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排序方式: 共有1397条查询结果,搜索用时 15 毫秒
1.
International Journal of Theoretical Physics - The number of qubits involved in a quantum system increases as the quantum computation is being progressed. Restrictions in monolithic quantum...  相似文献   
2.
Structural Chemistry - This is an analysis report on the use of density functional theory (DFT) to investigate the potentials of pristine and amino acid–functionalized C4B32 borospherenes in...  相似文献   
3.
In this work, a vanillin complex is immobilized onto MCM-41 and characterized by FT-IR, X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, thermogravimetric analysis, and BET techniques. This supported Schiff base complex was found to be an efficient and recoverable catalyst for the chemoselective oxidation of sulfides into sulfoxides and thiols into their corresponding disulfides (using hydrogen peroxide as a green oxidant) and also a suitable catalyst for the preparation of 2,3-dihydroquinazolin-4(1H)-one derivatives in water at 90°C. Using this protocol, we show that a variety of disulfides, sulfoxides, and 2,3-dihydroquinazolin-4(1H)-one derivatives can be synthesized in green conditions. The catalyst can be recovered and recycled for further reactions without appreciable loss of catalytic performance.  相似文献   
4.
Yashtini  Maryam 《Optimization Letters》2020,14(6):1435-1458
Optimization Letters - SENSitivity Encoding (SENSE) is an effective mathematical formulation for reconstructing under-sampled MRI data obtained in Parallel Magnetic Resonance Imaging (Parallel...  相似文献   
5.
Copper supported on magnetite nanoparticles modified with environmentally friendly ligand tricine was devised for synthesis of acetamides via C–C oxidative cleavage of ketones with amines. The catalyst was characterized using different techniques, including Fourier transform infrared, X-ray diffraction, scannin electron microscopy, vibrating sample magnetometry, thermogravimetric analysis, and energy dispersive x-ray spectroscopy. The protocol showed relatively high yields of acetamide products. Furthermore, the magnetic recovery of the catalyst rendered the overall process fast and efficient. It was used in the reaction for six consecutive cycles with negligible loss of catalytic activity. This research is the first report of application of magnetic nanocatalysts for synthesis of acetamides from ketones of low activity through a C–C bond cleavage strategy.  相似文献   
6.
Research on Chemical Intermediates - A nanostructured composite material was produced through sol–gel-assisted ionic liquid (IL) synthesized TiO2, WO3 and functionalized reduced graphene...  相似文献   
7.
Research on Chemical Intermediates - A novel magnetically heterogeneous nanocatalyst has been successfully synthesized via the immobilization of piperazine on tris (hydroxymethyl)...  相似文献   
8.
A novel approach using Monte Carlo method applied to simulation of low‐density polyethylene (LDPE) polymerization in tubular reactor showing topological characteristics, and the comprehensive kinetic mechanism has been taken into consideration. The results show the precise details of the structure of a chain in the three levels of the backbone, the main branches, and branches on branch. The chain types include dead polymer, dead polymer with unsaturated end, and live polymer with primary radical, secondary radical, and tertiary radical. In this work, the branches on branch were identified in terms of number, length, and position of the branch. Sixty percent of branches on branch are 1 to 5 carbons long, and the longest branch on branch is about 50 carbons. Thus, this study provides a tool for more accurately mapping the polymer chains architecture, superior to determine the number, and position of long‐ and short‐chain branches in past researches. Finally, this approach will advance the prediction of microstructure‐related properties of polymer one step further.  相似文献   
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