- Catalytic pyrolysis of cellulose in ionic liquid [bmim]OTf
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This study discussed the catalytic cracking process of cellulose in ionic liquid 1-butyl-3-methylimidazolium trifluoromethanesulfonate ([bmim]OTF) under 180 °C, 240 °C and 340 °C, found that [bmim]OTF is an effective catalyst which can effectively reduce the pyrolysis temperature(nearly 200 °C) of the cellulose. FRIR, XRD and SEM were used to analyze the structure characterization of fiber before and after the cracking; GC-MS was used for liquid phase products analysis; GC was used to analyze gas phase products. The results showed that the cellulose pyrolysis in [bmim]OTf mainly generated CO2, CO and H2, also generated 2-furfuryl alcohol, 2,5-dimethyl-1,5-diallyl-3-alcohol, 1,4-butyrolactone, 5-methyl furfural, 4-hydroxy butyric acid, vinyl propionate, 1-acetoxyl group-2-butanone, furan formate tetrahydrofuran methyl ester liquid product, and thus simulated the evolution mechanism of cellulose pyrolysis products based on the basic model of cellulose monomer.
- Qu, Guangfei,He, Weiwei,Cai, Yingying,Huang, Xi,Ning, Ping
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p. 390 - 396
(2016/05/19)
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- Benzimidazole compound
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An object of the present invention is to provide a novel chemical compound useful as a therapeutic or prophylactic agent for acid-related diseases, having an excellent inhibitory effect against gastric acid secretion, an excellent effect of maintaining the inhibitory effect against gastric acid secretion, thereby maintaining intragastric pH high for a long time, and having more safety and appropriate physicochemical stability. Provided is a compound represented by where R1 and R3 may be the same or different and each represent a hydrogen atom or a C1-C6 alkyl group; R2 represents (5,5-dimethyl-1,3-dioxan-2-yl)methoxy group, 5,7-dioxaspiro[2.5]oct-6-ylmethoxy group, 1,5,9-trioxaspiro[5.5]undec-3-ylmethoxy group, or (2,2-dimethyl-1,3-dioxan-5-yl)methoxy group; R4, R5, R6 and R7 represent a hydrogen atom, halogen atom, C1-C6 alkyl group, C1-C6 haloalkyl group, C1-C6 alkoxy group or C1-C6 haloalkoxy group; and W1 represents a single bond, methylene or ethylene group, a salt thereof or a solvate of these.
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Page/Page column 65
(2008/06/13)
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- Direct and facile syntheses of heterocyclic vinyl-C-nucleosides for recognition of inverted base pairs by DNA triple helix formation: First report by direct Wittig route
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(Chemical Equation Presented) The ability to recognize specific gene sequences canonically would allow precise means for genetic intervention. However, specific recognition of two of the four possible base pairs by triplex-forming oligonucleotides (TFO) as X·T-A and Y·C-G within a triplex currently remains elusive. A series of C1-vinyl nucleosides have been proposed, and their stability and specificity have been evaluated extensively by molecular dynamics simulation. Because most C-nucleoside syntheses extend through direct substitution at the C1-position, a more convenient strategy for their syntheses via a direct Wittig coupling is presented here.
- Rothman, Jeffrey H.
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p. 3945 - 3948
(2008/02/01)
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- Fine particulate matter (PM) and organic speciation of fireplace emissions
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This paper presents a summary of fireplace particle size and organic speciation data gathered to date in an ongoing project. Tests are being conducted in a residential wood combustion (RWC) laboratory on three factory- built fireplaces. RWC wood smoke particles 10 μm (PM10) consist primarily of a mixture of organic compounds that have condensed into droplets; therefore, the size distribution and total mass are influenced by temperature of the sample during its collection. During the series 1 tests (15 tests), the dilution tunnel used to cool and dilute the stack gases gave an average mixed gas temperature of 47.3 °C and an average dilution ratio of 4.3. Averages for the PM2.5 (particles 2.5 μm) and PM10 fractions were 74 and 84%, respectively. For the series 2 tests, the dilution tunnel was modified, reducing the average mixed gas temperatures to 33.8 °C and increasing the average dilution ratio to 11.0 in tests completed to date. PM2.5 and PM10 fractions were 83 and 91%, respectively. Since typical winter time mixed gas temperatures would usually be less than 10 °C, these size fraction results (even from the series 2 tests) probably represent the lower bound; the PM10 and PM2.5 size fractions might be higher at typical winter temperatures. The particles collected on the first stage (cutpoint ? 11.7 μm) were light gray and appeared to include inorganic ash. Particles collected on the remainder of the stages were black and appeared to be condensed organics because there was noticeable lateral bleeding of the collected materials into the filter substrate. Total particulate emission rates ranged from 10.3 to 58.4 g/h; corresponding emission factors ranged from 3.3 to 14.9 g/kg of dry wood burned. A wide range of Environmental Protection Agency (EPA) Method 8270 semivolatile organic compounds were found in the emissions; of the 17 target compounds quantified, major constituents are phenol, 2-methylphenol, 4- methylphenol, 2,4-dimethylphenol, and naphthalene. An account is given on fireplace particle size and organic speciation data gathered to date in an ongoing project. Total particulate matter emission rates and the results of analyses for semivolatile organics in the emissions are discussed.
- Purvis, Carol R.,Mccrillis, Robert C.,Kariher, Peter H.
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p. 1653 - 1658
(2007/10/03)
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- Gas-phase reaction of n-butyl acetate with the hydroxyl radical under simulated tropospheric conditions: Relative rate constant and product study
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The gas-phase reaction of n-butyl acetate with hydroxyl radicals has been studied in an environmental smog chamber at 298 K. atmospheric pressure, and simulated tropospheric concentrations The rate constant for this reaction has been determined by a relative method and the experimental result, relative to n-octane used as reference compound, is k = 5.2 ± 0.5 × 10-12 cm3 molecule-1 s-1 This value appears to be about 25% higher than absolute rate constants found in the literature, but agrees very well with the other relative determination. Two reaction products have been identified and their production yield has been estimated, each accounting for about (15 ± 5)% of the overall OH reaction processes The two observed products are 2-oxobutyl acetate (CH3-CO-O-CH2-CO-CH2-CH3) and 3-oxobutyl acetate (CH3-CO-O-CH2-CH2-CO-CH3) The accuracy of the relative rate constant obtained is examined considering the evolution of the reactivity of the alkoxy end of the esters. Formation mechanisms for the two observed products are proposed and the likely other degradation channels are discussed
- Veillerot,Foster,Guillermo,Galloo
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p. 235 - 243
(2007/10/03)
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- Chemistry of Dioxiranes. 21. Thermal Reactions of Dioxiranes
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Thermolysis of dioxiranes in solutions of their parent ketones or in mixtures of the parent ketone and a foreign ketone leads to the formation of esters.The results are explained by postulating a free-radical mechanism involving H atom abstraction from the ketones.The resulting radicals are converted to the observed esters by reaction with acyloxy radicals derived from homolysis of the dioxiranes.Autodecomposition of dimethyldioxirane in acetone solution at room temperature gives methyl acetate at a very slow rate.When catalyzed by BF3 etherate the same decomposition proceeds much more rapidly and is accompanied by acetol formation.
- Singh, Megh,Murray, Robert W.
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p. 4263 - 4270
(2007/10/02)
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