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1.
Catalysis Letters - A new zirconium based carbonaceous solid acid catalyst Zr@CC-PA with both Lewis and Bronsted acidic sites was prepared by simultaneous carbonization and phosphonation of glucose... 相似文献
2.
Maimaitiaili Tayier Yunfeng Zhao Dengle Duan Rongge Zou Yunpu Wang Roger Ruan 《木材化学与工艺学杂志》2020,40(3):190-199
AbstractLignin biochar-catalytic depolymerization using biochar Fe-600, Fe-800, Ni-600, Ni-800 catalysts under microwave-heating (180?°C for 30?min) was explored in an ethanol/formic acid (1:1) media. Non-catalyst depolymerization was also studied and compared with the biochar-catalysts results. Characteristics of the bio-char catalysts were analyze by BET, XRD, and FT-IR. GPC, FT-IR, and MALDI-TOF MS spectrometry were also used to characterize the depolymerization products. The experimental results showed that the SBET, Vt, and Vmec and average pore diameter of the biochars are considerably dependent on the preparation temperature and type of cation (Ni2+ or Fe3+). The maximum yield of bio-oil product was obtained as 85?wt% with the addition of biochar Ni-600 and the total amount of oligomers or monomers with a molecular weight of 164 to 446 reaches 80.4%. 相似文献
3.
Vrushali Dengle-Pulate Parul Chandorkar Sunil Bhagwat Asmita Ashutosh Prabhune 《Journal of surfactants and detergents》2014,17(3):543-552
In recent years, researchers have developed biosurfactants for industrial, pharmaceutical and medical applications revealing the promising biological activities of these biomolecules. One of the best studied microbial surfactants are glycolipids, especially sophorolipids (SLs) produced by selected non-pathogenic yeast species of Candida. They are biodegradable, non-toxic and are environmentally friendly. Sophorolipid production was carried out using glucose as the hydrophilic source and lauryl alcohol C12–14, as the hydrophobic source using Candida bombicola ATCC 22214. Primary characterization of the SL obtained using lauryl alcohol (SLLA) was done by FTIR which depicted the presence of alkyl sophorosides/SLs. Antimicrobial activity testing revealed that SLLA showed complete inhibition against gram negative bacteria, Escherichia coli (ATCC 8739) Pseudomonas aeruginosa (ATCC 9027) at 30 and 1 μg/ml at a contact time of 2 and 4 h respectively. Whereas for gram positive bacteria Staphylococcus aureus (ATCC 6358), Bacillus subtilis (ATCC 6633), complete inhibition was observed at 6 and 1 μg/ml respectively at a contact time of 4 h. The formed SLLA showed noteworthy inhibition against the pathogenic yeast Candida albicans (ATCC 2091) at 50 μg/ml with a contact time of 4 h. These values are remarkably low compared to reported values of oleic acid SLs and linolenic acid SLs which were studied for antimicrobial properties. Scanning electron microscopy analysis of the treated cells revealed the changes in morphology and topography of the microorganisms. 相似文献
4.
Vrushali A. Bokil Yingda Cheng Yan Jiang Fengyan Li Puttha Sakkaplangkul 《Journal of scientific computing》2018,77(1):330-371
In this paper, we consider electromagnetic (EM) wave propagation in nonlinear optical media in one spatial dimension. We model the EM wave propagation by the time-dependent Maxwell’s equations coupled with a system of nonlinear ordinary differential equations (ODEs) for the response of the medium to the EM waves. The nonlinearity in the ODEs describes the instantaneous electronic Kerr response and the residual Raman molecular vibrational response. The ODEs also include the single resonance linear Lorentz dispersion. For such model, we will design and analyze fully discrete finite difference time domain (FDTD) methods that have arbitrary (even) order in space and second order in time. It is challenging to achieve provable stability for fully discrete methods, and this depends on the choices of temporal discretizations of the nonlinear terms. In Bokil et al. (J Comput Phys 350:420–452, 2017), we proposed novel modifications of second-order leap-frog and trapezoidal temporal schemes in the context of discontinuous Galerkin methods to discretize the nonlinear terms in this Maxwell model. Here, we continue this work by developing similar time discretizations within the framework of FDTD methods. More specifically, we design fully discrete modified leap-frog FDTD methods which are proved to be stable under appropriate CFL conditions. These method can be viewed as an extension of the Yee-FDTD scheme to this nonlinear Maxwell model. We also design fully discrete trapezoidal FDTD methods which are proved to be unconditionally stable. The performance of the fully discrete FDTD methods are demonstrated through numerical experiments involving kink, antikink waves and third harmonic generation in soliton propagation. 相似文献
5.
Vrushali Shelke B. K. Sonawane M. P. Bhole D. S. Patil 《Journal of Materials Science: Materials in Electronics》2012,23(2):451-456
Electrical, optical and structural properties of tin doped ZnO thin films were investigated for various tin (Sn) doping concentrations.
