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1.
An analogy is uncovered between the nuclear reaction rate in a dense neutral plasma and the energy equipartition rate in a strongly magnetized non-neutral plasma. In strong magnetic fields, cyclotron energy, like nuclear energy, is released only through rare close collisions between charges. The probability of such collisions is enhanced by plasma screening effects, just as in nuclear reactions. Enhancements of up to 10(10) are measured in simulations of cyclotron energy equipartition and are compared to the theory of screened nuclear reactions.  相似文献   
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Gel permeation chromatograms of a hindered-phenolic, branched condensation polymer display pronounced bimodality at high conversion. The true molecular weight distributions, obtained by means of a GPC calibration curve based on narrow-distribution fractions, exhibit corresponding anomalous high-molecular-weight “shoulders.” These results are discussed in terms of preferential aggregation and reaction of the higher-molecular-weight species during the polymerization, promoted by intermolecular hydrogen bonding in the apolar reaction medium.  相似文献   
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Deep-inelastic structure functions W1 and W2 have been extracted from electron-proton scattering cross sections that were measured in recent experiments at SLAC. The structure functions display deviations from scaling in the variable ω in the kinetic range 1.5 ? ω ? 3.0 and 2 ? Q2 ? 15 GeV2.  相似文献   
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Proton pulsed field gradient (PFG) NMR was used to study the diffusion of poly(diallyldimethylammonium chloride) (PDADMAC) in coacervates formed from this polycation and the protein bovine serum albumin (BSA). Application of high (up to 30 T/m) magnetic field gradients in PFG NMR measurements allowed probing the diffusion of PDADMAC on a length scale of displacements as small as 100 nm in coacervates formed at different pH's and ionic strengths, i.e., conditions of varying protein-polycation interaction energy. Studies were carried out for a broad range of diffusion times and corresponding values of the mean square displacements. Several ensembles of PDADMAC polycations with different diffusivities were observed in the measured range of diffusion times. The existence of these ensembles and the pattern of their changes with increasing diffusion time support the hypothesis about the microscopic heterogeneity of PDADMAC-BSA coacervates and also provide evidence for the dynamic disintegration and reformation of dense domains.  相似文献   
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Protein adsorption was studied by in-situ ATR-FT-IR spectroscopy of consecutively deposited polyelectrolyte multilayer systems terminated either with poly(ethyleneimine) (PEI) or polyanions, such as poly-(acrylic acid) (PAC), poly(maleic acid-co-propylene) (PMA-P) or poly(vinyl sulfate) (PVS). The influence of the polyanion type, pH and ionic strength was investigated. Negatively charged human serum albumin (HSA) was strongly repelled by multilayers terminated with weak polyanions (PAC, PMA-P), whereas moderate attraction was observed for those terminated with the strong polyanion PVS. Changing the pH from 7.4 to 5 resulted in enhanced HSA adsorption onto PAC-terminated multilayers. An increase in ionic strength diminished the attractive HSA adsorption onto PEI-terminated multilayers. For the PEI/PAC system, the biomedically relevant adsorption of human fibrinogen (FGN) is determined via its isoelectric point in accordance with three other proteins.  相似文献   
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We discuss briefly the basic (integrable)representation of the ucr, comprising the operators A ,its adjoint A+, and N (which is equal toN+), satisfying AN – NA = A. There areno additional relations between the operators, in general. The ucrinclude the ccr, car, deformed bosons and fermions, andmany other systems as special cases. The principalstructure theorem asserts that every integrablerepresentation of the ucr is determined by a sequencegeneralizing the [n]-sequence of deformationtheory.  相似文献   
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