检索结果-南通市图书馆

Effect of nitrile butadiene rubber hardness on the sealing characteristics of hydraulic O-ring rod seals

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of zhejiang University-Science A(Applied Physics & Engineering) 2024年第1期25卷 63-78页

作者： Xiaoxuan LI Bingqing WANG Xudong PENG Yuntang LI Xiaolu LI Yuan CHEN Jie JIN College of Quality and Safety Engineering China Jiliang UniversityHangzhou310018China College of Mechanical and Electrical Engineering China Jiliang UniversityHangzhou310018China College of Mechanical Engineering Zhejiang University of TechnologyHangzhou310023China

The nitrile butadiene rubber(NBR)hardness effect on the sealing characteristics of hydraulic O-ring rod seals is analyzed based on a mixed lubrication elastohydrodynamic *** studies are conducted to reveal the mechanism of the influence of rubber hardness on the static and dynamic behavior of *** optimized selections of rubber hardness are then investigated under different *** show that the low hardness seal is prone to stress concentration due to the extrusion effect under high pressure conditions;it is also more prone to leaking.A high hardness seal can better prevent leakage by reducing film thickness but it will cause large frictional power loss and increase the probability of wear *** choice of low hardness is recommended to reduce friction with the premise that leakage requirements are met.

关键词： Nitrile butadiene rubber(NBR)hardness Sealing characteristics Optimized selection O-ring seal

Numerical modeling and experimental investigation of a two-phase sink vortex and its fluid-solid vibration characteristics

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of zhejiang University-Science A(Applied Physics & Engineering) 2024年第1期25卷 47-62页

作者： Zichao YIN Yesha NI Lin LI Tong WANG Jiafeng WU Zhe LI Dapeng TAN College of Mechanical Engineering Zhejiang University of TechnologyHangzhou310014China State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhou310058China

A sink vortex is a common physical phenomenon in continuous casting,chemical extraction,water conservancy,and other industrial processes,and often causes damage and loss in ***,the real-time monitoring of the sink vortex state is important for improving industrial production ***,its suction-extraction phenomenon and shock vibration characteristics in the course of its formation are complex mechanical dynamic factors for flow field state *** address this issue,we set up a multi-physics model using the level set method(LSM)for a free sink vortex to study the two-phase interaction ***,a fluid–solid coupling dynamic model was deduced to investigate the shock vibration characteristics and reveal the transition mechanism of the critical flow *** numerical results show that the coupling energy shock induces a pressure oscillation phenomenon,which appears to be a transient enhancement of vibration at the vortex penetration *** central part of the transient enhancement signal is a high-frequency *** on the dynamic coupling model,an experimental observation platform was established to verify the accuracy of the numerical *** water-model experiment results were accordant with the numerical *** above results provide a reference for fluid state recognition and active vortex control for industrial monitoring systems,such as those in aerospace pipe transport,hydropower generation,and microfluidic devices.

关键词： Free sink vortex Fluid-solid coupling Level set method(LSM) Multi-physics model Vibration characteristics

Accelerating solar driven CO_(2) reduction via sulfur-doping boosted water dissociation and proton transfer

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano research 2024年第3期17卷 1056-1065页

作者： Ke Yan Liang Chen Yangguang Hu Ting Wang Cong Chen Chao Gao Youju Huang Benxia Li School of Chemistry and Chemical Engineering Key Laboratory of Surface&Interface Science of Polymer Materials of Zhejiang ProvinceZhejiang Sci-Tech UniversityHangzhou 310018China College of Material Chemistry and Chemical EngineeringKey Laboratory of Organosilicon Chemistry and Material TechnologyMinistry of EducationHangzhou Normal UniversityHangzhou 311121China School of Chemistry and Materials Science University of Science and Technology of ChinaHefei 230026China

