排序方式: 共有9条查询结果,搜索用时 15 毫秒
1
1.
MoO2 microspheres were synthesized by a facile wet chemical method using the molybdenum trioxide as an inorganic precursor and paraphenylendiamine as a reducing agent and also a template, via a hydrothermal way. The as prepared product was characterized by XRD, SEM, TEM, DTA–TG, and IR. It was found that this product was composed by MoO2 nanoparticles encapsulated into the organic shell microspheres with diameters of 1–3 μm. The influence of the temperature on the crystallinity of the products was investigated. Optimal conditions founded were: reaction temperature: 220 °C, reaction time: 72 h and cooling time remains unchanged. The possible formation mechanism of MoO2 microspheres was also discussed. 相似文献
2.
Bernard N Chemla F Ferreira F Mostefai N Normant JF 《Chemistry (Weinheim an der Bergstrasse, Germany)》2002,8(14):3139-3147
The carbometalation reaction of allyl- and crotylzinc bromide with metalated disubstituted homoallylic ethers gives tri- or tetrasubstituted 5-hexenyl ethers with excellent control of the diastereoselectivity. The stereochemistry of this reaction is discussed and has been attributed to an early transition state with chelation to the oxygen atom in the energetically favored conformer as the stereodetermining step. 相似文献
3.
Rosa Nechak Yamina Benmalek Naouel Boufroua Bellara Nedjar Kolli Sophie Poulain Martini 《合成通讯》2019,49(15):1895-1905
The reaction of thiosemicarbazones with various α-chloroketones in the presence of anhydrous NaOAc led to 4-thiazolines 5, 7 or 1,3,4-thiadiazines 11 in good yields. Structure elucidation was carried out by 1H, 13C, and FT-IR spectroscopy. The purity of these new products was confirmed by HRMS. A possible mechanism for the formation of 5, 7, and 11 was discussed. All the synthesized novel 4-thiazoline and 1,3,4-thiadiazine derivatives were evaluated in vitro for their antibacterial and antifungal activities against six pathogenic bacteria and a strain of yeast: Escherichia coli ATCC 25992, Pseudomonas aeruginosa ATCC 27852, Staphylococcus aureus ATCC 25923 methicillin-resistant, Staphylococcus aureus ATCC 43300 methicillin-sensitive, Micrococcus luteus ATCC 4698 Enterococcus faecalis ATCC 29212 and Candida albicans IPA (200). Some compounds exhibited relatively significant antibacterial and antifungal activities. 相似文献
4.
5.
Naouel Ben Ali 《Journal of Mathematical Analysis and Applications》2006,320(1):78-94
In this paper, we prove that the system formed by some of generalized eigenvectors of the operator T0+εT1+ε2T2+? which are analytic on ε, forms a Riesz basis of the separable Hilbert space H, where ε∈C and T0,T1,T2,… some linear transformations on H which have the same domain D⊆H. After that, we give an application for a problem concerning the radiation of a vibrating structure in a light fluid. 相似文献
6.
Adriana Silva Vanessa Silva Gilberto Igrejas Isabel Gaivo Alfredo Aires Naouel Klibi Maria de Lurdes Enes Dapkevicius Patrícia Valento Virgílio Falco Patrícia Poeta 《Molecules (Basel, Switzerland)》2021,26(8)
The emergence of antibiotic-resistance in bacteria has limited the ability to treat bacterial infections, besides increasing their morbidity and mortality at the global scale. The need for alternative solutions to deal with this problem is urgent and has brought about a renewed interest in natural products as sources of potential antimicrobials. The wine industry is responsible for the production of vast amounts of waste and by-products, with associated environmental problems. These residues are rich in bioactive secondary metabolites, especially phenolic compounds. Some phenolics are bacteriostatic/bactericidal against several pathogenic bacteria and may have a synergistic action towards antibiotics, mitigating or reverting bacterial resistance to these drugs. Complex phenolic mixtures, such as those present in winemaking residues (pomace, skins, stalks, leaves, and especially seeds), are even more effective as antimicrobials and could be used in combined therapy, thereby contributing to management of the antibiotic resistance crisis. This review focuses on the potentialities of winemaking by-products, their extracts, and constituents as chemotherapeutic antibacterial agents. 相似文献
7.
A. Iratni R. KatebiM. Mostefai 《Communications in Nonlinear Science & Numerical Simulation》2012,17(4):1739-1752
This paper presents the design of a new robust nonlinear estimator for estimation of states of nonlinear systems. Two approaches are considered based on the state-dependent Riccati equation formulation and the technique of H-infinity control design. The proposed method differs from other well-known state estimators, because not only nonlinear dynamics but also the robustness is taken into account. The proposed method is implemented and tested on a biological wastewater system. The simulation study compares the Extended Kalman Estimator (EKE), the State-Dependent Riccati Estimator (SDRE), and the Extended H-infinity Estimator (EHE) with a new proposed State Dependent H-infinity Estimator (SDHE). The results are compared for different weather conditions, i.e. dry, rain and storm, showing a superior performance of the proposed method. 相似文献
8.
This paper is devoted to the investigation of the essential approximate point spectrum and the essential defect spectrum of a 2 × 2 block operator matrix on a product of Banach spaces. The obtained results are applied to a two‐group transport operators with general boundary conditions in the Banach space Lp ([–a, a ] × [–1, 1]) × Lp ([–a, a ] × [–1, 1]), a > 0, p ≥ 1 (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
9.
1