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The Bipolar Field-Effect Transistor:II.Drift-Diffusion Current Theory(Two-MOS-Gates on Pure-Base)
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作者 薩支唐 揭斌斌 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2007年第12期1849-1859,共11页
This paper describes the drift-diffusion theory of the bipolar field-effect transistor (BiFET) with two identical and connected metal-oxide-silicon-gates (MOS-gates) on a thin-pure-base. Analytical solution is obt... This paper describes the drift-diffusion theory of the bipolar field-effect transistor (BiFET) with two identical and connected metal-oxide-silicon-gates (MOS-gates) on a thin-pure-base. Analytical solution is obtained by partitioning the two-dimensional transistor into two one-dimensional problems coupled by the parametric sur- face-electric-potential. Total and component output and transfer currents and conductances versus D. C. voltages from the drift-diffusion theory, and their deviations from the electrochemical (quasi-Fermi) potential-gradient theory,are presented over practical ranges of thicknesses of the silicon base and gate oxide. A substantial contri- bution from the longitudinal gradient of the square of the transverse electric field is shown. 展开更多
关键词 bipolar field-effect transistor theory MOS field-effect transistor simultaneous electron and holesurface and volume channels surface potential~ longitudinal gradient of transverse electric field
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Phase velocity in 2D TTI media 被引量:6
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作者 Xuan Yihua He Qiaodeng Lin Yan 《Applied Geophysics》 SCIE CSCD 2007年第1期25-28,共4页
We derive an expression for phase velocity in 2D tilted transverse isotropy (TTI) media. Snapshots of phase velocity in TTI and transverse isotropy (TI) model media are simulated and analyzed using the derived exp... We derive an expression for phase velocity in 2D tilted transverse isotropy (TTI) media. Snapshots of phase velocity in TTI and transverse isotropy (TI) model media are simulated and analyzed using the derived expression. In addition, the x-component character differences between the modeled phase velocities of the two media models are compared and analyzed. 展开更多
关键词 tilted transverse isotropy TTI media transverse isotropy TI media phase velocity.
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The analysis and application of simplified two-parameter moveout equation for C-waves in VTI anisotropy media
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作者 李晓明 陈双全 李向阳 《Applied Geophysics》 SCIE CSCD 2013年第4期477-487,512,共12页
Several parameters are needed to describe the converted-wave (C-wave) moveout in processing multi-component seismic data, because of asymmetric raypaths and anisotropy. As the number of parameters increases, the con... Several parameters are needed to describe the converted-wave (C-wave) moveout in processing multi-component seismic data, because of asymmetric raypaths and anisotropy. As the number of parameters increases, the converted wave data processing and analysis becomes more complex. This paper develops a new moveout equation with two parameters for C-waves in vertical transverse isotropy (VTI) media. The two parameters are the C-wave stacking velocity (Vc2) and the squared velocity ratio (7v,i) between the horizontal P-wave velocity and C-wave stacking velocity. The new equation has fewer parameters, but retains the same applicability as previous ones. The applicability of the new equation and the accuracy of the parameter estimation are checked using model and real data. The form of the new equation is the same as that for layered isotropic media. The new equation can simplify the procedure for C-wave processing and parameter estimation in VTI media, and can be applied to real C-wave processing and interpretation. Accurate Vc2 and Yvti can be deduced from C-wave data alone using the double-scanning method, and the velocity ratio model is suitable for event matching between P- and C-wave data. 展开更多
关键词 Converted-wave moveout equation double-scanning ANISOTROPY normal moveout correction
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Numerical simulation of VIV for an elastic cylinder mounted on the spring supports with low mass-ratio
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作者 徐俊凌 朱仁庆 《Journal of Marine Science and Application》 2009年第3期237-245,共9页
