期刊文献+
共找到9,601篇文章
< 1 2 250 >
每页显示 20 50 100
Adverse Effects of Permanent Waving and Hair Relaxation—Assessment by Scanning Electron Microscopy (SEM)
1
作者 Tokuya Omi Seiji Kawana 《Journal of Cosmetics, Dermatological Sciences and Applications》 2013年第3期45-48,共4页
Permanent waving is very popular in Japan. Polypeptide chains (main chains) form the principal components of hair, and they are lined up longitudinally. Hair relaxation is also called straight permanent waving, and th... Permanent waving is very popular in Japan. Polypeptide chains (main chains) form the principal components of hair, and they are lined up longitudinally. Hair relaxation is also called straight permanent waving, and there are methods that change curly or wavy hair into straight hair. Hair damage as a result of winding, combing, and using high-temperature hairdressing irons is also often seen. By using scanning electron micrographs (SEM) we showed broken hairs and hair damage caused by permanent wave solutions. The hair damage is obvious when comparisons are made with the condition of the hair surface, condition of the cuticle, etc. Hair swelling by permanent wave solutions, manipulations such as winding, etc., inadequate rinsing with water, procedures on injured hair at the outset, etc., are considered possible reasons for any of these types of injury. 展开更多
关键词 PERMANENT waving HAIR RELAXATION SCANNING Electron MICROGRAPHS (SEM) HAIR Damage
下载PDF
Guo Rong and the Song 'Red Flag Is Waving'
2
《China & The World Cultural Exchange》 2001年第6期42-44,共3页
关键词 Guo Rong and the Song Red Flag Is waving
下载PDF
Waving Military Banners, A Popular Stunt in Jian'ou
3
作者 Wu Shuijin 《China & The World Cultural Exchange》 2000年第5期20-21,共2页
关键词 waving Military Banners A Popular Stunt in Jian’ou
下载PDF
基于装置得分的北太平洋波浪能资源评估
4
作者 刘威 时健 +1 位作者 张弛 陶爱峰 《中国海洋大学学报(自然科学版)》 CAS CSCD 北大核心 2024年第7期63-71,共9页
针对波浪能发电量取决于当地波浪特征和波浪能发电装置,而传统单一的波能流密度评估法则只考虑了地区波浪特性,未结合装置加以分析,评估结果偏向理论的问题,本文利用欧洲中期天气预报中心(European Centre for Medium-Range Weather For... 针对波浪能发电量取决于当地波浪特征和波浪能发电装置,而传统单一的波能流密度评估法则只考虑了地区波浪特性,未结合装置加以分析,评估结果偏向理论的问题,本文利用欧洲中期天气预报中心(European Centre for Medium-Range Weather Forecasts, ECMWF)提供的第五代大气再分析数据集(ECMWF Reanalysis v5, ERA5)中的再分析波浪数据,通过装置得分的波浪能评估方法对北太平洋区域1979—2020年波浪能的空间分布进行了分析。结果表明:在本研究所涉及的地区中,纬度较高的地区波能流密度大且装置得分高,本研究所用评估方法的结论同传统评估方法一致,但在中国南海和部分太平洋纬度较低的地区,发电装置有着较好的连续发电条件,发电效率较高。不同装置间的适配区域也有很大不同,AquaBuoy和Pelamis装置的最佳适用区位于北太平洋纬度较高的地区,而Wave Dragon装置的最佳适用区范围更广,在150°E—160°W之间的纬度较低的地区也表现突出。对于中国南海海域,AquaBuoy装置的适配性最好,而北太平洋纬度较高的地区则最适合布置Pelamis装置,北太平洋纬度中游和较低区域最适合布置Wave Dragon装置。 展开更多
关键词 第五代大气再分析数据集 北太平洋 可利用波浪能 AquaBuoy装置 Pelamis装置 Wave Dragon装置
下载PDF
Hybrid-Vlasov simulation of soft X-ray emissions at the Earth’s dayside magnetospheric boundaries 被引量:2
5
作者 M.Grandin H.K.Connor +5 位作者 S.Hoilijoki M.Battarbee Y.Pfau-Kempf U.Ganse K.Papadakis M.Palmroth 《Earth and Planetary Physics》 EI CSCD 2024年第1期70-88,共19页
Solar wind charge exchange produces emissions in the soft X-ray energy range which can enable the study of near-Earth space regions such as the magnetopause,the magnetosheath and the polar cusps by remote sensing tech... Solar wind charge exchange produces emissions in the soft X-ray energy range which can enable the study of near-Earth space regions such as the magnetopause,the magnetosheath and the polar cusps by remote sensing techniques.The Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)and Lunar Environment heliospheric X-ray Imager(LEXI)missions aim to obtain soft Xray images of near-Earth space thanks to their Soft X-ray Imager(SXI)instruments.While earlier modeling works have already simulated soft X-ray images as might be obtained by SMILE SXI during its mission,the numerical models used so far are all based on the magnetohydrodynamics description of the space plasma.To investigate the possible signatures of ion-kinetic-scale processes in soft Xray images,we use for the first time a global hybrid-Vlasov simulation of the geospace from the Vlasiator model.The simulation is driven by fast and tenuous solar wind conditions and purely southward interplanetary magnetic field.We first produce global X-ray images of the dayside near-Earth space by placing a virtual imaging satellite at two different locations,providing meridional and equatorial views.We then analyze regional features present in the images and show that they correspond to signatures in soft X-ray emissions of mirrormode wave structures in the magnetosheath and flux transfer events(FTEs)at the magnetopause.Our results suggest that,although the time scales associated with the motion of those transient phenomena will likely be significantly smaller