Nd:YAG纳秒激光诱导硅表面微结构的演化     

袁春华  李晓红  唐多昌  杨宏道  李国强 《海洋学报》2010,32(10):7015-7019

利用Nd:YAG纳秒激光(波长为532和355 nm)对单晶硅在真空中进行了累积脉冲辐照,研究了表面微结构的演化情况.在激光辐照的初始阶段,532和355 nm激光脉冲均在硅表面诱导出了波纹结构,后者辐照硅表面后形成了近似同心但稍显混乱的环形波纹结构.随着脉冲数的增加,波纹结构逐渐演化为一种类似珠形的凹凸结构,最后形成准规则排列的微米量级锥形结构,该微结构的生长依赖于表面张力波和结构自组织.分析发现,形成的交叉环形结构主要是在355 nm激光辐照硅的过程中,表面张力波导致波纹结构部分叠加的结果.  相似文献   

Soil evolution features of debris flow waste-shoal land   总被引：1，自引：1，他引：0  

Peng Cui  Yonggang Ge  Jianqi Zhuang  Daojie Wang 《山地科学学报》2009,6(2):181-188

The reclamation and utilization of debris flow waste-shoal land plays an important role in the mitigation and control of debris flow hazards, which thus contributes a lot to the exploitation of insufficient land resources in mountainous areas and the reduction of losses caused by debris flow. The aim of this paper is to discuss the features and mechanism of soil evolution of debris flow waste-shoal land so as to search for the available modes of its reclamation and utilization. The Jiangjiagou Ravine, a typical debris flow ravine, was selected to study soil evolution features of debris flow waste-shoal land based on the analysis of soil physieochemical properties and soil microstructure. It was found that the soil evolution rates of debris flow waste-shoal land varied with different modes of reclamation. For the land which had been reclaimed for less than lO years, soil evolved most rapidly in paddy fields, and more rapidly in dry farmland than in naturally restored waste-shoal land. For the land which had been used for more than lo years, the soil evolution rates of dry farmland, naturally restored waste-shoal land and paddy farmland decreased in the file. For the same utilization period of time, significant differences were recognized in soil evolution features under different modes of reclamation. Analysis data showed that soil clay content, soil thickness, the psephicity of skeleton particles and contents of microaggregates （〈0.02 mm） in paddy farmland were all highest. Soil nutrients and porosity of dry farmland were better than those of paddy farmland and naturally restored waste-shoal land, and those of paddy farmland were superior to those of naturally restored waste-shoal land. Paddy farmland characterized by rapid pedogenesis, stable evolution and high utilizability was the priority candidate for the reclamation and utilization of debris flow waste -shoal land.  相似文献   

文蛤Meretrix meretrix血细胞形态与分类     

李俊辉  刘亮明  杜晓东  邓岳文 《广东海洋大学学报》2009,29(4):75-78

光镜观察湛江南三地区文蛤血细胞的形态与结构特征,并进行分类。按细胞大小、形态和结构特征可将文蛤血细胞分为4类:透明细胞、小颗粒细胞、大颗粒细胞和淋巴细胞。细胞直径有统计学上显著性差异(P<0.05),分别为10.11±0.44μm、10.99±0.32μm、9.63±0.41μm和9.22±0.25μm。透明细胞是血细胞中的主要成分,细胞质中无颗粒;小颗粒细胞的细胞质中存在大量细小颗粒;大颗粒细胞细胞质中的颗粒直径有1.0～2.5μm;淋巴细胞是血细胞中含量最少的,有很高的核质比,大约为0.5。  相似文献   

Biometric,microstructural, and high-resolution trace element studies in Crassostrea gigas of Cantabria (Bay of Biscay,Spain): Anthropogenic and seasonal influences     

