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一种基于相对区分表的属性约简算法 被引量:7
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作者 张维 杨青 张清国 《计算机工程与设计》 CSCD 2004年第5期766-768,775,共4页
属性约简是知识获取中的核心问题之一。为了能较高效率地获得属性约简,在Rough Set理论基础上构造出了相对区分表,将基于相对区分表的属性的简的判定算法(JRA)作为子算法并结合归纳属性的简算法的优点,设计出了基于相对区分表的归纳属... 属性约简是知识获取中的核心问题之一。为了能较高效率地获得属性约简,在Rough Set理论基础上构造出了相对区分表,将基于相对区分表的属性的简的判定算法(JRA)作为子算法并结合归纳属性的简算法的优点,设计出了基于相对区分表的归纳属性约简算法(RA)。算例说明该算法具有较高的属性约简效率,并能取得较好的约简结果。 展开更多
关键词 相对区分表 属性约简 判定算法 (JRA RA 知识获取 ROUGH SET理论
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情绪体验范围和区分性量表中文版在医学院大学生中应用的效度和信度 被引量:2
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作者 汪海彬 张俊杰 +2 位作者 刘婷 姚本先 朱运影 《中国心理卫生杂志》 CSSCI CSCD 北大核心 2015年第7期549-550,共2页
情绪复杂性(emotional complexity)的本质在于情绪概念系统的分化和整合程度,其对个体的身心健康和社会适应有重要意义。Lane等于1987年编制了情绪觉察水平量表(Levels of Emotional Aw areness Scale,LEAS)来测量情绪复杂性,但由... 情绪复杂性(emotional complexity)的本质在于情绪概念系统的分化和整合程度,其对个体的身心健康和社会适应有重要意义。Lane等于1987年编制了情绪觉察水平量表(Levels of Emotional Aw areness Scale,LEAS)来测量情绪复杂性,但由于其计分繁琐, 展开更多
关键词 情绪复杂性 情绪体验范围和区分性量 信度 效度
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上海FDI碳足迹测度与分解——基于区分内外资企业异质性的省际投入产出表 被引量:1
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作者 张晓娣 范磊 《上海经济研究》 北大核心 2024年第6期99-113,共15页
基于区分内资企业和外资企业异质性的中国省际投入产出模型最新研究成果,本文追溯1997-2017年间代表年份国内价值链中外资企业的碳足迹,全面评价各省外资活动为满足最终生产的生命周期碳排放水平。全国层面,外资碳足迹占碳排放总量比重... 基于区分内资企业和外资企业异质性的中国省际投入产出模型最新研究成果,本文追溯1997-2017年间代表年份国内价值链中外资企业的碳足迹,全面评价各省外资活动为满足最终生产的生命周期碳排放水平。全国层面,外资碳足迹占碳排放总量比重呈现上升再下降的态势,峰值出现在2007年。上海FDI价值链碳排放呈现如下特征:占全国比重不断下降,但长三角三省一市整体比重有所提升;随着上海转向以服务业为主的经济结构,外资碳足迹也呈现出从化工、冶金等高碳产业向机械电气、高端装备等先进制造业,以及商务、信息等现代服务业转移的趋势;碳足迹的主要来源地从能源富集省份和重化工省份,向长三角地区、中东部产业及物流发达省份转移。研究结果凸显出建立碳足迹数据、增强服务业低碳治理的迫切性,以及在界定地区碳排放责任时,应充分考虑国内价值链分工,重视外资企业跨省域产业链布局对碳排放的影响。 展开更多
关键词 FDI 碳足迹 国内价值链 区分所有制的省际投入产出
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MMPI中美T分对精神分裂症与正常人区分效度的对照研究 被引量:3
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作者 韩岭 施为义 +2 位作者 刘素兰 张诚 陈虹 《中国心理卫生杂志》 CSSCI CSCD 北大核心 1994年第3期114-117,共4页
采用明尼苏达多相个性调查(MMPI)中国版399题,对106例精神分裂症与100例正常人进行测查,比较中国T分(不加K)60划界与美国T分(加K)70划界两种标准下的量表区分度。结果发现,采用中国T分60划界后,F,... 采用明尼苏达多相个性调查(MMPI)中国版399题,对106例精神分裂症与100例正常人进行测查,比较中国T分(不加K)60划界与美国T分(加K)70划界两种标准下的量表区分度。结果发现,采用中国T分60划界后,F,Sc(8)与Pa(6)量表以及由这三个量表组成的两点或三点编码方式敏感性显著下降(P<0.05~0.01),但特异性大都改善。上述结果在一效度检验组中得到证实。最后对造成上述现象的原因及中国T分划界标准的临床应用价值作了讨论。 展开更多
关键词 MMPI 区分 精神分裂症
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一种基于粗集的决策表求核算法
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作者 蔡莉 胡学钢 《安徽大学学报(自然科学版)》 CAS 北大核心 2007年第6期24-27,共4页
决策表是粗集理论的处理对象,其核属性的计算往往是决策信息约简过程的出发点和关键.大多数决策表的求核方法是基于差别矩阵的,具有较高的时间复杂度和空间复杂度.基于区分表,提出一种效率更高的计算核属性的算法,并验证了算法的正确性.
关键词 粗集 决策 差别矩阵 区分表
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商标法中“同一种商品或服务”的司法认定 被引量:2
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作者 陈胜蓝 周林彬 《东南学术》 CSSCI 北大核心 2016年第6期153-159,共7页
在当前经济转型背景下,对商标法中"同一种商品或服务"的认定,应以保护、鼓励市场创新为导向,以相关商品或服务的实质内容作为司法认定的主要依据,以区分表为重要参考,准确把握区分表的文本变化及其主旨精神,结合相关公众的一... 在当前经济转型背景下,对商标法中"同一种商品或服务"的认定,应以保护、鼓励市场创新为导向,以相关商品或服务的实质内容作为司法认定的主要依据,以区分表为重要参考,准确把握区分表的文本变化及其主旨精神,结合相关公众的一般认识和相关领域的商事惯例进行综合判断。 展开更多
关键词 商标侵权 同一种商品或服务 司法认定 区分表
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Expression and Phylogenetic Analysis of Pea Actin Isoforms 被引量:5
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作者 江元清 赵武玲 《Acta Botanica Sinica》 CSCD 2002年第12期1456-1461,共6页
