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1.
The formation of slip bands is the main mechanism of cyclic deformation in pure Al. Their density, orientation and heights in polycrystalline Al were investigated during cycling. Types, sizes and densities of precipitates are responsible for the mode of cyclic deformation in AlCu4 pure alloy. In technical Al alloys intermetallic phases have detrimental effects on deformation homogeneity and largely govern the fatigue mechanism of the material and especially microcrack initiation.  相似文献   
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过去,作者曾发表了多种光敏引发体系引发烯类单体光聚合的工作,在研究2,2-二甲氧基苯乙酮在氧存在下引发甲基丙烯酸甲酯光聚合时,结合在聚合物链端的引发剂碎片具有光化学活性,在光聚合反应中产生高分子自由基,发生再次聚合,出现高分子量  相似文献   
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Conclusions The pyridinium cyclopentadienylidechromium(molybdenum) tricarbonyl complexes were synthesized and a study was made of their IR, NMR, and mass spectra.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 227–228, January, 1977.The authors express their gratitude to N. I. Vasyukova and G. A. Panosyan for taking the mass and NMR spectra.  相似文献   
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The formation of molecular complexes of zinc 5,15-dipentyl-2,3,7,8,12,13,17,18-octamethylporphin (ZnP) with nitrogen bases (L = 2-methylimidazole (2-Me-Im), imidazole (Im), pyridine (Py), 3,5-dimethylpyrazole (DMP), and dimethylformanmide (DMF)) was studied by spectrophotometric titration and quantum-chemical calculations. The stability constant was found to increase linearly with the basicity of the extra ligand and to be proportional to the shift of the fundamental absorption bands in the UV/Vis spectra. The structure of the compound formed as a result of the intermolecular interaction of the macrocyclic complex with a base was determined. The structures of zinc porphyrin and its extra complexes were optimized by the PM3 quantum chemical technique. The geometric and energetic characteristics of the compounds were obtained. A correlation between the calculated interaction energy of the central metal atom and the nitrogen atom of the extra ligand, on the one hand, and the stability of Zn porphyrin extra complexes, on the other hand, was established. The dependence of the zinc-extra ligand bond strength on the basicity of the additional molecular ligand was established. An effect of steric strain on the coordination properties of the metal porphyrin was noted.  相似文献   
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A new form of MP...H solv + metalloporphyrins is found and studied in the strong acid medium, the conditions of its formation and the qualitative reaction of its determination are established. It is shown that the same form has the H4TPP2+ dication (TPP is the 5,10,15,20-tetraphenyl-21H,23H-porphyrine dianion). The stability in different acid media and in the isolated state, spectral properties and the structure of H+-associates of porphyrins are analyzed in detail by UV-visible and 1H NMR spectroscopy and quantum chemical calculations. It is shown that they have a unique two-band visible electronic spectrum with the bands near 540 nm and 700 nm, which weakly depend on the type of the central atom in the complex and noticeably change when the chromophore is functionally substituted. The proton location the ion-molecular associate and the cases of the formation of H+-associates with higher stoichiometry are revealed.  相似文献   
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The thermal reaction of Ru3(CO)10(-Ph2PCH2PPh2) (1) with enyne PhCH=CHCCPh afforded the trinuclear ruthenium clusters Ru3(CO)6{3-P(Ph)CH2PPh2}{3-C(Ph)=CHCC(Ph)(1,2-C6H4)C(=0)} (2), Ru3(-H)(CO)5{3-P(Ph)CH2PPh2}{3-C(Ph)=CHCC(Ph)(1,2-C6H4)C(—0)} (3), and Ru3(CO)6(-CO){3-P(Ph)CH2PPh2}{3-C(C=CPh2)CH=C(H)Ph} (4) and also two isomers of Ru3(CO)5(-CO)(-Ph2PCH2PPh2){3-C4Ph2(CH=CHPh)2} (5a and 5b). Clusters 2, 3, and 4 were characterized by IR spectroscopy, 1H and 31P NMR spectroscopy, and X-ray diffraction analysis. The reaction of complex 1 with enyne FcCH=CHCCFc gave rise to the Ru3(CO)6{3-P(Ph)CH2PPh2}{3-C(Fc)=CHCC(Fc)(1,2-C6H4)C(=0)} (6) and Ru3(-H)(CO)5{3-P(Ph)CH2PPh2}{3-C(Fc)=CHCC(Fc)(1,2-C6H4)C(—0)} (7) clusters. According to the spectral data, the latter compounds are isostructural to complexes 2 and 3, respectively.  相似文献   
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