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复碱化混凝土孔溶液的ph.(英文)

建筑材料学报 2003年第2期6卷 111-117页

作者： A. Gerdes f. h. wittmann Research.Center Karlsruh. KarlsruheAedificat Institute Freiburg Germany Germany

碳化混凝土的复碱化是用碳酸钙缓冲溶液浸渍混凝土的电化学过程,目的是使混凝土孔溶液的ph.稳定在10以上,从而防止混凝土的进一步碳化.然而,该方法的实际应用表明:虽然孔溶液中已明显含有足量的碱(Na+,K+,Li+),但ph.仍降到10以下.本... 详细信息

碳化混凝土的复碱化是用碳酸钙缓冲溶液浸渍混凝土的电化学过程,目的是使混凝土孔溶液的ph.稳定在10以上,从而防止混凝土的进一步碳化.然而,该方法的实际应用表明:虽然孔溶液中已明显含有足量的碱(Na+,K+,Li+),但ph.仍降到10以下.本文通过试验提出了一个用以解释ph.随时间降低的假说,结果表明:由于混凝土孔溶液中存在溶解的硫酸盐,因此单纯提高孔溶液的碱离子(碳酸盐)相对含量,不能确保其ph.高于10.用提出的化学机理可解释混凝土电化学复碱化技术实际应用中观察到的现象,但是,由于混凝土孔溶液中溶解离子相互作用十分复杂,目前还不能在复碱化技术中对其加以考虑,因此复碱化技术尚不能被进一步推荐应用.

关键词：碳化混凝土复碱化硫酸盐孔溶液 ph.

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混凝土冻融损伤后的吸水特性

建筑材料学报 2011年第2期14卷 155-159,195页

作者：张鹏张连水赵铁军 f. h. wittmann E. LEh.ANN 金祖权青岛理工大学土木工程学院山东青岛266033 弗莱堡Aedif.cat研究所弗莱堡D-79100 Paul Sch.rrer Institute裂变中子源中心 Villigen PSI CH-5232

对掺与未掺引气剂的混凝土进行了冻融破坏,通过吸水试验和中子辐射试验,研究了冻融损伤对掺与未掺引气剂混凝土吸水特性的影响.结果表明,中子成像技术能够实现对非透明性混凝土材料吸水演进过程的可视化观测和定量分析.未掺引气剂的混... 详细信息

对掺与未掺引气剂的混凝土进行了冻融破坏,通过吸水试验和中子辐射试验,研究了冻融损伤对掺与未掺引气剂混凝土吸水特性的影响.结果表明,中子成像技术能够实现对非透明性混凝土材料吸水演进过程的可视化观测和定量分析.未掺引气剂的混凝土其抗冻性较差,在10次冻融循环后动弹模量损失14%的情况下,其水分渗透深度约增30%;掺加引气剂后,即使遭受200次冻融循环,混凝土的整体动弹模量也无明显损失,但200次冻融循环后,混凝土表层出现部分剥落,水分渗透速率及深度均相应增大.在评价混凝土冻融损伤时,除整体动弹模量损失外,还需考虑冻融损伤对混凝土吸水性能的影响.

关键词：冻融损伤动弹模量中子成像吸水水分渗透深度

Ef.ect of.cold-working on corrosion induced damage in lug joints

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Def.nce Tech.ology（防务技术） 2024年第6期36卷 175-182页

作者： Ramanath.M.N Ch.kmath.L. Murth. h. Department of.Aerospace Engineering Indian Institute of Technology-MadrasChennai 600036India Department of.Aeronautical Engineering KLS Gogte Institute of TechnologyBelagavi 590008India

Lug joints are pref.rred joineries f.r transf.rring h.avy loads to parent components in aerospace *** experience corrosion due to environmental conditions,improper surf.ce f.nish.s and rubbing displacement between th. pin and *** causes damage of.dif.erent sizes and sh.pes near th. *** degradation due to corrosion-induced damage is modelled as a th.ough.pit at one of.th. identif.ed critical locations th.ough.stress *** ef.ect of.th.s pit on f.tigue crack initiation lif. is ***-h.le is pre-stressed by cold-working and th. benef.ts of.inducing plastic wake on th. intended perf.rmance of.th. lug joint during th. damages due to corrosion are brough. out and compared with.non-cold-worked *** analysis is perf.rmed on th.s lug joint with.*** results obtained h.gh.igh. th. benef.ts of.cold-working and th. meth.dology can be extended to damage growth.and analyse th. ef.ect of.surf.ce treatments f.r better structural integrity of.components of.aerospace veh.cles.

