检索结果-南通市图书馆

Effects of soil crust on the collapsing erosion of colluvial deposits with granite residual soil

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 Mountain Science 2024年第8期21卷 2579-2591页

作者： LIU weiping ZENG Bohan WANG Tianhuan DUAN Junyi School of Infrastructure Engineering Nanchang UniversityNanchang 330031China

Collapsing erosion is a unique phenomenon commonly observed on the granite residue hillslopes in the tropical and subtropical regions of southern China,characterized by its abrupt occurrence and significant erosion ***,the impacts of soil crust conditions on the erosion of colluvial deposits with granite residual soils have only been studied to a limited *** address this issue,this study investigates the impacts of three soil crust conditions(i.e.,without crust,10-minute crust,and 20-minute crust)on gully morphology,rainfall infiltration,and runoff and sediment yield during slope erosion of colluvial deposits with granite residues(classified as Acrisols)in Yudu County,Ganzhou City,Jiangxi Province,China,using simulated rainfall tests and photographic *** results showed that as the strength of the soil crust increased,the capacity of moisture infiltration and the width and depth of the gully as well as the sediment concentration and yield ratio decreased;at the same time,the runoff ratio *** sediment yield in the without-crust test was found to be 1.24 and 1.43 times higher than that observed in the 10-minute crust and 20-minute crust tests,*** results indicate that soil crusts can effectively prevent slope erosion and moisture infiltration,while providing valuable insights for the management of soil erosion in natural environments.

关键词： Granite residual soil Colluvial deposits Slope erosion Soil crust Sediment yield

Joint Transmit and Reflective Beamforming Design for Active IRS-Aided SWIPT Systems

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Electronics 2024年第2期33卷 536-548页

作者： weiping SHI Qingqing WU Di WU Feng SHU Jiangzhou WANG School of Electronic and Optical Engineering Nanjing University of Science and Technology Department of Electronic Engineering Shanghai Jiao Tong University School of Information and Communication Engineering Hainan University Department of Automation Shanghai Jiao Tong University School of Engineering University of Kent

To further improve the performance of passive intelligent reflecting surface(IRS)-assisted communication systems and mitigate the serious path loss due to “double-fading ” of IRS-assisted links, an active IRS-aided simultaneous wireless information and power transfer(SWIPT) system is investigated. This paper jointly optimizes the transmit beamforming at the base station(BS) and the phase shifts at the active IRS in order to maximize the power collected by the energy harvesting receiver under both perfect and imperfect channel state information(CSI)states, subject to the signal-to-interference-noise ratio constraint of the information decoding receiver, and the power constraints of the BS/IRS. Under perfect CSI, the alternating optimization algorithm is utilized for obtaining the transmit beamforming at the BS and the phase shifts at the active IRS. For each subproblem, we first transform nonconvex objective function and constraints into convex ones by performing a first-order Taylor expansion. Then, each subproblem is solved by using the interior point method. Given that obtaining perfect CSI is impractical, two robust beamforming designs are proposed for imperfect CSI case. Under the bounded CSI error model, we first transform the non-convex optimization problem into two semidefinite programming subproblems, and then solve each subproblem based on S-procedure and sequential rank-one constraint relaxation(SROCR) techniques. Under the stochastic CSI error model, the alternating optimization method is applied in an iterative manner based on Bernstein-type inequality and SROCR technique. Simulation results show that both robust and non-robust schemes for active IRS-assisted SWIPT systems can achieve extremely superior performance over conventional passive IRS-assisted systems under the same overall power budget.

