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91.
The paper presents the nature of variations of clouds and total ozone over Kolkata (22°34′N, 88°24′E), India. The low-level
cloud over Kolkata has been noticed to occur for many days and nights, particularly in the months from June to September.
The low level cloud occurrences were minimum in winter months. The effect of cloud occurrence on ozone concentration has been
critically analyzed and explained. It has been observed that the concentration of ozone increased with the increase of cloud
occurrence. The related possible chemical explanation for ozone production processes has been offered. 相似文献
92.
We prove the Cartan and Choquet properties for the fine topology on a complete metric space equipped with a doubling measure supporting a p-Poincaré inequality, 1 < p < ∞. We apply these key tools to establish a fine version of the Kellogg property, characterize finely continuous functions by means of quasicontinuous functions, and show that capacitary measures associated with Cheeger supersolutions are supported by the fine boundary of the set. 相似文献
93.
Sukhendu Jana Sayan Das Debasish De Utpal Gangopadhyay Prajit Ghosh Anup Mondal 《Applied Physics A: Materials Science & Processing》2014,114(3):965-972
The annealing effect on structural and optical properties of the Diamond-like Nanocomposite (DLN) thin film deposited on glass substrate by Plasma Assisted Chemical Vapor Deposition (PACVD) method has been investigated. The films were annealed at temperature ranging from 300 to 600 °C, with 100 °C interval for 9 minutes by rapid thermal process (RTP) under vacuum. The structural changes of the annealed films have been studied using Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, Scanning Electron Microscope (SEM), and optical parameters have been determined using transmittance and reflectance spectra in UV-UIS-NIR range. The result shows that the refractive index increases gradually from 1.79 to 2.84 with annealing temperature due to out-diffusion of H by breaking Si–H and C–H bond leads to Si–C bond, i.e. more cross linking structure. In higher temperature range, graphitization also enhanced the refractive index. However, the optical band gap at up to 400 °C initially increases from 3.05 to 3.20 eV and then decreases due to graphitization. The film has a great potential to be used as anti-reflection coating (ARC) on silicon-based solar cell. 相似文献
94.
95.
Kalyanmoy Jana Somnath Das Tithi Maity Maidul Hossain Subhas Chandra Debnath 《Journal of Coordination Chemistry》2018,71(10):1497-1509
A new Co(II) complex of general formula [Co(L)2] has been synthesized from a NNO tridentate Schiff base ligand, 2-[(piperidin-2-ylmethylimino)-methyl]-phenol (L). The title complex is characterized by elemental, spectroscopic, antibacterial, and single crystal X-ray structural studies. X-Ray crystallography reveals that the complex shows a distorted octahedral geometry around the Co(II) ion. The complex was tested against several bacteria and shows good antibacterial activities against almost all of the bacteria. The interactions of the title complex with calf thymus deoxyribonucleic acid (CT-DNA) have been investigated by electronic absorption and fluorescence spectroscopy, showing that the complex interacts with CT-DNA via partial intercalation. Thermogravimetric analysis (TGA) of the complex has also been reported and the result shows that the complex is thermally stable up to 134 °C. 相似文献
96.
97.
Zbyněk Brůža Dr. Jiří Kratochvíl Prof. Jeremy N. Harvey Dr. Lubomír Rulíšek Dr. Lucie Nováková Jana Maříková Dr. Jiří Kuneš Prof. Pavel Kočovský Prof. Milan Pour 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(34):8053-8060
Pyran-2-ones 3 undergo a novel Pd0-catalyzed 1,3-rearrangement to afford isomers 6 . The reaction proceeds via an η2-Pd complex, the pyramidalization of which (confirmed by quantum chemistry calculations) offers a favorable antiperiplanar alignment of the Pd−C and allylic C−O bonds ( C ), thus allowing the formation of an η3-Pd intermediate. Subsequent rotation and rate-limiting recombination with the carboxylate arm then gives isomeric pyran-2-ones 6 . The calculated free energies reproduce the observed kinetics semi-quantitatively. 相似文献
98.
Dr. Sara Realista Janaína C. Almeida Sofia A. Milheiro Dr. Nuno A. G. Bandeira Dr. Luis G. Alves Dr. Filipe Madeira Prof. Dr. Maria José Calhorda Dr. Paulo N. Martinho 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(50):11670-11679
Three CoII octaazacryptates, with different substituents on the aromatic rings (Br, NO2, CCH), were synthesised and characterised. These and the already published non-substituted cryptate catalysed CO2 photoreduction to CO and CH4 under blue visible light at room temperature. Although CO was observed after short irradiation times and a large range of catalyst concentrations, CH4 was only observed after longer irradiation periods, such as 30 h, but with a small catalyst concentration (25 nm ). Experiments with 13C labelled CO2 showed that CO is formed and reacts further when the reaction time is long. The CCH catalyst is deactivated faster than the others and the more efficient catalyst for CH4 production is the one with Br. This reactivity trend was explained by an energy decomposition analysis based on DFT calculations. 相似文献
99.
Massimo Brochetta Tania Borsari Sukdev Bag Dr. Sadhan Jana Siddhartha Maiti Prof. Dr. Alessio Porta Prof. Dr. Daniel B. Werz Prof. Dr. Giuseppe Zanoni Prof. Dr. Debabrata Maiti 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(44):10323-10327
The development of efficient and mild methods for the synthesis of organofluorine compounds is of foremost interest in various fields of chemistry. A direct pyrimidine-based selective meta-C−H perfluoroalkenylation of arenes involving several commercially available perfluoroolefins is described. The synthetic versatility of the protocol is demonstrated by an extensive substrate scope including different benzylsulfonyl, alkylarene and phenylacetic acid scaffolds. The generality of this methodology including the meta-C−H perfluoroalkenylation of Ibuprofen, the facile cleavage of the directing group and gram-scale reactions are presented. 相似文献
100.
Lea Kremer Elisabeth Hennes Alexandra Brause Andrei Ursu Lucas Robke Hideaki T. Matsubayashi Yuta Nihongaki Jana Flegel Ivana Mejdrov Jan Eickhoff Matthias Baumann Radim Nencka Petra Janning Susanne Kordes Hans R. Schler Jared Sterneckert Takanari Inoue Slava Ziegler Herbert Waldmann 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(46):16770-16781