Features of degradation and recovery of the optical properties of coatings based on ZnO powder modified with nanoparticles after irradiation

The effect of electron irradiation with energy of 30?keV and fluence up to 7?×?10¹⁶?cm^?2 on diffuse reflection spectra in situ of coatings based on ZnO powders unmodified and modified with zirconium dioxide and aluminum oxide nanopowders was investigated. The higher radiation stability of coatings based on modified pigments in comparison to unmodified pigments has been established. A significant recovery of the reflection spectra of irradiated coatings after exposure to residual vacuum and air was shown.     

减少光学元件亚表面缺陷的方法研究

针对强激光光学元件的应用要求,对光学材料在研磨和抛光过程中形成的亚表面缺陷进行了分析,并借鉴小工具数控抛光和Marangoni界面效应,提出采用数控化学刻蚀技术来实现光学表面面形和微结构形貌的高准确度加工.通过实验对亚表面缺陷的分布位置和特性进行了分析,实验验证了在静止和移动条件下Marangoni界面效应的存在.对材料的定量去除进行了实验,提出了亚表面缺陷的去除方法.     

珠宝店的光环境氛围指标及消费者心理感知的差异评价

珠宝是高端消费奢侈品,购物时的品质和美好的视觉体验影响消费者的购买行为,决定着品牌价值的提升.随着L ED光源的迅速普及与应用,在珠宝店的氛围营造上,照明因素(色温、照度和显色指数等)的作用越来越显著,本文针对珠宝店中四种色温条件下的氛围评价指标进行研究.采用可调色温的L ED光源,模拟珠宝店展示台的照明环境,运用可靠...     

Pressure screening and fluctuations at the bottom of a granular column

We report sets of precise and reproducible measurements on the static pressure at the bottom of a granular column. We make a quantitative analysis of the pressure saturation when the column height is increased. We evidence a great sensitivity of the measurements with the global packing fraction and the eventual presence of shear bands at the boundaries. We also show the limit of the classical Janssen model and discuss these experimental results under the scope of recently proposed theoretical frameworks. Received 7 September 1998 and Received in final form 28 January 1999     

Tuning magnetic,electronic, and optical properties of Mn-doped NiCr2O4 via microwave method

The main aim of the paper to the synthesis of Mn (x)-doped NiCr₂O₄ nanoparticles by varying Mn content (x = 0.00%, 0.01%, 0.02%, and 0.03%) by microwave method for correlating the effect of NiCr₂O₄ on structural, optical, and magnetic properties of the materials. Understanding the optical, magnetic, and structural properties of huge reservoir factors has essential applications in various aspects of materials science. Our study is to relate the reduction of grain size of Mn content in NiCr₂O₄ host material. The XRD results revealed that there was an apparent decrease in the characteristic peaks of Mn in the MnNiCr₂O₄ nanostructure. Particularly, the peak position of (2 2 0) and (3 1 1) planes was decreased. This decrease in peak position is attributed to the creation of defects or disorders due to the Mn ions in the chromite lattice structure. This inter-site Mn cation migration is responsible for the breaking of long-range cation order and the introduction of defects at both the T-site and O-sublattices site simultaneously.     

Solution combustion synthesis of calcium zirconate, CaZrO3, powders

Single-phase CaZrO₃ powder was prepared by heating at 300 °C an aqueous solution of Ca(NO₃)₂, ZrO(NO₃)₂ and β-C₃H₇NO₂ (molar ratio=3:3:4). TG-DTA analysis indicated that an intense exothermic reaction occurred at 255 °C, which lead to the formation of a voluminous white powder. No additional annealing was required, as pure crystalline CaZrO₃ resulted directly from the combustion reaction. Although no advanced milling was performed, the specific surface area of the powder was 21.5 m²/g. The average crystallite size of CaZrO₃ was 23.9 nm. After sintering in air at 1400 °C for 2 h, the pellets - shaped by uniaxial pressing at 200 MPa - reached 95% of the theoretical density, had no open pores and were slightly translucent.     

New polishing method using water-based slurry under AC electric field for glass substrate

We proposed an AC electric field-assisted novel polishing method for borosilicate glass plate with water-based slurry. It has been found that the applied electric field operates effectively in positioning the slurry with abrasives in the polishing area. In-situ observations also confirmed that the AC electric field affected the motion of slurry. Under optimal polishing conditions, the processing time of borosilicate glass plate was shortened compared to AC electric field free conditions. Furthermore, the polishing removal amount was increased from 14 to 22 μm for a polishing time of 30 min. This suggests that the productivity could be enhanced by 1.5 times by applying electric field during polishing.     

氢化物-原子荧光光谱法测定金属饰品中的砷和汞

采用氢化物-原子荧光光谱法测定金属饰品中砷和汞.用体积比为3:1的浓硝酸和浓盐酸微波消解样品.结果表明:砷和汞方法的检出限分别为0.079μg/L和0.037μg/L;砷、汞RSD分别为1.89%和4.82%;砷的加标回收率为99.6%,汞的加标回收率为96.0%.该方法快速简便,能满足饰品的日用检验要求.     

X射线荧光光谱粉末直接压片法测定哈默斯雷铁矿中的主次元素含量

本方法采用塑料环作镶圈，粉末直接压片，用X射线荧光光谱法测定哈默斯雷铁矿中的TFe、SiO2、Al2O3、P、S、Cu、MgO和Na2O的含量，试验结果表明：基体影响无需进行校正，方法的准确度和精密度均较高，结果令人满意。     

Thermal stability of amorphous Mg50Ni50 alloy produced by mechanical alloying

Amorphous Mg₅₀Ni₅₀ alloy was produced by mechanical alloying (MA) of the elemental powders Mg and Ni using a SPEX 8000D mill. The alloyed powders were microstructurally characterized by X-ray diffraction (XRD). The thermal transformation of amorphous Mg₅₀Ni₅₀ into stable intermetallics (Mg₅₀Ni₅₀ → remaining amorphous + Mg₂Ni → Mg₂Ni + MgNi₂) was analyzed using the Kissinger and isoconversional methods based on the non-isothermal differential scanning calorimetry (DSC) experiments. The apparent activation energies (E_a) and the transformation diagrams, temperature-time-transformation (T-T-T) and temperature-heating rate-transformation (T-HR-T), were obtained for both processes. A good agreement was observed between the calculated transformation curves and the experimental data, which verifies the reliability of the method utilized.