共查询到20条相似文献,搜索用时 46 毫秒
1.
V. Ya. Artyukhov A. A. Akhrem N. A. Borisevich V. A. Ksenzov V. G. Maier A. L. Mikhal'chuk G. B. Tolstorozhev 《Journal of Applied Spectroscopy》2001,68(1):1-8
Using the semiempirical method of partial neglect of differential overlap (PNDO), we have calculated the wave functions, energies, orbital configurations of electronic states, oscillator strengths of transitions, electronic density distributions, and dipole moments for the molecule of biologically active 8–azagona–12,17–dione, containing a conformationally rigid –acyl––aminovinylcarbonyl fragment. It has been established that as to their orbital nature the excited lower and higher singlet electronic states of this molecule are of the n*– and * type respectively. The results of the theoretical analysis are in good qualitative agreement with the spectral data on absorption and luminescence. The calculations of the intermolecular interaction of the compound under consideration with a medium show that the molecular systems under consideration can possess a dynamic multicenter structure. 相似文献
2.
Magnetostriction of amorphous Fe79Mo8Cu1B12, (Fe12Co1)79Mo8Cu1B12 and (Fe9Co1)79Mo8Cu1B12 prepared by planar flow casting was measured using a direct method. The results indicate that magnetostriction in parallel (λ∥) and perpendicular (λ⊥) directions of applied magnetic field is linearly dependent on magnetic field. In order to determine the influences of chemical composition and the conditions of sample preparation the magnetostriction of pure BCC-Fe, Cu and Mo were also measured. Samples containing Co with Curie temperatures slightly above room temperatures were shown to exhibit a hybrid magnetostriction behaviour with both ferromagnetic and paramagnetic features. 相似文献
3.
Akio Suzuki 《高压研究》2018,38(2):145-152
A high pressure X-ray diffraction study of RhOOH was carried out up to 17.44?GPa to investigate the compression behavior of an oxyhydroxide with an InOOH-related structure. A fit to the third-order Birch–Murnaghan equation of state gave K0?=?208?±?6?GPa, and K′?=?9.4?±?1.3. The temperature derivative of the bulk modulus was found to be ?K/?T?=??0.06?±?0.02?GPa K?1. The refined parameters for volume thermal expansion were α0?=?2.7?±?0.3?×?10?5 K?1; α1?=?1.7?±?1.1?×?10?8 K?2 in the polynomial form (α(T)?=?α0?+?α1(T?300)). Our results show that RhOOH is very incompressible, and has a higher bulk modulus than other InOOH-structured oxyhydroxides (e.g. δ-AlOOH, ε-FeOOH, and γ-MnOOH). 相似文献
4.
Likun Pan Shiqing Xu Xinjuan Liu Wei Qin Zhuo Sun Weitao Zheng Chang Q. Sun 《Surface Science Reports》2013,68(3-4):418-445
Nanoscaled or porous silicon (p-Si) with and without surface passivation exhibits unusually tunable properties that its parent bulk does never show. Such property tunability amplifies the applicability of Si in the concurrent and upcoming technologies. However, consistent understanding of the fundamental nature of nanoscaled Si remains a high challenge. This article aims to address the recent progress in this regard with focus on reconciling the tunable dielectric, electronic, phononic, and photonic properties of p-Si in terms of skin dominance. We show that the skin-depth bond contraction, local quantum entrapment, and electron localization is responsible for the size-induced property tunability. The shorter and stronger bonds between undercoordinated skin atoms result in the local densification and quantum entrapment of the binding energy and the bonding electrons, which in turn polarizes the dangling bond electrons. Such local entrapment modifies the Hamiltonian and associated properties such as the band gap, core level shift, Stokes shift (electron–phonon interaction), phonon and dielectric relaxation. Therefore, given the known trend of one property change, one is expected to be able to predict the variation of the rest based on the notations of the bond order–length–strength correlation and local bond average approach (BOLS-LBA). Furthermore, skin bond reformation due to Al, Cu, and Ti metallization and O and F passivation adds another freedom to enhance or attenuate the size effect. The developed formulations, spectral analytical methods, and importantly, the established database and knowledge could be of use in engineering p-Si and beyond for desired functions. 相似文献
5.
