期刊文献+
共找到3篇文章
< 1 >
每页显示 20 50 100
蓝回绕特性的研究 被引量:1
1
作者 曾艺蓉 《天文学报》 CSCD 北大核心 2003年第2期103-109,共7页
研究了可以影响蓝回绕(blue loops)的各种主要因素,发现蓝回绕的形状和中心氦燃烧阶段的总产能率的变化相关联,而总产能率的变化主要来源于壳层氢燃烧和中心氦燃烧产能率的变化,所以蓝回绕主要与壳层氢燃烧和中心氦燃烧产能率的变化相... 研究了可以影响蓝回绕(blue loops)的各种主要因素,发现蓝回绕的形状和中心氦燃烧阶段的总产能率的变化相关联,而总产能率的变化主要来源于壳层氢燃烧和中心氦燃烧产能率的变化,所以蓝回绕主要与壳层氢燃烧和中心氦燃烧产能率的变化相联系。壳层氢产能率的变化主要与氢丰度变化区(μ-梯度区)的氢丰度分布轮廓(X-profile),μ-梯度区的温度,以及外对流区的深入程度密切相关。氦核的大小和温度会影响中心氦燃烧产能率的变化,中心氦燃烧产能率的变化不仅对总产能率的变化有贡献,而且也会影响亮层氢燃烧产能率的变化。 展开更多
关键词 蓝回绕 总产能率 壳层氢燃烧 中心氦燃烧 恒星 演化
下载PDF
Impacts of Carbon Tax Policy on CO_2 Mitigation and Economic Growth in China 被引量:3
2
作者 Shenglii Zhou Minjun Shi +1 位作者 Na Li Yongna Yuan 《Advances in Climate Change Research》 SCIE 2011年第3期124-133,共10页
In this paper we examine the impacts of carbon tax policy on CO2 mitigation effects and economic growth in China by using a dynamic energy-environment-economy computable general equilibrium (CGE) model. The results ... In this paper we examine the impacts of carbon tax policy on CO2 mitigation effects and economic growth in China by using a dynamic energy-environment-economy computable general equilibrium (CGE) model. The results show that 30, 60, and 90 RMB per ton CO2 of carbon tax rate will lead to a reduction of CO2 emissions by 4.52%, 8.59%, and 12.26%, as well as a decline in the GDP by 0.11%, 0.25%, and 0.39% in 2020, respectively, if carbon tax revenues are collected by the government. Moreover, with energy efficiency improvements the CO2 emission per unit of GDP will equally drop by 34.79%, 37.49%, and 39.92% in 2020, respectively. Negative impacts on sectors and households will be alleviated if carbon tax revenues are returned to these sectors and households. 展开更多
关键词 dynamic energy-environment-economy CGE model carbon tax mitigation effect economic impact
下载PDF
Remote Sensing Indices to Measure the Seasonal Dynamics of Photosynthesis in a Southern China Subtropical Evergreen Forest 被引量:1
3
作者 SUN Leigang WANG Shaoqiang +5 位作者 Robert A.MICKLER CHEN Jinghua YU Quanzhou QIAN Zhaohui ZHOU Guoyi MENG Ze 《Journal of Resources and Ecology》 CSCD 2019年第2期112-126,共15页
The accurate measurement of the dynamics of photosynthesis in China’s subtropical evergreen forest ecosystems is an important contribution to carbon(C) sink estimates in global terrestrial ecosystems and their respon... The accurate measurement of the dynamics of photosynthesis in China’s subtropical evergreen forest ecosystems is an important contribution to carbon(C) sink estimates in global terrestrial ecosystems and their responses to climate change. Eddy covariance has historically been the only direct method to assess C flux of whole ecosystems with high temporal resolution, but it suffers from limited spatial resolution. During the last decade, continuous global monitoring of plant primary productivity from spectroradiometer sensors on flux towers and satellites has extended the temporal and spatial coverage of C flux observations. In this study, we evaluated the performance of two physiological remote sensing indices, fluorescence reflectance index(FRI) and photochemical reflectance index(PRI), to measure the seasonal variations of photosynthesis in a subtropical evergreen forest ecosystem using continuous canopy spectral and flux measurements in the Dinghushan Nature Reserve in southern China.The more commonly used NDVI has been shown to be saturated and mainly affected by illumination(R^2=0.88, p <0.001), but FRI and PRI could better track the seasonal dynamics of plant photosynthetic functioning by comparison and are less affected by illumination(R^2=0.13 and R^2=0.51, respectively) at the seasonal scale. FRI correlated better with daily gross primary production(GPP) in the morning hours than in the afternoon hours, in contrast to PRI which correlated better with light-use efficiency(LUE) in the afternoon hours. Both FRI and PRI could show greater correlations with GPP and LUE respectively in the senescence season than in the recovery-growth season. When incident PAR was taken into account, the relationship between GPP and FRI was improved and the correlation coefficient increased from 0.22 to 0.69(p < 0.001). The strength of the correlation increased significantly in the senescence season(R^2=0.79, p < 0.001). Our results demonstrate the application of FRI and PRI as physiological indices for the accurate measurement of the seasonal dynamics of plant community photosynthesis in a subtropical evergreen forest, and suggest these indices may be applied to carbon cycle models to improve the estimation of regional carbon budgets. 展开更多
关键词 fluorescence reflectance index(FRI) photochemical reflectance index(PRI) PHOTOSYNTHESIS gross primary productivity(GPP) light-use efficiency(LUE) subtropical evergreen forest
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部