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Impact of the Assimilation Frequency of Radar Data with the ARPS 3DVar and Cloud Analysis System on Forecasts of a Squall Line in Southern China 预览
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作者 Yujie PAN Mingjun WANG 《大气科学进展:英文版》 SCIE CAS CSCD 2019年第2期160-172,共13页
Assimilation configurations have significant impacts on analysis results and subsequent forecasts.A squall line system that occurred on 23 April 2007 over southern China was used to investigate the impacts of the data... Assimilation configurations have significant impacts on analysis results and subsequent forecasts.A squall line system that occurred on 23 April 2007 over southern China was used to investigate the impacts of the data assimilation frequency of radar data on analyses and forecasts.A three-dimensional variational system was used to assimilate radial velocity data,and a cloud analysis system was used for reflectivity assimilation with a 2-h assimilation window covering the initial stage of the squall line.Two operators of radar reflectivity for cloud analyses corresponding to single-and double-moment schemes were used.In this study,we examined the sensitivity of assimilation frequency using 10-,20-,30-,and 60-min assimilation intervals.The results showed that analysis fields were not consistent with model dynamics and microphysics in general;thus,model states,including dynamic and microphysical variables,required approximately 20 min to reach a new balance after data assimilation in all experiments.Moreover,a 20-min data assimilation interval generally produced better forecasts for both single-and double-moment schemes in terms of equitable threat and bias scores.We conclude that a higher data assimilation frequency can produce a more intense cold pool and rear inflow jets but does not necessarily lead to a better forecast. 展开更多
关键词 cloud analysis RADAR DATA ASSIMILATION DATA ASSIMILATION INTERVAL
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从占婆长诗看占婆的覆灭与被同化(1832~1835) 预览
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作者 尼古拉·韦伯 杨丽叶(译) 《海洋史研究》 2019年第1期204-228,共25页
根据越南的官方档案,1832年占婆王国①的最后一个公国潘陀浪并入越南,其领土被划为宁顺府和咸顺府,并入越南平顺省。尽管吞并标志着东南亚最负盛名的古国之一占婆的灭亡,但在越南的官方文献只是将其简略为省级政区的重组而已。不过,占... 根据越南的官方档案,1832年占婆王国①的最后一个公国潘陀浪并入越南,其领土被划为宁顺府和咸顺府,并入越南平顺省。尽管吞并标志着东南亚最负盛名的古国之一占婆的灭亡,但在越南的官方文献只是将其简略为省级政区的重组而已。不过,占婆文献却提供了完全不同的角度,认为1832年占婆并入越南是占婆人民生活的转折点。这些文献记载了潘陀浪发生的变化,以及顺化朝廷为将占婆并为越南一个省所推行的一系列改革。 展开更多
关键词 同化 文献记载 人民生活 越南 东南亚 官方
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Towards reliable Arctic sea ice prediction using multivariate data assimilation
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作者 Jiping Liu Zhiqiang Chen +11 位作者 Yongyun Hu Yuanyuan Zhang Yifan Ding Xiao Cheng Qinghua Yang Lars Nerger Gunnar Spreen Radley Horton Jun Inoue Chaoyuan Yang Ming Li Mirong Song 《科学通报:英文版》 SCIE EI CSCD 2019年第1期63-72,共10页
Rapid declines in Arctic sea ice have captured attention and pose significant challenges to a variety of stakeholders.There is a rising demand for Arctic sea ice prediction at daily to seasonal time scales,which is pa... Rapid declines in Arctic sea ice have captured attention and pose significant challenges to a variety of stakeholders.There is a rising demand for Arctic sea ice prediction at daily to seasonal time scales,which is partly a sea ice initial condition problem,Thus,a multivariate data assimilation that integrates sea ice observations to generate realistic and skillful model initialization is needed to improve predictive skill of Arctic sea ice.Sea ice data assimilation is a relatively new research area,In this review paper,we focus on two