基于滤波技术的上海日最大电力负荷气象预报模型     

傅新姝  谈建国 《气象科技》2015,43(6):1209-1212

电力负荷与气象条件密切相关,为建立上海市日最大电力负荷的预报模型,利用2010—2013年上海市日最大电力负荷数据及同期气象资料,分析日最大电力负荷的时间变化特征及其与气象因子的相关性,并基于滤波技术将日最大电力负荷分离为时间趋势项和逐日变化项,用逐步回归方法针对冬季和夏季分别建立预测模型。结果表明：①上海日最大电力负荷的各个节假日效应存在差异,春节节假日效应持续时间最长,影响最大,国庆节假期前半段节假日效应明显大于后半段。夏季的周末效应最强。②采用逐步回归方法建立的气象预报模型效果较好,回代年和预测年的平均预测相对误差均小于5%。  相似文献   

The toxic effects of copper on larvae of the barnacle species Chthamalus challengeri     

齐磊磊  王影  沙婧婧  王悠  唐学玺 《中国海洋湖沼学报》2015,33(2):400-409

With the increased use of copper(Cu)-based antifouling(AF) paints,copper has become a potential threat to marine organisms. Experiments were performed to investigate the effects of copper on larvae of the barnacle Chthamalus challengeri. These experiments attempted to identify a more sensitive index to monitor copper pollution in marine environments. The 24 h LC5 0 ranged from 156.07 μg/L(nauplius II) to 817.15 μg/L(cypris) and the no observed effect concentration(NOEC) ranged from 81.75 μg/L(nauplius II) to 571.04 μg/L(cypris). The cypris settlement rate declined significantly when copper concentrations ≥135 μg/L. No cypris was found in the copper concentration of 60 and 75 μg/L treatment groups stressed for 22 d. Nauplius II moulting was not affected by exposure to copper for 24 h; however,when extended to 48 h,the percent moulted in 75 μg/L treatment group was declined to 37.12%,which was significant lower( P 0.05) than that in the control group. The phototaxis of nauplius II decreased significantly when copper concentrations ≥45 μg/L. Despite an initial significant increase at copper concentrations of 30 μg/L,ammonia excretion rate decreased when copper concentrations ≥60 μg/L. These results suggested that:(1) nauplius II could not develop to the cypris when the copper concentration ≥60 μg/L;(2) cypris settlement is more susceptible to copper than cypris mortality rate;(3) nauplius II is the most sensitive larval stage;(4) nauplius II ammonia excretion rate is the most sensitive index to copper and might be as the indicator for copper pollution monitoring.  相似文献   

Satellite derived upper ocean thermal structure and its application to tropical cyclone intensity forecasting in the Indian Ocean     

孙春健  王喜冬  崔晓健  张晓爽  张连新  邵彩霞  吴新荣  付红丽  李威 《中国海洋湖沼学报》2015,33(5):1219-1232

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Erratum to: Nutrients distribution and trophic status assessment in the northern Beibu Gulf,China     

赖俊翔  姜发军  柯珂  许铭本  雷富  陈波 《中国海洋湖沼学报》2015,33(1):289-289

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Huff模型支持下的基础教育资源分布分析     

张静华  任福  刘江涛  席宇亮  肖克 《地理信息世界》2015,(2):44-50

在回顾国内外教育资源空间可达性研究的基础上,以广东省深圳市为例,以小学为分析单元,利用Huff模型进行各小学的学位压力研究。并将Huff模型与重力模型、距离模型进行比较。实验结果为,深圳的小学的学位压力主要集中在0.5~1.4范围,其中,有81所学校的学位压力为0.5~0.75,178所学校为0.75~1.25之间,大于1.25的有39所学校。学位压力大于1.25的学校,集中分布在福田区,其他街道中存在个别的学校学位压力偏大。结果表明Huff比其他模型好。为学校的空间布局提供合理化建议。  相似文献   

高压输电线散射斑雷达像空间位置形成条件分析     

侯爱羚  李陶  李沙  吴文豪  徐侃  刘艳 《测绘工程》2015,(4):53-57

TerraSAR雷达卫星条带模式影像中高压输电线产生亮度极高的散射斑点,利用湖北段1 000kV特高压输电线路的雷达影像和铁塔GPS坐标,研究了该区域150组输电线散射斑的形成条件和雷达像空间相对位置变化规律。研究表明,输电线的夹角、跨度和垂曲率是影响散射斑形成以及雷达像空间位置的主要因素。输电线散射斑产生于导线与卫星飞行方向的夹角±15°以内。当夹角由负到正变化时,其导线散射斑在雷达像空间的位置由北向南移动,但是其移动量与夹角变化不成正比。在夹角近似相同的情况下,导线跨度越大即其垂曲率越大,散射斑的位置越靠近导线垂直平分线。  相似文献   

