动态配位空间的构筑与调控

“配位空间”(Coordination Space)是无机-有机杂化体系中的构筑基元通过配位键连接形成的具有特定结构和功能的空间。这一概念为基于配位键的框架体系的定向构筑与结构-性能调控提供了新的视角。作为典型的无机-有机杂化材料,金属-有机框架(Metal-Organic Framework,MOF)及金属有机笼(Metal-Organic Cage,MOC)等近年来受到广泛关注。这类材料的构筑与性能调控的核心可以认为是对其配位空间的结构设计与性能调控。具有刺激响应性的MOF可展现动态的配位空间,使其在吸附分离、传感、药物投递等方面具有重要的应用前景。本文将以动态金属有机框架的相关研究为基础简述动态配位空间研究的近期进展,包括其动态行为产生的结构基础、诱发因素及相关性能,归纳结构-性能的关系,为相关研究提供参考。     

中墩斜置对连续箱梁弯扭性能的影响

为了揭示中墩斜支承对连续箱梁力学性能的影响,本文考虑约束扭转和竖向挠曲耦合作用,建立了斜支承连续箱梁的力法方程,并获得了内力和变形的解析式.选取斜支承两跨连续箱梁为数值算例,分别计算了竖向对称和偏心均布荷载作用下的内力和变形,并用ANSYS软件计算了控制截面的弯矩.计算结果表明,本文方法计算的弯矩与ANSYS计算值吻合...     

Study of closed orbit response to magnet vibrations at the SSRF storage ring

This paper presents the analytical and simulation responses of the closed orbit distortion in the SSRF storage ring to random and plane wave like magnet vibrations respectively. It is shown that the use of girder is very beneficial in the view of suppressing this response function. Effect of the independently supported gradient bending magnets to the closed orbit response is given. An analytic formula is written to give a rough estimate of the closed orbit distortion due to ground motion, taking into account the closed orbit response function and girder transfer function. As an example, the result of SSRF case is given.     

Something out of nothing: a Bayesian learning computational model for the social construction of value

ABSTRACT

This article develops a formalism for the social construction of value. Using a model based on Bayesian agents, it demonstrates how “something” arises out of “nothing” via the emergence of durable value conventions and shows how the developed framework can be used to investigate socially constructed valuations under a variety of circumstances. The resulting analysis clarifies why assumptions that collectives will converge upon the “intrinsic” (i.e., non-socially originating) value of an object (e.g., market efficiency) may not hold for mixed social and non-social valuation regimes, explains the dependency of socially constructed valuations on early accidents, demonstrates the effects of confident actors on constructed values, and identifies the production of time-dependent ratcheting effects from the interaction of bubbles with value conventions.     

高速铁路连续箱型梁桥的动力响应与减振分析

根据列车具体的轴距和轴重,建立了和谐号动车组CRH380AL型列车简化模型;对高速铁路两跨连续梁桥采用多自由度欧拉伯努利梁单元进行主梁的模拟,并将液体黏滞阻尼器模拟为有限元阻尼单元;采用Newmark直接积分方法求解了高速列车作用下的连续梁桥运动方程,数值分析了列车车速以及液体黏滞阻尼器的阻尼系数对于高速铁路连续梁桥振动响应的影响。结果表明:黏滞阻尼器对于桥梁具有明显的减振效果,阻尼力不仅与阻尼系数有关还与列车时速有关;同一黏滞阻尼器条件下,桥梁的最大加速度并不随列车速度的增加而单调增加,而是在某些特定列车车速下桥梁的最大加速度出现了峰值,且随着黏滞阻尼器的阻尼系数增大,桥梁振动响应峰值处的最大加速度减幅不同;同一列车时速的条件下,桥梁的减振效果并不是随着阻尼系数的递增呈正比递增,而是随着阻尼系数的增大,阻尼器的减振效果增幅在减小。     

Constructing permutation polynomials from piecewise permutations

We present a construction of permutation polynomials over finite fields by using some piecewise permutations. Based on a matrix approach and an interpolation approach, several classes of piecewise permutation polynomials are obtained.     

简支及悬臂箱梁在角隅轴向荷载作用下的翼板纵向应力

基于能量变分原理，拟定轴向荷载作用下箱梁的纵向位移函数，得到关于翼板剪切变形引起的位移差函数的基本微分方程，继而推导出箱梁翼板纵向应力表达式，并首次得出角隅轴向荷载作用下翼板出现应力不均匀分布的荷载及边界条件。通过对一模型箱梁进行计算，并与通用有限元软件ANSYS壳单元计算结果进行比较，验证了该方法和所推导公式的正确性。研究结果表明，当作用于简支箱梁截面角隅处的轴向荷载（合力无偏心）为集中或分布荷载时，翼板不产生纵向应力不均匀现象；当作用于悬臂箱梁截面角隅处的轴向荷载（合力无偏心）为集中荷载时，翼板不产生纵向应力不均匀现象，而当荷载轴向分布时，翼板将产生纵向应力不均匀现象。实际工程中，横力弯曲使悬臂箱梁产生剪力滞效应，这种效应会与轴向分布荷载产生的效应叠加，设计时对此应予以充分考虑。     

分子模拟实验课程建设的探索与实践

We put forward the idea of building a molecular simulation experiment course. After two-year teaching practice, we write the experiment textbook which not only covers the classic experimental projects, but also includes the frontier hot issues, and open exploration experiment. This article summarizes the teaching requirements, basic content, assessment methods, the initial achievements made so far and the prospects for the future.     

地方综合性大学化学创新人才培养课程新体系的建设

构建课程新体系和改革教学内容是高等教育改革永恒的主题。本文立足于地方综合性大学的特点,通过构建"四位一体"课程新体系,形成三层次的课程模块,进行多角度、多层面的课程内容改革,为化学创新型人才的培养奠定了基础。     

A refined cavity construction algorithm for the conductor‐like screening model

A cavity construction algorithm based on the triangulation of an iso‐surface is introduced as a new standard for dielectric continuum solvation calculations with the Conductor‐like Screening Model COSMO. It overcomes deficiencies which have become apparent for the original COSMO standard cavity, especially in concave regions of the molecular shaped cavity. The new standard, called FINE Cavity, is described in this article with several application examples. The earlier COSMO cavity construction algorithms are described for comparison. © 2018 Wiley Periodicals, Inc.