Microbiologically influenced corrosion resistance enhancement of coppercontaining high entropy alloy Fe_(x)Cu_(1−x)CoNiCrMn against Pseudomonas aeruginosa

To enhance the microbiologically influenced corrosion(MIC)resistance of FeCoNiCrMn high entropy alloy(HEAs),a series of Fe_(x)Cu_((1−x))CoNiCrMn(x=1,0.75,0.5,and 0.25)HEAs were prepared.Microstructural characteristics,corrosion behavior(morphology observation and electrochemical properties),and antimicrobial performance of Fe_(x)Cu_((1−x))CoNiCrMn HEAs were evaluated in a medium inoculated with typical corrosive microorganism Pseudomonas aeruginosa.The aim was to identify copper-containing FeCoNiCrMn HEAs that balance corrosion resistance and antimicrobial properties.Results revealed that all Fe_(x)Cu_((1−x))CoNiCrMn(x=1,0.75,0.5,and 0.25)HEAs exhibited an FCC(face centered cubic)phase,with significant grain refinement observed in Fe_(0.75)Cu_(0.25)CoNiCrMn HEA.Electrochemical tests indicated that Fe_(0.75)Cu_(0.25)CoNiCrMn HEA demonstrated lower corrosion current density(i_(corr))and pitting potential(E_(pit))compared to other Fe_(x)Cu_((1−x))CoNiCrMn HEAs in P.aeruginosa-inoculated medium,exhibiting superior resistance to MIC.Anti-microbial tests showed that after 14 d of immersion,Fe_(0.75)Cu_(0.25)CoNiCrMn achieved an antibacterial rate of 89.5%,effectively inhibiting the adhesion and biofilm formation of P.aeruginosa,thereby achieving resistance to MIC.

Electrochemical behavior of microbiologically influenced corrosion on Fe_3Al in marine environment

In this article, microbiologically influenced corrosion behavior of Fe3Al intermetallie compound in microorganism culture medium has been investigated by using weight loss methods, electrochemical techniques, and electron microscopy. Polarization curves showed that a sharp electrical current peak caused by surface pitting could be observed after Fe3Al electrodes were immersed in culture medium for 15 days when the polarization potential was about -790 mV vs SCE. Based on the electrochemical impedance spectroscopy （EIS） and the equivalent circuit parameters of the associated system, the corrosion products were found to exhibit a two-layer structured feature and the microorganisms could induce pitting and erosion corrosion of the inner layer. In addition, the passivating film of the inner layer was absolutely destroyed by microbial metabolic products.

Microbiologically influenced corrosion of cable bolts in underground coal mines:The effect of Acidithiobacillus ferrooxidans

Reports on corrosion failure of cable bolts,used in mining and civil industries,have been increasing in the past two decades.The previous studies found that pitting corrosion on the surface of a cable bolt can initiate premature failure of the bolt.In this study,the role of Acidithiobacillus ferrooxidans(A.ferrooxidans)bacterium in the occurrence of pitting corrosion in cable bolts was studied.Stressed coupons,made from the wires of cable bolts,were immersed in testing bottles containing groundwater collected from an underground coal mine and a mixture of A.ferrooxidans and geomaterials.It was observed that A.ferrooxidans caused pitting corrosion on the surface of cable bolts in the near-neutral environment.The presence of geomaterials slightly affected the p H of the environment;however,it did not have any significant influence on the corrosion activity of A.ferrooxidans.This study suggests that the common bacterium A.ferrooxidans found in many underground environments can be a threat to cable bolts'integrity by creating initiation points for other catastrophic failures such as stress corrosion cracking.

THE ELECTROCHEMICAL BEHAVIOR OF OCEANIC MICROBIOLOGICAL INFLUENCED CORROSION ON CARBON STEEL

The corrosion behavior of carbon steel in the medium of marine microorganisms was investigated by electrochemical impedance spectra, polarization curves, and so on. Experimental results showed that the corrosion potential of carbon steel moved in a negative direction in the unpurified marine microorganism solution, and the polarization style of the cathodic process did not change. The electrochemical impedance spectra showed that the impedance value of the electrode decreased in the medium with bacteria, which indicated that the existence of microorganism could accelerate the corrosion progress of carbon steel.

