掺硼金刚石薄膜电极在水处理中应用的研究进展

掺硼金刚石(BDD)薄膜电极作为一种新型的电极材料,在水溶液中电解时具有较宽的电位窗口,在浓酸浓碱中具有很好的耐腐蚀性,其表面不易吸附污染物,与它的同素异构体电极及其他普通电极相比,具有更好的化学、物理性能,从而表现出潜在的功能,近年来被科研人员用于废水处理,并取得了很好的处理效果,对近期BDD薄膜电极的制备、在污水处理中的应用及其进展进行了总结与讨论.     

采用微电极测定溶解氧有效扩散系数的研究

生物载体内部溶解氧的传质是影响载体同步硝化反硝化性能的重要因素.介绍了一种以溶解氧微电极为测试工具,获得球形生物载体内部溶解氧扩散系数的方法.采用自制的溶解氧微电极检测沿载体半径方向上的溶解氧分布,结合扩散-反应方程拟合获得载体内部的溶解氧有效扩散系数.结果表明,在载体填充率为25%的情况下,连续流球形载体反应器可实现同步硝化反硝化,对有机物的去除负荷达到5.6 kg/(m³·d).沿载体半径方向里层1/2区域范围内溶解氧消耗为零,载体内能够形成明显的缺氧/厌氧区.溶解氧分布曲线的拟合结果表明,载体内部溶解氧有效扩散系数为0.017?2　m²/d,传质过程以紊动传质为主.     

硅藻土复合材料净化室内空气的实验研究

利用硅藻土复合材料对室内空气中三种主要污染物甲醛、氨和苯进行了净化研究,比较了普通硅藻土和硅藻土复合材料对三种污染物的去除效果。测试了硅藻土复合材料的平衡吸附量,及其在空气流速、净化时间和吸附剂量条件下对污染物去除率的影响。结果表明:硅藻土复合材料的净化性能优于普通硅藻土,对甲醛、氨和苯的平衡吸附量分别为132μg/g、95μg/g和87μg/g,最佳去除率分别为67%、91%和53%,吸附剂量在一定范围内改变对硅藻土复合材料的净化效率影响不大,而空气流速和净化时间存在最佳值。     

Multi-metric evaluation of the models WARM,CropSyst, and WOFOST for rice

WARM (Water Accounting Rice Model) simulates paddy rice (Oryza sativa L.), based on temperature-driven development and radiation-driven crop growth. It also simulates: biomass partitioning, floodwater effect on temperature, spikelet sterility, floodwater and chemicals management, and soil hydrology. Biomass estimates from WARM were evaluated and compared with the ones from two generic crop models (CropSyst, WOFOST). The test-area was the Po Valley (Italy). Data collected at six sites from 1989 to 2004 from rice crops grown under flooded and non-limiting conditions were split into a calibration (to estimate some model parameters) and a validation set. For model evaluation, a fuzzy-logic based multiple-metrics indicator (MQI) was used: 0 (best) ≤ MQI ≤ 1 (worst). WARM estimates compared well with the actual data (mean MQI = 0.037 against 0.167 and 0.173 with CropSyst and WOFOST, respectively). On an average, the three models performed similarly for individual validation metrics such as modelling efficiency (EF > 0.90) and correlation coefficient (R > 0.98). WARM performed best in a weighed measure of the Akaike Information Criterion: (worst) 0<wk<1$0<w_k<1$ (best), considering estimation accuracy and number of parameters required to achieve it (mean wk=0.983$w_k=0.983$ against 0.007 and ∼0.000 with CropSyst and WOFOST, respectively). WARM results were sensitive to 30% of the model parameters (ratio being lower with both CropSyst, <10%, and WOFOST, <20%), but appeared the easiest model to use because of the lowest number of crop parameters required (10 against 15 and 34 with CropSyst and WOFOST, respectively). This study provides a concrete example of the possibilities offered using a range of assessment metrics to evaluate model estimates, predictive capabilities, and complexity.     

重点环保城市二氧化硫扩散特性的研究

根据高、中、低架源排放污染物与地面环境质量的关系和《全国污染物排放申报登记》数据分析得出的每年各环保重点城市由高、中、低烟囱排放的二氧化硫,以及由1996年度《全国环境质量报告书》中给出的二氧化硫年均浓度,得出每个城市的年平均扩散系数。依据各城市的年平均扩散系数计算结果,将各城市划为不利于污染物扩散、较不利于污染物扩散、较利于污染物扩散和利于污染物扩散的4种类型,本方法在制订二氧化硫排放总量控制方案时,具有指导意义。      

确定二氧化硫总量控制目标方法的研究

分析了城市二氧化硫地面浓度来源,提出了高、中、低架源对地面浓度贡献的理论,由城市污染源排放结构导出该城市的年平均扩散系数,确定城市二氧化硫地面环境质量控制目标,从而可以得出各城市二氧化硫总量控制目标值      

氯代芳香化合物的KOW与对数拓扑指数和路径指数的相关性

本文用１ｇＫｏｗ表征氯代芳香化合物的生物降解能力,并分别以对数拓扑指数（ＬＴＩ）和路径指数（ＰＩ）为自变量,建立了新的预测模型。结果表明,回归方程的预测值与实验值十分吻合,相关系数接近于１,平均标准偏差小于０．１。     

回采工作面安全性灰色评价模型分辨系数p对评价结果的影响分析

阐述了对回采工作面安全性进行客观而准确评价的重要性。灰色关联理论应用于安全评价过程中 ,就其分辨系数 p选择所存在的问题进行了理论分析 ,并用实例验证了分辨系数对评价结果的影响 ,得出了分辨系数 p必须大于 0 .4的结论。这对灰色关联理论在安全评价中的应用研究 ,具有一定的参考价值。     

中国高新技术产业的地理格局与地理集中

与传统产业相比,高新技术产业对地理集中具有更加强烈的内在要求,这导致其地理格局与传统产业具有明显的差别。在产业集中指数等相关理论方法和实证分析的基础上,力图从地理学视角,结合高新技术产业的时间序列数据和2008年断面数据,从整体产业和分行业研究了高新技术产业地理格局和地理集中的现状和变动趋势。研究发现,我国高新技术产业高度集中在沿海省区和陕、川两省,省区间差距悬殊;高新技术产业产值份额同经济发展显著相关。时间序列分析表明：长时间尺度产业集中持续增强,近年来趋于稳定;地理格局逐渐清晰,核心省区凸显。不同行业由于产业性质、发展基础、资源需求和市场群体的差异,有其各自的集中态势和演变趋势。     

Chlorophenols and other related derivatives of environmental concern: properties, distribution and microbial degradation processes

Chlorophenols are chlorinated aromatic compound structures and are commonly found in pesticide preparations as well as industrial wastes. They are recalcitrant to biodegradation and consequently persistent in the environment. A variety of chlorophenols derivatives compounds are highly toxic, mutagenic and carcinogenic for living organisms. Biological transformation by microorganisms is one of the key remediation options that can be exploited to solve environmental pollution problems caused by these notorious compounds. The key enzymes in the microbial degradation of chlorophenols are the oxygenases and dioxygenases. These enzymes can be engineered for enhanced degradation of highly chlorinated aromatic compounds through directed evolution methods. This review underscores the mechanisms of chlorophenols biodegradation with the view to understanding how bioremediation processes can be optimized for cleaning up chloroaromatic contaminated environments.