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14篇 您的检索式:作者名="Yaokun Li"
    题名 作者 年代 出处 被引量
1Numerical simulation on the seismic absorption effect of the cushion in rigid-pile composite foundation显示文摘In order to quantitatively study the seismic absorption effect of the cushion on a superstructure, a numerical simulation and parametric study are carried out on the overall FEA model of a rigid-pile composite foundation in ABAQUS. A simulation of a shaking table test on a rigid mass block is first completed with ABAQUS and EERA, and the effectiveness of the Drucker-Prager constitutive model and the finite-infinite element coupling method is proved. Dynamic time-history analysis of the overall model under frequent and rare earthquakes is carried out using seismic waves from the El Centro, Kobe, and Bonds earthquakes. The different responses of rigid-pile composite foundations and pile-raft foundations are discussed. Furthermore, the influence of thickness and modulus of cushion, and ground acceleration on the seismic absorption effect of the cushion are analyzed. The results show that: 1) the seismic absorption effect of a cushion is good under rare earthquakes, with an absorption ratio of about 0.85; and 2) the seismic absorption effect is strongly affected by cushion thickness and ground acceleration.Han Xiaolei Li Yaokun Ji Jing Ying Junhao Li Weichen Dai Baicheng 2016Earthquake Engineering and Engineering Vibration2016,15,2:5
2Intrinsically Stretchable Organic-Tribotronic-Transistor for Tactile Sensing显示文摘Stretchable electronics are of great significance for the development of the next-generation smart interactive systems.Here,we propose an intrinsically stretchable organic tribotronic transistor(SOTT)without a top gate electrode,which is composed of a stretchable substrate,silver nanowire electrodes,semiconductor blends,and a nonpolar elastomer dielectric.The drain-source current of the SOTT can be modulated by external contact electrification with the dielectric layer.Under 0-50%stretching both parallel and perpendicular to the channel directions,the SOTT retains great output performance.After being stretched to 50%for thousands of cycles,the SOTT can survive with excellent stability.Moreover,the SOTT can be conformably attached to the human hand,which can be used for tactile signal perception in human-machine interaction and for controlling smart home devices and robots.This work has realized a stretchable tribotronic transistor as the tactile sensor for smart interaction,which has extended the application of tribotronics in the human-machine interface,wearable electronics,and robotics.Junqing Zhao Tianzhao Bu Xiaohan Zhang Yaokun Pang Wenjian Li Zhi Zhang Guoxu Liu Zhong Lin Wang Chi Zhang 2020Research2020,,1:4
3Two equilibria of the Antarctic Circumpolar Current and its associated Meridional Overturning Circulation显示文摘The Antarctic Circumpolar Current (ACC) and its associated Meridional Overturning Circulation (MOC) is investigated through a nonlinear inertia theory model, which consists of two layers--an upper Ekman layer driven mainly by sea surface wind stress and a lower thermocline controlled by ideal fluid nonlinear equations which can be solved by identifying the form of the arbitrary functions. The results show that the thermocline has a two-equilibrium solution though given the same Ekman layer condition. Compared to the first equilibrium, the second one has a heavier intensity and deeper circulation, which seems more consistent with the existing data.CHAO JiPing LI YaoKun 2012Science China Earth Sciences2012,55,2:3
4Structure of the Indian Ocean Meridional Overturning Circulation and its relationship with the zonal wind stress显示文摘We studied the structure of the Indian Ocean(IO)Meridional Overturning Circulation(MOC)by applying a nonlinear inertia theory and analyzed the coupled relationship between zonal wind stress and MOC anomalies.Our results show that the inertia theory can represent the main characteristics of the IO MOC:the subtropical cell(STC)and cross-equator cell(CEC).The stream function in equatorial and northern IO changes a sign from winter to summer.The anomalies of the zonal wind stress and stream function can be decomposed into summer monsoon mode,winter monsoon mode,and abnormal mode by using the singular vector decomposition(SVD)analysis.The first two modes correlate with the transport through 20°S and equator simultaneously whereas the relationship obscures between the third mode and transports across 20°S and equator,showing the complex air-sea interaction process.The transport experiences multi-time scale variability according to the continuous power spectrum analysis,with major periods in inter-annual and decadal scale.LI YaoKun CHAO JiPing 2014Science China Earth Sciences2014,57,2:2
