Defect‐free half‐V‐mode ferroelectric liquid‐crystal device

Abstract— The horizontal chevron defect found in a half‐V‐mode ferroelectric‐liquid‐crystal (HV‐FLC) device can be suppressed by lowering the FLC's total free energy. The energy levels between spontaneous polarization (PS) up and down domains were degenerated by asymmetrical‐alignment treatments. The difference in the polar surface coefficient (γ²) was the key to suppressing the alignment defect. Alignment layers with opposite surface polarities and different anchoring energies were applied to control the sign and value of γ². The asymmetric cells of PIrub ‐ PIplasma (rubbed polyimide and plasma‐treated polyimide surfaces), PVArub ‐ PIplasma (rubbed polyvinyl alcohol and plasma‐treated polyimide surfaces), and PVArub ‐ PIplasma (both rubbed PI and PVA) alignment conditions presented defect‐free alignment textures under a slow‐cooling process. Among these different alignment treatments, the PVArub ‐ PIrub treated cell demonstrated the best alignment result, benefited by the largest difference in polar surface coefficient.     

人字形中心支撑钢框架近场地震下层剪力分布

为研究人字形中心支撑钢框架（CBSF）弹塑性状态下层剪力分布,设计了6个具有理想屈服模式的CBSF结构,采用非线性动力时程分析法获得了结构在近场地震下的层剪力分布,提出了层剪力分布模式,并同已有的层剪力分布模式进行了对比.分析表明,近场速度脉冲效应对CBSF结构层剪力分布影响较大;提出的层剪力分布模式在精度上优于已有的层剪力分布模式.     

神经网络在研究岩石断裂韧度尺寸效应的应用

介绍了人工神经网络在预测人字形切槽巴西圆盘试样(CCNBD)断裂韧度时的应用，通过分析表明，神经网络得到的断裂韧度预测值比CCNBD尺度律公式得到的值更加接近实验值，神经网络直接基于实验数据进行训练，不需要作任何假设，对于构形比较复杂，试样制备时难以满足完全几何相似的CCNBD试样，研究其尺寸效应是比较有利的。     

Near‐to‐eye display with diffractive exit pupil expander having chevron design

Abstract— Near‐to‐eye displays (NEDs) provide a unique way to perceive a larger image than the device itself. The user acceptance of commercially available NEDs has not been high partly because of reported physiological symptoms. Devices also tend to be thick and heavy, and therefore uncomfortable to wear. To overcome these shortcomings and to make a very usable device, a new approach was needed. By using very thin plastic light guides with diffractive structures on the surfaces, many of the known obstacles can be notably reduced. These exit pupil expanders (EPEs) enable a light and thin design for see‐through NEDs. The so‐called chevron EPE was designed to further improve the design and usability aspects of NEDs. The diffractive EPE has typically one incoupling grating area that delivers light into the light guide symmetrically towards the left and right eyes. By using slanted or overhanging gratings, the incoupling is very asymmetric. If the incoupling area is divided into two parts, each having opposite slanting angles, the EPE plate can be cut in half, and the left and right parts can be separated. The plates can be further tilted to a chevron shape following more closely the human face and mimicking the conventional eyeglass design. The reflection of the light from the tilted plate is directed out from the image‐forming optics, and therefore the contrast is improved. The privacy of the usage is improved because at the output the secondary beams are harder to observe. Because the device is brought closer to face, it enables better weight balance. The chevron geometry partially prevents the ambient light from the sides to enter the diffractive structures, and thus the unwanted reflections are also reduced. Furthermore, the half‐size of the chevron EPE parts from the undivided EPE results in a better production yield.     

滑移线连续和平稳分布的变径车轮设计

基于轮地接触动力学理论,设计出一种适应沙壤土环境、具有内外双层紧贴刚性轮片和中部轮刺的新型变径车轮.分析了变径轮不同断面与土壤的作用机理和土壤流动滑移模型,通过对滑移线公式详细推导和数值计算,获得其滑移半径和等效轮周的变化规律,提出了以断面高度为主、倾角为辅的设计思想.建立了满足平稳和连续滑移线模型的剪切滑移交错层断面...     

密炼机漏粉分析和进料门门封改造

分析常见的密炼机漏粉现象,指出改进思路,通过对进料门门封改进,使其在打开关闭门的运动过程中,磨擦阻力降低,磨损量减小,达到易拆易装寿命长的目的。采用了无润滑密封设计,其结果使我公司的密炼机密封结构更趋于合理,主机密封性能得到提高,使机台环境卫生、厂区周边环境进一步改善。     

大厚板高强钢补焊横向裂纹试验及产生机理

大厚板高强钢构件补焊易产生横向冷裂纹,为了探究其补焊横向裂纹的产生原因,设计了一种小窗口两端加强约束裂纹试验方法来模拟现场施工情况,预制出补焊的横向裂纹.通过金相观察和微观硬度测.试结果表明,在补焊区域出现较大横向裂纹,裂纹面与焊接方向呈45°,这主要是由于氢含量过高和拘束应力过大而引起的氢致裂纹,并在补焊底部熔合区出...     

折流板式除雾器的结垢与控制措施

针对锅炉脱硫系统折流板式除雾器在运行过程中发生的结垢、堵塞问题,阐述了折板式除雾器的工作原理和布置型式,从设计不合理、烟气流速变化无常、吸收塔浆液过饱和度较大、氧化效果不理想等方面分析了折流板式除雾器结垢的原因,提出了减缓除雾器结垢的控制措施,有效地抑制了除雾器的结垢,确保了脱硫系统正常运行.