1 中国国检测试控股集团股份有限公司，北京 100024
2 中车青岛四方机车车辆股份有限公司，青岛 266111
高速动车组列车空调系统为乘员提供舒适乘车环境的同时也消耗了大量的能源，侧窗玻璃约占车身侧墙面积的30%，对列车空调系统的负荷影响很大。本文研究了列车静止和运动状态下侧窗玻璃的隔热性能，同时研究了玻璃组成和辐射率对侧窗玻璃隔热性能的影响。结果表明：列车静止状态下，随着玻璃辐射率从0.070增加到0.837，夹层中空玻璃的传热系数增加了105%，夹层-中空真空复合玻璃的传热系数增加了209%；列车高速运动状态下，夹层中空玻璃的传热系数增加了120%，夹层-中空真空复合玻璃的传热系数增加了228%。
高速动车组 侧窗玻璃 静止状态 运动状态 辐射率 传热系数 high-speed EMU bodyside window glass stationary status motion status emissivity thermal transmittance coefficient
1 宁波大学材料科学与化学工程学院, 宁波 315211
2 中国科学院宁波材料技术与工程研究所, 石墨烯工程实验室, 宁波 315201
在石墨烯的化学气相沉积工艺中, 铜箔是决定石墨烯薄膜质量的重要因素。传统铜箔由于制备工艺的限制, 存在大量的缺陷, 导致石墨烯薄膜的成核密度较高。本工作选用抛光铝板、抛光不锈钢板、微晶玻璃和SiO2/Si作为基材, 用热蒸镀法制备了不同粗糙度的铜箔, 并详细讨论了以该系列铜箔生长高平整度石墨烯薄膜的条件及铜箔对石墨烯薄膜品质的影响。实验结果表明, 铜箔以(111)取向为主, 与基材分离后, 表面具有纳米级平整度。在生长石墨烯后, 从SiO2/Si剥离的铜箔成核密度是4种基材中最小的。同时, 从SiO2/Si剥离的铜箔晶体结构变化最不明显, 具有良好的结晶性, 表面几乎不存在铜晶界缺陷。当压强为3 000 Pa, 氢气和甲烷流速分别为300 mL/min和0.5 mL/min时, 可以获得约1 mm横向尺寸的石墨烯单晶晶畴。
石墨烯薄膜 高平整度 抛光基材 热蒸镀 SiO2/Si基材 铜箔 成核密度 graphene film high flatness polished substrate thermal evaporation SiO2/Si substrate Cu foil nucleation density
武汉科技大学，省部共建耐火材料与冶金国家重点实验室，武汉 430081
以发泡-注凝工艺所制备的硅藻土多孔陶瓷为基体，借助溶剂热法原位生成的SiO2微球提高硅藻土多孔陶瓷的表面粗糙度，以Capstone FS-50 (CS-50)为改性剂改变多孔陶瓷的润湿状态，制备可用于油水乳液连续分离的SiO2微球和CS-50共改性的超亲水-超疏油硅藻土多孔陶瓷(SSMDPC)，研究了TEOS和NH3·H2O加入量及CS-50溶液的浓度对所制备改性试样微观形貌、润湿性及油水分离性能的影响。研究表明：SSMDPC在空气中和水下的油接触角最高分别可达153°和158°；其最佳制备工艺条件如下：TEOS和NH3·H2O加入量及CS-50溶液的掺杂量分别为5%(体积分数)和2%及5%。SSMDPC对食用油/水混合液体及食用油/水乳液(5:95，质量比)的连续分离通量和分离效率分别为162.3 kg·min-1·m-2和98.3%、93.7 kg·min-1·m-2和91.3%；SSMDPC在pH=1、pH=14、1 mol/L NaCl、-196 ℃及200 ℃的条件下，仍能保持稳定的亲水疏油性，说明其在油水乳液分离方面具有广阔的应用前景。
油水乳液 超亲水-超疏油 硅藻土多孔陶瓷 表面改性 oil-water emulsion superhydrophilic-superoleophobic diatomite porous ceramics surface modification
1 北京工业大学材料与制造学部, 北京 100124
2 工业大数据应用技术国家工程实验室, 北京 100124
3 北京建筑材料科学研究总院有限公司, 北京 100041
4 固废资源化利用与节能建材国家重点实验室, 北京 100041
在自修复水泥基材料中, 微胶囊与水泥基体间的界面结合决定着微胶囊被裂缝触发的概率, 从而影响自修复效果。本文针对吸水性微胶囊的界面结合问题, 利用硅烷偶联剂KH550修饰环氧/海藻酸钙微胶囊表面, 以改善其与水泥基体间的界面结合情况。采用X射线光电子能谱仪、电感耦合等离子体发射光谱仪等表征硅烷偶联剂在微胶囊表面的键合状况, 利用压汞法分析水泥基材料的孔结构, 并测试水泥基材料的抗渗性与自修复效果。结果表明, 硅烷偶联剂能够与微胶囊外壁的海藻酸钙发生化学键合, 微胶囊与水泥基体间的界面结合得到有效改善, 水泥基体中有害孔数量减少, 无害孔和少害孔数量增加, 水泥基材料的抗渗性和自修复效果获得提升。
水泥基材料 自修复 吸水性微胶囊 硅烷偶联剂 界面修饰 环氧/海藻酸钙微胶囊 cement-based material self-healing water absorbent microcapsule silane coupling agent interface modification epoxy/calcium alginate microcapsule
Lei Han 1,2,3Yuanbin Gao 1,2,3Sheng Hang 1,2,3Chunshuang Chu 1,2,3,*[ ... ]Zi-Hui Zhang 1,2,3,**
Author Affiliations
Abstract
1 State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin 300401, China
2 Key Laboratory of Electronic Materials and Devices of Tianjin, School of Electronics and Information Engineering, Hebei University of Technology, Tianjin 300401, China
3 Hebei Key Laboratory of Advanced Laser Technology and Equipment, Tianjin 300401, China
4 Key Engineering Center of Flat-Panel-Display Glass and Equipment, Shijiazhuang 050035, China
The hole injection capability is essentially important for GaN-based vertical cavity surface emitting lasers (VCSELs) to enhance the laser power. In this work, we propose GaN-based VCSELs with the p-AlGaN/p-GaN structure as the p-type hole supplier to facilitate the hole injection. The p-AlGaN/p-GaN heterojunction is able to store the electric field and thus can moderately adjust the drift velocity and the kinetic energy for holes, which can improve the thermionic emission process for holes to travel across the p-type electron blocking layer (p-EBL). Besides, the valence band barrier height in the p-EBL can be reduced as a result of usage of the p-AlGaN layer. Therefore, the better stimulated radiative recombination rate and the increased laser power are obtained, thus enhancing the 3 dB frequency bandwidth. Moreover, we also investigate the impact of the p-AlGaN/p-GaN structure with various AlN compositions in the p-AlGaN layer on the hole injection capability, the laser power, and the 3 dB frequency bandwidth.
