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Influence of water coupling coefficient on the blasting effect of red sandstone specimens 被引量:1
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作者 Yang Li Renshu Yang +1 位作者 Yanbing Wang Dairui Fu 《International Journal of Coal Science & Technology》 EI CAS CSCD 2024年第1期148-166,共19页
This study investigates the impact of different water coupling coefficients on the blasting effect of red sandstone.The analysis is based on the theories of detonation wave and elastic wave,focusing on the variation i... This study investigates the impact of different water coupling coefficients on the blasting effect of red sandstone.The analysis is based on the theories of detonation wave and elastic wave,focusing on the variation in wall pressure of the blasting holes.Using DDNP explosive as the explosive load,blasting tests were conducted on red sandstone specimens with four different water coupling coefficients:1.20,1.33,1.50,and 2.00.The study examines the morphologies of the rock specimens after blasting under these different water coupling coefficients.Additionally,the fractal dimensions of the surface cracks resulting from the blasting were calculated to provide a quantitative evaluation of the extent of rock damage.CT scanning and 3D reconstruction were performed on the post-blasting specimens to visually depict the extent of damage and fractures within the rock.Additionally,the volume fractal dimension and damage degree of the post-blasting specimens are calculated.The findings are then combined with numerical simulation to facilitate auxiliary analysis.The results demonstrate that an increase in the water coupling coefficient leads to a reduction in the peak pressure on the hole wall and the crushing zone,enabling more of the explosion energy to be utilized for crack propagation following the explosion.The specimens exhibited distinct failure patterns,resulting in corresponding changes in fractal dimensions.The simulated pore wall pressure–time curve validated the derived theoretical results,whereas the stress cloud map and explosion energy-time curve demonstrated the buffering effect of the water medium.As the water coupling coefficient increases,the buffering effect of the water medium becomes increasingly prominent. 展开更多
关键词 Water coupling coefficient Radial uncoupled charge Numerical simulation Fractal dimension
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Feedback analysis and design of inductive power links driven by Class-E amplifiers with variable coupling coefficients
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作者 Tian-liang YANG Chun-yu ZHAO Da-yue CHEN 《Journal of Zhejiang University-Science C(Computers and Electronics)》 SCIE EI 2010年第8期629-636,共8页
The efficiency of inductive power links driven by Class-E amplifiers may deteriorate due to variation in the coupling coefficient when the relative position of the radio frequency (RF) coils changes.To solve this prob... The efficiency of inductive power links driven by Class-E amplifiers may deteriorate due to variation in the coupling coefficient when the relative position of the radio frequency (RF) coils changes.To solve this problem,a new design methodology of power links is presented in this paper.The aim of the new design is to use the feedback signal,which is a phase difference between the driving signal and the output current of the Class-E amplifier,to adjust the duty cycle and angular frequency of the driving signal to maintain the optimum state of the inductive power link,and to adjust the supply voltage to keep the output power constant when the coupling coefficient of the RF coils changes.The parameter adjustments with respect to the coupling coefficient and the feedback signal are derived from the design equation of the inductive power link.To validate the feedback control rules,a prototype of the inductive power link was constructed,and its performance validated with the coupling coefficient set at 0.2 and a duty cycle of 0.5.The experimental results showed that,by adjusting the duty cycle,the angular frequency,and the supply voltage,the power link can be kept in optimal operation with a constant output power when the coupling coefficient changes from 0.2 to 0.1 to 0.25. 展开更多
关键词 Inductive power link Closed-loop Class-E amplifier High efficient Variable coupling coefficient
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Effects of Three Coupling Coefficients on the Spectrum Characteristics of Superstructure Fiber Grating
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作者 YUAN Yinquan,GUO Zhenqiang, WEN Xiaoyan Key Laboratory of Fiber Optic Sensing Technology and Information Processing of Ministry of Education,Wuhan University of Technology,Wuhan 430070,Hubei,China 《Wuhan University Journal of Natural Sciences》 CAS 2009年第4期333-337,共5页
