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61.
Luciano Telesca Michele Lovallo Abuo El-Ela Amin Mohamed Mohamed ElGabry Sherif El-hady Kamal M. Abou Elenean Rafaat ElShafey Fat ElBary 《Physica A》2012
The interevent-time (IET) and interevent-distance (IED) series of seismic events occurred at Aswan area (Egypt) from 2004 to 2010 were investigated by means of the Fisher Information Measure and the Shannon entropy. The analysis was performed varying the depth and the magnitude thresholds. The results point out to an increase of level of organization and order with the decrease of magnitude threshold and the increase of depth threshold for the IET series, while the IED series are characterized by a level of uncertainty approximately constant with the threshold magnitude. The complexity measure, calculated as the product of the Fisher Information Measure and the Shannon entropy power, presents very similar pattern for both the types of seismic series, indicating an increasing complexity with the decrease of the threshold magnitude and the increase of the threshold depth. 相似文献
62.
63.
Dr. Ritesh Haldar Kamal Batra Stefan Michael Marschner Dr. Agnieszka B. Kuc Dr. Stefan Zahn Prof. Dr. Roland A. Fischer Prof. Dr. Stefan Bräse Prof. Dr. Thomas Heine Prof. Dr. Christof Wöll 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(33):7847-7851
In organic photovoltaics, porphyrins (PPs) are among the most promising compounds owing to their large absorption cross-section, wide spectral range, and stability. Nevertheless, a precise adjustment of absorption band positions to reach a full coverage of the so-called green gap has not been achieved yet. We demonstrate that a tuning of the PP Q- and Soret bands can be carried out by using a computational approach for which substitution patterns are optimized in silico. The most promising candidate structures were then synthesized. The experimental UV/Vis data for the solvated compounds were in excellent agreement with the theoretical predictions. By attaching further functionalities, which allow the use of PP chromophores as linkers for the assembly of metal-organic frameworks (MOFs), we were able to exploit packing effects resulting in pronounced redshifts, which allowed further optimization of the photophysical properties of PP assemblies. Finally, we use a layer-by-layer method to assemble the PP linkers into surface-mounted MOFs (SURMOFs), thus obtaining high optical quality, homogeneous and crystalline multilayer films. Experimental results are in full accord with the calculations, demonstrating the huge potential of computational screening methods in tailoring MOF and SURMOF photophysical properties. 相似文献
64.
Asif Nisar Muhammad Saeed Muhammad Usman Majid Muneer Muhammad Adeel Iltaf Khan Javaid Akhtar 《国际化学动力学杂志》2020,52(10):645-654
Photodegradation of organic pollutants strongly depends on design of metal oxide semiconductor photocatalysts. Graphene, if composited with ZnO, can effectively enhance its photocatalytic performance for the eradication of pollutants from aqueous medium. Here in, ZnO-rGO is reported as highly active catalyst for degradation of methylene blue. A 200-mg/L solution of methylene blue dye was completely degraded within 1 h in comparison to 74% and 56% degradation over ZnO and rGO, respectively. The commonly used mechanisms of heterogeneous catalytic reactions, the Langmuir-Hinshelwood mechanism, and the Eley-Rideal mechanisms, were used to describe the reaction kinetics. The Langmuir-Hinshelwood mechanism was found as more favorable in this study. Apparent activation energy, Eap, true activation energy, ET, entropy, ΔS, and enthalpy, ΔH were calculated as 36.2 kJ/mol, 13.1 kJ/mol, 197.5 J/mol, and 23.1 kJ/mol, respectively. 相似文献
65.
Dr. Saud Asif Ahmed Qiao-Bo Liao Qi Shen Dr. Mirza Muhammad Faran Ashraf Baig Juan Zhou Cai-Feng Shi Dr. Pir Muhammad Dr. Sumaira Hanif Prof. Kai Xi Prof. Xing-Hua Xia Prof. Kang Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(57):12996-13001
Layered/two-dimensional covalent organic frameworks (2D COF) are crystalline porous materials composed of light elements linked by strong covalent bonds. Interlayer force is one of the main factors directing the formation of a stacked layer structure, which plays a vital role in the stability, crystallinity, and porosity of layered COFs. The as-developed new way to modulate the interlayer force of imine-linked 2D TAPB-PDA-COF (TAPB = 1,3,5-tris(4-aminophenyl)benzene, PDA = terephthaldehyde) by only adjusting the pH of the solution. At alkaline and neutral pH, the pore size of the COF decreases from 34 Å due to the turbostratic effect. Under highly acidic conditions (pH 1), TAPB-PDA-COF shows a faster and stronger turbostratic effect, thus causing the 2D structure to exfoliate. This yields bulk quantities of an exfoliated few/single-layer 2D COF, which was well dispersed and displayed a clear Tyndall effect (TE). Furthermore, nanopipette-based electrochemical testing also confirms the slipping of layers with increase towards acidic pH. A model of pH-dependent layer slipping of TAPB-PDA-COF was proposed. This controllable pH-dependent change in the layer structure may open a new door for potential applications in controlled gas adsorption/desorption and drug loading/releasing. 相似文献
66.
Mohamed Ben Ayed Rabeh Ghoudi Kamal Ould Bouh 《NoDEA : Nonlinear Differential Equations and Applications》2012,19(6):629-662
In this paper, we consider the problem of prescribing the scalar curvature under minimal boundary conditions on the four dimensional half sphere. Using dynamical and topological methods involving the study of the critical points at infinity of the associated variational structure, we prove some existence results like Bahri-Coron theorem. Furthermore, we consider the approximate subcritical problem and we construct some solutions which blow up at two different points, one of them lay on the boundary and the other one is an interior point. 相似文献
67.
68.
Lakhera Shradha Rana Meenakshi Devlal Kamal Celik Ismail Yadav Rohitash 《Structural chemistry》2022,33(3):703-719
Structural Chemistry - Tridax procumbens is a flowering plant of the Asteraceae family with a wide range of medicinal uses like anti-inflammatory, anti-diabetic, anti-microbial, immunomodulatory,... 相似文献
69.
70.
J. Klusoň Kamal L. Panigrahi 《The European Physical Journal C - Particles and Fields》2011,71(3):1595
We continue our study of the Lorentz-breaking string theories. These theories are defined as string theory with modified Hamiltonian
constraint which breaks the Lorentz symmetry of target space-time. We analyze the properties of this theory in the target
space-time that possesses isometry along one direction. We also derive the T-duality rules for Lorentz-breaking string theories
and show that they are the same as that of Buscher’s T-duality for the relativistic strings. 相似文献