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Variation in transboundary flow of Nujiang River and its correlation with summer monsoon under the effect of the Longitudinal Range-Gorge

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Science Bulletin 2007年第S2期 148-155页

作者： YOU WeiHong~(1+) GUO ZhiRong~(1,2) HE DaMing~3 1 department of atmospheric sciences,School of Resource Environment and Earth Science,Yunnan university,Kunming 650091,china 2 department of atmospheric sciences,nanjing information engineering university,nanjing 210044,china 3 Asia International Rivers Center,Yunnan university,Kunming 650091,china

The relationship between the variations of the Nujiang River transboundary flow and the summer mon- soon activity under the topographical effect of the Longitudinal Range-Gorge（LRG）is *** study is based on statistical analysis of the observed river flow data,and their correlation with the reanalyzed U/V wind fields of the National Centers for Environment Prediction（NCEP）and the National Center for atmospheric Research（NCAR）,and the data of the Outgoing Longwave Radiation（OLR）of the National Oceanic and atmospheric Administration（NOAA）.It is concluded that the transboundary river flow is predominantly concentrated in the wet or rainy season（from May to October）,particularly in the summer or flood season（from June to August）.There is a clear tendency for the transboundary river flow to increase with time since 1970s,particularly apparent since *** to the topographical"east-west barrier and north-south corridor"effects of the LRG,the summer river flow variations are largely correlated with winds of the southerly and northerly at both high and low *** contrast, the river flow variations are apparently correlated wIth winds of the easterly and westerly only at the high altitudes,not at the low *** correlation between the OLR and the river flow varla- tions is also *** relationships are quantitatively described using two summer monsoon indices proposed in this *** index MI2includes both dynamical and thermodynamical effects and givee a generally good representation of the transboundary river flow variations in the LRG region of the Nujiang River *** MI2represents stronger summer monsoon activity and higher transboundary river flow,while smaller MI2suggests weaker monsoon circulation and lower water flow.

关键词： Longitudinal Range-Gorge(LRG) Nujiang River transboundary river flow summer monsoon monsoon index

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On the interannual variation in spring atmospheric inter-hemispheric oscillation linked to synchronous climate in china

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Progress in Natural Science:Materials International 2009年第9期19卷 1125-1131页

作者： Chuhan Lu, Zhaoyong Guan * Key Laboratory of Meteorological Disaster of Ministry of Education and College of atmospheric sciences, nanjing university of information Science and Technology, nanjing 210044, china [a]Key Laboratory of Meteorological Disaster of Ministry of Education and College of atmospheric sciences Nanjing University of Information Science and Technology Nanjing 210044 China

Based on NCEP/NCAR monthly mean reanalysis data and surface observations of Chinese stations, inter-hemispheric oscillations (IHO) of spring atmospheric mass on an interannual basis in conjunction with the linkage to the synchronous climate over china are studied. Results suggest that the spring IHO exhibits a significant seesaw pattern for air mass at bi-hemispheric mid-high latitudes, with a consistent vertical circulation structure. The EOF decomposition of zonally mean surface pressures without signals of Arctic Oscillation (AO) and Antarctic Oscillation (AAO) indicates that the EOF1 IHO feature is remarkable, with the corresponding time coeficients correlated with the spring IHO index (IIHO) at 0.93; the spring IHO bears a close relation to the synchronous climate in china, showing the surface pressure, temperature and relative humidity over the country to be in good correlation with IIHO; the spring duststorms in Qinghai, Gansu, Shaanxi and Inner Mongolia have bearing on IHO. Positive-phase IIHO promotes the strengthening of the Siberian high, during which zonal winds between 60°E and 150°W show a longitudinal teleconnection structure extending from the Arctic to Antarctica, leading to positive westerly wind anomalies over Asia, affecting the spring climate of china.

