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杨氏干涉实验中双孔的振动对衬比度的影响

物理通报 2024年第7期 105-107,112页

作者：骆素华姜向前哈尔滨工业大学物理学院黑龙江哈尔滨150001

研究了杨氏干涉实验中双孔的振动对衬比度的影响.利用复振幅叠加方法给出了当两个孔做振动方向相反的简谐振动时一对双孔对任一场点、任意时刻的光强表达式,进而给出双孔做简谐振动时双孔的分布函数.利用分布函数得到干涉场的稳态分布,... 详细信息

研究了杨氏干涉实验中双孔的振动对衬比度的影响.利用复振幅叠加方法给出了当两个孔做振动方向相反的简谐振动时一对双孔对任一场点、任意时刻的光强表达式,进而给出双孔做简谐振动时双孔的分布函数.利用分布函数得到干涉场的稳态分布,由光场的稳态分布得到衬比度,发现衬比度随位置呈一个振幅衰减的拉比振荡形式.

关键词：杨氏干涉衬比度拉比振荡

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基于层次分析法的水生植物景观评价

安徽农学通报 2024年第11期30卷 91-96页

作者：张亚平蒋向前胡普炜合肥市滨湖新区建设投资有限公司安徽合肥230601 安徽省林业局安徽合肥230001

本文基于层次分析法,从植物适应性、观赏价值、生态价值和种植养护难度4个方面,构建水生植物景观综合评价体系,确定包含植物成活情况、观赏特性多样性和水体净化能力在内的15项评价因子,并采用该体系对研究区荷花等常见水生植物进行景... 详细信息

本文基于层次分析法,从植物适应性、观赏价值、生态价值和种植养护难度4个方面,构建水生植物景观综合评价体系,确定包含植物成活情况、观赏特性多样性和水体净化能力在内的15项评价因子,并采用该体系对研究区荷花等常见水生植物进行景观综合评价,筛选出优等级(Ⅰ级)景观评价植物6种、良等级(Ⅱ级)景观评价植物29种、一般等级(Ⅲ级)景观评价植物2种。结果表明,荷花、黄菖蒲、睡莲、芦竹、雨久花和梭鱼草等物种具有较好的环境适应性,较高的观赏和生态价值,种植和养护难度较低,具有推广价值;德国鸢尾和喜旱莲子草等物种在某些方面存在一定缺陷,限制了其在水生植物景观中的运用。同时,沉水植物因具有优良的水生态功能,在水生植物景观配置中须加以重视,外来入侵植物黄菖蒲、伊乐藻、粉绿狐尾藻、凤眼莲和喜旱莲子草等在实际应用中也应充分考虑其生态安全性等因素。

关键词：层次分析法水生植物景观评价生物多样性环境适应性

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Operational requirements analysis method based on question answering of WEKG

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Journal of Systems Engineering and Electronics 2024年第2期35卷 386-395页

作者： ZHANG Zhiwei DOU Yajie XU xiangqian MA Yufeng jiang jiang TAN Yuejin College of Systems Engineering National University of Defense TechnologyChangsha 410073China

The weapon and equipment operational requirement analysis(WEORA) is a necessary condition to win a future war,among which the acquisition of knowledge about weapons and equipment is a great challenge. The main challenge is that the existing weapons and equipment data fails to carry out structured knowledge representation, and knowledge navigation based on natural language cannot efficiently support the WEORA. To solve above problem, this research proposes a method based on question answering(QA) of weapons and equipment knowledge graph(WEKG) to construct and navigate the knowledge related to weapons and equipment in the WEORA. This method firstly constructs the WEKG, and builds a neutral network-based QA system over the WEKG by means of semantic parsing for knowledge navigation. Finally, the method is evaluated and a chatbot on the QA system is developed for the WEORA. Our proposed method has good performance in the accuracy and efficiency of searching target knowledge, and can well assist the WEORA.

