Shear capacity of reinforced concrete columns strengthened with CFRP sheet

INTRODUCTION There is increased need in recent years for strengthening or rehabilitation of existing reinforced concrete structures adversely affected by overloading, construction material deterioration, seismic loads, structural deformation, etc. An effective method for increasing the shear capacity of reinforced concrete columns is the use of externally bonded carbon fiber reinforced plastic (CFRP) systems (ACI, 2002). FRP systems were first applied to reinforced concrete col-umns i…     

Reducing students’ carbon footprints using personal carbon footprint management system based on environmental behavioural theory and persuasive technology

This study applied environmental behavioural theories to develop a personal carbon footprint management system and used persuasive technology to implement it. The system serves as an educational system to improve the determinants of students’ low-carbon behaviours, to promote low-carbon concepts and to facilitate their carbon management. To assess the validity of the system, high school students were chosen to participate in an experiment, the results of which reveal (1) the system has significant and positive short-term and relatively long-term effects on the reduction of their self-reported carbon footprint, (2) the system significantly improves their carbon footprint awareness and perceived behavioural control (PBC), and it also promotes behavioural subjective norms, (3) reduction of their self-reported carbon footprint is significantly correlated to PBC, carbon footprint awareness and attitude and (4) PBC is the most critical determinant of carbon reduction. Suggestions are accordingly made.     

纳米碳—PVC膜修饰电极测定镉

介绍了用纳米碳-PVC膜修饰电极测定痕量镉的新方法。优化了各种试验条件,如支持电解质的选择、pH值的影响、修饰剂的用量、富集电位及时间、扫描速率等。     

Modeling water and carbon fluxes above summer maize field in North China Plain with back-propagation neural networks

INTRODUCTION Dynamics of carbon and water vapor fluxesexchange between the atmosphere and the ecosystembiosphere, depend on complex and non-liner interplayamong physiological, ecological, biochemical andedaphic factors and meteorological conditions (Jarvis,1995; Leuning et al., 1995). There are many studiesquantifying the fluxes across different time and spacescales as well as assessing the environment con-straints on them by some kinds of biophysical orempirical models whose resul…     

甘肃省生态足迹动态测度与分析

生态足迹分析法现已广泛应用于各种可持续发展的测度,文章应用该方法对甘肃省的可持续发展状况进行了评价和分析.在1996-2003年间,每隔一年计算出甘肃省的生态足迹,以此来对甘肃省可持续发展状况的动态变化进行测度和分析.计算结果表明,人均需求足迹整体为上升趋势,人均供给足迹整体为下降趋势;生态冗余只有1996年为正,即处于可持续发展状态;其余4个年份均为负值,即为不可持续发展状态.在历年人均生态足迹需求的各组成土地类型中,化石燃料用地和耕地是主要的两个组成类型,其次是草地;在人均生态足迹供给的组成中,耕地和草地是最主要的两个组成类型.     

Hypocholesterolemic and hepatoprotective effects of flaxseed chutney: Evidence from animal studies

Rats fed with hypercholesterolemic diet showed a significant increase in serum total—cholesterol, liver homogenate total-cholesterol, HDL-cholesterol and changed LDL-cholesterol, and HDL/LDL ratio in comparison to control. Flaxseedchutney (FC) supplemented diet (15%, w/w) was found to be more effective in restoring lipid profile changes in rats fed with cholesterol, (1.0%). The activities of serum marker enzymes glutamate oxaloacetate transminase (GOT), glutamate pyruvate transaminase (GPT) and alkaline phosphatase (ALP) were elevated significantly in carbon tetrachloride induced rats. Administration of flaxseedchutney (15%, w/w) resulted in depletion of serum marker enzymes and exhibited recoupment thus showing significant hepatoprotective effect. It was observed that flaxseedchutney supplemented diet could lower the serum cholesterol and as a potential source of antioxidants it could exert protection against hepatotoxic damage induced by carbon tetrachloride (CCl₄) in rats.     

