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81.
D. Udayakumar A. John Kiran A. Vasudeva Adhikari K. Chandrasekharan G. Umesh H.D. Shashikala 《Chemical physics》2006
The third-order nonlinear optical properties of newly synthesized soluble polyoxadiazoles containing 3,4-dialkoxythiophenes were investigated by using Z-scan and degenerate four-wave mixing (DFWM) techniques. The measurements were performed at 532 nm with 7 ns pulses from a Nd:YAG laser. We found a good agreement between the values of χ(3) determined from both the experiments. Z-scan results indicate a negative nonlinear refractive index, n2, whose magnitude is of the order of 10−10 esu for all the copolymers. The variation of nonlinear response among the copolymers clearly indicates the dependence of χ(3) on donor and acceptor type of units present in these copolymers. The copolymers exhibit strong reverse saturable absorption and good optical limiting properties at 532 nm. 相似文献
82.
T. Kiran Kumar S. Venkataratnam K. Venkata Reddy 《Radiation Physics and Chemistry》1996,48(6):707-710
Effective atomic numbers (Zeff) of different clay minerals are calculated for total photon interaction in the energy region 10 keV–10 MeV. The variation of Zeff with energy is discussed by comparing with the similar studies made for alloys and compounds from our laboratory. 相似文献
83.
84.
Vinod D. Gupta Abhinav B. Tathe Vikas S. Padalkar Vikas S. Patil Kiran R. Phatangare Prashant G. Umape Ponnadurai Ramasami Nagaiyan Sekar 《Journal of fluorescence》2013,23(6):1121-1138
Push-pull chromophores attached to carbazole based π-conjugating spacers bearing N-alkylamino donors, cyanovinyl and carbethoxy acceptors have been studied by the means of UV-Visible measurements. The intramolecular charge transfer (ICT) of these π-conjugated systems has also been tested by investigating the ability of the solute molecules to undergo shifts in their fluorescence emission maxima with increasing solvent polarity. Density Functional Theory [B3LYP/6-31G(d)] and Time Dependent Density Functional Theory [TD-B3LYP/6-31G(d)] computations have been used to have more understanding of the structural, molecular, electronic and photophysical parameters of push-pull dyes. The largest wavelength difference between the experimental and computed electronic absorption maxima was 45 nm. For emission, a largest difference of 61 nm was observed. The ground state and excited state dipole moments in different solvents were determined using experimental solvatochromic data and computed Onsager radii. The dipole moments of the molecules in the excited state were observed to be higher than in the ground state. 相似文献
85.
The paper deals with numerical investigation of the effect of plaque morphology on the flow characteristics in a diseased coronary artery using realistic plaque morphology. The morphological information of the lumen and the plaque is obtained from intravascular ultrasound imaging measurements of 42 patients performed at Cleveland Clinic Foundation, Ohio. For this data, study of Bhaganagar et al. (2010) [1] has revealed the stenosis for 42 patients can be categorized into four types – type I (peak-valley), type II (ascending), type III (descending), and type IV (diffuse). The aim of the present study is to isolate the effect of shape of the stenosis on the flow characteristics for a given degree of the stenosis. In this study, we conduct fluid dynamic simulations for the four stenosis types (type I–IV) and analyze the differences in the flow characteristics between these types. Finely refined tetrahedral mesh for the 3-D solid model of the artery with plaques has been generated. The 3-D steady flow simulations were performed using the turbulence (k–ε) model in a finite volume based computational fluid dynamics solver. The axial velocity, the radial velocity, turbulence kinetic energy and wall shear stress profiles of the plaque have been analyzed. From the axial and radial velocity profiles results the differences in the velocity patterns are significantly visible at proximal as well as distal to the throat, region of maximum stenosis. Turbulent kinetic energy and wall shear stress profiles have revealed significant differences in the vicinity of the plaque. Additional unsteady flow simulations have been performed to validate the hypothesis of the significance of plaque morphology in flow alterations in diseased coronary artery. The results revealed the importance of accounting for plaque morphology in addition to plaque height to accurately characterize the turbulent flow in a diseased coronary artery. 相似文献
86.
Gan Z Kwak HT Bird M Cross T Gor'kov P Brey W Shetty K 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2008,191(1):135-140
Resistive and resistive-superconducting hybrid magnets can generate dc magnetic fields much higher than conventional superconducting NMR magnets but the field spatial homogeneity and temporal stability are usually not sufficient for high-resolution NMR experiments. Hardware and technique development addressing these issues are presented for high-resolution NMR at magnetic fields up to 40T. Passive ferromagnetic shimming and magic-angle spinning are used effectively to reduce the broadening from inhomogeneous magnetic field. A phase correction technique based on simultaneous heteronuclear detection is developed to compensate magnetic field fluctuations to achieve high spectral resolution. 相似文献
87.
Kiran S. Hon Hemantkumar N. Akolkar Bhausaheb K. Karale 《Journal of heterocyclic chemistry》2019,56(6):1780-1786
A series of novel 1‐methyl‐3‐(4‐phenyl‐4H‐1,2,4‐triazol‐3‐yl)‐1H‐indazoles was synthesized in three steps from 5‐(1‐methyl‐1H‐indazol‐3‐yl)‐4‐phenyl‐2H‐1,2,4‐triazole‐3(4H)‐thiones. 5‐(1‐Methyl‐1H‐indazol‐3‐yl)‐4‐phenyl‐2H‐1,2,4‐triazole‐3(4H)‐thiones were converted into 1‐methyl‐3‐(5‐(methylsulfonyl)‐4‐phenyl‐4H‐1,2,4‐triazol‐3‐yl)‐1H‐indazoles upon methylation followed by treatment with aq. KMnO4. The reaction of 1‐methyl‐3‐(5‐(methylsulfonyl)‐4‐phenyl‐4H‐1,2,4‐triazol‐3‐yl)‐1H‐indazoles with Raney nickel resulted in desulphonylation to afford corresponding 1‐methyl‐3‐(4‐phenyl‐4H‐1,2,4‐triazol‐3‐yl)‐1H‐indazoles. All the new synthesized compounds were characterized by spectral techniques. 相似文献
88.
Yu Wang Kiran M. Patil Shuanghong Yan Panke Zhang Weiming Guo Yuqin Wang Hong‐Yuan Chen Dennis Gillingham Shuo Huang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(25):8520-8524
O6‐carboxymethylguanine (O6‐CMG) is a highly mutagenic alkylation product of DNA, triggering transition mutations relevant to gastrointestinal cancer. However, precise localization of a single O6‐CMG with conventional sequencing platforms is challenging. Here nanopore sequencing (NPS), which directly senses single DNA bases according to their physiochemical properties, was employed to detect O6‐CMG. A unique O6‐CMG signal was observed during NPS and a single‐event call accuracy of >95 % was achieved. Moreover, O6‐CMG was found to be a replication obstacle for Phi29 DNA polymerase (Phi29 DNAP), suggesting this lesion could cause DNA sequencing biases in next generation sequencing (NGS) approaches. 相似文献
89.
Kiran K. Sarasija M. Ananda Rao Boddu Namratha V. Ashok D. Srinivasa Rao A. 《Russian Journal of General Chemistry》2019,89(9):1859-1866
Russian Journal of General Chemistry - A series of novel 1,4-substituted bis-aralkyl and aryl 1,2,3-triazoles bearing thiophene chalcones are synthesized via the Claisen condensation of bis... 相似文献
90.
Journal of Solid State Electrochemistry - Heteroatom functionalities in activated carbons have a positive effect on their electrochemical properties. High surface area, reasonable heteroatom... 相似文献