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2022 29th International Conference on Nuclear Engineering, ICONE 2022

作者： Gao, Yingqi Wang, Ben Cao, Jianguo Luo, Qianqian Cao, Yuan Zhang, Zhihao Wang, Lian Gao, Bo School of Mechanical Engineering University of Science and Technology Beijing Beijing China Institute of Artificial Intelligence University of Science and Technology Beijing Beijing China National Engineering Research Center of Flat Rolling Equipment University of Science and Technology Beijing Beijing China State Nuclear Bao Ti Zirconium Industry Company Shanxi Baoji China Institute of Advanced Materials and Technology University of Science and Technology Beijing Beijing China

ISBN: (纸本)9780791886458

Zr-Sn-Nb zirconium alloys are widely used in the field of nuclear power instead of traditional zirconium alloys and can be used as structural materials for nuclear power fuel assemblies. In this paper, the constitutive relation of high temperature plastic deformation of Zr-Sn-Nb alloy for nuclear power is described. Gleeble-3800 thermal simulation tester was used to conduct compression tests at different temperatures (450~700℃) and deformation rates (0.01~10s-1), stress-strain curves under different deformation conditions were drawn based on stress-strain data. According to the analysis of flow stress curve types, Zr-Sn-Nb alloy shows obvious temperature sensitivity and strain rate sensitivity. Under the condition of low temperature and high strain rate, the power dissipation efficiency is calculated according to Murty instability discriminant. Zirconium alloy material shows flow instability due to the formation of adiabatic shear band. In order to control the successful rolling of microstructure, careful process design must be carried out to avoid the flow instability zone. Based on the types of stress-strain curves, the curves are divided into work hardening stage and dynamic recovery (DRV)/dynamic recrystallization (DRX) stage. A piecewise constitutive model is established, which can accurately predict the machining properties of Zr-Sn-Nb alloy for nuclear power. Copyright © 2022 by ASME.

关键词： Constitutive models

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Magnetic parity violation and Parity-time-reversal-symmetric magnets

arXiv

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arXiv 2024年

作者： Watanabe, Hikaru Yanase, Youichi Research Center for Advanced Science and Technology University of Tokyo Meguro-ku Tokyo153-8904 Japan Department of Physics Graduate School of Science Kyoto University Kyoto606-8502 Japan

Parity-time-reversal symmetry (PT symmetry), a symmetry for the combined operations of space inversion (P) and time reversal (T ), is a fundamental concept of physics and characterizes the functionality of materials as well as P and T symmetries. In particular, the PT -symmetric systems can be found in the centrosymmetric crystals undergoing the parity-violating magnetic order which we call the odd-parity magnetic multipole order. While this spontaneous order leaves PT symmetry intact, the simultaneous violation of P and T symmetries gives rise to various emergent responses that are qualitatively different from those allowed by the nonmagnetic P-symmetry breaking or by the ferromagnetic order. In this review, we introduce candidates hosting the intriguing spontaneous order and overview the characteristic physical responses. Various off-diagonal and/or nonreciprocal responses are identified, which are closely related to the unusual electronic structures such as hidden spin-momentum locking and asymmetric band dispersion. © 2024, CC0.

关键词： Electronic structure

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Deep Stacked Ensemble Learning Model for COVID-19 Classification

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Computers, Materials & Continua 2022年第3期70卷 5467-5486页

作者： G.Madhu B.Lalith Bharadwaj Rohit Boddeda Sai Vardhan K.Sandeep Kautish Khalid Alnowibet Adel F.Alrasheedi Ali Wagdy Mohamed Department of Information Technology VNRVJIETHyderabad500090India Department of Computer Science and Engineering VNRVJIETHyderabad500090India LBEF Campus Kathmandu44600Nepal Statistics and Operations Research Department College of ScienceKing Saud UniversityRiyadh11451Kingdom of Saudi Arabia Operations Research Department Faculty of Graduate Studies for Statistical ResearchCairo UniversityGiza12613Egypt Wireless Intelligent Networks Center(WINC) School of Engineering and Applied SciencesNile UniversityGiza12588Egypt