Pea ( Pisum sativum Linn.) actin gene family contains at least three isoforms (PEAcⅠ, PEAcⅡand PEAcⅢ), and the DNA sequence of these isoforms show high similarity in the coding regions and significant divergence... Pea ( Pisum sativum Linn.) actin gene family contains at least three isoforms (PEAcⅠ, PEAcⅡand PEAcⅢ), and the DNA sequence of these isoforms show high similarity in the coding regions and significant divergence in the untranslated regions. RT_PCR and Southern blotting using 3′_untranslated region (3′_UTR) as specific probe revealed that pea isoactin genes were expressed in roots, stems, leaves, tendrils, pollen and juvenile siliques, but displayed different patterns of transcript accumulation. Two_fold serial dilution electrophoresis showed PEAcⅠ mRNA preferentially accumulated in rapidly developing tissues: it peaked in seven days' stem; remained at a rather high level in leaves within a month but decreased significantly later; varied a little in tendrils and reached a median and a very low level respectively in juvenile siliques and in pollen. PEAcⅡ displayed somewhat similar expression pattern to PEAcⅠ. The observed differences in sequences and transcript accumulation patterns suggest that the individual pea actin genes may differ in their transcriptional regulation and cellular function. Phylogenetic tree of actins showed that pea actin isoforms are as diverged from each other as they are from other plant actins, and pea actins might have originated from a common ancestor before the divergence of the dicot and monocot plants. 展开更多
关键词 ACTIN 3′_untranslated region (3′_UTR) differential expression molecular evolution pea ( Pisum sativum )
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THEOREMS OF INTERVAL FUZZY SET AND ITS OPERATION RULES 被引量:3
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作者 吴顺祥 曹达 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2012年第2期136-144,共9页
Although the concept of interval fuzzy set and its properties have been defined, its three theorems and their effectiveness are not proved. Therefore, the knowledge presentation and its operation rules of interval fuz... Although the concept of interval fuzzy set and its properties have been defined, its three theorems and their effectiveness are not proved. Therefore, the knowledge presentation and its operation rules of interval fuzzy set are studied firstly, and then the cut set of interval fuzzy set is proposed. Moreover, the decomposition theo- rem, the representation theorem and the extension theorem of interval fuzzy set are presented. Finally, examples are given to demonstrate that the classical fuzzy set is a special case of interval fuzzy set and interval fuzzy set is an effective expansion of the classical fuzzy set. 展开更多
关键词 interval fuzzy set decomposition theorem representation theorem extension theorem
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On Univalent Functions in Multiply Connected Domains
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作者 杨维奇 《Journal of Beijing Institute of Technology》 EI CAS 1994年第2期99-113,共15页
The present article is an account of results on univalent functions in multiply connected domains obtained by the author. It contains two rery simple proofs of Villat's formula; Schwarz's formula, Poisson'... The present article is an account of results on univalent functions in multiply connected domains obtained by the author. It contains two rery simple proofs of Villat's formula; Schwarz's formula, Poisson's formula and Poisson-Jensen formula in multiply connected domains; the differentiability theorem with respect to the parameter of analytic function family containing one parametric variable on multiply connected domains; variation theorem and parametric representation theorem of univalent functions in multiply connected domains; the solution of an extremal problem of differentiable functionals. 展开更多
关键词 univalent functions integral representation variational methods/multiply connected domains parametric representation method extremal problem
