淀粉—g—PGMA与甘氨酸反应产物对金,钯,铬,镉的吸附性能

淀粉改性官能团化作为金属离子的吸附剂用于废水处理已有报道,但吸附效果不理想,应用范围受限制。本文将玉米淀粉接枝甲基丙烯酸缩水甘油酯共聚物(Cs-g-PGMA)与甘氨酸反应,得到Cs-g-PGMA-Gly作为吸附剂,可以去除水中的Cd~(2 )、Cr~(3 )等有害元素,而且在适当的pH条件下还可富集分离Au~(3 )、Pd~(2 )。     

嵌入多孔硅中的C60分子的发光行为

1990年团簇C60分子分离的成功[1],立即引起了科学界的极大重视,有关C60分子的超导电性、光谱特性以及电子能级结构的研究报道与日俱增,由于单个C60分子是直径为7.1Å的球形分子,因而在某种程度上对于由C60分子聚集而成的具有几个纳米尺寸的CBO微晶的体系应该也具有类似于半导体超微粒低维量子限域的物理特性.     

一种实用的多功能的函数拟合程序

研制了函数拟合程序.本程序主要特点在于可键盘或联机输入实验数据.利用计算机图示功能,手动、或自动拟合,以寻求最佳。本系统能打印出拟合后各参数的最佳值。并能在数字绘图仪上分别画出实验数据和理论曲线或光谱分解后的各分立子谱带。     

不同链长二元分子卟啉酞菁(TTP－O－(CH2)n－O－Pc的三阶光学非线

利用简并四波混频(DFWM)方法测量二元分子卟啉酞菁的三阶非线性极化系数X(3)值。得到二元分子卟啉酞菁的X(3)值比它们单元分子卟啉、酞菁的X(3)值大,二元分子卟啉酞菁的X(3)值起初是随链长的增加而增加(Xn=3(3) >Xn=2(3)),链长增至n=3时,X(3)值达到最大值。当链长进一步增加时,二元分子卟啉酞菁的(X(3)值反而下降(Xn=3(3)>Xn=4(3) >Xn=5(3))。这同二元分子中卟啉、酞菁分子由柔性链连接有关。本文对结果给出可能的解释。     

Aa—Bb,Cc,Dd缩聚反应的固化理论

本文讨论了A_a-B_b,C_c,D_d缩聚反应.给出了溶胶-凝胶分配公式、凝胶化条件、分布函数和适合固化全过程的高分子矩的循环公式,以及k次矩的解析表示式.     

Promoted dehydrogenation in ammine lithium borohydride supported by carbon nanotubes

In this paper, ammine lithium borohydride (LiBH(4)·NH(3)) was successfully impregnated into multi-walled carbon nanotubes (CNTs) through a melting technique. X-ray diffraction, scanning electron microscopy, Brunauer-Emmett-Teller, and density measurements were employed to confirm the formation of the nanostructured LiBH(4)·NH(3)/CNTs composites. As a consequence, it was found that the dehydrogenation of the loaded LiBH(4)·NH(3) was remarkably enhanced, showing an onset dehydrogenation at temperatures below 100 °C, together with a prominent desorption of pure hydrogen at around 280 °C, with a capacity as high as 6.7 wt.%, while only a trace of H(2) liberation was present for the pristine LiBH(4)·NH(3) in the same temperature range. Structural examination indicated that the significant modification of the thermal decomposition route of LiBH(4)·NH(3) achieved in the present study is due to the CNT-assisted formation of B-N-based hydride composite, starting at a temperature below 100 °C. It is demonstrated that the formation of this B-N-based hydride covalently stabilized the [NH] groups that were weakly coordinated on Li cations in the pristine LiBH(4)·NH(3)via strong B-N bonds, and furthermore, accounted for the substantial hydrogen desorption at higher temperatures.     

Copper-mediated cyanation of aryl halide with the combined cyanide source

A simple copper-mediated cyanation of aryl halide with the combination of ammonium bicarbonate and N,N-dimethylformamide as a cyanide source is achieved, providing nitriles in moderate to good yields. This new approach represents an exceedingly practical and safe method for the synthesis of aryl nitriles.     

The palladium-catalyzed cyanation of indole C-H bonds with the combination of NH4HCO3 and DMSO as a safe cyanide source

A palladium-catalyzed cyanation of the 3-position of indole sp(2) C-H bonds by the combination of NH(4)HCO(3) and DMSO as the "CN" source was achieved to provide aromatic nitriles in moderate to good yields with excellent regioselectivity. It represents a practical and safe cyanation method.     

Electronic properties investigation of silicon supersaturated with tellurium

Hall measurements as a function of temperature and current–voltage (I–V) measurements have been used to study the electronic properties of silicon supersaturated with tellurium (Te). The samples were fabricated by ion implantation, followed by thermal annealing at different temperatures in N₂ and by rapid quenching. The experiment results show that the effects on the resistivity and on the Hall effect of samples implanted with high doses of Te are almost insensitive to temperature. This is not consistent with those of low dose Te implanted samples. The dark I–V characteristics and white light I–V characteristics of the junction between the high dose Te implanted layer and the substrate were also investigated. The pn junctions of samples with non equilibrium dopant concentrations exhibit decreased rectification, but increased photon to electron conversion efficiency.     

苯丙氨酸锂催化醛和胺以及三甲基硅腈三组分的Strecker反应(英文)

以苯丙氨基酸锂为催化剂,成功催化了醛、胺和三甲基硅腈三组分的Strecker反应,并结合一系列氨基酸盐催化剂的筛选以及各种溶剂的选择优化了反应条件.结果表明,利用所述反应可以得到较高收率的α-氨基腈;该三组份的Strecker反应具有反应条件温和、反应收率较高、操作简便、无需繁琐的分离步骤、催化剂便宜且环境友好等优点.