期刊文献+
共找到3篇文章
< 1 >
每页显示 20 50 100
ISM模型在数控机床装配过程质量评价的运用 被引量:2
1
作者 梁迪 钟彦恺 王记 《沈阳大学学报(自然科学版)》 CAS 2018年第5期409-413,共5页
针对数控机床装配过程中的质量波动问题,对装配过程质量波动传递和累积模式、波动影响因素之间关系进行分析,运用图论方法将数控机床装配过程影响关系拓扑结构简化为有向图和邻接矩阵,运用布尔代数方法计算可达矩阵,建立数控机床质量波... 针对数控机床装配过程中的质量波动问题,对装配过程质量波动传递和累积模式、波动影响因素之间关系进行分析,运用图论方法将数控机床装配过程影响关系拓扑结构简化为有向图和邻接矩阵,运用布尔代数方法计算可达矩阵,建立数控机床质量波动解释结构模型.该方法解决了数控机床装配过程中影响质量问题因素的优先次序和层级关系,同时也适用于复杂系统的波动溯源问题. 展开更多
关键词 解释结构模型 数控机床 邻接矩阵 布尔代数
下载PDF
轻质气泡土在地铁上方路基填筑工程中的应用研究 被引量:3
2
作者 钟颜开 刘中山 《市政技术》 2019年第3期58-60,111,共4页
笔者以既有地铁结构正上方的广州市迎宾大道延长线道路工程为例,选用轻质气泡土作为路基填料,并对其优点及密度控制、施工要点、试验、监控等内容进行了详细阐述。实践表明,该类型填料即可满足路基的强度要求,又保证了既有地铁结构的安... 笔者以既有地铁结构正上方的广州市迎宾大道延长线道路工程为例,选用轻质气泡土作为路基填料,并对其优点及密度控制、施工要点、试验、监控等内容进行了详细阐述。实践表明,该类型填料即可满足路基的强度要求,又保证了既有地铁结构的安全,对类似地铁正上方的市政道路工程的路基填筑具有一定的借鉴价值。 展开更多
关键词 既有地铁结构 安全 路基填料 轻质气泡土 密度控制
下载PDF
Rapid loss of leguminous species in the semi-arid grasslands of northern China under climate change and mowing from 1982 to 2011
3
作者 XU Bo HUGJILTU Minggagud +4 位作者 BAOYIN Taogetao zhong yankai BAO Qinghai ZHOU Yanlin LIU Zhiying 《Journal of Arid Land》 SCIE CSCD 2020年第5期752-765,共14页
Effects of mowing on the composition and diversity of grasslands varied with climate change(e.g.,precipitation and temperature).However,the interactive effects of long-term mowing and climate change on the diversity a... Effects of mowing on the composition and diversity of grasslands varied with climate change(e.g.,precipitation and temperature).However,the interactive effects of long-term mowing and climate change on the diversity and stability of leguminous and non-leguminous species in the semi-arid grasslands are largely unknown.Here,we used in situ monitoring data from 1982 to 2011 to examine the effects of continuous mowing and climate change on the plant biomass and diversity of leguminous and non-leguminous species,and soil total nitrogen in the typical semi-arid grasslands of northern China.Results showed that the biomass and diversity of leguminous species significantly decreased with the increasing in the biomass and diversity of non-leguminous species during the 30-a period.Variations in biomass were mainly affected by the long-term mowing,while variations in diversity were mainly explained by the climate change.Moreover,the normalized change rates of diversity in leguminous species were significantly higher than those in non-leguminous species.Mowing and temperature together contributed to the diversity changes of leguminous species,with mowing accounting for 50.0%and temperature 28.0%.Temporal stability of leguminous species was substantially lower than that of non-leguminous species.Consequently,soil total nitrogen decreased in the 2000s compared with the 1980s.These findings demonstrated that leguminous species were more sensitive to the long-term mowing and climate change than non-leguminous species in the semi-arid grasslands.Thus,reseeding appropriate leguminous plants when mowing in the semi-arid grasslands may be a better strategy to improve nitrogen levels of grassland ecosystems and maintain ecosystem biodiversity. 展开更多
关键词 climate change diversity LEGUME MOWING PRODUCTIVITY SUCCESSION temporal stability
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部