g******7
发帖数: 1433 | 1 2月份在国内住过一晚上，用的是Cash+Point，之前注册那个4000每晚的promotion前几
天拿到了4000点，酒店显示BONUS BEGINNINGS 1ST STAY(D2E)，请问这个bonus对应这
个promotion的？
有其他人也显示BONUS BEGINNINGS 1ST STAY(D2E)？ |
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N********n
发帖数: 8363 | 2
IBM's debt to equity ration is 130%. The worst in the industry. On the
other hand, AAPL's D2E is 0%. Great. GOOG's D2E is 7%. Solid. INTC 16%.
Fine. MSFT 23%. Fine. ORCL 36%. Fine.
Sound companies would not run up that much debt when there are funding
troubles everywhere and a global debt debacle going on. So stop acting
like a fool and learn how to read a balance sheet a little bit. |
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s*********n
发帖数: 18 | 4 我的方程如下：
U=2*Sin(alpha*t)
P=f1(e, de/dt, dphai/dt,theta,U) (关系式已知)
WX=Integrate (P*cos(theta)), theta varies in[0, pi]
WY=Integrate (P*sin(theta)), theta varies in[0, pi]
Fcos(phai)=WX(e,de/dt,dphai/dt)+m*(d2e/d2t)-m*e*(dphai/dt)*(dphai/dt) (1)
Fsin(phai)=WY(e,de/dt,dphai/dt)+m*e*(d2phai/d2t)+2*m*(de/dt)*(dphai/dt) (2)
Objective: Solve (1) and (2) for e(t) and phai(t).
Known: F, m,
Initial conditions: e(0)=0.5, phai(0)=0.5, de and dphai are assumed to be
zero.
My approa |
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s*********n
发帖数: 18 | 5 我的方程如下：
P=f1(e, de/dt, dphai/dt,theta) (关系式已知)
WX=Integrate (P*cos(theta)), theta varies among[0, 2*pi]
WY=Integrate (P*sin(theta)), theta varies among[0, 2*pi]
Fcos(phai)=WX(e,de/dt,dphai/dt)+m*(d2e/d2t)-m*e*(dphai/dt)*(dphai/dt) (1)
Fsin(phai)=WY(e,de/dt,dphai/dt)+m*e*(d2phai/d2t)+2*m*(de/dt)*(dphai/dt) (2)
Objective: Solve (1) and (2) for e(t) and phai(t).
Known: e(0)=0.5, e(2*pi)=0.5, phai(0)=0.5, phai(2*pi)=0.5,
de and dphai need to be assumed.
麻烦讲讲求解的步骤。多谢。 |
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c*****y
发帖数: 6 | 6 Thanks!
I have two further questions to trouble you.
(1) Why young's modulus is proportional to d2E/dr2 at r=req?
(2) Why at T2, the binding potential should be like the red curve? |
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F****y
发帖数: 145 | 7 (1) Why young's modulus is proportional to d2E/dr2 at r=req?
Consider a spring,
F=kx;
The potential energy E=1/2Kx^2;
K=d^2E/dx^2
(2) Why at T2, the binding potential should be like the red curve?
Generally,
Total energy = potential energy + kinetical energy
Kinetical energy = KT
T increasing results in the increase of kinetical energy and the decrease of
potential energy if total energy is conservation. |
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