Study of pre-scission particle emissions and fission probability of the l78W produced in fusion reactions

A dynamical model based on one-dimensional Langevin equations was used to calculate the average pre-fission multiplicities of neutrons, light charged particles, and the fission probability for compound nucleus 17Sw produced in fusion reactions. The pre-seission multiplicities of particles and fission probability are calculated and compared with the experimental data over a wide range of excitation energy. A modified wall and window dissipation with a reduction coefficient, ks, has been used in the Langevin equations for reproducing experimental data. It was shown that the results of the calculations are in good agreement with the experimental data by using values of ks in the range 0.24〈 ks 〈0.47.     

Energy dissipation of a ring-like metal rubber isolator

Metal rubber （MR） is a kind of homogeneous poroelastic damping material made of metal wire. In this paper, by ana- lyzing the forces on the MR isolator and the MR element, the hysteresis loops of the force and deformation are studied and verified by experiments. The results show that the force and displacement hysteresis loop of the MR isolator is described by the force and deformation hysteresis loops of the MR elements. In addition, the relationship between the energy dissipation coefficient of the MR element and that of the MR isolator is derived. The energy dissipation coefficient is programmed and calculated by MATLAB using experimental data, and the results are compared with the theoretical value. It is the basis for the design and applied research of the MR isolator in a future study.     

Half-Lives of Spherical Proton Emitters

The distorted-wave Born approximation （DWBA） method is used to calculate the half-lives of spherical proton emitters. The calculated results are in agreement with the experimental data, The sensitivity of the half-lives to the depth of central potential V0 is investigated by using the DWBA method. The half-lives of spherical proton emitters are insensitive to the detail of their nuclear potential.     

Two-dimensional Langevin modeling of fission dynamics of the excited compound nuclei ~(188)Pt,~(227)Pa and ~(251)Es

A stochastic approach based on one-and two-dimensional Langevin equations is applied to calculate the pre-scission neutron multiplicity,fission probability,anisotropy of fission fragment angular distribution,fission cross section and the evaporation cross section for the compound nuclei ~(188)Pt,~(227)Pa and ~(251)Es in an intermediate range of excitation energies.The chaos weighted wall and window friction formula are used in the Langevin equations.The elongation parameter,c,is used as the first dimension and projection of the total spin of the compound nucleus onto the symmetry axis,K,considered as the second dimension in Langevin dynamical calculations.A constant dissipation coefficient of K,γk=0.077(MeV zs)~(-1/2),is used in two-dimensional calculations to reproduce the above mentioned experimental data.Comparison of the theoretical results of the pre-scission neutron multiplicity,fission probability,fission cross section and the evaporation cross section with the experimental data shows that the results of two-dimensional calculations are in better agreement with the experimental data.Furthermore,it is shown that the two-dimensional Langevin equations together with a dissipation coefficient of K,γk=0.077(MeV zs)~(-1/2),can satisfactorily reproduce the anisotropy of fission fragment angular distribution for the heavy compound nucleus(251)~Es.However,a larger value of γk=0.250(MeV zs)~(-1/2)is needed to reproduce the anisotropy of fission fragment angular distribution for the lighter compound nucleus(227)Pa.     

Do the Experimental Violations of Bell Inequalities Require a Non-Local Interpretation of Quantum Mechanics？

Since the data show that Bell inequalities are violated experimentally, we must conclude that any hidden variable theory （which correctly predicts experimental data ） will be non-local. But, to conclude that the experimental violations of Bell inequalities show quantum mechanics to be non-local is unjustified. Specifically, the key assumptions required to obtain a Bell inequality are （ 1 ） locality and （2） the assignment of meaningful （ non- negative） probabilities to seemingly physical correlations （Bell expresses these correlations via ＂ hidden variables＂ ）. Since the Bell inequality is violated by experiment, at least one of these assumptions is wrong. The widespread conclusion that locality must be relinquished is valid only if we retain the previously mentioned correlations （ ＂hidden variables＂ ）. We will demonstrate that the latter are not physical observables - they are not elements of physical reality.     

A Proposed Reaction Channel for the Synthesis of the Superheavy Nucleus Z=109

We apply a statistical-evaporation model (HIVAP) to calculate the cross sections of superheavy elements, mainly about actinide targets and compare with some available experimental data. A reaction channel ^30Si 4 ^243Am is proposed for the synthesis of the element Z=109 and the cross section is estimated.     

