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1.
The angular variations of the five-fold differential cross section obtained by using different wave functions of helium are
compared with experimental data. It is found that in the coplanar geometry two kinematical arrangements, (i) equal energy
sharing between the two ejected electrons with one of them ejected along the momentum transfer direction and the other along
varying direction and (ii) the Bethe ridge condition with fixed sum of ejected electron energies and varying angle between
them, are very sensitive to e-e correlations contained in the target wave function. This comparison has been used to show
that open-shell class of wave functions better incorporate e-e correlations than the closed-shell class. 相似文献
2.
The aim of this brief report is to study the behaviour of sheath structure in a multi-component plasma with dust-neutral collisions.
The plasma consists of electrons, ions, micron size negatively charged dust particles and neutrals. The sheath-edge potential
and sheath width are calculated for collisionally dominated sheath. Comparison of collisionless and collisionally dominated
sheath are made. 相似文献
3.
Christopher J. Orme John R. Klaehn Mason K. Harrup Thomas A. Luther Eric S. Peterson Frederick F. Stewart 《Journal of membrane science》2006,280(1-2):175-184
The synthesis, characterization, and gas permeability of 10 new polyphosphazenes has been studied. Additionally, the first gas permeation data has been collected on hydrolytically unstable poly[bis-(chloro)phosphazene]. Gases used in this study include CO2, CH4, O2, N2, H2, and Ar. CO2 was the most permeable gas through any of the phosphazenes and a direct correlation between the Tg of the polymer and CO2 transport was noted with permeability increasing with decreasing polymer Tg. To a lesser degree, permeability of all the other gases studied also yielded increases with decreasing polymer Tg. The trend observed for these new polymers was further supported by published data for other phosphazenes. Furthermore, permeability data for all gases were found to correlate to the gas condensability and the gas critical pressures, except for hydrogen, suggesting that the nature of the gas is also a significant factor for permeation through rubbery phosphazene membranes. Ideal separation factors () for the CO2/H2 and CO2/CH4 gas pairs were calculated. For CO2/CH4, no increase in was observed with decreasing Tg, however increases in were noted for the CO2/H2 pair. 相似文献
4.
The symmetric sinc-Galerkin method developed by Lund, when appliedto the second-order self-adjoint boundary value problem, givesrise to a symmetric coefficient matrix has a special structureso that it can be advantageously used in solving the discretesystem. In this paper, we employ the preconditioned conjugategradient method with banded matrices as preconditioners. Weprove that the condition number of the preconditioned matrixis uniformly bounded by a constant independent of the size ofthe matrix. In particular, we show that the solution of an n-by-ndiscrete symmetric sinc-Galerkin system can be obtained in O(nlog n) operations. We also extend our method to the self-adjointelliptic partial differential equation. Numerical results aregiven to illustrate the effectiveness of our fast iterativesolvers. 相似文献
5.
The angular distribution of the five-fold differential cross section for the electron impact double ionization of He (21
S) and He (23
S) has been studied. The kinematical conditions for maxima/minima in the angular distribution for the two cases have been compared.
The two-step process for the double ionization is found to contribute very little in the triplet case. 相似文献
6.
MK Bhide RM Kadam MD Sastry Ajay Singh Shashwati Sen Manmeet Kaur DK Aswal SK Gupta VC Sahni 《Pramana》2002,58(5-6):799-802
Microwave absorption studies have been carried out on MgB2 superconductor using a standard X-band EPR spectrometer. The modulated low-field microwave absorption signals recorded for
polycrystalline (grain size ∼ 10 μm) samples suggested the absence of weak-link character. The field dependent direct microwave
absorption has been found to obey a ✓H dependence with two different slopes, which indicated a transition from strongly pinned lattice to flux flow regime. 相似文献
7.
Mason K. Harrup Michael G. Jones Linda Polson Byron White 《Journal of Sol-Gel Science and Technology》2008,47(3):243-251
Investigations were performed into the suitability of novel composites to serve as materials for subsurface permeable reactive
barriers (PRBs). These new materials are Type I composites—they are preformed organic polymers embedded in an inorganic matrix
without significant covalent bonding between the components. The required properties for these materials to function efficiently
are: (1) a tunable water passing rate to approximate the hydraulic conductivity of the subsurface environment where the PRB
will be placed, (2) sufficient mechanical strength (both wet and dry) to maintain barrier integrity, (3) the ability to incorporate
selective metal sequestration agents so that they remain active—yet do not leach from the barrier, and (4) to be deployable
through direct injection methods such that trenching is not needed. Additionally, there is a need to keep the technology as
low cost as possible, while remaining reliable. Results recently obtained in our laboratory show that our materials, remarkably,
exhibit all of these properties and show great promise as vadose zone deployable PRBs. 相似文献
8.
Dean R. Peterman Leigh R. Martin John R. Klaehn Mason K. Harrup Mitchell R. Greenhalgh Thomas A. Luther 《Journal of Radioanalytical and Nuclear Chemistry》2009,282(2):527-531
A new extractant for the separation of actinide(III) and lanthanide(III) cations, bis(o-trifluoromethylphenyl) phosphinic acid (2) was synthesized. The synthetic route employed mirrors one that was employed to produce the sulfur containing analog bis(o-trifluoromethylphenyl) dithiophosphinic acid (1). Classic radiochemical methods and absorbance spectroscopy were used to study the coordination chemistry of the Am-dithiophosphinic
acid and Am-phosphinic acid complexes. 相似文献
9.
MK Hossain-Ibrahim K Rezajooi JK MacNally MRJ Mason AR Lieberman PN Anderson 《BMC neuroscience》2006,7(1):8-21
Background
Inflammation around cell bodies of primary sensory neurons and retinal ganglion cells enhances expression of neuronal growth-associated genes and stimulates axonal regeneration. We have asked if inflammation would have similar effects on corticospinal neurons, which normally show little response to spinal cord injury. Lipopolysaccharide (LPS) was applied onto the pial surface of the motor cortex of adult rats with or without concomitant injury of the corticospinal tract at C4. Inflammation around corticospinal tract cell bodies in the motor cortex was assessed by immunohistochemistry for OX42 (a microglia and macrophage marker). Expression of growth-associated genes c-jun, ATF3, SCG10 and GAP-43 was investigated by immunohistochemistry or in situ hybridisation. 相似文献10.
González-Rivera Carlos Harrup Anthony Aguilar Carla Amaro-Villeda Adrián M. Ramírez-Argáez Marco A. 《Journal of Thermal Analysis and Calorimetry》2020,140(4):1825-1836
Journal of Thermal Analysis and Calorimetry - In this work, a new computer-aided cooling curve analysis method (CA-CCA) called metal/mold energy balance method (MEB) is presented. Its originality... 相似文献