请不要清除路边草

每逢喜庆节假日,或卫生大检查,或创建国家环境保护模范城市,都要清理卫生,甚至组织较大规模地群众性爱国卫生运动,人们在解决脏、乱、差的同时,往往将路边、墙角下、或庭院周边的野生杂草视为不卫生之物,全部被清除掉,有的领导还以清理死角为由令其铲除,甚至做为重点检查对象,认为这才算打扫卫生最彻底。但这恰好相反,不仅没有保持好     

土壤中重金属污染的植物修复强化技术概览

土壤中重金属残留会严重破坏土壤环境,直接威胁到农作物及食品的安全,进而会影响到人类的生产和生活,因此对重金属污染土壤进行修复和治理十分必要。植物修复是一种有着广阔应用前景、环境友好型的原位修复技术。在分析土壤中重金属来源的基础上,展现了不同类型植物材料的优缺点及其对土壤中重金属的处理能力,并针对植物修复技术面临的问题,探讨了化学措施、生物措施、农艺措施和基因工程等几种主要植物修复强化技术的作用机制、研究现状及其优缺点,重点分析了在植物修复技术中各种强化技术措施的发展现状及其存在的弊端,并对未来植物修复强化技术的发展方向进行了展望。     

二沉池设计补正

静沉试验法是常用的二沉池设计方法 ,但是仍存在一些问题。在分析大量有关资料的基础上 ,对该法作了较深入的研究。结果表明 ,静沉试验法能够体现二沉池的实际沉降行为 ,但对浓缩时间的解法需要加以纠正。该设计方法可以更好地应用于优化设计之中。     

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.     

我国植物资源保护利用的新问题

我国植物资源保护利用的新问题ＮｅｗＣｈａｌｌｅｎｇｅｏｆＰｌａｎｔＲｅｓｏｕｒｃｅｓＣｏｎｓｅｒｖａｔｉｏｎａｎｄＵｔｉｌｉｚａｔｉｏｎｉｎＣｈｉｎａ谢笃初（深圳实验学校５１８０２８）随着人类生存环境的恶化，植物作为地球生态系统主体的地位，表现得越来...     

磺胺与8-羟基喹啉重氮偶联反应的研究及应用

研究了磺胺 亚硝酸根 8 羟基喹啉的重氮偶联反应 ,利用其所形成的偶氮染料在 50 2nm处有最大吸收 ,建立了测定NO- 2 的新方法。在 0～ 1 .4mg/L范围内 ,亚硝酸根离子的浓度与吸光度有良好线性关系。检测限为 3 .7× 1 0 - 3mg/L ,表现摩尔吸收系数是 3 .4×1 0 4 L/mol·cm。     

九岭幕阜山濒稀植物的分布及其环境关系

本文研究了九岭幕阜山濒稀植物的保护现状、区系结构、地理分布特征及其与环境的关系。本区保存有国家保护植物３２种，这些植物分布类型多样。特有现象显著，区系起源古老。它们主要分布于海拔５００～１５００ｍ的阔叶林内，具有明显的地理局限性和生态脆弱性。人为对阔叶林生态环境的破坏是导致物种濒危的主要原因，保护濒稀植物最重要的是要确实保护和恢复本区良好的阔叶林生态系统。     

藻类急性毒性实验阳性参比毒物的筛选

研究了８种化合物对一种淡水绿藻－斜生栅藻的毒性作用。结果表明斜生栅藻时Ｃｄｓｏ４，的毒性作用敏感，又由于Ｃｄｓｏ４具有性质稳定、重复性好、方便易得等特点，因此被选为我们的阳性参比毒物。ｃｄｓｏ４的９６ＥＣ５０值为０．５４３ｍｇ／Ｌ（细胞数），０．８８ｍｇ／Ｌ（光密度）。