Surveying the role of excitation energy in probing nuclear dissipation

A dynamical Langevin model is employed to calculate the excess of the evaporation residue cross sections of the ^194Pb nucleus over that predicted by the standard statistical model as a function of nuclear dissipation strength. It is shown that large excitation energy can increase the effects of nuclear dissipation on the excess of the evaporation residues and the sensitivity of this excess to the dissipation strength,and that more higher excitation energies have little contribution to further raising this sensitivity. These results suggest that on the experimental side,producing those compound systems with moderate excitation energy is sucient for a good determination of the pre-saddle nuclear dissipation strength by measuring the evaporation residue cross section,and that forming an extremely highly excited system does not considerably improve the sensitivity of evaporation residues to the dissipation strength.     

Reflection-Asymmetric Shell Model Description of the Neutron-Rich^142，145Ba Nuclei

The reflection asymmetric shell model has been applied to describe the octupole deformed bands in neutron-rich even-even ^142Ba and odd-N^145Ba nuclei. The alternating parity bands of ^142Ba and the simplex s = -i bands of^145Ba are calculated and compared with the available experimental data. The calculated results are in good agreement with the experimental data. The spin and parity assignments of ground-state of^145Ba are discussed.The results show that the present work is a useful attempt to further explore the nuclear reflection asymmetry in neutron rich region.     

Adaptive nonlinear prediction of ocean reverberation

An adaptive nonlinear prediction algorithm is proposed to predict ocean reverberation based on the phase space reconstruction of nonlinear dynamic system. The prediction algorithm is tested by experimental reverberation data measured in two areas, and the one-step forward prediction results are in good agreement with the experimental data. If the errors between the predicted and experimental data are chosen as the variable to detect the target in the reverberation series, the reverberation is suppressed and the signal-to-reverberation ratio is improved.     

Photoproduction of Vector Meson Ф off Deuteron in QCD Inspired Model

Based on the quark-gluon contents of nucleon and strongly believing that the force mediators, Pomeron and its counterpart in the conventional approach of Regge theory, for high energy diffractive process would be the tensor glueball and Odderon respectively, we discuss photo-production of vector meson Ф off the deuteron at energy less than 3 GeV in the QCD inspired model in which the quark gluon degrees of freedom and glueball, Odderon exchange are taken into account. A calculation is performed for γ ＋ D →Ф ＋ D, and the theoretical predictions of the differential cross section dσ^γD/dt, are presented and compared with available experimental data. Our QCD inspired model reproduces data quite well in the whole range of the experimental measurements up to ｜t｜ ≌ 0.4 GeV. Our results can be used to extract γn → Фn data, which cannot be measured in experiment.     

Preparation and Decoherence of Two-Atom Entangled States in a Dissipative Cavity

We present a scheme for generating four pairs of two-atom Einstein Podolsky-Rosen （EPR） states using the simultaneous interaction of the two atoms with a single-mode cavity field under a large detuning condition. The influence of cavity dissipation on the prepared EPR states is investigated by means of the superoperator method and the state fidelity. It is shown that some kinds of the prepared EPR states are robust against cavity dissipation and the intensity of the field, and maintain their entanglement invariance, and the others are fragile and completely destroyed by the action of cavity dissipation and the intensity of the field in the long-time limit. Decoherence time of the fragile entangled states is extremely small for a typical cavity-QED experimental data.     

Computer-generated-hologram-accelerated computing method based on mixed programming

Component object model technology is used to solve problems encountered when using three-dimentional （3D） objects to conduct computer-generated hologram （CGH） fast coding. MATLAB and C/C＋＋ are combined for relevant programming under experimental conditions. The proposed method effectively reduces the time required for holographic encoding of large amounts of 3D object data. The CGH- accelerated computing method based on mixed programming is proven to be highly reliable and practical by testing the 3D data of different data volumes. According to the test results, the proposed method improves the efficiency of holographic encoding. The higher the data volume is, the more significantly the computation speed is improved.     

B（E2） value of even-even ^108-112Pd isotopes by interacting boson model-1

This work studies the systematic reduced transition probabilities B（E2）↓, intrinsic quadrupole moments and deformation parameters of Pd isotopes with even neutrons from N =62 to 66. The downward reduced transition probabilities B（E2）↓from gamma transition 8^＋to 6^＋, 6^＋ to 4^＋, 4^＋ to 2^＋ and 2^＋ to 0＋states of even-even108 112Pd isotopes were calculated by the Interacting Boson Model（IBM-1） and compared with the available previous experimental results. The ratio of the excitation energies of the first 4＋and the first 2＋excited states, R4/2, is also studied for the classification of symmetry of these nuclei. Furthermore we have studied systematically the transition rate R = B（E2： L＋ →（L 2）＋）/B（E2 ： 2＋ →0＋） of some of the low-lying quadrupole collective states in comparison with the available experimental data. The associated quadrupole moments and deformation parameters have been calculated. The results of this calculation are in good agreement with the corresponding available experimental data. The108 112Pd isotopes show the O（6） symmetry.     

