Structural Change in Au^3＋-Doped BK7 Glass Irradiated by Femtosecond Laser

We report on structural change in an Au^3＋-doped BK7 glass irradiated by an infrared femtosecond laser at 800 nm. A grating structure is inscribed in the glass sample. The glass sample is then annealed at various temperatures. Structural change of the grating is observed by an optical microscope. Absorption spectra indicate that colour centres are induced after the laser irradiation, and they decrease with increasing annealing temperature. Au nanoparticles are precipitated at high temperatures （≥ 600℃）. The mechanisms of the phenomena are discussed.     

Magnetocaloric effect in ErCo2 compound

The ErCo2 compound is prepared by arc-melting and its entropy changes are calculated using Maxwell relation. Its entropy change reaches 38 J/（kg·K） and its refrigerant capacity achieves 291 J/kg at 0-5 T. The mean field approximation is used to calculate the magnetic entropy of ErCo2 compound. Results estimated by using the Maxwell relation deviate from mean field approximation calculations in ferrimagnetic state; however, the data obtained by the two ways are consistent in the vicinity of phase transition or at higher temperatures. This indicates that entropy changes are mainly derived from magnetic degree of freedom, and the lattice has almost no contribution to the entropy change in the vicinity of phase transition but its influence is obvious in the ferrimagnetic state below TC.     

Laser-diode excited intense upconversion luminescence of Er^3＋ in bismuth-lead-germanate glasses

We have investigated infrared-to-visible upconversion luminescence of Er^3＋ in bismuth-lead-germanate glasses. The UV cutoff wavelength is shortened while its lifetime is increased almost linearly, with PbF2 substituting for PbO in the bismuth-lead germanate glasses. Three emissions centred at around 529, 545 and 657 nm are clearly observed, which are identified as originating from the ^2H11/2→^4 I15/2,^4S3/2→^4 I15/2 and ^4 F9/2 →^4 I15/2 transitions, respectively. It is noted that all the upconversion emission intensities increase with PbF2 concentration increasing. The ratio between the intensities of red and green emissions increases with the increasing of PbF2 content. Energy transfer processes and nonradiative phonon-assisted decays account for the populations of the ^2 H11/2,^4 S3/2 and ^4F 9/2 levels. The quadratic dependence of fluorescence on excitation laser power confirms a two-photon process to contribute to the upconversion emissions.     

Propagation Properties of Gaussian-Shaped and Double-Side Unsymmetrical Metallic Nano-Corrugations

A Gaussian-shaped and double-side unsymmetrical groove structure is presented. Rigorous calculation of the optical properties of the structure is performed on the basis of a multiple multipole program. We analyse the effect of the grating period, the groove width and the film thickness on transmission and reflectance. Simulation results demonstrate that surface-plasmon-polariton resonance positions depend strongly on the structure period and can be changed slightly by the variation of incomplete perforation thickness, while the resonance peak values can be controlled by tuning the groove width. Our results not only give an insight into the physical mechanisms of the double-side unsymmetrical gratings, but also open a way to design novel nano-photonic devices.     

Electrical Characterization of Metal-Insulator-Metal Capacitors with Atomic-Layer-Deposited HfO2 Dielectrics for Radio Frequency Integrated Circuit Application

Metal-insulator-metal （MIM） capacitors with atomic-layer-deposited HfO2 dielectric and TaN electrodes are investigated for rf integrated circuit applications. For 12nm HfO2, the fabricated capacitor exhibits a high capacitance density of 15.5fF/μm2 at 100kHz, a small leakage current density of 6.4 × 10^-9 A/cm^2 at 1.8V and 125℃, a breakdown electric field of 2.6 MV//cm as well as voltage coefficients of capacitance （VCCs） of 2110ppm/V^2 and -824 ppm/V at 100kHz. Further, it is deduced that the conduction mechanism in the high field range is dominated by the Poole-Frenkel emission, and the conduction mechanism in the low field range is possibly related to trap-assisted tunnelling. Finally, comparison of various HfO2 MIM capacitors is present, suggesting that the present MIM capacitor is a promising candidate for future rf integrated circuit application.     

巴乌（Bay，Zoltan，1900-1992）匈牙利物理学家（Physicist，Hungary）

雷达是利用金属物体对电磁波的反射来测定物体的方位的。用脉冲装置测量电离层高度的工作对雷达的发明有启发。由于在军事上用途大，在二战中发展较快。研究规模仅次于美、英两国发展原子弹和德国发展V2火箭所投入的人力物力。巴乌也独立地对发展雷达作出了贡献。匈牙利邮票B15中画有1946年生产的手持雷达。     

ICF靶用空心玻璃微球耐压性能测试

 利用自行研制的空心微球耐外压装置和充气装置，测试了目前激光惯性约束聚变实验打靶使用的空心玻璃微球耐内压能力和耐外压能力。空心玻璃微球采用液滴法制备，直径为180～250 mm、壁厚为0.8~4.0 mm。理论计算表明，当微球纵横比超过90时，耐外压能力与球壳材料的杨氏模量有关，由此测量得到的空心玻璃微球杨氏模量为55~75 GPa。玻璃微球的耐内压能力主要与球壳材料的抗拉强度有关，实验测量得到的玻璃微球抗拉强度为90~140 MPa。     

掺铒铋酸盐玻璃光谱性质的组分依赖性研究

通过测试掺铒铋酸盐玻璃43Bi2O3-xB2O3-（57-x）SiO2（x=10，20，30，40，50mol％）中Er^3＋离子的吸收光谱、荧光光谱、荧光寿命及荧光强度，结合Judd—Ofelt和McCumber理论，对玻璃中Er^3＋离子光谱性质随玻璃组分的依赖关系进行了系统研究．研究结果显示，掺铒铋酸盐玻璃具有较其它玻璃优异的光谱性质．随着玻璃中组分B2O3含量的增加，强度参量Ω6、荧光半高宽和能级^4I15／2→^4I13/2间自发辐射跃迁几率相应增加，而荧光寿命、荧光强度和受激发射峰值截面相应减小，带宽品质因子（σe^pcak×FWHM）在组分B2O3含量30mol％时达到最大．     

肖特TFT-LCD玻璃熔化炉全新亮相——投资6千万元 创造100个就业岗位

总部位于德国美茵兹的科技型企业—肖特股份有限公司（SCHOTT AG）近日宣布其位于耶拿厂的大型薄膜晶体管液晶显示器（TFT—LCD）玻璃基板全新熔化炉正式投放运行。肖特集团投资6千万欧元，建造了其行2个平板显示器专用的熔化炉，为耶拿的肖特显示器玻璃有限公司创造了100多个就业岗位。     

尚智之选：多普达C858智能手机

供你耍酷的至尊商务名器终于进化了，从838到C858，多普达将其大卖的侧滑智能手机带入了第二代。与838中性的设计风格相比，C858明显男性化了。2．8英寸的显示屏占据了正面的绝大部分位置，哑光银色的功能键区被安排在其下。C858的前壳为金属材质面板，