For the superstructure fiber grating (SFG) consisting of fiber Bragg grating (FBG) and long-period fiber grating (LPFG), there exist three kinds of coupling: the contra-directional coupling between forward prop... For the superstructure fiber grating (SFG) consisting of fiber Bragg grating (FBG) and long-period fiber grating (LPFG), there exist three kinds of coupling: the contra-directional coupling between forward propagating core mode and backward propagating core mode, the contra-directional coupling between core mode and cladding mode, and the co-directional coupling between core mode and cladding mode. By using the similarity transformation method for the coupled mode equations, the effects of three coupling coefficients κcoL, κclL, and κsL on the transmission and re- flection spectra of SFG have been investigated. The simulations show that the overall intensity of the transmission spectrum of SFG is decided by LPFG, that the main lobes of the transmission and reflectivity spectra of SFG are decided by coupling coefficients κcoL and κsL, and that the side lobes of the transmission and reflectivity spectra are decided by coupling coefficients κclL and κsL. 展开更多
关键词 superstructure fiber grating coupled mode theory coupling coefficient
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On the Couplings between Chebyshev Coefficients as Derived from the Monthly Mean Geopotential Fields at 500 hPa over East Asia and the Southern Oscillation
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作者 陈万隆 Chu Pao-Shin 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1990年第3期347-353,共7页
The first six Chebyshev polynomial coefficients (i.e., A00, A01, A10, A11, A02, A20) were derived from monthly mean geopotential height over East Asia for the period 1951-1983. Spectral analysis of these coefficients ... The first six Chebyshev polynomial coefficients (i.e., A00, A01, A10, A11, A02, A20) were derived from monthly mean geopotential height over East Asia for the period 1951-1983. Spectral analysis of these coefficients reveals relative maxima of power in the frequency bands of 200 months (- 16.7 years), 25 months (the quasi-biennial oscillation), 5-6 months, and 2-3 months. Cross-spectral characteristics between Chebyshev coefficients and the Southern Oscillation Index (SOI) were also explored. Coherence spectrum for the zonal and meridional circulation index (A01 and A 10) with the SOI was significant near 4 years, the QBO, and 2-3 months. Some physical explanations were offered for the spatial linkages (i.e., teleconnections) between the SO and atmospheric circulation anomalies overEast Asia. 展开更多
关键词 OVER On the couplings between Chebyshev coefficients as Derived from the Monthly Mean Geopotential Fields at 500 hPa over East Asia and the Southern Oscillation Asia
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Nondegenerate solitons of the(2+1)-dimensional coupled nonlinear Schrodinger equations with variable coefficients in nonlinear optical fibers
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作者 杨薇 程雪苹 +1 位作者 金桂鸣 王佳楠 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第12期170-178,共9页
We derive the multi-hump nondegenerate solitons for the(2+1)-dimensional coupled nonlinear Schrodinger equations with propagation distance dependent diffraction,nonlinearity and gain(loss)using the developing Hirota b... We derive the multi-hump nondegenerate solitons for the(2+1)-dimensional coupled nonlinear Schrodinger equations with propagation distance dependent diffraction,nonlinearity and gain(loss)using the developing Hirota bilinear method,and analyze the dynamical behaviors of these nondegenerate solitons.The results show that the shapes of the nondegenerate solitons are controllable by selecting different wave numbers,varying diffraction and nonlinearity parameters.In addition,when all the variable coefficients are chosen to be constant,the solutions obtained in this study reduce to the shape-preserving nondegenerate solitons.Finally,it is found that the nondegenerate two-soliton solutions can be bounded to form a double-hump two-soliton molecule after making the velocity of one double-hump soliton resonate with that of the other one. 展开更多
关键词 nondegenerate solitons variable coefficients coupled nonlinear Schr?dinger equations Hirota bilinear method
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The BTFR and MOND with Redshifts of Graviton Energy
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作者 Firmin J. Oliveira 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2024年第4期1903-1917,共15页
