Morphology, growth and carbohydrate storage of the plant Typha angustifolia at different water depths

Morphological characteristics, growth and carbohydrate storage dynamics of Typha angustifolia in relation to water depth were investigated. The study was based on observations carried out in two stands, namely Akigase and Teganuma, for two growth seasons. The latter stand was about two times deeper than the former. Teganuma stands exhibited significantly higher number of thick shoots compared to those of Akigase. Conversely, the difference in shoot heights between the two stands was insignificant. The same was true for rhizome lengths. Rhizome diameters were significantly bigger for Teganuma compared to Akigase. Furthermore, both the above and belowground biomass were significantly higher for Teganuma compared to those of Akigase. Teganuma stands allocated 55% of the total biomass to the aboveground parts, while Akigase stands allocated 60%. Similarly, Teganuma exhibited significantly higher stocks of total non-structural carbohydrates (TNC) compared to Akigase. The higher number of thick shoots and the relatively bigger rhizome diameters in Teganuma are seemingly important tolerance strategies in maintaining effective aeration into the rhizosphere, by reducing internal resistance. In addition, the higher TNC stocks and biomass help not only to enhance survival under anoxia for longer durations, they also provide firm substrate anchorage in the deeper Teganuma stands.     

如何搞好国有大中型亏损企业的环境保护工作

本文揭示了目前在国有大中型亏损企业中开展环境保护工作的困难与问题，指出这是关系到实现我国中目标的重大课题，并提出了一系列搞好国有大中型亏 企业环境工作的对策和措施，希望能引起社会各界特别是国有大中型企业领导们的重视。     

化学气相沉积法对13X分子筛孔径修饰及吸附性能研究

化学气相沉积法可对１３Ｘ分子筛进行孔径修饰，并用于含重金属离子废水的净化处理。研究结果表明，随１３Ｘ分子筛外表面ＳｉＯ２沉积量的增加，孔径收缩。     

关于环形风道比摩阻两种计算方法

就通风空调工程中具有特殊应用的环形风道的摩擦阻力计算问题进行了分析，根据流体力学原理，提出了采用流量当量直径法和直接利用圆形风道计算图风道的比摩阻2种方法，第2种计算方法与流量当量直径法比较，查表时更直接。     

Changes in the upper limits of tree species distribution in the Western Caucasus (Belaya River basin) related to recent climate warming

To estimate the response of tree vegetation to recent climate warming in the Western Caucasus, the population state of several tree species at the upper limit of their distribution has been estimated in three mountain massifs in the Belaya River basin. For this purpose, the average and maximum stem diameters, vitality, and age of trees have been determined in the transitional zone between middle-mountain and high-mountain beech-fir forests (1400–1700 m a.s.l.) and in crooked birch forests growing at the upper timberline (1810–2025 m). The upper limits of Acer platanoides, A. pseudoplatanus, Ulmus glabra, and Betula litwinowii have shown a tendency to rise. The upper limit of Abies nordmanniana has remained unchanged over the past few decades, which may be explained by a decrease in moisture supply during the warm season.     

电焊熔珠对棉布和聚氨酯泡沫的引燃能力研究

研究了加载电压对电焊熔珠数目和粒径分布的影响,在模拟装置上实验了电焊对棉布、聚氨酯泡沫和纸张的引燃性能.结果表明,随着加载电压升高,电焊熔珠的数目逐渐减少,熔珠粒径逐渐增大,引燃能力逐渐增强.固体材料性质对电焊熔珠引燃能力也有很大影响,表面粗糙,易蓄热材料容易被点燃.电焊熔珠引燃棉布、聚氨酯泡沫和纸张的临界电压为37.5V、40V和45V.     

