Subjects: Materials Science >> Materials Science (General) submitted time 2023-03-31 Cooperative journals: 《腐蚀科学与防护技术》
Abstract： Research progress on corrosion of carbon steels induced by SRB is reviewed in terms of the formation mechanism of biofilm, the traditional corrosion mechanism of SRB, mechanism of biocatalysis cathodic sulfate reduction, and the corrosion of carbon steels under the deposit scale induced by SRB biomineralization. In addition, the paper focused on the key role of the theory of bioenergetics and bioelectrochemistry in understanding the mechanism of MIC induced by SRB. The novel technologies and methods for control of SRB biofilm which provide reference for control of SRB corrosion are introduced.
Subjects: Materials Science >> Materials Science (General) submitted time 2023-03-31 Cooperative journals: 《腐蚀科学与防护技术》
Abstract： Corrosion inhibition performance of common inhibitors such as lauric acid and thioure for carbon steel in a CO2-saturated and SRB-containing artificial sewage was studied by means of electrochemical methods, mass loss method, three-dimensional stereoscopic microscope and quantitative measurement of the bacteria amount. The results show that in a sterilized and CO2-saturated medium, the inhibition efficiencies of lauric acid and thiourea were 98.6%, 94.6% respectively; the two inhibitors lauric acid and thiourea were all mix-type inhibitors which mainly suppress the cathodic process. In the SRB-containing and CO2-saturated medium, lauric acid and thiourea exhibit low inhibition efficiency: 62.9% and 53.5%, respectively, while there exist a lot of corrosion pits on the steel surface; and the inhibitors lauric acid and thiourea can promote the growth of SRB, while the metabolites of SRB prevent the adsorption of lauric acid and thiourea on the metal surface. Therefore, the two inhibitors may not be suitable to apply in those SRB-containing environments.
Subjects: Materials Science >> Materials Science (General) submitted time 2023-03-31 Cooperative journals: 《腐蚀科学与防护技术》
Abstract： The situatuion concering corrosion and scaling of the inner wall of sewage gathering pipelines in oil field was investigated by means of scanning electron microscopy (SEM) with energy dispersive X-ray spectrometry (EDS), X-ray diffracmeter (XRD) and three-dimensional stereoscopic microscopy. The results indicated that after exposure to the sewage for 30 d a scale of deposits ca 169.6 μm in thickness could be observed on the surface of test samples, which consisted maily of extracellular polymeric substance with iron sulfides, the product of sulfate reducing bacteria metabolism, while beneath the scale the pipeline steel suffered from pitting corrosion with a maximum pit depth 23.96 μm; however after exposure for the same period in the same medium but with continuously adding organic guanidine bactericide of a dose 100 mg/L, the thickness of corrosion products scale was lowed to only ca 48.6 μm, besides, the corrosion of the substrate beneath the scale was light. It may be concluded that one of the reasons responsible to the localized perforation of pipelines was the SRB induced corrosion.
Subjects: Other Disciplines >> Synthetic discipline submitted time 2023-03-28 Cooperative journals: 《中国科学院院刊》
Abstract： The Qinghai-Tibet Plateau is the source of major Asian rivers such as the Yangtze River, the Yellow River, and the Yarlung Zangbo River, which is known as Asia’s water tower. Analysis on the evolution rule and variation trend of surface water and groundwater resources in the Qinghai-Tibet Plateau is of great strategic and scientific importance to the water resources, water ecological protection, and future regional development of the Qinghai-Tibet Plateau. Based on the analysis of the observed runoff series of hydrological stations in the main rivers within source areas, it is found that the surface runoffs in most areas of the Qinghai-Tibet Plateau show an increasing trend impacted by climate change in terms of more precipitation and rising temperature, and indicates significant changes in seasonal processes. The runoffs increase more significantly in the source areas of the Yangtze, Nujiang, and Yarlung Zangbo rivers. The results demonstrate that the dominant factor is increased glacier and snow melting flow to more groundwater and growth of plateau lakes, due to temperature rising. With the depletion of glacier and snowpack, the melting water will be reduced in future. Therefore, the break point of increase to decrease will arise in some river runoffs. Thus, the water security of this region will face new problems and challenges. High attention should be paid to the global change impact to water resources evolution in the Qinghai-Tibet Plateau, and positive responsive measures should be taken.
Subjects: Biology >> Zoology submitted time 2017-10-23 Cooperative journals: 《动物营养学报》
Abstract：本试验旨在研究采用真代谢能（TME）法评定3种蒸煮酶解羽毛粉对于肉鸭的能量和氨基酸营养价值，为合理开发和利用羽毛粉蛋白质资源提供基础数据。3种羽毛粉（Ⅰ~Ⅲ）分别为42日龄樱桃谷肉鸭羽毛粉、550日龄罗曼蛋鸡羽毛粉和100日龄三黄肉鸡羽毛粉。试验选取20只7周龄樱桃谷肉鸭，随机分为4个处理，每个处理5个重复，每个重复1只肉鸭，单笼饲养。处理1（T1）为测定羽毛粉Ⅰ，处理2（T2）为测定羽毛粉Ⅱ，处理3（T3）为测定羽毛粉Ⅲ，处理4（T4）为饥饿处理。试验期为7 d。结果表明：1）以干物质（DM）为基础，3种羽毛粉的总能（GE）分别为21.31、21.02和20.18 MJ/kg，表观代谢能（AME）分别为13.71、12.29和12.10 kJ/kg，TME分别为14.83、13.42和13.22 MJ/kg。2）以DM为基础，3种羽毛粉的粗蛋白质（CP）含量分别为91.05%、87.31%和91.06%；3种羽毛粉的总氨基酸（TAA）含量都在80%以上，但不同羽毛粉的氨基酸含量差异较大。3）3种羽毛粉的TAA表观可代谢率为别为81.51%、73.07%和76.85%，TAA真可代谢率分别为85.09%、76.89%和80.43%。3种羽毛粉的表观可利用氨基酸和真可利用氨基酸含量也存在显著差异（P＜0.05）。由此可见，利用TME法测定毛粉能量与氨基酸的营养价值，发现3种羽毛粉的代谢能（ME）、表观可利用氨基酸和真可利用氨基酸存在明显差异。羽毛粉Ⅰ的GE、ME、CP及TAA代谢率均高于羽毛粉Ⅱ和羽毛粉Ⅲ。
Subjects: Materials Science >> Materials Science (General) submitted time 2017-03-31 Cooperative journals: 《腐蚀科学与防护技术》
Abstract：采用电化学方法、腐蚀失重法及表面分析手段研究了X80钢在含有铁细菌（IOB）的油田产出水中的腐蚀行为研究。结果表明，IOB明显的促进了X80钢的均匀腐蚀及局部腐蚀。在空白的油田产出水中，X80钢腐蚀速率随时间延长先减小后增大。含有菌的油田产出水介质中，X80碳钢腐蚀速率先快速减小后又快速增大。含有铁细菌(IOB)的体系形成的生物膜较为疏松，同时可以看到大量的腐蚀产物及IOB细胞。而且通过3D三维立体显微镜可以看出含有IOB体系表面腐蚀较为严重且具有点蚀坑产生。极化曲线分析和失重分析都表明IOB的存在促进了X80碳钢的腐蚀。铁氧化菌可以加速X80管线碳钢的腐蚀。
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