challenges for implementing multivariate data assimilation systems for sea ice forecast,First,to address the challenge of limited spatiotemporal coverage and large uncertainties of observations,we discuss sea ice parameters derived from satellite remote sensing that (1)have been utilized for improved model initialization,including concentration,thickness and drift,and (2)are currently under develop- ment with the potential for enhancing the predictability of Arctic sea ice,including melt ponds and sea ice leads.Second,to strive to generate the "best"estimate of sea ice initial conditions by combining model simulations]forecasts and observations,we review capabilities and limitations of different data assimilation techniques that have been developed and used to assimilate observed sea ice parameters in dynamical models. 展开更多
关键词 ARCTIC sea ice PREDICTION Remote sensing Data ASSIMILATION
Latest Progress of the Chinese Meteorological Satellite Program and Core Data Processing Technologies 预览
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作者 Peng ZHANG Qifeng LU +9 位作者 Xiuqing HU Songyan GU Lei YANG Min MIN Lin CHEN Na XU Ling Sun Wenguang BAI Gang MA Di XIAN 《大气科学进展:英文版》 SCIE CAS CSCD 2019年第9期1027-1045,共19页
In this paper,the latest progress,major achievements and future plans of Chinese meteorological satellites and the core data processing techniques are discussed.First,the latest three FengYun(FY)meteorological satelli... In this paper,the latest progress,major achievements and future plans of Chinese meteorological satellites and the core data processing techniques are discussed.First,the latest three FengYun(FY)meteorological satellites(FY-2H,FY-3D,and FY-4A)and their primary objectives are introduced Second,the core image navigation techniques and accuracies of the FY meteorological satellites are elaborated,including the latest geostationary(FY-2/4)and polar-orbit(FY-3)satellites.Third,the radiometric calibration techniques and accuracies of reflective solar bands,thermal infrared bands,and passive microwave bands for FY meteorological satellites are discussed.It also illustrates the latest progress of real-time calibration with the onboard calibration system and validation with different methods,including the vicarious China radiance calibration site calibration,pseudo invariant calibration site calibration,deep convective clouds calibration,and lunar calibration.Fourth,recent progress of meteorological satellite data assimilation applications and quantitative science produce are summarized at length.The main progress is in meteorological satellite data assimilation by using microwave and hyper-spectral infrared sensors in global and regional numerical weather prediction models.Lastly,the latest progress in radiative transfer,absorption and scattering calculations for satellite remote sensing is summarized,and some important research using a new radiative transfer model are illustrated. 展开更多
关键词 METEOROLOGICAL SATELLITE GEOLOCATION calibration and VALIDATION SATELLITE data ASSIMILATION RADIATIVE transfer model
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Current Status and Future Challenges of Weather Radar Polarimetry: Bridging the Gap between Radar Meteorology/Hydrology/Engineering and Numerical Weather Prediction 预览
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作者 Guifu ZHANG Vivek N.MAHALE +25 位作者 Bryan J.PUTNAM Youcun QI Qing CAO Andrew D. BYRD Petar BUKOVCIC Dusan S.ZRNIC Jidong GAO Ming XUE Youngsun JUNG Heather D.REEVES Pamela L.HEINSELMAN Alexander RYZHKOV Robert D. PALMER Pengfei ZHANG Mark WEBER Greg M.MCFARQUHAR Berrien MOORE III Yan ZHANG Jian ZHANG J.VIVEKANANDAN Yasser AL-RASHID Richard L.ICE Daniel S.BERKOWITZ Chong-chi TONG Caleb FULTON Richard J. DOVIAK 《大气科学进展:英文版》 SCIE CAS CSCD 2019年第6期571-588,共18页
