The chemical looping gasification uses an oxygen carrier for solid fuel gasification by supplying insufficient lattice oxygen. The effect of gasifying medium on the coal chemical looping gasification with Ca SO4 as ox...The chemical looping gasification uses an oxygen carrier for solid fuel gasification by supplying insufficient lattice oxygen. The effect of gasifying medium on the coal chemical looping gasification with Ca SO4 as oxygen carrier is investigated in this paper. The thermodynamical analysis indicates that the addition of steam and CO2 into the system can reduce the reaction temperature, at which the concentration of syngas reaches its maximum value.Experimental result in thermogravimetric analyzer and a fixed-bed reactor shows that the mixture sample goes through three stages, drying stage, pyrolysis stage and chemical looping gasification stage, with the temperature for three different gaseous media. The peak fitting and isoconversional methods are used to determine the reaction mechanism of the complex reactions in the chemical looping gasification process. It demonstrates that the gasifying medium(steam or CO2) boosts the chemical looping process by reducing the activation energy in the overall reaction and gasification reactions of coal char. However, the mechanism using steam as the gasifying medium differs from that using CO2. With steam as the gasifying medium, parallel reactions occur in the beginning stage, followed by a limiting stage shifting from a kinetic to a diffusion regime. It is opposite to the reaction mechanism with CO2 as the gasifying medium.展开更多
Introduction Chemical Abstracts Service （CAS）, a division of the American Chemical Society, is the most authoritative and comprehensive source for chemical information. CAS databases, including CAS REGISTRYSM, the g...Introduction Chemical Abstracts Service （CAS）, a division of the American Chemical Society, is the most authoritative and comprehensive source for chemical information. CAS databases, including CAS REGISTRYSM, the gold standard for substance information, are curated and quality-controlled by CAS scientists. Combining these databases with advanced search and analysis technologies, CAS delivers the most complete, cross-linked, and effective digital information environment for scientific research and discovery through such products as SciFinder, STN, STN Express, and STN AnaVistTM, as well as services, such as Science IP.展开更多
Chemical Abstracts(CA),a reputable international search tool,which involves the widest disciplinary field,collects the most literature types,offers the most searching ways,and has the most prodigious volumes,is edited...Chemical Abstracts(CA),a reputable international search tool,which involves the widest disciplinary field,collects the most literature types,offers the most searching ways,and has the most prodigious volumes,is edited and published by CAS-Chemical Abstracts in the USA.CA has reported more than 10 000 kinds of technology journals,technology reports,meeting papers,academic dissertations,data chronicles,technique reports,new books,and audiovisuals。展开更多
Chemical Abstracts(CA),a reputable international search tool,which involves the widest disciplinary field,collects the most literature types,offers the most searching ways,and has the most prodigious volumes,is edited...Chemical Abstracts(CA),a reputable international search tool,which involves the widest disciplinary field,collects the most literature types,offers the most searching ways,and has the most prodigious volumes,is edited and published by CAS-Chemical Abstracts in the USA.展开更多
Different fluxes were used to synthesize long persistence phosphors, calcium sulfides activated by Eu 2+ and Tm 3+ , by convenient solid state method. The phosphor using NH 4F as a flux has good crystallini...Different fluxes were used to synthesize long persistence phosphors, calcium sulfides activated by Eu 2+ and Tm 3+ , by convenient solid state method. The phosphor using NH 4F as a flux has good crystallinity and large particle size, its stability against water and other atmospheric components is enhanced, and its afterglow is longer and fluorescent intensity is more intense than those of the phosphor using NH 4Cl as flux. Their PL intensities varied with time in moist air were measured, no remarkable change was found for those prepared with NH 4F flux in contrast with NH 4Cl as flux. So using NH 4F as flux is a good method to enhance the stability of alkaline earth sulfides.展开更多
Laser-induced voltage effects in c-axis oriented Ca3Co4O9 thin films have been studied with samples fabricated on 10°tilted LaAIO3 （001） substrates by a simple chemical solution deposition method. An open-circu...Laser-induced voltage effects in c-axis oriented Ca3Co4O9 thin films have been studied with samples fabricated on 10°tilted LaAIO3 （001） substrates by a simple chemical solution deposition method. An open-circuit voltage with a rise time of about 10 ns and full width at half maximum of about 28 ns is detected when the film surface is irradiated by a 308-nm laser pulse with a duration of 25 ns. Besides, opemcircuit voltage signals are also observed when the film surface is irradiated separately by the laser pulses of 532 nm and 1064 nm. The results indicate that Ca3Co4O9 thin films have a great potential application in the wide range photodetctor from the ultraviolet to near infrared regions.展开更多
