仿生硅藻结构圆周位置和间距对轴承润滑性能的影响*

基于硅藻结构,在水润滑轴承表面设计矩形-半球型复合型织构,采用流固耦合的方法研究不同织构位置角度和织构间距下的复合型织构轴承的润滑性能,并与光滑轴承和单层织构轴承润滑性能进行对比。结果表明：复合型织构轴承的摩擦力和摩擦因数始终小于单层织构轴承和光滑轴承,且在织构位置角度超过22.5°~45°范围内的某一角度后,复合型织构轴承的最大水膜压力大于单层织构轴承;在不同间距条件下,随着织构位置角度的增大,复合型织构轴承最大水膜压力呈先增加后减小的趋势,摩擦因数呈现先减小后增加的趋势;在织构间距为5°且织构位置角度为45°时,复合型织构轴承的摩擦学特性最优。     

多孔储液介质自润滑机理研究进展

多孔储液介质是启发自关节软骨的仿生摩擦材料,因具有良好的自润滑性能,在工业生产中发挥着重要作用。早期多孔储液介质多是针对不同基体材料及骨架结构进行优化设计,或是根据单因素理想边界建立润滑数值模型,对多孔储液介质的润滑机理缺乏系统的理论描述,限制了其大规模的工业应用。根据不同的结构形式和润滑机理,将多孔储液介质分为有限直孔储液介质和随机多孔储液介质,总结了有限直孔储液介质中空化现象、流体运动、惯性效应、气-液耦合对润滑性能的影响,论述了基于渗流力学、流-固耦合作用的随机多孔储液介质自润滑理论的发展,以及多孔储液介质的应用现状。分析和讨论了多孔储液介质自润滑机理研究的难点问题,对推动多孔储液介质润滑机理的研究和工程实践应用具有重要的参考意义。     

What can cognitive psychology and sensory evaluation learn from each other?

Two questions are addressed in this paper: What can cognitive psychology bring to sensory evaluation? And what can cognitive psychology learn from sensory evaluation? In the first part, I will argue that one important contribution from psychology to sensory evaluation is to interpret flavor as a cognitively unified system made of three anatomically separated systems (smell, taste, and the trigeminal system). In the second part, I will argue that the applied field of sensory evaluation stresses the importance of using ecologically valid, naturalistic stimuli. Sensory evaluation also provides results that challenge accepted interpretations in psychology, especially in the field of evaluation of expertise.     

牛血清白蛋白与柚皮素复合物的非变性质谱研究

血清白蛋白是血液中最丰富的蛋白,研究其与药物的结合情况对了解药物在体内的运输和分布具有重要意义。本研究以柚皮素为模型药物,采用非变性质谱法研究牛血清白蛋白（BSA）与柚皮素的相互作用情况。结果表明,BSA与柚皮素形成了化学计量比为1∶1和1∶2的非共价复合物,二者亲和力较强（平衡解离常数Kd1=（7.82±0.03） μmol/L,Kd2=（9.63±0.02） μmol/L),结合速度快,5 min左右即可达到饱和。该方法具有操作简便、检测快速、样品消耗量小、无需标记等优点,可为其他药物与血清白蛋白的相互作用研究提供参考。     

超大型地下洞室群的三维地震响应分析

在大型水电站、核电站的地下厂房及大型地铁车站等超大型地下洞室群结构的动力反应分析中 ,围岩的动刚度特性不仅涉及到围岩对结构的动力约束作用 ,而且也是地震动输入机制的关键和地下结构分析中的难点。采用阻尼影响抽取法研究了围岩动刚度的动力特性 ,提出了岩石地下结构抗震分析的实用算法。该算法具有较好的精度和计算效率。在此基础上对溪洛渡超大型地下洞室群的抗震安全性进行了评价。     

楔形压杆的非弹性稳定研究

在已有的楔形单元弹性刚度方程的基础上,推导了它的弹塑性增量刚度方程,并利用所得到的结果研究了轴心和偏心楔形压杆在强轴平面内的非弹性稳定,得到了各种楔率下楔形压杆的柱子曲线和轴力-弯矩相关曲线.     

Capitalising on multiplicity: a transdisciplinary systems approach to landscape research

Different disciplines have landscape as the focal point of their research. They are successful in presenting new findings about landscapes within their specialisation, but collaboration—and thus, transfer of knowledge across disciplinary boundaries—is seldom realised because a common approach that bridges the gaps between disciplines is missing. Instead, different landscape concepts exist side by side. Yet, cooperation is required to tackle the various environmental and social problems related to landscapes. This paper provides an overview of the historical development of landscape concepts originating from different cultural and scientific trends, and presents a new complex concept of landscape, which is designed to enable transdisciplinary landscape research. The transdisciplinary landscape concept is based on five dimensions of landscapes: the spatial entity, the mental entity, the temporal dimension, the nexus of nature and culture, and the systemic properties of landscapes. In contrast to other approaches, it unites dimensions that are usually the domain of individual disciplines and makes it, thus, possible to capitalise on plurality in landscape research. The concept promotes landscape as the combination of the subsystems known as the geo-, bio- and noo-sphere, and is illustrated by the people–landscape interaction model. The concept can be applied to all human–landscape-related research, but is exemplified by two studies that have investigated the relationship between landscape and second-home tourism, and landscape and farming, respectively.     

交通荷载作用下土工格栅加筋路基的弹塑性分析

基于所提出的土工格栅与土动力相互作用有限元分析模型和分析程序G－D,对路面下铺设土工格栅的道路模型和不加筋道路模型进行动力响应对比分析,研究在交通荷载作用下加筋路基位移和加速度响应特性和土工格栅与土的相互作用对加速度的影响,以揭示土工格栅的加筋机理和效果。     

用时域法和频时域法识别桥面移动车载

基于欧拉梁模型,本文利用时域法和频时域法由桥梁响应识别桥面移动车载并重点讨论了几个主要参数对识别结果的影响。这些参数包括模态数、采样频率、车速、响应测点位置和测点数等。结果表明：车桥试验室模型是成功的,用时域法和频时域法均能得到满意的识别结果,但以时域法实用性更强、精度更高,可以直接用于桥面移动车载识别的现场试验。     

Modelling of load interaction and overload effect on fatigue damage of steel bridges

This paper studies the effects of load sequence and interaction, and overloading effect on the fatigue damage of bridges on the basis of a non-linear fatigue damage model. The model is derived from the theory of continuum damage mechanics for high-cycle fatigue. Fatigue behaviour at two levels of constant stress range is first discussed in detail. The formulation for the effective fatigue strength of the predamaged members is then derived, and the results predicted by the model are compared with the experimental data for two stress level tests and other results obtained from linear and double linear fatigue damage models. The variation of cycle ratio and fatigue life due to overloading is secondly investigated; the equations for evaluating the effect of overloading on fatigue damage accumulation on bridges at normal traffic loading are then derived. It has been demonstrated that the developed model can well describe the effect of load sequence and interaction and has also been verified by comparing the predicted results obtained by the model with the experimental data based on two levels of stress tests. The effect of accidental overloading on the fatigue damage of existing bridges can also be evaluated using the model. The model is applied to evaluate the fatigue damage and service life of the Tsing Ma Bridge, an essential portion of the transport network for the Hong Kong airport, under normal traffic loading and possible accidental overloading.