An Approach to Constructing a Rheological Model of a Strain-Hardening Medium

The one-dimensional constitutive equations of strain-hardening materials subject to nonlinear creep are derived. The solution is found using the hypothesis of unified deformation curve based on the similarity of the tensile and isochronic creep curves. A generalized rheological model is constructed which accounts for the instantaneous strain rate, loading rate, and the mode of strain hardening. This model is used to derive one-dimensional constitutive equations for linear viscoelastic, nonlinear viscoelastic, and linear- and nonlinear-hardening viscoelastoplastic materials. It is shown that the creep of linear viscoelastic and linear-hardening viscoelastoplastic materials is transient. For nonlinear viscoelastic and nonlinear-hardening viscoelastoplastic materials, all the characteristic stages of creep are present     

跨文化商务谈判中的人际语

人际语作为跨文化商务谈判的一部分被认为是交换信息和情感的一种方式,拥有丰富的人际语知识可以帮助人们在谈判中有效地避免不必要的冲突和误会。文章讨论了人际语在谈判开始、谈判中以及谈判结束阶段的应用,以说明人际语对商务谈判效果的影响。     

购物中心被动设计节能潜力的标准化模拟

通过标准化的建模及模拟,对购物中心被动设计在方案阶段的节能潜力展开量化评价。以寒冷地区为例,提取出具有典型气候特征的3种购物中心标准几何模型和运行参数;并选取Grasshopper和EnergyPlus分别作为参数化建模和能耗模拟软件;同时,从场地、建筑和围护结构3个层面,总结出影响购物中心节能潜力的24个被动设计参量;最终通过模拟得到24个被动设计参量在3种标准模型中的节能潜力及排序。结果表明：入口风速、走廊空间、天窗面积比和屋面传热系数是影响寒冷地区购物中心节能潜力的4个重要设计参量,此结果可为设计师在方案阶段进行建筑优化设计提供量化指导。     

Spin polarization and structure of molecular oxygen adsorbed on Fe(1 1 0)

We investigated the structural and magnetic properties of Fe(1 1 0) for molecular oxygen adsorption at room temperature. For the c(2 × 2) and c(3 × 1) superstructures, spin-polarized secondary electron emission (SPSEE) induced by protons and electrons reveals a nearly unchanged polarization compared to clean Fe(1 1 0). An appreciable decrease in polarization is found for the disordered layer of oxygen at a coverage Θ ≈ 1. This decrease is more pronounced for the spin polarization determined by electron capture (EC) to excited atomic He levels after grazing scattering. From a comparison of data obtained by proton-induced SPSEE and spin-polarized EC we conclude that the polarization at the vacuum boundary vanishes for an oxygen coverage Θ ≈ 1 while the polarization in the underlying Fe substrate layers is hardly changed.     

不同发展阶段高中化学教师的PCK表征研究*——以“物质的量”主题为例

为探讨不同发展阶段的高中化学教师对于“物质的量”主题的认识,聚焦学科教学知识(PCK)的2个基本组成部分:(1)学生理解的知识,(2)教学策略和表征知识。基于PCK课堂观察量表和CoRe模型,对比分析新手、熟手、专家型教师关于“物质的量”主题的PCK表征。研究结果表明,不同发展阶段化学教师的PCK存在差异,教师对学生知识的理解影响了教学策略和表征方式的决策。     

Influence of the physiological stage and the content of soluble solids on the anthocyanin extractability of Vitis vinifera L. cv. Tempranillo grapes

The influence and the extent of the anthocyanin extractability from grape skins at different physiological stages and different soluble solids contents within each stage were investigated. For this purpose three different physiological stages (pre-harvest, harvest and over-ripening) and three soluble solids contents (22, 24 and 26 °Brix) within each stage were taken into account using Vitis vinifera L. cv. Tempranillo.     

具外来感染者和急慢性阶段流行病模型的周期解

建立和研究了一类具有外来感染者和急慢性阶段的流行病模型.我们假设单位时间内有常数量的外来感染者进入所研究地区,并且假设模型具有周期感染率.我们将利用重合度的延拓定理,导出模型周期解的存在性.     

分阶段成形结构过程控制的无应力状态控制法

建立了分段成形桥梁任意施工过程的力学平衡方程,由力学平衡方程推演出分阶段施工桥梁过程控制的核心是构件单元的无应力状态量。通过单元的无应力状态量的控制和调整解决了分阶段施工桥梁的安装计算问题;利用无应力状态量一定的前提下,内力和位移与施工过程无关的原理,实现了施工中多工序并行作业,解决了施工中临时荷载和温度影响的自动过滤问题。     

分期BOT项目期权定价特许权期的决策模型与分析

假设项目公司将BOT(建设-经营-移交)项目分期实施且同时移交,基于实物期权理论建立BOT项目分期实施的期权博弈模型和决策定价方法.在保证政府收益和项目建设质量不受损失的前提下,对如何科学地确定特许权期作了深入详尽的论证和分析,最后通过工程实例的计算和实证分析验证该模型的可行性和有效性.