Linear Relations, Differential Inclusions, and Degenerate Semigroups

A generalized linear differential equation in a Banach space is studied. The construction of a phase space and solutions with the help of the spectral theory of linear operators, ergodic theorems, and degenerate semigroups of linear operators is carried out.     

波长检测技术在温度测量中的应用

提出一种波长检测技术实现温度测量的方法,利用FBG传感器对温度等物理量实施监测,具有测试精度高,应用场合不受限制等特点,当环境参数发生变化时,光纤光栅的有效折射率和光栅周期会受到影响,将引起光纤光栅峰值波长的偏移,依据反射光谱结构的变化,可知道其温度的变化趋势。实验测试结果表明,在温度变化0.1°,波长变化1pm,温度和波长具有良好的线性关系。     

傅里叶变换红外光谱仪遥测污染云团的吸收光谱算法

遥感傅里叶变换红外光谱技术因其具有对污染源作无干扰监测、多组分的同时连续测定、区域性或大范围地区的测量等优点,因而已广泛的应用于遥感测量技术。利用傅里叶变换红外(FTIR)光谱仪远距离探测目标,根据探测的目标源是否充满光谱仪的视场,建立了三种辐射模型。在所建立模型的基础上,选用了D&P公司生产的便携式Model-101型傅里叶变换红外光谱仪,实时探测目标云团和背景,运用差谱法和发射光谱法对探测结果进行了光谱分析,进而得到了扣除背景影响后的目标云团吸收光谱。给出了相应的仿真实验结果示例。实验结果表明,由差谱法得到的结果准确度较好。     

Ⅰ类超晶格势阱中能级分布及电子跃迁规律研究

在研究大量实验曲线的基础上,指出势阱所有能级均有一定的宽度,电子或空穴在各能级中出现的概率符合正态分布,从理论上分析了I类超晶格和双势垒单势阱的发光光谱与吸收光谱·解释了GaAs/Ga1-xAlxAs多量子阱和超晶格吸收光谱吸收边及量子阱变窄时各吸收峰的“蓝移现象”及GaAs/Ga1-xAlxAs双势垒单量子阱样品的电流—电压特性曲线及电导—电压特性曲线的特征和出现的“负阻效应”·     

Sequential nonlinear estimation with nonaugmented priors

How can the basic compatibility of theory and observations be investigated for nonlinear processes without requiring stochastic characterizations for residual error terms? The present paper proposes a flexible least-cost approach. For each possible estimatex for the sequence of process states, letc _D (x) andx _M(x) denote the costs incurred for deviations away from the prior dynamic specifications and prior measurement specifications, respectively. Define the cost-efficiency frontier to be the greatest lower bound for the set of all possible cost pairs [c _D (x),c _M(x)], conditional on the given observations. State sequence estimatesx that attain the cost-efficiency frontier indicate the possible ways that the actual process could have developed over time in a manner minimally incompatible with the prior dynamic and measurement specifications. An algorithm is developed for the exact sequential updating of the cost-efficient state sequence estimates as the duration of the process increases and additional observations are obtained.     

Nd∶NaR(WO_4)_2晶体生长(R=Bi,Y)

采用提拉法生长出了掺钕钨酸铋钠[Nd∶NaBi(WO4)2,简称Nd∶NBW]和掺钕钨酸钇钠[Nd∶NaY(WO4)2,简称Nd∶NYW]晶体,并给出了制备无开裂优质Nd∶NBW和Nd∶NYW晶体的最佳生长工艺参数。从XRD分析得到Nd∶NBW和Nd∶NYW晶体的晶胞参数,并分析了晶体的拉曼光谱,认为二者结构基本相同,为四方晶系、白钨矿结构、I41/a空间群。由吸收光谱可以看出,Nd∶NBW在802nm有较强的吸收峰,Nd∶NYW在804nm、752nm、586nm附近有较强、较宽的吸收峰,二者均适合于LD泵浦;计算了晶体中Nd3+的吸收截面积。     

非参数回归函数之改良基于分割的估计的强相合性（英）

设(X,Y),(X1,Y1),…,(XnYn)为取值于 Rd× R的 i．i．d．随机变量,E(|Y|) ＜∞．设mn(x)为回归函数m(x)=E(|Y|X=x)基于分割的估计,本文在对mn(x)进行改良的条件下得到改良的基于分割的强相合估计．     

偏硅酸钙中Pr3+的4f5d态的光谱特性及Pr3+→Gd3+的能量传递

合成了高效发射UV光的CaSiO3:Pr^3 新型荧光体，研究了室温下Pr^3 的4f5d态的发射和激发光谱，Pr^3 的4f5d态的最低子能级向4f^2组态的^3H4，^3H6和^1G4能级跃迁产生UV发射，并不伴随有4f-4f能级跃迁的可见光发射。Pr^3 的浓度猝灭是由于辐射和无辐射能量传递造成的，同时，在CaSiO3中，存在Pr^3 →Cd^3 的能量传递，探讨了其能量传递特性。     

On a recursive method for the estimation of unknown parameters of partially observed chaotic systems

We investigate a recently proposed method for on-line parameter estimation and synchronization in chaotic systems. This novel technique has been shown effective to estimate a single unknown parameter of a primary chaotic system with known functional form that is only partially observed through a scalar time series. It works by periodically updating the parameter of interest in a secondary system, with the same functional form as the primary one but no explicit coupling between their dynamic variables, in order to minimize a suitably defined cost function. In this paper, we review the basics of the method, and investigate its robustness and new extensions. In particular, we study the performance of the novel technique in the presence of noise (either observational, i.e., an additive contamination of the observed time series, or dynamical, i.e., a random perturbation of the system dynamics) and when there is a mismatch between the primary and secondary systems. Numerical results, including comparisons with other techniques, are presented. Finally, we investigate the extension of the original method to perform the estimation of two unknown parameters and illustrate its effectiveness by means of computer simulations.     

高性能ZnO纳米块体材料的制备及其拉曼光谱学特征

利用六面顶高压设备制备了高密度、低脆性、纳米级的ZnO块体材料，用MDI/JADE5 X射线衍射仪(Cu靶)和XL30S-FEG场发射扫描电子显微镜对高压样品的相组成、晶粒尺寸及微观形貌进行了表征.利用E55+FRA106/5傅里叶变换激光拉曼光谱仪通过ZnO块体样品位于50—500cm^-1之内的拉曼光谱, 研究了极性半导体纳米材料的拉曼光谱学特征.发现在极性半导体ZnO纳米块体材料中，没有出现明显的尺寸限制效应. 关键词： ZnO纳米块体 拉曼光谱 尺寸限制效应