川西南山区聚落宜居性的空间差异分析

结合山区实际情况,建立山区聚落宜居性评价指标体系。利用山区聚落宜居性评价模型对川西南山区26个区县进行系统评价,计算出川西南山区聚落宜居性指数。在此基础上通过ESDA分析和相关性分析,研究川西南山区聚落宜居性的空间差异,结果表明:（1）川西南山区聚落宜居性存在正的相关性,表现出很强的空间集聚特征;（2）在空间格局上,川西南山区聚落宜居性呈现东南-西北两极分化格局,并且以西昌、攀枝花、石棉为3个核心呈核心-边缘梯级结构模式特点;（3）H H空间关联模式集中连片分布在安宁河谷一带,L L空间关联模式集中连片分布于大小凉山一带,西昌、石棉呈现H L空间关联模式;（4）川西南山区聚落宜居性与自然环境宜居度、经济宜居度、社会宜居度均具有极显著的相关性     

二硫化碳萃取—气相色谱法同时测定含盐酸废水中的甲苯、邻氯甲苯、对氯甲苯和氯化苄

建立了二硫化碳萃取—气相色谱法同时测定含盐酸废水中甲苯、邻氯甲苯、对氯甲苯和氯化苄的方法,并应用于实际水样的测定。采用二硫化碳萃取含盐酸废水中的甲苯、邻氯甲苯、对氯甲苯、氯化苄,待测物质经30QC3/AC20（30 m×0.32 mm×0.50 μm）毛细管柱气相分离。采用保留时间定性,外标法定量。实验结果表明,甲苯、邻氯甲苯、对氯甲苯和氯化苄的质量浓度在0.2~100.0 mg/L范围内与对应的峰面积呈良好的线性关系,检出限分别为0.09,0.12,0.13,0.10 mg/L。该方法的精密度和准确度较高,相对标准偏差小于2%,加标回收率在96.4%~101.0%之间。     

不同调理剂对微生物降解餐厨垃圾的影响

为了探索不同调理剂对微生物降解餐厨垃圾效果的影响,本实验选取了木屑(桦木)、米糠、泥炭、花生壳、稻壳等材料分别作为主要调理剂,以餐厨垃圾的重量减量率作为评价降解效果指标,测定实验过程中的温度、含水率、pH值、微生物生物量及重量的变化。实验结果表明,影响餐厨垃圾降解效果主要因素有温度和含水率;以木屑和米糠为主要调理剂的保温性能最优,其余材料热量散失较快;以50%木屑处理的调理剂含水率适宜,能达到最适含水率要求(50%);同时,以50%木屑(桦木)为主要调理剂处理的减量率最高。     

Self‐protective reactions to peer abusive supervision: The moderating role of prevention focus and the mediating role of performance instrumentality

Across 3 studies, we apply a self‐protection perspective of observed mistreatment to examine a moderated mediation model on “when” and “why” third parties are motivated by peer abusive supervision. We hypothesize that prevention‐focused third parties will increase their performance effort as a response to peer abusive supervision, and this effect is mediated by performance instrumentality. In a field study of working adults (Study 1) and an experimental study that manipulated peer abusive supervision (Study 2), we found that peer abusive supervision interacted with third parties' prevention focus to predict their performance effort such that peer abuse was positively related to third parties' performance effort only for those high on prevention focus. Results were replicated in a second field study of working adults (Study 3). Further, we found support for the mediating effect of performance instrumentality. The theoretical and practical implications of our results are discussed.     

射频加热强化土壤气相抽提技术的应用

热强化土壤气相抽提技术是一种高效的土壤治理技术,广泛应用于包气带土壤中挥发性有机污染物的去除。在天津某有机污染场地开展射频加热强化土壤气提技术应用研究,研究了射频阳极连接方式对场地加热效果的影响,并考察了该技术对实验场地的实际修复效果。结果表明,射频阳极采用并联方式连接对场地的加热效果较好,加热10 d后,场地温度升高约40℃;随着SVE系统工作时间的延长,场地温度逐渐下降,土壤气中TVOCs的浓度逐渐下降;经过约2个月的修复,中浅层土壤中污染物的总去除率约90%,氯仿去除率达95%,深层土壤中的污染物去除率约64%。     

烟气脱硝低温选择性催化还原金属氧化物催化剂的研究进展

低温选择性催化还原(SCR)技术具有很高的脱硝效率。概述了低温SCR金属氧化物催化剂的制备方法和性能,分析了催化剂的失活原因和再生方法,探讨了催化反应的机理,并介绍了低温SCR技术在工业烟气脱硝中的应用案例。SCR催化剂未来的发展不仅要以低温下的高活性和高选择性为主要目的,还要考虑到催化剂的抗失活性能(如抗硫性和抗水稳定性)和操作温度范围,使其可广泛应用于不同的工况中,以满足我国日益提高的环保要求。     

