Ultrafast non-linear optical properties of Ge20As25Se55 chalcogenide films

The non-resonant third-order non-linear optical properties of amorphous Ge₂₀As₂₅Se₅₅ films were studied experimentally by the method of the femtosecond optical heterodyne detection of optical Kerr effect. The real and imaginary parts of complex third-order optical non-linearity could be effectively separated and their values and signs could be also determined, which were 6.6 × 10⁻¹² and −2.4 × 10⁻¹² esu, respectively. Amorphous Ge₂₀As₂₅Se₅₅ films showed a very fast response in the range of 200 fs under ultrafast excitation. The ultrafast response and large third-order non-linearity are attributed to the ultrafast distortion of the electron orbitals surrounding the average positions of the nucleus of Ge, As and Se atoms. The high third-order susceptibility and a fast response time of amorphous Ge₂₀As₂₅Se₅₅ films makes it a promising material for application in advanced techniques especially in optical switching.     

Investigation on the barrier height and inhomogeneity of nickel silicide Schottky

The apparent Schottky barrier height (SBH) of the nickel silicide Schottky contacts annealed at different temperatures was investigated based on temperature dependence of I-V characteristic. Thermionic emission-diffusion (TED) theory, single Gaussian and double Gaussian models were employed to fit I-V experimental data. It is found the single Gaussian and double Gaussian SB distribution model can give a very good fit to the I-V characteristic of apparent SBH for different annealing temperatures. Also, the apparent SBH and the leakage current increase with annealing temperatures under reverse voltage. In addition, the homogeneity of interfaces for the samples annealed at temperatures of 500 and 600 °C is much better than that of the samples annealed at temperatures of 400, 700, and 800 °C. This may result from the phase transformation of nickel silicide due to the different annealing temperatures and from the low Schottky barrier (SB) patches.     

Corrigendum to the paper ``Adjoining an Order Unit to a Matrix Ordered Space'

An error has been detected (and also corrected) in Theorem 2.8 of the paper entitled “Adjoining an Order Unit to a Matrix Ordered Space” (Positivity, (2005)9: 207–223; DOI ). Accordingly, some of the results of the paper have been modified. Also, a notion of C*-matricially, Riesz normed spaces has been introduced.     

充分发挥计算机辅助教学作用

本文就计算机在物理实验方面的辅助教学进行了较为深刻的研究和探索，并提出可行性的方案。     

氙灯泵浦新型晶体Nd∶S－VAP调Q激光器腔内倍频研究

采用氙灯泵浦晶体Ｎｄ∶Ｓ－ＶＡＰ，ＫＴＰ晶体腔内倍频，实现了Ｎｄ∶Ｓ－ＶＡＰ晶体０．５３２５μｍ绿光激光ＢＤＮ染料片调Ｑ运转。测量了输出绿光激光的特性及不同腔长和染料片小信号透过率情况下的输出能量及脉冲宽度，给出了染料片调Ｑ腔内倍频的耦合波方程组，数值求解方程组，所得的理论数据与实验结果很好地相符     

陡前沿脉冲产生的受激布里渊散射稳定性研究

受激布里渊散射转换效率及相位共轭保真度的稳定性与泵浦脉冲的前沿上升时间有关，对前沿上升时间与介质声学声子寿命接近的泵浦脉冲，在泵浦能量超过受激布里渊散射阈值较多时，会造成严重的相位共轭保真度不稳定。本文针对上升前沿时间为２ｎｓ的泵浦脉冲及声学声子寿命的１ｎｓ和ＣＣｌ４介质，在泵浦脉冲前沿根部引入缓慢上升的小信号后，采用振放双池受激布里渊散射相位共轭镜，在泵浦激光能量达到５００倍受激布里渊散射阈值时     

A GENERAL FORM OF THE INCREMENTS OF A TWO-PARAMETER WIENER PROCESS

In this paper,we consider a general form of the increments for a two-parameter Wiener process.Both the Csorgo-Revesz‘s increments and a class of the lag increments are the special cases of this general form of increments.Our results imply the theorem that have been given by Csorgo and Revesz(1978),and some of their conditions are removed.     

Sr1-xLaxTiO3的高温高压合成及XPS研究

 利用高温高压方法合成了有稀土元素La掺杂的钙钛矿氧化物Sr_1-xLa_xTiO₃。XRD测试表明，在x≤0.5时，样品基本为单相，呈立方相；晶胞体积随x的增加而增加，在x=0.4时开始减小。XPS测量发现，样品中存在Ti离子的变价。讨论了Ti离子价态的变化对晶格参数的影响。     

球上加权Bergman空间上的Schatten类Hankel算子

本文给出了超球上加权Ｂｅｒｇｍａｎ空间上Ｈａｎｋｅｌ算子属于Ｓｃｈａｔｔｅｎｐ－类（２≤ｐ＜＋∞）的一个充要条件，推广了文［１０］中的主要结果。