资源类型

期刊论文 197

会议视频 13

年份

2024 1

2023 23

2022 32

2021 18

2020 21

2019 22

2018 10

2017 7

2016 4

2015 10

2014 4

2012 4

2011 3

2010 7

2009 5

2008 5

2007 5

2006 4

2005 1

2004 4

展开 ︾

关键词

光纤通信 3

能源 3

人工智能 2

低成本 2

光纤传感技术 2

增材制造 2

神经网络 2

4D打印 1

5G 1

AF/PSTM 1

ANSYS 1

F-B双相钢 1

GPS 1

G蛋白偶联受体 1

NNI 1

PIC16F877A 1

PSTM图像分解 1

PSTM数值模拟 1

PSTM消假像 1

展开 ︾

检索范围:

排序: 展示方式:

Design and calibration of a new high-definition three-dimensional laparoscopic system

Jia TANG,Li-qiang WANG,Bo YUAN,Hong JIANG,Qi-ming ZHU

《信息与电子工程前沿(英文)》 2015年 第16卷 第1期   页码 79-84 doi: 10.1631/FITEE.1400149

摘要: We present a high-definition (HD) 3D laparoscopic system including a dual channel optical system, two cameras, a camera control unit (CCU), and an HD 3D monitor. This laparoscopic system is capable of outputting dual high-definition videos and providing vivid 3D images. A modified pinhole camera model is used for camera calibration and a new method of depth measurement to improve precision. The average error of depth measurement measured by experiment (about 1.13 mm) was small in proportion to the large range in distance of the system (10-150 mm). The new method is applicable to any calibrated binocular vision system.

关键词: Dual optical channels     Three dimensional     Camera calibration     Pinhole model     Depth measurement     Laparoscopic system    

Correlated channel model-based secure communications in dual-hop wireless communication networks Article

Zhen-hua YUAN, Chen CHEN, Xiang CHENG, Guo-cheng LV, Liu-qing YANG, Ye JIN

《信息与电子工程前沿(英文)》 2017年 第18卷 第6期   页码 796-807 doi: 10.1631/FITEE.1700023

摘要: 主要研究在相关信道模型条件下两跳无线通信网络的中继物理层安全波束成形方案设计问题。系统模型由1个发送节点、1个合法接收节点、1个窃听节点和1个采用放大转发策略的中继节点构成,其中中继节点装备多天线,而其他节点都装备单天线,窃听节点靠近合法接收节点进行窃听,从而使得二者与中继节点之间的信道具有相关性。中继节点无法获得窃听信道的瞬时信道状态信息,只可获得合法信道的瞬时状态信息,以及合法信道与窃听信道之间的相关性信息,据此中继节点可推导出窃听信道状态的条件概率分布。以系统近似遍历安全容量为优化目标,研究了2种中继波束成形方案:1最大化合法信道容量的“广义匹配转发方案”;2“普通阶波束成形方案”。另外,还讨论了基于遍历安全容量下界的“下界最优化波束成形方案”。与上述两方案比对,“广义匹配转发方案”是最优的秩-1方案,“普通阶波束成形方案”则是基于近似遍历安全容量的迭代最优的中继转发方案。通过仿真对各波束成形方案的性能进行比较,验证了本文的分析。从仿真结果还可以看出:当中继节点发送功率较低,或者第二跳信道增益较低时,“广义匹配转发方案”的性能优于“普通阶波束成形方案”。

关键词: 物理层安全;中继波束成形;相关信道;遍历安全速率;凸优化    

Incorporation of 3-dimensional lycopodium with hydrophobic nature and interconnected nano-channels into