5Variations in Wave Energy and Amplitudes along the Energy Dispersion Paths of Nonstationary Barotropic Rossby Waves显示文摘The variations in the wave energy and the amplitude along the energy dispersion paths of the barotropic Rossby waves in zonally symmetric basic flow are studied by solving the wave energy equation,which expresses that the wave energy variability is determined by the divergence of the group velocity and the energy budget from the basic flow.The results suggest that both the wave energy and the amplitude of a leading wave increase significantly in the propagating region that is located south of the jet axis and enclosed by a southern critical line and a northern turning latitude.The leading wave gains the barotropic energy from the basic flow by eddy activities.The amplitude continuously climbs up a peak at the turning latitude due to increasing wave energy and enlarging horizontal scale(shrinking total wavenumber).Both the wave energy and the amplitude eventually decrease when the trailing wave continuously approaches southward to the critical line.The trailing wave decays and its energy is continuously absorbed by the basic flow.Furthermore,both the wave energy and the amplitude oscillate with a limited range in the propagating region that is located near the jet axis and enclosed by two turning latitudes.Both the leading and trailing waves neither develop nor decay significantly.The jet works as a waveguide to allow the waves to propagate a long distance.Yaokun LI Jiping CHAO Yanyan KANG 2021Advances in Atmospheric Sciences2021,38,1:1
6Experimental study on the shear behavior of the interface between cushion materials and the concrete raft显示文摘Cushion is a layer of granular materials between the raft and the ground. The shear behavior of the interface between the cushion and the raft may influence the seismic performance of the superstructure. In order to quantify such influences, horizontal shear tests on the interfaces between different cushion materials and concrete raft under monotonic and cyclic loading were carried out. The vertical pressure P_v, material type and cushion thickness h_c were taken as variables. Conclusions include: 1) under monotonic loading, P_v is the most significant factor; the shear resistance P_(hmax) increases as P_v increases, but the normalized factor of resistance μ_n has an opposite tendency; 2) for the materials used in this study, μ_n varies from 0.40 to 0.70, the interface friction angle δ_s varies from 20° to 35°, while u_(max) varies from 3 mm to 15 mm; 3) under cyclic loading, the interface behavior can be abstracted as a 'three-segment' back-bone curve, the main parameters include μ_n, the displacement u_1 and stiffness K_1 of the elastic stage, the displacement u_2 and stiffness K_2 of the plastic stage; 4) by observation and statistical analysis, the significance of different factors, together with values of K_1, K_2 and μ_n have been obtained.Li Yaokun Han Xiaolei Khaled Galal Ji Jing 2018Earthquake Engineering and Engineering Vibration2018,17,1:1
7Tribotronic bipolar junction transistor for mechanical frequency monitoring and use as touch switch显示文摘Tribotronics,a new field that involves the coupling of triboelectricity and semiconductors,has attracted great interest in the nanoenergy and nanoelectronics domains.This paper proposes a tribotronic bipolar junction transistor(TBJT)that incorporates a bipolar junction transistor and a triboelectric nanogenerator(TENG)in the single-electrode mode.When the mobile triboelectric layer slides on the device surface for electrification,a bias voltage is created and applied to the emitter junction,and then the base current from the TENG is amplified.Based on the fabricated TBJT,a mechanical frequency monitoring sensor with high sensitivity and excellent stability and a finger-triggered touch switch were developed.This work demonstrated for the first time a tribotronic device with simultaneously controlled voltage and current voltage/current simultaneously controlled tribotronic device,which has promising potential applications in micro/nano-sensors,human-machine interactions,intelligent instrumentation,wearable electronics,and other applications.Fengben Xi Yaokun Pang Wenjian Li Tianzhao Bu Junqing Zhao Guoxu Liu Tong Guo Wenbo Liu Chi Zhang 2018Microsystems & Nanoengineering2018,4,1:1
