Recent content by Jamalll

  1. J

    Wiegner Eckart theorem, I don't understand it

    Well I am sorry but there is not a single mind which can desolve this? Baby I am only human! please...pretty plase
  2. J

    Quasicrystals, explain those terms please

    I have been reading this article and google-ing and still nothing, so here it goes What is: -P-type icosahedral? -Tsai-type quasicrystal? -1/1 cubic approximant? -six-dimensional lattice parameter a6D? -why has (this is example) powder X-ray diffraction spectrum just 2 high...
  3. J

    Wiegner Eckart theorem, I don't understand it

    hey, thanks for reply... But I still can not make any sense out of it... I know I repeat myself, but how do you "convert" coordinates in spin operator? What is the significance of "m" and" m' "? I know it is the state of nucleus with spin "I" and spin projection "m", right?
  4. J

    Wiegner Eckart theorem, I don't understand it

    Hello, In derivation of quadrupole effect (which influences NMR spectrum for nuclei with spin ≥ 1/2), there is one step I do not understand, it is Eckart Wiegner theorem, more specific: just relavant equations: Qαβ=∫(3xαxβ-δαβr2)ρdr So here is the W-E...
  5. J

    Mathematical physics, density of probability

    ok, I really appreciate your effort, but now I am really convinced I shall kill myself. Sorry. I mean, there is not a single person who can solve this, and I am on the verge of extinction. And this is not even for 7 out of 10. Obviously I can not finish my colledge. I AM JUST TOO STUPID! (and...
  6. J

    Mathematical physics, density of probability

    sstarting point should be of the form: ths sum goes for black and transperent I(D)=Ʃρ(d)exp(-μd)I(D-d) can anyone solve this? This is from mathematical physics, we had poisson, binomial distributions etc...
  7. J

    Mathematical physics, density of probability

    Yes, you are right, let us say there are "blocks", layers of them. But each layer is either "transparent" either "black" (this is binomially distributed) AND the thickness of each layer (d) is distributed lie this: ρ(d)=1/λexp(-λd) The question is, how is intensity that goes through dependent...
  8. J

    Mathematical physics, density of probability

    mathematical physics, density of probability, please help! Homework Statement My problem is a problem of light going through 1: two different media, each with it's own absorption coefficient (let us say "black" ones have μ and "transparent" have 0. ) 2: when light passes through...
  9. J

    Mathematical physics, density of probability

    exactly! number of black blocks follows binomial distribution which goes into Poisson distribution if the number of blocks is large (which we can take for granted), stil there is p=0.5 chance, but for Poissonian dist it has to be small enough so <N>=Z*p stays constant...so I am not sure about...
  10. J

    Mathematical physics, density of probability

    well this is great, sounds it is the right path. However, the real problem lies in ρ(a). If we have just distribution for each individual block thickness (x), say w(x)= k*exp(-k*x), how can we get probability, ρ(a), that the SUM over black blocks equals a?
  11. J

    Mathematical physics, density of probability

    I actually got a tip (quite reliable), that the easiest way is to start with x...is the thickness of the "whole thing" a...somewhere between 0 and x, it could be either black block or transparent one I(x)=Ʃ(w(a)*exp(-c*a)*I(x-a))+W(x)*exp(-c*x) the sum goes through all black and...
  12. J

    Mathematical physics, density of probability

    @clamtrox really appreciate your replies, but it is not laziness that got me here. I have been working on this for months (really!), and I came with one solutionof convolution of densities of probability in the sense l= thickness if dP/dl= g(l)=k*exp(-k*l)...this is desnity of...
  13. J

    Mathematical physics, density of probability

    well not exactly: when it goes through one block (length x1), it diminishes I=I(o)exp(-c*x1) when it goes through another (x2) I=I(o)exp(-c*x2)...etc but in half cases there are transparent blocks, and the lengths (x1, x2, ...) are distributed exponentially I know this one is not...
  14. J

    Mathematical physics, density of probability

    Homework Statement So I have to calculate the transmission of light, which goes through random black and "transparent" blocks (p=0.5), but the thickness (x) of each block is distributed exponentially dP/dx=1/t*exp(-x/t). When light goes through black block, it diminishes (I stands for...
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