2,688 research outputs found
An explicit model for the adiabatic evolution of quantum observables driven by 1D shape resonances
This paper is concerned with a linearized version of the transport problem
where the Schr\"{o}dinger-Poisson operator is replaced by a non-autonomous
Hamiltonian, slowly varying in time. We consider an explicitly solvable model
where a semiclassical island is described by a flat potential barrier, while a
time dependent 'delta' interaction is used as a model for a single quantum
well. Introducing, in addition to the complex deformation, a further
modification formed by artificial interface conditions, we give a reduced
equation for the adiabatic evolution of the sheet density of charges
accumulating around the interaction point.Comment: latex; 26 page
Asymptotic Analysis of a Schrödinger-Poisson System with Quantum Wells and Macroscopic Nonlinearities in Dimension 1
2000 Mathematics Subject Classification: 35Q02, 35Q05, 35Q10, 35B40.We consider the stationary one dimensional Schrödinger-Poisson system on a bounded interval with a background potential describing a quantum well. Using a partition function which forces the particles to remain in the quantum well, the limit h®0 in the nonlinear system leads to a uniquely solved nonlinear problem with concentrated particle density. It allows to conclude about the convergence of the solution
An improved transient algorithm for the simulation of a resonant tunneling diode
40 pagesA fast algorithm is proposed for the simulation of the transient evolution of a resonant tunneling diode by a multiscale approach. The problem is modeled by the time-dependent Schrödinger-Poisson system. By decomposing the wave function into a non resonant part and a resonant part, the fast algorithm is designed by combining standard finite difference method for the Schrödinger-Poisson equation with proper time-dependent and/or nonlinear transmission boundary condition. In addition, with a suitable interpolation of the non resonant one, an accurate and fast algorithm is presented for the computation of the resonant part via the projection method. With this two scale decomposition, the new numerical method can save the computational time significantly
Evaluation of Some Genotypes of Wheat (Triticum Durum L.) Under Conditions in Al Jabal Al Akhdar - Libya.
The experiment was conducted at the research farm of the College of Agriculture during the season (2019-2020) to evaluate the performance of six genetic compositions under semi-arid conditions using the green fodder. These compositions were obtained from the International Center for Agricultural Research in Dry Areas (ICARDA) and the International Maize and Wheat Improvement Center (CIMMYT), compared to the local variety "Ain Al-Faras." The treatments were planted according to a randomized complete block design (RCBD) with three replications. Significant differences were observed among all the genetic compositions for all the studied traits. The variety "Ain Al-Faras" outperformed the other genetic compositions in plant height, spike length, number of grains per spike, grain yield, straw yield, and biological weight, with values of 86 cm, 9.65 cm, 61 grains/spike, 1.14 tons/ha, 10.68 tons/ha, and 11.82 tons/ha, respectively. Genetic composition 2020-741 also excelled in the trait of number of grains per spike (52.33), while genetic composition D2020-72 exhibited superiority in the trait of thousand-grain weight (63.35 g). Moreover, genetic composition D2020-4 showed a higher harvest index compared to the other genetic compositions, with a value of 12.91. The results indicated that the values of phenotypic variance were close to the values of genetic variance for most of the studied traits. The highest heritability ratio was observed for the traits of number of grains per spike and grain yield. High relative genetic advance values were recorded along with high values of specific combining ability for both the number of grains per spike and grain yield. Therefore, it is possible to infer the genetic composition through morphological data, and such traits can be considered as selection criteria for improving these crops
Roughness in BO/BH/Z-ALGEBRA
The main goal of this paper, present the concepts of rough BO/BH/Z- Algebra
as extended of the concept of BO/BH/Z-algebra respectively. The other goal is
to consider the (strong) set-valued mapping in these algebraic structures. The
concept of a (strong) set-valued BO/BH/Z-morphism in BO/BH/Z algebras is
investigated with several properties. Using the concept of generalized
approximation space and ideal of BO/BH/Z-algebra, we consider another type of
generalized lower and upper approximations based on the ideal. In addition,
some properties are studied
MAGNETIC HILLS AND OPTICAL ILLUSION IN KURDISTAN REGION
“Anti-Gravity Hills", or “Magnetic Hills”, are natural places where apparently defying the law of gravity. In some places in Kurdistan region these magnetic hills exist. This type of hills appears to go uphill is really going downhill. The purpose of the present work was to register an unknown magnetic hill, and a water channel of abnormal apparent direction of flow! And to study what types of physical properties are behind these, we investigated that optical illusion, and a false horizon line are behind
Roughness in Anti Semigroup
In this paper, we present the concepts of the upper and lower approximations
of Anti-rough subgroups, Anti-rough subsemigroups, and homeomorphisms of
Anti-Rough anti-semigroups in approximation spaces. Specify the concepts of
rough in Finite anti-groups of types(4) are studies. Moreover, some properties
of approximations and these algebraic structures are introduced. In addition,
we give the definition of homomorphism anti-group
Hybrid of Eddy Current Probe Based on Permanent Magnet and GMR Sensor
The eddy current testing (ECT) is used to inspect a material to determine its properties without destroying its utility. The applications include detection of flaws in aircrafts, pipeline, etc. An ECT is a weak sensitivity to a subsurface defect. Applications of giant magnetic sensors (GMR) are increasingly applied to the measurement of weak magnetic fields related to the currents they cause. In this paper, GMR sensor with magnet bar (permanent) is utilized. The proposed probe system is utilized to study the impact of the width and depth defect on the signal of eddy current testing. The maximum depth of flaw in a mild steel can be revealed by using this probe. The graph of the difference between the peak amplitude and the penetration depth of each slot of a different width of the two bands of mild steel shows the increase of the signal for each slot and flat above 3mm. The experimental result proves the inability of a PMGMR probe to detect a defect at a depth of 3mm on a surface defect
- …