基于概念图的单元知识结构化方法——以高中物理“原子结构”单元为例

立足于核心素养培养的大概念教学是目前课堂教学改革的方向之一,大概念教学倡导基于整体的单元设计.以高中物理"原子结构"为例,从解读学科课程标准,确立单元教学观念目标;解析学科教材内容,确定单元核心概念;分析学生的认知、心理层次,设计学习进阶路径3个方面探讨基于概念图的单元知识结构化方法,为基于整体的单元教学设计提供参考.     

First-principles study of atomic and electronic structures of kaolinite in soft rock

Kaolinite is a kind of clay mineral which often causes large deformations in soft-rock tunnel engineering and thus causes safety issues. To deal with these engineering safety issues, the physical/chemical properties of the kaolinite should be studied from basic viewpoints. By using the density-functional theory, in this paper, the atomic and the electronic structures of the kaolinite are studied within the local-density approximation (LDA). It is found that the kaolinite has a large indirect band gap with the conduction band minimum (CBM) and the valence band maximum (VBM) being at the Γ and the B points, respectively. The chemical bonding between the cation and the oxygen anion in kaolinite is mainly ionic, accompanied by a minor covalent component. It is pointed that the VBM and the CBM of kaolinite consist of oxygen 2p and cation s states, respectively. The bond lengths between different cations and anions, as well as of the different OH groups, are also compared.     

船舶焊接技术的缺陷类型及其处理对策

基于船舶焊接技术缺陷类型与成因的分析、总结,提出船舶焊接缺陷的处理对策,包括焊缝修补要点、焊缝内外部缺陷的防控措施,最后对焊接缺陷区域定位、缺陷特征提取和缺陷分类识别的方法进行举例,旨在为今后深入研究船舶焊接缺陷的检测与识别方法提供理论指导.     

加权Fock空间F_α~2上的测不准原理的推广（英文）

对α 0,本文主要研究了复平面上的加权Fock空间F_α~2上的自伴算子和线性算子的测不准原理.利用泛函分析中的一般性原理,在F_α~2上构造了两个线性算子Tf=(f′)/α和T*=zf.进一步,构造了满足条件的两个自伴算子A和B,使得[A,B]为恒等算子的常数倍,得到了F_α~2上更精确的算子的测不准原理形式,其中T*是T的对偶算子,[A,B]=AB-BA为A和B的换位置.本文的结果推广并完善了屈非非和朱克和在文献[1]和[2]中的结果.