Microstructure study of chrome oxide bricks used in cool slurry gasifiers/Gao Zhenxin,Wang Zhanmin, Fan Muxu,Zhu Dexian, Fan Lixia, Zhang Wei, Liu Baikuan//Naihuo Cailiao. - 2017,51 （6） ： 401Abstract： For more in-...Microstructure study of chrome oxide bricks used in cool slurry gasifiers/Gao Zhenxin,Wang Zhanmin, Fan Muxu,Zhu Dexian, Fan Lixia, Zhang Wei, Liu Baikuan//Naihuo Cailiao. - 2017,51 （6） ： 401Abstract： For more in-depth research on erosion mechanism of re-bonded chrome oxide bricks for coal slurry gasifiers, the chemical composition and microstructure of the bricks before and after use were analyzed by means of X-ray fluorescence spectrometry, and FESEM-EDS.展开更多
Tl2Ba2Ca2Cu3O10 was reported to be a superconductor with a highest transition temperature of 125 K among the homologous series of Tl2Ba2Can-1CunO2n＋4. The direct information on the Cu ion site at the atomic level is ...Tl2Ba2Ca2Cu3O10 was reported to be a superconductor with a highest transition temperature of 125 K among the homologous series of Tl2Ba2Can-1CunO2n＋4. The direct information on the Cu ion site at the atomic level is important for elucidating the superconductivity mechanism. The local bond properties of Tl2Ba2Ca2Cu3O10 were studied using the average band-gap model. The calculated results show that the covalency of Cu（1）-O bond is 0.561, and the average covalency of Cu（2）-O is 0.296. Mossbauer isomer shifts of 57Fe in Tl2Ba2Ca2Cu3O10 were calculated using the chemical surrounding factor, defined by covalency and electronic polarizability. It is verified that for lower doping, Fe substitute the Cu at the Cu （1） site in forms of Fe^3＋ and Fe^4＋; for higher doping, Fe^3＋ and Fe^4＋ ion occupies Cu（1） and Cu（2） site respectively. The studies show that the determination of the correspondence between spectrum components and actual copper sites occupied by MSssbauer nucleus was made easier with the aid of the calculation results of the chemical bond parameters.展开更多
To achieve the continuous maintainence of optimum quality state of flue- cured tobacco laminas and the effective regulation and control on alcoholization time for controlled atmosphere storage （CAS） method in the pr...To achieve the continuous maintainence of optimum quality state of flue- cured tobacco laminas and the effective regulation and control on alcoholization time for controlled atmosphere storage （CAS） method in the process of storage, the lam- ina samples of natural alcoholization for 1 year were selected. Comparable analysis on the appearance quality, chemical components and sensory quality of flue-cured tobacco laminas in the process of alcoholization was carried out by using the meth- ods of CAS and natural alcoholization. The results showed that appearance and color through the treatment of natural alcoholization were deep, browning and ac- companied by the phenomenon of oil, while color scale of flue-cured tobacco lami- nas through the treatment of CAS was uniform, fullness was better, and these two methods were close or identical after opening for 3 months. The contents of total sugar and reducing sugar during the process of alcoholization were also gradually decreased, but the ratio of reducing sugar to total sugar of laminas via CAS was higher than that of the natural alcoholization treatment. Compared with the natural alcoholization,the descending trends of total nitrogen and nicotine contents during CAS were gentler, the ratio via CAS was closer to 1, and the coordination of chemical components was more superior. During the period of alcoholization for 6 to 12 months, sensory quality of laminas via the natural alcoholization treatment was more superior than that of CAS treatment. However, after 18 months of alcoholiza- tion, sensory quality of laminas via the CAS treatment was more superior than that of the natural alcoholization treatment, and the CAS treatment could improve opti- mum sensory quality by 0.5 to 1.5 scores. Additionally, the CAS treatment could prolong the time of optimum alcoholization quality for 6 months, compared with the treatment of natural alcoholization. The CAS method could influence the alcohoJiza- tion quality of flue-cured tobacco laminas and prolong the retention period of opti- mum quality status for flue-cured tobacco laminas by regulating the environmental aas composition, thereby realizin.q quality control of flue-cured tobacco laminas.展开更多
-The impact of several chemical poisons on the Arca granosa absorbing 45Ca was studied. The results showed that the absorption of 45Ca in the blood and the soft tissue by Arca granosa was inhibited by the inorganic co...-The impact of several chemical poisons on the Arca granosa absorbing 45Ca was studied. The results showed that the absorption of 45Ca in the blood and the soft tissue by Arca granosa was inhibited by the inorganic compounds of Cu, Zn, Pd, Cd, Hg and so on, among which the inhibition of Cd was the strongest, next was that of Cu and Hg. But the inhibition of the absorption of 45Ca in the shell of Arca granosa was little. The impact of three kinds of energy metabolism inhibitory substances on the absorption of 45Ca by the Area granosa showed that the absorption was an active transfer process.展开更多