than the integration time of the SMILE and LEXI imagers,mirror-mode structures and FTEs can cumulatively produce detectable signatures in the soft X-ray images.For instance,a local increase by 30%in the proton density at the dayside magnetopause resulting from the transit of multiple FTEs leads to a 12%enhancement in the line-of-sight-and time-integrated soft X-ray emissivity originating from this region.Likewise,a proton density increase by 14%in the magnetosheath associated with mirror-mode structures can result in an enhancement in the soft X-ray signal by 4%.These are likely conservative estimates,given that the solar wind conditions used in the Vlasiator run can be expected to generate weaker soft X-ray emissions than the more common denser solar wind.These results will contribute to the preparatory work for the SMILE and LEXI missions by providing the community with quantitative estimates of the effects of small-scale,transient phenomena occurring on the dayside. 展开更多
关键词 MAGNETOSPHERE MAGNETOSHEATH numerical simulation SMILE LEXI soft X-ray emissions hybrid-Vlasov model polar cusp flux transfer events mirror-mode waves
下载PDF
ANALYSIS OF HYDRODYNAMICS FOR TWO-DIMENSIONAL FLOW AROUND WAVING PLATES 被引量:2
6
作者 ZHANG Cheng ZHUANG Li-Xian LU Xi-Yun 《Journal of Hydrodynamics》 SCIE EI CSCD 2007年第1期18-22,共5页
Hydrodynamic characteristics for two-dimensional flow around a waving plate are investigated. Under large Reynolds number approximation, the flow is assumed to be a combination of the outer potential flow and a thin v... Hydrodynamic characteristics for two-dimensional flow around a waving plate are investigated. Under large Reynolds number approximation, the flow is assumed to be a combination of the outer potential flow and a thin vortex layer, which consists of a boundary layer and a shed free shear layer. A nonlinear mathematical formulation for describing the outer unsteady potential flow coupled with an unsteady boundary layer equation for the inner viscous flow adjacent to the waving plate is developed. A semi-analytical method with a nonlinear Kutta condition imposed at the trailing edge is used to solve the velocity field of the outer flow and the evolution of wake vortex induced by a large-amplitude waving plate. The unsteady boundary layer equation is solved by extending Pohlhausen's method to its unsteady counterpart. The thrust and viscous drag coefficients, propulsive efficiency, and the pattern of wake vortex sheet are discussed. 展开更多
关键词 waving plate fish swimming unsteadyboundary layer vortex shedding
原文传递
Synchronous waving in fiddler crabs: a review 被引量:1
7
作者 Patricia Ruth Yvonne Backwell 《Current Zoology》 SCIE CAS CSCD 2019年第1期83-88,共6页
Many animals that use acoustic communication synchronize their mate attract!on signals: individuals precisely time their calls to overlap those of their neighbors. In contrast, synchrony in the mate attraction display... Many animals that use acoustic communication synchronize their mate attract!on signals: individuals precisely time their calls to overlap those of their neighbors. In contrast, synchrony in the mate attraction displays of species with visual/motion-based signals is rare. It has only been documented in five species of fiddler crabs. In all of them, small groups of males wave their single large claw in close synchrony. Here, I review what we know about synchrony in fiddler crabs, comparing the five species with each other to determine whether similar mechanisms and functions are comm on to all. I also propose future research questions that, if answered, would shed light on synchronous behavior in both visual and acoustic signallers. 展开更多
关键词 fiddler CRAB synchrony waving MATE CHOICE WAVE TIMING visual signal
原文传递
Probability Distribution Characteristics of Strong Nonlinear Waves Under Typhoon Conditions in the Northern South China Sea
8
作者 GONG Yijie XIE Botao +2 位作者 FU Dianfu WANG Zhifeng PANG Liang 《Journal of Ocean University of China》 SCIE CAS CSCD 2024年第3期583-593,共11页
