期刊文献+
共找到3篇文章
< 1 >
每页显示 20 50 100
基于林德斯泰特-庞加莱法的双节拍器耦合系统同步规律研究
1
作者 谭景芳 王成会 莫润阳 《物理与工程》 2023年第5期46-52,共7页
本文在双节拍器耦合系统动力学方程的基础上,利用Runge-Kutta(龙格-库塔)法对振动系统进行数值分析,通过摆杆摆角随时间演化的曲线图像,讨论影响系统同步性质的因素。利用L-P(林德斯泰特-庞加莱)法研究相同双节拍器耦合系统的系统参数... 本文在双节拍器耦合系统动力学方程的基础上,利用Runge-Kutta(龙格-库塔)法对振动系统进行数值分析,通过摆杆摆角随时间演化的曲线图像,讨论影响系统同步性质的因素。利用L-P(林德斯泰特-庞加莱)法研究相同双节拍器耦合系统的系统参数对于摆杆摆动振幅和摆动频率的影响,得到无耦合双节拍器系统的近似解,结合数值分析比较系统参数对同步周期和振幅的影响;在理论分析得到的近似同步周期中设定同步系数q值,并通过拟合函数进行拟合,拟合后得到的同步周期与数值分析的周期基本一致。本文能为更好地理解耦合系统的同步性质提供参考,也能为学生进行双节拍器同步物理实验提供一些理论参考,增强学生理论联系实际的能力。 展开更多
关键词 耦合同步 振动系统 频率响应
在线阅读 下载PDF
Relationships between Genetic Diversity of Vascular Plant Species and Climate Factors 被引量:1
2
作者 tan jingfang WAN Jizhong +1 位作者 LUO Fangli YU Feihai 《Journal of Resources and Ecology》 CSCD 2018年第6期663-672,共10页
Genetic diversity is crucial for plants to respond to global climate change,and exploring relationships between genetic diversity and climatic factors may help predict how global climate change will shape the genetic ... Genetic diversity is crucial for plants to respond to global climate change,and exploring relationships between genetic diversity and climatic factors may help predict how global climate change will shape the genetic diversity of plants in the future.So far,however,the extent and magnitude of the impact of climatic factors on the genetic diversity of plants has not been clarified.We collected data from 68published papers on two widely used measures of genetic diversity of populations (average expected heterozygosity (He)and average observed heterozygosity (Ho))and on localities of populations of 79vascular plants,and extracted data on 19 climatic factors from WorldClim.We then explored the relationships between measures of genetic diversity and climatic factors using linear regressions.He of plant populations was significantly correlated with climatic factors in 58.7%(44)of the 75 species that used He as a measure of genetic diversity,and Ho was correlated with climatic factors in 65.1% (41)of the 63 species that used this genetic diversity measure.In general,Mean Temperature of Wettest Quarter, Precipitation Seasonality,Precipitation of Driest Quarter and Temperature Seasonality played a vital role in shaping He,and Ho was mostly correlated with Precipitation of Warmest Quarter,Mean Temperature of Wettest Quarter, Precipitation of Driest Quarter and Precipitation of Driest Month.Also,the proportion of the significant correlations between genetic diversity of populations and climatic factors was higher for woody than for herbaceous species, and different climatic factors played different roles in shaping genetic diversity of these two growth forms.Our results suggest that climate may play an important role in shaping genetic diversity of plant populations,that climatic change in the future may alter genetic diversity of plants,and that genetic diversity of different plant forms may respond to climatic change differently. 展开更多
关键词 average expected heterozygosity average observed heterozygosity climate change growth form genetic variation SSR
原文传递
蔡和森民生思想述论
3
作者 谭景芳 《理论界》 2020年第4期21-28,共8页
民生问题的解决直接关系到社会的和谐与稳定,蔡和森在分析了近代中国半殖民地半封建社会的国情后,明确强调要通过建立社会主义制度创设解决民生问题的制度前提,通过发展生产力为民生问题的解决奠定坚实的物质基础;同时,他还提出要大力... 民生问题的解决直接关系到社会的和谐与稳定,蔡和森在分析了近代中国半殖民地半封建社会的国情后,明确强调要通过建立社会主义制度创设解决民生问题的制度前提,通过发展生产力为民生问题的解决奠定坚实的物质基础;同时,他还提出要大力组织以"涨工资、减工时、改善生存环境"为目的的工人运动、以"打土豪、分田地"为目的的农民运动等一系列具体举措,这对近代中国民生问题的解决意义重大。他的民生思想中科学的内容,是毛泽东思想的重要组成部分,对于决胜全面建成小康社会具有重要的指导意义。 展开更多
关键词 蔡和森 民生思想 当代启示
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部