Kayalvizhi, R.Neyvasagam, K.Shanthi, R. VijayaAbel, M. John...
12页
查看更多>>摘要：In this work, a cost-effective and ecologically friendly way was chosen for the preparation of magnesium oxide (MgO) and gadolinium doped MgO (Gd3+-doped MgO) nanoparticles. The Gd3+ ions caused a shift in the acceptor level, which is proved by the obtained band gap values of the samples which is found to be reduced for Gd3+-doped MgO rather than pure MgO. Three bands related to F (+) and F oxygen deficiency defects may be seen in the photoluminescence spectra of produced nanomaterials. Crystallinity, particle size, and surface area, of these synthetic photocatalyst were all measured. The photo activity of Gd3+-doped MgO with different weight percent (1, 3, and 5) of Gd3+ has been studied in Methyl Orange (MO) and Methylene Blue (MB) degradation. The photocatalytic behavior of magnesium oxide nanoparticles and rare earth element Gd3+-doped magnesium oxide was studied, and the photocatalytic rate was enhanced by doping of gadolinium under UV radiation was observed. The impact of operational variables like pH and PZC was evaluated. When the efficiency of all pro-duced nanoparticles was compared, it was discovered that the 5 wt% Gd-doped MgO nano powder performed better rather than the rest of the materials.
查看更多>>摘要：The mechanism of quantum dots (QDs) as fluorescent nano sensor to detect metal ions remains controversial. Herein, we investigate the mechanism from the perspectives of fluorescence polarization and light scattering, where CdTe QDs are employed as a model fluorescent sensor and Hg(2+& nbsp;)ion is used as a model quencher. When the QDs react with Hg2+, we observed that the fluorescence is quenched while light scattering is enhanced and the fluorescence anisotropy is increased. This indicates that Hg2+ destabilizes the QDs and drives them to agglomerate, which might be an important contributor to the fluorescence quenching. This work provides novel insights to explain the mechanism of QDs as fluorescent probe to detect metal ions.
Guerra, Jacob G.Kumar, PrarthanaBajwa, BhvandipKrishnan, V. V....
6页
查看更多>>摘要：The purpose of this investigation is to determine if enthalpy-entropy compensation (EEC) is a valid concept when the experiments are performed on a set of molecules in multiple solvents. Dynamic nuclear magnetic resonance (DNMR) experiments are performed on a series of analogs derived from N, N-diethyl-m-toluamide (DEET) in six different solvents of varying dielectric constant from toluene-d8 (epsilon = 2.38) to dimethyl sulfoxide-d6 (epsilon = 46.7). The thermodynamic parameters of the restricted rotation to the solvent dielectric constant do not have a straightforward correlation relationship between them. However, the activation enthalpy and entropy of more than sixty different experimental measurements indicate that enthalpy-entropy compensation (EEC) is independent of the solvent condition with a compensation temperature of 287.81 +/- 3.95 K. The results, therefore, support the broader role of EEC on the partial amide bond dynamics in the DEET analogs over the temperature range studied.
查看更多>>摘要：In the present study, by defining new representative equations based on the transport crossover functions stemming from the application of renormalization group theory to the transport phenomena, as well as using Perturbed Chain Statistical Associating Fluid equation of state to calculate equilibrium quantities and their partial derivatives in and out of the critical regions (up to 2pc) to obtain thermal conductivity and diffusivity of some hydrocarbons. The results show that in the critical regions a good consistency with the available literature data is obtained, the AAD% of both thermal conductivity and diffusivity of the studied hydrocarbons ranged from 1.5% to 5%.
查看更多>>摘要：The magnetically separable nanocomposite of gamma-Fe2O3/montmorillonite (gamma-Fe2O3/Mt) has been synthesized by a hydrothermal method. The as-obtained nanocomposite is composed of a single phase of gamma-Fe2O3 nanoparticles homogeneously dispersed in a montmorillonite structure with high photocatalytic activity for rhodamine B photodegradation. Physicochemical characterization revealed particle sizes ranging from 10 to 30 nm with a band-gap energy of 2.3 eV. This study reveals a significant contribution of the adsorption mechanism to the degradation mechanism. The nanocomposite could be easily separated and reused by magnetic separation owing to its magnetism of 22 emu/g. The nanocomposite is also reusable without any chemical change until five cycles.