关键词： Lug joint Corrosion Crack initiation Cold-working Structural integrity

Editorial f.r th. Special Issue on Emerging Tech.ology and Advanced Application of.Nondestructive Detection f.r Power Equipment

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Ch.nese Journal of.Electrical Engineering 2024年第1期10卷 1-2页

作者： Li J. Mei h. Li S. Tianjin University China Tsingh.a Sh.nzh.n International Graduate Sch.ol China Lanzh.u Jiaotong University China

Th. rapid development of.clean and renewable energy tech.ologies represented by wind and solar energy,as well as th. continuous growth.of.load demand,h.ve put f.rward h.gh.r requirements f.r th. saf. operation of.th. power *** perf.rmance of.power equipment based on traditional dielectric materials is of.en limited by various def.cts generated during molding,transportation,assembly,and operation,wh.ch.cannot meet th. reliability requirements of.power systems in th. new *** detection is an essential tech.ical meth.d in industrial development,wh.ch.can detect and evaluate th. def.ct and damage status of.in-service equipment,key components,and materials with.ut damaging th. object.

关键词： service Application operation

Microstructure evolution and sh.pe memory beh.viors of.Ni_(47)Ti_(44)Nb_(9)alloy subjected to multistep th.rmomech.nical loading with.dif.erent prestrain levels

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Journal of.Materials Science & Tech.ology 2024年第4期171卷 80-93页

作者： Y.h.Zh.ng h.Li Z.W.Yang X.Liu Q.f.Gu State Key Laboratory of.Solidif.cation Processing School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072China Sh.anxi Key Laboratory of.h.gh.Perf.rmance Precision f.rming Tech.ology and Equipment Northwestern Polytechnical UniversityXi’an 710072China

Ni_(47)Ti_(44)Nb_(9)sh.pe memory alloy(SMA)is a promising material in th. aerospace f.eld due to its wide transf.rmation *** application of.sh.pe memory ef.ect depends on multistep th.rmomech.n-ical loading,viz.,low-temperature def.rmation and subsequent h.ating to ***-temperature def.rmation prestrain plays a pivotal role in sh.pe memory properties tailoring of.SMA ***,microstructure evolution and def.rmation mech.nisms of.Ni_(47)Ti_(44)Nb_(9)SMA subjected to vari-ous prestrain levels are still *** th.s end,microstructure evolution and sh.pe memory beh.viors of.Ni_(47)Ti_(44)Nb_(9)alloy subjected to multistep th.rmomech.nical loading with.prestrain levels of.8%-16%at-28℃(M_(s)+30℃)were *** results demonstrate th.t th. stress-strain curve of.th. specimen exh.bits f.ur distinct stages at a maximal prestrain of.16%.Wh.reas stageⅡand stageⅢend at prestrains of.8%and∼12%,*** stageⅡ,th. stress-induced martensitic transf.rmation is accompanied by th. dislocation slip of.th. NiTi matrix andβ-Nb *** stageⅢ,in addition to th. h.gh.r density of.dislocations and f.rth.r growth.of.stress-induced martensite variants(SIMVs),(001)compound twins are introduced as a result of.th.(001)def.rmation twinning in stress-induced ***{20-1}martensite twins are gradually introduced in stageⅣ.Correspondingly,af.er subsequent unloading and h.ating,a h.gh.r density of.114}austenite twins f.rm in th. specimen with.a larger prestrain of.16%.With.increasing prestrain f.om 8%to 16%,th. recoverable strainε_(re)^(T)upon h.ating increases f.rst and th.n ***ε_(re)^(T)obtains a maximum of.7.03%at 10%prestrain and de-creases to 6.17%at 16%*** increase of._(re)^(T)can be attributed to th. f.rmation of.new SIMVs,th. f.rth.r growth.of.existing SIMVs,and th. recoverable(001)compound *** th. decrease of._(re)^(T)is mainly associated with.th. irrecoverable strain by{20−1}martensite *** ef.e

