转动喇曼散射截面的群论计算

本文利用群链U(4)U(3)O(3)描述双原子分子N_2和O_2振转谱的对称性质,并利用群论方法计算了N_2和O_2分子转动喇曼散射的跃迁矩阵元,给出了它们的转动喇曼散射的截面。结果与实验较好地符合。     

关于自同构作用下的不变元

文章主要讨论了代数（环）、（双）Ｈｏｐｆ代数中自同构作用下不变元素的性质，得到一些新的结果：设Ａ是有限维半单代数，则ＡｕｔＡ作用下的不变元属于中心，并且举出反例说明这个性质不能一般化到有限维代数、有限维半单（双）Ｈｏｐｆ代数．     

FFT动态相位重建算法的滤波窗影响分析

为了优化相位重建算法,针对波面干涉图的傅里叶频谱,分析了不同滤波窗口的分布特征和频谱响应,通过计算机仿真和实验测试,确定了FFT动态相位重建算法的最佳滤波窗口类型。其中处理仿真干涉图重建的波面与原始波面的波面峰谷值残差为0.008 5λ,波面均方根值残差为0.000 1λ;处理实验干涉图获得的波面与移相干涉测量法获得的波面峰谷值残差为0.009 3λ,波面均方根值残差为0.000 5λ。结果表明:选取Hamming窗进行滤波处理并重建的相位经拟合后得到的波面较参考波面的面形残差最小,相位重建精度优于0.01λ,可进一步应用于大口径光学元件的测量中。     

摆臂式三点光学镜面支撑系统的研究

提出了一种摆臂式三点光学镜面支撑系统,分析了其结构原理和工作性能,给出了实现的方法和制造工艺。该支撑系统具有结构简单、刚度恒定以及无附加温度应力等特点,可用于中小型光学镜面和光学元件的支撑,特别适用于空间仪器的光学加工领域。     

Effect of water vapour on particulate matter emission during oxyfuel combustion of char and in situ volatiles generated from rapid pyrolysis of chromated-copper-arsenate-treated wood

This paper reports the effect of water vapour on particulate matter (PM) during the separate combustion of in situ volatiles and char generated from chromated-copper-arsenate-treated (CCAT) wood at 1300 °C. Combustion of in situ volatiles produces only PM with aerodynamic diameter?<1?µm (i.e., PM₁), dominantly PM with aerodynamic diameter?<0.1?µm (i.e., PM_0.1). Water vapour could significantly enhance the nucleation, coagulation and condensation of fine particles and reduce the capture of Na and K by the alumina reactor tube via reduced formation of alkali aluminates, leading to increases in both yield and modal diameter of PM_0.1. Water vapour could also enhance char fragmentation hence increase the yield of PM with aerodynamic diameter between 1 and 10?µm (i.e., PM_1–10) during char combustion. For trace elements, during in situ volatiles combustion, volatile elements (As, Cr, Ni, Cu and Pb) are only presented in PM₁ and water vapour alters the particle size distributions (PSDs) but has little effect on the yields of these trace elements. During char combustion, As, Cr, Cu and Ni are present in both PM₁ and PM_1–10 while the non-volatile Mn and Ti are only present in PM_1–10. Increasing water vapour content increases the yields of As, Cr, Cu, Ni, Mn and Ti in PM_1-10 due to enhanced char fragmentation. During char combustion, water vapour also originates less oxidising conditions locally for enhancing As release, promotes the generation of gaseous chromium oxyhydroxides and inhabits the production of NiCl₂ (g), leading to increased yields of As and Cr and decreased yield of Ni in PM_0.1.     

Raman Scattering Tensors in Biological Molecules and Their Assemblies

INTRODUCTION

The tensor associated with a Raman band plays an important role in determining the band intensity and its structural significance. Each Raman tensor interrelates two electric vectors, that of the exciting radiation (i.e. laser photon) and that of the Raman scattered radiation (i.e. the inelastically scattered photon which results from the exchange of a vibrational quantum between the exciting photon and the molecule). The Raman tensor is obtained formally as the first derivative of the molecular polarizability tensor, the derivative being taken with respect to the vibrational normal coordinate. In other words, the Raman tensor associated with a vibrational Raman band is an indicator of how the polarizability of the molecule oscillates with the molecular normal mode of vibration.     

土壤金属元素近红外光谱定量校正模型适应性初步研究

为研究土壤金属元素近红外光谱定量校正模型适应性,采用近红外光谱结合偏最小二乘算法,针对风干土壤中的K,As,Hg,Cu,Zn,Pb,Cr,Cd元素,在剔除异常值后,建立定量校正模型;并对风干、烘干处理的外部验证集样品分别预测上述元素含量。结果表明,风干外部验证集样品的预测值-参考值相关系数皆大于相应烘干外部验证集样品的预测值-参考值相关系数;风干外部验证集各元素的预测值-参考值均具有显著的相关关系,烘干外部验证集中K,Hg,Cr的预测值-参考值之间不具有显著的相关关系。对土壤金属元素近红外光谱定量校正模型的适应性进行了初步研究,可为土壤中金属元素快速定量监测方法以及农产品产地环境监测等提供一定的参考。     

Determination of 25 elements in the complex oxide mineral zirconolite by analytical electron microscopy

In this paper we describe a technique for the determination of 25 elements in natural zirconolite using energy-dispersive analytical electron microscopy (AEM). The method presented here allows one to quantitatively investigate the chemistry of submicron-scale zones in complex oxide minerals. The effects of electron channeling, thickness variability and variations in detector resolution were minimized by using a controlled set of operating procedures and instrument parameters. To provide a high level of accurayy, k_ATI-factors were determined from standards for most of the 25 elements of interest, including all of the major elements. Each analytical spectrum is reduced to a set of raw peak counts (and errors) using a digital top-hat filter to suppress background followed by multiple least squares fitting of reference spectra. Counting times of 12–15 min per analysis were required to provide suitable counting statistics. Results are presented for zirconolite samples from the contact metamorphic aureole of the Bergell granodiorite intrusion, Switzerland-Italy. A comparison of 43 AEM analyses with 15 analyses obtained by wavelength-dispersive electron probe microanalysis (EPMA) shows that there is excellent agreement between the two data sets in the amounts of individual elements present, chemical trends and overall stoichiometry. An assessment of the combined data set shows that the major substitution mechanisms in the Bergell samples are coupled substitutions involving the M5,6- and M8-sites of the zirconolite structure: ^M8Ca²⁺ + ^M5,6Ti⁴⁺→^M8REE³⁺ + ^M5,6(Al,Fe)³⁺ and ^M8Ca²⁺ + ^M5,6Ti⁴⁺→^M8(Th,U)⁴⁺ + ^M5,6 (Mg,Fe)²⁺.     

两种土壤中五种有毒元素的研究

本文通过对五种有毒金属（Pb,Hg,As,Cd,Cr)被土壤吸附后分配系数及形态变化的测定,对它们在土壤中的量变和质变规律进行了探讨,从而为推论其吸附机理和防止地下水及农作物污染等方面提供了科学依据。     

微波消解ICP-MS法测定根和根茎类生药中11种微量元素

建立了微波消解技术ICP-MS法测定了根及根茎类生药中的铬、锰、镍、钴、铜、锌、砷、硒、钼、镉和铅11种微量元素的方法。对同时适用于两类生药的各微量元素分析的前处理方法进行了研究,从消解体系、酸用量、消解程序等几方面对微波消解条件进行了优化,为同类生药的消解提供了参考。方法检出限为0.001～0.260 μg·g-1,相对标准偏差为0.4%～3.1%,回收率为90%～110%。