共查询到20条相似文献,搜索用时 31 毫秒
1.
Classical molecular dynamics simulations are used to investigate the fission gas Xe behavior in a U-Mo alloy fuel matrix. The embedded atom method potential proposed by Smirnova et al. is used to describe the U-Mo-Xe system. The results show that the initial configuration of interstitial Xe atoms in U-Mo alloys is very instable and has a strong tendency to get together and to form a Xe bubble by ejecting the adjacent U atoms and Mo atoms from their former normal lattice sites. The pressure in Xe bubbles is initially quite high and then drops with increasing Xe concentration obviously. The matrix swelling of U-Mo alloys associated with the Xe bubble growth follows approximately a linear relationship with the ratio of Xe to U at low Xe concentration while the rate of swelling increases rapidly at high Xe concentration. The simulation results are in good agreement with the experimental data. The recovery of the damaged structure in the U-Mo alloys matrix is also investigated. It is shown that a damaged structure cannot be recovered completely after a system is relaxed for a long time while still having lots of defects. 相似文献
2.
The Yang–Baxter equation is reinvestigated in the framework of triple system. By requiring the rational R matrix of the Yang–Baxter equation satisfying the generalized Filippov condition, we derive a relation with respect to the rational R matrix. Moreover the case of the super Yang–Baxter equation is also investigated. 相似文献
3.
Synthesis,Characterization of 9, 9'-Bianthracene and Fabrication of 9, 9'-Bianthracene Field-Effect Transistors 下载免费PDF全文
We synthesize and purify 9, 9'-bianthracene with the purity up to 96.4%. The electronic and crystallographic structures of 9, 9'-bianthracene are studied. The results of a joint experimental investigation based on a combination of x-ray diffraction (XRD) spectra, hydrogen nuclear magnetic (HNMR) spectra, infrared absorption (FT-IR) spectra, and mass spectra (MS) of 9, 9'-bianthracene are obtained. The uniform compact film is observed by an atomic-force microscope (AFM). Organic field effect transistors (OFETs) with an active layer based on the synthesized 9, 9'-bianthracene are fabricated for the first time. Its field-effect mobility is as large as 0.067 cm^2 /(V·s) and the on/off ratio is above 5 ×10^4. The result demonstrates that the oligomerization of a small semiconductor molecule is an effective method to develop high-mobility organic semiconductors. 相似文献
4.
A new approach to formulizing a new high-order matrix spectral
problem from a normal 2× 2 matrix modified Korteweg--de Vries
(mKdV) spectral problem is presented. It is found that the
isospectral evolution equation hierarchy of this new higher-order
matrix spectral problem turns out to be the well-known mKdV equation
hierarchy. By using the binary nonlinearization method, a new
integrable decomposition of the mKdV equation is obtained in the
sense of Liouville. The proof of the integrability shows that
r-matrix structure is very interesting. 相似文献
5.
The properties of the eigenspace of nonintegrable quantum systems are explored in detail in the light of the viewpoint of quantum-classical completely correspondence proposed recently by Xu et al.The changes of the topological structure in the state space of autonomous quantum system due to the nonlinear resonance are displayed numerically with the uncertainty measure of a special initial state ρα(λ) and the transformation matrix U(λ δλ-λ-δλ),The statistical behavior of the subspace occupied by the state in eigenspace of quantum nonintegrable system is discussed carefully with the help of a special renormalization method.The results show that the randomness of effective Hamilonian matrix,the transition matrix and the nearest level spacings in this region can be described by random matrix theory.And the extent of agreement of our calculation with the prediction of GOE is in correspondence to the extent of the classical torus violation. 相似文献
6.
《中国物理C(英文版)》2021,(9)
The BLMSSM is an extension of the minimal supersymmetric standard model(MSSM).Its local gauge group is SU(3)_C×SU(2)_L×U(1)_Y×U(1)_B×U(1)_L.Supposing the lightest scalar neutrino is a dark matter candidate,we study the relic density and the spin independent cross section of sneutrino scattering off a nucleon.We calculate the numerical results in detail and find a suitable parameter space.The numerical discussion can confine the parameter space and provide a reference for dark matter research. 相似文献
7.
