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An approach to prediction of the South China Sea summer monsoon onset 被引量:6
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作者 胡敦欣 于乐江 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2008年第4期421-424,共4页
在现在的纸,在发作和热在西方的太平洋在温暖的水池的上面的层满足的华南海夏天季风( SCSSM )之间的关联为时期用海洋学数据集的 Scripps 机构被检验 1955 1998 并且预言的一条途径 SCSSM 发作被建议。关联嘘在那里欠那存在内部 SCSSM... 在现在的纸,在发作和热在西方的太平洋在温暖的水池的上面的层满足的华南海夏天季风( SCSSM )之间的关联为时期用海洋学数据集的 Scripps 机构被检验 1955 1998 并且预言的一条途径 SCSSM 发作被建议。关联嘘在那里欠那存在内部 SCSSM 发作的十的可变性温暖的水池而非在它的中心附近的中心向西在区域与最大的关联系数在 1970 界定,从另外的因素暗示某些效果而且包含了 ENSO。因为关联为在 1970 前的时期是差的,在 1970 以后的温暖的水池的热内容异例被用来预先显示 SCSSM 的早或迟了的发作。一个理想的代表性的区域(为温暖的水池热内容的 1 °× 1 °) 在 3 ° N /138 ° E 与它的中心被决定。系在到中心的最近的道(道热带的空气海洋数组) 在 2 ° N /137 ° E,并且选择为预言计算热内容。在 2 ° N /137 ° E 的 TAO 绳索能被用来在上面的层与热内容预言 SCSSM 发作,这被建议,如果在 SCSSM 发作和温暖的水池的热内容之间的关联象的一样跑在 1970 以后。在另一方面,如果状况做,在 1970 前喜欢,代表性的车站与相对差的关联在 13 ° S /74 ° E 被决定,意味着在西方的太平洋的温暖的水池比印度洋在 SCSSM 发作起更多的重要作用。 展开更多
关键词 中国 南海 夏季季候风 热量 水温
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Is Model Parameter Error Related to a Significant Spring Predictability Barrier for El Nio events? Results from a Theoretical Model 被引量:25
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作者 段晚锁 张蕊 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2010年第5期1003-1013,共11页
Within a theoretical ENSO model, the authors investigated whether or not the errors superimposed on model parameters could cause a significant "spring predictability barrier" (SPB) for El Nio events. First, sensit... Within a theoretical ENSO model, the authors investigated whether or not the errors superimposed on model parameters could cause a significant "spring predictability barrier" (SPB) for El Nio events. First, sensitivity experiments were respectively performed to the air-sea coupling parameter, α and the thermocline effect coefficient μ. The results showed that the uncertainties superimposed on each of the two parameters did not exhibit an obvious season-dependent evolution; furthermore, the uncertainties caused a very small prediction error and consequently failed to yield a significant SPB. Subsequently, the conditional nonlinear optimal perturbation (CNOP) approach was used to study the effect of the optimal mode (CNOP-P) of the uncertainties of the two parameters on the SPB and to demonstrate that the CNOP-P errors neither presented a unified season-dependent evolution for different El Nio events nor caused a large prediction error, and therefore did not cause a significant SPB. The parameter errors played only a trivial role in yielding a significant SPB. To further validate this conclusion, the authors investigated the effect of the optimal combined mode (i.e. CNOP error) of initial and model errors on SPB. The results illustrated that the CNOP errors tended to have a significant season-dependent evolution, with the largest error growth rate in the spring, and yielded a large prediction error, inducing a significant SPB. The inference, therefore, is that initial errors, rather than model parameter errors, may be the dominant source of uncertainties that cause a significant SPB for El Nio events. These results indicate that the ability to forecast ENSO could be greatly increased by improving the initialization of the forecast model. 展开更多
关键词 ENSO predictability optimal perturbation error growth model parameters
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Bankruptcy Prediction for Chinese Firms: Comparing Data Mining Tools With Logit Analysis
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作者 Wikil Kwak Xiaoyan Cheng +3 位作者 Jinlan Ni Yong Shi Guan Gong Nian Yan 《Journal of Modern Accounting and Auditing》 2014年第10期1030-1037,共8页
关键词 数据挖掘工具 中国企业 预测模型 破产 模型分析 资本市场 社会文化 企业数据
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Historical trends of heavy metal contamination and their sources in lacustrine sediment from Xijiu Lake,Taihu Lake Catchment,China 被引量:18
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作者 Haijian Bing Yanhong Wu +1 位作者 Zhaobin Sun Shuchun Yao 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2011年第10期1671-1678,共8页
