立方SrZrO3电子结构和光学性质的研究

采用基于密度泛函理论（DFT）框架下广义梯度近似平面波超软赝势法,计算了立方SrZrO3的电子结构和光学性质。计算结果表明立方SrZrO3为间接带隙钙钛矿型复合氧化物,计算得到的最小带隙为3.33eV。计算并分析了立方SrZrO3的复介电函数、复折射率、吸收系数、反射率、损失函数和光电导率,计算得到静态介电常数为3.40,折射率为1.86,吸收系数的最大峰值为468431.8cm1,反射峰的最大值为0.472,理论计算结果与其他文献结果基本一致,并利用分子轨道理论解释了立方SrZrO3电子结构和光学性质之间的关系,这为立方SrZrO3的应用提供了理论参考数据。     

Ge-Ⅲ亚稳相光学性质的第一性原理研究

采用基于密度泛函理论的第一性原理方法研究了Ge-Ⅲ亚稳相的电子结构和光学性质。Ge-Ⅲ相晶体是一种直接带隙半导体（带隙为0.46 eV）。对光学函数的计算表明,Ge-Ⅲ相晶体是一种具有高介电常数和高折射率的晶体。其静介电常数ε1（0）和静态折射率n（0）分别为33.9和5.82,大于相应的Ge-Ⅰ相晶体的值（16和4.0）。光子能量在2.38-14.9 eV（等离子体能量Ep）范围内,ε1（ω）〈0,整个晶体显示金属性;在高频透明区（能量大于Ep）,ε1（ω）〉0,显示介电性。从光吸收谱上看,Ge-Ⅲ相晶体的主要光吸收区位于整个可见光及部分紫外光谱区,在能量为4.51eV处达到最大值2.77×10^5cm^-1。Ge-Ⅲ相晶体的透过率在0-0.46eV范围可达0.5,表明它可作为一种红外光学材料。在高能区（大于14.9 eV）,反射率随能量的增加而骤减,透过率随能量的增加急剧增大,整个晶体表现出紫外透过的特征。能量损失谱上只有一个特征峰位于14.9 eV,对应于Ge-Ⅲ相晶体的等离子体能量。     

反钙钛矿晶体Sc3AlN电子结构和光学性质的第一性原理研究

采用基于密度泛函理论的第一性原理的分子动力学方法,对立方反钙钛矿Sc3AlN的电子结构和光学性质进行了计算．系统分析了Sc3AlN电子结构和成键情况,并利用计算的能带结构和态密度分析了Sc3AlN的介电函数实部和虚部以及由它们派生出来的光学常数,即折射率、反射谱、吸收谱、光电导率和能量损失函数等．计算结果表明Sc3AlN属于导体材料,其价带主要由Al的2s2p,Sc的3d态电子构成,导带主要由Sc的3d态电子构成,静态介电常数ε1（O）=22．1,折射率n（0）=4．7．     

F覆盖度对石墨烯体系电子结构和光学性能的影响

为了研究不同F覆盖度下石墨烯吸附体系的电子结构和光学性能,采用第一性原理对本征石墨烯和石墨烯吸附体系进行了几何优化,计算并分析了各体系的吸附能、能带结构、电子态密度、光吸收系数与反射率.结果表明,F原子稳定吸附在石墨烯的顶位,当F覆盖度为6.2%时,体系吸附能最大.F原子的吸附打开了石墨烯的能隙,使其由半金属型转变为半导体型.当F覆盖度为3.1%时,体系能隙值最大.与本征石墨烯相比,石墨烯吸附体系在费米能级处的电子态密度值增大,当F覆盖度为9.4%时,可以获得最大态密度值.石墨烯吸附体系的光吸收系数和反射率峰值相比本征石墨烯均明显减小,且F覆盖度越大,峰值减小程度越显著.在一定波长范围内吸附体系的吸收系数和反射率均出现蓝移现象.     

铟对Bi2Te3光电性质的影响

采用基于第一性原理的密度泛函理论平面波超软势法,对InxBi2-xTe3晶体的电子结构进行了模拟计算.系统分析了形成能、能带结构、电子态密度以及复介电函数.计算结果表明：在In的比例x小于0.4的范围内,InxBi2-xTe3仍属于半导体材料,但从直接能隙变为间接能隙,能隙宽度也随着In增加而减小.     

