DNA/粘土矿物界面反应特性研究     

吴平霄  唐旖旎 《矿物学报》2012,(Z1):183-185

表生环境中富含酶、DNA(Deoxyribonucleic Acid)等生物活性物质及粘土矿物、氧化物、有机质等非生命物质。这些胞外DNA与土壤活性颗粒紧密相连,对核酸酶的降解有较强的抗性,可在环境中持久存在(Paget等,1998)。粘土矿物  相似文献   

钠化蒙脱石吸附Cu、Pb、Zn、Cd的实验研究     

周秀艳  薛向欣  刘鸥  曹伯康 《矿物学报》2012,(Z1):125-126

目前处理重金属废水的工艺中,吸附法是比较常用的方法(胥焕岩等,2004;何宏平等,1999;鲁安怀等,2000)。天然膨润土、蒙脱石、海泡石、硅藻土等粘土矿物具有较大的比表面积,对重金属离子具有吸附作用、离子交换作用和化学活性  相似文献   

区分毛细和吸附作用的非饱和土抗剪强度模型     

徐筱  赵成刚  蔡国庆 《岩土力学》2018,39(6):2059-2064

基于对非饱和土中孔隙水毛细和吸附作用的区分,得到了一种机制明确的非饱和土抗剪强度模型。首先,假定两种非饱和土的特殊状态,即只存在毛细作用的理想毛细状态和只存在吸附作用的理想吸附状态。分别给出了这两种理想状态的抗剪强度模型,其中毛细作用的影响可表示为考虑气化过程的有效饱和度和吸力的乘积,吸附作用的影响可初步简化表示为表观黏聚力的最大值。其次,利用二元介质模型,认为非饱和土中土-水作用是由这两种理想状态的不同权重组合而成。通过气化概率分布函数,表示了实际非饱和土中两种理想状态的参与比重,建立了适用于较广吸力变化范围的非饱和土抗剪强度模型。最后,通过与试验结果及当前流行的模型拟合结果的对比,验证了所建立的模型的合理性。研究表明,在考虑吸力对非饱和土力学性质的影响时,应该区分吸力的不同作用。  相似文献   

Synthesis and Photocatalytic Activity of Ti-pillared Bentonite   总被引：1，自引：0，他引：1  

TANG Jianwen WU Pingxiao ZHENG Shaoyan LIU Yun WANG Feifei XIE Xianfa 《《地质学报》英文版》2006,80(2):273-277

Ti-pillared bentonite has been successfully prepared using a modified method that can induce the transformation of TiO2 pillar from amorphous to anatase phase at a low temperature （150℃）. The value of d0.01 =1.94 nm obtained by Ti-pillared bentonite is larger than that of corresponding raw clay （1.56 nm）. Due to large numbers of Ti-pillars formed, the Ti-pillared bentonite shows an excellent ability in adsorbing Rhodamine B （RB）. The photocatalytic activity and kinetic equation are investigated by decomposing RB solution under the UV irradiation. It is found that the Ti- pillared bentonite shows super photocatalytic activity for the degradation of RB solution compared with the untreated bentonite and pure TiO2, and the kinetic equation of the degradation of RB solution is a 1.5-oder equation.  相似文献   

A Study of Chromium Adsorption on Natural Goethite Biomineralized with Iron Bacteria   总被引：1，自引：0，他引：1  

SUN Zhenya ZHU Chunshui HUANG Jiangbo GONG Wenqi CHEN Hesheng MU Shanbin 《《地质学报》英文版》2006,80(4):597-603

