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Benchmark measurements of the ionization balance of non-local-thermodynamic-equilibrium gold plasmas
Heeter RF Hansen SB Fournier KB Foord ME Froula DH Mackinnon AJ May MJ Schneider MB Young BK 《Physical review letters》2007,99(19):195001
We present a series of benchmark measurements of the ionization balance of well-characterized gold plasmas with and without external radiation fields at electron densities near 10{21} cm{-3} and electron temperatures spanning the range 0.8 to 2.4 keV. We have analyzed time- and space-resolved M-shell gold emission spectra using a sophisticated collisional-radiative model with hybrid level structure, finding average ion charges Z ranging from 42 to 50. At the lower temperatures, the spectra exhibit significant sensitivity to external radiation fields and include emission features from complex N-shell ions. The measured spectra and inferred Z provide a stringent test for non-local-thermodynamic-equilibrium models of complex high-Z ions. 相似文献
154.
Mallard Chatelier Angus Smith und G. Forbes 《Fresenius' Journal of Analytical Chemistry》1880,19(1):474-476
Ohne Zusammenfassung 相似文献
155.
Reversed-phase nonporous silica (RP-NPS) of 1.5 microm dp is employed to demonstrate rapid and efficient separations in packed capillary electrochromatography (CEC). Two methods for packing capillaries and two techniques to manufacture frits used to hold the packing in place are evaluated for their effect upon separation performance using polyaromatic hydrocarbons (PAHs) and polar neutral pharmaceutical compounds. Attention is given to conditioning of the packed capillaries for high efficiency separations without necessity for sodium dodecyl sulfate (SDS). Separation conditions for the nonporous materials were modified from those previously determined on porous reversed-phase silica. Feasibility for method development and validation of a parent pharmaceutical compound and related impurities in the range of 0.1-120% of a 5 mg/mL concentration was assessed and reported. An approach to improving detection sensitivity through use of large-bore capillaries is briefly discussed. 相似文献
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157.
Local hydrodynamics of solvent near diffusing dendrimers: A test of the new Stokes–Einstein relation
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We have reported a new Stokes–Einstein relation (SER) for size determination and tested it by different nanoparticles. We assumed that the breakdown for SER results from local increases in viscosity. Here we investigate hydrodynamics of solvent near dendrimers to further test generality of our new theory. We discuss simulations of dendrimers in comparison to nanoparticles, experimental data on dendrimers from literature, and our theory. Local viscosity and local diffusivity of solvent near dendrimers are estimated by persistence times and exchange times, respectively. We find that the local dynamics of solvent near dendrimers of low density stay almost the same as that of bulk solvent. While the motions of solvent particles slow down near dendrimers of high density. This is similar with changes in local dynamics of solvent near nanoparticles. According to the causes we proposed for the deviation of SER, this is consistent with our findings that the SER works for the dendrimers of low density, while it fails for the dendrimers of high density. The new SER is then tested to predict size of the dendrimers accurately. Taking this together with the results for the nanoparticles, we believe that the new theory is general. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55, 1380–1392 相似文献
158.
T. Repsilber M. Borghesi J.-C. Gauthier K. Löwenbrück A. Mackinnon V. Malka P. Patel G. Pretzler L. Romagnani T. Toncian O. Willi 《Applied physics. B, Lasers and optics》2005,80(7):905-913
A method for obtaining quantitative information about electric field and charge distributions from proton imaging measurements
of laser-induced plasmas is presented. A parameterised charge distribution is used as target plasma. The deflection of a proton
beam by the electric field of such a plasma is simulated numerically as well as the resulting proton density, which will be
obtained on a screen behind the plasma according to the proton imaging technique. The parameters of the specific charge distributions
are delivered by a combination of linear regression and nonlinear fitting of the calculated proton density distribution to
the measured optical density of a radiochromic film screen changed by proton exposure. It is shown that superpositions of
spherical Gaussian charge distributions as target plasma are sufficient to simulate various structures in proton imaging measurements,
which makes this method very flexible. 相似文献
159.
L. Mackinnon 《Foundations of Physics》1978,8(3-4):157-176
It is assumed that the motion of a particle in spacetime does not depend on the motion relative to it of any observer or of any frame of reference. Thus if the particle has an internal vibration of the type hypothesized by de Broglie, the phase of that vibration at any point in spacetime must appear to be the same to all observers, i.e., the same in all frames of reference. Each observer or reference frame will have its own de Broglie wave for the particle. The phase of the particle's vibration must, by definition, be the same as that of all possible de Broglie waves at the point where the particle is. By superimposing all these possible de Broglie waves, a wave packet is formed centered in space on the particle. The formation of such a packet is discussed with the help of spacetime diagrams; the packet does not spread with time. The relevance of this packet to the wave mechanics of Schrödinger is discussed; it is also pointed out that any vibration can lead to such a packet. 相似文献
160.