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41.
Rajendran Satheeshkumar 《合成通讯》2017,47(10):990-998
A new class of dibenzo[b,j][1,10]phenanthrolines has been prepared. The synthon acridones were achieved in very good yield by a one-pot reaction of 2-amino-5-chloro or 2′-chloro/flouro-substituted benzophenones with 1,2-cyclohexanedione in the presence of freshly prepared Eaton’s reagent (phosphorus pentoxide–methanesulfonic acid) without solvent, through Friedländer synthesis. Then these intermediates were reacted with 2-amino-3,5-dibromobenzaldehyde to afford 1,3-dibromo-10-chloro-8-aryl-6,7-dihydrodibenzo[b,j][1,10]phenanthroline. Also an one-pot reaction between 2?mol of 2-amino-5-chloro aryl benzophenones with 1?mol of 1,2-cyclohexanedione to get 3,10-dichloro-5,8-diaryl-6,7-dihydrodibenzo[b,j][1,10]phenanthroline has also been reported. The newly synthesized structures of the compounds were deduced by spectroscopic techniques. 相似文献
42.
Tin oxide (SnO2) nanoparticles were synthesized by the reaction of SnCl4·5H2O in methanol, ethanol and water via sol–gel method. The samples were characterized by X-ray diffraction (XRD), Fourier transform
infrared, Scanning electron microscopy and Transmission electron microscopy. The optical properties of the as-prepared samples
were investigated. The XRD analysis showed well crystallized tetragonal SnO2 can be obtained and the crystal sizes were 3.9, 4.5 and 5 nm for the sample calcined at 400 °C for 2 h. It was found that
solvents played important roles in the particle size effect of nanocrystalline SnO2. 相似文献
43.
Sippel KH Genis C Govindasamy L Agbandje-McKenna M Kiddle JJ Tripp BC McKenna R 《The journal of physical chemistry letters》2010,1(19):2898-2902
Thioxolone acts as a prodrug in the presence of carbonic anhydrase II (CA II), whereby the molecule is cleaved by thioester hydrolysis to the carbonic anhydrase inhibitor, 4-mercaptobenzene-1,3-diol (TH0). Thioxolone was soaked into the proton transfer mutant H64A of CA II in an effort to capture a reaction intermediate via X-ray crystallography. Structure determination of the 1.2 ? resolution data revealed the TH0 had been modified to a 4,4'-disulfanediyldibenzene-1,3-diol, a product of crystallization conditions, and a zinc ligated 2,4-dihydroxybenzenesulfenic acid, most likely induced by radiation damage. Neither ligand was likely a result of an enzymatic mechanism. 相似文献
44.
Indhumathi Kulandhaisamy Dinesh Babu Rajendran Malathi Kanagasabai Gunasekaran Gurusamy Balaji Moorthy Jithila V. George 《Waves in Random and Complex Media》2017,27(1):38-46
In this paper, an analog multiband phase shifter using slotline configuration is proposed. To implement the design, a pair of modified Split Ring Resonator (SRR) is employed. The periodic property of SRR provides multiband characteristics, whether the coupling slot gives the phase variations over the bands. The operation is well explained with an equivalent circuit model and its characteristics have been studied both in simulation and measurement. The prototype operates in 1.77–2.16, 3.5–3.97, 5.08–5.33, 6.43–6.93, and 8.01–8.59 GHz frequency bands which can be utilized for GSM, GPS, WLAN, C-band, and X-band applications, respectively. 相似文献
45.
We briefly review the recent progress in obtaining (2+1) dimensional integrable generalizations of soliton equations in (1+1)
dimensions. Then, we develop an algorithmic procedure to obtain interesting classes of solutions to these systems. In particular
using a Painlevé singularity structure analysis approach, we investigate their integrability properties and obtain their appropriate
Hirota bilinearized forms. We identify line solitons and from which we introduce the concept of ghost solitons, which are
patently boundary effects characteristic of these (2+1) dimensional integrable systems. Generalizing these solutions, we obtain
exponentially localized solutions, namely the dromions which are driven by the boundaries. We also point out the interesting
possibility that while the physical field itself may not be localized, either the potential or composite fields may get localized.
