检索结果-南通市图书馆

Structure and Magnetic Properties of Magnetostrictive feGa film on Single-Crystal(100) GaAs and(001) Si Substrate fabricated by Pulsed Laser Deposition

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2018年第6期31卷 623-628页

作者： Y.Zhang M.Turghun C.J.Huang T.wang f.f.wang W.Z.Shi Key Laboratory of Optoelectronic Material and Device Shanghai Normal University Mathematics and Science College Shanghai Normal University

feGa thin film has been deposited on（100）-oriented GaAs and（001）-oriented Si substrates with different film thicknesses and laser energy densities at room temperature by pulsed laser deposition *** structure and static magnetic of feGa film have great changes depending on the substrate and energy density of pulsed laser.X-ray diffraction reveals the presence of first-order order–disorder structure ofgrain phase and disordered bcc A2 structure on GaAs *** coercivity and remanence of feGa film on GaAs substrate ratio show a regular dependence on the thickness and energy ***,film on Si substrate did not exhibit structure change,which can be attributed to a large lattice mismatch between feGa and Si.

关键词： Magnetostrictive film Soft magnetic film Texture Galfenol

Experimental and numerical investigations of bonding interface behavior in stationary shoulder friction stir lap welding

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2019年第1期35卷 192-200页

作者： Q.Wen W.Y.Li W.B.wang f.f.wang Y.J.Gao V.Patel State Key Laboratory of Solidification Processing Shaanxi Key Laboratory of Friction Welding Technologies Northwestern Polytechnical University China fSW Center China Academy of Launch Vehicle Technology Beijing Institute of Astronautical Systems Engineering Capital Aerospace Machinery Company Pandit Deendayal Petroleum University

Stationary shoulder friction stir lap welding(SSfSLW) was employed to weld 2024 aluminum alloy. A coupled Eulerian-Lagrangian(CEL) model was developed to investigate the lap interface behavior during SSfSLW. Numerical results of material movement and equivalent plastic strain were in good agreement with the experimental work. With increasing welding speed, the distances from the hook tip to the top surface of the upper workpiece on the retreating side(RS) and the advancing side(AS) increase, while the distance between two wave-shaped alclads decreases. A symmetric interface bending is observed on the AS and the RS during plunging, while the interface bending on the AS is bigger than that on the RS during welding. The peak temperature of the interface on the AS is higher than that on the RS. The equivalent plastic strain gradually increases as the distance to the weld center decreases, and its peak value is obtained near the bottom of the weld.

关键词： Stationary shoulder friction stir lap welding Coupled Eulerian-Lagrangian Temperature field Material distribution Equivalent plastic strain

Rapid post-earthquake safety assessment of low-rise reinforced concrete structures

在线全文

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2025年第1期24卷 101-112页

作者： Koji Tsuchimoto Yasutaka Narazaki Billie f.Spencer,Jr. International Design Division Design DepartmentTaisei CorporationTokyo 163-0606Japan Zhejiang University–University of Illinois Urbana-Champaign Institute Zhejiang UniversityHaining 314400China Civil and Environmental Engineering University of Illinois Urbana-ChampaignUrbana 61821USA

Many countries throughout the world have experienced large earthquakes,which cause building damage or *** such earthquakes,structures must be inspected rapidly to judge whether they are safe to *** facilitate the inspection process,the authors previously developed a rapid building safety assessment system using sparse acceleration measurements for steel framed *** proposed system modeled nonlinearity in the measurement data using a calibrated simplified lumped-mass model and convolutional neural networks(CNNs),based on which the buildinglevel damage index was estimated rapidly after *** proposed system was validated for a nonlinear 3D numerical model of a five-story steel building,and later for a large-scale specimen of an 18-story building in Japan tested on the E-Defense shaking ***,the applicability of the safety assessment system for reinforced concrete(RC)structures with complex hysteretic material nonlinearity has yet to be explored;the previous approach based on a simplified lumpedmass model with a Bouc-Wen hysteretic model does not accurately represent the inherent nonlinear behavior and resulting damage states of RC *** study extends the rapid building safety assessment system to low-rise RC moment resisting frame structures representing typical residential apartments in ***,a safety classification for RC structures based on a damage index consistent with the current state of practice is ***,a 3D nonlinear numerical model of a two-story moment frame structure is created.A simplified lumped-mass nonlinear model is developed and calibrated using the 3D model,incorporating the Takeda degradation model for the RC material *** model is used to simulate the seismic response and associated damage sensitive features(DSf)for random ground *** resulting database of responses is used to train a convolutional neural network(CNN)that performs rapid safety ***

关键词： rapid post-earthquake safety assessment acceleration interstory drift angle damage sensitive feature convolutional neural network RC structure simplified non-linear analysis model Takeda degradation model

Energy Meteorology for the Evaluation of Solar farm Thermal Impacts on Desert Habitats