关键词： operational requirement analysis weapons and equipment knowledge graph(WEKG) question answering(QA) neutral network

Performance Analysis and Evaluation of Geometric Parameters in Stereo Deflectometry

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Engineering 2018年第6期4卷 806-815页

作者： Yongjia Xu Feng Gao xiangqian jiang EPSRC Future Advanced Metrology Hub University of HuddersfieldHuddersfield HD1 3DHUK

This paper presents a novel geometric parameters analysis to improve the measurement accuracy of stereo *** deflectometry can be used to obtain form information for freeform specular surfaces.A measurement system based on stereo deflectometry typically consists of a fringe-displaying screen,a main camera,and a reference *** arrangement of the components of a stereo deflectometry system is important for achieving high-accuracy *** this paper,four geometric parameters of a stereo deflectometry system are analyzed and evaluated:the distance between the main camera and the measured object surface,the angle between the main camera ray and the surface normal,the distance between the fringe-displaying screen and the object,and the angle between the main camera and the reference *** influence of the geometric parameters on the measurement accuracy is *** are performed using simulated and experimental *** experimental results confirm the impact of these parameters on the measurement accuracy.A measurement system based on the proposed analysis has been set up to measure a stock concave *** a comparison of the given surface parameters of the concave mirror,a global measurement accuracy of 154.2 nm was achieved.

关键词： Optical metrology Error analysis Stereo deflectometry Three-dimensional shape measurement Performance evaluation Simulation

Surface texture evaluation of additively manufactured metallic cellular scaffolds for acetabular implants using *** computed tomography

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Bio-Design and Manufacturing 2019年第2期2卷 55-64页

作者： Shan Lou Luca Pagani Wenhan Zeng Muhammad U.Ghori xiangqian jiang Paul J.Scott EPSRC Future Metrology Hub University of HuddersfieldQueensgateHuddersfield HD1 3DHUK Department of Pharmacy University of HuddersfieldQueensgateHuddersfield HD1 3DHUK

The surface topography of acetabular implants plays a key role in providing cell attachment and *** measurement and characterisation of the surface texture of the cellular scaffold layer on the acetabular cup are very difficult due to the 3D nature of scaffold *** is proposed to use X-ray computed tomography(XCT)to measure the surface texture of an electron beam melting-produced titanium acetabular *** surface texture of its cellular scaffold is evaluated using the newly developed 3D surface texture parameters,which allows surface characterisation on 3D triangular mesh *** commonly used height parameters,*** arithmetical mean height Sa,the root mean square height Sq,the skewness Ssk and the kurtosis Sku,are calculated from surface patches extracted from the XCT scanned triangular mesh *** addition,the surface peak density and pit density,which are more related to cell communication and proliferation,are estimated based on the 3D watershed *** Wolf pruning with an empirical threshold 12μm is used to control the over-segmentation.

关键词： Additive manufacturing Cellular scaffold Surface texture X-ray computed tomography

An improved initial rotor position estimation method using high-frequency pulsating voltage injection for PMSM

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Defence Technology（防务技术） 2024年第3期33卷 19-29页

作者： Yang jiang Ming Cheng School of Electrical Engineering Southeast UniversityNanjing 210096China

High frequency pulsating voltage injection method is a good candidate for detecting the initial rotor position of permanent magnet synchronous ***,traditional methods require a large number of filters,which leads to the deterioration of system stability and dynamic *** order to solve these problems,a new signal demodulation method is proposed in this *** proposed new method can directly obtain the amplitude of high-frequency current,thus eliminating the use of filters,improving system stability and dynamic performance and saving the work of adjusting filter *** addition,a new magnetic polarity detection method is proposed,which is robust to current measurement ***,experiments verify the effectiveness of the method.

