柱撑粘土矿物层间域的性质及其环境意义   总被引：10，自引：3，他引：10  

吴平霄  叶代启  明彩兵 《矿物岩石地球化学通报》2002,21(4):228-233

柱撑粘土矿物是近年来胺国内外矿物学广泛关注的矿物材料之一。柱撑粘土矿物层间域是一个特殊的化学反应场所。本系统评述了氮氧化物、重金属离子、阴离子、肥料养分及有机污染物等环境污染物在柱撑粘土矿物层间域中的催化还原、吸附、脱附、控释及光催化反应机理，着重阐述了柱撑粘土矿物的层间域性质，讨论了它们的环境化学行为对环境的影响和意义。  相似文献   

层柱粘土材料制备与应用研究   总被引：9，自引：1，他引：9  

周春晖  葛忠华  李春生  李小年 《矿物岩石地球化学通报》2002,21(4):242-246

简述了层柱粘土矿物材料研究与应用的现状和进展。利用粘土矿物蒙脱石作母体，通过大体积的铝、锆、硅等交联剂插层可制成层柱多孔材料，在酸催化、氧化还原催化中均有十分广阔的应用前景。研究表明，改进制备工艺后可提高层柱蒙脱石的热稳定性、比表面积和催化活性；通过酸或表面活性剂等预处理，再进行粘土的支撑，可以调节和控制层柱粘土的结构与性能；采用有机改性和模板导向等技术，可获得孔径介于大微孔和中孔之间的新型层柱粘土矿物材料，并应用于大分子催化反应与吸附，为粘土矿物材料合成和应用开辟了新方向。  相似文献   

Unstable Climate Oscillations during the Late Holocene in the Eastern Bransfield Basin, Antarctic Peninsula     

Boo-Keun Khim  Ho Il Yoon  Cheon Yun Kang  Jang Jun Bahk 《Quaternary Research》2002,58(3):234

Core A9-EB2 from the eastern Bransfield Basin, Antarctic Peninsula, consists of pelagic (diatom ooze-clay couplets and bioturbated diatom ooze) and hemipelagic (bioturbated mud) sediments interbedded with turbidites (homogeneous mud and silt–clay couplets). The cyclic and laminated nature of these pelagic sediments represents alternation between the deposition of diatom-rich biogenic sediments and of terrigenous sediments. Sediment properties and geochemical data explain the contrasting lamination, with light layers being finer-grained and relatively rich in total organic carbon and biogenic silica content. Also, the high-resolution magnetic susceptibility (MS) variations highlight distinct features: high MS values coincide with clastic-rich sections and low MS values correspond to biogenic sections. The chronology developed for core A9-EB2 accounts for anomalous ages associated with turbidites and shows a linear sedimentation rate of approximately 87 cm/10³ yr, which is supported by an accumulation rate of 80 cm/10³ yr calculated from ²¹⁰Pb activity. The late Holocene records clearly identify Neoglacial events of the Little Ice Age (LIA) and Medieval Warm Period (MWP). Other unexplained climatic events comparable in duration and amplitude to the LIA and MWP events also appear in the MS record, suggesting intrinsically unstable climatic conditions during the late Holocene in the Bransfield Basin of Antarctic Peninsula.  相似文献   

Study on Paleoenvironment since Late Glacial Eooch in Lanzhou Area, China     

Yang Guifang  Yin Hongfu  Li ChangAn 《中国地质大学学报(英文版)》2002,13(1)

The Hongzuisi Section in Lanzhou area is used to infer the paleoclimate since the late glacial epoch. Through combined analysis of organic carbon isotope and CaCO3 content, paleoenvironment evolution of Hongzuisi Section since the late glacial epoch is discussed. There were changes in both drymoist and warm-cold. Especially the climate changes can be compared with synchronous sections of other areas, which provides useful information for our future forecast.  相似文献   

Phototransformation of aromatic pollutants in solar light: Photolysis versus photosensitized reactions under natural water conditions   总被引：3，自引：0，他引：3  

Delphine Vialaton  Claire Richard 《Aquatic Sciences - Research Across Boundaries》2002,64(2):207-215

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中国耕地有机质含量变化对土地生产力影响的定量研究   总被引：23，自引：6，他引：23  