Exploring efficient photocatalysts for solar driven CO_(2) reduction with water(H_(2)O)as a proton donor is highly imperative but remains a great challenge because the synchronous enhancement of CO_(2) activation,H_(2)O dissociation and proton transfer is hardly achieved on a ***,the sluggish H_(2)O dissociation impedes the photocatalytic CO_(2) reduction reaction involving multiple proton–electron coupling transfer ***,a sulfur-doped BiOCl(S-BiOCl)photocatalyst with abundant oxygen vacancies(OV)is developed,which exhibits broadband-light harvesting across solar spectrum and distinct photothermal effect due to *** photocatalytic CO_(2) reduction with H_(2)O in a gas–solid system,the high CO yield of 49.76μmol·g_(cat)^(-1)·h^(-1) with 100%selectivity is achieved over the S-BiOCl catalyst under a simulated *** H_(2)O-assisted CO_(2) reduction reaction on S-BiOCl catalyst is triggered by photocatalysis and the photothermal heating further enhances the reaction *** kinetic isotope experiments indicate that the sluggish H_(2)O dissociation affects the whole photocatalytic CO_(2) reduction *** presence of oxygen vacancies promotes the adsorption and activation of H_(2)O and CO_(2),and the doped S sites play a crucial role in boosting H_(2)O dissociation and accelerating the dynamic migration of hydrogen *** a result,the ingenious integration of OV defects,S sites and photothermal effect in S-BiOCl catalyst conjointly contributes to the significant improvement in photocatalytic CO_(2) reduction performance.

关键词： BiOCl sulfur doping photocatalytic CO_(2)reduction H_(2)O activation proton feeding

Janus Quasi‑Solid Electrolyte Membranes with Asymmetric Porous Structure for High‑Performance Lithium‑Metal Batteries

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano-Micro Letters 2024年第6期16卷 221-232页

作者： Zerui Chen Wei Zhao Qian Liu Yifei Xu Qinghe Wang Jinmin Lin Hao Bin Wu Institute for Composites Science Innovation(InCSI)and State Key Laboratory of Silicon and Advanced Semiconductor Materials School of Materials Science and EngineeringZhejiang UniversityHangzhou 310027People’s Republic of China

Quasi-solid electrolytes(QSEs)based on nanoporous materials are promising candidates to construct high-performance Limetal batteries(LMBs).However,simultaneously boosting the ionic conductivity(σ)and lithium-ion transference number(t^(+)) of liquid electrolyte confined in porous matrix remains ***,we report a novel Janus MOFLi/MSLi QSEs with asymmetric porous structure to inherit the benefits of both mesoporous and microporous *** Janus QSE composed of mesoporous silica and microporous MOF exhibits a neat Li^(+) conductivity of 1.5.10^(–4)S cm^(−1) with t^(+) of 0.71.A partially de-solvated structure and preference distribution of Li^(+)near the Lewis base O atoms were depicted by MD ***,the nanoporous structure enabled efficient ion flux regulation,promoting the homogenous deposition of Li^(+).When incorporated in Li||Cu cells,the MOFLi/MSLi QSEs demonstrated a high Coulombic efficiency of 98.1%,surpassing that of liquid electrolytes(96.3%).Additionally,NCM 622||Li batteries equipped with MOFLi/MSLi QSEs exhibited promising rate performance and could operate stably for over 200 cycles at 1 *** results highlight the potential of Janus MOFLi/MSLi QSEs as promising candidates for next-generation LMBs.

关键词： Metal-organic frameworks Mesoporous silicas Quasi-solid electrolytes Janus structure Lithium-metal battery

Continuous adaptive gaits manipulation for three-fingered robotic hands via bioinspired fingertip contact events

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Biomimetic Intelligence & Robotics 2024年第1期4卷 59-69页

作者： Xiaolong Ma Jianhua Zhang Binrui Wang Jincheng Huang Guanjun Bao College of Mechanical and Electrical Engineering China Jiliang UniversityHangzhou 310018China School of Mechanical Engineering University of Science and Technology BeijingBeijing 100083China College of Mechanical Engineering Zhejiang University of TechnologyHangzhou 310023China Key Laboratory of Special Purpose Equipment and Advanced Processing Technology Ministry of Education and Zhejiang ProvinceZhejiang University of TechnologyHangzhou 310023China

