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981.
Three structural variants of azo substituted achiral bent-core compounds are reported. Here, the effect of symmetrical and non-symmetrical arms at 1,3-positions of the central phenyl ring on the mesogenic properties of the resulting bent-core azo compounds is studied. The structures of all the compounds synthesised are confirmed by the organic spectroscopic methods. The liquid crystalline properties are investigated using polarising optical microscopy, differential scanning calorimetry and X-ray diffraction studies. It was found that the non-symmetrical molecules are more conducive to mesomorphism than the symmetrical ones. We observed B1 (Colr), B2 (SmCAPA) and B7 mesophases in these compounds. The B7 mesophase was found to have a modulated layer structure. Interestingly, a reversible field-induced transition from the B7-like structure to the racemic SmCAPF was also observed. We also report the photo-induced studies in the B7 mesophase and make a comparison of these results with those obtained in a B2 mesophase. From our studies, we observed that these effects are more profound in the case of B7 mesophase when compared to the B2 mesophase in such systems. 相似文献
982.
983.
Surbhi Gupta Ridham Bakshi Suram Singh Arun Bharti G. H. Bhat J. A. Sheikh 《中国物理C(英文版)》2020,44(7):074108-074108-10
In this study, the multi-quasiparticle triaxial projected shell model (TPSM) is applied to investigate \begin{document}$\gamma$\end{document} ![]()
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-vibrational bands in transitional nuclei of \begin{document}$^{118-128}{\rm{Xe}}$\end{document} ![]()
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. We report that each triaxial intrinsic state has a \begin{document}$\gamma$\end{document} ![]()
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-band built on it. The TPSM approach is evaluated by the comparison of TPSM results with available experimental data, which shows a satisfactory agreement. The energy ratios, B(E2) transition rates, and signature splitting of the \begin{document}$\gamma$\end{document} ![]()
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-vibrational band are calculated. 相似文献
984.
985.
986.
An insight into the schizophrenic self‐assembly of thermo and proton sensitive graphene oxide grafted block copolymer
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Nabasmita Maity Atanu Kuila Dhruba P. Chatterjee Debasish Mandal Arun K. Nandi 《Journal of polymer science. Part A, Polymer chemistry》2016,54(24):3878-3887
In order to study the self‐assembly of block copolymer grafted from graphene oxide (GO) by the fluorescence of GO, poly(ε‐caprolactone) (PCL)‐block‐poly(dimethyl aminoethyl methacrylate) (PDMAEMA) is grafted from its surface using consecutive ring opening (ROP) and atom transfer radical polymerization (ATRP). GO‐g‐(PCL13‐b‐PDMAEMA117) (GPCLD) at pH 9.2 exhibits cloud point (Tc) at 32 °C. At pH 9.2 HRTEM images indicate schizophrenic morphology from vesicle at 26 °C to annular ring at 30 °C followed by giant size aggregation at 38 °C. But the reference block copolymer (PCL14‐b‐PDMAEMA126, PCLD), synthesized using benzyl alcohol as ROP initiator, exhibits only core–shell morphology whose size increases with rising temperature at pH 9.2. GPCLD solution exhibits good photoluminescence (PL) property arising from GO at pH 9.2 and PL‐intensity increases abruptly during phase transition. Both Tc and size of GPCLD assembly can be reversibly tuned by CO2 and N2 gas purging. 1H NMR spectra exhibit a gradual shift of resonance peaks of the protons on CO2 bubbling. Thus at pH 9.2 and at 38 °C the GPCLD acts as a good CO2 sensor. Additionally, the GPCLD vesicle can load hydrophobic guest molecules which can be released by triggering with CO2. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 3878–3887 相似文献
987.
988.
Qing He Hongfei Li Debarun Bhattacharjya Dhaivat P Parikh Arun Hampapur 《The Journal of the Operational Research Society》2015,66(3):392-404
Analysing track geometry defects is critical for safe and effective railway transportation. Rectifying the appropriate number, types and combinations of geo-defects can effectively reduce the probability of derailments. In this paper, we propose an analytical framework to assist geo-defect rectification decision making. Our major contributions lie in formulating and integrating the following three data-driven models: (1) A track deterioration model to capture the degradation process of different types of geo-defects; (2) A survival model to assess the dynamic derailment risk as a function of track defect and traffic conditions; (3) An optimization model to plan track rectification activities with two different objectives: a cost-based formulation (CF) and a risk-based formulation (RF). We apply these approaches to solve the optimal rectification planning problem for a real-world railway application. We show that the proposed formulations are efficient as well as effective, as compared with existing strategies currently in practice. 相似文献
989.
990.
Ajay R. Tilekar Arun R. Jagdale Gagan Kukreja G. Gautham Shenoy Neelima Sinha 《Tetrahedron: Asymmetry》2017,28(1):153-161
An organocatalytic ‘one-pot’ synthesis of highly functionalized 3,4,5,6-tetrasubstituted dihydropyrans has been developed. Excellent enantio- and diastereo selectivity with good yields are some of the salient features of this methodology. This reaction takes advantage of proline based catalysts and follows stepwise sequential transformations including Knoevenagel condensation–Michael addition–hemiacetalization towards the synthesis of complex dihydropyranol framework. 相似文献