搜索结果: 16-30 共查到“知识库 带电粒子光学”相关记录107条 . 查询时间(2.266 秒)
基于自适应t分布变异的粒子群特征选择方法
特征选择 粒子群优化 互信息
2013/11/19
在分析粒子群优化（particle swarm optimization, PSO）的基础上，提出了一种基于自适应t分布变异的简化粒子群特征选择方法。针对PSO容易陷入局部收敛的缺陷，通过对群体极值进行自适应t分布变异，使其跳出局部收敛。为了解决随机选择初始群体可能会延长搜索时间这一问题，将互信息引入到算法中。通过计算特征与类别的相关性来确定每个特征的入选概率，根据概率值生成一个近似最优粒子，使粒...
DNA折纸术是近年来提出的一种新颖的DNA自组装方法, 是DNA纳米技术和DNA自组装领域的重大研究进展之一. 与传统的DNA自组装技术不同, DNA折纸术通过一条长的环状单链DNA与一系列预设计的短链DNA片段碱基互补配对, 构造出高度复杂的二维纳米图案和三维纳米结构. 与传统纳米自组装方法相比, DNA折纸术构造的二维、三维纳米结构, 具有更佳的精细程度和可控性, 而且其实验条件要求低, 操作...
针对复杂系统的实时故障诊断问题，引入一种多目标离散粒子群优化(DPSO)算法对测试集进行优化，以实现有效的故障监测与隔离。在建立系统相关性模型的基础上，针对系统实时监视和实时诊断中故障检测数、故障隔离数、测试个数和测试成本等指标，分别设计了优化故障检测测试集和故障诊断测试集的多目标适应度函数。应用实例表明，该算法能快速地对测试集进行优化，提高实时诊断的效率，并可作为改进系统测试性设计中的一种测试综...
为了准确辨识电动舵机的参数，提出了一种混合遗传粒子群优化算法。该算法的具体步骤是对所有粒子进行交叉操作，并对粒子交叉前后的适应度函数进行比较。如果适应度优于前者，则进行粒子替换。仿真结果表明，该算法能够减少寻优迭代次数，缩短优化计算时间，具有良好的实用性。
In situ variability of mass-specific beam attenuation and backscattering of marine particles with respect to particle size, density, and composition
mass-specific beam attenuation size density composition
2014/4/4
This study analyzes relationships between concentration of suspended particles represented by dry mass,
[SPM], or area, [AC], and optical properties including particulate beam attenuation (cp), side ...
Seasonal and interannual variations of community metabolism rates of a Posidonia oceanica seagrass meadow
community metabolism Seasonal interannual variations
2014/4/4
We report gross primary production (GPP), community respiration (CR), and net community production
(NCP) over a Posidonia oceanica meadow at 10 m in Corsica (Bay of Revellata) based on the open water...
Nearshore hydrodynamics as loading and forcing factors for Escherichia coli contamination at an embayed beach
Nearshore hydrodynamics loading embayed beach
2014/4/4
Numerical simulations of the transport and fate of Escherichia coli were conducted at Chicago’s 63rd Street
Beach, an embayed beach that had the highest mean E. coli concentration among 23 similar La...
Short Calculation of Particle Transport Properties in Hydrogen Gas
Hydrogen Transport property Diffusion Thermophoresis Migration
2016/3/28
Usage of hydrogen gas has increased due to fast development of the fuel cell technology. Currently, little attention is
paid to particles in hydrogen gas, however, particles in hydrogen gas have grea...
Dynamical Magnetic and Nuclear Polarization in Complex Spin Systems: Semi-magnetic II-VI Quantum Dots
Dynamical Magnetic and Nuclear Polarization in Complex Spin Systems: Semi-magnetic II-VI Quantum Dots
2012/2/27
Dynamical magnetic and nuclear polarization in complex spin systems is discussed on the example of transfer of spin from exciton to the central spin of magnetic impurity in a quantum dot in the presen...
思想实验探秘粒子世界（图）
思想实验 粒子
2013/8/7
在思想实验中，人们似乎以一个无知的状态为起点，静坐，沉思……无需任何新的经验数据的介入，就可得到新的知识。这些“新知识”在科学史中的许多关键时刻，都发挥了无可替代的作用。比如说，伽利略的自由落体运动实验、麦克斯韦妖实验、爱因斯坦的追光实验等。可除了知道思想实验是在思维中运作，具有实验的一般形象外，人们很难清楚地说出它们究竟是什么。但这并不能遮掩住思想实验以其独特的魅力，在科学史中闪现出耀眼的光芒。
Polarized electric dipole moment of well-deformed reflection asymmetric nuclei
well-deformed reflection asymmetric nuclei Polarized electric dipole moment
2011/7/20
The expression for polarized electric dipole moment of well-deformed reflection asymmetric nuclei is obtained in the framework of liquid-drop model in the case of geometrically similar proton and neut...
Surfatron acceleration of a relativistic particle by electromagnetic plane wave
Surfatron acceleration relativistic particle electromagnetic plane wave
2010/11/16
We study motion of a relativistic charged particle in a plane slow electromagnetic wave and background uniform magnetic field. The wave propagates normally to the background field. Under certain condi...
Spatially probed electron-electron scattering in a two-dimensional electron gas
Spatially probed electron-electron two-dimensional electron gas
2010/11/17
Using scanning gate microscopy (SGM), we probe the scattering between a beam of electrons and a
two-dimensional electron gas (2DEG) as a function of the beam's injection energy, and distance from the...
Intrinsic electron-glassiness in strongly-localized Be films
Intrinsic electron-glassiness strongly-localized Be films
2010/11/18
We present results of out–of-equilibrium transport measurements made on strongly-localized Beryllium films and demonstrate that these films exhibit all the earmarks of intrinsic electron-glasses. Thes...
Quantum Rabi Oscillation of Trapped Ion Driven by Coherent Pulse Streams
Quantum Rabi Oscillation Trapped Ion Driven Coherent Pulse Streams
2010/11/9
Quantum Rabi oscillations driven by a pulse stream are basic operations in Cirac-Zoller scheme of quantum computation. We investigate the failure probability and population inversion of quantum Rabi ...