检索结果-南通市图书馆

累积叠轧焊Al/Mg/Al多层复合材料的腐蚀行为

在线全文

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 2024年第1期34卷 122-138页

作者： Ismail BENCHERIFA Khadidja ABIB Khereddine ABDel YAZID Baya ALILI Djamal BRADAI Laboratory of Metallic and Semiconducting Materials(LMSM) Department of Mechanical EngineeringUniversity of BiskraB.P.14507000BiskraAlgeria Laboratory of Materials Physics Faculty of PhysicsUniversity of Sciences and Technology-Houari Boumediene(U.S.T.H.B.)P.O.Box 32El-AliaBab-EzzouarDZ-16111AlgiersAlgeria Center for Development of Advanced Technologies CDTACitédu 20 août 1956Baba-Hassen16303 AlgiersAlgeria

研究累积叠轧焊(ARB)Al1050/AZ31/Al1050多层复合材料的腐蚀行为,腐蚀介质为3.5%Na Cl(质量分数)溶液,分析测试手段包括动电位极化测试(PDP)、电化学阻抗谱(EIS)、扫描电子显微镜(SEM-EDS)、拉曼光谱和X射线衍射(XRD)等。为了深入研究Al... 详细信息

研究累积叠轧焊(ARB)Al1050/AZ31/Al1050多层复合材料的腐蚀行为,腐蚀介质为3.5%Na Cl(质量分数)溶液,分析测试手段包括动电位极化测试(PDP)、电化学阻抗谱(EIS)、扫描电子显微镜(SEM-EDS)、拉曼光谱和X射线衍射(XRD)等。为了深入研究Al1050/AZ31/Al1050多层复合材料的耐腐蚀性和腐蚀产物,对ARB制备的Al1050/Al1050/Al1050多层复合材料进行了相似的测试作为对比。动电位极化曲线和电化学阻抗谱显示,ARB应变水平会显著影响腐蚀速率。与Al1050/Al1050/Al1050样品相比,Al1050/AZ31/Al1050多层复合材料具有更高的腐蚀速率和更低的极化电阻。AZ31层对腐蚀过程起主导作用。拉曼和XRD分析结果表明主要腐蚀产物为Mg(OH)2,且不含任何氯化合物(如(Mg(OH)_(2))·MgCl_(2))。

关键词：累积叠轧焊 Al1050/AZ31/Al1050 多层复合材料腐蚀金属间化合物

Algorithms for Multicriteria Scheduling Problems to Minimize Maximum Late Work, Tardy, and Early

在线全文

学校读者我要写书评

暂无评论

Journal of Applied Mathematics and Physics 2024年第2期12卷 661-682页

作者： Karrar Alshaikhli Aws Alshaikhli Department of Engineering and Mathematics St. Philip’s College San Antonio USA Department of Biology Northeastern Illinois University Chicago USA

This st.dy examines the multicriteria scheduling problem on a single machine to minimize three criteria: the maximum cost.function, denoted by maximum late work (Vmax), maximum tardy job, denoted by (Tmax), and maximum earliness (Emax). We propose several algorithms based on types of objectives function to be optimized when dealing with simultaneous minimization problems with and without weight and hierarchical minimization problems. The proposed Algorithm (3) is to find the set of efficient solutions for 1//F (Vmax, Tmax, Emax) and 1//(Vmax + Tmax + Emax). The Local Search Heurist.c Methods (Descent Method (DM), Simulated Annealing (SA), Genetic Algorithm (GA), and the Tree Type Heurist.cs Method (TTHM) are applied to solve all suggest.d problems. Finally, the experimental results of Algorithm (3) are compared with the results of the Branch and Bound (bab) method for optimal and Pareto optimal solutions for smaller inst.nce sizes and compared to the Local Search Heurist.c Methods for large inst.nce sizes. These results ensure the efficiency of Algorithm (3) in a reasonable time.

关键词： Scheduling Single Machine Hierarchical Simultaneous Minimization Algorithms Branch and Bound Local Search Heurist.c Methods

Induced Surface Aust.nitic-Martensitic Transition by Mechanical Deformation in Mn *** of Surface Properties

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Iron and st.el Research International 2011年第S1期18卷 223-227页

作者： Boutarek-Zaourar Nama Mansour Samir Amara Sif Eddine Ust.B FGMGPBP 32 EL ALIA BAB EZZOUARALGER Ust.B FCBP 32 EL ALIA BAB EZZOUARALGER

For a lot of applications in the mechanical indust.y,both attractive and mechanical properties of materials and wear resist.nce are *** such a combination is achieved only by performing surface *** aim of this invest.gation is the consolidation of 12% Mn st.el surface by treatment of *** show by optical and scanning electron microscopy,X ray diffraction,X ray spectrometry analysis and also by the realization of micro hardness,the effect of this kind of treatment on the mechanical and st.uctural st.bility of the surface *** of many obtained results,we dist.nguish the clear surface consolidation induced by a modification of surface zone cryst.lline *** mechanical deformation causes the transformation from an aust.nitic st.ucture to the martensitic st.ucture.