Mn掺杂c-ZrO2电子和光学性质的第一性原理研究

基于DFT+U第一性原理计算,预测了过渡金属锰（Mn）掺杂立方氧化锆（c-ZrO₂）体系的电子和光学性质。当c-ZrO₂中的Zr原子被Mn原子取代后,体系的电子态密度图表明体系的带隙减小,同时价带顶的电子密度明显增加使得价带展宽约5%。在自旋向上通道中,费米面附近的电子密度源于Mn 3d电子与O 2p电子的强烈混合,使得掺杂体系具有半金属铁磁性能,这也可能是引起体系带隙减小的原因。本研究还表明,通过Mn掺杂,体系折射率明显增加,在约为2.8 eV 低能区域形成新的坡度陡峭的光吸收峰,这一发现使Mn掺杂c-ZrO₂用作光吸收材料成为可能。通过Zener双交换机制解释了体系的铁磁性能,该理论也曾用于解释其他化合物;同时也探讨了体系的电子结构和光学性质之间的联系。     

Electronic and optical properties of anion-doped c-ZrO_2 from first-principles calculations

Using the first-principles calculations based on density functional theory（DFT）,the structure stability,electronic and some optical properties of C and N doped cubic ZrO2（c-ZrO2） in 24-atom systems were investigated.It is found from the formation energies calculations that N ions are easier to be doped into c-ZrO2 than C ions.The electronic structure results show that Zr8O15C and Zr8O15N systems are semiconductors with the band gap of 2.3 eV and 2.8 eV,respectively,which are lower than that of the pure ZrO2（3.349 eV）.And optical properties results depict that anion doping,especially C adding,can enhance the static dielectric function,visible and ultraviolet light absorption and reflecting ability of c-ZrO2 crystal.     

含柠檬酸配体的钨氧配合物的合成、光谱及电子结构

报道了W／O柠檬酸配合物的合成及结构,并用元素分析、红外光谱、紫外-可见光谱、光电子能谱、核磁、热重-差热分析等手段进行了表征．而且还用EHMO方法研究了配合物的电子结构．解释了该类配合物的羧基红外振动峰是一宽峰且有劈裂的特点．     

Ce-Mg合金体系弹性性质与电子结构的第一性原理研究

为了探讨Ce-Mg体系金属间化合物的力学性质与其晶体结构相联系的微观机制,采用基于密度泛函理论的第一性原理计算方法,系统研究了3种立方Ce-Mg体系金属间化合物CeMg、CeMg2和CeMg3的电子结构和弹性性质。计算结果表明,CeMg3有最高的体模量和剪切模量,分别为41.1GPa和30.7GPa,CeMg2的体模量和剪切模量则在3种金属间化合物中最低,分别为35.1GPa和14.0GPa。CeMg、CeMg2和CeMg3均满足立方晶系力学稳定性要求,CeMg3与CeMg为脆性材料,而CeMg2为延性材料。各向异性性质分析表明,CeMg具有很高的弹性各向异性,而CeMg2的体模量、剪切模量以及杨氏模量尽管最低,但其显示出良好的各向同性性能。计算CO-HP及电荷密度分布揭示了Ce-Mg合金体系弹性性质的变化与体系中化学成键差异密切相关,晶体中Mg-Mg键较强的材料比晶体中Ce-Mg键较强的材料有着更好的延展性。     

Cu掺杂对氧化锡纳米晶结构、形貌及其光学性能的影响

以无机盐SnCl2 为原料 ,通过形成配合物前躯体制备了氧化锡及铜离子掺杂氧化锡纳米晶 .XRD表明两纳米晶体系均为金红石相SnO2 .通过对两纳米晶体系的TEM HRTEM微结构分析 ,发现掺杂体系的粒径有明显降低 ,而且颗粒边界也较未掺杂体系清晰 .通过对两纳米晶体系的紫外图谱的研究 ,发现Cu掺杂后SnO2 纳米晶的吸收带边发生红移 .且铜离子掺杂后导致体系的UV图谱中出现两激子峰     

