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同态关系的关系矩阵
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作者 杨留记 《西北大学学报(自然科学版)》 CAS CSCD 1996年第5期371-373,共3页
同态关系的关系矩阵@杨留记...
关键词 等价关系 关系矩阵 同态关系 同态
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正则密码群并半群的两个等价刻画 被引量:2
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作者 王正攀 潘慧兰 冷静 《西南大学学报(自然科学版)》 CAS CSCD 北大核心 2013年第10期60-62,共3页
借助同余和关系同态,证明了以下3条性质在完全正则半群S=(Y;Sα)上等价:(i)S是正则密码群并半群;(ii)■a∈S,等价关系ρa={(x,y)∈S×S:(axa)0=(aya)0}是S上的同余;(iii)■α,β∈Y,α≥β,存在关系同态Φα,β:Sα—→ρα,β 2Sβ... 借助同余和关系同态,证明了以下3条性质在完全正则半群S=(Y;Sα)上等价:(i)S是正则密码群并半群;(ii)■a∈S,等价关系ρa={(x,y)∈S×S:(axa)0=(aya)0}是S上的同余;(iii)■α,β∈Y,α≥β,存在关系同态Φα,β:Sα—→ρα,β 2Sβ,使得■a∈Sα,b∈Sβ,有ab=(aΦα,βb)b,且ba=b(aΦα,βb). 展开更多
关键词 同余 关系同态 正则密码群并半群
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粗糙模糊子格
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作者 郝景 李庆国 《湖南大学学报(自然科学版)》 EI CAS CSCD 北大核心 2012年第6期90-92,共3页
提出了格的模糊同余的概念,定义了粗糙模糊子格,粗糙模糊理想和滤子.并且讨论了它的一些基本性质.引入模糊关系同态的概念,并得出了模糊关系同态保持粗糙上逼近.
关键词 模糊同余关系 模糊子格 粗糙模糊子格 模糊关系同态
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一类正则半群上的若干探讨 被引量:5
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作者 陈忠 宋杰 《贵州大学学报(自然科学版)》 2014年第3期5-7,共3页
设S为正则半群,S的逆子半群S0称为S的逆断面,如果S的每个元在S0有唯一的逆元。本文对具有逆断面的正则半群上的格林等价关系,同态关系作出探讨。
关键词 正则半群 逆断面 格林等价关系 同态关系
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商Riesz空间注记
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作者 王石安 余彩玉 《华南农业大学学报》 CAS CSCD 1995年第1期122-126,共5页
给出Riesz空间关于下定向子空间所作商空间仍是Riesz空间的特征。同时讨论了Riesz空间之间的同态关系。
关键词 RIESZ空间 理想 商空间 同态关系
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Web数据转换模式映射优化方法 被引量:1
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作者 纪宇航 李贵 +2 位作者 李征宇 韩子扬 曹科研 《数据挖掘》 2020年第1期76-89,共14页
Web数据转换是Web异构数据源集成的重要研究之一,通常分为实例层和模式层两方面进行。本文的研究主要针对模式层,由于给定的源到目标模式映射通常使数据转换结果包含大量冗余,为了生成不含冗余的数据作为数据转换核解,本文设计了一种基... Web数据转换是Web异构数据源集成的重要研究之一,通常分为实例层和模式层两方面进行。本文的研究主要针对模式层,由于给定的源到目标模式映射通常使数据转换结果包含大量冗余,为了生成不含冗余的数据作为数据转换核解,本文设计了一种基于同态关系的模式映射设计与优化方法。该方法首先引入模式映射之间的同态关系作为模式映射重写方法基础,通过对模式映射进行分解,定义不同规则生成的数据冗余的大小程度,确定需要重写的规则。最后将给定的模式映射重写为能够直接生成核解的核模式映射,并将其转换为可执行的SQL语句来计算核解。本文实验使用来自中国土地市场网的数据验证本文方法的有效性。 展开更多
关键词 Web大数据 数据转换 模式映射 核解 同态关系
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群上的一类fuzzy关系
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作者 张传志 《山东大学学报(自然科学版)》 CSCD 1990年第2期258-263,共6页
本文给出了群上的 fuzzy 同态关系及 fuzzy 化同态映射的概念,讨论了它们之间的联系。
关键词 模糊同态关系 模糊子群
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Research on Ecological Protection and Restoration Measures in Altay Region based on the Coupling Perspective of the Mountains-Rivers-Forests-Farmlands-Lakes-Grasslands System 被引量:9
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作者 LI Yi LIU Yujie +3 位作者 ZHANG Qiang ZHU Sufeng LIU Hao LIU Shufang 《Journal of Resources and Ecology》 CSCD 2021年第6期791-800,共10页
The adoption of both Nature-based Solutions(NbS)and a system perspective is a hot issue and an area in which there is much room for improvement in ecological protection and restoration.The study takes Altay region as ... The adoption of both Nature-based Solutions(NbS)and a system perspective is a hot issue and an area in which there is much room for improvement in ecological protection and restoration.The study takes Altay region as an example,an area located in Xinjiang,China,which is an important ecological corridor of the national key functional area and the core area of the Belt and Road but has a fragile ecological environment and needs much enhancement in ecological protection and restoration.Guided by the concept of"mountains-rivers-forestsfarmlands-lakes-grasslands(MRFFLG)system is a life community",the coupling relationship of the various MRFFLG elements,the main ecological environmental problems and the integrated countermeasures for protection and restoration in Altay region have