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991.
Ghosh Kamal Kumar Ray Dipankar Chanda Pranab 《International Journal of Theoretical Physics》1989,28(1):111-117
We present the complete set of solutions of the coupled differential equations of the form ()2=(), 2
=(). Equations of this form appear in several physical situations. 相似文献
992.
Infrared and Raman spectroscopy were used to characterise synthetic mixed carbonate and vanadate hydrotalcites of formula Mg6Al2(OH)16(CO3)2−, (VO4)3−·4H2 O. The spectra were used to assess the molecular assembly of the cations and anions in the hydrotalcite structure. The spectra may be conveniently subdivided into spectral features based on (1) the carbonate anion (2) the hydroxyl units and (3) water units. Bands were assigned to the hydroxyl stretching vibrations of water. Three types of carbonate anions were identified: (1) carbonate hydrogen‐bonded to water in the interlayer, (2) carbonate hydrogen‐bonded to the hydrotalcite hydroxyl surface and (3) free carbonate anions. It is proposed that the water is highly structured in the hydrotalcite, as it is hydrogen‐bonded to both the carbonate and the hydroxyl surface. The spectra were used to assess the contamination of carbonate in an open reacting vessel in the synthesis of vanadate hydrotalcites of formula Mg6Al2(OH)16(CO3)2−, (VO4)3−·4H2 O. Bands have been assigned to vanadate anions in the infrared and Raman spectra associated with V O bonds. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
993.
In this paper, we address the question whether in a given Banach space, a Chebyshev center of a nonempty bounded subset can be a farthest point of the set. We obtain a characterization of two-dimensional real strictly convex spaces as those ones where a Chebyshev center cannot contribute to the set of farthest points of a subset. In dimension greater than two, every non-Hilbert smooth space contains a subset whose Chebyshev center is a farthest point. We explore the scenario in uniformly convex Banach spaces and further study the roles played by centerability and Mcompactness in the scheme of things to obtain a step by step characterization of strictly convex Banach spaces. 相似文献
994.
K. J. Patel G. G. Bhatt J. R. Ray Priya Suryavanshi C. J. Panchal 《Journal of Solid State Electrochemistry》2017,21(2):337-347
Electrochromic devices (ECDs) are currently attracting much interest in academic and industry for both research and their commercial applications because of their controllable transmission, absorption, and/or reflectance. This paper reviews the progress that has taken place from 1969 until the year 2015 with regard to all-solid-state inorganic ECD fabrication. The main aim of this review article is to provide an easy entrance to literature of all-inorganic solid-state ECD. 相似文献
995.
S. S. Riaz S. Banarjee S. Kar D. S. Ray 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,53(4):509-515
We consider a reaction-diffusion system in crossed electric and magnetic fields lying on the reaction plane. It is shown that
a
charge separation along the direction normal to the reaction plane
resulting in a diffusional flux may cause a differential flow
induced chemical instability and stationary pattern formation on a
homogeneous steady state. This pattern is generically different from
a Turing pattern modified by the crossed fields. The special role of
magnetic field is emphasized. Our theoretical analysis is
corroborated by numerical simulation on a reaction-diffusion system
in three dimensions. 相似文献
996.
Keller Fcred A. Bates Delicia Ruiz Ray Nguyen Quang 《Applied biochemistry and biotechnology》1998,(1):137-148
Several strains and genera of yeast, includingSaccharomyces cerevisiae D5A,Pachysolen tannophilus, S. cerevisiae K-l,Brettanomyces custersii, Candida shehatae, andCandida acidothermophilum, are screened for growth on dilute acid-pretreated softwood prehydrolysate. Selected softwood species found in forest underbrush
of the western United States, which contain predominantly hexosan hemicellulose, were studied. This phase of the work emphasized
debarked Douglas fir. The two best initial isolates were gradually selected for improved growth by adaptation to increasing
prehydrolysate concentrations in batch culture, with due consideration of nutrient requirements. Microaerophilic conditions
were evaluated to encourage tolerance of pretreatment hydrolysate, as well as ethanol product. Adaptation and simultaneous
saccharification and fermentation (SSF) results are used to illustrate improved performance with an adapted strain, compared
to the wild type. 相似文献
997.
