桉树叶提取液还原石墨烯电极提高微生物燃料电池产电性能的研究

将桉树叶提取液绿色还原氧化石墨烯(G-rGO)电极和微生物还原氧化石墨烯(B-rGO)电极依次作为微生物燃料电池(MFC)阳极,采用红外光谱(FTIR)、X射线衍射(XRD)、扫描电镜(SEM)对所制备的电极进行表征,并采用循环伏安法(CV)、交流阻抗法(EIS)对比2种电极的电化学性能.结果发现,G-rGO阳极的内阻为243.87Ω,应用于MFC时最大功率密度和最大输出电压分别为18.77 W·m~(-3)和760 mV,对照组B-rGO电极的内阻为299.11Ω,将其应用于MFC时最大功率密度和最大输出电压分别为13.16 W·m~(-3)和635 mV,对照组未修饰阳极的内阻为375.21Ω,最大功率密度和最大输出电压分别为8.97 W·m~(-3)和480 mV.研究表明,G-rGO电极电阻更小,导电性能更优越.     

锈蚀钢筋混凝土圆柱抗震性能的试验研究

对不同锈蚀程度的钢筋混凝土圆柱进行低周反复试验,研究了不同轴压比下的钢筋锈蚀率对钢筋混凝土圆柱滞回曲线、骨架曲线、刚度、延性及耗能能力的影响;给出了试件累积耗能、屈服荷栽、极限荷栽、荷栽最大值和位移延性系数与钢筋锈蚀率和轴压比的关系.研究表明,随着钢筋锈蚀率和轴压比的增大,试件的滞回曲线趋于干瘪,骨架曲线下降段变陡,试...     

硫化矿物中无机盐及重金属离子溶出的影响因素探讨

基于浸泡试验,在不同的时间、温度、酸碱度、固液比等条件下研究硫化矿物中无机盐和重金属离子的溶出反应,得到影响该溶出反应的重要因素,为实际矿业生产过程中硫化矿物的堆放和处理提供了理论依据.     

事故归因理论探讨

以时间和空间为主线介绍了事故归因理论,包括单一因素归因理论、人物合一归因理论和系统归因理论.并将系统论与安全科学相结合,提出事故归因辨证思想和理念.     

中国《产品包装法》现状及其立法构想

随着中国社会经济的迅猛发展,包装带来的环境污染、资源浪费等问题日益受到广泛关注.从循环经济的科学理念和可持续发展战略指导思想出发,分析了国内外关于包装法规的研究动态,论述了制定<产品包装法>的基本原则,并就立法、执法和配套措施等问题提出了相应的建议.     

Changes of organic acid exudation and rhizosphere pH in rice plants under chromium stress.

The effect of chromium (Cr) stress on the changes of rhizosphere pH, organic acid exudation, and Cr accumulation in plants was studied using two rice genotypes differing in grain Cr accumulation. The results showed that rhizosphere pH increased with increasing level of Cr in the culture solution and with an extended time of Cr exposure. Among the six organic acids examined in this experiment, oxalic and malic acid contents were relatively higher, and had a significant positive correlation with the rhizosphere pH, indicating that they play an important role in changing rhizosphere pH. The Cr content in roots was significantly higher than that in stems and leaves. Cr accumulation in plants was significantly and positively correlated with rhizosphere pH, and the exudation of oxalic, malic and citric acids, suggesting that an increase in rhizosphere pH, and exudation of oxalic, malic and citric acid enhances Cr accumulation in rice plants.     

Influence of metal ion on sorption of p-nitrophenol onto sediment in the presence of cetylpyridinium chloride

Heavy metals and surfactants have a significant effect on the sorption of organic contaminants. In this study, batch equilibrium experiments were carried out to investigate the influence of Pb(NO(3))(2) on the sorption of p-nitrophenol (PNP) onto sediments in the presence of cationic surfactant cetylpyridinium chloride (CPC). Results indicated that in the complex system containing PNP, Pb(NO(3))(2) and CPC, the sorption of PNP decreased with increasing concentration of Pb(NO(3))(2) due primarily to competing for adsorption sites. Likewise, partitioning of PNP in adsorbed surfactant layers and micelles decreased with increasing level of Pb(NO(3))(2). Moreover, the influence of different metal ions (Pb(2+), Cd(2+), Zn(2+)) was examined and results indicated that the presence of heavy metals inhibited the sorption of PNP in the order: Pb(2+)>Cd(2+)>Zn(2+). The competitive effect of the heavy metals was in agreement with the hydration energy and hydrated radius. The results are believed to provide a useful insight into describing the transport and fate of PNP in natural environments.     

Mechanism of decolorization and degradation of CI Direct Red 23 by ozonation combined with sonolysis

The decolorization and degradation of CI Direct Red 23, which is suspected to be carcinogenic, were investigated using ozonation combined with sonolysis. The results showed that the combination of ozonation and sonolysis was a highly effective way to remove color from waste water. The operational parameters, namely concentration of the dye, pH, ozone dose and ultrasonic density, were investigated during the process. The decolorization of the dye followed pseudo-first-order kinetics. Increasing the initial concentration of Direct Red 23 led to a decreasing rate constant. The optimum pH for the reaction was 8.0, and both lower and higher pH decreased the removal rate. The effect of the ozone dose on the dye decolorization was much greater than that of the sonolysis density. Intermediates such as naphthalene-2-sulfonic acid, 1-naphthol, urea and acetamide were detected by gas chromatography coupled with mass spectrometry in the absence of pH buffer, while nitrate and sulfate ions and formic, acetic and oxalic acids were detected by ion chromatography. A tentative degradation pathway was proposed without any further quantitative analyses. During the degradation, all nitrogen atoms and phenyl groups of Direct Red 23 were degraded into urea, nitrate ion, nitrogen and formic, acetic and oxalic acids, etc.     

Comparative on Causes and Accumulation of Selenium in the Tree-rings Ambient High-selenium Coal Combustion Area from Yutangba, Hubei, China

Toxic trace elements emitted during coal combustion are the main sources of air pollution. They are released into the atmosphere mainly in the forms of fine ash, smoke and flue, and thus adversely affect plant, animal and human health. Selenium is one of toxic and the most volatile in coal. Large amount of atmospheric emission of selenium, as well as selenium present and scrubber stockpiles in ash may create serious environmental problems. In the paper, on the basis of investigating the abundance and distribution of selenium in plant-rings during recent 20 years, the bioaccumulation of selenium is explained that selenium in plant, which were collected from the village of selenium-rich coal combustion, is much higher than that in plants collected away from the village of selenium-rich coal combustion. The main origins of selenium are selenium-rich coal combustion and high-selenium rock weathered. The selenium recycle by food chain and selenium will accumulate and redistribute in environments.     

絮凝剂PAN-DCD与甲基橙相互作用中的热力学研究

用平衡渗析法研究了有机高分子絮凝剂ＰＡＮ－ＤＣＤ与甲基橙（ＭＯ）在２０,２５,３０,３５℃下相互作用的热力学,求得结合常数Ｋ和热力学参数△Ｇ,△Ｈ,△Ｓ,在对不同絮凝剂结构进行表征的基础上,探讨了不同ＰＡＮ,ＤＣＤ配比对合成的絮凝剂与ＭＯ相互作用的影响,结果表明：ＰＡＮ－ＤＣＤ与ＭＯ的相互作用中能量作用是主要的：随ＰＡＮ与ＤＣＤ的比值增大,合成的絮凝剂ＰＤ１,ＰＤ２,ＰＤ３在常温下与ＭＯ的结合程试