检索结果-内蒙古大学图书馆

Effect of Er_(30)Cu_(70) on microstructure and properties of sintered Nd-Fe-B by grain boundary reconstruction

Journal of Rare Earths 2024年第2期42卷 345-353,I0004页

作者： Kai Wang Yongtao Dai Jianqiu Deng Jiang Wang Huaiying Zhou Qingrong Yao Weichao Huang Guangxi Key Laboratory of Information Materials Schoolof Materials Science and EngineeringGuilin University of Electronic TechnologyGuilin54004China China Rare Metals and Rare Earth(Guangxi)Jinyuan New Materials Co Ltd.Hezhou542603China

Usually it is generally believed that the Er element forms the Er_(2)Fe_(14)B phase,which will seriously deteriorate the magnetic ***,here we report the balance of corrosion resistance and coercivity in Nd-Fe-B sintered magnets through using simple Er_(30)Cu_(70) additive whose price is much lower than Dy and *** reasonably controlling Er_(30)Cu_(70) addition,the corrosion resistance is improved at the minimum limit of reducing the magnetic *** studying the influence mechanism of Er element,it is found that the main effect of Er elements is to replace the Nd elements at the edge of the main phase grains to form a(Er,Nd)_(2)Fe_(14)B shell with low H_(A),resulting in the reduction of magnetic *** improvement of corrosion resistance mainly comes from the more stable Cu element introduced at the grain *** the same time,the target magnets also show different advantages under different heat treatment *** findings may spur progress towards developing the lowcost permanent magnets that rival the commercial Nd-Fe-B counterpart.

关键词： Er_(30)Cu_(70)alloy Grain boundary reconstruction Magnetic properties Corrosion resistance Heat treatment Rare earths

来源：评论

学校读者我要写书评

暂无评论

Action Recognition and Detection Based on Deep Learning: A Comprehensive Summary

引用

Computers, Materials & Continua 2023年第10期77卷 1-23页

作者： Yong Li Qiming Liang Bo Gan Xiaolong Cui College of Information Engineering Engineering University of PAPXi’an710086China PAP of Heilongjiang Province Heihe DetachmentHeihe164300China National Key Laboratory of Science and Technology on Electromagnetic Energy Naval University of EngineeringWuhan430033China Joint Laboratory of Counter Terrorism Command and Information Engineering Engineering University of PAPXi’an710086China

Action recognition and detection is an important research topic in computer vision,which can be divided into action recognition and action *** present,the distinction between action recognition and action detection is not clear,and the relevant reviews are not ***,this paper summarized the action recognition and detection methods and datasets based on deep learning to accurately present the research status in this ***,according to the way that temporal and spatial features are extracted from the model,the commonly used models of action recognition are divided into the two stream models,the temporal models,the spatiotemporal models and the transformer models according to the *** this paper briefly analyzes the characteristics of the four models and introduces the accuracy of various algorithms in common data ***,from the perspective of tasks to be completed,action detection is further divided into temporal action detection and spatiotemporal action detection,and commonly used datasets are *** the perspectives of the twostage method and one-stage method,various algorithms of temporal action detection are reviewed,and the various algorithms of spatiotemporal action detection are summarized in ***,the relationship between different parts of action recognition and detection is discussed,the difficulties faced by the current research are summarized in detail,and future development was prospected。

关键词： Action recognition action detection deep learning convolutional neural networks dataset

来源：评论

学校读者我要写书评

暂无评论

Tuning the atomic configuration environment of MnN_(4) sites by Co cooperation for efficient oxygen reduction

引用

Journal of Energy Chemistry 2023年第7期82卷 547-559,I0012页

作者： Jing Wang Haihong Zhong Jun Yang Huiyu Li Pinggui Tang Yongjun Feng Dianqing Li State Key Laboratory of Chemical Resource Engineering Beijing Engineering Center for Hierarchical CatalystsCollege of ChemistryBeijing University of Chemical TechnologyBeijing 100029China College of Science Hainan UniversityHaikou 570228HainanChina State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China

