检索结果-内蒙古大学图书馆

Photonics Research 2022年第8期10卷 1971-1977页

作者： LI LIU RUXUE WANG XUYI ZHAO WENFU YU YI JIN QIAN GONG AIMIN WU State Key Laboratory of Functional Materials for Informatics 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 Key Laboratory of Terahertz Solid State Technology Shanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai 200050China Centre for Optical and Electromagnetic Research and International Research Center for Advanced Photonics College of Optical Science and EngineeringZhejiang UniversityHangzhou 310058China

Bound states in the continuum(BICs) can make subwavelength dielectric resonators sustain low radiation leakage, paving a new way to minimize the device size, enhance photoluminescence, and even realize lasing. Here, we present a quasi-BIC-supporting Ga As nanodisk with embedded In As quantum dots as a compact bright on-chip light source, which is realized by heterogeneous integration, avoiding complex multilayered construction and subsequent mismatch and defects. The emitters are grown inside the nanodisk to match the mode field distribution to form strong light–matter interaction. One fabricated sample demonstrates a photoluminescence peak sustaining a quality factor up to 68 enhanced by the quasi-BIC, and the emitting effect can be further promoted by improving the epilayer quality and optimizing the layer-transferring process in the fabrication. This work provides a promising solution to building an ultracompact optical source to be integrated on a silicon photonic chip for high-density integration.

关键词： emitter resonator dielectric

An Automated Penetration Semantic Knowledge Mining Algorithm Based on Bayesian Inference

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2021年第3期66卷 2573-2585页

作者： Yichao Zang Tairan Hu Tianyang Zhou Wanjiang Deng State Key Laboratory of Mathematical Engineering and Advanced Computing Zhengzhou450000China National Engineering Technology Research Center of the Digital Switching System Zhengzhou450000China NUS Business School National University of SingaporeSingapore119077Singapore

Mining penetration testing semantic knowledge hidden in vast amounts of raw penetration testing data is of vital importance for automated penetration *** rule mining,a data mining technique,has been studied and explored for a long ***,few studies have focused on knowledge discovery in the penetration testing *** experimental result reveals that the long-tail distribution of penetration testing data nullifies the effectiveness of associative rule mining algorithms that are based on frequent *** address this problem,a Bayesian inference based penetration semantic knowledge mining algorithm is ***,a directed bipartite graph model,a kind of Bayesian network,is constructed to formalize penetration testing ***,we adopt the maximum likelihood estimate method to optimize the model parameters and decompose a large Bayesian network into smaller networks based on conditional independence of variables for improved solution ***,irrelevant variable elimination is adopted to extract penetration semantic knowledge from the conditional probability distribution of the *** experimental results show that the proposed method can discover penetration semantic knowledge from raw penetration testing data effectively and efficiently.

关键词： Penetration semantic knowledge automated penetration testing Bayesian inference cyber security

Regioisomeric Polymer Semiconductors Based on Cyano-Functionalized Dialkoxybithiophenes:Structure-Property Relationship and Photovoltaic Performance

学校读者我要写书评

暂无评论

Transactions of Tianjin University 2022年第5期28卷 385-397页

作者： Qingqing Bai Jun Huang Han Guo Suxiang Ma Jie Yang Bin Liu Kun Yang Huiliang Sun Han Young Woo Li Niu Xugang Guo Center for Advanced Analytical Science School of Chemistry and Chemical EngineeringGuangzhou UniversityGuangzhou 510006China Department of Materials Science and Engineering Southern University of Science and TechnologyShenzhen 518055China State Key Laboratory of Luminescent Materials and Devices South China University of TechnologyGuangdong 510640China Department of Chemistry Korea UniversitySeoul 136-713South Korea

