In this paper,the thermal effects on the buckling of functionally graded（FG） nanobeams subjected to various types of thermal loading including uniform,linear and non-linear temperature changes are investigated based...In this paper,the thermal effects on the buckling of functionally graded（FG） nanobeams subjected to various types of thermal loading including uniform,linear and non-linear temperature changes are investigated based on the nonlocal third-order shear deformation beam theory.The material properties of FG nanobeam are supposed to vary gradually along the thickness direction according to the power-law form.The governing equations are derived through Hamilton＇s principle and solved analytically.Comparison examples are performed to verify the present results.Obtained results are presented for thermal buckling analysis of FG nanobeams such as the effects of the power-law index,nonlocal parameter,slenderness ratio and thermal loading in detail.展开更多
We evaluate the influence of temperature on the behavior of a three-phase clock-driven metal–oxide–semiconductor （MOS） chaotic circuit. The chaotic circuit consists of two nonlinear functions, a level shifter, and...We evaluate the influence of temperature on the behavior of a three-phase clock-driven metal–oxide–semiconductor （MOS） chaotic circuit. The chaotic circuit consists of two nonlinear functions, a level shifter, and three sample and hold blocks. It is necessary to analyze a CMOS-based chaotic circuit with respect to variation in temperature for stability because the circuit is sensitive to the behavior of the circuit design parameters. The temperature dependence of the proposed chaotic circuit is investigated via the simulation program with integrated circuit emphasis （SPICE） using 0.6-μm CMOS process technology with a 5-V power supply and a 20-kHz clock frequency. The simulation results demonstrate the effects of temperature on the chaotic dynamics of the proposed chaotic circuit. The time series, frequency spectra, bifurcation phenomena, and Lyapunov exponent results are provided.展开更多
The power-function exponent b of at-a-station hydraulic geometry(AHG)depicts the temporal response of river hydraulic parameters to changing discharge and is crucial for hydraulic modeling,habitat assessment,and river...The power-function exponent b of at-a-station hydraulic geometry(AHG)depicts the temporal response of river hydraulic parameters to changing discharge and is crucial for hydraulic modeling,habitat assessment,and river management.However,previous research,limited by field measurements,offers only a fragmentary understanding of the AHG exponent b in confined areas.Additionally,it remains challenging to establish the correlation between b and the climatic regime of a river.To offer a more comprehensive scope of AHG,this study assesses the width-discharge AHG exponents of 1,568 river reaches by pairing multi-temporal river width data from 1.19 million Landsat images with discharge observations from>17,000 gauge stations worldwide.The results show that b has a median value of 0.213,consistent with values reported in previous regional studies,but it exhibits complex relationships with 3 spatial dimensions-latitude,elevation,and drainage area.We further analyze the spatial variations in b against>200 physiographic and climatic factors,and find that reaches characterized by cohesive soil,high forest coverage,and less anthropogenic influences typically exhibit lower values of b,indicating a weaker response of width to discharge changes.By labeling 4 planimetric river morphologic types globally,we show that braided reaches exhibit the highest median of b,followed by straight,anabranching,and meandering reaches.The differences can be well explained by the climatic conditions of the river reaches as shown on the Budyko curve.This study lays the foundation for AHG research in ungauged regions using satellite remote sensing,expanding global hydraulic data and enhancing the understanding of the spatial variability and influencing factors of hydraulic geometry worldwide.展开更多
文摘In this paper,the thermal effects on the buckling of functionally graded（FG） nanobeams subjected to various types of thermal loading including uniform,linear and non-linear temperature changes are investigated based on the nonlocal third-order shear deformation beam theory.The material properties of FG nanobeam are supposed to vary gradually along the thickness direction according to the power-law form.The governing equations are derived through Hamilton＇s principle and solved analytically.Comparison examples are performed to verify the present results.Obtained results are presented for thermal buckling analysis of FG nanobeams such as the effects of the power-law index,nonlocal parameter,slenderness ratio and thermal loading in detail.
基金Project supported by the Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(Grant No.2011-0011698)
文摘We evaluate the influence of temperature on the behavior of a three-phase clock-driven metal–oxide–semiconductor （MOS） chaotic circuit. The chaotic circuit consists of two nonlinear functions, a level shifter, and three sample and hold blocks. It is necessary to analyze a CMOS-based chaotic circuit with respect to variation in temperature for stability because the circuit is sensitive to the behavior of the circuit design parameters. The temperature dependence of the proposed chaotic circuit is investigated via the simulation program with integrated circuit emphasis （SPICE） using 0.6-μm CMOS process technology with a 5-V power supply and a 20-kHz clock frequency. The simulation results demonstrate the effects of temperature on the chaotic dynamics of the proposed chaotic circuit. The time series, frequency spectra, bifurcation phenomena, and Lyapunov exponent results are provided.
基金supported by the National Natural Science Foundation of China(42371481)the Beijing Nova Program(20230484302)the Yunnan Provincial Science and Technology Project at Southwest United Graduate School(grant no.202302AO370012).
文摘The power-function exponent b of at-a-station hydraulic geometry(AHG)depicts the temporal response of river hydraulic parameters to changing discharge and is crucial for hydraulic modeling,habitat assessment,and river management.However,previous research,limited by field measurements,offers only a fragmentary understanding of the AHG exponent b in confined areas.Additionally,it remains challenging to establish the correlation between b and the climatic regime of a river.To offer a more comprehensive scope of AHG,this study assesses the width-discharge AHG exponents of 1,568 river reaches by pairing multi-temporal river width data from 1.19 million Landsat images with discharge observations from>17,000 gauge stations worldwide.The results show that b has a median value of 0.213,consistent with values reported in previous regional studies,but it exhibits complex relationships with 3 spatial dimensions-latitude,elevation,and drainage area.We further analyze the spatial variations in b against>200 physiographic and climatic factors,and find that reaches characterized by cohesive soil,high forest coverage,and less anthropogenic influences typically exhibit lower values of b,indicating a weaker response of width to discharge changes.By labeling 4 planimetric river morphologic types globally,we show that braided reaches exhibit the highest median of b,followed by straight,anabranching,and meandering reaches.The differences can be well explained by the climatic conditions of the river reaches as shown on the Budyko curve.This study lays the foundation for AHG research in ungauged regions using satellite remote sensing,expanding global hydraulic data and enhancing the understanding of the spatial variability and influencing factors of hydraulic geometry worldwide.