M. Bender K. Rutz P.-G. Reinhard J.A. Maruhn 《The European Physical Journal A - Hadrons and Nuclei》2000,7(4):467-478
We study the influence of the scheme for the correction for spurious center–of–mass motion on the fit of effective interactions
for self–consistent nuclear mean–field calculations. We find that interactions with very simple center–of–mass correction
have significantly larger surface coefficients than interactions for which the center–of–mass correction was calculated for
the actual many–body state during the fit. The reason for that is that the effective interaction has to counteract the wrong
trends with nucleon number of all simplified schemes for center–of–mass correction which puts a wrong trend with mass number
into the effective interaction itself. The effect becomes clearly visible when looking at the deformation energy of largely
deformed systems, e.g. superdeformed states or fission barriers of heavy nuclei.
Received: 6 September 1999 相似文献
6.
Russian Physics Journal - Using the methods of dark-field electron microscopy analysis, energy-dispersive X-ray microanalysis, hardness measurements and scratch testing, the variations of elemental... 相似文献
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Transition metal dichalcogenides with a layered structure are well known for their self-lubricating properties, particularly in a vacuum or dry atmosphere. The macrotribological properties of these films have been studied extensively. However, the tribological behaviour of these films in the nanonewton load range has hardly been reported. Study of tribological properties with load in the nanonewton range is required for applications related to microelectromechanical systems or nanoelectromechanical systems. In view of the above, the hardness, surface force, friction force, etc. of Mo–Se–C films were investigated at an applied load in the nanonewton range using a nanoindenter and atomic force microscopy. The effect of carbon content, applied load and scanning speed on the friction coefficient was determined. Data pertaining to topography, lateral force and pull-off force of various surfaces are illustrated. The observed nanotribological behaviour of these films is analysed in the light of their nanohardness. The results indicate that the friction force of all the films is very low and in general dependent on surface force. However, a film having the highest carbon content exhibits the maximum friction force. With increasing carbon content of the films tested, the hardness increases and wear decreases. The above results pertain to investigations under ambient conditions. 相似文献
9.
Belysheva D. N. Sinel’shchikova O. Yu. Tyurnina N. G. Tyurnina Z. G. Sviridov S. I. Tumarkin A. V. Zlygostov M. V. Ugolkov V. L. 《Physics of the Solid State》2019,61(12):2371-2375
Physics of the Solid State - The influence of composition of glycine–nitrate systems on the completeness of the formation of solid solutions of barium–strontium metatitanate was... 相似文献
10.
《Physica B: Condensed Matter》2000,275(1-3):248-252
The energetic model of ferromagnetic hysteresis calculates the magnetic state of materials by minimizing the total energy function for statistical domain behavior. The approach shows good agreement with the magnetization curves of mechanically alloyed Pr9Fe85B6 powder, heat treated at different temperatures. 相似文献
11.
M. Shang Q. Feng Y.L. Jiao L. Xiao M.H. Zheng Q.Z. Yan C.C. Ge 《Physica C: Superconductivity and its Applications》2010,470(11-12):491-495
The intrinsic effects of nanoscopic MnO2 powders addition combined with Fe cation substitutions for copper sites on the microstructure and superconductive properties of YBa2Cu3O7?δ (Y123) melt-solidified bulks have been investigated. On the one hand, an increase in Y2BaCuO5 (Y211) particle pushing, leading to an inhomogeneous bulk microstructure, is caused by increasing MnO2 content due to increased net interfacial energy, Δσ0; and, on the other hand, an addition of MnO2 powders is effective in enhancing both the δTc-type and δl-type pinning. It also shows that the Fe addition helps to optimize the high magnetic field performance and Y211 particle distribution in textured pellets. Further, this experiment suggests that a combination of the element substitution and the nanoscopic particle is a beneficial way to optimize the microstructure and superconductive properties of single-domain bulk superconductors. 相似文献
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The two-point gauge correlation function in Yang–Mills–Chern–Simons theory in three dimensional Euclidean space is analysed by taking into account the non-perturbative effects of the Gribov horizon. In this way, we are able to describe the confinement and de-confinement regimes, which naturally depend on the topological mass and on the gauge coupling constant of the theory. 相似文献
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G. A. Malygin V. I. Nikolaev A. I. Averkin A. P. Zograf 《Physics of the Solid State》2016,58(12):2488-2493
The compression diagram of Ni49Fe18Ga27Co6 alloy crystals in the [011] direction was studied until full shape memory strain at various temperatures in the range of 259–340 K. It is found that all load curves are anomalously shaped and contain portions of sharp and gradual decreases in deformation stresses. Simulation of pseudo-elastic stress–strain curves within the theory of diffuse martensitic transitions, describing not only equilibrium of phases, but also the kinetics of the transition between them, shows that elastic interphase stresses during martensitic reactions Ll 2 → 14M and 14M → Ll 0 characteristic of this alloy can be responsible for the extraordinary shape of compression diagrams. 相似文献
16.
