共查询到20条相似文献，搜索用时 109 毫秒
1.
2.
微粒矿物的地球化学活性与生物活性 总被引：9，自引：0，他引：9
丁振华 《矿物岩石地球化学通报》1998,(4)
微粒矿物的粒径为几个纳米到几十个微米,因其颗粒小、表面积大,具有不同于块体矿物的表面结构和化学活性。本文将主要讨论这一粒级矿物的地球化学活性和生物活性。１矿物微粒的物理化学特性微粒矿物的物理化学性质主要取决于微粒的表面化学性质与体积效应,即表面原子结... 相似文献
3.
4.
青蛤贝壳韧带的结构色及微结构 总被引：2，自引：1，他引：2
采用XRD、热失重分析、反射光谱及高分辨FE-SEM对青蛤贝壳韧带的矿物组成,结构色及微结构进行系统研究,结果表明:1)青蛤韧带由78%文石矿物,18%的蛋白质及少量的水组成,文石矿物呈纤维状,纤维的直径约138 nm,相邻纤维中心的间距约164 nm;2)韧带可呈现蓝,黄色结构色;3)韧带具有明显的层状结构特征,生长层的厚20μm~40μm,同一生长层中文石纤维长轴定向排列,而相邻层纤维长轴的定向不一致,并呈现一种新的结构类型“-交叉棱柱层”结构。再者,青蛤韧带中的文石纤维构成了一类特殊的2D准周期光子晶体。 相似文献
5.
大气粉尘中的矿物及其环境健康效应研究进展 总被引：3，自引：0，他引：3
大气粉尘中的矿物主要来源于土壤尘、建筑工地和局地扬尘,颗粒较小,一般呈不规则形状,表面凹凸不平。矿物粉尘具有很强的生物活性,对人体健康、生物效应有其特有的生理作用。矿物粉尘表面活性基团影响粉尘的生物效应。矿物粉尘本身或刺激吞噬细胞而产生的自由基对细胞的损伤和粉尘性疾病的形成起着至关重要的作用。大气粉尘成分、表面特性以及矿物粉尘对人体正常宿主菌群的抑制性和毒性效应研究是矿物粉尘环境健康效应研究的重要方向。 相似文献
6.
工业矿物纤维粉尘的表面特性研究 总被引：9，自引：0，他引：9
本文在对比研究了７种工业矿物纤维表面官能团和表面行为的基础上讨论了矿物纤维粉尘对人体的危害性及对环境影响的毒理因素,强调矿物与生物体之间的相互作用要重视矿物表面／细胞物理化学作用,提出矿物纤维表面特征是表征其生物活性的关键因子,如表面活性域等,而纤维性只是矿物表面特性的表征因素之一。 相似文献
7.
纤水镁石是一种天然水镁石矿物,呈纤维状集合体,纤维束的分散是其有效利用的前提;同时,矿物表面极性基团OH-与有机基体的相容性差,进行表面改性可改善其在材料中的分散性和相容性,对于扩展纤维的应用领域有重要意义。 相似文献
8.
纤维矿物粉尘环境矿物学与环境医学研究的新进展 总被引：12，自引：3，他引：9
本文全面评述了纤维矿物粉尘在环境安全性方面的研究成果与目前存在的主要不足,提出除应注重纤维间的特性差异（纤维剂量、长度、细度）的要求外,还应注意制样方法、样品产地、成因、成分等方面的影响,强调纤维断键、活性自由基、活性中心、纤维电荷、催化性质、氧化－还原强度,“表面介体”等因素的作用,阐明从表面活性及矿物－生物化学作用方面揭示纤维粉尘致病机理的重要性、即从矿物表面官能团、表面综合性状来探讨天然纤维 相似文献
9.
10.
四川石棉矿产出四种蛇纹石矿物:纤蛇纹石,Povlen型纤蛇纹石、利蛇纹石和叶蛇纹石。它们的形态、结构、化学成分和红外光谱各具特征,本文对此进行了描述和讨论。纤蛇纹石以纵纤维脉和横纤维脉形式产出,以斜纤蛇纹石为主,含少量正纤和副纤蛇纹石。纵纤维蛇纹石可能由地壳浅层中的大气热水形成。Povlen型纤蛇纹石是蛇纹石族矿物的一个新变种,其形态、结构和化学成分都不同于其他蛇纹石矿物。 相似文献
11.
