检索结果-南通市图书馆

沉积气压对氮化钒(VN)涂层微结构及其性能的影响

在线全文

学校读者我要写书评

暂无评论

引用

润滑与密封 2021年第5期46卷 68-74页

作者：刘怡飞包改磊李助军李磊罗锡才田灿鑫广州铁路职业技术学院机电工程学院广东广州510430 华南理工大学国家金属材料近净成形工程技术研究中心广东广州510640 岭南师范学院物理科学与技术学院广东湛江524048

为研究沉积气压对VN涂层力学性能和摩擦性能的影响,采用离子镀制备VN涂层,利用X射线衍射仪、扫描电子显微镜等设备检测VN涂层的物相结构、表面形貌,采用划痕仪测试基体与涂层的膜基结合力,采用摩擦磨损试验机测试涂层的摩擦因数。结果表... 详细信息

为研究沉积气压对VN涂层力学性能和摩擦性能的影响,采用离子镀制备VN涂层,利用X射线衍射仪、扫描电子显微镜等设备检测VN涂层的物相结构、表面形貌,采用划痕仪测试基体与涂层的膜基结合力,采用摩擦磨损试验机测试涂层的摩擦因数。结果表明:随着沉积氮气气压的升高,VN衍射峰强度逐渐增强,具有(200)晶面择优取向,表面平整度高;随着沉积氮气气压变化,涂层显微硬度和膜基结合力呈抛物线变化趋势,在氮气气压为1.0 Pa时,涂层硬度最高为HV2284,结合力最大为45 N,并具有稳定的摩擦因数,平均摩擦因数为0.85。通过调控沉积气压,多弧离子镀技术可以制备出性能更优越的VN涂层。

关键词：多弧离子镀 VN涂层沉积气压结合强度摩擦因数

Panoramic Insights into Microevolution and Macroevolution of A Prevotella copri-containing Lineage in Primate Guts

在线全文

学校读者我要写书评

暂无评论

引用

Genomics, Proteomics & Bioinformatics 2022年第2期20卷 334-349页

作者： Hao Li Jan P.Meier-Kolthoff canxin Hu Zhongjie Wang Jun Zhu Wei Zheng Yun tian Feng Guo School of Life Sciences Xiamen UniversityXiamen 361102China Department of Bioinformatics Leibniz Institute DSMZ–German Collection of Microorganisms and Cell CulturesD-38124 BraunschweigGermany Fujian Provincial Universities Key Laboratory of Microbial Resource Xiamen UniversityXiamen 361102China

Prevotella copri and its related taxa are widely detected in mammalian gut microbiomes and have been linked with an enterotype in ***,their microevolution and macroevolution among hosts are poorly *** this study,extensively collected marker genes and genomes were analyzed to trace their evolutionary history,host specificity,and biogeographic *** based on marker genes and genomes suggest that a ***-containing lineage(PCL)harbors diverse species in higher ***,*** in the human gut consisted of multiple groups exhibiting high genomic divergence and conspicuous but non-strict biogeographic *** African strains with high genomic divergence from other strains were phylogenetically located at the root of the species,indicating the co-evolutionary history of *** and Homo ***,although long-term co-evolution between PCL and higher primates was revealed,sporadic signals of co-speciation and extensive host jumping of PCL members were suggested among higher *** and phylogenetic analyses indicated that *** and other PCL species found in domesticated mammals had been recently transmitted from ***,strong evidence was found on the extensively horizontal transfer of genes(e.g.,genes encoding carbohydrate-active enzymes)among sympatric *** groups and PCL species in the same primate *** study provides panoramic insights into the combined effects of vertical and horizontal transmission,as well as potential niche adaptation,on the microevolutionary and macroevolutionary history for an enterotyperepresentative lineage.

关键词： Prevotella copri Co-speciation Gut microbiome Host Biogeography

在线全文

学校读者我要写书评

暂无评论

黑芝麻功能成分的构效关系

引用

食品科学技术学报 2019年第6期37卷 1-7页

作者：金征宇蔡灿欣田耀旗陆振猷江南大学食品科学与技术国家重点实验室/食品学院江苏无锡214122 南方黑芝麻集团广西南宁530022

黑芝麻作为"药食同源"食材,自古以来就被认为是养生保健的佳品,其营养保健价值为人们所共识。黑芝麻含有丰富的蛋白质、矿物质、不饱和脂肪酸、维生素、木脂素类物质以及黑色素等功能成分,具有独特的营养保健和慢性病预防功效。论述了... 详细信息

黑芝麻作为"药食同源"食材,自古以来就被认为是养生保健的佳品,其营养保健价值为人们所共识。黑芝麻含有丰富的蛋白质、矿物质、不饱和脂肪酸、维生素、木脂素类物质以及黑色素等功能成分,具有独特的营养保健和慢性病预防功效。论述了黑芝麻的典型功能成分、功效及其作用共性机制,并通过具体案例,重点阐述了典型功能成分对人体作用的共性机制,其中包括黑色素与乌发润发,芝麻素与抗氧化,芝麻木脂素与清胆固醇,木脂素与降血糖、降血脂,芝麻素与抗癌、抗肿瘤,矿物质元素与补气养血、牙齿保健等功能间的构效关系,并提出了黑芝麻功效及在保健食品等新产品研发领域上的热点,还提出了对黑芝麻的功能性成分进行单一化、精细化的研究趋势,并且建议建立黑芝麻功能性成分健康信息数据库,旨在为进一步开发新型黑芝麻功能产品提供重要科学依据。

关键词：黑芝麻黑脂麻功能成分共性机制构效关系