Fluorine in drinking water and urine in the urban and rural areas of northwestern China——Its determination by a fluoride ion selective electrode

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 ...     

兰州至关中电线积冰与导线线径及高度关系

对2006—2007年、2007—2008年冬季甘肃、陕西、宁夏多个测点不同线径、不同架线高度电线积冰观测资料分析可知,不同线径电线积冰的净直径、净厚度、等效厚度、积冰重量间存在显著线性关系。直径为26 mm导线电线积冰重量约为18 mm导线的1.2倍,是4 mm铁丝的1.3倍。直径为26 mm导线与直径为18 mm导线电线积冰间的各项关系都较26 mm导线与4 mm铁丝的线性关系更为显著;大直径导线电线积冰的净直径、净厚度、等效厚度均小于4 mm铁丝;26 mm导线与18 mm导线电线积冰的净直径、等效厚度基本相等。电线积冰等效厚度是架设高度比的幂函数;忽略水滴下沉速度,在假定捕获系数为常数、假定时间各物理量均衡不变情况下,电线积冰重量与电线导线线径成正比,且随架设高度的增加而增加。     

XKL-W1型动力箱样机核级(1E)抗震试验研究

依据电气设备核级抗震Ⅰ类(1E)标准,在模拟现场安装的条件下,对XKL-W1型动力箱样机在每个组合方向进行两次SSE模拟地震反应谱考核试验,测定样机各测点的地震响应加速度,并在试验前后分别进行白噪声扫描试验,以确定样机的自振特性。研究结果显示：样机Y向整体刚度小于X向,各子结构呈现各自特征;试验中的开关动作对各测点地震响应影响较强;在考核频段(0-50Hz)内样机各结构有较丰富的自振频率,虽然试验前后自振特性略有改变,但变化不大。经检验,考核试验后样机结构完整,各项电气功能正常,通过了电气设备核级抗震Ⅰ类试验考核,验证了样机设计与加工的合理性。该项研究成果也为以后我国核工业类似产品的设计与定型提供了可靠的依据。     

城市地下空间三维地质模型可视化技术研究

目前,城市地下空间信息化发展面临着海量数据组织、管理和可视化显示等亟需解决的关键问题。本文顺应国家新型智慧城市建设趋势,提出并实现了城市地下空间三维地质模型可视化技术,构建地质三维模型分级数据,按照不规则四叉树结构形成LOD数据;基于构建的三维空间网格码规范编码,运用降维、非布尔运算的方法,实现最大精度化的地下空间模型数据无限逼近的融合;并采用多渲染引擎的混合渲染架构,支持DirectX、WebGL（OpenGL ES）、OSG（OpenGL）和游戏引擎（Unreal Engine）等多引擎渲染,实现TB级地下时空数据的真实感可视化与高效调度,为城市地下空间开发利用提供数据支持和辅助决策分析支撑。     

Study on Seismicity Triggered by Water Injection in Mine Wells in Zigong Using ETAS Model

In order to reveal the relationship between water injection in mine wells in the Zigong area and seismicity,we divide the historical earthquakes of ML≥1. 2 into 3 phases according to seismicity behavior,and the ETAS model parameters are then inversed by the POWELL method. The results show that phase 1 and 2,in which there is no water injection,have moderate-to-low ratio of background earthquakes ( 40% ～ 50%),and aftershocks are relatively less for a single earthquake sequence. In phase 3,where there is wate...     

初探玉门砾岩沉积速率时空变化对气候-构造相互作用的意义

气候-构造相互作用是目前固体地球和全球变化中最前沿的核心科学问题,地表侵蚀是气候-构造之间的桥梁纽带,地层沉积速率则是地表侵蚀强弱的直接响应.祁连山北缘-河西走廊在约4～2Ma期间沉积了一套粗粒相磨拉石-玉门砾岩,是研究气候-构造相互作用的一个理想产物,目前其气候或构造的主要成因存在争议.本文尝试阐述祁连山北缘-河西走...     

Distribution characteristics of seamount cobalt-rich ferromanganese crusts and the determination of the size of areas for exploration and exploitation

In 2001, the International Seabed Authority (ISBA) initiated the consideration relating to the Regulations for Prospecting and Exploration for Hydrothermal Polymetallic Sulphides and Cobalt-rich Ferromanganese Crusts in the Area at its 7th session. Since then, the consideration of the Regulations has been mainly focused on the size of areas to be allocated for exploration and exploitation of the crusts. This paper, based on the investigation data and the analysis of the distribution characteristics of the crusts, suggests a model for determining the size of areas for exploration and exploitation of the crusts, taking into account various factors such as production scale, crust thickness and grade, mineable area proportion, recovery efficiency, exploration venture, and so on. Through the modeling, the paper suggests that the exploration area (the area covered by each application for approval of a plan of work for exploration of cobalt-rich crusts) shall be 4 856 km² and the exploitation area (the mine site area) shall be 1 214 km², for 20 years of 1 million wet tonnes annual production.     

微型生态系统中鲢、鳙下行影响的实验研究——1.浮游生物群落和初级生产力

在营养物供给量较大的实验条件下,鲢、鳙放养明显地改变了微型生态系统的群落结构、代谢和理化环境,以致实验后期鳙单养和鲢、鳙混养系统出现不同程度的富营养化。微型生态系统中浮游植物密度的增长不完全由营养级联效应所致,但初级生产力的组间差异可大致依据营养级联假说来解释。实验结果认为,以提高鱼产量为目标的鲢、鳙高密度放养,对加速营养物来源丰富的天然水域的富营养化起着重要的作用。     

颈椎病的CT,CTM,MRI扫描诊断165例分析

本文回顾性的报告分析了１６５例颈椎病，ＣＴ５０例、ＣＴＭ１５例、ＭＲＩ１００例。ＭＲＩ比ＣＴ和ＣＴＭ更精确而且没有损害。但ＣＴ和ＣＴＭ则可补充ＭＲＩ对颈椎和韧带的观察不足。三种方法的结合使用，将对临床诊断和治疗起重要作用。     

雪剪切变形与断裂实验研究

雪的抗剪力与抗剪强度是雪崩释放机理研究和冰雪工程中很重要的力学参数．本实验是在剪切应变率（ε）为1．8×10-6～33×10－3·S－1的条件下进行的，分为10个剪切应变率等级，共做了36个非均质雪剪切实验．研究结果表明，雪的抗剪力与抗剪切强度与实验温度，尤其是剪切应变率的关系甚为密切．雪的脆－塑临界剪切应变率约为10-4·S-1．