Oil-Induced environmental Kuznets curve in organization of petroleum exporting countries (OPEC)

This study investigates the environmental Kuznets curve (EKC) hypothesis in 10 of the Organization of Petroleum Exporting Countries (OPEC). To realize the study’s aims a time series model is built based on the period 1977–2008, utilizing the ecological footprint as an environmental indicator and income, labour, capital, oil consumption and oil price as economic indicators. Employing the Autoregressive Distributed Lag (ARDL) approach, by comparing the short and long-run income elasticities, the EKC hypothesis is present in six OPEC countries namely Algeria, Iraq, Venezuela, Nigeria, Qatar and Kuwait. Moreover, the Toda–Yamamoto–Dolado–Lütkepohl (TYDL) causality tests outcome show that, after oil consumption, the most significant factors in increasing ecological footprint are labor and capital. This implies the relocation of pollution intensive industries to almost all of the OPEC countries. However, oil prices reduce environmental damage by its negative effect on the ecological footprint. From the outcome of this study it is important for the investigated countries to reduce their consumption of fossil fuel energy since it represents an important source of pollution. This can be achieved by allocating more labor and capital in projects and investments on renewable energy, energy efficiency and energy saving.     

Study on recycled asphalt concrete for use in surface course in airport pavement

This research investigated the possibility of using recycled asphalt concrete as surface course in airport pavement. The basic properties of recycled asphalt binder after short- and long-term aging were firstly tested and compared with those of the virgin asphalt. Then, a series of laboratory tests were performed to evaluate the performance of recycled asphalt concrete (containing 40% and 70% RAP), in which the HMA mixture without RAP was used as a control. Furthermore, an experimental pavement consisting of three sections (corresponding to 0%, 40% and 70% RAP content) was constructed to verify the laboratory test results. These results indicated that the recycled asphalt could achieve the similar properties against long-term aging as virgin asphalt. Recycled asphalt concrete containing 40% RAP could be used as surface course in airport pavement as it exhibited similar performance as control mixture both from the laboratory and experimental pavement test results. On the contrary, recycled asphalt concrete containing 70% RAP was not recommended as its fatigue property was much poorer compared with that of virgin asphalt mixture.     

道路车辆电气和电子设备样品在振动冲击等动力学试验中的安装

在试验方法和要求标准化后,振动冲击等动力学试验中的安装问题是决定试验是否合理和试验成败的关键要素。道路车辆电子元件和设备型样品的动力学试验是考核样品安装在车辆上使用条件下的适用性。振动试验还叠加了温度和温度变化环境,条件尤为复杂严酷。文内介绍了动力学试验中的安装需要考虑的技术要素,为试验实施中妥善合理地进行样品安装提供支持.     

改性沸石对2,4-二氯苯酚的去除作用

采用溴化十六烷基三甲铵(HDTMAB)制备改性沸石,在与天然沸石对比的基础上,研究了改性沸石在动态条件下去除2,4-DCP的效果。并对影响去除率的主要因素,包括沸石粒径、进水浓度,进水流速,沸石用量,进水pH值等进行研究。结果表明,细粒改性沸石在pH2.5左右时处理低浓度2,4-DCP溶液时,能取得较好的去除效果,流速较低时去除率最高可达80%以上。     

高强钢绞线-聚合物砂浆加固低强度砖砌体的试验研究

提出了采用高强钢绞线-聚合物砂浆技术对低强度砖墙进行抗震加固的方法,通过一片采用高强钢铰线-聚合物砂浆面层加固的墙体和一片未加固的对比墙体的低周反复荷载试验,对该加固方法进行了检验。详细地分析了这两片墙体的破坏形态、极限承载力、滞回特性、耗能能力及刚度退化等抗震性能,并提出了加固墙体的抗剪承载力计算公式。研究结果表明,高强钢绞线-聚合物砂浆加固方法能有效地提高墙体的极限承载力,改善墙体的延性和刚度退化,并提高墙体的能量消耗能力,从而提高墙体的抗震性能。     

硝化抑制剂的加量对生化需氧量值影响的探讨

BOD作为衡量水体受有机污染程度的重要指标,其反映的可生化降解性是其他参数无法替代的。在5日生化培养时间内,硝化作用的耗氧量取决于是否存在足够数量的能进行此种氧化作用的微生物,许多二级生化处理的出水和受污染较久的水体中,往往含有大量硝化微生物,因此测定这种水样时应抑制其硝化反应。通过对特定水体硝化抑制剂添加与否及加量多少对BOD5测定结果的影响,分析并探讨抑制特定水体硝化过程的最佳条件。在严格质量控制的基础上,对特定行业和环境水体的实际样品进行硝化抑制剂添加与否和加量及时间培养曲线等对比实验,通过所得到的比对数据以化学需氧量值与BOD5之间关系为基准,对硝化抑制剂的加量进行了探究。     

