经光阑衍射的平顶涡旋光束位相奇点的演化特性

推导出了平顶涡旋光束通过有光阑ABCD光学系统的传输解析式,并以光阑透镜和矩形光阑系统为例,与平顶光束比较研究了截断参量、相对离轴距离和光束阶数对衍射场中位相奇点演化特性的影响.数值计算表明,平顶涡旋光束通过上述光学系统均存在位相奇点,即使源处涡旋被光阑阻拦时,衍射场中也会出现位相奇点;而平顶光束通过光阑透镜系统存在刃型位错,随着截断参量增大,会发生刃型位错的演化和湮灭现象,且平顶光束通过矩形光阑系统没有发现位相奇点.     

多光束法布里-珀罗干涉实验的计算机模拟简

用计算机数值计算的方法,模拟了法布里-珀罗多光束干涉实验的光强分布,并与双光束等倾干涉条纹进行了比较,分析了薄膜反射率对法布里-珀罗干涉实验的波长分辨率影响。     

Global well-posedness for a class of 2D Boussinesq systems with fractional dissipation

The incompressible Boussinesq equations not only have many applications in modeling fluids and geophysical fluids but also are mathematically important. The well-posedness and related problem on the Boussinesq equations have recently attracted considerable interest. This paper examines the global regularity issue on the 2D Boussinesq equations with fractional Laplacian dissipation and thermal diffusion. Attention is focused on the case when the thermal diffusion dominates. We establish the global well-posedness for the 2D Boussinesq equations with a new range of fractional powers of the Laplacian.     

磁场敏感性水凝胶研究进展

磁场敏感性水凝胶是一类由聚合物三维网络和磁性组分所构成的复合凝胶,其在药物控制释放、人工肌肉、酶的固定与蛋白质分离等领域具有良好的应用前景。本文综述了磁场敏感性水凝胶的制备方法及其在上述领域的应用。     

四甲基碳酸氢铵的合成研究

四甲基氢氧化铵(TMAH)是一种有机碱,因其在较低的加热温度下即可分解变为气体[1,2],作为催化剂来应用时不残留,所以在工业催化、科研及电子工业领域都有着极为广泛的应用.     

基于π-π相互作用合成星型聚丙烯腈-石墨烯复合材料

首先合成含有6个羟基的三亚苯衍生物,然后通过氧化还原引发体系合成了星型聚丙烯腈聚合物(SPAN),最后在星型聚丙烯腈的N,N-二甲基甲酰胺溶液(DMF)中用水合肼还原氧化石墨得到均一稳定的溶液。分别通过红外光谱(FT-IR)、核磁共振谱(1H-NMR)、凝胶渗透色谱(GPC)、扫描电镜(SEM)等对产物进行表征。结果表明,星型聚丙烯腈成功吸附到石墨烯表面。     

Firm behavioral response to multiple sources of risky cash flow

We extend previous research to demonstrate that risk-averse firms can appear to be risk-seeking when facing multiple sources of risky cash flow. While our model requires that cash flows from operations are independently, uniformly distributed, we are able to demonstrate that three previous derived results hold with multiple sources of risk. Using chance constrained programming, we demonstrate that binding probability constraints can cause (1) a higher degree of aversion to illiquidity to induce increased risk taking; (2) apparent risk-seeking behavior; and (3) an increase in endowment to lead to lower expected profit.     

基于飞轮储能的并网风电场有功功率及频率控制方法研究

为平缓风电场输出,实现大规模风电并网并参与系统的频率控制,设计了一个基于永磁同步电机的飞轮储能系统,利用飞轮储能系统的快速充放电能力实现了风电场并网有功功率与一次频率控制.研究了飞轮储能系统的参考功率计算方法,根据该参考功率的变化实现储能系统充放电运行状态的转化.在Matlab/Simulink中建立了该储能系统模型,进行了风电场并网的有功功率及频率控制仿真,仿真结果表明该方法可以有效地平缓风电场的有功功率输出,参与系统的一次调频.     

非线性发展方程混合问题解的爆破性质

讨论了具有第三类非线性边界条件的非线性发展方程的混合问题,并在已知函数满足某些假设的条件下,利用抛物型方程的最大值原理和凸性方法,证明了该问题的解在有限时间内爆破.     

Separation of injectable salidroside by column chromatography of macroporous resins for treating myocardial ischemia

The objective of the present study is to develop a method for large-scale separating and purifying salidroside from rhodiola kirilowii roots and for preparing injectable medicinal ingredient.Crude extract of salidroside was prepared by water-ethanol system,and purified by column chromatography of macroporous resins.Static adsorption and desorption studies were performed on six kinds of macroporous resins,and SP825 resin was chosen,followed by optimizing process parameters.The optimum sample volume,feed concentration,ratio of diameter to height,and feeding flow rate were 1.5 bed volumes(BV),15 mg/mL,1:10 and 1 BV/h,respectively.Dynamic desorption was performed consecutively with 8 BV of distilled water,3 BV of 5% ethanol and 8 BV of 10% ethanol at a flow rate of 2 BV/h.After three cycles in separating 3.5 tons of rhodiola kirilowii roots,salidroside purity was increased from 3.4% in the crude extract to 93.6% in purified salidroside product.This study provides a novel method to separate salidroside for injectable use.