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川西北上寺剖面下三叠统飞仙关组一段砾屑灰岩沉积特征及成因
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作者 乔丹 张彪 +2 位作者 银河 段雄 时志强 《沉积与特提斯地质》 CAS CSCD 北大核心 2024年第2期384-398,共15页
广元上寺剖面早三叠世砾屑灰岩对上扬子地区P-T事件后的古环境变化研究具有重要的理论意义。本文以下三叠统飞仙关组一段格里斯巴赫亚阶的砾屑灰岩为研究对象,通过沉积学、岩石学方法,结合不同砾屑灰岩碳、氧同位素变化特征来分析其可... 广元上寺剖面早三叠世砾屑灰岩对上扬子地区P-T事件后的古环境变化研究具有重要的理论意义。本文以下三叠统飞仙关组一段格里斯巴赫亚阶的砾屑灰岩为研究对象,通过沉积学、岩石学方法,结合不同砾屑灰岩碳、氧同位素变化特征来分析其可能的成因。结果表明,这些砾屑灰岩可划分出4大类:剖面下部的Ⅰ型砾屑灰岩,形状不规则,大小混杂,缺乏板条状砾屑,推测为重力流成因;Ⅱ型砾屑灰岩(角砾状灰岩)砾屑直径大,含大量分米级板条状砾屑,推测为强度和频率急剧增加的风暴诱发的沉积;Ⅲ型砾屑灰岩(扁平砾屑灰岩)的砾屑平行于层面分布,平面上呈扁平状,垂向切片呈竹叶状,具有倒“小”字、菊花状构造和局部呈叠瓦状排列等特征,推测为机械-压溶复合成因;Ⅳ型砾屑灰岩显示为蠕虫状灰岩,代表着水动力条件相对较弱的环境,推测为生物-机械复合成因。风暴对先期沉积的灰岩的撕裂是扁平砾屑形成的基础,后期成岩过程中泥质填隙物与灰岩砾屑的差异压实是扁平砾屑灰岩形成的又一原因。蠕虫状灰岩可能为生物-风暴、成岩作用共同的结果,与扁平砾屑灰岩在成因上有一定的联系。上寺剖面飞一段碳酸盐岩碳同位素曲线显示出缓慢上升的趋势,角砾状灰岩(Ⅱ型砾屑灰岩)发育后期碳同位素发生正偏,指示着沉积环境的过渡转折,可能和这一时期风暴作用对海洋的影响致使浮游微生物繁盛有关。 展开更多
关键词 早三叠世 格里斯巴赫亚阶 飞仙关组一段 扁平砾屑灰岩 蠕虫状灰岩
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Multiresponsive,easy-reversible,and dual-visual Pt(Ⅱ)salt nanostructures for advanced anti-counterfeiting application
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作者 Zhen Su§ Depeng Li§ +5 位作者 Lixin Zhang Si Tian Yuhong Su Xiaoyun Hu duan xiong Qingqing Guan 《Nano Research》 SCIE EI CSCD 2024年第1期372-381,共10页
Smart materials that integrate multi-stimuli response,full reversibility,and dual-visual read-out channel are highly desired for anticounterfeiting and information encryption applications.Herein,we developed a multire... Smart materials that integrate multi-stimuli response,full reversibility,and dual-visual read-out channel are highly desired for anticounterfeiting and information encryption applications.Herein,we developed a multiresponsive perchlorate terpyridyl Pt(Ⅱ)nano complex which could undergo fully reversible conversion between three forms stimulated by water or formaldehyde molecule due to the extent of Pt–Pt interaction.Meanwhile,a dual-visual channel,i.e.,the colorimetric channel changed from yellow to orange or red and the corresponding luminescent channel from orange to orange-red or red,has also been found.The weak and equivalent strength of ion-dipole interaction and hydrogen bond that generated between formaldehyde/water and Pt(II)salt result in the easy-control reversibility between the three forms.Furthermore,by introducing different polymer matrices,1Cl·ClO_(4)@PMMA(1Cl·ClO_(4):[Pt(tpy)Cl]·ClO4,tpy:2,2':6',2''-terpyridine),PMMA:poly(methyl methacrylate))and 1Cl·ClO4@PVA(PVA:polyvinyl alcohol)are successfully constructed,which exhibit different reversible behaviors since the PMMA and PVA matrix exert different influences on the strength of hydrogen-bond.Those smart Pt(II)salt nanostructures present great potential for high-security-level anticounterfeiting application. 展开更多
关键词 Pt(II)complex multiresponse REVERSIBILITY anticounterfeiting information encryption
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