不同粒径空气颗粒物中11种多环芳烃的分析测定

将五段多孔冲击分级器 (粒径分级 :≤ 1 .1 ,1 .1～ 2 .0 ,2 .0～ 3 .3 ,3 .3～ 7.0 ,≥ 7.0μm)与大流量采样器连接 ,采集呼和浩特市冬夏两季空气颗粒物样品 ,用高压液相色谱仪 (HPLC)测定样品中的蒽 (An)、菲 (Ph)、萤蒽 (Fl)、芘 (Py)、(Ch)、苯并 [a]蒽 (Ba A)、苯并 [a]芘 (Ba P)、二甲基苯并 [a]蒽 (DMBa A)、二苯并 [ah]蒽 (DBah A)、苯并 [ghi] (Bghi P)和晕苯 (Cor)等 1 1种多环芳烃化合物 (PAHs)。数据表明 :呼和浩特市空气颗粒物中 PAHs的浓度较高 ;有约 97%的 PAHs富集于可吸入颗粒中。     

Including Riparian Vegetation in the Definition of Morphologic Reference Conditions for Large Rivers: A Case Study for Europe’s Western Plains

Methods for defining and retrieving reference conditions for large rivers were explored with emphasis on hydromorphologic and biologic quality indicators. For a set of four large rivers in the European Western Plains ecoregion, i.e., the rivers Meuse, Loire, Allier, and Dordogne, reference reaches were selected based on geomorphologic characteristics. A survey of riparian land use, vegetation, and bed geometry was done for the selected reaches. Responses of the riparian landscape to hydromorphologic conditions were determined with a set of existing and newly developed measures of riparian dynamics and forest development. Strong correlations were observed at the reach and local levels between the ratios of width to depth and embankment and the developed measures of riparian dynamics and forest. Boundary conditions for riparian forest development were determined for the hydromorphologic and biologic indicators of riparian dynamics and vegetation structure. These conditions also proved useful for determining the presence of sustainable populations of Populus nigra and Salix purpurea. From this agreement between abiotic and biotic boundary conditions, a set of useful reference conditions was determined, and a framework for the definition of reference and good status conditions subsequently evolved. Finally, a proposal for assessment and monitoring the proposed indicators is discussed for its applicability.     

Determination of granule size distribution in a UASB reactor

Granular sludge is the key factor for an efficient operation of an upflow anaerobic sludge blanket (UASB) reactor. In order to monitor the granularity of anaerobic sludge, the determination of the granule size distribution is of vital importance. For this reason, several techniques have been proposed; however, they are either tedious, imprecise or expensive and hardly applicable in full-scale treatment plants. There was then the need for a simple and low-cost technique. This technique involves the determination of the settling velocities of a sludge sample and of extrapolating the corresponding diameters using a mathematical algorithm. In the proposed algorithm, the granules density was calculated, the flow regime was examined and finally the granule size distribution was obtained. Two very important correlations were suggested by the experimental results. The granule density and diameter were strongly correlated with the VSS/TSS ratio.     

Rehabilitating Agricultural Streams in Australia with Wood: A Review

Worldwide, the ecological condition of streams and rivers has been impaired by agricultural practices such as broadscale modification of catchments, high nutrient and sediment inputs, loss of riparian vegetation, and altered hydrology. Typical responses include channel incision, excessive sedimentation, declining water quality, and loss of in-stream habitat complexity and biodiversity. We review these impacts, focusing on the potential benefits and limitations of wood reintroduction as a transitional rehabilitation technique in these agricultural landscapes using Australian examples. In streams, wood plays key roles in shaping velocity and sedimentation profiles, forming pools, and strengthening banks. In the simplified channels typical of many agricultural streams, wood provides habitat for fauna, substrate for biofilms, and refuge from predators and flow extremes, and enhances in-stream diversity of fish and macroinvertebrates.Most previous restoration studies involving wood reintroduction have been in forested landscapes, but some results might be extrapolated to agricultural streams. In these studies, wood enhanced diversity of fish and macroinvertebrates, increased storage of organic material and sediment, and improved bed and bank stability. Failure to meet restoration objectives appeared most likely where channel incision was severe and in highly degraded environments. Methods for wood reintroduction have logistical advantages over many other restoration techniques, being relatively low cost and low maintenance. Wood reintroduction is a viable transitional restoration technique for agricultural landscapes likely to rapidly improve stream condition if sources of colonists are viable and water quality is suitable.