Interfacial forces between silica surfaces measured by atomic force microscopy

Colloidal particle stability and some other interfacial phenomena are governed by interfacial force interactions. The two well known forces are van der Waals force and electrostatic force, as documented by the classical Derjaguin, Landau, Verwey, and Overbeek (DLVO) theory. Moreover, advances in modern instrumentation and colloid science suggested that some short-ranged forces or structure forces are important for relevant colloidal systems. The interfacial and/or molecular forces can be measured as a resultant force as function of separation distance by atomic force microscopy (AFM) colloid probe. This article presents a discussion on AFM colloid probe measurement of silica particle and silica wafer surfaces in solutions with some technical notifications in measurement and data convolution mechanisms. The measured forces are then analyzed and discussed based on the ‘constant charge’ and ‘constant potential’ models of DLVO theory. The di erence between the prediction of DLVO theory and the measured results indicates that there is a strong short-range structure force between the two hydrophilic surfaces, even at extremely low ionic concentration, such as Milli-Q water purity solution.     

己内酰胺-四丁基溴化铵类离子液体吸收SO2效率的研究

采用己内酰胺-四丁基溴化铵为原料,按摩尔配比为2∶1配制成[CPL][TBAB]类离子液体,制备的离子液体与乙醇溶液按体积比为1.5∶1混合以降低其粘度,利用筛板塔进行吸收实验,考察最佳吸收条件及最大吸收效率。结果表明,在实验条件下,最大的吸收效率条件为:离子液体的流量为60 L/h,SO2的流量为0.2 L/min,SO2为30℃,最大吸收效率为47.6%。     

我国部分商品粮基地土壤重金属污染的差异分析与综合评价探讨

根据1988年全国农业环境质量状况调查资料,选取我国部分商品粮基地县土壤重金属污染数据(污染指数),通过多元统计分析,揭示了各商品粮基地土壤重金属污染的差异与分类.建立模糊综合评判模型对各商品粮基地土壤污染状况进行了综合评价,得到了各商品粮基地土壤污染程度的相对排序.      

爆炸焊接的安全评估和安全防护措施

根据爆炸焊接的装药特点,对爆炸焊接炸药的使用、爆炸产生的地震波、毒气、噪音等的安全性进行了分析,给出了定量的计算公式,同时还针对不同的爆破危害,提出了相应的安全防护措施     

UV-catalytic treatment of spent caustic from ethene plant with hydrogen peroxide and ozone oxidation

The performance of UV/H2O2, UV/O3 and UV/H2O2/O3 oxidation systems for treating spent caustic from an ethylene plant was investigated, in UV/H2O2 system, with the increase of H202 dosage, removal efficiencies of COD and the ratio of biochemical oxygen demand(BOD) to chemical oxygen demand(COD) of the effluent were increased and a better performance was obtained than the H2O2 system alone. In UV/H2O2 system, removal efficiency of COD reach 68% under the optimum condition, and BOD/COD ratio was significantly increased from 0.22 to 0.52. In UV/O3 system, with the increase of O3 dosage, removal efficiency of COD and BOD/COD ratio were increased, and a better performance was obtained than the O3 system alone. Under the optimum condition, removal efficiency of COD was 54%, and BOD/COD ratio was significantly increased from 0.22 to 0.48. In UV/H2O2/O3 system, COD removal efficiency was found to be 22.0% higher than UV/O3 system.     

企业安全文化在安全管理中的创新实践

辽河油田公司作为油气生产、集输和销售企业,具有高风险的行业特点,始终面临着严峻的安全生产形势。因此,在加强安全管理的同时,积极推进企业安全文化建设,不断提高企业的整体安全素质,对于增强员工安全防范意识,减少安全生产事故,实现企业安全发展具有十分重要的意义。     

亚热带水库沉积物钻孔中有机质的历史记录及其环境意义

氢指数(HI)是重要的有机质评价参数,能够反映沉积有机质中脂肪大分子物质的相对含量,并用于反演水生生态系统的历史初级生产力,有助于研究藻类生产力对污染物的富集作用。为了探讨氢指数的环境指示作用,选择了亚热带的3座水库作为研究对象,采用Rock-Eval热解与生物标志物-中性糖方法相结合的研究技术,研究了沉积钻孔有机质的来源与特征;并结合210Pb和137Cs定年技术,综合运用氢指数和总糖含量对水库的初级生产力进行了重建。结果表明:中富营养的增塘和联安水库沉积有机质主要来源于浮游藻类,且受降解的程度较小,而贫营养的新丰江水库钻孔下层有机质主要是受降解作用或陆源高等植物等的影响。近年来,3个水库的HI值都有显著性的增加,且与其对应的总糖含量以及近50年来的滑动平均温度都高度的相关,说明这些水库都经历了气候变暖所引起的初级生产力增长。同时,升高的水库生产力扩大了沉积物剖面中重金属和多环芳烃的累积。     

