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81.
Nidhi Vyas Bhawana Pandey Animesh Ojha Abhinav Grover 《International journal of quantum chemistry》2019,119(24):e26025
Conversion of free nitrogen to ammonia is a required chemical reaction for both biologically and industrially but their mechanism, specifically the attachment of electron and proton transfer during the cycle, is still doubtful. In this view, a thorough knowledge of the mechanism is crucial. In this article, we employ a density functional method on [(TPB)FeN2]−, the iron-dinitrogen complex carrying the tris(phosphine)borone (TPB) ligand, for the ammonia production with the inclusion of electrons and protons. The electronic structures, reactivity, and mechanistic possibilities have been extensively explored using the B3LYP functional. Both asymmetric and symmetric pathways in addition to the possible intermediates species and transition states are considered here. Our results conclude tremendously small energy barrier of 3.5 kJ/mol for the first protonation (S = 1/2) for the N─H bond activation by the [(TPB)FeN2]− species. However, high activation barrier for the third protonation was estimated to be 78.5 kJ/mol, which is explained by the high energy of the unoccupied δx2-y2 orbital in 1ts4 species. The computed spectroscopic parameters such as absorption, electron paramagnetic resonance, and Mössbauer also established the electronic structure details of the species. The calculated parameters are compatible with the experimental results. 相似文献
82.
We establish conditions under which K-spaces in the limiting real interpolation involving slowly varying functions can be described by means of J-spaces and we also solve the reverse problem. To this end, we prove several versions of the fundamental lemma of the real interpolation theory. We apply our results to obtain density theorems for the corresponding limiting interpolation spaces. 相似文献
83.
We present the performance limits on three-dimensional (3D) localization accuracy of currently used methods of wide-field superlocalization microscopy. The three methods investigated are double-helix microscopy, astigmatic imaging, and biplane detection. In the shot-noise limit, Cramer-Rao lower bound calculations show that, among these techniques, the double-helix microscope exhibits the best axial and 3D localization accuracy over short as well as long depth-of-field systems. The fundamental advantage of engineered point-spread function systems, like the double-helix, stems from the additional degrees of freedom available to control diffraction in three dimensions over variable regions of interest. 相似文献
84.
Swartzlander GA 《Optics letters》2006,31(13):2042-2044
A vortex lens is a useful optical device having applications ranging from astronomy to microscopy. Current vortex masks operate across a narrow bandwidth. Two design schemes are proposed for creating a vortex across a bandwidth exceeding 100 nm in the visible region of the spectrum. 相似文献
85.
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87.
We propose a novel method that, for the first time to our knowledge, makes it possible to tailor the spectral response of an input grating coupler. This method is based on the idea of computer-generated waveguide holography. Grating couplers with different spectral responses have been designed and fabricated, and experimental results are presented that demonstrate the effectiveness of the proposed method. 相似文献
88.
V. Grover 《Journal of solid state chemistry》2004,177(11):4197-4204
The phase relations in the CeO2-Gd2O3-ZrO2 system have been established after slowly cooling the samples from 1400 °C. Ceria has been used as a surrogate material in place of plutonia. About 80 compositions in Zr1−xGdxO2−x/2, Ce1−xGdxO2−x/2, Ce1−xZrxO2.00, (Zr0.5Ce0.5)1−xGdxO2−x/2, (Ce0.5Gd0.5)1−xZrxO1.75+x/4, (Zr0.5Gd0.5)1−xCexO1.75+x/4, and (Ce0.8Zr0.2)xGd1−xO1.5+x/2 were prepared by a three steps heating protocol. Based on the refinement of the XRD data, several phase regions namely; cubic fluorite type solid solution, C-type solid solution, and various biphasic regions could be delineated. This system showed the existence of a very wide cubic phase field. About 17.5 mol% GdO1.5 was found to fully stabilize the cubic zirconia. On the other hand ceria did not stabilize the cubic zirconia. The anion-excess gadolinia, i.e., Gd1−xCexO1.5+x was found to retain the C-type lattite unlike pure gadolinia. The ternary phase relations were mainly characterized by the presence of wide homogeneity ranges of fluorite type or C-type phases. 相似文献
89.
Junjun Tan Li Zhang Ming-Chien Hsieh Jay T. Goodwin Martha A. Grover David G. Lynn 《Chemical science》2021,12(8):3025
Progressive solute-rich polymer phase transitions provide pathways for achieving ordered supramolecular assemblies. Intrinsically disordered protein domains specifically regulate information in biological networks via conformational ordering. Here we consider a molecular tagging strategy to control ordering transitions in polymeric materials and provide a proof-of-principle minimal peptide phase network captured with a dynamic chemical network.Substrate initiated assembly of a dynamic chemical network. 相似文献
90.
New observations in support of the revised constitution for pinastric acid based on a study of its reactions with o-phenylene diamine, dimethylaniline, and oxidation with sodium periodate. 相似文献