关键词： Wireless communication Semidefinite programming Array signal processing Simulation Stochastic processes Transforms Receivers

A review of ^(17)O isotopic labeling techniques for solid-state NMR structural studies of metal oxides in lithium-ion batteries

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Magnetic Resonance Letters 2024年第2期4卷 46-53页

作者： Xiaoli Xia Lei Zhu weiping Tang Luming Peng Junchao Chen School of Chemistry and Chemical Engineering Shanghai Jiao Tong University800 Dongchuan RoadShanghai200240China Key Laboratory of Mesoscopic Chemistry of Ministry of Education and Collaborative Innovation Center of Chemistry for Life Sciences School of Chemistry and Chemical EngineeringNanjing University163 Xianlin RoadNanjing210023China State Key Laboratory of Space Power-Sources Technology Shanghai Institute of Space Power-SourcesShanghai200245China

Recent advances in utilizing ^(17)O isotopic labeling methods for solid-state nuclear magnetic resonance(NMR)investigations of metal oxides for lithium-ion batteries have yielded extensive insights into their structural and dynamic ***,we commence with a brief introduction to recent research on lithium-ion battery oxide materials studied using ^(17)O solid-state NMR *** we delve into a review of ^(17)O isotopic labeling methods for tagging oxygen sites in both the bulk and surfaces of metal *** last,the unresolved problems and the future research directions for advancing the ^(17)O labeling technique are discussed.

关键词： ^(17)O solid-state NMR ^(17)O isotopic labeling methods Bulk and surfaces of metal oxides DFT calculation

Elastohydrodynamic Lubrication Interface Stiffness and Damping Considering Asperity Lateral Contact

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2024年第1期37卷 109-123页

作者： Zhiqiang Gao Yu Zhang Xian Wei Yanfang Zhu Lixia Peng weiping Fu Wen Wang School of Mechanical and Precision Instrument Engineering Xi'an University of TechnologyXi'an 710048China School of Intelligent Manufacturing Panzhihua UniversityPanzhihua 617000China Material Corrosion and Protection Key Laboratory of Sichuan Province Sichuan University of Light Chemical TechnologyYibin 644002China School of Mechanical Engineering Anyang Institute of TechnologyAnyang 455099China

Elastohydrodynamic lubrication(EHL)point contact occurs between two rough surfaces at the mesoscopic level,while the interaction of rough surfaces involves contact between asperities at the microscale *** most cases,the contact between asperities within an interface takes the form of lateral contact rather than peak *** devoid of contact asperities are filled with lubricating ***,conventional models often oversimplify lateral contact forms as interactions between asperities and a smooth,rigid *** simplifications fail to accurately represent the true contact conditions and can lead to inaccuracies in the analysis of EHL’s contact *** address this issue,we have developed a novel EHL interface model comprising two rough *** model allows us to explore the influence of asperity height,contact angle,and contact azimuth angle on EHL interface performance.

关键词： EHL interface Asperity lateral contact Contact stiffness Damping

Frost deformation and microstructure evolution of porous rock under uniform and unidirectional freeze-thaw conditions

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 Mountain Science 2024年第8期21卷 2855-2869页

作者： LV Zhitao LIU Jintao WAN Ling LIU weiping School of Infrastructure Engineering Nanchang UniversityNanchang 330031China College of Civil Engineering and Architecture Nanchang Hangkong UniversityNanchang 330063China

The frost deterioration and deformation of porous rock are commonly investigated under uniform freeze-thaw(FT)***,the unidirectional FT condition,which is also prevalent in engineering practice,has received limited ***,a comparative study on frost deformation and microstructure evolution of porous rock under both uniform and unidirectional FT conditions was ***,frost deformation experiments of rock were conducted under cyclic uniform and unidirectional FT action,*** illustrate that frost deformation of saturated rock exhibits isotropic characteristics under uniform FT cycles,while it shows anisotropic characteristics under unidirectional FT condition with both the frost heaving strain and residual strain along FT direction much higher than those perpendicular to FT ***,the peak value and residual value of cumulative frost strain vary as logarithmic functions with cycle number under both uniform and unidirectional FT ***,the microstructure evolution of rock suffered cyclic uniform and unidirectional FT action were *** uniform FT cycles,newly generated pores uniformly distribute in rock and pore structure of rock remains isotropic in micro scale,and thus the frost deformation shows isotropic characteristics in macro *** unidirectional FT cycles,micro-cracks or pore belts generate with their orientation nearly perpendicular to the FT direction,and rock structure gradually becomes anisotropic in micro scale,resulting in the anisotropic characteristics of frost deformation in macro scale.