After decades of research and development, the WSR-88 D(NEXRAD) network in the United States was upgraded with dual-polarization capability, providing polarimetric radar data(PRD) that have the potential to improve we... After decades of research and development, the WSR-88 D(NEXRAD) network in the United States was upgraded with dual-polarization capability, providing polarimetric radar data(PRD) that have the potential to improve weather observations,quantification, forecasting, and warnings. The weather radar networks in China and other countries are also being upgraded with dual-polarization capability. Now, with radar polarimetry technology having matured, and PRD available both nationally and globally, it is important to understand the current status and future challenges and opportunities. The potential impact of PRD has been limited by their oftentimes subjective and empirical use. More importantly, the community has not begun to regularly derive from PRD the state parameters, such as water mixing ratios and number concentrations, used in numerical weather prediction(NWP) models.In this review, we summarize the current status of weather radar polarimetry, discuss the issues and limitations of PRD usage, and explore potential approaches to more efficiently use PRD for quantitative precipitation estimation and forecasting based on statistical retrieval with physical constraints where prior information is used and observation error is included. This approach aligns the observation-based retrievals favored by the radar meteorology community with the model-based analysis of the NWP community. We also examine the challenges and opportunities of polarimetric phased array radar research and development for future weather observation. 展开更多
关键词 WEATHER RADAR POLARIMETRY RADAR METEOROLOGY numerical WEATHER prediction data assimilation MICROPHYSICS parameterization forward operator
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Regional and Global Land Data Assimilation Systems: Innovations,Challenges, and Prospects
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作者 Youlong XIA Zengchao HAO +5 位作者 Chunxiang SHI Yaohui LI Jesse MENG Tongren XU Xinying WU Baoqing ZHANG 《气象学报:英文版》 SCIE CSCD 2019年第2期159-189,共31页
Since the North American and Global Land Data Assimilation Systems(NLDAS and GLDAS) were established in2004, significant progress has been made in development of regional and global LDASs. National, regional, projectb... Since the North American and Global Land Data Assimilation Systems(NLDAS and GLDAS) were established in2004, significant progress has been made in development of regional and global LDASs. National, regional, projectbased, and global LDASs are widely developed across the world. This paper summarizes and overviews the development, current status, applications, challenges, and future prospects of these LDASs. We first introduce various regional and global LDASs including their development history and innovations, and then discuss the evaluation, validation, and applications(from numerical model prediction to water resources management) of these LDASs. More importantly, we document in detail some specific challenges that the LDASs are facing: quality of the in-situ observations, satellite retrievals, reanalysis data, surface meteorological forcing data, and soil and vegetation databases;land surface model physical process treatment and parameter calibration;land data assimilation difficulties;and spatial scale incompatibility problems. Finally, some prospects such as the use of land information system software, the unified global LDAS system with nesting concept and hyper-resolution, and uncertainty estimates for model structure,parameters, and forcing are discussed. 展开更多
