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Symplectic Approach on the Wave Propagation Problem for Periodic Structures with Uncertainty

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Acta Mechanica Solida Sinica 2019年第3期32卷 287-297页

作者： Yan Zhao Hui Liang youwei zhang Jiahao Lin State Key Laboratory of Structural Analysis for Industrial Equipment Department of Engineering Mechanics International Center for Computational Mechanics Dalian University of Technology Dalian 116023 China

An effective method is proposed in this paper for the symplectic eigenvalue problem of a periodic structure with uniform stochastic properties. Since structural parameters are uncertain, the symplectic transfer matrix of a typical substructure, which is described in the state space, also has sto chastic proper ties. An effec tive spec tral st ochastic finite elemen t method is adopted to ensure the symplectic orthogonality of the random symplectic matrix on the premise of certain precision. By means of the Rayleigh quotient method, the symplectic eigenvalue problem of random symplectic matrix is investigated. On the basis of this, the mean value and the standard deviation of the random eigenvalues are fully discussed. The comparison between the numerical results derived from the proposed method and the Monte-Carlo simulation indicates that the proposed method has high precision. This research provides a useful guidance for the dynamic analysis of periodic structures with stochastic properties.

关键词： Periodic structures Spectrum method Random symplectic matrix Symplectic eigenvalue

Topology Optimization Considering Steady-State Structural Dynamic Responses via Moving Morphable Component(MMC)Approach

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Acta Mechanica Solida Sinica 2022年第6期35卷 949-960页

作者： Jialin Li youwei zhang Zongliang Du Weisheng zhang Xinglin Guo Xu Guo State Key Laboratory of Structural Analysis for Industrial Equipment Department of Engineering MechanicsInternational Research Center for Computational MechanicsDalian University of TechnologyDalian116023China Ningbo Institute of Dalian University of Technology Ningbo315016China

This work presents a moving morphable component(MMC)-based framework for solving topology optimization problems considering both single-frequency and band-frequency steady-state structural dynamic *** this work,a set of morphable components are introduced as the basic building blocks for topology optimization,and the optimized structural layout can be found by optimizing the parameters characterizing the locations and geometries of the components *** degree of freedom(DOF)elimination technique is also employed to delete unnecessary DOFs at each *** the proposed approach solves the corresponding optimization problems in an explicit way,some challenging issues(e.g.,the large computational burden related to finite element analysis and sensitivity analysis,the localized eigenmodes in low material density regions,and the impact of excitation frequency on the optimization process)associated with the traditional approaches can be circumvented *** results show that the proposed approach is effective for solving topology optimization problems involving structural dynamic behaviors,especially when high-frequency responses are considered.

关键词： Topology optimization Moving morphable component(MMC) Structural dynamic response Dynamic compliance

Single source precursor derived SiBCNHf ceramic with enhanced high-temperature microwave absorption and antioxidation

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Journal of Materials Science & Technology 2022年第31期126卷 215-227页

作者： Yan Song Ziyu Liu Xicheng zhang Runqiu Zhu youwei zhang Pinggui Liu Lihua He Jie Kong MOE Key Laboratory of Space Applied Physics and Chemistry School of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi’an 710072China AECC Beijing Institute of Aeronautical Materials Beijing 100095China

Electromagnetic(EM)wave-absorbing materials with high-temperature-resistance are urgently desirable to eliminate EM interference in extreme *** derived ceramics(PDC)route is being evolved as an effective strategy to solve the ***,a single source hyperbranched polyborosi-lazane precursor containing hafnium(hb-PBSZ-Hf)is introduced and the SiBCNHf ceramic is obtained by further *** micro-sized tissues including HfC,SiC,HfB 2 nanocrystals and segregated carbons are in situ generated during annealing which not only increase EM wave absorption ability(minimum re-flection coefficient(RC_(min))is-56.71 dB with a thickness of 2.5 mm,effective absorption bandwidth(EAB)is 3.4 GHz),but also improve antioxidation property(less than 2 wt.%mass fluctuation at 1400℃in air).Theoretical simulation of complex permittivity suggests that SiBCNHf ceramic has an RC_(min)of less than-5 dB for the whole X-band even at 1100℃.Such SiBCNHf ceramic with superior high-temperature-resistance and antioxidation performance derived from single source precursors possesses great potential for EM wave absorbing coatings in high-temperature and harsh environments.

关键词： hb-PBSZ-Hf precursor SiBCNHf ceramic EM wave absorption Antioxidation performance

A New Style Tilt-Quadrotor:Modeling and Exploration of its Dynamical Characteristics 36

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A New Style Tilt-Quadrotor:Modeling and Exploration of its D...

