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Astronomical time scale-based analysis of Miocene sedimentation rates and their controlling factors in the Zhujiang River Mouth Basin 认领 引用
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作者 Bianqing Guo Di Gao +4 位作者 Guangrong Peng Meng Li Yanshu Yin Guangxu Wang Wei Wu 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2025年第12期139-152,共14页
The Zhujiang River Mouth Basin,a primary depocenter for terrigenous sediments in the western Pacific,presents a semienclosed tectonic setting with limited exchange with the open ocean.This unique feature enables syste... The Zhujiang River Mouth Basin,a primary depocenter for terrigenous sediments in the western Pacific,presents a semienclosed tectonic setting with limited exchange with the open ocean.This unique feature enables systematic linkages among sedimentary processes,climate change,regional sea-level fluctuations,and tectonic events.To explore these linkages,this study focuses on Well PY35 in the Baiyun Sag of the Zhujiang River Mouth Basin.By integrating microfossil analysis with Milankovitch cycle analysis of well log data,an astronomical time scale(ATS)(17.54-7.80 Ma)and a high-resolution stratigraphic framework were established,allowing for the calculation of sedimentation rates across different hierarchical sequences and time intervals.The results indicate that between 17.54 Ma and 7.80 Ma,the sedimentation rate initially increased and then decreased,ranging from 6.1 cm/ka to 45.7 cm/ka,with an average rate of 22.2 cm/ka.During the Middle Miocene Climatic Optimum(MMCO),sedimentation rates were moderate and exhibited an increasing trend,largely driven by increased sediment input due to enhanced weathering from rising temperatures and by expanded accommodation space resulting from tectonic subsidence.Meanwhile,the Middle Miocene Climate Transition(MMCT)was marked by a notable rise in sedimentation rates,consistent with a major sea-level fall due to global cooling,which promoted the direct seaward progradation of marginal sediments.The Late Middle Miocene to Late Miocene had the lowest sedimentation rates,which can be attributed to reduced weathering under cold and arid conditions,along with a sea-level rise induced by regional tectonics.The short-term increase in the sedimentation rate observed at 10.4 Ma may have been driven by sea-level fluctuations.This study provides both theoretical and empirical support for understanding the influence of abrupt climate changes on sedimentary processes. 展开更多
关键词 Miocene astronomical time scale sedimentation rate Milankovitch cycle stratigraphic framework
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A methodology of Lagrangian integral time scale in cavitating flow based on finite-time Lyapunov exponent 认领 引用
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作者 Peifeng LIN Tianyu ZANG Jinming ZHANG 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2025年第12期2407-2426,共20页
The Lagrangian integral time scale(LITS)is a crucial characteristic for investigating the changes in fluid dynamics induced by the chaotic nature,and the finitetime Lyapunov exponent(FTLE)serves as a key measure in th... The Lagrangian integral time scale(LITS)is a crucial characteristic for investigating the changes in fluid dynamics induced by the chaotic nature,and the finitetime Lyapunov exponent(FTLE)serves as a key measure in the analysis of chaos.In this study,a new LITS model with an explicit theoretical basis and broad applicability is proposed based on the FTLE,along with a verification and evaluation criterion grounded in the Lagrangian velocity correlation coefficient.The model is used to cavitating the flow around a Clark-Y hydrofoil,and the LITS is investigated.It leads to the determination of model constants applicable to cavitating flow.The model is evaluated by the Lagrangian velocity correlation coefficient in comparison with other solution methods.All the results show that the LITS model can offer a new perspective and a new approach for studying the changes in fluid dynamics from a Lagrangian viewpoint. 展开更多
关键词 Lagrangian integral time scale(LITS) finite-time Lyapunov exponent(FTLE) cavitating flow correlation coefficient fluid dynamics
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Two-phase micro-and macro-time scales in particle-laden turbulent channel flows 认领 引用
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作者 Bing Wang Michael Manhart 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2012年第3期595-604,共10页
