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Molecular behaviors in thin film lubrication——Part one: Film formation for different polarities of molecules

Friction 2019年第4期7卷 372-387页

作者： Shaohua ZHANG Yijun QIAO Yuhong LIU Liran MA Jianbin luo State Key Laboratory of Tribology Tsinghua UniversityBeijing100084China Beijing Key Laboratory of Long-life Technology of Precise Rotation and Transmission Mechanisms Beijing Institute of ControlEngineeringBeijing100094China

There are three unsolved problems in thin film lubrication(TFL) since it was proposed 20 years ago, i.e., the determination of the type of molecules that can enter the contact region efficiently during sliding, the orientation of molecules in the contact region, and the effect of solid surfaces on the liquid molecular orientation in TFL. In order to answer the first two questions, an in situ measurement system comprising a self-designed Raman microscopy and relative optical interference intensity(ROⅡ) system was set up to study the molecular behaviors. A variety of binary mixtures were used as lubricants in the test, and the concentration distribution profile and orientation of the additive molecules in TFL were characterized. The molecular behavior was determined via a combination of shearing, confinement, and surface adsorption. Furthermore, the difference in molecular polarity resulted in different competing effect of surface adsorption and intermolecular interaction, the influence of which on molecular behavior was discussed. Polar additive molecules interacted with the steel surface and exhibited an enrichment effect in the Hertz contact region when added into a nonpolar base oil. No enrichment effect was observed for nonpolar molecules that were added into the nonpolar base oil and polar molecules added into polar base oil. The enrichment of additive molecules enhanced the film-forming ability of the lubricant and resulted in a reduction in the friction coefficient of up to 61%. The orderly arrangement of the additive molecules was another reason for the friction-reducing. A binary multilayer model was proposed to illuminate the molecular behavior in the TFL, and the model was supported by contrary experiment results in elastohydrodynamic lubrication. This research may aid in understanding the nanoscale lubrication mechanism in TFL and the development of novel liquid lubricants.

关键词： thin film lubrication in situ Raman spectroscopy molecular distribution molecular orientation

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Observation of the supercritical Pearl River plume front under the downwelling-favorable winds

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Science China Earth Sciences 2015年第11期58卷 2059-2066页

作者： BAI Peng GU YanZhen luo Lin ZHANG WanLei FAN KaiGuo College of Physical and Environmental Oceanography Ocean University of China College of Information Science and Engineering Ocean University of China Institute of Space and Earth Information Science Chinese University of Hong Kong State Key Laboratory of Tropical Oceanography South China Sea Institute of Oceanology Chinese Academy of Sciences Qinhuangdao Marine Environmental Monitoring Central Station of SOA 91039 Army PLA

For the Pearl River plume, the supercritical, distinct plume front appears in downwelling-favorable winds, which is easily observed due to the distinct boundary between the plume water and the ambient water. In this paper, in situ and satellite observations of a plume front are utilized to explore the Pearl River plume front properties under the downwelling-favorable winds. Field observations clearly show frontal structure, especially the two-layer structure in the plume water and the downward-motion of water in the frontal region. The Advanced Synthetic Aperture Radar(ASAR) images are also analyzed to unveil the plume front: there is a white stripe on the west side out of the river mouth under downwelling-favorable winds, which is identified as a supercritical plume front, and the width of the plume front is about 250 m. The normalized velocity gradient shows the intense velocity convergence in the front region. Also, analyses of ASAR images imply that the river discharge plays an important role in controlling the location and shape of the front.

关键词： cruise observations Pearl River plume front ASAR winds

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Semantic segmentation of agricultural images:A survey

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Information Processing in Agriculture 2024年第2期11卷 172-186页

作者： Zifei luo Wenzhu Yang Yunfeng Yuan Ruru Gou Xiaonan Li School of Cyber Security and Computer Hebei UniversityHebei 071002China Hebei Machine Vision Engineering Research Center BaodingHebei 071002China College of Education Hebei UniversityHebei 071002China

