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Le Fang Wei-Tao Gong Manivannan Kalavathi Dhinakaran Li Shang Gui-Ling Ning 《Chemical Papers》2016,70(5):663-666
A novel Hg2+ ion induced reversible ring contraction was achieved employing the intramolecular reaction of isobutylene with an aromatic hydroxyl group of cyclophane; reversibility of the reaction was facilitated by excess addition of NaBH4 which also resulted in complexation. The ring contraction and expansion was monitored by UV-VIS absorption, and by fluorescence and 1H NMR spectra. Switchable fluorescence behavior (on—off—on) was observed when the ring-size was tuned from a 19-membered ring to an 18-membered and vice versa. This fine tuning has the potential to be applied in the construction of new supramolecular devices. 相似文献
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S. G. Li Q. Gong C. F. Cao X. Z. Wang J. Y. Yan Y. Wang H. L. Wang 《Optical and Quantum Electronics》2014,46(5):623-640
Since the external cavity quantum dot laser was first demonstrated, the performances have been improved in terms of operation temperature, output power, pulse generator and tuneability based on the naturally size fluctuation of quantum dot. Nowadays, the external cavity quantum dot sources have been successfully used in different absorption spectroscope techniques, in industry, biomedical and research. In this paper we reviewed the recent developments of quantum dot lasers operated in a grating-coupled external cavity system where a single frequency and wide tunable wavelength range were easily obtained by adjusting the grating angle. In all cases, we mainly stressed the significant progresses in understanding of basic optical and electronic properties to enable the importance steps forward. The prospects for further progress directed towards stability, mode-hoping-free tuning range, miniaturization and integration of the external cavity quantum dot lasers also reviewed. 相似文献
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Premchand B. Shelke Suraj N. Mali Hemchandra K. Chaudhari Amit P. Pratap 《Journal of heterocyclic chemistry》2019,56(11):3048-3054
Chitosan hydrochloride as biopolymer‐based, renewable, and recyclable heterogeneous catalyst was used for efficient one‐pot synthesis of perimidine derivatives. This newly developed greener methodology provides a very simple and greener route for the synthesis of perimidines in short time with excellent yield. 相似文献
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A novel spectrofluorimetric method to determine abiraterone acetate and its active metabolite, abiraterone was developed, based on the fact that fluorescence intensity of abiraterone acetate and abiraterone could be enhanced in β-cyclodextrin (β-CD) due to the formation of the inclusion complex. The inclusion interaction of β-CD and abiraterone acetate and the β-cyclodextrin sensitized spectrofluorimetry was examined. The various factors influencing fluorescence were discussed in details. The results showed that under the optimized conditions, the linear range of calibration curve for the determination of biraterone acetate and abiraterone was 0.20?~?6.0 μg/mL, and the detection limit (LOD) was 6.8 (r?=?0.997) or 6.6 ng/mL (r?=?0.996), respectively. No interference was observed from common co-existing substances or pharmaceutical excipient. The method was successfully applied to the analysis of abiraterone acetate in pharmaceutical formulation and abiraterone in human serum/urine. 相似文献
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