been analyzed in this study.The study shows that Altay region has a typical meta-ecosystem of mountain,oasis,and desert,and the connections by rivers and lakes make the ecosystem links within the region much closer.The interweaving of resource-environmental-ecological issues of the aquatic ecosystem,degradation of the quality of terrestrial ecosystems such as forests,grasslands and farmlands,the increased ecosystem fragmentation and ecological risks are the major ecological environmental issues in this region.This study takes the improvement of the ecosystem health and function in Altay region as the core goal of regional ecological protection and restoration.First,we establish a zoning governance pattern from the perspective of ecosystem integrity;second,we design governance strategies for different zones with the goal of synergistic improvements in the ecosystem functions;and finally,we clarify the key engineering tasks in different zones from the perspective of ecosystem services.Ecological conservation and restoration of the MRFFLG system is a prime example of the application and development of NbS in China.This paper constructs an analytical framework for identifying regional life communities,diagnosing ecological protection and restoration of zoning problems,and proposing classified solutions for ecological protection tasks for the protection of the MRFFLG system.This research will enrich the theory and technology for the protection and restoration of MRFFLG systems,and provide guidance for the practice of ecological protection and restoration in Altay region. 展开更多
关键词 mountains-rivers-forests-farmlands-lakes-grasslands life community coupling relationships ecological protection and restoration systematic management Altay region
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Source of the condensates from the Hetianhe Field and the genetic relationship between the condensates and their associated gases
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作者 SONG DaoFu WANG TieGuan +1 位作者 LI MeiJun NI ZhiYong 《Science China Earth Sciences》 SCIE EI CAS CSCD 2015年第9期1566-1576,共11页
A detailed correlation of Hetianhe condensates versus typical source rocks from the Tarim Basin was established. Moreover, the genetic relationship between the condensates and their associated gases was also studied b... A detailed correlation of Hetianhe condensates versus typical source rocks from the Tarim Basin was established. Moreover, the genetic relationship between the condensates and their associated gases was also studied based on their geochemical com- positions and fluid inclusion data. Hetianhe condensates are characterized by high pristine/phytane (Pr/Ph) ratios, high relative abundances of Czs regular steranes, C26-C27 triaromatic steroids, and triaromatic dinosteranes, and relatively heavy stable car- bon isotopic compositions. They geochemically correlate well with the Cambrian source rocks, indicating that these conden- sates are derived from the Cambrian rocks. Based on several molecular maturity parameters, the condensates are recognized as being moderately to highly mature, which are too low in maturity to extensively crack into gases. The gases and condensates of the Hetianhe Field are derived from the same source rocks and the gases are from oil-cracking; however, clear evidence indi- cates that the gases were not cracked from their associated condensates and that the gas generation from oil-cracking did not occur in the present reservoirs. The liquid condensates produced from wellheads were likely dissolved in their associated gases underground and carried into the reservoirs by the gases. 展开更多
关键词 Hetianhe Field CONDENSATE MATURITY oil-source rock correlation genetic relationship
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