Removal of carbofuran is not affected by co-application of chlorpyrifos in a coconut fiber/compost based biomixture after aging or pre-exposure

Biomixtures constitute the biologically active part of biopurification systems(BPS), which are used to treat pesticide-containing wastewater. The aim of this work was to determine whether co-application of chlorpyrifos(CLP) affects the removal of carbofuran(CFN)(both insecticide/nematicides) in a coconut fiber–compost–soil biomixture(FCS biomixture), after aging or previous exposure to CFN. Removal of CFN and two of its transformation products(3-hydroxycarbofuran and 3-ketocarbofuran) was enhanced in pre-exposed biomixtures in comparison to aged biomixtures. The co-application of CLP did not affect CFN removal, which suggests that CLP does not inhibit microbial populations in charge of CFN transformation.Contrary to the removal behavior, mineralization of radiolabeled14C-pesticides showed higher mineralization rates of CFN in aged biomixtures(with respect to freshly prepared or pre-exposed biomixtures). In the case of CLP, mineralization was favored in freshly prepared biomixtures, which could be ascribed to high sorption during aging and microbial inhibition by CFN in pre-exposure. Regardless of removal and mineralization results, toxicological assays revealed a steep decrease in the acute toxicity of the matrix on the microcrustacean Daphnia magna(over 97%) after 8 days of treatment of individual pesticides or the mixture CFN/CLP.Results suggest that FCS biomixtures are suitable to be used in BPS for the treatment of wastewater in fields where both pesticides are employed.     

BiPO_4-BiVO_4复合光催化剂的制备及其光催化性能

采用水热法制备了BiPO_4-BiVO_4复合光催化剂,运用XRD,SEM,UV-Vis DRS技术对其进行了表征,并以亚甲基蓝为目标降解物考察了复合光催化剂在模拟太阳光下的光催化性能。实验结果表明:当BiPO_4与BiVO_4的摩尔比(磷钒比)为2∶8时BiPO_4-BiVO_4的光催化性能最优,光照180 min时对亚甲基蓝(初始质量浓度5mg/L)的降解率达96.20%,反应速率常数为0.018 1 min-1,明显优于单纯BiPO_4和BiVO_4。表征结果显示:单斜相的BiPO_4与BiVO_4晶粒实现了复合生长,BiPO_4-BiVO_4(磷钒比2∶8)的晶粒粒径比单纯BiPO_4和BiVO_4小;复合光催化剂在紫外光和可见光区均具有较好的光响应,且其禁带宽度较BiPO_4明显减小。     

Emotional appeal in recruitment advertising and applicant attraction: Unpacking national cultural differences

We investigated the impact of the type of emotional appeal (ego‐focused vs. other‐focused) used in recruiting advertisements on applicant attraction to firms through two experimental studies across three countries (the United States, China, and Singapore). In Study 1, we made a traditional cultural comparison between the United States and China, whose dominant cultural values are characterized by individualism and collectivism, respectively. We found applicants in the United States were more strongly attracted to firms whose recruiting advertisements were based on an ego‐focused emotional appeal, while applicants in China were more attracted to firms that used ads with an other‐focused emotional appeal. Study 2 was conducted in bicultural Singapore. We primed bicultural applicants to be either the individualistic or collectivistic aspect of their cultural heritage. Applicants with individualist priming were attracted to recruiting advertisements with an ego‐focused emotional appeal, whereas applicants with collectivist priming were attracted to advertisements with an other‐focused emotional appeal. In addition, both studies revealed that a job applicant's regulatory focus (promotion vs. prevention) mediated the influence of national culture on the relationship between type of emotional appeal and applicant attraction to firms. Practical implications and suggestions for future research also are discussed. Copyright © 2016 John Wiley & Sons, Ltd.     

EPA PMF5．0在浦东新区降水源解析中的使用研究

使用EPA PMF5．0模型,以浦东新区降水源解析为例,按照使用前监测数据和不确定度数据收集、模型运行前数据判读、基本模型运行前最佳因子数确定以及模型旋转前后因子贡献比变化,对降水中多种阳离子和阴离子分别进行讨论,在离子贡献汇总中得到其主要贡献的阴阳离子。 EPA PMF5．0方法的使用,为大气降水在污染源治理和管理等领域提供了新的研究思路,同时也对基层监测站开展源解析具有参考作用。     

梭罗沟金矿氧化矿选矿废水破氰处理试验研究

四川省梭罗沟金矿氧化矿选矿过程中产生的氰化尾矿浆水呈较强碱性,COD、CN-、Cu+、Ni2+、Zn2+浓度超出《污水综合排放标准》(GB 8978-1996)一级标准限值,特别是CN+超标515倍.通过加入不同剂量漂白粉,对氰化尾矿浆水进行破氰处理实验,使破氰尾矿浆澄清水呈中性,CN-和各离子浓度均满足《污水综合排放标准》(GB 8978-1996)一级标准,最终得到针对处理梭罗沟金矿氰化尾矿浆水适合的漂白粉用量.     

