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81.
Haghighi Arman Maleki Akbar El Haj Assad Mamdouh Chen Lingen Alhuyi Nazari Mohammad Safdari Shadloo Mostafa 《Journal of Thermal Analysis and Calorimetry》2022,147(10):5533-5547
Journal of Thermal Analysis and Calorimetry - Heat pipes are broadly applied for thermal management of devices with high heat flux. Due to the dependency of their efficient operating range on the... 相似文献
82.
Avat Arman Taherpour Elahe Rajaeian Hadi Shafiei Maryam Malekdar 《Structural chemistry》2013,24(2):523-534
The energy contents in alkynes may be increased further by bending the normally linear triple bond, as in the small cycloalkynes. The strain energy in the cycloalkynes increases as the size of the ring decreases. Cycloadditions of 1,3-dipoles with alkynes occur by concerted mechanisms. In this study, the reactivity and strain energy effect of the cycloalkynes with substituted 1,2,3-triazoles R–N3 (R = H, CH3, and Ph) by the use of B3LYP/6-31G** level method will be discussed. The investigation of the structured properties, theoretical thermodynamic and kinetic data, i.e., ΔrG, ΔG* and rate constants of the reactions in 298 K will be presented. 相似文献
83.
B R Linton M S Goodman E Fan S A van Arman A D Hamilton 《The Journal of organic chemistry》2001,66(22):7313-7319
Recognition of dicarboxylates by bis-functional hydrogen-bonding receptors displays divergent thermodynamics in different solvent systems. NMR titration and isothermal titration calorimetry indicated that neutral bis-urea and bis-thiourea receptors form exothermic complexes with dicarboxylates in DMSO, with a near zero entropic contribution to binding. The increased binding strength of bis-guanidinium receptors precluded quantitative measurement of binding constants in DMSO, but titration calorimetry offered a qualitative picture of the association. Formation of these 1:1 complexes was also exothermic, but additional endothermic events occurred at both lower and higher host-guest ratios. These events indicated multiple binding equilibria but did not always occur at a discrete 2:1 or 1:2 host-guest molar ratio, suggesting higher aggregates. With increasing amounts of methanol as solvent, bis-guanidinium receptors form more endothermic complexes with dicarboxylates, with a favorable entropy of association. This switch from association driven by enthalpy to one driven by entropy may reflect a change from complexation involving the formation of hydrogen bonds to that promoted by solvent liberation from binding sites. 相似文献
84.
Avat Arman Taherpour Mahnaz Mahmoodi Fard Chegeni Mohammad Mehdi Khodaei Negin Tamasoki 《Journal of the Iranian Chemical Society》2017,14(8):1613-1632
Metiamide is a class of medications called H2-receptor antagonist or H2 blockers. It decreases the amount of acid made in the stomach. It is commonly used in the treatment for peptic ulcer disease and gastroesophageal reflux disease. In this study, the metiamide tautomer stability, structural data, HOMO and LUMO (energies and shapes), ΔΕ HOMO–LUMO gaps, UV–visible data and graphs, dipole moments, Mulliken charges, and thermodynamic and kinetic stabilities in aqueous media as a biological solvent and some of the different media (vacuum, H2O, Et-OH and DMSO) were investigated for the tautomers of metiamide by the density functional theory DFT-B3LYP/6-31G* method. The results presented that the probability of the adaptability and compatibility of which tautomer (T1–T6) are better than the other tautomers for interactions with the pattern and structural map of the H2-receptor. The diversities of the interaction points and mosaic patterns of the T3 and T4 tautomers in H2O media with the imaginary H2-receptor were investigated. 相似文献
85.
Dirhodium(II)‐Catalyzed Annulation of Enoldiazoacetamides with α‐Diazoketones: An Efficient and Highly Selective Approach to Fused and Bridged Ring Systems 下载免费PDF全文
Dr. Qing‐Qing Cheng Julietta Yedoyan Dr. Hadi Arman Prof. Dr. Michael P. Doyle 《Angewandte Chemie (International ed. in English)》2016,55(18):5573-5576
A dirhodium(II)‐catalyzed annulation reaction between two structurally different diazocarbonyl compounds furnishes the donor–acceptor cyclopropane‐fused benzoxa[3.2.1]octane scaffold with excellent chemo‐, regio‐, and diastereoselectivity under exceptionally mild conditions. The composite transformation occurs by [3+2]‐cycloaddition between donor–acceptor cyclopropenes generated from enoldiazoacetamides and carbonyl ylides formed from intramolecular carbene–carbonyl cyclization in one pot with one catalyst. The annulation products can be readily transformed into benzoxa[3.3.1]nonane and hexahydronaphthofuran derivatives with exact stereocontrol. This method allows the efficient construction of three fused and bridged ring systems, all of which are important skeletons of numerous biologically active natural products. 相似文献
86.
The forthcoming experiments on neutrino mass measurement using beta decay, open a new window to explore the large extra dimension model. The Kaluza–Klein tower of neutrinos in large extra dimension contributes to the Kurie function of beta decay that can be tested kinematically. In addition to providing an alternative approach using just the kinematical properties, we show that KATRIN can probe the compactification radius of extra dimensions down to 0.2 μm which is better, at least by a factor of two, than the upper limits from neutrino oscillation experiments. 相似文献
87.
88.
Journal of Visualization - The interior of a square cavity containing nanofluid with copper (Cu) nanoparticles (NPs) was simulated by a computational fluid dynamics (CFD) method. The flow rate... 相似文献
89.
This research proposes a new extendable platform for an unmanned ground vehicle to overcome the obstacle climbing issue. The new platform is basically established on scissor mechanism principles which have been innovated to achieve long and rigid displacement. A couple of scissor mechanisms are embedded in the rover platform adjusting the mass center of rover respect to the rear and front wheels. Accordingly, it yields geometric control of the contact forces, which can simultaneously reduce the slip of the wheels and increase the performance of the obstacle climbing up. To demonstrate the performance of the proposed platform, the 3D kinematics is derived. Subsequently, the stick-slip Euler-Lagrange dynamics is derived and a three-level controller including the torque optimization is implemented to simulate the rover facing obstacles. Finally, without any hardware prototyping, the extendable rover is simulated and compared with a typical fixed-geometry rover to show the enhancement of the climbing ability by using the proposed concept. Moreover, controlling the normal contact forces of the wheels yields the slip reduction, which subsequently, increases the traction force. 相似文献
90.