多级厌氧法处理螺旋霉素工业发酵菌渣效果的研究简

通过自主设计的多级厌氧反应器系统来考察半连续处理螺旋霉素工业发酵菌渣的效果。该系统总反应体积为44 L,由4个11 L的升流式厌氧反应罐组成,罐体间采用串联方式连接。121 d的连续运行周期分为3个阶段,各阶段的有机负荷率分别为1.27、1.82和2.73 kg COD/（m³·d）。全过程中主要监测了各级罐体的产气量和螺旋霉素的降解。结果表明,多级厌氧反应器系统启动初期会出现产气不稳定现象,经过2个月的运行之后系统达到稳定状态。在有机负荷达到2.73 kg COD/（m³·d）时,各级罐体仍能稳定运行,总产气的45%集中在1号罐。在系统启动初期,螺旋霉素不能被明显降解。运行约80 d后,整个体系达到了快速降解螺旋霉素的状态,在2.73 kg COD/（m³·d）的有机负荷率下,螺旋霉素降解率达到97%,同时可溶性COD降解率也达到了90%。     

兰州地区垃圾填埋场黄土腾发盖层降水入渗模拟

在半干旱地区,利用腾发盖层代替传统盖层,在相同的防渗效果下可以减少垃圾填埋场设计过度造成的浪费。以兰州地区为例,实验测试得到兰州黄土的土水特征曲线,求得田间持水量和萎蔫含水量;结合兰州地区2007—2008年气象资料,利用Hydrus-1D软件,模拟了透过盖层的降水入渗量,分析了黄土盖层替代传统盖层的可行性。研究结果显示,31 cm厚的黄土盖层理论上可以满足阻止降水入渗的要求,与传统盖层相比,具有成本低、施工简单的优点。     

Source profiles of volatile organic compounds associated with solvent use in Beijing,China

Compositions of volatile organic compound (VOC) emissions from painting applications and printing processes were sampled and measured by gas chromatography–mass spectrometry/flame ionization detection (GC–MS/FID) in Beijing. Toluene and C8 aromatics were the most abundant species, accounting for 76% of the total VOCs emitted from paint applications. The major species in printing emissions included heavier alkanes and aromatics, such as n-nonane, n-decane, n-undecane, toluene, and m/p-xylene. Measurements of VOCs obtained from furniture paint emissions in 2003 and 2007 suggest a quick decline in benzene levels associated with formulation changes in furniture paints during these years. A comparison of VOC source profiles for painting and printing between Beijing and other parts of the world showed significant region-specific discrepancies, probably because of different market demands and environmental standards. We conducted the evaluation of the source reactivities for various VOC emission sources. The ozone formation potential (OFP) for unit mass of VOCs source emissions is the highest for paint applications. Substituting solvent-based paints by water-based in Beijing will lead to an OFP reduction of 152,000 tons per year, which is more than 1/4 of the OFPs for VOCs emissions from vehicle exhaust in the city.     

Variations and sources of ambient formaldehyde for the 2008 Beijing Olympic games

As the host city of the 2008 Olympic games, Beijing implemented a series of air pollution control measures before and during the Olympic games. Ambient formaldehyde (HCHO) concentrations were measured using a fluorometric instrument based on a diffusion scrubber and the Hantzsch reaction; hydrocarbons were simultaneously measured using gas chromatography–mass spectrometry (GC–MS). Meteorological parameters, CO, O₃, and NO₂ concentrations were measured by standard commercial instrumentation. In four separate periods: (a) before the vehicle plate number control (3–19 July); (b) during the Olympic Games (8–24 August); (c) during the Paralympic Games (6–17 September) and (d) after the vehicle control was ceased (21–28 September), the average HCHO mixing ratios were 7.31 ± 2.67 ppbv, 5.54 ± 2.41 ppbv, 8.72 ± 2.48 ppbv, and 6.42 ± 2.79 ppbv, while the total non-methane hydrocarbons (NMHCs) measured were 30.41 ± 18.08 ppbv, 18.12 ± 9.38 ppbv, 30.50 ± 13.37 ppbv, and 33.33 ± 15.85 ppbv, respectively. Both HCHO and NMHC levels were the lowest during the Olympic games, and increased again during the Paralympic games even with the same vehicle control measures operative. Similar diurnal HCHO and O₃ patterns indicated that photo-oxidation of NMHCs may be the major source of HCHO. The diurnal profile of total NMHCs was very similar to that of NO₂ and CO: morning and evening peaks appeared in rush hours, indicating even after strict vehicle control, automobile emission may still be the dominant source of the HCHO precursors. The contributions of HCHO, alkanes, alkenes, and aromatics to OH loss rates were also calculated. HCHO contributed 22 ± 3% to the total VOCs and 24 ± 1% to the total OH loss rate. HCHO was not only important in term of abundance, but also important in chemical reactivity in the air.