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Journal of Modern Power Systems and Clean Energy 2024年第1期12卷 287-298页

作者： Yifeng Liu Xiaoping Zhou Quan Chen Hanhang Yin Lerong Hong Hao Tian Ying Chen Siyuan Li the College of Electrical and Information Engineering Hunan UniversityChangsha 410082China the Zhejiang Magtron Intelligent Technology Limited Cooperation Jiaxing 314000China the State Grid Qianjiang Electric Power Company Qianjiang 433100China

Line commutated converter based high-voltage direct-current(LCC-HVDC)transmissions are prone to harmonic oscillation under weak *** modeling is an effective method for assessing interaction ***,this paper proposes an improved calculation method for the DC voltage and AC currents of commutation stations to address the complex linearization of the commutation process and constructs an overall harmonic state-space(HSS)model of an *** on the HSS model,the closed-loop AC impedances on the LCC-HVDC sending and receiving ends are then derived and *** impedance characteristics of the LCC-HVDC are then analyzed to provide a physical explanation for the harmonic oscillation of the *** effects of the grid strength and control parameters on system stability are also *** improve the impedance characteristics and operating stability of the LCC-HVDC system,a virtual impedance based stability enhancement control is proposed,and a parameter design method is considered to ensure satisfactory phase margins at both the sending and receiving ***,simulation results are presented to verify the validity of the impedance model and virtual impedance based stability enhancement control.

关键词： Line commutated converter based high-voltage direct-current(LCC-HVDC)transmission harmonic state space stability analysis harmonic oscillation virtual impedance

Spatial distribution of surface energy fluxes over the Loess Plateau in China and its relationship with climate and the environment

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Science China Earth Sciences 2014年第9期57卷 2135-2147页

作者： ZHANG Qiang ZHANG Liang HUANG Jing ZHANG LiYang WANG WenYu SHA Sha Institute of Arid Meteorology China Meteorological Administration Key Laboratory of Arid Climatic Change and Reducing Disaster of Gansu Province Key Open Laboratory of Arid Climatic Change and Disaster Reduction of China meteorological Administration meteorological bureau of Gansu College of Atmospheric Sciences Lanzhou University meteorological bureau of Yongjia

China's Loess Plateau is located at the edge of the Asian summer monsoon in a transition zone of climate and ecology. In the Loess Plateau, climate and environments change along with space, which has an obvious impact on the spatial distribution of surface energy fluxes. Because of scarce land-surface observation sites and short observation time in this area, previous studies have failed to fully understand the land-surface energy balance characteristics over the entire the Loess Plateau and their effect mechanisms. In this paper, we first test the simulation ability of the Community Land Model(CLM) model by comparing its simulated data with observed data. Based on the simulation data for the Loess Plateau over the past thirty years, we then analyze the spatial distribution of surface energy fluxes and compare the pattern differences between the area averages for the driest year and wettest year. Furthermore, we analyze the relationship between the spatial distribution of the components of the surface energy balance with longitude, latitude, altitude, precipitation and temperature. The main results are as follows: the spatial distribution of surface energy fluxes are significantly different, with the surface net radiation and sensible heat flux increasing from south to north and latent heat flux and soil heat flux decreasing from southeast to northwest. The sensible heat flux at the driest point is nearly twice as high as that at the wettest point, whereas the latent heat flux and soil heat flux at the driest point are half as much as that at the wettest point. The impact of variations of annual precipitation on the components of the surface energy balance is also obvious, and the maximum magnitude of the changes to the sensible heat flux and latent heat flux is nearly 30%. To a certain extent, geographical factors(including longitude, latitude, and altitude) and climate factors(including temperature and precipitation) affect the surface energy fluxes. However, the

关键词： Loess Plateau components of surface energy balance spatial distribution climatic and geographical factors effect mechanism

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ANALYSIS OF RAINSTORMS ASSOCIATED WITH SIMILAR TRACK TROPICAL CYCLONES HAITANG (0505) AND BILIS (0604)

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Journal of Tropical Meteorology 2009年第1期15卷 111-115页

作者：余贞寿陈宣淼倪东鸿冀春晓谢海华 Wenzhou meteorological bureau Yueqin meteorological bureau Key Laboratory of meteorological Disaster of Ministry of Education NUIST Zhejiang Institute of meteorological Sciences

