types and their changes along the Northeast china Transect (NECT) and the North-South Transect of Eastern china (NSTEC) were simulated in order to understand the driving mechanisms of vegetation changes under climatic change. The results indicated that the vegetation distribution patterns would change significantly under future climate, and the major factors driving the vegetation changes were water and heat. However, the responses of various vegetation types to the changes in water and heat factors were obviously different. The vegetation changes were more sensi- tive to heat factors than to water factors. Thus, in the future climate warming will significantly affect vegetation distribution patterns.

关键词： driving mechanism vegetation terrestrial transect climatic change plant functional types

Pollen limitation and variation in floral longevity in gynodioecious Potentilla tanacetifolia

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Journal of Systematics and Evolution 2011年第6期49卷 539-545页

作者： 1,2Hong YAO 1Yi-Bo LUO 1(State Key Laboratory of Systematic and Evolutionary Botany,Institute of Botany,chinese academy of sciences,beijing 100093,china) 2(graduate university of the chinese academy of sciences,beijing 100049,china) (State Key Laboratory of Systematic and Evolutionary Botany Institute of Botany Chinese Academy of Sciences Beijing 100093 China) (graduate university of the chinese academy of sciences Beijing 100049 China)

Pollination limitation is common in flowering plants and is thought to be a factor driving the evolution of floral *** plasticity of floral longevity to pollination may be an adaptation of plants to pollen ***,this adaptation is less critical in short-lived *** evaluate pollen limitation and the plasticity of floral longevity to pollination in Potentilla tanacetifolia,a gynodioecious herb with short-lived flowers,we analyzed its breeding system,tested sex-differential pollen limitation,and compared variations in floral display size in natural populations in Duolun County,Inner Mongolia,*** pollination experiments and pollinator exclusion treatments revealed that *** is self-compatible and non-autonomously apomictic and shows sex-differential pollen *** plasticity of floral longevity to pollination was observed;the floral duration of female plants was prolonged by approximately 3-4 hours with pollination exclusion ***,the percentage of flowers displayed on female plants during pollination exclusion treatment was significantly higher than that during natural *** natural pollination conditions,the percentage of flowers displayed on female plants was significantly higher than on hermaphrodite ***,approximately 50%of the pollen grains spread out of the anthers of hermaphrodite flowers within 2 h of anthesis;the number of pollen grains adhering to the stigmas of hermaphrodite flowers was significantly higher than that adhering to female flowers when flowers shed their *** results indicate that variation in floral longevity may be an adaptive strategy to pollination conditions for gynodioecious ***.

关键词： floral longevity gynodioecy plasticity pollen limitation Potentilla tanacetifolia.

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 sciences,beijing 100049,china 2Purple Mountain Observatory,chinese academy of sciences,Nanjing 210008,china 3 National Astronomical Observatories,chinese academy of sciences,beijing 100012,china graduate university of chinese academy of sciences 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