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Microstructure, tensile properties and creep behavior of Al-12Si-3.5Cu-2Ni-0.8Mg alloy produced by different casting technologies

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Journal of Materials Science & Technology 2018年第7期34卷 1222-1228页

作者： Lijie Zuo Bing Ye Jian Feng xiangyang kong Haiyan Jiang Wenjiang Ding National Engineering Research Center of Light Alloy Net Forming and State Key Laboratory of Metal Matrix Composites Shanghai Jiao Tong University Shanghai 200240 China Institute of Materials for Mobile Energy School of Materials Sdence and Engineering ShanghaiJiao Tong University Shanghai 200240 China

The relationship between the as-cast microstructure and mechanical properties of the ***- 2Ni-0.8Mg alloys produced by permanent mold casting （PMC） and high pressure die casting （HPDC） is investigated. The alloys in both PMC and HPDC consist of Al, Si, A15 Cu2 MgsSi6, Al3 CuNi, and Al Cu4Ni phase. However, the microstructure of the HPDC alloy is significantly refined. Compared to the PMC alloy, the ultimate tensile strength of the HPDC alloy is significantly increased from 244 MPa to 310 MPa, while the elongation shows a reverse trend at room temperature. At low stress and temperature range, slight variations of stress exponent and activation energy indicate that the minimum creep rate is controlled by the grain boundary creep. Then the minimum creep rate is higher for the specimen with the smaller grain size, where grain boundary creep is the dominant creep mechanism. At high stress region, the stress exponent for the PMC alloy and HPDC alloy is 5.18 and 3.07, respectively. The different stress exponents and activation energies measured at high stress and high temperature range indicates that the creep mechanism varies with the casting technologies.2017 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science ＆ Technology.

关键词： Microstructure Tensile properties CreepHigh pressure die casting

A Detection Method of Earthquake Precursory Anomalies Using the Four-Component Borehole Strainmeter

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Open Journal of Earthquake Research 2018年第2期7卷 124-140页

作者： xiangyang kong Kaizhi Su Fujinawa Yukio Noda Yoichi Earthquake Administration of Shandong Province Jinan China Institute of Crustal Dynamics China Earthquake Administration (CEA) Beijing China Organization for Development of Resilient Communities Tokyo Japan Tierra-Tecnica Co. Ltd. Tokyo Japan

Strainmeters have been used to detect earthquake precursory anomalies in many countries. An innovated four-component strainmeter with four sensing units set at 45 degrees intervals, named SKZ strainmeter, was developed and used in China. The design, with a few unique features, allows high-sensitivity monitoring of the regime of the crustal strain field, as well as the self-consistencies of the instrument. One of the most difficult problems in the earthquake precursory investigation is to efficiently detect anomalies from large amount of data. Pattern recognition of waveforms is widely used, but it is time-consuming and relies more or less investigator’s experience and decision. In this study, the consistency factors of the paired components were firstly shown to be utilized to detect anomalies possibly related with imminent earthquakes. Here, rather than using the consistency factors, the correlation coefficients of the two orthogonal strain data were used to detect. SKZ strainmeters have been installed at more than ten sites in China, exhibited high efficiency and reliability in precursory monitoring since. Anomalous variations from a few stations during two recent earthquakes in south China were analyzed. During normal stages, diurnal earth tides could be clearly observed with very little urban noises. Though the consistency factors may have near constant bias, their correlation coefficients remain near 1.0, greater than 0.99. During the imminent preparatory stage of earthquake occurrence, non-planar strain may appear and the correlation coefficients drop noticeably. The analysis showed that the correlation coefficient between the two orthogonal components is a useful parameter in post-processing of the strain data to detect precursory anomalies. The resultant resolving power is shown to be some one-order larger compared with previous methods.

关键词： Borehole Strainmeter Earthquake Observation Technology Pre-Seismic Anomalies Data Filtering

A quasi-3D Fano resonance cavity on optical fiber end-facet for high signal-to-noise ratio dip-and-read surface plasmon sensing

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Light(Advanced Manufacturing) 2022年第4期3卷 39-49页

作者： Xiaqing Sun Zeyu Lei Hao Zhong Chenjia He Sihang Liu Qingfeng Meng Qingwei Liu Shengfu Chen xiangyang kong Tian Yang State Key Laboratory of Advanced Optical Communication Systems and Networks Key Laboratory for Thin Film and Microfabrication of the Ministry of EducationSchool of Electronic Information and Electrical EngineeringShanghai Jiao Tong UniversityShanghai 200240China School of Material Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China Key Laboratory of Biomass Chemical Engineering College of Chemical and Biological EngineeringZhejiang UniversityHangzhou 310027China

