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1.
Size-dependent energy shift of photoemission spectra with respect to bulk sample has been examined for colloidally prepared CdSe nanoparticles with a series of particle sizes. The core-level shifts are well described by a theoretical calculation based on a final-state effect model, whereas an additional initial-state effect due to quantum confinement is required to elucidate the valence-band edge shifts. The results indicate that the interaction between the photohole and the dielectric background in the final state has to be considered in photoemission measurements for organics-passivated nanoparticles. The calculated results in the literature appear to overestimate the initial-state effect compared to our experimental observation. 相似文献
2.
M. Dineykhan S. A. Zhaugasheva A. Isadykov N. Sagimbaeva 《Physics of Particles and Nuclei Letters》2013,10(6):501-507
Energies of the singlet and triplet positronium states are analytically calculated considering the annihilation and loop corrections in a functional approach. The dependences of the constituent mass of constituent particles on the initial-state masses and the corresponding quantum number are derived. The wave function at the origin of coordinates is calculated and the decay widths of ortho- and parapositronium are determined. The result corresponds satisfactorily to available experimental data. 相似文献
3.
考虑初态He原子电子间的关联效应、末态敲出电子与剩余束缚电子间的关联效应和末态屏蔽效应, 计算和分析了在共面、大能量损失和小动量转移这一特殊几何条件下730eV电子离化He原子的三重微分截面. 所得结果与Stevenson等人的相对实验数据和CCC理论计算结果进行比较发现: 所得到的理论曲线能够反映实验数据给出的三重微分截面的结构特征. 相似文献
4.
考虑初态He原子电子间的关联效应、末态敲出电子与剩余束缚电子间的关联效应和末态屏蔽效应, 计算和分析了在共面、大能量损失和小动量转移这一特殊几何条件下730eV电子离化He原子的三重微分截面. 所得结果与Stevenson等人的相对实验数据和CCC理论计算结果进行比较发现: 所得到的理论曲线能够反映实验数据给出的三重微分截面的结构特征. 相似文献
5.
P. Laukkanen M.P.J. Punkkinen M. Ahola-Tuomi J. Lång K. Schulte A. Pietzsch M. Kuzmin J. Sadowski J. Adell R.E. Perälä M. Ropo K. Kokko L. Vitos B. Johansson M. Pessa I.J. Väyrynen 《Journal of Electron Spectroscopy and Related Phenomena》2010
We have studied In-stabilized c(8 × 2)-reconstructed InAs(1 0 0) and InSb(1 0 0) semiconductor surfaces, which play a key role in growing improved III–V interfaces for electronics devices, by core-level photoelectron spectroscopy and first-principles calculations. The calculated surface core-level shifts (SCLSs) for the ζ and ζa models, which have been previously established to describe the atomic structures of the III–V(1 0 0)c(8 × 2) surfaces, yield hitherto not reported interpretation for the As 3d, In 4d, and Sb 4d core-level spectra of the III–V(1 0 0)c(8 × 2) surfaces, concerning the number and origins of SCLSs. The fitting analysis of the measured spectra with the calculated ζ and ζa SCLS values shows that the InSb spectra are reproduced by the ζ SCLSs better than by the ζa SCLSs. Interestingly, the ζa fits agree better with the InAs spectra than the ζ fits do, indicating that the ζa model describes the InAs surface better than the InSb surface. These results are in agreement with previous X-ray diffraction data. Furthermore, an introduction of the complete-screening model, which includes both the initial and final state effects, does not improve the fitting of the InSb spectra, proposing the suitability of the initial-state model for the SCLSs of the III–V(1 0 0)c(8 × 2) surfaces. The found SCLSs are discussed with the ab initio on-site charges. 相似文献
6.
P. Pakhlov 《中国物理C(英文版)》2008,32(6)
We present a search for new charmonium like states in e+e- annihilation using the initial-state radiation and the process e+e-→J/ψ D(*)D(*). The analyses are based on a huge data sample recorded near the T(4S) resonance with the Belle detector at the KEKB e+e- asymmetric-energy collider. 相似文献
7.
By means of the nuclear parton distribution studied only with lepton deep-inelastic scattering experimental data, the J/ψ ``normal nuclear absorption' and energy loss effects are studied in a Glauber formalism at HERA and RHIC energies. Assuming that the absorption cross section σabs increases with thecharmonium-nucleon center of mass energy, the results reveal a significant dependence of the σabs on rapidity y at RHIC energies. The initial-state energy loss effect, which is found important only at HERA energies, is also considered, and its influence should be eliminated when we studied the absorption effect at low collision energies. Finally, we also present the theoretical prediction for LHC. 相似文献
8.
M. Betz E.A. Veit J. Haidenbauer 《The European Physical Journal A - Hadrons and Nuclei》2002,14(1):113-124
p annihilation into two pions and three pions is studied in a baryon exchange model. Annihilation diagrams involving nucleon
as well as Δ-resonance exchanges are included consistently in the two- and three-pion channels. Effects from the initial-state
interaction are fully taken into account. A comparison of the influence of the Δ exchange on the considered annihilation channels
is made and reveals that its importance for three-pion annihilation is strongly reduced as compared to two-pion annihilation.
