The combined effects of isothermal annealing and pre-compression on the mechanical properties of Cu36Zr48Al8Ag8 bulk metallic glass （BMG） were investigated. The as-cast specimens were first annealed at 743 K for 10 ...The combined effects of isothermal annealing and pre-compression on the mechanical properties of Cu36Zr48Al8Ag8 bulk metallic glass （BMG） were investigated. The as-cast specimens were first annealed at 743 K for 10 min, and then pre-compressed under 800 MPa for 1, 3, 5 and 10 h, respectively. The results indicated that annealing resulted in the formation of nanocrystals with a diameter of -10 nm in the amorphous matrix and a drastic decrease of the free volume, leading to complete loss of the plasticity of the BMG. Applying pre-compression under a stress of 800 MPa for a proper duration （5 h） resumed part of the lost free volume in the BMG matrix and therefore partially recovered the plasticity. A very long period of pre-compression （10 h） decreased the free volume again, which was caused by the excessive crystal growth.展开更多
我国土壤镉污染区与水稻种植区在空间分布上基本吻合,这严重威胁了粮食安全与人体健康,是亟需解决的土壤环境问题。伴矿景天是我国近年发现的镉超富集植物,是修复土壤镉污染的理想植物。本文以“伴矿景天”和“Sedum plumbizincicola”...我国土壤镉污染区与水稻种植区在空间分布上基本吻合,这严重威胁了粮食安全与人体健康,是亟需解决的土壤环境问题。伴矿景天是我国近年发现的镉超富集植物,是修复土壤镉污染的理想植物。本文以“伴矿景天”和“Sedum plumbizincicola”为关键词,从中国知网和Web of Science数据库共收集文献280篇,采用文献计量分析软件VOSviewer分析国内外研究现状,分别从伴矿景天对镉的吸收转运和富集机制、解毒机理、田间修复现状、修复效果强化措施和产后处理技术5个方面综述了现阶段的主要研究成果,并进一步阐述了伴矿景天田间修复推广应用面临的问题和挑战,提出未来研究应集中探索伴矿景天的修复效率提升和实际推广应用。展开更多
养猪产业对保障人民的基本生活需求、推动经济发展以及应对各种挑战都具有十分重要的作用。针对生猪行业特殊的周期现象,本文围绕猪周期对养猪企业盈余管理的影响,采用文献研究法和案例研究法等,阐释了猪周期对企业盈余管理的影响,描述...养猪产业对保障人民的基本生活需求、推动经济发展以及应对各种挑战都具有十分重要的作用。针对生猪行业特殊的周期现象,本文围绕猪周期对养猪企业盈余管理的影响,采用文献研究法和案例研究法等,阐释了猪周期对企业盈余管理的影响,描述了产业链视角的养猪行业现状,分析了养猪行业在猪周期背景下的盈余管理动机,探讨了牧原股份在猪周期背景下盈余管理的影响和实施盈余管理的手段,并提出了消除猪周期影响下企业实施盈余管理的有效建议。The pig farming industry plays a crucial role in ensuring the basic living needs of the people, promoting economic development, and addressing various challenges. In response to the unique cyclical phenomenon in the pig industry, this study focuses on the impact of pig cycles on earnings management in pig farming enterprises. Through literature research and case study methods, the impact of pig cycles on earnings management in enterprises is explained, and the current situation of the pig farming industry from the perspective of the industry chain is described. The motivation for earnings management in the pig farming industry under the background of pig cycles is analyzed, and the impact of earnings management and implementation of earnings management means by Muyuan Shares under the background of pig cycles are explored. Effective suggestions are proposed to eliminate the impact of pig cycles on the implementation of earnings management measures in enterprises.展开更多
基金Projects(51328101,51301142)supported by the National Natural Science Foundation of ChinaProject(2015JJ2206)supported by Hunan Provincial Natural Science Foundation of China
文摘The combined effects of isothermal annealing and pre-compression on the mechanical properties of Cu36Zr48Al8Ag8 bulk metallic glass （BMG） were investigated. The as-cast specimens were first annealed at 743 K for 10 min, and then pre-compressed under 800 MPa for 1, 3, 5 and 10 h, respectively. The results indicated that annealing resulted in the formation of nanocrystals with a diameter of -10 nm in the amorphous matrix and a drastic decrease of the free volume, leading to complete loss of the plasticity of the BMG. Applying pre-compression under a stress of 800 MPa for a proper duration （5 h） resumed part of the lost free volume in the BMG matrix and therefore partially recovered the plasticity. A very long period of pre-compression （10 h） decreased the free volume again, which was caused by the excessive crystal growth.
文摘我国土壤镉污染区与水稻种植区在空间分布上基本吻合,这严重威胁了粮食安全与人体健康,是亟需解决的土壤环境问题。伴矿景天是我国近年发现的镉超富集植物,是修复土壤镉污染的理想植物。本文以“伴矿景天”和“Sedum plumbizincicola”为关键词,从中国知网和Web of Science数据库共收集文献280篇,采用文献计量分析软件VOSviewer分析国内外研究现状,分别从伴矿景天对镉的吸收转运和富集机制、解毒机理、田间修复现状、修复效果强化措施和产后处理技术5个方面综述了现阶段的主要研究成果,并进一步阐述了伴矿景天田间修复推广应用面临的问题和挑战,提出未来研究应集中探索伴矿景天的修复效率提升和实际推广应用。
文摘养猪产业对保障人民的基本生活需求、推动经济发展以及应对各种挑战都具有十分重要的作用。针对生猪行业特殊的周期现象,本文围绕猪周期对养猪企业盈余管理的影响,采用文献研究法和案例研究法等,阐释了猪周期对企业盈余管理的影响,描述了产业链视角的养猪行业现状,分析了养猪行业在猪周期背景下的盈余管理动机,探讨了牧原股份在猪周期背景下盈余管理的影响和实施盈余管理的手段,并提出了消除猪周期影响下企业实施盈余管理的有效建议。The pig farming industry plays a crucial role in ensuring the basic living needs of the people, promoting economic development, and addressing various challenges. In response to the unique cyclical phenomenon in the pig industry, this study focuses on the impact of pig cycles on earnings management in pig farming enterprises. Through literature research and case study methods, the impact of pig cycles on earnings management in enterprises is explained, and the current situation of the pig farming industry from the perspective of the industry chain is described. The motivation for earnings management in the pig farming industry under the background of pig cycles is analyzed, and the impact of earnings management and implementation of earnings management means by Muyuan Shares under the background of pig cycles are explored. Effective suggestions are proposed to eliminate the impact of pig cycles on the implementation of earnings management measures in enterprises.
