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Experimental Investigations on the Out-of-Plane Sub-harmonic Vibration of a Circular Dielectric Elastomer Actuator

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Acta Mechanica Solida Sinica 2019年第5期32卷 591-598页

作者： Cheng Ma Meng Yang Kun Jia Tongqing Lu State Key Laboratory for Strength and Vibration of Mechanical Structure Department of Engineering MechanicsXi'an Jiaotong UniversityXi'an 710049China

Dielectric elastomers have found interesting applications in soft loudspeakers,where vibrations subject to alternating electrical excitations are the key *** there are many t heore tical studies on the nonlinear vibrations of dielec trie elasto mers subject to electromechanical coupling loads,the systematic experimental research is *** this work,we design a simple experimental setup to observe the out-of-plane vibrations of a circular dielec trie elastomer *** find that the dielec trie elastomer has different response modes including the harmonic,super-harmonic and sub-harmonic responses at different excitation *** analyze the responses by using the short-time Fourier *** find that the equivalent voltage and the AC/DC ratio are the main parameters affecting the occurrence of sub-harmonic *** phenomenon of mode shift is also observed in our *** experimental observations provide a deeper unders tanding of the dynamic responses of dielec trie elasto mer subject to electromechanical loads.

关键词： Dielectric elastomer Nonlinear vibration Harmonic response Sub-harmonic response

Wave mode computing method using the step-split Padé parabolic equation

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Chinese Physics B 2022年第9期31卷 354-361页

作者： Chuan-Xiu Xu Guang-Ying Zheng Hangzhou Applied Acoustics Research Institute Hangzhou 310023China Science and Technology on Sonar Laboratory Hangzhou 310023China

Models based on a parabolic equation(PE)can accurately predict sound propagation problems in range-dependent ocean ***,this method has developed rapidly in recent *** with normal mode theory,PE focuses on numerical calculation,which is difficult to use in the mode domain analysis of sound propagation,such as the calculation of mode phase velocity and group *** broaden the capability of PE models in analyzing the underwater sound field,a wave mode calculation method based on PE is proposed in this ***-split Pade PE recursive matrix equations are combined to obtain a propagation ***,the eigenvalue decomposition technique is applied to the matrix to extract sound mode eigenvalues and *** experiments on some typical waveguides are performed to test the accuracy and flexibility of the new *** on different orders of Padéapproximant demonstrate angle limitations in PE and the missing root problem is also discussed to prove the advantage of the new *** PE mode method can be expanded in the future to solve smooth wave modes in ocean waveguides,including fluctuating boundaries and sound speed profiles.

关键词： parabolic equation propagation matrix eigenvalue decomposition

Density functional theory investigation of carbon monoxide adsorption on the kaolinite(001) surface

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Chinese Physics B 2017年第7期26卷 495-500页

作者：赵健何满潮胡祥星高炜 State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining and Technology

Carbon monoxide（CO） is a gaseous pollutant with adverse effects on human health and the environment. Kaolinite is a natural mineral resource that can be used for different applications, including that it can also be used for retention of pollutant gases. The adsorption behavior of carbon monoxide molecules on the（001） surface of kaolinite was studied systematically by using density-functional theory and supercell models for a range coverage from 0.11 to 1.0 monolayers（ML）. The CO adsorbed on the three-fold hollow, two-fold bridge, and one-fold top sites of the kaolinite（001） was tilted with respect to the surface. The strongest adsorbed site of carbon monoxide on the kaolinite（001） surface is the hollow site followed by the bridge and top site. The adsorption energy of CO decreased when increasing the coverage, thus indicating the lower stability of surface adsorption due to the repulsion of neighboring CO molecules. In addition to the adsorption structures and energetics, the lattice relaxation, the electronic density of states, and the different charge distribution have been investigated for different surface coverages.

关键词： kaolinite adsorption carbon monoxide density functional theory

Monomer-dependent synthesis of secondary amine-linked triazine-based two-dimensional polymers nanosheets

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Science China Chemistry 2020年第7期63卷 966-972页

作者： Ranran Zhao Chaoqun Niu Mohamed FAly Aboud Imran Shakir Chengbing Yu Yuxi Xu School of Materials Science and Engineering Shanghai UniversityShanghai 201800China School of Engineering Westlake UniversityHangzhou 310024China Sustainable Energy Technologies Center College of EngineeringKing Saud UniversityRiyadh 11421Kingdom of Saudi Arabia

Expanding the structural diversity of crystalline two-dimensional polymers(2DPs) is highly desired but remains a considerable challenge. Herein we report the first synthesis of novel crystalline secondary amine-linked triazine-based 2DPs(SAT-2DPs) by using benzidine or 4, 4′′-diamino-p-terphenyl and cyanuric chloride under solvothermal conditions. We find the structures of diamine-based monomers play a crucial role in deciding whether the synthesized material is crystalline 2DPs nanosheets or amorphous nanoparticles, which is unexpected and provides an important understanding of the 2D polymerization *** obtained SAT-2DPs not only show a lateral size of micrometers and an ultrathin thickness of a few nanometers, but also demonstrate high crystallinity with a unique ABC stacking configuration, excellent solvent dispersibility and superior thermal stability. In addition, the resultant SAT-2DPs are used to guide uniform lithium-ion deposition due to their abundant nitrogen atoms and ordered open channels. The assembled asymmetric coin cells(Li|Cu) with SAT-2DPs realize the average coulombic efficient up to 99.3% during discharge-charge cycles. This work provides valuable insights into the synthesis of new 2DPs for various applications.

