Spectral radiance reconstruction from trichromatic camera responses based on orthogonal test and regularized algorithm

Reconstruction of spectral information based on multi‐channel image system is a significant problem in color reproduction, detection, and recognition. A spectral radiance reconstruction from trichromatic digital camera responses is researched in this article. The mapping relationship between the trichromatic imaging system response and the incident spectral radiance is analyzed. Then, in order to remove the ill‐posedness of the problem, a regularized constraint solution model of spectral radiance reconstruction matrix is established. And the spectral radiance can be reconstructed by spectral radiance reconstruction matrices and trichromatic imaging system response. Finally, the spectral radiance reconstruction matrix is estimated by the system radiometric calibration experiment. The input radiance is offered by a LCD display. A 3‐factor and 9‐level orthogonal test is designed for the calibration experiment, and a test set of 24 colors is used for precision analysis. The results show that the average relative mean error of our method is 8.69%, it is lower than that of Wiener filtering method by 2.84%. The method can reconstruct spectral radiance information effectively.     

Cyclic thermal shock resistance of h-BN composite ceramics with La2O3–Al2O3–SiO2 addition

The effects of La₂O₃–Al₂O₃–SiO₂ addition on the thermal conductivity, coefficient of thermal expansion (CTE), Young's modulus and cyclic thermal shock resistance of hot-pressed h-BN composite ceramics were investigated. The samples were heated to 1000 °C and then quenched to room temperature with 1–50 cycles, and the residual flexural strength was used to evaluate cyclic thermal shock resistance. h-BN composite ceramics containing 10 vol% La₂O₃–Al₂O₃ and 20 vol% SiO₂ addition exhibited the highest flexural strength, thermal conductivity and relatively low CTE, which were beneficial to the excellent thermal shock resistance. In addition, the viscous amorphous phase of ternary La₂O₃–Al₂O₃–SiO₂ system could accommodate and relax thermal stress contributing to the high thermal shock resistance. Therefore, the residual flexural strength still maintained the value of 234.3 MPa (86.9% of initial strength) after 50 cycles of thermal shock.     

Effects of the joining process on the microstructure and properties of liquid-phase-sintered SiC-SiC joints formed with Ti foil

The joining of liquid-phase sintered SiC (LPS-SiC) ceramics was conducted using spark plasma sintering (SPS), through solid state diffusion bonding, with Ti-metal foil as a joining interlayer. Samples were joined at 1400 °C, under applied pressures of either 10 or 30 MPa, and with different atmospheres (argon, Ar, vs. vacuum). It was demonstrated that the shear strength of the joints increased with an increase in the applied joining pressure. The joining atmosphere also affected on both the microstructure and shear strength of the SiC joints. The composition and microstructure of the interlayer were examined to understand the mechanism. As a result, a SiC-SiC joining with a good mechanical performance could be achieved under an Ar environment, which in turn could provide a cost-effective approach and greatly widen the applications of SiC ceramic components with complex shape.     

管状带式输送机在线纠扭托辊的研究与应用

管状带式输送机是一种新型环保的散状物料连续输送设备,在运行过程中受各种因素影响,头、尾过渡段经常会跑偏,管状段经常会扭转,常规停机调偏纠扭方法已不能胜任复杂路线长距离管带机稳定运行的要求。为适应市场发展趋势,设计人员分析了管带机扭转原因,结合纠扭基本原理及常规纠扭方法,新开发出一种在线(不停机)纠扭托辊并投入项目应用。     

Edge induced band bending in van der Waals heterojunctions: A first principle study

Nano Research - The dangling bond free nature of two-dimensional (2D) material surface/interface makes van der Waals (vdW) heterostructure attractive for novel electronic and optoelectronic...     

微型步进马达线架组自动卷线设备设计

微型步进马达线圈组卷线上下料基本靠手动作业,效率低下,同时因工人技术水平的不同造成产品品质不稳定的问题多发.为此专门设计了微型步进马达线圈组自动卷线及上下料设备.通过结合现阶段的先进工业技术,采用振动盘分离区分进料,多机构并联三菱PLC及威纶人机界面触摸屏研发了此微型步进马达线圈组自动上下料及卷线设备.通过该设备实现了微型步进马达因工人不足导致产能减少和品质多发问题,减少企业成本,提升产品品质.     

基于随机振动仿真分析的阵列天线结构改进

某型阵列天线属于机载设备,在做完随机振动试验后,第2个天线单元的一个辐射板被振裂.为了快速找到断裂原因,改进天线结构,利用有限元仿真软件ANSYS Workbench进行随机振动仿真分析.分析结果表明:原天线单元辐射板根部圆角太小,产生较大应力集中,最大3σ应力为102.74 MPa,超过材料疲劳极限应力87 MPa;改进后的天线结构,最大3σ应力降低24.2％,其数值为77.85 MPa,小于疲劳极限应力,满足设计要求.最终,改进后的天线结构顺利通过振动试验,有效验证了仿真分析与结构改进的合理性.     

Investigation of the piezoelectric and anti-reduction properties of (Ba,Ca) (Ti,Sn, Hf) textured ceramics prepared under low oxygen partial pressure conditions at low sintering temperatures

Multilayer piezoelectric ceramics must be sintered in a reducing atmosphere, preventing oxidation of the inner base metal. Plate-like textured (Ba, Ca)(Ti, Sn, Hf)O₃ ceramics with a <001> preferred orientation were successfully developed at a low oxygen partial pressure (PO₂:10^?8 atm) using a BaTiO₃ (BT) template with sintering temperatures < 1300 °C, which is beneficial for multilayer applications using base metal co-firing with ceramics. When adding the 3 wt% BT template, the proposed samples had a Lottgering factor of 84 %, piezoelectric coefficients d₃₃ = 324 pC/N, -d₃₁ = 122 (pC/N), and Q_m = 452, and the strain values increased from 0.07 % for the randomly oriented ceramics to 0.115 % at 20 kV/cm for the textured ceramics, confirming that the texturing behavior assisted the grain growth and improved both the soft and hard behaviors and insulation resistance of the proposed lead-free ceramics. These findings make a significant contribution to the production of high-power piezoelectric components.