生态足迹计算模型应用中热点问题及探讨

简要介绍了生态足迹计算模型,论述了近年国际上争论的几个主要热点问题,数据的准确完整性,初级产品与二级产品,均衡因子与产量因子,全球产量与本地产量,以及能源足迹计算等,并对其进行了探讨和指出今后研究发展的方向。     

电化学转盘/电凝聚法处理模拟活性染料废水的研究

采用一种新的电化学方法--电化学转盘/电凝聚法来处理模拟活性翠蓝KN-G废水,考察了电压、转速、pH、反应时间对色度、TOC去除率的影响,并确定了最佳反应条件.在最佳反应条件(电压12 V,转速70 r/min,pH为4～5,反应时间为60 min)下,色度和TOC去除率可分别达到95.3%和73.5%.并初步探讨了活性翠蓝KN-G的降解机理.     

Petroleum contaminated soil in Oman: Evaluation of bioremediation treatment and potential for reuse in hot asphalt mix concrete

This paper presents a study that aims at evaluating the leaching characteristics of petroleum contaminated soils as well as their application in hot mix asphalt concrete. Soil samples are environmentally characterized in terms of their total heavy metals and hydrocarbon compounds and leachability. The total petroleum hydrocarbon (TPH) present in the PCS before and after treatment was determined to be 6.8% and 5.3% by dry weight, indicating a reduction of 1% in the TPH of PCS due to the current treatment employed. Results of the total heavy metal analysis on soils indicate that the concentrations of heavy metals are lower when extraction of the soil samples is carried out using hexane in comparison to TCE. The results show that the clean soils present in the vicinity of contaminated sites contain heavy metals in the following decreasing order: nickel (Ni), followed by chromium (Cr), zinc (Zn), copper (Cu), lead (Pb), and vanadium (V). The current treatment practice employed for remediation of the contaminated soil reduces the concentrations of nickel and chromium, but increases the concentrations of all remaining heavy metals.     

高氟温泉水中氟在周边水环境中的分布特征与评价

针对温泉水中高氟现象,本实验利用离子选择性电极法,分析测定高氟温泉水周边河水中氟含量及河水底泥中氟含量。通过对高氟温泉水分布特征的研究可初步得知,温泉中高氟在周边水环境中分布因其氟含量大、不易被重视,对环境的影响相对较大。     

Effect of aging level on viscoelastic properties of asphalt binder containing waste polyethylene

Due to inherent advantages, waste polyethylene (generated from domestic sources) has been used as asphalt modifier. This article discusses viscoelastic properties of the polyethylene modified asphalt binder. Several asphalt concrete mixtures were designed by varying polyethylene and asphalt content. Shredded polyethylene incorporated into asphalt concrete by dry mixing process. Using optimised asphalt content (at several polyethylene percentages), mixtures were prepared and compacted. These compacted specimens were aged for different duration in convection oven. Asphalt binder (from aged specimens) was extracted and tested for its viscoelastic properties using dynamic shear rheometer. Comparison of mastercurves indicated increase in complex modulus and decrease in phase angle values with addition of polyethylene at all reduced frequencies. However, the extent of change was highly dependent on frequency, aging duration and polyethylene content. This indicates that the addition of polyethylene provides more resilience to asphalt binder especially with less aging time. Storage modulus mastercurves (at lower frequencies) and relaxation modulus values (at longer time) indicate polyethylene provides additional stiffening to binder. Further, changes in viscous modulus with addition of polyethylene were marginal. Overall results indicate that waste polyethylene improves the properties of asphalt binder over extended loading period when heated for less time during mixing.     

辐射板强化喷管换热与红外抑制效果试验研究

试验研究了在发动机喷管中加装金属辐射板前后,喷管壁面温度、热喷流温度与喷管红外辐射特征的变化。结果表明,加装金属辐射板后,热喷流与喷管壁面之间的热量传递显著增强,热喷流中心温度降低,壁面温度明显升高,在90°方向上,热喷流3～5μm波段的红外辐射强度降低了38.5%。文中从热喷流、喷管壁面以及金属辐射板等相关部件的温度变化情况对红外辐射强度的变化原因进行了解释。      

诺氟沙星对生物转盘反应器处理污染河水性能的影响

诺氟沙星作为一种常用的氟喹诺酮类抗生素,普遍存在于自然水体中,其输入会刺激水环境进而影响受污染水体的处理效果.为了探究诺氟沙星对反应器处理污染河水性能的影响,向反应器中投加不同浓度的诺氟沙星,研究反应器中NH~+_4-N、TN、TP和COD_(Mn)去除率及生物膜特性的变化.结果表明,不同浓度的诺氟沙星对反应器中污染物去除率的影响不同.诺氟沙星浓度为0.05μg·L~(-1)时,对NH~+_4-N、TN去除率的影响表现为先促进后抑制;随着诺氟沙星浓度的持续增加,对NH~+_4-N、TN去除率的影响更加显著(p0.05).反应器TP的去除率随诺氟沙星添加浓度的不断增加而明显降低,且添加浓度越高下降趋势越明显(p0.05).而诺氟沙星的存在对COD_(Mn)去除没有明显作用(p0.05).诺氟沙星的添加使生物膜VSS/TSS、TTC-脱氢酶活性降低,同时,微生物为进行自我保护分泌了大量EPS从而增加了蛋白和多糖含量.诺氟沙星的存在改变了生物膜EPS化学组分及化学含量,并且降低了生物膜物种多样性和丰富度.     

室外风压、火风压对建筑物热压中和面位置的影响

首次提出风压与热压可完全分解 ,风压不改变热压本身的压力特性的观点 ,确定风压与热压共同作用下的新的中和面 ;提出火灾层火风压造成的空气渗进、烟气的排出过程属内部循环的观点 ;对于火灾烟气窜入建筑内部竖井通道的情况 ,则根据中和面上下各楼层总渗进、渗出平衡的观点 ,确定火灾引起的新的中和面位置。     

热轧工作辊失效原因分析

主要分析了热轧过程温度及轧制力对工作辊寿命的影响.指出提高工作辊使用寿命的几种措施.     

NiTi形状记忆合金的加工方法

对NiTi形状记忆合金的多种加工方法如锻造、热挤压、轧制和拉拔、冷加工、粉末成形、包套碎片挤压成形、溅射沉积加工等进行了详细介绍。