《化学科学与工程前沿(英文)》 2023年 第17卷 第9期   页码 1162-1182 doi: 10.1007/s11705-022-2276-6

摘要: In the present research, for the first time, lycopodium as a novel nanofiller was incorporated into a polyvinylidene fluoride matrix to fabricate lycopodium/polyvinylidene fluoride flat-sheet membrane for desalination applications by vacuum membrane distillation process. The prepared lycopodium/polyvinylidene fluoride membranes and lycopodium were characterized by field emission scanning electron microscopy, X-ray diffraction, Fourier transform infrared, energy dispersive X-ray, and mapping analyses. Water contact angle and liquid entry pressure measurements were also performed. Response surface methodology was applied to optimize membrane structure and performance. The optimized lycopodium/polyvinylidene fluoride membrane exhibits superior performance compared to the neat polyvinylidene fluoride membrane in terms of flux, salt rejection, water contact angle, and hydrophobicity. In vacuum membrane distillation experiments, using a 15000 ppm NaCl solution as a feed at 70 °C, the neat polyvinylidene fluoride membrane, optimum membrane, and agglomerated membrane (with high lycopodium loading) demonstrated 3.80, 25.20, and 14.83 LMH flux and 63.30%, 99.99%, 99.96% salt rejection, respectively. This improvement in flux and salt rejection of the optimized membrane was related to the presence of lycopodium with hydrophobic nature and interconnected nano-channels in membrane structure. It was found that lycopodium, as the most hydrophobic material, effectively influences the membrane performance and structure for membrane distillation applications.

关键词: lycopodium     hydrophobicity     vacuum membrane distillation     desalination    

Electroconductive RGO-MXene membranes with wettability-regulated channels: improved water permeability

《环境科学与工程前沿(英文)》 2023年 第17卷 第1期 doi: 10.1007/s11783-023-1601-8

摘要:

● Electroconductive RGO-MXene membranes were fabricated.

关键词: Reduced graphene oxide     MXene     Membrane     Water permeance     Dye rejection     Electro-assistance    

Development of surface reconstruction algorithms for optical interferometric measurement

Dongxu WU, Fengzhou FANG

《机械工程前沿(英文)》 2021年 第16卷 第1期   页码 1-31 doi: 10.1007/s11465-020-0602-6

摘要: Optical interferometry is a powerful tool for measuring and characterizing areal surface topography in precision manufacturing. A variety of instruments based on optical interferometry have been developed to meet the measurement needs in various applications, but the existing techniques are simply not enough to meet the ever-increasing requirements in terms of accuracy, speed, robustness, and dynamic range, especially in on-line or on-machine conditions. This paper provides an in-depth perspective of surface topography reconstruction for optical interferometric measurements. Principles, configurations, and applications of typical optical interferometers with different capabilities and limitations are presented. Theoretical background and recent advances of fringe analysis algorithms, including coherence peak sensing and phase-shifting algorithm, are summarized. The new developments in measurement accuracy and repeatability, noise resistance, self-calibration ability, and computational efficiency are discussed. This paper also presents the new challenges that optical interferometry techniques are facing in surface topography measurement. To address these challenges, advanced techniques in image stitching, on-machine measurement, intelligent sampling, parallel computing, and deep learning are explored to improve the functional performance of optical interferometry in future manufacturing metrology.

关键词: surface topography     measurement     optical interferometry     coherence envelope     phase-shifting algorithm    

Precision glass molding: Toward an optimal fabrication of optical lenses

Liangchi ZHANG,Weidong LIU

《机械工程前沿(英文)》 2017年 第12卷 第1期   页码 3-17 doi: 10.1007/s11465-017-0408-3

摘要:

It is costly and time consuming to use machining processes, such as grinding, polishing and lapping, to produce optical glass lenses with complex features. Precision glass molding (PGM) has thus been developed to realize an efficient manufacture of such optical components in a single step. However, PGM faces various technical challenges. For example, a PGM process must be carried out within the super-cooled region of optical glass above its glass transition temperature, in which the material has an unstable non-equilibrium structure. Within a narrow window of allowable temperature variation, the glass viscosity can change from 105 to 1012 Pa·s due to the kinetic fragility of the super-cooled liquid. This makes a PGM process sensitive to its molding temperature. In addition, because of the structural relaxation in this temperature window, the atomic structure that governs the material properties is strongly dependent on time and thermal history. Such complexity often leads to residual stresses and shape distortion in a lens molded, causing unexpected changes in density and refractive index. This review will discuss some of the central issues in PGM processes and provide a method based on a manufacturing chain consideration from mold material selection, property and deformation characterization of optical glass to process optimization. The realization of such optimization is a necessary step for the Industry 4.0 of PGM.