A flagship research project ofthe country during the Ninth Five-Year Plan period (1996-2000), thestudy was conducted under the ae-gis of CAS with financial supportfrom MOST. Remarkable academicprogress has been achiev...A flagship research project ofthe country during the Ninth Five-Year Plan period (1996-2000), thestudy was conducted under the ae-gis of CAS with financial supportfrom MOST. Remarkable academicprogress has been achieved over thepast years, according to the panel.展开更多
基金Supported by the Research and Development Program of the Korea Institute of Energy Research(KIER)(B4-2431-04)the National Natural Science Foundation of China(21276129,20876079)the Natural Science Funds for Distinguished Young Scholar in Shandong Province(JQ200904)
文摘The chemical looping gasification uses an oxygen carrier for solid fuel gasification by supplying insufficient lattice oxygen. The effect of gasifying medium on the coal chemical looping gasification with Ca SO4 as oxygen carrier is investigated in this paper. The thermodynamical analysis indicates that the addition of steam and CO2 into the system can reduce the reaction temperature, at which the concentration of syngas reaches its maximum value.Experimental result in thermogravimetric analyzer and a fixed-bed reactor shows that the mixture sample goes through three stages, drying stage, pyrolysis stage and chemical looping gasification stage, with the temperature for three different gaseous media. The peak fitting and isoconversional methods are used to determine the reaction mechanism of the complex reactions in the chemical looping gasification process. It demonstrates that the gasifying medium(steam or CO2) boosts the chemical looping process by reducing the activation energy in the overall reaction and gasification reactions of coal char. However, the mechanism using steam as the gasifying medium differs from that using CO2. With steam as the gasifying medium, parallel reactions occur in the beginning stage, followed by a limiting stage shifting from a kinetic to a diffusion regime. It is opposite to the reaction mechanism with CO2 as the gasifying medium.
文摘Introduction Chemical Abstracts Service （CAS）, a division of the American Chemical Society, is the most authoritative and comprehensive source for chemical information. CAS databases, including CAS REGISTRYSM, the gold standard for substance information, are curated and quality-controlled by CAS scientists. Combining these databases with advanced search and analysis technologies, CAS delivers the most complete, cross-linked, and effective digital information environment for scientific research and discovery through such products as SciFinder, STN, STN Express, and STN AnaVistTM, as well as services, such as Science IP.
文摘Chemical Abstracts(CA),a reputable international search tool,which involves the widest disciplinary field,collects the most literature types,offers the most searching ways,and has the most prodigious volumes,is edited and published by CAS-Chemical Abstracts in the USA.CA has reported more than 10 000 kinds of technology journals,technology reports,meeting papers,academic dissertations,data chronicles,technique reports,new books,and audiovisuals。
文摘Chemical Abstracts(CA),a reputable international search tool,which involves the widest disciplinary field,collects the most literature types,offers the most searching ways,and has the most prodigious volumes,is edited and published by CAS-Chemical Abstracts in the USA.
文摘Different fluxes were used to synthesize long persistence phosphors, calcium sulfides activated by Eu 2+ and Tm 3+ , by convenient solid state method. The phosphor using NH 4F as a flux has good crystallinity and large particle size, its stability against water and other atmospheric components is enhanced, and its afterglow is longer and fluorescent intensity is more intense than those of the phosphor using NH 4Cl as flux. Their PL intensities varied with time in moist air were measured, no remarkable change was found for those prepared with NH 4F flux in contrast with NH 4Cl as flux. So using NH 4F as flux is a good method to enhance the stability of alkaline earth sulfides.
基金Project supported by the Young Scientists Fund of the National Natural Science Foundation of China (Grant No. 10904030)the Natural Science Foundation of Hebei Province, China (Grant No. A2009000144)
文摘Laser-induced voltage effects in c-axis oriented Ca3Co4O9 thin films have been studied with samples fabricated on 10°tilted LaAIO3 （001） substrates by a simple chemical solution deposition method. An open-circuit voltage with a rise time of about 10 ns and full width at half maximum of about 28 ns is detected when the film surface is irradiated by a 308-nm laser pulse with a duration of 25 ns. Besides, opemcircuit voltage signals are also observed when the film surface is irradiated separately by the laser pulses of 532 nm and 1064 nm. The results indicate that Ca3Co4O9 thin films have a great potential application in the wide range photodetctor from the ultraviolet to near infrared regions.
