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Composite anti-disturbance predictive control of unmanned systems with time-delay using multi-dimensional Taylor network 被引量:1
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作者 Chenlong LI Wenshuo LI Zejun ZHANG 《Chinese Journal of Aeronautics》 2025年第7期589-600,共12页
A composite anti-disturbance predictive control strategy employing a Multi-dimensional Taylor Network(MTN)is presented for unmanned systems subject to time-delay and multi-source disturbances.First,the multi-source di... A composite anti-disturbance predictive control strategy employing a Multi-dimensional Taylor Network(MTN)is presented for unmanned systems subject to time-delay and multi-source disturbances.First,the multi-source disturbances are addressed according to their specific characteristics as follows:(A)an MTN data-driven model,which is used for uncertainty description,is designed accompanied with the mechanism model to represent the unmanned systems;(B)an adaptive MTN filter is used to remove the influence of the internal disturbance;(C)an MTN disturbance observer is constructed to estimate and compensate for the influence of the external disturbance;(D)the Extended Kalman Filter(EKF)algorithm is utilized as the learning mechanism for MTNs.Second,to address the time-delay effect,a recursiveτstep-ahead MTN predictive model is designed utilizing recursive technology,aiming to mitigate the impact of time-delay,and the EKF algorithm is employed as its learning mechanism.Then,the MTN predictive control law is designed based on the quadratic performance index.By implementing the proposed composite controller to unmanned systems,simultaneous feedforward compensation and feedback suppression to the multi-source disturbances are conducted.Finally,the convergence of the MTN and the stability of the closed-loop system are established utilizing the Lyapunov theorem.Two exemplary applications of unmanned systems involving unmanned vehicle and rigid spacecraft are presented to validate the effectiveness of the proposed approach. 展开更多
关键词 multi-dimensional Taylor network Composite anti-disturbance Predictive control Unmanned systems Multi-source disturbances TIME-DELAY
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Retraced Multi-dimensional Chinese Logic System behind Chinese Medicine
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作者 Edwin C.L.Yu 《Chinese Medicine and Culture》 2025年第1期1-12,共12页
The ancient tacit knowledge behind the logic system permeated the culture and promoted numerous impactful inventions throughout the history. Traditional Chinese medicine with its effectiveness should also have stemmed... The ancient tacit knowledge behind the logic system permeated the culture and promoted numerous impactful inventions throughout the history. Traditional Chinese medicine with its effectiveness should also have stemmed out from such logic system. This article aims to rearticulate the underlying lucid multi-dimensional logic system, which faded in obscurity only because of time-out loss of the mid-right concept. Retracing this past tacit but important concept could uncover a multi-dimensional system over a point relating to all matters while capturing the central core of the matter. The seemingly unmanageable multidimensional logic was strengthened by verification processes which affirmed its further extensions, and made up the language of the people, the concepts of yin-yang(阴阳), and the development of extensions of Ba Gua(八卦) derivatives, which furthered the interpretation of the space-time properties and Chinese medicine. 展开更多
关键词 multi-dimensional logic system Traditional Chinese medicine YIN-YANG
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Effective stress dissipation by multi-dimensional architecture engineering for ultrafast and ultralong sodium storage
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作者 Man Zhang Jing Zhu +7 位作者 Qianqian Li Fenghua Zheng Sijiang Hu Youguo Huang Hongqiang Wang Xing Ou Qichang Pan Qingyu Li 《Journal of Energy Chemistry》 2025年第2期619-629,I0013,共12页
Stress accumulation is a key factor leading to sodium storage performance deterioration for NiSe_(2)-based anodes.Therefore,inhibiting the concentrated local stress during the sodiataion/desodiation process is crucial... Stress accumulation is a key factor leading to sodium storage performance deterioration for NiSe_(2)-based anodes.Therefore,inhibiting the concentrated local stress during the sodiataion/desodiation process is crucial for acquiring stable NiSe2-based materials for sodium-ion batteries(SIBs),Herein,a stress dissipation strategy driven by architecture engineering is proposed,which can achieve ultrafast and ultralong sodium storage properties.Different from the conventional sphere-like or rod-like architecture,the three-dimensional(3D)flower-like NiSe_(2)@C composite is delicately designed and assembled with onedimensional nanorods and carbon framework.More importantly,the fundamental mechanism of improved structure stability is unveiled by simulations and experimental results simultaneously.It demonstrates that this designed multidimensional flower-like architecture with dispersed nanorods can balance the structural mismatch,avoid concentrated local strain,and relax the internal stress,mainly induced by the unavoidable volume variation during the repeated conversion processes.Moreover,it can provide more Na^(+)-storage sites and multi-directional migration pathways,leading to a fast Na^(+)-migration channel with boosted reaction kinetic.As expected,it delivers superior rate performance(441 mA h g^(-1)at 5.0 A g^(-1))and long cycling stability(563 mA h g^(-1)at 1.0 A g^(-1)over 1000 cycles)for SIBs.This work provides useful insights for designing high-performance conversion-based anode materials for SIBs. 展开更多
关键词 Stress dissipation multi-dimensional architecture Structure engineering Conversion-based anodes Sodium-ion batteries