关键词: precision glass molding     optical lens     constitutive modeling     optimization     manufacturing chain     Industry 4.0    

国外光纤光纤带和带状光缆技术的最新发展

刘良炎

《中国工程科学》 2001年 第3卷 第9期   页码 86-94

摘要:

综合介绍了近年国外关于低衰耗的色散补偿光纤,非零色散位移光纤,用于恶劣环境的碳涂覆和氮化硅涂覆光纤的研究;光纤带制造技术包括光纤带的结构、涂层、性能、生产工艺,大芯数光纤带状光缆包括层绞式松管、中心松管式、骨架式、干缆芯带状光缆的设计制造技术的最新进展。

关键词: 光纤通信     低衰耗光纤     光纤带     光纤带状光缆    

成像光学工程面临的光学问题

潘君骅

《中国工程科学》 2000年 第2卷 第3期   页码 32-35

摘要:

文章简单论述了现代成像光学主要领域的情况,指出非球面反射系统是发展的必然趋势。讨论了加工与检验方面的基本情况及应着重深人研究的问题。对镜坯材料也提了一点看法。

关键词: 成像光学     非球面反射镜     光学设计     光学加工与检验    

Effects of critical geometric parameters on the optical performance of a conical cavity receiver

Hu XIAO, Yanping ZHANG, Cong YOU, Chongzhe ZOU, Quentin FALCOZ

《能源前沿(英文)》 2019年 第13卷 第4期   页码 673-683 doi: 10.1007/s11708-019-0630-2

摘要: The optical performance of a receiver has a great influence on the efficiency and stability of a solar thermal power system. Most of the literature focuses on the optical performance of receivers with different geometric shapes, but less research is conducted on the effects of critical geometric parameters. In this paper, the commercial software TracePro was used to investigate the effects of some factors on a conical cavity receiver, such as the conical angle, the number of loops of the helical tube, and the distance between the focal point of the collector and the aperture. These factors affect the optical efficiency, the maximum heat flux density, and the light distribution in the conical cavity. The optical performance of the conical receiver was studied and analyzed using the Monte Carlo ray tracing method. To make a reliable simulation, the helical tube was attached to the inner wall of the cavity in the proposed model. The results showed that the amount of light rays reaching the helical tube increases with the increasing of the conical angle, while the optical efficiency decreases and the maximum heat flux density increases. The increase in the number of loops contributed to an increase in the optical efficiency and a uniform light distribution. The conical cavity receiver had an optimal optical performance when the focal point of the collector was near the aperture.

关键词: parabolic collector     conical cavity receiver     critical geometric parameters     optical performance    

Shear stress distribution prediction in symmetric compound channels using data mining and machine learning

Zohreh SHEIKH KHOZANI, Khabat KHOSRAVI, Mohammadamin TORABI, Amir MOSAVI, Bahram REZAEI, Timon RABCZUK

《结构与土木工程前沿(英文)》 2020年 第14卷 第5期   页码 1097-1109 doi: 10.1007/s11709-020-0634-3

摘要: Shear stress distribution prediction in open channels is of utmost importance in hydraulic structural engineering as it directly affects the design of stable channels. In this study, at first, a series of experimental tests were conducted to assess the shear stress distribution in prismatic compound channels. The shear stress values around the whole wetted perimeter were measured in the compound channel with different floodplain widths also in different flow depths in subcritical and supercritical conditions. A set of, data mining and machine learning algorithms including Random Forest (RF), M5P, Random Committee, KStar and Additive Regression implemented on attained data to predict the shear stress distribution in the compound channel. Results indicated among these five models; RF method indicated the most precise results with the highest value of 0.9. Finally, the most powerful data mining method which studied in this research compared with two well-known analytical models of Shiono and Knight method (SKM) and Shannon method to acquire the proposed model functioning in predicting the shear stress distribution. The results showed that the RF model has the best prediction performance compared to SKM and Shannon models.

