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81.
Product studies were made using the Fourier transform infrared method in the uv (300–400-nm) photolysis of mixtures containing CH3SCH3, C2H5ONO, and NO in ppm concentrations in 700 torr of O2–N2 diluent. Methyl thionitrite, CH3SNO, arising from the reaction CH3S + NO, was detected as an intermediate product. In addition, the yields of the major sulfur-containing products SO2 and CH3SO3H coincided with those of the oxidation of the CH3S radicals generated directly by the photodissociation of CH3SNO. The formation of CH3S in the HO-initiated oxidation of CH3SCH3 in the presence of NO suggests a reaction scheme involving the H-abstraction reaction HO + CH3SCH3 → CH3SCH2 + H2O as the primary step. 相似文献
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Ana Joci Stefan Breitenbach Danica Bajuk-Bogdanovi Igor A. Pati Christoph Unterweger Christian Fürst Tamara Lazarevi-Pati 《Molecules (Basel, Switzerland)》2022,27(5)
Extensive use of pesticides resulting in their accumulation in the environment presents a hazard for their non-target species, including humans. Hence, efficient remediation strategies are needed, and, in this sense, adsorption is seen as the most straightforward approach. We have studied activated carbon fibers (ACFs) derived from viscose fibers impregnated with diammonium hydrogen phosphate (DAHP). By changing the amount of DAHP in the impregnation step, the chemical composition and textural properties of ACFs are effectively tuned, affecting their performance for dimethoate removal from water. The prepared ACFs effectively reduced the toxicity of treated water samples, both deionized water solutions and spiked tap water samples, under batch conditions and in dynamic filtration experiments. Using the results of physicochemical characterization and dimethoate adsorption measurements, multiple linear regression models were made to reliably predict performance towards dimethoate removal from water. These models can be used to quickly screen among larger sets of possible adsorbents and guide the development of novel, highly efficient adsorbents for dimethoate removal from water. 相似文献
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Ohne ZusammenfassungMit 6 Abbildungen 相似文献
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Marília Cavalcanti Coriolano Cynarha Daysy Cardoso da Silva Cristiane Moutinho Lagos de Melo Ranilson de Souza Bezerra Athiê Jorge Guerra Santos Valéria Rêgo Alves Pereira Luana Cassandra Breitenbach Barroso Coelho 《Applied biochemistry and biotechnology》2012,168(5):1335-1348
This work reports the isolation of a serum lectin from cobia fish (Rachycentron canadum) named RcaL. Immunomodulatory activity on mice splenocyte experimental cultures through cytotoxic assays and cytokine production were also performed. RcaL was obtained through precipitation with ammonium sulphate and affinity chromatography on a Concanavalin A-Sepharose 4B column. The ammonium sulphate fraction F3 showed the highest specific hemagglutinating activity and was applied to affinity chromatography. The lectin was eluted with methyl-α-d-mannopyranoside. RcaL showed highest affinity for methyl-α-d-mannopyranoside and d-mannose; eluted fractions of RcaL agglutinated rabbit erythrocytes (titre, 128?1) retained 66 % of chromatographed lectin activity, and the obtained purification factor was 1.14. Under reducing conditions, a polypeptide band of 19.2 kDa was revealed in sodium dodecyl sulphate polyacrylamide gel electrophoresis (PAGE). PAGE confirmed RcaL as an acidic protein revealed in a single band. Cytotoxic and immunomodulatory assays with RcaL in mice splenocyte cultures showed that the lectin was not cytotoxic and induced higher interferon gamma and nitric oxide production in splenocyte cultures. Purified RcaL induced preferential Th1 response, suggesting that it acts as an immunomodulatory compound. 相似文献
88.
The reaction 2NO2 + ROH = RONO + HNO3 (R = CH3 or C2H5) has been studied using the FTIR method at reactant pressures from 0.1 to 1.0 torr at 25°C. The termolecular rate constant for the forward reaction was determined to be (5.7 ± 0.6) × 10?37 cm6/molec2·s for CH3OH and (5.7 ± 0.8) × 10?37 cm6/molec2·s for C2H5OH, that is, d[RONO]/dt = k[NO2]2[ROH]. The corresponding equilibrium constants were measured as 1.36 ± 0.06 and 0.550 ± 0.025 torr?1, respectively. These results are consistent with those of a previous study based on the NO2 decay measurements at reactant pressures from 1 to 10 torr. 相似文献
89.
Using the FTIR method, chlorine nitrite (ClONO) and nitryl chloride (ClNO2) were identified as reaction products in the photolysis of Cl2-NO2 mixtures. The observed yields of ClONO (? 80%) and ClNO2 (? 20%) suggest that Cl atom adds mainly to the O atom rather than the N atom of NO2 molecule. 相似文献
90.
According to a reaction scheme which as its main features assumes that polymerization is predominantly in the interior of the monomer swollen polyvinyl chloride) particles and that all the decaying initiator finally contributes to the polymerization within the polymer particles, the ratio kp (f/kt)½ = K (where kp, kt are rate constants for chain propagation and chain termination, respectively, within the particles and f is initiator efficiency) has been calculated for bulk polymerization of vinyl chloride at three temperatures. K is found to be markedly larger than the corresponding quantity for homogeneous solution polymerization, e.g., at 50°C it is seven times this latter quantity. The characteristic ratio K shows a marked negative temperature dependence, which corresponds to approximately -4.5 kcal/mole for Ep - (Et/2), when f is assumed to be independent of temperature. This behavior is quite consistent with a strong gel effect being operative at the site of reaction, i.e., the swollen polymer particles can be taken as equivalent to a homogeneous polymerization system at high conversion. 相似文献