Facile synthesis of gold nanoplates by thermally reducing AuCl_4~- with aniline

We herein report a one-step,wet-chemical approach to synthesizing gold nanoplates in large quantities via the AuCl_4~-thermal reduction process by aniline,without introducing additional capping agent or suffactant.It is found that the reduction kinetics of AuCl_4~-is greatly altered by varying the initial molar ratio of aniline to AuCl_4~-.Moreover,further investigation reveals that the in- situ formed polyaniline could serve effectively as a capping agent to preferably adsorb the{111}facets of gold crys...     

不等式约束最优化无严格互补条件下的快速收敛序列线性方程组算法

本文讨论无严格互补性的非线性不等式约束最优化问题,建立了一个新的序列线性方程组算法。算法每次迭代只需解一个线性方程组或计算一次广义梯度投影,并不要求Lagrange函数的近似Hessian阵正定。在较弱的假设下,证明了算法的整体收敛性、强收敛性、超线性收敛性及二次收敛速度。还对算法进行了有效的数值试验。     

Michael Additiion of Alkyl Amine to α,β-Unsaturated Carbonyl Compounds Catalyzed by KF／Al2O3

The β-aminocarboxylic acid derivatives were synthesized by Michael addition reaction ofalkyl amine and α,β-unsaturated carbonyl compounds in the presence of potassium fluoride onalumina.     

Effect of Transition Metals on Selective Hydrogenation of Cinnamaldehyde over Pt／ZrO2 Catalysts

The effect of transition metals (Cr, Mn, Fe, Co and Ni) on the hydrogenation of cinnamaldehyde over Pt/ZrO2 catalysts was studied in ethanol at 343K under 2.0MPa H2 pressure. PtCo/ZrO2 and PtFe/ZrO2 catalysts exhibit high selectivity and activity of hydrogenation for C=O (93.8% at 87.3% conversion and 83.6% at 88.6% conversion, respectively), and PtNi/ZrO2 exhibits high selectivity of hydrogenation for C=C (64.3% at 70.6% conversion). In the presence of trace H2O and NaOH, over the PtNi/ZrO2 (0.4wt%Ni) catalyst the selectivity to hydrocinnamalde hydereaches 90.6% and the conversion of cinnamaldehyde is 90.5%.     

Friedel-Crafts Acylation of Ferrocene Catalyzed by Solid Superacid, Silica-supported Polytrifluoromethanesulfosiloxane

Solid superacid, silica-supported polytrifluoromethanesulfosiloxane (SiO2-Si-SCF3) was firstly used in the Friedel-Crafts acylation of ferrocene as a novel catalyst. IR spectra, WAXD and specific surface area of the superacid SiO2-Si-SCF3 were also investigated.     

色散缓变光纤的非线性啁啾效应

由于光孤子在光纤中传输受到啁啾效应等多种因素的影响 ,使孤子脉宽展宽 ,光脉冲在终端变得不可检测 ,严重影响误码率 ,所以研究不同因素对孤子脉宽的影响有其重要意义。本文求解了色散缓变光纤中含频率非线性啁啾效应的NLS方程 ,由得到的孤子解讨论了非线性啁啾效应和色散缓变效应对孤子脉宽的影响 ,由此说明 ,色散缓减效应等效长距离分布参数光纤放大器的增益 ,它导致非线性效应增加 ,孤子进一步被压缩 ,非线性啁啾效应使孤子在z值较小时 ,其脉宽收缩 ,在z值较大时又使孤子脉宽展宽。     

La_(0.5)Sm_(0.2)Sr_(0.3)MnO_3/Ag_x中的室温磁电阻增强

用固相反应法制备La0.5Sm0.2Sr0.3MnO3/(Ag2O)x/2(x=0.00,0.04,0.08,0.25,0.30)样品,通过M～T曲线,ρ～T曲线,ρ～T拟合曲线,研究样品的磁性质、输运行为、输运机制及磁电阻效应.结果表明:少量掺杂时Ag可能参与反应.掺杂量较多时,Ag主要以金属态分离到母体颗粒的界面处,使体系形成两相复合体.少量的Ag掺杂可以明显提高自旋相关散射产生的晶界磁电阻.掺Ag为30%摩尔比时,样品的电阻率较低掺杂样品的电阻率降低一个数量级,在300K、0.5T磁场下,磁电阻明显增强,达到9.4%,这与颗粒母体界面结构的改善有关,也与材料电阻率的降低有关.     

含丙磺舒高分子药物纳米微球的制备

非甾体抗炎药丙磺舒与甲基丙烯酸 2 羟乙酯 (HEMA)反应制得含丙磺舒单体HP ,此单体在乙醇 /水体系中与甲基丙烯酸甲酯 (MMA)共聚得到含丙磺舒高分子药物纳米微球 ,聚合产物用1H NMR ,FTIR ,GPC和TEM进行了表征。结果表明HP中丙磺舒以酯键连接到甲基丙烯酸 2 羟乙酯上 ,微球由HP和MMA的共聚物构成 ,平均直径为 ( 90± 5 )nm ,含丙磺舒 4 7 4 % ,含药量较高。     

有机共沉淀-火焰原子吸收光谱法测定高纯稀土氧化物中痕量铅镉钴镍铁铜

本文研究了吡咯啶二硫代氨基甲酸铵(APDC)共沉淀痕量铅镉钴镍铁铜的最佳条件;金属-PDC配合物的稳定性及共存元素的干扰等。沉淀溶解于小体积的甲基异丁酮(MIBK)中,采用微量进样技术,将有机相直接喷入空气-乙炔火焰,原子吸收光谱法测定之。该法已成功地应用于荧光级氧化镧和氧化钇中题示元素的测定。     

Banach空间奇摄动非线性微分方程的边值问题

对Banach空间中奇摄动非线性微分方程的边值问题，当空间弱序列完备时，证明存在单调序列{vn}和{un}分别一致收敛于两点边值问题的最大解和最小解．