Interactions between benzotriazole and corncob biochars pyrolyzed at different temperature     

XING Chen  YU Cheng-long  BI Er-ping  DAI Jin-e 《地下水科学与工程》2016,4(4):320-327

The sorption of ionizable benzotriazole (BTA) to corncob biochars pyrolyzed at different temperature (i.e., 300 oC, 500 oC and 800 oC) was investigated in this study. Biochars produced at higher temperature showed higher surface area, micropore volume and aromaticity. Consequently, the sorption of BTA changed from absorption to adsorption for biochars pyrolyzed at 300 oC and 800 oC, respectively. Solution pH affected speciation of BTA and surface charge properties of biochars. For BTA0, H-bond, partition and micropore filling are dominant sorption mechanisms. For BTA-, it is suggested that negative charge-assisted H-bond plays an important role in sorption. Corncob biochar pyrolyzed at high temperature (e.g., 800 oC) showed the highest sorption affinity for BTA. Ca2+ in solution enhanced BTA- and BTA0 sorption through cation-bridge and surface complexation.  相似文献   

非饱和心墙料的固结不排水试验特性     

毕庆涛  殷宗泽  丁树云 《岩土力学》2009,30(5):1271-1274

土石坝心墙在施工期间处于非饱和状态,且坝体是分级填筑的。应力变形计算时将载荷分成若干级增量,每一级增量假设瞬间完成,等固结一段时间后再施加下一级载荷。由于施加荷载的瞬间来不及排水,因此,总应力法计算参数可以由固结不排水、不排气试验取得。通过三轴试验,揭示了非饱和心墙料的固结、应力-应变及侧向变形特征,探讨了固结过程中体积应变随时间的变化规律,建立了切线泊松比与围压的双曲线关系模型。  相似文献   

贵州喀斯特与非喀斯特农业生态地质环境质量对比研究   总被引：3，自引：0，他引：3  

任明强  张家德  卢正艳  罗明学  毕坤  陈蓉 《中国岩溶》2009,28(4):397-401

为寻求喀斯特地区农产品低劣的根源,通过调查和采样测试对比研究了贵州碳酸盐岩和非碳酸盐岩地质环境和农作物产品质量的差异。结果表明:（1）非碳酸盐岩的微量元素含量为10.894 2×10-3,而碳酸岩的为35.322 7×10-4;非碳酸盐岩地区耕作土中有效态微量元素含量为3.260 5×10-4,碳酸盐岩分布区的耕作土仅为1.014×10-4,彼此相差3倍;（2）优质农作物多产于非碳酸盐岩地区,随机调查贵州省内38个优质水稻产地,有33个位于非碳酸盐岩地区,仅有5个在碳酸盐岩区。茶叶、马铃薯、西瓜等也有此类规律。由此认为,喀斯特环境缺乏多种矿物营养元素,是形成其农作物质量低下的根本原因,也是贵州喀斯特农业生态环境脆弱的内在原因。   相似文献   

Simulation of spring flows from a karst aquifer with an artificial neural network   总被引：1，自引：0，他引：1  

Caihong Hu  Yonghong Hao  Tian‐Chyi J. Yeh  Bo Pang  Zening Wu 《水文研究》2008,22(5):596-604

In China, 9·5% of the landmass is karst terrain and of that 47,000 km² is located in semiarid regions. In these regions the karst aquifers feed many large karst springs within basins of thousands of square kilometres. Spring discharges reflect the fluctuation of ground water level and variability of ground water storage in the basins. However, karst aquifers are highly heterogeneous and monitoring data are sparse in these regions. Therefore, for sustainable utilization and conservation of karst ground water it is necessary to simulate the spring flows to acquire better understanding of karst hydrological processes. The purpose of this study is to develop a parsimonious model that accurately simulates spring discharges using an artificial neural network (ANN) model. The karst spring aquifer was treated as a non‐linear input/output system to simulate the response of karst spring flow to precipitation and applied the model to the Niangziguan Springs, located in the east of Shanxi Province, China and a representative of karst springs in a semiarid area. Moreover, the ANN model was compared with a previous time‐lag linear model and it was found that the ANN model performed better. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