COVID-19 is a growing problem worldwide with a high mortality *** a result,the World Health Organization(WHO)declared it a *** order to limit the spread of the disease,a fast and accurate diagnosis is required.A reverse transcript polymerase chain reaction(RT-PCR)test is often used to detect the ***,since this test is time-consuming,a chest computed tomography(CT)or plain chest X-ray(CXR)is sometimes *** value of automated diagnosis is that it saves time and money by minimizing human *** significant contributions are made by our *** initial purpose is to use the essential finetuning methodology to test the action and efficiency of a variety of vision models,ranging from Inception to Neural Architecture Search(NAS)***,by plotting class activationmaps(CAMs)for individual networks and assessing classification efficiency with AUC-ROC curves,the behavior of these models is visually ***,stacked ensembles techniques were used to provide greater generalization by combining finetuned models with six ensemble neural *** stacked ensembles,the generalization of the models ***,the ensemble model created by combining all of the finetuned networks obtained a state-of-the-art COVID-19 accuracy detection score of 99.17%.The precision and recall rates were 99.99%and 89.79%,respectively,highlighting the robustness of stacked *** proposed ensemble approach performed well in the classification of the COVID-19 lesions on CXR according to the experimental results.

关键词： COVID-19 classification class activation maps(CAMs)visualization finetuning stacked ensembles automated diagnosis deep learning

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Harvesting random embedding for high-frequency change-point detection in temporal complex systems

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National science Review 2022年第4期9卷 92-104页

作者： Jia-Wen Hou Huan-Fei Ma Dake He Jie Sun Qing Nie Wei Lin Research Institute of Intelligent Complex Systems Fudan University Centre for Computational Systems Biology Institute of Science and Technology for Brain-Inspired IntelligenceFudan University School of Mathematical Sciences Soochow University Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine School of Mathematical Sciences and Shanghai Center for Mathematical Sciences Fudan University Department of Mathematics Department of Developmental and Cell Biologyand NSF-Simons Center for Multiscale Cell Fate ResearchUniversity of California Shanghai Key Laboratory for Contemporary Applied Mathematics LNMS (Fudan University)and LCNBI (Fudan University) State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain ScienceInstitutes of Brain ScienceFudan University

Recent investigations have revealed that dynamics of complex networks and systems are crucially dependent on the temporal structures. Accurate detection of the time instant at which a system changes its internal structures has become a tremendously significant mission, beneficial to fully understanding the underlying mechanisms of evolving systems, and adequately modeling and predicting the dynamics of the systems as well. In real-world applications, due to a lack of prior knowledge on the explicit equations of evolving systems, an open challenge is how to develop a practical and model-free method to achieve the mission based merely on the time-series data recorded from real-world systems. Here, we develop such a model-free approach, named temporal change-point detection(TCD), and integrate both dynamical and statistical methods to address this important challenge in a novel way. The proposed TCD approach, basing on exploitation of spatial information of the observed time series of high dimensions, is able not only to detect the separate change points of the concerned systems without knowing, a priori, any information of the equations of the systems, but also to harvest all the change points emergent in a relatively high-frequency manner, which cannot be directly achieved by using the existing methods and *** effectiveness is comprehensively demonstrated using the data from the representative complex dynamics and real-world systems from biology to geology and even to social science.

关键词： temporal systems time series change-point detection complex dynamical systems

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Highly efficient Quantum Rods LEDs for LCD backlights

Highly efficient Quantum Rods LEDs for LCD backlights

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International Conference on Display technology, ICDT 2022

作者： Srivastava, Abhishek Kumar State Key Laboratory of Advanced Displays and Optoelectronics Technologies Centre for Display Research IAS Center for Quantum Technologies Department Electronic and Computer Engineering The Hong Kong University of Science and Technology Hong Kong