关键词： nanosheets,two-dimensional polymers crystalline solution synthesis monomer-dependent

Genome sequencing brought Gossypium biology research into a new era

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Science China(Life Sciences) 2017年第12期60卷 1463-1466页

作者： Fuguang Li Zuoren Yang Zhi Wang Zhao'en Yang State Key Laboratory of Cotton Biology Institute of Cotton ResearchChinese Academy of Agricultural SciencesAnyang 455000China

The first sequenced diploid cotton genome was published in2012 by the group led by the Institute of Cotton Research,Chinese Academy of Agricultural *** genomics research subsequently entered a period of rapid developm... 详细信息

关键词： Genome sequencing brought Gossypium biology research a new era

PAI-1 Derived from Alveolar Type 2 Cells Drives Aging-Associated Pulmonary Fibrosis

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Engineering 2024年第11期42卷 74-87页

作者： Rui Quan Chenhong Shi Yanan Sun Chengying Zhang Ran Bi Yiran Zhang Xin Bi Bin Liu Ziheng Dong Dekui Jin Yixuan Li Key Laboratory of Functional Dairy Co-Constructed by the Ministry of Education and Beijing MunicipalityBeijing 100083China Department of General Practice The Third Medical Center of the Chinese PLA General HospitalBeijing 100039China Department of Thoracic Surgery The Third Medical Center of the Chinese PLA General HospitalBeijing 100039China Center for Nanomedicine and Department of Anesthesiology Brigham and Women’s HospitalHarvard Medical SchoolBostonMA 02115USA School of Computer and Information Engineering Luoyang Institute of Science and TechnologyLuoyang 471023China

Pulmonary fibrosis(PF)is a lethal lung disease that predominantly affects older adults;however,whether and how aging triggers fibrosis remains *** pinpoint the predominant initiating factors of PF,we first analyzed single-cell RNA sequencing(scRNA-seq)data from the lung tissues of 45 normal donors and 51 PF patients and found that aging might serve as the primary catalyst for PF *** further investigate the influence of aging on PF formation,we conducted a comprehensive and thorough study employing a natural aging mouse *** found that dynamic alterations in the quantity and types of collagen fibers during aging-induced PF progression,especially in collagenous(Col)I,emerged as the predominant driver of *** then investigated the regulation of Col I synthesis during aging using primary alveolar type 2(AT2)cells and A549 cells line through conditioned media and Transwell cocul-ture,and found that secretions—particularly plasminogen activator inhibitor(PAI)-1—from aged AT2 cells promoted fibrosis and enhanced collagen type I alpha 1(Col1al)production via the transforming growth factor(TGF)-b/small mother against decapentaplegic(Smad)2/3 ***,scRNA-seq and a histological analysis of human lung tissue demonstrated a significant upregulation of SERPINE1(the gene encoding PAI-1)and PAI-1 expression in both aging lung tissue and AT2 cells,which was consistent with our findings from animal experiments,providing additional evidence for the pivotal role of PAI-1 during aging and the development of *** research demonstrates that PAI-1,a crucial factor secreted by aging AT2 cells,exerts a pivotal role in promoting the synthesis of Col1a1 in fibroblasts,subsequently leading to Col I deposition,and in driving the progression of PF by mediating the TGF-b/Smad2/3 *** find-ings offer critical evidence for the involvement of epithelial dysfunction in age-related PF and provides potential novel therapeutic targets for clinical interventio

关键词： Aging Pulmonary fibrosis Alveolar type 2 cells PAI-1

Double-kill contribution of high-roughness high-density porous carbon electrodes to mechanically self-sensing supercapacitors

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Nano Research 2024年第7期17卷 6157-6167页

作者： Jue Huang Pengyu Liu Yiqun Wang Keren Dai Qingyun Dou Yajiang Yin Xiaofeng Wang Zheng You Department of Precision Instrument Tsinghua UniversityBeijing 100084China State Key Laboratory of Precision Measurement Technology and Instruments Beijing 100084China Department of Materials Science and Engineering Sun Yat-Sen UniversityGuangzhou 510275China ZNDY of Ministerial Key Laboratory School of Mechanical EngineeringNanjing University of Science and TechnologyNanjing 210094China Qiyuan Laboratory Beijing 100095China