Finally, the possibility of generating an even wider class of localized solutions is hinted by using curved solitons. 相似文献
46.
Ultrasound assisted phase-transfer catalytic epoxidation of 1,7-octadiene - a kinetic study 总被引:1,自引:0,他引:1
An ultrasound assisted phase-transfer catalyzed epoxidation of 1,7-octadiene is greatly enhanced by using a cocatalyst of phosphotungstic acid in the presence of hydrogen peroxide in an organic solvent/aqueous solution two-phase medium. An active intermediate of the catalyst (Q3PW12(O)nO40, where Q = R4N+) produced from the reaction of phosphotungstic acid, hydrogen peroxide, and Aliquat 336. A rational mechanism of epoxidation is proposed to account for the reaction from the experimental evidence. The organic-phase reactions, including two series reactions, are the rate-controlling steps to produce two products, viz., 1,2-epoxy-7-octene and 1,2,7,8-diepoxyoctane. The kinetics of epoxidation, including the characteristics of the catalyst and the effect of the amount of cocatalyst, agitation speed, quaternary ammonium salts, amount of Aliquat 336, amount of hydrogen peroxide, amount of chloroform, pH value, organic solvents, and temperature on the conversion of 1,7-octadiene were investigated in detail. A kinetic model was built, from which a pseudo-first-order rate law is sufficient to describe the behavior of the reaction. 相似文献
47.
48.
Vinoth Kumar Rajendran Padmavathy Bakthavathsalam Baquir Mohammed Jaffar Ali 《Mikrochimica acta》2014,181(15-16):1815-1821
We are describing immunochromatographic test strips with smart phone-based fluorescence readout. They are intended for use in the detection of the foodborne bacterial pathogens Salmonella spp. and Escherichia coli O157. Silica nanoparticles (SiNPs) were doped with FITC and Ru(bpy), conjugated to the respective antibodies, and then used in a conventional lateral flow immunoassay (LFIA). Fluorescence was recorded by inserting the nitrocellulose strip into a smart phone-based fluorimeter consisting of a light weight (40 g) optical module containing an LED light source, a fluorescence filter set and a lens attached to the integrated camera of the cell phone in order to acquire high-resolution fluorescence images. The images were analysed by exploiting the quick image processing application of the cell phone and enable the detection of pathogens within few minutes. This LFIA is capable of detecting pathogens in concentrations as low as 105 cfu mL?1 directly from test samples without pre-enrichment. The detection is one order of magnitude better compared to gold nanoparticle-based LFIAs under similar condition. The successful combination of fluorescent nanoparticle-based pathogen detection by LFIAs with a smart phone-based detection platform has resulted in a portable device with improved diagnosis features and having potential application in diagnostics and environmental monitoring. Figure
The successful combination of fluorescent nanoparticle-based pathogen detection by lateral flow immunoassay with a smart phone-based detection platform has resulted in a portable device that enables rapid and reliable bacterial detection holding large potential in diagnostics and environmental monitoring 相似文献
49.
The non-steady-state concentration for an EC reaction at planar electrode is derived. The analytical expression for the concentration
for EC reaction is reported for small and large value of reaction rate. The asymptotic expression for the non-steady-state
current for EC reaction is also derived. The analytical solutions for normalized current response were formulated using the
method of Laplace transformation. The concentration and current are compared with available limiting case results, and are
found to be in good agreement. 相似文献
50.
Improved results on robust stability of neutral systems with mixed time-varying delays and nonlinear perturbations 总被引:1,自引:0,他引:1
This paper considers the problem of robust stability of neutral systems with mixed time-varying delays and nonlinear perturbations. Two type uncertainties such as nonlinear time-varying parameter perturbations and norm-bounded uncertainties have been discussed. Based on the new Lyapunov–Krasovskii functional with triple integral terms, some integral inequalities and convex combination technique, a new delay-dependent stability criterion for the system is established in terms of linear matrix inequalities (LMIs). Finally, four numerical examples are given to illustrate the effectiveness and an improvement over some existing results in the literature with the proposed results. 相似文献