Carbon-based N-coordinated Mn(Mn-N_(x)/C)single-atom electrocatalysts are considered as one of the most desirable non-precious oxygen reduction reaction(ORR)candidates due to their insignificant Fenton reactivity,high abundance,and intriguing electrocatalytic ***,current MnN_(x)/C single-atom electrocatalysts suffer from high overpotentials because of their low intrinsic activity and unsatisfactory chemical ***,through an in-situ polymerization-assisted pyrolysis,the Co as a second metal is introduced into the Mn-N_(x)/C system to construct Co,Mn-N_(x)dual-metallic sites,which atomically disperse in N-doped 1D carbon nanorods,denoted as Co,Mn-N/CNR and *** electron microscopy and X-ray absorption spectroscopy(XAS)techniques,we verify the uniform dispersion of CoN4and MnN4atomic sites and confirm the effect of Co doping on the MnN_(4) electronic *** functional theory(DFT)calculations further elucidate that the energy barrier of ratedetermining step(^(*)OH desorption)decreases over the 2 N-bridged MnCoN_(6) moieties related to the pure MnN_(4).This work provides an effective strategy to modulate the local coordination environment and electronic structure of MnN_(4) active sites for improving their ORR activity and stability.

关键词： Dual-atom sites Oxygen reduction reaction M-Nx/C catalysts Coordination environment Electronic structure Synergistic effect

来源：评论

学校读者我要写书评

暂无评论

Self-healable, recyclable, ultrastretchable, and high-performanceNO_(2) sensors based on an organohydrogel for room and sub-zero temperature and wireless operation

引用

SmartMat 2023年第1期4卷 168-184页

作者： Qiongling Ding Zijing Zhou Hao Wang Zixuan Wu Kai Tao Bo-Ru Yang Xi Xie Jun Fu Jin Wu State Key Laboratory of Optoelectronic Materials and Technologies and the Guangdong Province Key Laboratory of Display Material and Technology School of Electronics and Information TechnologySun Yat-sen UniversityGuangzhouChina Ministry of Education Key Laboratory of Micro and Nano Systems for Aerospace Northwestern Polytechnical UniversityXi'anChina School of Materials Science and Engineering Sun Yat-sen UniversityGuangzhouChina

To date,development of high-performance,stretchable gas sensors operating at and below room temperature(RT)remains a challenge in terms of traditional sensing ***,we report on a high-performance NO_(2) gas sensor based on a self-healable,recyclable,ultrastretchable,and stable polyvinyl alcohol–cellulose nanofibril double-network organohydrogel,which features ultrahigh sensitivity(372%/ppm),low limit of detection(2.23 ppb),relatively fast response and recovery time(41/144 s for 250 ppb NO_(2)),good selectivity against interfering gases(NH3,CO_(2),ethanol,and acetone),excellent reversibility,repeatability,and long-term stability at RT or even at−20°*** particular,this sensor shows outstanding stability against large deformations and mechanical damages so that it works normally after rapid self-healing or remolding after undergoing mechanical damage without significant performance degradation,which has major advantages compared to state-of-the-art gas *** high NO_(2) sensitivity and selectivity are attributed to the selective redox reactions at the threephase interface of gas,gel,and electrode,which is even boosted by applying tensile *** a specific electrical circuit design,a wireless NO_(2) alarm system based on this sensor is created to enable continuous,real-time,and wireless NO_(2) detection to avoid the risk of exposure to NO_(2) higher than threshold concentrations.

