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Comparative analysis of temperature and CO2 fluxes for winter wheat in Tibetan Plain and North china Plain using the EMD method

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Progress in Natural Science:Materials International 2006年第10期16卷 1066-1071页

作者： JIANG Zhaoyang, YU Qiang, LEI Shuhe, WANG Tianduo, SUN Xiaomin and ZHANG Renhua ( chinese academy of meteorological Science, beijing 100081, china Institute of Geographic sciences and Natural Resources Research, chinese academy of sciences, beijing 100101, china Mathematics Department, Ocean University of china, Qingdao 266071, china Shanghai Institute of Plant Physiology and Ecology, chinese academy of sciences, Shanghai 200032, china) chinese academy of meteorological Science Beijing 100081 China Institute of Geographic sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China Mathematics Department Ocean University of China Qingdao 266071 China Shanghai Institute of Plant Physiology and Ecology Chinese Academy of Sciences Shanghai 200032 China

Comparative study of spectral properties of temperature and CO2 fluxes measured by eddy covariance method at Yucheng (36°57'N, 116°36'E, 28 m a.s.l., in the North china Plain) and at Lhasa (29°41'N, 91°20'E, 3688 m a.s. 1., on the Tibetan Plateau) is described using the empirical mode decomposition (EMD) method. The main results are: (1) The intrinsic oscillation modes or intrinsic mode functions (IMFs) were extracted from data of temperature ( T) and CO2 fluxes (F) measured at Yucheng ( T1 and F1) and Lhasa ( T2 and F2) . (2) Hilbert transform was applied to these IMF components, then the Hubert-Huang spectra and the marginal spectra of these data were obtained. (3) Comparison of temperature and CO2 fluxes in North china Plain and on Tibetan Plain illustrated that the characteristic frequencies corresponding to T1, F1, T2 and F2 are 0.05 Hz, 0.03 Hz, 0.014 Hz and 0.005 Hz, respectively.

关键词： empirical mode decomposition (EMD) intrinsic mode function (IMF) flux Hilbert transform wheat Tibet.

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PRELIMINARY STUDY ON SAND - DUST STORM DISASTER AND COUNTERMEASURES IN china

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chinese Geographical Science 2002年第1期12卷 9-13页

作者： ZHANG Qing yang, ZHAO Xi you, ZHANG Yuan, LI Li(chinese academy of meteorological sciences, beijing 100081, P.R.china) chinese academy of Meterological sciences Beijing P. R. China

As a kind of natural disasters, sand dust storms frequently occur in deserts and their surrounding areas. The occurrence of this disaster in china′s northwest and north china has exerted an extremely adverse effect upon the environment in china. The management of sand dust storms is of a systematic project closely related with the environment such as agriculture, ecosystem, forestry, water conservancy, meteorology and other aspects. Therefore, studies of the formation, the basic features, causes, temporal spatial distribution, developing trend and related disasters of sand dust storms in china are conducted based on satellite data. The experience of sand dust storms control and countermeasures in the United States and some other countries are referred. Meanwhile, preliminary countermeasures relating to sand dust storms in china are proposed.

关键词： sand-dust storm in china spatial and temporal distribution meteorologicaldisaster countermeasures of sand-dust storms

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Direct Optimization of Low-thrust Many-revolution Earth-orbit Transfers

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chinese Journal of Aeronautics 2009年第4期22卷 426-433页

作者： Gao Yang academy of Opto-Electronics,chinese academy of sciences,beijing 100190,china academy of Opto-Electronics Chinese Academy of Sciences Beijing 100190 China

Low-thrust Earth-orbit transfers with 10^- 5-order thrust-to-weight ratios involve a large number of orbital revolutions which poses a real challenge to trajectory optimization. This article develops a direct method to optimize minimum-time low-thrust many-revolution Earth-orbit transfers. A parameterized control law in each orbit, in the form of the true optimal control, is proposed, and the time history of the parameters governing the control law is interpolated through a finite number of nodal values. The orbital averaging method is used to significantly reduce the computational workload and the trajectory optimization is conducted based on the orbital averaging dynamics expressed by nonsingular equinoctial elements. Furthermore, Earth＇s shadowing and perturbation effects are taken into account. The optimal transfer problem is thus converted to the parameter optimization problem that can be solved by nonlinear programming. Taking advantage of the mapping between the parameterized control law and the Lyapunov control law, a technique is proposed to acquire good initial guesses for optimization variables, which results in enlarged convergence domain of the direct optimization method. Numerical examples of optimal Earth-orbit transfers are presented.

