粘土矿物去除废水中磷的效应与机理

磷的任意排放引起水体富营养化造成了水体污染,减少磷排放已经引起了社会的关注。粘土矿物资源丰富,具有特殊的结构组成,对磷的去除有着良好的效果,特别是改性的粘土矿物。因此,系统总结粘土矿物对磷的去除效果与机理,为更好的开发粘土矿物在废水处理的应用奠定基础。     

黄土中粘土矿物的提取及其对氯吡硫磷的吸附行为研究

以黄土为原料并从中提取粘土矿物,研究粘土矿物对氯吡硫磷的吸附行为,并从吸附等温线,动力学和热力学角度对其吸附机理进行探讨.吸附等温线模型研究表明,粘土矿物对氯吡硫磷的吸附属于Langmuir和Freundlich的复合型吸附;吸附动力学模型研究表明,该过程符合拟二级动力学方程;吸附热力学参数研究表明,该过程是一个自发的吸热反应,且主要作用为氢键吸附.研究结果有助于进一步探究土壤中残留农药的自净机理.     

对贵州红粘土的剖面特征分析及成因的探讨

红粘土作为特殊土中的一种,其特殊性质是由成分和结构控制,且成分和结构取决于红粘土的成因。为了探讨红粘土的成因从而深入了解其特殊性,该文结合试验对贵州岩溶地区8个红粘土剖面48个样品的常量元素和微量元素作出分析和对比,对红粘土剖面粘土矿物特征作出分析。验证了红粘土主要是在溶蚀－交代作用和红土化作用两个阶段形成,并且与母岩成分、CO2含量、气候条件、地形地貌等有关。     

苯酚废水电化学处理方法研究

利用红外光谱分析(FITR)、X射线粉晶衍射(XRD)、差热分析(DTA)、扫描电镜(SEM)等测试手段对天然粘土矿物累托石及自制的铁/累托石复合材料的结构性能进行分析;并对两种累托石材料对模拟的苯酚废水中苯酚的电化学降解过程及效果进行了研究,得出了其动力学方程.结果表明:电催化铁/累托石复合材料比天然粘土矿物累托石能更好地催化降解模拟苯酚废水中的苯酚,其降解的速度较快,降解率较高.而两者结构差异不大,表明对累托石的改性过程主要在层间进行,既能保持累托石原来的优良性能,又能将铁离子固定化.     

聚合物-粘土纳米复合材料

介绍了用于聚合物-粘土矿物纳米复合材料的蒙脱石的基本结构、性能和纳米化原理，报道了蒙脱石的有机改性方法和层间扦入方法，评述了该复合体系的研究进展.     

凹凸棒石粘土的改性处理和应用研究进展

凹凸棒石粘土由于其特有的纤维状形貌、高比表面积、微孔孔道和稳定的结晶态结构,在吸附、脱色、流变性和催化等方面有非常广泛的工业应用.本文较为全面地综述了凹凸棒石粘土的活化改性处理方法,总结了目前凹凸棒土的实际应用领域,指出其工业应用发展前景.     

聚合物—粘土纳米复合材料

介绍了用于聚合物-粘土矿物纳米复合材料的蒙脱石的基本结构、性能和纳米化原理，报道了蒙脱石的有机改性方法和层间扦入方法，评述了该复合体系的研究进展。     

PS与土遗址作用机理的初步探讨

PS　作为一种新型的无机加固材料 ,应用于土遗址的保护 ,可大大提高土遗址的力学强度和抗风蚀能力 ,本文通过XRD、SEM、TEM等现代分析手段研究了PS与土遗址间的作用机理。实验证明 ,经PS加固后的土遗址中粘土矿物的结晶度有所降低、改变了粘土矿物本身的微观结构 ,形成了一种非晶态的硅铝酸盐凝胶体 ,这种结构增加了土遗址的力学强度和抗风蚀能力 ,对土遗址的保护具有良好作用。     

壳聚糖及其低聚物制备方法的研究进展

壳聚糖资源丰富,已被广泛应用于化工、环保、医药等众多领域,低聚壳聚糖是一种具有多种功能的活性制剂。本文综述了壳聚糖及低聚壳聚糖制备方法的研究及进展。     

BC/WPU功能涂膜制备及性能研究

以环保型水性聚氨酯(WPU)作成膜物,把环保、高附加值及功能化作为涂膜设计理念,以低成本竹炭(BC)作功能助剂,旨在合成宜居多功能涂膜,通过BC改性及优化配方制备了BC/WPU功能涂膜。研究了BC改性剂种类、用量和添加量、粒度及分散时间等因素对功能涂膜性能的影响。结果表明:γ-胺丙基三乙氧基硅烷(γ-APTES)改性BC/WPU功能涂膜具有优异的导电、力学性能;在γ-APTES为BC质量的2%、BC用量为20%、BC粒度为500目、分散40 min条件下,制备的涂膜体积电阻率为1.7×104Ω.cm,铅笔硬度为4H,冲击强度≥70kg.cm,耐洗刷性能≥11350次。     

正常固结饱和粘性土孔隙水压力性状分析

通过正常固结饱和粘性土的三轴固结不排水试验,分析了在正常固结饱和粘性土在三轴固结不排水应力路径下考虑土应力应变非线性的孔隙水压力方程,根据有效应力路径唯一性原理,推导出适用于其他应力路径下正常固结饱和粘性土的孔隙水压力方程,并通过一个工程实例验证方程的工程实用性。     

柱撑粘土皂石的合成及其表征

用水热法合成了柱撑粘土皂石,用羟基铝与其交联,并对其进行了表征.合成出的柱撑粘土皂石显示出较高的热稳定性,在结构上也与文献报道相符.     

