Fe3O4@Ag纳米粒子的制备与表征

采用共沉淀法制备了Fe3O4纳米颗粒,并以之为原料利用晶种生长法进一步制备Fe3O4@ Ag复合纳米材料.利用紫外-可见吸收光谱和表面增强拉曼散射光谱对复合纳米材料的性能进行表征,显示Fe3O4@ Ag复合纳米材料具有良好的SERS活性.     

近红外吸收光谱技术快速检测奶制品中添加三聚氰胺

对奶制品中添加三聚氰胺的近红外吸收光谱快速检测技术进行了可行性研究。实验分别配置了8组不同三聚氰胺含量的纯牛奶样品,用FTIR光谱仪测量其吸收谱,并偏最小二乘法建立数学模型。研究结果表明,应用近红外吸收光谱技术可以对奶制品中添加三聚氰胺进行快速检测。     

正常和异常血清的共振散射光谱

用日本岛津RF-5301荧光分光光度计研究了高甘油三脂、高胆同醇、高血糖血清和正常血清的散射光谱及同一生化指标不同浓度血清散射光谱的规律.实验结果表明,正常血清散射光谱与高血脂和高血糖血清散射光谱的特征峰差异明显,可以据此区分正常和高血糖、高血脂血清;同一生化指标不同浓度血清散射光谱的峰值强度随血脂、血糖浓度的增大而增...     

自发喇曼成像法在线测量流场组分浓度（Ⅱ）

介绍了利用自发Raman散射光谱测量低压气流组分绝对浓度的方法，在流动状态下得到了不同压力的自发喇曼散射光谱，检测最低压力为133Pa；对于含N2氧气流在已知N2浓度时实时标定检测了O2的绝对浓度，测量误差小于8％。，     

表面增强拉曼光谱检测鸡蛋蛋清内三聚氰胺的定量方法研究

三聚氰胺对人体有害,鸡蛋内三聚氰胺定量检测非常有必要。以鸡蛋蛋清为研究对象,应用表面增强拉曼光谱技术结合化学计量学方法对蛋清内三聚氰胺进行了定量检测。首先采用人工饲养蛋鸡的方法获取含有三聚氰胺的样品鸡蛋。然后使用便携式拉曼光谱检测仪(Opto Trace RamTracer-200)和拉曼增强试剂测定蛋清的表面增强拉曼光谱,同时利用气相色谱质谱技术测定相应蛋清中三聚氰胺的含量。利用Raman Analyzer对拉曼光谱基线进行校正。应用相关系数法从表面增强拉曼光谱中选取320个光谱变量作为输入变量,建立偏最小二乘定量校正模型;并应用谱峰分解法建立谱峰分解定量校正模型。两种模型建立过程中均选定90个样本做为模型校正集,44个样本做为模型验证集,两种模型都有较好的预测效果。偏最小二乘定量校正模型预测值与气相色谱质谱联用法(GC-MS)测定值的决定系数R2为0.856,预测均方根误差RMSEP为1.547;谱峰分解定量校正模型R2为0.947,RMSEP为0.893。实验结果表明,该方法能有效定量检测鸡蛋内三聚氰胺,检测一个样本仅需15 min,为蛋品的三聚氰胺检测提供了一种新途径。     

一种血流变参数在体实时探测方法

介绍了一种新的在体实时监测血流变参数的光学方法——光散射法。设计了一种实用的同轴多光纤探针装置。在装置中间,其中一根光纤用于传输入射激光,周围多根光纤与中心光纤等间隔,用于接收血液中的散射光。用扫描法布里-珀罗干涉仪产生散射光谱。结果表明,用该装置测得了含成分的液体、实血和不同血液成分的光散射光谱。     

激光等离子体的受激Brillouin散射

 研究了激光等离子体背向和侧向受激Brillouin散射光谱结构。激光等离子体相互作用时,受激Brillouin散射光谱受激光等离子体状态的影响而产生Doppler效应。当激光以45° 入射不同材料的平面靶时,等离子体运动产生不同的二维效应,高Z材料产生的等离子体冕区主要沿靶法向运动,受激Brillouin散射光谱在侧向产生较大蓝移,而低Z材料则主要在激光入射方向产生较大蓝移。     

共振光散射法测定三聚氰胺

应用共振散射光谱技术建立三聚氰胺检测新方法。三聚氰胺可使甲醇体系在567nm处的共振散射光明显增强。在优化实验条件下,体系的ΔI值与三聚氰胺的浓度在0.7—16.0mg/L之间具有良好的线性关系,线性方程为ΔIRLS=40.53C(mg/L)-2.64,r=0.9993;检出限为0.21mg/L;样品加标回收率为92.6%—102.3%。方法灵敏,操作简便,分析成本低,用于奶粉中三聚氰胺的测定,结果满意。     

自发喇曼成像法在线测量流场组分浓度(II)

 介绍了利用自发Raman散射光谱测量低压气流组分绝对浓度的方法，在流动状态下得到了不同压力下的自发喇曼散射光谱，检测最低压力为133帕；对于含N₂氧气流在已知N₂浓度时实时标定检测了O₂的绝对浓度，测量误差小于8%。     