王卫  李秀彬 《地理科学》2002,22(1):24-28

在土地持续利用与管理研究中，土地质量变化对土地生产力影响的定量研究是核心内容之一。借助新古典经济学的生产函数法，构建了我国耕地的生产函数模型，定量模拟了我国耕地有机质含量变化的边际产出率性和边际生产力。初步结果表明，由于我国长期存在耕过度利用导致有机质含量及肥力下降问题，当前提高耕地质量的增产潜力十分可观。  相似文献   

Total N,total P and organic matters content in floodplain soils of Xianghai Nature Reserve     

Deng Wei  Zhai Jin-liang  He Yan 《地理学报(英文版)》2002,12(1):58-64

Soil sediment samples of 10 layers with a spacing of 10 cm each were collected in different floodplain zones adjacent to Huolin River in the Xianghai Nature Reserve, and contents of total N, total P and organic matters were analyzed. The results showed that contents of total N, total P and organic matters were generally decreasing with the increase of distance from sample locations to the river channel, and contents of the three items were generally higher in the upper soil layer than that in the lower soil layer. The content variations displayed how flooding functions influenced nutrient matter content variations in floodplain soils since the flood inundation frequencies of the sample locations varied. The correlation analysis displayed that there were remarkable relativities between total N, total P and organic matters within definite spatial distance from the Huolin River channel.  相似文献   

Floodplain–river ecosystems: lateral connections and the implications of human interference     

Martin C. Thoms   《Geomorphology》2003,56(3-4):335

Floodplains are ecotones that form a transition between aquatic and terrestrial environments. These important ecosystems can be described as dynamic spatial mosaics in which water plays an important role in connecting various patches on the floodplain surface. Hydrological connections facilitate the exchange of carbon and nutrients between the river channel and the floodplain and therefore influence the productivity of the entire river system. This paper examines the influence of hydrological connections on the potential exchange of dissolved organic carbon between a large Australian floodplain to a river channel, and the effects of land and water developments on these exchanges. The paper proposes that an understanding of floodplain ecosystems requires an interdisciplinary approach—a recognition of the importance of the three disciplines hydrology, geomorphology and ecology. Large-scale water-resources and floodplain development has significantly altered the spatial and temporal patterns of hydrological characteristics in the Lower Balonne floodplain, Australia. The magnitude, frequency and duration of flooding events have all been reduced. The construction of levees and water storages has also reduced the reactive floodplain surface area. The presented data show the impacts of these changes on the potential supply of dissolved organic carbon from the floodplain surface during periods of inundation. Annual reductions of up to 1293 tonnes of dissolved organic carbon supply were noted and reductions were especially significant for floods with an average recurrence interval of 2 years or less. Some small flood events no longer facilitate the potential supply of dissolved organic carbon from the floodplain to the river channel because of water-resources and floodplain developments.  相似文献   

TiO2柱撑蒙脱石的X射线衍射和扫描电镜研究   总被引：5，自引：0，他引：5  

李湘祁  汤德平  翁国坚 《福建地质》2003,22(1):33-36

通过TiCL4在HCL溶液中的水解制备了TiO2柱撑蒙脱石，用X射线粉末衍射（XRD）、扫描电镜（SEM）及N2吸附－脱附实验对所得材料进行表征。结果表明，煅烧能有效地改善柱撑蒙脱石层间TiO2柱体的结晶程度，但同时也会引起TiO2晶粒长大、比表面积下降以及硅酸盐片层之间平行有序分布的程度降低。  相似文献   

剥片高岭土的有机改性   总被引：12，自引：0，他引：12  

孙红  刘志强  单永奎  何鸣元 《矿物学报》2003,23(2):97-101

用醋酸钾进行插层形成高岭土—醋酸钾复合体。通过X射线检测，高岭土层间距明显增大。将此复合体通过水洗，除去醋酸钾，高岭土即被剥片。剥片后高岭土粒径变小，但保持了高岭土的基本层状结构。用偶联剂对剥片后高岭土进行有机改性，形成高岭土有机复合物。“有效活化指数”的测定实验表明，利用此种方法制备的剥片高岭土有机改性效果很好。  相似文献