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Relief Degree of Land Surface and Population Distribution of Mountainous Areas in China 被引量:12
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作者 LIU Ying DENG Wei SONG Xue-qian 《Journal of Mountain Science》 SCIE CSCD 2015年第2期518-532,共15页
Evaluation on the population pressure in the mountainous areas is a necessary condition for the protection and good governance. The evaluation depends on accurate population density assessment. Traditional methods use... Evaluation on the population pressure in the mountainous areas is a necessary condition for the protection and good governance. The evaluation depends on accurate population density assessment. Traditional methods used to calculate population density often adopt the administrative region as a scale for statistical analysis. These methods did not consider the effects of the relief degree of land surface(RDLS) on the population distribution. Therefore they cannot accurately reflect the degree of population aggregation, especially in mountainous areas. To explore this issue further, we took the mountainous areas of China as the research area. China has A total area of 666 km2 can be classified as mountainous area,accounting for 69.4% of the country's total landmass. The data used in this research included the digital elevation model(DEM) of China at a scale of 1:1,000,000, National population density raster data, the DEM and the national population density raster data. First, we determined the relief degree of land surface(RDLS). Next, we conducted a correlation analysis between the population distribution and the RDLS using the Statistical Package for Social Science(SPSS). Based on the correlation analysis results and population distribution, this new method was used to revise the provincial population density of themountainous areas. The revised results were used to determine the population pressure of different mountainous areas. Overall, the following results were obtained:(1) The RDLS was low in most mountainous areas(with a value between 0 and 3.5) and exhibited a spatial pattern that followed the physiognomy of China;(2) The relationship between the RDLS and population density were logarithmic, with an R2 value up to 0.798(p<0.05), and the correlation decreased from east to west;(3) The difference between the revised population density(RPD) and the traditional population density(PD) was larger in the southeastern region of China than in the northwestern region;(4) In addition, compared with traditional results, the revised result indicated that the population pressure was larger. Based on these results, the following conclusions were made:(1) the revised method for estimating population density that incorporates the RDLS is reasonable and practical,(2) the potential population pressure in the southeastern mountainous areas is substantial,(3) the characteristics of the terrain in the high mountainous areas are important for the scattered distribution of the population, and(4) the population distribution of mountainous areas in China should be guided by local conditions, such as social, economic, and topographic conditions. 展开更多
关键词 Land surface Relief degree Population density Population pressure Population distribution MOUNTAIN China
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A new species of Thysanarthria Orchymont from China,with the first record T.bifida(Coleoptera:Hydrophilidae)in Vietnam 被引量:1
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作者 Fenglong JIA Shujiao JIANG Zhenming YANG 《Entomotaxonomia》 CSCD 2020年第3期227-230,共4页