It is found that annihilation into three uncorrelated pions can yield up to 10% of the total experimentally observed three-pion
annihilation cross-section.
Received: 16 January 2002 / Accepted: 20 February 2002 相似文献
9.
A.A. Raduta E. Garrido E. Moya de Guerra 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2001,15(1):65-77
Some properties of small sodium clusters, comprising up to 45 atoms, are described using a projected spherical single particle
basis. The variation of the cluster shape and inner density with the number of atoms is studied. Seemingly chestnut, clusterization
and halo like structures are identified for several metallic clusters. Static polarizabilities and plasmon frequencies are
calculated and compared with experimental data and with results obtained in different approaches.
Received 28 November 2000 and Received in final form 15 February 2001 相似文献
10.
N. Singh A. K.S. Jha M. Mohan 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2006,38(2):285-291
Breit-Pauli Energy levels, oscillator strengths and transition probabilities
for all the transitions in Cl I between the fine structure levels of
3s2 3p5, 3s2 3p43d, 3s2 3p44s and 3s23p44p states are calculated using extensive configuration interaction (CI) wave functions. We have also determined the lifetimes
of 3s2 3p43d, 3s2 3p44s and 3s2 3p44p levels. The
relativistic effects are included through Breit-Pauli approximation via spin-orbit, Darwin and mass correction terms. Prior
to the calculations of the oscillator strengths and transition probabilities, we fine-tune the CI coefficient using experimental
energies. Our results are compared with experimental and other available theoretical data. The calculated energy levels are
in close agreement with most of the NIST compiled data. We predict new lifetime data for several levels where no other theoretical
and/or experimental results are available, which will form the basis for the
future experimental work.
Electronic supplementary material Online Material 相似文献
11.
G. I. Gakh M. I. Konchatnij N. P. Merenkov 《Journal of Experimental and Theoretical Physics》2001,92(6):930-939
Deep inelastic scattering events of a longitudinally polarized electron by a polarized proton with a tagged collinear photon radiated from the initial-state electron are considered. The corresponding cross section is derived in the Born approximation. The model-independent radiative corrections to the Born cross section are also calculated. The obtained result is applied to the elastic scattering. 相似文献
12.
The effects of soft gluonic corrections to non-leptonic processes are considered. Implications for hyperon, charmed baryon and heavy meson decays are discussed. Methods to disentangle the effects of final-state gluons, initial-state gluons and other soft effects such as final-state hadronic interactions are given. 相似文献
13.
Exact time-dependent density functionals remember both the entire history of the density and the initial wave function. We show that the two effects are intimately related, and all history dependence can be written as initial-state dependence, including that of the exchange-correlation kernel. For states that can be evolved from a ground state, all initial-state dependence is a dependence on a pseudo-prehistory, providing a route to excited-state densities from time-dependent density functional theory. 相似文献
14.
E. S. Henriques A. V. Solov'yov 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,46(3):471-481
The unbinding process of a protein-ligand complex of major biological interest
was investigated by means of a computational approach at atomistic classical
mechanical level. An energy minimisation-based technique was used to determine
the dissociation paths of the system by probing only a relevant set of
generalized coordinates. The complex problem was reduced to a low-dimensional
scanning along a selected distance between the protein and the ligand.
Orientational coordinates of the escaping fragment (the ligand) were also
assessed in order to further characterise the unbinding. Solvent effects were
accounted for by means of the Poisson–Boltzmann continuum model. The
corresponding dissociation time was derived from the calculated barrier
height, in compliance with the experimentally reported Arrhenius-like
behaviour. The computed results are in good agreement with the available
experimental data. 相似文献
15.
G. L. Chen H. Y. Lu C. Wang J. S. Liu R. X. Li G. Q. Ni Z. Z. Xu 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,47(2):303-307
We propose a plasma channel scheme to obtain an improved
table-top laser driven fusion neutron yield as a result of explosions of
large deuterium clusters irradiated by an intense laser pulse. A cylindrical
plasma channel is created by two moderate intensity laser prepulses at the
edge of a deuterium cluster jet along which an intense main laser pulse
propagates several nanoseconds later. With the aid of this plasma channel,
the main laser pulse will be allowed to deposit its energy into the central
region of the deuterium gas jet where the cluster sizes are larger and the
atomic density is higher. The plasma channel formation and its impact on the
deuterium ion energy spectrum and the consequent fusion neutron yield have
been investigated. The calculated results show that a remarkable increase of
the table-top laser driven fusion neutron yield would be expected. 相似文献
16.
