堇青石蜂窝陶瓷负载锰氧化物催化分解臭氧性能

为了提高臭氧分解催化剂的实际应用能力,通过采用过渡金属锰氧化物为原料与铝胶混合涂覆到堇青石蜂窝陶瓷载体表面,制备了不同锰氧化物负载的整体式催化剂。 然后在常温常压下考察了整体式催化剂分解臭氧的性能。 通过X射线衍射(XRD)、扫描电子显微镜(SEM)、拉曼(Raman)光谱、X射线光电子能谱仪(XPS)、BET比表面积法和程序升温还原技术(H₂-TPR)对催化剂进行了表征。 研究结果表明,不同锰氧化物催化剂的活性按以下顺序排列:氧化锰八面体分子筛(OMS-2)＞MnO₂＞Mn₂O₃＞Mn₃O₄＞MnO。 相比其它锰氧化物,OMS-2负载的整体式催化剂对臭氧的反应活性最高,这可能归因于OMS-2具有较大的比表面积和较好的还原性能,从而有利于表面氧空位的生成和参与臭氧分解反应。 研究结果为提高堇青石蜂窝陶瓷负载型整体式催化剂应用于臭氧分解的性能提供了理论依据。     

Investigation of the By-products Formed during the Catalytic Synthesis of 4,4＇-Methylenedimethyldiphenylcarbamate

The structures of the by-products formed during the catalytic synthesis of 4,4＇-methyldiphenylcarbamate （MDC） by the reaction of 4,4＇-methylenedianiline （MDA） with dimethyl carbonate （DMC） were identified and then the mechanisms of their formation were proposed.     

用电沉积法在氧化铝模板中制备氧化锌纳米线的研究

利用直流电沉积法在阳极氧化铝模板的有序孔洞中生长了氧化锌纳米线,首次在氧气氛围中将锌氧化成氧化锌.用场发射扫描电子显微镜(FE-SEM)和X射线衍射仪(XRD)对其形貌及成分进行表征和分析.结果表明,氧化铝模板的有序孔洞中填充了高致密、均一连续的锌纳米线.在氧气氛围中,800 ℃下氧化2 h,氧化铝中的锌纳米线己全部氧化成氧化锌纳米线.光致发光光谱表明,氧化锌纳米线在496 nm处有较强蓝绿光发射.     

Bi4Ti3O12/Ag/AgCl复合纤维的制备及可见光催化性能

本文合成了钛酸铋/银/氯化银(Bi4 Ti3O12/Ag/AgC1,BTO/Ag/AgCl)复合纳米纤维,并研究了其可见光催化性能.通过静电纺丝技术和高温煅烧制备了BTO纳米纤维,采用沉淀-光照还原法在BTO纳米纤维表面负载了Ag/AgC1纳米颗粒获得BTO/Ag/AgC1复合纤维.结果 表明,BTO和Ag/AgC1均具有良好的结晶性能,BTO/Ag/AgC1比单纯的BTO纳米纤维具有更强的可见光吸收.光催化测试表明,由于Ag/AgC1对可见光吸收的增加,以及与BTO间形成的半导体异质结,BTO/Ag/AgC1复合纳米纤维对染料RhB的光催化降解效率均高于纯的BTO纳米纤维,经100 min光照后可由29;提高到80;.     

Li2CO3掺杂对0.94Mg2SiO4-0.06Ca0.9Sr0.1TiO3陶瓷微波介电性能的影响

采用传统固相反应法,研究了Li2CO3掺杂对0.94Mg2SiO4-0.06Ca0.9Sr01TiO3微波介质陶瓷的烧结性能和介电性能的影响.结果表明,烧结助剂Li2 CO3的引入未改变陶瓷的相组成.添加适量的Li2CO3可以促进烧结,烧结温度由1440℃降低到1355℃,而且介电性能也得到了优化,Q ×f值有明显的提高;过量Li2CO3的引入,降低了材料的致密性,增加了陶瓷的介电损耗.在1355℃烧结,保温3h,添加0.50wt; Li2 CO3的0.94Mg2SiO4-0.06Ca09Sr0.1TiO3陶瓷获得最佳的介电性能:εr=7.96,Q×f=96409 GHz(f=14.571 GHz),τf=+4.62 ppm/℃.     

Low Temperature Preparation and Absorption Spectra of Nanocrystalline Pb1-xLaxTiO3 Thin Film on ITO Conducting Glass Substrate

Nanocrystalline precursors of Pb_1-xLa_xTiO₃ (PLT, x=0.06, 0.10, 0.14 and 0.20) thin film were prepared on ordinary ITO conducting glass substrate using sol-gel and pulling method. After the precursors were calcined at low temperature of 185-400℃ in air atmosphere for 1-6 h, the resulted nanocrystalline thin film was characterized by XRD, SEM and AFM. The spectra show that the solid state chemical reaction and the grain size of the nanocrystalline thin film relate not only to the precursor preparing method, but also to the distribution of different components in the precursor. The UV-VI spectrum measurement of the transparent PLT film indicates that its optical absorption bands have extended into the visible region and a change in its absorption pattern with the increase of mean grain size was also observed. As the transparent nanocrystalline PLT thin film with small grain size possesses wider optical absorption band in range of 320-800 nm, the material of Pb_1-xLa_xTiO₃ with suitable component and mean grain size can be used in the fabrication of dye-sensitized photoelectronchemistry solar cell instead of TiO₂. And the higher photoelectric efficiency can be expected.     

半自动催化光度滴定法测定生物样品中的锰

报道了以催化光度返滴定法来测定锰含量的新方法 .以EDTA作络合剂 ,Mn(II)为返滴定剂 ,滴定终点由锰 (II)催化高碘酸钾氧化结晶紫的褪色反应来指示 .在体系中加入表面活性剂 (TritonX - 10 0 )可改善反应条件 ,使测定可在室温下进行 ,用半自动化装置使操作连续、快速、简便 .用该方法测定鸡肝、人发、啤酒中的锰含量 ,结果与原子吸收光谱法所得结果相吻合     

建设项目区间数属性评价的集对分析方法

针对建设项目承包商优选涉及到定量和定性两类指标属性评价问题,将集对分析理论应用于建设项目区间数指标属性评价决策.通过属性区间数值的同一、差异、对立的集对分析概念延伸,完成建设项目承包商优选评价.方法计算简单,通过案例分析表明,模型是可行和合理的,取得较为满意的结果.     

卡西米尔效应的格林函数计算方法

介绍了卡西米尔效应的严格格林函数表达式.作为应用,计算了4种边界条件下两平行板之间的卡西米尔能量.     

Study of low momentum track reconstruction for the BESⅢ main drift chamber

In order to overcome the difficulty brought by the circling charged tracks with transverse momentum less than 120 MeV in the BESⅢ Main Drift Chamber(MDC),a specialized method called TCurlFinder was developed.This tracking method focuses on the charged track reconstruction under 120 MeV and possesses a special mechanism to reject background noise hits.The performance of the package has been carefully checked and tuned by both Monte Carlo data and real data.The study shows that this tracking method could obviously enhance the reconstruction efficiency in the low transverse momentum region,providing physics analysis with more and reliable data.