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1.
A method has been developed for the determination of hydroperoxides in poly-(2,6-dimethyl-1,4-phenyleneoxide), with a standard deviation of ±2.5%; the senstivity is 3 × 10-2 mol ROOH/g polymer. The method has been applied for studies of thermo- and photooxidative degradation of this polymer.  相似文献   

2.
The equilibrium and kinetics of solvent extraction of Cu2+ from aqueous solutions containing equimolar EDTA with Aliquat 336 in n‐decanol and kerosene at 298 K were investigated. The concentrations of Cu2+ (8–50 mol m?3), Cl? (5–60 mol m?3), and Aliquat 336 (20–100 mol m?3) were varied. A semi‐empirical model with three parameters was proposed to describe the equilibrium behavior, in which the non‐idealities in both aqueous and organic phases were considered. Over the ranges studied, the model agreed reasonably well with the experimental data (standard deviation, 15%). The forward and backward reaction rate constants were determined as (5.31 ± 0.16)×10?6 m9/4 mol?3/4 s?1 and (2.62 ± 0.09)×10?7 s?1, respectively, at 298 K. An interfacial reaction mechanism was proposed, which revealed that the reaction between the chelated anions and trimeric amine molecules at the interface was rate limiting. The derived rate laws were consistent with the experimental results. © 2002 Society of Chemical Industry  相似文献   

3.
The construction and characteristic performance of a new potentiometric PVC membrane sensor responsive for sodium dodecyl sulfate (SDS) are described. The sensor is based on the use of cetyltrimethylammonium‐tetraphenylborate (CTA‐TPB) ion‐pair complex as electroactive material in PVC matrix in presence of dioctyl phthalate as a solvent mediator. The sensor exhibits a rapid, stable and near‐Nernstian response for SDS over the concentration range of 5 × 10?3–5 × 10?6 mol dm?3 at 25 ± 2 °C and the pH range 4–8.5 with slope of 59.6 mV/decade change in SDS concentration. The lower detection limit is 5 × 10?6 mol dm?3 and the response time is 45 s. The determination of selectivity coefficients for different anions shows there is no interference except that of dodecyl benzene sulfonate (DBS?) ion which has a strong interference. The results obtained in the determination of SDS in toothpastes, using this sensor as an indicator electrode, were compared with those obtained from the spectrophotometric method using methylene blue as the reagent.  相似文献   

4.
It is demonstrated by the use of spin traps that during the early stages of thermal processing of PVC considerable concentrations (> 3 × 10?6 mol g?1) of free radicals are produced which are primarily responsible for the initial products (hydroperoxides, unsaturation, and hydrogen chloride) previously shown to be formed in the polymer. From a semiquantitative analysis of these products, it is estimated that more than 50% of the radicals are formed from hydroperoxides and the rest by mechanoscission of the polymer chain. The spin traps are effective processing stabilizers in combination with a tin maleate HC1 scavenger. One of them (2-methyl-2-nitroso propane, MNP) has also been shown to be a photoantioxidant.  相似文献   

5.
Jojoba, [Simmondsia chinensis (Link) Schneider] is a commercially important dioecious, desert shrub which is mainly cultivated for liquid wax (oil) present in its seeds (40–60 %). The oil is being utilized by the cosmetic, pharmaceuticals, and other industries for certain formulations. In this study, gender based differences in biochemical and physiological parameters were examined in relation to natural drought conditions. The amount of protein, proline, cysteine, chlorophyll a and b, carotenoids and enzymatic activities were evaluated in leaves of male and female Jojoba genotypes. Significant differences between genders were found which was attributed to higher drought tolerance of males than females. Males showed higher contents of protein (113.05 ± 0.88 mg g?1 FW), proline (95.13 ± 2.33 µmol g?1 FW), cysteine (42.47 ± 2.69 µmol g?1 FW) than females (proteins: 70.77 ± 0.52 mg g?1 FW, proline: 66.61 ± 1.75 µmol g?1 FW, cysteine: 17.84 ± 3.00 µmol g?1 FW). Malondialdehyde (MDA) content was lower in male genotypes (18.29 ± 0.53 µmol g?1 FW) than female genotypes (23.02 ± 0.70 µmol g?1 FW). Higher activities of catalase (CAT) [0.088 ± 0.005 nkat mg?1 protein], guaiacol peroxidase (GPX) [0.006 ± 0.001 nkat mg?1 protein], glutathione reductase (GR) [9.02 ± 0.04 nkat mg?1 protein], ascorbate peroxidase (APX) [4.28 ± 0.08 nkat mg?1 protein] and superoxide dismutase (SOD) [151.75 ± 3.58 nkat mg?1 protein] were found in males compared to females [CAT: 0.007 ± 00 nkat mg?1 protein, GPX: 0.003 ± 00 nkat mg?1 protein, GR: 6.40 ± 0.06 nkat mg?1 protein, APX: 3.08 ± 0.06 nkat mg?1 protein, SOD: 52.51 ± 1.73 nkat mg?1 protein]. Chlorophyll b content was also higher in males than females.  相似文献   