The micro- and macro-time scales in two-phase turbulent channel flows are investigated using the direct nu- merical simulation and the Lagrangian particle trajectory methods for the fluid- and the particle-phases, res... The micro- and macro-time scales in two-phase turbulent channel flows are investigated using the direct nu- merical simulation and the Lagrangian particle trajectory methods for the fluid- and the particle-phases, respectively. Lagrangian and Eulerian time scales of both phases are cal- culated using velocity correlation functions. Due to flow anisotropy, micro-time scales are not the same with the theo- retical estimations in large Reynolds number （isotropic） tur- bulence. Lagrangian macro-time scales of particle-phase and of fluid-phase seen by particles are both dependent on particle Stokes number. The fluid-phase Lagrangian inte- gral time scales increase with distance from the wall, longer than those time scales seen by particles. The Eulerian inte- gral macro-time scales increase in near-wall regions but de- crease in out-layer regions. The moving Eulerian time scales are also investigated and compared with Lagrangian integral time scales, and in good agreement with previous measure- ments and numerical predictions. For the fluid particles the micro Eulerian time scales are longer than the Lagrangian ones in the near wall regions, while away from the walls the micro Lagrangian time scales are longer. The Lagrangian integral time scales are longer than the Eulerian ones. The results are useful for further understanding two-phase flow physics and especially for constructing accurate prediction models of inertial particle dispersion. 展开更多
关键词 Micro-time scale Lagrangian integral timescale ~ Moving Eulerian time scale Particle-laden turbulentflow ~ Particle Stokes number Direct numerical simulation（DNS） Lagrangian trajectory method
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Lagrangian time scales and its relationship to Eulerian equivalents in turbulent channel flow 认领 引用
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作者 罗剑平 卢志明 刘宇陆 《Journal of Shanghai University(English Edition)》 2010年第1期71-75,共5页
Lagrangian and Eulerian time scales were obtained from the direct numerical simulation of turbulent channel flow at two Reynolds numbers based on the friction velocity and channel half-height, Rer= 80, 100. The Lagran... Lagrangian and Eulerian time scales were obtained from the direct numerical simulation of turbulent channel flow at two Reynolds numbers based on the friction velocity and channel half-height, Rer= 80, 100. The Lagrangian integral time scales and time microscales were compared to their Eulerian equivalents. It is found that the ratio of Lagrangian to TL Eulerian integral time scales is given by TE/TiE= 1 ＋ 0.1y＋ for y＋ ≤ 10, and that the ratios between the Lagrangian to theEulerian time microscales are almost the same irrespective of the components. Those increase with y＋ are approximated by ≈ 2.75 - 1.75 exp （-v＋/a） . These results also show that these expressions are independent of the Reynolds number. 展开更多
关键词 turbulent channel flow Lagrangian time scale Eulerian time scale direct numerical simulation （DNS）
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Multiple Time Scale Analysis of River Runoff Using Wavelet Transform for Dagujia River Basin, Yantai, China 认领 引用 被引量：10
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作者 LIU Delin LILT Xianzhao +2 位作者 LI Bicheng ZHAO Shiwei LI Xiguo 《Chinese Geographical Science》 SCIE 2009年第2期158-167,共10页
Based on monthly river runoff and meteorological data, a method of Morlet wavelet transform was used to analyze the multiple time scale characteristics of river runoff in the Dagujia River Basin, Yantai City, Shandong... Based on monthly river runoff and meteorological data, a method of Morlet wavelet transform was used to analyze the multiple time scale characteristics of river runoff in the Dagujia River Basin, Yantai City, Shandong Province. The results showed that the total annual river runoffin the Dagujia River Basin decreased significantly from 1966 to 2004, and the rate of decrease was 48× 10^6ma/10yr, which was higher than the mean value of most rivers in China. Multiple time scale characteristics existed, which accounted for different aspects of the changes in annual river runoff, and the major periods of the runofftime series were identified as about 28 years, 14 years and 4 years with decreasing levels of fluctuation. The river runoff evolution process was controlled by changes in precipitation to a certain extent, but it was also greatly influenced by human activities. Also, for different time periods and scales, the impacts of climate changes and human activities on annual river runoff evolution occurred at the same time. Changes in the annual river runoffwere mainly associated with climate change before the 1980s and with human activities after 1981. 展开更多
