碱性纳米MnO2/AC混合超级电容器

采用低热固相反应法制备出纳米MnO2活性材料.循环伏安测试结果表明,在6 mol.L-1KOH电解液中,MnO2电极在-0.3~0.6 V(vs.Hg/HgO)的电压范围内表现出较好的超电容特性.恒流充放电结果表明,以MnO2为正极、活性炭(AC)为负极组成的碱性MnO2/AC混合电容器在比电流为100 mA.g-1、充放电电压范围为0~1.5 V条件下的放电比电容可达66.2 F.g-1.同样条件下,MnO2与活性炭质量比为80∶20的复合正极与活性炭负极组成的(MnO2 AC)/AC混合电容器的比电容可达78.2 F.g-1.     

Biodegradation of dissolved organic carbon in soil extracts and leachates from a temperate forest stand and its relationship to ultraviolet absorbance

The amount and biodegradability of dissolved organic carbon (DOC) in forest floors can contribute to carbon sequestration in soils and the release of CO 2-C from soil to the atmosphere.There is only limited knowledge about the biodegradation of DOC in soil extracts and leachates due to the limitations inherent in degradation experiments.Differences in the biodegradation of DOC were studied in forest soil extracts using cold and hot water and 4 mmol/L CaCl 2 solution and in soil leachates sampled under different conditions over a wide range of DOC concentrations.From these results,we developed a simple and rapid method for determining the biodegradable organic C in forest floors.The hot water extracts and CaCl 2 extracts after CH 3 Cl fumigation contained higher concentrations of biodegradable organic C than the cold water extracts and CaCl 2 extracts before fumigation,with rapid DOC degradation occurring 24-48 h after incubation with an inoculum,followed by slow DOC degradation till 120-168 h into the incubation.During a 7-d incubation with an inoculum,the variation in DOC degradation in the different soil extracts was consistent with the change in special UV absorbance at 254 nm.Relatively higher levels of biodegradable organic C were detected in soil leachates from the forest canopy than in forest gaps between April and October 2008 (P <0.05).Relatively lower concentrations of DOC and biodegradable organic C were observed in soil leachates from N-fertilized plots during the growing season compared with the control,with the exception of the plot treated with KNO 3 at a rate of 45 kg N ha 1 a 1.Around 77.4% to 96.3% of the variability in the biodegradable organic C concentrations in the forest floors could be accounted for by the initial DOC concentration and UV absorbance at 254 nm.Compared with the conventional inoculum incubation method,the method of analyzing UV absorbance at 254 nm is less time consuming and requires a much smaller sample volume.The results suggest that the regression models obtained using the initial DOC concentration and UV absorbance can provide a rapid,simple and reliable method for determining the biodegradable organic C content,especially in field studies involving relatively large numbers of samples.     

全封闭碳纤维与高强钢丝复合拉索的弹性模量

探讨了全封闭复合拉索的协调工作机理,即要求芯部高强钢丝束与碳纤维筋弹性模量接近或相等;研究了高强钢丝束捻距与弹性模量间的关系;推导了37股高强钢丝束弹性模量的计算表达式,通过有限元分析验证了表达式的正确性.试验表明,碳纤维筋弹性模量可以达到与高强钢丝束的弹性模量相近的要求.结论表明:复合拉索中的索力按照碳纤维筋与高强钢...     

