滑板砖柔性检测系统

本文介绍一种滑板砖柔性检测系统。它能胜于节流开关的滑板砖平整度、厚度的自动检测。本文章给出总体方案，测量方法，原理和主要功能。     

关于提高组合机床利用率的实践

介绍大幅度提高组合机床利用率的探索与尝试。经实践证明，所研制的组合机床结构新颖，具有柔性功能，可一机多用，适合我厂的实际情况，收到了显的经济效益。     

生态学视角下健康城市规划理论框架的构建

伴随着快速城镇化和城市现代化,环境污染、气候变化等问题引发了新公共卫生问题,重构城市规划与公共卫生之间的合作关系对解决这些问题具有重要意义。在国际范围内,健康城市运动的发展为健康城市规划提供了行动框架和原则,但健康城市规划缺乏扎实的理论依据。城市系统的复杂性是构建健康城市规划理论框架的主要挑战,在复杂性科学背景下,研究基于生态学视角,将弹性概念和社会生态学理论引入健康城市规划理论框架的构建中,以期为健康城市规划的制定与实施提供一定的理论基础。     

基于弹性理念的物流园空间规划布局方法探讨

物流园的发展是一个动态过程,需具备一定弹性以适应市场的发展。柳州市河西物流园空间规划在空间布局上采用空间生成模型,在地块控制上采用弹性划分方式。同时,使用按需设计的单元设计思路,形成了"一心、两轴、两带、四片、多组团"的空间结构,通过规划各层面的策略对空间规划的实施进行督促和引导,促进规划弹性的实现。     

The value of flexible fuel mixing in hydrogen-fueled gas turbines – A techno-economic study

In electricity systems mainly supplied with variable renewable electricity (VRE), the variable generation must be balanced. Hydrogen as an energy carrier, combined with storage, has the ability to shift electricity generation in time and thereby support the electricity system. The aim of this work is to analyze the competitiveness of hydrogen-fueled gas turbines, including both open and combined cycles, with flexible fuel mixing of hydrogen and biomethane in zero-carbon emissions electricity systems. The work applies a techno-economic optimization model to future European electricity systems with high shares of VRE.The results show that the most competitive gas turbine option is a combined cycle configuration that is capable of handling up to 100% hydrogen, fed with various mixtures of hydrogen and biomethane. The results also indicate that the endogenously calculated hydrogen cost rarely exceeds 5 €/kg_H2 when used in gas turbines, and that a hydrogen cost of 3–4 €/kg_H2 is, for most of the scenarios investigated, competitive. Furthermore, the results show that hydrogen gas turbines are more competitive in wind-based energy systems, as compared to solar-based systems, in that the fluctuations of the electricity generation in the former are fewer, more irregular and of longer duration. Thus, it is the characteristics of an energy system, and not necessarily the cost of hydrogen, that determine the competitiveness of hydrogen gas turbines.     

弹性连杆机构的动态稳定性研究

研究了一般形式的弹性连杆机构的动力稳定性问题，在忽略结构阻尼的情况下，从理论上研究了低价临界转速的分布规律，给出了低价临界转速与机构一个运动周期固有频率平均值的显式关系表达式。用这一关系式求得的低价临界转速和数值方法得到的识别结果进行了比较，说明了本文方法的有效性。     

Determination of flexibility factors in curved pipes with end restraints using a semi-analytic formulation

Piping systems are structural sets used in the chemical industry, conventional or nuclear power plants and fluid transport in general-purpose process equipment. They include curved elements built as parts of toroidal thin-walled structures. The mechanical behaviour of such structural assemblies is of leading importance for satisfactory performance and safety standards of the installations. This paper presents a semi-analytic formulation based on Fourier trigonometric series for solving the pure bending problem in curved pipes. A pipe element is considered as a part of a toroidal shell. A displacement formulation pipe element was developed with Fourier series. The solution of this problem is solved from a system of differential equations using mathematical software. To build-up the solution, a simple but efficient deformation model, from a semi-membrane behaviour, was followed here, given the geometry and thin shell assumption. The flexibility factors are compared with the ASME code for some elbow dimensions adopted from ISO 1127. The stress field distribution was also calculated.     

Carbon nanotubes: properties,synthesis, purification,and medical applications

Current discoveries of different forms of carbon nanostructures have motivated research on their applications in various fields. They hold promise for applications in medicine, gene, and drug delivery areas. Many different production methods for carbon nanotubes (CNTs) have been introduced; functionalization, filling, doping, and chemical modification have been achieved, and characterization, separation, and manipulation of individual CNTs are now possible. Parameters such as structure, surface area, surface charge, size distribution, surface chemistry, and agglomeration state as well as purity of the samples have considerable impact on the reactivity of carbon nanotubes. Otherwise, the strength and flexibility of carbon nanotubes make them of potential use in controlling other nanoscale structures, which suggests they will have a significant role in nanotechnology engineering.     

剪力和弯矩共同作用下钢筋混凝土结构的框架单元模型分析

模拟剪力和弯矩共同作用下钢筋混凝土结构的响应,包括发生在开裂后和极限荷载范围时的各项性能。目前的2维(平面应力和平面应变)和3维非线性有限元方程模拟上述结构响应的成本很高,而且不适用于日常工程实践。提出1种新型框架单元模型,结合高效的带梁-柱单元的平面内全耦合剪切-正常节段模型,适用于已得到试验结果验证的结构分析。标准剪切下的应力和应变假定为由一系列多项式形函数组成;每一个应力分布受内部材料状况影响。框架结构的非线性分析采用的是广义矩阵法,利用文献资料验证该模型,通过试验验证剪切应变对结构响应的影响程度。试验结果和模型分析结果吻合较好。该模型得到的混凝土和钢筋的位移、应变和应力及不同的破坏类型,比之前模型的分析结果更精确。     

分光光度计的测量结果不确定度分析

本文简述了误差与不确定度概念,并以可见分光光度计的测量结果不确定度分析为实例,详细描述了不确定度分析与计算方法。