关键词 multiple time scale river runoff climate change Morlet wavelet transform Dagujia River
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New results on global exponential stability of competitive neural networks with different time scales and time-varying delays 认领 引用 被引量：11
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作者 崔宝同 陈君 楼旭阳 《Chinese Physics B》 SCIE EI CAS 2008年第5期1670-1677,共8页
This paper studies the global exponential stability of competitive neural networks with different time scales and time-varying delays. By using the method of the proper Lyapunov functions and inequality technique, som... This paper studies the global exponential stability of competitive neural networks with different time scales and time-varying delays. By using the method of the proper Lyapunov functions and inequality technique, some sufficient conditions are presented for global exponential stability of delay competitive neural networks with different time scales. These conditions obtained have important leading significance in the designs and applications of global exponential stability for competitive neural networks. Finally, an example with its simulation is provided to demonstrate the usefulness of the proposed criteria. 展开更多
关键词 competitive neural network different time scale global exponential stability delay
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OSCILLATION FOR NONAUTONOMOUS NEUTRAL DYNAMIC DELAY EQUATIONS ON TIME SCALES 认领 引用 被引量：7
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作者 刘爱莲 吴洪武 +1 位作者 朱思铭 Ronald M.Mathsen 《Acta Mathematica Scientia》 SCIE 2006年第1期99-106,共8页
The article is concerned with oscillation of nonautonomous neutral dynamic delay equations on time scales. Sufficient conditions are established for the existence of bounded positive solutions and for oscillation of a... The article is concerned with oscillation of nonautonomous neutral dynamic delay equations on time scales. Sufficient conditions are established for the existence of bounded positive solutions and for oscillation of all solutions of this equation. Some results extend known results for difference equations when the time scale is the set Z^＋ of positive integers and for differential equations when the time scale is the set IR of real numbers. 展开更多
关键词 Time scale Δ-derivative neutral delay equation oscillation
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Noether symmetry and conserved quantity for dynamical system with non-standard Lagrangians on time scales 认领 引用 被引量：12
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作者 宋静 张毅 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第8期201-209,共9页
This paper focuses on studying the Noether symmetry and the conserved quantity with non-standard Lagrangians, namely exponential Lagrangians and power-law Lagrangians on time scales. Firstly, for each case, the Hamilt... This paper focuses on studying the Noether symmetry and the conserved quantity with non-standard Lagrangians, namely exponential Lagrangians and power-law Lagrangians on time scales. Firstly, for each case, the Hamilton prin- ciple based on the action with non-standard Lagrangians on time scales is established, with which the corresponding Euler-Lagrange equation is given. Secondly, according to the invariance of the Hamilton action under the infinitesimal transformation, the Noether theorem for the dynamical system with non-standard Lagrangians on time scales is established. The proof of the theorem consists of two steps. First, it is proved under the infinitesimal transformations of a special one-parameter group without transforming time. Second, utilizing the technique of time-re-parameterization, the Noether theorem in a general form is obtained. The Noether-type conserved quantities with non-standard Lagrangians in both clas- sical and discrete cases are given. Finally, an example in Friedmann-Robertson-Walker spacetime and an example about second order Duffing equation are given to illustrate the application of the results. 展开更多
关键词 time scale non-standard Lagrangian Noether symmetry conserved quantity
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The effect of polymer type on electric breakdown strength on a nanosecond time scale 认领 引用 被引量：3
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作者 赵亮 苏建仓 +1 位作者 潘亚峰 张喜波 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第3期158-163,共6页
