小组工作(Social Group Work),是社会工作专业三大基本工作方法之一,旨在通过有目的小组活动,协助个人开发潜能、实现成长。大学生小组工作,是以大学生为服务对象开展的小组工作领域。笔者运用行动研究方法,在近三年的实践基础上,提出&q...小组工作(Social Group Work),是社会工作专业三大基本工作方法之一,旨在通过有目的小组活动,协助个人开发潜能、实现成长。大学生小组工作,是以大学生为服务对象开展的小组工作领域。笔者运用行动研究方法,在近三年的实践基础上,提出"GEC大学生小组工作模式"(以下简称GEC模式),即针对不同年级大学生所面临的实际问题,分别开展成长小组(Growth Group)、增能小组(Empowerment Group)、职业生涯规划小组(Ca-reer Planning Group),真正实现"小组伴我成长"的理念。本文将阐述GEC模式的提出背景、运行机制、实践情况及评估结果。展开更多
We investigate the elastic and the thermodynamic properties of nanolaminate V2GeC by using the ab initio pseudopotential total energy method. The axial compressibility shows that the c axis is always stiffer than the ...We investigate the elastic and the thermodynamic properties of nanolaminate V2GeC by using the ab initio pseudopotential total energy method. The axial compressibility shows that the c axis is always stiffer than the a axis. The elastic constant calculations demonstrate that the structural stability is within 0-800 GPa. The calculations of Young＇s and shear moduli reveal the softening behaviour at about 300 GPa. The Possion ratio makes a higher ionic or a weaker covalent contribution to intra-atomic bonding and the degree of ionicity increases with pressure. The relationship between brittleness and ductility shows that V2GeC is brittle in ambient conditions and the brittleness decreases and ductility increases with pressure. Moveover, we find that V2CeC is largely isotropic in compression and in shear, and the degree of isotropy decreases with pressure. The Griineisen parameter, the Debye temperature and the thermal expansion coefficient are also successfully obtained for the first time.展开更多
This paper presented a new Floquet analysis used to calculate the radiation for 1-D and 2-D coupled periodic antenna systems. In this way, an accurate evaluation of mutual coupling can be proven by using a new mutual ...This paper presented a new Floquet analysis used to calculate the radiation for 1-D and 2-D coupled periodic antenna systems. In this way, an accurate evaluation of mutual coupling can be proven by using a new mutual interaction expression that was based on Fourier analysis. Then, this work indicated how Floquet analysis can be used to study a finite array with uniform amplitude and linear phase distribution in both x and y directions. To modelize the proposed structures, two formulations were given in a spectral and spatial domain, where the Moment (MoM) method combined with a generalized equivalent circuit (GEC) method was applied. Radiation pattern of coupled periodic antenna was shown by varying many parameters, such as frequencies, distance and Floquet states. The 3-D radiation beam of the coupled antenna array was analyzed and compared in several steering angles θs and coupling values dx. The simulation of this structure demonstrated that directivity decreased at higher coupling values. The secondary lobs in the antenna radiation pattern affected the main lobe gain by energy dispersal and considerable increasing of side lobe level (SLL) may be achieved. Therefore, the sweeping of the radiation beam in several steering directions affected the electromagnetic performance of the antenna system: the directivity at the steering angle θs = π⁄3 was more damaged and had 19.99 dB while the second at θs = 0 had about 35.11 dB. This parametric study of coupled structure used to concept smart periodic antenna with sweeping radiation beam.展开更多
在7月12日结束的GECCO 2020国际会议中,华中科技大学计算机学院吕志鹏教授课题组与华为云擎天架构算法团队深度合作,同时获得了最优相机布局(Optimal Camera Placement,OCP)与单成本集合覆盖问题(Unicost Set Covering Problem,USCP)竞...在7月12日结束的GECCO 2020国际会议中,华中科技大学计算机学院吕志鹏教授课题组与华为云擎天架构算法团队深度合作,同时获得了最优相机布局(Optimal Camera Placement,OCP)与单成本集合覆盖问题(Unicost Set Covering Problem,USCP)竞赛两项分赛道的冠军及总冠军。GECCO会议始办于1999年,是进化计算领域最重要的盛会之一。展开更多
In previous modeling works, the waveguide radiation in the free space is modeled using an infinite flange in aperture plan. In this paper, we propose a new formulation to analyze the radiation of twin rectangular wave...In previous modeling works, the waveguide radiation in the free space is modeled using an infinite flange in aperture plan. In this paper, we propose a new formulation to analyze the radiation of twin rectangular waveguides in free space. Our formulation consists firstly in simulating the free space as rectangular waveguide and seeking the appropriate dimensions that do not affect scattering parameters. In the second step, we use the symmetry principle to reduce the coupling problem to single guide radiating in the free space. Moreover, for more simplification, we consider a concentric discontinuity to solve this latter. This approach is based on moments method combined to the generalized equivalent circuit method (MoM-GEC) in order to reduce the number of unknown problems and alleviate their computation. Obtained numerical results are presented and discussed. A good agreement with literature is shown and the boundary conditions are verified.