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媒体新生态系统的建构与国际化路径分析 被引量:1
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作者 党东耀 《新闻大学》 CSSCI 北大核心 2016年第6期109-116,134,共9页
随着媒介技术的快速发展,新媒体的出现极大地改变了我国媒体的结构。互联网公司积极融入世界的信息技术、资本和内容市场,从而在传媒业不断扩张,传媒业进入了一种混合媒介系统。在此背景下急需建构新的媒介生态系统,以发挥技术、资本和... 随着媒介技术的快速发展,新媒体的出现极大地改变了我国媒体的结构。互联网公司积极融入世界的信息技术、资本和内容市场,从而在传媒业不断扩张,传媒业进入了一种混合媒介系统。在此背景下急需建构新的媒介生态系统,以发挥技术、资本和政府的整体作用,延伸价值链条、实现资本证券化,建立产权制度体系,从而促进传统媒体和新媒体、媒体信息传播和多元服务体系、国有媒体和新兴媒体的深度融合,使我国媒体具备和世界信息、技术和资本市场接轨的能力,提升国际竞争力,打造国际化传播格局。 展开更多
关键词 新媒介 混合媒介系统 生态系统:国际化
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Interannual variability in soil respiration from terrestrial ecosystems in China and its response to climate change 被引量:9
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作者 CHEN ShuTao HUANG Yao +4 位作者 ZOU JianWen SHI YanShu LU YanYu ZHANG Wen HU ZhengHua 《Science China Earth Sciences》 SCIE EI CAS 2012年第12期2091-2098,共8页
Soil respiration is an important process in terrestrial carbon cycle.Concerning terrestrial ecosystems in China, quantifying the spatiotemporal pattern of soil respiration at the regional scale is critical in providin... Soil respiration is an important process in terrestrial carbon cycle.Concerning terrestrial ecosystems in China, quantifying the spatiotemporal pattern of soil respiration at the regional scale is critical in providing a theoretical basis for evaluating carbon budget.In this study, we used an empirically based, semi-mechanistic model including climate and soil properties to estimate annual soil respiration from terrestrial ecosystems in China from 1970 to 2009.We further analyzed the relationship between interannual variability in soil respiration and climatic factors (air temperature and precipitation).Results indicated that the distribution of annual soil respiration showed clear spatial patterns.The highest and lowest annual soil respiration rates appeared in southeastern China and northwestern China, respectively, which was in accordance with the spatial patterns of mean annual air temperature and annual precipitation.Although the mean annual air temperature in northwestern China was higher than that in some regions of northeastern china, a greater topsoil organic carbon storage in northeastern China might result in the higher annual soil respiration in this region.By contrast, lower temperature, less precipitation and smaller topsoil organic carbon pool incurred the lowest annual soil respiration in northwestern China.Annual soil respiration from terrestrial ecosystems in China varied from 4.58 to 5.19 PgCa-1 between 1970 and 2009.During this time period, on average, annual soil respiration was estimated to be 4.83 PgCa-1 .Annual soil respiration in China accounted for 4.93%-6.01% of the global annual soil CO2 emission.The interannual variability in soil respiration depended on the interannual variability in precipitation and mean air temperature.In order to reduce the uncertainty in estimating annual soil respiration at regional scale, more in situ measurements of soil respiration and relevant factors (e.g.climate, soil and vegetation) should be made simultaneously and historical soil property data sets should also be established. 展开更多
关键词 China soil respiration temporal variability CLIMATE
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