Ion chemistry of groundwater and the possible controls within Lhasa River Basin,SW Tibetan Plateau

In order to study the major ion chemistry and controls of groundwater, 65 groundwater samples were collected and their major ions measured from wells within Lhasa River Basin. Groundwater has the characteristics of slightly alkaline and moderate total dissolved solid (TDS). TDS concentration ranged from 122.0 to 489.9 mg/L with a median value of 271.2 mg/L. Almost all the groundwater samples suited for drinking and irrigation. The major cations of groundwater are Ca²⁺ and Mg²⁺, accounting for 59.6 and 31.3% of the cations, respectively. Meanwhile, HCO₃^? and SO₄^2? constituted about 56.7 and 36.9% of the anions, respectively, in Lhasa River Basin. The hydrochemical type of groundwater is HCO₃-SO₄-Ca-Mg. The chemical composition of groundwater samples located in the middle of Gibbs model, which indicates that the major chemical process of groundwater is controlled by rock weathering. Carbonate weathering was the dominant hydro-geochemical process controlling the concentration of major ions in groundwater within Lhasa River Basin, but silicate weathering also plays an important role.     

Effect of the Dry Ashing Method on Cadmium Isotope Measurements in Soil and Plant Samples

A dry ashing method is commonly used to remove organic material from samples prior to geochemical analysis. In the course of this study, the Cd isotope ratios of a series of soil and plant reference materials and samples were studied to evaluate the effect of the dry ashing method on measurement results of Cd isotope ratios. The samples were pre‐treated using the dry ashing method and high‐pressure bomb for comparison. The results show that the digestion using high‐pressure bombs did not lead to Cd loss, but using the dry ashing method would cause different proportions of Cd loss. The whole range of Cd isotope difference between two methods was from ?0.07‰ to 3.01‰. There was also an obvious difference in measured Cd isotope ratios from the same leaf sample pre‐treated independently by the dry ashing method, indicating that the amount of Cd loss and the effect on Cd isotope measurement during dry ashing is related to the properties of the samples. Therefore, dry ashing may not be appropriate for the removal of organic material in Cd isotope ratio measurement, especially for samples with high organic contents. The δ^114/110Cd values of reference materials NIST SRM 1573a and GSD‐30 are reported for the first time in this study.     

Recent expansion of talus slopes in the northern Taihang Mountain Range,China: an example from the Xiaowutai Region

Landslides - Talus slopes play an important role in landscape evolution in some mid-altitude mountains. In this study, we analyzed talus slope activity on Xiaowutai Mountain in the Northern Taihang...     

喜马拉雅东部三叠系涅如组地球化学和碎屑锆石U-Pb年代学特征及构造意义

喜马拉雅中—新生代地层沉积于印度被动大陆边缘,三叠系沉积物物源分析是冈瓦纳大陆裂解和古地理研究的重要载体.特提斯喜马拉雅东段上三叠统涅如组碎屑岩的物质来源和沉积背景具有较大的争议,本次研究采集隆子县斗玉乡晚三叠世粉砂质板岩进行碎屑锆石U-Pb年代学和全岩主微量元素地球化学分析.涅如组碎屑锆石年龄具有两个明显的峰值:206～224Ma(峰值213 Ma)和462～567Ma(峰值512 Ma),表明涅如组沉积时代为晚三叠世诺利期.涅如组w(SiO2)含量较低(平均值为57.7％),w(Al2O3)值较高(17.2％),轻稀土元素富集,重稀土元素亏损,轻稀土/重稀土元素平均值为8.1.高场强元素中Nb,Ta,Ti亏损,Zr,Hf,Th,U富集;大离子亲石元素中Ba,Sr亏损,Rb和K富集.综合分析认为源区岩石以酸性岩浆岩为主.本次研究认为上三叠统涅如组浊流相沉积形成于裂谷环境,代表新特提斯洋的打开;标志着拉萨板块从冈瓦纳大陆北缘裂解,并开始向北漂移.     

