Preparation of Copper Chromite by Vaccum Freezing Drying Method and Its Catalytic Activity for Sulfuric Acid Decomposition

Iodine sulfur (IS) process is one of the most promising routes for massive and CO₂‐free hydrogen production. Among the three reactions IS process composed, decomposition of sulfuric acid is the most energy intensive step and has to be conducted in the presence of catalyst. In this work, copper chromite (CuCr₂O₄) was prepared, characterized, and used as the catalyst for sulfuric acid decomposition reaction. The co‐precipitation preparation method of CuCr₂O₄ which featured in vacuum freezing drying (VFD), was applied, and the main factors which influence the structure of CuCr₂O₄ such as pH values of the co‐precipitation solution and calcination temperature were investigated. Results showed that pH value affected the size of copper chromite granule, when pH was between 7 and 8, the size of prepared CuCr₂O₄ was in nanometer scale. Calcination temperature influenced the purity of the crystal. The samples were characterized by XRD, TEM and BET. The catalytic activity of CuCr₂O₄ prepared by VFD was evaluated and compared with CuCr₂O₄ prepared by usual co‐precipitation method and Pt/Al₂O₃. Results showed that the activity of CuCr₂O₄ was close to that of Pt catalyst, but apparently higher than that of CuCr₂O₄ prepared by usual method. In addition, it presents good stability in the 70 h test. Therefore, it was promising to be used in the sulfuric acid decomposition step of IS process.     

Husimi算符与热真空态的Husimi分布函数

利用Husimi算符作为一个纯态密度算符的事实,我们导出了热场态的Husimi函数及其边缘分布.通过绘制相空间的Husimi分布图形,我们简要讨论了高斯展宽参数以及热真空态的温度对Husimi函数的影响.     

Realization of a unique time evolution unitary operator in Klein Gordon theory

The scattering theory for the Klein Gordon equation, with time-dependent potential and in a non-static space-time, is considered. Using the Klein Gordon equation formulated in the Hubert spaceL ²(R ³) and the Einstein’s relativistic equation in the spaceL ²(R ³, dx) and establishing the equivalence of the vacuum states of their linearized forms in the Hubert spaceL ²(R ³) with the help of unique symmetric symplectic operator, the time evolution unitary operatorU(t) has been fixed for the Klein Gordon equation, incorporating either the positive or negative frequencies, in the infinite dimensional Hubert spaceL ²(R ³).     

固溶体半导体ZnS1-xTex(0≤x≤1)多晶薄膜的制备及特性研究

ZnS1-xTex是制作短波长光波段光电子器件和紫外探测器的理想材料。本文介绍了ZnS1-xTex多晶薄膜的真空蒸镀制备情况，并用原子力显微镜、X射线衍射仪、能量色散谱仪、紫外．可见分光光度计、荧光光谱分析仪等对制备的多晶薄膜的性质进行了测试和分析，发现该多晶薄膜保持了单晶薄膜的紫外吸收、光致发光等良好特性。     

测量低真空系统压强的U型管油压强计

本文介绍了一种测量范围为１ｍｍＨｇ—２０ｍｍＨｇ，测量精度为０．１ｍｍＨｇ的低真空测量装置及其使用条件和方法。有效地代替了以水银为媒质的旋转式麦氏真空计。     

Vacuum states on compressible Navier-Stokes equations with general density-dependent viscosity and general pressure law

In this paper,we study the one-dimensional motion of viscous gas with a general pres- sure law and a general density-dependent viscosity coefficient when the initial density connects to the vacuum state with a jump.We prove the global existence and the uniqueness of weak solutions to the compressible Navier-Stokes equations by using the line method.For this,some new a priori estimates are obtained to take care of the general viscosity coefficientμ(ρ)instead ofρ~θ.     

Effect of vacuum, oxygen and carbon dioxide on the track registration in SR-90 and CR-39

The molecular structure of SR-90 and CR-39 is very similar except that the average length of carbonate linkages in SR-90 is 1.6 times longer than in CR-39. However, the effect of vacuum and carbon dioxide (CO₂) on the track registration of these two detectors is very different: 1) the sensitivity of CR-39 becomes very low in vacuum; the sensitivity of SR-90 does not go down to zero even after storage in vacuum for a long time; 2) the sensitivity of SR-90 decreases both in air and in vacuum but the original sensitivity can be restored by storing it in CO₂ of 13 atm for several days. We also found that the sensitization of latent tracks by oxygen (O₂) is effective only at the time of irradiation but the sensitization by CO₂ is effective after irradiation.     

Elliptical Solutions to the Standard Cosmology Model with Realistic Values of Matter Density

We have examined a solution to the FRW model of the Einstein and de Sitter Universe, often termed the standard model of cosmology, using wide values for the normalized cosmic constant (Ω_∧) and spacetime curvature (Ω _k ) with proposed values of normalized matter density. These solutions were evaluated using a combination of the third type of elliptical equations and were found to display critical points for redshift z, between 1 and 3, when Ω_∧ is positive. These critical points occur at values for normalized cosmic constant higher than those currently thought important, though we find this solution interesting because the Ω_∧ term may increase in dominance as the Universe evolves bringing this discontinuity into importance. We also find positive Ω_∧tends towards attractive at values of z which are commonly observed for distant galaxies.     

Global classical solutions to the compressible micropolar viscous fluids with large oscillations and vacuum

In this paper, we consider the three dimensional Cauchy problem of the compressible micropolar viscous flows. We prove the existence of unique global classical solution for smooth initial data with small initial energy but possibly large oscillations and the initial density may allowed to contain the interior and far field vacuum states. Furthermore, the large time behavior of the solution is obtained as well.     

Vacuum Rabi Splitting and Kerr Effect of a Hybrid Spin–Magnon–Photon System

The vacuum Rabi splitting and Kerr effect are investigated theoretically in a hybrid spin–magnon–photon system, where the nitrogen-vacancy center in diamond driven by two light fields is coupled to a spherical micromagnet embedded in a superconducting coplanar waveguide resonator. The results indicate that the phenomenon of the Mollow triplet and vacuum Rabi splitting can appear by controlling the spin–magnon coupling and magnon–photon coupling. It is shown that the probe absorption spectrum can be adjusted effectively via the pump frequency detuning. Moreover, it is demonstrated that the optical Kerr effect can be tuned by changing the Rabi frequency. This work may provide a possibility for the applications in quantum information processing and quantum sensing of magnetic signal.