排序方式: 共有5条查询结果,搜索用时 0 毫秒
1
1.
电力系统负荷预测是电力系统发电计划的重要组成部分,也是电力系统经济运行的基础。本文在应用GM(1,1)模型的基础上,建立了两种应用残差对预测数据进修正的模型。实例表明本文提出的方法较传统GM(1,1)模型有更高的精度。 相似文献
2.
3.
Hay SI Cox J Rogers DJ Randolph SE Stern DI Shanks GD Myers MF Snow RW 《Nature》2002,415(6874):905-909
The public health and economic consequences of Plasmodium falciparum malaria are once again regarded as priorities for global development. There has been much speculation on whether anthropogenic climate change is exacerbating the malaria problem, especially in areas of high altitude where P. falciparum transmission is limited by low temperature. The International Panel on Climate Change has concluded that there is likely to be a net extension in the distribution of malaria and an increase in incidence within this range. We investigated long-term meteorological trends in four high-altitude sites in East Africa, where increases in malaria have been reported in the past two decades. Here we show that temperature, rainfall, vapour pressure and the number of months suitable for P. falciparum transmission have not changed significantly during the past century or during the period of reported malaria resurgence. A high degree of temporal and spatial variation in the climate of East Africa suggests further that claimed associations between local malaria resurgences and regional changes in climate are overly simplistic. 相似文献
4.
Ludovic Dume′ e Aaron Thornton Kallista Sears Ju¨ rg Schu¨ tz Niall Finn Steven Spoljari Robert Shanks Chris Skourtis Mikel Duke Stephen Gray 《自然科学进展(英文版)》2012,22(6):673-683
In-situ thermal expansion tests on a series of carbon nanotube bucky-paper composites
were performed with direct heating within a synchrotron SAXS source. The impact of the samples
density and morphology as well as the chemistry and degree of decoration of the carbon nanotubes
on the scattering patterns were investigated and correlated to the materials macro-properties. The
results demonstrate that simple densification techniques, such as acetone dipping or gold electroless
deposition, could reduce greatly the displacements of the carbon nanotubes within the structure
and lead to more thermally stable material. 相似文献
5.
Optical isomers of propranolol 总被引:25,自引:0,他引:25
1