关键词： Ni_(47)Ti_(44)Nb_(9)sh.pe memory alloy Wide transf.rmation h.steresis Th.rmomech.nical loading Microstructure evolution Sh.pe memory beh.viors Stress-induced martensitic transf.rmation Def.rmation twinning

A Compreh.nsive Review on Ch.rging Topologies and Power Electronic Converter Solutions f.r Electric Veh.cles

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Journal of.Modern Power Systems and Clean Energy 2024年第3期12卷 675-694页

作者： Abdelf.tah.Ali h.ssam h.h.Mousa Mostaf. f.Sh.aban Mah.r A.Azzouz Ah.ed S.A.Awad th. Department of.Electrical Engineering American University of Sharjah26666 SharjahUnited Arab Emirates th. Department of.Electrical Engineering South Valley University83523 QenaEgypt th. Department of.Electrical and Computer Engineering University of WindsorWindsorON N9B 3P4 Canada Electrical Engineering Department Qatar UniversityDoha 2713Qatar Department of.Electrical and Computer Engineering Sultan Qaboos UniversityMuscat123Oman

Electric veh.cles(EVs)are becoming more popular worldwide due to environmental concerns,f.el security,and price *** perf.rmance of.EVs relies on th. energy stored in th.ir batteries,wh.ch.can be ch.rged using eith.r AC(slow)or DC(f.st)***,EVs can also be used as mobile power storage devices using veh.cle-to-grid(V2G)*** electronic converters(PECs)h.ve a constructive role in EV applications,both.in ch.rging EVs and in ***,th.s paper compreh.nsively investigates th. state of.th. art of.EV ch.rging topologies and PEC solutions f.r EV *** examines PECs f.om th. point of.view of.th.ir classif.cations,conf.gurations,control approach.s,and f.ture research.prospects and th.ir impacts on power *** can be classif.ed into various topologies:DC-DC converters,AC-DC converters,DC-AC converters,and AC-AC *** address th. limitations of.traditional DC-DC converters such.as switch.ng losses,size,and h.gh.electromagnetic interf.rence(EMI),resonant converters and multiport converters are being used in h.gh.voltage EV ***,power-train converters h.ve been modif.ed f.r h.gh.ef.iciency and reliability in EV *** paper of.ers an overview of.ch.rging topologies,PECs,ch.llenges with.solutions,and f.ture trends in th. f.eld of.th. EV ch.rging station applications.

关键词： Ch.rging station ch.rging topology electric veh.cle power electronic converter veh.cle-to-grid

Connections Between Induction Generator Ef.ect and Open-loop Modal Proximity to Cause Sub-synch.onous Oscillations in Series-compensated Power System

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CSEE Journal of.Power and Energy Systems 2024年第3期10卷 963-973页

作者： Wenjuan Du Yang Wang h.f.Wang Tao Zh.o Tim Littler College of.Electrical Engineering Sichuan UniversityChengduChina Sch.ol of.Electrical Engineering the Queen’s University of BelfastBelfastUK IEEE

Th. induction generator ef.ect(IGE)and th. openloop modal proximity(OLMP)are two dif.erent reasons wh. subsynch.onous oscillations(SSOs)in a series-compensated power system(SCPS)may *** IGE attributes th. growing SSOs to negative resistance,wh.le th. OLMP explains th. SSO mech.nism f.om th. standpoint of.modal *** th.s paper,we investigate th. connections between th. IGE and th. OLMP th.ough.equivalent RLC circuit and open-loop modal *** investigation is conducted f.r two types of.seriescompensated power systems wh.re eith.r a synch.onous generator or a Df.G is connected at th. sending *** investigation reveals th. conditions,in wh.ch.th. IGE and th. OLMP may jointly cause th. growing SSOs,i.e.,both.th. IGE and th. OLMP can explain wh. th. growing SSOs ***,th. investigation indicates th.t th. IGE and th. OLMP may be totally irrelevant and lead to growing SSOs *** implies th.t it is possible th.t in a SCPS,th. growing SSOs are only due to th. IGE,and th. OLMP is non-existent,and vice ***,wh.n th. growing SSOs occurs in a SCPS,examination based on both.th. IGE and th. OLMP sh.uld be caref.lly conducted in order to f.nd if.th. oscillatory instability is due to th. IGE,or th. OLMP,or both.of.th.m.

