三光气与酚制备三氯甲氧基甲酸芳酯研究

研究了不同取代酚与三光气的反应,得到七种未见报道的新化合物,以IR、MS、1H NMR、13C NMR对产物进行了表征,并探索得到合适的反应催化剂、反应物浓度配比、反应时间,讨论了酚上不同取代基对反应的影响,收率在78.5～90.5%之间。     

Tensor force effect on proton shell structure in neutron-rich Ca isotopes

In the framework of the Skyrme-Hartree-Fock approach with 36 sets of the TI J parameterizations,the tensor force effect on the evolution of the single-proton states in the calcium isotopes is systematically investigated.It is shown that the single-proton states with higher angular momenta are influenced significantly by the tensor force and the trend in the evolution of somesingle-particle energy differences with the mass number of the isotopes depends sensitively on a parameter βT associated with the intensity of the tensor force.To understand this phenomenon,we analyze the spin-orbit potentials and the radial wave functions of relevant single-proton orbits in detail.In addition,it is found that some TI J interactions could cause the 2s1/21d3/2 energy level inversion in 48Ca.     

Application of wavelet transform in-ray spectra analysis

The frequency distribution of different ingredients in-ray spectra,e.g.,photo-peak,fluctuations of counts and Compton region,is separately analyzed.After wavelet transform of-ray spectra,the wavelet coefficients of a photo-peak increase with transforming scales and these coefficients show direct proportion with intensity of peak at determinate scale.A novel algorithm based on wavelet transform is proposed and studied.The results indicate that most of the photo-peaks in multi-spectra can be determined accurately,the-rays energy and intensity of the peak can also be determined.This method has the prospect of being applied in on-line multi-spectra analysis in such fields as radioprotection and nuclear safety monitoring.     

Magnetic properties and magnetocaloric effects in amorphous and crystalline Gd55Co35Ni10 ribbons

The magnetic properties and magnetocaloric effects of amorphous and crystalline Gd55Co35Ni10 ribbons are investigated.A main phase with a Ho 12 Co 7-type monoclinic structure(space group P21/c) and a minor phase with a Ho4Co3-type hexagonal structure(space group P63/m) are obtained for crystalline ribbon after annealing.The amorphous ribbons order ferromagnetically and undergo a second-order transition at 192 K.For crystalline Gd55Co35Ni10 ribbons,two magnetic phase transitions occur at 158 and 214 K,respectively.The peak value of-△SM under a field change of 0-5 T is 6.5 J/kg K at 192 K for amorphous Gd55Co35Ni10 ribbons.A relatively large magnetic entropy change(～5.0 J/kg K) under a field change of 0-5 T for the crystalline Gd55Co35Ni10 ribbons is obtained in the temperature interval range of 154-214 K.The large platform of magnetic entropy change and the negligible thermal/magnetic hysteresis loss mean the crystalline Gd55Co35Ni10 compound can satisfy the requirement of the Ericsson-type refrigerator working in the temperature range from 154K to 214K.     

Optical bistability based on surface plasmon coupled between two noble metal films involving Kerr materials

We successfully investigate an optical bistability phenomenon in a layered structure consisting of Kretschmann configuration involving the Kerr-type nonlinear and the silver film. Pure theoretical approaches are employed to investigate that the surface plasmon could easily be coupled and both the reflection and transmission curves versus the incident intensity forms optical bistability. The transmission curves are greatly influenced by the thickness of the second silver film. These results may be useful for designing novel surface plasmon-based optical devices and will be essential for future classical and quantum information processes.     

椭偏光谱对复数折射率薄膜的研究——ITO膜光学常数的色散和生长规律

本文提出一个利用椭偏光谱测量复数折射率薄膜的方法。由于引入一个新的目标函数,把搜索的参量空间的维数减至四维,因此不但可以测得薄膜的光学常数和厚度,并且可同时确定衬底的光学常数。我们应用这个方法对射频溅射在硅衬底上生长的ITO膜光学常数的色散和生长规律进行了初步研究,发现硅衬底的表观光学常数也发生了变化 关键词：     

二维颗粒膜超导电性

我们对二维排列的Sn颗粒膜进行了低温R-T特性研究。样品是在充有氧气的真空室内用热蒸发方法制备的。因为颗粒尺寸、颗粒分布和颗粒间距的随机性,使得颗粒之间的Josephson耦合和热激发电子的hopping过程的强弱,在不同的样品中不同,观测到的结果可以理解为以下三类:1)向零电阻的K-T转变;2)电阻极小转变;3)金属-绝缘转变。 关键词：     

金属-绝缘体-半导体(Au-SiO2-Si)隧道结的负阻现象与发光特性

制备了Au-SiO_{2-Si结构MIS隧道发光结.测试并分析了该结的发光特性及电流-电压(I-V)特性.指出结的发光是由各膜层界面激发的表面等离极化激元(Surface Plasmon Polariton.SPP)与膜层表面粗糙度相互耦合的结果.观察到MIS结I-V特性中存在的负阻现象,采用SPP对电子的束缚模型对这一现象进行了初步分析.利用原子力显微镜(AFM)对结的表面形貌进行了观测,由此讨论了MIS隧道结的发光与电子在结内的隧穿输运特性之间的内在关系. 关键词：}     

La2CuO4在平行CuO2面磁场中的磁转变

本文在平均场近似下,给出一个关于在平行CuO₂面的磁场作用下,La₂CuO₄的磁转变理论。理论给出的临界磁场随温度T的变化,在定性上与实验相符。但是,从本文理论看,不存在多重临界点。简单讨论了理论和实验不符合的原因。 关键词：     

HT-6B托卡马克参数下低杂波驱动电流的密度窗口

在简晰的物理模型下,采用数值方法,研究了HT-6B托卡马克参数下的低杂波射线轨迹,波谱移动,功率吸收和驱动电流分布。结果表明,存在着驱动电流的密度窗口,即仅在一定的等离子体密度范围内才能驱动电流(通常在理论和实验上仅注意到驱动电流的密度上限)。文中对这种密度窗口的存在给予了物理解释,并进而讨论了影响驱动电流效率的主要因素。 关键词：