Effect of local structure on electron paramagnetic resonance spectra for trigonal [Cr(H_2O)_6]^(3+) coordination complex in the sulfate alums series:a ligand field theory study

A simple theoretical method is introduced for studying the interrelation between electronic and molecular structures.By diagonalizing the 120 × 120 complete energy matrices,the relationships between zero-field splitting （ZFS） parameter D and local distortion parameter △θ for Cr^3＋ ions doped,separately,in α- and β- alums are investigated.Our results indicate that there exists an approximately linear relationship between D and △θ in a temperature range 4.2-297 K and the signs of D and △θ are opposite to each other.Moreover,in order to understand the contribution of spin-orbit coupling coefficient ζ to ZFS parameter D,the relation between D and ζ is also discussed.

Electron paramagnetic resonance studies of the chelate-based ionic liquid in different solvents

The electron paramagnetic resonance spectra of the chelate-based ionic liquid[C_(10)mim][Cu(F_6-acac)_3]in different solvents have been obtained at 120 K.It was found that the values of the^(63)Cu hyperfine coupling constants(A_(IL))of[C_(10)mim][Cu(F_6-acac)_3]in molecular solvents were from 116 to 180 Gauss.Moreover,the A_(IL)values in general ionic liquids are more complicated,and two sets of peaks can often be observed in their electron paramagnetic resonance spectra.Based on the Kamlet-Taft parameters,relative permittivity,the experimental results were discussed in terms of solvation effect and coordination of the solvents.

Angle-dependent spin wave spectra of permalloy ring arrays

We investigated the angle-dependent spin wave spectra of permalloy ring arrays with the fixed outer diameter and various inner diameters by ferromagnetic resonance spectroscopy and micromagnetic simulation.When the field is obliquely applied to the ring,local resonance mode can be observed in different parts of the rings.And the resonance mode will change to perpendicular spin standing waves if the magnetic field is applied along the perpendicular direction.The simulation results demonstrated this evolution and implied more resonance modes that maybe exist.And the mathematical fitting results based on the Kittel equation further proved the existence of local resonance mode.

Isolation,Purification and Spectral Characteristics of Soluble Guanylate Cyclase from Bovine Lung

We isolated and purified high purity and high activity soluble Guanylate cyclase(sGC) from bovine lung. The electronic absorption and resonance Raman spectra of the ferrous and ferric forms of sGC were recorded. In the ferrous state of sGC, the electronic absorption spectra showed a sharp peak at 431 nm and a single broad peak in the α/β region at 559 nm. The resonance Raman spectra of sGC(ferrous) showed a stronger band at 1357 cm -1 and a single peak at 1473 cm -1 . For the ferric form of sGC, the Soret band was at 390 nm and resonance Raman peak was at 1375 cm -1 . These spectra show that the heme iron of the ferrous and ferric sGC are all 5 coordination and high spin.

Structural characterization and immunostimulatory activity of a water-soluble polysaccharide from abalone(Haliotis discus hannai Ino)muscle

A water-soluble polysaccharide from abalone muscle(AMPP)was isolated.The contents of carbohydrate,protein,uronic acid,and sulfate in AMPP were 83.5%,0.5%,2.7%,and 2.6%,respectively.High-performance liquid chromatography analysis indicated that AMPP was homogeneous and had an average molecular weight of approximately 3.2 kDa.The main monosaccharides of AMPP were glucose(Glc)and mannose with a molar ratio of 99.7:0.3.The structural characteristics of AMPP were elucidated through methylation analysis,Fourier transform infrared spectroscopy,and nuclear magnetic resonance spectroscopy.The linkages of AMPP consisted of terminal,1,4-linked,1,6-linked,and 1,4,6-linked Glcp with a molar ratio of 3.1:7.2:1.0:2.5.In one repeat unit of the proposed AMPP structure,the backbone chain was composed of eight 1→4 glycosidic bonds and one 1→6 glycosidic bond,with three branch chains linked by 1→6 glycosidic bond.In addition,AMPP was found to possess potent immunostimulatory activity via rising phagocytosis of RAW264.7 cells and promoting secretion of TNF-α.

Study of Microwave Multiphoton Transition of Rydberg Potassium Atom by Using B-Spline

Abstract The B-spline expansion technique and time-dependent two-level approach are applied to study the interaction between the microwave field and potassium atoms in a static electric field. We obtain theoretical multiphoton resonance spectra that can be compared with the experimental data. We also obtain the time evolution of the final state in different microwave fields.

A systematic analysis of the radial resonance frequency spectra of the PZT-based (Zr/Ti=52/48) piezoceramic thin disks

In this paper,both the ID radial mode and the equivalent circuit of a piezoceramic disk resonator were theoretically analyzed based on IEEE standards.And then,the radial resonance frequency spectra of the PZT-based(Nb/Ce co-doped Pb(Zro.s2Ti0.48)O3,abbreviated as PZT-NC)piezoceramic circular disks were measured by an impedance analyzer.A set of resonance frequency spectra including six electrical parameters:Z,R,X,Y,G,and B,were used for making a value distinction between three possible resonance frequencies,and between three possible antiresonance frequencies.A new-form Nyquist diagram was depicted to describe the position relations of these characteristic frequencies.Such a complete resonance frequency spectrum was used to perform the accurate calculation of some material constants and electromechanical coupling parameters for the PZT-NC piezoceramics.Further,the frequency dependence of the AC conductive behavior of the specimen was characterized by the complex impedance measurement.The values of AC conductivity at resonance/antiresonance were deduced from the equivalent circuit parameters.Moreover,the Van Dyke circuit model was assigned to each element contribution and the simulated curves showed a nice fitting with the experimental results.Finally,an additional impedance analysis associated with resonance frequency calculation revealed a complicated coupled vibration mode existing in the annular disk specimen.

Microwave synthesis and spectroscopic characterization of manganese oxalate nanocrystals

The microwave synthesis of MnC204.2H2O nanoparticles was performed through the thermal double decomposition of oxalic acid dihydrate （C2H204.2H20） and Mn（OAc）2.4H2O solutions using a CATA-2R microwave reactor. Structural characterization was performed using X-ray diffraction （XRD）, particle size and shape were analyzed using transmission electron microscopy （TEM）. The chemical in the structures was investigated using electron paramagnetic resonance （EPR） as well as optical absorption spectra and near-infrared （NIR） spectroscopies. The nanocrystals produced with this method were pure and had a distorted rhombic octahedral structure.Manganese oxalate

Electronic structure evolutions driven by oxygen vacancy in SrCoO3-x films

Ionic defects, such as oxygen vacancies, play a crucial role in the magnetic and electronic states of transition metal oxides. Control of oxygen vacancy is beneficial to the technological applications, such as catalysis and energy conversion. Here, we investigate the electronic structure of SrCoO3-x as a function of oxygen content(x). We found that the hybridization extent between Co 3d and O 2p increased with the reduction of oxygen vacancies. The valence band maximum of SrCoO2.5+δ has a typical O 2p characteristic. With further increasing oxygen content, the Co ions transform from a high spin Co3+ to an intermediate spin Co4+, resulting in a transition of SrCoO3-x from insulator to metal. Our results on the electronic structure evolution with the oxygen vacancies in SrCoO3-x not only illustrate a spin state transition of Co ions,but also indicate a perspective application in catalysis and energy field.