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Satish Gaddam Harshavardhan Reddy Kasireddy Karnakar Konkala Ramesh Katla Nageswar Yadavalli Venkata Durga 《中国化学快报》2014,25(5):732-736
A simple and practical method for the synthesis of N-substituted-2-aminobenzothiazoles via a crosscoupling reaction of 2-iodo anilines with isothiocyanates is envisaged using nano copper oxide as a recyclable catalyst and Cs2CO3as a base in PEG-400,as a bio-degradable,reusable,inexpensive and nontoxic reaction medium,under ligand-free conditions.The present tandem process underlines environmental acceptability to access a wide range of N-substituted-2-aminobenzothiazoles in good to excellent yields. 相似文献
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We discuss the notion of spin squeezing considering two mutually exclusive classes of spin-s states, namely, oriented and non-oriented states. Our analysis shows that the oriented states are not squeezed while non-oriented
states exhibit squeezing. We also present a new scheme for construction of spin-s states using 2s spinors oriented along different axes. Taking the case of s=1, we show that the ‘non-oriented’ nature and hence squeezing arise from the intrinsic quantum correlations that exist among
the spinors in the coupled state. 相似文献
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The photoinduced shift in the optical absorption edge and changes in the optical constants and their dispersion in the vicinity of the absorption edge (2–5 eV) have been studied in obliquely deposited thin films of Ge-chalcogenides. The variation of photo-optical changes as a function of various deposition conditions and composition throws light on the role of built-in microstructure and the relevant physical parameters necessary for the occurrence of large photoeffects. The photoinduced optical changes in 80°-films are partly (≈33%) reversible. This (reversible) part is equal to the total (completely reversible) optical changes in 0°-films. The irreversible part (≈67%) has been attributed to the observed photoinduced volume changes. The reversible optical changes have been understood in terms of configurational distortion and modifications in the electronic energy band structure, near the band edges induced by band gap irradiation. 相似文献
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The aim of this brief report is to study the behaviour of sheath structure in a multi-component plasma with dust-neutral collisions.
The plasma consists of electrons, ions, micron size negatively charged dust particles and neutrals. The sheath-edge potential
and sheath width are calculated for collisionally dominated sheath. Comparison of collisionless and collisionally dominated
sheath are made. 相似文献
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Analysis of a TE011 mode composite sapphire-rutile dielectric resonator has been carried out to study the temperature variation of resonance
frequency, close to the Cs atomic clock hyperfine frequency of 9.192 GHz. The complementary behavior of dielectric permittivity
with temperature of the composite has been exploited to obtain the desired turning point in the resonant frequency. The frequency
of the composite structure is found to be independent of the shield diameter beyond four times the puck diameter. 相似文献
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J.S. Yadav K. Premalatha S.J. Harshavardhan B.V. Subba Reddy 《Tetrahedron letters》2008,49(48):6765-6767
The synthesis of the styryl lactone Leiocarpin C has been achieved in a highly stereoselective manner using Jacobsen’s kinetic resolution, Sharpless asymmetric epoxidation and Sharpless asymmetric dihydroxylation as key steps. This is the first total synthesis of Leiocarpin C, and thus establishes for the first time the absolute stereochemistry of this natural product. 相似文献
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Santu Shrestha Kamal Prasad Sapkota Insup Lee Md Akherul Islam Anil Pandey Narayan Gyawali Jeasmin Akter Harshavardhan Mohan Taeho Shin Sukmin Jeong Jae Ryang Hahn 《Molecules (Basel, Switzerland)》2022,27(24)
A facile two-step synthesis of ternary hetero-composites of ZnO, CuO, and single-walled carbon nanotubes (SWCNTs) was developed through a recrystallization process followed by annealing. A series of nanocomposites were prepared by varying the weight ratio of copper(II) acetate hydrate and zinc(II) acetate dihydrate and keeping the weight ratio of SWCNTs constant. The results revealed the formation of heterojunctions (ZnO–SWCNT–CuO, ZSC) of three crystal structures adjacent to each other, forming a ternary wurtzite-structured nanoparticles along with defects. Enhanced charge separation (electron-hole pairs), reduced band gap, defect-enhanced specific surface area, and promoted oxidation potential were key factors for the enhanced photocatalytic activity of the ternary nanocomposites. OH• radicals were the main active species during dye degradation, and O2−• and h+ were also involved to a lesser extent. A type II heterojunction mechanism approach is proposed based on the charge carrier migration pattern. Among the synthesized nanocomposites, the sample prepared using copper(II) acetate hydrate and zinc(II) acetate dihydrate in a 1: 9 ratio (designated a ZSC3) showed the highest photocatalytic activity. ZSC3 achieved 99.2% photodecomposition of methylene blue in 20 min, 94.1% photodecomposition of Congo red in 60 min, and 99.6% photodecomposition of Rhodamine B in 40 min under simulated sunlight. Additionally, ZSC3 showed excellent reusability and stability, maintaining 96.7% of its activity even after five successive uses. Based on overall results, the ZSC sample was proposed as an excellent candidate for water purification applications. 相似文献
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J.S. Yadav B.V.S. Reddy Gakul Baishya S.J. Harshavardhan Ch. Janardhana Chary Manoj Kumar Gupta 《Tetrahedron letters》2005,46(20):3569-3572
Alkenes undergo smooth bromo- and iodohydroxylation with N-bromo- and N-iodosuccinimides/water, respectively, using the air and moisture stable ionic liquid [bmim]BF4 as a novel recyclable reaction medium in high to quantitative yields. N-Halosuccinimides show enhanced reactivity in ionic liquids thereby reducing the reaction times and improving the yields considerably. 相似文献