George, AnnsVijoy, P. S.Joseph, CyriacJose, Jeena Rose...
5页
查看更多>>摘要：The present work reports the excitation dependent photoemission properties of Er3+/Sm3+ co-activated multi component borosilicate glasses prepared through melting and rapid quenching technique. The energy transfer (ET) from Er3+-> Sm3+ ions within the co-doped glasses was confirmed by means of spectral overlap diagram, photoluminescent emission spectra and the decay time profiles. The appreciable variation in emission intensity and the average lifetime values along with the rise in Sm3+ ion concentration substantiates the presence of ET and the estimated CIE co-ordinates corroborates that the prepared glasses emanate light in both cool white and reddish-orange region with respect to the applied excitation wavelengths.
查看更多>>摘要：We investigate the thermal photoassociation dynamics of the Mg atoms, from the X-1 sigma(+)(g) state to the (1)(1)pi(g) state, or to the other three higher excited states i) = (1)(1)pi(u), (2)(1)pi(u), (2)(1)sigma(+)(u). The weak two-photon coupling between X-1 sigma(+)(g) and (1)(1)pi(g), the strong three-photon couplings between X-1 sigma(+)(g) and |i), and the one-photon couplings between (1)(1)pi(g) and |i) can form several different transition paths. We find that X-1 sigma(+)(g) +3PLANCK CONSTANT OVER TWO PI omega i)? g ? -& nbsp;PLANCK CONSTANT OVER TWO PI omega(1)(1)pi(g) is the major path and the "V "-type Raman transition path from |i) to (1)(1)pi(g) takes the second place.
查看更多>>摘要：This research put forward a simple and rapid fluorescence probe method based on competition strategy to detect homocysteine. The host-guest interaction behavior between cucurbit[7]uril and homocysteine was further studied via UV-vis spectroscopy, Fourier transform infrared spectroscopy, molecular modeling, and 1H NMR spectroscopy in aqueous solution. Under the optimal detection conditions, the fluorescence intensity of the cucurbit[7]uril-berberine complex declined linearly with increasing concentration of homocysteine in the range from 5 to 200 mu M, and the limit of detection was 1.76 mu M. Meanwhile, it was also successfully employed to detect homocysteine in serum samples with the recovery rate of 85.1% to 102.0%.
查看更多>>摘要：In this study, activated carbon operated by microwave (MW) pretreatment and further MW regeneration was used to remove sulfachloropyridazine (SCP) to explore the influence of MW on activated carbon. The results reveal the adsorption capacity (q(e,exp)) of pretreated activated carbon (PAC) was double that of the original activated carbon (OAC). With an increase in adsorption/MW times, the q(e,exp) of regenerated activated carbon (RAC) did not change much. Through Brunauer-Emmett-Teller (BET) analyses, the Micropore volume of PAC (V-micro = 0.4035 cm(3)g(-1)) was higher than that of OAC (V-micro = 0.1548 cm(3)g(-1)), this indicated that PAC creates a large number of micropores as a result of MW pretreatment. Also, S-BET of RAC kept within a stable range (824.97-868.88 cm(2)g(-1)), and S-BET of 6th-RAC was still as high as 861.18 m(2)g(-1) after 6 continuous adsorption/MW cycles, which indicated the activated carbon restored stable properties after multiple microwave regeneration.
查看更多>>摘要：The adsorption of metal atoms on two-dimensional (2D) nanomaterials shows promising applications in many aspects. In this work, the adsorption performance of 30 metal atoms on 2D graphene-like BC(3 )and AlC3 nano sheets have been systematically studied by density functional theory calculations. We determined the optimal adsorption strength and adsorption sites of metal atoms and analyzed the electronic properties and magnetic of "M@BC3 " and "M@AlC3 ". The results indicate that the existence of B and Al atoms can effectively improve the adsorption capability of metal atoms, meanwhile, the adsorption of metal atoms significantly changes the electronic and magnetic properties of 2D BC3 and AlC3 nanosheets.
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Elsevier