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1.
A complex optical model potential rewritten by the concept of bonded atom, which considers the overlap of electron clouds, is employed to calculate the total cross sections for electron scattering from several simple molecules (O_2, H_2O, H_2, O_3, CO and CO_2) consisting of C, H and O atoms in an incident energy range of 100-2000eV by the use of the additivity rule at Hartree-Fock level. In the study, the complex optical potential composed of static, exchange, correlation polarization plus absorption contributions firstly uses the bonded-atom concept. The quantitative molecular total cross section results are compared with experimental data and with the other calculations wherever available and good agreement is obtained. It is shown that the additivity rule along with the complex optical model potential rewritten by the concept of bonded atom can be used successfully to calculate the total cross section of electron-molecule scattering above 100eV, whereas the rule together with the complex optical model potential not rewritten by the concept of bonded atom is only successfully used above 300-500eV. So, the introduction of the bonded-atom concept in the complex optical potential can improve the accuracy of the total cross section calculations.  相似文献   

2.
We propose the concept of an incident angle in the form of complex number and analyse planar optical waveguides by applying the concept. The complex angle of incidence is concerned with the modelling of prism–gap–waveguide structures. It is shown that, when optical waveguides are analysed by means of the transfer matrix method, the proposed concept enables us to find solutions faster and more accurately than by using the method utilizing the leaky structure. This revised version was published online in November 2006 with corrections to the Cover Date.  相似文献   

3.
The Monte Carlo ray-tracing method (MCRT) based on the concept of radiation distribution factor is extended to solve radiative heat transfer problem in turbulent fluctuating media under the optically thin fluctuation approximation. A one-dimensional non-scattering turbulent fluctuating media is considered, in which the mean temperature and absorption coefficient distribution are assumed and the shape of probability density function is given. The distribution of the time-averaged volume radiation heat source is solved by MCRT and direct integration method. It is shown that the results of MCRT based on the concept of radiation distribution factor agree with these of integration solution very well, but results of MCRT based on the concept of radiative transfer coefficient do not agree with these of integration solution. The solution of time-averaged radiative transfer equation by the concept of radiative transfer coefficient should be treated with caution.  相似文献   

4.
We propose and discuss a novel concept of robust set stabilization by permissible controls; this concept is helpful when dealing with both a priori information of model parameters and different permissible controls including quantum measurements. Both controllability and stabilization can be regarded as the special case of the novel concept. An instance is presented for a kind of uncertain open quantum systems to further justify this generalized concept. It is underlined that a new type of hybrid control based on periodically perturbed projective measurements can be the permissible control of uncertain open quantum systems when perturbed projective measurements are available. The sufficient conditions are given for the robust set stabilization of uncertain quantum open systems by the hybrid control, and the design of the hybrid control is reduced to selecting the period of measurements.  相似文献   

5.
Three-way concept analysis (3WCA) is extended research of formal concept analysis (FCA) by combining three-way decision. The three-way object oriented concept lattice (OEOL) is one of the important data structures which integrates rough set, concept lattice and three-way decision in 3WCA. In the paper, we investigate the characteristics of formal context based on the isomorphic relationship among the kinds of concept lattices with OEOL. Firstly, II-dual intersectable attributes and II-dual intersectable context are proposed and the relationship between the type I-dual intersectable context(dual intersectable context) and the type II-dual intersectable context are studied. In addition, the relationship among the kinds of concept lattices with OEOL are studied when the formal context is both I-dual intersectable context and II-dual intersectable context. Finally, the inverse problems of the above conclusions are discussed and the following two conclusions are obtained: (1) the formal context is the type II-dual intersectable context, when the object oriented concept lattice and OEOL are isomorphic. (2) In addition, the formal context is the type I-dual intersectable context, when the concept lattice and OEOL are anti-isomorphic.  相似文献   

6.
We present the concept of integrated processing to combine intuitive processing of neural networks with logical processing of the conventional digital computer. We investigate a way to embody the concept in the neural network system by introducing external constraints in terms of external input. The effect of the external input is analyzed using the generalized projection method. The concept of integrated processing is applied to an image associative memory system, and the system is optically implemented for high-speed parallel processing incorporating it with the computer. The experimental result is presented to illustrate the effectiveness of the external input to control the output of the image associative memory.  相似文献   

