Analysis of the Structure of Thin Films of Zn‐Porphyrins by the Kinetics of the Fluorescence Anisotropy

The structure of thin films of Zntetraoctylphenylporphyrin (ZnTOPP) obtained by the spinning method is investigated. The kinetics of the decay of the fluorescence anisotropy of the films is analyzed in the form of a sum of exponents and by simulating the orientation of ZnTOPP complexes on the substrate (quartz) surface with allowance for the processes of the electron excitation energy transfer. The ZnTOPP films have a lamellar structure where individual layers form ordered domains. Within a domain, linear nonintersecting stacks of molecules are formed. In each stack the planes of the molecules are collinear, oriented perpendicularly to the surface of the substrate base, and form an angle of 45° with the directing axis of a stack.     

Determination of the Elemental Composition of Chalcogenide Powders by the X‐Ray Fluorescence Method

A procedure of xray spectral fluorescence analysis of the elemental composition of As _x S_100–x chalcogenide powder samples is developed and its metrological characteristics are established. In determining the content of the components in an As₅₀S₅₀ sample, the relative standard deviation was 0.0030 for As and 0.0035 for S. The results of the xray spectral fluorescence analysis are in good agreement with the data of a gravimetric method.     

Spectral Differences of the Molecule-ion Adducts of β-Cyclodextrin and Lithium Carbonate

分别在磁力搅拌、水热和研磨条件下制得了碳酸锂和β-环糊精的三个加合物1、2和3．粉末X射线衍射和傅立叶变换红外显示了三个加合物的形成信息及其谱学差异．SEM提供了它们不同于β-环糊精的表面结构．热重和微分热重显示这些加合物在热稳定性上存在着较大差异．     

The Opacity of the Solar Spectral Lines of CII 133.5 nm

Because the intensity ratio between two spectral lines arising from the same upper level can depend on opacity, we determine the optical depth of the solar atmosphere CII emission at about 133.5 nm. By introducing the measured abundance of carbon and the results of ionization balance calculations, we estimate the line-of-sight physical thickness of the regions emitting CII lines at about 133.5 nm. This discussion will be significant in the analysis of the solar spectrum.     

Evaluation of the Intensities of Spectral Lines under the Influence of Interferences and the Determination of Global Maxima of the Mass–Spectrum Peaks

We describe the technique by which the intensity of spectral lines can be evaluated and the global maxima of the mass–spectrum peaks under the influence of pulse interferences can be defined using an experimental setup based on a commercial MX–7304A mass spectrometer, IBM personal computer (PC), and a digital extremum regulator that allows one to ignore local extrema and bring about automatic search for a global maximum of the mass–spectrum peak and its tracking with an accuracy of 0.0012% at a speed of response of 50 kHz, elevated speeds of the scanning of masses 500 amu/sec, and stability of regulation.     

Spectral‐Polarization Contrasts in the Problems of Remote Sensing

The results of the investigation of the angular and spectralpolarization characteristics of 4501080nm radiation reflected from the surfaces of natural (leaves of trees, bark) and artificial (colored smooth surface, fabric) objects are discussed. Based on a study of the contrasts between these characteristics, we have determined the most informative spectralpolarization characteristics and the spectral and angular intervals the use of which in remote optical observations of objects would allow their most effective discrimination.     

Modeling of Lidar Sounding of Meteorological Parameters of the Atmosphere in the Spectral Region of 2 μm

Results of the numerical modeling of lidar sounding of meteorological parameters of the atmosphere by the differential absorption method in the spectral region of 2 m are reported. A choice of the steam absorption lines suitable for sounding temperature and moisture content profiles in the lower troposphere is made. Systematic errors in reconstruction of temperature profiles are analyzed. It is shown that the errors in reconstruction of temperature and moisture content profiles have acceptable values within the entire range of heights 0–2 km.     