移动地图中的矢量瓦片组织方法研究     

何猛  蔡忠亮  任福 《测绘信息与工程》2015,40(2)

针对矢量数据地图发布,提出移动地图中矢量瓦片的组织方法,阐述了矢量数据的组织与管理、LOD技术和瓦片的构建、矢量瓦片地图的索引和显示.根据矢量数据的特点,确定矢量瓦片构建和存储方式,采用文件分层分级进行存储.  相似文献   

BEMD-based two-dimensional SAR autofocus algorithm     

Yang Li  Jing Zhang  Chengbin Fu  Dalong Wang 《国际地球制图》2015,30(10):1163-1171

The two-dimensional (2D) autofocus algorithm simultaneously compensates both the residual range migration and propagation-induced phase errors. However, the unsuitable selection of prominent points would reduce the performance of autofocus. Bi-dimensional empirical mode decomposition (BEMD) can decompose a synthetic aperture radar (SAR) image into some different sub-images corresponding to different frequency components. Using proposed 2D autofocus algorithm along with BEMD would help us in selecting the suitable prominent points and give a considerable improvement in the performance of SAR autofocus. In further support of that conclusion, some simulations using real SAR data are demonstrated.  相似文献   

市县级不动产统一登记信息平台建设探讨     

尹鹏程  黄亮  付丽莉  张浩  邓玉锋 《国土资源信息化》2015,(2):38-42

不动产统一登记信息平台的建立是不动产统一登记工作实现信息实时更新和共享的基础。以构建不动产统一登记信息平台为主线,提出了以土地为核心的不动产单元构建方法,构建了以不动产单元为基础的不动产权利登记体系。在此基础上,明晰了不动产统一登记信息平台在国土资源信息化总体框架中的定位,以徐州市为例,给出了市(县)级不动产统一登记信息平台建设的主要内容,对当前不动产统一登记信息平台的建设进行了有益的探索。  相似文献   

Recent progress and future directions of ChinaFLUX     

Yu Guirui  Fu Yuling  Sun Xiaomin  Wen Xuefa  Zhang Leiming 《中国科学D辑(英文版)》2006,49(2):1-23

The eddy covariance technique has emerged as an important tool to directly measure carbon dioxide, water vapor and heat fluxes between the terrestrial ecosystem and the atmosphere after a long history of fundamental research and technological developments. With the realization of regional networks of flux measurements in North American, European, Asia, Brazil, Australia and Africa, a global-scale network of micrometeorological flux measurement (FLUXNET) was established in 1998. FLUXNET has made great progresses in investigating the environmental mechanisms controlling carbon and water cycles, quantifying spatial-temporal patterns of carbon budget and seeking the “missing carbon sink” in global terrestrial ecosystems in the past ten years. The global-scale flux measurement also built a platform for international communication in the fields of resource, ecology and environment sciences. With the continuous development of flux research, FLUXNET will introduce and explore new techniques to extend the application fields of flux measurement and to answer questions in the fields of bio-geography, eco-hydrology, meteorology, climate change, remote sensing and modeling with eddy covariance flux data. As an important part of FLUXNET, ChinaFLUX has made significant progresses in the past three years on the methodology and technique of eddy covariance flux measurement, on the responses of CO₂ and H₂O exchange between the terrestrial ecosystem and the atmosphere to environmental change, and on flux modeling development. Results showed that the major forests on the North-South Transect of Eastern China (NSTEC) were all carbon sinks during 2003 to 2005, and the alpine meadows on the Tibet Plateau were also small carbon sinks. However, the reserved natural grassland, Leymus chinensis steppe in Inner Mongolia, was a carbon source. On a regional scale, temperature and precipitation are the primary climatic factors that determined the carbon balance in major terrestrial ecosystems in China. Finally, the current research emphasis and future directions of ChinaFLUX were presented. By combining flux network and terrestrial transect, ChinaFLUX will develop integrated research with multi-scale, multi-process, multi-subject observations, placing emphasis on the mechanism and coupling relationships between water, carbon and nitrogen cycles in terrestrial ecosystems.  相似文献