Sol gel method was used to deposit the films on microscopic glass slides and silicon substrate. UV–Visible spectrometer analysis
showed excellent optically transparent oscillating natures with transparency above 85% in the visible range. Band gap of 3.24 eV
was deduced for Sn doping concentration of 4 at% using envelope method. Scanning electron microscopy (SEM) was employed to
study the morphology of the films. Crystallinity of the film was investigated by X-Ray diffraction (XRD), which revealed polycrystalline
nature with orientation towards c-axis. Resistivity of 3.11 Ω-cm with minimum stress value of 8.11 × 10−3 MPa was measured for Sn doping concentration of 4 at%. 相似文献
6.
Dengle Duan Zongcai Tu Hui Wang Xiaomei Sha Xiumei Zhu 《International Journal of Food Properties》2017,20(4):734-744
The effect of dynamic high-pressure microfluidization on physicochemical and rheological properties of rice amylose pastes were examined. The amylose dispersions were pressurized at 60, 100, 140, and 180 MPa. The microfluidization treated rice amylose showed elevated solubility, swelling power, and moisture absorbability. The retrogradability was significantly decreased with the pressure increase. Iodine blue value showed a significant increase at 60~140 MPa, while a slight decrease at 180 MPa. The rheological results indicated that native amylose was a non-Newtonian fluid and displayed pseudoplastic fluids characteristics. The amylose moved toward a Newtonian fluid behavior and its rheopexy decreased with the pressure increased. 相似文献
7.
Kanchan M. Samant Vrushali S. Joshi Geeta Sharma Sudhir Kapoor Santosh K. Haram 《Electrochimica acta》2011,(5):2081
We report the electrodics of methanol oxidation on Pt-multiwalled carbon nanotube composites (Pt-f-MWCNTs), prepared by γ-radiolysis of K2PtCl6 in the presence of HOOC-functionalized multiwalled carbon nanotubes. The electrocatalytic activity for the methanol oxidation was studied using cyclic and linear sweep voltammetric techniques on the stationary indium tin oxide and rotating gold disc electrodes, respectively. Higher values of oxidative (anodic) current were obtained using Pt-f-MWCNTs compared to the polycrystalline Pt electrode. This phenomenon is attributed to the synergistic effect of oxy groups on MWCNTs, which alleviate CO poisoning. The electrodics of the reaction at various temperatures was studied using linear sweep voltammetry (LSV) on a rotating disc gold electrode, modified with the composite. From the Koutecky-Levich plots, the standard rate constant (k0) was determined to be 7.9 ± 1.9 × 10−8 cm s−1. 相似文献
8.
Vrushali Dengle Pulate Sunil Bhagwat Asmita Prabhune 《Journal of surfactants and detergents》2013,16(2):173-181
Sophorolipids (SL) are glycolipid biosurfactants abundantly produced from different feedstocks by yeasts and have been widely developed for various applications. The amphipathic structures of sophorolipids imparts to them surfactant type properties. These biosurfactants are readily isolated in high yield and are nontoxic and biodegradable, which make them industrially interesting as surfactants or emulsifiers. Sophorolipid production was carried out using glucose as a hydrophilic source and lauryl alcohol C12–14, as a hydrophobic source by Candida bombicola (ATCC 22214). Process economics and environmental attractiveness was increased by using a low cost substrate. Optimization studies were carried out where the effect of glucose concentration, pH, temperature and metal ions on sophorolipid production was studied. Optimum production of sophorolipid obtained using lauryl alcohol (SLLA) was achieved after 96 h, the initial pH of the medium was 6.0 with 10 % glucose at 30 °C. Primary characterization of SLLA was done by FTIR. The SLLA showed high physicochemical properties in terms of the surface activities when compared with synthetic surfactants including dodecyl tetraethylene glycol ether and sodium lauryl sulfate. The surface tension of SLLA thus obtained was found to be 24 mN/m with a critical micellar concentration (CMC) value of 0.68 mg/L. Antimicrobial testing showed that SLLA have potent antimicrobial activity against both gram negative bacteria, Escherichia coli (ATCC 8739) and gram positive cocci, Staphylococcus aureuss (ATCC 2079). 相似文献
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Aluminum doped ZnO thin film nanostructures were prepared by spin coating deposition on glass and silicon substrates. Electrical, optical and structural properties of these films were analyzed in order to investigate their dependence on post annealing temperature and number of coating cycles. Ultraviolet–Visible spectrophotometry and X-Ray diffraction (XRD) analysis confirmed that the films are optically transparent and polycrystalline in nature. Scanning electron microscopy (SEM) reveals worm like homogeneous morphology. Chemical analysis was carried out by Fourier transform infrared spectroscopy (FTIR). Atomic force microscopy (AFM) showed mountain and valley like nanostructure. Optimized films with a low resistivity of 2.11 × 10−1 Ω cm were obtained at open air annealing temperature of 375 °C. 相似文献