Spectral–kinetic characteristics of the F2 laser transition

A theoretical model for the F₂(D–A) laser transitions is built. The model includes a scheme of the main laser transitions proposed. A value of the radiative lifetime of the upper laser level in the conventional kinetic models of the F₂ laser is proved to be underestimated by one order of magnitude. A general theory of steady-state light amplification in a molecular laser with non-equilibrium vibrational distribution is developed. Relations of the small-signal gain and the saturating energy flux with parameters of molecular electronic–vibrational kinetics are established. The theory is applied to explain properties of F₂ laser amplifiers. PACS 31.70.Hq; 42.55.Lt     

Root Asymptotics of Spectral Polynomials for the Lamé Operator

The study of polynomial solutions to the classical Lamé equation in its algebraic form, or equivalently, of double-periodic solutions of its Weierstrass form has a long history. Such solutions appear at integer values of the spectral parameter and their respective eigenvalues serve as the ends of bands in the boundary value problem for the corresponding Schrödinger equation with finite gap potential given by the Weierstrass $\wpThe study of polynomial solutions to the classical Lamé equation in its algebraic form, or equivalently, of double-periodic solutions of its Weierstrass form has a long history. Such solutions appear at integer values of the spectral parameter and their respective eigenvalues serve as the ends of bands in the boundary value problem for the corresponding Schr?dinger equation with finite gap potential given by the Weierstrass -function on the real line. In this paper we establish several natural (and equivalent) formulas in terms of hypergeometric and elliptic type integrals for the density of the appropriately scaled asymptotic distribution of these eigenvalues when the integer-valued spectral parameter tends to infinity. We also show that this density satisfies a Heun differential equation with four singularities.     

Renormalization of the Asymptotically Expanded Yang–Mills Spectral Action

We study renormalizability aspects of the spectral action for the Yang–Mills system on a flat 4-dimensional background manifold, focusing on its asymptotic expansion. Interpreting the latter as a higher-derivative gauge theory, a power-counting argument shows that it is superrenormalizable. We determine the counterterms at one-loop using zeta function regularization in a background field gauge and establish their gauge invariance. Consequently, the corresponding field theory can be renormalized by a simple shift of the spectral function appearing in the spectral action.     

Spectral Complex for Controlling the Parameters of the Plasmachemical‐Reactor Working Medium

An automated spectral complex for controlling the parameters of the plasmachemicalreactor working medium by the emission and absorption spectra in the 200–1100 and 2000–5000nm ranges has been developed. To record radiation, a CCD array and a pyroelectric detector are used. Control of the spectral device functions, data recording, and the obtaining of results reflecting the workingmedium parameters and the concentration in it of components being measured are carried out by means of a personal computer. The complex makes it possible to study the temporal behavior of the workingmedium parameters being measured with a resolution of up to 10^–2 sec.     

Study on the Relationship between the Depth of Spectral Absorption and the Content of the Mineral Composition of BiotiteSCIEI北大核心CSCD

The mineral composition of rock is one of the main factors affecting the spectral reflectance characteristics, and it' s an important reason for generating various rock characteristic' spectra. This study choose the rock samples provided by Jet Propulsion Laboratory (JPL) (including all kinds of mineral percentage of rocks, and spectral reflectances range from 0. 35 to 2. 50 Elm wavelength measured by ASD spectrometer), and the various types of mineral spectral reflectances contained within the rocks are the essential data. Using the spectral linear mixture model of rocks and their minerals, firstly, a simulation study on the mixture of rock and mineral composition is achieved, the experimental results indicate that rock spectral curves using the model which based on the theory of the linear mixture are able to simulate better and preserve the absorption characteristics of various mineral components well. Then, 8 samples which contain biotite mineral are picked from the rock spectra of igneous, biotite contents and the absorption depth characteristics of spectral reflection at 2. 332 tan, furthermore, a variety of linear and nonlinear normal statistical models are used to fit the relationship between the depth of absorption spectra and the content of the mineral composition of biotite, finally, a new simulation model is build up with the Growth and the Exponential curve model, and a statistical response relationship between the spectral absorption depth and the rock mineral contents is simulated by using the new model, the fitting results show that the correlation coefficient reaches 0. 998 4 and the standard deviation is 0. 572, although the standard deviation using Growth and Exponential model is less than the two model combined with the new model fitting the standard deviation, the correlation coefficient of the new model had significantly increased, which suggesting that the new model fitting effect is closer to the measured values of samples, it proves that the simulation results of new model is closer to the measured value.     

