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排序方式: 共有209条查询结果,搜索用时 15 毫秒
11.
KM Varier AM Vinodkumar NVSV Prasad PV Madhusudhana Rao DL Sastry Lagy T Baby MC Radhakrishna NG Puttaswamy JJ Das P Sugathan N Madhavan AK Sinha DO Kataria 《Pramana》1999,53(3):529-533
Large enhancements have been observed in the sub-barrier fusion cross sections for Ti+Ni systems in our previous studies.
Coupled channel calculations incorporating couplings to 2+ and 3− states failed to explain these enhancements completely. A possibilty of transfer channels contributing to the residual enhancements
had been suggested. In order to investigate the role of relevant transfer channels, measurements of one- and two-nucleon transfer
were carried out for 46,48Ti+61Ni systems. The present paper gives the results of these studies. 相似文献
12.
MJ Singh DO Kataria N Madhavan P Sugathan JJ Das DK Awasthi AK Sinha R Shanker 《Pramana》1999,53(4):743-764
A projectile ion-recoil ion coincidence technique has been employed to study the multiple ionization and the charge transfer
processes in collisions of 60–120 MeV Si
q+ (q = 4−14) ions with neutral argon atoms. The relative contribution of different ionization channels, namely; direct ionization,
electron capture and electron loss leading to the production of slow moving multiply charged argon recoil ions have been investigated.
The data reported on the present collision system result from a direct measurement in the considered impact energy for the
first time. The total ionization cross-sections for the recoil ions are shown to scale as q
1.7/E
p
0.5
, where E
p is the energy in MeV of the projectile and q its charge state. The recoil fractions for the cases of total- and direct ionizations are found to decrease with increasing
recoil charge state j. The total ionization fractions of the recoils are seen to depend on q and to show the presence of a ‘shell-effect’ of the target. Further, the fractions are found to vary as 1/j
2 upto j = 8+. The average recoil charge state 〈j〉 increases slowly with q and with the number of lost or captured electrons from or into the projectile respectively. The projectile charge changing
cross-sections σ
qq′ are found to decrease with increasing q for loss ionization and to increase with q for direct-and capture ionization processes respectively. The physics behind various scaling rules that are found to follow
our data for different ionization processes is reviewed and discussed. 相似文献
13.
Introduction to focus issue: mesoscales in complex networks 总被引:1,自引:0,他引:1
14.
Paul Gundel Gema Martinez‐Criado Martin C. Schubert Juan Angel Sans Wolfram Kwapil Wilhelm Warta Eicke R. Weber 《固体物理学:研究快报》2009,3(9):275-277
Synchrotron based X‐ray excited optical luminescence (XEOL) has been measured with many direct bandgap semiconductors. We present XEOL measurements on crystalline silicon (Si), obtained despite of its indirect bandgap and the consequently low luminescence efficiency. Spectra of monocrystalline and multicrystalline (mc) Si at room temperature are compared to theoretical spectra. A possible application in the synchrotron‐based research on mc‐Si is exemplified by combining XEOL, X‐ray fluorescence (XRF) spectroscopy, photoluminescence (PL) spectroscopy, and microscope images of grain boundaries. This approach can be utilized to investigate the recombination activity of metal precipitates, to analyze areas of different lifetimes on mc‐Si samples and to correlate additional material parameters to XRF measurements. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
15.
16.
The properties of the negative parity states of55Fe and57Fe are investigated in the framework of the intermediate coupling model. In the model, a neutron or a quasineutron is coupled to anharmonic vibrations of the core. Anharmonicities of the vibrations are estimated through the observed properties of the core. Energy levels, spectroscopic factors and electromagnetic properties have been calculated. The results of the present calculations are also compared with available experimental results and other theoretical results. The model reasonably accounts for many of the properties of the low-lying states. 相似文献
17.
The kinetic curves at infinite temperature for the solid-state reactions of the interface shrinkage type were drawn theoretically by taking account the particle size distribution in the sample mixture. The CRTA curves for the reactions with the particle size distribution can be drawn by utilizing the universal kinetic curves at infinite temperature. The proper kinetic treatment for the CRTA curves with the particle size distribution is discussed in connection with the property of the kinetic equation with respect to the particle size distribution. The present kinetic consideration is taken as a simulation for the reactions with a certain distribution in among the reactant particles, produced preferably by the mass and heat transfer phenomena during the thermoanalytical measurements. The merit of the rate jump method by a single cyclic CRTA curve is also discussed on the basis of the present results. 相似文献
18.
Manuel Castillo Julio J. Criado Benigno Macías María V. Vaquero 《Transition Metal Chemistry》1986,11(12):476-479
Summary Barium salts of the dithiocarbamate derivates of the amino acids: DL-valine, L-valine, DL-leucine, DL-isoleucine and L-proline have been synthesized. The anions have been used to obtain the corresponding nickel(II) complexes in acid form. The complexes are diamagnetic, and coordination takes place in a near-square planar geometry around the nickel(II) ion through the sulphur atoms of the dithiocarbamate moiety, the structure being confirmed by i.r.,1H n.m.r., u.v.-vis spectros copies and by chemical analysis.No significant difference has been found between the physicochemical properties (i.r. and 'H n.m.r. spectra and magnetic properties) of the complexes prepared from the dithiocarbamate derivatives of DL- and L-valine, but d-d bands in the u.v.-vis spectra show a slight different intensity. 相似文献
19.
J. Málek J. šesták F. Rouquerol J. Rouquerol J. M. Criado A. Ortega 《Journal of Thermal Analysis and Calorimetry》1992,38(1-2):71-87
The applicability of both conventional Thermal Analysis (TA) and Controlled Rate Thermal Analysis (CRTA) for kinetic analysis is discussed. It is shown that TA method can give a reliable kinetic information and meaningful kinetic parameters especially for solid state transformation. On the other hand the CRTA method is more suitable for decomposition process where one or more gasses are evolved. A consistent and reliable method of kinetic analysis is proposed for both techniques. This method is illustrated to analyze the crystallization process of chalcogenide glass and the decomposition of dolomite. 相似文献
20.