关键词: compound channel     machine learning     SKM model     shear stress distribution     data mining models    

A novel task-oriented framework for dual-arm robotic assembly task

《机械工程前沿(英文)》 2021年 第16卷 第3期   页码 528-545 doi: 10.1007/s11465-021-0638-2

摘要: In industrial manufacturing, the deployment of dual-arm robots in assembly tasks has become a trend. However, making the dual-arm robots more intelligent in such applications is still an open, challenging issue. This paper proposes a novel framework that combines task-oriented motion planning with visual perception to facilitate robot deployment from perception to execution and finish assembly problems by using dual-arm robots. In this framework, visual perception is first employed to track the effects of the robot behaviors and observe states of the workpieces, where the performance of tasks can be abstracted as a high-level state for intelligent reasoning. The assembly task and manipulation sequences can be obtained by analyzing and reasoning the state transition trajectory of the environment as well as the workpieces. Next, the corresponding assembly manipulation can be generated and parameterized according to the differences between adjacent states by combining with the prebuilt knowledge of the scenarios. Experiments are set up with a dual-arm robotic system (ABB YuMi and an RGB-D camera) to validate the proposed framework. Experimental results demonstrate the effectiveness of the proposed framework and the promising value of its practical application.

关键词: dual-arm assembly     AI reasoning     intelligent system     task-oriented motion planning     visual perception    

Recent advancements in optical microstructure fabrication through glass molding process

Tianfeng ZHOU,Xiaohua LIU,Zhiqiang LIANG,Yang LIU,Jiaqing XIE,Xibin WANG

《机械工程前沿(英文)》 2017年 第12卷 第1期   页码 46-65 doi: 10.1007/s11465-017-0425-2

摘要:

Optical microstructures are increasingly applied in several fields, such as optical systems, precision measurement, and microfluid chips. Microstructures include microgrooves, microprisms, and microlenses. This paper presents an overview of optical microstructure fabrication through glass molding and highlights the applications of optical microstructures in mold fabrication and glass molding. The glass-mold interface friction and adhesion are also discussed. Moreover, the latest advancements in glass molding technologies are detailed, including new mold materials and their fabrication methods, viscoelastic constitutive modeling of glass, and microstructure molding process, as well as ultrasonic vibration-assisted molding technology.

关键词: optical microstructure     microgroove     microlens     glass molding process     single-point diamond cutting    

真空光镊技术综述 Special Feature on Precision Measurement and Inst

Nan LI, Xun-min ZHU, Wen-qiang LI, Zhen-hai FU, Meng-zhu HU, Hui-zhu HU

《信息与电子工程前沿(英文)》 2019年 第20卷 第5期   页码 655-673 doi: 10.1631/FITEE.1900095

摘要: 光镊技术自上世纪七十年代由阿瑟·阿什金开创以来,作为捕获和操纵中性粒子的通用工具,已在分子生物学、纳米技术和实验物理学等领域得到广泛研究和应用。基于光镊技术的传感与精密测量系统,通过激光束悬浮传感单元,而非与装置固连,相比传统固态传感器,无机械耗散。此外,与液体或空气介质中的光镊系统不同,在真空中运作的光镊系统可实现传感单元与环境的完全隔离。基于上述优势,基础物理学和应用物理学领域科学家对真空光镊开展了大量研究。本文回顾了真空光镊技术的基本概念和发展历史,帮助读者全面了解该领域。

