The abelian(p+1)-form gauge field is inherently coupled to the p-brane worldvolume.After quantization,the corresponding p-form gauge transformation is associated with the local phase ambiguity of the p-brane wave func...The abelian(p+1)-form gauge field is inherently coupled to the p-brane worldvolume.After quantization,the corresponding p-form gauge transformation is associated with the local phase ambiguity of the p-brane wave functional.In essence,p-form gauge symmetry can be realized as a special construction of generic zero-form gauge symmetry in the functional space of p-brane configurations.The non-abelian generalization is straightforward in the functional space language.To simplify the analysis,we further introduce a toy model where the infinite dimensional functional space of p-brane configurations is replaced by a finite dimensional matrix space.After taking the symmetric trace in the matrix model,the original discussions of the p-form gauge symmetry can be inherited by the toy model.展开更多
In this paper,we aim to explore the properties and applications on the operators consisting of the Hodge star operator together with the exterior derivative,whose action on an arbitrary p-form field in n-dimensional s...In this paper,we aim to explore the properties and applications on the operators consisting of the Hodge star operator together with the exterior derivative,whose action on an arbitrary p-form field in n-dimensional spacetimes makes its form degree remain invariant.Such operations are able to generate a variety of p-forms with the even-order derivatives of the p-form.To do this,we first investigate the properties of the operators,such as the Laplace–de Rham operator,the codifferential and their combinations,as well as the applications of the operators in the construction of conserved currents.On the basis of two general p-forms,then we construct a general n-form with higher-order derivatives.Finally,we propose that such an n-form could be applied to define a generalized Lagrangian with respect to a p-form field according to the fact that it includes the ordinary Lagrangians for the p-form and scalar fields as special cases.展开更多
高耸结构P-Δ效应的传统分析方法一般难以考虑时变轴力作用,有可能会低估P-Δ效应对结构安全性的影响.本文应用求积单元法(weak form quadrature element method,QEM),针对分布质量结构体系和含有集中质量的结构体系分别建立Hermite型...高耸结构P-Δ效应的传统分析方法一般难以考虑时变轴力作用,有可能会低估P-Δ效应对结构安全性的影响.本文应用求积单元法(weak form quadrature element method,QEM),针对分布质量结构体系和含有集中质量的结构体系分别建立Hermite型求积单元模型,发展了一种高耸结构P-Δ效应高阶精确分析方法.该方法能够应用于具有突变质量的结构体系,可处理任意轴向荷载引起的动力P-Δ效应问题,无需迭代计算即可获得高精度的P-Δ效应解答,同时能准确地揭示竖向荷载以及时变轴力对高耸结构特性的影响规律.通过对3个不同类型案例的比较分析,验证了本文方法的可行性和准确性.数值分析结果表明,本文方法可以实现高精度的P-Δ效应分析,对于质量均匀分布和含有集中质量的结构体系仅需使用一个求积单元即可获得非常精确的动态响应结果.展开更多
在焊接热输入相同的条件下对比研究了直流反接的熔化极惰性气体保护焊(Gas metal arc welding,GMAW)中直流脉冲模式(Pulsed gas metal arc welding,P-GMAW)和恒流模式(Constant current gas metal arc welding,CC-GMAW)对5083-H111铝合...在焊接热输入相同的条件下对比研究了直流反接的熔化极惰性气体保护焊(Gas metal arc welding,GMAW)中直流脉冲模式(Pulsed gas metal arc welding,P-GMAW)和恒流模式(Constant current gas metal arc welding,CC-GMAW)对5083-H111铝合金薄板焊接接头的成形、微观组织和力学性能等的影响。结果表明:5083铝合金P-GMAW焊接接头成型平整美观,脉冲在一定程度上抑制了焊缝气孔的生成。热输入相同时P-GMAW焊缝内生成的柱状晶面积占比更大,表明P-GMAW热源焊接的熔池温度梯度更大。两种模式焊缝的力学性能相近,接头强度约为288~303 MPa,达到了母材抗拉强度的90%。接头的断裂位置均在焊缝区,断口呈韧性断裂的韧窝形貌,焊缝强度的降低与其粗大的晶粒和气孔缺陷有关。展开更多
基金supported by National Natural Science Foundation of China(Grants No.12275217,12247103).
文摘The abelian(p+1)-form gauge field is inherently coupled to the p-brane worldvolume.After quantization,the corresponding p-form gauge transformation is associated with the local phase ambiguity of the p-brane wave functional.In essence,p-form gauge symmetry can be realized as a special construction of generic zero-form gauge symmetry in the functional space of p-brane configurations.The non-abelian generalization is straightforward in the functional space language.To simplify the analysis,we further introduce a toy model where the infinite dimensional functional space of p-brane configurations is replaced by a finite dimensional matrix space.After taking the symmetric trace in the matrix model,the original discussions of the p-form gauge symmetry can be inherited by the toy model.
基金supported by the Natural Science Foundation of China under Grant Nos.11865006 and 11505036partially supported by the Technology Department of Guizhou province Fund under Grant Nos.[2018]5769 and[2016]1104。
文摘In this paper,we aim to explore the properties and applications on the operators consisting of the Hodge star operator together with the exterior derivative,whose action on an arbitrary p-form field in n-dimensional spacetimes makes its form degree remain invariant.Such operations are able to generate a variety of p-forms with the even-order derivatives of the p-form.To do this,we first investigate the properties of the operators,such as the Laplace–de Rham operator,the codifferential and their combinations,as well as the applications of the operators in the construction of conserved currents.On the basis of two general p-forms,then we construct a general n-form with higher-order derivatives.Finally,we propose that such an n-form could be applied to define a generalized Lagrangian with respect to a p-form field according to the fact that it includes the ordinary Lagrangians for the p-form and scalar fields as special cases.
文摘高耸结构P-Δ效应的传统分析方法一般难以考虑时变轴力作用,有可能会低估P-Δ效应对结构安全性的影响.本文应用求积单元法(weak form quadrature element method,QEM),针对分布质量结构体系和含有集中质量的结构体系分别建立Hermite型求积单元模型,发展了一种高耸结构P-Δ效应高阶精确分析方法.该方法能够应用于具有突变质量的结构体系,可处理任意轴向荷载引起的动力P-Δ效应问题,无需迭代计算即可获得高精度的P-Δ效应解答,同时能准确地揭示竖向荷载以及时变轴力对高耸结构特性的影响规律.通过对3个不同类型案例的比较分析,验证了本文方法的可行性和准确性.数值分析结果表明,本文方法可以实现高精度的P-Δ效应分析,对于质量均匀分布和含有集中质量的结构体系仅需使用一个求积单元即可获得非常精确的动态响应结果.
文摘在焊接热输入相同的条件下对比研究了直流反接的熔化极惰性气体保护焊(Gas metal arc welding,GMAW)中直流脉冲模式(Pulsed gas metal arc welding,P-GMAW)和恒流模式(Constant current gas metal arc welding,CC-GMAW)对5083-H111铝合金薄板焊接接头的成形、微观组织和力学性能等的影响。结果表明:5083铝合金P-GMAW焊接接头成型平整美观,脉冲在一定程度上抑制了焊缝气孔的生成。热输入相同时P-GMAW焊缝内生成的柱状晶面积占比更大,表明P-GMAW热源焊接的熔池温度梯度更大。两种模式焊缝的力学性能相近,接头强度约为288~303 MPa,达到了母材抗拉强度的90%。接头的断裂位置均在焊缝区,断口呈韧性断裂的韧窝形貌,焊缝强度的降低与其粗大的晶粒和气孔缺陷有关。
