期刊文献+
共找到6篇文章
< 1 >
每页显示 20 50 100
Thoughts on Energy Solutions to Alleviation of Air Pollution during the Heating Period in Key Areas
1
作者 Zhao Wei Hu Zhengxin Wang Sheng 《Meteorological and Environmental Research》 CAS 2019年第4期7-10,共4页
Since the implementation of the Action Plan for Air Pollution Prevention and Control , all regions of China have steadily promoted the prevention and control of air pollution and achieved results continuously. However... Since the implementation of the Action Plan for Air Pollution Prevention and Control , all regions of China have steadily promoted the prevention and control of air pollution and achieved results continuously. However, the atmospheric environment in key areas such as Beijing-Tianjin-Hebei region, the Yangtze River Delta region, and Fenwei Plain is still severe, and especially during the heating period heavy pollution occurs frequently, which has become the focus and difficulty of improving the quality of the atmospheric environment and is also the weakest link of China s air pollution control at present. How to alleviate air pollution, how to win the battle of pollution prevention and control, how to hold the fruits of the blue sky defense war, energy consumption is key. 展开更多
关键词 Alleviation key areas key CITIES Heating period Prevention and control of air pollution Blue SKY defense ENERGY solution
下载PDF
China's Economy Enters Key Period of Softlanding
2
《China's Foreign Trade》 2005年第20期16-,共1页
China’s economy is now at a key period for softlanding in light of growing investment, the driving force of its fast eco-nomic expansion, according to a report by a task force for theState Development and Reform Comm... China’s economy is now at a key period for softlanding in light of growing investment, the driving force of its fast eco-nomic expansion, according to a report by a task force for theState Development and Reform Commission(SDRC). 展开更多
关键词 China’s Economy Enters key period of Softlanding
下载PDF
Puncturing Period on the Performance of Punctured Turbo Codes
3
作者 Xu Heng\|ping, Pan Sheng, Zhao Xun, Rong Meng\|tian Department of Electronic Engineering, Shanghai Jiaotong University, Shanghai 200030, Shanghai, China 《Wuhan University Journal of Natural Sciences》 EI CAS 2002年第3期319-322,共4页
Puncturing is the predominant strategy to construct high code rate turbo codes. Puncturing period is a crucial parameter influencing the performance of punctured turbo codes (PTC). Here we developed a new puncturing s... Puncturing is the predominant strategy to construct high code rate turbo codes. Puncturing period is a crucial parameter influencing the performance of punctured turbo codes (PTC). Here we developed a new puncturing scheme of turbo codes, with which the puncturing period on the performance of PTC is studied. Consequently, suggestions on selecting the puncturing period are proposed. 展开更多
关键词 key words puncturing period puncturing table AWGN turbo codes
下载PDF
The Reflective Function of Differential System 被引量:4
4
作者 Zhou Zheng xin Department of Mathematics, University of Yangzhou, Yangzhou 225002, Jiangsu, China 《Wuhan University Journal of Natural Sciences》 CAS 2002年第4期383-387,共5页
This article deals with the reflective function of the differential systems. The results are applied to discussion of the existence and stability of the periodic solutions of these systems.
关键词 key words reflective function periodic solution STABILITY
下载PDF
Variation of sea ice extent in different regions of the Arctic Ocean 被引量:4
5
作者 CHEN Ping ZHAO Jinping 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2017年第8期9-19,共11页
Sea ice in the Arctic has been reducing rapidly in the past half century due to global warming. This study analyzes the variations of sea ice extent in the entire Arctic Ocean and its sub regions. The results indicate... Sea ice in the Arctic has been reducing rapidly in the past half century due to global warming. This study analyzes the variations of sea ice extent in the entire Arctic Ocean and its sub regions. The results indicate that sea ice extent reduction during 1979-2013 is most significant in summer, following by that in autumn, winter and spring. In years with rich sea ice, sea ice extent anomaly with seasonal cycle removed changes with a period of 4-6 years. The year of 2003-2006 is the ice-rich period with diverse regional difference in this century. In years with poor sea ice, sea ice margin retreats further north in the Arctic. Sea ice in the Fram Strait changes in an opposite way to that in the entire Arctic. Sea ice coverage index in melting-freezing period is an critical indicator for sea ice changes, which shows an coincident change in the Arctic and sub regions. Since 2002, Region C2 in north of the Pacific sector contributes most to sea ice changes in the central Aarctic, followed by C1 and C3. Sea ice changes in different regions show three relationships. The correlation coefficient between sea ice coverage index of the Chukchi Sea and that of the East Siberian Sea is high, suggesting good consistency of ice variation. In the Atlantic sector, sea ice changes are coincided with each other between the Kara Sea and the Barents Sea as a result of warm inflow into the Kara Sea from the Barents Sea. Sea ice changes in the central Arctic are affected by surrounding seas. 展开更多
关键词 key words: Arctic sea ice extent period of 4-6 years sea ice margin sea ice coverage indices
下载PDF
Restoration of eroded stratal thickness in key periods of tectonic change in a multi-stage superimposed Tarim Basin in China 被引量:1
6
作者 Liu Hao1, Wang Yingmin2 1. School of Marine Sciences, China University of Geosciences (Beijing), Beijing 100083, China 2. School of Geosciences, China University of Petroleum (Beijing), Beijing 102249, China 《Journal of Palaeogeography》 SCIE 2012年第2期149-171,共23页
With an area of 56×104km2, the Tarim Basin is the largest inland basin in China and is also generally acknowledged as one of the most important areas for potential oil and gas exploration. On the basis of data fr... With an area of 56×104km2, the Tarim Basin is the largest inland basin in China and is also generally acknowledged as one of the most important areas for potential oil and gas exploration. On the basis of data from 22 regional seismic profiles and 40 drilling wells, 15 important first-order and second-order regional unconformities were defined.Almost all the main unconformities are superimposed unconfomities. Since the Cambrian, 5 key periods of tectonic change have occurred during the evolution of the Tarim Basin. The total eroded stratal thickness of the above-mentioned unconformities was calculated by using the method of virtual extrapolation of seismic reflection. The results indicate that the total eroded stratal thickness of different periods is quite different in different locations of the basin. Taking the Upper-Middle Ordovician as an example, its thickness restoration of eroded strata was calculated into individual stages i.e. its thickness restoration of eroded strata was calculated to different tectonic periods. Otherwise, as for the specific period of tectonic change, the underlying strata were, respectively eroded and thus the thickness restoration of eroded strata was calculated into individual intervals. Taking the Early Hercynian period as an example, the eroded stratal thickness was calculated into individual intervals to calculate the ratio of intervals of various ages occupying the total eroded thickness. The results show that for the same stratum, its degree of erosion is quite different in different periods and at different locations, due to the varying influence of tectonic movement. The unconformities of some key periods of tectonic change have different controls on the degree of erosion and the eroded range of the individual period of the underlying strata which are the typical characteristics of multi-stage superimposition of unconformities in the Tarim Basin. 展开更多
关键词 Tarim Basin extrapolation of virtual surface key period of tectonic change superimposed unconformity restoration of eroded stratal thickness
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部