Calculation of Specific Heat for Aluminium Thin Films

We employ Prasher＇s non-dimensional form to analyse the size effects on specific heat of Al thin films. Compared the calculation results of pure aluminium film with the experimental data, it is found that the reduction of phonon states is not the main reason of the size effect on the specific heat Al thin films with thickness from lOnm to 37Onm. However, the Al thin film in air usually has an oxidation layer and the specific heat of the layer is smaller than Al. By including the contribution of the oxidation layer to the thin-film specific heat, the calculation results are much closer to the experimental data. This may be a possible reason of the size effects on specific heat of Al thin films.     

Study of BESⅢ MUC offline software with cosmic-ray data

Cosmic-ray data of 90 M events have been collected and used for calibration,alignment as well as detector tuning. A special tracking algorithm for the BESⅢ muon counter is developed and verified with Monte-Carlo simulation and then further confirmed with the cosmic-ray data. The obtained strip resolutions are in good agreement with the design values. A new alignment approach for the BESⅢ muon counter is confirmed with the cosmic-ray data and proposed to be used in future analysis of experimental data.     

Simulation of the fission dynamics of the excited compound nuclei ~(206)Po and ~(168)Yb produced in the reactions ~(12)C+~(194)Pt and ~(18)O+~(150)Sm

A two-dimensional dynamical model based on the Langevin equation was used to study the fission dynamics of the compound nuclei ~(206)Po and ~(168)Yb produced in the reactions ~(12)C+~(194)Pt and ~(18)O+~(150)Sm,respectively.The fission cross section and average pre-scission neutron multiplicity were calculated for the compound nuclei ~(206)Po and ~(168)Yb,and results of the calculations compared with the experimental data.The elongation coordinate was used as the first dimension and the projection of the total spin of the compound nucleus onto the symmetry axis,K,considered as the second dimension in the Langevin dynamical calculations.In the two-dimensional calculations,a constant dissipation coefficient of K and a non-constant dissipation coefficient have been used to reproduce the abovementioned experimental data.It is shown that the two-dimensional Langevin equation can satisfactorily reproduce the fission cross section and average pre-scission neutron multiplicity for the compound nuclei ~(206)Po and ~(168)Yb by using constant values of the dissipation coefficient of K equal to γκ=0.18(MeV zs)~(-1/2) and γκ= 0.20(MeV zs)~(-1/2)for the compound nuclei ~(206)Po and ~(168)Yb,respectively.     

Contribution of Quark Structure Term in Nucleon Electric and Magnetic Form Factors

The constituent quarks in the nucleon have always been considered as a point-like particle in the relativisticconstituent quark model. However its calculation results of GE^n agree poorly with the new experimental data. Theelectromagnetic structure of light front constituent quarks is considered in this paper. We find that the calculationresults have good agreement with the new experimental data of GE^n after considering the contribution of the quarkstructure term. This treatment seems to be able to improve the fit to experimental data of GEp/GMp,√Q2F2p/kpF1p,and GEn/GMn as well.     

Theoretical Analysis and New Formulae for Half-Lives of Proton Emission

The proton radioactivity hMf-lives of spherical proton emitters are calculated by the cluster model with the con- tribution of a centrifugal potential barrier considered separately. The results are compared with the experimental data and other theoretical data, and good agreement is found for most nuclei. In addition, two formulae are pro- posed for the proton decay half-life of spherical proton emitters through the least squares fit to the experimental data available, and could reproduce the experimental half-lives successfully.     

A theoretical study of the oxygen K-edge near-edge X-ray absorption fine structure of N20/Ir（110）

A multiple-scattering chtster method is employed to calculate the oxygen K-edge near-edge X-ray absorption fine structure of N20/Ir（110） and its monolayer. Two peaks and one weak resonance appear in both cases. The self- consistent field DV-Xa calculations of the peaks and resonance show that the physical origin of the pre-edge peak x is different from those of the main peak 1 and the other weak resonance al. This setup is intrinsic to the N20 monolayer, owing to the interaction between the neighbouring molecular chains in the monolayer and partly to the adsorbed atomic oxygen, according to both the theoretical and experimental data.     

Systematical law of (n, γ) reaction cross sections of even-even nuclei

We have derived a formula for the neutron radiative capture cross section in the framework of a statistical model approach to nuclear reactions. Based on this formula, new systematics are established between the (n, γ) reaction cross section and the energy level density of a compound nucleus or a relative neutron excess of an even-even target nucleus for neutron incident energy above the resonance region to MeV. Good agreement with experimental data suggests that this new systematical law is helpful to analyze the experimental data.