直流电表的选择使用

测量仪器的准确度指测量仪器的示值接近真值的能力。     

仪器装备成高校竞争力新重点

现在高校实行排名，实验室装备如何是必须要看的硬件，已成为高校竞争力新重点。现在在仪器使用上，“冷热不均”的分化表现很明显，一些用于纯科学的基础研究设备使用率不高，存在一定程度的闲置浪费，而一些可以为工厂、企业服务的设备则是炙手可热。相关人士建议说，尽可能建立科学仪器的共用协作机制，使仪器走出以院所和部门的“深闺”，面向全社会按市场规律公开合理配置资源。这样一来，某些以高价买来的仪器就能养活自身，而那些不常用的仪器也能提高使用效率，避免重复购置。     

汞使用过程中的几个技巧

汞，俗称水银，由于它的比热小、密度大、具有金属光泽、不浸润性等特性，因而广泛应用于物理实验教学．笔者根据教学实践经验，对汞使用中遇到的问题，进行处理的技巧，介绍给同仁，不妨一试．     

家用微波炉

本文扼要叙述微波加热的基本原理，方法和特点，介绍微波炉箱的基本结构和烹调食品应注意的事项。     

Bidirectional Mapping between a Biphoton Polarization State and a Single-Photon Two-Qubit State

How to manipulate （operate or measure） single photons efficiently and simply is the basic problem in optical quantum information processing. We first present an efficient scheme to transform a biphoton polarization state to a corresponding single-photon state encoded by its polarization and spatial modes. This single-photon state carries both the information of the controlled and target photons. It will make the realization of bipartite positive- operator-valued measurements efficiently and simply. Moreover, the inverse transformation from the single-photon state back to the corresponding biphoton polarization state is also proposed. Using both the transformations, the realization of the arbitrary two-qubit unitary operation is simple with an M-Z interferometer. All the schemes are feasible with the current experimental technology.     

Cluster Consensus of Nonlinearly Coupled Multi-Agent Systems in Directed Graphs

We investigate the cluster consensus problem in directed networks of nonlinearly coupled multi-agent systems by using pinning control. Depending on the community structure generated by the group partition of the underlying digraph, various clusters can be made coherently independent by applying feedback injections to a fraction of the agents. Sufficient conditions for cluster consensus are obtained using algebraic graph theory and matrix theory and some simulations results are included to illustrate the method.     

Emission enhancement in Er^3＋/Pr^3＋-codoped germanate glasses and their use as a 2.7-μm laser material

Emission enhancement at 2.7 μm is observed in Er^3＋/Pr^3＋--codoped germanate glasses when pumped by a 980-nm laser diode. Significant reductions in 1.5-μm emission and upeonversion intensity indicate efficient energy transfer between Er^3＋ and Pr^3＋; the energy transfer efficiency is as high as 77.4%. The mechanisms of energy transfer are discussed in detail. The calculated emission cross-section of Er^3＋/Pr^3＋- codoped germanate glass is 8.44× 10 ^-21 cm^2, which suggests that Er^3＋/Pr^3＋-codoped germanate glass can be used to achieve efficient 2.7-μm emission.     

MgH分子X2Σ+,A2Π和B2Σ+电子态的势能函数

利用QCISD(T),SAC-CI方法和cc-pVQZ,aug-cc-pVTZ,6-311 G及6-311 G(3df,2pd)基组,对MgH分子的基态X2Σ ,第一简并激发态A2Π和第二激发态B2Σ 的结构进行优化计算.通过对4个基组计算结果进行比较,得出6-311 G(3df,2pd)基组为最优基组.使用6-311 G(3df,2pd)基组和QCISD(T)方法对基态X2Σ ,SAC-CI方法对激发态A2Π和B2Σ 进行单点能扫描计算,然后采用Murrell-Sorbie函数及修正的Murrell-Sorbie C6函数进行拟合,得到了相应电子态的势能函数参数和对应的光谱常数.计算结果表明,用修正的Murrell-Sorbie C6函数计算得到的MgH分子基态和第一简并激发态的光谱常数ωe,ωexe,Be,αe与实验数据吻合很好.表明修正后的Murrell-Sorbie C6函数能更为准确地描述MgH分子的基态和第一激发态的势能函数.     

验证感生电场存在的实验

针对磁场变化时激发产生的感生电场很难演示的问题,设计了演示感生电场存在的实验. 该实验将不同功能的仪器组合起来使用,通过亥姆霍兹线圈的交变磁场对带电粒子的作用效果,直观说明感生电场的存在.     

低速/微振动测量实验中的激光多普勒频移计算机测量方法

基于实验教学使用的迈克耳孙干涉仪开发出的低速/微振动测量实验系统,给出了一种激光多普勒频移的计算机自动测量方法,并通过大量的比较实验数据,验证了激光多普勒频移计算机自动测量方法的有效性.