关键词： low thrust orbital transfer optimization direct method orbital averaging Lyapunov method

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Climate effects of nuclear war in china

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Journal of Environmental sciences 1993年第2期5卷 230-240页

作者： Cao Hongxingchinese academy of meteorological sciences, beijing 100081, chinaWang Yongzhong Lin Yunmeibeijing Institute of Meteorology, beijing 100081, china chinese academy of meteorological sciences Beijing 100081 China. China

By utilizing simulations of climatic respponse to nuclear smoke, which were made by the Lawrence Livermore National Laboratory, USA, climate change in china induced by a large-scale nuclear war is analysed. Remarkable climate change in china following nuclear smoke injections is found. The surface air temperature decreases dramatically around all china, surface cooling is 13 ℃ averaging over whole china in July and maximum cooling is 23. 4 ℃ , 3 ℃ cooling in January and maximum 8℃ for the 150 Tg smoke injection (equivalent to the base-line nuclear war). However, the change in temperature is unhomogeneous, implying that the rise in temperature happens over some parts of china. An averaging precipitation decrease in many of months of the experimental year. The precipitation defect is dependent on a scale of nuclear war, the deduction is 1.8mm/day averaging over china in July in the 150 Tg smoke injection, and 0.1 mm/d in January. Nevertheless, the precipitation enhancement in a few months over some regions is found. This dramatic climate change brings catastrophe to agriculture, ecology, as well as socio-economics.

关键词： nuclear winter climate simulation precipitation change.

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Urban effects and summer thunderstorms in a tropical cyclone affected situation over Guangzhou city

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Science china Earth sciences 2007年第12期50卷 1867-1876页

作者： MENG WeiGuang1,3,YAN JingHua1 & HU HaiBo2 1 Institute of Tropical and Marine Meteorology,chinese meteorological Administration(CMA),Guangzhou 510080,china 2 Institute of Urban Meteorology,CMA,beijing 100089,china 3 State Key Laboratory of Severe Weather,chinese academy of meteorological sciences,beijing 100081,china Institute of Tropical and Marine Meteorology Chinese Meteorological Administration (CMA) Guangzhou China State Key Laboratory of Severe Weather Chinese Academy of Meteorological Sciences Beijing China Institute of Urban Meteorology CMA Beijing China

With data mainly from Guangzhou mesonet Automatic Weather Stations(AWS),Guangzhou Doppler Radar and satellite TBB data,characteristics and evolution of the urban heat island(UHI) over Guang-zhou City were analyzed in a tropical cyclone affected situation for early August *** particular,two thunderstorms occurring during this period respectively at the night of 4 August and in the afternoon of 7 August were investigated to study the relationships between the development of thunderstorms and the *** showed that two thunderstorms were associated with the UHI *** induced local air convergence and initiated the thunderstorm *** cases showed a general agreement in time and space for the locations of maximum UHI,convergence,convection,and *** was found to be more favorable to developing in time periods and locations with stronger intensity of *** also showed that,due to the urban effects,both thunderstorms got strengthened when moving over Guangzhou City,with maximum radar echoes observed right over the urban area and precipitation located within the *** these features reveal that two thunderstorms were urban-induced storms.

关键词： summer thunderstorms, urban heat islands (UHI), urban effects, tropical cyclone

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Arabian Peninsula-North Pacific Oscillation and its association with the Asian summer monsoon

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Science china Earth sciences 2008年第7期51卷 1001-1012页

作者： SUN JianQi1, YUAN Wei2 & GAO YuZhong3 1 Nansen-Zhu International Research Centre, Institute of Atmospheric Physics, chinese academy of sciences, beijing 100029, china 2 china meteorological Administration Training Centre, beijing 100081, china 3 Heilongjiang meteorological Observatory, Harbin 150030, china Nansen-Zhu International Research Centre Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China china meteorological Administration Training Centre Beijing China Heilongjiang meteorological Observatory Harbin China

Using correlation and EOF analyses on sea level pressure from 57-year NCEP-NCAR reanalysis data, the Arabian Peninsula-North Pacific Oscillation (APNPO) is identified. The APNPO reflects the co-variability between the North Pacific high and South Asian summer monsoon low. This teleconnec- tion pattern is closely related to the Asian summer monsoon. On interannual timescale, it co-varies with both the East Asian summer monsoon (EASM) and South Asian summer monsoon (SASM); on decadal timescale, it co-varies with the EASM: both exhibit two abrupt climate changes in the middle 1960s and the late 1970s respectively. The possible physical process for the connections between the APNPO and Asian summer monsoon is then explored by analyzing the APNPO-related atmospheric circulations. The results show that with a strong APNPO, the Somali Jet, SASM flow, EASM flow, and South Asian high are all enhanced, and an anomalous anticyclone is produced at the upper level over northeast china via a zonal wave train. Meanwhile, the moisture transportation to the Asian monsoon regions is also strengthened in a strong APNPO year, leading to a strong moisture convergence over India and northern china. All these changes of circulations and moisture conditions finally result in an anoma- lous Asian summer monsoon and monsoon rainfall over India and northern china. In addition, the APNPO has a good persistence from spring to summer. The spring APNPO is also significantly corre- lated with Asian summer monsoon variability. The spring APNPO might therefore provide valuable in- formation for the prediction of Asian summer monsoon.