条斑紫菜中磷和钙的亚细胞分布及其与富集砷的关系

研究条斑紫菜中磷和钙的亚细胞分布,并探讨其与条斑紫菜富集砷的关系。结果表明:条斑紫菜吸收磷、钙主要分布在细胞壁组分中,平均占总磷含量的53.9%,占总钙含量的61.25%,其次为细胞液。与对照组相比(砷暴露浓度0.5 mg·L~(-1)),在添加磷浓度为0.1 mg·L~(-1)和1.0 mg·L~(-1)处理组中,条斑紫菜中磷、砷之间呈现协同效应;当添加磷浓度为5.0 mg·L~(-1)和10.0 mg·L~(-1)时,条斑紫菜中磷、砷之间则呈现拮抗作用,砷的富集量分别比照组下降61.37%和72.73%。经添加钙液暴露过的条斑紫菜,当钙暴露浓度为1 000 mg·L~(-1)时其对砷的富集量比对照组减少15.51%。可知,5.0 mg·L~(-1)磷处理条斑紫菜,条斑紫菜对砷的富集受到明显的抑制。     

Characteristics and mixing state of S-rich particles in haze episodes in Beijing

Direct individual analysis using Scanning Electron Microscopy combined with online observation was conducted to examine the S-rich particles in PM_2.5 of two typical polluted haze episodes in summer and winter from 2014 to 2015 in Beijing. Four major types of S-rich particles, including secondary CaSO₄ particles (mainly observed in summer), S-rich mineral particles (SRM), S-rich water droplets (SRW) and (C, O, S)-rich particles (COS) were identified.We found the different typical morphologies and element distributions of S-rich particles and considered that (C, O, S)-rich particles had two major mixing states in different seasons. On the basis of the S-rich particles’ relative abundances, S concentrations and their relationships with PM_2.5 as well as the seasonal comparison, we revealed that the S-participated formation degrees of SRM and SRW would enhance with increasing PM_2.5 concentration. Moreover, C-rich matter and sulfate had seasonally different but significant impacts on the formation of COS.

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铅处理对茴香植株生长及精油组分的影响

为了揭示铅对茴香（Foeniculum vulgare L.）生长和次生代谢产物-精油组分的影响及茴香植株对铅的吸收累积特性,本试验采用水培方法,在霍格兰营养液中加入铅,设计0（对照）、1 mg·L^-1、5 mg·L^-1、10 mg·L^-1处理,研究了不同铅质量浓度对茴香植株生长、精油组分及茴香植株对铅吸收累积的影响。结果表明：不同铅质量浓度处理对茴香植株的形态、生物量、色素质量分数、碳和氮质量分数、铅的吸收累积及精油组分均有影响。随着铅质量浓度的增加,茴香植株的株高呈降低趋势,且各处理之间差异显著,真叶数大致也呈降低趋势,但仅10 mg·L^-1处理显著低于对照,各处理的最大叶长差异均不显著,最大叶宽仅对照与5 mg·L^-1处理之间差异显著。随着铅质量浓度的增加,地上部鲜质量和干质量均呈逐渐降低趋势,且铅处理后的地上部鲜质量和干质量均显著低于对照,地下部鲜质量和干质量呈逐渐升高趋势,但铅处理后的地下部鲜质量和干质量与对照差异均不显著,根冠比呈逐渐增加趋势,但仅10 mg·L^-1处理显著高于对照。随着铅质量浓度的增加,叶绿素a、叶绿素b、叶绿素a＋b和类胡萝卜素质量分数均呈降低趋势,且均低于对照,叶绿素a/叶绿素b以5 mg·L^-1处理最高,但仅显著高于1 mg·L^-1处理。铅处理后,可溶性蛋白质质量分数均高于对照,但仅1 mg·L^-1处理和5 mg·L^-1处理显著高于对照,全氮质量分数与可溶性蛋白质质量分数的变化趋势基本一致,但各处理之间差异均不显著;随铅质量浓度的增加,可溶性糖质量分数呈降低趋势,除1 mg·L^-1处理显著高于对照外,其余铅处理均显著低于对照,各处理的全碳质量分数与对照差异均不显著。随铅质量浓度的增加,茴香植株对铅的吸收累积显著增加。不同铅质量浓度处理下的反式-茴香脑含量和含氧化合物均显著低于对照,以5 mg·L^-1铅处理最低,而柠檬烯含量和单萜类化合物均显著高于对照,以5 mg·L^-1铅处理最高;随铅质量浓度的增加,倍半萜类化合物含量呈降低趋势,且均低于对照。因此,铅能抑制茴香植株的生长;随铅质量浓度的增加,茴香植株对铅的吸收累积显著增加;铅处理能影响茴香精油组分,显著降低反式-茴香脑和含氧化合物含量,而显著提高柠檬烯和单萜类化合物含量。