关键词: 光镊;真空光阱;激光冷却    

Improved nitrogen removal in dual-contaminated surface water by photocatalysis

Yongming ZHANG, Rong YAN, Zhen ZOU, Jiewei WANG, Bruce E. RITTMANN

《环境科学与工程前沿(英文)》 2012年 第6卷 第3期   页码 428-436 doi: 10.1007/s11783-012-0401-3

摘要: River waters in China have dual contamination by nutrients and recalcitrant organic compounds. In principle, the organic compounds could be used to drive denitrification of nitrate, thus arresting eutrophication potential, if the recalcitrant organics could be made bioavailable. This study investigated the potential to make the recalcitrant organics bioavailable through photocatalysis. Batch denitrification tests in a biofilm reactor demonstrated that dual-contaminated river water was short of available electron donor, which resulted in low total nitrogen (TN) removal by denitrification. However, the denitrification rate was increased significantly by adding glucose or by making the organic matters of the river water more bioavailable through photocatalysis. Photocatalysis for 15 min increased the Chemical Oxygen Demand (COD) of the river water from 53 to 84 mg·L and led to a 4-fold increase in TN removal. The increase in TN removal gave the same effect as adding 92 mg·L of glucose. During the photocatalysis experiments, the COD increased because photocatalysis transformed organic molecules from those that are resistant to dichromate oxidation in the COD test to those that can be oxidized by dichromate. This phenomenon was verified by testing photocatalysis of pyridine added to the river water. These findings point to the potential for N removal via denitrification after photocatalysis, and they also suggest that the rivers in China may be far more polluted than indicated by COD assays.

关键词: dual contamination     eutrophication     photocatalysis     remediation     surface water    

光传送网中光监控通道信号Q值在线监测技术

唐勇,孙小菡,张明德,丁东

《中国工程科学》 2001年 第3卷 第12期   页码 71-75

摘要:

提出了一种带有光监控通道(OSC)子系统的光传送网(OTN)分层结构模型,分析了OSC中的信号特点,指出OSC信号质量决定了运行、管理和维护(OAM)信号的可靠性。依据Q值与误码率(BER)的一一对应关系,提出了一种可在线监测OSC信号Q值的方案,并基于数字信号处理芯片(DSP)技术设计了监测模块,实现了OSC信号在线Q值监测。

关键词: 光传送网(OTN)     光监控通道(OSC)     运行、管理和维护(OAM)     Q值监测    

标题 作者 时间 类型 操作

Design and calibration of a new high-definition three-dimensional laparoscopic system

Jia TANG,Li-qiang WANG,Bo YUAN,Hong JIANG,Qi-ming ZHU

期刊论文

Correlated channel model-based secure communications in dual-hop wireless communication networks

Zhen-hua YUAN, Chen CHEN, Xiang CHENG, Guo-cheng LV, Liu-qing YANG, Ye JIN

期刊论文

Incorporation of 3-dimensional lycopodium with hydrophobic nature and interconnected nano-channels into

期刊论文

Electroconductive RGO-MXene membranes with wettability-regulated channels: improved water permeability

期刊论文

Development of surface reconstruction algorithms for optical interferometric measurement

Dongxu WU, Fengzhou FANG

期刊论文

Precision glass molding: Toward an optimal fabrication of optical lenses

Liangchi ZHANG,Weidong LIU

期刊论文

国外光纤光纤带和带状光缆技术的最新发展

刘良炎

期刊论文

成像光学工程面临的光学问题

潘君骅

期刊论文

Effects of critical geometric parameters on the optical performance of a conical cavity receiver

Hu XIAO, Yanping ZHANG, Cong YOU, Chongzhe ZOU, Quentin FALCOZ

期刊论文

Shear stress distribution prediction in symmetric compound channels using data mining and machine learning

Zohreh SHEIKH KHOZANI, Khabat KHOSRAVI, Mohammadamin TORABI, Amir MOSAVI, Bahram REZAEI, Timon RABCZUK

期刊论文

A novel task-oriented framework for dual-arm robotic assembly task

期刊论文

Recent advancements in optical microstructure fabrication through glass molding process

Tianfeng ZHOU,Xiaohua LIU,Zhiqiang LIANG,Yang LIU,Jiaqing XIE,Xibin WANG

期刊论文

真空光镊技术综述

Nan LI, Xun-min ZHU, Wen-qiang LI, Zhen-hai FU, Meng-zhu HU, Hui-zhu HU

期刊论文

Improved nitrogen removal in dual-contaminated surface water by photocatalysis

Yongming ZHANG, Rong YAN, Zhen ZOU, Jiewei WANG, Bruce E. RITTMANN

期刊论文

光传送网中光监控通道信号Q值在线监测技术

唐勇,孙小菡,张明德,丁东

期刊论文