Effect of Metal Cation on Absorption and Fluorescence Spectra of Metal Complexes of 8-Hydroxyquinoline∗

8-Hydroxyquinoline complexes of Na(I), Ca(II), Mg(II), Zn(II), Mn(II), Cu(II), Al(III), In(III) and La(III) are synthesized. Photoluminescence and UV-vis absorption spectra of them are reported. Except complexes of Cu(II), and Mn(II), these complexes show photoluminescence. With the increase of polarization force of metal cation, their photoluminescence peaks reveal red-shift and two broad absorption bands in UV-vis absorption spectra appear split and red-shift.

     

Recurrence Spectra of the Rydberg Hydrogen Atom near Two Parallel Metal Surfaces

Using closed orbit theory, we study the influence of the two parallel metal surfaces on the recurrence spectra of a hydrogen atom placed in the region between the two surfaces. The results show that the metal surfaces have significant effect on the photoabsorption process. Each resonance peak in the recurrence spectra is associated with one electronic closed orbit. In our work, we put the first metal surface at the critical value dc and vary the second metal surface. The results show that when the distances between the hydrogen atom and the two metal surfaces are close to the critical valuedc, the number of the closed orbits is the greatest and there are more peaks in the recurrence spectra. When the distance between the atom and the second metal surface is larger or smaller than dc, the number of the closed orbits decreases and there are fewer peaks in the recurrence spectra. The agreement between the semiclassical calculation spectra and the quantum calculation spectra suggests that our analysis is correct.     

Quantum Spectra of Hydrogen Atoms in Various Magnetic Fields with the Closed Orbit Theory

The quantum spectra of hydrogen atoms in various magnetic fields have been calculated with the closed orbit theory.The magnitude of the magnetic field decreases from 5.96 T to 0.56 T with a step of 0.6T.We demonstrate schematically that the closed orbits disappear with the decrease of the magnitude of the magnetic field when the corresponding finite resolution of experiment is fixed.This may give us a good way to control the shape and the number of the closed orbits in the system,and thus to control where a peak should exist in the Fourier transformation of the quantum spectra.     

Systematic multi-configuration Dirac-Fock calculations of the Kα and Kβ X-ray spectra of silicon ions

The transition energies, absorption oscillator strengths, line strengths and transition probabilities between computed levels are reported for the He-like to Ne-like Silicon ion sequences. Wavefunctions were determined relativistic configuration interaction (RCI) and multi-configuration Dirac-Fock (MCDF) technique included the Breit interaction, quantum electrodynamic (QED) corrections and nuclear mass corrections. The calculated values are in good agreement with the available experimental data and the recent theoretical values obtained from other methods. These data provide reference values for the level lifetimes, charge state distributions, and average charge of silicon plasmas.     

Raman Spectra of Alkali and Alkaline Earth Metal Salts of Inosine 5′-Monophosphoric Acid

Crystalline Li(I), Na(I), K(I), Mg(II), Ca(II), Sr(II), Ba(II) and Cd(II) salts of inosine 5′-monophosphoric acid, H₂(IMP), were obtained and characterized by Raman spectroscopy. Splitting of the imidazolic 1480 cm⁻¹ band was observed for the N(7)-bound Ca(IMP)·6H₂O, Ba(IMP)·6H₂O, Sr(IMP)·6H₂O and Cd(IMP)·4H₂O compounds. The Li(I), Mg(II), Ca(II) and Cd(II) ions bind directly to the phosphate group, and no direct coordination involving the carbonyl C(6)O group was observed in the compounds reported here. Some Raman spectral features in the 750–700 cm⁻¹ range seem to reflect the nucleoside structure of the inosine moiety     

The Influence of Various Divalent Metal Ions (Mn2+, Co2+, and Cu2+) Substitution on the Structural and Magnetic Properties of Nickel–Zinc Spinel Ferrite

Physics of the Solid State - Ni0.7 – xZn0.3MxFe2O4 (M = Mn2+, Co2+, and Cu2+; x = 0, 0.1, 0.3, 0.5, and 0.7) spinel-type ferrite were fabricated through citrate technique....     

Emission Spectra of Molecular Gases N2 and CO2 in the Range of 3–20 nm upon Pulsed Laser Excitation of Various Gas-Jet Targets

Optics and Spectroscopy - Results of investigation of emission spectra of N2 and CO2 upon pulsed laser excitation are presented. The spectral range between 3 and 20 nm was studied using a Nd:YAG...     

The triple-α process and the origin of the elements

The triple-α process is the nuclear fusion of helium to carbon. Two ⁴He nuclei collide and form an unstable state of ⁸Be. Before this can decay back a third α-particle collides with it to form a ¹²C nucleus. The reaction rate is probably the most temperature sensitive known to physics because there is a resonant state of the ¹²C nucleus at just the energy of the ⁸Be? and the ⁴He that have the greatest chance of penetrating the Coulomb barrier. The reaction takes place in stars that have exhausted their central hydrogen fuel. Most interesting are the asymptotic giants that can dredge the carbon produced to the surface and return it, perhaps first processing it to nitrogen, to the interstellar medium. The fortuitous energy of the resonant state of ¹²C and its consequences are crucial to the way stars evolve and the abundance of carbon on the Earth.     