6.
A graft copolymer based on a polysaccharide (sodium salt of carboxymethylcellulose) and a vinyl monomer (acrylamide) has been synthesized in a nitrogen atmosphere, and its reaction conditions have been optimized for a better yield with ferrous sulfate and potassium bromate as a redox initiator. The effects of ferrous ion, bromate ion, hydrogen ion, sodium carboxymethylcellulose, and acrylamide along with the reaction time and temperature have been studied through the determination of the grafting parameters: the grafting ratio, add‐on, conversion, efficiency, homopolymer, and rate of grafting. The maximum yield has been found to occur when the acrylamide concentration is 8.0 × 10?2 mol/dm3, whereas the maximum conversion occurs at a minimum concentration of acrylamide, that is, at 3.0 × 10?2 mol/dm3. The grafting parameters have been found to increase with an increasing concentration of the redox initiator (Fe2+, from 2.0 × 10?3 to 10.0 × 10?3 mol/dm3; BrO, from 2.2 × 10?3 to 4.0 × 10?3 mol/dm3). The maximum efficiency occurs with a reaction time of 210 min. The rate of grafting has been found to be maximum up to 60 min; after that, it decreases rapidly. In this article, it is shown that the hydrogen ion leads to a very clear decrease in the grafting parameters as its concentration increases from 2.1 × 10?3 to 11.3 × 10?3 mol/dm3. Grafted gum and ungrafted gum have been characterized with Fourier transform infrared spectroscopy and thermogravimetric analysis. A probable mechanism has been suggested for graft copolymerization. It has been observed that the graft copolymer is thermally more stable than the parent backbone. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008  相似文献   

7.
《分离科学与技术》2012,47(12):1793-1801
The sorption behavior of silver ions on rice husk has been investigated in detail. Various physico-chemical parameters were optimized to simulate the best conditions in which this material can be used as an adsorbent. Maximum adsorption was observed at 0.001 mol L?1 of acid solutions (HNO3, H2SO4 and HClO4) using 0.5 g of adsorbent for 9.27 × 10?5 mol L?1 silver concentration in fifteen minutes equilibration time. The adsorption of silver was decreased with the increase in the concentrations of all the acids used. The kinetic data indicated an intraparticle diffusion process with sorption being pseudo-second order. The determined rate constant k2 was 14.707 ± 1.832 mol g?1 min?1. The adsorption data obeyed the Freundlich, Langmuir, and Dubinin-Radushkevich isotherms over the silver concentration range of 1.85 × 10?4 to 1.16 × 10?3 mol L?1. The characteristic Freundlich constants, that is, 1/n = 0.38 ± 0.033 and K = 0.271 ± 0.104 m mol g?1 whereas the Langmuir constants Q = (1.504 ± 0.054) × 10?2 m mol g?1 and b = (16.582 ± 2.227) × 103 dm3 mol?1 have been computed for the sorption system. The sorption mean free energy from the Dubinin-Radushkevich isotherm is 12.16 ± 0.82 kJ mol?1 indicating ion-exchange mechanism of chemisorption. The uptake of silver increases with the rise in temperature (283–333 K). Thermodynamic quantities, namely, ΔG, ΔS, and ΔH have also been calculated for the system. The sorption process was found to be endothermic. The effect of other cations and anions on the adsorption of silver has also been studied.  相似文献   

