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有机质调控下企鹅贝及其附壳珍珠的珍珠层螺旋生长成核 被引量:3
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作者 黄艺兰 亓利剑 《宝石和宝石学杂志》 CAS 2006年第2期20-24,共5页
采用环境扫描电子显微镜和高分辨透射电镜对海南三亚企鹅贝及其附壳珍珠不同部位的结构特征进行研究,并配合稀盐酸(0.5%)和EDTA试剂对样品进行脱钙处理。研究结果表明,该地区海水成因的珍珠层中有机质薄膜对珍珠层的螺旋生长成核和结晶... 采用环境扫描电子显微镜和高分辨透射电镜对海南三亚企鹅贝及其附壳珍珠不同部位的结构特征进行研究,并配合稀盐酸(0.5%)和EDTA试剂对样品进行脱钙处理。研究结果表明,该地区海水成因的珍珠层中有机质薄膜对珍珠层的螺旋生长成核和结晶取向起到了严格的调控作用,它为文石或方解石晶体的生长提供一个有效的定位或成核中心;有机质与文石微晶在时间和空间上的螺旋交互生长具有周期性,从而产生珍珠层表面的这种结构形态。企鹅贝珍珠层的形成归因于层间有机质薄膜的初始螺旋成核作用;有机质薄膜直接诱导了文石晶核的形成并调控珍珠层螺旋生长,促使文石微片晶与有机质膜螺旋有序交生,控制文石晶体的结晶取向和组装方式,并导致螺旋生长层的形成。 展开更多
关键词 珍珠层 有机质薄膜 企鹅贝 附壳珍珠 螺旋生长成核 环境扫描电子显微镜
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试论动物非矿化组织的保存 被引量:9
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作者 张兴亮 舒德干 《沉积学报》 CAS CSCD 北大核心 2001年第1期13-19,共7页
动物非矿物化组织在特异埋葬条件下可保存为化石。缺氧和快速埋葬有利于非矿化组织的保存 ,但不能阻止微生物的破坏作用。无菌环境下可保存软躯体组织 ,但在构造变动和古气候变迁等因素的影响下会彻底破坏 ,不可能在地质历史时期长期存... 动物非矿物化组织在特异埋葬条件下可保存为化石。缺氧和快速埋葬有利于非矿化组织的保存 ,但不能阻止微生物的破坏作用。无菌环境下可保存软躯体组织 ,但在构造变动和古气候变迁等因素的影响下会彻底破坏 ,不可能在地质历史时期长期存在。最稳定的保存形式是与成岩作用有关的保存类型和以碳化有机质薄膜形式的保存类型。与动物非矿化组织保存有关的常见成岩自生矿物有磷酸盐矿物、碳酸盐矿物和黄铁矿等。其中 ,磷酸盐矿物在成岩作用过程中结晶最早 ,可以保存动物的微细构造。这些矿物可以矿化交代动物的肉质和角质使其成为矿化实体 ;也可以呈假形、铸型或铸模等形式保存。布尔吉斯页岩保存类型中 ,非矿化组织以碳化有机质薄膜或含水的铝硅酸盐矿物两种形式保存。前者可能与粘土矿物吸附有机质、阻止酶的降解作用有关 。 展开更多
关键词 非矿化组织 保存 成岩作用 矿化交代作用 自生矿物 动物 碳化有机质薄膜 快速埋藏
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企鹅珍珠贝珍珠层螺旋位错生长
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作者 亓利剑 黄艺兰 +1 位作者 周祖翼 周征宇 《中国科学:地球科学》 CSCD 北大核心 2011年第6期865-872,共8页
基于近海各种环境因子的响应,产自中国海南岛沿岸海域的企鹅珍珠贝珍珠层表层发育一组‘螺旋位错’微结构.透射和扫描电子显微镜测试结果表明,由企鹅珍珠贝外套膜上皮细胞组织周期性分泌的有机质多以薄膜的形式预先构筑初始螺旋位错生... 基于近海各种环境因子的响应,产自中国海南岛沿岸海域的企鹅珍珠贝珍珠层表层发育一组‘螺旋位错’微结构.透射和扫描电子显微镜测试结果表明,由企鹅珍珠贝外套膜上皮细胞组织周期性分泌的有机质多以薄膜的形式预先构筑初始螺旋位错生长模板,在有机质薄膜的诱导和螺旋调制下,无定形碳酸钙质点通过择位取向和螺旋位错生长,逐步演变为具长程有序的假六方文石微板片,与其外延螺旋生长的细分散状有机质一并兼有择优识别和粘附无定形碳酸钙质点的功能.无数微米-纳米尺度的文石微板片参与有机质薄膜的集群互动和螺旋位错自组装,并沿c轴方向呈蜷线状逐层向前堆垛,形成具螺旋位错生长结构的珍珠层. 展开更多
关键词 企鹅珍珠贝 珍珠层 有机质薄膜 文石微板片 螺旋位错
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Mass transport through metal organic framework membranes 被引量:9
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作者 Yi Guo Xinsheng Peng 《Science China Materials》 SCIE EI CSCD 2019年第1期25-42,共18页
Metal-organic frameworks(MOFs), which are composed of metal nodes and organic ligands, possess crystal phase, ordered well-defined porous structure and large surface area. Since first reported in 1990, MOFs have attra... Metal-organic frameworks(MOFs), which are composed of metal nodes and organic ligands, possess crystal phase, ordered well-defined porous structure and large surface area. Since first reported in 1990, MOFs have attracted extensive attention and the fabrication of MOF membranes has expanded their applications and endowed them