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Enhanced galloping energy harvester with cooperative mode of vibration and collision

Applied Mathematics and Mechanics(English Edition) 2022年第7期43卷 945-958页

作者： Qiong WANG Zewen CHEN Linchuan ZHAO Meng LI Hongxiang ZOU Kexiang WEI xizheng zhang Wenming zhang Hunan Provincial Key Laboratory of Vehicle Power and Transmission System Hunan Institute of EngineeringXiangtan 411104Hunan ProvinceChina State Key Laboratory of Mechanical System and Vibration School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China

The low power and narrow speed range remain bottlenecks that constrain the application of small-scale wind energy harvesting.This paper proposes a simple,lowcost,and reliable method to address these critical issues.A galloping energy harvester with the cooperative mode of vibration and collision(GEH-VC)is presented.A pair of curved boundaries attached with functional materials are introduced,which not only improve the performance of the vibration energy harvesting system,but also convert more mechanical energy into electrical energy during collision.The beam deforms and the piezoelectric energy harvester(PEH)generates electricity during the flow-induced vibration.In addition,the beam contacts and separates from the boundaries,and the triboelectric nanogenerator(TENG)generates electricity during the collision.In order to reduce the influence of the boundaries on the aerodynamic performance and the feasibility of increasing the working area of the TENG,a vertical structure is designed.When the wind speed is high,the curved boundaries maintain a stable amplitude of the vibration system and increase the frequency of the vibration system,thereby avoiding damage to the piezoelectric sheet and improving the electromechanical conversion efficiency,and the TENG works with the PEH to generate electricity.Since the boundaries can protect the PEH at high wind speeds,its stiffness can be designed to be low to start working at low wind speeds.The electromechanical coupling dynamic model is established according to the GEH-VC operating principle and is verified experimentally.The results show that the GEH-VC has a wide range of operating wind speeds,and the average power can be increased by 180%compared with the traditional galloping PEH.The GEH-VC prototype is demonstrated to power a commercial temperature sensor.This study provides a novel perspective on the design of hybrid electromechanical conversion mechanisms,that is,to combine and collaborate based on their respective characteristics.

关键词： energy harvesting wind energy galloping piezoelectric energy harvester(PEH)

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含时紧束缚模型中的波包动力学

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天津师范大学学报（自然科学版） 2024年第1期44卷 34-41,55页

作者：王羽婷张禧征天津师范大学物理与材料科学学院天津300387

为了发展与构建新的量子调控方法与机制,基于含时磁通作用的一维紧束缚环体系,通过计算系统的能谱和传播子,研究了含时外场下单粒子波包的动力学行为.结果表明:矢势可以以相位的形式出现在紧束缚模型的二次量子化哈密顿量中,且其含时变... 详细信息

为了发展与构建新的量子调控方法与机制,基于含时磁通作用的一维紧束缚环体系,通过计算系统的能谱和传播子,研究了含时外场下单粒子波包的动力学行为.结果表明:矢势可以以相位的形式出现在紧束缚模型的二次量子化哈密顿量中,且其含时变化所诱导的波包动力学效应与存在外电场时系统的动力学效应相同,表现为与经典物理中的法拉第电磁感应定律一致,这种与经典物理相对应的关系为人们构建新的量子调控机制提供了重要的指导思想.

关键词：量子控制含时紧束缚波包半经典近似动力学

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Fuzzy Adaptive Filtering-Based Energy Management for Hybrid Energy Storage System

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Computer Systems Science & Engineering 2021年第1期36卷 117-130页

作者： xizheng zhang zhangyu Lu Chongzhuo Tan Zeyu Wang School of Electrical and Information Engineering Hunan Institute of EngineeringXiangtan411104China School of Robotics Hunan UniversityChangsha410082China

Regarding the problem of the short driving distance of pure electric vehicles,a battery,super-capacitor,and DC/DC converter are combined to form a hybrid energy storage system(HESS).A fuzzy adaptive filtering-based energy management strategy(FAFBEMS)is proposed to allocate the required power of the vehicle.Firstly,the state of charge(SOC)of the super-capacitor is limited according to the driving/braking mode of the vehicle to ensure that it is in a suitable working state,and fuzzy rules are designed to adaptively adjust the filtering time constant,to realize reasonable power allocation.Then,the positive and negative power are determined,and the average power of driving/braking is calculated so as to limit the power amplitude to protect the battery.To verify the proposed FAFBEMS strategy for HESS,simulations are performed under the UDDS(Urban Dynamometer Driving Schedule)driving cycle.The results show that the FAFBEMS strategy can effectively reduce the current amplitude of the battery,and the final SOC of the battery and super-capacitor is optimized to varying degrees.The energy consumption is 7.8%less than that of the rule-based energy management strategy,10.9%less than that of the fuzzy control energy management strategy,and 13.1%less than that of the filtering-based energy management strategy,which verifies the effectiveness of the FAFBEMS strategy.