8.
The distribution of hydroperoxides among lipid fractions (namely neutral lipids, glycolipids, sphingolipids, and phospholipids) of the oleaginous fungus Cunninghamella echinulata was studied during the growth cycle. The lipid hydroperoxide content of total lipids increased during growth. Neutral lipids contained a small amount of hydroperoxides (0.78×10–4–5×10–4 µmol/mg), glycolipids plus sphingolipids contained large amounts of hydroperoxides (14×10–4–17.6×10–4 µmol/mg), while the hydroperoxide content of phospholipids increased greatly during growth (from 4.6×10–4 to 38×10–4 µmol/mg). In addition, the distribution of lipid hydroperoxides among the major phospholipid classes indicated that the neutral phospholipids, namely phosphatidylcholine and phosphatidylethanolamine, were more susceptible to peroxidation than the anionic ones (i.e. phosphatidylinositol and phosphatidylserine). A novel parameter, namely “specific lipid peroxidizability”, which is able to evaluate the susceptibility to peroxidation (peroxidizability) of each lipid fraction/class due to the nature of the lipid itself, was introduced. By using this parameter it was found that peroxidizability depended on the nature of the individual lipid rather than on its polyunsaturated fatty acid content.  相似文献   

9.
《分离科学与技术》2012,47(15):1363-1375
Abstract

Adsorption of microamounts of silver on manganese dioxide from nitric and perchloric acid solutions has been studied and optimized with respect to shaking time, concentrations of electrolyte, adsorbent, and adsorbate. Maximum adsorp- tion (>99.5%) has been achieved from 0.01 mol/dm3 acid solution using 50 mg oxide at 10?5 mol/dm3 silver concentration after 30 min shaking. The adsorption decreases with increasing concentration of acid and adsorbate from both the acids. The presence of a 104-fold greater concentration of cyanide, thiocyanate, thiosulfate, and Pb(II) than silver reduces the adsorption drastically. The adsorption of silver follows the Freundlich adsorption isotherm over the entire concentration range investigated from 9.27 × 10?6 to 2.92 × 10?3 mol/dm3 with a value of A = 49 mmol/g and 1/n = 0.93. Moreover, the Langmuir adsorption isotherm is also valid except at the lowest and highest concentrations. The values of the limiting adsorption concentrtion (Cm ) have been found to be 1 mmol/g and of the equilibrium constant for adsorption 87 dm3/mol at 23 ± 2°C.  相似文献   

10.
《分离科学与技术》2012,47(14):2104-2112
The sorption behavior of lead ions on coconut coir has been investigated to decontaminate lead ions from aqueous solutions. Various physico-chemical parameters were optimized to simulate the best conditions in which this material can be used as an adsorbent. Maximum adsorption was observed at 0.0001 to 0.001 mol L?1 of acid solutions (HNO3, HCl and HClO4) using 0.4 g of adsorbent for 4.83 × 10?5 mol L?1 lead concentration in ten minutes equilibration time. The adsorption of lead was decreased with the increase in the concentrations of all the acids used. The kinetic data indicated an intraparticle diffusion process with sorption being pseudo-second order. The determined rate constant k2 was 8.8912 g mg?1 min?1. The adsorption data obeyed the Freundlich isotherm over the lead concentration range of 2.41 × 10?4 to 1.45 × 10?3 mol L?1. The characteristic Freundlich constants i.e., 1/n = 0.44 ± 0.02 and K = 0.184 ± 0.0096 m mol g?1 have been computed for the sorption system. The sorption mean free energy from the Dubinin-Radushkevich isotherm is 10.48 ± 0.72 kJ mol?1 indicating the ion-exchange mechanism of chemisorption. The uptake of lead increases with the rise in temperature (293–333 K). Thermodynamic quantities i.e., ΔG, ΔS, and ΔH have also been calculated for the system. The sorption process was found to be endothermic. The proposed procedure was successfully applied for the removal of lead from battery wastewater samples.  相似文献   

