地下水库及其在水资源开发和保护中的应用     

付晓刚  万伟锋  毛正君 《地下水》2007,29(1):65-67,77

从地下水库的不同概念出发,探讨了地下水库的定义,指出地下水库并不是单纯的含水层或者储水构造,而是一种地下水开发系统工程.在此基础上介绍了地下水库的基本组成及各组成部分的作用、地下水库的优缺点以及其发展趋势,最后分析了地下水库在我国不同地区水资源开发和保护中的广阔应用前景.  相似文献   

13X沸石处理含赖氨酸废水的实验研究     

王英滨姜波  李婧婧肖万 《岩石矿物学杂志》2007,26(1):90-94

用合成的13X沸石对废水中氨基酸(赖氨酸)进行静态吸附实验,研究了pH、温度、吸附时间、沸石用量等对吸附率的影响,结果表明,室温下沸石对赖氨酸的吸附平衡时间为30min,pH=pKa1=2.2时,赖氨酸在沸石上的吸附效果最好,吸附率大于82%,饱和吸附量达51.73mg.g-1。吸附等温线近似呈直线型,表明离子交换机制是沸石吸附氨基酸的主要方式。对已饱和吸附的沸石用饱和氯化钠溶液进行再生实验,赖氨酸的解吸率大于95%,沸石可重复使用。实验研究表明可用13X分子筛处理含氨基酸废水,为实际处理含氨基酸废水提供了可行性依据。  相似文献   

学习刘东生先生环境地质观、深入环境演化与过程研究——贺东生院士九十华诞          下载免费PDF全文

万国江 《第四纪研究》2007,27(6):915-918

1972年刘东生先生发表了"环境地质学的出现".刘东生院士的环境地质观聚焦于:环境地质学发展的动力源于社会需要、地球环境系统的整体性及其与人类关系的相互依存性.35年来,地质环境的地球化学研究以区域环境质量和全球环境变化两大科学问题作为基本目标,经历了调查评价-区域综合-界面机理的3个发展阶段,在典型区域环境演化及环境-生态效应方面取得了重要进展.环境地质学以"地质学与人类"为宗旨,将在21世纪为人类谋求更多的福祉.  相似文献   

青藏高原东北部的库仑应力积累演化对大地震发生的影响   总被引：27，自引：4，他引：27       下载免费PDF全文

万永革  沈正康  曾跃华  盛书中 《地震学报》2007,29(2):115-129

假定地震可以模拟为多层弹粘性介质中的位错，考虑大地震(Mge;7.0)和GPS数据得出的长期构造加载为形变源，依据多层麦克斯韦弹粘性介质中位错产生的应力变化，计算得到了地震产生的应力变化，给出了青藏高原东北部1920年以来积累库仑破裂应力演化. 地震破裂的断层长度、宽度和滑动量根据前人统计公式和野外地质调查得到. 研究表明，20次Mge;7.0地震中， 除1990年共和地震、1952年当雄地震和1976年松潘双震的后一个事件外，17次大地震均发生在库仑破裂应力变化为正的区域， 触发率达85%. 本研究为中长期地震危险性估计在一定程度上提供了基础数据.   相似文献   

Quantifying drainage components and salt and water balance in YinNan Irrigation District,China, based on a controlled drainage experiment   总被引：1，自引：0，他引：1  

Zhonghua Jia  Wan Luo  Shuxing Fang  Liang Wang  ShiYing Tian 《水文研究》2007,21(14):1875-1881

YinNan Irrigation District (YNID) is located in the upper reaches of the Yellow River in NingXia, China. Its irrigated area is about 80 000 ha, with one‐third of it for rice production. The major part of its drainage system was constructed between the 1950s and 1970s to maintain the salt and water balances of the district. The system, however, has been reported as draining the agricultural lands excessively by several studies. In addition to field, lateral and main drainage ditches, agricultural fields of YNID are also under the influence of the Yellow River channel and some low‐lying depressions, thus forming a dual drainage system. Owing to difficulties in irrigation inflow measurement, evaluation of the existing drainage system often appears to be elusive. Based on a dual drainage assumption and an on‐site controlled drainage experiment, we present a detailed analysis on drainage components and the salt and water balance of YNID. Results show that, by implementing controlled drainage, shallow drainage from field ditches can be reduced by 60%. Deep drainage from main ditches, the Yellow River channel and low‐lying depressions is relatively stable year around, and it neutralized the potential effect of controlled drainage on salinity increase. Drainage water salinity calculated from the dual subsurface drainage model was consistent with field observations, proving that the dual drainage assumption is valid for the study area. Based on this study, field water management practices of the irrigation district can be better targeted and fairly evaluated. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