R. Higuera-Ruiz  J. Elorza 《Estuarine, Coastal and Shelf Science》2009

Living Crassostrea gigas oysters of different ages and sizes were collected in three estuaries of Cantabria (Bay of Biscay, Spain): San Vicente de la Barquera Estuary, Santander Bay, and Marismas de Santoña Estuary. The main objective was to determine different shell responses to variable environmental parameters. A shell morphological study, based on three biometric indices, indicates that oysters of Santander Bay have two significant shell anomalies: abnormal thickening of the right valve and loss of vital cavity volume. These shell abnormalities are related with the presence in these waters of the chemical tributyltin. In the other two estuaries, the oysters show no detectable anomalies. Four shell microstructures have been distinguished: Regular Simple Prismatic, Regular Foliated, cone-Complex Cross Foliated, and Chalk. In Santander Bay oysters, the Chalk forms a “root-type” framework, whereas in the other two estuaries it forms a more compact microstructure. It is proposed that exposure to tributyltin has produced this modification. High-spatial-resolution geochemical transects have been carried out on the Regular Foliated microstructure in the umbo region in order to evaluate the distribution of Mg, Sr, and Na. The elements analysed exhibit clear cyclic variations in San Vicente de la Barquera Estuary and Marismas de Santoña Estuary oysters, related with seasonal periods, and characterised by broad maxima during months in which the waters are warmer and have higher salinity. These patterns are buffered in Santander Bay oysters. Our results demonstrate that biometric, microstructural, and high-resolution trace element studies in oyster shells can provide information about contaminants and seasonal variations in the estuarine environment.  相似文献   

立窑水泥熟料显微结构特征     

白开寅  王平  李王宾 《地球科学与环境学报》2006,28(2):65-68

以陕西某水泥厂立窑熟料为研究对象,利用偏光显微镜对水泥正常熟料、过烧和欠烧熟料进行了显微结构分析,揭示了水泥熟料显微结构与烧结过程中室内温度、通风、氧分布等烧结工艺的关系。正常熟料尽管符合出厂条件,但由于烧结工艺实施不合理,使得熟料显微结构欠缺,导致熟料水化性能和抗压强度降低。研究结果表明,正常熟料、过烧和欠烧熟料的判定与C2S的干涉色高低有直接关系。研究结果可用于各水泥厂熟料质量检测和烧结工艺制定。  相似文献   

小秦岭构造岩及其与金矿化关系     

盛吉虎  徐莉  尉向东  刘长命 《河南国土资源》1996,(4)

根据小秦岭地区含金石英脉与糜棱岩的空间分布关系可将石英脉分为交代脉、拉张脉、剪切脉、角砾岩脉和裂隙脉等五种类型，它们是不同构造阶段的产物。脉体宏观构造、微观构造、包体测压数据及石英Ｘ射线研究表明，脉体的充填、定位与容矿空间扩张同时形成，容矿空间的形成是含金热液液压致裂作用的直接结果。本文详细研究了构造岩的岩石学、岩相学特征，并对构造岩的形成条件及与金矿化关系等做了初步探讨  相似文献   

浙江白垩系两种掌鳞杉科化石微细结构及其古环境意义   总被引：2，自引：0，他引：2  

任文秀  孙柏年  李相传  吴靖宇  肖良  王永栋 《地质学报》2008,82(5):577-583

利用扫描电镜和生物光学显微镜对采自浙江新昌镜岭馆头组的两种已绝灭的松柏类掌鳞杉科植物Pseudofrenelopsis papillosa Chow and Tsao和Pseudofrenelopsis parceramosa Watson细微结构进行了观察研究。其中P.papillosa无论从宏观形态还是表皮构造都与模式标本完全一致;而定为Pseudofrenelopsis parceramosa的标本节间角质层较为光滑,气孔排列规则,副卫细胞上未见乳突,此外该标本气孔器大小、自由叶大小、节间长度等方面都与Pseudofrenelopsis中的其他种不太相同。并利用化石P.parceramosa的气孔比率通过最近现生亲缘种法恢复了早白垩世晚期大气CO2浓度为861~1047ml/L,得出用本种恢复早白垩世晚期CO2浓度时应用石炭纪标准较为准确,说明本种可以作为环境指标。  相似文献   

