洁霉素生产废水处理的研究

采用水解（酸化）－二段投菌生物接触氧化－混凝工艺处理浓度洁霉素废水,中试结果表明：进水ＣＯＤ浓度为３５００－５０００ｍｇ／Ｌ范围时,出水ＣＯＤ平均去除率大于９５％,进水ＢＯＤ浓度为１０００－１５００ｍｇ／Ｌ范围时,出水ＢＯＤ平均去除率大于９６％,各项指标达到国家ＧＢ８９７８－８８排放标准。     

京杭运河江苏段底栖动物群落结构调查

通过2018年5月在京杭运河江苏段布设23个采样点调查底栖动物群落结构和生境状况,并用Shannon-Wie-ner多样性指数评价底栖动物多样性,用聚类法分析采样点底栖动物群落结构相似性,用ANOSIM分析检验聚类组差异性,用SIMPER对聚类组作主要特征物种分析.结果显示:23个采样点共采集底栖动物42种,其中甲壳纲...     

铁路接触网安全性评价方法及工程应用

地下工程穿越既有接触网时会对接触网系统的安全性产生较大影响,基于铁路接触网的设计标准和规范要求,提出一种接触网安全性的评价方法,其中包括计算工况选取、接触网位移分析、支柱负载分析及参数检算4部分。结合北京地铁某区间盾构隧道穿越火车站接触网工程实例,对该方法的有效性进行了研究。结果表明,工况1下,接触网处于安全状态;工况2下接触导线高度变化量超限。建议当盾构开挖通过一个接触网支柱后,要迅速对已通过接触网支柱进行处理,恢复到原来状态,避免2个或3个接触网支柱同时发生大于10 mm的基础沉降以及超过0.2%的支柱倾斜量。     

基于ABAQUS的呼吸防护面具卡扣装配设计

在对呼吸防护面具结构和装配力学分析的基础上,确定了卡扣装配尺寸、受力、变形的关系表达式。在表达式的基础上,建立了环型卡扣装配分析模型,并用ABAQUS软件分析了卡扣不同过盈量和插入角对卡扣连接和装配力的影响,进而根据最大装配力、最大应变与许用应变的关系,得到了环型卡扣的最佳过盈量、最佳插入角,满足了装配可靠、连接紧凑和密封性好的要求。     

强化微污染原水净化效果的生产性应用研究

针对姚江水源受污染的现状和原传统净水工艺去除污染效率低、药耗大等缺点,对宁波市梅林水厂的传统净水工艺进行了改进,并对改进前后的去除污染效率进行了对比试验研究．结果表明,在姚江水质为ｐＨ６．５－７．６、浊度７－２０ＮＴＵ、色度２５－３７度、ＮＨ＋４－Ｎ０．２５－９．０ｍｇ／Ｌ、ＮＯ－２－Ｎ０．０２５—０．２５ｍｇ／Ｌ、ＣＯＤＭｎ６－１８．９ｍｇ／Ｌ的条件下,改进后的生化工艺系统对浊度、色度、ＮＨ＋４－Ｎ、ＮＯ－２－Ｎ及ＣＯＤＭｎ的平均去除率比传统工艺分别提高了２４．５％、３０．０％、５８．５％、７０．０％和２７．５％,除污染效果明显优于传统净水工艺;并且可节约矾耗５０％以上和氯耗７７％左右．     

Early Responses to Acute Ozone Exposure in Two Fagus Sylvatica Clones Differing in Xeromorphic Adaptations: Photosynthetic and Stomatal Processes, Membrane and Epicuticular Characteristics

Two Fagus sylvatica L. clones were used to investigate the early responses to acute O₃ exposure (150 nL L⁻¹, i.e., 1.35× ambient hourly peak in rural Italy) and whether xeromorphic adaptations affect gas exchange, membrane, and epicuticular responses. One clone originated in a wet and temperate climate in Central Italy (Tuscany); the other clone originated in a warmer and drier climate in the southern-most part of the F. sylvatica distribution (Sicily). Because of higher base gas exchange rates, the most negative effects of O₃ exposure (gas exchange impairment, uncoupling between net photosynthesis and stomatal conductance, increased membrane lipid peroxidation) were found in the southern clone. Xeromorphic adaptations (higher epicuticular waxes and stomatal density, lower leaf wettability and size) were found in this clone. Our results suggest that xeromorphism may increase O₃ sensitivity in species not adapted to face water stress, like the mesophilic F. sylvatica, when experiments are carried out with full irrigation. We present evidence describing the relationship between gas exchange and number and status of stomata. Stomatal density and the structural damage to stomata resulting from O₃ exposure did not affect gas exchange: In fact, non-stomatal limitations to photosynthesis prevailed over stomatal limitations.     