关键词 LAND data ASSIMILATION system (LDAS) REGIONAL and GLOBAL LDASs in-situ observation satellite RETRIEVAL LAND surface model (LSM)
Involvement of sulfur assimilation in the low β subunit content of soybean seed storage protein revealed by comparative transcriptome analysis 预览
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作者 Xi Zhang Ruixin Xu +7 位作者 Wei Hu Wan Wang Dezhi Han Fan Zhang Yongzhe Gu Yong Guo Jun Wang Lijuan Qiu 《作物学报:英文版》 CAS CSCD 2019年第4期504-515,共12页
The β subunit of soybean [Glycine max (L.) Merr.] seed storage protein is of great significance in sulfur-containing amino acid balance and soybean processing properties. The objective of this study was to elucidate ... The β subunit of soybean [Glycine max (L.) Merr.] seed storage protein is of great significance in sulfur-containing amino acid balance and soybean processing properties. The objective of this study was to elucidate the relationship between the β subunit and sulfur-containing amino acid composition, and the potential regulatory mechanism. The β subunit was independently accumulated in comparison with other major subunits (α/α′, acidic, basic, and A3) during seed filling, and a low level of β subunit content (BSC) was formed during the accumulation process. In low-BSC mature seeds, crude protein, oil content, and fatty acid composition were not changed, but sulfur-containing amino acids (Cys + Met) in the low- BSC seeds increased significantly (by 31.5%), suggesting that an internal regulatory mechanism within seed might be responsible for the rebalance of seed protein composition and that sulfur assimilation might be deeply involved in β subunit accumulation. Transcriptomic analysis revealed that genes involved in anabolism of cysteine, methionine, and glutathione were up-regulated but those involved in the catabolism of these compounds were down-regulated, suggesting a relationship between the elevation of methionine and glutathione and low BSC. Our study sheds light on seed composition in low BSC lines and on the potential molecular regulatory mechanism of β subunit accumulation, broadening our understanding of soybean seed protein synthesis and its regulation. 展开更多
关键词 SOYBEAN β SUBUNIT TRANSCRIPTOME analysis Sulfur-containing amino ACIDS SULFUR ASSIMILATION
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TOPOGRAPHY-DEPENDENT HORIZONTAL LOCALIZATION SCALE SCHEME IN GRAPES-MESO HYBRID EN-3DVAR ASSIMILATION SYSTEM
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作者 夏宇 陈静 +3 位作者 智协飞 庄照荣 陈良吕 王婧卓 《热带气象学报:英文版》 SCIE 2019年第2期245-256,共12页
Based on the GRAPES-MESO hybrid En-3 DVAR(Ensemble three-dimension hybrid data assimilation for Global/Regional Assimilation and Prediction system) constructed by China Meteorological Administration, a 7-day simulatio... Based on the GRAPES-MESO hybrid En-3 DVAR(Ensemble three-dimension hybrid data assimilation for Global/Regional Assimilation and Prediction system) constructed by China Meteorological Administration, a 7-day simulation(from 10 July 2015 to 16 July 2015) is conducted for horizontal localization scales. 