Comparison Between GAMIL, and CAM2 on Interannual Variability Simulation     

杨军丽  王斌  郭裕福  万慧  季仲贞 《大气科学进展》2007,24(1):82-88

Recently, a new atmospheric general circulation model （GAMIL： Grid-point Atmospheric Model of IAP LASG） has been developed at the Institute of Atmospheric Physics （IAP）, Chinese Academy of Sciences （CAS）, which is based on the Community Atmospheric Model Version 2 （CAM2） of the National Center for Atmospheric Research （NCAR）. Since the two models have the same physical processes but different dynamical cores, the interannual variability simulation performances of the two models are compared. The ensemble approach is used to reduce model internal variability. In general, the simulation performances of the two models are similar. Both models have good per- formance in simulating total space-time variability and the Southern Oscillation Index. GAMIL performs better in the Eastern Asian winter circulation simulation than CAM2, and the model internal variability of GAMIL has a better response to external forcing than that of CAM2. These indicate that the improvement of the dynamic core is very important. It is also verified that there is less predictability in the middle and high latitudes than in the low latitudes.  相似文献   

云南5月雨量的多尺度变化及与其相联系的大气环流异常   总被引：1，自引：1，他引：1  

万云霞  程建刚  陈新梅  孙绩华  严华生 《气象科学》2007,27(5):543-548

本文运用小波分析和功率谱分析方法对云南5月雨量的多尺度时间演变特征进行了分析,结果表明,云南5月雨量具有明显的年际和年代际变化特征。对与这两种时间尺度相关联的大气环流异常进行了分析,发现两者具有显著的差异。云南5月雨量的年际变化与冰岛低压、欧洲槽、南亚高压、中西太平洋ITCZ以及孟湾附近的低压系统的变化有着密切的关系,云南5月雨量的年代际-气候态变化与热带各系统的强度、乌山脊、阿留申低压关系密切。  相似文献   

A holistic approach to aligning geospatial data with multidimensional similarity measuring     

Li Yu  Peiyuan Qiu  Xiliang Liu  Bo Wan 《International Journal of Digital Earth》2018,11(8):845-862

Semantically aligning the heterogeneous geospatial datasets (GDs) produced by different organizations demands efficient similarity matching methods. However, the strategies employed to align the schema (concept and property) and instances are usually not reusable, and the effects of unbalanced information tend to be neglected in GD alignment. To solve this problem, a holistic approach is presented in this paper to integrally align the geospatial entities (concepts, properties and instances) simultaneously. Spatial, lexical, structural and extensional similarity metrics are designed and automatically aggregated by means of approval voting. The presented approach is validated with real geographical semantic webs, Geonames and OpenStreetMap. Compared with the well-known extensional-based aligning system, the presented approach not only considers more information involved in GD alignment, but also avoids the artificial parameter setting in metric aggregation. It reduces the dependency on specific information, and makes the alignment more robust under the unbalanced distribution of various information.  相似文献   

An elastoplastic description of frictional destructuration in natural clays and shales     

Morteza Mohamadi  Richard Wan  Zhifu Shen 《Acta Geotechnica》2018,13(4):911-924

The existence of structuration in natural clays and shales is believed to change their stiffness, yielding, dilatancy and strength characteristics. These constitutive features are widely known to ultimately reunite with those of the reconstituted parent soil upon large straining. However, some experimental results show that such reunification may not occur in isotropic/one-dimensional compression, especially with regard to the critical state friction angle. This peculiar phenomenon has been barely addressed in constitutive models for natural geomaterials. Hence, the present study aims at introducing a structure-dependent critical state friction angle within the subloading yield framework. A new internal variable is introduced in the model of Nakai et al. (Soils Found 51(6):1149–1168, 2011) to capture subtle irreversible degradation of the structured critical state line which also serves as the threshold between contractive and dilatant volume changes. Additionally, a new evolution rule for the proposed destructuration factor is developed by considering important microstructural information revealed by discrete element method simulations. The proposed new modifications not only enhance the model capabilities in predicting bonding effects, but also enrich the classical stress-dilatancy equation by rendering it a function of void ratio, mean stress and the microstructural state. Model simulations of laboratory experimental tests on the Colorado shale as well as Bacinetto clay are presented in order to illustrate the improved predictive capabilities of the new model.  相似文献   

隧道洞口段位于滑坡体上的处治方法     

唐连权  万小乐 《江苏地质》2018,42(2):328-333

隧道洞口段选址在滑坡体上的现象较为常见。以玉园隧道为工程实例,阐述了隧道洞口段滑坡地质灾害的成因及防治方法,通过数值计算针对性地提出该滑坡的应急处治措施。计算结果表明现有变形体为牵引式变形,卸载方案不利于其稳定,进而提出抗滑桩+降水、抗滑桩+旋喷桩2种方案,探讨2种处治方案的比较与选择,为类似的工程提供经验。  相似文献