关键词： Arabian Peninsula-North Pacific Oscillation East Asian summer monsoon South Asian summer monsoon wave train abrupt climate change

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Impacts of climate change on development rate and production of corn in the northeastern china

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Journal of Environmental sciences 1993年第2期5卷 201-208页

作者： Guo Jianping, Gao Suhua Pan Yaruchinese academy of meteorological sciences, beijing 100081, china chinese academy of meteorological sciences Beijing 100081 China China

In this paper, the impacts of climate change on development rate and production of corn in the northeastern china are discussed. The results show that the higher the temperature is, the faster the development rate will be. And the more the precipitation is, the slower the development rate will be. Of which, air temperature is the controlling factor of corn development rate. The influences of development rate on corn yield are remarkable. The impacts of development rate on production in first and last periods are great, and small in the middle two periods. The development rate is positive by relate with corn production from sowing to emergence stage and negative during other periods. So, it is very important to arrange a suitable sowing time for com cultivating in the northeastern china.

关键词： climate change development rate corn.

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2023 Guideline for the management of hypertension in the elderly population in china

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Journal of Geriatric Cardiology 2024年第6期21卷 589-630页

作者： Hypertension Branch of chinese Geriatrics Society,beijing Hypertension Association,National Clinical Research Center of the Geriatric Diseases Qi HUA Li FAN Zeng-Wu WANG Jing LI 不详 Xuanwu Hospital Capital Medical UniversityBeijingChina chinese PLA General Hospital BeijingChina Fuwai Hospital Chinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina

Preamble Hypertension is one of the most common chronic diseases and the primary risk factor for stroke,myocardial infarction and even cardiovascular *** than half of the elderly population has high blood *** people are a unique group,and strategies for the prevention,diagnosis,evaluation,and treatment of hypertension in elderly individuals differ significantly from those in the general population.

关键词： hypertension prevention diagnosis

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Size-dependent hydroxyl radicals generation induced by SiO_2 ultra-fine particles: The role of surface iron

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Science china Chemistry 2009年第7期52卷 1033-1041页

作者： SHANG Yu1, ZHU Tong1, LI Yi1,2 & ZHAO JinCai3 1 College of Environmental sciences and Engineering, Peking University, beijing 100871, china 2 chinese academy of meteorological sciences, beijing 100871, china 3 Institute of Chemistry, chinese academy of sciences, beijing 100871, china College of Environmental sciences and Engineering Peking University Beijing China chinese academy of meteorological sciences Beijing China Institute of Chemistry Chinese Academy of Sciences Beijing China

Oxidative stress and hydroxyl radicals (·OH) play important roles in adverse health effects caused by inhalable ambient air particles (PM10). The ultra-fine fraction of PM10 has been hypothesized as one of the critical contributors to ·OH generation. Both in vivo and in vitro studies have shown that ultra-fine particles (UFPs) or nano-particles generate more ·OH than larger particles with identical mass and composition. Both the surface area and surface-adsorbed redox-active metals have been suggested as factors to determine the oxidative capacity of UFPs. In this study, the ·OH-generating capability of dif-ferent sizes of SiO2 particles was investigated in order to determine which factor influences particle-induced ·OH generation. The amount of ·OH generated in both acellular and cellular systems was quantified using a capillary electrophoresis method following exposure to SiO2 particles with diameters of 14, 100, and 500 nm. The amount of ·OH was strongly dependent on particle size, and a significant enhancement was observed only with 14 nm particles. Further studies indicated a close association between ·OH and iron ion concentration (R2 = 0.812, p<0.01). Washed particles, with their surface iron being removed, did not generate ·OH. The iron-containing leachate from these washings was able to enhance ·OH production as untreated particles did. Therefore, the presence of adsorbed iron on the surface of the SiO2 particles is presented as a possible mechanism of UPFs-induced ·OH generation. The SiO2 acted as an inert substrate, and the surface of ultra-fine SiO2 particles acted as a carrier for iron.

关键词： ultra-fine particles nano-particles ·OH oxidative stress size-effect

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Modelling　the　meteorological　influence　on　the　yellowing　of　spring　wheat　leaves

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Journal of Environmental sciences 1994年第2期6卷 252-259页

作者： Wang Futang Wang Shili(chinese academy of meteorological sciences, beijing 100081,china)Li Youwen Guo Yousan Wei Yurong(meteorological Institute of Inner Mongolia Autonomous Region)

The yellowed-leaf rate is one of the important variables in simulation models for thegrowth of spring wheat. Based on the field experiments (1985-1988), the evolution of yellowed-leafrate of spring wheat is analyzed. The functional relationship between the yellowing process of greenleaves and the development stages of spring wheat is established. Based on modelling and correctingfor the yellowing proass of green leaves affected by temperature and moisture, the synthetic modelfor simulating the dynaniical evolution of yellowed-leaf rate is constructed. The numerical experi-inents show that the result of the modelling is satisfactory.

关键词： simulation model meteorological influence,spring wheat.

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