水体沉积物重金属质量基准研究新进展——生物效应数据库法

根据加拿大、美国佛罗里达、澳大利亚、新西兰、中国香港等国家和地区水体沉积物质量基准研究的最新资料 ,综述了目前国际上广泛采用的用于制定沉积物质量基准的新方法——生物效应数据库法 ,介绍了该方法制定基准研究和应用的新进展     

综合预应力与陀螺效应的TLJ500土工离心机模态分析

目的 分析获得离心机运转时各综合效应对其模态频率的影响.方法 从理论上推导结构在无离心场时,仅考虑预应力刚化效应和仅考虑旋转软化效应与综合考虑各效应时结构固有频率之间的关系.建立TLJ500土工离心机静止状态及运转状态的有限元模型,并根据TLJ500静止状态的模态试验结果对有限元模型中主轴轴承部位的材料参数进行修正识别,获得可信度更高的模型.再将修正识别得到的主轴轴承参数代入离心机运转状态的有限元模型,开展离心机运转状态的模态分析,结合理论分析结果,计算得到综合考虑预应力刚化效应与旋转软化效应时离心机关心模态频率的结果.结果 运转状态TLJ500离心机关心模态频率计算结果与试验结果比较一致.结论 仿真结果验证了文中方法的可行性,为离心机临界转速设计提供了一种可信的数值模拟预测方法.     

臭氧和模拟酸雨对冬小麦气体交换、生长和产量的复合影响

为探明酸雨和臭氧(O3)对作物是否存在复合影响,运用田间原位开顶气室研究了pH4.0模拟酸雨(SAR)和O3对冬小麦气体交换、生长和产量的影响.该实验包括3种处理:CF处理采用经活性炭过滤后的空气,作为对照;CF100处理采用经活性炭过滤后的空气加人恒定浓度为100 nL·L-1的O3;CF100 SAR处理为在CF100的基础上对冬小麦喷施pH 4.0模拟酸雨,喷施量为150 mL·m-2,每10d一次.结果表明:①CF100和CF100 SAR组冬小麦叶片细胞膜系统受到破坏,光合色素含量和气体交换参数降低,抑制了作物生长,导致生物量和产量下降.与CF相比,CF100和CF100 SAR处理下冬小麦产量分别降低了68.2%和63.6%;②与CF100组相比,CF100 SAR组对冬小麦细胞膜系统和叶绿素a含量产生显著的复合影响(p＜0.05),而对叶绿素b和类胡萝卜素含量、气体交换、小麦生长、生物量和产量的复合影响不显著.     

三唑磷农药废水厌氧处理可行性研究

采用厌氧流化率工艺处理在唑磷农药废水，必须降低原水中ＮＨ３－Ｎ含量，调整营养比例，当ＣＯＤ：Ｎ：Ｐ＝（１８０～２００）：５：１时，在中温厌氧消化条件下，ＣＯＤ含量可从４１７０ｍｇ／ｌ，去除率约５０％，沼气产率达到０．２５６ｍ＾３／ｍ＾３．ｄ。因此，把厌氧处理作为好氧处理的预处理单元，能确保整个处理系统出水达标。     

淮南市可吸入颗粒物研究的若干建议

由于可吸入颗粒物严重影响大气环境质量和人体健康,对其研究愈来愈受到重视.我国北京、南京、重庆等城市对可吸入颗粒物均做过系统的研究,而目前在淮南市仍是空白.总结近年来可吸入颗粒物方面的研究成果,对淮南市在此方面的研究提出若干建议,供研究者参考.     

