基于特性校正技术的宽量程垂直螺翼式水表的研制

在传统机械水表基础上,增加旋转量机电转换装置、嵌入式计算机系统、特性校正算法和数据处理软件等,可以使机械水表改造成极宽量程的新型水表。它的流量测量范围Q3/Q1在满足测量准确度条件下可扩至R=1000以上,但前提是机械水表要有良好的测量重复性、长期工作的稳定性,以及很高的测量灵敏阈。文章介绍了宽量程垂直螺翼式水表旋转量转换原理和水表误差特性的校正方法,使新研制的水表性能指标达到了较高水平。     

气液两相流水平管系结点处影响区相分离模型分析

依据“分离流线影响区域”理论对两相流在Ｔ型和Ｙ型分叉管中的相分离现象进行数值模拟,参照国外发表的实验结果,进行了数值对比,总的结果表明较为理想。同时通过计算发现分叉管的分叉角度对两相流的相分离程度有着一定的影响,并作了相应的分析。另外还对入口参数Ｘ１对相分离效果的影响进行了计算和分析。     

Electrically Conductive Hydrogel Nerve Guidance Conduits for Peripheral Nerve Regeneration

Peripheral nerve injuries are serious conditions, and surgical treatment has critical limitations. Therefore, nerve guidance conduits (NGCs) are proposed as an alternative. In this study, multifunctional NGCs are fabricated for the regeneration of injured peripheral nerves. Graphene oxide (GO) and gelatin‐methacrylate (GelMA) are polymerized and chemically reduced to form reduced (GO/GelMA) (r(GO/GelMA)). The prepared materials present good electrical conductivity, flexibility, mechanical stability, and permeability, which are suitable for use as NGCs. In vitro studies show 2.1‐ and 1.4‐fold promotion of neuritogenesis of PC12 neuronal cells on r(GO/GelMA) compared to GelMA and unreduced GO/GelMA, respectively. Animal studies using a rat sciatic nerve injury model with a 10 mm gap between the proximal and distal regions of the defect reveal that r(GO/GelMA) NGCs significantly enhance peripheral nerve regeneration, indicated by improved muscle weight increase, electro‐conduction velocity, and sciatic nerve function index. Specifically, r(GO/GelMA) NGCs are utilized to potentiate regrowth with myelination in rat sciatic nerves followed by histological, immunohistological, and morphometrical analyses. This study successfully shows the feasibility of electrically conductive hydrogel NGCs as functional conduits for improved nerve regeneration in a preclinical study, where these NGCs can not only mimic nerve tissues but also strongly promote nerve regeneration.     

供水管道输水管材的比较

文中阐述了球墨铸铁管、预应力钢筒混凝土管、钢管、预应力混凝土管及玻璃钢管管材的特点，并从水力条件、物理性能、施工方便程度、工程造价等方面做了比较，提出推荐性意见。