水体系中Fe(Ⅱ)/K2S2O8降解敌草隆的研究

在初始pH 7.0的Fe(Ⅱ)/K2S2O8体系中,分别研究了K2S2O8和Fe(Ⅱ)初始浓度以及Fe(Ⅱ)分批加入对敌草隆降解的影响,结果表明,在pH 7.0,K2S2O8和Fe(Ⅱ)初始浓度分别为2.0mmol·l-1和1.0mmol·l-1时,反应300min后,0.1mmol·l-1敌草隆的降解率达到40.0%,Fe(Ⅱ)分批加入能够促进敌草隆的降解.另外,通过对Fe(Ⅱ)/K2S2O8,EDTA-Fe(Ⅱ)/K2S2O8,柠檬酸-Fe(Ⅱ)/K2S2O8以及K2S2O3-Fe(Ⅱ)/K2S2O8四种Fe(Ⅱ)/K2S2O8体系的对比研究,发现在Fe(Ⅱ)/K2S2O8体系中,加入Fe(Ⅱ)的螯合剂EDTA和柠檬酸以及还原剂K2S2O3能够明显促进敌草隆降解.采用分子探针法的竞争实验鉴定了体系中产生的硫酸根自由基.     

紫外二次曲线法测定硝酸盐氮方法探讨

利用紫外二次曲线法测定水体中的硝酸盐氮,测量上限可达12.00mg/L,方法检出限为0.02mg/L。分析了7个浓度的硝酸盐氮标准样,实验室内相对标准偏差为1.3%,相对误差1.3%,各淡水水样加标回收率在94%～107%之间,符合水质监测的质量保证要求。氯离子干扰分析表明:氯离子在220nm处无特定吸收,浓度高达20g/L的氯离子对测定结果也无影响。试验取3份海水样品,加标2.0mg/L,回收率为99.6%±3.2%,达到实验室质量控制要求,利用该法测定含高浓度氯离子水样中的硝酸盐氮具有一定的可行性。     

发生氢气分离离子色谱法间接测定水中硫化物

利用ＫＢＨ４在酸性条件下分解产生的氢气为载气分离水中硫化物,用ＮａＯＨ—Ｈ２Ｏ２溶液吸收Ｈ２Ｓ,并将其氧化为ＳＯ２－４,用离子色谱法测定ＳＯ２－４。方法用于各种水样中硫化物的测定,相对标准偏差为１．５８％,回收率在９０．５％到９８．２％之间。方法适用于水中硫化物的测定     

Biosorption of copper ions from dilute aqueous solutions on base treated rubber (Hevea brasiliensis) leaves powder: kinetics, isotherm, and biosorption mechanisms

The effciency of sodium hydroxide treated rubber (Hevea brasiliensis) leaves powder (NHBL) for removing copper ions from aqueous solutions has been investigated. The e?ects of physicochemical parameters on biosorption capacities such as stirring speed, pH, biosorbent dose, initial concentrations of copper, and ionic strength were studied. The biosorption capacities of NHBL increased with increase in pH, stirring speed and copper concentration but decreased with increase in biosorbent dose and ionic strength...     

关于化学需氧量测定中化学反应的研究

研究了高氯样品COD测定中的化学反应,发现测定中产生的白色沉淀是AgCl而不是HgCl2,并推断了Cl-在COD测定中的反应机理.讨论了AgNO3、HgSO4加入量对测定结果的影响,重点分析了当AgNO3不足与过量时的数据.当试样体积20.00ml,按0.4g HgSO4络合2000mg/LCl-的比例,投加HgSO4掩蔽10000mg/L Cl-可取得满意结果.     

