重庆市汞污染的观测研究

为研究重庆市区汞污染状况,2004年9~11月,同步观测了重庆市近郊铁山坪小流域（TSP）和观音桥(GYQ)两个区域的全沉降、穿透水、地表径流和土壤中的总汞含量,估算了小流域中汞的输入输出通量,分析了城区和郊区的大气汞沉降和分布特征。结果表明,重庆已在一定程度上受到汞污染。在TSP,湿沉降是汞输入的主要方式,也就是说,在TSP,细颗粒是大气汞的主要来源,表层土则是大气汞的一个主要的汇。GYQ区域的汞污染比TSP相对严重。在GYQ,除了湿沉降以外,干沉降是汞来源的重要形式,表明在GYQ,粗颗粒可能对大气汞有很大的贡献。因此,本地源的排放对城区的影响比对郊区的影响大,尤其是城区火电站附近的土壤样品比郊区土壤的汞含量高很多,说明火电站是大气汞的重要来源之一。     

Effect of Sb dopant amount on the structure and electrocatalytic capability of Ti/Sb-SnO2 electrodes in the oxidation of 4-chlorophenol

Ti/Sb-SnO_2 anodes were prepared by thermal decomposition to examine the influence',of the amount of Sb dopant on the structure and electrocatalytic capability of the electrodes in the oxidation of 4-chlorophenol.The physicochemical properties of the Sb-SnO_2 coating were markedly influenced by different amounts of Sb dopant.The electrodes,which contained 5% Sb dopant in the coating, presented a much more homogenous surface and much smaller mud-cracks,compared with Ti/Sb-SnO_2 electrodes containing 10% or 15% Sb dopant,which exibited larger mud cracks and pores on the surface.However,the main microstructure remained unchanged with the addition of the Sb dopant.No new crystal phase was observed by X-ray diffraction(XRD).The electrochemical oxidation of 4-chlorophenol on the Ti/SnO_2 electrode with 5% Sb dopant was inclined to electrochemical combustion;while for those containing more Sb dopant,intermediate species were accumulated.The electrodes with 5% Sb dopant showed the highest efficiency in the bulk electrolysis of 4-chlorophenol at a current density of 20 mA/cm~2 for 180 min;and the removal rates of 4-chlorophenol and COD were 51.0% and 48.9%,respectively.     

阿克苏地区春季土壤水分垂直向运动

土壤中毛管水是传递压力的,毛管水运动的方向,受土壤上层温度变化和土面蒸发制约,与土壤中汽态水的运动方向（由热至冷）一致。下午和晚上因地面辐射而冷却,闭塞空气收缩,潜水向上通过毛细管吸入闭塞空气中,潜水位下降;上午和白天因地面日晒,土温升高,闭塞空气膨胀,排出较粗毛管水,成为重力水而下渗,抬升潜水位。春天大风,土温升高,晚上使潜水位升高,白天土面蒸发加大,又使潜水位下降。用潜水蒸渗仪,可测到大风天改变土壤水分运行的方向。     

具有特定拓扑结构的聚烯烃高分子的合成

具有特定拓扑结构的聚合物合成一直是高分子合成化学领域的一个重要研究内容，设计和合成具有特定拓扑结构的聚烯烃高分子更是进一步发掘聚烯烃这一量大面广的通用高分子材料的性能、开拓其新的应用领域的重要手段。在催化剂和聚合方法的研究取得重要进展的基础上，近年来国际上在合成不同拓扑结构（包括嵌段、接枝、梳型和星型）的聚烯烃高分子研究方面发展也较快，所合成的部分高分子亦显示出独特的功能性。本文首先综述不同拓扑结构聚烯烃高分子合成的研究现状，然后结合近期化学所在此领域的研究进展，提出独特的以苯乙烯封端反应性聚烯烃为模块构建拓扑结构聚烯烃的新思路。     

REAL-TIME SOIL WATER MONITORING FOR OPTIMUM WATER MANAGEMENT1

Abstract: Efficient water resource management is one of the most important policy issues facing agriculture in Hawaii in the years ahead. Soil water sensors, multisensor capacitance probes (MCP), have been successfully used for different water management projects. These MCPs monitor water content at multiple depths and at various locations in real-time. The objectives of this study were to determine the effect of water content on field soil bulk density of Wahiawa silty clay tropical soil; measure field saturated hydraulic conductivity of this tropical soil: calibrate MCP system for this soil: and monitor and evaluate real-time soil water content variations under a tomato crop using the calibrated MCP system. Sensor calibration was conducted under laboratory conditions. Soil bulk density at different water contents and saturated hydraulic conductivity were measured on the field. Bulk density increased with increasing water content: there was a 30 percent bulk density increase as a result of 0.25 cm³ cm^-3 water content variation. Compared with the manufacturer's calibration, site specific laboratory calibration of MCP gave a more accurate determination of soil water. Field determined saturated hydraulic conductivity was higher than laboratory determined values reported in the literature for the same soil type. Real-time soil water content monitoring within the root zone showed substantial variations due to water input (irrigation and rainfall) and water output (evapotranspiration and deep percolations). However, water content variations were much further reduced in the soil layer below the root zone.     

