Time—Resolved Photoluminescence Studies of AlInGaN Alloys

We study the two samples of AlInGaN,i.e.,1-μm Gan grown at 1030℃ on the buffer and followed by a 0.6μm-thick epilayer of AlInGaN under the low pressure of 76 Torr and the AlInGaN layer deposited diectly on the buffer layer without the high-temperature GaN layer,by temperature-dependent photoluminescence(PL) spectroscopy and picosecond time-resolved photoluminescence(TRPL) spectroscopy.The TRPL signals of both the samples were fitted well as a stretched exponential decay at all temperatures,indicating significant disorder in the material.We attribute the disorder to nanoscale quantum dots or discs of high indium concentration.Temperature dependence of dispersive exponent β shows that the stretched exponential decay of the two samples comes from dfferent mechanisms.The different depths of the localization potential account for the difference,which is illustrated by the results of temperature dependence of radiative recombination lifetime and PL peak energy.     

Moessbauer Investigation of the Ferromagnetic Coupling in Copper-Iron Polycyanides

One of the Prussian blue analogs, molecular magnet Cu3^Ⅲ [Fe^Ⅲ (CN)6]2.11.6H2 O, was investigated by Moessbauer spectroscopy. It was found that transition temperature was around Tc = 18.5 K from paramagnetic phase to ferromagnetic phase. The β value of the critical exponent is around 0.338 at magnetic ordering temperature.Therefore, the ferromagnetic coupling interaction of Cu-Fe cyanide could be clearly explained by spin wave theory.     

恐龙不同部位化石的激光拉曼光谱

应用波长为785nm的激光拉曼光对来自武定九厂地区的两个不同部位的恐龙化石样品研究测试,首次在1000 cm-1~1800 cm-1波数段得到碳氢物质的拉曼峰图谱。在该波数范围内,颈椎化石和尾椎化石都有强、弱两类特征峰。它们的强特征峰与源地关系不大,即同一地区的化石特征峰并不很相似。弱拉曼峰与围岩的拉曼峰相似。恐龙化石的强拉曼峰来源于生物遗体分解剩下的碳氢类物质成分,弱拉曼峰源于石化过程中外部填充物质的成分。     

An asymptotic solving method for the periodic solution of a class of disturbed nonlinear evolution equation

<正>A class of disturbed evolution equation is considered using a simple and valid technique.We first introduce the periodic traveling-wave solution of a corresponding typical evolution equation.Then the approximate solution for an original disturbed evolution equation is obtained using the asymptotic method.We point out that the series of approximate solution is convergent and the accuracy of the asymptotic solution is studied using the fixed point theorem for the functional analysis.     

肿瘤组织自体荧光光谱测量与分析

首先介绍了对人工培养鼠肿瘤组织的激光诱导荧光光谱的实验测量结果，并与同一机体正常组织的自体荧光光谱进行了比较，然后对肿瘤组织自体荧光的来源，与正常组织光谱特征差异的本质进行了详细分析，从而得出结论，生物组织自体荧光光谱能够反映肿瘤组织的特异性，可以作为组织诊断的依据。     

一种无磁低振微型同轴脉冲管制冷机

脉冲管制冷机与超导量子干涉仪耦合进行微弱磁场测量是脉冲管制冷机的一个主要应用方向。本文系统分析了脉冲管制冷机的主要干扰源并给出其相应的解决办法,并据此设计制造了一台无磁低振微型同轴脉冲管制冷机。以实现同轴脉冲管制冷机的低振动、低电磁干扰化,并最终实现利用脉冲管制冷机有效冷却包括高温超导量子干涉仪在内的对电磁干扰要求极严格的高温超导器件。     

均匀分层介质中标准矢量波函数的构成

研究了在均匀分层介质中构成标准矢量波函数的必要条件。研究结果表明在均匀分层介质中构成标准矢量波函数一般需遵循Morse-Feshbach判据外，领示矢量只能选取与折射率变化方向一致的那根坐标轴单位矢量。但在某些特定的条件下，对领示矢量的选取条件可以放宽为只需遵循Morse-Feshbach判据即可。     

磁场对重电子金属CeCu6-xNix低温电阻的影响

测量了重电子金属CeCu6-xNix（x=0,0.5,0.1)，在1.8k-300k温度范围的电阻及磁场对电阻的影响（H=0,5T,10T),实验表明样品电阻的极大值对应的温度Tmax随着掺Ni含量的增大向温度降低的方向移动,而加磁场后Tmax随磁场的增加向高温方向移动,中从Kondo相互作用和相干散射的角度对这一现象的物理机制进行了分析.     

荧光法研究β-环糊精(CD)体系中有机小分子对萘酚离解常数的影响

本文研究了 9种有机小分子存在下两种萘酚在 β CD超分子体系中的离解常数 (Kc)及不同有机小分子与 β CD、两种萘酚的相互作用。实验表明 :小分子的加入可有效改变 β CD空腔的极性。对 1 萘酚而言 ,KC 随乙腈、甲醇、乙醇、丁酮加入而减小 ;对 2 萘酚而言 ,KC 则随丁酮、乙腈、丙酮、乙二醇、正丁醇、甲醇的加入而增大。有机小分子与萘酚 / β CD包合物的作用机理可从形成氢键和溶剂效应得到合理的解释。