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31.
The Incorporation of Titania into Modified Silicates for Solar Photodegradation of Aqueous Species 总被引:2,自引:0,他引:2
Lowell R. Matthews David Avnir Alexander D. Modestov Srinivasan Sampath Ovadia Lev 《Journal of Sol-Gel Science and Technology》1997,8(1-3):619-623
A new class of sol-gel-derived photocatalytic materials has been synthesized and used in solar-assisted photodegradation studies. The materials are comprised of a homogeneous dispersion of commercial TiO2 powder into silica and organically modified silicate (Ormosil) hosts. The efficiency of the photocatalytic properties of these TiO2-containing materials was determined by their relative performance in the solar photodecomposition of aqueous rhodamine B. The improved adsorption properties of the modified materials compared to commercial TiO2 increase the photodecomposition rate and the buoyancy properties, although excess hydrophobicity decreases the wetted section of the catalyst and its photocatalytic performance. These materials can be used as floatable catalysts for solar-assisted water purification. 相似文献
32.
P. Rajaram B. Viswanathan G. Aravamudan V. Srinivasan M.V.C. Sastri 《Thermochimica Acta》1973,7(2):123-129
The reaction of MoO3 with various oxides of manganese (MnO, Mn2O3, Mn3O4 and MnO2) and with MnCO3 has been studied in air and nitrogen atmospheres employing DTA, TG and X-ray diffraction methods, with a view to elucidating the conditions for the formation of MnMoO4. Thermal decomposition of MnCO3 has also been studied in air and nitrogen atmospheres to help understand the mechanism of the reaction between MnCO3 and MoO3. The studies reveal that, whereas MnO, Mn2O3 and MnO2 react smoothly with MoO3 to form MnMoO4, Mn3O4 does not react with MoO3 in the temperature range investigated (48O–6OO°C). An equimolar mixture of MnCO3 and MoO3 reacts in air to yield MnMoO4, while only a mixture of Mn3O4 and MoO3 remains as final product when the same reaction is carried out in nitrogen. Marker studies reveal that manganese ions are the main diffusing species in the reaction between MoO3 and manganese oxides that result in MnMoO4. 相似文献
33.
Carbonate radicals react with aliphatic amines by a dual mechanism, viz. (i) hydrogen abstraction and (ii) electron transfer. The former is more probable with primary amines. Tertiary amines react via electron transfer. Both mechanisms may operate in secondary amines. Cyclic tertiary amines react with different rates and their relative reactivities are explained on the basis of the concept of Hoffmann's ‘through bond’ interaction. 相似文献
34.
Kui Wu Nathan A. Yee Sangeetha Srinivasan Amir Mahmoodi Michael Zakharian Jose M. Mejia Oneto Maksim Royzen 《Chemical science》2021,12(21):7583
Correction for ‘Click activated protodrugs against cancer increase the therapeutic potential of chemotherapy through local capture and activation’ by Kui Wu et al., Chem. Sci., 2021, 12, 1259–1271, DOI: 10.1039/D0SC06099B.The authors regret that the reference to the bond-breaking bioorthogonal chemistry, termed ‘click-to-release’ was omitted from the original article. In addition, we would like to include a reference describing the synthesis of compound 1, which is an intermediate to the protodrugs described in the original article. These references are listed below as ref. 1 and 2.The Royal Society of Chemistry apologizes for these errors and any consequent inconvenience to authors and readers. 相似文献
35.
Ghosh S Krishnan A Das PK Ramakrishnan S 《Journal of the American Chemical Society》2003,125(6):1602-1606
The critical micelle concentration (CMC) of several surfactants that contain an NLO chromophore, either at the hydrocarbon tail, or at the hydrophilic headgroup, or even as a counterion, was determined by hyper-Rayleigh scattering (HRS). In all cases, the HRS signal exhibited a similar variation with surfactant concentration, wherein the CMC is inferred from a rather unprecedented drop in the signal intensity. This drop is attributed to the formation of small pre-micellar aggregates, whose concentrations become negligible above CMC. In addition, a probe molecule, which upon protonation yielded a species with significantly enhanced HRS intensity, was developed and its utility for the determination of the CMC of simple fatty acids was demonstrated. 相似文献
36.
Numerical Algorithms - A parabolic convection-diffusion-reaction problem is discretized by the non-symmetric interior penalty Galerkin (NIPG) method in space and discontinuous Galerkin (DG) method... 相似文献
37.
38.
On laser melt treatment,Sliding Wear of pearlitic ductile iron reduced from severe metallic wear to oxidative mild wear by nearly two orders of magnitude at 7.5 ms–1 over a load range of 14–31 kg cm–2; resistance toCavitation Erosion improved by a factor ofseven in corrosive media and surface hardness increased from 20–22 to 40–58 HRc. Laser melting could effectively reduceCorrosion rates in dilute acids by nearly 40%.These improvements were caused by the ultrafine microstructure (1–41 ,DAS), microhardness (700–900,HV
0,1) and the consequent high resistance to plastic flow and subsurface crack initiation.In this investigation, pin-on-disc adhesive wear, ultrasonic vibratory cavitation erosion and potentiodynamic corrosion in synthetic sea water and 0.01 N H2SO4, were assessed after laser surface melting or transformation hardening of hyper-eutectic ductile iron, typically employed in automotive and marine engine components by using CO2 CW or Nd-YAG pulsed high power laser. Also the processing parameters viz, beam power (P), scan rate (U), and specific energy intensity (P/UD
b
2
) for threshold and specific depth of transformation hardening or melting have been determined. 相似文献
39.
40.