Enhanced Laser Cooling of Rare-Earth-Ion-Doped Composite Material

We predict enhanced laser cooling performance of rare-earth-ions-doped glasses containing nanometre-sized ultrafine particles, which can be achieved by the enhanucement of locai field around rare earth ions, owing to the surface plasma resonance of small metallic particles. The influence of energy transfer between ions and the particle is theoretically discussed. Depending on the particle size and the ion emission quantum efficiency, the enhancement of the absorption is predicted. It is concluded that the absorption are greatly enhanced in these composite materials, the cooling power is increased as compared to the bulk material.     

AFM Study on the Formation Mechanism and Microstructure of Ni Atomic Aggregates on Liquid Substrates

We study the formation mechanism and microstructure of nickel （Ni） atomic aggregates on the silicone oil surfaces by atomic force microscopy （AFM）. Initially, the deposited atoms nucleate and form the compact clusters on the liquid surfaces. Then they perform Brownian motion and adhere upon impact. Finally the branched aggregates are formed. The Ni aggregates exhibit granular structure. The mean size of the granularities in the aggregates is of the order of 10 nm and it decreases with the nominal film thickness. The experiment shows that the Ni aggregates perform a directional diffusion towards the sample edge. The interpretation for this phenomenon is presented.     

N-(4-羟基-苯基)-甘草次酸酰胺的合成

以18β-甘草次酸和4-氨基苯酚为原料,在N,N＇-二环己基碳二酰亚胺(DCC),1-羟基苯并三唑(HOBt)/4-N,N-甲基吡啶(DMAP),N-甲基吗啉(NMM)作用下合成了N-(4-羟基-苯基)-甘草次酸酰胺,通过DCC、DCC/HOBt催化有机酸形成酯、酰胺反应的历程解释了在DCC/HOBt催化体系中目标化合...     

一种近似测量换能器效率及其等效电参数的简易方法

本文提出了一种近似测量换能器效率的简易方法.在换能器负载对其共振频率影响不大的情况,利用换能器的等效电路,根据换能器效率的定义,推出了只依赖于频率及谐振时换能器两端电压与电流之间相位角的效率表达式,把测量阻抗的要求变成了测量相位角的要求,与导纳圆法比较,所用仪器简单,测量迅速,克服了导纳圆法中逐点测量及逼近的麻烦,为迅速分析换能器的性能提供了一条简单的测量途径.     

激光喇曼分光计超低杂散光测试中有关问题的探讨

本文根据激光喇曼分光计中超低杂散光测试的若干特殊问题提出了几点考虑。为了获得10~(-12)量级以下的杂散光测试限,文章重点就本实验所用的测试光源,前置单色器,光入射方式、分段减光方法及光电检测系统等问题进行了一些讨论,并给出了相应的实验结果。     

Condensation Behavior of Ag Aggregates on Liquid Surfaces

We report a condensation behavior of silver aggregates on silicone oil surfaces. The deposited Ag atoms diffuse and aggregate on the oil surface, and then form granular clusters and ramified islands. The apparent Ag coverage of the total area increases linearly with the nominal film thickness h for h 〈 0.9nm. However, the coverage exhibits a fluctuation behavior for 1.0 nm 〈 h〈 2.5 nm. It is found that the anomalous behavior of the coverage is resulted from a characteristic material condensation process in the aggregates.     

硒化前后电沉积贫铜和富铜的Cu(In1-xGax)Se2薄膜成分及结构的比较

采用电沉积法获得了接近化学计量比的贫铜和富铜的Cu(In1-xGax)Se2(CIGS)预置层,研究比较了两种预置层及其硒化处理后的成分和结构特性.得到了明确的实验证据证明,硒化后富铜薄膜中的CuxSe相会聚集凝结成结晶颗粒分散在表面.研究表明:在固态源硒化处理后,薄膜成分基本不变;当预置层中原子比Cu/(In+Ga)<1.1时,硒化后薄膜表面存在大量的裂纹;而当Cu/(In+Ga) >1.2时,可以消除裂纹的产生,形成等轴状小晶粒;富铜预置层硒化时蒸发沉积少量In,Ga和Se后,电池效率已达到6.8%;而贫铜预置层硒化后直接制备的电池效率大于2%,值得进一步深入研究.     

Fusion and fission solitons for the (2+1)-dimensional generalized Breor-Kaup system

With a projective equation and a linear variable separation method, this paper derives new families of variable separation solutions (including solitory wave solutions, periodic wave solutions, and rational function solutions) with arbitrary functions for (2+1)-dimensional generalized Breor-Kaup (GBK) system. Based on the derived solitary wave excitation, it obtains fusion and fission solitons.     

分期付款期权在基于教育基金保险的期权中的应用

文献[1]提出了一种基于教育基金保险的欧式看涨期权,它赋予合约持有人在约定时间以约定价格购买连续支付固定年限的教育年金保险的权利,本文在[1]的基础上进一步提出基于教育基金保险的分期付款期权,该期权进一步改进了基于教育基金保险的欧式看涨期权,它赋予期权持有人分期支付期权费的权利,而不是一次性支付期权费,经过首期期权费的支付,期权持有人可以在继续支付期权费以持有期权和中断期权费的支付让期权作废之间选择,这样就可以使投资者在必要的时候取消期权,从而避免无效成本支出.该期权更加方便于低收入家庭和欲将资本用于其它高回报的投资的家庭进行教育投资.本文用后向递推和二叉树方法的方法给出期权定价公式,并确定分期支付的期权费的范围.     

光导管系统自然通风效果的CFD研究

本文利用CFD方法对光导管系统的自然通风进行模拟,综合分析了在不同大小和方向的室外风速下,风帽结构、通风管长、管道间距及光导管直径对自然通风效果的影响,结果表明,H型通风末端结构具有较好的通风效果,管长、管道间距与通风量之间存在最小风量极值点,通风量随着管道直径的增加而增大,这些结果为具有自然通风功能光导管系统实用化提供了理论指导.