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Research on Multi-Dimensional Collaborative Strategies in Design Management,Investment Management,and Beyond from the Perspective of Whole-Process Engineering Consulting
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作者 Zexin Chen 《Journal of Architectural Research and Development》 2025年第5期21-28,共8页
This paper explores whole-process engineering consulting,including its application models in public buildings and elderly-friendly projects,such as service integration and whole lifecycle management.It also addresses ... This paper explores whole-process engineering consulting,including its application models in public buildings and elderly-friendly projects,such as service integration and whole lifecycle management.It also addresses the construction of multi-dimensional collaborative theoretical models,public space streamline organization,and other aspects,emphasizing the importance of multi-dimensional collaboration.Additionally,it highlights the role of talent cultivation and digital transformation in enhancing project efficiency. 展开更多
关键词 Whole-process engineering consulting multi-dimensional collaboration Project efficiency
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Practical Application of the Multi-Dimensional Interactive Teaching Model in College English
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作者 Bo Sun 《Journal of Contemporary Educational Research》 2025年第10期106-111,共6页
The multi-dimensional interactive teaching model significantly enhances the effectiveness of college English instruction by emphasizing dynamic engagement between teachers and students,as well as among students themse... The multi-dimensional interactive teaching model significantly enhances the effectiveness of college English instruction by emphasizing dynamic engagement between teachers and students,as well as among students themselves.This paper explores practical strategies for implementing this model,focusing on four key aspects:deepening teachers’understanding of the model through continuous learning,innovating interactive methods such as questioning techniques and practical activities,leveraging modern technology to integrate resources and track learning progress,and establishing a communication platform that centers on student participation.By adopting these approaches,the model fosters a student-centered classroom environment,improves comprehensive English application skills,and optimizes overall teaching quality. 展开更多
关键词 multi-dimensional interactive teaching model Student-centered approach Teacher-student interaction
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Construction of the Practice System of Landscape Architecture Major Based on“Multi-dimensional Integration”
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作者 LI Yinan DING Juan +4 位作者 ZHU Yan WU Jing ZHAO Zhiyan LI Jie XIANG Cheng 《Journal of Landscape Research》 2025年第3期89-92,共4页
During the critical transformation period of landscape architecture major after the adjustment of disciplinary structure and the changes in market demand,private colleges and universities,as important places for culti... During the critical transformation period of landscape architecture major after the adjustment of disciplinary structure and the changes in market demand,private colleges and universities,as important places for cultivating local talents,have pain points such as uneven quality of teachers and students and weak innovation and practice.The practice system with“multi-dimensional Integration”integrates four dimensions:interdisciplinary integration,spatial and temporal intersection,historical inheritance,and behavioral activity,deepens the disciplinary connotation,and integrates the three elements of nature,humanity,and technology,aiming to provide a new path for private colleges and universities to cultivate application-oriented and compound talents with innovative capabilities.In terms of optimizing talent cultivation and adapting to industry changes,this system provides thinking and reference for landscape architecture major,helping the major reshape its core competitiveness and promoting educational innovation and industry development. 展开更多
关键词 Landscape architecture Practice system multi-dimensional integration”model Talent cultivation Teaching reform
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Reliability of multi-dimensional network systems with nodes having stochastic connection ranges
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作者 FU Yuqiang MA Xiaoyang ZHAO Fei 《Journal of Systems Engineering and Electronics》 2025年第4期1017-1023,共7页
This paper proposes a reliability evaluation model for a multi-dimensional network system,which has potential to be applied to the internet of things or other practical networks.A multi-dimensional network system with... This paper proposes a reliability evaluation model for a multi-dimensional network system,which has potential to be applied to the internet of things or other practical networks.A multi-dimensional network system with one source element and multiple sink elements is considered first.Each element can con-nect with other elements within a stochastic connection ranges.The system is regarded as successful as long as the source ele-ment remains connected with all sink elements.An importance measure is proposed to evaluate the performance of non-source elements.Furthermore,to calculate the system reliability and the element importance measure,a multi-valued decision diagram based approach is structured and its complexity is analyzed.Finally,a numerical example about the signal transfer station system is illustrated to analyze the system reliability and the ele-ment importance measure. 展开更多
关键词 multi-dimensional network multi-valued decision diagram stochastic connection range reliability analysis impor-tance measure.