Based on the concepts of fast polarization, effective electric field and electron impact ionization criterion, the effect of polymer type on electric breakdown strength （EBD） on a nanosecond time scale is investigat... Based on the concepts of fast polarization, effective electric field and electron impact ionization criterion, the effect of polymer type on electric breakdown strength （EBD） on a nanosecond time scale is investigated, and a formula that qualitatively characterizes the relation between the electric breakdown strength and the polymer type is derived. According to this formula, it is found that the electric breakdown strength decreases with an increase in the effective relative dielectric constants of the polymers. By calculating the effective relative dielectric constants for different types of polymers, the theoretical relation for the electric breakdown strengths of common polymers is predicted. To verify the prediction, the polymers of PE （polyethylene）, PTFE （polytetrafluoroethelene）, PMMA （organic glass） and Nylon are tested with a nanosecond-pulse generator. The experimental result shows EBD （PTFE） 〉 EBD （PMMA） 〉 EBD （Nylon） 〉 EBD （PE）. This result is consistent with the theoretical prediction. 展开更多
关键词 electric breakdown strength polymer type nanosecond time scale fast polarization phenomenon
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Astronomical time scale of the Turonian constrained by multiple paleoclimate proxies 认领 引用 被引量：6
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作者 Chao Ma Mingsong Li 《Geoscience Frontiers》 SCIE CAS CSCD 2020年第4期1345-1352,共8页
One of the clocks that record the Earth history is(quasi-) periodic astronomical cycles.These cycles influence the climate that can be ultimately stored in sedimentary rocks.By cracking these(quasi-) periodic sediment... One of the clocks that record the Earth history is(quasi-) periodic astronomical cycles.These cycles influence the climate that can be ultimately stored in sedimentary rocks.By cracking these(quasi-) periodic sedimentation signals,high resolution astronomical time scale(ATS) can be obtained.Paleoclimate proxies are widely used to extract astronomical cycles.However different proxies may respond differently to astronomical signals and nonastronomical noises including tectonics,diagenesis,and measurement error among others.Astronomical time scale constructed based on a single proxy where its signal-to-noise ratio is low may have uncertainty that is difficult to evaluate but can be revealed by utilizing other proxies.Here,we test eight astronomical age models using two astrochro no logical methods from four paleoclimate proxies(i.e.,color reflection L~* and b~*,natural gamma radiation,and bulk density) from the Turonian to the Coniacian of the Cretaceous Period at the Demerara Rise in the equatorial Atlantic.The two astrochronological methods are time calibration using long eccentricity bandpass filtering(E1 bandpass) and tracking the long eccentricity from evolutive harmonic analysis(tracking EHA).The statistical mean and standard deviation of four age models from the four proxies are calculated to construct one integrated age model with age uncertainty in each method.Results demonstrate that extracting astronomical signals from multiple paleoclimate proxies is a valid method to estimate age model uncertainties.Anchored at the Cenomanian/Turonian boundary with an age of 93.9 ± 0.15 Ma from biostratigraphy,the ages for CC11/CC12(calcareous nannofossil zones),Turonian/Coniacian(CC12/CC13),CC13/CC14,and Coniacian/Santonian boundaries are 91.25±0.20 Ma,89.87±0.20 Ma,86.36±0.33 Ma,and 86.03±0.32 Ma in E1 bandpass method,compared with 91.17±0.36 Ma,89.74±0.38 Ma,86.13±1.31 Ma,and 85.80±1.33 Ma respectively in tracking EHA method.These results are consistent with previous studies within error and provide a reliable estimation of uncertainties of the ages. 展开更多
关键词 Astrochronology Astronomical time scale Uncertainty Cretaceous Turonian Demerara rise
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Southern Ocean SST Variability and Its Relationship with ENSO on Inter-Decadal Time Scales 认领 引用 被引量：4
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作者 YAN Li DU Yan ZHANG Lan 《Journal of Ocean University of China》 SCIE CAS 2013年第2期287-294,共8页
