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Trapping and Driving Individual Charged Micro-particles in Fluid with an Electrostatic Device

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Nano-Micro Letters 2016年第3期8卷 270-281页

作者： Jingjing Xu Zijing Lei jingkun guo Jie Huang Wei Wang Uta Reibetanz Shengyong Xu Key Laboratory for the Physics & Chemistry of Nanodevices and Department of Electronics Peking University Institute of Microelectronics Peking University Medical Faculty Institute for Medical Physics and Biophysics University of Leipzig

A variety of micro-tweezers techniques, such as optical tweezers, magnetic tweezers, and dielectrophoresis technique, have been applied intensively in precise characterization of micro/nanoparticles and bio-molecules. They have contributed remarkably in better understanding of working mechanisms of individual sub-cell organelles, proteins, and DNA. In this paper, we present a controllable electrostatic device embedded in a microchannel, which is capable of driving,trapping, and releasing charged micro-particles suspended in microfluid, demonstrating the basic concepts of electrostatic tweezers. Such a device is scalable to smaller size and offers an alternative to currently used micro-tweezers for application in sorting, selecting, manipulating, and analyzing individual micro/nanoparticles. Furthermore, the system offers the potential in being combined with dielectrophoresis and other techniques to create hybrid micro-manipulation systems.

关键词： Electrostatic tweezers Charged particles Coulomb potential well Manipulation Trap

Integrated optical-readout of a high-Q mechanical out-of-plane mode

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Light(Science & Applications) 2022年第10期11卷 2485-2491页

作者： jingkun guo Simon Groblacher Kavli Institute of Nanoscience Department of Quantum NanoscienceDelft University of Technology2628CJ DelftThe Netherlands

The rapid development of high-QM macroscopic mechanical resonators has enabled great advances in *** improvements could allow for quantum-limited or quantum-enhanced applications at ambient *** of the remaining challenges include the integration of high-QM structures on a chip,while simultaneously achieving large coupling strengths through an optical ***,we present a versatile fabrication method,which allows us to build fully integrated optomechanical *** place a photonic crystal cavity directly above a mechanical resonator with high-QM fundamental out-of-plane mode,separated by a small *** highly confined optical field has a large overlap with the mechanical mode,enabling strong optomechanical interaction ***,we implement a novel photonic crystal design,which allows for a very large cavity photon number,a highly important feature for optomechanical experiments and sensor *** versatile approach is not limited to our particular design but allows for integrating an out-of-plane optical read-out into almost any device ***,it can be scaled to large arrays and paves the way to realizing quantum experiments and applications with mechanical resonators based on high-QM out-of-plane modes alike.

关键词： optical resonator mode

Tape Casting of Al_2O_3-TiB_2/Al_2O_3-Nano-TiC Multilayer Composites

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Journal of Materials Science & Technology 1997年第4期13卷 324-326页

作者： Yuping ZENG Dongliang JIANG Shouhong TAN and jingkun guo(Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China) Shanghai Institute of Ceramics Chinese Academy of Sciences Shanghai 200050 China

Ceramic tapes, containing Al2O3-25 wt pct TiB2(B) and Al2O3-25 wt pct nano-TiC (c), have been obtained by tape casting process. Numerous tapes (about 60～80 tapes) were prepared by stacking in turn the composition (B) and (C), laminating under 10 MPa pressure, eliminating the solvent and burning out the polymer additives. The final green bodies were hot pressed at 1750℃ and 30 MPa. The composite has a bending strength of 568 MPa and a fracture toughness of 5.8 M Pa·m1/2. SEM analysis exhibits that Al2O3 particle growth was inhibited by TiC particles in C. but TiB2 particles could not hinder Al2O3 growth in B. The curves of GTA indicates that all organic additives could be removed completely above 600℃

关键词： Nano TiB Al Tape Casting of Al2O3-TiB2/Al2O3-Nano-TiC Multilayer Composites TiC

Solid-state-reaction fabrication and properties of a high-doping Nd:YAG transparent laser ceramic

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Frontiers of Chemical Science and Engineering 2008年第3期2卷 248-252页

作者： Jiang LI Yusong WU Yubai PAN Wenbin LIU Liqiong AN Shiwei WANG jingkun guo Shanghai Institute of Ceramics Chinese Academy of SciencesShanghai 200050China Graduate School of the Chinese Academy of Sciences Beijing 10039China

High-quality neodymium-doped yttrium aluminum garnet(Nd:YAG)transparent ceramic(4.0 mole percent)was fabricated by a solid-state reaction method and vacuum *** microstructure,optical transmittance,spectral properties and laser performance were *** average grain size of the sample is about 10 *** transmittance of a 2.8-mm thick sample reaches 79.5%at the laser wavelength of 1064 *** highest absorption peak is centered at 807 nm and the absorption coefficient is 13.9 cm^(-1).The absorption coefficient at the laser wavelength is 0.2 cm^(-1).The main emission peak is at 1064 nm and the fluorescence lifetime is 102 ms.A laser diode(808 nm)whose maximum output is about 1000 mW was used as a pump source and an endpumped laser experiment was *** 1064 nm-CW-laser output was obtained and the threshold is 733 *** 998 mW of maximum absorbed pump power,a laser output of 17 mW is obtained with a slope efficiency of 6.1%.

