排序方式: 共有22条查询结果,搜索用时 218 毫秒
1.
Rahma Boussessi Andrea Pietropolli Charmet Paolo Stoppa Vincenzo Barone 《Molecular physics》2020,118(11)
Quantum-chemical calculations assist the analysis of laboratory spectra, and often provide the only means to determine spectroscopic data that cannot be accessed experimentally. Accurate predictions of vibrational and rotational spectroscopic parameters are required for applications in the field of high-resolution molecular spectroscopy. While the accuracy issue of the quantum-chemical calculation of vibrational properties and of equilibrium structures has been addressed in the literature, the same is not true for centrifugal distortion constants that however play an essential role for the interpretation of remote sensing data. In this work, the performance of several model chemistries, rooted mainly in density functional theory, in computing sextic centrifugal distortion constants is assessed employing a benchmark set of molecules of both atmospheric and astrochemical relevance. The Jensen’s (aug-)pcs-n basis sets, different flavours of Dunning’s triple-ζ basis sets and the SNSD basis set, are employed in conjunction with different functionals, and their predictions are benchmarked against experimental and theoretical data at the coupled cluster level of theory. This study also demonstrates the reliability of the calculation of sextic centrifugal distortion constants within the Gaussian16 rev. B.01 program package. Reliable predictions of the sextic centrifugal distortion constants for the gauche- and trans-conformers of ethyl-mercaptan are also presented. 相似文献
2.
Craig M. Anderson Garrett Brown Matthew W. Greenberg David Yu Nellie Bowen Rahma Ahmed Melissa Yost-Bido Alina Wray 《Tetrahedron letters》2019,60(43):151156
Several thiophene-based N^C ligands were synthesized. Strategically, a bromide was incorporated on the 2-position of the thiophene ring. When allowed to react with the platinum tetramethyl dimer, [Pt2Me4(µ-SMe2)2], platinum(IV) platinacycles were formed by oxidative addition of the C(sp2)-X bond. These platinum(IV) compounds were characterized by NMR and HRMS. The platinum (IV) compounds were subsequently subjected to thermolysis. A series of reactions occurred, including selective C-C reduction elimination and selective C-H oxidative addition, giving mixtures of platinum(II) products with varying degrees of regioselectivity. 相似文献
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Over the last years, several variants of multi-constrained Vehicle Routing Problems (VRPs) have been studied, forming a class of problems known as Rich Vehicle Routing Problems (RVRPs). The purpose of the paper is twofold: (i) to provide a comprehensive and relevant taxonomy for the RVRP literature and (ii) to propose an elaborate definition of RVRPs. To this end, selected papers addressing various cases are classified using the proposed taxonomy. Once the articles have been classified, a cluster analysis based on two discriminating criteria is performed and leads to the definition of RVRPs. 相似文献
4.
Ali Ahmed Mohammed Tahir Fadhil Rahma 《The European physical journal. Special topics》2020,229(6-7):943-952
Diabetes mellitus (DM) is probably one of the most popular diseases among people. In this disorder, a malfunction occurs in the insulin-glucose regulatory system. To model the DM pathophysiology, we propose a computational model for the insulin-glucose regulatory system. In this differential equation model, the complex behavior of this biological system has been considered. This model shows chaos and bifurcating properties which have been seen in dynamical diseases. We have analyzed static and dynamical properties of the proposed model to show its strength and capability to represent different types of diabetes and other dysfunction in the insulin-glucose system.
相似文献5.
El Mouhi Rahma El Khattabi Souad Hachi Mohamed Fitri Asmae Benjelloun Adil Touimi Benzakour Mohammed Mcharfi Mohammed Bouachrine Mohammed 《Research on Chemical Intermediates》2019,45(3):1327-1340
Research on Chemical Intermediates - Eight novel organic compounds with donor–π–acceptor (D–π–A) structure were designed for use as donors in organic bulk... 相似文献
6.
Giansante C Raffy G Schäfer C Rahma H Kao MT Olive AG Del Guerzo A 《Journal of the American Chemical Society》2011,133(2):316-325
The self-assembly of a blue-emitting light-harvesting organogelator and specifically designed highly fluorescent tetracenes yields nanofibers with tunable emissive properties. In particular, under near-UV excitation, white light emission is achieved in organogels and dry films of nanofibers. Confocal fluorescence microspectroscopy demonstrates that each individual nanofiber emits white light. A kinetic study shows that an energy transfer (ET) occurs between the blue-emitting anthracene derivative and the green- and red-emitting tetracenes, while inter-tetracene ETs also take place. Moreover, microscopy unravels that the nanofibers emit polarized emission in the blue spectral region, while at wavelengths higher than 500 nm the emission is not significantly polarized. 相似文献
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Abd Mariam Hussein Tahir Fadhil Rahma Al-Suhail Ghaida A. Pham Viet-Thanh 《Nonlinear dynamics》2017,90(4):2583-2598
Nonlinear Dynamics - Recently, the time delay has considerable attention in the existence of chaos in the nonlinear dynamical systems. In this paper, we therefore develop a new cascade-coupled... 相似文献
10.
Ashraf A. Aly Alan B. Brown Mohamed Abdel‐Aziz Gamal El‐Din A. A. Abuo‐Rahma Mohamed F. Radwan Mohamed Ramadan Amira M. Gamal‐Eldeen 《Journal of heterocyclic chemistry》2012,49(4):726-731
Reaction of 3‐aroyl‐1‐arylthioureas with dimethyl but‐2‐ynedioate in dichloromethane and catalyzed by triphenylphosphine at ?5°C led to (Z)‐methyl 2‐[(Z)‐2‐(4‐aroylimino)‐4‐oxo‐3‐aryl‐1,3‐thiazolidin‐5‐ylidene]acetates in good yields. The mechanism is discussed. X‐ray structure analysis of one thiazolidine derivative is described. Antitumor and antioxidant activities have been investigated. One derivative of 1,3‐thiazolidine showed moderate antiproliferative in vitro activity against hepatocellular carcinoma Hep‐G2, whereas another 1,3‐thiazolidine introduced effective antioxidant activity compared to ascorbic acid. 相似文献