关键词： Hybrid energy storage system energy management fuzzy adaptiveﬁltering electric vehicle

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Study on biomechanical mechanism of bone remodeling

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医用生物力学 2013年第S1期28卷 93-94页

作者： xizheng zhang Institute of Medical Equipment Academy of Military Medical Sciences

Background Bone is a dynamic tissue that constantly undergoes remodeling in which a coupled process of bone formation and resorption continues throughout life.This remodeling is necessary to maintain the structural integrity of the skeleton under conditions of changing mechanical forces.It is important to develop bone remodeling theory in order to explain bone development and to instruct bone disease therapy and rehabilitation.However,the process and mechanism are not fully understood.Our study was carried out to investigate biomechanical mechanism of bone remodeling with the respect to bone tissue/cell mechanobiology,computational biomechanics and animal model.

关键词： remodeling rehabilitation constantly maintain understood scaffold skeleton explain integrity intermittent

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Characterization and evaluation of a femtosecond laser-induced osseointegration and an anti-inflammatory structure generated on a titanium alloy

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Regenerative Biomaterials 2021年第2期8卷 104-117页

作者： Yang Liu Zhongying Rui Wei Cheng Licheng Song Yunqiang Xu Ruixin Li xizheng zhang Department of Orthopedics Tianjin Medical University General HospitalTianjin 300052China Institute of Medical Service Support Institute of Systems EngineeringAcademy of Military SciencesTianjinChina Department of Nuclear Medicine Tianjin Medical University General HospitalTianjin 300052China Tianjin Key Laboratory of Oral and Maxillofacial Function Reconstruction Tianjin Stomatological HospitalThe Affiliated Stomatological Hospital of Nankai UniversityTianjin 300041China

Cell–material interactions during early osseointegration of the bone–implant interface are critical and involve crosstalk between osteoblasts and osteoclasts.The surface properties of titanium implants also play a critical role in cell–material interactions.In this study,femtosecond laser treatment and sandblasting were used to alter the surface morphology,roughness and wettability of a titanium alloy.Osteoblasts and osteoclasts were then cultured on the resulting titanium alloy disks.Four disk groups were tested:a polished titanium alloy(pTi)control;a hydrophilic micro-dislocation titanium alloy(sandblasted Ti(STi));a hydrophobic nano-mastoid Ti alloy(femtosecond laser-treated Ti(FTi));and a hydrophilic hierarchical hybrid micro-/nanostructured Ti alloy[femtosecond laser-treated and sandblasted Ti(FSTi)].The titanium surface treated by the femtosecond laser and sandblasting showed higher biomineralization activity and lower cytotoxicity in simulated body fluid and lactate dehydrogenase assays.Compared to the control surface,the multifunctional titanium surface induced a better cellular response in terms of proliferation,differentiation,mineralization and collagen secretion.Further investigation of macrophage polarization revealed that increased anti-inflammatory factor secretion and decreased proinflammatory factor secretion occurred in the early response of macrophages.Based on the above results,the synergistic effect of the surface properties produced an excellent cellular response at the bone–implant interface,which was mainly reflected by the promotion of early ossteointegration andmacrophage polarization.