This report is about the graviton redshift theory (GRST) which hypothesises the redshift of the energy of gravitons traveling in fields. A new source of energy loss in galaxy dynamics is introduced. Due to the hypothe... This report is about the graviton redshift theory (GRST) which hypothesises the redshift of the energy of gravitons traveling in fields. A new source of energy loss in galaxy dynamics is introduced. Due to the hypothetical interactions of gravitons with the expansion of the universe, which causes an energy loss of the gravitons due to cosmological redshift, the rotation equation for galaxies, which previously had the Newtonian potential energy and the graviton gravitational redshift energy loss, is now updated with the graviton cosmological redshift energy loss. From the galaxy rotation equation, the baryonic Tully-Fisher relation (BTFR) and the modified Newtonian dynamics (MOND) are defined in radial distribution form. Fits to galaxy rotation motion are detailed. A cosmic connection for the BTFR is defined. The result is that galaxy rotation curves are fully accounted for with the GRST rotation equation and the BTFR and MOND theories are incorporated into a unified framework. 展开更多
关键词 GRAVITONS Gravitational Redshift Cosmological Redshift Graviton coupling coefficients Spiral Galaxies
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Principle of Cross Coupling Between Vertical Heat Turbulent Transport and Vertical Velocity and Determination of Cross Coupling Coefficient 被引量:5
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作者 陈晋北 胡隐樵 张镭 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2007年第1期89-100,共12页
It has been proved that there exists a cross coupling between vertical heat turbulent transport and vertical velocity by using linear thermodynamics. This result asserts that the vertical component of heat turbulent t... It has been proved that there exists a cross coupling between vertical heat turbulent transport and vertical velocity by using linear thermodynamics. This result asserts that the vertical component of heat turbulent transport flux is composed of both the transport of the vertical potential temperature gradient and the coupling transport of the vertical velocity. In this paper, the coupling effect of vertical velocity on vertical heat turbulent transportation is validated by using observed data from the atmospheric boundary layer to determine cross coupling coefficients, and a series of significant properties of turbulent transportation are opened out. These properties indicate that the cross coupling coefficient is a logarithm function of the dimensionless vertical velocity and dimensionless height, and is not only related to the friction velocity u., but also to the coupling roughness height zwo and the coupling temperature Two of the vertical velocity. In addition, the function relations suggest that only when the vertical velocity magnitude conforms to the limitation IW/u. I # 1, and is above the level zwo, then the vertical velocity leads to the cross coupling effect on the vertical heat turbulent transport flux. The cross coupling theory and experimental results provide a challenge to the traditional turbulent K closure theory and the Monin-Obukhov similarity theory. 展开更多
关键词 linear thermodynamic turbulent transportation atmospheric boundary layer coupling coefficients
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Coupling Between the Group—Related Coherent States
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作者 LIGuang-Hua HEHui-Yong 《Communications in Theoretical Physics》 SCIE CAS CSCD 2001年第1期1-6,共6页
When two representations of the Lie algebra are coupled, the coupling integral kernels are presented to relate the coupled to uncoupled group-related coherent states. These kernels have a connection with usual couplin... When two representations of the Lie algebra are coupled, the coupling integral kernels are presented to relate the coupled to uncoupled group-related coherent states. These kernels have a connection with usual coupling coefficients. The explicit expressions of these kernels for and are given. When the direct product of three representations is formed in two ways, the recoupling integral kernels relating to the coupled group-related coherent states corresponding to two different schemes are introduced, and the relations between these kernels and the general recoupling coefficients are obtained. The properties of these kernels are discussed. 展开更多
关键词 group-related coherent states coupling coefficients coupling integral kernel recoupling integral kernel
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Estimation of Mutual Coupling Coefficient of the Array by Simulated Annealing Algorithm 被引量:1
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作者 GAO Huo-tao ZHENG Xia LI Yong-xu 《Wuhan University Journal of Natural Sciences》 CAS 2005年第6期1000-1004,共5页