Cyano substitution is vital to the molecular design of polymer semiconductors toward highly efficient organic solar ***,how regioselectivity impacts relevant optoelectronic properties in cyano-substituted bithiophene systems remain poorly *** regioisomeric cyano-functionalized dialkoxybithiophenes BT_(HH),BT_(HT),and BT_(TT) with headto-head,head-to-tail,and tail-to-tail linkage,respectively,were synthesized and characterized in this *** resulting polymer semiconductors(PBDTBTs)based on these building blocks were prepared *** regiochemistry and property relationships of PBDTBTs were investigated in *** BTHH moiety has a higher torsional barrier than the analogs BT_(HT) and BT_(TT),and the regiochemistry of dialkoxybithiophenes leads to fine modulation in the optoelectronic properties of these polymers,such as optical absorption,band gap,and energy levels of frontier molecular *** field-effect transistors based on PBDTBT_(HH) had higher hole mobility(4.4×10^(-3) cm^(2)/(V·s))than those(ca.10^(-4) cm^(2)/(V·s))of the other two polymer *** different short-circuit current densities and fill factors were obtained in polymer solar cells using PBDTBTs as the electron *** difference was probed in greater detail by performing space-charge-limited current mobility,thin-film morphology,and transient photocurrent/photovoltage *** findings highlight that the BTHH unit is a promising building block for the construction of polymer donors for highperformance organic photovoltaic cells.

关键词： Cyano substitution Regioselectivity Organic photovoltaic cells Polymer semiconductors Mobility

Guest ions pre-intercalation strategy of manganese-oxides for supercapacitor and battery applications

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2021年第9期30卷 480-493页

作者： Lina Chen Chongyang Hao Yamin Zhang Youri Wei Linna Dai Jun Cheng Hongqiang Zhang Lijie Ci State Key Lab of Advanced Welding and Joining School of Materials Science and EngineeringHarbin Institute of Technology(Shenzhen)Shenzhen 518055GuangdongChina Key Laboratory for Liquid-Solid Structural Evolution&Processing of Materials(Ministry of Education) School of Materials Science and EngineeringShandong UniversityJinan 250061ShandongChina

Optimization of intrinsic structure of electrode materials plays decisive roles in promoting the development of energy storage systems to meet the fast-growing requirements in the *** engineering has been proved to be an effective way to obtain adequate active sites,preferable ion diffusion channels and stable structure,thus enhance the performance of *** in-depth understanding of the correlation among synthesis,structure and performance will significantly promote the development of excellent materials and energy storage ***,in this review,recent advances in regards to cation preintercalation engineering in Mn-based electrode materials for rechargeable metal ion batteries are systematically *** guest cations can expand interlayer space to promote ion diffusion kinetics,serve as pillars to stabilize structure,control composition and valence to switch electrochemical behavior,thus improve the overall performance of secondary ***,the existing challenges and perspectives are provided for the interlayer engineering and its promotion to battery industry.

关键词： Interlayer engineering Electrode materials Energy storage devices

Elemental Distribution and Site Occupancy in a Co-Ni-Al-Ti-Ta-W Superalloy

学校读者我要写书评

暂无评论

SSRN 2024年

作者： Zhang, Jiachen Lu, Wenjie Lu, Fan Na, Qingze Yan, Pan Su, Haijun Zhang, Guojun School of Materials Science and Engineering Xi'an University of Technology Xi’an710048 China State Key Laboratory of Solidification Processing Northwestern Polytechnical University Xi’an710072 China State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing Beijing100083 China

γ′-precipitate strengthened cobalt-based superalloys show promise for higher temperature-capability over nickel-based superalloys due to higher melting temperatures. This study investigates a multicomponent CoNi-based superalloy with composition 54Co-30Ni-9Al-1Ta-4Ti-2W (at.%) in terms of elemental partitioning and site occupancy. APT reveals preferential partitioning of Ni, Al, Ti, Ta and W to the γ′-precipitate and Co to the γ-matrix. HAADF-STEM and EDS along the [001] zone axis of γ′-precipitate with L12 structure indicate that Co, Ni substitute on A-sites, while Al, Ti, Ta, W prefer the B-sites. DFT calculations further confirm the results of partitioning behaviors and site preferences. Clarifying elemental partitioning and site occupancy provides insights into alloy design principles for advanced CoNi-based superalloys. © 2024, The Authors. All rights reserved.