The radiolytic behavior and mechanism of calixarene crown ether under γ-irradiation

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作者： Feng Lin youwei zhang Yanjun Lu Xiaodong zhang School of Automation Shenyang Aerospace University

ISBN: (纸本)9781538629185

The underactuation of the standard quadrotor（ four independent control input versus six output） is a serious problem which can be solved by tilting four *** steering wheel is installed on each axle of the original quadrotor so that the quadrotor turns into an actuation system（eight-input versus six-output）. In this paper, the dynamic model of the tilt-quadrotor is established, and the validity of the model is verified by the simulation of MATLAB. The simulation results show that the tilt-quadrotor unmanned aerial vehicle can not only realize the basic motion of the ordinary quadrotor unmanned aerial vehicle, but also realize the horizontal movement with the zero attitude angle;The vertical direction of the movement or hover movement can be achieved with the nonzero attitude angle, which fully proved the tilt-quadrotor can achieve decoupling movement, can solve the ordinary quadrotor underactuation problem.

关键词： Tilt-quadrotor modeling simulation

来源： cnki会议评论

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Chinese Science Bulletin 2013年第14期58卷 1663-1669页

作者： AO YinYong PENG Jing zhang youwei YUAN LiYong YU ChuHong LI JiuQiang ZHAI MaoLin Beijing National Laboratory for Molecular Sciences (BNLMS) Department of Applied Chemistry College of Chemistry and Molecular Engineering Peking University Institute of High Energy Physics Chinese Academy of Sciences

Bis(2-propyloxy)calix[4]crown-6 (BPC6) is an effective separation agent for cesium removing from spent nuclear fuel. The study on radiolytic behavior of BPC6 itself under γ-irradiation was required for evaluating its feasibility of practical application. It was found that BPC6 exhibited excellent radiation stability at dose less than 100 kGy. However, the isopropyl groups in BPC6 under- went oxidation and dealkylation to form carbonyl groups and phenolic hydroxyl groups at dose above 300 kGy, respectively. When the dose was more than 1000 kGy, the ring opening of crown ether structure of BPC6 resulted in the formation of phenolic hydroxyl groups as well. The formation of radiolytic products containing phenolic hydroxyl groups during the irradiation of BPC was confirmed by using FeCl 3 as a probe. Combining with the radiolytic behavior of two model chemicals (1-isopropoxybenzene and benzo-18-crown-6 ether), the radiolytic behavior and mechanism of BPC6 under -irradiation was testified further.

关键词：行为冠醚机制杯芳烃异丙氧基辐射稳定性烷基化反应酚羟基

The Application of Mechatronics Technology in Mechanical Engineering and Its Developing Direction

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International Journal of Technology Management 2013年第3期 8-10页

作者： youwei zhang Mechanical Engineering Department Langfang Polytechnic Institute Langfang city Hebei Province 065000 China

The development of modern science and technology has promoted the overlapping and mutual penetration among different disciplines, which led to the technological innovations in the field of mechanical engineering. The mechatronics technology conforms to the law of development of science and technology in today, and combines the mechanical technology and electronic technology together to integrate the logistics, energy flow and information flow. This paper briefly describes the concept of mechatronics and the elements of mechatronics technology, and elaborates on the application of mechatronics technology in three different areas of the Machinery Industry in the form of living examples, finally introduces the future developing direction of mechatronics technology.

关键词： Mechatronics Technology Mechanical Engineering Application Development

Chemical screen identifies shikonin as a broad DNA damage response inhibitor that enhances chemotherapy through inhibiting ATM and ATR

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Acta Pharmaceutica Sinica B 2022年第3期12卷 1339-1350页

作者： Fangfang Wang Sora Jin Franklin Mayca Pozo Danmei Tian Xiyang Tang Yi Dai Xinsheng Yao Jinshan Tang youwei zhang Institute of Traditional Chinese Medicine and Natural Products College of PharmacyJinan UniversityGuangzhou 510632China Guangdong Province Key Laboratory of Pharmacodynamic Constituents of Traditional Chinese Medicine and New Drug Research Jinan UniversityGuangzhou 510632China Department of Pharmacology Case Comprehensive Cancer CenterCase Western Reserve University School of MedicineClevelandOH 44106USA

DNA damage response(DDR)is a highly conserved genome surveillance mechanism that preserves cell viability in the presence of chemotherapeutic ***,small molecules that inhibit DDR are expected to enhance the anti-cancer effect of *** a recent chemical library screen,we identified shikonin as an inhibitor that strongly suppressed DDR activated by various chemotherapeutic drugs in cancer cell lines derived from different ***,shikonin inhibited the activation of ataxia telangiectasia mutated(ATM),and to a lesser degree ATM and RAD3-related(ATR),two master upstream regulators of the DDR signal,through inducing degradation of ATM and ATR-interacting protein(ATRIP),an obligate associating protein of ATR,*** a result of DDR inhibition,shikonin enhanced the anti-cancer effect of chemotherapeutic drugs in both cell cultures and in mouse *** degradation of ATRIP is proteasome dependent,that of ATM depends on caspase-and lysosome-,but not *** of ATM significantly mitigated DDR inhibition and cell death induced by shikonin and chemotherapeutic *** novel findings reveal shikonin as a pan DDR inhibitor and identify ATM as a primary factor in determining the chemo sensitizing effect of *** data may facilitate the development of shikonin and its derivatives as potential chemotherapy sensitizers through inducing ATM degradation.