关键词： Frost deformation Microstructure evolution Porous rock Unidirectional freeze-thaw cycles Uniform freeze-thaw cycles

Differential response of radial growth and δ^(13)C in Qinghai spruce(Picea crassifolia) to climate change on the southern and northern slopes of the Qilian Mountains in Northwest China

在线全文

学校读者我要写书评

暂无评论

Journal of Forestry Research 2024年第3期35卷 205-218页

作者： Li Qin Huaming Shang weiping Liu Yuting Fan Kexiang Liu Tongwen Zhang Ruibo Zhang Key Laboratory of Tree-Ring Physical and Chemical Research(CMA)/Xinjiang Key Laboratory of Tree-Ring Ecology Institute of Desert MeteorologyChina Meteorological AdministrationUrimqi 830002People's Republicof China Xinjiang Meteorological Information Center Urimqi 830002People's Republic of China

Tree radial growth can have significantly differ-ent responses to climate change depending on the *** elucidate the effects of climate on radial growth and stable carbon isotope(δ^(13)C)fractionation of Qing-hai spruce(Picea crassifolia),a widely distributed native conifer in northwestern China in different environments,we developed chronologies for tree-ring widths and δ^(13)C in trees on the southern and northern slopes of the Qilian Mountains,and analysed the relationship between these tree-ring variables and major climatic ***-ring widths were strongly influenced by climatic factors early in the growing season,and the radial growth in trees on the northern slopes was more sensitive to climate than in trees on the ***-ring δ^(13)C was more sensitive to climate than radial growth.δ^(13)C fractionation was mainly influenced by summer temperature and precipitation early in the growing *** conductance more strongly limited stable carbon isotope fractionation in tree rings than photosynthetic rate *** response between tree rings and climate in mountains gradually weakened as climate *** in radial growth and stable carbon isotope fractionation of *** in response to climate in the Qilian Mountains may be further complicated by continued climate change.

关键词： Tree rings Qinghai spruce(Picea crassifolia Kom.) Stable carbon isotope(δ^(13)C) Qilian Mountains:Climate change

Role of 5-hydroxytryptamine type 3 receptors in the regulation of anxiety reactions

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2024年第1期25卷 23-37页

作者： Yinan DU Zhiwei LI Yukui ZHAO Jing HAN weiping HU Zhiqiang LIU MOE Key Laboratory of Modern Teaching Technology Shaanxi Normal UniversityXi’an710062China

5-Hydroxytryptamine(5-HT)type 3 receptor(5-HT_(3)R)is the only type of ligand-gated ion channel in the 5-HT receptor *** the high permeability of Na+,K+,and Ca2+and activation of subsequent voltage-gated calcium channels(VGCCs),5-HT_(3)R induces a rapid increase of neuronal excitability or the release of neurotransmitters from axon terminals in the central nervous system(CNS).5-HT_(3)Rs are widely expressed in the medial prefrontal cortex(mPFC),amygdala(AMYG),hippocampus(HIP),periaqueductal gray(PAG),and other brain regions closely associated with anxiety *** have a bidirectional regulatory effect on anxiety reactions by acting on different types of cells in different brain regions.5-HT_(3)Rs mediate the activation of the cholecystokinin(CCK)system in the AMYG,and theγ-aminobutyric acid(GABA)“disinhibition”mechanism in the prelimbic area of the mPFC promotes anxiety by the activation of GABAergic intermediate inhibitory neurons(IINs).In contrast,a 5-HT_(3)R-induced GABA“disinhibition”mechanism in the infralimbic area of the mPFC and the ventral HIP produces anxiolytic effects.5-HT_(2)R-mediated regulation of anxiety reactions are also activated by 5-HT_(3)R-activated 5-HT release in the HIP and *** provides a theoretical basis for the treatment of anxiety disorders or the production of anxiolytic drugs by targeting 5-HT_(3)***,given the circuit specific modulation of 5-HT_(3)Rs on emotion,systemic use of 5-HT_(3)R agonism or antagonism alone seems unlikely to remedy anxiety,which deeply hinders the current clinical application of 5-HT_(3)R ***,the exploitation of circuit targeting methods or a combined drug strategy might be a useful developmental approach in the future.