The generation and propagation mechanism of strong nonlinear waves in the South China Sea is an essential research area.In this study,the third-generation wave model WAVEWATCH III is employed to simulate wave fields u... The generation and propagation mechanism of strong nonlinear waves in the South China Sea is an essential research area.In this study,the third-generation wave model WAVEWATCH III is employed to simulate wave fields under extreme sea states.The model,integrating the ST6 source term,is validated against observed data,demonstrating its credibility.The spatial distribution of the occurrence probability of strong nonlinear waves during typhoons is shown,and the waves in the straits and the northeastern part of the South China Sea show strong nonlinear characteristics.The high-order spectral model HOS-ocean is employed to simulate the random wave surface series beneath five different platform areas.The waves during the typhoon exhibit strong nonlinear characteristics,and freak waves exist.The space-varying probability model is established to describe the short-term probability distribution of nonlinear wave series.The exceedance probability distributions of the wave surface beneath different platform areas are compared and analyzed.The results show that with an increase in the platform area,the probability of a strong nonlinear wave beneath the platform increases. 展开更多
关键词 strong nonlinear wave TYPHOON wave series probability distribution model exceedance probability
下载PDF
Long-Term Extreme Wave Characteristics in the Water Adjacent to China Based on ERA5 Reanalysis Data
9
作者 DU Wenyan ZHANG Xuri +4 位作者 SHI Hongyuan LI Guanyu ZHOU Zhengqiao YOU Zaijin ZHANG Kuncheng 《Journal of Ocean University of China》 CAS CSCD 2024年第1期1-10,共10页
Extreme waves have a profound impact on coastal infrastructure;thus,understanding the variation law of risky analysis and disaster prevention in coastal zones is necessary.This paper analyzed the spatiotemporal charac... Extreme waves have a profound impact on coastal infrastructure;thus,understanding the variation law of risky analysis and disaster prevention in coastal zones is necessary.This paper analyzed the spatiotemporal characteristics of extreme wave heights adjacent to China from 1979 to 2018 based on the ERA5 datasets.Nonstationary extreme value analysis is undertaken in eight repre-sentative points to investigate the trends in the values of 50-and 100-year wave heights.Results show that the mean value of extreme waves is the largest in the eastern part of Taiwan Island and the smallest in the Bohai Sea from 1979 to 2018.Only the extreme wave height in the northeastern part of Taiwan Island shows a significant increase trend in the study area.Nonstationary analysis shows remarkable variations in the values of 50-and 100-year significant wave heights in eight points.Considering the annual mean change,E1,E2,S1,and S2 present an increasing trend,while S3 shows a decreasing trend.Most points for the seasonal mean change demon-strate an increasing trend in spring and winter,while other points show a decreasing trend in summer and autumn.Notably,the E1 point growth rate is large in autumn,which is related to the change in typhoon intensity and the northward movement of the typhoon path. 展开更多
关键词 extreme wave height NEVA wave climate ERA5 reanalysis
下载PDF
A Novel Method for Forecasting Freak Wave Occurrence in A Short Crested Coastal Sea
10
作者 WANG Ying-guang 《China Ocean Engineering》 SCIE EI CSCD 2024年第1期104-116,共13页
In order to forecast the distribution of crest amplitudes and the occurrence of freak waves in a short crested coastal sea,a novel transformed linear simulation method is initially proposed in this paper.A Hermite tra... In order to forecast the distribution of crest amplitudes and the occurrence of freak waves in a short crested coastal sea,a novel transformed linear simulation method is initially proposed in this paper.A Hermite transformation model expressed as a monotonic cubic polynomial serves as the foundation for the novel simulation technique.The wave crest amplitude exceedance probabilities of two sea states-one with a directional wave spectrum based on the measured wave elevation data at the Yura coast and the other with a typical directional JONSWAP wave spectrum-have been predicted using the novel simulation method that has been proposed.The likelihood that a particular critical wave crest amplitude will be exceeded is directly correlated with the probability that freak waves will occur.It is shown that the novel simulation approach suggested can provide predictions that are more precise than those obtained from the Rayleigh crest amplitude distribution model,the Jahns and Wheeler crest amplitude distribution model,or the conventional linear simulation method.This study also demonstrated that the nonlinear simulation method is less effective than the novel simulation method in terms of efficiency. 展开更多
关键词 wave crest amplitude freak waves short crested sea transformed linear simulation
下载PDF
Contrasts of bimodal tropical instability waves(TIWs)-induced wind stress perturbations in the Pacific Ocean among observations,ocean models,and coupled climate models
11
