期刊文献+
共找到2篇文章
< 1 >
每页显示 20 50 100
花尾榛鸡的非对称性比和成体存活率(英文)
1
作者 Marc MONTADERT Patrick LEONARD 《动物学报》 SCIE CAS CSCD 北大核心 2006年第4期655-662,共8页
1999至2002年,在法国东南部的阿尔卑斯山,通过无线电追踪方法研究了花尾榛鸡的性比问题。首先,我们通过直接观测无线电标记雄性的配对比例,在消除可能的捕捉误差后,发现繁殖种群性比为1.26(即未配对的雄性占21%)。然后,我们估计了标记... 1999至2002年,在法国东南部的阿尔卑斯山,通过无线电追踪方法研究了花尾榛鸡的性比问题。首先,我们通过直接观测无线电标记雄性的配对比例,在消除可能的捕捉误差后,发现繁殖种群性比为1.26(即未配对的雄性占21%)。然后,我们估计了标记个体的存活率和繁殖成功率。在假设窝扩散时幼体的性比平衡的前提下,通过两性和两个年龄组(幼体,<10月龄的个体;成体>10月龄的个体)的确定性统计模型,得到的理论性比为1.22(即未配对的雄性占18%),这一结果与实际观测的性比十分接近。我们认为,雌性死亡率高导致的两性存活率差异可以解释雄性性比偏高现象。我们进而讨论了花尾榛鸡整个分布区内居间强度的非对称性比的适应意义,以及在衰退的花尾榛鸡种群中雌性数量极端不足的后果. 展开更多
关键词 花尾榛鸡 无线电追踪 性比 存活
下载PDF
The Production of CNT Flower-Like Structures with 3-Fold and 4-Fold Symmetries on a Pt/Si Substrate
2
作者 Madjid Arab Marjorie David +1 位作者 Jean-Christophe Valmalette Christophe Ramseyer 《Advances in Chemical Engineering and Science》 2013年第1期78-81,共4页
Carbon nanotubes flower (CNTs-F) films were prepared by catalytic chemical vapor deposition (CVD) on a platinum (Pt) thin layer, supported on a silicon wafer. The products were synthesized from an aerosol composed of ... Carbon nanotubes flower (CNTs-F) films were prepared by catalytic chemical vapor deposition (CVD) on a platinum (Pt) thin layer, supported on a silicon wafer. The products were synthesized from an aerosol composed of ferrocene and toluene, as catalyst and carbon precursor respectively, at 820. The high synthesis temperature induces a modification of a Pt thin layer to a nano-structured island giving rise to the formation of CNTs-F during the following films growth step by CVD process. The suggested mechanism involves the selective diffusion of the catalyst and carbon atoms through the Pt grain boundaries. This results in the appearance of flower-like structures with 3-and 4-fold symmetries. 展开更多
关键词 Carbon Nanotube Aerosol-CVD 3-Fold and 4-Fold Symmetries Flower Shape
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部