Empirical orthogonal function （EOF） analysis reveals a co-variability of Sea surface temperatures （SSTs） in the Southern Hemisphere （0°-60°S）. In the South Indian and Atlantic Oceans, there is a subtro... Empirical orthogonal function （EOF） analysis reveals a co-variability of Sea surface temperatures （SSTs） in the Southern Hemisphere （0°-60°S）. In the South Indian and Atlantic Oceans, there is a subtropical dipole pattern slanted in the southwest-northeast direction. In the South Pacific Ocean, a meridional tripole structure emerges, whose middle pole co-varies with the dipoles in the South Indian and Atlantic Oceans and is used in this study to track subtropical Pacific variability. The South Indian and Atlantic Ocean dipoles and the subtropical Pacific variability are phase-locked in austral summer. On the inter-decadal time scales, the dipoles in the South Indian and Atlantic Oceans weaken in amplitude after 1979/1980. No such weakening is found in the subtropical South Pacific Ocean. Interestingly, despite the reduced amplitude, the correlation of the Indian Ocean and Atlantic dipoles with E1 Nino and Southern Oscillation （ENSO） are enhanced after 1979/1980. The same increase in correlation is found for subtropical South Pacific variability after 1979/1980. These inter-decadal modulations imply that the Southern Hemisphere participates in part of the climate shift in the late 1970s. The correlation between Southern Hemisphere SST and ENSO reduces after 2000. 展开更多
关键词 Southern Ocean SST ENSO subtropical dipole inter-decadal time scales
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Methods of reduction for Lagrange systems on time scales with nabla derivatives 认领 引用 被引量：5
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作者 Shi-Xin Jin Yi Zhang 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第1期243-249,共7页
The Routh and Whittaker methods of reduction for Lagrange system on time scales with nabla derivatives are studied.The equations of motion for Lagrange system on time scales are established, and their cyclic integrals... The Routh and Whittaker methods of reduction for Lagrange system on time scales with nabla derivatives are studied.The equations of motion for Lagrange system on time scales are established, and their cyclic integrals and generalized energy integrals are given. The Routh functions and Whittaker functions of Lagrange system are constructed, and the order of differential equations of motion for the system are reduced by using the cyclic integrals or the generalized energy integrals with nabla derivatives. The results show that the reduced Routh equations and Whittaker equations hold the form of Lagrnage equations with nabla derivatives. Finally, two examples are given to illustrate the application of the results. 展开更多
关键词 reduction of dynamical system cyclic integral energy integral time scales
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Generalized Chaplygin equations for nonholonomic systems on time scales 认领 引用 被引量：7
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作者 金世欣 张毅 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第2期267-272,共6页
The generalized Chaplygin equations for nonholonomic systems on time scales are proposed and studied. The Hamil- ton principle for nonholonomic systems on time scales is established, and the corresponding generalized ... The generalized Chaplygin equations for nonholonomic systems on time scales are proposed and studied. The Hamil- ton principle for nonholonomic systems on time scales is established, and the corresponding generalized Chaplygin equa- tions are deduced. The reduced Chaplygin equations are also presented. Two special cases of the generalized Chaplygin equations on time scales, where the time scales are equal to the set of real numbers and the integer set, are discussed. Finally, several examples are given to illustrate the application of the results. 展开更多
关键词 nonholonomic system generalized Chaplygin equations time scales
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Application of Time Scale to Parameters Tuning of Active Disturbance Rejection Controller for Induction Motor 认领 引用 被引量：2
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作者 邵立伟 廖晓钟 张宇河 《Journal of Beijing Institute of Technology》 EI CAS 2007年第4期419-423,共5页
Active disturbance rejection controller (ADRC) has good performance in induction motor (IM) control system, but controller parameter is difficult to tune. A method of tuning ADRC parameter by time scale is analyzed. T... Active disturbance rejection controller (ADRC) has good performance in induction motor (IM) control system, but controller parameter is difficult to tune. A method of tuning ADRC parameter by time scale is analyzed. The IM time scale is obtained by theoretical analysis. Combining the relations between scale time and ADRC parameters, ADRC parameter tuning in IM vector control based stator flux oriented is obtained. This parameter tuning method is validated by simulations and it provides a new technique for tuning of ADRC parameters of IM. 展开更多
关键词 time scale active disturbance rejection controller parameter tuning
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MULTIPLE TIME SCALE ANALYSIS OF CLIMATE VARIATION IN Macao DURING THE LAST 100 YEARS 认领 引用 被引量：1
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作者 冯瑞权 吴池胜 +5 位作者 王婷 何夏江 王安宇 刘吉 梁必骐 梁嘉静 《Journal of Tropical Meteorology》 SCIE 2012年第1期21-31,共11页