7.
一种基于约束概念格的恒星光谱数据自动分类方法   总被引:1,自引:0,他引:1  
概念格是数据分析与知识提取的一种有效形式化工具,约束概念格是一种新的概念格结构,具有构造的时空复杂性低,所提取知识的实用性和针对性强等特点。针对海量恒星光谱自动分类任务,依据约束概念格结点外延与训练样本数据集等价划分之间的关系,通过引入外延支持度和划分支持度的概念,提出了一种基于约束概念格的恒星光谱数据分类规则挖掘方法,并采用SDSS恒星光谱数据集,实验验证了由该方法所提取出的分类规则具有较高的分类效率和分类正确率,从而为海量的恒星光谱数据自动分类提供了一种有效方法。  相似文献   

8.
在实验上用实时观察法和Kyropoulos技术生长水杨酸苯脂单晶,研究晶体形貌随过冷度的变化关系。在理论上采用Hartman-Perdok的PBC方法,分析水杨酸苯脂单晶形貌和晶体结构的关系。应用木原的核心势能模型,扩展了PBC理论。解析的晶体形貌与实时观察法得到的晶体形貌相当一致。 关键词:  相似文献   

9.
利用可加性规则,使用Hartree-Fock波函数,采用由束缚原子概念修正过的复光学势(由静电势、极化势及吸收势三部分组成),在30—3000eV内对正电子被CO,HCl,NH3和SiH4散射的总截面进行了计算,且将计算结果与实验结果及其他理论计算结果进行了比较.结果表明,利用被束缚原子概念修正过的复光学势及可加性规则进行计算,所得结果与实验结果的符合程度要比利用未被束缚原子概念修正的复光学势及可加性规则进行计算得到的结果好很多.因此,在复光学势中采用束缚原子概念可提高正电子被分子散射的总截面的计算准确度. 关键词: 正电子散射 可加性规则 束缚原子 总截面  相似文献   

10.
We discuss the concept of quantum vacuum in comparison with the classical concept of vacuum in the context of light-wave propagation. The role played by quantum fluctuations is examined with respect to the behaviour of photons as the quanta of electromagnetic field and also in relation to the fact that photons can be regarded as non-zero mass particles. In this context, photon mass is defined from Klein–Gordon equation.  相似文献   

11.
为提高光学相关图像识别的准确度和抗畸变能力,引入多重复合匹配滤波器概念,探讨一种新的识别思路。它融合了综合鉴别函数和K-L变换的经典思想,改善了单个匹配滤波器动态范围太小的状况,对图像尺度变换有较宽的适应范围,从而提高了光学模式识别系统的识别效率。仿真结果表明,对尺度缩小1/2的情况,采用此思路可使其滤波的刷新速度比常规方法提高4倍,从而验证了算法的有效性和可行性。  相似文献   

12.
13.
利用可加性规则,使用HartreeFock波函数,采用由束缚原子概念修正过的复光学势(由静 电势、交换势、修正极化势及吸收势这四部分组成),在较大的能量(30—5000eV)范围内对 电子被甲烷及氯代甲烷(CH4,CCl4,CHCl3,CH2Cl2和CH 3Cl)散射的总截面进行了计算,且将计算结果与实验结果及其他理论计算 结果进行 了比较.结果表明,利用被束缚原子概念修正过的复光学势及可加性规则进行计算,所得结 果的精度要比利用未被束缚原子概念修正的复光学势及可加性规则进行计算得到的结果好很 多.因此,在复光学势中采用束缚原子概念可提高电子被分子散射的总截面的计算准确度. 关键词: 电子散射 可加性规则 束缚原子 总截面  相似文献   

14.
In this paper, the concept of “nonlocality”, which is carried by the internal variable (ω) ascribed to each point (x), is first investigated generally in connection with the concept of “unified” gauge field. Next, as a typical example, a Finslerian “nonlocal” field is considered, which is obtained by taking for ω a vector (ξ), and two examples are proposed: one is a unified field with Randers metric and the other is a micro-gravitational field endowed with space-time fluctuation.  相似文献   