Effect of bulk density of coking coal on swelling pressure

Coking coals are the important raw materials for the iron and steel industries and play an important role on its sustainable development, especially on the stamp-charging coke making with the characteristics of increasing the bulk density. There is a significance on the reasonable usage of the coking coal resource with the reduced production cost, improved efficiency of the economy to develop the stamp-charging coke making technology. Important effects of the density of coking coal on the coking and caking properties were investigated. In the article, the maximum values of swelling pressure and variation of Laowan gas coal and Xinjian 1/3 coking coal, Longhu fat coal and Didao coking coal, which were mined at Shenyang and Qitaihe respectively, were investigated under different bulk densities during the coking. The results showed that when the values of density increased from 0.85 ton/m³ to 1.05 ton/m³, for the Laowan gas coal, swelling pressure variation and even the maximum value changed slightly. The swelling pressure was 3.63 KPa when the density was improved to 1.05 ton/m³; for the Xinjian 1/3 coking coal, the values of swelling pressure changed significantly and the maximum values was 82.88 KPa with the density improved to 1.05 when the coal was heated to 600℃. The coke porosity, which was investigated by automatic microphotometer, decreased from 47.4% to 33.1% with the increasing of the density from 0.85 ton/m³ to 1.05 ton/m³, and the decreased value was 14.3%. Meanwhile, the pore structures of four cokes were characterized by an optical microscope.     

Effect of bulk density of coking coal on swelling pressure

Coking coals are the important raw materials for the iron and steel industries and play an important role on its sustainable development, especially on the stamp-charging coke making with the characteristics of increasing the bulk density. There is a significance on the reasonable usage of the coking coal resource with the reduced production cost, improved efficiency of the economy to develop the stamp-charging coke making technology. Important effects of the density of coking coal on the coking and caking properties were investigated. In the article, the maximum values of swelling pressure and variation of Laowan gas coal and Xinjian 1/3 coking coal, Longhu fat coal and Didao coking coal, which were mined at Shenyang and Qitaihe respectively, were investigated under different bulk densities during the coking. The results showed that when the values of density increased from 0.85 ton/m³ to 1.05 ton/m³, for the Laowan gas coal, swelling pressure variation and even the maximum value changed slightly. The swelling pressure was 3.63 KPa when the density was improved to 1.05 ton/m³; for the Xinjian 1/3 coking coal, the values of swelling pressure changed significantly and the maximum values was 82.88 KPa with the density improved to 1.05 when the coal was heated to 600°C. The coke porosity, which was investigated by automatic microphotometer, decreased from 47.4% to 33.1% with the increasing of the density from 0.85 ton/m³ to 1.05 ton/m³, and the decreased value was 14.3%. Meanwhile, the pore structures of four cokes were characterized by an optical microscope.     

应用CAMEO软件包预测聚合反应器丙烯泄漏影响范围

为了能够准确地预测聚合反应器发生泄漏时丙烯的扩散分布,提高应急救援工作效率,应用CAMEO软件包进行预测,通过该软件包中ALOHA、MARPLOT软件连用,解决了量化和图形显示问题。     

土壤容重改变对锌/镉超累积植物遏兰菜根系特征及吸镉的影响

为了探讨土壤容重的变化对锌/镉超累积植物遏兰菜(Thlaspi caerulescens)根系形态特征及吸收土壤中镉、锌的影响,采用土壤盆栽方法,研究了土壤结构改良剂(EB.a)对镉污染土壤(2.12 mg.kg-1)的容重和遏兰菜提取镉/锌效率的影响.EB.a用量分别为0、0.1%和2%,植物种植100 d后收获.结果表明,EB.a可有效地降低土壤容重,2%EB.a处理土壤容重从1.27g.cm-3降至1.09 g.cm-3;土壤容重的降低,促进了遏兰菜根系和地上部的生长;植物的总根长、根毛长、根冠比均显著提高(p0.05).随着植物根长的增加,遏兰菜地上部提取镉/锌总量均显著提高(p0.05).与对照相比,2%EB.a处理致使遏兰菜总根长增加了2.6倍,植物地上部镉浓度和提取总量分别提高了20%和30%,镉提取效率由15%提高至19%;但遏兰菜的地上部锌浓度和提取总量并没有显著变化.研究结果证实了改善土壤结构可以促进遏兰菜根系的生长从而提高植物对镉的提取效率.     

磁性离子印迹聚合物的制备及其对水中Pb(Ⅱ)的吸附

以铅离子为模板离子、乙二醇二甲基丙烯酸酯和偶氮二异丁腈为交联剂和引发剂、稀盐酸为洗脱剂,采用微波辅助反相乳液悬浮聚合法,制备了磁性离子印迹聚合物(MIIP),通过SEM、FTIR、XRD和BET技术对其进行了表征,并将其用于水中Pb(Ⅱ)的吸附.在初始质量浓度60 mg/L、溶液pH 6、吸附温度303 K、吸附时间6...