混沌实验数据处理及仿真

大学物理实验中混沌实验大多采用观察现象的方法进行,本实验采用蔡氏电路(Chua s circuit)产生混沌行为.在观察不同初始值条件下出现的倍周期分岔、阵发混沌、奇异吸引子等相图及现象的基础上,通过对采集数据进行处理,对负电阻伏安特性进行分段线性拟合,用功率频谱法、计算机仿真方法(龙格-库塔数值积分法)对混沌现象进行描绘,将实验数据与非线性方程组的数值解相结合,呈现出混沌现象的本质.     

激光光源粒子计数器响应曲线对粒子折射率敏感度及多值性的分析

采用激光作光源的光学粒子计数器(L_OPC)克服了白炽灯作光源时使用寿命短、发光强度不稳定、需要经常标定的缺点,但激光波长的单一也带来了一些问题,如响应曲线对折射率敏感度的变化和多值性等问题。利用Mie散射理论,通过数值模拟实验,对L_OPC的这些问题进行了分析,提出了L_OPC实验样机的设计参数。     

ICP-AES测定镍基焊料中的磷

通过酸溶解试验、基体共存元素干扰实验等,建立了ICP-AES测定镍基焊料中高含量磷的分析方法.样品加标回收率为100.5%-101.0%,相对标准偏差小于0.80%.该方法简便、快速、准确可靠.     

对光谱快速定量分析的探讨

通过固定光谱校准曲线,压缩光谱谱带间隙,可降低测试成本,工作效率提高1.5倍,分析质量准确可靠.     

Nonlinear Effects for Bose Einstein Condensates in Optical Lattices

Cold atoms and, more recently, Bose-Einstein condensates （BEC＇s） in optical lattices have attracted increasing interest since their first realization. In particular, the formal similarity between the wavefunction of a BEC inside the periodic potential of an optical lattice and of the electrons in a crystal lattice has triggered theoretical and experimental efforts alike. Many phenomena from condensed matter physics, such as Bloch oscillations and Landau-Zener tunneling have been shown to be observable also in optical lattices. An important difference between electrons in a crystal lattice and a BEC inside the periodic potential of an optical lattice is the strength of the self interaction and hence the magnitude of the nonlinearity of the system. Electrons in a metal are almost noninteracting, whereas atoms inside a BEC interact strongly. A＇ perturbation approach is appropriate in the former case while in the latter the full nonlinearity must be taken into account. From this feature new physics is expected. Most experiments to date have been carried out in the regime of shallow lattice depth, for which the system is well described by the mean field Gross-Pitaevskii equation with a periodic potential. Moreover, the nonlinearity induced by the mean-field of the condensate has been shown, both theoretically and experimentally, to give rise to instabilities in certain regions of the Brillouin zone. These instabilities are not present in the corresponding linear system, i.e. the electron system. Experimental and theoretical results on the subject of nonlinear Landau-Zener tunneling and nonlinearity-induced instabilities in a Bose-Einstein condensate interacting with an external periodic potential will be presented.     

贝塞尔-高斯脉冲光束在色散介质中的时间和光谱特性

 对等衍射长度贝塞尔-高斯脉冲光束在色散介质中的时间和光谱特性作了研究，结果表明，通过选择适当的空间参数，贝塞尔-高斯脉冲光束沿轴上传输时，脉冲宽度不变。传输距离小于无衍射长度时，随衍射角增加，功率谱形状未变，脉冲波形保持不变；传输距离大于无衍射长度时，随衍射角增加，光谱由蓝移变为红移，脉冲展宽。     

8 mm回旋行波管和返波管的三折螺旋波纹波导色散分析

 三折螺旋波纹波导使TE11模和TE21模相互耦合，其色散曲线能够在宽频带内与电子回旋共振，因此需要对色散方程进行研究。提出了适合工程实用的行波模式和返波模式的色散方程，并对方程中的耦合系数进行了简化，误差在1%左右。利用CST软件的VBA语言对螺旋波纹波导进行建模和计算，根据模拟得到的传输特性曲线的特点，提出一种模拟方法，将模拟与理论计算得到的色散曲线作对比，误差在5%左右。     

一种在弱酸性介质中有电化学发光性能的鲁米诺衍生物

报道了一种鲁米诺的衍生物-3-(1-乙酰丙酮偶氮)苯二甲酰肼在酸性介质中的电化学发光行为,该化合物与鲁米诺类似,发生两步电化学氧化反应,但其氧化电位较鲁米诺低约0.5V,在氧化铟锡玻璃电极上具有良好的电化学发光性能,有效地避免了氧化铟锡玻璃电极本身的发光干扰.不仅在碱性介质中具有较高的电化学发光效率,而且在酸性介质中也产生较稳定的电化学发光,在1.0×10-6mol/L以上浓度,电化学发光强度与浓度有良好的线性关系.     

K_(1,n)-free图具有给定性质的[a,b]-因子的一个充分条件

图G称为K1,n-free图,如果它不含K1,n作为其导出子图.对K1,n-free图具有给定性质的[a,b]-因子涉及到最小度条件进行了研究,得到一个充分条件.     

Σ-原子能级的理论计算与分析

通过对Σ-原子的理论分析,数值求解了相应的Dirac方程,得到 了一组Σ-原子的能级值,与实验数据相当吻合;其结果连同K-原子的情况支持了Batty 光学模型势在奇异原子中应用的正确性,进而表明核子间的强相互作用力为吸引力.