作者 Kai MA Chuanyu LIU +1 位作者 Junli XU Fan WANG 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2024年第1期1-23,共23页
The coupling between wind stress perturbations and sea surface temperature(SST)perturbations induced by tropical instability waves(TIWs)in the Pacific Ocean has been revealed previously and proven crucial to both the ... The coupling between wind stress perturbations and sea surface temperature(SST)perturbations induced by tropical instability waves(TIWs)in the Pacific Ocean has been revealed previously and proven crucial to both the atmosphere and ocean.However,an overlooked fact by previous studies is that the loosely defined“TIWs”actually consist of two modes,including the Yanai wave-based TIW on the equator(hereafter eTIW)and the Rossby wave-based TIW off the equator(hereafter vTIW).Hence,the individual feedbacks of the wind stress to the bimodal TIWs remain unexplored.In this study,individual coupling relationships are established for both eTIW and v TIW,including the relationship between the TIW-induced SST perturbations and two components of wind stress perturbations,and the relationship between the TIW-induced wind stress perturbation divergence(curl)and the downwind(crosswind)TIW-induced SST gradients.Results show that,due to different distributions of eTIW and vTIW,the coupling strength induced by the eTIW is stronger on the equator,and that by the vTIW is stronger off the equator.The results of any of eTIW and vTIW are higher than those of the loosely defined TIWs.We further investigated how well the coupling relationships remained in several widely recognized oceanic general circulation models and fully coupled climate models.However,the coupling relationships cannot be well represented in most numerical models.Finally,we confirmed that higher resolution usually corresponds to more accurate simulation.Therefore,the coupling models established in this study are complementary to previous research and can be used to refine the oceanic and coupled climate models. 展开更多
关键词 bimodal tropical instability waves mesoscale air-sea interaction coupled models Yanai wave
下载PDF
Comparisons of Wave Force Model Effects on the Structural Responses and Fatigue Loads of a Semi-Submersible Floating Wind Turbine
12
作者 HAN Yanqing LE Conghuan +1 位作者 ZHANG Puyang XU Shengnan 《Journal of Ocean University of China》 CAS CSCD 2024年第1期69-79,共11页
The selection of wave force models will significantly impact the structural responses of floating wind turbines.In this study,comparisons of wave force model effects on the structural responses and fatigue loads of a ... The selection of wave force models will significantly impact the structural responses of floating wind turbines.In this study,comparisons of wave force model effects on the structural responses and fatigue loads of a semi-submersible floating wind turbine(SFWT)were conducted.Simulations were performed by employing the Morison equation(ME)with linear or second-order wave kinematics and potential flow theory(PFT)with first-or second-order wave forces.A comparison of regular waves,irregular waves,and coupled wind/waves analyses with the experimental data showed that many of the simulation results and experimental data are relatively consistent.However,notable discrepancies are found in the response amplitude operators for platform heave,tower base bending moment,and tension in mooring lines.PFT models give more satisfactory results of heave but more significant discrepan-cies in tower base bending moment than the ME models.In irregular wave analyses,low-frequency resonances were captured by PFT models with second-order difference-frequency terms,and high-frequency resonances were captured by the ME models or PFT models with second-order sum-frequency terms.These force models capture the response frequencies but do not reasonably predict the response amplitudes.The coupled wind/waves analyses showed more satisfactory results than the wave-only analyses.However,an important detail to note is that this satisfactory result is based on the overprediction of wind-induced responses. 展开更多
关键词 floating wind turbine wave force model potential flow theory Morison equation second-order wave forces
下载PDF
基于人工边界条件的波面相位解析重建
13
作者 刘晓蕾 尹弘栗 +2 位作者 韩博宇 马学文 张云驰 《哈尔滨工程大学学报(英文版)》 CSCD 2024年第1期101-112,共12页
