Recent content by runnerwei

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    Graduate X ray questions:What material is suitable in windows for hard X-rays?

    What material is suitable in windows for hard X-rays? What material would you choose as reflective coating of X-rays mirrors for radiation at 200 eV? Why?
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    Graduate B and H field for a long rod and a disk

    What dose BC mean?
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    Graduate B and H field for a long rod and a disk

    What dose BC mean?
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    Graduate B and H field for a long rod and a disk

    It is something related to the concept demagnetization. For a ellipse, the demagnetizating factor is the same everywhere.
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    Graduate B and H field for a long rod and a disk

    As shown in the figure attached. If both have the magnetization M, what will the B field and H fied for each object look like? why? I have no hint how to answear this question, can anyone help? any reply highly appreciated.
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    Graduate How to reach the conclusion that L=0 and S=0 if the shell is filled?

    The text says that the spin momenta of those electrons cancel each other so S=0. The text also says that the orbital momenta of those electrons cancel each other so L=0. But, if there are electrons with quantum numbers (l1,s1) and (l2,s2), using S-L coupling, the L=l1+l2,l1+l2-1,...\l1-l2\...
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    Graduate Why filled shell of electrons has L=0 and S=0?

    As according to the coupling rule, the allowed values for S is S=s1+s2,s1-s2. As s1=s2=1/2, S can have two values, 0 and 1. So how would they say that S=0, rather than S=1?
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    Graduate Why filled shell of electrons has L=0 and S=0?

    The text says that the spin momenta of those electrons cancel each other so S=0. The text also says that the orbital momenta of those electrons cancel each other so L=0. But, if there are electrons with quantum numbers (l1,s1) and (l2,s2), using S-L coupling, the L=l1+l2,l1+l2-1,...\l1-l2\...