Concentrations of Cd, Cr, Cu, Pb, Zn and Hg in Xijiu Lake sediment from the Taihu Lake catchment, China, were analyzed. Their contamination state was investigated based on the geoaccumulation index and enrichment fact... Concentrations of Cd, Cr, Cu, Pb, Zn and Hg in Xijiu Lake sediment from the Taihu Lake catchment, China, were analyzed. Their contamination state was investigated based on the geoaccumulation index and enrichment factors. Statistical analysis was used to differentiate the anthropogenic versus natural sources of heavy metals (HMs), and the anthropogenic accumulation fluxes were calculated to quantify anthropogenic contribution to HMs. The results indicated that the lake sediment had been heavily contaminated by Cd, enrichment of Zn and Hg was at a relatively high level, while that of Cu and Pb was in the lower-to-moderate level and Cr was in the low enrichment level. Sources of Cr in the sediment were mainly from natural inputs, while other metals, especially Cd, were predominantly derived from anthropogenic sources. In the past century, anthropogenic accumulation fluxes of Pb, Zn and Hg increased by 0.147.3 mg/(cm2-yr), 2.4-398.1 mg/(cm2.yr), and 3.7-110.3 ng/(m2.yr), respectively, accounting for most inputs of HMs entering the sediment. The contamination state of HMs varied with industrial development of the catchment, which demonstrated that contamination started in the early 20th century, reached the maximal level between the mid-1970s and mid-1990s, and decreased a little after the implementation of constraints on high contamination industries, although the contamination of some HMs, such as Cd, Zn and Hg, is still at high levels. 展开更多
关键词 accumulation fluxes CONTAMINATION heavy metals human activity sediment Xijiu Lake
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Recent area and ice volume change of Kangwure Glacier in the middle of Himalayas 被引量:17
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作者 MA LingLong TIAN LiDe +1 位作者 PU JianChen WANG PengLing 《Chinese Science Bulletin》 SCIE EI CAS 2010年第20期2088-2096,共9页
This paper calculated and evaluated the area and ice volume changes of Kangwure Glacier in Mt.Xixiabangma,middle of Himalayas in the past 3 decades,based on the field survey of glacier boundary position by differentia... This paper calculated and evaluated the area and ice volume changes of Kangwure Glacier in Mt.Xixiabangma,middle of Himalayas in the past 3 decades,based on the field survey of glacier boundary position by differential GPS and glacier depth by Ground Penetrating Radar(GPR),together with the topographic map and remote sense data.The studied data showed that the Kangwure Glacier has experienced significant mass deficit since the 1970s,with 34.2%of area loss,48.2%ofice volume loss and 7.5 m of average thickness decrease.This result revealed that the ice volume loss of Himalayan glaciers was more serious than expected.Analysis of meteorological data from two weather stations in the region of Mt.Xixiabangma,shows that the air temperature of this region has risen from the middle of the 20th century to the beginning of the 21st century.Significant retreat of Himalayas glacier driven by climatic warming will have a remarkable impact on hydrology and ecosystem. 展开更多
关键词 喜马拉雅山 冰川变化 冰川面积 冰量 差分GPS 地质雷达 探地雷达 遥感数据
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Hydrothermal synthesis and characterization of NiS flower-like architectures 被引量:1
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作者 Hai Zhou Baoliang Lv +1 位作者 Dong Wu Yuhan Sun 《Particuology》 SCIE EI CAS CSCD 2012年第6期783-788,共6页
Under the influence of thiocyanate anions (SCN-) and cetyltrimethyl ammonium bromide (CTAB), NiS flower-like architectures were successfully synthesized by a one-step hydrothermal method. The syn-thesized flower-l... Under the influence of thiocyanate anions (SCN-) and cetyltrimethyl ammonium bromide (CTAB), NiS flower-like architectures were successfully synthesized by a one-step hydrothermal method. The syn-thesized flower-like architectures, with a multilayered and highly ordered texture, have diameters of several micrometers. X-ray powder diffraction (XRD) shows that the NiS flower-like architectures are rhombohedral crystalline. On the basis of condition-dependent experiments, the diffusion-limited aggregation (DLA) model and cage effect were used to explain the growth process of rhombohedral crystalline NiS flower-like architectures. Magnetic measurements showed that the coercivity (He) of the as-obtained NiS flower-like architectures was 102.14 Oe. 展开更多
关键词 Nanostructures Chemical synthesis Electron microscopy Magnetic properties
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Spatial distribution and pollution assessment of heavy metals in urban soils from southwest China 被引量:87
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作者 Guanghui Guo Fengchang Wu +1 位作者 Fazhi Xie Ruiqing Zhang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2012年第3期410-418,共9页
