Excitation Function ofTa181(d,p)Ta182

Abstract

EDITOR 459The initial condition on H is that it be uniform throughout all space. The boundary condition is that H have a value Ho independent of time on the surface of the cylinder (r-ro). The solution of Eq. (1) subject to these conditions isxfj exp(a n 2 u)fy(u)-l]rf«|. (2) Here, we have R~r/c\ 0 *, T**/<TX 0 , X 0 /X(/)=/(T), a = r 0 /cAo*, ^(r)==exp|^J o /(«)d«J;and the aa n are the positive zeros of the bessel function Jo. One can show that Eq.(2) approaches asymptotically the wellknown solution HoJo(iR)/Jo(ia). The relaxation time for the nth summand in Eq. (2) iswhere j n -aa n . The longest relaxation time, r 0 , is of the order of milliseconds in a one-centimeter diameter cylinder.The supercurrent and the ordinary ohmic current can be calculated from Eq. (2). One finds that the asymptotic form of the supercurrent agrees with the solution obtained by F. and H. London, while the ohmic current goes to zero for large values of the time.An explicit solution of Eq. (1) with appropriate boundary conditions can also be obtained for the superconducting to normal transition. It can be shown that H approaches Ho asymptotically. The initial stages of the relaxation are rather complicated, since they depend in detail on the function /(r).Superconductivity can also be destroyed by passing a large current through a specimen. If the currents are parallel to the axis of the cylinder, the following equation for H can be derived:( 3) The displacement current has again been neglected. The solution of Eq. (3) subject to appropriate boundary and initial conditions iswhere the a/3 n are the zeros of J\. One sees from the form of the solution that the conclusions reached in the case of a constant external field hold without essential modification in this case also. Since the smallest zero of Ji is larger than that of /o, one can expect slightly smaller relaxation times in the constant current case. For large values of the time, H approaches asymptotically the known solution HoJi(iR)/Ji(ia).T HE excitation function of Ta. m (d, ^>)Ta 182 was measured 1 by the well-known stack foil technique. Forty 0.00025-in. thick (~10 mg/cm 2 ) Ta foils were bombarded with the deuteron beam from the University of Pittsburgh cyclotron. The energy of the Q 7 UJ UJ

Analysis of polymer viscoelastic properties based on compressive creep tests during hot embossing for two‐dimensional polyethylene terephthalate nanochannels

“…According to the experimental results in [20,24], the embossing time was considered to be more important than the embossing pressure, which is contrary to our results. However, when the polymer was imprinted by a nanomold, the influence of pressure on the polymer flow was greater than that of time [25]. The possible reason is that the filling behavior of polymer during the nano hot embossing process is different from that during micro hot embossing.…”