SRPES investigation of tungsten oxide in different oxidation states

The microstructure and morphology of metal oxide films have a large influence on the sensitivity, selectivity and stability of the gas sensors and catalysts. Considering that the sensing properties of thin film sensors are strongly related to their microstructures and to the exact stoichiometry of their surfaces, an accurate control of these parameters is extremely important for the production of sensors with reproducible behavior. In this paper, an influence of preparation and annealing conditions on the physical and chemical properties of tungsten oxide thin film is investigated. Two types of samples having polycrystalline structure were prepared by different methods (deposition under UHV conditions, oxidation of metallic tungsten layer in air). The samples were reduced by heating in UHV at different temperatures and/or by Ar ion bombardment. It was found that the stability of tungsten oxide layer with respect to the treatment procedures depends strongly on the preparation conditions of the sample. The reduction process is discussed in terms of different oxidation states resolved in the W4f photoelectron spectrum. Easy reducibility of the tungsten oxide layer prepared by vacuum deposition was found to be a consequence of its nano-crystalline structure.     

Formations of n-order two-soliton bound states in Bose–Einstein condensates with spatiotemporally modulated nonlinearities

The formations of n-order two-soliton bound states (TSBSs) in the Bose–Einstein condensates with spatiotemporally modulated nonlinearities are studied. Exact analytical expressions of the n-order TSBSs are derived by means of the similarity transformations. Further, the numerical simulations are carried out, consistent with the analytical results very well. The stability analysis shows that the solutions can be stable. Our results indicate that the attractive spatiotemporal inhomogeneous nonlinearities can support n-order TSBSs, which has the potential applications to the generation of matter-wave bright solitons in harmonic traps.     

Generalized Bethe ansatz solution of a one-dimensional asymmetric exclusion process on a ring with blockage

We present a model for a one-dimensional anisotropic exclusion process describing particles moving deterministically on a ring of lengthL with a single defect, across which they move with probability 0 p 1. This model is equivalent to a two-dimensional, six-vertex model in an extreme anisotropic limit with a defect line interpolating between open and periodic boundary conditions. We solve this model with a Bethe ansatz generalized to this kind of boundary condition. We discuss in detail the steady state and derive exact expressions for the currentj, the density profilen(x), and the two-point density correlation function. In the thermodynamic limitL the phase diagram shows three phases, a low-density phase, a coexistence phase, and a high-density phase related to the low-density phase by a particle-hole symmetry. In the low-density phase the density profile decays exponentially with the distance from the boundary to its bulk value on a length scale . On the phase transition line diverges and the currentj approaches its critical valuej _c = p as a power law,j _c – j ^–1/2. In the coexistence phase the width of the interface between the high-density region and the low-density region is proportional toL ^1/2 if the density f 1/2 and=0 independent ofL if = 1/2. The (connected) two-point correlation function turns out to be of a scaling form with a space-dependent amplitude n(x₁, x₂) =A(x₂)A ^Ke^–r/ withr = x ₂ –x ₁ and a critical exponent = 0.     

Oh型分子三重简并态Hamiltonian算符的研究

本文应用群论原理及不可约张量性质，详细推导了Ｏｈ型分子三重简并态Ａｍａｔ－Ｎｉｅｌｓｅｎ方案中精确到四级的Ｈａｍｉｌｔｏｎｉａｎ算符，为Ｏｈ型分子精细结构理论和光谱的进一步研究做了数学上的准备。     

类锂铝复合机制产生X光激光的等离子体状态

本文从速率方程出发,讨论了类锂铝复合等离子体的激发态结构,衰减常数,反转率和小信号增益等表征介质增益特性的物理量以及它们随电子温度,电子密度和光子逃逸几率的变化。找到了进行类锂铝离子通过复合机制产生X光激光设计应创造的等离子体状态目标区域。还讨论了这些物理量随原子序数变化的定标律。     

f0（975）和Ф（1020）介子对中子星物质的影响

利用相对论平均场理论，考虑了σ＊，Ф介子及重子八重态{N，P，A，∑^-，∑0,∑＋，Ξ^-，Ξ^0}，研究了中子星的性质．发现当考虑了σ＊，Ф介子的贡献时，超子出现的临界重子数密度降低了，超子数目增加了，超子星的转变密度poH降低了，物态方程变软，最大质量变小而相应的中子星半径增大，中子星的中心重子数密度、中心能量密度和中心压强均降低．     

Ce∶YAG透明陶瓷的制备及性能研究

以高纯Al_2O_3、Y_2O_3和CeO_2为原料,采用固相法制备Ce∶YAG(掺铈钇铝石榴石)透明陶瓷,研究了稀土离子掺杂浓度以及烧结温度对陶瓷样品光学性能的影响。结果表明:陶瓷片透过率随着烧结温度的升高而增大,1750℃烧结获得的0.5%Ce∶YAG陶瓷片的透过率高达81.7%。Ce∶YAG陶瓷片的激发峰和发射峰分别位于350nm和530nm处,在白光LED领域具有极大的应用价值。     

锕系核集体运动的负宇称态

从锕系区40多个核的正负宇称态的实验数据,如激发能、J^π、电偶极跃迁等,得到一系列与核结构有关的物理量,如宇称劈裂能级差δE_I,正负宇称带的第一和第二类转动惯量J⁽¹⁾和J⁽²⁾及第一负宇称态的电偶极跃迁强度比等,以及它们与角动量I或转动角频率ω的动力学和核子数A的系统行为,从而为研究锕系核负宇称态的产生机制及动力学特点提供了信息.     

Influence of the weakly interacting light U boson on the properties of massive protoneutron stars

Considering the octet baryons in relativistic mean field theory and selecting entropy per baryon S=l,we calculate and discuss the influence of U bosons on the equation of state,mass-radius,moment of inertia and gravitational redshift of massive protoneutron stars(PNSs).The effective coupling constant gu of U bosons and nucleons is selected from 0 to 70 GeV~(-2).The results indicate that U bosons will stiffen the equation of state(EOS).The influence of U bosons on the pressure is more obvious at low density than high density,while the influence of U bosons on the energy density is more obvious at high density than low density.The U bosons play a significant role in increasing the maximum mass and radius of PNS.When the value of gu changes from 0 to 70 GeV~(-2),the maximum mass of a massive PNS increases from 2.11M_⊙ to 2.58M_⊙,and the radius of a PNS corresponding to PSR J0348+0432 increases from 13.71 km to 24.35 km.The U bosons will increase the moment of inertia and decrease the gravitational redshift of a PNS.For the PNS of the massive PSR J0348+0432,the radius and moment of inertia vary directly with gu,and the gravitational redshift varies approximately inversely with gu.