It is generally thought that the influence of comparable track typhoons is approximately similar, but in fact their wind and especially their rainstorm distribution are often very different. Therefore, a contrastive analysis of rainstorms by tropical cyclones (TCs) Haitang (0505) and Bilis (0604), which are of a similar track, is designed to help understand the mechanism of the TC rainstorm and to improve forecasting skills. The daily rainfall of TC Haitang (0505) and Bilis (0604) is diagnosed and compared. The result indicates that these two TCs have similar precipitation distribution before landfall but different precipitation characteristics after landfall. Using NCEP/GFS analysis data, the synoptic situation is analyzed; water vapor transportation is discussed regarding the calculated water vapor flux and divergence. The results show that the heavy rainfall in the Zhejiang and Fujian Provinces associated with Haitang (0505) and Bilis (0604) before landfall results from a peripheral easterly wind, a combination of the tropical cyclone and the terrain. After landfall and moving far inland of the storm, the precipitation of Haitang is caused by water vapor convergence carried by its own circulation; it is much weaker than that in the coastal area. One of the important contributing factors to heavy rainstorms in southeast Zhejiang is a southeast jet stream, which is maintained over the southeast coast. In contrast, the South China Sea monsoon circulation transports large amounts of water vapor into Bilis – when a water-vapor transport belt south of the tropical cyclone significantly strengthens – which strengthens the transport. Then, it causes water vapor flux to converge on the south side of Bilis and diverge on the north side. Precipitation is much stronger on the south side than that on the north side. After Bilis travels far inland, the cold air guided by a north trough travels into the TC and remarkably enhances precipitation. In summary, combining vertical wi

关键词： weather forecast tropical cyclones typhoon rainstorms similar tracks water vapor flux vertical wind shear

Effects of urbanization on daily temperature extremes in North China

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Journal of Geographical Sciences 2014年第2期24卷 349-362页

作者： SI Pengt ZHENG Zuofang REN Yu LIANG Dongpo LI Mingcai SHU Wenjun Tianjin meteorological Information Center Tianjin Meteorological Bureau Tianjin 300074 China Institute of Urban Meteorology China Meteorological Administration Beijing 100089 China Tianjin Climate Center Tianjin Meteorological Bureau Tianjin 300074 China Beijing Climate Center Beijing Meteorological Bureau Beijing 100089 China

The regional changes of daily temperature extremes in North China caused by ur- banization are studied further from observed facts and model estimates on the basis of ho- mogenized daily series of maximum and minimum temperature observations from 268 mete- orological stations, NCEP/DOE AMIP- Ⅱ reanalysis data （R-2）, and the data of simulations by regional climate model （RegCM3）. The observed facts of regional warming on long time scales are obtained by analyzing the indices of temperature extremes during two time periods of 1961-2010 and 1951-2010. For urbanization effect, the contributions to decreases in an- nual and winter diurnal temperature range （DTR） are 56.0% and 52.9%, respectively, and increases in the lowest minimum temperature （TNn） are 35.7% and 26.2% by comparison of urban and rural observations. Obtained by R-2 data with observations for contrast, on the other hand, increase in the number of annual warm nights （TN90p） contributed by urbaniza- tion is 60.9%. And observed facts of regional warming in daily temperature extremes are also reflected in the simulations, but what difference is urbanization progress at rural areas in North China would be prominent in the next few years relative to urban areas to some extent from model estimates.

关键词： urbanization daily temperature extremes significant contribution North China

Climatic characteristics of high temperature in East China during 1961-2005

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Journal of Geographical Sciences 2008年第3期18卷 283-294页

作者： SHI Jun TANG Xu CUI Linli Shanghai Climate Center Shanghai Meteorological Bureau Shanghai 200030 China Shanghai meteorological bureau Shanghai 200030 China Shanghai Center for Satellite Remote Sensing and Application Shanghai Meteorological Bureau shanghai 201100 China

Based on the daily maximum temperature data covering the period 1961-2005, temporal and spatial characteristics and their changing in mean annual and monthly high temperature days（HTDs）and the mean daily maximum temperature（MDMT）during annual and monthly HTDs in East China were *** results show that the mean annual HTDs were 15.1 and the MDMT during annual HTDs was 36.3℃in the past 45 *** the mean annual HTDs and the MDMT during annual HTDs were negative anomaly in the1980s and positive anomaly in the other periods of time,oscillating with a cycle of about 12-15 *** mean annual HTDs were more in the southern part,but less in the northern part of East *** MDMT during annual HTDs was higher in Zhejiang,Anhui and Jiangxi provinces in the central and western parts of East *** high temperature process（HTP） was more in the southwestern part,but less in northeastern part of East *** the HTDs and the numbers of HTP were at most in July,and the MDMT during monthly HTDs was also the highest in *** the first 5 years of the 21st century,the mean annual HTDs and the MDMT during annual HTDs increased at most of the stations,both the mean monthly HTDs and the MDMT during monthly HTDs were positive anomalies from April to October,the number of each type of HTP generally was at most and the MDMT in each type of HTP was also the highest.