Temperature Dependence of the Fluorescence Emission Intensity of Eu/TiO2 Nanocrystals

The samples of europium ions doped titanium dioxide （Eu^3＋/TiO2） nanocrystals are synthesized by a modified sol-gel method with hydrothermal treatment. The x-ray diffraction and scanning electron microscopy are used to characterize the sample. The temperature-dependent fluorescence emission effect of Eu^3＋-doped samples is investigated. It is found that under the excitation of 514.5nm light, the emission intensity of Eu^3＋ reaches a maximum value at 450K among various Eu^3＋ dopant concentrations in Eu^3＋ /TiO2 nanocrystals. The variation of the emission intensity may be attributed to the photon-assist absorption and the temperature-quenching effect.     

Spectral Theory of the Klein–Gordon Equation in Pontryagin Spaces

In this paper we investigate an abstract Klein–Gordon equation by means of indefinite inner product methods. We show that, under certain assumptions on the potential which are more general than in previous works, the corresponding linear operator A is self-adjoint in the Pontryagin space induced by the so-called energy inner product. The operator A possesses a spectral function with critical points, the essential spectrum of A is real with a gap around 0, and the non-real spectrum consists of at most finitely many pairs of complex conjugate eigenvalues of finite algebraic multiplicity; the number of these pairs is related to the ‘size’ of the potential. Moreover, A generates a group of bounded unitary operators in the Pontryagin space . Finally, the conditions on the potential required in the paper are illustrated for the Klein–Gordon equation in ; they include potentials consisting of a Coulomb part and an L _p -part with n ≤ p < ∞.Branko Najman: Deceased     

Spectral Analysis of the Disordered Stochastic¶1-D Ising Model

We consider the generator of the Glauber dynamics for a 1-D Ising model with random bounded potential at any temperature. We prove that for any realization of the potential the spectrum of the generator is the union of separate branches (so-called k-particles branches, k= 0,1,2,…), and with probability one it is a nonrandom set. We find the location of the spectrum and prove the localization for the one-particle branch of the spectrum. As a consequence we find a lower bound for the spectral gap for any realization of the random potential. Received: 22 September 1998 / Accepted: 12 February 1999     

Density Dependence of the Detailed Spectral Line Effects on the Opacity of Astrophysical Abundant Elements： oxygen

A full relativistic detailed-level-accounting approach has been developed independently to deal with the detailed spectral line effects on the opacity of the third most abundant element in stars: oxygen. The atomic energy levels and the oscillator strengths of the radiative transitions between the energy levels are obtained by carrying out the full relativistic one-configuration Dirac-Fock calculations. The photoionization cross sections are obtained via an average atom scheme with a consideration for the splitting of the ionization threshold due to the ionization stages and the term-couplings. As an example, the spectra resolved opacities and the mean opacities of oxygen are calculated to show the importance of the detailed spectral line profiles with the density of the matter.     

Spectral density of the radiation excited by the field of a β particle in a diamondlike nanofilm

The generation of photon polaritons by a field of a moving ?? particle is numerically simulated. These polaritons are localized in a crystal nanofilm with a diamondlike structure. Expressions for the spectral density of the radiation excited by the field of a charged particle in a quasi-two-dimensional film are deduced.     

Spectral Fluctuations of Schrödinger Operators Generated by Critical Points of the Potential

Starting from the spectrum of Schrödinger operators on ${\mathbb R}^nStarting from the spectrum of Schr?dinger operators on , we propose a method to detect critical points of the potential. We argue semi-classically on the basis of a mathematically rigorous version of Gutzwiller's trace formula which expresses spectral statistics in term of classical orbits. A critical point of the potential with zero momentum is an equilibrium of the flow and generates certain singularities in the spectrum. Via sharp spectral estimates, this fluctuation indicates the presence of a critical point and allows to reconstruct partially the local shape of the potential. Some generalizations of this approach are also proposed.     

Possibility of Using the Effect of Radio‐Optical Resonance for Spectral Analysis of Radio Signals

The absorption spectrum of optically oriented Cs atoms which is induced by a train of radiofrequency pulses is compared to the spectral components of the radio field. Possibilities of using the results obtained in the development of widerange microwave spectrum analyzers of high resolution are indicated.     

Development of a Computer Program to Predict the β-Lactamase Activity on the Basis of Ampicillin Fluorescence Values

Decrease in ampicillin fluorescence values (Ex. 385 nM, Em. 460 nM) were correlated with the increase in the pUC 19 plasmid-encoded -lactamase activity of Escherichia coli DH5. The fluorescence data were then utilized for the development of a computer program in MS DOS Q BASIC to predict the -lactamase activity.