Validation of a steel dual-core self-centering brace (DC-SCB) for seismic resistance: from brace member to one-story one-bay braced frame tests

A steel dual-core self-centering brace (DC-SCB) is an innovative structural member that provides both energy dissipation and self-centering properties to structures, reducing maximum and residual drifts of structures in earthquakes. The axial deformation capacity of the DC-SCB is doubled by a parallel arrangement of two inner cores, one outer box and two sets of tensioning elements. This paper presents cyclic test results of a DC-SCB component and a fullscale one-story, one-bay steel frame with a DC-SCB. The DC-SCB that was near 8 m-long was tested to evaluate its cyclic behavior and durability. The DC-SCB performed well under a total of three increasing cyclic loading tests and 60 lowcycle fatigue loading tests without failure. The maximum axial load of the DC-SCB was near 1700 kN at an interstory drift of 2.5%. Moreover, a three-story dual-core self-centering braced frame (DC-SCBF) with a single-diagonal DC-SCB was designed and its first-story, one-bay DC-SCBF subassembly specimen was tested in multiple earthquake-type loadings. The one-story, one-bay subassembly frame specimen performed well up to an interstory drift of 2% with yielding at the column base and local buckling in the steel beam; no damage of the DC-SCB was found after all tests. The maximum residual drift of the DC-SCBF caused by beam local buckling was 0.5% in 2.0% drift cycles.     

Coupled-line-based millimeter-wave CMOS spiral power dividers with tapered TLs

Analog Integrated Circuits and Signal Processing - We propose a power divider comprising of two parallel λ/4 coupled lines with a shared input signal line. An isolation resistor R is included...     

运动营养对身体机能改善的研究进展

随着人们对健康越来越重视, 越来越多的民众开始注重体育锻炼, 而如何提高人体的运动机能, 成为国内外学者日益关注的焦点。运动营养是指运动食品中所含的对运动能力有所提高的一类营养物质。运动食品中的营养成分通常可以分为2类: 基本营养物质类, 活性或功能因子类。本文对当前国内外关于运动营养的研究进行了综述, 讨论了基本营养物质类如糖、蛋白质、脂肪等在运动机体中的代谢情况, 以及活性或功能因子类如咖啡因、牛磺酸、碳酸氢钠、植物活性物质等对人体运动机能的影响, 以期为运动营养产品的开发提供一定的理论指导依据。     

有机酸对提高机体运动能力的影响及风险评估

随着人们运动健身意识的增强, 能提升运动能力的食品越来越受到欢迎。目前研究表明一些有机酸具有延缓疲劳、提高机体糖原储备量的功能, 从而提升运动能力。有机酸对于体育运动有着积极意义, 尤其是耐力性运动和需要减控体重的运动项目。本文对有机酸的种类、有机酸在体内的代谢机制、有机酸的主要生理功能、有机酸与运动能力的关系以及机体补充有机酸的风险评估进行了综述, 并阐述了补充有机酸的收益和风险以及评估方法, 为有机酸运动食品的研发提供参考。     

多项剩余油研究技术在马岭油田开发中的综合应用

油田进入中高含水开发阶段，剩余油分布较为零散，通过单一手段研究剩余油分布，很难准确描述剩余油分布。利用多种手段监测剩余油分布，寻找潜力油层，调整开发方案，指导油田开发实践，进而提高油田采收率已势在必行。2004年以来，马岭油田充分利用动态分析方法、剩余油测试技术、数值模拟技术及检查井、观察井研究等相结合方法．通过反复对比、分析、论证，实现剩余油分布描述从定性分析向定量的转化，进而指导油田开发实践，取得了良好的经济效益，实现增加地质储量230×10^4t，可采储量75×10^4t，提高采收率0．5％。探索出了符合马岭油田剩余油分布研究的科学方法，并对开发同类油田有一定指导意义。