阿拉尔河悬浮物对铀的吸附影响研究          下载免费PDF全文

钟翼  许建新  韩积斌  徐凯 《盐湖研究》2020,28(1):112-122

为了解阿拉尔河悬浮物对铀的吸附特性,通过静态吸附实验,研究了吸附时间、pH值、温度和铀初始浓度等因素对模拟含铀水中U(VI)去除率的影响,并从热力学和动力学方面对吸附过程进行了分析。结果表明,在T=25℃,溶液初始pH=7,接触时间为16 h时,悬浮物对铀的平衡吸附率最佳,为95.48%。随着铀初始浓度的增加,吸附量增加,但吸附率随之下降,升高温度有利于铀的吸附。铀在悬浮物上的吸附过程符合Langmuir等温吸附方程,说明悬浮物对铀为单分子层吸附,且化学吸附占主导地位。吸附动力学过程可用准二级吸附动力学模型描述,表明吸附主要受动力学控制,由两个以上步骤共同控制。FTIR和EDS分析结果表明,吸附过程中铀主要与悬浮物表面活性基团螯合并以表面络合吸附为主。吸附前后的能谱对比分析表明,吸附过程中存在离子交换行为。因此,悬浮物对铀的吸附机理是以表面络合吸附和离子交换为主、物理吸附为辅的混合吸附过程。  相似文献   

Grain‐scale pressure variations and chemical equilibrium in high‐grade metamorphic rocks     

L. Tajčmanová  Y. Podladchikov  R. Powell  E. Moulas  J.C. Vrijmoed  J.A.D. Connolly 《Journal of Metamorphic Geology》2014,32(2):195-207

In the classical view of metamorphic microstructures, fast viscous relaxation (and so constant pressure) is assumed, with diffusion being the limiting factor in equilibration. This contribution is focused on the only other possible scenario – fast diffusion and slow viscous relaxation – and brings an alternative interpretation of microstructures typical of high‐grade metamorphic rocks. In contrast to the pressure vessel mechanical model applied to pressure variation associated with coesite inclusions in various host minerals, a multi‐anvil mechanical model is proposed in which strong single crystals and weak grain boundaries can maintain pressure variation at geological time‐scales in a polycrystalline material. In such a mechanical context, exsolution lamellae in feldspar are used to show that feldspar can sustain large differential stresses (>10 kbar) at geological time‐scales. Furthermore, it is argued that the existence of grain‐scale pressure gradients combined with diffusional equilibrium may explain chemical zoning preserved in reaction rims. Assuming zero net flux across the microstructure, an equilibrium thermodynamic method is introduced for inferring pressure variation corresponding to the chemical zoning. This new barometric method is applied to plagioclase rims around kyanite in felsic granulite (Bohemian Massif, Czech Republic), yielding a grain‐scale pressure variation of 8 kbar. In this approach, kinetic factors are not invoked to account for mineral composition zoning preserved in rocks metamorphosed at high grade.  相似文献   

Research on the Optimization of Capital for the Governance of Bulk Coal in Beijing-Tianjin-Hebei Region     

DU Xiaolin  FENG Xiangzhao  ZHAO Mengxue  WANG Min 《资源与生态学报(英文版)》2019,10(1):48-55

Beijing, Tianjin and Hebei each contributed to the comprehensive governance of bulk coal to treat bulk coal pollution in a mutually beneficial way in 2017. The cooperative game theory is used in this paper to study the environmental benefits and cost effectiveness brought about by this comprehensive governance strategy, primarily focusing on the issue of how to maximize the environmental benefits by choosing an appropriate strategy since the benefits to Beijing, Tianjin and Hebei are closely related. Therefore, the linear optimization, game theory and Shapley value method in the cooperative game model are used to find the ways to minimize the total governance cost of bulk coal in the three areas. In addition, the issues of how to carry out rational distribution and transfer of governance capital among the three places are explored according to the actual amounts of consumption of bulk coal, the influence of the coal burning on the PM_2.5 and the actual cost of coal governance in Beijing, Tianjin and Hebei in 2017. The results show that the governance task in Hebei Province is the most onerous, and requires more investment than the other two cities. Thus, it requires the support from other two cities, with the amount of increased capital required of about 600 million Yuan. At the same time, the cost saved after optimization in Tianjin is calculated to be the largest, which thus can be adjusted appropriately and allocated to Hebei for the governance of bulk coal. The model constructed in this paper can not only be used to solve the issues related to bulk coal consumption in Beijing, Tianjin and Hebei, but also to carry out the effective distribution of capital, by which a win-win scenario among the three places can be achieved.  相似文献   

