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The influence of ultrasonic vibration on parts properties during incremental sheet forming

Advances in Manufacturing 2021年第2期9卷 250-261页

作者： Yan-Le Li zi-Jian Wang Wei-Dong Zhai zi-Nan Cheng Fang-Yi Li Xiao-qiang Li Key Laboratory of High Efficiency and Clean Mechanical Manufacture Ministry of EducationSchool of Mechanical EngineeringShandong UniversityJinan 250061People’s Republic of China National Demonstration Center for Experimental Mechanical Engineering Education Shandong UniversityJinan 250061People’s Republic of China School of Mechanical Engineering and Automation Beihang UniversityBeijing 100083People’s Republic of China

The integration of ultrasonic vibration into sheet forming process can significantly reduce the forming force and bring benefits including the enhancement of surface quality,the enhancement of formability and the reduction of ***,the influencing mechanisms of the high-frequency vibration on parts properties during the incremental sheet forming(ISF)process are not well known,preventing a more efficient forming *** paper comprehensively investigates the effects of different process parameters(vibration amplitude,step-down size,rotation speed and forming angle)on the micro-hardness,minimum thickness,forming limit and residual stress of the formed ***,a series of truncated pyramids were formed with an experimental platform designed for the ultrasonic-assisted incremental sheet ***,microhardness tests,minimum thickness measurements and residual stress tests were performed for the formed *** results showed that the surface micro-hardness of the formed part was reduced since the vibration stress induced by the ultrasonic vibration within the material which eliminated the original internal *** superimposed University,Beijing 100083,People’s Republic of China ultrasonic vibration can effectively uniform the residual stress and thickness distribution,arid improve the forming limit in the case of the small deformation *** addition,through the tensile fracture analysis of the formed part,it is shown that the elongation of material is improved and the elastic modulus and hardening index are *** findings of the present work lay the foundation for a better integration of the ultrasonic vibration system into the incremental sheet forming process.

关键词： Incremental sheet forming(ISF) Ultrasonic vibration Residual stress Forming limit

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Stress Control in GaN Grown on 6H-SiC by Metalorganic Chemical Vapor Deposition

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Chinese Physics Letters 2011年第4期28卷 223-226页

作者： CHEN Yao jiang Yang XU Pei-qiang MA zi-Guang WANG Xiao-Li WANG Lu JIA Hai-qiang CHEN Hong Beijing National Laboratory of Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190

The strain in GaN epitaxial layers grown on 611-SiC substrates with an AIN buffer by metalorganic chemical vapor deposition is *** is found that the insertion of a graded AlGaN layer between the GaN layer and the AIN buffer can change the signs of strain.A compressive strain in an overgrown thick(2μm)GaN layer is ***-resolution x-ray diffraction,Raman spectroscopy and photoluminescence measurements are used to determine the strain state in the GaN *** mechanism of stress control by inserting graded AlGaN in subsequent GaN layers is discussed briefly.

关键词： GaN AlGaN graded

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The Generalized Joint Density of States and Its Application to Exploring the Pairing Symmetry of High-Tc Superconductors

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Chinese Physics Letters 2013年第5期30卷 144-147页

作者： ZHANG Dan-Bo HAN qiang WANG zi-Dan Department of Physics Renmin University of ChinaBeijing 100872 Department of Physics and Center of Theoretical and Computational Physics The University of Hong KongPokfulam RoadHong Kong

We introduce a generalized joint density of states(GJDOS),which incorporates the coherent factors into the JDOS,to study quasiparticle interference(QPI)in *** intimate relation between the Fourier-transformed local density of states and GJDOS is revealed:they correspond respectively to the real and imaginary parts of a generalized impurity-response function,and particularly share the same angular factors and singular boundaries,as seen from our approximate analytic results for d-wave ***,our numerical GJDOS analysis agrees well with the QPI patten of d-wave cuprates and s_(±)-wave iron-based ***,we illustrate that the present GJDOS scenario can uncover the sign features of the superconducting gap and thus can be used to explore the pairing symmetry of the A_(1-x)Fe_(2-y)Se_(2)(A=K,Cs,etc)superconductors.

关键词： imaginary symmetry transformed

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Fault detection for centrifugal chillers using a Kernel Entropy Component Analysis (KECA) method

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Building Simulation 2021年第1期14卷 53-61页

作者： Yudong Xia qiang Ding Zhao Li Aipeng jiang School of Automation(School of Artificial Intelligence) Hangzhou Dianzi UniversityHangzhouChina Institute of Refrigeration and Cryogenics Zhejiang UniversityHangzhouChina School of Environment&Architecture University of Shanghai for Science&TechnologyShanghaiChina

Fault detection is beneficial for chiller routine operation management in building automation *** the limitations of traditional principal component analysis(PCA)algorithm for chiller fault detection,a so-called kernel entropy component analysis(KECA)method has been developed and the development results are reported in this *** traditional PCA,in KECA,the feature extraction or dimensionality reduction is implemented in a new space,called kernel feature *** new space is nonlinearly related to the input *** data set in the kernel feature space is projected onto a principal component subspace constructed by the feature space principal axes determined by the maximum Rényi entropy rather than the top *** proposed KECA is more suitable to deal with nonlinear process without Gaussian *** the available experimental data from ASHRAE RP-1043,seven typical chiller faults were tested by the proposed KECA method,and the results were compared to that of *** statistics,i.e.T2 and squared prediction error(SPE),were employed for fault detection *** fault detection results showed that the proposed KECA method had a better performance in terms of a higher detection accuracy in comparison to the traditional *** the seven typical faults,the fault detection ratios were over 55%,even at their corresponding least severity level when using the proposed KECA based chiller fault detection method.