We propose a method for estimating the mutual coupling coefficient among antennas in this paper which is based on the principle of signal subspace and the simulated annealing (SA) algorithm. The computer simulation ... We propose a method for estimating the mutual coupling coefficient among antennas in this paper which is based on the principle of signal subspace and the simulated annealing (SA) algorithm. The computer simulation has been conducted to illustrate the' excellent performance of this method and to demonstrate that it is statistically efficient. The benefit of this new method is that calibration signals and unknown signals can be received simultaneously, during the course of calibration. 展开更多
关键词 mutual coupling coefficient from array estimation of mutual coupling coefficient simulated annealing(SA) algorithm
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EXPLICIT SOLUTIONS TO THE COUPLED KdV EQUATIONS WITH VARIABLE COEFFICIENTS 被引量:1
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作者 徐桂琼 李志斌 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2005年第1期101-107,共7页
By means of sn-function expansion method and cn-function expansion method, several kinds of explicit solutions to the coupled KdV equations with variable coefficients are obtained, which include three sets of periodic... By means of sn-function expansion method and cn-function expansion method, several kinds of explicit solutions to the coupled KdV equations with variable coefficients are obtained, which include three sets of periodic wave-like solutions. These solutions degenerate to solitary wave-like solutions at a certain limit. Some new solutions are presented. 展开更多
关键词 cn-function method sn-function method periodic wave-like solution solitary wave-like solution coupled KdV equations with variable coefficient
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Study on Wireless Power Transmission for Gastrointestinal Microsystems Based on Inductive Coupling 被引量:8
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作者 MA Guan-ying YAN Guo-zheng HE Xiu 《Chinese Journal of Biomedical Engineering(English Edition)》 2007年第2期71-78,共8页
Wireless power transmission based on inductive coupling for remotely implanted micro devices has been considered in this paper. The receiving coil, integrated in microsystems and the external transmitting coil compose... Wireless power transmission based on inductive coupling for remotely implanted micro devices has been considered in this paper. The receiving coil, integrated in microsystems and the external transmitting coil compose a loosely coupled transformer. The coupling coefficient was calculated and measured on spacing misalignments. The geometric size of transmitting coil was analyzed for the target of remotely delivering power. The received power was maximized by choosing appropriate value of frequency, tuning capacitance and the load resistance. A conventional full bridge rectifier circuit was employed to convert ac to dc voltage. The received dc power was up to 160 mW with a transmitting vohage of 5 Vrms when the receiving coil was placed at the center of the transmitting coil. This may meet the requirement of some microsystems for high power over a long time. 展开更多
关键词 power transmission gastrointestinal tract microsystems coupling coefficient
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Calculation of the Coupling Coefficient of Twin-Core Fiber Based on the Supermode Theory with Finite Element Method 被引量:1
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作者 Tianhao Zhao Wenhua Ren +1 位作者 Tingya Yin Fan Wang 《Optics and Photonics Journal》 2021年第8期402-411,共10页
<div style="text-align:justify;"> Currently, coupled mode theory (CMT) is widely used for calculating the coupling coefficient of twin-core fibers (TCFs) that are used in a broad range of important app... <div style="text-align:justify;"> Currently, coupled mode theory (CMT) is widely used for calculating the coupling coefficient of twin-core fibers (TCFs) that are used in a broad range of important applications. This approach is highly accurate for scenarios with weak coupling between the cores but shows significant errors in the strong coupling scenarios, necessitating the use of a more accurate method for coupling coefficient calculations. Therefore, in this work, we calculate the coupling coefficients of TCFs using the supermode theory with finite element method (FEM) that has higher accuracy than CMT, particularly for the strong coupling TCF. To investigate the origin of the differences between the results obtained by these two methods, the modal field distributions of the supermodes of TCF are simulated and analyzed in detail. </div> 展开更多
关键词 coupling Coefficient Twin-Core Fiber Supermode Theory Finite Element Method Coupled Mode Theory
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A design of resonant cavity with an improved coupling-adjusting mechanism for the W-band EPR spectrometer
