拉伸法制备聚四氟乙烯平板膜的研究进展

聚四氟乙烯(PTFE)因其自身的优异性能,吸引了国内外众多专家学者的注意力。PTFE拉伸平板膜具有独特的“原纤-节点”结构,在航天、汽车、化工、医疗等领域有着广阔的应用前景。文中主要综述了在采用机械拉伸法制备PTFE平板膜过程中,通过控制原料种类与组成、设备、工艺参数等方式来调控糊料挤出物和薄膜的结构性能。最后,对PTFE独特的成纤和拉伸成孔机理与工艺参数之间的研究进行了展望,指明了PTFE平板膜应用领域的研究方向。

Green and compatible industrial development in Western China

Western China has lagged a lot in terms of industrial structure and economic development,compared with the national average.And China announced its target of CO_2 emission reduction,i.e.by 2020,CO_2 emission per GDP will drop by40-45%compared with 2005.The target will be incorporated into China's long-term industrial planning.Against this background,this paper will make a comprehensive examination of the industrial development of Western China,aiming to discover a green and compatible way.First,we analyze the spatiotemporal evolution of regional industrial structure for the period 2000-2010.Second,we try to discover the industrial structure optimization path for Western China by employing the Vector Auto Regression model.Lastly,we try to provide some advice and suggestions for further industrial development in Western China.Our examination shows that further industrial development in Western China should pay full attention to resource conservation and recycling,and develop on a green and compatible path.

Occurrence Regularity of Fruit Physiological Disease Spongy Tissue in Zihua Mango(Mangifera indica L.)

[ Objective ] The aim was to study the occurrence regularity of fruit physiological disease spongy tissue in Zihua mango （Mangifera indica L. ）. [ Meth. od] Main features of disease symptoms of Zihua mango fruit spongy tissue were investigated from 2002 to 2005 ,and the correlation between the incidence of Zihua mango fruit spongy tissue and its external factors （ fruit maturity, fruit size and fruit yield per plant） was analyzed comprehensively. [Result] The main features of disease symptoms appeared depressed cavity in the middle or lower part of fruit, forming spongy-like cavity. Immature fruits basically had no incidence. The dis- ease began to appear before 10 d of maturity. The disease incidence rate had extremely positive correlation with fruit weight, fruit vertical diameter or cross diame- ter. [ Conclusion] The research provides reference for field diagnoses, identification, preharvest and postharvest uninjurous test of fruit physiological disease suonaw tissue.

Input-occupancy-output models of the non-competitive type and their application - an examination of the China-US trade surplus

本文构建了一种能够反映中国加工贸易特点的非竞争（进口）型投入占用产出模型，提出了一个国家全部出口与分部门、分大类商品的单位出口对国内增加值和就业的拉动效应的计算方法，从数学上证明了出口总值等于出口商品所包含的完全国内增加值与完全进口额之和，并据此编制了2002年中美两国的非竞争（进口）型投入占用产出表，测算和分析了中美两国出口对各自国内增加值和就业的影响。

China’s intra-and inter-national carbon emission transfers by province:A nested network perspective

Since China carries an increasingly significant responsibility in carbon emission reduction,a systematic assessment from the multi-scale and multi-regional perspective is essential to examine the region-specific carbon emissions and different kinds of carbon transfer patterns.By identifying carbon emission flows among 31 domestic provincial administrative regions and 184 foreign countries/economies,this work examines the domestic and foreign carbon emission flows of Chinese provinces/municipalities based on the intra-and inter-national relations.Overall,the provinces and municipalities in China are divided into 4 patterns according to carbon emission flows,among which inland provinces mainly engage in domestic carbon emission transfers,western regions generally receive carbon emissions with main carbon outflows in northeastern and central provinces,and coastal regions play an essential role in balancing carbon emission surpluses and deficits between domestic and foreign regions.For different sub-regions in China,recognizing carbon emission transfer relations contributes to the synergetic and sustainable regional development from a tele-connected perspective.With the nested network analysis,the multi-scale and multiregional assessments focusing upon China’s provinces and municipalities extend the existing research to both national and global scales,providing a solid foundation for sustainable regional development in China.

Pathways to peak carbon emissions in China by 2030: An analysis in relation to the economic growth rate

With less than ten years left to meet its pledge to peak carbon dioxide emissions(peak emissions hereafter) by 2030,China has entered a critical emissions reduction stage. How to meet this commitment in a context in which GDP per capita will double from 2020 by 2035 is a major decision-making issue for the Chinese government and people and one which warrants further study. To reveal the relationships between the GDP growth rate, the rate of decrease of carbon intensity and the time to reach peak emissions, this study translates the question as to “when China's carbon emissions peak will occur” into “how can one control the rate of carbon intensity decrease at a given GDP growth rate”. In the light of the results of a random forest algorithm used to identify and project the key drivers of carbon intensity in China, a mathematical model was developed to simulate different scenarios relating to decreases in carbon intensity. The date at which Chinese carbon emissions will peak is predicted by comparing the rate of decrease of carbon intensity with the GDP growth rate. The results show that the time to peak emissions depends on the relationship between the rate of decrease of carbon intensity and the GDP growth rate, where the former depends mainly on the energy structure and policy. If China's annual GDP growth rate were 5.0% during the 15th Five-Year Plan, and if the share of non-fossil energy in total energy consumption were 23.0% or above, China's carbon emissions will peak before2030. If the share of non-fossil fuels were 20.0% or less, China might not be able to reach its 2030 target. In this latter case an acceleration in the pace of energy restructuring would be required to reach peak emissions before 2030. The projected peak emissions scenarios suggest that the carbon peak will occur between 2025 to 2029, with average peak emissions of 11.2 billion tons and a distribution ranging from a minimum of 10.5 billion and a maximum of 11.9 billion tons. If the GDP growth rate were4.5%, 5.5% or 6.0% during the 15th Five-year Plan, the share of non-fossil energy must reach 23.0%, 25.0% or 27.0%,respectively, to ensure that emissions peak by 2030. The results of this study provide a series of reference points for China's pursuit of feasible pathways to peak carbon emissions by 2030.