Impact detecting and counting are fundamental functions of fuses used in hard target penetration ***,detection failure caused by battery breakdown in high-g acceleration environments poses a vulnerability for such *** paper introduces a novel supercapacitor that combines energy storage and high-g impact detection,called self-sensing *** deliberately inducing a transient soft short-circuit during shock in the supercapacitor,it is possible to detect external impact by its transient voltage *** realize this concept,firstly,by introducing the contact theory and force-induced percolation model,the electrode strength and roughness are found to have key impacts on the formation of soft ***,to meet the needs for sensitivity and capacity,a high-density porous carbon(HDPC)that combines high mechanical strength and porosity,is selected as a suitable candidate based on the analysis ***,a two-step curing method is proposed to prepare the high-roughness HDPC(HRHDPC)electrode and to assemble the self-sensing *** to the rich specific surface of the electrodes and the high surface strength and roughness conducive to the formation of transient soft short circuits,the self-sensing supercapacitor not only possesses an excellent specific capacitance(171 F/g at 0.5 A/g)but also generates significant voltage response signals when subjected to high-g impacts ranging from 8000g to 31,***,the self-sensing supercapacitor is applied to compose a successive high-g impact counting system and compared to traditional solutions(sensors and tantalum capacitors)in the military *** results show that the self-sensing supercapacitor-based system exhibits advantages in terms of size,power consumption,and counting accuracy.

关键词： supercapacitor self-sensing soft short-circuit impact sensing

Genome-wide analysis of BES1 genes in Gossypium revealed their evolutionary conserved roles in brassinosteroid signaling

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Science China(Life Sciences) 2018年第12期61卷 1566-1582页

作者： Zhao Liu Ghulam Qanmber Lili Lu Wenqiang Qin Ji Liu Jie Li Shuya Ma Zhaoen Yang Zuoren Yang State Key Laboratory of Cotton Biology Key Laboratory of Biological and Genetic Breeding of Cotton Institute of Cotton Research Chinese Academy of Agricultural Sciences School of Agricultural Sciences Zhengzhou University

Brassinosteroids(BRs), which are essential phytohormones for plant growth and development, are important for cotton fiber development. Additionally, BES1 transcription factors are critical for BR signal transduction. However, cotton BES1 family genes have not been comprehensively characterized. In this study, we identified 11 BES1 genes in G. arboreum, 11 in ***, 16 in G. barbadense, and 22 in G. hirsutum. The BES1 sequences were significantly conserved in the Arabidopsis thaliana, rice, and upland cotton genomes. A total of 94 BES1 genes from 10 different plant species were divided into three clades according to the neighbor-joining and minimum-evolution methods. Moreover, the exon/intron patterns and motif distributions were highly conserved among the A. thaliana and cotton BES1 genes. The collinearity among the orthologs from the At and Dt subgenomes was estimated. Segmental duplications in the At and Dt subgenomes were primarily responsible for the expansion of the cotton BES1 gene family. Of the GhBES1 genes, GhBES1.4_At/Dt exhibited BL-induced expression and was predominantly expressed in fibers. Furthermore, Col-0/mGhBES1.4_At plants produced curled leaves with long and bent petioles. These transgenic plants also exhibited decreased hypocotyl sensitivity to brassinazole and constitutive BR induced/repressed gene expression patterns. The constitutive BR responses of the plants overexpressing mGhBES1.4_At were similar to those of the bes1-D mutant.

关键词： G.hirsutum brassinosteroids BES1 phylogenetic collinearity duplication hormones curled leaves hypocotyl

Conjugate Vectors Method Applied to Asymmetrical Fault Analysis of Power Electronized Power Systems

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CSEE Journal of Power and Energy Systems 2024年第4期10卷 1536-1549页

作者： Yingbiao Li Xing Liu Jiabing Hu Jianhang Zhu Jianbo Guo State Key Laboratory of Advanced Electromagnetic Technology(Huazhong University of Science and Technology) Wuhan 430074China China Electric Power Research Institute Beijing 100192China

With the wide application of power electronized resources(PERs),the amplitude and frequency of voltages show significant time-varying characteristics under asymmetrical *** a result,the traditional phasor model,impedance model,and symmetrical components method based on the constant amplitude and frequency of voltages are facing great ***,a novel asymmetrical fault analysis method based on conjugate vectors is proposed in this paper which can meet the modeling and analysis requirements of the network excited by voltages with time-varying amplitude/***,asymmetrical fault characteristics are *** an application,a faulted phase identification(FPI)strategy is proposed based on the fault *** correctness and superiority of the asymmetrical fault analysis method and FPI strategy are verified in time-domain simulations and a real-time digital simulator.

关键词： Asymmetrical fault characteristics conjugate vectors method dynamic asymmetrical fault analysis time-varying amplitude/frequency