不同自然暴露方法对聚丙烯老化的影响

采用直接大气暴露、玻璃板下暴露和百页窗下暴露3种自然暴露方法,研究了聚丙烯塑料外观、力学性能和熔融指数在海南自然暴露过程中的变化,考察了光、热、氧对聚丙烯老化的影响。结果表明：自然环境下,光和热均是引起聚丙烯老化降解的主要因素．并且光的作用更强．氧对聚丙烯老化的影响很小：冲击强度对聚丙烯的老化相当敏感．海南自然暴露9个月时．直接大气暴露的聚丙烯试样冲击强度保持率下降至原始的10％左右。     

细菌脱氢酶活性生物测试法用于水质毒性检测的改进

从培养基配方、菌种来源、激活时间、菌液用量以及检测方式等几个方面对脱氢酶快速毒性检测法进行了改进,确定了整个体系的操作方法。并用HgCl2和NaN3验证了改进后方法的可行性。结果表明,以天然地表水作为菌种来源,转接培养1次后,混合细菌的脱氢酶活性的稳定性便可达到实验要求。样品液与菌液按照6∶1的比例混合效果较好。混合体系在37℃恒温培养箱中激活50min以上细菌可完全活化,最终检测可用普通分光光度计进行。改进后的方法解决了原方法菌液失活过快,实验稳定性较差的问题,同时克服了检测仪器难以购买的问题,使这一方法得以在普通实验室实现。     

On equilibration of pore water in column leaching tests

Column leaching tests are closer to natural conditions than batch shaking tests and in the last years have become more popular for assessing the release potential of pollutants from a variety of solids such as contaminated soils, waste, recycling and construction materials. Uncertainties still exist regarding equilibration of the percolating water with the solids, that might potentially lead to underestimation of contaminant concentrations in the effluent. The intention of this paper is to show that equilibration of pore water in a finite bath is fundamentally different from release of a certain fraction of the pollutant from a sample and that equilibrium is reached much faster at low liquid-to-solid ratios typical for column experiments (<0.25) than in batch tests with much higher liquid-to-solid ratios (e.g. 2–10). Two mass transfer mechanisms are elucidated: First-order type release (film diffusion) and intraparticle diffusion. For the latter, mass transfer slows down with time and sooner or later non-equilibrium conditions are observed at the column outlet after percolation has been started. Time scales of equilibrium leaching can be estimated based on a comparison of column length with the length of the mass transfer zone, which is equivalent to a Damköhler number approach. Mass transfer and diffusion coefficients used in this study apply to mass transfer mechanisms limited by diffusion in water, which is typical for release of organic compounds but also for dissolution of soluble minerals such as calcite, gypsum or similar. As a conclusion based on these theoretical considerations column tests (a) equilibrate much faster than batch leaching tests and (b) the equilibrium concentrations are maintained in the column effluent even for slow intraparticle diffusion limited desorption for extended periods of time (>days). Since for equilibration the specific surface area is crucial, the harmonic mean of the grain size is relevant (small grain sizes result in high concentrations even after short pre-equilibration of a column). The absolute time scales calculated with linear sorption and aqueous diffusion aim at organic compounds and are not valid for sparingly soluble mineral phases (e.g. metal oxides and silicates). However, the general findings on how different liquid-to-solid ratios and specific surface area influence equilibration time scales also apply to other mass transfer mechanisms.     

跌落/撞击载荷下装药结构的安全性评估方法

目的 提出装药结构在跌落/撞击事故条件下安全性的定量评估方法.方法 针对装药结构跌落/撞击条件下含能部件非冲击点火存在的不确定性大、缺乏可供工程应用的点火判据等问题,采用基于数理统计思想的定量评估思路,建立"3类试验+1种方法"的安全性评估体系,并提出试验设计、方法选取和评估实施的方法及要求,可供工程应用.结果 采用该方法,开展了某装药结构跌落安全性的定量评估,通过标准试验探索获得了特定约束下的起爆阈值范围,通过设计并开展多发能包络整体级响应的构型试验,获得的实验数据可作为评估的样本数据.采用单侧置信下限方法进行了定量评估,获得了安全度为0.99999(置信度0.9)的定量评估结果.结论 该方法可实现对武器装备、航天发动机跌落/撞击条件下安全性的定量评估,但该方法仅适用于装药结构具有足够安全裕度的情况.