48 h forecasts have been designed for each test, and seven different horizontal localization scales of 250, 500, 750, 1000, 1250, 1500 and 1750 km are set. The 7-day simulation results show that the optimal horizontal localization scales over the Tibetan Plateau and the plain area are 1500 km and 1000 km, respectively. As a result, based on the GRAPES-MESO hybrid En-3 DVAR, a topography-dependent horizontal localization scale scheme(hereinafter referred to as GRAPES-MESO hybrid En-3 DVAR-TD-HLS) has been constructed. The data assimilation and forecast experiments have been implemented by GRAPES-MESO hybrid En-3 DVAR, 3 DVAR and GRAPES-MESO hybrid En-3 DVAR-TD-HLS, and then the analysis and forecast field of these three systems are compared. The results show that the analysis field and forecast field within 30 h of GRAPES-MESO hybrid En-3 DVAR-TD-HLS are better than those of the other two data assimilation systems. Particularly in the analysis field, the root mean square error(RMSE) of u_wind and v_wind in the entire vertical levels is significantly less than that of the other two systems. The time series of total RMSE indicate, in the 6-30 h forecast range, that the forecast result of En-3 DVAR-TD-HLS is better than that of the other two systems, but the En-3 DVAR and 3 DVAR are equivalent in terms of their forecast skills. The 36-48 h forecasts of three data assimilation systems have similar forecast skill. 展开更多
关键词 GRAPES-MESO HYBRID En-3DVAR data assimilation topography-dependent HORIZONTAL LOCALIZATION scales
Full waveform inversion based on the ensemble Kalman filter method using uniform sampling without replacement
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作者 Jian Wang Dinghui Yang +1 位作者 Hao Jing Hao Wu 《科学通报:英文版》 SCIE EI CSCD 2019年第5期321-330,共10页
Full waveform inversion(FWI)has been increasingly more and more important in seismology to better understand the interior structure of the Earth.FWI,by taking advantage of both the traveltime and amplitude in the data... Full waveform inversion(FWI)has been increasingly more and more important in seismology to better understand the interior structure of the Earth.FWI,by taking advantage of both the traveltime and amplitude in the data,provides high-resolution model parameters of the earth which can produce images with high resolution.However,this inversion method conventionally suffers from non-uniqueness due to many local minima of the objective function and large computing costs.In this study,we propose a new FWI method in a semi-random framework by integrating the ensemble Kalman filter and uniform sampling without replacement.Numerical results demonstrate that the new method can achieve highresolution results and a wider convergence domain.Accordingly,the new method overcomes the disadvantage of conventional FWIs that depend strongly on the initial model. 展开更多
关键词 Data ASSIMILATION ENSEMBLE KALMAN filter UNIFORM sampling without REPLACEMENT Full WAVEFORM inversion
高层管理支持、 IT资源与IT吸收的关系研究
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作者 高沛然 张金隆 +1 位作者 艾学轶 张亚军 《管理评论》 CSSCI 北大核心 2019年第5期128-138,290共12页
在信息系统领域,高层管理支持一直被认为是IT吸收过程中的重要变量。然而,关于高层管理支持与IT吸收的关系却存在着争议,并且先前的研究较少同时考虑高层管理支持和IT资源部署,忽视了IT资源部署对高层管理支持效用的影响。因此,本文基... 在信息系统领域,高层管理支持一直被认为是IT吸收过程中的重要变量。然而,关于高层管理支持与IT吸收的关系却存在着争议,并且先前的研究较少同时考虑高层管理支持和IT资源部署,忽视了IT资源部署对高层管理支持效用的影响。因此,本文基于全球112个样本组织,探讨CEO支持这一高层管理支持通过IT基础设施资源和IT人力资源对IT吸收结果变量IT业务跨越能力的影响。研究结果表明:IT基础设施资源和IT人力资源完全中介了CEO支持和IT业务跨越能力的关系,同时IT基础设施资源负向调节IT人力资源与IT业务跨越能力之间的关系,从而减弱了IT人力资源的中介作用。 展开更多
关键词 CEO支持 IT基础设施资源 IT人力资源 IT吸收
从戏曲电影发展史看影戏关系的嬗变——兼论戏曲与中国电影民族化 预览
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作者 王艳 《美育学刊》 2019年第2期72-78,共7页
多样性和多元化是文化艺术的生命力所在,电影的民族特色是构成多样性的重要特征。综观世界电影的不同民族流派,从传统戏剧、歌舞、诗歌等艺术形式中汲取灵感来塑造电影民族性的案例比比皆是。在中国,戏曲被认为是融合了中国古典审美意... 多样性和多元化是文化艺术的生命力所在,电影的民族特色是构成多样性的重要特征。综观世界电影的不同民族流派,从传统戏剧、歌舞、诗歌等艺术形式中汲取灵感来塑造电影民族性的案例比比皆是。在中国,戏曲被认为是融合了中国古典审美意象和民族传统艺术形式的综合艺术,百年来,无论是对影戏的理论研究还是融合两种艺术形式的创作实践都积累了丰富的经验和案例。对于中国电影民族化问题的讨论,重新审视戏曲和中国电影的关系无疑具有现实意义和重要价值。 展开更多