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作者 Yu He Runqi Kang +2 位作者 Zhifu Shi Xing Rong Jiangfeng Du 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第11期115-120,共6页
We report a new design of resonant cavity for a W-band electron paramagnetic resonance(EPR)spectrometer.An improved coupling-adjusting mechanism,which is robust,compact,and suits with both solenoid-type and split-pair... We report a new design of resonant cavity for a W-band electron paramagnetic resonance(EPR)spectrometer.An improved coupling-adjusting mechanism,which is robust,compact,and suits with both solenoid-type and split-pair magnets,is utilized on the cavity,and thus enables both continuous-wave(CW)and pulsed EPR experiments.It is achieved by a tiny metal cylinder in the iris.The coupling coefficient can be varied from 0.2 to 17.9.Furthermore,two pistons at each end of the cavity allow for adjustment of the resonant frequency.A horizontal TE_(011) geometry also makes the cavity compatible with the two frequently used types of magnets.The coupling-varying ability has been demonstrated by reflection coefficient(S_(11))measurement.CW and pulsed EPR experiments have been conducted.The performance data indicates a prospect of wide applications of the cavity in fields of physics,chemistry and biology. 展开更多
关键词 electron paramagnetic resonance W-BAND microwave cavity coupling coefficient
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The influences of environmental factors on the air-sea coupling coefficient
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作者 Yanmin Zhang Yifan Wang +2 位作者 Yunhua Wang Yining Bai Chaofang Zhao 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2022年第2期147-155,共9页
The response relationship between equivalent neutral wind speed anomaly(ENWSA)and sea-air temperature difference anomaly(SATDA)has been analyzed over four typical sea regions,i.e.,the Kuroshio Extension,the Gulf Strea... The response relationship between equivalent neutral wind speed anomaly(ENWSA)and sea-air temperature difference anomaly(SATDA)has been analyzed over four typical sea regions,i.e.,the Kuroshio Extension,the Gulf Stream,the Brazil-Malvinas Confluence and the Agulhas Return Current.The results show that ENWSA is more sensitive to SATDA than sea surface temperature anomaly(SSTA),which implies that SATDA seems to be a more suitable parameter than SSTA to analyze the mesoscale air-sea interactions.Here,the slope of the linear relation between ENWSA and SATDA is defined as the air-sea coupling coefficient.It is found that the values of the coupling coefficient over the four typical sea areas have obvious seasonal variations and geographical differences.In order to reveal the reason of the seasonal variation and geographical difference of the coupling coefficient,the influences of some environmental background factors,such as the spatially averaged sea surface temperature(SST),the spatially averaged air temperature,the spatially averaged sea-air temperature difference and the spatially averaged equivalent neutral wind speed,on the coupling coefficient are discussed in detail.The results reveal that the background sea-air temperature difference is an important environmental factor which directly affects the magnitude of the coupling coefficients,meanwhile,the seasonal and geographical variations of the coupling coefficient. 展开更多
关键词 air-sea coupling coefficient SST equivalent neutral wind speed sea-air temperature difference
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Coupling characteristics of laterally coupled gratings with slots
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作者 Kun Tian Yonggang Zou +5 位作者 Linlin Shi He Zhang Yingtian Xu Jie Fan Hui Tang Xiaohui Ma 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第11期352-357,共6页
Laterally-coupled ridge-waveguide distributed feedback lasers fabricated without epitaxial regrowth steps have the advantages of process simplification and low cost.We present a laterally coupled grating with slots.Th... Laterally-coupled ridge-waveguide distributed feedback lasers fabricated without epitaxial regrowth steps have the advantages of process simplification and low cost.We present a laterally coupled grating with slots.The slots etched between the ridge and grating area are designed to suppress the lateral diffusion of carriers and to reduce the influence of the aspect-ratio-dependent-etching effect on the grating morphology in the etching process.Moreover,the grating height in this structure can be decreased to lower the aspect ratio significantly,which is advantageous over the conventional laterally coupled ridge waveguide gratings.The effects of five main structural parameters on the coupling characteristics of gratings are studied by MODE Solutions.It is found that varying the lateral width of the grating can be used as an effective way to tune the coupling strength;narrow slots(100 nm and 300 nm)and wide ridge(2μm–4μm)promote the stability of grating coupling coefficient and device performance.It is important to note that the grating bottom should be fabricated precisely.The comparative study of carrier distribution and mode field distribution shows that the introduction of narrow slots can strengthen the competitive advantage and stability of the fundamental mode. 展开更多
