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排序方式: 共有340条查询结果,搜索用时 46 毫秒
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Savithri Krishnaswamy Prabhakaran Rathinasabapathi Paulpandi Manickam Enoch Israel V. M. V. Mohan Palathurai Subramaniam 《Transition Metal Chemistry》2020,45(7):443-455
Transition Metal Chemistry - A highly sensitive and selective imidazole-based fluorescent “on–off” probe, (2-(4,5-bis((E)-4-methoxystyryl)-1H-imidazol-2-yl) phenol) (BMIP), is... 相似文献
333.
Dr. Senthil Subramaniam Dr. Mond F. Guo Tanmayi Bathena Michel Gray Dr. Xiao Zhang Abraham Martinez Dr. Libor Kovarik Dr. Konstantinos A. Goulas Dr. Karthikeyan K. Ramasamy 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(34):14658-14665
Ethanol can be used as a platform molecule for synthesizing valuable chemicals and fuel precursors. Direct synthesis of C5+ ketones, building blocks for lubricants and hydrocarbon fuels, from ethanol was achieved over a stable Pd-promoted ZnO-ZrO2 catalyst. The sequence of reaction steps involved in the C5+ ketone formation from ethanol was determined. The key reaction steps were found to be the in situ generation of the acetone intermediate and the cross-aldol condensation between the reaction intermediates acetaldehyde and acetone. The formation of a Pd–Zn alloy in situ was identified to be the critical factor in maintaining high yield to the C5+ ketones and the stability of the catalyst. A yield of >70 % to C5+ ketones was achieved over a 0.1 % Pd-ZnO-ZrO2 mixed oxide catalyst, and the catalyst was demonstrated to be stable beyond 2000 hours on stream without any catalyst deactivation. 相似文献
334.
Yeh-Siang L Subramaniam G Hadi AH Murugan D Mustafa MR 《Molecules (Basel, Switzerland)》2011,16(4):2990-3000
Generation of reactive oxygen species plays a pivotal role in the development of cardiovascular diseases. The present study describes the effects of the methanolic extract of Phoebe grandis (MPG) stem bark on reactive oxygen species-induced endothelial dysfunction in vitro. Endothelium-dependent (acetylcholine, ACh) and -independent relaxation (sodium nitroprusside, SNP) was investigated from isolated rat aorta of Sprague-Dawley (SD) in the presence of the β-NADH (enzymatic superoxide inducer) and MPG extract. Superoxide anion production in aortic vessels was measured by lucigen chemiluminesence. Thirty minutes incubation of the rat aorta in vitro with β-NADH increased superoxide radical production and significantly inhibited ACh-induced relaxations. Pretreatment with MPG (0.5, 5 and 50 μg/mL) restored the ACh-induced relaxations (R(max): 92.29% ± 2.93, 91.02% ± 4.54 and 88.31 ± 2.36, respectively) in the presence of β-NADH. MPG was ineffective in reversing the impaired ACh-induced relaxations caused by pyrogallol, a non-enzymatic superoxide generator. Superoxide dismutase (a superoxide scavenger), however, reversed the impaired ACh relaxations induced by both β-NADH and pyrogallol. MPG also markedly inhibited the β-NADH-induced generation of the superoxide radicals. Furthermore, MPG scavenging peroxyl radicals generated by tBuOOH (10?? M).These results indicate that MPG may improve the endothelium dependent relaxations to ACh through its scavenging activity as well as by inhibiting the NADH/NADPH oxidase induced generation of superoxide anions. 相似文献
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Subramaniam Selvi Rathinasamy Sakthivel Kalidass Mathiyalagan Arumugham Arunkumar 《Complexity》2015,21(1):214-228
In this article, the problem of reliable gain‐scheduled H∞ performance optimization and controller design for a class of discrete‐time networked control system (NCS) is discussed. The main aim of this work is to design a gain‐scheduled controller, which consists of not only the constant parameters but also the time‐varying parameter such that NCS is asymptotically stable. In particular, the proposed gain‐scheduled controller is not only based on fixed gains but also the measured time‐varying parameter. Further, the result is extended to obtain a robust reliable gain‐scheduled H∞ control by considering both unknown disturbances and linear fractional transformation parametric uncertainties in the system model. By constructing a parameter‐dependent Lyapunov–Krasovskii functional, a new set of sufficient conditions are obtained in terms of linear matrix inequalities (LMIs). The existence conditions for controllers are formulated in the form of LMIs, and the controller design is cast into a convex optimization problem subject to LMI constraints. Finally, a numerical example based on a station‐keeping satellite system is given to demonstrate the effectiveness and applicability of the proposed reliable control law. © 2014 Wiley Periodicals, Inc. Complexity 21: 214–228, 2015 相似文献
337.
Arasambattu K. Mohanakrishnan Ramalingam Balamurugan Neelamegam Ramesh Manoharan Mathiselvam Subramaniam Manavalan 《合成通讯》2013,43(24):4343-4352
A direct method for the preparation of N‐protected/free indole‐7‐carboxaldehyde is reported from the corresponding N‐protected 7‐bromomethylindoles using three different conditions. 相似文献
338.
Obuse H Subramaniam AR Furusaki A Gruzberg IA Ludwig AW 《Physical review letters》2008,101(11):116802
We study multifractal spectra of critical wave functions at the integer quantum Hall plateau transition using the Chalker-Coddington network model. Our numerical results provide important new constraints which any critical theory for the transition will have to satisfy. We find a nonparabolic multifractal spectrum and determine the ratio of boundary to bulk multifractal exponents. Our results rule out an exactly parabolic spectrum that has been the centerpiece in a number of proposals for critical field theories of the transition. In addition, we demonstrate analytically exact parabolicity of the related boundary spectra in the two-dimensional chiral orthogonal "Gade-Wegner" symmetry class. 相似文献
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