大型煤炭企业供应链多目标优化研究

在构建大型煤炭企业供应链结构的基础上,分析了煤炭供应链不确定性的因素,进而建立了大型煤炭企业供应链系统的多目标优化模型,模型以利润最大化和客户满意度最大化为目标;而且设计了广义遗传算法求解非线性多目标决策模型,并证实广义遗传算法比传统的遗传算法在求解供应链问题上更具优势.最后通过实证得出结论,模型符合大型煤炭企业实际情况.     

On Models of Nonlinear Evolution Paths in Adiabatic Quantum Algorithms

In this paper,we study two different nonlinear interpolating paths in adiabatic evolution algorithms for solving a particular class of quantum search problems where both the initial and final Hamiltonian are one-dimensional projector Hamiltonians on the corresponding ground state.If the overlap between the initial state and final state of the quantum system is not equal to zero,both of these models can provide a constant time speedup over the usual adiabatic algorithms by increasing some another corresponding "complexity".But when the initial state has a zero overlap with the solution state in the problem,the second model leads to an infinite time complexity of the algorithm for whatever interpolating functions being applied while the first one can still provide a constant running time.However,inspired by a related reference,a variant of the first model can be constructed which also fails for the problem when the overlap is exactly equal to zero if we want to make up the "intrinsic" fault of the second model - an increase in energy.Two concrete theorems are given to serve as explanations why neither of these two models can improve the usual adiabatic evolution algorithms for the phenomenon above.These just tell us what should be noted when using certain nonlinear evolution paths in adiabatic quantum algorithms for some special kind of problems.     

充水压力管道受弹体冲击破坏的实验研究

报导了厚壁管 (外径D =4 5mm ,壁厚H =3mm)和薄壁管 (外径D =4 4mm ,壁厚H =1mm)两组充水压力管道的撞击穿透破坏实验结果 .借助落锤装置实现对三跨连续管梁撞击加载 ,冲头形状有平头、半球头和 90°圆锥头三种 .实验为内空管和管内充水加压 0MPa ,5MPa ,10MPa ,15MPa和 2 0MPa六种工况 .实验得到了不同工况下的破坏模式 ,同时记录了撞击过程中管内压力变化时程曲线及冲击力时程曲线 .实验结果表明 ,内充介质显著降低了薄壁管的穿透能量 ,而对厚壁管的降低程度较小 .随内充介质的压力增高 ,穿透能量也有不同程度的降低 .     

几种演示影响刚体滚动因素的物理实验仪

改进和研制了几种演示刚体平面平行运动(滚动)的物理实验仪,突出演示了转动惯量、滚动半径、刚体质量等因素对运动的影响．仪器结构简单,构思巧妙,演示效果良好．     

永磁体同性磁极相吸现象的研究

永磁体的磁极同性相斥异性相吸现象是人所共知的常识,但在一定条件下却能表现出同性磁极相吸现象．本文对这一现象进行了讨论．     

强震作用下RC延性框架的简化计算

提出了一种RC延性框架抗震设计方法,选取合理的倒塌机构并用虚功原理将其转化为等效的单自由度系统,针对选取的倒塌机构、设防烈度及场地条件计算刚塑性反应谱并据此计算结构的动力需求。以五层和九层RC框架为算例并与弹塑性时程分析比较,研究表明该方法计算简单,精度可靠,可以满足强烈地震作用下RC延性框架抗震设计要求。     

Generation of fast protons in moderate-intensity laser－plasma interaction from rear sheath

Forward fast protons are generated by the moderate-intensity laser--foil interaction. Protons with maximum energy 190~keV are measured by using magnetic spectrometer and CR-39 solid state track detectors along the direction normal to the rear surface. The experimental results are also modeled by the particle-in-cell method, investigating the time-varying electron temperature and the rear sheath field. The temporal and spatial structure of the sheath electrical field, revealed in the simulation, suggests that these protons are accelerated by target normal sheath acceleration (TNSA) mechanism.     

载荷和电压对纯铜滚动载流摩擦学性能的影响

基于FTM-CF100型滚动载流摩擦试验机,研究了纯铜滚动载流摩擦副在不同载荷和外加电压下的性能变化规律,并利用扫描电子显微镜、白光干涉三维形貌仪等对摩擦表面进行微观分析,揭示了稳态运行时性能变化的机理.研究表明:增加载荷和增加电压均促进粗糙接触表面发生形变,真实接触面积的增加降低了接触电阻,摩擦区域粗糙度的改善提高了动态摩擦系数和动态电阻的稳定性.但电阻热促进材料黏着,因而同一载荷下载流摩擦系数高于单纯机械摩擦系数,且随外加电压的增加持续增加.     

乳化液环境中WC/a-C:H薄膜摩擦行为的研究

采用等离子体增强化学气相沉积复合磁控溅射法制备了WC/a-C:H薄膜.使用X射线衍射仪、扫描电镜、X射线光电子能谱、拉曼光谱和透射电镜表征了薄膜结构和组成,并使用球盘往复摩擦试验机测试薄膜在不同体系乳化液环境中的摩擦学性能.结果表明:WC/a-C:H薄膜具有典型的类金刚石结构,WC以β-WC1-x相的形式存在. WC在碳基薄膜中的掺杂使WC/a-C:H薄膜的硬度和弹性模量分别变化至11和140 GPa.油膜、水膜与转移膜的协同润滑效应能够提升其耐磨能力.适宜的浓度配比和薄膜表面石墨化程度是影响摩擦的关键因素.     

轴向载荷下功能梯度材料Timoshenko梁动力屈曲分析

假设功能梯度材料Timoshenko梁各项物性参数只沿厚度方向按幂函数进行连续变化,研究了功能梯度材料Timoshenko梁的动力屈曲。基于一阶剪切理论,采用Hamilton原理推导出轴向载荷作用下,功能梯度材料Timoshenko梁动力屈曲的控制方程。利用里兹法与棣莫弗公式相结合,获得了功能梯度材料Timoshenko梁在夹支-固支边界条件下动力屈曲临界载荷的解析表达式和屈曲解。应用MATLAB编程计算,讨论了功能梯度材料Timoshenko梁的几何尺寸、梯度指数、模态数、材料构成、泊松比以及弹性模量对临界载荷的影响。结果表明:功能梯度材料Timoshenko梁动力屈曲临界载荷随梁长度的增大而减小,随着梯度指数的增大而减小,随模态数的增大而增大,说明冲击载荷越大,高阶模态越容易被激发;随着泊松比和弹性模量的增大而增大,且泊松比的影响较小,而弹性模量的影响较大。由于剪切项的影响,临界载荷-临界长度的关系曲线在加载端变化趋势平缓。随着模态数的增大,梁的屈曲模态越为复杂。