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排序方式: 共有112条查询结果,搜索用时 15 毫秒
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Bappaditya Samanta Xiao‐Chao Yang Yuval Ofir Dr. Myoung‐Hawn Park Debabrata Patra Sarit S. Agasti Oscar R. Miranda Zhi‐Hong Mo Prof. Vincent M. Rotello Prof. 《Angewandte Chemie (International ed. in English)》2009,48(29):5341-5344
Involuntary association : Anionic β‐galactosidase enzymes associate with positively charged Au nanoparticles to produce reduced‐charge conjugates, which assemble at oil–water interfaces to result in stable microcapsules (see picture). The microcapsules were formed quickly and showed high enzymatic activity, which makes them promising materials for biotechnology applications.
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Dr. Kaushik Kundu Paribesh Acharyya Krishnendu Maji Ranjan Sasmal Prof. Sarit S. Agasti Prof. Kanishka Biswas 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(31):13193-13200
Two-dimensional (2D) lead-free halide perovskites have generated enormous perception in the field of optoelectronics due to their fascinating optical properties. However, an in-depth understanding on their shape-controlled charge-carrier recombination dynamics is still lacking, which could be resolved by exploring the photoluminescence (PL) blinking behaviour at the single-particle level. Herein, we demonstrate, for the first time, the synthesis of nanocrystals (NCs) and 2D nanosheets (NSs) of layered mixed halide, Cs3Bi2I6Cl3, by solution-based method. We applied fluorescence microscopy and super-resolution optical imaging at single-particle level to investigate their morphology-dependent PL properties. Narrow emission line widths and passivation of non-radiative defects were evidenced for 2D layered nanostructures, whereas the activation of shallow trap states was recognized at 77 K. Interestingly, individual NCs were found to display temporal intermittency (blinking) in PL emission. On the other hand, NS showed temporal PL intensity fluctuations within localized domains of the crystal. In addition, super-resolution optical image of the NS from localization-based method showed spatial inhomogeneity of the PL intensity within perovskite crystal. 相似文献
84.
Surfactant-assisted route to synthesize well-aligned ZnO nanorod arrays on sol-gel-derived ZnO thin films 总被引:1,自引:0,他引:1
Dev A Panda SK Kar S Chakrabarti S Chaudhuri S 《The journal of physical chemistry. B》2006,110(29):14266-14272
Anisotropic growth of ZnO nanorod arrays on ZnO thin films was achieved at a temperature of 90 degrees C by a surfactant-assisted soft chemical approach with control over size and orientation. ZnO thin films with c-axis preferred orientation had been achieved by the sol-gel technique. Lengths, diameters, and the degree of alignment of the ZnO nanorods were controlled by changing the experimental parameters. It was observed that the surfactant was essential to restrict the lateral growth of the nanorods, whereas the pH level of the reaction medium controlled the length of the nanorods. On the other hand, the orientation of the nanorods depended on the crystalline orientation of the film as well as the pH of the reaction medium. Room-temperature photoluminescence studies revealed that the ZnO nanorods with the best alignment exhibited the best emission property. The ZnO nanorods exhibited a strong UV emission peak at approximately 3.22 eV, ascribed to the band-edge emission. The field emission studies of the well-aligned nanorod arrays exhibited a low turn-on field of 1.7 V/microm to get an emission current density of 0.1 microA/cm(2). 相似文献
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Summary The oxovanadium(IV) complexes [(VOSO4·H2O)2L] and [(VO)2L1(-SO4)] (L = hydrazone ligands derived from 1,4-dihydrazinophthalazine and benzaldehyde, 4-chlorobenzaldehyde, 4-methoxybenzaldehyde or acetophenone; L 1H2 = hydrazone ligands derived from 1,4-dihydrazinophthalazine and salicylaldehyde, 2-hydroxyacetophenone or 2-hydroxynaphthaldehyde) have been prepared and characterized by elemental analyses, electrical conductance, magnetic moments and spectral data. Reduced magnetic moments are observed for all sulfato-bridged derivatives, indicating antiferromagnetically coupled vanadium(IV) centres. The vanadium(IV) centres appear to have five-coordinated stereochemistries in the systems which involve two metals bound to each ligand. The thermal behaviour of the complexes was investigated by t.g. and d.t.g. techniques. The antifungal and antiviral activities of the hydrazones and their corresponding complexes were also investigated. The screening results have been correlated with the structural features of the tested compounds. 相似文献
87.
Zaineb Calcuttawala Anirban Kundu Soumitra Nandi Sunando Kumar Patra 《The European Physical Journal C - Particles and Fields》2017,77(9):650
The decay \(b\rightarrow s\nu {\bar{\nu }}\) has received comparatively less attention than the semileptonic decay \(b\rightarrow s\ell ^+\ell ^-\), because neutrinos pass undetected and hence the process offers lesser number of observables. We show how the decay \(b\rightarrow s~+\) invisible(s) can shed light, even with a limited number of observables, on possible new physics beyond the Standard Model and also show, quantitatively, the reach of future B factories like SuperBelle to uncover such new physics. Depending on the operator structure of new physics, different channels may act as the best possible probe. We show, using the optimal observable technique, how almost the entire parameter space allowed till now can successfully be probed at a high-luminosity B factory. 相似文献
88.
Soumitra Ghara Surjit Kumar 《Journal of Mathematical Analysis and Applications》2019,469(2):1015-1027
We show, by means of a class of examples, that if and are two positive definite kernels on the unit disc such that the multiplication by the coordinate function on the corresponding reproducing kernel Hilbert space is subnormal, then the multiplication operator on the Hilbert space determined by their sum need not be subnormal. This settles a recent conjecture of Gregory T. Adams, Nathan S. Feldman and Paul J. McGuire in the negative. We also discuss some cases for which the answer is affirmative. 相似文献
89.
Morris MJ Negishi Y Pazsint C Schonhoft JD Basu S 《Journal of the American Chemical Society》2010,132(50):17831-17839
RNA G-quadruplexes located within the 5'-UTR of mRNA are almost always known to be associated with repression of cap-dependent translation. However, in this report we present functional as well as structural evidence that sequence redundancy in a G-rich segment within the 5'-UTR of human VEGF mRNA supports a 'switchable' RNA G-quadruplex structure that is essential for IRES-mediated translation initiation. Additionally, utilization of a specific combination of G-tracts within this segment allows for the conformational switch that implies a tunable regulatory role of the quadruplex structure in translation initiation. A sequence engineered from a functionally handicapped mutant moderately rescued the activity, further indicating the importance of G-quadruplex structure for VEGF IRES-A function. This to our knowledge is the first report of a conformationally flexible RNA G-quadruplex which is essential for IRES-mediated translation initiation. 相似文献
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