关键词 戏曲电影 同化 民族化
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一种新型约束多目标帝国竞争算法
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作者 操三强 雷德明 《信息与控制》 CSCD 北大核心 2019年第4期437-444,451共9页
针对约束多目标优化问题,提出了一种基于约束违背程度和Pareto支配的有效约束处理策略,并设计了一种新型多目标帝国竞争算法(MOICA).该算法采用一种简化的初始帝国构建过程,在同化过程引入了向外部档案内非劣解学习的机制,并基于帝国势... 针对约束多目标优化问题,提出了一种基于约束违背程度和Pareto支配的有效约束处理策略,并设计了一种新型多目标帝国竞争算法(MOICA).该算法采用一种简化的初始帝国构建过程,在同化过程引入了向外部档案内非劣解学习的机制,并基于帝国势力新定义的帝国竞争新方法以获取问题高质量的解.选用了7个测试问题CF1~CF7进行计算实验并和多种算法进行对比.计算结果表明, MOICA在求解约束多目标优化问题方面具有较强的搜索能力和优势. 展开更多
关键词 多目标优化问题 约束处理 帝国竞争算法 同化
扬雄“蝇,东齐谓之羊”古今考
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作者 钱曾怡 《中国语文》 CSSCI 北大核心 2019年第4期387-391,510共6页
扬雄《方言》“蝇,东齐谓之羊”。在现代山东中部一些方言中,双音词“苍蝇”读为ts'a■^213-21ia■^0,说明西汉时期“蝇”为“羊”的读音至今仍然保存。本文用地图显示其分布地区,并从古代文献和今山东方言两方面进行考察说明:历代... 扬雄《方言》“蝇,东齐谓之羊”。在现代山东中部一些方言中,双音词“苍蝇”读为ts'a■^213-21ia■^0,说明西汉时期“蝇”为“羊”的读音至今仍然保存。本文用地图显示其分布地区,并从古代文献和今山东方言两方面进行考察说明:历代文献并没有单字“蝇”作“羊”的记载;从现代山东方言的情况推断,东齐谓之“羊”的“蝇”字,当是在双音节“苍蝇”这个词中,后字的韵母受前字韵母同化的结果:苍a■蝇i■→苍ia■蝇ia■。 展开更多
关键词 扬雄方言 苍蝇 古今考 山东方言 复音词 音变 同化
A COMPARISON OF THE BLENDING AND CONSTRAINING METHODS TO INTRODUCE LARGE-SCALE INFORMATION INTO GRAPES MESOSCALE ANALYSIS
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作者 杨枚锦 龚建东 +2 位作者 王瑞春 庄照荣 徐枝芳 《热带气象学报:英文版》 SCIE 2019年第2期227-244,共18页
To solve the problem of mesoscale analysis error accumulation after a period of continuous cycle data assimilation(CCDA), a blending method and a constraining method are compared to introduce global analysis informati... To solve the problem of mesoscale analysis error accumulation after a period of continuous cycle data assimilation(CCDA), a blending method and a constraining method are compared to introduce global analysis information into the Global/Regional Assimilation and Prediction Enhanced System mesoscale three-dimensional variational data assimilation system(GRAPES-Meso 3 DVar). Based on a spatial filter used to obtain a blended analysis,the blending method is weighted toward the T639 global analysis for scales larger than the cutoff wavelength of 1,200 km and toward the GRAPES mesoscale analysis for wavelengths below that. The constraining method considers the T639 global analysis data as an extra source of information to be added in the 3 DVar cost function. The cloud-resolving GRAPES-Meso system(3 km resolution) with a 3 h analysis cycle update is chosen, and forecast experiments on an extreme precipitation event over the eastern part of China are presented. The comparison shows that the inclusion of large-scale information with both methods has a positive impact on the regional model, in which the 3 h background forecasts are slightly closer to the radiosonde observations. The results also show that both methods are effective in improving large-scale analysis while reserving the well-featured mesoscale information, leading to an enhancement in the balance and accuracy of the analysis. Subjective verification reveals that the introduction of large-scale information has a visible beneficial impact on the forecast of precipitation location and intensity. The methodologies and experiences presented in this paper could serve as a reference for ongoing efforts toward the development of multi-scale analysis in GRAPES-Meso. 展开更多
关键词 numerical prediction data assimilation BLENDING and constraining method LARGE-SCALE INFORMATION GRAPES mesoscale analysis
双雷达风场反演拼图在登陆台风“莫兰蒂”(1614)强降水精细预报中的同化应用试验 预览
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作者 王叶红 赵玉春 +1 位作者 罗昌荣 韩颂雨 《气象学报》 CAS CSCD 北大核心 2019年第4期617-644,共28页