关键词： hydrogel NO_(2)gas sensor self-healing and recyclable organohydrogel stretchable and wearable electronics wireless gas sensor

来源：评论

学校读者我要写书评

暂无评论

A Reflectarray With Low Profile Based on the Method of Choosing the Certain Phase Constant

引用

IEEE Antennas and Wireless Propagation Letters 2025年第6期24卷 1397-1401页

作者： Li, Wenting Lin, Wenting Li, Ruiyang He, Yejun Gao, Yao Zhang, Chong Gao, Steven State Key Laboratory of Radio Frequency Heterogeneous Integration School of Electronic and Information Engineering Shenzhen University Shenzhen China School of Electrical and Information Engineering Zhengzhou University Zhengzhou China School of Information Engineering Chang'an University Xi'an China School of Information Science and Engineering Shenyang University of Technology Shenyang China Department of Electronic Engineering Chinese University of Hong Kong Hong Kong China

In this letter, a reflectarray antenna with a small focal diameter ratio (F\D) is presented. It is found that when the F\D is extremely small, the phase constant used in calculating the required reflection phase on the reflecting surface significantly affects the radiation pattern. In certain cases, an unsuitable phase constant can even cause the main beam to split. The unit cell is implemented as a stacked patch, and the reflecting surface comprises 14 × 14 elements. The effect of the phase constant on the radiation pattern is analyzed, and two reflectarrays with phase constants of 90° and 180°, both operating at 10 GHz with an F\D of 0.05, are compared. These two reflectarrays are simulated, fabricated, and measured. The measured results show good agreement with the simulations. Within the operating band, the reflectarray with a phase constant of 90° achieves a maximum measured gain of 20.42 dBi, with the first sidelobe level (SLL1) below -10 dB. The radiation pattern of the reflectarray with a phase constant of 180° is totally distorted, resulting in a measured gain of 6.56 dBi at 10 GHz and an SLL1 of -5.8 dB. © 2002-2011 IEEE.

关键词： Reflection

来源：评论

学校读者我要写书评

暂无评论

Experimental study on phase noise of terahertz quantum cascade laser frequency comb and dual-comb sources

引用

Journal of Semiconductors 2024年第12期45卷 112-118页

作者： Lulu Zheng Xianglong Bi Xuhong Ma Guibin Liu Binbin Liu Kang Zhou Hua Li Key Laboratory of Terahertz Solid State Technology Shanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai 200050China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Chongqing Key Laboratory of Precision Optics Chongqing Institute of East China Normal UniversityChongqing 401120China

Frequency combs with equally spaced frequency lines show great potentials for applications in spectroscopy,imag-ing,communications,and so *** the terahertz frequency region,the quantum cascade laser(QCL)is an ideal radiation source for frequency comb and dual-comb *** systematic evaluation of phase noise characteristics of terahertz QCL frequency comb and dual-comb sources is of great importance for high precision *** this work,we present detailed measurements and analysis of the phase noise characteristics of terahertz QCL frequency comb and dual-comb sources emitting around 4.2 THz with repetition frequencies of~6.2 *** measurement results for the current noise of the direct current(DC)sources(that are used to electrically pump the terahertz QCLs)indicate that at 100 Hz,the current noise for DC-1 and DC-2 is 0.3895 and 0.0982 nA/Hz1/2,*** levels of current noise can be safely *** phase noise of radio frequency(RF)generators(that are employed for injection locking and phase locking),intermode beatnotes,and dual-comb signals with and without phase-locked loop(PLL)are all measured and *** experimental results show that in the free-running mode,the phase noise of the intermode beatnote signals is always lower than that of the dual-comb sig-nals across all ***,the phase noise induced by the RF generators is *** employing the phase lock-ing technique,the phase noise of the intermode beatnote and dual-comb signals in the low offset frequency band can be signifi-cantly *** an offset frequency of 100 Hz,the measured phase noise values of the dual-comb line without and with phase locking are 15.026 and-64.801 dBc/Hz,respectively.