撞击事件诱发核反应热力学过程及其在事件地质学研究中的意义   总被引：1，自引：0，他引：1  

周瑶琪 《现代地质》1995,9(1):91-98

摘要：从大规模撞击事件的基本动力学和热力学公式推导出发,讨论了白垩纪－第三纪界线（Ｋ／Ｔ界线）事件能量随时间的释放过程,并对发生热核聚变反应的条件进行了分析。最后,还对其可能的事件地质学意义进行了讨论．  相似文献   

海洋浮游植物的生物富集热力学模型——对疏水性污染有机物生物富集双箱热力学模型   总被引：4，自引：0，他引：4  

王修林  马延军  郁伟军  程刚 《中国海洋大学学报(自然科学版)》1998,(2)

依据疏水性有机物（ＨＯＣ）在有机相／水相之间简单物理化学分配的基本原理,提出了浮游植物对ＨＯＣ生物富集双箱热力学模型。得出浮游植物对ＨＯＣ的生物富集因子ＢＣＦ与浮游植物比表面积Ｓ,有机物正辛醇／水分配系数ｋｏｗ,有机物在水中浓度Ｃｗ之间皆存在ｌｏｇ－ｌｏｇ相关性的结论,并且由海洋浮游植物对氯代苯的生物富集实验结果验证了该模型。  相似文献   

地震层析成像反演中3种广义解的误差分析与评价   总被引：8，自引：3，他引：5       下载免费PDF全文

常旭  卢孟夏  刘伊克 《地球物理学报》1999,(5):1

在地震波速度和地震波　值层析成像中,对于非线性反演问题解的可靠性研究非常重要．为了讨论ＡＲＴ（ＡｌｇｅｂｒａｉｃＲｅｃｏｎｓｔｒｕｃｔｉｏｎ　Ｔｅｃｈｎｉｑｕｅ）、ＳＶＤ（Ｓｉｎｇｕｌａｒ　ＶａｌｕｅＤｅｃｏｍｐｏｓｉｔｉｏｎ）、ＬＳＱＷ（ＬｅａｓｔＳｕａｒｅ）３种方法的算法稳定性以及反演效果,本研究将这３种算法用于求解非常病态问题和一般稳定问题,根据数值计算结果,分别给出了在非常病态问题和一般稳定问题中３种算法的相对误差及其算法稳定性评价．进而针对３种算法在同一地质模型上的速度成像结果进行了比较,为地震层析成像反演效果分析提供了定量参数．  相似文献   

非混溶饱和两相渗流与孔隙介质耦合作用的理论研究——数学模型   总被引：1，自引：0，他引：1       下载免费PDF全文

薛世峰  宋惠珍 《地震地质》1999,21(3):243

基于连续介质力学的一般理论,在黑油多相渗流理论模型的基础上,推导了非混溶饱和两相渗流与变形孔隙介质耦合作用的数学模型方程,并对流固耦合效应进行了初步的讨论  相似文献   

岩石视反射率研究   总被引：1，自引：0，他引：1  

邢立新  刘嘉宜  孟伟 《国土资源遥感》1999,10(2):29-33

根据对净月潭地区自然条件状况的分析和样品采集及数据预处理情况,采用线性回归方法对岩石视反射率进行研究与探讨。  相似文献   

测量极值问题的经验解式--兼论绝对和极小问题   总被引：4，自引：0，他引：4  

周江文 《测绘学报》1999,28(1):11-14

测量上有许多极值问题,如各种准则下的平差,权的最优分配,网的优化方案等,多可归于线性极值问题,且多不适用寻常数学解法。但同型问题往往已经作过多次解算。因此本文以单纯形法为主,强调利用已有经验,直接逼近优解,或经少数次迭进达到优解,然后极值条件加以验证。为此文中着重提出通用解式及优解条件,期能得出优解公式,有相当的适用范围。  相似文献   

兰坪盆地遥感地质及化探综合分析在成矿预测中的应用   总被引：2，自引：0，他引：2  

廖崇高  陈建平  刘登忠 《国土资源遥感》1999,(4):622

在遥感图像目视解译的基础上,对兰坪盆地的线性构造和环形构造做了详细定量分析,结合已知矿床（ 点） 分布及地球化学异常分析,圈定出了４ 个最有利的成矿远景区,这对进一步研究和指导该区找矿十分有用。  相似文献