GLOBAL ANALYSIS OF SPECTRA OF THE PO2 RADICAL IN THE GAS PHASE

A global analysis of all available and identified spectra of the PO₂ radical has been performed. In this analysis, the infrared spectra of the ν₃ band, the microwave and far infrared laser magnetic resonance transitions in the ground state are fitted simultaneously to the effective Hamiltonian for asymmetric top molecules. Since the analysis absorbs reliable experimental data extensively, it bears the most precise and most complete set of molecular constants for PO₂. These molecular constants can be used to reproduce the spectra of PO₂ accurately. Attention is also paid to the similarity and difference between PO₂ and NO₂.     

Determination of human skin optical properties in vivo from reflectance spectroscopic measurements

A novel approach has been proved to quickly and non-invasively determine the optical properties of human skin in vivo. It is based on the diffuse reflectance approximation model and subjected to the well established library of absorption spectra of water and hemoglobin. Under the nonlinear least-square algorithm, fitting the measured spectra in the range of 400-1000 nm to the diffusion approximation model, the reduced scattering coefficient and absorption coefficient of skin tissue can be quickly determined in vivo. The results show that this method is convenient and suitable for the real-time clinical application.     

Theoretical Analysis of Neutron Double-Differential Cross Section of n ＋^19F at 14.2 MeV

A new light nuclear reaction model has been developed and the double-differential measurements of lp shell nuclei have been analyzed successfully. Now, the application of this model is expanded to 19F of the 2s-ld shell nucleus. The double-differential cross section of total outgoing neutron for n ＋^19F reactions at En=14.2 MeV has been calculated and analyzed, which agrees fairly well with the experimental measurements. In this paper, the contributions from different reaction channels to the double-differential cross sections have been analyzed in detail. The calculations indicate that this light nudear reaction model is also able to be used for the 2s-ld shell nucleus so long as the related level scheme couM be provided sufficiently.     

Effects of South China Sea/western North Pacific summer monsoon on tropospheric biennial oscillation （TBO）

Several theories have been developed to explain tropical biennial oscillation (TBO), as an air--sea interactive system to impact Asian and global weather and climate, and some models have been established to produce a TBO. A simple 5-box model, with almost all the key processes associated with TBO, can produce a TBO by including air--sea interactions in the monsoon regions. Despite that, the South China Sea/western North Pacific summer monsoon (SCS/WNPSM), a very important monsoon subsystem, is neglected. In this paper, based on the dynamical framework of 5-box model, the term of SCS/WNPSM has been added and a 6-box model has been developed. Comparing the difference of TBO sensibilities with several key parameters, air--sea coupling coefficient α, SST-thermocline feedback coefficient γ and wind-evaporation feedback coefficient λ, between the modified model and original model, TBO is more sensible to the parameters in the new model. The results imply that the eastern Pacific and local wind-evaporation play more important roles in the TBO when including SCS/WNPSM.     

NEXAFS multiple scattering calculations of KO2

Since many years the oxidation of alkali metals has being attracted much interest due to the catalytic properties of metal promoters and the simple electronic structure of alkali atoms.The alkali-oxides phase diagram indicates that the interaction of oxygen with alkali metals can lead to the formation of different atomic O^2 ions and molecular O2 and O2^2- ions.Potassium superoxide has been prepared in situ and high resolution O e-edge absorption NEXAFS spectra have been measured at the VUV beam-Line at ELETTRA facility.The experimental data have been analyzed by multiple scattering approach deriving many geometrical and electronic is of the KO2 type with an O-O distance of about 1.35A and that the transition involving singleπ molecular empty state of the superoxied O2 anion has a fine structure.Multiple Scattering self consistent calculation indicates that the bond between oxygen anion adn K atom is totally ionic and that the fine structure is essentially due to solid state effects.     

An interconnect width and spacing optimization model considering scattering effect

As the feature size of the CMOS integrated circuit continues to shrink, the more and more serious scattering effect has a serious impact on interconnection performance, such as delay and bandwidth. Based on the impact of the scattering effect on latency and bandwidth, this paper first presents the quality-factor model which optimises latency and bandwidth effectively with the consideration of the scattering effect. Then we obtain the analytical model of line width and spacing with application of curve-fitting method. The proposed model has been verified and compared based on the nano-scale CMOS technology. This optimisation model algorithm is simple and can be applied to the interconnection system optimal design of nano-scale integrated circuits.     

Theoretical Analysis of the Neutron Double Differential Cross Section of n 16O at En=14.1 MeV

Based on the unified Hauser-Fshbach and exciton model,a new model has been developed for the light nucleus reactions.The analysis of the neutron energy-angular spectra of n 16O reaction has been performed.The fitting of the experimental data indicates that this method is successful for calculating the double-differential cross section of the light nucleus.     