关键词： terahertz quantum cascade laser frequency comb dual-comb phase noise

来源：评论

学校读者我要写书评

暂无评论

Fast and low-cost determination of prostate-specific antigen using paper-based immunodevice modified with Cu@CuS@Au NPs nanocages

引用

Biosurface and Biotribology 2025年第1期11卷 1-9页

作者： Yi Duan Qi Wu Jiangtao Lin Yourong Duan Qi Wang Yuanyuan Li State Key Laboratory of Systems Medicine for Cancer Shanghai Cancer InstituteRenji HospitalSchool of MedicineShanghai Jiao Tong UniversityShanghaiChina Key Laboratory for Advanced Materials and Institute of Fine Chemicals Shanghai Key Laboratory of Functional Materials ChemistrySchool of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghaiChina

In this study,the authors designed a paper-based electrochemical immunodevice modified with copper embedded in copper sulphide hollow nanocages wrapped with Au nanoparticles(Cu@CuS@Au NPs)for the specific detection of prostate-specific antigen(PSA),aiming to advance point-of-care *** large specific surface area of Cu@CuS nanocages enables efficient capture of biotin antibodies,leading to the direct amplification of the signal through the inhibition of electron transport in the redox process of Cu,eliminating the need for universal redox electron ***,Au NPs on the surface of Cu@CuS can accelerate charge transfer and conjugate with *** hierarchical morphology and structure of Cu@CuS nanocages were characterised using scanning electron microscopy and transmission electron *** fabrication process of the immunodevice was monitored using cyclic voltammetry and electrochemical impedance spectroscopy *** was sensitively detected using differential pulse voltammetry on this proposed immunodevice within a linear range from 0 to 100 ng/ml(R^(2)=0.996),achieving a low detection limit of 0.077 ng/*** addition,the practicality of the developed immunosensor has been proven by successfully detecting PSA in human serum samples obtained from clinical *** integration of electrochemical sensors and microfluidic devices holds promise for developing cost-effective approaches in clinical immunoassays.

关键词： biointerface electrochemical impedance spectroscopy

来源：评论

学校读者我要写书评

暂无评论

Facial expression recognition under occlusion conditions based on multi-feature cross-attention

引用

Journal of Intelligent and Fuzzy systems 2024年第4期46卷 9841-9856页

作者： Guo, Sheng Tan, Mian Cai, Shan Zhang, Zaijun Liang, Yihui Feng, Hongxi Zou, Xue Wang, Lin School of Data Science and Information Engineering Guizhou Key Laboratory of Pattern Recognition and Intelligent System Guizhou Minzu University Guiyang China School of Mathematics and Statistics Qiannan Normal University for Nationalities Key Laboratory of Complex Systems and Intelligent Optimization of Guizhou Province Duyun China Zhongshan Institute University of Electronic Science and Technology of China Zhongshan China Guizhou Aerospace Tianma Electromechanical Technology Co LTD Zunyi China

Although facial expression recognition (FER) has a wide range of applications, it may be difficult to achieve under local occlusion conditions which may result in the loss of valuable expression features. This issue has motivated the present study, as a part of which an effective multi-feature cross-attention network (MFCA-Net) is proposed. The MFCA-Net consists of a two-branch network comprising a multi-feature convolution module and a local cross-attention module. Thus, it enables decomposition of facial features into multiple sub-features by the multi-feature convolution module to reduce the impact of local occlusion on facial expression feature extraction. In the next step, the local cross-attention module distinguishes between occluded and unoccluded sub-features and focuses on the latter to facilitate FER. When the MFCA-Net performance is evaluated by applying it to three public large-scale datasets (RAF-DB, FERPlus, and AffectNet), the experimental results confirm its good robustness. Further validation is performed on a real FER dataset with local occlusion of the face. © 2024 – IOS Press.