基于BRDF理论的散射光谱加和性研究

依据双向反射分布函数理论,推导出散射光谱的加和性原理。散射光谱加和性是指对于材质质点之间无相互作用的平面漫反射体系,在光源与入射面材质不存在干涉、衍射、荧光、光谱上转换和光谱下转换等相互转换作用,且无光化学现象及非线性效应发生的前提下,且符合能量守恒定律的同时,由单光源或多光源照射的材料的散射光谱,等于该材料中每种材质的散射光谱的线性叠加。实验上,以几种材料的散射光谱为例,通过改变探测条件、照明条件和材质比例,进行了散射光谱加和性的实验验证,并且针对实验结果进行了误差分析。单光源条件下的最大实验误差为2.64%,多光源条件下则为2.35%,加和计算偏差均在实验误差允许范围内。由此证明了材料的散射光谱具有加和性,不受组成的材质差异性、材质的面积比例组合多样性、以及实验条件多变性影响。散射光谱加和性的首次提出,不仅为基于散射光谱的复杂结构体的特征提取及识别研究提供了确切的理论依据和有效的分析方法,而且对相关的实验分析和应用研究有着重要的借鉴和参考意义。     

Radionuclides in deposition in the Ignalina NPP region in 2005

Results of radionuclide activity concentration measurements in deposition and ground-level air conducted at the station of the Institute of Physics situated 3.5 km from the Ignalina Nuclear Power Plant (Ignalina NPP) in 2005 are analyzed. Atmospheric depositional fluxes of ⁷Be, ⁶⁰Co and ¹³⁷Cs are estimated. Radionuclide particle deposition rates are calculated. The Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model of the global dispersion and deposition is used to explain variations in the ¹³⁷Cs activity concentration in the ground-level air in the Ignalina NPP region in 2005. An increase in the ¹³⁷Cs activity concentration of up to 17.4 μBq m⁻³ on 30 October-5 November is studied. Modelling results show that the Chernobyl NPP Unit 4 Sarcophagus and the radiocaesium resuspension from the Chernobyl NPP accident polluted regions are sources of ¹³⁷Cs to the environment of the Ignalina NPP. Results on solubility in water of aerosols — carriers of ¹³⁷Cs — are discussed.     

Universal scaling in BCS superconductivity in three dimensions in non-s waves

The solutions of a renormalized BCS equation are studied in three space dimensions in s, p and d waves for finite-range separable potentials in the weak to medium coupling region. In the weak-coupling limit, the present BCS model yields a small coherence length and a large critical temperature, , appropriate for some high- materials. The BCS gap, , and specific heat as a function of zero-temperature condensation energy are found to exhibit potential-independent universal scalings. The entropy, specific heat, spin susceptibility and penetration depth as a function of temperature exhibit universal scaling below in p and d waves. Received: 18 July 1997 / Revised: 8 September 1997 / Accepted: 29 September 1997     

Thermal convection in Rivlin-Ericksen elastico-viscous fluid in porous medium in hydromagnetics

The thermal instability of a layer of Rivlin-Ericksen elastico-viscous fluid in porous medium acted on by a uniform magnetic field is considered. For stationary convection, Rivlin-Ericksen elastico-viscous fluid behaves like a Newtonian fluid. The magnetic field is found to have stabilizing effect whereas medium permeability has destabilizing effect. The magnetic field introduces oscillatory modes in the system, A sufficient condition for the non-existence of overstability is also obtained.     

Fano-type features in magnetoabsorption in semiconductors

It is shown that bulk semiconductors exhibit strongly asymmetric Fano-type resonance profiles in magnetoabsorption processes involving the formation of hot electron-hole pairs (EHPs) and accompanied by the scattering of the EHPs by defects. This result is valid for transitions to electronic states with large Landau quantum numbers, when the Coulomb interaction plays a small role. The physical reason for such a sharp change in the magnetoabsorption coefficient as compared with the expected result for the ordinary density of states in a quantizing magnetic field is that the electronic excitations are quasi-one-dimensional. The form of the resonance absorption is in good qualitative agreement with the experimental data. Pis’ma Zh. éksp. Teor. Fiz. 63, No. 8, 619–622 (25 April 1996)     

Uncertainty in prediction and in inference

The concepts of uncertainty in prediction and inference are introduced and illustrated using the diffraction of light as an example. The close relationship between the concepts of uncertainty in inference and resolving power is noted. A general quantitative measure of uncertainty in inference can be obtained by means of the so-called statistical distance between probability distributions. When applied to quantum mechanics, this distance leads to a measure of the distinguishability of quantum states, which essentially is the absolute value of the matrix element between the states. The importance of this result to the quantum mechanical uncertainty principle is noted. The second part of the paper provides a derivation of the statistical distance on the basis of the so-called method of support.     

Supergravity in theory in 11 dimensions

We present the action and transformation laws of supergravity in 11 dimensions which is expected to be closely related to the O(8) theory in 4 dimensions after dimensional reduction.