关键词 Bragg gratings distributed feedback(DFB)lasers coupling coefficient mode field distribution
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Theory and test of underground explosions:Coupling rule between cratering and ground shock
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作者 Wei Guo Jie Li +4 位作者 Benjun Shi Tianhan Xu Xiaohui Xu Gan Li Jie Shi 《Underground Space》 SCIE EI CSCD 2024年第4期146-160,共15页
Calculating the parameters of the ground shock induced by an underground explosion is a complex energy coupling problem.It is difficult to establish a unified ground shock coupling law from limited test data.This pape... Calculating the parameters of the ground shock induced by an underground explosion is a complex energy coupling problem.It is difficult to establish a unified ground shock coupling law from limited test data.This paper summarizes the research results obtained at home and abroad and systematically analyzes the coupling mechanism of craters formed by an underground explosion and the ground shock.The differences between the concepts of"closed-explosion critical depth"and"equivalent closed-explosion critical depth"are clearly explained.The spreading of the ground shock energy is attributed to the explosive expansion of the air cavity,revealing a linear relationship between the volume of the cavity region(or the volume of the crack region)and the ground shock energy associated with the underground explosion.The proportionality factor is related to the mechanical properties of the medium and is independent of the magnitude of the explosion equivalent.Based on this,a theoretical calculation formula and conversion method for the ground shock coupling coefficient were established.Explosion tests were conducted in clay and Plexiglass under varying burial depths.The test results were consistent with the theoretically calculated results.Our study provides a theoretical basis for the design of explosion-resistant structures in underground engineering. 展开更多
关键词 Underground explosion Ground shock coupling coupling coefficient Equivalent closed explosion Experimental study
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New Insights into the Action of Gravitons in Spiral Galaxies
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作者 Firmin J. Oliveira 《Journal of High Energy Physics, Gravitation and Cosmology》 2023年第4期968-983,共16页
New details of the action of gravitons in spiral galaxies are described. The effect of the graviton energy loss is hypothesized to be coupled to the baryon mass in the galaxy. From this relation, it follows that the b... New details of the action of gravitons in spiral galaxies are described. The effect of the graviton energy loss is hypothesized to be coupled to the baryon mass in the galaxy. From this relation, it follows that the baryonic Tully-Fisher relation is applicable to not just the final velocity of the galaxy but also to the rotational velocity at each radial position. In addition, a quadratic equation for the baryonic mass distribution is derived from the equation of motion. These results are demonstrated by making fits to galaxy rotation curves using a mass to light ratio model as well as the quadratic model for the mass distribution. 展开更多
关键词 GRAVITONS Gravitational Redshift Graviton coupling Coefficient Spiral Galaxies Mass to Light Ratio
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A New Type Four-Fold Microstrip Hairpin Line Bandpass Filter at 1.82 GHz for TranslReceive Communication Systems
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作者 Jagdish Shivhare Shail Bala Jain 《Journal of Electrical Engineering》 2014年第2期82-85,共4页
A conventional hairpin-line resonator size is normally very large. This paper presents the design, simulation/optimization and measured results of a four-resonator multi-folded hairpin line microstrip bandpass filter ... A conventional hairpin-line resonator size is normally very large. This paper presents the design, simulation/optimization and measured results of a four-resonator multi-folded hairpin line microstrip bandpass filter at 1.82 GHz, with great reduction in size compared to the conventional hairpin line structure. In the proposed filter, the cross couplings have been realized between adjacent and non-adjacent resonators. 展开更多
关键词 Miniaturized hairpin line multi-fold resonator selectivity coupling coefficients computed response ADS software.
