Fluorine in drinking water and urine in the urban and rural areas of northwestern China―Its determin

来源 :中国地球化学学报(英文版) | 被引量 : 0次 | 上传用户:huangli_java
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
In this study, the author determined fluorine in drinking water and urine of residents who are divided into four age groups (5, 12, 35-44, 65-74 aged), living in Huangling City, Shaanxi Province and at 6 villages of Qin'an County, Gansu Province, P.R.China. Some residents are living in fluorine exposure areas. A total of 929 residents (463 females and 466 males) involved in the study were selected from 7 tap water systems. Drinking water samples were collected from each area and analyzed using the fluoride ion-selective method. No positive correlation relationship was found between fluorine concentrations in urine and those in drinking water in the area where the fluorine concentrations of drinking water are within the range of 1-2 mg/L. The fluorine absorbed by resistents of different ages is different in amount. With the same concentrations of fluorine in drinking water, more fluorine would be absorbed by young residents than old residents. No difference can be seen in absorption amount of fluorine among different genders.
其他文献
结合莘县区域站的实际情况,就莘县区域站运行中存在的问题进行了分析,并提出了相应的对策及建议.
Exploration and research of fault activities are the fundamentals of earthquake prediction and prevention and disaster reduction. In order to determine the loca
本文主要根据测井资料,结合钻井及试油数据,对安塞油田王窑西南区储层进行综合评价,初步确定油藏分布规律。 Based on well logging data and drilling and oil testing dat
水库、河道、洼淀洪水预报方案的编制涉及到多种水文相关曲线图,作为水文预报的基础资料,对相关图的制作精度要求很高。结合水文相关曲线图的制作,研究和探讨计算机制图的误差校正方法,提出了一种适用于水文相关曲线图误差校正的拐点校正法,并以"海河流域实用水文预报方案"编制中的实例介绍了拐点校正法的应用。实际应用表明,拐点校正法对水文相关曲线的计算机制图误差具有良好的校正效果。
本文介绍了建立GPS测量控制网独立坐标系的具体方法及案例探讨.
随着我国工业化、城镇化进程的快速推进,在地区之间劳动力的大规模流动迅速增加,也日益频繁。与此同时,现行基本医疗保障体制中,不同子制度之间的差异和分割分治状况极大地制
本文首先介绍了粗糙集理论的基本概念,包括等价关系、不可分辨关系、上下近似、粗糙集和简约;并且从空间数据挖掘、遥感影像处理、GIS不确定性、GIS数据分析、模糊地理对象建模和粗糙集与其它软计算方法的结合等六方面概述了粗糙集理论在GIS数据处理中应用的进展。
本文根据工程实践,结合太阳能产品的技术特点,从高速公路沿线外场设备耗电的准确核算与测试、蓄电池配置、设置充放电阈值、选配太阳能板等方面,总结出一整套外场监控设备选
许多测量施工单位在进行GPS静态测量时,都会遇到求解高程异常的问题。这样才能将大地高转化成正常高。论文用两种方法来求高程异常,其一,二次曲面模型的方法来求高程异常,其二,采用BP神经网络的方法来求高程异常,并对两者所求的高程异常的精度进行分析,从论文中看到BP神经网络对求解高程异常的精度高,从而为BP神经网络在测量中的应用提供借鉴。
基于模块可分性研究,可找到最佳的复杂产品的系统模块分割原则,从而为复杂产品设计、模块分系统转包、供应链协同优化提供指导.对模块化与汽车模块进行简介,汽车系统用模块化