关键词： Induction generator ef.ect open-loop modal proximity series compensation sub-synch.onous oscillations

Optimization of.Stealth.atch.Network Security System f.r th. Detection and Mitigation of.Distributed Denial of.Service (DDoS) Attack: Application to Smart Grid System

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Communications and Network 2024年第3期16卷 108-134页

作者： Emmanuel S. Kolawole Penrose S. Cof.e Joh. h. f.ller Cajetan M. Akujuobi Emmanuel A. Dada Justin f. f.reman Pamela h. Obiomon Electrical and Computer Engineering Department Prairie View A&M University Prairie View TX USA

Th. Smart Grid is an enh.ncement of.th. traditional grid system and employs new tech.ologies and soph.sticated communication tech.iques f.r electrical power transmission and distribution. Th. Smart Grid’s communication network sh.res inf.rmation about status of.its several integrated IEDs (Intelligent Electronic Devices). h.wever, th. IEDs connected th.ough.ut th. Smart Grid, open opportunities f.r attackers to interf.re with.th. communications and utilities resources or take clients’ private data. Th.s development h.s introduced new cyber-security ch.llenges f.r th. Smart Grid and is a very concerning issue because of.emerging cyber-th.eats and security incidents th.t h.ve occurred recently all over th. world. Th. purpose of.th.s research.is to detect and mitigate Distributed Denial of.Service [DDoS] with.application to th. Electrical Smart Grid System by deploying an optimized Stealth.atch.Secure Network analytics tool. In th.s paper, th. DDoS attack in th. Smart Grid communication networks was modeled using Stealth.atch.tool. Th. simulated network consisted of.Secure Network Analytic tools virtual mach.nes (VMs), electrical Grid network communication topology, attackers and Target VMs. f.nally, th. experiments and simulations were perf.rmed, and th. research.results sh.wed th.t Stealth.atch.analytic tool is very ef.ective in detecting and mitigating DDoS attacks in th. Smart Grid System with.ut causing any blackout or sh.tdown of.any internal systems as compared to oth.r tools such.as GNS3, NeSSi2, NISST f.amework, OMNeT++, INET f.amework, ReaSE, NS2, NS3, M5 Simulator, OPNET, PLC & TIA Portal management Sof.ware wh.ch.do not h.ve th. capability to do so. Also, using Stealth.atch.tool to create a security baseline f.r Smart Grid environment, contributes to risk mitigation and sound security h.giene.

关键词： Smart Grid System Distributed Denial of.Service (DDoS) Attack Intrusion Detection and Prevention Systems Detection Mitigation and Stealth.atch

Spalling ch.racteristics of.h.gh.temperature treated granitic rock at dif.erent strain rates

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Journal of.Rock Mech.nics and Geotech.ical Engineering 2024年第4期16卷 1280-1288页

作者： L.f.f.n Q.h.Yang X.L.Du Th. Key Laboratory of.Urban Security and Disaster Engineering of.Ministry of.Education Beijing University of TechnologyBeijing100124China

Th. dynamic spalling ch.racteristics of.rock are important f.r stability analysis in rock *** paper presented an experimental investigation on th. dynamic spalling ch.racteristics of.granite with.dif.erent temperatures and strain rates.A series of.dynamic spalling tests with.dif.erent impact velocities were conducted on th.rmally treated granite at dif.erent *** dynamic spalling strength. of.granite with.dif.erent temperatures and strain rates were determined.A model was proposed to correlate th. dynamic spalling strength.of.granite,h.gh.temperature and strain *** results sh.w th.t th. spalling strength.of.granite decreases with.increasing ***,th. spalling strength.of.granite with.a h.gh.r strain rate is larger th.n th.t with.a lower strain *** proposed model can describe th. relationsh.p among dynamic spalling strength.of.granite,h.gh.temperature and strain rate.

关键词： Dynamic spalling ch.racteristics h.gh.temperature Strain rate Dynamic loading Granite