GaN-based VCSEL hole injection laser power modulation response Chinese Optics Letters
2022, 20(3): 031402
1 湖北中烟工业有限责任公司, 湖北 武汉 430050
2 湖北工业大学机械工程学院, 湖北 武汉 430068
3 上海市激光技术研究所, 上海市激光束精细加工重点实验室, 上海 200233
在介绍SLM进行光束整形原理的基础上, 分析了二元光栅、闪耀光栅和正弦光栅三种光栅的结构特性, 并根据影响整形光束质量的性能指标, 以方向光斑为例, 设计了不同周期的相位掩模图。成像和加工试验表明, SLM上加载三种光栅形成的掩模图, 均可以将高斯分布的圆形光斑整形为平顶的方形光斑, 但闪耀光栅的整形效果明显优于另外两种光栅。在闪耀光栅周期为120 μm时, 局部能量利用率达到91.86%, 均方根误差为0.039, 整形后光束具有较好的均匀性。
光束整形 二元光栅 闪耀光栅 正弦光栅 beam shaping binary grating blazed grating sinusoidal grating
武汉科技大学，省部共建耐火材料与冶金国家重点实验室，武汉 430081
先采用发泡-注凝成型法制备了硅藻土多孔陶瓷，并以此为基体，以Capstone FS-50(CS-50)为改性剂，通过真空浸渍法制备了超亲水-疏油硅藻土多孔陶瓷，研究了烧结温度对硅藻土多孔陶瓷物相组成、显微形貌及常温物理性能及CS-50用量(质量分数)对改性硅藻土多孔陶瓷表面的油接触角及化学稳定性的影响。结果表明：随着烧结温度的升高(1 100~1 200 ℃)，硅藻土多孔陶瓷中圆盘状硅藻土自身的多孔结构被堵塞的越来越严重，孔隙率由84.3%降至81.6%，而抗压强度从0.93 MPa增至2.01 MPa；随着CS-50用量的增大，所制备改性硅藻土多孔陶瓷的油接触角呈先增加后趋于稳定的变化趋势；当CS-50的用量为5%(质量分数)时，改性多孔陶瓷的油接触角高达138°，且其水接触角约为0°。此外，改性硅藻土多孔陶瓷在强酸、强碱以及盐腐蚀条件下，仍能保持稳定的亲水疏油性能。
发泡-注凝成型 表面改性 硅藻土多孔陶瓷 超亲水-疏油 foam-gelcasting surface modification diatomite porous ceramics superhydrophilic-oleophobic
MOE Key Laboratory of Material Physics and Chemistry under Extraordinary Conditions, and Shaanxi Key Laboratory of Optical Information Technology, School of Science, Northwestern Polytechnical University, Xi’an 710072, China
Frontiers of Optoelectronics
2019, 12(1): 0169–87
Author Affiliations
Abstract
MOE Key Laboratory of Material Physics and Chemistry under Extraordinary Conditions, and Shaanxi Key Laboratory of Optical Information Technology, School of Science, Northwestern Polytechnical University, Xi’an 710129, China
We propose an efficient and robust method to generate tunable vector beams by employing a single phase-type spatial light modulator (SLM). With this method, a linearly polarized Gaussian beam can be converted into a vector beam with arbitrarily controllable polarization state, phase, and amplitude. The energy loss during the conversion is greatly reduced and depends mainly on the reflectivity of the SLM. We experimentally demonstrate that conversion efficiency of about 47% is achieved by using an SLM with reflectivity of 62%. Several typical vector beams, including cylindrical vector beams, vector beams on higher order Poincaré spheres, and arbitrary vector beams attached with phases and with tunable amplitude, are generated and verified experimentally. This method is also expected to create high-power vector beams and play important roles in optical fabrication and light trapping.
Polarization Singular optics Spatial light modulators Photonics Research
2018, 6(4): 04000228
