BiOCl/AgCl复合材料可见光光催化活性和稳定性研究

采用化学共沉淀法合成BiOCl/AgCl复合催化剂,利用XRD、SEM、XPS、ICP、DRS、EIS等表征对所制备的样品进行了分析,通过在可见光下降解甲基橙(MO)来评价催化剂的催化活性和稳定性,结果表明与纯AgCl相比,BiOCl/AgCl复合催化剂具有较好的光催化活性和稳定性,这是因为BiOCl的复合既能加速电子的转移,提高光生电子-空穴对的分离率,又能够有效地抑制AgCl在光催化反应过程中的溶解.     

SOLITON EXCITATIONS IN A DIATOMIC LATTICE WITH NONLINEAR ON-SITE POTENTIAL

We consider the soliton excitations in a diatomic chain with nonlinear on-site potential based on a quell-discreteness approximation, Different from the theoretical approach devel-oped before, our method is valid in the whole Brillouin zone of phonons. The gap solitons observed recently in a nonlinear diatomic pendulum lattice can be well explained qualita-tively. It is also shown that if the wave number of the carrier wave is near the edge of the Brillouin zone, the results coinside with that of Kivshar and Flytzanis about the gap solitons in diatomic lattices when the difference of mass between two kinds of atoms becomes small.     

计及表面张力的非传播孤波理论

本文研究了表面张力对非传播孤波运动的影响,对Larraza和Putterman的理论进行了修正。发现表面张力使孤波横向振动频率范围增大,振幅增高,宽度减小。当表面张力系数a=0时,结果与Larraza和Putterman的理论相一致。     

水杨醛缩苯胺锌及其薄膜的谱学性能

合成了一种新型的发光材料水杨醛缩苯胺锌(SAZ),利用真空热蒸镀制备了高质量、纳米级薄膜,利用红外光谱、差热-热重谱、X射线衍射谱、UV-Vis吸收谱、荧光光谱研究了水杨醛缩苯胺锌及其薄膜的结构、晶态、热稳定性以及光学特性,并利用循环伏安法、UV-Vis吸收谱确定了该材料的能级结构。结果表明,水杨醛缩苯胺锌无定性薄膜具有较高的热稳定性,在紫外光激发下产生绿色荧光,色纯度高, 亮度高。水杨醛缩苯胺锌薄膜在大气环境下存放,荧光衰减比8-羟基喹啉铝快,但受紫外光照射时,荧光衰减比8-羟基喹啉铝慢。水杨醛缩苯胺锌的HOMO能级为-5.659 eV,LUMO能级为-3.054 eV,禁带宽度为2.604 eV。     

Numerical simulation for separation of multi-phase immiscible fluids in porous media

Based on a lattice Boltzmann method and general principles of porous flow, a numerical technique is presented for analysing the separation of multi-phase immiscible fluids in porous media. The total body force acting on fluid particles is modified by axiding relative permeability in Nithiarasu＇s expression with an axiditional surface tension term. As a test of this model, we simulate the phase separation for the case of two immiscible fluids. The numerical results show that the two coupling relative permeability coefficients K12 and K21 have the same magnitude, so the linear flux-forcing relationships satisfy Onsager reciprocity. Phase separation phenomenon is shown with the time evolution of density distribution and bears a strong similarity to the results obtained from other numerical models and the flows in sands. At the same time, the dynamical rules in this model are local, therefore it can be run on massively parallel computers with well computational efficiency.     

利用(麥曲)霉淀粉酶测定粮食作物皮壳中淀粉含量的改进方法

一、前言粮食中淀粉之測定方法,随着含淀粉量多少的不同而一般采用如下两种方法: (1)酸分解法(即酸化法); (2)酶分解法(即酵素法)。前者适用于含淀粉量較高的原料,如玉米、高粱、谷子、糜子、荞麦、莜麦等粮食作物。后者适用于含淀粉量較低的原料,特别是粮食作物皮壳,如稻糠、高粱糠、谷糠和一些野生植物原料等。     

TEMPORAL OPTICAL SOLITONS VIA MULTISTEP χ(2) CASCADING

We consider a multistep χ⁽²⁾ cascading for light pulses with the dispersion of the system taken into account. Using the method of multiple scales we derive a set of coupled envelope equations governing the nonlinear evolution of the fundamental, second and third harmonic waves involved simultaneously in two nonlinear optical processes, i.e. second harmonic generation and sum frequency mixing. We show that three-wave temporal optical solitons are possible in three-and four-step cascading in the presence of a group-velocity mismatch between different pulses.