在线全文

学校读者我要写书评

暂无评论

ADVANCES IN ATMOSPHERIC SCIENCES 2025年第2期42卷 313-326页

作者： Coimbra, Carlos f. M. Univ Calif San Diego Ctr Excellence Renewable Resource Integrat Jacobs Sch Engn Dept Mech & Aerosp Engn La Jolla CA 92093 USA Univ Calif San Diego Ctr Energy Res La Jolla CA 92093 USA

This work addresses challenges and opportunities in the evaluation of solar power plant impacts, with a particular focus on thermal effects of solar plants on the environment and vice-versa. Large-scale solar power plants are often sited in arid or desert habitats, which tend to include fauna and flora that are highly sensitive to changes in temperature and humidity. Our understanding of both shortwave (solar) and longwave (terrestrial) radiation processes in solar power plants is complete enough to render the modeling of radiation fluxes with high confidence for most applications. In contrast to radiation, the convective environment in large-scale solar power plants is much more difficult to characterize. Wind direction, wind speed, turbulence intensity, dust concentration, ground condition, panel configuration density, orientation and distribution throughout the solar field, all affect the local environment, the balance between radiation and convection, and in turn, the performance and thermal impact of solar power plants. Because the temperatures of the two sides of photovoltaic (PV) panels depend on detailed convection-radiation balances, the uncertainty associated with convection affects the heat and mass transfer balances as well. Those balances are critically important in estimating the thermal impact of large-scale solar farms on local habitats. Here we discuss outstanding issues related with these transfer processes for utility-scale solar generation and highlight potential pathways to gain useful knowledge about the convective environment directly from solar farms under operating conditions. (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic), (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic). (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic), (sic)

关键词： environmental impact solar farms thermal balances shortwave and longwave radiation convection (sic)(sic)(sic)(sic) (sic)(sic)(sic)(sic)(sic)(sic) (sic)(sic)(sic) (sic)(sic)(sic)(sic)(sic)(sic)(sic) (sic)(sic)

Magnitude, spatial patterns and drivers of methane fluxes from coastal salt marshes and mangrove forests in China

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Earth Sciences 2025年第3期68卷 850-866页

作者： Yixuan YU Derrick Y.f.LAI Minjie HU Chuan TONG Key Laboratory of Humid Subtropical Eco-geographical Process of Ministry of Education Fujian Normal University School of Geographical Sciences Fujian Normal University Department of Geography and Resource Management The Chinese University of Hong Kong

Methane（CH4） is a highly potent greenhouse gas due to its high radiative forcing and global warming *** the magnitude, spatial patterns, and drivers of CH4emission from wetlands at the regional scale is crucial for formulating suitable strategies to mitigate future climate change. In this study, we synthesized the CH4flux data reported for major plant communities in the coastal salt marshes and mangrove forests in China and produced a spatial map of CH4fluxes from the mangrove sediments and salt marshes in China based on the results of machine learning models. Moreover, we examined the main drivers of CH4flux from these coastal wetlands and estimated the annual CH4emissions from the salt marshes and mangrove forests in different coastal provinces of China using a bottom-up approach. Our results showed that the mean CH4fluxes from the salt marsh and mangrove ecosystems in China were 2.22±0.29 and 2.26±0.55 mg m-2h-1, respectively. Across China, the total annual CH4emission from salt marshes was 31,179.75 Mg CH4a-1, while that from mangroves was 5,533.97 Mg CH4a-1with the sediments contributing to 12.7%(701.64 Mg CH4a-1) of the total efflux. The salt marshes and mangroves in China accounted for 2.75% and 0.14%–0.15% of the global annual CH4emissions from these two ecosystems,respectively. Moreover, we found that CH4emissions from the salt marshes and mangroves could offset the cooling impact arising from net carbon dioxide uptake by 88% and 53%, respectively, over a 100-year time scale. Mean annual temperature, soil moisture, and soil organic carbon content were the main factors controlling CH4emissions from these coastal ***, we found that CH4fluxes from the salt marshes in China decreased with latitude, which implied a possible increase in marsh CH4emission in response to global warming that should be considered carefully when developing nature-based climate solutions to achieve national goals for carbon neutrality.

关键词： Salt marsh Mangrove Methane flux Spatial pattern Driving factors China

同方期刊数据库

Energy Meteorology for the Evaluation of Solar farm Thermal Impacts on Desert Habitats

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2025年第02期 313-326页

作者： Carlos f.M.COIMBRA Department of Mechanical and Aerospace Engineering Jacobs School of Engineering Center of Excellence in Renewable Resource Integration and Center for Energy Research University of California San Diego

This work addresses challenges and opportunities in the evaluation of solar power plant impacts, with a particular focus on thermal effects of solar plants on the environment and vice-versa. Large-scale solar power plants are often sited in arid or desert habitats, which tend to include fauna and flora that are highly sensitive to changes in temperature and humidity. Our understanding of both shortwave(solar) and longwave(terrestrial) radiation processes in solar power plants is complete enough to render the modeling of radiation fluxes with high confidence for most applications. In contrast to radiation, the convective environment in large-scale solar power plants is much more difficult to characterize. Wind direction, wind speed, turbulence intensity, dust concentration, ground condition, panel configuration density, orientation and distribution throughout the solar field, all affect the local environment, the balance between radiation and convection,and in turn, the performance and thermal impact of solar power plants. Because the temperatures of the two sides of photovoltaic(PV) panels depend on detailed convection–radiation balances, the uncertainty associated with convection affects the heat and mass transfer balances as well. Those balances are critically important in estimating the thermal impact of large-scale solar farms on local habitats. Here we discuss outstanding issues related with these transfer processes for utility-scale solar generation and highlight potential pathways to gain useful knowledge about the convective environment directly from solar farms under operating conditions.