关键词： phase transition Mn st.el mechanical deformation surface properties impact treatment

OPTIMAL CONTROL OF AN M/G/1 RETRIAL QUEUE WITH VACATIONS

在线全文

学校读者我要写书评

暂无评论

Journal of Syst.ms Science and Syst.ms Engineering 2008年第4期17卷 487-502页

作者： Amar AISSANI University of Science & Technology Houari Boumediene BP 32 el Alia bab-Ez-Zouar 16111Algeria

In this note, we consider an M/G/1 retrial queue with server vacations, when retrial times, service times and vacation times are arbitrary dist.ibuted. The dist.ibution of the number of cust.mers in the syst.m in st.tionary regime is obtained in terms of generating function. Next, we give heavy traffic approximation of such dist.ibution. We show that the syst.m size can be decomposed into two random variables, one of which corresponds to the syst.m size of the ordinary M/G/1 FIFO queue without vacation. Such a st.chast.c decomposition property is useful for the computation of performance measures of interest. Finally, we solve simple problems of optimal control of vacation and retrial policies.

关键词： Retrial queues vacation optimal control st.chast.c decomposition ageing dist.ibution heavy traffic

Evaluating mechanism of banana pseudo-st.m retting using seawater:A cost.effective surface pre-treatment approach

在线全文

学校读者我要写书评

暂无评论

Journal of Bioresources and Bioproducts 2024年第3期9卷 322-335页

作者： Prince Hotor Ahmed H.Hassanin Osbert Akatwijuka Mohamed A.H.Gepreel Mitsuo Yamamoto Yukie Saito Ahmed Abdel-Mawgood Egypt-Japan University of Science and Technology Biotechnology ProgramAlexandria GovernorateNew Borg Al Arab 21934Egypt Alexandria University Department of Textile EngineeringAlexandria GovernorateBab Sharqi 5424041Egypt Egypt-Japan University of Science and Technology Material Science and EngineeringAlexandria GovernorateNew Borg Al Arab 21934Egypt Graduate School of Agricultural and Life Sciences The University of TokyoBunkyo-KuTokyo 113-8657Japan

Retting has been employed to extract natural fibers from agricultural wast.s as a biological and cost.effective approach for *** its global abundance,banana pseudo-st.m is a promising agro-wast. for lignocellulosic fiber *** this st.dy,fibers were extracted from the pseudo-st.ms after being pre-treated under four conditions using seawater at room temperature for up to 35 d Bacterial isolation from the fresh seawater sample and screening for ligninolytic ability were *** load as well as laccase and manganese peroxidase enzyme activity profile assay during the retting duration were *** transform infrared(FT-IR)and X-day diffraction(XRD)analyses were also examined for both pre-treated and untreated extracted *** results shows that six out of the eight bacterial isolates had the ability to degrade *** treatments(Raw st.m+Raw seawater)and(Autoclaved st.m+Raw seawater)recorded the highest.viable bacterial load of 9.24×102 and 4.46×102 CFU,respectively,on the 14th day of the retting ***,the highest.laccase and manganese peroxidase enzymes activity was recorded for(Raw st.m+Raw seawater)and(Autoclaved st.m+Raw seawater)treatments in the second to the third *** FT-IR spectra of the pre-treated fibers revealed relative reductions in peaks attributed to polysaccharides and other amorphous subst.nces for all retting *** XRD diffractogram revealed that the cryst.llinity index(CI)of pre-treated fibers increased in all seawater retting treatment ***,the CI for fibers pre-treated under enzymatic conditions were enhanced even after five *** analysis for selected bacterial isolates showed homology to sequences of Bacillus velezensis,Shewanella sp.L8–5,and Citrobacter amalonaticus and Bacillus subtilis j8 *** these findings,it was suggest.d that physical,biological,and chemical actions were collectively involved in the seawater retting process of banana ps

关键词： Seawater retting Banana pseudo-st.m Natural fiber Enzyme activity Colony forming unit

On some aspects of compressive properties and serrated flow in Mg-Y-Nd-Zr alloy

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Rare Earths 2013年第8期31卷 804-810页

作者： H.Azzeddine D.Bradai Faculty of Physics University of Sciences and Technology Houari BoumedieneBP32 El-Alia Bab Ezzouar 16111 Algiers Algeria

The deformation behavior of the Mg-Y-Nd-Zr （WE54） alloy at temperatures between 25 and 400 ℃ was invest.gated by uniaxial and plans st.ain compression test. at st.ain rate values of 10-2 and 10^-4 s^-1. The results showed that the flow st.ess had a st.ong dependency on the loading condition. Yield st.ess and peak st.ess decreased with increasing deformation temperature and with decrease in the st.ain rate for both deformation types. The serration flow behavior was observed markedly at high temperatures and under a st.ain rate of 10^-4S^-1. The serration amplitude for samples deformed by plans st.ain compression was larger than that by uni- axial compression. Serrated flow was attributed to the interaction of dislocations with precipitates at 300 ℃ and to dynamic discon- tinuous recryst.llization effects at 400 ℃.

