Preparation and Properties of Embeddable Ag/AgCl Gelling Reference Electrode for Rebars Corrosion Monitoring in Concrete     

汤雁冰  王胜年  陈龙  范志宏 《海洋工程》2015,29(6):925-932

Reference electrodes are a key part for corrosion monitoring and measurement of rebars in concrete. A reference electrode that can be buried in concrete is fabricated by using Ag/AgCl electrode and methyl cellulose gelling electrolyte. The stability, repeatability and anti-polarization of the reference electrode are investigated; the influences of the inner electrolyte loss, exterior OH? contamination, and temperature on the potential of the reference electrode are also investigated in this paper. The results show that the reference electrode has good stability, repeatability, and anti- polarization. The influences of inner electrolyte loss, exterior OH? contamination, and temperature on the potential of the reference electrode are minimal. Therefore, it can be used for corrosion monitoring and measurement of rebars in concrete.  相似文献   

高磷铁矿石成分分析标准物质研制   总被引：3，自引：3，他引：0  

曾美云  陈燕波  刘金  王迪民 《岩矿测试》2019,38(2):212-221

高磷铁矿石的分析测试过程需要基体组分相似、含量适中、定值组分全的标准物质进行质量监控,目前我国没有高磷铁矿石标准物质,现有铁矿石标准物质因基体组分不尽相同,磷元素含量大部分低于0.25%,而高磷铁矿石中磷含量均高于0.25%,这些标准物质难以满足高磷铁矿石产品的分析测试质量监控要求。基于此,本文研制了3个高磷铁矿石成分分析标准物质,样品分别采集于鄂西地区湖北宜昌秭归县野狼坪矿区、湖北恩施长岭矿区(武钢矿区)、湖北宜昌长阳县火烧坪矿区(宝钢长阳矿区),磷和铁含量均呈一定梯度,基本覆盖高磷铁矿的含量范围。均匀性和稳定性对SiO_2、Al_2O_3、TiO_2、P、K_2O、Na_2O、Fe、MnO、CaO、MgO、FeO、LOI、S、Cu、Pb、Zn、Cr、Ni、Co、Cd、Sr、Ba、V、As、Hg共25个组分进行检验,均匀性检验采用方差分析F检验法和测试结果的相对标准偏差进行评价,稳定性检验采用直线拟合,t检验法进行评估。经检验,样品均匀性、稳定性良好;定值采用11家实验室协作,采用2种以上不同原理的方法进行测试,定值组分包括主量元素、微量元素共25项,其中24项提供认定值及不确定度,Hg提供参考值。磷的含量分别为0.285%、不确定度0.010%,0.735%、不确定度0.020%,1.73%、不确定度0.05%,总铁含量分别为35.18%、不确定度0.20%,41.46%、不确定度0.20%,51.44%、不确定度0.13%。本次研制的高磷铁矿石标准物质可用于高磷铁矿的勘查、评价和综合利用开发中对标准物质的需求。  相似文献   

路面类型对多年冻土区片块石路基热状态的影响   总被引：3，自引：2，他引：1  

王青志  房建宏  晁刚  薛兆锋 《冰川冻土》2019,41(5):1087-1097

为了研究不同路面类型对高温多年冻土区路基的热稳定性的影响,基于温度监测数据,针对沥青混凝土路面和水泥混凝土路面下片块石路基温度、热流密度、热收支变化、冻融循环过程及冻土上限变化进行了详细的分析。发现沥青混凝土路面和水泥混凝土路面都对片块石路基的温度有较大的影响,但沥青混凝土路面影响程度和深度远比水泥混凝土路面大。片块石路基中心热收支量呈上升趋势,沥青混凝土路面下其上升速率大于水泥混凝土路面,且路基阳坡热收支量大于阴坡。无论路面材料为沥青混凝土路面还是水泥混凝土路面,片块石路基阴阳坡路肩冻土仍处于不断退化阶段,而阳坡冻土上限下降速率明显大于阴坡。与普通路基相比,片块石层的存在能大幅度抬升或减缓路基冻土上限下降,且浅色水泥混凝土路面更有利于路基的热稳定性。  相似文献   