The present work aimed to determine the mineralogical composition of Ypresian series and to clarify the influence of the dissolution of siliceous frustules on the genesis of fibrous clay minerals. The specimens sampled from CPG trench are mainly constituted of silica-rich rocks at Mides area located at the western part of Gafsa-Metlaoui basin. The samples were investigated using X-ray diffraction (XRD) and scanning electron microscopy (SEM) in order to determine texture of constituents. The data obtained indicate that the bulk rock samples are mainly made up of opal CT and clay minerals. The latter consists of palygorskite-sepiolite minerals associated with smectite and few amount of illite. The trend of mineralogical composition indicates that fibrous clay minerals are more concentrated at the upper part. SEM observations indicated that palygorskite mineral appears as thread-like facies, which surround foliated texture of smectite in the lower part of the Mides section, although with the low Mg activity confirmed by the absence of dolomite. But, at the upper part of the Mides section, SEM observations revealed the occurrence of siliceous frustules, which have numerous dissolved areas and replacement of carbonate tests by silica. The dissolution saturated the depositional environment with silica which is required for the formation of palygorskite and sepiolite minerals, in addition to high Mg activity confirmed by the presence of dolomite in the bulk rock, which is required basically for the formation of sepiolite. Although the genesis mode of palygorskite and sepiolite is similar with very little difference, the genesis of sepiolite needs a high alkalinity than the formation of palygorskite. 相似文献
12.
《Journal of African Earth Sciences》2006,44(5):491-504
This paper presents mineralogical and geochemical data from several continental sequences located in Central (Ain Ghréwiss and Kébar) and Central-Southern Tunisia (Selja, Kef Schefeir, Shib, Oum El Kcheb and Haidoudi). These sequences vary in age from Late Palaeocene to Early Oligocene and contain considerable quantities of fibrous clays (up to 75% palygorskite and 90% sepiolite). These clays appear in assocation with carbonates (mainly dolomite), detrital aluminosilicates (illite, Al smectites, mixed-layers illite–smectite and kaolinite), quartz and lesser quantities of gypsum and halite. The textural characteristics observed by electron microscopy, the trace and rare earth elements contents and their distribution in the various mineral phases, together with the isotopic composition of dolomite and fibrous clays, provide good clues as to the genesis of the neoformed minerals. Thus, the sepiolite would have precipitated directly in lacustrine, playa-lake or sebka environments under alkaline conditions, high Si and Mg and low Al activity, and arid to semiarid climate. On the other hand, the palygorskite would have formed by transformation of already existing illite and/or smectite type aluminosilicates in solutions in equilibrium with isotopically heavier and, therefore, more evaporated solutions than the sepiolite. 相似文献
13.
Asbestos and other fibrous minerals contained in the serpentinites of the Gimigliano-Mount Reventino Unit (Calabria,S-Italy) 总被引：1，自引：1，他引：0
Andrea Bloise Teresa Critelli Manuela Catalano Carmine Apollaro Domenico Miriello Alessandro Croce Eugenio Barrese Francesca Liberi Eugenio Piluso Caterina Rinaudo Elena Belluso 《Environmental Earth Sciences》2014,71(8):3773-3786
Serpentinites are metamorphic rocks with good technological properties and valuable ornamental characteristics, which have been exploited since ancient times. Actually, their use is limited and monitored in several countries worldwide because they can contain fibrous asbestos minerals that may be carcinogenic. Furthermore, certain types of fibrous minerals can be confused with asbestos, and must therefore be carefully investigated. We have investigated the possible presence of the asbestos and non-asbestos fibrous phases contained in serpentinitic rocks in a meta-ophiolitic sequence from the Gimigliano-Mount Reventino Unit (Southern Italy), which had not been previously assessed. The detection and quantification of asbestos and the correct distinction of the fibrous non-asbestos minerals are very important not only from a scientific point of view, but also from a legislative one. This is especially the case for the administrative agencies that have to take decisions with regards to the implementation of public and occupational health protection measures (e.g., in road yards and quarry excavations). As a consequence of this, serpentinitic rock samples have been characterized in detail through X-ray powder diffraction, scanning and transmission electron microscopy combined with energy-dispersive spectrometry, analytical electron microscopy (SEM–EDS and TEM–AEM), differential scanning calorimetry, thermogravimetry and micro-Raman spectroscopy. Two kinds of asbestos and four kinds of non-asbestos fibrous silicates have been detected in the examined samples. In order of decreasing abundance these are polygonal serpentine, chrysotile, fibrous antigorite, tremolite, gedrite and magnesiohornblende. The size, morphology, crystallinity and chemical composition of the fibres were also discussed, in the light of the possible role these properties could play in the carcinogenic effect on human health. 相似文献
14.
