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71.
Salim Saranya Sankaran Radhika Cheriya Mukkolakkal Afsina Abdulla Gopinathan Anilkumar 《Journal of heterocyclic chemistry》2021,58(8):1570-1580
The synthesis of heterocyclic compounds has been a hot topic for several decades. Synthetic organic chemists are always in search of new methodologies which are greener for the synthesis of heterocyclic compounds. The ultrasound-assisted reactions have contributed much to this field. This review focuses on the impact of sonochemistry in the synthesis of heterocyclic compounds and covers the literature from 2009 to 2020. 相似文献
72.
The Ramanujan Journal - The 15 primes 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 41, 47, 59, 71 are called the supersingular primes: they occur in several contexts in number theory and also,... 相似文献
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P. Shahul Hameed G. Sankaran Pillai G. Satheeshkumar R. Mathiyarasu 《Journal of Radioanalytical and Nuclear Chemistry》2014,300(3):1081-1088
Tiruchirappalli district is naturally endowed with rich building material resources which are also used in neighboring districts. Hence, measurements of activity concentrations and absorbed dose rate of primordial radionuclides (238U, 232Th and 40K) in the rock samples collected from 14 sedimentary rocks and 9 igneous rocks were carried out employing gamma ray spectrometry. In sedimentary rocks the geometric mean activity concentrations of 238U, 232Th and 40K were found to be 7.4, 29.5 and 233.6 Bq kg?1, respectively. On the other hand in igneous rocks geometric mean activity concentrations of 238U, 232Th and 40K were distinctly higher and found to be 13.1, 105.7 and 888.8 Bq kg?1, respectively. The mean radium equivalent activity (Raeq) recorded in both sedimentary (20.8 Bq kg?1) and igneous rocks (245.4 Bq kg?1) were well within the limit prescribed for dwellings (370 Bq kg?1) except Vilathupatti (689.3 Bq kg?1) and Narthamalai (371.6 Bq kg?1). The mean absorbed dose rate from igneous rock (115 nGy h?1) exceeded the prescribed limit of 55 nGy h?1. The mean indoor annual effective dose from the sedimentary rock (0.056 mSv y?1) and igneous rock (0.580 mSv y?1) did not exceed the prescribed limit (1 mSv y?1) except the igneous rock from Vilathupatti (1.51 mSv y?1). The study concludes that sedimentary and igneous rocks analyzed were radiologically safe when used as building materials except igneous rock from Vilathupatti and Narthamalai. 相似文献
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LetG n,k denote the Grassmann manifold ofk-planes in ?n. We show that for any continuous mapf: G n,k→Gn,l the induced map inZ/2-cohomology is either zero in positive dimensions or has image in the subring generated by w1(γn, k), provided 1≤l<k≤[n/2] andn≥k+2l-1. Our main application is to obtain negative results on the existence of equivariant maps between oriented Grassmann manifolds. We also obtain positive results in many cases on the existence of equivariant maps between oriented Grassmann manifolds. 相似文献
77.
Pownsamy Kannan Kuyam Rathinavelu Sankaran 《Reaction Kinetics and Catalysis Letters》2005,85(2):231-238
Summary Oxidation of pentaamminecobalt(III) complexes of α-aminoacids by bis(2,2¢-bipyridyl) copper(II) permanganate in 50% HOAc-50% H2O (v/v) aqueous acetic acid medium. This oxidation as a diagnostic tool to find out the fraction proceeding by synchronous cleavages of N-H and C-C bonds. 相似文献
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Lin Guo Jia Yi Har Jagadish Sankaran Yimian Hong Balakrishnan Kannan Dr. Thorsten Wohland Dr. 《Chemphyschem》2008,9(5):721-728
Molecular diffusion in biological membranes is a determining factor in cell signaling and cell function. In the past few decades, three main fluorescence spectroscopy techniques have emerged that are capable of measuring molecular diffusion in artificial and biological membranes at very different concentration ranges and spatial resolutions. The widely used methods of fluorescence recovery after photobleaching (FRAP) and single‐particle tracking (SPT) can determine absolute diffusion coefficients at high (>100 μm?2) and very low surface concentrations (single‐molecule level), respectively. Fluorescence correlation spectroscopy (FCS), on the other hand, is well‐suited for the intermediate concentration range of about 0.1–100 μm?2. However, FCS in general requires calibration with a standard dye of known diffusion coefficient, and yields only relative measurements with respect to the calibration. A variant of FCS, z‐scan FCS, is calibration‐free for membrane measurements, but requires several experiments at different well‐controlled focusing positions. A recently established FCS method, electron‐multiplying charge‐coupled‐device‐based total internal reflection FCS (TIR‐FCS), referred to here as imaging TIR‐FCS (ITIR–FCS), is also independent of calibration standards, but to our knowledge no direct comparison between these different methods has been made. Herein, we seek to establish a comparison between FRAP, SPT, FCS, and ITIR–FCS by measuring the lateral diffusion coefficients in two model systems, namely, supported lipid bilayers and giant unilamellar vesicles. 相似文献
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