Theory and test research on permeability of coal and rock body influenced by mining

Stress distribution rules and deformation and failure properties of coal and rockbodies influenced by mining were analyzed.Experimental research on permeability of coaland rock samples under different loading conditions was finished in the laboratory.In-situmeasurement of coal permeability influenced by actual mining was done as well.Theoryanalysis show that permeability varied with damage development of coal and rock understress,and the influence of fissure on permeability was greatest.Laboratory results showthat under different loading conditions permeability was different and it varied with stress,which indicated that permeability was directly related to the loading process.In-situ testsshowed that permeability is related to abutment stress to some degree.The above resultsmay be referenced to gas prevention and drainage.

Characteristics of Authigenic Pyrite and its Sulfur Isotopes Influenced by Methane Seep--Taking the Core A at Site 79 of the Middle Okinawa Trough as an Example

Objective Authigenic pyrite often develops extensively in marine sediments,which is an important product of sulfate reduction in an anoxic environment.It has a specific appearance and complicated sulfur isotopic properties,and acts as important evidence of methane seep in marine sediments.Strong AOM（anaerobic oxidation of methane）activity has developed in the Okinawa Trough.

Chinese Students’ Adaptation of Social Intercourse Influenced by Different Cultural Contexts of China and America in American Universities

1 Statement of the Purpose (1) Statement of the purpose The purpose of the research isto study Chinese studends' adaptation of social intercourse influenced by different cultural contexts of China and America in American universities.And the study will also try to find out the exact problems and obstacles during Chinese students' adapting period in American universities.

Anticorrosive Properties of Green Silver Nanoparticles to Prevent Microbiologically Influenced Corrosion on Copper in the Marine Environment

Microbiologically influenced corrosion is a global problem especially materials used in marine engineering.In that respect,inhibitors are widely used to control fouling and corrosion in marine systems.Most techniques used in inhibitor production are expensive and considered hazardous to the ecosystem.Therefore,scientists are motivated to explore natsural and green products as potent corrosion inhibitors especially in nano size.In this study,antibacterial and anticorrosive properties of green silver nanoparticles(AgNPs)were studied through weight loss,electrochemical characterization,and surface analysis techniques.The corrosion of copper(Cu)in artificial seawater(ASW),Halomonas variabilis(H.variabilis)NOSK,and H.variabilis+AgNPs was monitored using electrochemical measurements like open circuit potential(OCP),electrochemical impedance spectroscopy(EIS),and potentiodynamic polarization curves.AgNPs showed excellent antibacterial activity against pathogenic microorganisms.Electrochemical studies demonstrate a noticeable decrease in OCP and current density in ASW containing H.variabilis+AgNPs compared to both ASW and ASW inoculated with bacterium,which confirmed the decrease of corrosion rate of copper.Furthermore,the obtained voltammograms show that the silver nanoparticles were adsorbed on the copper electrode surface from the corrosion solution.Thus,the results prove that the novel idea of green silver nanoparticles acts as an anticorrosive film in the marine environment.

Simulation of scenario earthquake influenced field by using GIS

The method for estimating the site effect on groundmotion specified by Borcherdt (1994a, 1994b) is briefly introducedin the paper. This method and the detail geological data and site classification data in San Francisco bay area ofCalifornia, the United States. are applied to simulate the influenced field of scenario earthquake by GIS technology,and the software for simulating has been drawn up. The paper is a partial result of cooperative research project betweenChina Seismological Bureau and US Geological Survey.

Research on Willingness and Influenced Factors of Delayed Retirement

Extending the retirement age is an inevitable trend with the extension of the life expectancy of the population, reducing the financial burden of pensions, increasing the utilization rate of human capital, alleviating the shortage of the labor market and other social problems. More and more countries are beginning to impose extended retirement policies, like United States, South Korea, Canada and Nordic countries and so on, all have taken some measures to delay retirement. However, the general social recognition is not high. Both the aged group, the education level and the individual＇s lifestyle have a significant impact on the delayed retirement age policy. Severe aging situation puts the future pension system at risk, based on the interests of the country, delayed retirement will help utilize the human capital and relieve the country＇ s financial pressure; from individual perspective, extending retirement age can help reduce the provision for the aged people. This article based on previous literatures review, through conducted the survey of people in Halmstad to analyze the local citizen＇s perception on delayed retirement and the influencing factors behind. Concluded that willingness of delayed retirement among people is not very high, reasons vary from different kinds of people.