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Multi-dimensional hydrogen bonds regulated emissions of single-molecule system enabling surficial hydrophobicity/hydrophilicity mapping
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作者 Hao Gu Rui Li +6 位作者 Qiuying Li Sheng Lu Yahui Chen Xiaoning Yang Huili Ma Zhijun Xu Xiaoqiang Chen 《Chinese Chemical Letters》 2025年第5期515-520,共6页
Constructing multi-dimensional hydrogen bond(H-bond)regulated single-molecule systems with multiemission remains a challenge.Herein,we report the design of a new excited-state intramolecular proton transfer(ESIPT)feat... Constructing multi-dimensional hydrogen bond(H-bond)regulated single-molecule systems with multiemission remains a challenge.Herein,we report the design of a new excited-state intramolecular proton transfer(ESIPT)featured chromophore(HBT-DPI)that shows flexible emission tunability via the multidimensional regulation of intra-and intermolecular H-bonds.The feature of switchable intramolecular Hbonds is induced via incorporating several hydrogen bond acceptors and donors into one single HBT-DPI molecule,allowing the“turn on/off”of ESIPT process by forming isomers with distinct intramolecular Hbonds configurations.In response to different external H-bonding environments,the obtained four types of crystal/cocrystals vary in the contents of isomers and the molecular packing modes,which are mainly guided by the intermolecular H-bonds,exhibiting non-emissive features or emissions ranging from green to orange.Utilizing the feature of intermolecular H-bond guided molecular packing,we demonstrate the utility of this fluorescent material for visualizing hydrophobic/hydrophilic areas on large-scale heterogeneous surfaces of modified poly(1,1-difluoroethylene)(PVDF)membranes and quantitatively estimating the surface hydrophobicity,providing a new approach for hydrophobicity/hydrophilicity monitoring and measurement.Overall,this study represents a new design strategy for constructing multi-dimensional hydrogen bond regulated ESIPT-based fluorescent materials that enable multiple emissions and unique applications. 展开更多
关键词 multi-dimensional hydrogen bonds Emission regulation Hydrophobicity/hydrophilicity Surficial mapping Excited-state intramolecular proton transfer
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A novel multi-dimensional isolation platform for low-frequency excitations:analysis and experiment
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作者 Lingjun MENG Xiuting SUN Jian XU 《Applied Mathematics and Mechanics(English Edition)》 2025年第12期2241-2264,共24页
To break the limitations of the multi-dimensional(M-D)vibration isolation(VI)platforms with the Stewart-Gough design,such as strongly coupling motions,excessive friction in connections,heavy weight,and limited workspa... To break the limitations of the multi-dimensional(M-D)vibration isolation(VI)platforms with the Stewart-Gough design,such as strongly coupling motions,excessive friction in connections,heavy weight,and limited workspace,this study processes a novel platform integrated by a stiffness-adjustable origami spring sub-structure and a parallel mechanism.The origami-based stiffness-adjustable spring realizes low-frequency VI,and the parallel mechanism symmetry design realizes motions decoupling.In the origami-based sub-leg,the parallel-stack-assembly(PSA)design mechanism with two Miura origami configurations is proposed to generate a symmetrical negative stiffness property.Paired with a linear positive stiffness spring,the origami-based sub-leg has wide-amplitude-high-static-low-dynamic stiffness(WA-HSLDS)characteristics in one direction.Then,with construction of the parallel mechanism connected with origami-based sub-legs,an M-D VI platform is achieved,whose motions in the vertical direction and yaw direction are decoupled with the motions in the other directions.Based on the dynamic model and incremental harmonic balance(IHB)with the arc-length continuation method,appropriate structural parameters in the parallel mechanism part are figured out,and the accurate transmissibility in different directions is defined,which gives the parametric influencing investigations for realization of low-frequency VI performances.Finally,experiments are conducted to validate the accuracy and feasibility of the theoretical methods,and to demonstrate the performance of M-D low-frequency isolation with load-carrying capacity of the proposed VI platform.The integration of the origami into the parallel mechanism results in a compact,efficient,and flexible platform with nonlinear adjustability,offering new possibilities for lightweight M-D VI,and developing the practical applications in high-precision platforms in ocean and aerospace environments. 展开更多