11.
The activated rate theory (ART) for solid-phase crystallization has been interpreted to assess its key features with previous data for spray-dried lactose and new data for spray-dried sucrose. The theory implies that the kinetic parameters for the two sugars should be different due to the differences in their structural configurations. The activation enthalpy for solid-phase crystal growth has been found to be 39 ± 2 kJ/mol for lactose and 68 ± 4 kJ/mol for sucrose. These activation enthalpies are close to the values for liquid-phase crystallization (40 kJ mol?1 for lactose; 66–75 kJ mol?1 for sucrose) from previous literature, suggesting that the theory might apply to both liquid- and solid-phase crystallization. There are also physical arguments for suggesting that the activated state in the new theory has features of both solid- and liquid-phase crystallization. For lactose and sucrose, the crystal growth rate constants at 25°C have been found to be 1.4 × 10?4 s?1and 2.5 × 10?5 s?1, respectively, similar to the literature values of 1.3 × 10?4 s?1and 3 × 10?5 s?1, respectively. The difference in the thermodynamic parameters between the two sugars has been found to be significant, as expected from the differences in their structures. Interpreting the sucrose data in terms of the Williams-Landel-Ferry equation and the Avrami equation has shown their limitations and inconsistencies for the new sucrose data, as found previously for lactose. Key features of the ART are highlighted and discussed. These features include minimum activation enthalpies and maximum activation entropies at particular moisture contents for each sugar and minimum and maximum moisture contents below which crystallization is predicted to occur very slowly.  相似文献   

12.
Asymmetric structures were fabricated by depositing Y2O3‐doped SiO2 (Si/Y) membranes onto γ‐Al2O3 supported by tubular α‐Al2O3. The thickness of the Y2O3‐doped SiO2 deposits was approximately 100 nm. The deposits/membranes have micropores with a pore diameter ~ <0.40–0.55 nm. Pore size distribution measurements were conducted directly on the membranes before and after hydrothermal treatment with a nano‐permporometer. The gas permeance properties of the membranes were measured in the temperature range 100°C–500°C. The Y‐doped SiO2 membrane (Si/Y = 3/1) was found to exhibit asymptotically stable permeances of 2.39 × 10?7 mol/m2/s/Pa for He and 6.19 × 10?10 mol/m2/s/Pa for CO2, with a high selectivity of 386 (He/CO2) at 500°C for 20 h in the presence of steam. The Y‐doped silica membranes exhibit very high gas permeances for molecules with smaller kinetic diameters. The apparent activation energies of the H2 permeance at 400°C were 24.2 ± 0.2 and 21.3 ± 0.7 kJ/mol for SiO2 and Si/Y, respectively.  相似文献   

13.
The results of adiabatic compressibility measurements for two copolymers, acrylic acid-vinyl pyrrolidone (AA—VP) and N-dimethylaminoethyl methacrylate-vinyl pyrrolidone (DAM—VP), in three different solvents, namely, water, methanol, and dioxane, have been described. The molecular weight of copolymers was determined by the light scattering method and the IR and NMR spectra of the polymers and copolymers were examined to establish that the alternating acrylic acid–vinyl pyrrolidone and N-dimethylaminoethyl methacrylate–vinyl pyrrolidone structure exists in the copolymers. The AA—VP copolymer behaves as a slightly weaker acid than the homopolymer of acrylic acid, while DAM—VP copolymer is very feebly basic and has the same strength as that of the homopolymer of N-dimethylaminoethyl methacrylate. The reduced viscosity for the two copolymers in aqueous solution is very low (~0.08 dL/g for AA—VP copolymer). In methanol solution AA—VP and DAM—VP copolymers show a decrease of øK°2 and øV°2 by 61.6 × 10?4 cc/bar/mol and 8.0 cc/mol, and 191.0 × 10?4 cc/bar/mol and 20.0 cc/mol, respectively, over that of the values of aqueous solution. The void space around the solute is smaller in methanol than in water, and accordingly this decrease has been attributed to geometric effect. Only one copolymer, DAM—VP is soluble in dioxane, and the values are seen to have increased in this solution by 71.0 × 10?4 cc/bar/mol and 18.7 cc/mol, respectively, compared to the values obtained from aqueous solution. The experimentally determined øK°2 and øV°2 for AA—VP and DAM—VP copolymer are 0.6 × 10?4 cc/bar/mol, and 102.4 cc/mol and ?61.0 × 10?4 cc/bar/mol, 94.4 cc/mol, respectively, in aqueous solution, and ?12.0 × 10?4 cc/bar/mol, 211.0 cc/mol and ?203.0 × 10?4 cc/bar/mol, 191.0 cc/mol, respectively, in methanol solution. In dioxane solution the values for DAM—VP copolymer are 59.0 × 10?4 cc/bar/mol and 229.7 cc/mol, respectively. These experimentally determined values for AA—VP copolymer show an increase by 0.04 × 10?4 cc/bar/mol, 4.4 cc/mol and 28.3 × 10?4 cc/bar/mol, 8.0 cc/mol in aqueous and methanol solution, respectively, compared to calculated values determined on the basis of no interaction between acid and the pyrrolidone group. In contrast, the DAM—VP copolymer shows a decrease of 27.6 × 10?4 cc/bar/mol and 10.3 cc/mol, 149.3 × 10?4 cc/bar/mol and 20.2 cc/mol, and 23.0 × 10?4 cc/bar/mol and 4.1 cc/mol in aqueous, methanol, and dioxane solutions, respectively. In aqueous solution these differences between calculated and observed values have been attributed to a change of water structure around the copolymer chain. A similar effect is responsible for the difference of the values in the methanol solution also. In the dioxane solution the difference is rather small, and the solvent structure has probably not altered much due to the presence of the DAM unit in the chain.  相似文献   

