Age is a key factor affecting sexual selection,as many physical and social traits are age-related.Although studies of primate mate choice often consider particular age-related traits,few consider the collective effect...Age is a key factor affecting sexual selection,as many physical and social traits are age-related.Although studies of primate mate choice often consider particular age-related traits,few consider the collective effects of male age.We tested the hypothesis that female golden snub-nosed monkeys Rhinopithecus roxellana prefer prime aged males(10-15 years)over younger and older males.We examined a habituated,provisioned troop during a 3-year study in the Qinling Mountains,China.Prime age males were more likely to be resident males of 1-male units(OMUs)than males of other ages.Since females are free to transfer between OMUs,the number of females per OMU can be indicative of female preferences.We examined the number of females per OMU,and found that it increased with resident male age up to 7-8 years,and declined after 12 years,such that prime age resident males had more females than other resident males.Females also initiated extra-unit copulations with high-ranking prime age males at significantly higher rates than with other males.Nevertheless,females tended to transfer from OMUs with high-ranking,older resident males to those with low-ranking,younger resident males.Thus,females appear to use different strategies when choosing social mates and extra-unit mates(i.e.,different social contexts).We speculate that females may perceive early signs of aging in males and trade off the benefits and costs of high rank versus male senescence.This study lays the groundwork for future studies that examine possible direct and indirect benefits of such strategies.展开更多
随着静态同步串联补偿器(static synchronous series compensator,SSSC)的不断发展及应用,其构成和控制的复杂化对传统超高压输电线路保护提出了挑战,需对含SSSC的输电线路保护原理进行深入的研究。为此,运用串补输电线路的频域模型,分...随着静态同步串联补偿器(static synchronous series compensator,SSSC)的不断发展及应用,其构成和控制的复杂化对传统超高压输电线路保护提出了挑战,需对含SSSC的输电线路保护原理进行深入的研究。为此,运用串补输电线路的频域模型,分析了串补输电线路故障时故障电流的频率特征。分析结果表明,当串补线路区内、外发生故障时,保护安装处获得的频率分量的含量明显不同。对串补线路区内、外故障时的暂态高频信号频率成分的复杂度进行仿真分析,根据信号复杂度的变化特征,提出一种适应于串补线路的单端暂态量保护新方案。仿真结果表明,该方案性能不受故障类型、故障位置、过渡电阻、故障初始相角和串补度的影响,且具有良好的适应性和灵敏性。展开更多
基金This study was funded by the National Natural Science Foundation of China [31730104,31770425,32071495,and 31770411]the National Key Program of Research and Development,Ministry of Science and Technology[2016YFC0503200]+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences[XDB31000000]the Natural Science Basic Research Plan in Shaanxi Province of China[2019JM-258].
文摘Age is a key factor affecting sexual selection,as many physical and social traits are age-related.Although studies of primate mate choice often consider particular age-related traits,few consider the collective effects of male age.We tested the hypothesis that female golden snub-nosed monkeys Rhinopithecus roxellana prefer prime aged males(10-15 years)over younger and older males.We examined a habituated,provisioned troop during a 3-year study in the Qinling Mountains,China.Prime age males were more likely to be resident males of 1-male units(OMUs)than males of other ages.Since females are free to transfer between OMUs,the number of females per OMU can be indicative of female preferences.We examined the number of females per OMU,and found that it increased with resident male age up to 7-8 years,and declined after 12 years,such that prime age resident males had more females than other resident males.Females also initiated extra-unit copulations with high-ranking prime age males at significantly higher rates than with other males.Nevertheless,females tended to transfer from OMUs with high-ranking,older resident males to those with low-ranking,younger resident males.Thus,females appear to use different strategies when choosing social mates and extra-unit mates(i.e.,different social contexts).We speculate that females may perceive early signs of aging in males and trade off the benefits and costs of high rank versus male senescence.This study lays the groundwork for future studies that examine possible direct and indirect benefits of such strategies.
文摘随着静态同步串联补偿器(static synchronous series compensator,SSSC)的不断发展及应用,其构成和控制的复杂化对传统超高压输电线路保护提出了挑战,需对含SSSC的输电线路保护原理进行深入的研究。为此,运用串补输电线路的频域模型,分析了串补输电线路故障时故障电流的频率特征。分析结果表明,当串补线路区内、外发生故障时,保护安装处获得的频率分量的含量明显不同。对串补线路区内、外故障时的暂态高频信号频率成分的复杂度进行仿真分析,根据信号复杂度的变化特征,提出一种适应于串补线路的单端暂态量保护新方案。仿真结果表明,该方案性能不受故障类型、故障位置、过渡电阻、故障初始相角和串补度的影响,且具有良好的适应性和灵敏性。
