Heterogeneous Fenton degradation of azo dyes catalyzed by modified polyacrylonitrile fiber Fe complexes：QSPR (quantitative structure peorperty relationship) study

The amidoximated polyacrylonitrile (PAN) fiber Fe complexes were prepared and used as the heterogeneous Fenton catalysts for the degradation of 28 anionic water soluble azo dyes in water under visible irradiation. The multiple linear regression (MLR) method was employed to develop the quantitative structure property relationship (QSPR) model equations for the decoloration and mineralization of azo dyes. Moreover, the predictive ability of the QSPR model equations was assessed using Leave-one-out (LOO) and cross-validation (CV) methods. Additionally, the effect of Fe content of catalyst and the sodium chloride in water on QSPR model equations were also investigated. The results indicated that the heterogeneous photo-Fenton degradation of the azo dyes with different structures was conducted in the presence of the amidoximated PAN fiber Fe complex. The QSPR model equations for the dye decoloration and mineralization were successfully developed using MLR technique. MW/S (molecular weight divided by the number of sulphonate groups) and NN=N (the number of azo linkage) are considered as the most important determining factor for the dye degradation and mineralization, and there is a significant negative correlation betweenMW/S or NN=N and degradation percentage or total organic carbon (TOC) removal. Moreover, LOO and CV analysis suggested that the obtained QSPR model equations have the better prediction ability. The variation in Fe content of catalyst and the addition of sodium chloride did not alter the nature of the QSPR model equations.     

水源水库真核微生物种群结构季相演替特征

真核微生物广泛存在于水环境中且具有重要生态学功能,揭示其群落演替及其驱动因子对于研究水体生态系统的能量流动和物质循环具有重要意义.然而关于水源水库中真核微生物群落季相演替特征的研究却鲜见报道.本研究通过对李家河水库水质监测,并采用高通量测序技术和共生网络分析,探究了真核微生物种群结构的季相变化及其与水质因子的响应关系.结果表明,李家河水库水体pH处于(7.49±0.13)～(9.26±0.14),ρ(DO)最低为(7.80±0.33)mg·L-1,ρ(NH4+-N)最高为(0.31±0.01)mg·L-1,水质整体符合地表水Ⅱ类标准.真核微生物种群Shannon指数和Chao1丰富度指数夏季显著高于春秋季节.节肢动物门在春末至夏季中期为优势门,刺胞动物门和绿藻门为夏末至秋季的优势门.Telonema sp.为春末优势属(50.53％),扁藻属为夏初(30.11％)和秋初(41.34％)的优势属,Junceell asp.在夏末及秋季前中期均有较高相对丰度.杯鞭虫属(Bicosoeca sp.)、尖毛虫属(Oxytricha sp.)和壳虫属(Tintinraidium sp.)为共生网络中的关键节点,与其他真核微生物间具有显著负相关.RDA分析表明,真核微生物群落结构的季相分布受不同水质指标的调控且差异显著.本研究结果将为了解水源水库中的真核微生物群落结构动态变化及其与水环境的关系提供科学依据.     

Expressing forgiveness after interpersonal mistreatment: Power and status of forgivers influence transgressors' relationship restoration efforts

One adverse consequence of interpersonal mistreatment is that it damages the relationship between the victim and the transgressor. Scholars have promoted forgiveness of such mistreatment as a victim response that can motivate transgressors to work towards relationship restoration. Building on social exchange theory and the social perception literature, we provide an account of when transgressors are less (vs. more) willing to restore their relationship with the victim in response to forgiveness. Specifically, we argue that transgressors perceive forgiveness from a victim who has high (vs. low) power, relative to the transgressor, as insincere, making transgressors less willing to restore the relationship. We further argue that this effect of high (vs. low) victim power is pronounced especially when the victim also has low (vs. high) status. Two experiments and two field studies support these predictions. These findings highlight the relevance of studying how contextual conditions color transgressors' perceptions of victims' behavior to understand relationship restoration after interpersonal mistreatment.     

Estimating non-native plant richness with a species-accumulation model along roads

Monitoring non-native plant richness is important for biodiversity conservation and scientific research. The species-area model (SA model) has been used frequently to estimate the total species richness within a region. However, the conventional SA model may not provide robust estimations of non-native plant richness because the ecological processes associated with the accumulation of exotic and native plants may differ. Because roads strongly dictate the distributions of exotic plants, we propose a species-accumulation model along roads (SR model), rather than an SA model, to estimate the non-native plant richness within a region. Using 270 simulated data sets, we compared the differences in performance between the SR and SA models. A decision tree based on prediction accuracy was created to guide model application, which was validated using field data from 3 national nature reserves in 3 different provinces in China. The SR model significantly outperformed the SA model when non-native species were restricted to the roadsides and the proportion of uncommon exotic species was small. More importantly, the SR model accurately estimated the non-native plant richness in all field sites with an error of <1 species per site. We believe our new model meets the practical need to efficiently and robustly estimate non-native plant richness, which may facilitate effective biodiversity conservations and promote research on non-native plant invasion and vegetation dynamics.     