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 10974139, 10964002 and 11104247)the Natural Science Foundation of Guizhou Province, China (Grant No. [2009]2066)+1 种基金the Project of Aiding Elites' Research Condition of Guizhou Province, China (Grant No. TZJF-2008-42)the Science Foundation from Education Ministry of Zhejiang Province,China (Grant No. Y201121807)
文摘We investigate the elastic and the thermodynamic properties of nanolaminate V2GeC by using the ab initio pseudopotential total energy method. The axial compressibility shows that the c axis is always stiffer than the a axis. The elastic constant calculations demonstrate that the structural stability is within 0-800 GPa. The calculations of Young＇s and shear moduli reveal the softening behaviour at about 300 GPa. The Possion ratio makes a higher ionic or a weaker covalent contribution to intra-atomic bonding and the degree of ionicity increases with pressure. The relationship between brittleness and ductility shows that V2GeC is brittle in ambient conditions and the brittleness decreases and ductility increases with pressure. Moveover, we find that V2CeC is largely isotropic in compression and in shear, and the degree of isotropy decreases with pressure. The Griineisen parameter, the Debye temperature and the thermal expansion coefficient are also successfully obtained for the first time.
文摘This paper presented a new Floquet analysis used to calculate the radiation for 1-D and 2-D coupled periodic antenna systems. In this way, an accurate evaluation of mutual coupling can be proven by using a new mutual interaction expression that was based on Fourier analysis. Then, this work indicated how Floquet analysis can be used to study a finite array with uniform amplitude and linear phase distribution in both x and y directions. To modelize the proposed structures, two formulations were given in a spectral and spatial domain, where the Moment (MoM) method combined with a generalized equivalent circuit (GEC) method was applied. Radiation pattern of coupled periodic antenna was shown by varying many parameters, such as frequencies, distance and Floquet states. The 3-D radiation beam of the coupled antenna array was analyzed and compared in several steering angles θs and coupling values dx. The simulation of this structure demonstrated that directivity decreased at higher coupling values. The secondary lobs in the antenna radiation pattern affected the main lobe gain by energy dispersal and considerable increasing of side lobe level (SLL) may be achieved. Therefore, the sweeping of the radiation beam in several steering directions affected the electromagnetic performance of the antenna system: the directivity at the steering angle θs = π⁄3 was more damaged and had 19.99 dB while the second at θs = 0 had about 35.11 dB. This parametric study of coupled structure used to concept smart periodic antenna with sweeping radiation beam.
文摘在7月12日结束的GECCO 2020国际会议中,华中科技大学计算机学院吕志鹏教授课题组与华为云擎天架构算法团队深度合作,同时获得了最优相机布局(Optimal Camera Placement,OCP)与单成本集合覆盖问题(Unicost Set Covering Problem,USCP)竞赛两项分赛道的冠军及总冠军。GECCO会议始办于1999年,是进化计算领域最重要的盛会之一。
文摘In previous modeling works, the waveguide radiation in the free space is modeled using an infinite flange in aperture plan. In this paper, we propose a new formulation to analyze the radiation of twin rectangular waveguides in free space. Our formulation consists firstly in simulating the free space as rectangular waveguide and seeking the appropriate dimensions that do not affect scattering parameters. In the second step, we use the symmetry principle to reduce the coupling problem to single guide radiating in the free space. Moreover, for more simplification, we consider a concentric discontinuity to solve this latter. This approach is based on moments method combined to the generalized equivalent circuit method (MoM-GEC) in order to reduce the number of unknown problems and alleviate their computation. Obtained numerical results are presented and discussed. A good agreement with literature is shown and the boundary conditions are verified.