A new species,Thysanarthria rara sp.nov.,is described from China(Hunan,Guangdong).A photo of male genitalia of the new species is provided.This is the third known species in this genus from China.A key to all species ... A new species,Thysanarthria rara sp.nov.,is described from China(Hunan,Guangdong).A photo of male genitalia of the new species is provided.This is the third known species in this genus from China.A key to all species known from China is given.T.bifida Fikáček,2019 is recorded for the first time from Vietnam(Tonkin,Hoa-Binh). 展开更多
关键词 Chaetarthriinae TAXONOMY Oriental Region key
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Numerical modeling and dynamic analysis of the 2017 Xinmo landslide in Maoxian County, China 被引量:21
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作者 OUYANG Chao-jun ZHAO Wei +5 位作者 HE Si-ming WANG Dong-po ZHOU Shu AN Hui-cong WANG Zhong-wen CHENG Duo-xiang 《Journal of Mountain Science》 SCIE CSCD 2017年第9期1701-1711,共11页
A catastrophic landslide occurred at Xinmo village in Maoxian County, Sichuan Province,China, on June 24, 2017. A 2.87×106 m3 rock mass collapsed and entrained the surface soil layer along the landslide path. Eig... A catastrophic landslide occurred at Xinmo village in Maoxian County, Sichuan Province,China, on June 24, 2017. A 2.87×106 m3 rock mass collapsed and entrained the surface soil layer along the landslide path. Eighty-three people were killed or went missing and more than 103 houses were destroyed. In this paper, the geological conditions of the landslide are analyzed via field investigation and high-resolution imagery. The dynamic process and runout characteristics of the landslide are numerically analyzed using a depth-integrated continuum method and Mac Cormack-TVD finite difference algorithm.Computational results show that the evaluated area of the danger zone matchs well with the results of field investigation. It is worth noting that soil sprayed by the high-speed blast needs to be taken into account for such kind of large high-locality landslide. The maximum velocity is about 55 m/s, which is consistent with most cases. In addition, the potential danger zone of an unstable block is evaluated. The potential risk area evaluated by the efficient depthintegrated continuum method could play a significant role in disaster prevention and secondary hazard avoidance during rescue operations. 展开更多
关键词 Xinmo landslide Runout Numerical modeling Dynamic process Potential risk Highlocality landslide
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Comparative Utilization of Different Fibre Feedstuffs by Weaning/Growing Pigs in the Tropics 被引量:2
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作者 Emmanuel Oluropo Akinfala Omotola Macaulay Samuel Temitope Ogundeji 《Journal of Agricultural Science and Technology(A)》 2014年第2期149-154,共6页
This study was conducted to investigate the effect of feeding different fibre feedstuffs on the performance, nutrient utilization and economics of production of weaning/growing pigs. Five fibre feedstuffs--palm kernel... This study was conducted to investigate the effect of feeding different fibre feedstuffs on the performance, nutrient utilization and economics of production of weaning/growing pigs. Five fibre feedstuffs--palm kernel cake (PKC), wheat offal (WO), corn bran (CB), rice bran (RB) and brewers' dried grain (BDG) were used at 25% in each of the five experimental diets that were formulated in this study. Twenty weaner pigs (12.75 ± 0.6 kg) were used for the growth study while 15 pigs (14.95 ± 0.57 kg) were used for the digestibility study. The design of the experiment was completely