15.
X射线粉晶衍射仪定量测量海泡石矿样的实验条件 总被引：3，自引：3，他引：0
在完成海泡石矿石样品的矿物组成及相对含量测试、均匀性检验、稳定性和粒度分布特征检查的基础上,选择合适的X射线粉晶衍射定量测量海泡石的实验条件,利用海泡石、刚玉和萤石纯样配制一系列海泡石质量分数已知的标准样品,采用内标定量法、固体计数器和计数强度测试技术,对低、中、高3种不同含量的海泡石样品进行测量。结果表明:获得的海泡石样品定量测量数据符合现有的行业标准,采用的定量测试方法与测量条件满足黏土开采企业和实验研究单位测试要求,达到了X射线粉晶衍射法定量分析黏土矿物的目的。 相似文献
16.
刘德镒 《沉积与特提斯地质》1990,10(1):46-55
海泡石是一种富镁的纤维状粘土矿物,为链-层状结构的含水硅酸盐。在自然界中分布不广,很少形成单独的大量堆积。但是因为它具有一系列有别于其他粘土矿物的极其有用的物理化学性能,因此,有着广泛的工业用途。海泡石的成因大体分为两类,一是热液蚀变产物,常呈纤维状或“石棉”状,集合成脉状产出,规模较小,工业意义不大。另一类为沉积成因(包括成岩作用或新生作用而成),往往成为土状海泡石粘土,集合成层状、似层状或透镜状产出,规模一般较大,工业矿床多属此类成因。中国的海泡石粘土矿床都分布在中国南方,而且主要集中在下二叠统,其中湖南约占80％,所以被誉为“海泡石之乡”。在我国“科学的春天”里,湖南有关野外队先后发现了四个矿床和十来个矿点或矿化点。湖南地质研究所参加了地质矿产部“七五”期间重点攻 相似文献
17.
镉在蒙脱石等粘土矿物上的吸附行为研究 总被引：5，自引：0，他引：5
研究了土壤中主要硅酸盐粘土矿物蒙脱石、伊利石、高岭石、海泡石对重金属镉的吸附行为.结果表明:硅酸盐粘土矿物吸附镉受酸度和离子强度的影响;吸附反应是快反应,能很好地符合Lagergren二级吸附速度方程;优化条件下的高岭石对镉吸附很弱,蒙脱石、伊利石、海泡石对镉的实验饱和吸附容量分别为2.88、1.08、2.82 mg/g,蒙脱石吸附镉更适合Freundlich拟合,伊利石、海泡石对镉的吸附结果更适合Langmuir拟合;相关性分析表明,硅酸盐粘土矿物对镉的饱和吸附容量大小与其理化性质有关,其中矿物中氧化锰含量高低与其对镉饱和吸附容量大小的相关性达到极显著水平. 相似文献
18.
19.
陕西宁强海泡石赋存于二叠系泥灰岩、Ca-Mg质页岩和粘土中。本区海泡石呈纤 维状或纤维集合体。由于有高含量的水,折光率较低,平均为1.508,干涉色为灰色。该矿物的粉 晶衍射图谱最强线有12.17,7.47,6.70,4.51和4.32A。本文亦描述了该矿物的差热分析,热 重、化学分析和红外资料。 本区海泡石作为化学沉积物,形成于边缘海或内陆海中。特别是在铝浓度低,氧化硅浓度高,镁浓度高和pH为碱性的环境中更易形成。 相似文献
20.
It has been assumed that soil pendants form in a similar manner as stalactites, in which innermost laminae are the oldest and outer laminae are the youngest. This study presents a new interpretation for soil pendant development. Pahranagat Valley, Nevada, pendants contain features indicating continued precipitation through time at the clast–pendant contact, implying that the oldest deposits are not always found at the pendant–clast contact, as other studies have assumed. These features include a void at the clast–pendant contact where minerals such as calcium carbonate, silica, and/or fibrous silicate clays precipitate. In addition, fragments of the parent clast and detrital grains are incorporated into the pendant and are displaced and/or dissolved and result in the formation of sepiolite. This study indicates that pendants are complex, open systems that during and after their formation undergo chemical changes that complicate their usefulness for dating and paleoenvironmental analyses. 相似文献