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51.
A novel azophenol-quinazoline dyad 1 has been designed, synthesized and demonstrated as an efficient reversible multichannel pH indicator through distinct signalling in aqueous media. Owing to the competence between highly fluorescent quinazoline moiety and a well known fluorescence quencher diazo group, dyad 1 is moderately fluorescent in nature. Under acidic conditions 1 displays diverse fluorogenic changes (blue emission at pH 4.25; green at pH 1.80) while under basic condition (pH 11.80) chromogenic changes were observed. 相似文献
52.
P. Sreejith Shankar Serena Bigotti Paolo Lazzari Ilaria Manca Marco Spiga Monica Sani Matteo Zanda 《Tetrahedron letters》2013
Tubulysins are potent anti-mitotic natural compounds and a scalable and efficient synthetic route for generation of its analogues has been developed and extended to the synthesis of diastereoisomers and N-terminal analogues of tubulysin-U. Structure–activity-relationship studies on these synthetic analogues reaffirmed the significance of native stereochemistry of tubulysins for optimal biological activity and cytotoxicity. However, while modification of Tup stereochemistry has only minor effect on the tubulysins cytotoxicity, Tuv stereochemistry is critically important and modification of either Tuv stereocentre produced a dramatic drop in cytotoxicity. 相似文献
53.
Employing actinic light to alter/stabilise a particular thermodynamic phase via the photo-isomerisation of the constituent molecules is an interesting tool to investigate soft matter from a new dimension. This article focuses on our recent results on several aspects of these non-equilibrium phase transitions, which are isothermal in nature. We specifically discuss (i) the influence of different parameters, such as confinement, applied electric field, pressure etc., on the dynamics associated with both the photochemical transition driving the equilibrium nematic to the non-equilibrium isotropic phase and the thermal back relaxation recovering the nematic phase, (ii) unique light-driven disorder–order transition in a reentrant system, (iii) dynamic self-assembly of the smectic A phase, which is stabilised only in the presence of actinic light, (iv) novel temperature-intensity phase diagrams and an example of primary and secondary photo-ferroelectric effects in an antiferroelectric smectic C system. These results highlight the fact that the actinic light can be used as a new tool to study phase transitions and the associated critical phenomena that could also bring about effects that are not seen in equilibrium situations. 相似文献
54.
A simple, convenient and efficient protocol for the construction of an array of glycospiro-pyrroloisoquinolines using isoquinolinium ylide and a carbohydrate-derived exocyclic olefin in the presence of Cu(OTf)2–Et3N catalytic system is described. Isoquinoline and alkylbromoacetates/2-bromoacetophenones were employed to generate the azomethine ylides in the presence of Et3N in refluxing toluene and subsequent exposure to the olefin led to the desired isoquinoline derivatives. 相似文献
55.
Determination of calcium and iron in silicon and uranium silicide using ion chromatography 总被引:1,自引:0,他引:1
M. K. Das V. V. Raut S. B. Deb S. Jeyakumar M. K. Saxena B. S. Tomar 《Journal of Radioanalytical and Nuclear Chemistry》2014,302(3):1385-1390
Two separate ion chromatography methods were developed for the determination of calcium and iron in silicon and uranium silicide. A cation exchange separation with conductivity detection was developed for Ca. A reversed phase column modified with 50 mM camphor-10-sulphonic acid was used for separating Fe. Iron was detected photometrically. Linear calibrations for Ca (0.1–10 ppm) and Fe (0.5–25 ppm) were performed. Limits of detections for Ca and Fe are 0.03 and 0.2 ppm, respectively. The precision of the methods are better than 2 % for Ca at 0.2 ppm and Fe at 2 ppm. 相似文献
56.
B. Shankar Goud Y. Dharmendar Reddy S.R. Mishra M. Ijaz Khan Kamel Guedri Ahmed M. Galal 《印度化学会志》2022,99(8):100618
For this research, an examination on the magnetohydrodynamic flow of a micropolar fluid across a moving vertical porous plate for the presence of thermal radiation is achieved. It is necessary to translate the partial differential equations regulating the flow, heat, & mass transfer into dimensionless form employing proper non-dimensional variables, which are then cracked numerically by utilizing the Finite difference approach. Graphs are used to represent numerical values of various flow profiles; however, tables are used to represent the simulated values of rate coefficients. The velocity rises when the value of Grashof number, dimensionless viscosity ratio is raised, and the opposite effect is seen when the value of magnetic parameter, micro-gyration factor is raised. The result in skin friction coefficient improves when the values of magnetic parameter, micro-gyration factor, Prandtl number, and radiation are raised higher. 相似文献
57.
Singh Ajit Shankar Shukla S. K. Mishra Preeti Pandey A. K. 《Journal of Thermal Analysis and Calorimetry》2022,147(12):6665-6677
Journal of Thermal Analysis and Calorimetry - Phthalonitrile (PN) resins are high-temperature-resistant thermosetting polymers which find applications in military as well as aerospace owing to... 相似文献
58.
Devendra KC Deb Kumar Shah M. Shaheer Akhtar Mira Park Chong Yeal Kim O-Bong Yang Bishweshwar Pant 《Molecules (Basel, Switzerland)》2021,26(11)
This paper numerically explores the possibility of ultrathin layering and high efficiency of graphene as a back surface field (BSF) based on a CdTe solar cell by Personal computer one-dimensional (PC1D) simulation. CdTe solar cells have been characterized and studied by varying the carrier lifetime, doping concentration, thickness, and bandgap of the graphene layer. With simulation results, the highest short-circuit current (Isc = 2.09 A), power conversion efficiency (η = 15%), and quantum efficiency (QE~85%) were achieved at a carrier lifetime of 1 × 103 μs and a doping concentration of 1 × 1017 cm−3 of graphene as a BSF layer-based CdTe solar cell. The thickness of the graphene BSF layer (1 μm) was proven the ultrathin, optimal, and obtainable for the fabrication of high-performance CdTe solar cells, confirming the suitability of graphene material as a BSF. This simulation confirmed that a CdTe solar cell with the proposed graphene as the BSF layer might be highly efficient with optimized parameters for fabrication. 相似文献
59.
Awalekar Ramchandra Mohire Priyanka Patravale Ajinkya Salunkhe Shilpa Usmani Shams Jamale Dattatray Hangirgekar Shankar Kolekar Govind Anbhule Prashant 《Chemistry of Natural Compounds》2021,57(6):1000-1004
Chemistry of Natural Compounds - (3E,7Z)-Tetradecadienyl acetate, the major sex pheromone component of the potato pest Symmetrischema tangolias (Gyen), was stereoselectively synthesized from the... 相似文献
60.
Reu P. L. Blaysat B. Andó E. Bhattacharya K. Couture C. Couty V. Deb D. Fayad S. S. Iadicola M. A. Jaminion S. Klein M. Landauer A. K. Lava P. Liu M. Luan L. K. Olufsen S. N. Réthoré J Roubin E. Seidl D. T. Siebert T. Stamati O. Toussaint E. Turner D. Vemulapati C. S. R. Weikert T. Witz J. F. Witzel O. Yang J. 《Experimental Mechanics》2022,62(4):639-654
Experimental Mechanics - The DIC Challenge 2.0 follows on from the work accomplished in the first Digital Image Correlation (DIC) Challenge Reu et al. (Experimental Mechanics 58(7):1067, 1). The... 相似文献