利用福建龙岩、漳州、泉州新一代多普勒天气雷达和厦门海沧双偏振雷达探测资料,采用动态地球坐标系下双雷达三维风场反演与拼图技术,基于天气研究和预报模式(Weather Research and Forecasting,WRF)及其资料同化系统,对登陆台风"... 利用福建龙岩、漳州、泉州新一代多普勒天气雷达和厦门海沧双偏振雷达探测资料,采用动态地球坐标系下双雷达三维风场反演与拼图技术,基于天气研究和预报模式(Weather Research and Forecasting,WRF)及其资料同化系统,对登陆台风"莫兰蒂"(1614)引起的2016年9月14-15日福建强降水过程进行了双雷达风场反演拼图资料检验及其三维变分同化对强降水精细预报影响的数值试验,结果发现:(1)动态地球坐标系下双雷达反演风场能合理反映实际风场分布状况,其误差相对较小。相较厦门翔安风廓线雷达及厦门探空秒级测风数据,反演风风向(风速)平均绝对误差分别为7.8°(2.6 m/s)及3.4°(1.1 m/s);(2)反演风场水平方向稀疏化对同化及预报结果极为重要,过密的反演风场资料会给同化及预报结果带来负效果。文中采用18、6、2 km 3重嵌套,在3重嵌套区域均进行同化以及仅在2 km区域进行同化两种情况下,均表现为当反演风场资料水平分辨率提高到0.1°时,同化分析及预报的台风环流开始受到负影响;且当反演风场资料水平分辨率越高时,负效果越明显。敏感性试验结果显示,分辨率取0.2°时数值预报效果最好;(3)以美国国家环境预报中心全球预报系统(National Centers for Environmental Prediction/Global Forecast System,NCEP/GFS) 0.5°×0.5°分析场为初值,基于3个不同起报时刻(2016年9月14日14时、20时及15日02时)(北京时,下同)模拟的福建省境内台风内核雨带和螺旋雨带逐时演变、台风路径与强度、逐时降水TS评分和空间相关差异显著,其中14日14时起报试验效果最好;而14日20时起报试验效果最差,这与该试验初始台风大风轴风速明显偏大有关;(4)在上述3个不同起报时刻试验基础上,分别增加双雷达反演风场资料的三维变分同化后,福建境内地面风场和台风内核雨带、螺旋雨带逐时分布、逐时降水TS评分和空间相关� 展开更多
关键词 双雷达 风场反演 同化 台风 强降水
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Soils of Alpine, Subalpine Meadows and Meadow Steppes of Azerbaijan and the Peculiarities of Their Assimilation Potential in Relation to Organic Pollutants 预览
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作者 F.Sh. Keyseruxskaya S.I. Nadjafova 《生态学研究(英文)》 2019年第1期15-19,共5页
Azerbaijan is a country with a huge range of different soil types, which is due to its geographical location. The country is located in two climatic thermal zones, subboreal and subtropical, characterized by a peculia... Azerbaijan is a country with a huge range of different soil types, which is due to its geographical location. The country is located in two climatic thermal zones, subboreal and subtropical, characterized by a peculiar hydrothermal regime, diverse vegetation and soil fauna. For proper zoning of the soil cover of bioclimatic landscape zones and the development of effective organization of management systems, assessment of assimilation potential is of great importance, i.e. self-cleaning potential. The purpose of our research was to assess the actual assimilation capacity and self-cleaning ability of alpine and subalpine meadow soils and meadow steppes in case of their contamination with organic pollutants based on a comprehensive system analysis of biogenic and abiogenic factors. The collected material was comprehensively analyzed from the standpoint of the biogenicity and self-purification capacity of soils of various bioclimatic landscape zones from the standpoint of the danger of soil contamination with organic matter, based on the natural features of the soil and biogenic and abiogenic factors, and appropriately grouped according to the landscape feature. The analysis of the obtained data allows us to position the soils of the Alpine and subalpine meadows and meadow steppes on the growth of the assimilation potential in relation to organic pollutants in the following sequence: Mountain-meadow chernozem-like> Mountain-forest meadow> Mountain- meadow steppe> Mountain-meadow sod. 展开更多
关键词 Soil Landscapes Organic pollution SELF-CLEANING ASSIMILATION POTENTIAL
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挪威对萨米人的民族政策研究 预览
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作者 陈志英 《东北师大学报:哲学社会科学版》 CSSCI 北大核心 2019年第2期109-116,共8页
萨米人被称为北欧的印第安人,是北欧的土著居民。二战前,挪威官方对待萨米人的民族政策是建立在社会达尔文主义上的同化政策,意图将萨米人同化为挪威人,进而灭亡萨米族群。二战后,同化的民族政策逐渐转变为尊重和保护的民族政策,萨米人... 萨米人被称为北欧的印第安人,是北欧的土著居民。二战前,挪威官方对待萨米人的民族政策是建立在社会达尔文主义上的同化政策,意图将萨米人同化为挪威人,进而灭亡萨米族群。二战后,同化的民族政策逐渐转变为尊重和保护的民族政策,萨米人的权益逐渐得到承认和保障。挪威做法可借鉴的经验在于:其一,土著族群身份的确认和族群意识的形成是权利得到承认和尊重的前提;其二,特别重视土著民的文化权利,用充分的语言文字权作为形成和维系土著民族群意识的关键;其三,在族际关系的处理中尽量回避敏感性问题,避免直接的激烈对抗,用和平和规范的方式来实现具体权利的保障。 展开更多
关键词 萨米人 社会达尔文 同化 少数族群
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求解约束优化问题的新型帝国竞争算法