室内火灾烟雾对微波衰减的影响研究

针对建筑室内火灾烟雾环境对微波信号的干扰问题,利用火灾标准实验间和微波实验装置,研究棉绳阴燃、聚氨酯明火等四种典型火灾烟雾对频率分别为600 MHz和2.7GHz微波衰减特性的影响规律。在有和无火灾烟雾环境下,对比分析入射波频率、烟雾浓度、烟雾类型对微波衰减的影响。实验结果表明,四种火灾烟雾对微波传播有明显衰减,且衰减量均随烟雾浓度的增加而增加,而衰减速率逐渐减小。频率以及不同特性类型的烟雾对微波衰减特性的规律不同。最后,计算并修正了室内火灾烟雾环境下微波衰减因子模型的衰减因子,提高了该模型在火灾烟雾环境下的适用性和准确性。     

基于非对称流场流分离技术的纳米银分离监测方法

以纳米银(AgNPs)作为典型的纳米颗粒物,利用非对称流场流分离技术构建纳米颗粒物的分离监测方法。制备了柠檬酸盐稳定的AgNPs分散液,采用透射电镜、紫外可见分光光度计、Zeta电位分析仪对AgNPs分散液进行了表征。结果表明,AgNPs半径多数小于10 nm,最大吸收波长为400 nm,Zeta电位为-42.56 m V。采用非对称流场流分离仪对AgNPs进行粒径分离,得到UV-Vis信号谱图,并收集得到半径小于10 nm、10~30 nm、30~50 nm、50~70 nm、70~100nm范围的AgNPs颗粒,结合电感耦合等离子体质谱仪测定每个粒径范围内AgNPs的质量浓度。结果表明,该方法重现性良好,AgNPs在半径小于10 nm的范围内达到了UV-Vis吸收峰值,响应信号最高为0.022 5~0.027 5 V,表明半径小于10 nm的AgNPs浓度较高。半径小于10 nm、10~30 nm、30~50 nm、50~70 nm、70~100 nm范围内AgNPs的质量浓度分别为(1 021.86±61.74)μg/L、(323.23±45.83)μg/L、(72.90±32.14)μg/L、(44.64±9.28)μg/L、(39.12±5.04)μg/L,回收率为43.96%±0.84%。     

光学迷宫对飞机货舱感烟探测器响应性能的影响

针对飞机货舱火灾的探测延迟性问题,探讨了光学迷宫对点型光电感烟探测器响应性能的影响,实验研究了点型光电感烟探测器在有、无迷宫两种情况下烟雾探测的响应过程,对比分析了不同烟量时迷宫的作用,并提出探测器迷宫结构的改进设计思路。实验结果表明,在探测器响应过程中,有光学迷宫的探测器烟雾浓度波动幅度较小,迷宫对烟气有滞留作用,提高了探测器的稳定性;但迷宫会使探测腔室的烟雾浓度明显滞后且低于腔外,增大了探测器的迟滞时间,烟雾浓度较低时这种迟滞影响更为明显,严重影响货舱火警探测器的灵敏度。     

过氧化氢除藻及相关环境条件优化

采用室内培养的方式,通过正交试验研究了H_2O_2质量浓度、光照、pH值和温度4个因素复合作用对铜绿微囊藻去除的影响。结果表明,在所设置的各因素梯度范围内,对去除铜绿微囊藻影响最大的因素是H_2O_2质量浓度;光照和pH值对藻细胞数和叶绿素a的去除,以及H_2O_2残留量的影响各不相同;温度对藻细胞数的影响最小,对H_2O_2残留量的影响较小,对叶绿素a质量浓度的影响较大。除藻的最佳组合为A_1B_2C_3D_2,即光照为1 500 lx,H_2O_2质量浓度为50mg/L,pH值为8.5,温度为25℃。