The Application of Pedestrian Microscopic Simulation Technology in Researching the Influenced Realm around Urban Rail Transit Station

Under the background of urban rail transit＇s rapid development, urban rail transit station, as the only connection of urban space and rail transit, undertakes the responsibility of traffic organization and passenger volume distribution. Influenced urban realm around station becomes the focus of the optimization of the sustainable urban development. Pedestrian microscopic simulation method establishes the comprehensive dynamic behavior rules in a part of urban space through simulating the behavior law by digital tools, in which the internal demand and motive mechanism of the development and change of urban space fairly well by digital representing and analyzing relevant laws can be explained. After that, the research with the realm as the carrier analyzed the demand of each simulation level and the choice of simulation parameters based on analyzing the walking connection behavior characteristics, and then further established the methodology system of pedestrian microscopic simulation. At last, the research taking the study of influenced urban realm around typical station for sample explored the application method of optimizing of urban space and traffic organization based on AnyLogic platform.

Characteristics and factors that influenced damage to dams in the M_s 8.0 Wenchuan earthquake

Based on raw data from dams damaged in the Wenchuan earthquake, including many that were severely damaged, characteristics and factors that influenced the damage are discussed in this paper. Findings from this study include： severely damaged dams were densely distributed along the seismologic fault; small dams, especially small earth-rock dams, had the most serious damage that was caused by a variety of factors; the most serious damage was caused by seismic waves; damage was aggregated by aftershocks; and the extent of the damage patterns increased with the seismic intensity. Damage patterns varied in different intensity zones and cracking was the most common type of damage. Most of the dams had a good base with relatively high bearing capacity, and the walls of the earth-rock dams were mostly of clay soil. This type of base and body material mitigated some of the damage to dams. Reservoir maintenance and other factors also have a significant impact on the seismic safety of the dam. Finally, some recommendations to reduce seismic damage to dams are proposed.

MICROBIOLOGICALLY INFLUENCED CORROSION ON WELD OF STAINLESS STEEL 304L

The influence of welding defects on MIC (microbiologically influenced corrosion) was studied.The open circuit potential (OCP) was measured during MIC test. It was found that OCP shifted to a higher level when the system was inoculated with bacteria and it decreased dramatically when MIC started. Among a series of welding defects golden heat tint was found the most susceptible to MIC. The tubercles over pitting were observed with SEM. Some elements inside of the tubercles were analysed with EDXA. Microbiological analysis of a corroded and a non-corroded sample revealed no significant difference between them with the exception of the number of the manganeseoxidising bacteria.

NUMERIC ANALYSIS ON INFLUENCED FACTORS OF DISCONTINUOUS SURFACE DEFORMATION DUE TO STEEPLY-INCLINED SEAM MINING

This paper deals with the shape and influenced factors of surface non-continuous deformation due to mining. With finite element method, analysis are made to derive the relations between discontinuous deformation and mining affection, weak plane’s position & thickness, and mechanical property of weak-plane medium. The mutual affection of multiple weak-planes is also discussed. The results of the paper lay a foundation for constructing the calculation method of surface discontinuous deformation.

Analysis of Water Temperature Influenced by Arduino-Controlled on Solar Desalinator of Low Cost

The solar desalinator is a low cost installation and operation equipment that can contribute to tackling the problem of water shortages in the world.Because of the importance of this equipment,the present work has the objective to quantify the relation of the temperature of the water with the production of the equipment.For this,a compact desalinator with glass cover in square pyramidal form and a heating system controlled by a logic programmer was built.As a result,it was verified the efficiency of the logic controller as an auxiliary tool for experimental work and the relationship between temperature ranges and desalination production.

Microbiologically Influenced Corrosion Behavior of Fe_(40)(CoCrMnNi)_(60) and Fe_(60)(CoCrMnNi)_(40) Medium Entropy Alloys in the Presence of Pseudomonas Aeruginosa

In this work,the microbiologically influenced corrosion(MIC)of Fe_(40)(CoCrMnNi)_(60) and Fe_(60)(CoCrMnNi)_(40) medium entropy alloys(MEAs)induced by Pseudomonas aeruginosa(P.aeruginosa)was investigated.Corrosion behaviors during 14 days of immersion in sterile and P.aeruginosa-inoculated culture media are presented.Under sterile conditions,both MEAs exhibited good corrosion resistance against the culture medium solution.In the presence of P.aeruginosa,the pitting corrosion of MEAs was promoted.The results of inductively coupled plasma‒mass spectrometry(ICP‒MS)and potentiodynamic polarization tests showed that the presence of P.aeruginosa promoted the selective dissolution of passive film and accelerated the corrosion of MEAs.The results of X-ray photoelectron spectroscopy(XPS)and Mott-Schottky measurements further demonstrated the degradation effect of P.aeruginosa on the passive film.Compared with Fe_(60)(CoCrMnNi)_(40),Fe_(40)(CoCrMnNi)_(60) manifested better resistance to the MIC caused by P.aeruginosa,which may be attributed to more Cr oxides and fewer Fe oxides of the passive film.