Surface plasmon devices mounted at the end-facets of optical fibers are appealing candidates for rapid and point-of-care sensing applications,by offering a special dip-and-read operation *** present,these devices’noise-equivalent limits-of-detection lag far behind the free-space counterparts,leaving them incapable of most biosensing *** we report a quasi-3D Fano resonance cavity and its fabrication method to fundamentally improve the quality factor and coupling efficiency for fiber-coupled surface plasmon *** this device,the Fano resonance combines the high coupling efficiency of a Fabry-Pérot etalon and the high quality factor resonance of a plasmonic crystal *** quasi-3D device was fabricated on a planar substrate and transferred to a single-mode fiber end-facet,which requires a low-adhesion yet surface-plasmon-tunneling interface between the device and the planar *** an interface was realized with a nanocap-slit unit structure,of which the plasmonic crystal was consisted.A noise-equivalent limit of detection of~10-7 RIU was experimentally obtained,allowing bovine serum albumin physical adsorption to be distinguished at ng mL-1 level ***,breaking through the long-standing signal-to-noise ratio bottleneck,this work makes fiber end-facet surface plasmon devices into one of high sensitivity label-free sensing *** the same time,it provides an enabling top-down fabrication technology for making 3D plasmonic structures on fiber end-facets at the nanometer scale.

关键词： Surface plasmon Fano resonance Fiber end-facet

Fe-Co-Ni系高饱和磁感应强度及低剩磁软磁合金研究

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功能材料 2000年第5期31卷 479-480,483页

作者：孔向阳吴建生上海交通大学教育部高温材料及高温测试开放实验室上海200030

研究制备具有高饱和磁化强度和低剩磁的Fe -Co -Ni系软磁合金 ,实验结果表明 ,当成分设计使合金同时含有bcc相和fcc相 ,其中bcc相占 90 %左右时 ,合金饱和磁感应强度Bs>1.8T ,同时表现较低的饱和磁致伸缩系数 ,通过横向磁场热处理其剩... 详细信息

研究制备具有高饱和磁化强度和低剩磁的Fe -Co -Ni系软磁合金 ,实验结果表明 ,当成分设计使合金同时含有bcc相和fcc相 ,其中bcc相占 90 %左右时 ,合金饱和磁感应强度Bs>1.8T ,同时表现较低的饱和磁致伸缩系数 ,通过横向磁场热处理其剩磁值降低到 0 .2 5T左右。

关键词： Fe-Co-Ni合金软磁合金成分设计高饱和磁化强度低剩磁

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有机前驱体热解法合成单晶氮化硅纳米线

稀有金属材料与工程 2009年第S2期38卷 967-969页

作者：郭钢锋李晓伟冯文孔向阳上海交通大学

在高纯氮气气氛中采用有机前驱体热解法合成了氮化硅纳米线,对氮化硅纳米线所进行的详细的微观表征表明它们具有良好的单晶特性,其生长沿着α-Si3N4的[1010]方向并受VS机制所控制。在室温下用325nm激光对样品激发,观察到样品有很宽的强... 详细信息

在高纯氮气气氛中采用有机前驱体热解法合成了氮化硅纳米线,对氮化硅纳米线所进行的详细的微观表征表明它们具有良好的单晶特性,其生长沿着α-Si3N4的[1010]方向并受VS机制所控制。在室温下用325nm激光对样品激发,观察到样品有很宽的强光致发光带,在实验中用肉眼即能观察到从样品所发出的强光。考虑到通过稀土掺杂(如引入Nd、Eu、Er和Yb)等手段能够降低氮化硅纳米结构的能带从而进一步调控其光学性能,可以相信氮化硅纳米线在防伪发光材料领域将有着广阔的开发潜力。

关键词：防伪材料光致发光氮化硅纳米线有机前驱体

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电火花线切割高精度补偿控制系统

山东机械 2004年第5期 23-25页

作者：孔向阳济南市长清区地震台济南250300

通过对电火花数控系统的革新,建立一个附加的补偿系统,该补偿系统能够对机床导轨的轨迹误差和传动系统误差进行补偿,建立一个模拟的理想坐标格栅,此坐标格栅作为机床的工作参照坐标,使机床的加工精度得到大幅度的提高。对补偿系统的定... 详细信息