基于生态足迹和人文发展指数的可持续发展评价--以我国海洋渔业资源利用为例

可持续性评价是衡量社会发展状况的一个重要问题。基于生态足迹指数和人文发展指数构建了可持续性评价框架,运用该评价框架对我国社会发展及其对海洋渔业资源的影响进行了综合评价。结果表明：1991-2003年间,我国基于海洋渔业资源利用的社会发展处于不可持续的状态。最后就如何提高社会发展的可持续性水平,降低社会发展对海洋渔业资源的影响提出了一些建议。     

基于集对分析的城市生态足迹预测——以武汉市为例

自然生态环境是城市生态系统赖以生存和发展的重要物质基础，生态足迹作为生态环境承载状态测度的指标，受到社会、经济、人口等多种因素的影响，表现出时空动态性和不确定性特征。鉴于集对分析(SPA)在处理不确定性问题的优势，以武汉市为研究对象，将城市总生态足迹与其相关影响因子联系起来考虑，融合集对分析中的同异反模式识别的“择近原则”和聚类分析思想构造集对分析动态模型，模型精度较高，验证误差均小于0.3%。并对武汉市2005年～2020年总生态足迹发展趋势进行了预测。研究结果表明，2005年～2020年总生态足迹将由1 784.662×10⁴hm²增长到2 781.388×10⁴hm²，呈现出低于GDP、高于能源利用率增长速率的趋势，生态环境将进一步恶化，对此就武汉市生态系统的发展提出了对策与建议。最后，指出SPA动态模型对城市生态系统中生态足迹动态化方法的修正具有理论和实际意义。     

大面积建成区建筑密度遥感制图产品的精度验证

大面积建成区建筑密度遥感制图产品能够提供土地开发强度与人类居住环境的基础信息,是支撑人居环境研究和土地利用规划的重要数据。全球人类居住区层（global human settlement layer,GHSL）是由欧盟联合研究中心负责的大面积人居环境制图项目,建成区建筑密度遥感制图产品是GHSL重要的组成部分。目前该产品在欧美地区已经完成了GHSL建成区建筑密度遥感制图产品的验证。然而以中国为代表的东亚区域的建筑物形态和城市布局与欧美等区域有较大的差别,有必要在亚洲地区对其进一步验证。以中国的5个典型城市（上海、西安、长春、昆明和乌鲁木齐）大面积单体建筑物分布图为基础,通过聚合分析和邻域关键点搜寻匹配等算法,生成中国建成区建筑密度栅格图像产品作为验证数据,然后通过回归分析等方法,在像元尺度上对GHSL建成区遥感制图产品进行评价验证。结果显示,GHSL建成区建筑密度产品在较低分辨率下可以反映中国地区建筑密度情况,但在较高分辨率下在高值区过高估计密度。本研究可以为中国地区研发建成区建筑面积密度产品提供依据。     

The carbon footprint of active sport participants

Researchers examining carbon dioxide-equivalent emissions (carbon footprint) in sport have focused on sport events and, to a lesser extent, sport teams, but provided only average or aggregate values. The author takes the perspective of active sport participants and considers the heterogeneity of individual sport participation behavior. Using online surveys, adult active sport participants (n = 6537) in 20 different sports with main residence in Germany were asked to report their sport-travel behavior in 2015, including traveling in the context of regular (weekly) activity, sport competitions/tournaments, league games, day trips, and training camps/vacations. Annual carbon footprints were estimated using information about travel distances and transportation means. The results revealed an average annual carbon footprint of 844 kg of carbon dioxide-equivalent emissions, with individual sports producing more emissions than team/racket sports. Participants in nature sports had the highest emission levels. Regression analyses revealed that environmental consciousness significantly reduced carbon footprint in individual sports, but not in team/racket and nature sports, supporting the existence of an environmental value-action gap. Activity years, club membership, weekly exercise hours, performance level, and income were mainly positively associated with annual carbon footprint, while gender was insignificant. The findings have implications for policy makers and managers in sport associations and clubs.