关键词： Superalloys

Determination of the Gurson-Tvergaard-Needleman Damage Model Parameters for Simulating Small Punch Tests of Heat-Resistant Alloys

学校读者我要写书评

暂无评论

SSRN 2024年

作者： Li, Qiwen Zhao, Lei Wang, Xun Xu, Lianyong Han, Yongdian School of Materials Science and Engineering Tianjin University Tianjin300072 China Tianjin Key Laboratory of Advanced Joining Technology Tianjin300072 China State Key Laboratory of Engines Tianjin University Tianjin300350 China

The small punch (SP) test is utilized to assess the mechanical characteristics and damage progression of heat-resistant alloys. The inverse finite element analysis method incorporating SP tests is a parameter identification method based on adjusting the accuracy of the simulated load-displacement curves. In this paper, the elastoplastic parameters of the Hollomon model and the damage parameters of the Gurson-Tvergaard-Needleman (GTN) model are determined based on the undamaged and damaged stages of the load-displacement curves, respectively. The whole stress-strain curves of the tested materials are then built using the results of finite element simulations of the tensile specimens of ZG15Cr2Mo1, P91, 316H, and Hastelloy X at room and elevated temperatures. Comparison with uniaxial tensile tests indicates that the simulated stress-strain curves closely resemble the experimental data from the tensile testing. In addition, the simulated damage evolution characteristics of the SP specimens are consistent with the mechanical model based on the actual deformation behavior. It is possible to comprehend the damage evolution process by analyzing the SP specimens’ stress and strain change characteristics. © 2024, The Authors. All rights reserved.

关键词： Tensile testing

A Novel Green Deep Eutectic Solvent for One-Step Selective Separation of Valuable Metals from Spent Lithium Batteries: Bifunctional Effect and Mechanism

学校读者我要写书评

暂无评论

SSRN 2023年

作者： Yang, Ziyue Tang, Shujie Huo, Xiangtao Guo, Min Zhang, Mei State Key Laboratory of Advanced Metallurgy School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing100083 China

A novel green bifunctional deep eutectic solvent (DES) composed of ethylene glycol (EG) and tartaric acid (TA) was used for the efficient and selective recovery of lithium-ion batteries (LIBs) cathode materials (LiCoO2 and Li3.2Ni2.4Co1.0Mn1.4O8.3), in which one-step in situ separation of Li and Co/Ni/Mn was realized. The effects of experimental parameters on leaching efficiencies of Li and Co (ηLi and ηCo) from LiCoO2 were discussed, and the optimal reaction conditions were verified by the response surface method for the first time. Results demonstrated that under the optimal conditions (120 °C, 12 h, EG to TA mole ratio (MEG:TA)=5:1, solid to liquid ratio (RS/L)=20 g/L), the ηLi from LiCoO2 reached 98.34%, while Co was formed as purple precipitate cobalt tartrate (CoC4H4O6) which was transformed into black powder Co3O4 after calcination. Notably, the ηLi in DES 5EG:1TA was basically maintained at 80% after five cycles, indicative of its good cycle stability. Moreover, when the as-prepared DES was used to leach spent Li3.2Ni2.4Co1.0Mn1.4O8.3, the selective separation of Li (ηLi=98.86%) from other valuable elements Ni, Mn and Co in situ was also achieved, which proved that the DESs had good selective leaching capacity and practical application potential. © 2023, The Authors. All rights reserved.

关键词： Ethylene

Residual Stress Removal Under Pulsed Electric Current

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2020年第2期33卷 281-289页

作者： Siqi Xiang Xinfang Zhang State Key Laboratory of Advanced Metallurgy School of Metallurgical and Ecological EngineeringUniversity of Science and Technology BeijingBeijing 100083China

The effect of a pulsed electric current on the residual stress evolution of metal materials has been *** was found that the surface and internal residual stresses in the as-quenched samples were reduced dramatically by electropulsing.A large number of experimental data show that the residual stress reduction is proportional to the initial residual stress and related to the material properties and electropulsing *** the combined actions of drift electrons,Joule heating,and residual stress,the dislocation mobility was enhanced,resulting in plastic strain and the decrease in residual *** electrons played a unique role in the electropulsing treatment,acting as an additional force pushing dislocations *** dislocations ultimately accumulated at a grain boundary,forming a parallel ***,the phenomenological equation of the residual stress evolution under electropulsing was derived from the experimental data.