The multiple time scale climate changes are studied and calculated with statistical analysis and wavelet transformation on the basis of daily series of observed data over the period 1901-2007 in Macao.The result shows... The multiple time scale climate changes are studied and calculated with statistical analysis and wavelet transformation on the basis of daily series of observed data over the period 1901-2007 in Macao.The result shows that statistically significant oscillations with 2 to 5 years of period generally exist in the series of climate variables(e.g.annual mean surface air temperature and precipitation as well as evaporation etc.),but with obvious locality in time domain.The variation of annual mean surface air temperature has a quasi 60-year period.The phases of the 60-year variation approximately and consistently match that of Atlantic Multidecadal Oscillation(AMO).The oscillations of seasonal mean surface air temperature in summer and winter have the periods of quasi 30-year and quasi 60-year,respectively.These two periods of oscillations have statistically significant correlation with Pacific decadal oscillation(PDO) and AMO,individually.The multidecadal variations of the precipitation of the annually first flood period and annual evaporation are dominated by periods of quasi 30-year and quasi 50-year,respectively. 展开更多
关键词 climate change in Macao wavelet transformation multiple time scales
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Multiple time scales of fluvial processes—theory and applications 认领 引用 被引量：1
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作者 Zhixian Cao G.Pender Peng Hu 《Theoretical & Applied Mechanics Letters》 EI CAS 2011年第5期1-7,共7页
Fluvial processes comprise water flow,sediment transport and bed evolution,which normally feature distinct time scales.The time scales of sediment transport and bed deformation relative to the flow essentially measure... Fluvial processes comprise water flow,sediment transport and bed evolution,which normally feature distinct time scales.The time scales of sediment transport and bed deformation relative to the flow essentially measure how fast sediment transport adapts to capacity region in line with local flow scenario and the bed deforms in comparison with the flow,which literally dictates if a capacity based and/or decoupled model is justified.This paper synthesizes the recently developed multiscale theory for sediment-laden flows over erodible bed,with bed load and suspended load transport,respectively.It is unravelled that bed load transport can adapt to capacity sufficiently rapidly even under highly unsteady flows and thus a capacity model is mostly applicable,whereas a non-capacity model is critical for suspended sediment because of the lower rate of adaptation to capacity.Physically coupled modelling is critical for fluvial processes characterized by rapid bed variation.Applications are outlined on very active bed load sediment transported by flash floods and landslide dam break floods. 展开更多
关键词 sediment-laden flow fluvial processes capacityon-capacity model coupled/decoupled model multiple time scales flooding
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Mei’s symmetry theorem for time scales nonshifted mechanical systems 认领 引用 被引量：8
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作者 Yi Zhang 《Theoretical & Applied Mechanics Letters》 CAS CSCD 2021年第5期246-251,共6页
We focus on Mei symmetry for time scales nonshifted mechanical systems within Lagrangian framework and its resulting new conserved quantities.Firstly,the dynamic equations of time scales nonshifted holonomic systems a... We focus on Mei symmetry for time scales nonshifted mechanical systems within Lagrangian framework and its resulting new conserved quantities.Firstly,the dynamic equations of time scales nonshifted holonomic systems and time scales nonshifted nonholonomic systems are derived from the generalized Hamilton’s principle.Secondly,the definitions of Mei symmetry on time scales are given and its criterions are deduced.Finally,Mei’s symmetry theorems for time scales nonshifted holonomic conservative systems,time scales nonshifted holonomic nonconservative systems and time scales nonshifted nonholonomic systems are established and proved,and new conserved quantities of above systems are obtained.Results are illustrated with two examples. 展开更多
关键词 Mei’s symmetry theorem Nonholonomic system Nonconservative system Time scales Nonshifted calculus of variation
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Establishment of an astronomical time scale for the Shizigou Formation in the Qaidam Basin,Inner Asia and orbital forced evolution of lakes during The Pliocene 认领 引用 被引量：1
