排序方式: 共有17条查询结果,搜索用时 15 毫秒
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Manas Mahapatra Arnab Dutta Joy Sankar Deb Roy Ujjal Das Dr. Snehasis Banerjee Prof. Sanjit Dey Dr. Pijush Kanti Chattopadhyay Prof. Dilip K. Maiti Dr. Nayan Ranjan Singha 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(2):502-516
To circumvent costly fluorescent labeling, five nonconventional, multifunctional, intrinsically fluorescent aliphatic terpolymers ( 1 – 5 ) have been synthesized by C−C/C−N-coupled, solution polymerization of two non-emissive monomers with protrusions of fluorophore monomers generated in situ. These scalable terpolymers were suitable for sensing and high-performance exclusion of CuII, logic function, and bioimaging. The structures of the terpolymers, in situ attachment of fluorescent monomers, aggregation-induced enhanced emission, bioimaging ability, and super adsorption were investigated by 1H and 13C NMR, EPR, FTIR, X-ray photoelectron, UV/Vis, and atomic absorption spectroscopy, thermogravimetric analysis, high-resolution transmission electron microscopy, dynamic light scattering, solid-state fluorescence, fluorescence imaging, and fluorescence lifetime measurements, as well as by isotherm, kinetics, and thermodynamic studies. The geometries and electronic structures of the fluorophores and the absorption and emission properties of the terpolymers were examined by DFT, time-dependent DFT, and natural transition orbital analyses. For 1 , 2 , and 5 , the limits of detection were determined to be 1.03×10−7, 1.65×10−7, and 1.77×10−7 m , respectively, and the maximum adsorption capacities are 1575.21, 1433.70, and 1472.21 mg g−1, respectively. 相似文献
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Anupam Chakrabarti Pijush Topdar Abdul Hamid Sheikh 《European Journal of Mechanics - A/Solids》2006,25(6):981-995
The vibration and buckling characteristics of sandwich plates having laminated stiff layers are studied for different degrees of imperfections at the layer interfaces using a refined plate theory. With this plate theory, the through thickness variation of transverse shear stresses is represented by piece-wise parabolic functions where the continuity of these stresses is satisfied at the layer interfaces by taking jumps in the transverse shear strains at the interfaces. The transverse shear stresses free condition at the plate top and bottom surfaces is also satisfied. The inter-laminar imperfections are represented by in-plane displacement jumps at the layer interfaces and characterized by a linear spring layer model. It is quite interesting to note that this plate model having all these refined features requires unknowns only at the reference plane. To have generality in the analysis, finite element technique is adopted and it is carried out with a new triangular element developed for this purpose, as any existing element cannot model this plate model. As there is no published result on imperfect sandwich plates, the problems of perfect sandwich plates and imperfect ordinary laminates are used for validation. 相似文献
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In this study, polyaniline-titanium dioxide (PAni-TiO2) nanocomposite has been prepared and was utilized as an effective catalyst for photodegradation of methylene blue (MB) dyes from aqueous solution. Adsorption characteristic on the PAni-TiO2 surface and the aqueous solubility of the dyes also play an important role in the photodegradation of dye. Adsorption and photodegradation process occurs simultaneously on the surface of the catalyst at first adsorption occurs (21.5%) on the outer surface of the catalyst and then photodegrade the material up to (66.5%). In reaction mechanism OH· makes the vital role to the degradation of methylene blue and its intermediates. To know the surface and stability of the photocatalyst, it was characterized by FTIR, TEM, TGA–DTA, XRD, UV-vis spectrophotometer, and SEM analysis. Kinetic data indicate that up to 20 minutes photodegradation rates usually follows the pseudo-first-order reaction. After 20 minutes, it follows the Langmuir-Hinshelwood (LH) kinetics. Photo reactivity of PAni-TiO2 was studied with pH of solution, dosage of photocatalyst and concentration of dye. The reaction rate constant (r) and equilibrium binding constant (K) values were incredibly significant than other catalyst. 相似文献
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In recent years, study of parton distribution function (PDF) has itself become a topic of significant interest. To overcome
the shortcoming of the conventional PDF, several alternative methods have been proposed in recent years like neural network