关键词 multi-dimensional(M-D)vibration isolation(VI) wide-amplitude high-static-low-dynamic stiffness(WA-HSLDS) origami-based elastic spring parallel mechanism
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Research and Application of Multi-Dimensional and Three-Dimensional Teaching in Geriatric Nursing Teaching in the Context of Mass Entrepreneurship and Innovation
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作者 Xiuxian Mo 《Journal of Advances in Medicine Science》 2018年第1期12-15,共4页
Purpose:Study the specific application effect of multi-dimensional and three-dimensional teaching in Geriatric Nursing teaching in the context of mass entrepreneurship and innovation.Methods:Respectively select 80 nur... Purpose:Study the specific application effect of multi-dimensional and three-dimensional teaching in Geriatric Nursing teaching in the context of mass entrepreneurship and innovation.Methods:Respectively select 80 nursing undergraduates of 2015 and 80 nursing undergraduates of 2014 in our school as the research object of the experimental group and the control group.In terms of Geriatric Nursing teaching,nursing students in the control group adopt traditional classroom teaching methods to carry out,while students in the experimental group adopt multi-dimensional and three-dimensional teaching in the context of mass entrepreneurship and innovation.Then observe and compare the geriatric nursing knowledge scoring as well as theory and practice assessment results in the two groups taught with different methods.Results:It's obvious that the scoring of nursing students in the experimental group is higher than those in the control group in respect of geriatric nursing knowledge,and statistical significance exists in the between-group differences(P<0.05).The nursing students in the experimental group perform obviously better than those in the control group in terms of the results of theory,practice and comprehensive assessment as well as total score,and statistical significance exists in the between-group differences(P<0.05).Conclusion:Implementing Geriatric Nursing teaching for higher education nursing undergraduates with multi-dimensional and three-dimensional teaching in the context of mass entrepreneurship and innovation can remarkably improve nursing students'cognitive level in geriatric nursing as well as their mastery degree of theoretical,practical and comprehensive knowledge.Thus,the multi-dimensional and three-dimensional teaching mode in the context of mass entrepreneurship and innovation makes 80 nursing undergraduates of 2015 in our school direct beneficiaries,which could be popularized and applied in medical colleges. 展开更多
关键词 MASS ENTREPRENEURSHIP and INNOVATION multi-dimensional and three-dimensional teaching GERIATRIC NURSING
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Construction and Optimization of English Linguistic System in the Context of Multi-dimensional Perspective and Interactive Teaching
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作者 Jianbin Cui 《International Journal of Technology Management》 2016年第10期57-59,共3页
With the improvement of the quality education in our country, the teaching reform of college English teaching has been carried out. In the college English teaching system, we need the network-based autonomous teaching... With the improvement of the quality education in our country, the teaching reform of college English teaching has been carried out. In the college English teaching system, we need the network-based autonomous teaching mode, and effective evaluation system of English teaching is also necessary. A complete set of teaching evaluation system can truly reffect the teaching effect, and can promote the optimization of teaching activities as well. Therefore, in order to realize the effectiveness of English teaching and to expand the diversifi ed teaching mode, we need to build a complete set of English language system. Classroom teaching evaluation is one of the effective means to improve the teaching efficiency, which reffects the characteristics of college English courses. After the digitalization of the teaching methods, the network information produced in the teaching and management has obvious characteristics of large data. The optimized evaluation system of college English classroom teaching has realized the diversifi cation of evaluation subjects. 展开更多
关键词 Interactive Teaching multi-dimensional English Linguistic System Construction and Optimization.