关键词： femtosecond laser hybrid micro-/nanostructure cell–material interactions osseointegration macrophage polarization

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Effect of the same mechanical loading on osteogenesis and osteoclastogenesis in vitro

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Chinese Journal of Traumatology 2015年第3期18卷 150-156页

作者： Yong Guo Yang Wang Yinqin Liu Haitao Wang Chun Guo xizheng zhang Chaoyong Bei College ofBioteehnology Guilin Medical University Guilin 541004 China Department of Medicine Luohe Medical College Luohe 462000 China Institute of Medical Equipment Academy of Military Medical Sciences Tianjin 300161 China Department of Orthopedic Affiliated Hospital of Guilin Medical University. Guilin 541000 China

Purpose:To investigate the influence of the same mechanical loading on osteogenesis and osteoclastogenesis in vitro. Methods:Primary osteoblasts, bone marrow-derived mesenchymal stem cells (BMSCs, cultured in osteoinductive medium) and RAW264.7 cells cultured in osteoclast inductive medium were all subjected to a 1000 μstrain (μs) at 1 Hz cyclic mechanical stretch for 30 min (twice a day).Results:After mechanical stimulation, the alkaline phosphatase (ALP) activity, osteocalcin protein level of the osteoblasts and BMSCs were all enhanced, and the mRNA levels of ALP and collagen type I increased. Additionally, extracellular-deposited calcium of both osteoblasts and BMSCs increased. At the same time, the activity of secreted tartrate-resistant acid phosphatase, the number of tartrate-resistant acid phosphatase-positive multinucleated cells, matrix metalloproteinase-9 protein levels of RAW264.7 cells and the extracellular calcium solvency all decreased.Conclusion:The results demonstrated that 1000 μs cyclic mechanical loading enhanced osteoblasts activity, promoted osteoblastic differentiation of BMSCs and restrained osteoclastogenesis of RAW264.7 cells in vitro.

关键词：成骨细胞分化破骨细胞体外培养机械负荷 RAW264.7细胞骨髓间充质干细胞基质金属蛋白酶-9 骨髓基质干细胞

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Biomedical response of femurs in male Wistar rat in chronic hypergravity environments

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Medicine in Novel Technology and Devices 2022年第4期16卷 111-119页

作者： Lu Yu Shuping Wei Biao Han Lilan Gao Yang zhang xizheng zhang Key Laboratory of Biomechanics and Mechanobiology(Beihang University) Ministry of Education Beijing Advanced Innovation Center for Biomedical Engineering School of Biological Science and Medical EngineeringBeihang UniversityBeijing100083China Institute of Medical Service and Technology Academy of Military SciencesTianjin300161China Logistics University of Chinese People's Armed Police Force Tianjin300309China College of Biotechnology Guilin Medical UniversityGuilin541199China School of Mechanical Engineering Tianjin University of TechnologyTianjin300384China

Bone is sensitive to mechanical stimulation and plays a loading-bearing role in the human body.However,regulation of bone biomechanical properties in chronic hypergravity environments is still unclear.In this study,male Wistar rats exposed to chronic hypergravity environments(4g,8g,10g,and 20g)for 4 weeks were set as the hypergravity groups,and rats exposed to the normal gravity as the control group.Morphology parameters and bone remodeling factors were obtained by means of micro-CT,Western blot,and q-PCR.Mechanical properties of femurs were measured utilizing three points bending test and creep test and were fitted into a viscoelastic-viscoplastic constitutive equation.The results indicate osteoporosis occurred in femurs of hypergravity groups.Accordingly,the protein and gene expressions of bone remodeling factors(OPG,RANKL,runx2)in hypergravity groups were significantly different from that in the control group,demonstrating that bone formation level increased and bone resorption level decreased.Meanwhile,mechanical properties of femurs in hypergravity groups showed that Young's modulus of femurs in the 20g group was significantly higher than that in the control group.The viscoelastic-viscoplastic properties of bone tissue were changed in hypergravity environments.Among them,the 8g group was closest to the control group in morphology and mechanical properties.To sum up,the biomechanical response regulation of rat femur under 4-20g chronic hypergravity environments was presented.Hypergravity environments could lead to osteoporosis.The balance between bone formation and bone resorption would be disrupted in hypergravity groups due to bone adaptation.20g environment has a significant effect on elastic modulus on femurs.Due to the difference in biomechanical response of femurs,the viscoelastic-viscoplastic characteristics of femurs have a nonlinear relationship with hypergravity values.Bone tissue was least affected by 8g hypergravity in morphology and mechanical properties.