ZHOU Nan-Run JIA Fang 《理论物理通讯》2008,50(9):598-602
A rotational parameter Rθ has been introduced to complex wavelet transform (CWT). The rotational CWT (RCWT) corresponds to a matrix element 〈φ|U2(θ;μ;κ)[F〉 in the context of quantum mechanics, where U2(θ;μ;κ) is a two-mode rotational displacing-squeezing operator in the 〈η| representation. Based on this, the Parseval theorem and the inversion formula of RCWT have been proved. The concise proof not only manifestly shows the merit of Dirac's representation theory but also leads to a new orthogonal property of complex mother wavelets in parameter space. 相似文献
8.
The Hirota–Satsuma coupled KdV equations associated 2×2 matrix spectral problem is discussed by the dressing method,which is based on the factorization of integral operator on a line into a product of two Volterra integral operators.A new solution is obtained by choosing special kernel of integral operator. 相似文献
9.
The Darboux transformation of a differential-difference equation associated with a 3 × 3 matrix spectral problem is derived. As an application, explicit soliton solutions of the differential-difference equation are presented. 相似文献
10.
Large Third-Order Optical Nonlinearity of Cadmium Sulphide Nanoparticles Embedded in Polymer Thin Films 下载免费PDF全文
A simple method for synthesis of well dispersed cadmium sulphide nanoparticles embedded in a polyethylene glycol matrix (PEG 400) in thin film form is presented. The large blue shift of the band gap energy of the CdS nanoparticles compared to the bulk semiconductors is observed via UV-vis absorption spectra. Photoluminescence spectra of CdS nanocomposite films show that the emission peaks shift towards the longer wavelength with the increase of annealing temperature. Transmission electron microscopic images as well as Raman scattering studies confirm the CdS nanometer size particle formation within the polymer matrix. The particle size is about 8 nm. Selected area electron diffraction (SAED) shows the cubic zinc blende polycrystalline rings. Third-order optical nonlinearity of the CdS nanopartieles embedded in polymer thin films is studied with the Z-scan technique under 1064 nm excitation. The results show that the CdS nanocomposite film exhibits negative nonlinear refraction index and positive absorption coefficient. The film shows large optical nonlinearity, and the magnitude of the third-order nonlinear susceptibility of the film is calculated to be 1.73 × 10^-9 esu. The corresponding mechanism is discussed. 相似文献
11.
Unitary transformation of general nonoverlapping-image multimode interference couplers with any input and output ports 下载免费PDF全文
《中国物理 B》2020,(1)
An explanation of optical unitary transformation is presented for general nonoverlapping-image multimode interference(MMI) couplers with any number of input and output ports. The light transformation in the MMI coupler can be considered as an optical field matrix acting on an input light column vector. We investigate the general phase principle of output light image. The complete proof of nonoverlapping-image MMI coupler's optical unitarity along with the phase analysis of matrix element is provided. Based on a two-dimensional finite-difference time-domain(2 D-FDTD) simulation,the unitary transformation is obtained for a 4× 4 nonoverlapping-image MMI coupler within a deviation of 4× 10~(-2) for orthogonal invariance and 8× 10~(-2) for transvection invariance in the C-band spectral range. A compact 1 × 4 splitter based on cascaded MMI coupler is proposed, showing a phase deviation less than 5.4° while maintaining a low-loss performance in C-band spectra. 相似文献
12.
ZHU Jun-Yi GENG Xian-Guo 《理论物理通讯》2007,47(4):577-581
By resorting to the nonlinearization approach, a Neumann constraint associated with a discrete 3 × 3 matrix eigenvalue problem is considered. A new symplectic map of the Neumann type is obtained through nonlinearization of the discrete eigenvalue problem and its adjoint one. The generating function of integrals of motion is presented, by which the symplectic reap'is further proved to be completely integrable in the Liouville sense. 相似文献
13.
Quantum correlations among parts of a composite quantum system are a fundamental resource for several applications in quantum information. In general, quantum discord can measure quantum correlations. In that way, we investigate the quantum discord of the two-qubit system constructed from the Yang-Baxter Equation. The density matrix of this system is generated through the unitary Yang-Baxter matrix R. The analytical expression and numerical result of quantum discord and geometric measure of quantum discord are obtained for the Yang-Baxter system. These results show that quantum discord and geometric measure of quantum discord are only connect with the parameter θ, which is the important spectral parameter in Yang Baxter equation. 相似文献
14.