关键词： climatic characteristics high temperature days (HTDs) mean daily maximum temperature (MDMT) during HTDs high temperature process (HTP) East China

Satellite image analysis and study of Taklimakan Desert rain trails

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Science China Chemistry 1995年第9期38卷 1146-1153页

作者：徐希慧 Xinjiang meteorological bureau Urumqi 830002China

The Taklimakan Desert nephsystem and rain trails after heavy precipitation have been moni-tored continuously for 3 years by using TIROS-N/NOAA meteorological satellite of the United *** facts and its statistical characteristics of the desert rain trails are mainly *** weathersystems which form the deset rain trails are *** significance and some other problems of desertrain trails are also discussed.

关键词： satellite image monitoring desert heavy rainfall desert rain trails drought.

Spatial Distribution and Temporal Variation of the Winter Wheat Late Frost Disaster in Henan,China

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Acta meteorologica Sinica 2011年第2期25卷 249-259页

作者：张雪芬郑有飞王春乙陈怀亮任振和邹春辉 Nanjing University of Information Science & Technology meteorological Observation Centre of CMA Hainan Provincial meteorological bureau Henan Provincial meteorological bureau Chinese Academy of meteorological Sciences

The winter wheat late frost disaster（WFD） occurs mainly in the Yellow and Huaihe River area,of which Henan Province covers the most *** is the major area of wheat production in China,but it is severely hit by the *** this study,we construct a WFD index based on the minimum temperature and the winter wheat development period（WDP）.The WFD degrees and days at 30 agrometeorological stations in Henan Province during the period of 1981-2004 are *** the large-scale temporal variation analysis of WFD,the 24-yr WDP observation series is relatively short,so it is expanded by using the relation between the turning green date of winter wheat and the 5-day running mean temperature and that between the stem elongation phase and the effective cumulative temperature above a critical value of 2.5 ℃.The WFD data are also expanded for the last 50 years and are analyzed by using the empirical orthogonal function（EOF） and the Morlet wavelet *** in the spatial distribution and temporal variation of WFD are *** results show that the frequency of WFD is generally high,exceeding 40% in parts of Henan,and exhibits a rising trend in the period of *** variation trend of WFD degrees is similar to that of WFD days,and the areas with higher WFD degrees coincide the areas with more WFD ***,the WFD degree has a greater impact on the winter wheat yield than the WFD *** areas with high WFD degrees lie in the southeast and southwest of Henan,and the areas with low WFD degrees lie in the south of the Huaihe River and parts of western *** variations of the first and second EOF modes of the WFD degree display 16-and quasi-22-yr periodicities,*** areas of high（low） WFD frequency are distributed in the northern Henan and the southwest border of Henan（the northeast Henan and the middle part of southwest Henan）.The temporal variation of the first（second） EOF mode of WFD days exhibits a periodicity（periodicities

关键词： late frost disaster frost index EOF analysis Morlet wavelet analysis

铅冶炼场地土壤微生物群落结构与硫氧化菌作用

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Journal of Central South University 2024年第4期31卷 1050-1063页

作者：吴川陈虹任陆永平漆彦婷李海峰罗兴华陈玥如娄伟杨卫春李伟展 School of Metallurgy and Environment Central South UniversityChangsha 410083China Department of Science and Environmental Studies The Education University of Hong KongHong Kong 999007China China Railway Seventh bureau Group Nanjing Engineering Co. Ltd.Nanjing 210012China hunan Hikee Environmental Technology Co. Ltd.Changsha 410001China

长期的铅冶炼生产活动给周边地区带来了严重的重金属污染。重金属污染土壤的微生物群落结构和组成对其风险评估和污染修复具有重要意义。本文选择某铅冶炼区域的周边环境,研究重金属污染在垂直剖面上对土壤微生物群落结构和组成的影响... 详细信息

长期的铅冶炼生产活动给周边地区带来了严重的重金属污染。重金属污染土壤的微生物群落结构和组成对其风险评估和污染修复具有重要意义。本文选择某铅冶炼区域的周边环境,研究重金属污染在垂直剖面上对土壤微生物群落结构和组成的影响。结果表明,重金属含量随着土壤垂直深度的增加而逐渐降低,中度污染土壤中微生物群落多样性高于低污染土;无论污染程度如何,表层土壤微生物群落多样性均高于底层;相对丰度优势属包括Perlucidibaca、Limnobacter、Delftia、Hydrogenophaga、Thiobacillus、Sulfurifustis、Sphingopyxis,其中硫氧化菌(SOB)丰度较高。XRD结果表明,土壤中存在PbSO_(4),可能是由于SOB的富集对硫的氧化作用。这种硫循环特征可能是铅(Pb)转化为PbSO_(4)的稳定化修复潜力。