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On Evaluation of the New Edition College English Textbooks Based on Multi-dimensional Perspectives
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作者 WANG Da-peng 《International Journal of Technology Management》 2016年第7期74-77,共4页
Relative fi ndings about the evaluation of English textbooks in China are really rare. In this paper, the new edition college Englishtextbooks are analyzed and evaluated through drawing on the evaluation experience of... Relative fi ndings about the evaluation of English textbooks in China are really rare. In this paper, the new edition college Englishtextbooks are analyzed and evaluated through drawing on the evaluation experience of English textbooks of other countries. The conclusion wasdrawn through questionnaires that the multi-dimensional mode, as a mode of learning based on the multi-sensory experience of students, couldprovide students with broader space for free development and exploration. It could guide the compilation and improvement of textbooks. 展开更多
关键词 New edition College English textbooks multi-dimensional perspectives EVALUATION Tom Linsen
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The Continuation Task and the Model-as-Feedback Writing Task in L2 Writing Development:Timing of Model Texts
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作者 Xiaoyan Zhang 《Chinese Journal of Applied Linguistics》 2026年第1期76-91,160,共17页
This study compares the relative efficacy of the continuation task and the model-as-feedbackwriting (MAFW) task in EFL writing development. Ninety intermediate-level Chinese EFL learnerswere randomly assigned to a con... This study compares the relative efficacy of the continuation task and the model-as-feedbackwriting (MAFW) task in EFL writing development. Ninety intermediate-level Chinese EFL learnerswere randomly assigned to a continuation group, a MAFW group, and a control group, each with30 learners. A pretest and a posttest were used to gauge L2 writing development. Results showedthat the continuation task outperformed the MAFW task not only in enhancing the overall qualityof L2 writing, but also in promoting the quality of three components of L2 writing, namely, content,organization, and language. The finding has important implications for L2 writing teaching andlearning. 展开更多
关键词 continuation task model-as-feedback writing task L2 writing development timing of model texts
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The Study on College English Writing Based on Multi-dimensional Feed-back Mode
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作者 骆敏 徐敏娜 《海外英语》 2020年第12期273-274,共2页
The study constructed a multi-dimensional feedback mode integrating teacher feedback, peer feedback and network feedback, and applied it in the teaching of College English Writing. After 16 weeks of teaching, the stud... The study constructed a multi-dimensional feedback mode integrating teacher feedback, peer feedback and network feedback, and applied it in the teaching of College English Writing. After 16 weeks of teaching, the students in the multi-dimen-sional feedback class had significantly better overall writing scores than those in the teacher-feedback class. In terms of individual scores, multi-dimensional feedback played a better role in improving vocabulary and grammar than the class using teacher feed-back. However, there were no significant differences in the responses of writing tasks, coherence and cohesion. The study showed that most students were satisfied with the mode, believing that it was helpful to relieve writing anxiety, stimulate writing interest and improve their writing level. 展开更多
关键词 College English Writing multi-dimensional feedback MODE
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RNSQL:融合逆规范化的Text2SQL生成
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作者 帖军 范子琪 +2 位作者 孙翀 郑禄 朱柏尔 《计算机应用与软件》 北大核心 2025年第9期31-37,86,共8页
Text2SQL是自然语言处理科研领域中的一项重要任务,在研究智能问答系统中发挥关键性的作用,其核心任务是将自然语言描述的问题自动转换为SQL查询语句。当前研究重点为提高SQL子句任务的匹配准确率,但忽略了SQL的句法生成的正确性,涉及... Text2SQL是自然语言处理科研领域中的一项重要任务,在研究智能问答系统中发挥关键性的作用,其核心任务是将自然语言描述的问题自动转换为SQL查询语句。当前研究重点为提高SQL子句任务的匹配准确率,但忽略了SQL的句法生成的正确性,涉及多表连接的SQL生成仍存在大量错误。因此,提出一种基于神经网络的Text2SQL方法,该方法通过逆规范化技术,对数据库模式进行重构,关注SQL句法生成的正确性,称为逆规范化网络(Reverse Normalization SQL,RNSQL)。经理论分析和在公共数据集Spider上实验验证,RNSQL能有效提升Text2SQL任务的质量。 展开更多
关键词 逆规范化 语义解析 text2SQL 槽填充
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Structural Engineering of Hierarchical Aerogels Comprised of Multi-dimensional Gradient Carbon Nanoarchitectures for Highly Efficient Microwave Absorption 被引量:19
