大孔径聚砜超滤膜的研究

作者用向铸膜液中加水的方法对制备大孔膜进行了研究。选择适宜的聚砜浓度和水含量，可以制得截留分子量为１５万的聚砜超滤膜。该膜对丙种球蛋白的截留率＞９５％，纯水透水速度可达７０－８０ｍｌ／ｃｍ＾２·ｈ（０．１ＭＰａ）。     

以大数据建设驱动我国环境法治进程

我国环境法治经过40年的建设和实践,取得了一定的成就,但也面临着环境执法效率不足、环境立法滞后等实际问题。应用于环境领域的大数据技术,可以促进我国的环境立法进程,使得回应型立法和创新型立法成为可能;可以提升我国的环境执法能力,推动协同执法,规范执法程序;可以增强环境司法透明度,提升环境案件审判的科学性,同时通过司法大数据预测判断环境污染、生态破坏等问题的发展趋势并作出应对之策。但是当前,我国环境执法大数据建设尚面临缺乏顶层设计、标准不统一、部门间数据流通不畅等问题,需要通过相应的行政体制改革和法律机制建立来破除障碍。     

天津市小热电厂节能减排工作的分析与建议

天津市符合国发[2007]2号文中关停条件的小机组共39台．年耗标煤量达182．6万t。这些小机组技术落后。节能潜力很大。本文针对天津市这些小热电厂节能减排方法进行分析，建议开展相关节能技术诊断．达到因地制宜、优化匹配、节能减排的目的。     

治理流域污染刻不容缓

国家环保总局近期检查发现．各地江河湖泊污染日益严重。几大流域污水横流，污染纠份不断出现，深入治理流域污染已经刻不容缓。[编者按]     

西部大开发与可持续发展

１９９９年 ,中央提出西部大开发战略 ,这是继沿海开放战略之后中国实施的又一重大发展战略。那么 ,西部大开发战略究竟如何实施呢？１西部大开发应把知识资源开发放在首位国家领导人一再强调 ,加快开发西部地区要有新的思路。什么是新思路？就是要打破常规 ,打破传统发展模式想问题 ,就是按照不断变化着的新形势想问题。那么 ,西部大开发着眼点应放在什么地方 ,是自然资源大开发 ,还是知识资源大开发？我的思路是 ,西部大开发应该把知识资源开发放在重中之重的位置 ,走可持续发展道路。１．１决定一个地区经济增长的关键因素是知识因素土地…     

大口径薄壁无缝铝管变薄旋压工艺

介绍采用离心铸坯——变薄旋压方法制作大口径薄壁铝管的工艺.包括简要工艺流程、特点、适用范围等.该工艺为解决国内大口径薄壁无缝铝管提供了新的途径.     

夹扣的弯曲成形连续模

此文介绍一种在合理大间隙冲裁和延时回程的条件下,使落料件回位嵌入条料中,从而实现连续弯曲成形的一种工艺方法。     

Spatial analysis of plant detritus processing in a Mediterranean river type: the case of the River Tirso Basin,Sardinia, Italy

The river continuum concept represents the most general framework addressing the spatial variation of both structure and function in river ecosystems.In the Mediterranean ecoregion,summer drought events and dams constitute the main sources of local disturbance to the structure and functioning of river ecosystems occurring in the river basin.In this study,we analysed patterns of spatial variation of detritus processing in a 7th order river of the Mediterranean ecoregion(River Tirso,Sardinia0Italy)and in three 4th order sub-basins which were exposed to different summer drought pressures.The study was carried out on phragmites australis and Alnus glutionsa leaf detritus at 31 field sites in seasonal field experiment Detritus processing rates were higher for Alnus glutionsa than for Phragmites australis plant detritus.Processing rates of Alnus glutionsa leaves varied among seasons and study sites from 0.006d^-1 to 0.189d^-1 and those of Phragmites australis leaves ranged from 0.0008d^-1 to 0.102d^-1,with the lowest values occurring at sites exposed to summer drought.Seasons and sites accounted for a significant proportion of such variability.Alder detritus decay rates generally decreased with increasing stream order,while reed detritus decay rates generallyincreased on the same spatial gradient.Summer drought events affected these spatial patterns of variation by influencing significantly the decay rates of both plant detritus.The comparisons among and within sub-basins showed strong negative influence of summer drought on detritus processing rates.Similarly,in the entire River Tirso basin decay rates were always lower at disturbed than at undisturbed sites for each stream order;decay rates of reed detritus remained lower at those sites even after the end of the disturbance events,while alder decay rates recovered rapidly from the summer drought perturbations.The different recovery of the processing rates of the two leaves could also explain the different patterns of spatial variation observed between the two leaves.