As an important research topic in recent years,semantic segmentation has been widely applied to image understanding problems in various *** the successful application of deep learning methods in machine vision,the superior performance has been transferred to agricultural image processing by combining them with traditional *** segmentation methods have revolutionized the development of agricultural automation and are commonly used for crop cover and type analysis,pest and disease identification,*** frst give a review of the recent advances in traditional and deep learning methods for semantic segmentation of agricultural images according to different segmentation *** we introduce the traditional methods that can effectively utilize the original image information and the powerful performance of deep learningbased ***,we outline their applications in agricultural image *** our literature,we identify the challenges in agricultural image segmentation and summarize the innovative developments that address these *** robustness of the existing segmentation methods for processing complex images still needs to be improved urgently,and their generalization abilities are also *** particular,the limited number of labeled samples is a roadblock to new developed deep learning methods for their training and *** this,segmentation methods that augment the dataset or incorporate multimodal information enable deep learning methods to further improve the segmentation *** review provides a reference for the application of image semantic segmentation in the field of agricultural informatization.

关键词： Semantic segmentation Agricultural images Deep learning Convolution neural networks

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Microstructure and Properties of Joint Interface of Semisolid Stirring Brazing of Composites

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Journal of Materials Science & Technology 2012年第12期28卷 1163-1168页

作者： Huibin Xu Bofang Zhou Changhua Du Quanxiang luo Hongyou Chen School of Materials Science and Engineering Chongqing University of Technology Chongqing 400054 China State Key Laboratory of Advanced Welding and Joining Harbin Institute of Technology Harbin 150001 China

Stirring assisted brazing of SiC（p/A356） composites in air was investigated. A stirring was applied on one of the samples to be bonded at 455℃ during brazing. The filler metal was extruded and impacted intensively on the two surfaces of the base materials during stirring. It can be found that oxide film on the surface of the composites can be disrupted and removed through the observation by scanning electron microscopy （SEM）. The metallurgical bonds formed between the filler metal and the base materials. However, continuous residual oxide film was found at bottom joint interface, which limited the lift of joint strength. A stirring was applied once more after the samples were continuously heated up to 470 and 500℃, respectively. At this time, residual oxide film after the first of stirring can be broken by once more stirring. The bonds are mainly composed of a new alloy, which have a higher content of aluminum and are free of continuous oxide film, showing higher shear strength of 113 MPa than that of the base materials.

关键词： Composites Brazing Stirring Oxide

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MODELING ON DYNAMIC PROCESS OF MEMBRANE FOULING DURING FINITE CROSSFLOW ULTRAFILTRATION IN CHARGED SYSTEM

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Journal of Hydrodynamics 2006年第2期18卷 206-210页

作者： luo Ming-Liang PU Chun-sheng ZHAO Jian-qing College of Petroleum Engineering China University of Petroleum （East China） Dongying 257061 China College of Materials Science and Engineering South China University of Technology Guangzhou 510640 China

Flux decline during finite crossflow Ultrafiltration（UF） in charged system was investigated by perceiving membrane fouling as a dynamic process from non-equilibrium to equilibrium. Under the influence of the boundary condition at the initial section and cross flow, the equilibrium is first reached at the initial section of the crossflow filter and the front of the equilibrium region progresses with time toward the end of the filter. A mathematic model was developed to describe this dynamic process of membrane fouling in a charged system. With the model, the time-dependent flux and the time required to reach the steady state in a crossflow filtration can be easily determined. The fouling process under different conditions is simulated as illustrated with a demonstration of the newly developed model. The resulls of simulation show that there are jumps in the local flux at the front of the equilibrium region and the electrokinetic properties of charged UF system have a very substantial influence on the separation performance of membrane.

