碱金属激光器问题分析与研究展望

 简要概述了半导体泵浦碱金属激光器(DPAL)的产生背景与独特优势,以其特性为基础、应用为导向,基于国内外最新进展分析了谱线匹配、连续稳定运转和提高输出功率这三大问题,并对新型复合受激态准分子宽带泵浦碱金属激光器(XPAL)的基本原理及优缺点进行了阐述。通过对碱金属激光器现有解决思路进行对比和总结,在能级理论和缓冲气体作用机理、泵浦机理和腔结构以及高功率定标放大等方面,对未来可能的研究方向进行了展望,以期突破DPAL相关技术瓶颈,实现高能量高光束质量的红外激光输出。     

新试剂1-（偶氮苯基）-3-（4,5-二甲氧基-2-苯甲酸）-三氮烯与铜（Ⅱ）的显色反应

研究了1-（偶氮苯基）-3-（4,5-二甲氧基-2-苯甲酸）-三氮烯（ABDMBAT）试剂与Cu（Ⅱ）的显色反应。在TritonX-100的存在下,pH 11.0的Na2B4O7-NaOH缓冲溶液中,该试剂与铜形成红色络合物,ABDMBAT与Cu（Ⅱ）形成的络合物的最大吸收峰位于540nm处,表观摩尔吸光系数ε=8.26×104L.mol-1.cm-1,Cu（Ⅱ）在0—14μg/25mL范围内服从比耳定律。     

中草药透骨草中4种微量元素的形态分析

按照传统煎煮法对中草药透骨草中铜、锌、铁、镁4种元素进行提取;用微孔滤膜分离提取液中的可溶态与悬浮态;利用大孔吸附树脂柱对可溶态中的有机态与无机态进行分离;采用火焰原子吸收光谱法对各种形态中的4种元素进行测定。结果显示,透骨草中4种元素的总提取率在44.03%—63.15%之间,浸留比在79.46%—188.80%之间,悬浮态颗粒吸附率在10%左右。     

传统粉笔字教学与多媒体教学的影响分析

多媒体技术进入大学课堂推动了教学的改革,也引发了人们的进一步思考:传统粉笔字教学和多媒体教学从哪些方面影响着教学过程和教学质量?本文通过抽样调查,获取有关数据资料,运用因子分析方法对调查数据进行分析,寻找影响教学的因子,然后利用方差分析检验各因素的显著性,最后利用Logistic回归分析方法建立教学方式选择模型,进一步分析影响教学的各因素,为教学方式的选择提供了理论依据。     

Effect of viscosity on stability and accuracy of the two-component lattice Boltzmann method with a multiple-relaxation-time collision operator investigated by the acoustic attenuation model

A two-component lattice Boltzmann method (LBM) with a multiple-relaxation-time (MRT) collision operator is presented to improve the numerical stability of the single relaxation time (SRT) model. The macroscopic and the momentum conservation equations can be retrieved through the Chapman—Enskog (C-E) expansion analysis. The equilibrium moment with the diffusion term is calculated, a diffusion phenomenon is simulated by utilizing the developed model, and the numerical stability is verified. Furthermore, the binary mixture channel model is designed to simulate the sound attenuation phenomenon, and the obtained simulation results are found to be consistent with the analytical solutions. The sound attenuation model is used to study the numerical stability and calculation accuracy of the LBM model. The simulation results show the stability and accuracy of the MRT model and the SRT model under different viscosity conditions. Finally, we study the influence of the error between the macroscopic equation of the MRT model and the standard incompressible Navier—Stokes equation on the calculation accuracy of the model to demonstrate the general applicability of the conclusions drawn by the sound attenuation model in the present study.     

Fabrication and measurement of traceable pitch standard with a big area at trans-scale

Atom lithography with chromium can be utilized to fabricate a pitch standard,which is directly traceable to the wavelength of the laser standing waves. The result of a calibrated commercial AFM measurement demonstrates that the pitch standard is(212.8±0.1) nm with a peak-to-valley-height(PTVH) better than 20 nm. The measurement results show the high period accuracy of traceability with the standing laser wavelength(λ /2 = 212.78 nm). The Cr nano-grating covers a 1000 μm×500 μm area, with a PTVH better than 10 nm. The feature width broadening of the Cr nanostructure has been experimentally observed along the direction of the standing waves. The PTVH along the Gaussian laser direction is similar to a Gaussian distribution. Highly uniform periodic nanostructures with a big area at the millimeter scale, and the surface growth uniformity of the Cr nano-grating, show its great potential in the application of a traceable pitch standard at trans-scales.     

Transmission time in the reflectionless complex potential

A phase time definition directly obtained from the Schr6dinger equation is used to investigate the time delay of a particle scattered by complex reflectionless potential. The artifacts introduced by truncating in the numerical simulation are clarified. The time delay of the transmitted wave packet is found to be equal to the reflection time of the truncated potential. Both time delays are the same as the traversal time in the free space, but shorter than the time taken by a classical particle to pass the same potential.     

N-烷基-DO3A钆(Ⅲ)螯合物的合成、稳定性与弛豫性能

钆(Ⅲ)螯合物;DO3A衍生物;稳定性;弛豫率     

条件密度置信区间的覆盖精度

本文用经验似然方法讨论了条件密度的置信区间的构造. 通过对覆盖概率的Edgeworth展开得到了经验似然置信区间的覆盖精度, 同时证明了条件密度的经验似然置信区间的Bartlett可修正性     

四元Mg0.9Ti0.1Ni0.9X0.1(X=Mn,Zn,Co,Fe)系列合金的制备及性能研究

用机械合金化法合成了Mg0.9Ti0.1Ni0.9X0.1(X=Mn,Zn,Co,Fe)系列合金.X射线衍射(XRD)结构分析表明,用X部分替代Ni后,促进了Mg0.9Ti0.1Ni合金的非晶化过程.用Co和Fe部分替代Ni提高了合金的放电容量,但却降低了合金的循环稳定性.用Zn和Mn部分替代Ni提高了合金电极的循环寿命,尤其是Mg0.9Ti0.1Ni0.9Zn0.1合金电极经10个充放电循环后,其放电容量仍可达到313.8mA.h/g.对添加Co后的合金进行p-c-T测试发现,Mg0.9Ti0.1Ni0.9Co0.1合金的吸放氢容量明显比Mg0.9Ti0.1Ni合金高,这与电化学所测到的结果一致.