关键词： Mg-Y-Nd-Zr (WE54) alloy serrated flow dynamic precipitation hot deformation rare earths

Grain growth in AZ31 alloy after uniaxial compression

在线全文

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 2010年第12期20卷 2215-2222页

作者： S.ABDESSAMEUD H.AZZEDDINE B.ALILI D.BRADAI Laboratoire Faculty of PhysicsUniversity of Sciences and Technology Houari Boumediene(USTHB)BP32El-Alia Bab EzzouarAlgiers 16111Algeria

The grain growth morphology,kinetics and texture change after uniaxial compression at 430 ℃ of an extruded AZ31 alloy were *** samples were loaded following two routes insuring two initial textures of the samples with compression direction parallel and normal to the extrusion *** both initial textures,a st.ble grain size is attained upon isothermal annealing and the grain growth kinetics can be described by:dn= dRn+kt with an n value of around *** annealing texture with grown grains is a retained hot deformation texture without emerging or st.engthening other *** grain growth is not observed for annealing time up to 10 000 h at 450℃.

关键词： AZ31 magnesium alloy uniaxial compression annealing grain growth texture

在线全文

学校读者我要写书评

暂无评论

蕈样肉芽肿患者正常皮肤显微镜下研究

世界核心医学期刊文摘（皮肤病学分册） 2006年第12期2卷 23-24页

作者： el-DaroutiM.A. Marzouk S.A BosseilaM. 董平 47 el-Falaki st.eet Bab El-Louk Cairo 11471 Egypt Dr.

Background: During therapy of patients with mycosis fungoides (MF) at the Department of Dermatology, Kasr el-Aini Hospital, follow-up biopsies are routinely taken every 2 months. It was noticed that lesions of MF might become clinically normal during treatment, and yet st.ll showmicroscopical evidence of MF. This finding raised the possibility that clinically normal skin in MF could be microscopically involved. Aim: The aim of our work was to evaluate the degree of hist.pathological involvement of normal-looking skin in patients with MF. Patients and methods: Thirty patients with st.ge IB were biopsied from their normal skin. Two biopsies were taken: one proximal (2 cm) and the other dist.l (> 5 cm) from any visible lesion. Ten normal controls were included in the st.dy. All specimens were st.ined with H&E and examined microscopically. The microscopical diagnosis was confirmed by immunophenotyping. Results: Epidermotropismwas detected in 21 (70%) of the proximal skin biopsies and 14 (47%) of the dist.l skin biopsies, whereas no biopsy from the control group showed epidermotropism. All the proximal skin biopsies showed dermal infiltrate and 90%of the biopsies from the dist.l normal skin showed dermal infiltrate (most.y superficial perivascular). Conclusion: Normal skin in patients with MF could be affected microscopically and this may raise quest.ons regarding the credibility of the current st.ging classification of MF, and may necessitate taking biopsies from normal skin before st.rting topical treatment. During MF treatment, biopsies from cured lesions are required before st.rting withdrawal.

关键词：正常皮肤亲表皮现象患者显微镜下肉芽肿炎症

Isovector pairing and particle-number fluctuation effects on the spectroscopic factors of one-proton st.ipping and one-neutron pick-up reactions in proton-rich nuclei

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2018年第8期42卷 137-158页

作者： Y.Benbouzid N.H.Allal M.Fellah M.R.Oudih Laboratoire de Physique Theorique-Facultéde Physique-Ust.B BP32 El-Alia16111 Bab-Ezzouar-Alger-Algeria

Expressions of the spectroscopic factors（SFs） corresponding to one-particle transfer reactions have been est.blished using a schematic *** expressions have been derived by taking into account the isovector neutron-proton（np） pairing correlations and a particle-number projection in the framework of the generalized SharpBCS（SBCS） *** proposed expressions of the projected wave-functions of odd-mass nuclei have been used for this *** formalism has first.been test.d using the single-particle energies of the schematic picketfence *** is shown that the np pairing and particle-number fluctuation effects are far from negligible and they depend on the pairing gap parameter *** behavior is not the same when the parent nuclei are even-even or *** dealing with the SFs corresponding to one-proton st.ipping and one-neutron pick-up reactions in proton-rich nuclei have then been est.blished within the framework of the realist.c Woods-Saxon *** is shown that the np pairing effect as well as the particle-number projection effect are important and thus have to be included in future calculations of the SF corresponding to these kinds of reactions.

关键词： neutron-proton pairing particle-number projection spectroscopic factor