with a bright future in various fields. The mass transportation process through MOF membranes is vital during their diverse applications. In this review, the strategies of preparing continuous and well-intergrown MOF membranes are presented firstly.The selective transportation processes of gas molecules, liquid molecules and ions through MOF membranes are discussed in detail, respectively. The effects of pore entrance size, interaction, functional groups decorating on the ligands and guest components on mass transportation have been summarized in this review as well. In addition, MOF membranes with selective transportation performance demonstrate potential in separation, catalysis, energy transformation and storage devices,and so on. 展开更多
关键词 mass transportation metal-organic framework (MOF) membranes
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Dithienocarbazole- and benzothiadiazole-based donor-acceptor conjugated polymers for bulk heterojunction polymer solar cells
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作者 Ziqing Rong Yunfeng Deng +2 位作者 Zhiyuan Xie Yanhou Geng Fosong Wang 《Science China Chemistry》 SCIE EI CAS CSCD 2015年第2期294-300,共7页
Donor-acceptor (D-A)-conjugated polymers P(BT-C1) and P(BT-C2), with dithieno[2,3-b;7,6-b]carbazole (C1) or dithi- eno[3,2-b;6,7-b]carbazole (C2) as D-unit and benzothiadiazole (BT) as A-unit, were synthes... Donor-acceptor (D-A)-conjugated polymers P(BT-C1) and P(BT-C2), with dithieno[2,3-b;7,6-b]carbazole (C1) or dithi- eno[3,2-b;6,7-b]carbazole (C2) as D-unit and benzothiadiazole (BT) as A-unit, were synthesized. The optical bandgaps of the polymers are similar (1.84 and 1.88 eV, respectively). The structures of donor units noticeably influence the energy levels and backbone curvature of the polymers. P(BT-C1) shows a large backbone curvature; its highest occupied molecular orbital (HOMO) energy level is -5.18 eV, whereas P(BT-C2) displays a pseudo-straight backbone and has a HOMO energy level of -5.37 eV. The hole mobilities of the polymers without thermal annealing are 1.9×10^-3 and 2.7×10^-3 cm^2 V-1 s^-1 for P(BT-C1) and P(BT-C2), respectively, as measured by organic thin-film transistors (OTFTs). Polymer solar cells using P(BT-C1) and P(BT-C2) as the donor and phenyl-Cyl-butyric acid methyl ester (PCyLBM) as the acceptor were fabricated. Power conversion efficiencies (PCEs) of 4.9% and 5.0% were achieved for P(BT-C1) and P(BT-C2), respectively. The devices based on P(BT-C2) exhibited a higher Voc due to the deeper HOMO level of the polymer, which led to a slightly higher PCE. 展开更多
关键词 conjugated polymer dithienocarbazole BENZOTHIADIAZOLE polymer solar cells power conversion efficiency
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