关键词： transparent laser ceramic optical properties microstructure high-doping concentration solid state reaction

Morphological characteristics of α-Al_2O_3 crystallites obtained directly from hydro/solvothermal solvents

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Chinese Science Bulletin 1998年第2期43卷 163-166页

作者： WANG Buguo, TIAN Mingyuan, SHI Erwei, ZHONG Weizhuoand guo jingkun Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 201800, China Shanghai Institute of Ceramics Chinese Academy of Sciences Shanghai China

The morphological characteristics of α_Al-2O-3 crystallites obtained directly from hydro/solv othermal solvents are reported and the formation mechanisms of corundum morphology are discussed from crystal growth and crystal chemistry principles. The crystal growth process is considered as a process of incorporation of growth units on the growth interfaces, and the crystal morphology is determined by the linkage of the coordinated polyhedra.

关键词： hydrothermal crystallization α_Al-2O-3 crystallites morphology growth mechanisms.

PREPARATION OF WC-Co POWDER BY DIRECT REDUCTION AND CARBONIZATION

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China Particuology 2005年第5期3卷 286-288页

作者： Zhonglai Yi Gangqin Shao Xinglong Duan Peng Sun Xiaoliang Shi Zhen Xiong jingkun guo State Key Laboratory of Advanced Technology for Materials Synthesis & Processing Wuhan University of Technology Wuhan 430070 P. R. China

A new approach to produce superfine WC-Co powder by direct reduction and carbonization is proposed. Water-soluble salts containing W and Co were used as raw materials. Tungsten and cobalt oxide powder （CoWO4/WO3） was first formed by a spray-pyrolysis technique, which was then mixed with carbon black and converted to WC-Co composite powder at 950℃ for 4 h in N2 atmosphere. The resulting powder has a particle size of 100-300 nm.

关键词： tungsten carbide-cobalt (WC-Co) direct reduction and carbonization composite powder

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从复合材料到多相材料

材料研究学报 2000年第2期14卷 122-126页

作者：郭景坤中国科学院上海硅酸盐研究所

本文提出多相材料的概念，以模糊各类材料之间的界限运用纳米材料的工艺技术，并博采各类材料工艺之所长，以使用要求为材料研究的准则，做到以低成本制作材料和获得高的性能稳定性，通过对材料的设计，获得能满足使用要求的材料，叙述... 详细信息

本文提出多相材料的概念，以模糊各类材料之间的界限运用纳米材料的工艺技术，并博采各类材料工艺之所长，以使用要求为材料研究的准则，做到以低成本制作材料和获得高的性能稳定性，通过对材料的设计，获得能满足使用要求的材料，叙述了对陶瓷／金属多相材料、陶瓷／聚合物多相材料、金属／聚合物多相材料以及多相复合陶瓷材料的设想。

关键词：多相材料复合材料纳米材料

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农药在线混合均匀度高速摄影分析

农业机械学报 2011年第8期42卷 75-79页

作者：徐幼林郭敬坤郑加强南京林业大学机械电子工程学院南京210037 无锡市东方环境工程设计研究所无锡214125

利用高速摄影技术对农药混药装置在线混合均匀度进行了试验分析。选用聚苯乙烯颗粒作为示踪粒子跟随混合液流动,根据获得的粒子图像提取了粒子的质心坐标,对不同工况下混药装置的混合均匀度进行了分析计算,并得到泵工作条件对混合效果... 详细信息

利用高速摄影技术对农药混药装置在线混合均匀度进行了试验分析。选用聚苯乙烯颗粒作为示踪粒子跟随混合液流动,根据获得的粒子图像提取了粒子的质心坐标,对不同工况下混药装置的混合均匀度进行了分析计算,并得到泵工作条件对混合效果的影响以及粒子分布与混合效果的关系。研究结果表明,示踪粒子质心纵坐标分布与正态分布越接近,混合效果越好;当泵转速较低时,随着泵工作压力增大,混合均匀度增大;当泵的工作压力不变时,随着泵工作转速提高,混合均匀度提高。

关键词：植保机械混药器在线混合混合均匀度高速摄影

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混药器流体图像采集与分割方法

农业机械学报 2009年第1期40卷 83-86,90页

作者：郭敬坤徐幼林汪希伟南京林业大学机械电子工程学院南京210037

通过在农药中加入示踪粒子,利用高速摄像机采集喷雾机农药与清水通过混药器在线混合后流体混合图像的方法,研究了喷雾机农药与水在线混合的混合效果。对于原始粒子图像均匀度较差的问题,提出了基于形态学的校正方法,利用灰度增强的Otsu... 详细信息

通过在农药中加入示踪粒子,利用高速摄像机采集喷雾机农药与清水通过混药器在线混合后流体混合图像的方法,研究了喷雾机农药与水在线混合的混合效果。对于原始粒子图像均匀度较差的问题,提出了基于形态学的校正方法,利用灰度增强的Otsu法对粒子图像进行了有效分割,提取了粒子质心坐标等参数。

关键词：混药器流动图像处理阈值分割