基于STIRPAT模型的低碳经济策略分析——以辽宁省为例

随着社会经济的发展,大量温室气体的排放已引起严重的气候变化。辽宁省积极响应国家政策,发展低碳经济。采用1989～2009年辽宁省相关的统计数据,对STIRPAT模型进行了扩展分析,应用EViews6.0软件并使用时间序列分析方法,研究了辽宁省碳排放量的影响因素,并提出了相应的减排策略及建议。     

十六烷基胺-多壁碳纳米管复合物的制备及NO吸附性能

为制备在室温下对NO吸附性能优异的材料,采用十六烷基胺并通过化学缩合的方法对多壁碳纳米管进行了修饰,制备了十六烷基胺-多壁碳纳米管复合物,并分别采用TG-DSC,XRD,FT-IR,Raman,SEM等技术对所制备的复合物进行了表征.研究表明:十六烷基胺通过酰胺键修饰在多壁碳纳米管表面,经十六烷基胺修饰的碳纳米管结构基本没有发生变化.原位TG-MS结果表明:在室温下,经十六烷基胺修饰的多壁碳纳米管的NO吸附量是纯碳纳米管的8.58倍,其选择性吸附NO能力较纯碳纳米管明显提高.原因是十六烷基胺修饰的多壁碳纳米管n型电导能力增强,而使受电子体NO分子易与修饰的碳纳米管作用并发生化学吸附.     

Na+掺杂CoCr2O4尖晶石制备及其光催化性能

由于CoCr2O4尖晶石纳米粉体对二氧化碳和水合成甲酸具有光催化作用,采用溶胶凝胶法制备了Co0.8Na0.2Cr2O4尖晶石纳米粉体,用X射线衍射光谱仪(XRD)、紫外-可见光漫反射(UV-Vis DRS)、扫描电镜(SEM)对其成晶温度、晶体结构和光响应性能进行了表征。结果表明:CoCr2O4掺杂金属Na制备的Co0.8Na0.2Cr2O4属尖晶石结构,掺杂后晶格略有膨胀,禁带宽度变宽,吸光性能增强。在175 W高压汞灯照射下,Co0.8Na0.2Cr2O4比CoCr2O4对光催化还原CO2制取甲酸活性高。     

角锥型吸波材料应用新探

采用碳纤维与磁性微粉复合做成小尺寸角锥型吸波材料 ,具有良好的吸波性能 .角锥设计成高 1.5cm ,底座高 0 .35cm ,尖顶角 4 5° .经测量 ,2 # 材料在 2～ 18GHz频率范围内反射率在 - 10dB以下 ,3.72GHz处峰值反射率达 - 2 0 .86dB     

基于ArcGIS的土壤有机碳密度及储量计算

文章建立了基于栅格GIS的计算方法,以GIS空间分析模型为基础,在ArcGIS支持下,提取模型所需数据,实现栅格图层空间叠合运算及统计分析,获得了土壤有机碳密度分布图,并统计了土壤有机碳储量;以安徽省舒城县土壤为例进行分析,与土壤类型法比较,由于GIS方法的空间插值计算考虑了决定土壤有机碳密度及储量的土壤属性空间变异性,获得了较精确的结果,为统计土壤有机碳密度及储量提供了一个可能的途径。     

ACF酶催化空气净化材料的合成及甲醛降解机理

该文采用高分子材料与ACF（活性炭纤维）复合并负载模拟酶催化剂、纳米银杀菌剂,合成生态型空气净化复合材料;检测合成样品对甲醛的催化净化能力;进行样品抗茵测试。检测结果表明：试样对甲醛具有长期高效催化净化能力;对大肠杆菌、金黄色葡萄球菌抗茵率为100％;探讨了模拟酶催化分解甲醛的机理和反应历程。     

固相原位接枝炭黑的制备及其在涂料中的应用

采用固相原位接枝反应方法将炭黑(CB)与有机小分子在Haake转矩流变仪中进行接枝反应,制得接枝炭黑(GCB)。通过原子力显微镜(AFM)观察发现该接枝炭黑呈单分散分布,粒径为30 nm左右。将接枝炭黑制得涂料并考察其对涂料性能的影响,结果表明:与用未接枝炭黑制得的涂料相比,接枝炭黑制得的涂料在光泽度、附着力等方面均有较大提高。同时,扫描电子显微镜(SEM)也观察到接枝炭黑在涂料中均匀分散,且达到纳米级。