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作者 Yongpeng Zhao Xueqing Zuo +11 位作者 Yuan Guo Hui Huang Hao Zhang Ting Wang Ningxuan Wen Huan Chen Tianze Cong Javid Muhammad Xuan Yang Xinnan Wang Zeng Fan Lujun Pan 《Nano-Micro Letters》 SCIE EI CAS CSCD 2021年第9期344-363,共20页
Recently,multilevel structural carbon aerogels are deemed as attractive candidates for microwave absorbing materials.Nevertheless,excessive stack and agglomeration for low-dimension carbon nanomaterials inducing imped... Recently,multilevel structural carbon aerogels are deemed as attractive candidates for microwave absorbing materials.Nevertheless,excessive stack and agglomeration for low-dimension carbon nanomaterials inducing impedance mismatch are significant challenges.Herein,the delicate“3D helix-2D sheet-1D fiber-0D dot”hierarchical aerogels have been successfully synthesized,for the first time,by sequential processes of hydrothermal self-assembly and in-situ chemical vapor deposition method.Particularly,the graphene sheets are uniformly intercalated by 3D helical carbon nanocoils,which give a feasible solution to the mentioned problem and endows the as-obtained aerogel with abundant porous structures and better dielectric properties.Moreover,by adjusting the content of 0D core-shell structured particles and the parameters for growth of the 1D carbon nanofibers,tunable electromagnetic properties and excellent impedance matching are achieved,which plays a vital role in the microwave absorption performance.As expected,the optimized aerogels harvest excellent performance,including broad effective bandwidth and strong reflection loss at low filling ratio and thin thickness.This work gives valuable guidance and inspiration for the design of hierarchical materials comprised of dimensional gradient structures,which holds great application potential for electromagnetic wave attenuation. 展开更多
关键词 Hierarchical aerogels multi-dimensional gradient Carbon nanocoils Microwave absorption
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J-TEXT托卡马克相干成像光谱诊断系统设计
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作者 聂林 吴骏彬 +5 位作者 龙婷 雷驰 严伟 李杨波 张霄翼 J-TEXT实验团队 《核聚变与等离子体物理》 北大核心 2025年第3期273-279,共7页
相干成像光谱诊断是一种采用高速相机拍摄方式对等离子体边界的杂质离子流速进行二维成像的被动光谱诊断,对研究托卡马克边界和偏滤器等离子体环向旋转、杂质离子分布有着重要的作用。J-TEXT装置成功研制并部署了一套主要基于CⅢ线(464.... 相干成像光谱诊断是一种采用高速相机拍摄方式对等离子体边界的杂质离子流速进行二维成像的被动光谱诊断,对研究托卡马克边界和偏滤器等离子体环向旋转、杂质离子分布有着重要的作用。J-TEXT装置成功研制并部署了一套主要基于CⅢ线(464.88 nm)的相干成像光谱诊断系统。该系统的光学视场设计为12°,主要针对J-TEXT强场侧边缘等离子体区域进行观测。在性能指标方面,系统具备2 ms的时间分辨率,同时实现了11 mm(垂直方向)空间分辨率。目前该诊断系统已完成实验测试,并成功获取了等离子体边界的关键数据,为开展边界物理研究提供了新的实验手段。 展开更多
关键词 相干成像光谱诊断 环向速度 J-text托卡马克
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Seismic fragility analysis of highway bridges considering multi-dimensional performance limit state 被引量:17
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作者 Wang, Qi'ang Wu, Ziyan Liu, Shukui 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2012年第2期185-193,共9页
Fragility analysis for highway bridges has become increasingly important in the risk assessment of highway transportation networks exposed to seismic hazards. This study introduces a methodology to calculate fragility... Fragility analysis for highway bridges has become increasingly important in the risk assessment of highway transportation networks exposed to seismic hazards. This study introduces a methodology to calculate fragility that considers multi-dimensional performance limit state parameters and makes a first attempt to develop fragility curves for a multi-span continuous (MSC) concrete girder bridge considering two performance limit state parameters: column ductility and transverse deformation in the abutments. The main purpose of this paper is to show that the performance limit states, which are compared with the seismic response parameters in the calculation of fragility, should be properly modeled as randomly interdependent variables instead of deterministic quantities. The sensitivity of fragility curves is also investigated when the dependency between the limit states is different. The results indicate that the proposed method can be used to describe the vulnerable behavior of bridges which are sensitive to multiple response parameters and that the fragility information generated by this method will be more reliable and likely to be implemented into transportation network loss estimation. 展开更多