14.
A method is presented for surface encapsulation of nano-Fe3O4 by o-phenylenediamine via cross-linking using formaldehyde and glutaraldhyde for the formation of two newly designed magnetic nano-sorbents. These have been characterized by FT-IR, TGA, and SEM and maintained the magnetic and thermal stability characters. The metal capacity values of Pb(II) and Cd(II) have been optimized in presence of different physico-chemical parameters and confirmed the superior selectivity for Pb(II). Maximum capacity values of Pb(II) (7000-10000 ± 250-675 µmol g?1) and Cd(II) (1500-2250 ± 30-75 µmol g?1) at optimum conditions and excellent extraction values (94.10-100.0 ± 1.2-3.5%) from industrial wastewater have been identified.  相似文献   

15.
Copolymeric nanohydrogels based on N‐isopropylacrylamide, N‐(pyridin‐4‐ylmethyl)acrylamide and tert‐butyl‐2‐acrylamidoethyl carbamate, synthesized by microemulsion polymerization, were characterized using Fourier transform infrared spectroscopy and their size (38–52 nm) determined using quasielastic light scattering. Folic acid was covalently attached to the nanohydrogels (1.40 ± 0.07 mmol g?1). Tamoxifen (6.7 ± 0.2–7.3 ± 1.2 µg TMX mg?1 nanohydrogel), a hydrophobic anticancer drug, and 5‐fluorouracil (7.7 ± 0.7–10.14 ± 1.75 µg 5‐FU mg?1 nanohydrogel), a hydrophilic anticancer drug, were loaded into the nanohydrogels. Maximum in vitro TMX release (77–84% of loaded drug) depended on interactions of the drug with hydrophobic clusters of the nanogels; however, no nanogel/5‐FU interactions allowed total release of the loaded drug. The cytotoxicity of unloaded nanohydrogels in MCF7, T47D and HeLa cells was low. Cell uptake of nanogels without bound folic acid took place in the three cell types by unspecific internalization in a time‐dependent process. Cell uptake increased for folic acid‐targeted nanohydrogels in T47D and HeLa cells, which have folate receptors. The administration of 10 and 30 µmol L?1 TMX by TMX‐loaded nanogels and 10 µmol L?1 5‐FU by 5‐FU‐loaded nanogels was effective on the three cell types, and the best results were obtained for folic acid‐targeted nanohydrogels. Copyright © 2012 Society of Chemical Industry  相似文献   

16.
The aqueous polymerization of acrylamide initiated by potassium permanganate/β-hydroxybutyric acid has been studied volumetrically at 35 ± 0.01°C in an inert medium. The rate of polymerization shows nearly square root dependence on β-hydroxybutyric acid at low concentration (3.12 – 12.5 · 10?3 mol dm?3). The order with respect to potassium permanganate has been found to be 0.6 indicating thereby a bimolecular mode of termination. The polymerization rate has been varied linearly at low monomer concentrations i.e. from 2.5 –7.0 · 10?2 mol dm?3. The dependence of number average degree of polymerization on the initial rate of polymerization and temperature has been determined. The over-all activation energy has been found to be 51.66 kJ mol?1. A kinetic reaction scheme is proposed on the basis of experimental results.  相似文献   