At present,the measurement of the near wave field of ships mostly relies on shipborne radar.The commonly used shipborne radar is incoherent and cannot obtain information on wave surface velocity.Therefore,the mathemat... At present,the measurement of the near wave field of ships mostly relies on shipborne radar.The commonly used shipborne radar is incoherent and cannot obtain information on wave surface velocity.Therefore,the mathematical model of wave reconstruction is remarkably complex.As a new type of radar,coherent radar can obtain the radial velocity of the wave surface.Most wave surface reconstruction methods that use wave velocity are currently based on velocity potential.The difficulty of these methods lies in determining the initial value of the velocity integral.This paper proposes a wave surface reconstruction method based on an artificial boundary matrix.Numerical simulation data of regular and short-crest waves are used to verify the accuracy of this method.Simultaneously,the reconstruction stability under different wave velocity measurement errors is analyzed.The calculation results show that the proposed method can effectively realize the reconstruction of wave field. 展开更多
关键词 Coherent radar Wave velocity field Artificial boundary matrix Wave surface reconstruction Calculation stability
下载PDF
Experimental and numerical study on protective effect of RC blast wall against air shock wave
14
作者 Xin-zhe Nian Quan-min Xie +2 位作者 Xin-li Kong Ying-kang Yao Kui Huang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第1期567-579,共13页
Prototype experiments were carried out on the explosion-proof performance of the RC blast wall.The mass of TNT detonated in the experiments is 5 kg and 20 kg respectively.The shock wave overpressure was tested in diff... Prototype experiments were carried out on the explosion-proof performance of the RC blast wall.The mass of TNT detonated in the experiments is 5 kg and 20 kg respectively.The shock wave overpressure was tested in different regions.The above experiments were numerically simulated,and the simulated shock wave overpressure waveforms were compared with that tested and given by CONWEP program.The results show that the numerically simulated waveform is slightly different from the test waveform,but similar to CONWEP waveform.Through dimensional analysis and numerical simulation under different working conditions,the equation for the attenuation rate of the diffraction overpressure behind the blast wall was obtained.According to the corresponding standards,the degree of casualties and the damage degree of the brick concrete building at a certain distance behind the wall can be determined when parameters are set.The above results can provide a reference for the design and construction of the reinforced concrete blast wall. 展开更多
关键词 Blast wall Shock wave DIFFRACTION OVERPRESSURE Protection
下载PDF
Astrocytic calcium waves:unveiling their roles in sleep and arousal modulation
15
作者 Erxi Wu Dan Qi +1 位作者 Damir Nizamutdinov Jason H.Huang 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第5期984-987,共4页
Neuron-astrocyte interactions are vital for the brain’s connectome.Understanding astrocyte activities is crucial for comprehending the complex neural network,particularly the population-level functions of neurons in ... Neuron-astrocyte interactions are vital for the brain’s connectome.Understanding astrocyte activities is crucial for comprehending the complex neural network,particularly the population-level functions of neurons in different cortical states and associated behaviors in mammals.Studies on animal sleep and wakefulness have revealed distinct cortical synchrony patterns between neurons.Astrocytes,outnumbering neurons by nearly fivefold,support and regulate neuronal and synaptic function.Recent research on astrocyte activation during cortical state transitions has emphasized the influence of norepinephrine as a neurotransmitter and calcium waves as key components of ion channel signaling.This summary focuses on a few recent studies investigating astrocyte-neuron interactions in mouse models during sleep,wakefulness,and arousal levels,exploring the involvement of noradrenaline signaling,ion channels,and glutamatergic signaling in different cortical states.These findings highlight the significant impact of astrocytes on large-scale neuronal networks,influencing brain activity and responsiveness.Targeting astrocytic signaling pathways shows promise for treating sleep disorders and arousal dysregulation.More research is needed to understand astrocytic calcium signaling in different brain regions and its implications for dysregulated brain states,requiring future human studies to comprehensively investigate neuron-astrocyte interactions and pave the way for therapeutic interventions in sleep-and arousal-related disorders. 展开更多
关键词 AROUSAL ASTROCYTE calcium waves locus coeruleus neuron-astrocyte interaction NOREPINEPHRINE SLEEP WAKEFULNESS
下载PDF