基于区块链的Gossip协议优化研究

Gossip网络协议具有高效性和扩展性,广泛应用于区块链分布式系统的底层通信协议。针对联盟链中Gossip网络协议的冗余现象造成的传播效率下降,提出了Stack Gossip算法。该算法将收到的节点信息记录在信息栈中,避免向一个节点重复发送消息。实验发现,Stack Gossip算法不适用于大规模网络中节点数量过多的情况。为此,进一步提出Influence Gossip算法,其核心思路是节点通过评估邻居节点的信息影响力来选择通信的对等节点,在一定程度上避免了传统Gossip网络协议节点间传播的随机性。实验结果表明,与Random Gossip算法相比,Influence Gossip和Stack Gossip算法传播效率和产生的冗余有明显改进。

Geochemical identification of a source rock affected by migrated hydrocarbons and its geological significance:Fengcheng Formation,southern Mahu Sag,Junggar Basin,NW China

The Fengcheng Formation is a crucial source rock and the primary reservoir for oil accumulation in the Mahu Sag.Crude oils are distributed throughout the Fengcheng Formation,ranging from the edge to the interior of the sag in the southern Mahu Sag.These crude oils originate from in-situ source rocks in shallowly buried areas and the inner deep sag.During migration,the crude oil from the inner deep sag affects the source rocks close to carrier beds,leading to changes in the organic geochemical characteristics of the source rocks.These changes might alter source rock evaluations and oil-source correlation.Based on data such as total organic carbon(TOC),Rock-Eval pyrolysis of source rocks,and gas chromatography-mass spectrometry(GC-MS)of the saturated fraction,and considering the geological characteristics of the study area,we define the identification characteristics of source rock affected by migrated hydrocarbons and establish the various patterns of influence that migrated hydrocarbons have on the source rock of the Fengcheng Formation in the southern Mahu Sag.The source rocks of the Fengcheng Formation are mostly fair to good,containing mainly Type II organic matter and being thermally mature enough to generate oil.Source rocks affected by migrated hydrocarbons exhibit relatively high hydrocarbon contents(S1/TOC>110 mg HC/g TOC,Extract/TOC>30%,HC:hydrocarbon),relatively low Rock-Eval Tmax values,and relatively high tricyclic terpane contents with a descending and mountain-shaped distribution.Furthermore,biomarker composition parameters indicate a higher thermal maturity than in-situ source rocks.Through a comparison of the extract biomarker fingerprints of adjacent reservoirs and mudstones in different boreholes,three types of influence patterns of migrated hydrocarbons are identified:the edge-influence of thin sandstone-thick mudstone,the mixed-influence of sandstone-mudstone interbedded,and the full-influence of thick sandstone-thin mudstone.This finding reminds us that the influence of migrated hydrocarbons must be considered when evaluating source rocks and conducting oil-source correlation.

Toward a better understanding of microbiologically influenced corrosion caused by sulfate reducing bacteria

Sulfate reducing bacteria(SRB) are often the culprits of microbiologically influenced corrosion(MIC) in anoxic environments because sulfate is a ubiquitous oxidant. MIC of carbon steel caused by SRB is the most intensively investigated topic in MIC because of its practical importance. It is also because biogenic sulfides complicate mechanistic SRB MIC studies, making SRB MIC of carbon steel is a long-lasting topic that has generated considerable confusions. It is expedient to think that biogenic H_2S secreted by SRB acidifies the broth because it is an acid gas. However, this is not true because endogenous H_2S gets its H^+ from organic carbon oxidation and the fluid itself in the first place rather than an external source. Many people believe that biogenic H_2S is responsible for SRB MIC of carbon steel. However, in recent years,well designed mechanistic studies provided evidence that contradicts this misconception. Experimental data have shown that cathodic electron harvest by an SRB biofilm from elemental iron via extracellular electron transfer(EET) for energy production by SRB is the primary cause. It has been demonstrated that when a mature SRB biofilm is subjected to carbon source starvation, it switches to elemental iron as an electron source and becomes more corrosive. It is anticipated that manipulations of EET related genes will provide genetic-level evidence to support the biocathode theory in the future. This kind of new advances will likely lead to new gene probes or transcriptomics tools for detecting corrosive SRB strains that possess high EET capabilities.