关键词： Chemical screen Shikonin DNA damage Response ATM ATR ATRIP Protein degradation Chemo sensitizing

Influence of seeding promoters on the properties of CVD grown monolayer molybdenum disulfide

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Nano Research 2019年第4期12卷 823-827页

作者： Peng Yang Ai-Guo Yang Lingxiu Chen Jing Chen youwei zhang Haomin Wang Laigui Hu Rong-Jun zhang Ran Liu Xin-Ping Qu Zhi-Jun Qiu Chunxiao Cong State Key Laboratory of ASIC and System School of Information Science and Technology Fudan University Shanghai 200433 China State Key Laboratory of Functional Material for Informatics Shanghai Institute (rf Microsystem and Information Technology Chinese Academy of Sciences Changning Road 865 Shanghai 200050 China

Chemical vapor deposition (CVD) is the most efficient method to grow large-area two dimensional (2D) transition metal dichiacogenides (TMDCs) in high *** molybdenum disulfide (MoS2) and seed-assistant are the mostly selected 2D TMDC and growth strategy for such CVD processes,*** the advantages of seed catalysts in facilitating the nucleation,achieving higher yield and better repeatability,as well as their effects on the morphologies of as-grown MoS2 have been studied,the influence of seeding promoters on both optical and electrical properties of as-grown monolayer MoS2 is not known comprehensively,which is indeed critical for understanding fundamental physics and developing practical application of such emerging 2D *** this report,we systematically investigated the effect of different seeding promoters on the properties of CVD-grown monolayer *** is found that different seed molecules lead to different impacts on the optical and electrical properties of as-grown monolayer *** three different seed catalysts (perylene-3,4,9,10-tetracarboxylic acid tetrapotassium salt (PTAS),copper phthalocyanine (CuPc),and crystal violet (CV)),PTAS performs better in obtaining large area monolayer MoS2 with good optical quality and high electrical mobility than the other *** work gives a guide for modifying the properties of as-grown monolayer MoS2 and other 2D transition metal dichalcogenides in seeding promoters-assisted synthesis process.

关键词： transition metal dichalcogenides monolayer M0S2 seeding promoters chemical vapor deposition optical and electrical properties

Long-Range Electronic Effect-Promoted Ring-Opening Polymerization of Thioctic Acid to Produce Biomimetic Ionic Elastomers for Bioelectronics

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CCS Chemistry 2024年第3期6卷 761-773页

作者： Hongfei Huang Huijing Wang Lijie Sun Ruohan zhang Luzhi zhang ZekaiWu Yaxuan Zheng Yang Wang Wei Fu youwei zhang Rasoul Esmaeely Neisiany Zhengwei You State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Materials Science and EngineeringInstitute of Functional MaterialsDonghua UniversityResearch Base of Textile Materials for Flexible Electronics and Biomedical Applications(China Textile Engineering Society)Shanghai Engineering Research Center of Nano-Biomaterials and Regenerative MedicineShanghai 201620 Institute of Pediatric Translational Medicine Shanghai Children’s Medical CenterSchool of MedicineShanghai Jiao Tong UniversityShanghai 200127 Department of Materials and Polymer Engineering Faculty of EngineeringHakim Sabzevari UniversitySabzevar ***

Poly(disulfide)s have been widely used in flexible wearable electronics,smart materials,and drug *** synthesis of poly(disulfide)s usually utilizes external stimuli or toxic initiators to promote the ***,we indicated that the long-range electronic effect can significantly alter the reactivity of the disulfide ***,we established deprotonation-promoted ring-opening polymerization of thioctic acid(TA)as a highly effective and simple method to synthesize poly(disulfide)s due to the long-range electronic effect and nucleophilic *** external stimuli and initiators,simple mixing of TA and deprotonation reagent,choline bicarbonate,in different ratios at room temperature rapidly produced a series of high molecular weight(up to 772 kDa)ionic liquid crystal poly(disulfide)s elastomers with room temperature self-healing ability,adjustable conductivity(2.39×10^(−2)∼0.28×10^(−2)S m^(−1)),degradability,biocompatibility,antibacterial property,and tissue-like softness(Young’s moduli ranging from 18.2±6.0 to 111.1±36.7 kPa).The experiments and density functional theory calculations also revealed the principle of long-range electronic effect to establish a new synthetic strategy of poly(disulfide)s with superior properties favorable for bioelectronics.

关键词： self-healing elastomers thioctic acid ionic liquid bioelectronics