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121.
The corrosion rates of API X65 mild steel alloy in CO2 – containing produced water have been studied by weight loss technique, potentiodynamic polarization technique and characterization of the corroded surface techniques. The effect of temperature, speed of rotation, pH and acetic acid concentration were studied. The optimum condition in presence and absence of protective film were also addressed. The kinetic parameters and reaction behavior were discussed in details. Corrosion rates increases with increasing temperature, acetic acid concentration, and speed of rotation, and decreased with increasing solution pH. The primary corrosion product of API X65 mild steel is ferrous carbonate (FeCO3) at high temperatures, high pH's (alkaline media) and absence of acetic acid, which could act as a protective film so that CO2 corrosion rate can be reduced.  相似文献   
122.
Soil humic acids may favour the persistence of hexavalent chromium in soil   总被引:1,自引:0,他引:1  
The interaction between hexavalent chromium Cr(VI), as K2CrO4, and standard humic acids (HAs) in bulk solution was studied using three complementary analytical methods: UV-Visible spectroscopy, X-ray absorption spectroscopy and differential pulse stripping voltammetry. The observed UV-Vis and X-ray absorption spectra showed that, under our experimental conditions, HAs did not induce reduction of Cr(VI) to its trivalent chemical form. The interaction between Cr(VI) and HAs has rather led to the formation of Cr(VI)-HAs micelles via supramolecular chemical processes. The reported results could contribute towards explaining the relative persistence of ecotoxic hexavalent chromium in soils.  相似文献   
123.
本文概略地述评了X射线衍射方法在地学方面的应用现状:单晶结构分析和结构矿物学及其发展;X射线粉末法,特别是晶胞参数测定方法在造岩矿物研究中的应用;用单晶X射线照相研究造岩矿物调制结构;X射线粉末法在粘土矿物学及煤岩学上的应用,等等。 同时,还介绍了笔者在用X射线粉末法及单晶分析研究造岩矿物方面的主要成果。  相似文献   
124.
The Aliakmon River originates in the North Western part of Greece, traverses the Western part of Macedonia, and discharges into the Thermaikos Bay in the North Aegean Sea. Proton induced X-ray emission (PIXE) method with external beam was used for the determination of the metallic elements in the waters and sediments of the Aliakmon River. the pH, dissolved oxygen, conductivity, and total phosphate and nitrate concentrations were also monitored in the water samples. Data collected for a 20-month period indicate that the Aliakmon River can be still considered as an unpolluted river.  相似文献   
125.
在pH6.0的NH4AC-HAC缓冲介质中,以巯基纸吸附和富集Sb(Ⅲ),吸附Sb(Ⅲ)后的巯基纸用X射线荧光测定;吸附Sb(Ⅲ)后的溶液于1mol/LHcl介质中,以巯基纸吸附Sb(Ⅴ),并按同样方法测定Sb(Ⅴ)。  相似文献   
126.
本文用X射线粉末衍射法研究蒙脱石矿物的结晶度与其埋藏深度之间的关系,并作出地质解释。 在X射线粉末衍射图上,V/P值的大小即C轴的有序程度是蒙脱石结晶度的标志。V/P值与其生成时的深度有相关性,其相关曲线呈一似抛物线形。似抛物线的顶点位于不同的生成深度,这主要是各地区地热增温率及成矿温度不同所引起。  相似文献   
127.
李吉文  邹文良 《干旱环境监测》1994,8(4):227-228,242
对乌鲁木齐地区5所医院1所卫生防疫站的医用诊断X射线机房内空气中正负离子浓度进行了调查,结果表明:透视和摄片机房空气中正负离子浓度分别为474±118,312±104(个/cm3)和404±101,256±78(个/cm3).单极系数(n+/n-)分别为1.52和1.58。正离子浓度均高于对照组(P<0.01),n+/n-相当于对照组的1,37和1.42倍。开机后空气中正离子浓度显著高于开机前浓度,n+/n-开机后相当于开机前的1.66和1.59倍,呈现出X线机房空气中正负离子严重失调。提示应加强有害因素的防护。  相似文献   
128.
This is the first study seasonally applying Sphagnum papillosum moss bags and vertical snow samples for monitoring atmospheric pollution.Moss bags,exposed in January,were collected together with snow samples by early March 2012 near the Harjavalta Industrial Park in southwest Finland.Magnetic,chemical,scanning electron microscopy-energy dispersive X-ray spectroscopy(SEM-EDX),K-means clustering,and Tomlinson pollution load index(PLI)data showed parallel spatial trends of pollution dispersal for both materials.Results strengthen previous findings that concentrate and slag handling activities were important(dust)emission sources while the impact from Cu–Ni smelter's pipe remained secondary at closer distances.Statistically significant correlations existed between the variables of snow and moss bags.As a summary,both methods work well for sampling and are efficient pollutant accumulators.Moss bags can be used also in winter conditions and they provide more homogeneous and better controlled sampling method than snow samples.  相似文献   
129.
X射线荧光光谱分析法在土壤样品多元素分析中的应用   总被引:3,自引:0,他引:3  
用Epsilon5偏振能量色散X射线荧光光谱仪测定土壤样品中27种元素。方法的准确度用GBW07323和GSS-32标准样品验证,结果均在标准值范围内。方法的精密度用GBW07401标准样品检验,除Ni、Mo、Se和Pr四种元素的RSD〉10%外,其余被测元素的RSD均〈6.3%。实验表明用X射线荧光光谱分析法测定土壤样品中多种元素,具有方法简便、灵敏、准确,检出限低等特点。  相似文献   
130.
Due to the increase in the number of urinary calculi disease cases in Jordan, stone samples were collected from patients from various Jordanian hospitals (Princes Basma (PBH), King Abdullah University (KAUH), Al-Basheer (ABH) and Al-Mafraq (AMH)). This study concentrates on the effect of trace metals in patients of urinary calculi. Trace metals were detected in 110 urinary calculi samples using X-ray fluorescence (XRF) and atomic absorption spectroscopy (AAS) techniques. Of the calculi examined, 21 were pure calcium oxalate (CaOax), 29 were mixed calcium oxalate/uric acid, 23 were mixed calcium oxalate/phosphate (apatite), 25 were phosphate calculi (apatite/struvite), five were mixed calcium oxalate monohydrate/struvite, four were urate calculi (mixed ammonium acid urate/sodium acid urate) and three were pure cystine calculi. The concentration measurement of Ca and other trace metals levels has been found useful in understanding the mechanism of stone formation and in evaluating pathological factors. It has been found that Ca is the main constituent of the urinary calculi, especially those stones composed of calcium oxalate and calcium phosphate. The concentration of most of the trace metals that were analyzed was (Ca = 48.18, Na = 1.56, K = 0.9, Mg = 3.08, Fe = 1.17, Al = 0.49, Zn = 0.7, Cu = 0.19, Mn = 0.029, P = 10.35, S = 1.88, Sr = 0.306, Mo = 0.2, Cr = 0.146, Co = 0.05, Ni = 0.014)%. In conclusion, metals concentration in Jordanian patient’s urinary calculi samples was higher than its equivalents of other patients’. It has been noted that there is no concentration of toxic trace elements (like Li, V, Pb, Cd, and As). Some heavy metals, however, were detected Mo, Cr, Co and Ni as traces. P and S ions are present in few calculi stones as traces.  相似文献   
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