文摘Microstructure study of chrome oxide bricks used in cool slurry gasifiers/Gao Zhenxin,Wang Zhanmin, Fan Muxu,Zhu Dexian, Fan Lixia, Zhang Wei, Liu Baikuan//Naihuo Cailiao. - 2017,51 （6） ： 401Abstract： For more in-depth research on erosion mechanism of re-bonded chrome oxide bricks for coal slurry gasifiers, the chemical composition and microstructure of the bricks before and after use were analyzed by means of X-ray fluorescence spectrometry, and FESEM-EDS.
文摘Tl2Ba2Ca2Cu3O10 was reported to be a superconductor with a highest transition temperature of 125 K among the homologous series of Tl2Ba2Can-1CunO2n＋4. The direct information on the Cu ion site at the atomic level is important for elucidating the superconductivity mechanism. The local bond properties of Tl2Ba2Ca2Cu3O10 were studied using the average band-gap model. The calculated results show that the covalency of Cu（1）-O bond is 0.561, and the average covalency of Cu（2）-O is 0.296. Mossbauer isomer shifts of 57Fe in Tl2Ba2Ca2Cu3O10 were calculated using the chemical surrounding factor, defined by covalency and electronic polarizability. It is verified that for lower doping, Fe substitute the Cu at the Cu （1） site in forms of Fe^3＋ and Fe^4＋; for higher doping, Fe^3＋ and Fe^4＋ ion occupies Cu（1） and Cu（2） site respectively. The studies show that the determination of the correspondence between spectrum components and actual copper sites occupied by MSssbauer nucleus was made easier with the aid of the calculation results of the chemical bond parameters.
文摘To achieve the continuous maintainence of optimum quality state of flue- cured tobacco laminas and the effective regulation and control on alcoholization time for controlled atmosphere storage （CAS） method in the process of storage, the lam- ina samples of natural alcoholization for 1 year were selected. Comparable analysis on the appearance quality, chemical components and sensory quality of flue-cured tobacco laminas in the process of alcoholization was carried out by using the meth- ods of CAS and natural alcoholization. The results showed that appearance and color through the treatment of natural alcoholization were deep, browning and ac- companied by the phenomenon of oil, while color scale of flue-cured tobacco lami- nas through the treatment of CAS was uniform, fullness was better, and these two methods were close or identical after opening for 3 months. The contents of total sugar and reducing sugar during the process of alcoholization were also gradually decreased, but the ratio of reducing sugar to total sugar of laminas via CAS was higher than that of the natural alcoholization treatment. Compared with the natural alcoholization,the descending trends of total nitrogen and nicotine contents during CAS were gentler, the ratio via CAS was closer to 1, and the coordination of chemical components was more superior. During the period of alcoholization for 6 to 12 months, sensory quality of laminas via the natural alcoholization treatment was more superior than that of CAS treatment. However, after 18 months of alcoholiza- tion, sensory quality of laminas via the CAS treatment was more superior than that of the natural alcoholization treatment, and the CAS treatment could improve opti- mum sensory quality by 0.5 to 1.5 scores. Additionally, the CAS treatment could prolong the time of optimum alcoholization quality for 6 months, compared with the treatment of natural alcoholization. The CAS method could influence the alcohoJiza- tion quality of flue-cured tobacco laminas and prolong the retention period of opti- mum quality status for flue-cured tobacco laminas by regulating the environmental aas composition, thereby realizin.q quality control of flue-cured tobacco laminas.
文摘-The impact of several chemical poisons on the Arca granosa absorbing 45Ca was studied. The results showed that the absorption of 45Ca in the blood and the soft tissue by Arca granosa was inhibited by the inorganic compounds of Cu, Zn, Pd, Cd, Hg and so on, among which the inhibition of Cd was the strongest, next was that of Cu and Hg. But the inhibition of the absorption of 45Ca in the shell of Arca granosa was little. The impact of three kinds of energy metabolism inhibitory substances on the absorption of 45Ca by the Area granosa showed that the absorption was an active transfer process.
文摘A flagship research project ofthe country during the Ninth Five-Year Plan period (1996-2000), thestudy was conducted under the ae-gis of CAS with financial supportfrom MOST. Remarkable academicprogress has been achieved over thepast years, according to the panel.