Efficient white LEDs with efficacy of > 200 lm/W are much desirable for lighting and displays. LCDs is the market leader with an approximate 70% market share, particularly in the medium-to large-size display segment. The largest portion of power consumption for LCDs belongs to LCD backlight, accounting for 70%– 80% of the total power consumption, which strongly depends on the content and resolution of display panels. [1-8] The polarizer and color filters are the two main components responsible for high-power consumption. Although the phosphor-based LED backlights are much more efficient than the CCFL backlight, the efficiency of display backlight LEDs varies in the range of 70–85 lm/W. A large portion of the phosphor-based LED light is lost in color filters [1-5]. The LED efficacy further decreases at the high brightness required for outdoor applications [4]. Intensive efforts have been made to replace the phosphor with quantum dots-based downconverters, but the efficiency and stability of these devices are still in their infancy. Quantum rods (QRs), the elongated shape nanoparticles, show superior properties such as relatively larger Stokes shifts, polarized emission, and high light out-coupling efficiency in the solid-state. The challenges are as follows: 1. high quantum yield of QRs in the thin solid films covering the whole visible range;2. good in-plane alignment of the QRs on the LEDs;and 3. high photo-stability and low-temperature quenching. In this talk, we will try to discuss all these challenges. We will also discuss the merits of gradient alloyed CdSe/ZnXCd1-XS/ZnS and CdSe/CdS/ZnS core/shell/shell QRs downconverters showing high efficacy LEDs covering a wide color gamut. These QRs-based LEDs attain the luminous efficacy (LE) of 149 lm/W (@10mA), wide color gamut (118% NTSC), which is exceedingly higher than the state-of-the-art quantum dot and phosphor-based on-chip LED, which paves the way for the future display backlight with the efficacy of > 200 lm/W

关键词： Semiconductor quantum dots

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Mode-locking state switchable Er-doped fiber laser based on a hybrid scheme of graphene oxide and nonlinear polarization rotation

Mode-locking state switchable Er-doped fiber laser based on ...

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2022 Conference on Lasers and Electro-Optics Pacific Rim, CLEO/PR 2022

作者： Cai, Wei Cheng, Chih-Hsien Ye, Guanyu Jin, Lei Li, Li Set, Sze Y. Yamashita, Shinji Research Center for Advanced Science and Technology The University of Tokyo 4-6-1 Komaba Meguro-ku Tokyo153-8904 Japan Department of Physics Harbin Engineering University Harbin150001 China

We demonstrated a mode-locking state switchable Er-doped fiber laser based on the hybrid mode-locking scheme composed by nonlinear polarization rotation and graphene oxide coated side-polished fiber. Four stable switc... 详细信息

关键词： Graphene

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Spectral unmixing for multispectral fluorescence imaging using prior knowledge of spectral signatures 18

Spectral unmixing for multispectral fluorescence imaging usi...

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Multimodal Biomedical Imaging XVIII 2023

作者： Zhang, Ruirui Chen, Duofang Ren, Shenghan Chen, Feng Chen, Xueli Biomedical-photonics and Molecular Imaging Laboratory School of Life Science and Technology Xidian University Engineering Research Center of Molecular and Neuro Imaging Ministry of Education Shaanxi Xi'an710126 China Xi’an Key Laboratory of Intelligent Sensing and Regulation of Trans-Scale Life Information International Joint Research Center for Advanced Medical Imaging and Intelligent Diagnosis and Treatment School of Life Science and Technology Xidian University Shaanxi Xi'an710126 China Shanghai Electro-Mechanical Engineering Institute Shanghai201109 China

ISBN: (纸本)9781510658479

Multispectral imaging is becoming a key technique for biomedical research, but the crosstalk between autofluorescence and fluorescent material severely affects the interpretation of fluorescence images. Spectral unmixing is an effective technique for removing autofluorescence and separating fluorescent targets in multispectral fluorescence imaging. However, the effectiveness of most methods of spectral unmixing has a strong relationship with the noise in the image. In this work, we propose a multispectral fluorescence unmixing method based on a priori information to obtain the pure spectra and their corresponding abundance coefficients in the images. First, the obtained multispectral image is segmented into several superpixels using a superpixel segmentation method, and then the relative pure spectra are extracted using a spectral extraction algorithm on the superpixels. Since the autofluorescence distribution is spread over the whole body, the extracted spectra in which the autofluorescence can be considered as pure spectra are used as a priori knowledge for unmixing. The pixel spectral data that are similar to the set of relatively pure spectra are selected as the pure spectral candidate set. Then the pure spectra can be obtained using the Non-negative matrix factorization method with prior knowledge(NMF-upk). Finally, the abundance corresponding to each spectral feature can be obtained through the least square method. The proposed unmixing method is tested on simulated data and the results show that our unmixing algorithm outperforms other methods. © 2023 SPIE.