randomized. The results of the study showed that the performance of the experimental animals were significantly influenced (P 〈 0.05) by the dietary treatments. The apparent digestibility of the crude protein, crude fiber and ether extract showed significant differences (P 〈 0.05) while there was no significant difference (P 〉 0.05) in the apparent digestibility of their dry matter, ash and nitrogen free extract. The diet that contained WO had the best growth response and apparent nutrient digestibility. Results of economics of production also showed that diet with WO gave the best (P 〈 0.05) value in feed cost/'kg gain and net profit/animal. It can be concluded from this study that although all the animals fed the different fibre feedstuffs performed satisfactorily on all the parameters monitored, but for optimum growth, apparent nutrients digestibility and economics of production. WO should be used as a fibre feedstuff in the diets of weaning/growing pigs in the tropics. 展开更多
关键词 PIGS performance DIGESTIBILITY economics of production DIETS
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Efficient volume preserving approach for skeleton-based implicit surfaces
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作者 史红兵 童若锋 董金祥 《Journal of Zhejiang University Science》 EI CSCD 2003年第6期637-642,共6页
This paper presents an efficient way to preserve the volume of implicit surfaces generated by skeletons. Recursive subdivision is used to efficiently calculate the volume. The criterion for subdivision is obtained by ... This paper presents an efficient way to preserve the volume of implicit surfaces generated by skeletons. Recursive subdivision is used to efficiently calculate the volume. The criterion for subdivision is obtained by using the property of density functions and treating different types of skeletons respectively to get accurate minimum and maximum distances from a cube to a skeleton. Compared with the criterion generated by other ways such as using traditional Interval Analysis, Affine Arithmetic, or Lipschitz condition, our approach is much better both in speed and accuracy. 展开更多
关键词 Volume preserving Skeleton based implicit surface Subdivision criterion Interval analysis
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Studying surface structure in desert areas using multiple kinds of surface wave data 被引量:1
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作者 Cheng Suo Gang Tian Zhanjie Shi 《Applied Geophysics》 SCIE CSCD 2007年第1期1-7,共7页
Shallow surface wave methods are mostly used for investigation of the surface velocity structure in environmental and engineering geophysics in non-desert areas. For the special geological features of the Takelamagan ... Shallow surface wave methods are mostly used for investigation of the surface velocity structure in environmental and engineering geophysics in non-desert areas. For the special geological features of the Takelamagan Desert area, we use the multi-channel analysis of surface wave (MASW) method to process multi-channel shallow surface wave records to determine the near surface velocity structure in the desert area. We also process, analyze, and compare the surface waves in many-trace records extracted from the oil exploration shot gathers in the area. We show that the MASW method can determine detailed shallow velocity structure in desert areas and the many-trace records can be used to get detailed deep geological structure. The combination of the two different datasets can obtain the exact velocity structure upper 60 m depth in the survey area. 展开更多
关键词 desert area near surface structure shot records multi-channel analysis of surface wave.
