THE EFFECTS OF IMPROVING SEWAGE SLUDGE DIGESTION

A model was developed and tested to investigate the effects of various parameters on the processing costs of anaerobic digestion. The model was based on empirical data collected from full-scale plants which varied in size from 35,000 to 900,000 population equivalents. (Equivalent to loading rates of 0.5 to 2.7 kg VS/m³/d.) In spite of different operating regimes and conditions of the plants analysed, various relationships were discovered between: sludge quality and volatile solids destruction; sludge quality and biogas yield; and, effluent volatile solids and dewatering. Where correlations existed, these were used to make predictions on operating costs of the digestion and dewatering plant based on sensitivity analysis. The results of the model were used to make recommendations on how to optimise the operation of an anaerobic digestion plant.     

单层厂房排架结构体系可靠度分析

本文在构件截面可靠度研究的基础上，充分考虑了结构的塑性性能、失效截面的相关性，分析了单层厂房钢筋混凝土排架结构的体系可靠度。与现有结构体系可靠度分析方法相比较，本文方法简单、准确、可行。     

建筑自喷系统使用扩展覆盖边墙型喷头的探讨

针对轻危险级和危险级中 级建筑内居室上空为平顶板的场合,提出了使用扩展覆盖面边墙型EC喷头代替普通水平边墙型喷头的见解并就相关技术问题展开了讨论     

Planning and designing for the multiple use role of habitats in urban/suburban landscapes in the Great Basin

Most researchers agree that preserving, creating, and restoring urban wildlife habitats has to be an interdisciplinary undertaking if it is to succeed. Ecologists and wildlife biologists must be key participants. The culturally modified context of most urban habitats suggests that landscape architects also have a primary role to play.Open space in the urban/suburban environment is a scarce and valuable resource. Private and public sector pressure to convert these spaces to commercial or intensive recreational uses are immediate and intense. Presenting arguments to preserve or restore urban open space solely as habitat for wildlife is seldom successful. Decision makers are more likely to support urban wildlife habitat programs if other uses are also accommodated.There is a growing body of research data that suggests that wildlife are being adversely impacted by multiple uses of urban habitats. The challenge for planners and designers is to minimize adverse impacts and capitalize on those attributes of other uses that enhance habitat value. Planning for the temporal as well as spatial dimensions of site uses is required if the needs of wildlife are to be met.The paper presents three general areas in which landscape architects have traditionally contributed to an interdisciplinary approach to urban wildlife habitat planning: contextual perspective, problem solving process, and design/technical execution.Reflecting back on his past 10 years of experience as a landscape architect planning urban wildlife habitats, the author presents several case study projects in which: (A) accommodation of multiple use objectives, including wildlife habitat, was required; (B) interdisciplinary teams participated in the planning and design process; (C) key principles from the fields of landscape ecology, conservation biology and wildlife biology were applied to facility and activity location, habitat configuration, and management.Plans of completed projects are used to illustrate how habitat values were preserved or enhanced and multiple uses accommodated in public open spaces. The paper concludes with a brief summary of keys to success common to each project.     

城市地域文化特色塑造:乌鲁木齐二道桥民族风情一条街规划

问题 二道桥民族风情一条街位于乌鲁木齐市解放南路和胜利路地段，历来是多种少数民族聚集地。历史掌故上“二道桥”、“洋行街“，以经营新疆土特产和外国进口商品为主．具有100多年历史和浓郁民族风情。     

怎样扑救高层办公大楼火灾

1　掌握容易造成火势蔓延的部位　　有人说 ,高层办公大楼火灾不能被扑救 ;也有的人说 ,多数高层建筑火灾可以被第一条供水线路扑灭——很幸运。如果你能够用第一条水带线路作为控制火势发展的主要方向 ,就能够阻止火势的蔓延。由于热量通常向上传播 ,因而你必须到达着火楼层的上一楼层 ,阻止火势沿垂直方向蔓延。为了阻止高层办公大楼内的火势向上蔓延 ,消防队员应当懂得自己该观察哪些部位。这是一个不容忽视的环节 ,因为你不可能在一个 2 0 0 0 0 ft、拥有 15 0个房间的楼层中跑来跑去 ,通过嗅觉来寻找烟气。从以前发生过的高层建筑火灾…     

Toxicity bioassay of heavy metals in water using Tetrahymena pyriformis

The toxicities of five heavy metal compounds on the survival of the ciliated protozoan Tetrahymena pyriformis were determined. Three-day old cultured cells were exposed to five concentrations of each test compound in one or more of three water series; distilled, soft, and hard water. A culture of each sample was placed in a plastic petri dish and covered with mineral oil to prevent evaporation. The cells were counted initially, then again at 0·5 h, 1 h, 2 h, 1 day, 2 days, 3 days, and on the fourth day. Lethal threshold concentrations and tolerance limit medians were determined by graphic methods. On a weight bases cadmium was most toxic, followed in decreasing toxicity by mercury, cobalt, zinc, and lead. Compared to similar fish data, all heavy metals were more toxic to T. pyriformis except lead. The toxicity of lead in soft versus hard water exemplified an antagonistic effect with greater than seven times the amount of lead necessary in hard water to produce comparable mortality as lead in soft water. On the other hand, the toxicity of mercury is about twice as great in hard water as in soft water (a synergistic effect). T. pyriformis appears to be a more sensitive indicator than fish of heavy metal contamination of water. T. pyriformis bioassay should prove a good means of determining the existence of many water pollutants.     

The uptake of heavy metals by epiphytic bacteria on Alisma plantago-aquatica

Bacterial epiphytes on the surface of the fresh-water plant Alisma plantago-aquatica collected from a polluted river were found to be a major factor in contributing to the total metal concentrations of the plant. The removal of epiphytes from the leaf surface resulted in significant reductions in the concentrations of Cr (reduced by 15–50%), Cu (30–35%), Fe, Pb, and Zn (10–50%). While numbers of epiphytes and concentrations of heavy metals increased in samples collected from polluted water compared with from unpolluted water, the fraction of metals held by the epiphytes appeared to remain similar for all samples.     

考虑地形影响和多点激励的大跨高墩桥地震响应分析

提出一种综合考虑行波和地形影响的大跨结构在多点输入下的地震响应分析方法。首先计算P波在多种角度入射下两座山峰以及其间自由场地的时程响应,并以此作为两座山峰之间大跨桥梁的桥台及桥墩基础多支承点处的地震输入,这种地震输入综合了行波和地形的影响。然后基于多点激励下地震响应分析方法,编制有限元分析程序,在此基础上分析了考虑行波和地形综合影响下一座360m4跨高墩连续刚构桥的多点激励地震响应。从分析结果看,考虑地形效应和不考虑地形效应的差别较大,不考虑地形效应可能会较小的估计结构的内力响应。因此,大跨度结构地震响应分析应考虑地形的影响。本文分析结果可供抗震设计参考。