Synthesis of CuO nanoparticles through green route using Citrus limon juice and its application as nanosorbent for Cr(VI) remediation: Process optimization with RSM and ANN-GA based model

In present investigation, an attempt has been made for the synthesis of cupric oxide nanoparticles (CuONPs) through a green route by utilizing lemon juice extract as a bioreductant. The synthesized CuONPs were characterized through UV–visible spectroscopy, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The CuONPs were utilized for Cr(VI) removal from water through adsorption method in batch mode at different initial Cr(VI) concentration, pH, temperature and CuONPs dosage. The maximum uptake capacity of CuONPs was found to be 16.63 mg of Cr(VI)/g at pH 4.0. Implementation of response surface methodology (RSM) followed by artificial neural network hybridized with genetic algorithm (ANN-GA) approach has resulted maximum Cr(VI) adsorption of 98.8% under the optimized conditions of initial metal concentration 22.5 mg/L, pH 3.81, CuONPs dose 1.28 g/L and temperature 37.1 °C. Under optimum conditions, adsorption isotherm study was conducted, which showed that the fitness of experimental data was well achieved with Langmuir isotherm model illustrating monolayer pattern of adsorption. Thermodynamic study revealed that the process was spontaneous and endothermic in nature, while adsorption kinetics was best explained by pseudo-second order kinetic model.     

Effect of Co(Ⅱ) dopant on the removal of Methylene Blue by a dense copper terephthalate

In this research, for the first time, a series of Co(Ⅱ) doped copper terephthalate(Co X-Cu BDC,where X is doping percentage) were successfully synthesized via solvothermal method and were tested for dye removal application. The physical properties of Co X-CuBDC were studied by several techniques including X-ray diffraction(XRD), field emission scanning electron microscopy(FESEM), energy-dispersive spectroscopy(EDS), thermogravimetric analysis(TGA)and Brunauer–Emmett–Teller(BET) surface area analysis. The incorporation of Co(Ⅱ) dopant leads to isomorphic substitution of Cu(II) in the CuBDC framework with the maximum doping percentage of 22. Doping and parent MOFs which are non-porous were used for removal of Methylene Blue(MB) from aqueous solution. Adsorption capacity of Co22-CuBDC and CuBDC are 52 and 58 mg/g, respectively, both of which are higher than the adsorption capacity recorded from several high porosity MOFs. Adsorption kinetic studies indicate that adsorption process follows pseudo-second order model while the adsorption mechanism is dominated by electrostatic attraction. Overall, even though these materials show non-porous characteristic,it can be used effectively in wastewater treatment application.     

平面问题中主应变测量不确定度评定

目的实现平面场中主应变的测量不确定度评定。方法首先建立主应变的是非线性传播测量模型,然后应用基于二阶TAYLOR级数展开理论的不确定度传播方法(LPU方法),开展平面问题中主应变的测量不确定度评定。针对二种常用的应变花,建立以主应变为输出量、以应变花之三个方向测量应变为输入量的测量模型,并将二阶LPU方法应用于该模型。设计数值计算算例,以说明主应变不确定度的评定过程和方法,并与一阶LPU结果进行了比较。结果当应变花三个方向的应变测量结果相近时,文中方法与一阶LPU方法获得的主应变的不确定度评定结果存在明显的差异,主应变不确定度评定结果在数值上都大于应变花测量的不确定度。当应变花三个方向的应变测量结果相差较大时,文中方法和一阶LPU方法获得的主应变测量不确定度评定结果相差不大。结论特定情况下,主应变的测量不确定度值远大于应变花测量的不确定度,且与一阶LPU方法的评定结果有显著差异,二者可相差一倍。     

化纤油剂废水对污水处理的影响及对策

介绍化纤油剂废水的特点和其对污水生化处理的影响，总结目前采取的源头治理和分质处理所达到的效果，提出下一步的工作思路和目标。     

吸附生物降解法(AB工艺)A段反应机理分析

讨论了AB工艺由于其独特的工艺流程 ,改变了以往传统的活性污泥法建立动力学方程的边界条件 ,AB工艺A段在动力学方面与普通活性污泥法有所不同 ,本研究提出AB工艺A段主要是通过微生物的酶解作用 ,改变SS胶体颗粒的表面性质 ,促进其相互间吸附 ,絮凝的过程 ,研究了AB工艺A段的反应级数及动力学模式     

不同高程气溶胶中多环芳烃(PAHs)分布研究

通过对在广东省南海市不高程气溶胶及气溶胶中多环芳烃（ＰＡＨs）的分布研究认为，气 溶胶及气溶胶中的ＰＡＨs来源于地表主干道机动车的排放，优控多环芳烃总量在３次连续 采样中可能由于空气流动状态的差异产生产３种不同的组合类型。研究中发现部分ＰＡＨs的分布出现异常，即采样位置高的样品ＰＡＨs中轻质量、低环数的多环芳烃含量的高于采 样位置低的无序现象。     

Ranked set sampling: an annotated bibliography

The paper provides an up-to-date annotated bibliography of the literature on ranked set sampling. The bibliography includes all pertinent papers known to the authors, and is intended to cover applications as well as theoretical developments. The annotations are arranged in chronological order and are intended to be sufficiently complete and detailed that a reading from beginning to end would provide a statistically mature reader with a state-of-the-art survey of ranked set sampling, including historical development, current status, and future research directions and applications. A final section of the paper gives a listing of all annotated papers, arranged in alphabetical order by author.This paper was prepared with partial support from the United States Environmental Protection Agency under a Cooperative Agreement Number CR-821531. The contents have not been subject to Agency review and therefore do not necessarily reflect the views or policies of the Agency and no official endorsement should be inferred.     

聚结除油反应机理及其动力学分析

通过对几种聚结填料除油性能的对比试验,探讨分析了聚结除油反应机理及其动力学.结果表明,填料的空间构成形式对聚结除油效率有重要影响,当润湿聚结机理和碰撞聚结机理同时存在时,聚结效率可得到大幅度提高.当油珠颗粒尺寸超过10μm时,布朗运动聚结速率急剧减慢,而湍流的聚结速率急剧加快.聚结除油反应器内水力条件的紊动程度达到G≥500～700 s-1时,油珠颗粒的聚结速率和效率将得到大幅度提高.     

Biased parental investment and reproductive success in Gabbra pastoralists

Demographic data from 848 Gabbra households are used to examine the relationships between herd size and reproductive success in relation to sex, in a traditional, pastoralist population. The number of camels in the household herd has a significant positive effect on the reproductive success of both men and women, although the effect of wealth is greater for men, as predicted from evolutionary theory. The greater the number of elder brothers a man has, the lower his reproductive success, as a result of a smaller initial herd and a later age at marriage. This is not true for women –number of elder sisters does not have a measurable effect on a woman’s fertility, although it does have a small, negative effect on the size of her dowry. These results are interpreted as competition between same-sex siblings for parental investment, in the form of their father’s herd, which is more intense between sons than daughters as parental investments are greatest in males. Received: 30 June 1995/Accepted after revision: 23 October 1995     

物种灭绝的若干种可能的序

利用集合种群共存动力模式，研究了由于栖息地毁坏而导致物种灭绝的顺序问题．研究结果表明：在群落里各物种种群具有相等的死亡率的假设下，栖息地毁坏而导致物种的灭绝存在3种最基本可能的顺序，既最弱物种与最强物种相伴灭绝，最强物种与最弱物种是强弱交替灭绝，以及由强而弱依次灭绝．参7