一种测定非饱和土-水力学参数的方法

详细介绍了非饱和土-水力学参数联合测试系统,该系统分别利用轴平移技术和达西定律测定非饱和土土-水特征曲线和水相渗透系数。通过试验结果对比可以发现,由联合测试系统确定土-水特征曲线与压力板仪溢出水校正称量法确定的土-水特征曲线接近,但由联合测试系统确定的试样残余含水率比使用压力板仪溢出水校正称量法确定的试样含水率要小;由联合测试系统确定的渗透函数,当饱和度较大时,实测值与模型预测值较为接近;当饱和度较小时,实测值与模型预测值相差较大。     

Speciation analysis of metals （Tl, Cd and Pb） in Tl-containing pyrite and its cinder from Yunfu Mine, China, by ICP-MS with sequential extraction

The speciation of heavy metals such as thallium, cadmium and lead existing in pyrite and pyrite cinder was analyzed by ICP-MS with a sequential extraction procedure. The distribution patterns of these metals including exchangeable, reducible, oxidizable and residual fractions were obtained. Tl, Cd and Pb in pyrite and pyrite cinder samples from each extraction step were determined by inductively coupled plasma mass spectrometry (ICP-MS). Under the optimized instrumental conditions, detection limits of Tl, Cd and Pb in different matrices were within the range of 0.006–0.07 μg/L, and the relative standard deviations ranged from 0.8% to 1.2%. The accuracy of Tl, Cd and Pb determination was checked by analyzing two certified reference materials. The results demonstrate that trace Tl, Cd and Pb in the samples can be accurately determined. The sequential extraction results revealed that the percent contents of Tl, Cd and Pb in exchangeable, reducible and oxidizable fractions in pyrite cinder are different from those in pyrite and in pyrite cinder. Tl, Cd and Pb mostly are distributed in residual fraction. Therefore, the mobility of metals in pyrite is higher than that in pyrite cinder. Although distributions of Tl, Cd and Pb in the non-residual fraction are not dominant in pyrite cinder, the total concentrations of them could not be ignored. Consequently, attention must be paid to the risk of potential pollution by pyrite cinder.     

工程桩静载试验确定PHC管桩承载力

以工程实例介绍静压管桩基础的设计承载力取值,采用先施工工程桩进行静载试验,以其结果反算单桩竖向承载力,结合桩的入土长度等给出应用于工程实际的单桩竖向承载力设计值(R)的方法,供同行借鉴。     

Origin of the patchy emission pattern at the ZERT CO<Subscript>2</Subscript> release test

A numerical experiment was carried out to test whether the patchy CO₂ emission patterns observed at the Zero Emissions Research and Technology release facility are caused by the presence of packers that divide the horizontal injection well into six CO₂-injection zones. A three-dimensional model of the horizontal well and cobble–soil system was developed and simulations using TOUGH2/EOS7CA were carried out. Simulation results show patchy emissions for the seven-packer (six-injection-zone) configuration of the field test. Numerical experiments were then conducted for the cases of 24 packers (23 injection zones) and an effectively infinite number of packers. The time to surface breakthrough and the number of patches increased as the number of packers increased suggesting that packers and associated along-pipe flow are the origin of the patchy emissions. In addition, it was observed that early breakthrough occurs at locations where the horizontal well pipe is shallow and installed mostly in soil rather than the deeper cobble. In the cases where the pipe is installed at shallow depths and directly in the soil, higher pipe gas saturations occur than where the pipe is installed slightly deeper in the cobble. It is believed this is an effect mostly relevant to the model rather than the field system and arises through the influence of capillarity, permeability, and pipe elevation of the soil compared to the cobble adjacent to the pipe.     

河南水灾变化及典型水灾年大气环流异常特征分析

利用河南1950-2007年的逐年水灾统计数据,对水灾年的时间特征进行分析,并对典型水灾年大气环流的异常特征进行分析,结果表明:在1950-2007年的58 a中,河南年年都出现水灾,全省水灾受灾面积66.7万hm2的有28年;66.7万hm2的有30年,约2年一遇;受灾面积133.3万hm2的有17年,约4年一遇;333.3万hm2的有4年,约15年一遇。在河南的典型水灾年,中高纬度的长波和南支系统都有很强的稳定性;亚洲中高纬阻塞形势非常明显,在西西伯利亚上空出现了强烈的偏北风分量,因而冷空气暴发南下非常频繁;副热带高压脊线在24°N左右,584 dgpm线呈西南东北走向,将来自孟加拉湾和南海的充沛水汽带到内陆。河南省正处于来自北方的冷空气和南支系统带来的暖湿气流交汇的区域,这是造成河南省出现严重水灾的主要原因。     

高精度时间频率基准辅助GPS定位的研究与实现

介绍一种基于压控振荡器和GPS技术的时间频率基准，实现可编程脉冲、频率输出，达到了长期稳定性与短期稳定性兼优的目的。     

一维渗透固结中排水边界生成与识别的初步探讨

本文首先分析了内部与表部土层生成排水边界时的渗流方向并提出了绝对与相对排水边界的概念;然后分别讨论了绝对与相对排水边界的识别标准.     

发挥四川盆地卤水资源优势为实施西部大开发展宏图

四川盆地卤水为四川独具优势的液矿资源,具有分布广、产层多、品质优、资源富、气水同产和利于开发等特点和优势.充分发挥四川盆地卤水资源优势,加强综合开发利用,对振兴发展四川卤化工业,实施西部大开发战略大展宏图具有重要意义,必将取得显著的社会效益和经济效益.     

西吉—中卫地震测深剖面及其解释

通过对南北向的西吉－中卫宽角反射／折射剖面测探资料的二维处理、计算和解释，研究了中宁、中卫和同心一带弧形构造及两侧的壳幔速度结构和深部构造的基本特征。结果表明，3个区域的壳幔速度结构在纵向和横向上均具有明显的非均匀性，标志壳幔深部构造存在着差异，地壳厚度变化大，弧形构造带中部为一莫霍面隆起（深45．0km)，弧形构造带南北两侧上地壳中存在不同的低速块体。