关键词： fouling dynamics flux decline,Ultrafiltration(UF) charged system modeling

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A Methodology for Reliability of WSN Based on Software Defined Network in Adaptive Industrial Environment

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IEEE/CAA Journal of Automatica Sinica 2018年第1期5卷 74-82页

作者： Ying Duan Wenfeng Li Xiuwen Fu Yun luo Lin Yang School of Logistics Engineering Wuhan Universityof Technology Wuhan 430063 China Department of Computer Science and Application Zhengzhou University of AeronauticsZhengzhou 450015 China School of Logistics Engineering Wuhan University of Technology Wuhan 430063 China Institute of Logistics Science and Engineering Shanghai Maritime University Shanghai 201306 China IEEE

As communication technology and smart manufacturing have developed, the industrial internet of things(IIo T)has gained considerable attention from academia and *** sensor networks(WSNs) have many advantages with broad applications in many areas including environmental monitoring, which makes it a very important part of IIo T. However,energy depletion and hardware malfunctions can lead to node failures in WSNs. The industrial environment can also impact the wireless channel transmission, leading to network reliability problems, even with tightly coupled control and data planes in traditional networks, which obviously also enhances network management cost and complexity. In this paper, we introduce a new software defined network(SDN), and modify this network to propose a framework called the improved software defined wireless sensor network(improved SD-WSN). This proposed framework can address the following issues. 1) For a large scale heterogeneous network, it solves the problem of network management and smooth merging of a WSN into IIo T. 2) The network coverage problem is solved which improves the network reliability. 3) The framework addresses node failure due to various problems, particularly related to energy ***, it is necessary to improve the reliability of wireless sensor networks, by developing certain schemes to reduce energy consumption and the delay time of network nodes under IIo T conditions. Experiments have shown that the improved approach significantly reduces the energy consumption of nodes and the delay time, thus improving the reliability of WSN.

关键词： Industrial internet of things(IIo T) reliability software defined network(SDN) wireless sensor network(WSN)

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Accelerated thermal ageing on performance of polypropylene-based semiconducting screen for high voltage direct current cable applications-Effect of antioxidants

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High Voltage 2024年第2期9卷 410-418页

作者： Haitian Wang Yi luo Mingyu Zhou Xintong Ren George Chen GEIRI BerlinGermany The Tony Davies High Voltage Laboratory University of SouthamptonSouthamptonUK

The potential of using eco-friendly thermoplastic polypropylene(PP)-based insulation for high voltage direct current(HVDC)cable has been widely investigated but much less work on the PP-based semiconducting screen(SC).Considering a long service life(>30 years)under high temperature and high electrical stress is required for typical HVDC cables,and investigations on the effect of antioxidant(AO)concentration and thermal oxidative sta-bility,mechanical,and electrical properties of PP-based SCs have been *** has been demonstrated that an appropriate combination and amounts of AOs are critical for achieving high thermal stability and maintaining the mechanical properties of SC after ageing in a harsh environment(150°C,with Cu,in air,7 days).Although higher amounts of space charges have been observed in SC/PP/SC samples with higher AO concentrations,the impact on space charge behaviours is less after ageing,suggesting that ageing(or operating at high temperature)leads to microstructure evolution in SC and can potentially mitigate space accumulation in PP-based insulating materials.

关键词： microstructure thermal high

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Enhanced CO sensing properties of Pd modified ZnO porous nanosheets

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Chinese Chemical Letters 2020年第8期31卷 2033-2036页

作者： Na luo Bo Zhang Dan Zhang Jiaqiang Xu NEST Lab Department of ChemistryDepartment of PhysicsCollege of ScienceShanghai UniversityShanghai 200444China School of Materials Science and Engineering Cultivating Base for Key Laboratory of Environment-friendly Inorganic Materials in University of Henan ProvinceHenan Polytechnic UniversityJiaozuo 454000China

Noble metal is usually used to improve the gas sensing performance of metal oxide semiconductor(MOS)due to its better catalytic *** this work,we reported a synthesis of Pd/ZnO nanocomposite by an in situ reduction with ascorbic acid(AA).It was found that Pd/ZnO sensor has excellent selectivity to CO and the response of the Pd/ZnO sensor towards 100 ppm CO was as high as 15(Ra/Rg),obviously higher than that of the pristine ZnO sensor(1.4)when the working temperature is 220℃.Moreover,the pure ZnO sensor almost has no selectivity to CO,but the Pd/ZnO sensor has excellent selectivity to CO,which may be ascribed to the electronic sensitization of *** present results demonstrate that the Pd can significantly improve the gas-sensing performance of metal oxide semiconductor and the obtained sensor has great potential in monitoring coal mine gas.

