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51.
The corrosion and corrosion-abrasion resistance of some stainless steels in industrial phosphoric acid 30% P2O5 has been studied using electrochemical techniques. The corrosion rate of materials increases with the increase of temperature. Alloys which contain chromium, molybdenum and nitrogen in sufficient quantities present the best behaviour.In the abrasion-corrosion conditions, the experimental device set up allowed to follow continually samples electrochemical behaviour. Under dynamic conditions and without solid particles, the increase of acid projection speed has no effect on the alloys corrosion behaviour. The adding of abrasive leads to a general increase of corrosion rate and to a decrease of material resistance. Under these conditions, materials attack is controlled by synergistic effect between the abrasion and the impurities. The cast 30% Cr shows good resistance according to his high chromium content. 相似文献
52.
The infrared spectrum of isotopically pure CH2 79BrCl has been recorded at a resolution of 0.0025?cm?1 and 0.0023?cm?1 (FWHM) in the range 600–1600?cm?1 with a Bruker IFS 120 HR Fourier transform spectrometer in Wuppertal. Here we report the full rotational analysis of the ν3 and ν9 fundamentals of the most abundant species CH2 79Br35Cl . Improved ground state constants, up to quartic terms, have been obtained from ground state combination differences (GSCD) involving transitions of the fundamentals ν3, ν4, ν5 and ν9. Both ν3 and ν9 transitions were fitted to a Watson-type Hamiltonian in the S-reduction, yielding accurate molecular constants for the ν3 and ν9 excited states. Small local perturbations were observed in both bands. Prominent features in the spectra were assigned to the ν3 and ν9 fundamentals of the CH2 79Br37Cl isotopic species and the hot-bands ν3+ν6???ν6 and ν9+ν6???ν6 of CH2 79Br35Cl. 相似文献
53.
Ismail Bensaid Bachir Kerboua Abdelmajid Cheikh Abdelhamid Hadjoui 《Composite Interfaces》2013,20(5):387-401
This paper presents an improved bi-material beam theory with adhesive interface and the new prestressed-fiber reinforced polymer (FRP) – model, which has been applied to the study the problem of interfacial stresses. This work explicitly considers the interfacial slip effect on the structural performance by including both the effect of adherend shear deformations and the fiber volume fraction of the prestressed laminates. This new method needs only one differential equation to determine both shear and normal interfacial stress, which is one aspect that has not been taken into account by the previous studies in the literature. A parametrical study is carried out to show the effects of some design variables, e.g., stiffness and thickness of adhesive layer and FRP plate. 相似文献
54.
Didier Villemin Nawel Cheikh Liang Liao Nathalie Bar Jean-François Lohier Jana Sopkova Noureddine Choukchou-Braham Bachir Mostefa-Kara 《Tetrahedron》2012,68(24):4906-4918
Simple and efficient routes to the natural alkaloid Cerpegin and new analogues are described herein. In a first approach, we extend the scope of a one pot three steps reaction, which permits the synthesis of new analogues of Cerpegin, substituted in different ways. In a second line of approach, we present an unprecedented synthesis of Cerpegin and analogues where methylfuranones are condensed with dimethylformamide diethylacetal (DMFDEA) to yield enaminolactone esters, which react easily with various primary amines affording Cerpegin and new analogues. We applied this second approach to the synthesis of new bis-Cerpegins and N-amino-Cerpegins. Most of the syntheses are performed under environmental friendly conditions. 相似文献
55.
Benstâali W. Larbi Daho Bachir N. Bendella S. Belasri A. Harrache Z. Caillier B. 《Plasma Chemistry and Plasma Processing》2020,40(6):1585-1603
Plasma Chemistry and Plasma Processing - This work presents an electric and kinetic study of homogeneous dielectric barrier discharge (DBD) in pure krypton (Kr). The electrical characterization and... 相似文献
56.
Structural Chemistry - The results described in this work report a DFT/BP86 (using the TZ2P basis) study concerning the molecular and electronic structures of homotrinuclear and heterotrinuclear... 相似文献
57.
Berrichi A. Bachir R. Bedrane S. Choukchou-Braham N. Belkacemi K. 《Research on Chemical Intermediates》2019,45(6):3481-3495
Research on Chemical Intermediates - Propargylamines are key intermediates for the synthesis of many biologically active molecules. A new synthesis of propargylamines via a three component-coupling... 相似文献
58.
Structural Chemistry - DFT/B3LYP calculations with full geometry optimizations have been carried out on 1-phenylazo-2-naphthol and their metal complexes of formula M(MePhNap)2 (M?=?Ni,... 相似文献
59.
Chetioui Souheila Zouchoune Bachir Merazig Hocine Bouaoud Salah-Eddine Rouag DjamilAzeddine Djukic Jean-Pierre 《Transition Metal Chemistry》2021,46(2):91-101
Transition Metal Chemistry - The ortho-substituted (E)-1-((2-methoxyphenyl)diazenyl)naphthalen-2-ol and the meta-substituted (E)-1-((3-methoxyphenyl)diazenyl)naphthalen-2-ol were, respectively,... 相似文献
60.
Zouaoui Setifi Bachir Gaamoune Helen Stoeckli‐Evans Djamil‐Azzeddine Rouag Fatima Setifi 《Acta Crystallographica. Section C, Structural Chemistry》2010,66(10):m286-m289
The new high‐spin iron(II) complex, [Fe(C12H10N6)2(H2O)2](C8H3N4S)2 or [Fe(abpt)2(H2O)2](tcnsme)2 [where abpt is 4‐amino‐3,5‐di‐2‐pyridyl‐4H‐1,2,4‐triazole and tcnsme is the 1,1,3,3‐tetracyano‐2‐methylthiopropenide anion], consists of discrete [Fe(abpt)2(H2O)2]2+ dications, where the FeII ion is coordinated by two N,N′‐bidentate chelating abpt ligands in the equatorial plane and two water molecules in trans positions, generating a distorted octahedral [FeN4O2] environment. The cationic unit is neutralized by two polynitrile tcnsme anions, in which the C—N, C—C and C—S bond lengths indicate extensive electronic delocalization. In the crystal structure, the dications and anions are linked through O—H...N and N—H...N hydrogen bonds involving the water H atoms and those of the NH2 groups and the N atoms of the CN groups, leading to the formation of a three‐dimensional network. 相似文献