关键词： Air mass Inter-hemispheric oscillation (IHO) Spring climate china

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Two possible mechanisms for vortex self-organization

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Science china Earth sciences 2006年第2期49卷 202-211页

作者： LUO Zhexian2, ZHOU Xiuji1 & GAO Shouting3 1. Chinese Academy of Meteorological sciences, Beijing 100081, china 2. department of Space information Science, nanjing university of information Science and Technology, nanjing 210044, china 3. Institute of atmospheric Physics, Chinese Academy of sciences, Beijing 100029, china 2. department of Environmental Science Nanjing University of Information Science and Technology Nanjing 210044 China 1. Chinese Academy of Meteorological sciences Beijing 100081 China 3. Institute of atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

The vortex self-organization is investigated in this paper by four groups of numerical experiments within the framework of quasi-geostrophic model, and based on the experimental results two types of possible mechanisms for vortex self-organization are suggested. The meso-scale to-pography may enable separated vortices to merge into a larger scale vortex; and the interaction of meso-γ and meso-β scale systems may make separated vortices to self organize a typhoon-like vor-tex circulation.

关键词： vortex, self-organization, meso-scale topography, interaction of different scales.

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Interhemispheric atmospheric mass oscillation and its relation to interannual variations of the Asian monsoon in boreal summer

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Science china Earth sciences 2010年第9期53卷 1343-1350页

作者： LU ChuHan, GUAN ZhaoYong & CAI JiaXi Key Laboratory of Meteorological Disaster of Ministry of Education and College of atmospheric sciences, nanjing university of information Science & Technology, nanjing 210044, china 1. Key Laboratory of Meteorological Disaster of Ministry of Education and College of atmospheric sciences Nanjing University of Information Science & Technology Nanjing 210044 China

Using NCEP/NCAR reanalysis and precipitation records of Chinese stations, we have investigated the relationship of interhemispheric oscillation of air mass (IHO) with global lower-level circulation and monsoon anomalies in boreal summer. Our results show that the summer IHO explains a greater portion of variance in the abnormal distribution of atmospheric mass over 30°S-60°N as well as the Antarctic. The IHO strongly correlates to the variations of sea level pressure (SLP) in these regions. It is shown that IHO has some influences on both atmospheric mass transports and water vapor fluxes over 30°S-60°N in association with three anomalous cyclonic circulations over land areas of the eastern hemisphere, which is in close relation to the changes in summer monsoon intensity in eastern Asia and western Africa. Composites of summer rainfall anomalies in china for high and low IHO-index years indicate that the eastern Asian summer monsoon is more intense, with positive precipitation anomaly centers in northern and northeastern parts of china, as opposed to the negative center over the mid-lower reaches of the Yangtze River (MLRYR) in stronger IHO years. In weak IHO years, a feeble summer monsoon appears in eastern Asia, leading to positive center of precipitation anomalies displaced into the MLRYR. Furthermore, a teleconnection in wind fields between the western African and eastern Asian monsoon regions was observed in the middle and higher troposphere in the scenario of IHO. The anomalous cyclonic (anticyclonic) circulations along the path of this Africa-East Asia teleconnection were found to be just over the diabatic heating (cooling) centers, suggesting that diabatic forcings are responsible for the formation of this Africa-East Asia teleconnection.

关键词： interhemispheric oscillation Asian monsoon precipitation china boreal summer

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A relationship between the nonexistence of generalized bent functions and class groups

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Science china Mathematics 2010年第1期53卷 213-222页

作者： LIU FengMei 1,& YUE Qin 21 department of information Research,College of information engineering,information engineering university,Zhengzhou 450002,china 2 department of Mathematics,nanjing university of Aeronautics and Astronautics,nanjing 210016,china 1. department of information Research College of Information Engineering Information Engineering University Zhengzhou 450002 China2. Department of Mathematics Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

A new result on the nonexistence of generalized bent functions is presented by using properties of the decomposition law of primes in cyclotomic fields and properties of solutions of some Diophantine equations. At the same time,a method is given which can be used to simplify the known results. Then we give the bounds and the meaning in algebraic number theory of the parameters in our results.