一种新型复合式生物流化反应器混合特性的研究

对新型蜂窝状断面复合生物流化反应器进行了液体循环速率和水力停留时间分布曲线的测定，实验表明新型反应器具有抗冲击负荷强，接近CSTR反应器的特点，反应器随气量增大、载体投加量减少和进水量减少而更近似于CSTR反应器，通过理论分析，证明了影响液体循环速率的参数主要有气体流量(气含率)、反应器沿程和局部阻力系数以及Ad/Ar，并且得出液体循环速率与反应器高度的0．5次方成正比。     

Treatment of 2-phenylamino-3-methyl-6-di-n-butylaminofluoran production effluent by combination of biological treatments and Fenton＇s oxidation

High strength refractory organic stream is produced during the production of 2-phenylamino-3-methyl-6-di-n-butylaminofluoran （One Dye Black 2, abbr. ODB 2）, a novel heat-sensitive material with a promising market. In this study, a combination of acidificationprecipitation, primary biological treatment, Fenton＇s oxidation and another biological treatment was successfully used for the removal of COD from 18000-25000 mg/L to below 200 mg/L from the ODB 2 production wastewater in a pilot experiment. A COD removal of 70%-80% was achieved by acidification-precipitation under a pH of 2.5-3.0. The first step biodegradafion permitted an average COD removal of 70% under an hydraulic residence time （HRT） of 30 h. By batch tests, the optimum conditions of Fenton＇s oxidation were acquired as： Fe^2＋ dose 6.0 mmol/L; H2O2 dose 3000 mg/L; and reaction time 6 h. The second step biological treatment could ensure an effluent COD below 200 mg/L under an HRT of 10 h following the Fenton＇s treatment.     

Determination and discussion hydraulic retention time in membrane bioreactor system

Based on the microorganism kinetic model, the formula for computing hydraulic retention time in a membrane bioreactor system (MBR) is derived. With considering HRT as an evaluation index a combinational approach was used to discuss factors which have an effect on MBR. As a result, the influencing factors were listed in order from strength to weakness as: maximum specific removal rate K, saturation constant Ks, maintenance coefficient m, maximum specific growth rate ,ua and observed yield coefficient Yobs. Moreover, the formula was simplified, whose parameters were experimentally determined in petrochemical wastewater treatment. The simplified formula is θ= 1.1( 1/β -1)(Kｓ S)/KXo , for oetroehemical wastewater treatment K and Ko eaualed 0.185 and 154.2, resoectively.     

GIS支持下的水文生态效应评价混合型专家系统设计初探

文章从人工神经网络(ANN)、专家系统(ES)各自的优势和不足出发，结合地理信息系统(GIS)技术的特点，介绍了水文生态效应评价的混合型专家系统(HEMES)的基本结构模式和各模块的功能。然后抓住ANN、ES、GIS的共同作用因子一专家知识，从数据库结构、C 类方面探讨了三者集成的问题，并根据集成的思想探讨了相关功能设计。指出HEMES是一种更准确、易操作的评价技术，可作为相关管理、决策者的辅助工具。     

Carbon isotope ratios in logged and unlogged boreal forests: Examination of the potential for determining wildlife habitat use

Due to assimilation of recycled CO₂ from litter decomposition and photosynthetic changes in carbon fractionation at low light levels, the foliage at the base of a forest is often more depleted in¹³C compared to that exposed to the atmosphere in either the canopy or in open clearings. This is referred to as the canopy effect. African research has indicated that these habitat differences in foliar ¹³C can be substantial enough to affect the carbon isotope ratios of resident fauna. Previous work documenting a 30-year chronology on moose teeth from Isle Royale National Park indicated a progressive depletion in¹³C and suggested that this could be due to forest regrowth following extensive burning. The present study examined the assumption implicit in this hypothesis that foliar ¹³C varies between open and closed boreal forest sites. I found a marginal canopy effect of 2 ¹³C difference between upper canopy and ground flora for a forest in northwestern Ontario and an average difference of 1.2 in under- and mid-story vegetation between closed forests and open clear-cuts. Because of these small differences, the utility of carbon isotope analysis in quantifying temporally integrated exploitation of deforested habitats will be low for northern boreal locations. In denser forests, such as those in the tropics or western North American where the canopy effect can be expected to be much greater, ¹³C analysis may still offer some promise for determining selection by wildlife of disturbed habitats.