Coherence and Decoherence of a Localized Excitation on a Surface Adatom

A theory of coherent excitation of a localized state on an adatom by two-photon photoemission spectroscopy (TR-2PPE) is presented within a microscopic model and the time-dependent formalism.Coherent oscillation and incoherent population decay of the excitation are obtained,and are shown to attain well-defined lifetine constants only in the long-delay limit.In addition,we have found a competing excitation channel via electron transfer.The theory is applied to Cs/Cu (111),which reproduces a few qualitative features observed in recent experiments.The effect of atomic motion on the 2PPE spectra,which manifests dominantly as a redshift in the spectrum,has been analysed.     

Global nonequilibrium energy criterion for predicting strength of 316L stainless steel under complex loadings:Theoretical modeling and experimental validation

Classical strength criteria are developed based on some empirical assumptions and have been widely used in engineering to predict material strength owing to their simplicity. In some cases, however, considerable discrepancies arise between classicalstrength-criteria-based theoretical predictions and experimental results. Recently, a global nonequilibrium thermodynamics model has made important progress over classical models without resorting to any empirical assumptions. A prominent advance of this rational energy model is that it straightforwardly determines the dissipation energy density function, which is pertinent to inherent material ductility, through simple uniaxial and equi-biaxial tensions. In this study, a brief introduction of the nonequilibrium energy model was followed by systematic experimental investigation to determine the dissipation energy function and predict the material strength of pristine 316 L stainless steel-commonly used in engineering-under complex loadings. The results indicated that the strength contours predicted by the nonequilibrium energy criterion for complex loadings are consistent with the experimental results obtained for biaxial tension, implying that the nonequilibrium thermodynamics model is both reasonable and reliable. The prediction error was presumed to be induced by the anisotropy of the 316 L stainless steel sheets.     

PHOTOLUMINESCENCE STUDY ON Hg1-xCdxTe THIN FILM IMPLANTED WITH As ION

Photoluminescence spectra of a series of MBE-grown Hg_1-xCd_xTe samples with the same mole fraction of about x≈0.39 have been measured at different temperatures from 5 to 100 K. By aid of the temperature and exciting laser power dependence of photoluminescence peak energy and relative intensity, as well as of the comparison with other measurements, four main structures dominating in the photoluminescence spectra are attributed to band to band, D^oX, A^oX and D^oA^o transitions. A deep donor state level located at about 8.5meV below the bottom of the conduction band has been observed and is determined to be due to the arsenic-occupied mercury vacancies. Two acceptor levels located at about 14.5 meV and about 31.5 meV above the top of the valance band have also been found from the measuements, which are identified as the mercury vacancies and As in anion site, respectively.     

Electroluminescence from Si／SiO2 films deposited on p—Si substrates

The structure of Au/Si/SiO₂/p-Si has been fabricated using the magnetron sputtering technique. It has a very good rectifying behaviour. Visible electroluminescence (EL) has been observed from the Au/Si/SiO₂/p-Si structure at a forward bias of 5V or larger. A broad band with one peak around 650－660 nm appears in all the EL spectra of the structure. The effects of the thickness of the Si layer in the Si/SiO₂ films and of the input electrical power on EL spectra are studied systematically.     

Optical colours and polarization of a model reflection nebula

Simple models of a reflection nebula in the form of a plane-parallel slab containing smooth spherical solid particles in submicron size range have been considered. Single scattering has been assumed. The effect of varying the composition and size distribution function of the grains have been brought out in the calculations using Mie theory of scattering. The analytical part of the geometry of the problem has been treated quite rigorously and the resulting expression for nebular intensity has been presented in a somewhat new form. In this paper, the case of the star behind the nebula has been examined. A comparison of the theoretical results with the observations of the Merope nebula shows that the dirty ice grains with index of refraction about 1·3–0·1i and size parametera ₀ = 0·5μ give reasonable agreement with the colours. Simultaneously, the polarization in the visual and blue wavelength bands agree approximately up to offset angle of 6 minutes of arc. The larger offset angles pose an intriguing problem. The general trends of nebular colours and polarization with variation of real and imaginary parts of index of refraction and the size distribution parameter have been tabulated to serve as a guide for further study of reflection nebulae with the star in the rear. A part of this work was presented at the first scientific meeting of the Astronomical Society of India, held on 27 and 28 February 1974 at Hyderabad. An erratum to this article is available at .     

Creation of an Ultracold Plasma by Photoionizing Laser-Cooled Caesium Atom

The signals of ultracold plasma are observed by two-photon ionization of laser-cooled atom in a caesium magneto-optical trap. A simple model has been introduced to explain the creation of plasma, and the mechanism is further investigated by changing the energy of a pulsed dye laser and the number of initial cooled atoms.     

Extension of a Simple Model for f - d Transition and Applications to Reassignment of Excitation Spectra of Ho^3＋-Doped Crystals

We present an extension of the original simple model for f ~cl transition proposed by Duan and co-workers [Phys. Rev. B 66 （2002）155108; J. Alloys Compound. 366 （2004）34] to the case applicable to heavy lanthanide and actinide ions in crystals and apply it to the interpretation of the low-temperature f-d excitation spectra of rio^3＋ doped in crystals LiYF4 and CaF2. A consistent assignment of all the transition bands is obtained.     