Blue satellite structure near Heα and Heβ and redistribution of level populations

For a wide class of ions a mechanism for the emission of blue satellites close to the He-like resonance line in dense plasmas is proposed. It is based on the collisional transfer of population between autoionising levels. Detailed collisional radiative calculations involving all J-split autoionising levels are carried out for Al and may serve as a benchmark. A general consideration of redistribution effects inside the autoionising levels discovered diagnostically attractive density effects for laser-produced plasmas for both the He_α and He_β satellite structure.     

Shift measurements of Hα and Hβ lines in arc plasmas

Red shifts are reported for the H_α and H_β lines at electron densities of 10¹⁶–10¹⁷ cm^-3. The peak shift of the H_α line agrees with the ELC shift. For the H_β line, the dip shift exceeds the ELC shift systematically. The H_β dip shift is proportional to N_e/T.     

Measurement of Neutron Fluxes and Spectra during the NT-TBM Operation of CN HCSB

Neutronics measurement system provides neutron fluxes and spectra at the locations of beryllium multiplier and tritium breeder during the operation of the NT-TBM （D-D and D-T phase in ITER）. This is important for studying and assessing capabilities of beryllium multiplier and tritium breeder in the China helium cooled solid breeder （CNHCSB）. A special neutron diagnostic system has been proposed that allows to measure neutron fluxes and spectra without interrupt the operation of ITER. This system includes encapsulated foil activation analysis, micro-fission chamber detectors （MFC）, and a compact neutron spectrometer using natural diamond detector （NDD）.     

Gaseous Metal and the Problem of Vapor–Liquid (Insulator–Metal) Transition in Metal Vapors

Journal of Experimental and Theoretical Physics - We consider the main properties of a gaseous metal, viz., the state of metal vapor adjoining the vapor–fluid transition binodal. The gaseous...     

Structure of 12C and the triple-α process

We review experiments at IGISOL and associated work at ISOLDE and KVI on the use of the β-decays of ¹²N and ¹²B for the study of the structure of ¹²C and the consequences for the rate of the triple-α reaction in stars.     

X-ray Lα emission and LIII absorption spectra of copper compounds

The X-ray Lα _{1, 2} emission spectra and L_III absorption spectra in Cu, Cu₂O, CuCl, Cu₂S, CuO, CuCl₂, CuS, CuF₂ and Cu(en)₂Cl₂ are investigated. It is shown that the emission spectra of divalent copper compounds are considerably distorted due to a sharp absorption peak near the L_III edge. The nature of this peak is discussed and a relation is made with satellite peaks in X-ray photoelectron spectra.     

An Overview of the High‐Pressure Vibrational Spectra of Clays and Related Minerals

Abstract

An overview of the effect of high external pressures on clays and related minerals is presented. The results show that this is an area that will welcome further investigation in the future, especially in view of the importance of clay minerals in the Earths's mantle and, possibly, even in prebiotic chemistry in the formation of amino acids and the mineralogy of the Martian surface.     

Evaluation and analysis of the radiation force in laser trap

Forces exerted on a small transparent dielectric sphere in a Gaussian beam is an-alyzed.The stable position of the sphere in the Gaussian beam was calculated.The effects ofthe sphere size,the beam radius etc.on the exerted forces,on the equilibrium positions aswell as on other parameters of the sphere are discussed.     

Amyloid-β peptide aggregation and the influence of carbon nanoparticles

Soluble peptides or proteins can self-aggregate into insoluble, ordered amyloid fibrils under appropriate conditions.These amyloid aggregates are the hallmarks of several human diseases ranging from neurodegenerative disorders to systemic amyloidoses. In this review, we first introduce the common structural features of amyloid fibrils and the amyloid fibrillation kinetics determined from experimental studies. Then, we discuss the structural models of Alzheimer's amyloid-β(Aβ) fibrils derived from solid-state nuclear magnetic resonance spectroscopy. On the computational side, molecular dynamics simulations can provide atomic details of structures and the underlying oligomerization mechanisms. We finally summarize recent progress in atomistic simulation studies on the oligomerization of Aβ(including full-length Aβ and its fragments) and the influence of carbon nanoparticles.     

Correlation Between the IR Transmission Spectra and the CdZnTe Qualities

Tens of Cd0.9Zn0.1Te wafers from three ingots grown by the vertical Bridgman method (VBM) are characterized by infrared (IR) transmission. Four types of distinct IR transmission spectra are found for these wafers. Each of them corresponds to one kind of wafers with specified quaJities. At the same time, approximate mathematical relations exist between the wafer dislocation density and their IR transmissions at the wavenumber 4000cm^-1, as well as between the resistivity and the IR transmissions at the wavenumber 500cm^-1. The reasons of the above results are attempted to be given.     

Assignments of the 13C NMR Spectra of Enhydrin and 2′,3′-Dehydromelnerin A and the Molecular Structure of Enhydrin

Abstract

Two melampolide-type sesquiterpene lactones, enhydrin and 2,′ 3′-dehydromelnerin A, were isolated from a Louisiana population of Polymnia uvedalia. Their ¹³C NMR spectra were assigned using ¹³C-¹H correlation, DEPT and COLOC experiments. The molecular structure of enhydrin was established by single crystal X-ray diffraction.