To identify the concentrations and sources of heavy metals, and to assess soil environmental quality, 63 soil samples were collected in Yibin City, Sichuan Province, China. Mean concentrations of As, Pb, Zn, and Cu we... To identify the concentrations and sources of heavy metals, and to assess soil environmental quality, 63 soil samples were collected in Yibin City, Sichuan Province, China. Mean concentrations of As, Pb, Zn, and Cu were 10.55, 61.23, 138.88 and 56.35 mg/kg, respectively. As concentrations were comparable to background values, while Pb, Zn, and Cu concentrations were higher than their corresponding background values. Industrial areas exhibited the highest concentrations of As, Pb, Zn, and Cu, while the lowest concentrations occurred in parks. Statistical analysis was performed and two cluster groups of metals were identified with Pb, Zn, and Cu in one group and As in the other. Spatial distribution maps indicated that Pb, Zn, and Cu were mainly controlled by anthropogenic activities, whereas As could be mainly accounted for by soil parent materials. Pollution index values of As, Pb, Zn, and Cu varied in the range of 0.24-1.93, 0.66-7.24, 0.42-4.19, and 0.62-5.25, with mean values of 0.86, 1.98, 1.61, and 1.78, respectively. The integrated pollution index (IPI) values of these metals varied from 0.82 to 3.54, with a mean of 1.6 and more than 90% of soil samples were moderately or highly contaminated with heavy metals. The spatial distribution of IPI showed that newer urban areas displayed relatively lower heavy metal contamination in comparison with older urban areas. 展开更多
关键词 urban soils heavy metals pollution assessment spatial distribution
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Effects of annealing on luminescence efficiency of large-size YAG:Ce crystal grown by temperature gradient techniques 被引量:3
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作者 曹顿华 赵广军 +4 位作者 董勤 陈建玉 程艳 丁雨憧 邹军 《Chinese Optics Letters》 SCIE EI CAS CSCD 2010年第2期199-201,共3页
YAG:Ce crystal with a diameter of 110 mm is successfully grown by the temperature gradient technique (TGT). The effects of annealing on the luminescence efficiency of YAG:Ce crystal are investigated, and the optim... YAG:Ce crystal with a diameter of 110 mm is successfully grown by the temperature gradient technique (TGT). The effects of annealing on the luminescence efficiency of YAG:Ce crystal are investigated, and the optimal annealing temperature and atmosphere are obtained. The mechanism of variation behavior of the luminescence efficiency of YAG:Ce under different annealing conditions is discussed and some details on the luminescence associated with color centers are analyzed. 展开更多
关键词 ANNEALING CERIUM Cerium compounds Color centers LUMINESCENCE Thermal gradients
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Distribution of shrublands in relation to soil and climate in mid-subtropical China 被引量:1
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作者 Jiaxiang Li Gaoming Xiong +1 位作者 Wenting Xu Zongqiang Xie 《Journal of Plant Ecology》 SCIE 2016年第4期393-401,共9页
Aims Understanding relationships between vegetation and environments is of importance for ecosystem restoration and management.However,information on how environments influence the floristic patterns of shrublands is ... Aims Understanding relationships between vegetation and environments is of importance for ecosystem restoration and management.However,information on how environments influence the floristic patterns of shrublands is lack,especially in the subtropical China.In this study,we explored how environments regulate species composition of shrublands at landscape scale in mid-subtropical China.Methods We investigated species composition and measured the climate and soil environments for 207 shrubland plots in mid-subtropical China(24°39′-30°08′N,108°47′-114°15′E).We applied a hierarchical cluster analysis and indicator species analysis based on the Bray-Curtis similarity index to identify the main shrubland types and employed principal coordinate analysis(PCoA)to explore the relationship between floristic composition and environment.Important Findings We identified four shrubland types occurring in different environmental conditions.Montane shrubland,dominated by species suitable for cool climates(e.g.Rhododendron simsii),were distributed in steep areas at comparatively high altitudes;foothill shrubland,dominated by mesophilous species(e.g.Loropetalum chinense),were distributed in low mountains and hills;pioneer shrubland,dominated by fast grow and short-life cycles species(e.g.Rhus chinensis),were distributed at low altitudes with dense population;and finally,limestone shrubland,dominated by calcicole plants(e.g.Coriaria nepalensis),were distributed in the extensive karst areas.Communities occurring in high pH soils were completely separated from those in low pH soils according to the hierarchical cluster analysis.PCoA ordination associated the four types with distinct edaphic and climatic gradients.Soil pH explained 63.3%of variation in PCoA,followed by soil depth and soil bulk density. 展开更多
关键词 floristic composition vegetation-environment relationship environmental filtering principal coordinate analysis
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