关键词：

Dual modulation of homogeneous nanomaterialization and electrochemical activation enhancing zinc ion storage

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2025年第1期68卷 385-393页

作者： Jianwei wang Huan wang Kangning wang Wenhui wang Wenlin Zhang Yanzhong Zhen School of Chemistry&Chemical Engineering Yan’an UniversityYan’an 716000China

Vanadium-based electrode materials are widely investigated,but the low specific capacity and slow electrochemical kinetics in aqueous zinc-ion batteries still limit their commercial ***,the VS_(2)/Ca V_(4)O_(9)material with the morphology of nanoflower was synthesized by a one-step hydrothermal *** to the blocky structure of pure VS_(2)material,the VS_(2)/Ca V_(4)O_(9)material is composed of thinner homogeneous *** open structures could provide abundant electrochemical active sites and ion transport channels,and then promote the electrochemical reaction *** addition,they can also buffer the bulk strain during the reaction *** improve the utilization of vanadium elements,an in-situ electrochemical activation strategy is used to explore the storage performance of the VS_(2)/Ca V_(4)O_(9)material,the different activation voltage range of 0.4–1.6 and 0.4–1.4 V are selected,*** with the longer activation plateau of activated-VS_(2),the VS_(2)/Ca V_(4)O_(9)cathode could quickly reach the activation state in the range of 1.4–1.6 V and cause the release of additional Zn storage sites *** VS_(2)/Ca V_(4)O_(9)cathode delivers a higher power density of 37,000 W kg^(-1)and a significant energy density of 423 Wh kg^(-1).At the high current density of 15 A g^(-1),the VS_(2)/Ca V_(4)O_(9)cathode still has a discharge capacity of 183.9m Ah g^(-1)after 5,000 cycles,and the capacity decay rate per cycle is only 0.0042%.Continuous cyclic voltammetry(CV)curves,electrochemical impedance spectroscopy(EIS)measurements,density functional theory(DfT)calculation and galvanostatic intermittent titration technique(GITT)measurements demonstrate that the VS_(2)/Ca V_(4)O_(9)cathode has a faster ion diffusion/charge transfer ***,the assembled flexible device has an excellent mechanical stability.

关键词： dual modulation homogeneous nanomaterialization electrochemical activation zinc ion storage

Anomalous open orbits in Hofstadter spectrum of Chern insulator

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2025年第3期Mechanics & Astronomy) .卷 143-148页

作者： Haijiao Ji Peng Zhou Noah f.Q.Yuan Hua Jiang Haiwen Liu X.C.Xie Center for Advanced Quantum Studies Department of Physics Beijing Normal University Tsung-Dao Lee Institute Shanghai Jiao Tong University Department of Mathematics UC Berkeley Institute for Nanoelectronic Devices and Quantum Computing Fudan University International Center for Quantum Materials School of Physics Peking University Hefei National Laboratory

The nontrivial band topology of Chern insulator can enrich the content of its Hofstadter butterfly spectra, which is closely related to recent experiments in twisted bilayer graphene and cold atom systems. We investigate the Hofstadter spectrum for various models of Chern insulators under a rational flux φ0/q, here φ0=h/e and q being an integer. We find the number of splitting subbands is |q-C| with C denoting the Chern number of parent band. Importantly, anomalous open-orbital subbands with Chern numbers q-1 and-q-1 emerge unexpectedly, which are beyond the parameter window（-q/2, q/2） of the Diophantine equation studied by Thouless-Kohmoto-Nightingale-den Nijs [Phys. Rev. Lett. 49, 405（1982）]. The emergence of anomalous open orbits can be traced by analyzing the evolution of the Hofstadter spectrum, identifying as a new type of topological phase transition. These novel findings not only pinpoint the peculiar Hofstadter spectrum of Chern insulator, but also provide routes to study exotic characteristics beyond the Landau level physics.

关键词： Hofstadter spectrum topological phase transition open orbit

同方期刊数据库

The Dynamics of a Stochastic SEITR Model for Tuberculosis with Incomplete Treatment

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2025年第1期41卷 99-113页

作者： Xiao-dong wang Kai wang Department of Medical Engineering and Technology Xinjiang Medical UniversityUrumqiXinjiang 830017China

In this paper,a stochastic SEITR model is formulated to describe the transmission dynamics of tuberculosis with incompletely *** conditions for the existence of a stationary distribution and extinction are *** addition,numerical simulations are given to illustrate these analytical *** and numerical results show that large environmental perturbations can inhibit the spread of tuberculosis.

关键词： tuberculosis stationary distribution extinction