关键词： generalized bent function integral basis class group genus theory

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Large eddies induced by local impulse at wall of boundary layer with pressure gradients

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Progress in Natural Science:Materials International 2008年第7期18卷 873-878页

作者： Changgen Lu a,b,*, Weidong Caob, Yanmei Zhang b, Jintao Pengb a College of atmospheric Science, nanjing university of information Science & Technology, nanjing 210044, china b College of Environmental Science and engineering, Hohai university, nanjing 210098, china College of atmospheric Science Nanjing University of Information Science & Technology Nanjing 210044 China College of Environmental Science and engineering Hohai University Nanjing 210098 China

Large eddies induced by local impulse at the wall with pressure gradients in the boundary layer was studied by direct numerical sim- ulations. The results show that the amplitude evolution, the high and low speed stripes, the formation of streamwise vortices, the ejection and sweeping, inflexions and distortion at the mean velocity profiles, as well as other characteristics, are consistent with the experimental and other numerical results. It is also found that large eddies are easy to be excited with adverse pressure gradient in the boundary layer, and the growth of amplitudes, formation of streamwise vortices and the influencing area etc., are much larger than those with favorable pressure gradient in the boundary layer. In contrast, large eddies are hardly to be induced through local impulse disturbance at the wall with favorable pressure gradients in the boundary layer.

关键词： Boundary layer Pressure gradients Impulse Large eddies

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Features of aerosol optical depth and its relation to extreme temperatures in china during 1980–2001

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Acta Oceanologica Sinica 2011年第2期30卷 33-45页

作者： HU Ting SUN Zhaobo LI Zhaoxin Jiangsu Key Laboratory of Meteorological Disaster Nanjing University of Information Scienceand Technology Nanjing 210044 China The department of atmospheric Science Nanjing University of Information Science andTechnology Nanjing 210044 China Laboratoire de Meteorologie Dynamique CNRS France

Based on Total Ozone Mapping Spectrometer （TOMS） monthly aerosol optical thickness （AOT） measurements in 1980–2001 a study is made of space/time patterns and difference between land and sea of AOT 0.50 μm thick over china,which are put into correlation analysis with synchronous extreme temperature indices （warm/cold day and night）.Results suggest that 1） the long-term mean AOT over china is characterized by typical geography,with pronounced land-sea *** AOT has significant seasonality and its seasonal difference is diminished as a function of latitude.2） On the whole,the AOT displays an appreciably increasing trend,with the distinct increase in the eastern Qinghai-Tibetan plateau and SW china,North china,the mid-lower Changjiang （MiLY） valley as well as the South china Sea,but marginal decrease over western/northern Xinjiang and part of South china.3） The AOT over land and sea is marked by conspicuous intra-seasonal and -yearly oscillations,with remarkable periods at one-,two-yr and more （as interannual periods）.4） Land AOT change is well correlated with extremely temperature ***,the correlations of AOT to the extreme temperature indices are more significant in Eastern china with 110 ° E as the *** high-correlation regions are along the Southern china coastline,the Loess Plateau and the Sichuan Basin,and even higher in North china Plain and the mid-lower Changjiang River reaches.5） Simulations of LMDZ-regional model indicate that aerosol effects may result in cooling all over china,particularly in Eastern *** contribution of aerosol change may result in more decrease in the maximum temperature than the minimum,with decrease of 0.11/0.08 K for zonal average,respectively.

关键词： aerosol optical thickness extreme temperature index space/time pattern trend correlation

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Sufficient and necessary conditions for Lyapunov stability of Lorenz system and their application

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Science china(information sciences) 2010年第8期53卷 1574-1583页

作者： LUO Qi 1 , LIAO XiaoXin 2 & ZENG ZhiGang 2 1 College of information and Control, nanjing university of information Science and Technology, nanjing 210044, china 2 department of Control Science and engineering, Huazhong university of Science and Technology, Image Processing and Intelligent Control Key Laboratory of Education Ministry of china, Wuhan 430074, china 1. College of information and Control Nanjing University of Information Science and Technology Nanjing 210044 China2. Department of Control Science and Engineering Huazhong University of Science and Technology Image Processing and Intelligent Control Key Laboratory of Education Ministry of China Wuhan 430074 China

