SDN与非SDN的统一网络管理及其可拓实验思路

通过研究SDN与非SDN的统一网络管理,探索其可拓实验思路。首先提出SDN网络管理的"管理者—代理"模型和用于统一网络管理的网关,尝试引入可拓学,依据其可拓创新方法体系,在现有实验平台的基础上,采用共轭分析方法,探索SDN与非SDN的统一网络管理的可拓实验思路,最终为推进学校的"721"梯级、分类、多元人才培养模式改革建立一定的实践基础。

创意植物实验在中学课程中的应用与开发

选择以岭南师范学院附属中学设点来开展创意植物实验,利用师范高校优势以及校园特色植物资源,整合多方优势条件,以期设计开发具有实用性、趣味性以及环保性的创意植物实验。实验内容主要由植物拓染和制作植物标本构成,坚持贯彻“保护环境,变废为宝”的理念提高校园植物的利用价值,促进学生创新精神与实践能力的发展。

高中生物学实验教学的“五重境界”

通过相关实例,阐述高中生物学实验教学中应注重悟实验、做实验、评实验、拓实验和用实验,以切实提高学生的实验能力和学科素养。

The response of collision speed caused by the large bus to new flexible barrier

In order to study the response of collision speed caused by the large bus to new flexible barrier,in this paper,with the large bus as the carrier,the full-scale impact tests between flexible barrier and vehicle with the impact velocities of 40 km/h and 60 km/h were carried out separately,following the procedures of the test preparation,test processing,data acquisition, etc,which were based on the test platform of the Large Structure Crash Testing Laboratory of Changsha University of Science and Technology. The important test results which contain the damage of vehicles and barrier,the moving locus of vehicle,the occupant risk index,the maximum dynamic deformation, etc,were obtained through the analysis under the different collision speeds. These provide the necessary reference basis for the further research on the structure topology optimization and improve the comprehensive constraint performance to the flexible barrier.

A Quantitative Structure Property Relationship for Prediction of Flash Point of Alkanes Using Molecular Connectivity Indices

Many structure-property/activity studies use graph theoretical indices, which are based on the topological properties of a molecule viewed as a graph. Since topological indices can be derived directly from the molecular structure without any experimental effort, they provide a simple and straightforward method for property prediction. In this work the flash point of alkanes was modeled by a set of molecular connectivity indices （Х）, modified molecular connectivity indices （ ^mХ^v ） and valance molecular connectivity indices （ ^mХ^v ）, with ^mХ^v calculated using the hydrogen perturbation. A stepwise Multiple Linear Regression （MLR） method was used to select the best indices. The predicted flash points are in good agreement with the experimental data, with the average absolute deviation 4.3 K.

Flywheel Energy Storage System Based on Boost DC-AC Converter

To extend the operating speed range of a conventional configuration of FESS （flywheel energy storage system）, an additional DC-DC boost converter is required between the machine and grid side converters to regulate the output voltage. This paper presents a new FESS based on three-phase boost inverter topology. The proposed system facilitates voltage boost capability directly in a single-stage. The main advantage of the three-phase boost inverter is the deployment of only six switches and undersized passive elements to obtain a boosted AC output voltage weighed against the input DC supply. In this paper, FESS based on boost inverter topology is modeled and simulated using MATLAB/S1MULINK. An experimental setup has been built for the three-phase boost inverter to present its boosting capability. The simulation and experimental results sustain the proposed configuration.

A brief review on one-dimensional topological insulators and superconductors

Recently one-dimensional topological phases are gaining increasing attentions. Like two- and three-dimensional ones, Onedimensional systems are important in a complete understanding of the topological properties. One-dimensional topological phases have been realized using current experimental setups. Specially the signatures of Majorana fermions have been observed in onedimensional topological superconductors engineered with Rashiba nanowires. From the many studies, the paper reviews typical theoretical models of one-dimensional topological insulators and superconductors. For one-dimensional topological insulators, we introduce the Su-Schrieffer-Heeger, superlattices and Creutz models, while for topological superconductors the Kitaev model and Rashiba nanowire are introduced. These models not only provide an overview of one-dimensional topological phases, but also are the starting points for further studies.

Gapped topological kink states and topological corner states in honeycomb lattice

Based on the tight-binding calculations on honeycomb lattice and photonic experimental visualization on artificial graphene(AG), we report the domain-wall-induced gapped topological kink states and topological corner states. In honeycomb lattice, domain walls(DWs) with gapless topological kink states could be induced either by sublattice symmetry breaking or by lattice deformation. We find that the coexistence of these two mechanisms will induce DWs with gapped topological kink states. Significantly, the intersection of these two types of DWs gives rise to topological corner state localized at the crossing point.Through the manipulation of the DWs, we show AG with honeycomb lattice structure not only a versatile platform supporting multiple topological corner modes in a controlled manner, but also possessing promising applications such as fabricating topological quantum dots composed of gapped topological kink states and topological corner states.

Lagrangian-based spatial-temporal topological study on the evolution and migration of coherent structures in wall turbulence

In this work,we study the development,evolution,and migration of turbulent coherent structures in the turbulent boundary layer at Reτ=630 using time-resolved particle image velocimetry(TR-PIV).Multiple techniques,including multi-scale analysis,conditional averaging,cross-correlation,and spatial-temporal topological analysis are applied to extract the evolution principle,migration trajectory,and convection velocity vector of the targeted coherent structures from a Lagrangian perspective.The spanwise vortex structures with larger scale and intensity at a certain wall-normal height y were the main focus of the present study.In the statistical sense,spanwise vortex structures move away from the wall with the shape changing from a bulge to an ellipse,and finally to a circle.Two straight lines emerge from the mean transfer trajectory curve of the spanwise vortex,in which the horizontal one is located at the viscous sublayer(y^(+)<10),the other is a logarithmic straight line existing in the range of 50<y^(+)<120,and the inclination angle of the tangential migration path is fixed at around 12°.The streamwise convection velocity U_(c)of scaled spanwise vortex structures satisfies U_(c)/U_(∞)=0.5-0.6 below y=0.03δ(i.e.,U^(+)_(c)=11-13 undery^(+)=20).In particular,in the region of 50<y^(+)<120,the velocity growth curves of U_(c)and wall-normal convection velocity V_(c)follow the log-law distribution very well,and the slopes are consistent with that of the log-law region of the turbulent boundary layer.Our observations provide microscopic evidences of the logarithmic-linear distribution of the migration trajectory of spanwise vortex structures.

Majorana zero mode in the vortex of an artificial topological superconductor

Majorana fermion （MF）, an exotic particle that is identical to its own antiparticle, was recently found in solid matter as a quasiparticle excitation, the Majorana zero mode （MZM）, in the vortex of an artificial topological superconductor （TSC）. This artificial TSC, first proposed by Fu and Kane in 2008, is a heterostructure made of a topological insulator BiETe3 and an s-wave superconductor NbSe2. This paper will briefly review the experimental progresses based on the Bi2Te3/NbSe2 heterostructure. All evidences are self-consistent and reveal that the MZM exists in the center of vortex. Those experimental results are also supported by theory. This finding is a milestone in the research ofMajorana fermions in solid state physics and a starting point of MZM＇s application in topological quantum computation.