ABeF_3(A=Na,K,Rb,Cs)体系中Eu~(2+)的f→f跃迁发射

合成了一系列Eu~(2+)激活的碱金属氟化物一氟化铍复合氟化物(ABeF_3∶Eu~(2+))磷光体。观察到了f→f跃迁引起的Eu~(2+)很强的锐线发射,尖峰位于360nm附近。随碱金属原子电负性减小,峰值向短波方向稍有移动。得到了与A.S.T.M一致的结晶学数据。穆斯堡尔谱和电子能谱结果表明,体系中有少许Eu~(3+)与Eu~(2+)共存。     

Effect of crystalline microstructure on the photophysical performance of polymer／perylene composite films

To obtain high carrier mobility, better charge injection capability, and high photovoltaic device conversion efficiency, a powerful strategy is to improve the morphology of the polymer/dye composite films. Conjugated conducting polymer (CP) thin films doped with perylene derivative (PV) of various concentrations were prepared by spin-casting method, and their morphology and photovoltaic characteristics were examined. The change in morphology and molecular reorientation occurring in CP-PV composite films upon annealing at different temperatures was investigated using scanning electron microscopy, x-ray diffraction, Fourier transform infrared and UV-vis absorption. By changing the annealing temperature, PV microcrystallines of 8－10μm in size lying parallel to the substrate surface can be obtained. Annealing effect improved the photovoltaic performance of ITO/CP-PV/Al Schottky-type solar cells, which can be attributed to the formation of an electron conducting PV crystal network. Preliminary studies indicate that the morphological structure in CP-PV composite films has an important influence to their photovoltaic properties.     

Impact of microsecond-pulsed plasma-activated water on papaya seed germination and seedling growth

The seed of Carica papaya consists of a hard shell-like testa with inhibitors in vivo causing slow, erratic and asynchronous germination. In this work, plasma-activated water prepared by microsecond-pulsed plasma jets (μPAW) was applied to treat papaya seeds. The μPAW after plasma activation of 30 min was about 40 ℃. The reactive species such as NO₂, NO₃, and H₂O₂ in the μPAW activated from deionized water were measured and correlated to the seed germination rate and the seedling growth performance. The μPAW-treated papaya seed achieved a higher germination rate of 90%, which is 26% higher than the control group using deionized water. Comparing the results with a hot water (40 ℃) reference group showed that the reactive species in μPAW played primary roles in germination improvement, with little effect caused by the heat shock. The μPAW also sterilized the treated seeds, reducing the germination stress. The morphological change in the seeds was observed by SEM, showing an effect of physical etching after treatment promoting seed imbibition. The biochemical mechanism of the seed germination was deduced with reference to the evolution of surface chemistry, functional groups, and ABA content. The accelerated seed metabolism observed was corresponded to the chemical modification pathway. Besides, early seedlings developed from treated seeds were observed to be healthy, grow more leaves, and have better root structures. The content of MDA in the treated papaya seedlings decreased along with increased SOD and higher ion concentration. The μPAW that can be prepared at atmospheric pressure for bulk production offers a low-risk and cost-effective seed priming technology that may significantly increase the production of agricultural crops.     

表面金属有机化学—表面担载的三钌乙烯酮化合物及其催化性能

本文利用原位红外光谱方法研究了三钌乙烯酮化合物在无机载体SiO_2、SiO_2-Al_2O_3和MgO表面上的负载,发现[Ru_3(CO)_9(CCO)]~(2-)分别同SiO_2和SiO_2-Al_2O_3表面上的羟基反应,选择性地定量形成[HRu_3(CO)_9(CCO)]~-/SiO_2和H_2Ru_3(CO)_9(CCO)/SiO_2-Ai_2O_3,而在MgO表面上,[Ru_3(CO)_9(CCO)]~(2-)保持其结构。对~(13)CO同位素交换,H_2Ru_3(CO)_9(CCO)/SiO_2-Al_2O_3显示了很高活性,而[Ru_3(CO)_9(CCO)]~(2-)/MgO则完全不反应。在甲基化反应中,[Ru_3(CO)_9(CCO)]~(2-)/MgO对CH_3I显示了很高活性,但对CH_3Li却不反应,对H_2Ru_3(CO)_9(CCO)/SiO_2-Al_2O_3,它与CH_3I不显示活性,但却和CH_3Li较易反应;[HRu_3(CO)_9(CCO)]~-/SiO_2的甲基化的活性顺序处于上述MgO和SiO_2-Al_2O_3担体上的簇合物之间。通过乙烯甲酰化反应可以看到,在(Ru_3(CO)_9(CCO)]~(2-)/MgO上,对于含氧化合物的形成显示了高活性,而对于H_2Ru_3(CO)_9(CCO)/SiO_2-Al_2O_3则有利于形成烃类化合物。     

离子注入法在表面化学研究中应用的新进展

一、引言离子注入法(Ion Implantation)是半导体材料掺杂工艺中常用的一种手段,特别是制作大规模集成电路,这是一种必不可少的方法。然而,近年来,这一方法已逐渐从半导体工艺中延伸并转移到了其他学科领域。尤其在固态化     

关于质点的直线运动一些问题的讲解

在质点的直线运动诸公式中,除时间以外的物理量,都是矢量。因此它们不仅具有大小而且具有方向。可是这些运动方程式,实际上是数量式,也即是一般的代数方程式,所以解法与代数方程式的解法完全相同。方程式中每一个物理量的大小用它们的绝对值表示。若物理量是矢量,则矢量的方向就以正号或负号表示。矢量的方向是这样规定的:当物体沿一直线运动时,若要确定它的即时速度,位置,加速度,必须在此直线上选定一固定的参考点为原点。如果我们规定质点自原点开始运动的方向为初速度的方向,并规定此方向为正。其它诸矢量(位移,加速度,即时速度)与初速度同向则为正,反向为负。根据以上概念我们分别研究匀速直线     

2,5-环己二烯酮类的固相光化学(Ⅱ)

本文报道了2,4,6-三叔丁基-4-甲氧基-2,5-环己二烯酮的固相光化学反应,所得三种产物的比率随温度而变化,而液相光化学反应与温度无关。用带有NaNO₂滤色液的光照射该化合物,几乎得到100％的列米酮。在列米酮中加入少量萘的固相光化学反应所得产物的比率随萘量而变化。