关键词 highway bridge seismic hazard multi-dimensional performance limit state fragility curves sensitivity
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Hydraulic directional valve fault diagnosis using a weighted adaptive fusion of multi-dimensional features of a multi-sensor 被引量:12
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作者 Jin-chuan SHI Yan REN +1 位作者 He-sheng TANG Jia-wei XIANG 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2022年第4期257-271,共15页
Because the hydraulic directional valve usually works in a bad working environment and is disturbed by multi-factor noise,the traditional single sensor monitoring technology is difficult to use for an accurate diagnos... Because the hydraulic directional valve usually works in a bad working environment and is disturbed by multi-factor noise,the traditional single sensor monitoring technology is difficult to use for an accurate diagnosis of it.Therefore,a fault diagnosis method based on multi-sensor information fusion is proposed in this paper to reduce the inaccuracy and uncertainty of traditional single sensor information diagnosis technology and to realize accurate monitoring for the location or diagnosis of early faults in such valves in noisy environments.Firstly,the statistical features of signals collected by the multi-sensor are extracted and the depth features are obtained by a convolutional neural network(CNN)to form a complete and stable multi-dimensional feature set.Secondly,to obtain a weighted multi-dimensional feature set,the multi-dimensional feature sets of similar sensors are combined,and the entropy weight method is used to weight these features to reduce the interference of insensitive features.Finally,the attention mechanism is introduced to improve the dual-channel CNN,which is used to adaptively fuse the weighted multi-dimensional feature sets of heterogeneous sensors,to flexibly select heterogeneous sensor information so as to achieve an accurate diagnosis.Experimental results show that the weighted multi-dimensional feature set obtained by the proposed method has a high fault-representation ability and low information redundancy.It can diagnose simultaneously internal wear faults of the hydraulic directional valve and electromagnetic faults of actuators that are difficult to diagnose by traditional methods.This proposed method can achieve high fault-diagnosis accuracy under severe working conditions. 展开更多
关键词 Hydraulic directional valve Internal fault diagnosis Weighted multi-dimensional features Multi-sensor information fusion
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Applications of multi-dimensional schemes on unstructured grids for high-accuracy heat flux prediction 被引量:2
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作者 Yunbo Wan Nianhua Wang +1 位作者 Laiping Zhang Yewei Gui 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2020年第1期57-71,共15页
The simulation of hypersonic flows with fully unstructured(tetrahedral)grids has severe problems with respect to the prediction of stagnation region heating,due to the random face orientation without alignment to the ... The simulation of hypersonic flows with fully unstructured(tetrahedral)grids has severe problems with respect to the prediction of stagnation region heating,due to the random face orientation without alignment to the bow shock.To improve the accuracy of aero-heating predictions,three multi-dimensional approaches on unstructured grids are coupled in our Reynolds-averaged Navier-Stokes(RANS)solver,including multi-dimensional upwind flux reconstruction(MUP),multi-dimensional limiter(MLP-u2)and multi-dimensional gradient reconstruction(MLR).The coupled multi-dimensional RANS solver is validated by several typical verification and validation(V&V)cases,including hypersonic flows over a cylinder,a blunt biconic,and a double-ellipsoid,with commonly used prism/tetrahedral hybrid grids.Finally,the coupled multi-dimensional solver is applied to simulating the heat flux distribution over a 3D engineering configuration,i.e.a Hermes-like space shuttle model.The obtained numerical results are compared with experimental data.The predicted results demonstrate that the coupled multi-dimensional approach has a good prediction capability on aerodynamic heating over a wide range of complex engineering configurations. 展开更多
关键词 Heat-flux prediction Unstructured grid multi-dimensional gradient reconstruction multi-dimensional limiter multi-dimensional upwind scheme
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