临朐县矿政管理工作成效显著

2007年是整顿和规范矿产资源开发秩序工作的关键之年,临朐县国土资源局根据上级统一部署,结合临朐县具体情况,从矿产资源整合、矿业权审批、山石资源开发监督管理、地质环境保护与治理、矿业秩序监督等方面人手,加强日常监管力度,取得了明显成效。     

内蒙古荒漠草原沙生针茅(Stipa glareosa)、碱韭(Allium polyrhizum)和骆驼蓬(Peganum harmala)叶形态性状对土壤水氮耦合的响应

研究降水和氮沉降对荒漠草原植物叶形态性状的影响,对于预测未来全球变化下荒漠草原植物的生态适应具有重要意义.对增减雨(±50％)和氮添加(10 g·m-2.a-1)及其交互作用对乌拉特荒漠草原区优势植物叶形态性状的影响研究结果表明:(1)沙生针茅(Stipa glareosa)、碱韭(Allium polyrhizum)...     

气候变化对植物多样性的影响研究综述

植物多样性是生态系统结构和功能的基础,气候变化已对其产生了深刻的影响,甚至于严重威胁.植物多样性的减少或丧失必然会影响生态系统结构和功能的稳定性,导致严重的生态、经济和社会后果.植物多样性对气候变化的响应受控于气温和水分的动态平衡.本文系统总结了气候变暖和降水格局变化对植物多样性的影响,分析了气候变化对不同生态系统、群...     

干旱荒漠区土地利用方式快速转变对土壤入渗性能的影响

研究不同土地利用类型下土壤入渗及其影响因素,有助于城市土地利用管理及径流调节。以快速城市化的兰州新区6种土地利用类型为例,利用圆盘入渗仪,对土壤水分入渗过程进行了实地测量,并利用主成分分析对影响因素进行研究。结果表明：城市化过程中土地利用变化使土壤砂粒和容重增加,总孔隙度和饱和含水量降低;待建地和人工林地的土壤入渗参数值均低于其他土地利用类型。土壤入渗率与有机质含量、总孔隙度、饱和含水量、粉粒含量正相关,与容重和砂粒、黏粒含量负相关。城市化过程中土地利用类型向待建地的转变改变了土壤理化性质及土壤水分入渗能力。     

Environmental impact of fluidized solidified silt casting on surrounding water bodies

Abstract

With the growing demand for underwater refill engineering, the construction technology of implementing fluidized solidification in underwater pouring has recently received increased attention. However, the environmental impact of underwater casting on surrounding water bodies, especially when the silt is polluted, is still unclear. In this study, a simulated underwater pouring test and a static immersion release test were conducted separately to study the quality of the surrounding water during and after pouring. The results showed that fluidized-solidified silt casting could increase the pH of the surrounding water, even after the pouring had stopped, by approximately 1.0 and the turbidity could reach 200 NTU. No diffusion of Zn and Cu into the surrounding water was observed and while Ni and Cr exhibited slight diffusion, this was at a level well below international water quality standard. During construction, reducing the distance from the seafloor to the bottom of the pouring catheter could reduce the level of pollution. After construction, the use of neutral solidified materials can effectively reduce the pH of the surrounding water and the potential risk of heavy metal dissolution.     

仿真技术在深弹发射装置环境适应性分析中的应用

深弹发射装置安装在甲板部位,使用环境恶劣,过去均采用传统的试验方法进行环境适应性考核。最近几年,随着三维设计的广泛应用,仿真技术也开始发挥作用,以发射装置接线箱的冲击响应为例,介绍仿真技术在发射装置环境适应性分析中的应用。通过案例分析可知,仿真分析对于发现机械结构设计中的薄弱环节还是非常有效的,它突破了环境试验受限于试验样机和特定环境条件的限制,可以在较短的时间内得到仿真结果,对装备模型进行及时修正。