关键词： fault detection kernel entropy component analysis Renyi entropy water chillers

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基于改进人工神经网络的多指标冷鲜羊肉新鲜度无损检测

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光谱学与光谱分析 2025年第1期45卷 291-300页

作者：徐子洋姜新华翟成珺马学磊李靖内蒙古农业大学计算机与信息工程学院内蒙古呼和浩特010018 内蒙古自治区农牧业大数据研究与应用重点实验室内蒙古呼和浩特010018 内蒙古自治区教育考试院内蒙古呼和浩特010018

冷鲜羊肉新鲜度受多种因素影响,可通过多个理化和微生物指标综合评价。传统检测方法操作复杂、效率低。高光谱成像作为一种快速且非破坏性的检测技术,可以有效地检测冷鲜羊肉新鲜度改变过程中不同成分的变化。为了研究采用高光谱成像技... 详细信息

冷鲜羊肉新鲜度受多种因素影响,可通过多个理化和微生物指标综合评价。传统检测方法操作复杂、效率低。高光谱成像作为一种快速且非破坏性的检测技术,可以有效地检测冷鲜羊肉新鲜度改变过程中不同成分的变化。为了研究采用高光谱成像技术实现冷鲜羊肉新鲜度多指标评价的可行性,提出一种改进人工神经网络算法,通过重新定义损失函数加强标记之间的相关性,充分采用多个新鲜度指标对冷鲜羊肉新鲜度分类。试验收集了0~14 d冷鲜羊肉样本在400~1000 nm范围的高光谱图像,采用实验室方法测定挥发性盐基氮(TVB-N)、pH值、菌落总数(TAC)和大肠菌群近似数(ANC)指标值。通过S-G平滑滤波法和多元散射校正对冷鲜羊肉样本原始光谱数据进行预处理,采用连续投影法(SPA)选择光谱数据的18个特征波长作为输入数据,采用所提出的改进人工神经网络算法建立多指标冷鲜羊肉新鲜度等级模型。结果表明,改进人工神经网络对测试集的分类准确率达96%,三个新鲜度等级样本的识别率分别为100%、89.28%和98.68%,采用汉明损失(hamming loss)、1-错误率(one-error)、排序损失(ranking loss)和覆盖率(coverage)四种多标记模型指标进行评价,评价指标分别为0.008、0.002、0.0025和4.048。改进人工神经网络分类模型的准确率和各项模型评价指标均优于传统ANN,证明改进人工神经网络用于多指标冷鲜羊肉新鲜度的无损检测具有可行性。

关键词：无损检测高光谱神经网络多指标分类

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Optimizing the Copy-on-Write Mechanism of Docker by Dynamic Prefetching

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Tsinghua Science and Technology 2021年第3期26卷 266-274页

作者： Yan jiang Wei Liu Xuanhua Shi Weizhong qiang National Engineering Research Center for Big Data Technology and System Services Computing Technology and System LabHuazhong University of Science and TechnologyWuhan 430074China

Docker,as a mainstream container solution,adopts the Copy-on-Write(CoW)mechanism in its storage *** mechanism satisfies the need of different containers to share the same ***,when a single container performs operations such as modification of an image file,a duplicate is created in the upper readwrite layer,which contributes to the runtime *** the accessed image file is fairly large,this additional overhead becomes *** we present the concept of Dynamic Prefetching Strategy Optimization(DPSO),which optimizes the Co W mechanism for a Docker container on the basis of the dynamic prefetching *** the beginning of the container life cycle,DPSO pre-copies up the image files that are most likely to be copied up later to eliminate the overhead caused by performing this operation during application *** experimental results show that DPSO has an average prefetch accuracy of greater than 78%in complex scenarios and could effectively eliminate the overhead caused by the CoW mechanism.