Monitoring of environmental parameters for CO2 sequestration: a case study of Nagpur City, India

The use of native plants was examined in three rural communities in the semi-arid of the state of Pernambuco, in northeastern Brazil. The techniques employed in the present study combined a number of different techniques of data-gathering, including semi-structured interviews, guided tour, key-informants, and participating observation, and sampling of the vegetation to evaluate the biodiversity of useful plants. A total of 61 woody species were cataloged, mostly used for construction purposes or fuel. Among the species that stood out for their local importance and multiplicity of uses were: Myracrodruon urundeuva (Engl.) Fr. All., Schinopsis brasiliensis Engl., and Anadenanthera colubrina (Vell.) Brenan. The first two species are included in Brazilian lists of threatened species. Arguments are presented for strategies of management and conservation of plant resources in the semi-arid region that seek alternatives to the use of timber species and the development of alternative non-timber resources.     

微生物传感器的研究现状及在水环境监测中的应用

微生物传感器是一种迅速发展的环境监测手段。文章介绍了微生物传感器的构成及工作原理与研究现状,并对微生物传感器进行了分类。文章还讨论了微生物传感器在水环境监测中的应用,其中包括在BOD检测、有机物检测及生物毒性检测中的应用,并对其在实际监测应用中所遇问题进行了分析。     

Evaluation of hexavalent chromium removal in a continuous biological filter with the use of central composite design (CCD)

Hexavalent chromium is frequently found in industrial effluents as a result of the industrial applications of this compound and its anti-corrosive features. However, hexavalent chromium is extremely toxic, and its discharge in water is regulated, with a maximum limit of 0.1 mg/L in accordance with legislation established by CONAMA-Brazil (no. 397, April 3, 2008). To achieve lower discharge values, it is necessary to reduce from Cr(VI) to Cr(III), which is less toxic, and an economic alternative involves biological removal of this compound. Residence time distributions (RTDs) were measured to evaluate the behavior of actual biofilter operation conditions in a biofilter flow. The medium residence time distributions used were 8 and 24 h (recommended by the legislation). To optimize this process, a central composite design was used, considering the initial chromium concentration and pH as the independent variables and the removal of hexavalent chromium as the response. The boundary curves and surface response showed optimal behavior at 3.94 mg/L [Cr(0)] and a pH of 6.2. The removal process of hexavalent chromium is mathematically described by the Michaelis-Menten kinetic model. This model appropriately represents the variation of chromium concentration along the bioreactor.     

接触热阻对火灾下组合结构构件截面温度场的影响

结构的高温性能与抗火设计是工程设计中应解决的关键技术问题之一,对确保火灾下人民生命财产安全至关重要。对于以钢管混凝土柱、组合扁梁以及钢-混凝土组合楼板等为代表的钢-混凝土组合结构构件,由于截面构成相对复杂,致使其温度场分析以及后续的高温性能分析具有较强的特殊性。已有的针对组合结构构件的温度场分析模型中,多数研究者忽略或仅间接考虑钢与混凝土界面的接触热阻,使其分析结果无法反映组合构件这类具有复合接触界面的多梯度温度分布特性,其对温度值的预测也随之偏离实际情况。为此,针对钢管混凝土柱、组合扁梁以及钢-混凝土组合楼板3类组合结构构件,总结分析了有关考虑接触热阻的温度场分析模型,并结合作者的相关研究成果,重点讨论了如何在温度场分析模型中有效考虑界面上接触热阻,以及接触热阻对组合结构截面温度场的影响,为科学评价组合结构的抗火性能提供前提与基础。