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Characterization of Some Typical Soils of the Miombo Woodland Ecosystem of Kitonga Forest Reserve, Iringa, Tanzania: Physico-Chemical Properties and Classification 被引量:1
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作者 Hassan Bashiru Shelukindo Balthazar Msanya +3 位作者 Ernest Semu Sibaway Mwango Bal Ram Singh Pantaleo Munishi 《Journal of Agricultural Science and Technology(A)》 2014年第3期224-234,共11页
Despite the fact that miombo woodland soils have significant implications in global climate change processes, few studies have been done to characterize and classify the soils of the miombo woodland ecosystem of Tanza... Despite the fact that miombo woodland soils have significant implications in global climate change processes, few studies have been done to characterize and classify the soils of the miombo woodland ecosystem of Tanzania. The current study was carried out to map and classify soils of Kitonga Forest Reserve, which is a typical miombo woodland ecosystem, in order to generate relevant information for their use and management. A representative study area of 52 km2 was selected and mapped at a scale of 1:50,000 on the basis of relief. Ten representative soil profiles were excavated and described using standard methods. Soil samples were taken from genetic soil horizons and analyzed in the laboratory for physico-chemical characteristics using standard methods. Using field and laboratory analytical data, the soils were classified according to the FAO-World Reference Base (FAO-WRB) for Soil Resources system as Cambisols, Leptosols and Fluvisols. In the USDA-NRCS Soil Taxonomy system the soils were classified as Inceptisols and Entisols. Topographical features played an important role in soil formation. The different soil types differed in physico-chemical properties, hence exhibit differences in their potentials, constraints and need specific management strategies. Texture varied from sandy to different loams; pH from 5.1 to 5.9; organic carbon from 0.9 g/kg to 20 g/kg; and CEC from 3 cmol/(+)kg to 24 cmol/(+)kg. Sustainable management of miombo woodlands ecosystem soils requires reduced deforestation and reduced land degradation. 展开更多
关键词 Miombo woodlands soil properties soil classification Kitonga Forest Reserve Tanzania.
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MORPHOTECTONICS OF THE BASEMENT SURFACE OF THE WEST SIBERIAN BASIN WITHIN NADYM-TAZ INTERFLUVE
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作者 DEYEV E.V. ZINOVIEV S.V. 《Geotectonica et Metallogenia》 2003年第1期11-23,共13页
The map of reflecting horizon A, plotted on the basis of regional geophysical materials, yieldsinformation about the bottom topography of sedimentary cover of the West-Siberian Basin within Nadym-Taz interfluve. Throu... The map of reflecting horizon A, plotted on the basis of regional geophysical materials, yieldsinformation about the bottom topography of sedimentary cover of the West-Siberian Basin within Nadym-Taz interfluve. Through morphotectonic analysis about this surface, the authors are able tounderstand the distribution characteristics of the main topographic irregularities, with the blockstructure of the lower cover floors and underlying complexes as the focus.The largest irregularities are caused by the presence of three regional altitude steps, which show a regional tendency of basement being submerged in the north-north-east direction. Within these irregularities, the authors have distinguished some regions, which can be divided, based on the characteristics of morphostructural distribution, into two groups, i.e., areal (Nadym, Tol'ka, Urengoy)and belt (Tarko-Sale, Russko-Chasel'ka and Messoyakha). The first ones represent quasihomogeneous blocks, whose surfaces are complicated by irregular low-amplitude elevations and troughs and low-gradient zones with gradient values being up to 0.03, or they submerge stepwise, with the leveled areas being separated by zones with high gradients (0.07-0.15). The morphostructure of the other group of regions is characterized by the en-echelon distribution of contrastingly positive and negative elements with high values of slope gradients (higher than 0.1-0.2). 展开更多
关键词 MORPHOTECTONICS BASEMENT Siberia interfluve
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The Ecological Distributions of N, P Utilizing Bacteria and Heterotrophic Bacteria in the Moderate Hypoxia Zone of the Changjiang Estuary
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作者 LIU Jingjing DU Ping +4 位作者 ZENG Jiangning CHEN Quanzhen SHOU Lu LIAO Yibo JIANG Zhibing 《Journal of Ocean University of China》 SCIE CAS 2013年第4期589-598,共10页
