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991.
In the present work, the general method proposed earlier for calculating the distribution density and moments of the absorbed energy in isolated sensitive regions of absorbers irradiated by ionizing particles is developed and made specific for the electron-photon problem. Electron transfer is considered within the framework of a model using grouping of excitations and slipping ionization; the presence of electron equilibrium in the vicinity of sensitive regions is assumed. Two similar methods of calculating these characteristics are developed. Both reduce the initial problem to two independent problems: determining the electron spectrum in the sensitive region (in one of the methods, the spectrum of electron sources is also needed) and calculating the coefficients characterizing electron transfer in the sensitive region and its immediate vicinity.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 89–94, September. 相似文献
992.
J. Pal C. C. Dey S. Bose B. K. Sinha M. B. Chatterjee D. P. Mahapatra 《Zeitschrift für Physik A Hadrons and Nuclei》1987,356(3):281-286
The analogue of the 0+ ground state in 118Sn has been observed in the compound nucleus 118Sb through 117Sn(p,n γ) 117Sb reaction. The neutron decays of this analogue resonance have been studied from the deexciting γ-rays of the residual nucleus 117Sb. From off resonance excitation functions, spin assignments have been made to states in 117Sb, on the basis of Hauser-Feshbach formalism. The resonance parameters of the isobaric analogue resonance have been determined, including the total, proton and neutron decay widths. 相似文献
993.
Ohne Zusammenfassung 相似文献
994.
D. Gross 《Applied physics. B, Lasers and optics》2007,86(3):367-370
According to a classical result due to Hudson, the Wigner function of a pure, continuous-variable quantum state is non-negative
if and only if the state is Gaussian. We have proven an analogous statement for finite-dimensional quantum systems. In this
context, the role of Gaussian states is taken on by stabilizer states. The general results have been published in [1]. For
the case of systems of odd prime dimension, a different, greatly simplified method of proof can be employed which still exhibits
the main ideas. The present paper gives a self-contained account of these methods.
PACS 03.65.Fd; 03.65.Sq; 03.67.-a 相似文献
995.
We characterize δ-I-sets, discuss the relation between δ-sets, δ-I-sets and I
δ-sets and generalize some of the results. 相似文献
996.
This paper investigates the multivariable identification and controller design for the longitudinal channel of a Boeing 747 transport. The transfer function matrix of the system is identified using the prediction error (PE) identification method with multivariable ARX model. An ellipsoidal parametric uncertainty set is constructed from the covariance matrix of the identified parameters. It contains the parameters of actual system at a certain probability level. The identified models and the associated uncertainty sets are validated by measuring the worst-case ν-gap and then compared with the maximum value of the generalized stability margin. In automatic flight control system or autopilots, multiple specifications criteria are needed to be satisfied concurrently, such as good holding (small static altitude holding error), fast response, smooth transition (less oscillation, overshoot). The design of a Multiple Simultaneous Specifications (MSS) controller effectively and practically is a very significant and challenging job. Liu and Mills [H.H.T. Liu, J.K. Mills, Multiple specification design in flight control system, in: Proceedings of the American Control Conference, Chicago, Illinois, 2000, pp. 1365–1369] proposed a MSS controller design method using a convex combination approach. In this paper, we apply the method [H.H.T. Liu, J.K. Mills, Multiple specification design in flight control system, in: Proceedings of the American Control Conference, Chicago, Illinois, 2000, pp. 1365–1369; H.H.T. Liu, Design combination in integrated flight control, in: Proceedings of the American Control Conference, Arlington, Virginia, 2001, pp. 494–499; H.H.T. Liu, Multi-objective design for an integrated flight control system: a combination with model reduction approach, in: Proceedings of IEEE International Symposium on Computer Aided Control System Design, Glasgow, 2002, pp. 21–26] to design a MSS controller based on the identified models of the Boeing 747 transport aircraft longitudinal channel. The controllers are also validated by simulation using the true plant transfer functions. 相似文献
997.
A. Subramanian T.-Y. Choi L.X. Dong J. Tharian U. Sennhauser D. Poulikakos B.J. Nelson 《Applied Physics A: Materials Science & Processing》2007,89(1):133-139
We report on a novel method for local control of shell engineering in multiwalled carbon nanotubes (MWNTs) using Joule-heating
induced electric breakdown. By modulating the heat dissipation along a nanotube, we can confine its thinning and shell breakdown
to occur within localized regions of peak temperatures, which are distributed over one-half of the NT length. The modulation
is achieved by using suitably designed nanomachined heat sinks with different degrees of thermal coupling at different parts
of a current-carrying nanotube. The location of electric breakdown occurs precisely at the regions of high temperatures predicted
by the classical finite-element model of Joule heating in the MWNT. The experiments herein provide new insight into the electric
breakdown mechanism and prove unambiguously that shell removal occurs due to thermal stress, underpinning the diffusive nature
of MWNTs. The method demonstrated here has the potential to be a powerful tool in realizing MWNT bearings with complex architectures
for use in integrated nanoelectromechanical systems (NEMS). In addition, the breakdown current and power in the nanotubes
are significantly higher than those observed in nanotubes without heat removal via additional heat sinks. This indicates future
avenues for enhancing the performance of MWNTs in electrical interconnect and nanoelectronic applications.
PACS 73.63.Fg; 65.80.+n 相似文献
998.
In this paper we use the upper semifinite topology in hyperspaces to get results in normal Hausdorff topology. The advantage of this point of view is that the upper semifinite topology, although highly non-Hausdorff, is very easy to handle. By this way we treat different topics and relate topological properties on spaces with some topological properties in hyperspaces. This hyperspace is, of course, determined by the base space. We prove here some reciprocals which are not true for the usual Vietoris topology. We also point out that this framework is a very adequate one to construct the ?ech-Stone compactification of a normal space. We also describe compactness in terms of the second countability axiom and of the fixed point property. As a summary we relate non-Hausdorff topology with some facts in the core of normal Hausdorff topology. In some sense, we reinforce the unity of the subject. 相似文献
999.
Matthew D. Bailey Steven M. Shechter Andrew J. Schaefer 《Operations Research Letters》2006,34(3):307-315
We consider a general adversarial stochastic optimization model. Our model involves the design of a system that an adversary may subsequently attempt to destroy or degrade. We introduce SPAR, which utilizes mixed-integer programming for the design decision and a Markov decision process (MDP) for the modeling of our adversarial phase. 相似文献
1000.
B. Giner I. Gascón A. Villares C. Lafuente 《Journal of Thermal Analysis and Calorimetry》2006,83(3):735-745
The
relation between refractive index deviations and excess volumes for binary
mixtures formed by a cyclic ether and a haloalkane has been tested using several
methods: refractive index mixing rules and equations of state. Refractive
index deviations, excess volumes and molar refractions have been calculated
from experimental data of refractive indices and densities at two temperatures
298.15 and 313.15 K. Results obtained have been discussed in terms of intermolecular
interactions. Refractive indices were compared with those predicted by several
mixing rules. Excess volumes have also been correlated using several cubic
equations of state and finally a relation between parameter b
from equations of state and molar refraction has been provided. 相似文献