formalism. In the present work, x distribution of the non-singlet structure function is obtained using the recently reported complete solution of Taylor-approximated
DGLAP equation. The results are compared with exact results as well as CCFR data. 相似文献
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Binding interaction of transition metals copper, cadmium, and mercury with heme proteins were explored using isothermal calorimetry. Consequent conformational changes of the native proteins analyzed by circular dichroic spectroscopy revealed differential structural alteration of heme proteins. But, significant distortion in myoglobin structure was noted due to bioconjugation with mercury whose greater ionic radius may be responsible for this preferential behavior. 相似文献
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Souvik Misra Soumyajit Mukherjee Anamika Ghosh Pijush Singh Dr. Sanjoy Mondal Dr. Debes Ray Dr. Gourav Bhattacharya Dr. Debabani Ganguly Dr. Alok Ghosh Dr. V. K. Aswal Prof. Ajit K. Mahapatra Dr. Biswarup Satpati Dr. Jayanta Nanda 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(67):16744-16753
The design and development of soft biomaterials based on amino acid and short-peptide have gained much attention due to their potent biomedical applications. A slight alteration in the side-chain of single amino acid in a peptide or protein sequence has a huge impact on the structure and function. Phenylalanine is one of the most studied amino acids, which contains an aromatic phenyl group connected through a flexible −CH2− unit. In this work, we have examined whether flexibility and aromatic functionality of phenylalanine (Phe) are important in gel formation of model gelator Fmoc-Phe-OH or not. To examine this hypothesis, we synthesized Fmoc-derivatives of three analogues unnatural amino acids including cyclohexylalanine, phenylglycine, and homophenylalanine; which are slightly varied from Phe. Interestingly, all these three new analogues formed hydrogels in phosphate buffer at pH 7.0 having different gelation efficacy and kinetics. This study suggests that the presence of aromatic side-chain and flexibility are not mandatory for the gelation of this model gelator. Newly synthesized unnatural amino acid derivatives have also exhibited promising antimicrobial activity towards gram-positive bacteria by inhibiting cellular oxygen consumption. We further determined the biocompatibility of these amino acid derivatives by using a hemolysis assay on human blood cells. Overall studies described the development of single amino acid-based new injectable biomaterials with improved antimicrobial activity by the slight alteration in the side-chain of amino acid. 相似文献
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Pijush K. Ghosh 《International Journal of Theoretical Physics》2011,50(4):1143-1151
A class of non-Dirac-hermitian many-particle quantum systems admitting entirely real spectra and unitary time-evolution is
presented. These quantum models are isospectral with Dirac-hermitian systems and are exactly solvable. The general method
involves a realization of the basic canonical commutation relations defining the quantum system in terms of operators those
are hermitian with respect to a pre-determined positive definite metric in the Hilbert space. Appropriate combinations of
these operators result in a large number of pseudo-hermitian quantum systems admitting entirely real spectra and unitary time
evolution. Examples of a pseudo-hermitian rational Calogero model and XXZ spin-chain are considered. 相似文献
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Asif Ali Khan Rais Ahmad Anish Khan Pijush Kanti Mondal 《Arabian Journal of Chemistry》2013,6(4):361-368
In this paper, recycling of polyethyleneterephthalate (PET), a non-biodegradable plastic, was carried out by preparing unsaturated polyester Ce(IV) phosphate (USPECe(IV)P) composite cation exchanger. Various samples of USPECe(IV)P was prepared by mixing different volume ratios of unsaturated polyester in an inorganic Ce(IV) phosphate gel and characterized by TGA/DTA, XRD, SEM, Fourier transform infra-red spectroscopy (FTIR) instrumental methods. The composite has been employed as adsorbents for the removal of Malachite green dye from waste water. The nature of possible adsorbent and dye interaction was examined by the FTIR technique. The adsorption of MG was found to be maximum (98%) at pH 8. The extent of removal of MG was found to be dependent on adsorbent dose, temperature and time. The equilibrium data for adsorption was best represented by the Friendlich isotherm. Thermodynamic parameters (ΔH0 and ΔG0) suggest an endothermic and spontaneous process. Kinetic studies show better applicability of an intraparticle diffusion kinetic model. 相似文献