含新结构单元[Co3(SS)3(PR3)3]的钴化合物的磁性研究

通过含新结构单元钴化合物:Co₃(bdt)₃(PBu₃)₃(Ⅰ),Co₃(tdt)₃(PBu₃)₃(Ⅱ),[Co₃(bdt)₃(PPh₃)₃][CoBr₃(dmf)](Ⅲ)和[Co₃(edt)₃(PEtB)₃]₂[Co₂Cl₄(Et₂SO₂)₂](Ⅳ)(bdt=1,2-S₂C₆H₄^2-,tdt=4-Me-1,2-S₂C₆H₃^2-,edt=SCH₂CH₂S^2-)的磁极矩和¹H NMR等研究表明:它们均具顺磁性,钴原子之间存在着反铁磁偶合作用,同时还讨论了它们的磁学性质和分子结构之间关系。     

镧对SS400钢组织及力学性能的影响

研究了镧对SS400钢常温及低温力学性能的影响。结果表明,SS400钢的强度、塑性、冲击韧性以及硬度随镧含量的增加能够得到明显改善,但当镧加入量过大时,会造成SS400钢的强度、塑性、冲击韧性下降。将镧含量控制在0.016%左右能够有效提高其各项力学性能。镧提高SS400钢的力学性能,是其对钢净化钢液、变质夹杂、微合金化综合作用的结果。     

CFETR中心螺管模型线圈用316LN异型铠甲力学性能研究

改良后的316LN不锈钢因为其在低温下优异的延展性能,被选作为中国聚变工程实验堆(CFETR)中心螺线管(CSMC)的铠甲材料。主要对316LN铠甲材料进行了室温与低温下的力学性能测试,并进行了统计分析。实验结果表明316LN铠甲拥有非常好的拉伸性能。     

Comparative XPS analysis of passive layers composition formed on AISI 304 L SS after standard and high‐current density electropolishing

In the paper, there are described chemical compositions of passive surface layers formed on AISI 304 L (EN 1.4307) stainless steel after standard (EP50; i = 50 A/dm²) and high‐current density (EP1000; i = 1000 A/dm²) electropolishing. For the studies, a mixture of orthophosphoric and sulfuric acid electrolyte in proportion 1:4 was used. The survey and high‐resolution spectra of Cr 2p, Fe 2p, S 2p, P 2p, Ni 2p and C 1s are presented. On the basis of the obtained results it was noted that the chromium‐to‐iron ratio (Cr/Fe) after EP50 was about 3.5 times higher than that after EP1000 treatment. The phosphorus‐to‐sulfur ratios after EP50 and EP1000 electropolishing were 0.13 and 0.3, respectively, and nickel to the sum of chromium and iron coefficient (Ni/Cr + Fe) for both electrochemical polishing was equal to 0.04. Copyright © 2014 John Wiley & Sons, Ltd.     

∑上的非弱几乎周期的回复点集和SS混沌集

该文对单边符号空间上的转移自映射进行了讨论,证明了在非弱几乎周期的回复点集上存在不可数的SS混沌集.     

The effect of TiN nanoparticles deposition with different number of shots on SS316L by plasma focus device

In this paper, we present the result of TiN nanocrystalline deposition on SS316L, using a 4 kJ plasma focus (PF) device for 10, 20, and 30 focus shots. The effect of different number of focus shots on micro-structural changes of thin film is characterized by field emission scanning electron microscope. Existence of grains in different size confirms the formation of TiN nanocrystals on the surface of SS316L substrate. X-ray diffraction (XRD) reveals the formation of a nanocrystalline titanium nitride coating on the surface of SS316L samples. The crystalline size of TiN obtained from XRD data is strongly dependent on the number of focus shots. Thickness of the elements found on the surface of the treated sample that obtain by Rutherford backscattering spectroscopy (RBS) analysis is in the range of 150×10¹⁵?200×10¹⁵ atoms/cm². All the existence elements in the coated samples are identified by Particle Induced X-ray Emission (PIXE) spectra. Investigation on the corrosion resistance of TiN coatings was performed using an electrochemical potentiodynamic polarization. Our results suggest that TiN nanocrystalline implantation with proper ion fluences using PF can significantly improve the corrosion resistance of SS316L.     

An FMM for waveguide problems of 2-D Helmholtz’ equation and its application to eigenvalue problems

This paper discusses an FMM for solving waveguide problems and associated eigenvalue problems for Helmholtz’ equation in a two dimensional infinite strip with homogeneous Neumann boundary condition on the sides. Layer potentials with Green’s function for this problem are evaluated efficiently with the help of the method of images and FMM. We apply FMM to solve some boundary value problems in waveguides and associated resonance frequency problems using the Sakurai–Sugiura projection method after discussing the required analytic continuation of the solutions to complex frequencies. Some numerical examples show the accuracy and the efficiency of the proposed method.     

Ultraviolet emission properties of ZnO film with zinc deficiency by SS CVD

A-b axis orientation ZnO film on silicon (1 0 0) substrate has been prepared by a single source chemical vapor deposition technique. X-ray photoelectron spectroscopy results revealed that the film was very close to stoichiometry but with a small amount of zinc deficiency. Temperature-dependent (10-300 K) ultraviolet photoluminescence of the film was presented. Comparing the photon energy separation of the several groups in the near band edge ultraviolet luminescence bands, as well as the variation of the relative intensities and the shift of the luminescence lines at different temperatures, free-, bound-exciton and its assisted phonon emission were observed, which corresponded to the mechanism of the ultraviolet emission properties. A strong ultraviolet emission resulting from the recombination of free-exciton was observed at 300 K photoluminescence spectrum examined in atmosphere environment. Contrasted to the relatively weak ultraviolet emission of the film in vacuum, atmosphere environment was found to be an important contribution to the strong ultraviolet emission of the film.