《中国物理 B》2015,(12)
The first path-independent insertion-loss(PILOSS) strictly non-blocking 4×4 silicon electro–optic switch matrix is reported. The footprint of this switch matrix is only 4.6 mm×1.0 mm. Using single-arm modulation, the crosstalk measured in this test is-13 d B ~-27 d B. And a maximum crosstalk deterioration of 6d B caused by two-path interference is also found. 相似文献
15.
A New Numerical Approach to Evaluate Variation of Electric Field Strength at the End of Particle Trajectory in Nuclear Track Detectors 下载免费PDF全文
A geometrical model for an electrochemical etching (ECE) track in a dielectric detector is defined and a primaxy programme is written to generate the track. The generated track is transformed to an M× N matrix of primary voltages. Using a numerical method, the matrix of final voltages is computed, and using another numerical approach, the electric field strengths in the elements of detector volume are computed. The final field strength at the end of particle trajectory is obtained. The results of our numerical computation show that there are exact correlations between the field strength at the end of particle trajectory and the parameters of track under ECE. It is found that although two traditional models of Mason and Smythe in dielectrics can be partly applied for short and long tracks, none of them are able to explain the behaviour of field strength in a ‘general case'. Furthermore, we find that there is an expressive relationship between the field strength and the incidence angle of impacted particle, while the mentioned traditional models are not able to explain this effect. 相似文献
16.
We propose a systematic approach for generating Hamiltonian tri-integrable couplings of soliton hierarchies. The resulting approach is based on semi-direct sums of matrix Lie algebras consisting of 4 × 4 block matrix Lie algebras. We apply the approach to the AKNS soliton hierarchy, and Hamiltonian structures of the obtained tri-integrable couplings are constructed by the variational identity. 相似文献
17.
The rare isotope 236U has a half-life of 2.342(3)×107 years,and is produced principally by thermal neutron capture on 235U.The isotopic atom ratio of 236U/238U depends on the integral thermal neutron flux received by the material of interest.236U is potentially useful as a fingerprint for indicating the presence of neutron-irradiated uranium usually originating from nuclear activity.By extracting negative molecular ion UO- from the uranium oxide target,simulating the 236U16O- beam transport with 238U16O- an... 相似文献
18.
The dressing method based on the 2 × 2 matrix ■-problem is generalized to study the complex modified KdV equation(cmKdV). Through two linear constraint equations, the spatial and time spectral problems related to the cmKdV equation are derived. The gauge equivalence between the cmKdV equation and the Heisenberg chain equation is obtained. Using a recursive operator,a hierarchy of cmKdV with source is proposed. On the basis of the ■-equation, the N-solition solutions of the cmKdV equation are obt... 相似文献
19.
Relative enhancement of photoluminescence intensity of passivated silicon nanocrystals in a silicon dioxide matrix 下载免费PDF全文
Photoluminescence (PL) intensity of passivated silicon nanocrystals (Si NCs) embedded in a SiO 2 matrix is compared with that of unpassivated Si NCs. We investigate the relative enhancement of PL intensity (I R ) as a function of annealing temperature and implanted Si ion dose. The I R increases simultaneously with the annealing temperature. This demonstrates an increase in the number of dangling bonds (DBs) with the degree of Si crystallization varying via the annealing temperature. The increase in I R with implanted Si ion dose is also observed. We believe that the near-field interaction between DBs and neighboring Si NCs is an additional factor that reduces the PL efficiency of unpassivated Si NCs. 相似文献
20.
We present experimental measurements and theory of the diffusely backscattered Mueller matrix patterns that arise from illuminating a turbid medium with a polarized laser beam. Our technique employs polarized light from a He-Ne laser (λ=632.8nm) focused onto the surface of the scattering medium. A surface area of approximately 2×2 cm2 centred on the light input point is imaged through polarization analysis optics onto a CCD camera. The Mueller matrix is reconstructed by 49 intensity measurements with various orientations of polarizer and analyser. The measured Mueller matrix of polystyrene spheres is compared with the theory result of incoherent scattering of light by spheres. It shows that the azimuthal patterns of the Mueller matrix are determined by the symmetry of the turbid media and the shape of scattering particles. The result is further proved by experiments with polystyrene spheres of different concentrations in de-ionized water. 相似文献