INSTALLATION AND DEBUGGING OF REGIONAL FIELD EARTHQUAKE EMERGENCY SYSTEM     

GUO Dan-yang  HOU Zuo-liang  BI Ming-peng  SONG Si-ran  WANG Li-li  ZHAI Wen-jie 《东北地震研究》2008,24(4)

  相似文献   

区域现场地震工作系统的安装与调试     

郭丹阳  侯作亮  毕明鹏  宋思然  王丽莉  翟文杰 《东北地震研究》2008,24(4):41-48

针对灾害性地震发生后,地震应急部门的现场工作要求,设计了区域现场地震工作系统。提供可靠的地震现场调查和通讯手段,及时掌握震情、灾情信息,有效地进行应急指挥与调度。本文详细介绍了区域现场地震工作系统的设计思路、技术流程、设备功能和应用效果。  相似文献   

Hydraulic tomography for detecting fracture zone connectivity   总被引：1，自引：0，他引：1  

Hao Y  Yeh TC  Xiang J  Illman WA  Ando K  Hsu KC  Lee CH 《Ground water》2008,46(2):183-192

Fracture zones and their connectivity in geologic media are of great importance to ground water resources management as well as ground water contamination prevention and remediation. In this paper, we applied a recently developed hydraulic tomography (HT) technique and an analysis algorithm (sequential successive linear estimator) to synthetic fractured media. The application aims to explore the potential utility of the technique and the algorithm for characterizing fracture zone distribution and their connectivity. Results of this investigation showed that using HT with a limited number of wells, the fracture zone distribution and its connectivity (general pattern) can be mapped satisfactorily although estimated hydraulic property fields are smooth. As the number of wells and monitoring ports increases, the fracture zone distribution and connectivity become vivid and the estimated hydraulic properties approach true values. We hope that the success of this application may promote the development and application of the new generations of technology (i.e., hydraulic, tracer, pneumatic tomographic surveys) for mapping fractures and other features in geologic media.  相似文献   

大型地下洞室施工过程中的可靠性分析     

毕继红  张鹏飞  杜玉东 《岩土力学》2007,28(11):2415-2420

通过对Monte-Carlo随机有限元和系统可靠度计算的? 分支法的研究分析,考虑把二者联合起来分析洞室施工过程安全性,提出了一种大型地下洞室开挖过程中可靠度评价的方法。以海南工程为例,对地下洞室开挖过程中的每一步进行可靠性评价,分析比较了多层耦合法与分层逆作法之间洞室施工过程中的稳定性,比较了二者的优缺点。从而对多层耦合法施工有一个全面的了解和比较,为今后的大型洞室快速施工提供科学依据。  相似文献   

工程岩体分类方法在小浪底工程中的应用     

张绍民  刘丰收  毕晓东 《岩土力学》2007,28(11):2480-2484

利用国内外常用的RMR(Rock Mass Ruting)和Q工程岩体分类体系,对小浪底工程中的地下工程进行了岩体的分类研究,并根据分类结果提出了地下工程的支护措施,估计了岩体的抗剪强度和变形模量。工程实践结果表明,分类结果是合适的,依据分类结果制定的支护方案是合适的。运行结果表明工程处于稳定状态。  相似文献   

Modeling on coupled heat and moisture transfer in freezing soil using mixture theory     

Tiande Miao  Yonghong Niu  Li Guo  Changqing Zhang 《中国科学D辑(英文版)》1999,42(1):9-16

A set of perfect constitutive equations including the coupling effects of heat transfer and moisture migration is constructed for freezing soil, after analyzing its thermomechanic properties, in the framework of continuum mechanics and mixture theory. By applying the theory, the influence of void ratio on frost heaving is studied after proposing a criterion for formation of layered ice; the results obtained coincide with experimental data available in the literature. The temperature distribution of freezing soil is analyzed, the controlling equation deduced appears to be a nonlinear Burgers type equation with varying boundaries, which presents a theoretic foundation for studying the nonlinear effects of heat-moisture migration in the freezing process.  相似文献