高速公路破损现浇箱梁拆除及重建

京石高速公路K175＋132白陀北沟桥是我省正在运营的高速公路中首次进行破损现浇连续箱梁拆除施工的工程。随着我国国民经济的发展,高速公路的通车里程越来越多,相应地许多突发事故对桥梁的损害也将增多,如何尽快地修复受损的桥梁,保障高速公路的畅通,是未来公路工程养护及施工中必须解决的一个问题。本文通过该工程的施工,介绍怎样合理选用现阶段比较成熟的技术,对受损的桥梁现浇连续箱梁上部结构进行快速拆除及重建的经验。     

少年女子平衡木助跑团身前空翻的技术特点与训练探讨

本文对“女子平衡木助跑团身前空翻”的技术特点进行了理论分析，并根据这一技术的规律，提出了具体的训练方法。     

应用锚杆支护值得重视的一个问题

锚杆支护是煤巷采准巷道支护的发展方向，顶板条件对支护质量影响重大，本文通过对一次顶板事故的分析，定性、定量的探讨这一问题。     

钢筋混凝土连续箱梁温度收缩应力计算

提出了钢筋混凝土连续箱梁温度收缩应力计算的一种模式，并对这种计算模式作了详细阐述，为工程技术人员采取适当工艺和养护方法来控制混凝土早期裂缝的发生提供了一种依据．     

轴向扩散下不可压饱和多孔简支弹性杆的弯曲

Based on the mathematical model of the bending of the incompressible saturated poroelastic beam with axialdiffusion, the quasi-static bendings of the simply supported poroelastic beam subjected to a suddenly applied constant loadwere investigated, and the analytical solutions were obtained for different diffusion conditions of the pore fluid at the beamends. The deflections, the bending moments of the solid skeleton and the equivalent couples of the pore pressures werepresented in figures. It is also shown that the behavior of the saturated poroelastic beams depends closely on the diffusionconditions at the beam ends, especially for the equivalent couples of the pore pressures. It is found that the Mandel-Cryereffect also exists in the bending of the saturated poroelastic beams under specific diffusion conditions at the beam ends.     

高斯光束照射下的单缝衍射

根据菲涅耳-基尔霍夫衍射理论,将高斯光束的高斯振幅分布近似用抛物线代替,推导出高斯光束照射下单缝衍射光场分布的近似解及其成立条件,并通过实验和数值仿真,讨论了衍射光场的基本特性．     

简支钢—混凝土组合梁考虑滑移效应的曲率分布分析

对受均布荷载的简支钢—混凝土组合梁在考虑滑移效应时挠曲线的曲率进行了计算 ,并进行了曲率分布分析。     

Optical transition and carrier relaxation in self-assembled InAs/GaAs quantum dots with InAlAs and InGaAs combination cap layer by resonant excitation

The photoluminescence （PL） spectra of self-assembled InAs/GaAs quantum dots （QDs） with InAlAs/InGaAs combination cap layer grown by molecular beam epitaxy are studied under different excitation conditions.The intrinsic optical properties of InAs QDs are investigated under resonant excitation condition.A longitudinal optical （LO） phononassisted peak can be well resolved under Eex 〈 E GaAs g,which give evidence that the phonon-related process is dominated for carrier relaxation in InAs QDs with InAlAs/InGaAs combination cap layer when they are under resonant excitation condition.A rate equation model is established to interpret the difference of thermal activation energy （Ea）.The Ea measured under Eex 〈 E GaAs g,can exactly describe the intrinsic physical mechanism of temperature-induced quenching in InAs QDs,because it can be irrespective of the barrier materials.This result will benefit to validating the parameters of quantum dots infrared photodetector （QDIP） in sequent procedure of device fabrication.     

辐射技术处理环境污染物的研究

辐射技术以γ射线或电子束做为基本手段,在环境污染治理中的应用日益广泛.文中阐述了辐射技术的化学基础及其机理,进而介绍了电子束辐照烟气脱硫、辐照处理废水中难降解有机污染物的机理及应用,说明辐射技术在环境保护中具有重要作用.     

Effects of vacancies on interwall spacings of multi-walled carbon nanotubes

We use molecular dynamics （MD） simulations to study the effects of vacancies on tube diameters and interwall spacings of multi-walled carbon nanotubes （MWCNTs）. Two types of vacancies, double vacancy and three dangling-bond （3DB） single vacancy, are identified to have opposite effects on the tube size change, which explains the inconsistency of the experimentally measured interwall spacings of MWCNTs after electron beam irradiation. A theoretical model to quantitatively predict the shrunk structures of the irradiated MWCNTs is further developed. We also discuss the fabrications of prestressed MWCNTs, in which reduced interwall spacings are desired to enhance the overall elastic modulus and strength.