Z. Lj. Petrović J. V. Jovanović V. Stojanović Z. M. Raspopović Z. Ristivojević 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,48(1):87-94
We have used a simple semi-analytic — momentum transfer theory (MTT)
to develop negative halogen ions/noble gases momentum transfer
integral cross sections based on the available data for reduced
mobility at 300 K as a function of E/N. The unfolded cross
sections were validated or further improved by assuring a good agreement between our Monte
Carlo (MC) calculated transport data and the available
experimental results. The data are produced with an aim to provide plasma modellers with cross section data and transport
coefficients. We have also calculated the net
rates of elastic scattering and detachment. 相似文献
17.
M.G. Brik 《Journal of Physics and Chemistry of Solids》2008,69(10):2568-2577
A detailed first-principles analysis of the L2,3 X-ray absorption near edge structure (XANES) spectra, crystal field strength 10Dq, covalent effects and molecular orbitals (MO) position for all divalent 3d ions from Sc2+ to Cu2+ in cubic ZnS is performed in the present paper. The calculations were done in the framework of the first-principles fully relativistic discrete variational multi-electron (DVME) based on numerical solution of the Dirac equation with the local density approximation. As a result of the performed calculations, the L2,3 XANES spectra for all considered ions were calculated and assigned in terms of the electron configurations involved into the absorption transitions; fairly good agreement with available experimental data for Ti2+, Mn2+, Fe2+, Co2+ and Ni2+ is demonstrated. Experimental XANES spectra for Sc2+, V2+, Cr2+, Cu2+ not reported previously were also calculated for the sake of completeness of the present study to enable a systematic analysis of all calculated results for the whole series considered. It was shown that the L3 and L2 bands shift to the higher energies on increasing a 3d ion atomic number. In addition, the separation between the L3 and L2 bands, the crystal field strength 10Dq and mixture between the 3d ion and sulfur wave functions increase along the considered series, from Sc2+ to Cu2+. On the other hand, all orbitals of the 3d ions systematically lower down in the same direction. The above formulated trends were confirmed by the experimental data on the crystal field splittings and nephelauxetic effect. 相似文献
18.
Y. Benmimoun A. Bouhemadou R. Khenata A. H. Reshak B. Amrani M. Ameri H. Baltache 《The European Physical Journal B - Condensed Matter and Complex Systems》2008,61(2):165-171
The results of first-principles theoretical study of the structural,
electronic and optical properties of SrCl2 in its cubic structure, have
been performed using the full-potential linear augmented plane-wave method
plus local orbitals (FP-APW+lo) as implemented in the WIEN2k code. In this
approach both the local density approximation (LDA) and the generalized
gradient approximation (GGA) are used for the exchange-correlation (XC)
potential. Also we have used the Engel-Vosko GGA formalism, which optimizes
the corresponding potential for band structure calculations. We performed
these calculations with and without spin-orbit interactions. Including
spin-orbit coupling cause to lifts the triple degeneracy at Γ point
and a double degeneracy at X point. Results are given for structural
properties. The pressure dependence of elastic constants and band gaps are
investigated. The dielectric function, reflectivity spectra and refractive
index are calculated up to 30 eV. Also we calculated the pressure and volume
dependence of the static optical dielectric constant. 相似文献
19.
Y. Yuan K. Deng Y. Liu C. Tang G. Lu J. Yang X. Wang 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2006,40(2):243-246
The ground state structures of MC3 (M = Sc, V, and Cr) and their
anions have been investigated, employing the first-principles DFT
at the B3LYP level. The calculations predict that the equilibrium
geometries of both neutral MC3 and their anions are cyclic
structures with C2v symmetry. The Mulliken charge and spin
populations of MC3 and their anions have also been calculated,
and it is found the electron charge changes mainly take place on
the M atoms from anions to neutral molecules. The low-lying
excited states for the clusters are calculated with time-dependent
DFT to assign the features of the photoelectron spectra. Our
results agree well with the available experimental and theoretical
data. 相似文献
20.
H. Khosroabadi A. Tavana M. Akhavan 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,51(2):161-165
Ab initio total energy calculations have been performed for superconducting
GdBa2Cu3O7 and insulating PrBa2Cu3O7 using the
full-potential linear augmented plane-wave method in the local density
approximation (LDA) and generalized gradient approximation (GGA). The
comparison of the calculated unit cell volume and lattice parameters with
the experimental data indicates the improvement of these parameters in the
GGA relative to LDA. LDA and GGA give the equilibrium unit cell volume about
6% smaller and 1.25% larger than the experimental data, respectively
for both systems. Thus frozen phonon calculations have been performed to
determine the eigenvalues and eigenvectors of the k=0 Ag modes of the
two systems in equilibrium structure have been obtained in GGA. The
calculated frequencies in the GGA are in good agreement with the other LDA
calculations for similar systems. Comparison of computational data with
experimental data indicates that calculations determine the frequencies
about ten percent below the experimental data. Even by improving LDA to GGA
in these calculations, the calculated phonon frequencies have remained
almost ten percent below the experimental data, even though the calculated
unit cell volumes are nearly equal to the experimental data. So, applying
GGA has not considerably decreased the difference between the computational
and experimental data. The effect of Pr doping on the eigenvalues and
eigenvectors have also been investigated. 相似文献