童亭煤矿钻探取心施工方法          下载免费PDF全文

李培林  饶剑辉  高婷婷  任晓顺  刘莎莎  孙秀梅  王建鹏  欧阳博 《探矿工程》2019,46(2):44-49

通过介绍和分析安徽省童亭煤矿采空区的各段地层特性、岩性特征,指出了钻进和取心过程中的控制难点,采用了加大孔径结构、优化钻具组合及强化泥浆性能维护等技术措施;针对极其严重的缩径现象,采用大开小下的方法,克服了缩径造成的套管下放难题;采用加稠水泥浆灌注方法成功处理了φ114 mm套管在采空区段断裂问题和地层严重破碎、漏水问题,最终顺利完成了7个煤系地层钻孔施工,取得了良好的经济社会效益。  相似文献   

Determination of Gallium Isotopic Compositions in Reference Materials     

Lan‐ping Feng  Lian Zhou  Jinhua Liu  Zhao‐chu Hu  Yong‐sheng Liu 《Geostandards and Geoanalytical Research》2019,43(4):701-714

The interest in the study of gallium (Ga) stable isotope fractionation in low‐ and high‐temperature environments has increased significantly in the last few years. However, a unified reference material (RM) is still lacking for the Ga isotope research community, which hinders interlaboratory comparison between different groups. Consequently, certification of Ga isotopic reference materials for interlaboratory comparison is of high priority. In this study, Ga isotope ratio data for ten geological RMs including silicates, shales and ferromanganese nodules, and two pure Ga RMs including NIST SRM 994 and NIST SRM 3119a reported by three different groups, were determined by MC‐ICP‐MS. Sample matrices of geological RMs were separated by a two‐column separation method with the use of AG MP‐1M and AG 50‐X8 resin, separately, and quantitative recoveries of > 99% Ga were obtained for all geological RMs. Instrumental mass bias was corrected by the combined calibrator‐sample bracketing and internal normalisation model. Validation of the proposed method was performed by analysing synthetic solutions. After normalisation of all available δ⁷¹Ga data of geological RMs to a single Ga RM, results obtained in our study are in agreement with previously reported results.  相似文献   

Off‐Mount Calibration and One New Potential Pyrrhotite Reference Material for Sulfur Isotope Measurement by Secondary Ion Mass Spectrometry     

Rucao Li  Xiaoping Xia  Shenghong Yang  Huayong Chen  Qing Yang 《Geostandards and Geoanalytical Research》2019,43(1):177-187

Sulfur isotope measurements in three sulfide (two pyrite and one pyrrhotite) samples on two epoxy mounts showed that the mount‐to‐mount variation of raw δ³⁴S values was negligible when secondary ion mass spectrometry (SIMS) analytical settings remained stable. In consequence, an off‐mount calibration procedure for SIMS sulfur isotope analysis was applied in this study. YP136 is a pyrrhotite sample collected from northern Finland. Examination of thin sections with a polarising microscope, backscattered electron image analyses and wavelength dispersive spectrometry mapping showed that the sample grains display no internal growth or other zoning. A total of 318 sulfur isotope (spot) measurements conducted on more than 100 randomly selected grains yielded highly consistent sulfur isotope ratios. The repeatability of all the analytical results of ³⁴S/³²S was 0.3‰ (2s, n = 318), which is the same as that of the well‐characterised pyrite reference materials PPP‐1 and UWPy‐1. Its δ³⁴S value determined by gas mass spectrometry was 1.5 ± 0.1‰ (2s, n = 11), which agrees with the SIMS data (1.5 ± 0.3‰, 2s) calibrated by pyrrhotite reference material Po‐10. Therefore, YP136 pyrrhotite is considered a candidate reference material for in situ sulfur isotope determination.  相似文献   

High‐precision Determination of Gold Mass Fractions in Geological Reference Materials by Internal Standardisation     

Huai Cheng  Zaicong Wang  Kang Chen  Keqing Zong  Zongqi Zou  Tao He  Zhaochu Hu  Mario Fischer‐Gdde  Yanhong Liu 《Geostandards and Geoanalytical Research》2019,43(4):663-680