Calculated structure, elastic and electronic properties of Mg2Pb at high pressure

The effects of high pressure on structure,elastic and electronic properties of the intermetallic Mg₂Pb were calculated by the first-principles plane wave pseudo-potential method in the scheme of density functional theory（DFT）within the generalized gradient approximation.The elastic constants and Debye temperature obtained at 0 GPa are in good agreement with the available experiment data and other theoretical results.The electronic properties calculated suggest that the electronic density of states（DOS）at the Fermi level decreases under high pressure.     

一种基于物理层的光纤收发器远程管理方法

提出了一种基于物理层的光纤收发器远程管理方法，通过控制单片机I／O管腿电平的高低变化，实现了光线收发器的远程差错检测和指示，提高了网络维护的效率，增加了设备的性能／价格比．     

First-principles study on mechanical properties of LaMg3 and LaCuMg2

Abstract： With the substitution of part Mg in LaMg3 by Cu, the elastic constants CH and C12 increase while C44 decreases, implying an enhanced Poisson effect and smaller resistance to 〈001〉（100） shear. Furthermore, the bulk modulus B increases, while the shear modulus G, elastic modulus E and anisotropie ratio A are reduced. The calculated Debye temperature of LaCuMg2 is lower, implying the weaker interaction between atoms in LaCuMg2. Then, the stress-strain curves in entire range and the ideal strength at critical strain are studied. The present results show that the lowest ideal tensile strength for LaMg3 and LaCuMg2 is in the 〈100〉 direction. The ideal shear strength on the 〈 1 ^-1 0〉（110） slip system of LaMg3 is greater than LaCuMg2. The density of states and charge density distribution are further studied to understand the inherent mechanism of the mechanical properties.     

First-principles Investigation of the Structural,Electronic and Elastic Properties of Al2Ca and Al4Sr Phases in Mg-Al-Ca（Sr） Alloy

First-principles calculations have been carried out to investigate the structural stabilities, electronic structures and elastic properties of Mg17Al12, Al2Ca and Al4Sr phases. The optimized structural parameters are in good agreement with the experimental and other theoretical values. The calculated formation enthalpies and cohesive energies show that Al2Ca has the strongest alloying ability, and Al4Sr has the highest structural stability. The densities of states （DOS）, Mulliken electronic populations, and electronic charge density difference are obtained to reveal the underlying mechanism of structural stability. The bulk modulus, shear modulus, Young＇s modulus, and Poisson＇s ratio are estimated from the calculated elastic constants. The mechanical properties of these phases are further analyzed and discussed. The Gibbs free energy and Debye temperature are also calculated and discussed.     

The effect of hydrogen on the electronic structure of kink in bcc iron

The electronic structures of kinks in the [100](010) and 1/2[111](−110) edge dislocations in bcc iron containing hydrogen are investigated by means of the first-principles DMol method and the discrete variational method. The effects of hydrogen on the kinks are discussed. The results show that hydrogen forms weak bonding states with its neighboring host atoms, and since hydrogen draws charge from its neighboring host atoms, the interactions between most of the host atoms are weakened compared with those of the corresponding atomic pairs in the clean kinks. This indicates that the migration of kink, i.e. the motion of dislocation, is easier in the doping hydrogen kink than in the clean kink, which may be the solid solution softening effect resulting from the impurity hydrogen. Supported by the National Basic Research Program of China (Grant No. 2006CB605102) and Science Foundation of Central South University of Forestry & Technology (Grant No. 06y016)     

大型球面天线线馈源结构光机电综合设计研究

结合球面望远镜线馈源结构的特点,提出了一种球面望远镜线馈源结构的光机电一体化设计新方案,并对悬索结构的非线性静动力分析进行了初步探索．     

聚-氯对二甲基苯膜的制备与光学特性

以一氯对二甲基苯二聚体为原料,通过真空化学气相沉积法制备聚-氯对二甲基苯（Parylene C）膜,对该高分子膜材料的光学性能进行了研究。