With the development of the offshore deep water oil industry many researchers are focusing on the vortex-induced vibrations (VIV) of deep risers. In the present work, Reynolds-averaged Navier-Stokes (RANS) equatio... With the development of the offshore deep water oil industry many researchers are focusing on the vortex-induced vibrations (VIV) of deep risers. In the present work, Reynolds-averaged Navier-Stokes (RANS) equations were combined with the SST κ-ω turbulent model to simulate the stream-wise and transverse motion of an elastically mounted cylinder with a low mass-ratio, a natural frequency ratio of fx/fy = 1 and an Re number between 5 300 and 32 000, The four-order Runge-Kutta method was applied to solve the oscillating equation of the cylinder. The relationship between reduced velocity and parameters of the cylinder, including the lift coefficient, the drag coefficient, displacement and the vortex structure were then compared with recent experimental results and discussed in detail. The present numerical simulation reproduced effects have been observed in experiments, such as the lock-in phenomenon, the hysteretic phenomenon and beating behavior. 展开更多
关键词 VIV low mass ratio stream-wise and transverse motion TWO-DEGREE-OF-FREEDOM vortex shedding model CFD
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Asymmetric Green's functions for exponentially graded transversely isotropic substrate–coating system
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作者 F.Akbari A.Khojasteh M.Rahimian 《Journal of Central South University》 SCIE EI CAS CSCD 2018年第1期169-184,共16页
By virtue of a complete set of two displacement potentials,an analytical derivation of the elastostatic Green’s functions of an exponentially graded transversely isotropic substrate–coating system is presented.Three... By virtue of a complete set of two displacement potentials,an analytical derivation of the elastostatic Green’s functions of an exponentially graded transversely isotropic substrate–coating system is presented.Three-dimensional point–load and patch–load Green’s functions for stresses and displacements are given in line-integral representations.The formulation includes a complete set of transformed stress–potential and displacement–potential relations,with utilizing Fourier series and Hankel transforms.As illustrations,the present Green’s functions are degenerated to the special cases such as an exponentially graded half-space and a homogeneous two-layered half-space Green’s functions.Because of complicated integrand functions,the integrals are evaluated numerically and for numerical computation of the integrals,a robust and effective methodology is laid out which gives the necessary account of the presence of singularities of integration.Comparisons of the existing numerical solutions for homogeneous two-layered isotropic and transversely isotropic half-spaces are made to confirm the accuracy of the present solutions.Some typical numerical examples are also given to show the general features of the exponentially graded two-layered half-space Green’s functions that the effect of degree of variation of material properties will be recognized. 展开更多
关键词 functionally graded material transversely isotropic BI-MATERIAL Green’s function coating-substrate displacement potential
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High accuracy NMO correction and application for VTI media
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作者 ZHANG Bo HAN Liguo +2 位作者 TAN Chenqing HUANG Fei HAN Shoufu 《Global Geology》 2012年第1期78-84,共7页
It is difficult for normal moveout(NMO)correction of shallow long offset of vertical transversely isotropic medium,as seismic event after conventional NMO correction experienced strong stretching and distortion due to... It is difficult for normal moveout(NMO)correction of shallow long offset of vertical transversely isotropic medium,as seismic event after conventional NMO correction experienced strong stretching and distortion due to interleaving of signal.Even using higher order non-hyperbolic NMO correction,it still cannot get the right results.This paper aims to improve the accuracy of NMO correction.Based on the analysis of conventional NMO correction method and previous optimization move-out equation,we use longitudinal optimization method to correct seismic event.The results of the theoretical model and the real data show that our method can completely remove NMO stretching and greatly improve correction accuracy. 展开更多
关键词 long offset VTI NMO stretch longitudinal optimization
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Flexural behavior of in-plane bending glass structures for design method
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作者 吴丽丽 王元清 +2 位作者 严茂超 石永久 张恒秋 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第8期3133-3140,共8页