关键词： Convolution

来源：评论

学校读者我要写书评

暂无评论

Learning-based tracking control of AUV:Mixed policy improvement and game-based disturbance rejection

引用

CAAI Transactions on Intelligence technology 2025年第2期10卷 510-528页

作者： Jun Ye Hongbo Gao Manjiang Hu Yougang Bian Qingjia Cui Xiaohui Qin Rongjun Ding State Key Laboratory of Advanced Design and Manufacturing Technology for Vehicle College of Mechanical and Vehicle EngineeringHunan UniversityChangshaChina School of Information Science and Technology and Institute of Advanced TechnologyUniversity of Science and Technology of ChinaHefeiChina Nanyang Technological University SingaporeSingapore Wuxi Intelligent Control Research Institute of Hunan University Hunan UniversityWuxiChina

A mixed adaptive dynamic programming(ADP)scheme based on zero-sum game theory is developed to address optimal control problems of autonomous underwater vehicle(AUV)systems subject to disturbances and safe *** combining prior dynamic knowledge and actual sampled data,the proposed approach effectively mitigates the defect caused by the inaccurate dynamic model and significantly improves the training speed of the ADP ***,the dataset is enriched with sufficient reference data collected based on a nominal model without considering modelling ***,the control object interacts with the real environment and continuously gathers adequate sampled data in the *** comprehensively leverage the advantages of model-based and model-free methods during training,an adaptive tuning factor is introduced based on the dataset that possesses model-referenced information and conforms to the distribution of the real-world environment,which balances the influence of model-based control law and data-driven policy gradient on the direction of policy *** a result,the proposed approach accelerates the learning speed compared to data-driven methods,concurrently also enhancing the tracking performance in comparison to model-based control ***,the optimal control problem under disturbances is formulated as a zero-sum game,and the actor-critic-disturbance framework is introduced to approximate the optimal control input,cost function,and disturbance policy,***,the convergence property of the proposed algorithm based on the value iteration method is ***,an example of AUV path following based on the improved line-of-sight guidance is presented to demonstrate the effectiveness of the proposed method.

关键词： adaptive dynamic programming autonomous underwater vehicle game theory optimal control reinforcement learning

来源：评论

学校读者我要写书评

暂无评论

Proposal for valleytronic materials:Ferrovalley metal and valley gapless semiconductor

引用

Frontiers of physics 2024年第2期19卷 131-139页

作者： San-Dong Guo Yu-Ling Tao Guangzhao Wang Shaobo Chen Dong Huang Yee Sin Ang School of Electronic Engineering Xi’an University of Posts and TelecommunicationsXi’an 710121China Key Laboratory of Extraordinary Bond Engineering and Advanced Materials Technology of Chongqing School of Electronic Information EngineeringYangtze Normal UniversityChongqing 408100China College of Electronic and Information Engineering Anshun UniversityAnshun 561000China Science Mathematics and Technology(SMT)Singapore University of Technology and Design(SUTD)8 Somapah RoadSingapore 487372Singapore

Valleytronic materials can provide new degrees of freedom to future electronic *** this work,the concepts of the ferrovalley metal(FVM)and valley gapless semiconductor(VGS)are proposed,which can be achieved in valleytronic bilayer systems by electric field *** valleytronic bilayer systems,the interaction between out-of-plane ferroelectricity and A-type antiferromagnetism can induce layer-polarized anomalous valley Hall(LP-AVH)*** K and−K valleys of FVM are both metallic,and electron and hole carriers simultaneously *** the extreme case,the FVM can become VGS by analogizing spin gapless semiconductor(SGS).Moreover,it is proposed that the valley splitting enhancement and valley polarization reversal can be achieved by electric field engineering in valleytronic bilayer *** the bilayer RuBr_(2)as an example,our proposal is confirmed by the first-principle *** FVM and VGS can be achieved in bilayer RuBr_(2)by applying electric *** appropriate electric field range,increasing electric field can enhance valley splitting,and the valley polarization can be reversed by flipping electric field *** effectively tune valley properties by electric field in bilayer systems,the parent monolayer should possess out-of-plane magnetization,and have large valley *** results shed light on the possible role of electric field in tuning valleytronic bilayer systems,and provide a way to design the ferrovalley-related material by electric field.

关键词： valleytronics electric field bilayer

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：