通过对电火花数控系统的革新,建立一个附加的补偿系统,该补偿系统能够对机床导轨的轨迹误差和传动系统误差进行补偿,建立一个模拟的理想坐标格栅,此坐标格栅作为机床的工作参照坐标,使机床的加工精度得到大幅度的提高。对补偿系统的定期校验则可以弥补机床磨损造成的精度降低,使线切割机床的高精度工作寿命得到延长。

关键词：电火花线切割线切割机床数控系统机床导轨加工精度高精度补偿系统补偿控制轨迹误差坐标

基于非局部低秩和全变分的高光谱图像去条带方法

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航天返回与遥感 2024年第5期45卷 64-78页

作者：孔祥阳张娇王惠徐保根四川工程职业技术大学教育学院德阳618000 中国石化西南油气分公司采气一厂德阳618000 华东交通大学理学院南昌330013

受探测器的像素响应不均匀、传感器的机械运动以及图像采集过程中温度的变化等因素的影响,获取的高光谱图像中常包含条带噪声,而当前去条带方法往往着眼于条带的整体性质而忽略了条带的非局部相似性,难以取得较满意的去条带结果。针对... 详细信息

受探测器的像素响应不均匀、传感器的机械运动以及图像采集过程中温度的变化等因素的影响,获取的高光谱图像中常包含条带噪声,而当前去条带方法往往着眼于条带的整体性质而忽略了条带的非局部相似性,难以取得较满意的去条带结果。针对上述问题,文章通过分析条带噪声和干净图像的先验信息,提出了一种基于非局部低秩张量分解和全变分的去条带算法。该算法考虑了条带的非局部相似性,对与参考块相似的条带进行聚类,进而用张量低秩分解进行逼近,另外,还考虑了条带的方向和结构稀疏特征,通过联合高光谱图像的局部和非局部相似性,实现光谱畸变的有效降低。为评估该方法的去条带效果,分别进行了模拟数据试验和真实数据试验,其中模拟数据试验结果显示,在随机长度条带和整体条带情况下,该算法的平均峰值信噪比(MPSNR)和平均结构相似性指数(MSSIM)值分别比对比方法中最好的结果高出约2~3 dB和0.02~0.04,而平均光谱角匹配(MSAM)值降低约0.02~0.06;真实数据试验结果显示,该算法能够精确地估计和分离条带,恢复出受条带影响的图像信息,克服条带残留问题,并且其无参考评价指标逆方差系数(ICV)和平均相对偏差(MRD)均优于对比方法。文章提出的算法为去除高光谱图像中的条带噪声提供了一种有效的解决方案,有望为高光谱图像的后续应用提供有力的支撑。

关键词：高光谱图像去条带非局部低秩全变分增广拉格朗日乘子法

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基于方向和结构特征的遥感图像条带噪声分离方法

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电光与控制 2020年第1期27卷 6-11页

作者：孔祥阳彭群聂徐保根西北工业大学自动化学院西安710072 四川工程职业技术学院基础教学部四川德阳618000 光电控制技术重点实验室河南洛阳471000 华东交通大学理学院南昌330013

针对去除遥感图像条带噪声时易造成模糊或细节丢失等问题,分析研究干净图像及条带噪声的方向和结构特征,提出了遥感图像条带噪声分离方法。对于条带噪声,其稀疏结构特征表征为条带的组稀疏性和平滑性,结合条带的L2,1范数和沿条带方向的... 详细信息

针对去除遥感图像条带噪声时易造成模糊或细节丢失等问题,分析研究干净图像及条带噪声的方向和结构特征,提出了遥感图像条带噪声分离方法。对于条带噪声,其稀疏结构特征表征为条带的组稀疏性和平滑性,结合条带的L2,1范数和沿条带方向的梯度的L0范数实现特征约束;对于干净图像,其边缘连续性采用L1范数进行约束。考虑该约束模型的非凸性,采用基于近端交替方向乘子(PADMM)的算法进行快速求解。模拟数据和实际数据的实验结果表明,所提算法有效去除了图像中的条带噪声,同时高效保留原图像的细节信息,充分验证了算法的可行性和可靠性。

关键词：条带噪声非凸优化组稀疏方向特征结构特征

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一种短基线硐体应变仪

大地测量与地球动力学 2011年第B06期31卷 149-151页

作者：孔向阳张志慧杨玉永山东省地震局济南250300

实验发现,在硐体完整基岩1m深处,日温度波动只有硐体空气中日温度波动的的百分之一左右。将1m基线的硐体应变仪,用自应力水泥耦合在硐体1m深度的基岩槽中,可以提高硐体应变仪的稳定性和高频性能。

关键词：硐体应变自应力水泥耦合基岩槽稳定性高频