Experimental study was carried out on the in-plane bending behavior of glass plates without lateral supports, and the effects of the factors, such as height-to-span ratio, on the stability of glass panels were studied... Experimental study was carried out on the in-plane bending behavior of glass plates without lateral supports, and the effects of the factors, such as height-to-span ratio, on the stability of glass panels were studied. Results show that the in-plane bending glass plates with both ends simply supported and their upper edge free lose overall stability under loads, which belongs to the limit-point type of instability. It is found that the buckling load increases linearly with the increase of height-to-span ratio of the glass plates. The lateral stress of in-plane bending glass plates without lateral supports increases linearly under loads; while the large-area stress increases nonlinearly and the lateral stress is not the controlling factor of instability. In finite element analysis, the first buckling mode is regarded as the initial imperfection and imposed on the model as 1/1000 of the span of the components. The numerical buckling load according to the theory of large deflection is less than the experiment result, which is more conservative and can provide some reference for design. For the design method, when the in-plane load is imposed on the glass plate, its lateral strength and the deflection should be verified. Considering the stability of the in-plane bending glass plate without reliable lateral support, buckling is another possible failure mode and calls for verification. 展开更多
关键词 load-bearing glass structure flexural performance in-plane bending BUCKLING
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从人性假设的视角探究管理思想回归的内在历史逻辑 被引量:11
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作者 高小玲 刘巨钦 《管理科学》 2003年第4期25-31,共7页
在对管理思想历程作内在逻辑的流变而完整的把握、把管理思想的精髓与现实经济生活的最新发展联系起来的基础上 ,追寻出管理思想在时间维度上逐步人性化、在空间维度上由中方向西方再向中方回归的内在历史逻辑 ,为建立既源于古代管理思... 在对管理思想历程作内在逻辑的流变而完整的把握、把管理思想的精髓与现实经济生活的最新发展联系起来的基础上 ,追寻出管理思想在时间维度上逐步人性化、在空间维度上由中方向西方再向中方回归的内在历史逻辑 ,为建立既源于古代管理思想又符合潮流的中国式管理理论体系提供整体指导。 展开更多
关键词 历史向度 横向向度 三重属性 中国式管理
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Experimental investigation on flow characteristics of a transverse jet with an upstream vortex generator 被引量:1
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作者 Yan-hui ZHAO Jian-han LIANG +3 位作者 Shun-ping ZHANG Hong-yu REN Yu-xin ZHAO Shun-hua YANG 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2020年第8期636-651,共16页
This paper aims at probing the flow characteristics of a jet in supersonic crossflow(JISC)by installing a vortex generator(VG)upstream of the jet orifice.Nanoparticle planar laser scattering(NPLS)and stereo-particle i... This paper aims at probing the flow characteristics of a jet in supersonic crossflow(JISC)by installing a vortex generator(VG)upstream of the jet orifice.Nanoparticle planar laser scattering(NPLS)and stereo-particle image velocimetry(SPIV)technologies were employed to observe the flowfield,and three cases were designed for comparison.CASE0 stands for JISC without passive VG.In CASE1 and CASE2,VG is installed at 20 mm and 80 mm upstream away from the jet orifice,respectively.Transient flow structures show that two flow modes exist when the VG wake interacts with the JISC.In CASE1,vortices are induced from both sides of the jet plume because of the VG wake.This leads to a complex streamwise vortex system.Penetration and lateral diffusion are enhanced.In CASE2,intermittent large-scale eddies in the VG wake cause large streamwise vortices at the windward side of the jet.The penetration depth is also enhanced while the lateral diffusion is restrained.In addition,experimental results show that the penetration depth is approximately 8.5%higher in CASE1 than that in CASE0,and the lateral diffusion is larger by about 17.0%.In CASE2,the penetration is increased by about 26.2%,while the lateral diffusion is enhanced by just 0.5%. 展开更多
关键词 Vortex generator(VG) Jet in supersonic crossflow(JISC) Penetration depth and lateral diffusion Vortices structures
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Quantum Correlations in Infinite XY Spin-1/2 Chains and Quantum Phase Transition 被引量:2
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作者 谭小东 黄寿胜 金柏琪 《Communications in Theoretical Physics》 SCIE CAS CSCD 2013年第2期146-156,共11页
We examine the ability of quantum discord (QD) and entanglements (concurrence, EoF and negativity) to detect the critical points associated to quantum phase transitions (QPTs) for XY models, i.e., the isotropic XY mod... We examine the ability of quantum discord (QD) and entanglements (concurrence, EoF and negativity) to detect the critical points associated to quantum phase transitions (QPTs) for XY models, i.e., the isotropic XY model with three-spin interactions at zero temperature, and the anisotropic XY model in a transverse magnetic field h at finite temperatures. For the case of zero temperature, we found that both entanglements and QD can spotlight the critical points of QPTs for these two models. Moreover, QD versus distance M exhibits the long-range behavior of quantum correlation for the anisotropic XY model, while entanglement is short-ranged. For the case of finite temperatures, we found that negativity has the same behaviors with concurrence at or near transition points. Moreover, QD for the anisotropic XY model can increase with temperature even in the absence of a magnetic field. 展开更多
关键词 thermal quantum discord quantum phase transition XY model
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