8Effect of ternary transition metal sulfide FeNi_(2)S_(4)on hydrogen storage performance of MgH_(2)显示文摘Hydrogen storage is a key link in hydrogen economy,where solid-state hydrogen storage is considered as the most promising approach because it can meet the requirement of high density and safety.Thereinto,magnesium-based materials(MgH_(2))are currently deemed as an attractive candidate due to the potentially high hydrogen storage density(7.6 wt%),however,the stable thermodynamics and slow kinetics limit the practical application.In this study,we design a ternary transition metal sulfide FeNi_(2)S_(4)with a hollow balloon structure as a catalyst of MgH_(2)to address the above issues by constructing a MgH_(2)/Mg_(2)NiH_(4)-MgS/Fe system.Notably,the dehydrogenation/hydrogenation of MgH_(2)has been significantly improved due to the synergistic catalysis of active species of Mg_(2)Ni/Mg_(2)NiH_(4),MgS and Fe originated from the MgH_(2)-FeNi_(2)S_(4)composite.The hydrogen absorption capacity of the MgH_(2)-FeNi_(2)S_(4)composite reaches to 4.02 wt%at 373 K for 1 h,a sharp contrast to the milled-MgH_(2)(0.67 wt%).In terms of dehydrogenation process,the initial dehydrogenation temperature of the composite is 80 K lower than that of the milled-MgH_(2),and the dehydrogenation activation energy decreases by 95.7 kJ·mol-1 compared with the milled-MgH_(2)(161.2 kJ·mol^(-1)).This method provides a new strategy for improving the dehydrogenation/hydrogenation performance of the MgH_(2)material.Yaokun Fu Lu Zhang Yuan Li Sanyang Guo Han Yu Wenfeng Wang Kailiang Ren Wei Zhang Shumin Han 2023Journal of Magnesium and Alloys2023,11,8:0
9二维能量平衡模式中高纬度植被绿化的全球温度响应显示文摘在全球变暖的背景下,包含中纬度荒漠的干旱地区对气候的变化最为敏感,但高纬度植被绿化对中纬度荒漠地区域的气候影响仍然未知。本研究采用二维能量平衡模式研究高纬度地区植被绿化对中纬度荒漠的影响。研究结果表明,高纬度地区绿化会导致中纬度荒漠南边界后退,极地冰带和低纬度植被带扩大。同时,也会引发高纬度负温度异常和低纬度正温度异常。在CO2浓度增加试验中,中纬度荒漠的南北边界一直在扩展,直到CO2浓度达到600ppm(饱和状态)为止。BI Lu HE Yongli HUANG Jianping LI Yaokun GUAN Xiaodan LIU Xiaoyue 2020Atmospheric and Oceanic Science Letters2020,13,1:0
10The dynamical evolution theory of the isolated oasis system显示文摘Assume that an oasis and its surrounding desert consist of an isolated system without mass and energy exchange with the outer environment.The characteristics of oasis evolution have been explored under the condition of system energy conservation.The results show that oasis evolves with two equilibrium states.The first equilibrium suggests a stable expansive and an unstable degraded oasis whereas the second equilibrium indicates a stable shrink and an unstable increase of the oasis area.If one equilibrium state is unstable,the components of the isolated system(oasis and desert) would tend to be no energy exchange and they each reach to energy balance respectively.Oasis would maintain its initial area in this case.Further analyses point out that the two equilibrium states have completely different characteristics.In the first equilibrium state,a higher vegetation albedo,lower soil albedo and larger canopy resistance,and direr soil both contribute to the oasis area expansion,accompanying an excessive large desert soil and vegetation canopy temperature difference(SCTD).In the second equilibrium state,however,a lower vegetation albedo,higher soil albedo and small canopy resistance,and wetter soil benefit the oasis area to stay near its initial value,following a moderate SCTD.The convergent trajectories of the initial values in phase space are influenced by the separatrices of the equilibrium points.Higher temperature is an advantage factor for initial values convergent to the oasis expansion solution.LI YaoKun CHAO JiPing 2015Science China Earth Sciences2015,58,3:0
11Catalytic effect of MOF-derived transition metal catalyst FeCoS@C on hydrogen storage of magnesium显示文摘The introduction of the heterogeneous catalysts with high activity can significantly improve hydrogen storage performance of MgH_(2),therefore,in this paper,we synthesize a carbon-supported transition metal compound,FeCoS@C derivative from ZIF-67,by utilizing the in situ formed C dispersive multiphase Mg_(2)Co,α-Fe,Co_(3)Fe_(7),and MgS to implement catalysis to MgH_(2).Noteworthily,MgH_(2)-FeCoS@C rapidly ab-sorbs 6.78 wt%H_(2)within 60 s at 573 K and can also absorb 4.56 wt%H_(2)in 900 s at 473 K.Besides,the addition of FeCoS@C results in decreasing of the initial dehydrogenation temperatures of MgH_(2)from 620 to 550 K.The dehydrogenation activation energy of MgH_(2)decreases from 160.7 to 91.9 kJ mol^(-1).Studies show that the Mg_(2)Co,α-Fe,and Co_(3)Fe_(7)act as“hydrogen channels”to accelerate hydrogen transfer due to the presence of transition metals,and MgS with excellent catalytic effect formed from MgH_(2)-FeCoS@C provides a strong and stable catalytic effect.Besides,the carbon skeleton obtained by the carbonization of ZIF-67 not only serves as a dispersion for the multiphase catalytic system,but also provides more active sites for the catalysts.Our study shows that the multiphase and multiscale catalytic system provides an effective strategy for improving the hydrogen storage performance of MgH_(2).Yaokun Fu Lu Zhang Yuan Li Sanyang Guo Zhichao Yu Wenfeng Wang Kailiang Ren Qiuming Peng Shumin Han 2023Journal of Materials Science & Technology2023,,7:0
