x2−kx+k2−4=0. (1) Find the value of k such that both the solutions to the equation are positive; (2) Find the value of k such that there is only one positive solution to this equation.相关知识点: 试题来源: 解析 设关于 x 的一元二次方程 x2−kx+k2−4=0 的两个实根为...
In summary, a GNN model has been developed for predicting the effective properties of polycrystalline materials, where a polycrystalline microstructure is represented by a graph. Using the effective magnetostriction of Terfenol-D alloys as an example, the GNN model demonstrates a low relative error of...
(⋅; r) depends onΨ(r) and its derivative, and has no internal degrees of freedom. Since the quantum Hall system hasU(1) and translation symmetries, we impose them on the nonlinear equation to study the analogy of such a prototypical topological insulator. Concretely, theU(1) ...
Therefore, all influx contributions are neglected in equation (5). In general, only linear processes possess a constant half-life. Otherwise, the half-life depends on the initial concentration x i 0 and is therefore time-dependent. In this case, the above procedure is repeated for a series ...
Z(k,ω)=Rρ(0)ω(ω2cs−2−k2)[ω2m(k,ω)+ig(k2−0.5ω2γcs−2)], (6) whereρ(0) andR ~ 1.3 × 10−3are the water density and the ratio of the air and water densities at the ocean surface. In Equation (6), the sign of the vertical componentm(k...
d2(rP)dr2+k2(rP)=0,d2(rP)dr2+k2(rP)=0,and the general solution is: rP=Q+e−jkr+Q−ejkr.rP=Q+e-jkr+Q-ejkr. Using the Euler equation, ∂rP=−jkρcV∂rP=-jkρcV, where ρ is the air density, the particle velocity V is given by, Vρcr=Q+e−jkr−Q−e...
The ball has reference frame (Ball) and a sensor (Sensor). Ball and Sensor are rigidly linked.Sensoris a sensor of Fan pneumatic field. Output of Sensor is used (throughDisass) in differential equationsEquation. Otherwise Equation result is used for the reference frameBallmotion simulation. ...
Their approach exploited high- energy X-ray scattering to perform pair distribution function (PDF) analysis, truncation rod analysis and simulations using the Debye equation to show that lower pH causes migration of Mn from were the MnO2 nanosheet to the sheet surface. Thus, able to quantify Mn...
Without a barrier, such a wave packet has the form (ℏ = 1) $$\psi ^0(x,t) = {\int} A(k)\exp [ikx - iE(k)t]{\rm{d}}k = {\mathrm{exp}}[ipx - iE(p)t]G(x,t),$$ (3) where we have separated the smooth envelope G, which will play an important part in...
A spring-mass system has natural frequency of 5 r/s. It subjects to a damping ratio of 0.2 when placed in the air. Given initial conditions {x(0=0),& =0.5 m/s},determine the system?s frequency of v Cons...