关键词： Docker container Copy-on-Write(CoW) storage driver prefetch strategy

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Trend of robot-assisted surgery system in gastrointestinal and liver surgery: A bibliometric analysis

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World Journal of Gastrointestinal Surgery 2024年第9期16卷 3008-3019页

作者： Ze-Chuan Jin zi-qiang Wang Colorectal Cancer Center West China HospitalSichuan UniversityChengdu 610000Sichuan ProvinceChina Colorectal Cancer Center Department of General SurgeryWest China HospitalSichuan UniversityChengdu 610041Sichuan ProvinceChina

BACKGROUND Robot-assisted gastrointestinal and liver surgery has been an important development direction in the field of surgery in recent years and it is also one of the fastest developing and most concerning fields in surgical *** To illustrate the major areas of research and forward-looking directions over the past twenty-six *** Using the Web of Science Core Collection database,a comprehensive review of scholarly articles pertaining to robot-assisted gastrointestinal and liver surgery was researched out between 2000 and *** used Citespace(Version 6.2.4)and Bibliometrix package(Version 4.3.0)to visualize the analysis of all publications including country,institutional affiliations,authors,and *** In total,346 articles were *** Endoscopy had with the largest number of publications and was cited in this *** United States was a core research country in this *** University was the most productive *** current focus of this field is on rectal surgery,long-term prognosis,perioperative management,previous surgical experience,and the learning *** The scientific interest in robot-assisted gastrointestinal and liver surgery has experienced a significant rise since *** study provides new perspectives and ideas for future research in this field.

关键词： Bibliometric analysis Robot-assisted surgery system Gastrointestinal surgery Liver surgery Citespace

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Pterisemipol,a novel sesquiterpenoid from Pteris semipinnata L.

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Chinese Chemical Letters 2007年第11期18卷 1386-1388页

作者： qiang Zhang Li jiang Xuan State Key Laboratory of Drug Research Shanghai Institute of Materia Medica Shanghai Institutes for Biological Sciences Chinese Academy of Sciences Shanghai 201203 China

A novel sesquiterpenoid, pterisemipol, was isolated from Pteris semipinnata L. Its skeleton, namely pterisane, was considered to be rearranged from protoilludane and its structure was elucidated on the basis of spectr... 详细信息

关键词： Pwris semipinnata L. Ptedsemipol Ptedsane Sesquiterpenoid

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A Smooth Bidirectional Evolutionary Structural Optimization of Vibrational Structures for Natural Frequency and Dynamic Compliance

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Computer Modeling in Engineering & Sciences 2023年第6期135卷 2479-2496页

作者： Xiaoyan Teng qiang Li Xudong jiang Institute of Mechanical and Electrical Engineering Harbin Engineering UniversityHarbin150001China Institute of Mechanical Power Engineering Harbin University of Science and TechnologyHarbin150080China

A smooth bidirectional evolutionary structural optimization(SBESO),as a bidirectional version of SESO is proposed to solve the topological optimization of vibrating continuum structures for natural frequencies and dynamic compliance under the transient load.A weighted function is introduced to regulate the mass and stiffness matrix of an element,which has the inefficient element gradually removed from the design domain as if it were undergoing *** at maximizing the natural frequency of a structure,the frequency optimization formulation is proposed using the SBESO *** effects of various weight functions including constant,linear and sine functions on structural optimization are *** the equivalent static load(ESL)method,the dynamic stiffness optimization of a structure is formulated by the SBESO *** examples show that compared with the classic BESO method,the SBESO method can efficiently suppress the excessive element deletion by adjusting the element deletion rate and weight *** is also found that the proposed SBESO technique can obtain an efficient configuration and smooth boundary and demonstrate the advantages over the classic BESO technique.

关键词： Topology optimization smooth bi-directional evolutionary structural optimization(SBESO) eigenfrequency optimization dynamic stiffness optimization

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Neutrophil extracellular traps in gastrointestinal cancer

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World Journal of Gastroenterology 2021年第33期27卷 5474-5487页

作者： zi-qiang Chu Ke-Cheng Zhang Lin Chen Graduate School Chinese PLA General HospitalBeijing 100853China Institute of Basic Medical Sciences Chinese PLA General HospitalBeijing 100853China Department of General Surgery Chinese PLA General Hospital First Medical CenterBeijing 100853China

Gastrointestinal(GI)cancer is a high-risk malignancy and is characterized by high mortality and morbidity *** extracellular traps(NETs),a weblike structure consisting of chromatin DNA with interspersed cytoplasmic and granule proteins,are extruded by activated neutrophils to entrap and kill bacteria and ***,accumulating evidence shows that NETs are related to the progression and metastasis of *** clinical studies,NETs infiltrate primary GI cancer tissues and are even more abundant in metastatic *** quantity of NETs in peripheral blood is revealed to be associated with ascending clinical tumour stages,indicating the role of NETs as a prognostic markers in GI ***,several inhibitors of NETs or NET-related proteins have been discovered and used to exert anti-tumour effects in vitro or in vivo,suggesting that NETs can be regarded as targets in the treatment of GI *** this review,we will focus on the role of NETs in gastric cancer and colorectal cancer,generalizing their effects on tumour-related thrombosis,invasion and *** reports are also listed to show the latest evidences of how NETs affect GI ***,notwithstanding the scarcity of systematic studies elucidating the underlying mechanisms of the interaction between NETs and cancer cells,we highlight the potential importance of NETs as biomarkers and anti-tumour therapeutic targets.

关键词： Neutrophil extracellular traps Gastric cancer Colorectal cancer Biomarkers Therapeutic targets

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