Simultaneous effects of conduction band non-parabolicity and hydrostatic pressure on the binding energies of 1S, 2S, and 2P states along with diamagnetic susceptibility of an on-center hydrogenic impurity confined in ...Simultaneous effects of conduction band non-parabolicity and hydrostatic pressure on the binding energies of 1S, 2S, and 2P states along with diamagnetic susceptibility of an on-center hydrogenic impurity confined in typical GaAs/Alx- Ga1-x As spherical quantum dots are theoretically investigated using the matrix diagonalization method. In this regard, the effect of band non-parabolieity has been performed using the Luttinger-Kohn effective mass equation. The binding energies and the diamagnetic susceptibility of the hydrogenic impurity are computed as a function of the dot radius and different values of the pressure in the presence of conduction band non-parabolicity effect. The results we arrived at are as follows： the incorporation of the band edge non-parabolicity increases the binding energies and decreases the absolute value of the diamagnetic susceptibility for a given pressure and radius; the binding energies increase and the magnitude of the diamagnetic susceptibility reduces with increasing pressure.展开更多
Drainage layers provide permanent relief of hydrostatic water pressure, while the waterproof liner prevents any ingress of water into the tunnel. The durability and aging resistance of drainage membranes are of primar...Drainage layers provide permanent relief of hydrostatic water pressure, while the waterproof liner prevents any ingress of water into the tunnel. The durability and aging resistance of drainage membranes are of primary concern. This paper describes advantages and concerns related to the usage of, and the design with, polymeric drainboards in tunnel construction. Common degradation mechanisms associated with HDPE （high density polyethylene） sheets are described. The stringent requirements for the Gotthard Alpine Railway Tunnel through the Swiss Alps, e.g., high ambient temperatures of up to 45 ℃ and an expected service life of up to 100 years require outstanding aging resistance of polymeric drainage materials. The paper describes the methods deployed to investigate the long-term performance of HDPE drainboards, focusing on aging mechanisms. Details associated with the test procedures developed to reflect the specific properties of drainboards, as well as the results obtained, are presented. A summary table shows recommended product specifications needed to confine the aging properties of drainboards and to design a system performing adequately during the entire lifetime of the structure.展开更多
The present article concerns the continuum modelling of the mechanical behaviour and equilibrium shapes of two types of nano-scale objects： fluid lipid bilayer membranes and carbon nanostructures. A unified continuum...The present article concerns the continuum modelling of the mechanical behaviour and equilibrium shapes of two types of nano-scale objects： fluid lipid bilayer membranes and carbon nanostructures. A unified continuum model is used to handle four different ease studies. Two of them consist in representing in analytic form cylindrical and axisymmetric equilibrium configurations of single-wall carbon nanotubes and fluid lipid bilayer membranes subjected to uniform hydrostatic pressure. The third one is concerned with determination of possible shapes of junctions between a single-wall carbon nanotube and a fiat graphene sheet or another single-wall carbon nanotube. The last one deals with the mechanical behaviour of closed fluid lipid bilayer membranes （vesicles） adhering onto a fiat homogeneous rigid substrate subjected to micro-injection and uniform hydrostatic pressure.展开更多
文摘Simultaneous effects of conduction band non-parabolicity and hydrostatic pressure on the binding energies of 1S, 2S, and 2P states along with diamagnetic susceptibility of an on-center hydrogenic impurity confined in typical GaAs/Alx- Ga1-x As spherical quantum dots are theoretically investigated using the matrix diagonalization method. In this regard, the effect of band non-parabolieity has been performed using the Luttinger-Kohn effective mass equation. The binding energies and the diamagnetic susceptibility of the hydrogenic impurity are computed as a function of the dot radius and different values of the pressure in the presence of conduction band non-parabolicity effect. The results we arrived at are as follows： the incorporation of the band edge non-parabolicity increases the binding energies and decreases the absolute value of the diamagnetic susceptibility for a given pressure and radius; the binding energies increase and the magnitude of the diamagnetic susceptibility reduces with increasing pressure.
文摘Drainage layers provide permanent relief of hydrostatic water pressure, while the waterproof liner prevents any ingress of water into the tunnel. The durability and aging resistance of drainage membranes are of primary concern. This paper describes advantages and concerns related to the usage of, and the design with, polymeric drainboards in tunnel construction. Common degradation mechanisms associated with HDPE （high density polyethylene） sheets are described. The stringent requirements for the Gotthard Alpine Railway Tunnel through the Swiss Alps, e.g., high ambient temperatures of up to 45 ℃ and an expected service life of up to 100 years require outstanding aging resistance of polymeric drainage materials. The paper describes the methods deployed to investigate the long-term performance of HDPE drainboards, focusing on aging mechanisms. Details associated with the test procedures developed to reflect the specific properties of drainboards, as well as the results obtained, are presented. A summary table shows recommended product specifications needed to confine the aging properties of drainboards and to design a system performing adequately during the entire lifetime of the structure.
基金Supported by the Bulgarian Ministry of Education, Youth and Science under the Project "Science and Business" BG051PO001/3.3-05-001 within "Human Resources Development" Operational Program of the European Social Fund
文摘The present article concerns the continuum modelling of the mechanical behaviour and equilibrium shapes of two types of nano-scale objects： fluid lipid bilayer membranes and carbon nanostructures. A unified continuum model is used to handle four different ease studies. Two of them consist in representing in analytic form cylindrical and axisymmetric equilibrium configurations of single-wall carbon nanotubes and fluid lipid bilayer membranes subjected to uniform hydrostatic pressure. The third one is concerned with determination of possible shapes of junctions between a single-wall carbon nanotube and a fiat graphene sheet or another single-wall carbon nanotube. The last one deals with the mechanical behaviour of closed fluid lipid bilayer membranes （vesicles） adhering onto a fiat homogeneous rigid substrate subjected to micro-injection and uniform hydrostatic pressure.