Determination of gold abundances in natural rock is critical for applications, but very challenging. Here, we report a method for determining gold with a very low mass fraction (> 0.01 ng g^?1) in rocks. The method involves Carius tube digestion with reverse aqua regia, chromatographic separation to remove most of the sample matrix and measurement by high‐sensitivity ICP‐MS. The mono‐isotopic element gold was quantified by external calibration using an internal standardisation of gold to platinum that was precisely determined by isotope dilution. The method is robust and the obtained results are indistinguishable (< 5–10%, 2s) from those independently obtained by a standard addition technique on the same solution. The results from reference materials TDB‐1 and GPt‐2 are consistent with the certified values and those determined by HF‐aqua regia digestion, confirming the validity of the method. TDB‐1 (n = 20), GPt‐2 (n = 6), BHVO‐2 (n = 9) and other mafic RMs are homogenous for gold (10–20%, 2s) at the 2 g test portion level; however, sample heterogeneity affects some RMs. Gold and platinum‐group elements also display different extents of sample heterogeneity for different RMs. Given the homogeneity observed for TDB‐1, GPt‐2 and BHOV‐2, they are recommended as well‐suited RMs for inter‐laboratory comparison studies of gold.  相似文献   

Synthesis of In‐House Produced Calibrated Silver Phosphate with a Large Range of Oxygen Isotope Compositions     

Christophe Lcuyer  Franois Fourel  Magali Seris  Romain Amiot  Jean Goedert  Laurent Simon 《Geostandards and Geoanalytical Research》2019,43(4):681-688

The large range of stable oxygen isotope values of phosphate‐bearing minerals and dissolved phosphate of inorganic or organic origin requires the availability of in‐house produced calibrated silver phosphate of which isotopic ratios must closely bracket those of studied samples. We propose a simple protocol to synthesise Ag₃PO₄ in a wide range of oxygen isotope compositions based on the equilibrium isotopic fractionation factor and the kinetics and temperature of isotopic exchange in the phosphate–water system. Ag₃PO₄ crystals were obtained from KH₂PO₄ that was dissolved in water of known oxygen isotope composition. Isotopic exchange between dissolved phosphate and water took place at a desired and constant temperature into PYREX? tubes that were placed in a high precision oven for defined run‐times. Samples were withdrawn at desired times, quenched in cold water and precipitated as Ag₃PO₄. We provide a calculation sheet that computes the δ¹⁸O of precipitated Ag₃PO₄ as a function of time, temperature and δ¹⁸O of both reactants KH₂PO₄ and H₂O at t = 0. Predicted oxygen isotope compositions of synthesised silver phosphate range from ?7 to +31‰ VSMOW for a temperature range comprised between 110 and 130 °C and a range of water δ¹⁸O from ?20 to +15‰ VSMOW.  相似文献   

High‐Mg# Olivine,Clinopyroxene and Orthopyroxene Reference Materials for In Situ Oxygen Isotope Determination     

Guo‐Qiang Tang  Ben‐Xun Su  Qiu‐Li Li  Xiao‐Ping Xia  Jie‐Jun Jing  Lian‐Jun Feng  Laure Martin  Qing Yang  Xian‐Hua Li 《Geostandards and Geoanalytical Research》2019,43(4):585-593

Secondary ion mass spectrometry (SIMS) requires matrix‐matched reference materials to calibrate mass fractionation during oxygen isotope measurement. Over one thousand SIMS oxygen isotope measurements were conducted on eleven natural mineral samples (five olivines, three clinopyroxenes and three orthopyroxenes) in nineteen sessions using CAMECA IMS 1280 SIMS instruments to evaluate their potential as SIMS reference materials. The obtained results reveal oxygen isotope homogeneity of these samples. No matrix effect was measured for the same variety of mineral samples with limited Mg‐number variations (89.6–94.2, 90–91.9 and 90.1–92.1 for olivine, clinopyroxene and orthopyroxene, respectively). The recommended oxygen isotope compositions of these samples were determined using laser fluorination. These samples are therefore suitable to be used as reference materials for in situ oxygen isotope microanalysis.  相似文献   

The Tagliamento River: A model ecosystem of European importance   总被引：5，自引：0，他引：5  

Klement?TocknerEmail author  James?V.?Ward  David?B.?Arscott  Peter?J.?Edwards  Johannes?Kollmann  Angela?M.?Gurnell  Geoffrey?E.?Petts  Bruno?Maiolini 《Aquatic Sciences - Research Across Boundaries》2003,65(3):239-253

  相似文献