The simple filters discussed so far are characterized either by a single passband and/or a single stopband There are applications where filters with multiple passbands and stopbands are required The comb filter is an example of such filters

1 一定量的理想气体，由平衡状态A变到平衡状态B（pA = pB），则无论经历的是什么过程，系统必然 （A）对外作功 （B）内能增加 （C）从外界吸热 （D）向外界放热

1一门宽为a,今有一固有长度为Lo(Lo>a) 的水平细杆,在门外贴近门的平面内沿其长度 方向匀速运动,若站在门外的观察者认为此杆 的两端可同时被拉进此门,则该杆相对于门的 运动速度υ至少为多少?

Stability Condition in Terms of the Pole Locations A causal LTI digital filter is BIBO stable if and only if its impulse response h[n] is absolutely summable, i.e., We now develop a stability condition in terms of the pole locations of the transfer function H(z)

1. Introduction : Problems with large programs 2.The Game of Life (a continuing example) 3. Programming style 4. Coding, Testing ,and Further Refinement 5. Program Maintenance 6. Preview (a) Software Engineering (b) Problem Analysis (c) Requirements Specification (d) Coding 7. Pointers and Pitfalls 8. References

9-3 在一半径为R1=6.0cm的金属球A外面套有一个同 心的金属球壳B，已知球壳B的内、外半径分别为 R2=8.0cm, R3=10.0cm.设球A带有总电荷QA=3.0  10 -8 C. 球壳B带有总电荷QB=2.0  10 -8 C

性质1(线性性)设f(x)和8(x)都在[a,b上可积,k1和k2是常数 小函数kf(x)+k2g(x)在a,b上也可积,且有 ∫k/(x)+k8(x)x=k(x)dx+Jg(x)x 证对anb的任意一个划分 q=x0