SAED and HRTEM Investigation of Palygorskite     

CHEN Tao  WANG Hejing  ZHANG Xiaoping  ZHENG Nan 《《地质学报》英文版》2008,82(2):385-391

The microstructure of palygorskite from Longwang Mountain of Xuyu County, Jiangsu Province, was studied by energy dispersive X-ray analysis （EDX）, selected-area electron diffraction （SAED） and high-resolution transmission electron microscopy （HRTEM）. The average composition of the palygorskite studied is （Si7.38A10.62） （A10.96Fe^3＋ 0.62Mg2.86 0.56）Ca0.03K0.06O20（OH）2（OH2）4, which is rich in Mg. Several SAED patterns from a single crystal of palygorskite were obtained with different zone axes. The polymorphs （monoclinic and orthorhombic） are unequivocally distinguished by distant interplanar angles, even though they possess similar sets of d-values. High-resolution images of three principal zones （[010], [100] and [110]） were obtained. The lattice fringes on HRTEM images along [010] have spacings of 0.319 nm. These fringes are interpreted as periodic alterations of two tetrahedral （T） sheets and one octahedral （O） sheet （-TT-O-TT-O-）. We have directly observed trioctahedral and dioctahedral individual palygorskite particles along [100]. They are all presented as dark lines along [001], but the width of dark lines corresponding to trioctahedral crystals （0.913 nm） is twice that of the dioctahedral ones （0.456 nm）. This is because the trans.sites are occupied by cations in trioctahedral palygorskite. The width of dark lines along [110] is 1.024 nm, a bit thinner than the theoretical spacing （1.044 nm）. This is because water molecules quickly leave the structure upon the irradiation by the electron beam.  相似文献   

煤基石墨微结构的高分辨电镜研究   总被引：3，自引：0，他引：3  

郑辙 《矿物学报》1991,(3)

煤体经热变质作用形成的石墨叫煤基石墨。湖南省鲁塘地区煤基石墨,经与之共生的红柱石的相图分析,它属于低压相系矿物,在200—800℃和5.5×10~5Pa以下条件下形成。它的高分辨电子显微象显示,煤基石墨按其石墨化程度有四种类型微结构。因而。将煤基石墨划分为相继的四个石墨化阶段。同时有四种石墨产物,它们是:前石墨化阶段——芳层石墨;初石墨化阶段——微柱石墨;中石墨化阶段——柔绉石墨;高石墨化阶段——平直石墨  相似文献   

三种软体动物闭壳肌-壳界面结构研究     

朱曜曜  孙承君  宋影飞  蒋凤华  尹晓斐  唐敏  丁海兵 《海洋学报(英文版)》2016,35(8):57-64

闭壳肌的疤痕部位（AMS）是闭壳肌和壳的固定点。它是一个重要的有机-无机界面和应力分布面。尽管有一些近期的研究进展,我们对AMS组成和结构的了解仍然是有限的。这里,我们研究比较了三种双壳类动物：厚壳贻贝、栉孔扇贝、菲律宾蛤仔的AMS。结果表明这三种动物的AMS明显不同。厚壳贻贝和栉孔扇贝在AMS的壳结构珍珠片层上部有一柱状层,该层在厚壳贻贝中的结构更有规律。菲律宾蛤仔缺乏此柱状层。原子力显微镜结果显示在三种软体动物中AMS的结构比珍珠层结构更光滑。傅立叶变换红外分析结果显示珍珠层和AMS层组成成分略有不同。聚丙烯酰胺凝胶电泳蛋白分离结果显示在厚壳贻贝界面柱状层存在一种约70 kDa的蛋白。对这种蛋白的进一步分析显示其还有较高摩尔比的Asx（Asp+Asn）,Glx（Glu+Gln）和Gly。AMS的特殊结构和组成对其稳定性、粘性以及在该应力分散部位的功能有重要作用。  相似文献