Localized wave solutions and interactions of the (2+1)-dimensional Hirota-Satsuma-Ito equation
16
作者 巩乾坤 王惠 王云虎 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第4期409-416,共8页
This paper studies the(2+1)-dimensional Hirota-Satsuma-Ito equation.Based on an associated Hirota bilinear form,lump-type solution,two types of interaction solutions,and breather wave solution of the(2+1)-dimensional ... This paper studies the(2+1)-dimensional Hirota-Satsuma-Ito equation.Based on an associated Hirota bilinear form,lump-type solution,two types of interaction solutions,and breather wave solution of the(2+1)-dimensional Hirota-Satsuma-Ito equation are obtained,which are all related to the seed solution of the equation.It is interesting that the rogue wave is aroused by the interaction between one-lump soliton and a pair of resonance stripe solitons,and the fusion and fission phenomena are also found in the interaction between lump solitons and one-stripe soliton.Furthermore,the breather wave solution is also obtained by reducing the two-soliton solutions.The trajectory and period of the one-order breather wave are analyzed.The corresponding dynamical characteristics are demonstrated by the graphs. 展开更多
关键词 lump solution rogue wave solution breather wave solution (2+1)-dimensional Hirota-Satsuma-Ito equation
下载PDF
Nonlinear interaction of head-on solitary waves in integrable and nonintegrable systems
17
作者 张树甜 刘世鲲 +3 位作者 矫滕菲 孙敏 胡凤兰 黄德财 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第5期480-487,共8页
This study numerically investigates the nonlinear interaction of head-on solitary waves in a granular chain(a nonintegrable system)and compares the simulation results with the theoretical results in fluid(an integrabl... This study numerically investigates the nonlinear interaction of head-on solitary waves in a granular chain(a nonintegrable system)and compares the simulation results with the theoretical results in fluid(an integrable system).Three stages(the pre-in-phase traveling stage,the central-collision stage,and the post-in-phase traveling stage)are identified to describe the nonlinear interaction processes in the granular chain.The nonlinear scattering effect occurs in the central-collision stage,which decreases the amplitude of the incident solitary waves.Compared with the leading-time phase in the incident and separation collision processes,the lagging-time phase in the separation collision process is smaller.This asymmetrical nonlinear collision results in an occurrence of leading phase shifts of time and space in the post-in-phase traveling stage.We next find that the solitary wave amplitude does not influence the immediate space-phase shift in the granular chain.The space-phase shift of the post-in-phase traveling stage is only determined by the measurement position rather than the wave amplitude.The results are reversed in the fluid.An increase in solitary wave amplitude leads to decreased attachment,detachment,and residence times for granular chains and fluid.For the immediate time-phase shift,leading and lagging phenomena appear in the granular chain and the fluid,respectively.These results offer new knowledge for designing mechanical metamaterials and energy-mitigating systems. 展开更多
关键词 integrable system nonintegrable system granular chain solitary wave
下载PDF
Modeling Near-Field Impulsive Waves Generated by Deformable Landslide Using the HBP Model Based on the SPH Method
18
作者 WANG Wei WEI Weicheng +4 位作者 CHAI Bo XIA Hao WANG Yang DU Juan LIU Jizhixian 《Journal of Ocean University of China》 CAS CSCD 2024年第2期328-344,共17页
Landslide-generated impulsive waves(LGWs)in reservoir areas can seriously threaten waterway safety as well as hu-man life and properties around the two side slopes.The risk reduction and mitigation of such a hazard re... Landslide-generated impulsive waves(LGWs)in reservoir areas can seriously threaten waterway safety as well as hu-man life and properties around the two side slopes.The risk reduction and mitigation of such a hazard require the accurate prediction of near-field wave characteristics,such as wave amplitude and run-up.However,near-field LGW involves complicated fluid-solid interactions.Furthermore,the wave characteristics are closely related to various aspects,including the geometry and physical features of the slide,river,and body of water.However,the empirical or analytical methods used for rough estimation cannot derive accurate results,especially for deformable landslides,due to their significant geometry changes during the sliding process.In this study,the near-field waves generated by deformable landslides were simulated