Goethite, especially biogenic goethite, has high specific surface area and great capacity for the adsorption of many contaminants including metal ions and organic chelates. Chromium is a redox actively toxic metal ion that exists as either Cr^Ⅲ or Cr^Ⅵ in nature, and as such it is essential to understand its behavior of adsorption on natural goethite mineralized by iron bacteria, as Gallionella and Leptothrix in water body. The adsorption of Cr^3＋ and Cr^Ⅵ on naturally biomineralized goethite is studied in this paper. The results show that both Langmuir and Freundlich adsorption isothermal models are able to accurately describe the adsorption of these two ions. Investigation of SEM/EDS, TEM/EDS indicates that the two ions do not adsorb homogeneously on goethite owing to the different microstructures of goethite, and that the microspherical goethite has a greater adsorption capacity for chromium ions than the helical one. XPS data show that redox reaction of chromium on the surface of biomineralized goethite takes place in the adsorption of both Cr^3＋ and Cr^Ⅵ. The CrvI adsorbed on biogoethite is much easier to transform into CrIII than the oxidization of Cr^Ⅲ on the bio-goethite.  相似文献   

不同来源腐殖酸对海水中Cd（II）的吸附作用     

Sohn  M 李汉成 《地质地球化学》1992,(3):31-37

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A Two-Wave Scheme for Orographic Gravity Wave Drag Parameterization          下载免费PDF全文

WANG Yuan  CAI Ninghao  TANG Jinyun 《Acta Meteorologica Sinica》2008,22(2):152-161

When the magnitude of sub-scale ographic forcing is comparable with explicitly ordinary dynamic forcing, the drag effect reduced by ographic gravity wave is to be significant for maintaining dynamic balance of atmospheric circulation, as well as the momentum and energy transport. Such sub-scale ographic forcing should be introduced into numerically atmospheric model by means of drag being parameterized. Furthermore, the currently mature ographic gravity wave drag （OGWD） parameterization, i.e., the so-called first-generation （based on lineal single-wave theoretical framework） or the second-generation drag parameterization （including an important extra forcing by the contribution of critical level absorption）, cannot correctly and effectly describe the vertical profile of wave stress under the influence of ambient wind shearing. Based on aforementioned consideration, a new two-wave scheme was proposed to parameterize the ographic gravity wave drag by means of freely propagating gravity waves. It starts with a second order WKB approximation, and treats the wave stress attenuations caused by either the selective critical level absorption or the classical critical level absorption explicitly; while in the regions where critical levels are absent, it transports the wave stress vertically by two sinusoidal waves and deposits them and then damps them according to the wave saturation criteria. This scheme is thus used to conduct some sample computations over the Dabie Mountain region of East China, as an example. The results showed that the new two-wave scheme is able to model the vertical distribution of the wave stress more realistically.  相似文献   

电气石的电场效应及其在环境领域中的应用背景   总被引：6，自引：0，他引：6  

吴瑞华  汤云晖等 《岩石矿物学杂志》2001,20(4):474-476,484

电气石具有永久性的自发电极，电气石微粒的周围存在着以c轴轴面为两极的静电场。在电场作用下，水分子发生电解，形成活性分子H3O^ ，吸引水中的杂质、污垢，净化水质；OH^-和水分子结合形成负离子，改善人们的生活环境；电场对带电粒子有吸附作用，可以吸附粉尘，净化空气。电气石还具有高的机械化学稳定性，与沸石、蒙脱石等的吸附作用相比，电气石不具有饱和极限，可持续使用，重复利用率高，在环境领域具有很好的发展前景。  相似文献   

SiO2胶体的不稳定性与Ca^2＋离子的吸附作用     

Chan  SP 张传林 《国外地质与勘测》1996,(4):33-36

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地气测量研究现状及其影响因素   总被引：14，自引：0，他引：14  

曹建劲 《湖南地质》2001,20(2):154-156

地气测量是寻找深部隐伏矿床的一种化探新方法，目前这一方法已在许多国家和地区应用并迅速发展，作者着重综述了地气测量的研究历史、现状及存在的问题，指出了季节的变化、土壤中氢氧化铁及温度与pH值对纳米微料的吸附作用等问题，是地气测量效果的显著影响因素。  相似文献