The remarkable skill of changing its grasp status and relocating its fingers to perform continuous in-hand manipulation is essential for a multifingered anthropomorphic hand.A commonly utilized method of manipulation involves a series of basic movements executed by a high-level ***,it remains unclear how these primitives evolve into sophisticated finger gaits during ***,we propose an adaptive finger gait-based manipulation method that offers real-time regulation by dynamically changing the primitive interval to ensure the force/moment balance of the *** manipulation relies on contact events that act as triggers for real-time online replanning of multifinger *** identify four basic motion primitives of finger gaits and create a heuristic finger gait that enables the continuous object rotation of a round *** experimental results verify the effectiveness of the proposed *** the constant breaking and reengaging of contact between the fingers and the object during manipulation,the robotic hand can reliably manipulate the object without *** when the object is subjected to interfering forces,the proposed method demonstrates robustness in managing *** work has great potential for application to the dexterous operation of anthropomorphic multifingered hands.

关键词： Adaptive switch Contact event Continuous manipulation Multifinger gait Primitive

Defense and anti-defense mechanisms of bacteria and bacteriophages

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of zhejiang University-Science B(Biomedicine & Biotechnology) 2024年第3期25卷 181-196页

作者： Xiaoqing WANG Sebastian LEPTIHN School of Medicine Lishui UniversityLishui 323000China University of Edinburgh Medical School Biomedical SciencesCollege of Medicine&Veterinary MedicineThe University of EdinburghEdinburgh EH89JZUK HMU Health and Medical University Am Anger 64/73-99084 ErfurtGermany

In the post-antibiotic era,the overuse of antimicrobials has led to a massive increase in antimicrobial resistance,leaving medical doctors few or no treatment options to fight infections caused by *** use of bacteriophages is a promising alternative to treat infections,supplementing or possibly even replacing *** phages for therapy is possible,since these bacterial viruses can kill bacteria specifically,causing no harm to the normal ***,bacteria have developed a multitude of sophisticated and complex ways to resist infection by phages,including abortive infection and the clustered regularly interspersed short palindromic repeats(CRISPR)/CRISPR-associated(Cas)*** also can evolve and acquire new anti-defense strategies to continue *** in-depth exploration of both defense and anti-defense mechanisms would contribute to optimizing phage therapy,while we would also gain novel insights into the microbial *** this paper,we summarize recent research on bacterial phage resistance and phage anti-defense mechanisms,as well as collaborative win-win systems involving both virus and host.

关键词： Bacteriophage Phage resistance Abortive infection Phage therapy

Guidance strategy of motion camouflage for spacecraft pursuit-evasion game

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第3期37卷 312-319页

作者： Jianqing LI Chaoyong LI Yonghe ZHANG Space Information research Institute Hangzhou Dianzi UniversityHangzhou 310018China College of Electrical Engineering Zhejiang UniversityHangzhou 310027China Key Lab of Microsatellites Chinese Academy of SciencesShanghai 201210China

This work is inspired by a stealth pursuit behavior called motion camouflage whereby a pursuer approaches an evader while the pursuer camouflages itself against a predetermined *** formulate the spacecraft pursuit-evasion problem as a stealth pursuit strategy of motion camouflage,in which the pursuer tries to minimize a motion camouflage index defined in this *** Euler-Hill reference frame whose origin is set on the circular reference orbit is used to describe the *** on the rule of motion camouflage,a guidance strategy in open-loop form to achieve motion camouflage index is derived in which the pursuer lies on the camouflage constraint line connecting the central spacecraft and *** order to dispose of the dependence on the evader acceleration in the open-loop guidance strategy,we further consider the motion camouflage pursuit problem within an infinite-horizon nonlinear quadratic differential *** saddle point solution to the game is derived by using the state-dependent Riccati equation method,and the resulting closed-loop guidance strategy is effective in achieving motion *** are performed to demonstrate the capabilities of the proposed guidance strategies for the pursuit–evasion game scenario.