Evaluation of the use of psychometric scales in human–wildlife interaction research to determine attitudes and tolerance toward wildlife

Studies evaluating human–wildlife interactions (HWIs) in a conservation context often include psychometric scales to measure attitudes and tolerance toward wildlife. However, data quality is at risk when such scales are used without appropriate validation or reliability testing, potentially leading to erroneous interpretation or application of findings. We used 2 online databases (ProQuest Psych Info and Web of Science) to identify published HWI studies that included attitude and tolerance. We analyzed these studies to determine the methods used to measure attitudes or tolerance toward predators and other wildlife; determine the proportion of these methods applying psychometric scales; and evaluate the rigor with which the scales were used by examining whether the psychometric properties of validity and reliability were reported. From 2007 to 2017, 114 published studies were identified. Ninety-four (82%) used questionnaires and many of these (53 [56%]) utilized a psychometric scale. Most scales (39 [74%]) had at least 1 test of reliability reported, but reliance on a single test was notable, contrary to recommended practice. Fewer studies (35 [66%]) reported a test of validity, but this was primarily restricted to structural validity rather than more comprehensive testing. Encouragingly, HWI investigators increasingly utilized the necessary psychometric tools for designing and analyzing questionnaire data, but failure to assess the validity or reliability of psychometric scales used in over one-third of published HWI attitude research warrants attention. We advocate incorporation of more robust application of psychometric scales to advance understanding of stakeholder attitudes as they relate to HWI.     

流动注射—光度法联用测定海水中PO4-P

本法针对海水分析时严重的盐度和基体干扰,以监测的海水试样为载流,并在流动注射进样阀前流路上首次引入自制全容量阴离子交换柱,去除载流中的磷酸盐,使进入系统的载流盐度与试样一致,消除了基体干扰,并通过阴柱在线再生条件试验和工作曲线优化试验,建立了流动注射磷锑钼蓝(还原剂为抗坏血酸)光度法直接测定PO4-P浓度为Ⅰ类～Ⅳ类海水的新方法,能分辨海水类别。结果表明,在最适合条件下,该方法在PO4-P浓度5～80μg/L范围内峰高与浓度成线性关系,方法检出限为0.73μg/L,空白海水加10μg/L、30μg/L和60μg/L PO4-P标准物质连续进样,RSD分别为4.57%(n=5)、4.72%(n=4)和5.76%(n=4)。进行实际样品分析时,加标回收率为101%～102%,具有很好的准确性,与国家标准方法———磷钼蓝分光光度法比对,结果吻合,令人满意。     

基于硫桥杯[4]芳烃识别金属离子的荧光传感器的研究进展

综述了近些年以硫桥杯[4]芳烃为分子平台的新型荧光传感器的研究进展。详细介绍了不同基团修饰的硫桥杯芳烃衍生物通过非共价键作用力对Hg^2＋,Ag^＋,Fe^3＋,Cu^2＋等金属离子的选择性识别,并设计成不同类别的荧光传感器,以荧光光谱法为手段,进行分析研究。以杯芳烃为主体的荧光传感器具有简便快速、高选择性的特点,广泛应用于化学、生物、环境等领域。     

离子色谱法测定水中氯化物监测质量控制指标研究

研究了离子色谱法测定水中氯化物质量控制指标,提出精密度和准确度的建议控制指标,具有广泛指导意义。全国东、西、中部共12个省份的53家实验室参加测定工作。研究结果为：在一定的浓度范围内,RSD1．0％,RSD≤5．0％,RE≤±5．0％;加标回收率为95．0％～115．0％;RD≤4．0％。     

Energy conversion from electrolyte concentration gradient using charged nano-pores

Power generation based on the reversed electro-dialysis (RED) cell is studied both numerically and experimentally in this work. The membrane that separates the concentrated and dilute electrolytes is treated as a charged nano-pore array. Both numerical and experimental results show that the RED cell performance is similar to the typical electrochemical cell having a linearly varied current–voltage relation. The open circuit voltage and short-circuit current depend on the ion selectivity of the nano-pore membrane, which is related to the concentration ratio, pore surface charge density, and pore size. The highest energy conversion efficiencies are approximately 48% and 24% from numerical predictions and experimental measurements, respectively. The reason for this discrepancy is attributed to the inhomogenous pore size and surface charge density distributions of the Al₂O₃ membrane used in these experiments.