关键词：有色冶炼重金属土壤污染硫氧化菌微生物群落

Evaluation of Agricultural Climatic Resource Utilization During Spring Maize Cultivation in Northeast China Under Climate Change

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Acta meteorologica Sinica 2013年第5期27卷 758-768页

作者：郭建平赵俊芳袁彬冶明珠 Chinese Academy of meteorological Sciences Huafeng meteorological Media Group Xining meteorological bureau

Agricultural climatic resources （such as light,temperature,and water） are environmental factors that affect crop *** the effects of climate change on agricultural climatic resource utilization can provide a theoretical basis for adapting agricultural practices and distributions of agricultural *** study investigates these effects under the IPCC （Intergovernmental Panel on Climate Change） scenario A1B using daily data from the high-resolution RegCM3 （0.25° ×0.25°） during *** outputs are adjusted using corrections derived from daily observational data taken at 101 meteorological stations in Northeast China between 1971 and *** climatic suitability theory is used to assess demand for agricultural climatic resources in Northeast China during the cultivation of spring *** indices,i.e.,an average resource suitability index （Isr）,an average efficacy suitability index （Ise）,and an average resource utilization index （K）,are defined to quantitatively evaluate the effects of climate change on climatic resource utilization between 1951 and *** indices change significantly in both temporal and spatial dimensions in Northeast China under global *** three indices are projected to decrease in Liaoning Province from 1951 to 2100,with particularly sharp declines in Isr,Ise,and K after 2030,2021,and 2011,*** Jilin and Heilongjiang provinces,Isr is projected to increase slightly after 2011,while Ise increases slightly and K decreases slightly after *** spatial maxima of all three indices are projected to shift ***,warming of the climate in Northeast China is expected to negatively impact spring maize production,especially in Liaoning *** maize cultivation will likely need to shift northward and expand eastward to make efficient use of future agricultural climatic resources.

关键词： climate change Northeast China spring maize climatic suitability agricultural climatic resource utilization

Deep learning-based subseasonal to seasonal precipitation prediction in southwest China:Algorithm comparison and sensitivity to input features

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Earth and Planetary Physics 2023年第4期7卷 471-486页

作者： GuoLu Gao Yang Li XueYun Zhou XiaoMing Xiang JiaQi Li ShuCheng Yin Ya’an meteorological Observatory Sichuan Meteorological BureauYa’an Sichuan 625000China Plateau and Basin Rainstorm Drought and Flood Key Laboratory of Sichuan ProvinceChengdu 610000China College of Atmospheric Science Chengdu University of Information TechnologyChengdu 610225China meteorological Observation and Data Centre Sichuan Meteorological BureauChengdu 610072China Leshan meteorological Observatory Sichuan Meteorological BureauLeshan Sichuan 614000China Quanzhou meteorological Observatory Fujian Meteorological BureauQuanzhou Fujian 362000China

The prediction of precipitation at subseasonal to seasonal(S2S)timescales remains an enormous challenge because of the gap between weather and climate *** study compares three deep learning algorithms,namely,the long short-term memory recurrent(LSTM),gated recurrent unit(GRU),and recurrent neural network(RNN),and selects the optimal algorithm to establish an S2S precipitation prediction *** models were evaluated in four subregions of the Sichuan Province:the Plateau,Valley,eastern Basin,and western *** results showed that the RNN model had better performance than the LSTM and GRU *** could be because the RNN model had an advantage over the LSTM model in the transformation of climate indices with positive and negative *** the validation of test datasets,the RNN model successfully predicted the precipitation trend in most years during the wet season(May-October).The RNN model had a lower prediction bias(within±10%),higher sign accuracy of the precipitation trend(~88.95%),and greater accuracy of the maximum precipitation month(>0.85).For the prediction of different lead times,the RNN model was able to provide a stable trend prediction for summer precipitation,and the time correlation coefficient score was higher than that of the National Climate Center of ***,this study proposed a method to measure the sensitivity of the RNN model to different input features,which may provide unprecedented insights into the nonlinear relationship and complicated feedback process among climate *** results of the sensitivity distribution are as ***,the Niño 4 and Niño 3.4 indices were equally important for the prediction of wet season ***,the sensitivity of the snow cover on the Tibetan Plateau was higher than that in the Northern ***,an opposite sensitivity appeared in two different patterns of the Indian Ocean and sea ice concentrations in the Arctic and the Barents Sea.

关键词： recurrent neural network long short-term memory recurrent sensitivity analysis artificial intelligence explainability complex terrain southwest China