The distributions of N utilizing bacteria (denitrifying bacteria and ammonifying bacteria) ,P utilizing bacteria (organic phosphobacteria and inorganic phosphobacteria) and heterotrophic bacteria in the Changjiang Est... The distributions of N utilizing bacteria (denitrifying bacteria and ammonifying bacteria) ,P utilizing bacteria (organic phosphobacteria and inorganic phosphobacteria) and heterotrophic bacteria in the Changjiang Estuary,and the roles of main environmental factors in distributing bacteria,are explored with observations from two cruises in June and August 2006.Comparisons between the two important periods of initial hypoxia phase (June) and developed hypoxia phase (August) show differences in both bacterial distributions and the associated main environmental factors.First,the primary group of ammonifying bacteria has larger magnitude with spatial maximum value in the hypoxic stations related to sediment in August.The phosphobacterial abundance and detection rates in August are much lower than those in June,but the denitrifying bacterial abundance becomes greater in August.However,the difference of heterotrophic bacterial abundance between June and August is not obvious.Second,main environmental factors influencing bacteria vary from initial hypoxia phase to developed hypoxia phase.Two parameters (salinity and NO3) in surface water and five environmental parameters (pH,salinity,PO43,NO3and temperature) in bottom water and surface sediment play major roles in the bacterial abundance in June,while different parameter combinations (salinity and PO43) in surface water and different parameter combinations (DO,DOC,NO3,PO43 and pH) in bottom water and surface sediment play major roles in August.Moreover,the bottom bacteria distributions in area south of 31 N are related to the position of the Taiwan Warm Current in June.The bacterial abundance and distribution may respond to the environmental change in the hypoxia processes of initial phase and developed phase.During the hypoxia processes,the whole structure of bacterial functional groups probably turns to different states,causing the recycling of nutrient regeneration and aggravating hypoxia regionally. 展开更多
关键词 Changjiang Estuary HYPOXIA bacterial functional group
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商标侵权案件中类似商品的判断 被引量:4
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作者 王艳芳 《法律适用》 北大核心 2005年第12期67-69,共3页
关键词 商标侵权案件 类似商品 判断标准 《商标法》 中国 《类似商品和服务区分表
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Effects of Gaussian filter in processing GRACE data: Gravity rate of change at Lhasa,southern Tibet 被引量:5
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作者 SUN WenKe HASEGAWA Takashi +3 位作者 ZHANG XinLin FUKUDA Yoichi SHUM C. K. WANG Lei 《Science China Earth Sciences》 SCIE EI CAS 2011年第9期1378-1385,共8页
In this paper, the spatial gravity distribution over Tibetan Plateau and the gravity rate of change at Lhasa for different Gaussian filter radii are computed using GRACE data. Results show that the estimate of the gra... In this paper, the spatial gravity distribution over Tibetan Plateau and the gravity rate of change at Lhasa for different Gaussian filter radii are computed using GRACE data. Results show that the estimate of the gravity rate of change is spatialradius-dependent of the Ganssian filter. The GRACE-estimated gravity rate of change agrees well with the surface measured one. In other words, the GRACE-estimated gravity rate of change has a limited value as that obtained by surface measurement when the spatial filter radius reaches zero. Then numerical simulations are made for different spatial radii of the Gaussian filter to investigate its behaviors when applied to surface signals. Results show that the estimate of a physical signal is filter-radius dependent. If the computing area is equal to or less than the mass area, especially for a uniformly distributed mass, the estimate gives an almost correct result, no matter what filter radius is used. The estimate has large error because of the signal leakage caused by harmonic truncation if the computing area is much bigger than the mass distribution (or inverse for a small mass anomaly). If a mass anomaly is too small, it is difficult to recover it from space observation unless the filter radius is extremely small. If the computing point (or area) is outside the mass distribution, the estimated result is almost zero, particularly for small filter radii. These properties of the Gaussian filter are helpful in applying GRACE data in different geophysical problems with different spatial position and geometrical size. We further discuss physical sources causing the scalar gravity change at Lhasa. Discussions indicate that the gravity rate of change at Lhasa is not caused by the present-day ice melting (PDIM) (or Little Ice Age, LIA) effect because no ice melting occurs in Lhasa city and nearby. The gravity rate of change is attributable mainly to tectonic deformation associated with the Indian Plate collision. Simultaneous surface displacement, surface denudation, and GIA effects are not negligible. 展开更多
关键词 gravity change GRACE Gaussian filter Tibetan Plateau LHASA
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