顺义区地下水水源地脆弱性评价

从顺义区地下水源地的特点和实际情况出发,建立了顺义区地下水源地脆弱性综合评价指标体系,并基于该指标体系采用灰关联度评价方法对顺义区地下水源地进行脆弱性综合评价。将综合评价与固有脆弱性评价对比分析,结果表明,采用地下水水源地综合脆弱性与固有脆弱性相结合的评价方法评价结果更为科学合理,可以更好地评价顺义区地下水源地脆弱性。     

Modeling redistribution of α-HCH in Chinese soil induced by environment factors

This study explores long-term environmental fate of α-HCH in China from 1952 to 2007 using ChnGPERM (Chinese Gridded Pesticide Emission and Residue Model). The model captures well the temporal and spatial variations of α-HCH concentration in Chinese soils by comparing with a number of measured data across China in different periods. The results demonstrate α-HCH grasshopping effect in Eastern China and reveal several important features of the chemical in Northeast and Southeast China. It is found that Northeast China is a prominent sink region of α-HCH emitted from Chinese sources and α-HCH contamination in Southwest China is largely attributed to foreign sources. Southeast China is shown to be a major source contributing to α-HCH contamination in Northeast China, incurred by several environmental factors including temperature, soil organic carbon content, wind field and precipitation.     

中国海洋环境区域管理的政府横向协调机制研究

海洋环境区域管理的主体,涉及多个地方政府以及若干涉海部门,政府间横向关系复杂,鉴于海洋环境的特殊性,各主体只有相互合作才能更好地实现治理目标.由于彼此间存在不同的利益诉求.利益协调便在很大程度上决定着合作的成败.因此,良好的协调机制至关重要.本文在海洋区域管理的基础上提出海洋环境区域管理.首先对海洋环境区域管理政府横向协调机制的概念予以界定,并对内涵进行说明.在此基础上对我国目前海洋环境管理的政府问横向关系进行定性分析.区域内各地方政府间的关系体现为合作与自然无关联状态并存,涉海部门间处于矛盾的对立统一关系.从以上分析中得出结论,海洋环境区域管理的横向政府间存在不协调问题.构建我国海洋环境区域管理的政府横向协调机制应制定约束各政府主体的契约,健全跨行政区以及行政区内跨部门的组织机构,并从信息沟通、协商和利益分享与补偿三个方面完善运行机制.     

PTR-MS measurements and analysis of models for the calculation of Henry's law constants of monosulfides and disulfides

Sulfides are known for their strong odor impact even at very low concentrations. Here, we report Henry’s law constants (HLCs) measured at the nanomolar concentration range in water for monosulfides (dimethylsulfide, ethylmethylsulfide, diethylsulfide, allylmethylsulfide) and disulfides (dimethyldisulfide, diethylsulfide, dipropylsulfide) using a dynamic stripping technique coupled to Proton Transfer Reaction-Mass Spectrometry (PTR-MS). The experimental data were compared with literature values and to vapor/solubility calculations and their consistency was confirmed employing the extra-thermodynamic enthalpy-entropy compensation effect. Our experimental data are compatible with reported literature values, and they are typically lower than averaged experimental literature values by about 10%. Critical comparison with other freely available models (modeled vapor/solubility; group and bond additivity methods; Linear Solvation Energy Relationship; SPARC) was performed to validate their applicability to monosulfides and disulfides. Evaluation of theoretical models reveals a large deviation from our measured values by up to four times (in units of M atm⁻¹). Two group contribution models were adjusted in view of the new data, and HLCs for a list of sulfur compounds were calculated. Based on our findings we recommend the evaluation and adaption of theoretical models for monosulfides and disulfides to lower values of solubility and higher values of fugacity.     

部分含氯芳烃结构与孔雀鱼半数致死浓度(-logLC_(50))定量活性相关研究

构建了不同类型的分子顶点之间的电性关系作为结构描述符,对部分含氯芳烃化合物结构进行了参数化表征,共得到7个与化合物结构密切相关的结构描述符。逐步回归(SMR)筛选变量后,分别运用多元线性回归(MLR)和偏最小二乘回归(PLS)建立了化合物结构与孔雀鱼半数致死浓度(-log LC50)之间的关系模型,两模型建模相关系数(r2)分别为0.871、0.862;"留一法"交互检验的相关系数(Q2)分别为0.808、0.589。结果表明分子结构描述符能恰当地表征化合物结构特征,所建模型具有良好的稳定性和预测能力。     

上海城区地面沉降及其对地下水采灌量的响应

上海城区地面沉降主要是由超采地下水、松散沉积地层压实等因素共同作用导致的,并引发多种次生灾害。F4分层标监测数据指示的地面沉降情况,显示上海城区地面沉降表现为总体具有非线性变化的规律,特别是1980年代以来,表现出垂向逐渐增大的特点,在空间上也不断扩展,直至2001年才始有缓和的趋势。在不同时段,随地下水开采量及开采层次的变化,上海城区地面沉降表现出不同的特征。结合1990~2009年20年内第四含水层地下水采灌量数据,得出地面沉降对地下水采灌量的响应关系为:地下水开采量增加,地层沉降量增大;地下水开采量减少,地层沉降量减小,但地面沉降相对于地下水开采具有滞后性;随着逐年的回灌,地层沉降量减小,且地下水回灌效果与回灌层位有直接关系。