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PROPAGATION OF SURFACE ACOUSTIC WAVES IN PRESTRESSED ANISOTROPIC LAYERED PIEZOELECTRIC STRUCTURES 被引量:5
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作者 Liu Hua Kuang Zhenbang +2 位作者 Cai Zhengming Wang Tiejun Wang Zikun 《Acta Mechanica Solida Sinica》 SCIE EI 2003年第1期16-23,共8页
The propagation of surface acoustic waves in layered piezoelectric structureswith initial stresses is investigated. The phase velocity equations are obtained for electricallyfree and shorted cases, respectively. Effec... The propagation of surface acoustic waves in layered piezoelectric structureswith initial stresses is investigated. The phase velocity equations are obtained for electricallyfree and shorted cases, respectively. Effects of the initial stresses on the phase velocity and theelectromechanical coupling coefficient for the fundamental mode of the layered piezoelectricstructures are discussed. Numerical results for the c-axis oriented film of LiNbO_3 on a sapphiresubstrate are given. It is found that the fractional change in phase velocity is a linear functionwith the initial stresses, and the electromechanical coupling factor increases with an increase ofthe absolute values of the compressive initial stresses. The results are useful for the design ofsurface acoustic wave devices. 展开更多
关键词 surface acoustic waves layered piezoelectric structure phase velocity electromechanical coupling coefficient
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Propagations of Rayleigh and Love waves in ZnO films/glass substrates analyzed by three-dimensional finite element method 被引量:3
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作者 王艳 谢英才 +1 位作者 张淑仪 兰晓东 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第8期468-473,共6页
Propagation characteristics of surface acoustic waves(SAWs) in ZnO films/glass substrates are theoretically investigated by the three-dimensional(3D) finite element method. At first, for(11ˉ20) ZnO films/glass ... Propagation characteristics of surface acoustic waves(SAWs) in ZnO films/glass substrates are theoretically investigated by the three-dimensional(3D) finite element method. At first, for(11ˉ20) ZnO films/glass substrates, the simulation results confirm that the Rayleigh waves along the [0001] direction and Love waves along the [1ˉ100] direction are successfully excited in the multilayered structures. Next, the crystal orientations of the ZnO films are rotated, and the influences of ZnO films with different crystal orientations on SAW characterizations, including the phase velocity, electromechanical coupling coefficient, and temperature coefficient of frequency, are investigated. The results show that at appropriate h/λ, Rayleigh wave has a maximum k^2 of 2.4% in(90°, 56.5°, 0°) ZnO film/glass substrate structure; Love wave has a maximum k^2 of 3.81% in(56°, 90°, 0°) ZnO film/glass substrate structure. Meantime, for Rayleigh wave and Love wave devices, zero temperature coefficient of frequency(TCF) can be achieved at appropriate ratio of film thickness to SAW wavelength. These results show that SAW devices with higher k^2 or lower TCF can be fabricated by flexibly selecting the crystal orientations of ZnO films on glass substrates. 展开更多
关键词 surface acoustic wave ZnO films electromechanical coupling coefficient temperature coefficientof frequency 3D finite element method
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