关键词： Hypergravity Biomechanical response Femur Viscoelastic-viscoplastic properties Bone remodeling

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New mixed broadcast scheduling approach using neural networks and graph coloring in wireless sensor network

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Journal of Systems Engineering and Electronics 2009年第1期20卷 185-191页

作者： zhang xizheng Wang Yaonan Dept. of Computer Science Hunan Inst. of Engineering Xiangtan 411104 P. R. China School of Electrical and Information Engineering Hunan Univ. Changsha 410082 P. R. China

Due to the mutual interference and sharing of wireless links in TDMA wireless sensor networks, conflicts will occur when data messages are transmitting between nodes. The broadcast scheduling problem （BSP） is aimed to schedule each node in different slot of fixed length frame at least once, and the objective of BSP is to seek for the optimal feasible solution, which has the shortest length of frame slots, as well as the maximum node transmission. A two-stage mixed algorithm based on a fuzzy Hopfield neural network is proposed to solve this BSP in wireless sensor network. In the first stage, a modified sequential vertex coloring algorithm is adopted to obtain a minimal TDMA frame length. In the second stage, the fuzzy Hopfleld network is utilized to maximize the channel utilization ratio. Experimental results, obtained from the running on three benchmark graphs, show that the algorithm can achieve better performance with shorter frame length and higher channel utilizing ratio than other exiting BSP solutions.

关键词： wireless sensor network broadcast scheduling fuzzy Hopfield network graph coloring.

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SU(2) symmetry in a Hubbard model with spin-orbit coupling

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Science China(Physics,Mechanics & Astronomy) 2014年第11期57卷 2086-2091页

作者： zhang xizheng JIN Liang SONG Zhi College of Physics and Materials Science Tianjin Normal University School of Physics Nankai University

We study the underlying symmetry in a spin-orbit coupled tight-binding model with Hubbard interaction.It is shown that,in the absence of the on-site interaction,the system possesses the SU(2)symmetry arising from the time reversal symmetry.The influence of the on-site interaction on the symmetry depends on the topology of the networks:The SU(2)symmetry is shown to be the spin rotation symmetry of a simply-connected lattice even in the presence of the Hubbard interaction.On the contrary,the on-site interaction breaks the SU(2)symmetry of a multi-connected lattice.This fact indicates that a discrete spin-orbit coupled system has exclusive features from its counterpart in a continuous system.The obtained rigorous result is illustrated by a simple ring system.

关键词：时间反演对称性自旋轨道耦合 SU(2) Hubbard模型相互作用耦合系统紧束缚模型旋转对称性

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Analysis of the joint detection capability of the SMILE satellite and EISCAT-3D radar

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Earth and Planetary Physics 2024年第1期8卷 299-306页

作者： JiaoJiao zhang TianRan Sun xizheng Yu DaLin Li Hang Li JiaQi Guo ZongHua Ding Tao Chen Jian Wu Chi Wang State Key Laboratory of Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190China Key Laboratory of Solar Activity and Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 101408China Key Laboratory of Electronics and Information Technology for Space Systems Chinese Academy of SciencesBeijing 100190China China Research Institute of Radio-wave Propagation Qingdao 266075China

The Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)satellite is a small magnetosphere–ionosphere link explorer developed cooperatively between China and Europe.It pioneers the use of X-ray imaging technology to perform large-scale imaging of the Earth’s magnetosheath and polar cusp regions.It uses a high-precision ultraviolet imager to image the overall configuration of the aurora and monitor changes in the source of solar wind in real time,using in situ detection instruments to improve human understanding of the relationship between solar activity and changes in the Earth’s magnetic field.The SMILE satellite is scheduled to launch in 2025.The European Incoherent Scatter Sciences Association(EISCAT)-3D radar is a new generation of European incoherent scatter radar constructed by EISCAT and is the most advanced ground-based ionospheric experimental device in the high-latitude polar region.It has multibeam and multidirectional quasi-real-time three-dimensional(3D)imaging capabilities,continuous monitoring and operation capabilities,and multiple-baseline interferometry capabilities.Joint detection by the SMILE satellite and the EISCAT-3D radar is of great significance for revealing the coupling process of the solar wind–magnetosphere–ionosphere.Therefore,we performed an analysis of the joint detection capability of the SMILE satellite and EISCAT-3D,analyzed the period during which the two can perform joint detection,and defined the key scientific problems that can be solved by joint detection.In addition,we developed Web-based software to search for and visualize the joint detection period of the SMILE satellite and EISCAT-3D radar,which lays the foundation for subsequent joint detection experiments and scientific research.

关键词： Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)satellite European Incoherent Scatter Sciences Association(EISCAT)-3D radar joint detection

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