12A two-dimensional energy balance climate model on Mars显示文摘A two-dimensional energy balance climate model has been built to investigate the climate on Mars.The model takes into account the balance among solar radiation,longwave radiation,and energy transmission and can be solved analytically by Legendre polynomials.With the parameters for thermal diffusion and radiation processes being properly specified,the model can simulate a reasonable surface atmospheric temperature distribution but not a very perfect vertical atmospheric temperature distribution compared with numerical results,such as those from the Mars Climate Database.With varying solar radiation in a Martian year,the model can simulate the seasonal variation of the air temperature on Mars.With increasing dust content,the Martian atmosphere gradually warms.However,the warming is insignificant in the cold and warm scenarios,in which the dust mixing ratio varies moderately,whereas the warming is significant in the storm scenario,in which the dust mixing ratio increases dramatically.With an increasing albedo value of either the polar cap or the non-ice region,Mars gradually cools.The mean surface atmospheric temperature decreases moderately with an increasing polar ice albedo,whereas it increases dramatically with an increasing non-ice albedo.This increase occurs because the planetary albedo of the ice regions is smaller than that of the non-ice region.YaoKun Li JiPing Chao 2022Earth and Planetary Physics2022,6,3:0
13Variations in Amplitudes and Wave Energy along the Energy Dispersion Paths for Rossby Waves in the Quasigeostrophic Barotropic Model显示文摘Variations in wave energy and amplitude for Rossby waves are investigated by solving the wave energy equation for the quasigeostrophic barotropic potential vorticity model.The results suggest that compared with rays in the nondivergent barotropic model,rays in the divergent model can have enhanced meridional and zonal propagation,accompanied by a more dramatic variability in both wave energy and amplitude,which is caused by introducing the divergence effect of the free surface in the quasigeostrophic model.For rays propagating in a region enclosed by a turning latitude and a critical latitude,the wave energy approaches the maximum value inside the region,while the amplitude approaches the maximum at the turning latitude.Waves can develop when both the wave energy and amplitude increase.For rays propagating in a region enclosed by two turning latitudes,the wave energy approaches the minimum value at one turning latitude and the maximum value at the other latitude,while the total wavenumber approaches the maximum value inside the region.The resulting amplitude increases if the total wavenumber decreases or the wave energy increases more significantly and decreases if the total wavenumber increases or the wave energy decreases more significantly.The matched roles of the energy from the basic flow and the divergence of the group velocity contribute to the slightly oscillating wave energy,which causes a slightly oscillating amplitude as well as the slightly oscillating total wavenumber.Yaokun LI Jiping CHAO Yanyan KANG 2022Advances in Atmospheric Sciences2022,39,6:0
14Diet induced the change of mtDNA copy number and metabolism in Angus cattle显示文摘Background: Grass-fed and grain-fed Angus cattle differ in the diet regimes. However, the intricate mechanisms of different beef quality and other phenotypes induced by diet differences are still unclear. Diet affects mitochondrial function and dynamic behavior in response to changes in energy demand and supply. In this study, we examined the mtDNA copy number, mitochondria-related genes expression, and metabolic biomarkers in grass-fed and grainfed Angus cattle.Results: We found that the grass-fed group had a higher mtDNA copy number than the grain-fed group. Among different tissues, the mtDNA copy number was the highest in the liver than muscle, rumen, and spleen. Based on the transcriptome of the four tissues, a lower expression of mtDNA-encoded genes in the grass-fed group compared to the grain-fed group was discovered. For the mitochondria-related nuclear genes, however, most of them were significantly down-regulated in the muscle of the grass-fed group and up-regulated in the other three tissues. In which, COX6 A2, POLG2, PPIF, DCN, and NDUFA12, involving in ATP synthesis, mitochondrial replication,transcription, and maintenance, might contribute to the alterations of mtDNA copy number and gene expression.Meanwhile, 40 and 23 metabolic biomarkers were identified in the blood and muscle of the grain-fed group compared to a grass-fed group, respectively. Integrated analysis of the altered metabolites and gene expression revealed the high expression level of MDH1 in the grain-fed group might contribute to the mitochondrial NADH oxidation and spermidine metabolism for adapting the deletion mtDNA copy number.Conclusions: Overall, the study may provide further deep insight into the adaptive and regulatory modulations of the mitochondrial function in response to different feeding systems in Angus cattle.Ying Bai José A.Carrillo Yaokun Li Yanghua He Jiuzhou Song 2021Journal of Animal Science and Biotechnology2021,12,1:0
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