Seema Yadav Ajeet Singh Isha Mishra Sriparna Ray Shaikh M. Mobin Chandrakanta Dash 《应用有机金属化学》2019,33(7)
Well‐defined and air‐stable PEPPSI (Pyridine Enhanced Precatalyst Preparation Stabilization and Initiation) themed palladium bis‐N‐heterocyclic carbene complexes have been developed for the domino Sonogashira coupling/cyclization reaction of 2‐iodophenol with a variety of terminal alkynes and C‐H bond arylation of benzothiazole with aryl iodides. The PEPPSI themed palladium complexes, 2a and 2b were synthesized in good yields from the reaction of corresponding imidazolium salts with PdCl2 and K2CO3 in pyridine. The new air‐stable palladium‐NHC complexes were characterized by NMR spectroscopy, X‐ray crystallography, elemental analysis, and mass spectroscopy studies. The PEPPSI themed palladium(II) bis‐N‐heterocyclic carbene complexes 2a and 2b exhibited excellent catalytic activities for domino Sonogashira coupling/cyclization reaction of 2‐iodophenol with terminal alkynes yielding benzofuran derivatives. In addition, the palladium complexes, 2a and 2b successfully catalyzed the direct C‐H bond arylation of benzothiazole with aryl iodides as coupling partners in presence of CuI as co‐catalyst. 相似文献
998.
Teng Bao Jie Jin Mekdimu Mezemir Damtie Ke Wu Zhi Ming Yu Lie Wang Jun Chen Yong Zhang Ray L. Frost 《Journal of Saudi Chemical Society》2019,23(7):864-878
A zero-valent iron/rectorite nanocomposite (NZVI/rectorite) was developed as a heterogeneous H2O2 catalyst for P-chlorophenol degradation. The physicochemical properties of NZVI/rectorite were characterized by various techniques including X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy-dispersive spectrometry, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and Brunauer–Emmett–Teller analysis. Results showed that NZVI sphere nanoparticles were successfully loaded on the rectorite surface with less aggregation and good dispersion. Moreover, compared with acid-leached rectorite (30.91 m2/g), the NZVI/rectorite appeared to have larger surface area (50.75 m2/g). In addition, the effects of pH, reaction time, initial P-chlorophenol concentration, catalyst amount, and H2O2 dosage on the P-chlorophenol degradation were systematically investigated. Results showed that NZVI/rectorite presents better properties for the degradation and mineralization of P-chlorophenol compared with pristine NZVI due to the large surface area, low aggregation, and good dispersion of the former. The degradation mechanisms of P-chlorophenol by NZVI/rectorite were adsorption and reduction coupled with a Fenton-like reaction. Four successive runs of the stability and regeneration study also showed that the NZVI/rectorite were unchanged even after 100% of P-chlorophenol degradation ratio. This study has extended the application of NZVI/rectorite as environment function material for the removal of P-chlorophenol from the environment. 相似文献
999.
Rayón-López Nelly Martínez-Casillas Diana C. Miranda-Hernández Margarita Villafán-Vidales Heidi I. Rodríguez-López J. Luis Menchaca-Campos E. Carmina Cuentas-Gallegos A. Karina 《Journal of Solid State Electrochemistry》2019,23(3):707-716
Journal of Solid State Electrochemistry - High-crystalline tungsten trioxides (WO3) have been synthesized by an environmentally friendly method using concentrated solar energy. The obtained... 相似文献
1000.
On encapsulation inside the supercage of zeolite‐Y planar Cu (II)–Schiff base complexes show the modified structural, optical and functional properties. The electronic effect of the different substituent groups present in the catalyst plays the decisive role towards their reactivity in the homogeneous phase but after the encapsulation in zeolite Y, reactivity is mainly governed by the molecular dimensions of the guest complexes rather than the electronic factor of the substituent groups attached on them. These systems are well characterized with the help of different characterization tools like XRD analysis, SEM ‐ EDX, AAS, FTIR, XPS, DSC, TGA, BET and UV–Visible spectroscopy and the comparative optical and catalytic studies have provided a rational explanation of enhanced reactivity of zeolite encapsulated metal complexes for various oxidation reactions compared to their corresponding solution states. 相似文献