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作者 雷德明 操三强 李明 《控制与决策》 EI CSCD 北大核心 2019年第8期1663-1671,共9页
针对约束优化问题,提出一种约束处理的新策略,运用字典序方法同时优化问题的目标函数和约束违背程度,设计一种新型帝国竞争算法.该算法给出成本和归一化成本的新定义,以避免殖民国家势力为零,并应用嵌入殖民地间全局搜索的同化、基于优... 针对约束优化问题,提出一种约束处理的新策略,运用字典序方法同时优化问题的目标函数和约束违背程度,设计一种新型帝国竞争算法.该算法给出成本和归一化成本的新定义,以避免殖民国家势力为零,并应用嵌入殖民地间全局搜索的同化、基于优秀殖民地的革命、殖民国家的差分进化和新型帝国竞争等策略提高求解质量.基于两组约束优化标准测试函数的实验结果和算法对比表明,结合字典序方法的新型帝国竞争算法在约束优化问题的求解方面具有较强的优势. 展开更多
关键词 约束优化问题 字典序方法 帝国竞争算法 同化 革命
重构与攀附:粟特移民祖先认同变迁研究 预览
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作者 李乔 《中州学刊》 CSSCI 北大核心 2019年第7期134-138,共5页
通过对在洛阳出土的57方粟特人墓志分析可以看出,进入中原地区的粟特人,为了融入汉民族群体,受中原文化影响,开始对自己的祖先来源进行重新建构,即由最初认同先祖来自西域演变为对汉民族的认同,表现为:在姓氏起源上追求与汉民族同姓一致... 通过对在洛阳出土的57方粟特人墓志分析可以看出,进入中原地区的粟特人,为了融入汉民族群体,受中原文化影响,开始对自己的祖先来源进行重新建构,即由最初认同先祖来自西域演变为对汉民族的认同,表现为:在姓氏起源上追求与汉民族同姓一致,在郡望堂号上攀附汉民族同姓望族,但不同姓氏群体在同化进度和程度上又表现出较大的差异。 展开更多
关键词 粟特人 祖先认同 融合 汉化
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Improved simulation of carbon and water fluxes by assimilating multi-layer soil temperature and moisture into process-based biogeochemical model 预览
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作者 Min Yan Zengyuan Li +2 位作者 Xin Tian Li Zhang Yu Zhou 《森林生态系统:英文版》 CSCD 2019年第2期87-101,共15页
Background: Soil temperature and moisture are sensitive indicators in soil organic matter decomposition because they control global carbon and water cycles and their potential feedback to climatic variations. Although... Background: Soil temperature and moisture are sensitive indicators in soil organic matter decomposition because they control global carbon and water cycles and their potential feedback to climatic variations. Although the Biome-Biogeochemical Cycles (Biome-BGC) model is broadly applied in simulating forest carbon and water fluxes, its single-layer soil module cannot represent vertical variations in soil moisture. This study introduces the Biome-BGC MuSo model, which is composed of a multi-layer soil module and new modules pertaining to phenology and management for simulations of carbon and water fluxes. Although this model considers soil processes among active layers, estimates of soil-related variables might be biased, leading to inaccurate estimates of carbon and water fluxes. Methods: To improve the estimations of soil-related processes in Biome-BGC MuSo, this study assimilates ground-measured multi-layer daily soil temperature and moisture at the Changbai Mountains forest flux site by using the Ensemble Kalman Filter algorithm. The modeled estimates of water and carbon fluxes were evaluated with measurements using determination coefficient (R2) and root mean square error (RMSE). The differences in the RMSEs from Biome-BGC MuSo and the assimilated Biome-BGC MuSo were calculated (ΔRMSE), and the relationships between ΔRMSE and the climatic and biophysical factors were analyzed. Results: Compared with the original Biome-BGC model, Biome-BGC MuSo improved the simulations of ecosystem respiration (ER), net ecosystem exchange (NEE) and evapotranspiration (ET). Data assimilation of the soil-related variables into Biome-BGC MuSo in real time improved the accuracies of the simulated carbon and water fluxes (ET: R^2=0.81, RMSE=0.70 mm·d^-1;ER: R^2=0.85, RMSE=1.97 gC·m^-2·d^-1;NEE: R^2=0.70, RMSE=1.16 gC·m^-2·d^-1). Conclusions: This study proved that seasonal simulation of carbon and water fluxes are more accurate when using Biome-BGC MuSo with a multi-layer soil module than using Biome-BGC with a single-layer s 展开更多
关键词 BIOME-BGC MuSo SOIL temperature SOIL moisture ENSEMBLE KALMAN filter Data ASSIMILATION
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