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Cu/Cu(Ge,Zr)/SiO_2/Si多层膜界面可控反应及热稳定性研究
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作者 张彦坡 任丁 +4 位作者 林黎蔚 杨斌 王珊玲 刘波 徐可为 《金属学报》 SCIE EI CAS CSCD 北大核心 2013年第10期1264-1268,共5页
利用多靶磁控溅射技术在SiO_2/Si基体上沉积Cu/Cu(Ge,Zr)多层薄膜,采用四探针仪(FPPT),X射线衍射仪(XRD),高分辨透射电镜(HRTEM),X射线光电子能谱(XPS)和原位纳米电子束探针能谱(EDS)表征多层薄膜退火前后电阻率、微观结构和界面成分的... 利用多靶磁控溅射技术在SiO_2/Si基体上沉积Cu/Cu(Ge,Zr)多层薄膜,采用四探针仪(FPPT),X射线衍射仪(XRD),高分辨透射电镜(HRTEM),X射线光电子能谱(XPS)和原位纳米电子束探针能谱(EDS)表征多层薄膜退火前后电阻率、微观结构和界面成分的演变及行为.结果表明,在低温退火阶段(<200℃),Cu(Ge,Zr)膜层中Ge与Cu选择性反应形成低阻Cu_3Ge相,有效抑制Cu与Si的早期扩散;在高温下(>450℃),Zr原子在Cu_3Ge/SiO_2界面析出并与SiO_2层进一步反应形成稳定非晶ZrOx/ZrSiyOx化合物.Cu(Ge,Zr)薄膜中异质原子及与相邻膜层间分步选择性自反应合成高热稳Cu_3Ge/ZrO_x/ZrSi_yO_x复合阻挡层,使Cu/Cu(Ge,Zr)/SiO_2/Si多层膜具有高热稳定性. 展开更多
关键词 Cu(Ge Zr)薄膜 界面反应 选择性自反应 热稳定性
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Competition and the evolution of imperfect mimicry 被引量:1
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作者 David W. PFENNIG David W. KIKUCHI 《Current Zoology》 SCIE CAS CSCD 2012年第4期608-619,共12页
Mimicry is widely used to exemplify natural selection's power in promoting adaptation. Nonetheless, it has become increasingly clear that mimicry is frequently imprecise. Indeed, the phenotypic match is often poor be... Mimicry is widely used to exemplify natural selection's power in promoting adaptation. Nonetheless, it has become increasingly clear that mimicry is frequently imprecise. Indeed, the phenotypic match is often poor between mimics and models in many Batesian mimicry complexes and among co-mimics in many Mtillerian mimicry complexes. Here, we consider whether such imperfect mimicry represents an evolutionary compromise between predator-mediated selection favoring mimetic conver- gence on the one hand and competitively mediated selection favoring divergence on the other hand. Specifically, for mimicry to be effective, mimics and their models/co-mimics should occur together. Yet, co-occurring species that are phenotypically similar often compete for resources, successful reproduction, or both. As an adaptive response to minimize such costly interactions, in-teracting species may diverge phenotypically through an evolutionary process known as character displacement. Such divergence between mimics and their models/co-mimics may thereby result in imperfect mimicry. We review the various ways in which character displacement could promote imprecise mimicry, describe the conditions under which this process may be especially likely to produce imperfect mimicry, examine a possible case study, and discuss avenues for future research. Generally, character displacement may play an underappreciated role in fostering inexact mimicry . 展开更多
关键词 Batesian mimicry Character displacement HYBRIDIZATION MtUlerian mimicry Reproductive interference Selectivetrade-off
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