by smoothed particle hydrodynamics(SPH)based on multi-phase flow.The deformable landslides were generalized as a kind of viscous flow by adopting the Herschel-Bulkley-Papanastasiou(HBP)-based nonNewtonian rheology model.The HBP model is capable of producing deformable landslide dynamics even though the high-speed sliding process is involved.In this study,an idealized experiment case originating from Lituya LGW and a practical case of Gongjiafang LGW were reproduced for verification and demonstration.The simulation results of both cases show satisfactory consistency with the experiment/investigation data in terms of landslide movement and near-field impulsive wave characteristics,thus indicating the applicability and accuracy of the proposed method.Finally,the effects of the HBP model’s rheological parameters on the landslide dynamics and near-field wave characteristics are discussed,providing a parameter calibration method along with sug-gestions for further applications. 展开更多
关键词 deformable landslide impulsive waves NEAR-FIELD SPH nonNewtonian fluids
下载PDF
Tunable dispersion relations manipulated by strain in skyrmion-based magnonic crystals
19
作者 金兆年 何宣霖 +3 位作者 于超 方贺男 陈琳 陶志阔 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第1期692-696,共5页
We theoretically investigate the propagation characteristics of spin waves in skyrmion-based magnonic crystals. It is found that the dispersion relation can be manipulated by strains through magneto-elastic coupling. ... We theoretically investigate the propagation characteristics of spin waves in skyrmion-based magnonic crystals. It is found that the dispersion relation can be manipulated by strains through magneto-elastic coupling. Especially, the allowed bands and forbidden bands in dispersion relations shift to higher frequency with strain changing from compressive to tensile,while shifting to lower frequency with strain changing from tensile to compressive. We also confirm that the spin wave with specific frequency can pass the magnonic crystal or be blocked by tuning the strains. The result provides an advanced platform for studying the tunable skyrmion-based spin wave devices. 展开更多
关键词 SKYRMION magnonic crystal spin wave dispersion relation
下载PDF
Multiphase Interfacial Regulation Based on Hierarchical Porous Molybdenum Selenide to Build Anticorrosive and Multiband Tailorable Absorbers
20
作者 Tianbao Zhao Zirui Jia +3 位作者 Jinkun Liu Yan Zhang Guanglei Wu Pengfei Yin 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第1期85-105,共21页
Electromagnetic wave(EMW)absorbing materials have an irreplaceable position in the field of military stealth as well as in the field of electromagnetic pollution control.And in order to cope with the complex electroma... Electromagnetic wave(EMW)absorbing materials have an irreplaceable position in the field of military stealth as well as in the field of electromagnetic pollution control.And in order to cope with the complex electromagnetic environment,the design of multifunctional and multiband high efficiency EMW absorbers remains a tremendous challenge.In this work,we designed a three-dimensional porous structure via the salt melt synthesis strategy to optimize the impedance matching of the absorber.Also,through interfacial engineering,a molybdenum carbide transition layer was introduced between the molybdenum selenide nanoparticles and the three-dimensional porous carbon matrix to improve the absorption behavior of the absorber.The analysis indicates that the number and components of the heterogeneous interfaces have a significant impact on the EMW absorption performance of the absorber due to mechanisms such as interfacial polarization and conduction loss introduced by interfacial engineering.Wherein,the prepared MoSe_(2)/MoC/PNC composites showed excellent EMW absorption performance in C,X,and Ku bands,especially exhibiting a reflection loss of−59.09 dB and an effective absorption bandwidth of 6.96 GHz at 1.9 mm.The coordination between structure and components endows the absorber with strong absorption,broad bandwidth,thin thickness,and multi-frequency absorption characteristics.Remarkably,it can effectively reinforce the marine anticorrosion property of the epoxy resin coating on Q235 steel substrate.This study contributes to a deeper understanding of the relationship between interfacial engineering and the performance of EMW absorbers,and provides a reference for the design of multifunctional,multiband EMW absorption materials. 展开更多
关键词 Interfacial engineering ANTICORROSION MULTIBAND Electromagnetic wave absorber
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部