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作者 DunZhu JiaoBa MingZhen Zhang +6 位作者 GuoLong Liu JianGuo Hui ShaoHua Lin AiJing Li Jing Zhang Jing Peng YiQiao Fu 《Research in Cold and Arid Regions》 CSCD 2023年第5期239-252,共14页
The Qaidam Basin,as the largest inland basin within the Tibetan Plateau,has accumulated more than 10,000 m of Cenozoic continental sediments.It serves as a crucial research area for documenting Cenozoic climate change... The Qaidam Basin,as the largest inland basin within the Tibetan Plateau,has accumulated more than 10,000 m of Cenozoic continental sediments.It serves as a crucial research area for documenting Cenozoic climate changes and plateau uplift processes in the Asian interior.Additionally,the basin holds vast reserves of oil and gas resources,making high-resolution drilling data invaluable for studying paleoclimate.In this study,the longsequence lacustrine deposits of JS1 drill core across the Shizigou Formation in the Yiliping Depression at the western center of the basin were studied,aiming to establish an astronomical timescale for the Shizigou Formation and investigate the characteristics of paleoclimatic changes during the late Miocene to the Pliocene for the Asian interior.The analysis was carried out using high-resolution natural gamma ray(GR)data sequences,employing techniques such as spectral analysis,filtering,and wavelet analysis in cyclostratigraphy.The results indicated the presence of a stable Milankovitch orbital signal was perfectly recorded in the Shizigou Formation,primarily influenced by eccentricity cycles,with weaker obliquity and precession cycles.Using the stable and continuous 405 ka eccentricity cycle in astronomical tuning,a"floating"astronomical timescale with a duration of 6.1 Ma for the Yiliping depression's Shizigou Formation has been established.With reference to previously established stratigraphic age anchor points,an absolute astronomical timescale(2.5-8.6 Ma)has been ultimately provided for the Shizigou Formation.Simultaneously,a clear 100 ka short eccentricity cycle record has been identified during the Pliocene(5.3-2.5 Ma),which corresponds in time with the aridification within the basin during this Pliocene period.In addition,a comparison of the Pliocene natural gamma ray curve of the Qaidam Basin with global ice volume variations indicated that the basin's aridification was influenced by global cooling,with eccentricity-modulated precession cycles controlling solar radiation and subsequently affecting the evolution of lakes in the arid region of Inner Asia. 展开更多
关键词 Qaidam basin Shizigou Formation Astronomical time scale Astronomical tuning~100 ka orbital eccentricity
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Some integral inequalities on time scales 认领 引用 被引量：2
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作者 Adnan Tuna Servet Kutukcu 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2008年第1期23-29,共7页
In this article,we study the reverse HSlder type inequality and HSlder inequality in two dimensional case on time scales.We also obtain many integral inequalities by using HSlder inequalities on time scales which give... In this article,we study the reverse HSlder type inequality and HSlder inequality in two dimensional case on time scales.We also obtain many integral inequalities by using HSlder inequalities on time scales which give Hardy's inequalities as spacial cases. 展开更多
关键词 integral inequalities Hoelder's inequalities Hardy's inequalities time scales reverse inequality
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Oscillation of Second-order Nonlinear Dynamic Equation on Time Scales 认领 引用 被引量：7
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作者 YANG Jia-shan 《Chinese Quarterly Journal of Mathematics》 CSCD 2013年第2期172-179,共8页
： The oscillation for a class of second order nonlinear variable delay dynamic equation on time scales with nonlinear neutral term and damping term was discussed in this article. By using the generalized Riccati tech... ： The oscillation for a class of second order nonlinear variable delay dynamic equation on time scales with nonlinear neutral term and damping term was discussed in this article. By using the generalized Riccati technique, integral averaging technique and the time scales theory, some new sufficient conditions for oscillation of the equation are proposed. These results generalize and extend many knownresults for second order dynamic equations. Some examples are given to illustrate the main results of this article. 展开更多
关键词 time scales dynamic equations nonlinear neutral term damping term variable delay Riccati transformation oscillation
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