关键词： Pursuit-evasion problem Motion camouflage Differential game Guidance strategy Orbit control

The Combined Effect of Spin-Transfer Torque and Voltage-Controlled Strain Gradient on Magnetic Domain-Wall Dynamics:Toward Tunable Spintronic Neuron

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2024年第5期41卷 120-137页

作者：郁国良何鑫岩施胜宾邱阳朱明敏王嘉维李燕李元勋王杰周浩淼 College of Information Engineering China Jiliang UniversityHangzhou 310018China The Key Laboratory of Electromagnetic Wave Information Technology and Metrology of zhejiang Province Hangzhou 310018China Department of Engineering Mechanics Zhejiang UniversityHangzhou 310027China School of Electronic Science and Engineering University of Electronic Science and Technology of ChinaChengdu 611731China

Magnetic domain wall(DW), as one of the promising information carriers in spintronic devices, have been widely investigated owing to its nonlinear dynamics and tunable properties. Here, we theoretically and numerically demonstrate the DW dynamics driven by the synergistic interaction between current-induced spin-transfer torque(STT) and voltage-controlled strain gradient(VCSG) in multiferroic heterostructures. Through electromechanical and micromagnetic simulations, we show that a desirable strain gradient can be created and it further modulates the equilibrium position and velocity of the current-driven DW motion. Meanwhile, an analytical Thiele's model is developed to describe the steady motion of DW and the analytical results are quite consistent with the simulation data. Finally, we find that this combination effect can be leveraged to design DW-based biological neurons where the synergistic interaction between STT and VCSG-driven DW motion as integrating and leaking motivates mimicking leaky-integrate-and-fire(LIF) and self-reset function. Importantly, the firing response of the LIF neuron can be efficiently modulated, facilitating the exploration of tunable activation function generators, which can further help improve the computational capability of the neuromorphic system.

关键词： tunable synergistic integrating

Macrophage senescence in health and diseases

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Acta Pharmaceutica Sinica B 2024年第4期14卷 1508-1524页

作者： Longling Wang Wenxiang Hong Hong Zhu Qiaojun He Bo Yang Jiajia Wang Qinjie Weng Center for Drug Safety Evaluation and research Zhejiang Province Key Laboratory of Anti-Cancer Drug ResearchCollege of Pharmaceutical SciencesZhejiang UniversityHangzhou 310058China Nanhu Brain-Computer Interface Institute Hangzhou 311100China Taizhou Institute of zhejiang University Taizhou 318000China The Second Affiliated Hospital Zhejiang University School of MedicineHangzhou 310009China

Macrophage senescence,manifested by the special form of durable cell cycle arrest and chronic low-grade inflammation like senescence-associated secretory phenotype,has long been consid-ered *** senescence of macrophages may lead to maladaptation,immune dysfunction,and finally the development of age-related diseases,infections,autoimmune diseases,and ***,it is a ubiquitous,multi-factorial,and dynamic complex phenomenon that also plays roles in remodeled processes,including wound repair and *** this review,we summarize some general molecular changes and several specific biomarkers during macrophage senescence,which may bring new sight to recognize senescent macrophages in different ***,we take an in-depth look at the functional changes in senescent macrophages,including metabolism,autophagy,polarization,phagocytosis,antigen presentation,and infiltration or ***,some degenerations and diseases associated with senescent macrophages as well as the mechanisms or relevant genetic regulations of senescent macrophages are integrated,not only emphasizing the possibility of regulating macrophage senescence to benefit age-associated diseases but also has an implication on the finding of potential tar-gets ordrugs clinically.

关键词： Macrophages Senescence Molecular changes Functional alterations Aging tissues Age-associated diseases Drug treatment Genetic regulation