杂多酸型层柱状阴离子粘土的合成表征与酸碱催化行为

合成了1：12系列Keggin结构磷钨钒杂多阴离子柱撑阴离子粘土，用元素分析，XRD和IR对产物的组成和结构进行了表征，考察了合成产物在异丙醇反应中的酸碱催化行为。研究表明，柱撑材料表面同时存在酸碱两类催化活性中心，但其催化性能明显优于粘土前驱体和相应杂多酸盐，且在考察的温度范围内，其酸性随温度的升高而增加。     

A modified creep index and its application to viscoplastic modelling of soft clays

Conventional consolidation tests on reconstituted specimens of numerous natural soft clays show a decreasing of creep index Cae with increasing soil density. Based on all selected and conducted experimental results, a modified creep index Cae＊ defined in double logarithmic plane lge-lgt, was plotted for various clays, from which Cae＊ can be assumed as a constant for different soil densities. Then, the modified creep index was applied to a newly developed elastic viscoplastic model. In this way, the modified creep index Ca＊ can naturally take into account the nonlinear Cae revealing the influence of soil density in the soil assemblies without additional parameters. Finally, the enhanced model was incorporated into the finite element code ABAQUS and used to simulate a consolidation test and a test embankment. The improvement of simulations by the modified creep index was highlighted by comparing simulations using the conventional creep index Cae.     

结构性对黏性土渗透性状的影响研究

利用改进的固结渗透仪,通过对天然沉积软黏土原状样及重塑样进行固结渗透试验,对比分析了压缩过程中天然沉积土原状样与重塑样在同一孔隙比和同一应力水平下的渗透性状。研究结果表明,天然沉积土原状样e-log kv曲线位于重塑样的右边,但是两者差别不大;原状样的log kv-logσ’v关系曲线位于重塑样的上方,天然沉积土原状样与重塑样同一应力水平下的渗透系数的比值随着应力水平的增大而先增大后减小,在原状样固结屈服压力时达到最大值。     

基于CPTU测试的泻湖相沉积土固结屈服应力和OCR确定方法

回顾了基于CPTU测试成果确定粘土固结屈服应力和超固结比的方法,表明土的固结屈服应力和超固结比与CPTU测试参数之间不存在惟一的相关关系,仅仅针对某一地区的相关关系才是有效的.根据苏北里下河地区泻湖相沉积土的CPTU测试资料,对3种经验方法进行了比较.评价了固结屈服应力与CPTU测试参数现有经验关系的有效性,并且确定出适宜于里下河地区泻湖相沉积土的预测方法.结果表明:基于净锥尖阻力的相关关系比其他经验方法具有较高的精度,可以有效地预测该地区泻湖相沉积土的固结屈服应力和超固结比.     

EPR-RCGA-based modelling of compression index and RMSE-AIC-BIC-based model selection for Chinese marine clays and their engineering application

The compression index is a key parameter in the field of soft clay engineering. In this paper, we propose an improved method for correlating the compression index with the physical properties of intact Chinese marine clays that are involved in many construction projects in coastal regions in China. First, the compression index and some common physical properties of clays from 21 regions along the Chinese coast are extracted from the literature. Then, a basic regression analysis for the compression index using the natural water content and Atterberg limits is conducted. To improve the correlation performance, an evolutionary polynomial regression (EPR) and real coded genetic algorithm (RCGA) combined technique is adopted to formulate different equations involving different numbers of variables. An optimal correlation using only natural water content and liquid limit as input parameters is finally selected according to the root mean square error (RMSE), Akaike’s information criterion (AIC), and Bayesian information criterion (BIC). The proposed correlation is evaluated and shown to perform better than existing empirical correlations in predicting the compression index for all selected Chinese marine clays. This correlation is validated to be reliable and applicable to engineering applications through the prediction of the properties of an embankment on the southeast coast of China using finite element method. All comparisons show that the EPR and RCGA combined technique is powerful for correlating the compression index with the physical properties of the clay, and that model selection by RMSE, AIC, and BIC is effective. The proposed correlation could be used to update current formulations, and is applicable to engineering design in coastal regions of China.     

How do Teachers View Their Teaching and the Use of Teaching Resources?

This paper looks briefly at teachers' views and opinions of their use of various teaching methods and teaching resources. The study was limited to a single secondary school where a questionnaire was given to a small sample of 15 teachers in four departments. What was found was that in the Ideal World (where everything that was needed was available), the reasons given for various teaching methods used were mainly pupil dominated, but when it came to the actual methods being used, the reasons were mainly personal constraints of the teacher or organizational constraints. This dichotomy widened from the humanities field to the sciences field. With respect to the resources used, it could be hypothesised that most teachers felt they were not prepared to use new types of resources especially if they entailed acquiring new technical skills, more preparation, and a change of roles played by the teacher.     

生物化学课程教学方法的实践与探索

针对生物化学课程的特点和本人的教学实践,对生化课堂教学中运用到的启发式教学、多媒体教学、问题式教学、实验教学等六个方面进行了总结和归纳．与传统教学方法相比,这些方法更容易激发学生的积极性和主动性．     

二硫化四甲基秋兰姆合成方法进展

本文介绍了目前国内外使用的硫化促进剂种类及二硫化四甲基秋兰姆的各种生产方法。对各生产方法进行比较的结果,认为用氧气一步氧化法制备二硫化四甲基秋兰姆是目前较佳的工艺。