15.
A complex optical model potential modified by incorporating the concept of bonded atom, with the overlapping effect of electron clouds between two atoms in a molecule taken into consideration, is firstly employed to calculate the differential cross sections, elastic integral cross sections, and moment transfer cross sections for electron scattering from molecular nitrogen over the energy range 300—1000eV by using additivity rule model at Hartree—Fock level. The bonded-atom concept is used in the study of the complex optical model potential composed of static, exchange, correlation polarization and absorption contributions. The calculated quantitative molecular differential cross sections, elastic integral cross sections, and moment transfer cross sections are compared with the experimental and theoretical ones wherever available, and they are found to be in good agreement with each other. It is shown that the additivity rule model together with the complex optical model potential modified by incorporating the concept of bonded atom is completely suitable for the calculations of differential cross section, elastic integral cross section and moment transfer cross section over the intermediate- and high-energy ranges.  相似文献   

16.
Homogeneous charge compression ignition (HCCI) is a very promising future combustion concept for internal combustion engines. There are several technical difficulties associated with this concept, and precisely controlling the start of auto-ignition is the most prominent of them. In this paper, a novel concept to control the start of auto-ignition is presented. The concept is based on the fact that most HCCI engines are operated with high exhaust gas recirculation (EGR) rates in order to slow-down the fast combustion processes. Recirculated exhaust gas contains combustion products including moisture, which has a relative peak of the absorption coefficient around 3 μm. These water molecules absorb the incident erbium laser radiations (λ=2.79 μm) and get heated up to expedite ignition. In the present experimental work, auto-ignition conditions are locally attained in an experimental constant volume combustion chamber under simulated EGR conditions. Taking advantage of this feature, the time when the mixture is thought to “auto-ignite” could be adjusted/controlled by the laser pulse width optimisation, followed by its resonant absorption by water molecules present in recirculated exhaust gas.  相似文献   

17.
A new probabilistic-informational concept, earlier constructed by Mugur-Schächter, is further developed. Associated with Jaynes's principle, this concept permits one to define a measure for the distance between the state of a system evolving under stable constraints and the equilibrium with these constraints. An illustration is given for a gas evolving in a thermostated box. It appears that the free energy of the gas estimates the distance to equilibrium, the estimation being defined in abstract informational-probabilistic terms.  相似文献   

18.
We introduce the concept of "critical epinucleation to distinguish nucleation on surfaces with and without reconstruction. On a reconstructed surface, the critical classical nucleus is stable against dissociation, but may not yet break the underlying surface reconstruction. Consequently, there must exist a "critical epinucleus" that is not only stable but also has established the epiconfiguration by unreconstructing the underlying substrate. We illustrate this concept by first-principle calculation of homonucleation on reconstructed Si(001) surface where the critical epinucleus consists of six adatoms.  相似文献   

19.
A complex optical model potential modified by the concept of bonded atom, which takes into consideration the overlapping effect of electron clouds, is employed to calculate the total cross sections for electrons scattering from simple molecules (SO2, H2S, OCS, CS2 and SO3) containing the larger atom, sulfur, at 30-5000eV by using the additivity rule model at Hartree-Fock level. The quantitative molecular total cross section results are compared with those obtained in experiments and other calculations wherever available, and good agreement is obtained. It is shown that the additivity rule model together with the complex optical model potential modified by the concept of bonded atom can give the results closer to the experiments than the one unmodified by it. So, the introduction of bonded-atom concept in complex optical model potential betters the accuracy of the total cross section calculations of electrons from the molecules containing the larger atom, sulfur.  相似文献   

20.
The concept of photoinduced ion transfer in heterojunctions based on solid electrolytes with a mixed ionic-electronic (hole) conductivity is justified. This concept is confirmed by the experiments on photo-deposition of a metal in a heterojunction based on a solid electrolyte with a mixed conductivity. The possibility of using heterojunctions based on a solid electrolyte layer with a mixed ionic-electronic (hole) conductivity for optical recording of information is considered.  相似文献   

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