关键词： Initial position detection Signal demodulation algorithm Magnetic polarity detection Filter elimination

面向结构光三维测量的相位展开技术综述(特邀)

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红外与激光工程 2023年第8期52卷 15-37,I0008页

作者：张宗华李雁玲高峰高楠孟召宗蒋向前河北工业大学机械工程学院天津300130 赫德斯菲尔德大学精密技术中心赫德斯菲尔德HD13 DH

结构光三维形貌测量方法越来越多地应用于逆向工程、航空航天、生物医学、文物保护等领域。相位展开作为结构光三维测量中的一个关键环节对测量精度、速度和可靠性起着决定性作用。文中综述了相位展开技术的基本原理、国内外研究现状、... 详细信息

结构光三维形貌测量方法越来越多地应用于逆向工程、航空航天、生物医学、文物保护等领域。相位展开作为结构光三维测量中的一个关键环节对测量精度、速度和可靠性起着决定性作用。文中综述了相位展开技术的基本原理、国内外研究现状、各类方法的优缺点和未来发展方向。首先根据相位展开计算方法不同,将现有的用于结构光三维形貌测量技术的相位展开技术分为以下四类进行详细的介绍:时间相位展开技术、空间相位展开技术、基于深度学习的相位展开技术和其他相位展开技术;然后详细比较了各种技术的优缺点;最后总结了相位展开技术的特点并展望了该技术的未来研究方向。基于文中综述的内容,研究者们可用于了解各类相位展开技术的原理与进展,进而根据不同方法的特点对比结合应用需求和测量条件选择最有效的相位展开技术,实现三维形貌的精确测量。

关键词：相位展开三维形貌测量条纹投影绝对相位

Capturing Plateau-Rayleigh instability in silver nanowires via ultrafast electron microscopy

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Nano Research 2024年第9期17卷 8402-8407页

作者： Shuai jiang Volkan Ortalan Department of Materials Science and Engineering University of ConnecticutStorrsCT 06269USA

Understanding the structural stability of nanomaterials such as nanowires is imperative for their practical ***,using single-shot ultrafast transmission electron microscopy,we captured the Plateau-Rayleigh instability behavior of silver nanowires decomposing into silver nanoparticles upon laser irradiation on nanosecond time *** found that this dynamic process can be accelerated by a factor of 10 through increasing the peak laser fluence from 6.03 to 14.60 mJ/cm^(2).Moreover,by comparing the laser fluence required to initiate the Plateau-Rayleigh instability in silver nanowires on carbon and Formvar membranes,it was found that the main driving force for the Plateau-Rayleigh instability in this study was substrate *** element analysis and molecular dynamics simulations are also applied to estimate the temperature jump of the nanowires and atomistic behavior,*** addition,the complex motions of silver nanowires under laser irradiation were systematically investigated by combining the results of ultrafast transmission electron microscopy with scanning electron microscopy characterizations and were determined to be related to nanowire-membrane interactions or pre-existing stresses on the nanowires,which in turn demonstrated the potential of ultrafast transmission electron microscopy for the characterization of nanomaterials and devices under extreme conditions.

关键词： silver nanowire Plateau-Rayleigh instability ultrafast transmission electron microscopy molecular dynamics simulation

基于蛾眼仿生结构的钙钛矿太阳电池表界面光学调控

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太阳能学报 2024年第4期45卷 85-90页

作者：沈向前韩非蒋斯涵江舟周华新疆大学物理科学与技术学院新疆固态物理与器件重点实验室乌鲁木齐830046 山东大学物理学院济南250100

采用时域有限差分法(FDTD)和严格耦合波分析(RCWA),系统研究蛾眼仿生结构对钙钛矿太阳电池表面和界面的光学调控特性,同时通过等效介质理论(EMT)分析其中的增强机制。结果表明,蛾眼结构的引入可有效打破材料之间的界面限制,使折射率从... 详细信息

采用时域有限差分法(FDTD)和严格耦合波分析(RCWA),系统研究蛾眼仿生结构对钙钛矿太阳电池表面和界面的光学调控特性,同时通过等效介质理论(EMT)分析其中的增强机制。结果表明,蛾眼结构的引入可有效打破材料之间的界面限制,使折射率从突变转向梯度渐变,光波可几乎不受阻碍的穿过两种材料的交界面。经过优化调控,表面和界面的光学损失分别从3.52%和3.30%降到0.08%和0.06%,钙钛矿太阳电池的光电响应性能明显增强,转换效率相比平面电池提升14.93%。

关键词：钙钛矿太阳电池抗反射结构能量转换效率时域有限差分方法

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