17.
《分离科学与技术》2012,47(7):984-992
Incorporation of humic acid in the FDU-1 mesoporous silica improved Hg(II) adsorption and did not destroy the ordered network, providing surface area of 500 m2 g?1, pore volume of 0.9 cm3 g?1, and mean pore diameter of 10 nm. Carboxylic and phenolic groups increased the affinity by forming surface complexes with Hg(II). Isotherms (25.0 ± 0.1°C) were fitted to the Freundlich equation, exhibiting Kf values that increased with pH and 1/n that decreased to values < 1 with the heterogeneity of sites. Hg(II) desorption in 0.10 mol L?1 acetic acid was lower than 10%, suggesting that chemisorption processes govern the Hg(II) removal.  相似文献   

18.
Identification of the products of irradiated micelles of linolenic acid methyl ester (5×10?2mol · dm?3) in the presence of O2 has been studied using GC, chemical-ionization (CI/MS) and electron-ionization (EI/MS) mass spectrometry. CI/MS showed better results than EI/MS, where 17 products have been identified by the former method. However four products only have been recognized using latter method, this due to the disappearing of the molecular ion of the relatively high molecular weight products. The products include hydrocarbons, fatty acids, hydroxy compounds, hydroperoxides and epoxides.  相似文献   

19.
Sohn JH  Taki Y  Ushio H  Ohshima T 《Lipids》2005,40(2):203-209
A flow injection analysis (FIA) system coupled with a fluorescence detection system using diphenyl-1-pyrenylphosphine (DPPP) was developed as a highly sensitive and reproducible quantitative method of total lipid hydroperoxide analysis. Fluorescence analysis of DPPP oxide generated by the reaction of lipid hydroperoxides with DPPP enabled a quantitative determination of the total amount of lipid hydroperoxides. Use of 1-myristoyl-2-(12-((7-nitro-2-1,3-benzoxadiazol-4-yl)amino) dodecanoyl)-sn-glycero-3-phosphocholine as the internal standard improved the sensitivity and reproducibility of the analysis. Several commercially available edible oils, including soybean oil, rapeseed oil, olive oil, corn oil, canola oil, safflower oil, mixed vegetable oils, cod liver oil, and sardine oil were analyzed by the FIA system for the quantitative determination of total lipid hydroperoxides. The minimal amounts of sample oils required were 50 μg of soybean oil (PV=2.71 meq/kg) and 3 mg of sardine oil (PV=0.38 meq/kg) for a single injection. Thus, sensitivity was sufficient for the detection of a small amount and/or low concentration of hydroperoxides in common edible oils. The recovery of sample oils for the FIA system ranged between 87.2±2.6% and 102±5.1% when PV ranged between 0.38 and 58.8 meq/kg. The CV in the analyses of soybean oil (PV=3.25 meq/kg), cod liver oil (PV=6.71 meq/kg), rapeseed oil (PV=12.3 meq/kg), and sardine oil (PV=63.8 meq/kg) were 4.31, 5.66, 8.27, and 11.2%, respectively, demonstrating sufficient reproducibility of the FIA system for the determination of lipid hydroperoxides. The squared correlation (r 2) between the FIA system and the official AOCS iodometric titration method in a linear regression analysis was estimated at 0.9976 within the range of 0.35−77.8 meq/kg of PV (n=42). Thus, the FIA system provided satisfactory detection limits, recovery, and reproducibility. The FIA system was further applied to evaluate changes in the total amounts of lipid hydroperoxides in fish muscle stored on ice.  相似文献   

20.
This article provides evidences that hydride transfer is an important primary step in ozone reactions of formate and tertiary butanol in aqueous media. In both systems, one argument is the fact that the free hydroxyl radical yields are relative low ((40 ± 4)% and (7 ± 0.8)% for formate and tertiary butanol, respectively). Another hint is the high exergonicity of these reactions: ΔG = –249 kJ mol?1 for formate/ozone system and ΔG = –114 kJ mol?1 for hydride transfer followed by a methyl shift in the reaction between tertiary butanol and ozone. In addition, the main product of tertiary butanol ozonolysis is butan-2-one [(89 ± 3)%], a compound that is formed only via hydride transfer. For the reaction of ozone with formate an activation energy of (54.6 ± 1.2) kJ mol?1 and a pre-exponential term of (2.5 ± 1.2) × 1011 were determined (in the presence of tertiary butanol as ?OH scavenger) whereas for tertiary butanol the two activation parameters were (68.7 ± 1.9) kJ mol?1 and (2.0 ± 1.5) × 109, respectively.  相似文献   

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