关键词： Electroplastic Residual stress Dislocation movement Phenomenological equation

A Transformer-Based Modular Multitarget Tracking Algorithm Oriented Only to Measurements

学校读者我要写书评

暂无评论

SSRN 2024年

作者： Huang, Xiangsong Ma, Xun Guo, Limin Pan, Dapeng Gou, Wenhu College of Information and Communication Engineering Harbin Engineering University Harbin150001 China Key Laboratory of Advanced Marine Communication and Information Technology Ministry of Industry and Information Technology Harbin Engineering University Harbin150001 China AVIC United Technology Center for Electromagnetic Spectrum Collaborative Detection and Intelligent Cognition Harbin Engineering University Harbin150001 China

The purpose of multitarget tracking (MTT) is to estimate the state of an unknown and time-varying number of targets in scenarios from noisy *** are many issues that need to be solved in MTT, such as discrimination between measurements from targets and clutters, data association, target states prediction, trajectory management and target states estimation, etc. In this paper, a modular MTT algorithm based on Transformer and oriented only to measurements is proposed. In contrast to traditional Bayesian theory-based MTT algorithms, the proposed algorithm learns parameters such as clutter rate, detection probability, and target motion model from measurements or historical trajectories of the targets during the training, and tracks targets without making assumptions about these parameters in the inference. Therefore, the proposed algorithm has a better adaptive capability compared to the Bayesian theory-based MTT algorithms. Simulation experiments show that the proposed algorithm has better performance than the MTT algorithms based on Bayesian theory in complex scenarios with low detection probability, high clutter rate and target maneuvering. © 2024, The Authors. All rights reserved.

关键词： Clutter (information theory)

Dynamic V2V Channel Measurement and Modeling at Street Intersection Scenarios

学校读者我要写书评

暂无评论

Dynamic V2V Channel Measurement and Modeling at Street Inter...

作者： Yang, Mi Ai, Bo He, Ruisi Ma, Zhangfeng Mi, Hang Fei, Dan Zhong, Zhangdui Li, Yujian Li, Jing Beijing Jiaotong University State Key Laboratory of Rail Traffic Control and Safety Collaborative Innovation Center of Railway Traffic Safety Beijing100044 China Beijing Jiaotong University State Key Laboratory of Rail Traffic Control and Safety Beijing100044 China Peng Cheng Laboratory Shenzhen518055 China Shaoyang University College of Information Engineering Shaoyang422000 China Institute of Lightwave Technology Beijing Jiaotong University Key Laboratory of All Optical Network and Advanced Telecommunication Network of Emc Beijing100044 China

Vehicular communication has been widely concerned by academia and industry. Wireless channel characterization and modeling are the foundation of communication systems. Compared with typical road scenarios such as urban and suburban areas, wireless channel characterization in intersections is a challenging task. In this article, channel measurements at 5.9 GHz in street intersection scenarios are carried out and provide data for the characterization and modeling of time-varying vehicular channels. This article proposes a double-slope path loss model, which can accurately reflect the signal propagation loss at intersections. Furthermore, the time-varying spatial characteristics of multipath are extracted and analyzed, and the azimuth and elevation spread of arrival are statistically characterized. The influence of obstacles on multipath spatial characteristics in intersection scenarios is investigated. Then, we investigate the spatial stationarity of channels and analyze the possible reasons for the differences in spatial stationarity of different scenarios. In addition, based on multipath extraction, we quantitatively analyze the energy of dense multipath components in different propagation scenarios. The research in this article can enrich the investigation of vehicular channels and enable the analysis and design of vehicular communication systems. © 1963-2012 IEEE.

关键词： Vehicle to vehicle communications