微扫描技术对光电图像混淆噪声的影响

在分析采样理论和微扫描理论的基础上,引入了一个评价光电成像系统混淆噪声的品质因数,定量地分析了不同模式的微扫描对系统混淆噪声的改善程度。     

掺铒光纤放大器中上转换过程的影响

掺杂浓度的提高影响了掺铒光纤放大器(EDFA)的性能,对经典Giles模型提出了新的要求。首先研究了高掺杂下铒离子距离较小引起的上转换过程的机理,通过优化速率方程模型分析了上转换过程对EDFA的影响,得出了在泵浦光和信号光远远大于ASE光的假设下泵浦光和信号光沿光纤长度变化的近似表达式,并将该近似分析解与解析解进行了比较。仿真结果表明上转换过程会降低随光纤传输的信号光和泵浦光,影响EDFA的放大性能,并得出了当掺铒浓度大于2.95×1025m-3时,上转换过程的影响不能忽略的结论。     

Si中30度部分位错弯结运动特性的分子模拟

首先使用分子动力学方法(MD)得出了左弯结(LK)和右弯结(RK)在不同温度和剪应力作用下的速度特性和运动过程.然后利用基于紧束缚势(TB)的nudged elastic band(NEB)方法计算LK和RK的迁移势垒.由计算结果得出,单个LK或RK的势垒很高,运动速度相对较慢;LK中的多弯结对结构和由RK分解产生的右弯结-重构缺陷(RC)能够加速位错运动;其中,RC能促进30°部分位错更快地迁移.     

光谱对小球藻和等鞭金藻生长的影响

采用单色LED光源和荧光灯从效率和速率两个角度研究了光源光谱对海生小球藻和等鞭金藻8701生长的影响,结果表明,连续光谱能够促进较高的最大生长率,蓝光促进生长的效率较高,两者组合能够较好地兼顾效率和速率。为了定量描述光照中的光谱参量,引入光谱吸收系数,根据光源发射光谱和藻体吸收谱计算海藻对光源光谱的量子吸收效率,该系数与实验结果中相应的生长效率成正相关,能够初步以量化形式反映光谱与其生长效率的关系。     

Non-perturbative Aspects of QCD and Parameterized Quark Propagator

Based on the Global Color Symmetry Model, the non-perturbative Q, CD vacuum is investigated in the parameterized fully dressed quark propagator. Our theoretical predictions for various quantities characterized the QCD vacuum are in agreement with those predicted by many other phenomenologieal QCD inspired models. The successful predictions clearly indicate the extensive validity of our parameterized quark propagator used here. A detailed discussion on the arbitrariness in determining the integration cut-off parameter ofμ in calculating QCD vacuum condensates and a good method, which avoided the dependence of calculating results on the cut-off parameter is also strongly recommended to readers.     

Wigner Function and Phase Probability Distribution of q-Analogue of Squeezed One-Photon State

In this paper, in terms of the technique of integration within an ordered product （IWOP） of operators and the properties of the inverses of q-deformed annihilation and creation operators, normalizable q-analogue of the squeezed one-photon state, which is quite different from one introduced by Song and Fan [Int. 3. Theor. Phys. 41 （2002） 695], is constructed. Moreover, the Wigner function and phase probability distribution of q-analogue of the squeezed one-photon state are examined.     

Novel correction method for X-ray beam energy fluctuation of high energy DR system with a linear detector

A high energy digital radiography (DR) testing system has generated diverse scientific and technological interest in the field of industrial non-destructive testing. However, due to the limitations of manufacturing technology for accelerators, an energy fluctuation of the X-ray beam exists and leads to bright and dark streak artifacts in the DR image. Here we report the utilization of a new software-based method to correct the fluctuation artifacts. The correction method is performed using a high pass filtering operation to extract the high frequency information that reflects the X-ray beam energy fluctuation, and then subtracting it from the original image. Our experimental results show that this method is able to rule out the artifacts effectively and is readily implemented on a practical scanning system.     

超声波提取-火焰原子吸收光谱法测定金银花中的Fe、Cu和Pb

建立了湿法和超声波提取处理样品,火焰原子吸收光谱法测定金银花湿法消解液及超声波提取液中Fe,Cu和Pb元素含量的方法.金银花中3种元素的含量Fe＞Cu＞Pb,硝酸作为提取剂,提取元素的溶出率的大小:Cu＞Pb＞Fe,回收率为85％-107％,RSD为0.6-1.0％.结果表明,超声波提取能较好地提取金银花中微量元素,元...     

气相色谱法测定缩水甘油丁酸酯

采用气相色谱快速分析方法测定环氧氯丙烷反应体系中的缩水甘油丁酸酯.采用SE-30( φ3mm×1.5mm)填充柱,载气流量:48.86mL/min;柱温:100℃;气化室温度:185℃;热导检测器温度185℃;缩水甘油丁酸酯的量(x)与峰面积(y)有良好的线性关系; y=1594.1x+1370.1,R2=0.9993...     

新型红色荧光粉Na2Ca4(PO4)2SiO4:Eu3+,Bi3+的制备及发光特性

用高温固相法合成了用于白光LED的Na2Ca4(1-x-y)(PO4)2SiO4:xEu3+,yBi3+红色荧光粉.研究了助熔剂H3BO3、二次煅烧时间和稀土掺杂量等制备条件对样品发光性质的影响.结果表明,在1 200℃、助熔剂H3BO3加入量为样品质量的3.8%时可得到更有利于发光的α-NCPS基质,而且掺入Eu3+、Bi3+之后,基质的晶格结构没有发生明显变化;适宜的二次煅烧时间为1.5 h.Bi3+的共掺杂可以通过能量传递大幅提高Eu3+的发光强度,当Eu3+、Bi3+的摩尔分数分别为x=0.04和y=0.01时,粉体具有最强的红光发射.表明这种荧光粉是一种可很好用于近紫外芯片的白光LED的红色荧光粉.