The sufficient and necessary conditions for Lyapunov stability of the zero equilibrium point of Lorenz system are discussed, and some brief criteria are presented for globally exponential stability, globally asymptotical stability and instability. Furthermore, the behavior of the non-zero equilibrium point of Lorenz system is also investigated, and several sufficient and necessary conditions are provided for locally exponential stability and instability. The established theorems in this paper develop and extend the existing achievements on Lyapunov stability of Lorenz system. In conclusion, by applying the obtained results, some less conservative feedback-control laws are derived to guarantee the globally exponential stability of the chaos control of Chen system, Lu¨ system, Yang-Chen system and Yu-Xia Li system.

关键词： Lorenz system Lyapunov stability sufficient and necessary condition bifurcation values globally exponential synchronization

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Heterogeneous reaction of NO_2 with sea salt particles

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Science china Chemistry 2010年第12期53卷 2652-2656页

作者： YE ChunXiang 1,LI HongJun 1,ZHU Tong 1,SHANG Jing 1,ZHANG ZeFeng 1,2 & ZHAO DeFeng 1 1 State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental sciences and engineering,Peking university,Beijing 100871,china 2 College of atmospheric Physics,nanjing university of information Science and Technology,nanjing 210044,china 1. State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental sciences and engineering Peking University Beijing 100871 China2. College of Atmospheric Physics Nanjing University of Information Science and Technology Nanjing 210044 China

To understand how NO2 reacts with sea salt particles in the atmosphere of Mega-cities in coastal zones,the heterogeneous reaction of NO2 on the surface of wet sea salt was investigated with diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and ion chromatography (IC).Kinetic measurements indicated that nitrate formation on sea salt was second order in NO 2 concentration and reactive uptake coefficients were (5.51 ± 0.19) × 10-7 and 1.26 × 10-6 respectively under 0% and 20% relative humidity (RH) at NO 2 molecular concentration of 1.96 × 1015 mol/*** results showed that liquid water was formed at the site of MgCl2·6H2O,CaCl2·2H2O on the surface of sea salt and made the reaction more sustainable by releasing hydrated water and absorbing water from air even under a low RH (30%).Therefore,pure NaCl particles should not be used to represent sea salt in studies of the heterogeneous reaction with NO2.

关键词： sea salt particles diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) hydrated water absorbed water reactive uptake coefficient

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Performance of iteratively decoded bit-interleaved coded modulation with chaos based interleaving strategies

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Science china(information sciences) 2010年第4期53卷 833-841页

作者： ZOU XueLan1*, LIU WeiYan2 & FENG GuangZeng3 1department of Electronic and information engineering, Zhejiang Institute of Media and Communications, Hangzhou 310018, china 2department of information engineering, Jiangsu City Vocation College, nanjing 210036, china 3College of Communication and information engineering, nanjing university of Posts and Telecommunications, nanjing 210003, china 1. department of Electronic and information engineering Zhejiang Institute of Media and Communications Hangzhou 310018 China2. Department of Information Engineering Jiangsu City Vocation College Nanjing 210036 China3. College of Communication and Information Engineering Nanjing University of Posts and Telecommunications Nanjing 210003 China

Bit-interleaved coded modulation with iterative decoding (BICM-ID) is a bandwidth efficient trans- mission scheme which is well suitable for next-generation mobile communications. The interleaver design is critical to the high performance of BICM-ID. In this paper we investigate the application of the chaos theory to the interleaver design to further improve the performance of BICM-ID. A new interleaving scheme based on the chaos theory is proposed. Compared with the random interleaver, the proposed approach has the ad- vantages including lower system delay and higher transmission efficiency. Simulation results in both additive white Gaussian noise (AWGN) channel and Rayleigh fading channel are provided, which demonstrates that the new interleaver is better than the random interleaver and exhibits excellent performance when applied to the BICM-ID system.

关键词： chaos interleaving bit-interleaved coded modulation (BICM) iterative decoding

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