Technical Physics - The structural state in the zones of indentation and scratch testing of Ti–Al–Si–Cu–N gradient coatings has been studied using dark-field electron... 相似文献
18.
J. D. Betancur-Rios K. Nomura C. J. Wang G. A. Pérez Alcazar J. A. Tabares 《Hyperfine Interactions》2008,187(1-3):43-48
The purpose of this paper is to investigate the isothermal behavior of Fe–27.3Mn–7.6Al–C–6.5Cr–0.25Si–0.88Mo (Mo(0)) and Fe–27.3Mn–7.6Al–1.0C–6.5Cr–0.25Si (Mo(1)) alloys and compare it against Fe–9Cr–1Mo (FCR) commercial alloy. The experiments were carried out at 600°C, 700°C, 750°C and 850°C, each one during 72 h in static air. The oxidation kinetics was measured as a function of time using a Thermogravimetry analyzer (TGA). The structure and composition of the oxide scale were characterized by X-ray diffraction (XRD) and Integral Conversion Electron Mössbauer Spectroscopy (CEMS). The TGA results show that at all oxidation temperatures the sample FCR exhibit the lowest kinetic corrosion and the lowest weight gain, whereas Mo(0) the highest. By CEMS technique it were found a broad magnetic sextet, which has been fit by one hyperfine field distribution with mean hyperfine field characteristic to ferritic/martensite phase, one Fe3?+? doublet and one singlet for the Mo(0) and Mo(1) alloys. Samples oxidized at highest temperatures exhibit a strong paramagnetic line, probably due that the Cr or Mn oxides may be enriched on the surface. Then, the magnetic phase can be converted partially into austenite phase at highest temperatures. 相似文献
19.
In the present study, the structural and opto-mechanical properties of Ge–Sb–As–Se–S chalcogenide glasses have been investigated. For this purpose, different bulk glasses of Ge20Sb5As15Se60?xSx (0 ≤ x≤50) were prepared by conventional melt quenching technique in quartz ampoule and different characteristics of prepared glasses such as glass transition temperature, density, hardness, transmittance, optical band gap energy and refractive index were determined. The value of hardness and glass transition temperature of prepared glasses were found to increase with increasing the sulfur content as a result of formation of GeS4 tetrahedral units and increasing the network connectivity and average bonding energy. The optical energy gap (according to Tauc’s relation), transmittance and refractive index of prepared glasses are in direct relation with sulfur content. In this study, the highest value of transmittance (about 70%) and lowest value of refractive index (2–2.3) was achieved in Ge20Sb5As15Se40S20 and Ge20Sb5As15Se10S50 glasses, respectively. 相似文献
20.
Bart D’Hooghe 《International Journal of Theoretical Physics》2010,49(12):3069-3084
We adopt an operational approach to quantum mechanics in which a physical system is defined by the mathematical structure
of its set of states and properties. We present a model in which the maximal change of state of the system due to interaction
with the measurement context is controlled by a parameter which corresponds with the number N of possible outcomes in an experiment. In the case N=2 the system reduces to a model for the spin measurements on a quantum spin-1/2 particle. In the limit N→∞ the system is classical, i.e. the experiments are deterministic and its set of properties is a Boolean lattice. For intermediate
situations the change of state due to measurement is neither ‘maximal’ (i.e. quantum) nor ‘zero’ (i.e. classical). We show
that two of the axioms used in Piron’s representation theorem for quantum mechanics are violated, namely the covering law
and weak modularity. Next, we discuss a modified version of the model for which it is even impossible to define an orthocomplementation
on the set of properties. Another interesting feature for the intermediate situations of this model is that the probability
of a state transition in general not only depends on the two states involved, but also on the measurement context which induces
the state transition. 相似文献