Origin of hardening in spectra of cosmic ray nuclei at a few hundred GeV using AMS-02 data

Many experiments have confirmed spectral hardening at a few hundred GeV in the spectra of cosmic ray(CR)nuclei.Three different origins have been proposed:primary source acceleration,propagation,and the superposition of different kinds of sources.In this work,a broken power law has been employed to fit each of the spectra of cosmic ray nuclei from AMS-02 directly,for rigidities greater than 45 GeV.The fitting results of the break rigidity and the spectral index differences less than and greater than the break rigidity show complicated relationships among different nuclear species,which cannot be reproduced naturally by a simple primary source scenario or a propagation scenario.However,with a natural and simple assumption,the superposition of different kinds of sources could have the potential to explain the fitting results successfully.Spectra of CR nuclei from a single future experiment,such as DAMPE,will provide us the opportunity to do cross checks and reveal the properties of the different kinds of sources.     

Temperature-related performance of Yb^3＋：YAG disc lasers and optimum design for diamond cooling

In this paper the temperature-related performances of the Yb^3＋：YAG disc laser has been investigated based on quasi-three level rate equation model. A compact diamond window cooling scheme also has been demonstrated. In this cooling scheme, laser disc is placed between two thin discs of single crystal synthetic diamond, the heat transfer from Yb^3＋：YAG to the diamond, in the direction of the optical axis, and then rapidly conducted radically outward through the diamond to the cooling water at the circumference of the diamond/Yb^3＋ ：YAG assembly. Simulation results show that increasing the thickness of the diamond and the overlap-length （between diamond and water） decreases the disc temperature. Therefore a 0.3-0.5 mm thick diamond window with the overlap-length of 1.5 2.0 mm will provide acceptable cost effective cooling, e.g., with a pump intensity of 15 kW/cm^2 and repetitive rate of 10 Hz, to keep the maximum temperature of the lasing disc below a reasonable value （310K）, the heat exchange coefficient of water should be about 3000 W/m^2K.     

On the Nonlinear Growth of Multiphase Richtmyer-Meshkov Instability in Dilute Gas-Particles Flow

We discuss evolutions of nonlinear features in Richtmyer-Meshkov instability(RMI)f which are known as spikes and bubbles.In single-phase RMI,the nonlinear growth has been extensively studied but the relevant investigation in multiphase RMI is insufficient.Therefore,we illustrate the dynamic coupling behaviors between gas phase and particle phase and then analyze the growth of the nonlinear features theoretically.A universal model is proposed to describe the nonlinear finger(spike and bubble)growth velocity qualitatively in multiphase RMI.Both the effects of gas and particles have been taken into consideration in this model.Further,we derive the analytical expressions of the nonlinear growth model in limit cases(equilibrium How and frozen How).A novel compressible multiphase particle-in-cell(CMP-PIC)method is used to validate the applicability of this model.Numerical finger growth velocity matches well with our model.The present study reveals that particle volume fraction,particle density and Stokes number are the three key factors,which dominate the interphase momentum exchange and further induce the unique property of multiphase RMI.     

Mechanochemical Coupling of Kinesin Studied with a Neck-Linker Swing Model

A neck-linker swing model has been proposed in this work to investigate the mechanochemical coupling of kinesin. The difference between force-velocity curves given by force clamp and fixed trap respectively has been satisfactorily interpreted by this model. The study implies that ADP releasing and ATP hydrolysis are much less forcedependent in force clamp experiments than that in fixed trap experiments in the regime of moderate loading force, which might be a consequence of the delayed response of servo system in force clamp experiments.     

Low-order harmonic generation of hydrogen molecular ion in laser field studied by the two-state model

The low-order harmonic generation of hydrogen molecular ion interacting with a linearly polarized laser field has been investigated theoretically by using a simple two-state model. The validity of the two-state model is carefully examined by comparing the harmonic spectra of hydrogen molecular ion obtained from this model with those from the three-dimensional time-dependent Schr¨odinger equation. When combined with the Morlet transform of quantum time-frequency spectrum,the two-state model can be used to study the dynamical origin of the low-order harmonic generation of hydrogen molecular ion driven by low-frequency pulses. In addition, some interesting structures of the time profiles for low order harmonics are obtained.     

CALCULATIONS OF STRETCHING VIBRATIONAL OVERTONES AND COMBINATIONS OF ARSINE BY NONLINEAR MODEL

A three-parameter nonlinear model in nonlinear quantum theory,i.e.,the quantized discrete self trapping equation, has been used to calculate the vibrational energy spectrum, including the overtones and combinations with many excited quanta, of AsH stretches of arsine, AsH₃. The model calculations agree well with experiment and other calculations. It is shown that the dominant feature of the energy spectrum of AsH₃ molecule is a pattern of local mode pairs, and that when n≥4, all the vibrational energies are almost localized on a single AsH bond.