|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | Vegetation cover change and the driving factors over northwest China显示文摘In this paper the spatio-temporal variation of vegetation cover in northwest China during the period of 1982-2006 and its driving factors were analyzed using GIMMS/NDVI data. The annual average NDVI was increased with a rate of 0.0005/a in northwest China and there was an obvious difference between regions. The trend line slopes of NDVI were higher than 0.0005 in the Tianshan Moutains and Altay Mountains of Xinjiang,the Qilian Mountains of Gansu and the eastern part of Qinghai,which indicated the vegetation cover was significantly increased in these areas. The trend line slopes of NDVI were lower than 0.0005 in the southern region of Qinghai,the border regions of Shaanxi and Ningxia,the parts of Gansu and Tarim Basin,Turpan and Tuoli in Xinjiang,which indicated the vegetation cover was declined in these areas. The NDVI of woodland,grassland and cultivated land had an ascending tendency during the study period. The study shows that the vegetation cover change was caused by both natural factors and human activities in northwest China. The natural vegetation change,such as forests was influenced by climate change,while human activities were the main reason to the change of planting vegetation. The changes of vegetation covers for different elevations,slopes and slope aspects were quite different. When the elevation is exceeded to 4,000 m,the NDVI increasing trend was very low;the NDVI at the slope of less than 25° was increased by the ecological construction;the variation of NDVI on sunny slope was stronger than that on shady slope. The temperature rose significantly in recent 25 years in northwest China by an average rate of 0.67oC/10a,and precipitation increased by an average rate of 8.15 mm/10a after 1986. There was positive correlation between vegetation cover and temperature and annual precipitation changes. Rising temperature increased the evaporation and drought of soils,which is not conducive to plant growth,and the irrigation in agricultural areas reduced the correlation between agricultural vegetation NDVI and precipitation. The improvement of agricultural production level and the projects of ecological construction are very important causes for the NDVI increase in northwest China,and the ecological effect of large-scale ecological construction projects has appeared. | ShengPei DAI Bo ZHANG HaiJun WANG YaMin WANG LingXia GUO XingMei WANG Dan LI | 2011 | Journal of Arid Land2011，3，1： | 22 |
| 2 | Changes of annual accumulated temperature over Southern China during 1960-2011显示文摘The spatial and temporal variations of ≥10°C annual accumulated temperature(AAT10) were analyzed by using the linear trend line method, cumulative anomaly method and the multiple linear regression model(MLRM) interpolation method based on the daily meteorological observation data from 104 meteorological stations in Southern China and surrounding 39 meteorological stations from 1960 to 2011. The results show that:(1) From time scale point of view, the climatic trend of the AAT10 increased with an average of 7.54°C/decade in Southern China since 1960. The area of AAT10<6000°C decreased from 1960 to 2011, and the area of 6000°C8000°C increased from 1960 to 2011.(2) From spatial scale point of view, the AAT10 in Southern China reduced with increasing latitude and reduced with increasing altitude. The proportion of the area with 5000°C< AAT10<8000°C accounted for 70% of the study area, followed by the area of 4000°C8000°C was the least. Climate trend rate of the AAT10 at 99% of the meteorological stations was greater than zero, which indicated that the AAT10 increased significantly in the central Yunnan province, southern Guangdong province as well as Hainan Island.(3) Comparison of period A(1960–1989) and period B(1980–2011) with the change of temperature zones shows that the boundaries of cool temperate zone, mid-temperate zone and warm temperate zone shifted northward and shrank westward. The northern boundary of north subtropical zone and mid-subtropical zone shifted northward gradually by over 0.5° and 0.5° latitude, respectively. The western part of northern boundary of south subtropical zone and marginal tropical zone shifted northward by 0.2° and 0.4° latitude, respectively. The change of temperature zones was expanded to high altitude and latitude.(4) The increase of the AAT10 is conducive to the production of tropical crops planted, which will increase the planting area that was suitable for tropical crops, and expand the planting boundaries to high latitude and high altitude. | DAI Shengpei LI Hailiang LUO Hongxia ZHAO Yifei ZHANG Kexin | 2015 | Journal of Geographical Sciences2015，25，10： | 4 |
| 3 | In situ scanning FTIR microscopy and IR imaging of Pt electrode surface towards CO adsorption显示文摘 | Shigang Sun Shuangjin Hong Shengpei Chen Guoqiang Lu Hongping Dai Xiaoyin Xiao | 1999 | Science in China Series B: Chemistry1999，，3： | 1 |
| 4 | Simulation investigations on the marble deterioration by sulphur dioxide显示文摘This paper deals with investigations on corrosion of marble SO2. We have simulated oxidation of SO2 by photochemical process in the atmosphere. The experiments indicate that formation of SO3 aerosols is related to the concentration of SO2, the UV light intensity, the time of irradiation and the humidity of the air. The corrosion feature of surfaces of the marble and the depth profiles of sulphur were obtained by SEM (Scanning electron microscope), EDXA (Energy-dispersive X-ray analyzer) and SIMS (Secondary ion mass spectrometer). The results of experiments show the corrosive extent of marble depends on its compositions and microareas of marble, which contain lower silicon content can be easily corroded by SO2. | Gan Weitang, Dai Shugui, Liu Youying, Liu Zhaomeng, Zhang Qingmin,Zhou Xingdi, Su Shengpei, Liu Xiao, Zhu RuiZhi,Fu Xueqi and R. J. ChengDepartment of Chemistry,Nankai University,Tianjin 300071,ChinaAtmospheric Science Ressarch Center,State University of New York,Albany,N.Y.12222,USA | 1991 | Journal of Environmental Sciences1991，3，1： | 0 |
您所在的机构暂未开通此部分的功能，请联系管理员