关键词： Fluorescence imaging

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Kernel-based image reconstruction for delayed PET imaging

Kernel-based image reconstruction for delayed PET imaging

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IEEE Symposium on Nuclear science (NSS/MIC)

作者： Z. C. Song Z. X. Huang W. B. Li F. Xi J. P. Zhang S. L. Song Z. L. Hu School Of SCience Wuhan University Of Technology Wuhan China Lauterbur Research Center for Biomedical Imaging Shenzhen Institute of Advanced Technology Shenzhen China Department of Nuclear Medicine Fudan University Shanghai Cancer Center Shanghai China

ISBN: (数字)9798350388152

ISBN: (纸本)9798350388169

The initial positron emission tomography (PET) scan performed after tracer injection provides fundamental metabolic activity information of the heart. However, conducting another PET scan after a certain period following tracer injection allows for observation of the tracer distribution in cardiac tissue and any associated metabolic changes. By comparing delayed imaging with the initial scan, doctors can achieve a more comprehensive understanding of the dynamic changes in cardiac function, enabling better assessment of the patient’s cardiac health status and the development of personalized treatment plans. Our research focuses on delayed imaging utilizing PET images from the initial scan, a crucial and challenging task aimed at reconstructing PET images acquired after a certain period following tracer injection. We propose a novel kernel reconstruction approach that integrates autocorrelation texture features from Gray-Level Cooccurrence Matrix (GLCM). This new kernel function considers the correlation between grayscale and texture features from previous images, thereby enhancing the accuracy of delayed imaging PET reconstruction.

关键词： Microwave integrated circuits Cardiac tissue Semiconductor detectors Cardiac function Medical services Gray-scale Positron emission tomography

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Mode-locked Operation in a Coupled Microresonator System with Gain and Nonlinear Loss

Mode-locked Operation in a Coupled Microresonator System wit...

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2022 Conference on Lasers and Electro-Optics Pacific Rim, CLEO/PR 2022

作者： Imamura, Riku Tate, Yuki Nakashima, Ayata Nagashima, Keigo Fujii, Shun Tanabe, Takasumi Department of Electronics and Electrical Engineering Faculty of Science and Technology Keio University Yokohama223-8522 Japan Quantum Optoelectronics Research Team RIKEN Center for Advanced Photonics Saitama351-0198 Japan

We numerically study the mode-locking behavior in a system in which an erbium-doped resonator (gain) is coupled to a carbon-nanotube functionalized resonator (nonlinear loss). We find that mode-locking is possible eve... 详细信息

关键词： Carbon nanotubes

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Advances in ultra-high temperature ceramics,composites,and coatings

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Journal of advanced Ceramics 2022年第1期11卷 1-56页

作者： Dewei NI Yuan CHENG Jiaping ZHANG Ji-Xuan LIU Ji ZOU Bowen CHEN Haoyang WU Hejun LI Shaoming DONG Jiecai HAN Xinghong ZHANG Qiangang FU Guo-Jun ZHANG State Key Laboratory of High Performance Ceramics&Superfine Microstructure Structural Ceramics and Composites Engineering Research CenterShanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050China National Key Laboratory of Science and Technology on Advanced Composites in Special Environments Center for Composite Materials and StructuresHarbin Institute of TechnologyHarbin 150001China Shaanxi Key Laboratory of Fiber Reinforced Light Composite Materials Northwestern Polytechnical UniversityXi’an 710072China State Key Laboratory for Modification of Chemical Fibers and Polymer Materials Institute of Functional MaterialsDonghua UniversityShanghai 201620China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China University of Chinese Academy of Sciences Beijing 100049China

Ultra-high temperature ceramics(UHTCs)are generally referred to the carbides,nitrides,and borides of the transition metals,with the Group IVB compounds(Zr&Hf)and TaC as the main *** UHTCs are endowed with ultra-high melting points,excellent mechanical properties,and ablation resistance at elevated *** unique combinations of properties make them promising materials for extremely environmental structural applications in rocket and hypersonic vehicles,particularly nozzles,leading edges,and engine components,*** addition to bulk UHTCs,UHTC coatings and fiber reinforced UHTC composites are extensively developed and applied to avoid the intrinsic brittleness and poor thermal shock resistance of bulk ***,high-entropy UHTCs are developed rapidly and attract a lot of attention as an emerging direction for ultra-high temperature *** review presents the state of the art of processing approaches,microstructure design and properties of UHTCs from bulk materials to composites and coatings,as well as the future directions.

关键词： ultra-high temperature ceramics(UHTCs) coatings composites high-entropy ultra-high temperature ceramics

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