关键词： CO sensor ZnO nanosheet Pd modifying Low concentration Nanocomposite

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Recent progress in InGaZnO FETs for high-density 2T0C DRAM applications

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Science China(Information Sciences) 2023年第10期66卷 61-83页

作者： Shengzhe YAN Zhaori CONG Nianduan LU Jinshan YUE Qing luo Institute of Microelectronics of the Chinese Academy of Sciences University of Chinese Academy of Sciences

In the past several decades, the density and performance of transistors in a single chip have been increasing based on Moore’s Law. However, the slowdown of feature size reduction and memory wall in the von Neumann architecture restrict the improvement of system performance and energy efficiency. Thus the requirements of the emerging big data and artificial intelligence applications cannot be met. To address this issue, novel devices and architectures are being explored. Among them, the InGaZnO(IGZO) fieldeffect transistor(FET) device and the computing-in-memory(CIM) architecture can be possible solutions for high-density, high-performance, and high-efficiency applications. Herein, we review the recent progress in IGZO-based FETs for dynamic random access memory(DRAM) applications. The mechanism of IGZO FETs, compact modeling of IGZO transistors, progress of IGZO manufacturing process, IGZO circuit design,and IGZO-based CIM and 3D integration architectures are presented. Furthermore, the challenges and future trends of IGZO research are discussed.

关键词： IGZO FET 2T0C DRAM high density compact modeling computing-in-memory monolithic 3D integration

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Value of contrast-enhanced intraoperative ultrasound for cirrhotic patients with hepatocellular carcinoma:A report of 20 cases

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World Journal of Gastroenterology 2008年第25期14卷 4005-4010页

作者： Qiang Lu Yan luo Chao-Xin Yuan Yong Zeng Hong Wu zheng Lei Yao Zhong Yu-Ting Fan Hong-Hao Wang Yang luo Department ofSonography West China Hospital Sichuan University Chengdu610041 Sichuan Province China Department of General Surgery WestChina Hospital Sichuan University Chengdu 610041 SichuanProvince China

AIM： To assess the clinical value of contrast-enhanced intraoperative ultrasound （CE-IOUS） as a novel tool in partial hepatectomy for cirrhotic patients with hepatocellular carcinoma （HCC）. METHODS： From January 2007 to September 2007, a total of 20 consecutive cirrhotic patients with HCC scheduled to undergo partial hepatectomy were studied. Preoperative contrast enhanced computer tomography （CT） and/or magnetic resonance （MR） scans were performed within 1-2 wk before operation. Intraoperative ultrasound （IOUS） and CE-IOUS were carried out after mobilization of the liver. Lesions on precontrast and postcontrast scans were counted and mapped. CE-IOUS was performed with intravenous injection of ultrasound contrast agents SonoVue （Bracco Imaging, Milan, Italy）. Arterial, portal and late phases of contrast enhancement were recorded and analyzed. Nodules showing arterial phase hyper-enhancing and/or hypo-enhancing in late parenchymal phase were considered malignant and removed surgically. Ultrasound-guided biopsy and ethanol ablation would be an option if the nodule could not be removed surgically. Newly detected nodules on IOUS showing iso-enhancement in both arterial and late phases were considered benign. These nodules were either removed surgically if they were close to the main lesion or followed by examinations of alpha-fetoprotein （AFP） level and ultrasound and/or CT/MR every 3 too. RESULTS： IOUS found 41 nodules in total, among which 17 （41.46%） were newly detected compared to preoperative imaging. Thirty-three nodules were diagnosed malignant by CE-IOUS, including one missed by IOUS. The sensitivity and specificity of CE-IOUS on detecting HCC nodules are 100% （33/33 and 100% （9/9）, respectively. Nine nodules were considered benign by CE-IOUS, four was confirmed at histology and five by follow-up. CE-IOUS changed the surgical strategy in 35% （7/20） of patients and avoid unnecessary intervention in 30% （6/20） of patients. CONCLUSION： CE-IOUS is a useful mea

关键词： Cirrhosis Liver neoplasms Intraoperative ultrasound Microbubble contrast agent Hepatectomy

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