关键词： 5-Hydroxytryptamine type 3 receptor(5-HT_(3)R) Anxiety Medial prefrontal cortex Amygdala Hippocampus Periaqueductal gray

Microfluidic separation of particles by synergistic effect of geometry-induced hydrodynamics and magnetic field

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 Chemical Letters 2024年第2期35卷 380-385页

作者： Du Qiao Hongxia Li weiping Zhu Lili Zhu Danyang Zhao Honglin Li Key Laboratory for Precision & Non-traditional Machining Technology of Ministry of Education Dalian University of TechnologyDalian 116023China Shanghai Key Laboratory of New Drug Design School of PharmacyEast China University of Science and TechnologyShanghai 200237China Lingang Lab Shanghai 200031China

Microfluidic combined with magnetic field have been demonstrated to be the promising solutions for fast and low-damage particles ***,the difficulties in the precise layout of magnets and accurate prediction of particle trajectories lead to under and over separation of target particles.A novel particle separation lab-on-chip(LOC)prototype integrated with microstructures and micropolar arrays is designed and ***,a numerical model for the separation of magnetic particles by the synergistic effect of geometry-induced hydrodynamics and magnetic field is *** effect of geometry and magnetic field layout on particle deflection is systematically analyzed to implement accurate prediction of particle *** is found that the separation efficiency of magnetic particles increased from 50.2%to 91.7%and decreased from 88.6%to 85.7%in the range of depth factors from 15µm to 27µm and width factors from 30µm to 60µm,*** particular,the combined effect of the offset distance of permanent magnets and the distance from the main flow channel exhibits a significant difference from the conventional ***,the developed LOC prototype was generalized for extension to arbitrary *** work provides a new insight and robust method for the microfluidic separation of magnetic particles.

关键词： Microfluidic Particle separation Synergistic effect Hydrodynamics Magnetic field Numerical calculation

Time-of-flight resolved stimulated Raman scattering microscopy using counter-propagating ultraslow Bessel light bullets generation

在线全文

学校读者我要写书评

暂无评论

Light(Science & Applications) 2024年第7期13卷 1427-1440页

作者： Shulang Lin Li gong Zhiwei Huang Optical Bioimaging Laboratory Department of Biomedical EngineeringCollege of Design and EngineeringNational University of SingaporeSingapore 117576Singapore

We present a novel time-of-flight resolved Bessel light bullet-enabled stimulated Raman scattering(B2-SRS)microscopy for deeper tissue 3D chemical imaging with high resolution without a need for mechanical *** accomplish the tasks,we conceive a unique method to enable optical sectioning by generating the counterpropagating pump and Stokes Bessel light bullets in the sample,in which the group velocities of the Bessel light bullets are made ultraslow(e.g.,vg≈0.1c)and tunable by introducing programmable angular dispersions with a spatial light *** theoretically analyze the working principle of the collinear multicolor Bessel light bullet generations and velocity controls with the relative time-of-flight resolved detection for SRS 3D deep tissue *** have also built the B2-SRS imaging system and present the first demonstration of B2-SRS microscopy with Bessel light bullets for 3D chemical imaging in a variety of samples(e.g.,polymer bead phantoms,biological samples such as spring onion tissue and porcine brain)with high *** B2-SRS technique provides a>2-fold improvement in imaging depth in porcine brain tissue compared to conventional SRS *** method of optical sectioning in tissue using counter-propagating ultraslow Bessel light bullets developed in B2-SRS is generic and easy to perform and can be readily extended to other nonlinear optical imaging modalities to advance 3D microscopic imaging in biological and biomedical systems and beyond.

关键词： Bessel resolved propagating