Calcium looping method has been considered as one of the efficient options to capture C02 in the combustion Ilue gas. CaO-based sorbent is the basis for application of calcium looping and should be subjected to the se...Calcium looping method has been considered as one of the efficient options to capture C02 in the combustion Ilue gas. CaO-based sorbent is the basis for application of calcium looping and should be subjected to the severe calcination condition so as to obtain the concentrated C02 stream. In this research, CaO/CaZrO3 sorbents were synthesized using the sol-gel combustion synthesis （SGCS） method with urea as fuel. The cyclic reaction performance of the synthesized sorbents was evaluated on a lab-scaled reactor system through calcination at 950 ℃ in a pure C02 atmosphere and carbonation at 650 ℃ in the 15% （by volume） C02. The mass ratio of CaO to CaZr03 as 8：2 （designated as CasZr2） was screened as the best option among all the synthesized CaO sorbents for its high CO2 capture capacity and carbonation conversion at the initial cycle. And then a gradual decay in the C02 capture capacity was observed at the following 10 successive cycles, but hereafter stabilized throughout the later cycles. Furthermore, structural evolution of the carbonated CasZr2 over the looping cycles was investigated. With increasing looping cycles, the pore peak and mean grain size of the carbonated CasZr2 sorbent shifted to the bigger direction but both the surface area （SA） ratio and surface fractal dimension Ds decreased. Finally, morphological transformation of the carbonated CasZr2 was observed. Agglomeration and edge rounding of the newly formed CaC03 grains were found as aggravated at the cyclic carbonation stage. As a result, carbonation of CasZr2 with C02 was observed only confined to the external active CaO by the fast formation of the CaC03 shell outside, which occluded the further carbonation of the unreacted CaO inside. Therefore, enough attention should be paid to the carbonation stage and more effective activation measures should be explored to ensure the unreacted active CaO fully carbonatPd river the extended Ioonin cycles.展开更多
10%(volume fraction) SiCp/Al-Mg composites with different Mg contents were successfully fabricated by semi-solid mechanical stirring technique under optimum processing conditions.Effects of Mg content on microstructur...10%(volume fraction) SiCp/Al-Mg composites with different Mg contents were successfully fabricated by semi-solid mechanical stirring technique under optimum processing conditions.Effects of Mg content on microstructure and mechanical properties were studied by scanning electron microscopy(SEM),X-ray diffractometry(XRD) and transmission electron microscopy(TEM).The results indicate that SiC particles disperse homogeneously in Al-Mg matrix and interfacial reaction between Al matrix and SiC particles is effectively controlled.Distribution of SiCp reinforcement and interfacial bonding are improved by adding Mg.Additionally,the mechanical properties of composites are remarkably improved with the Mg content increasing.展开更多
Adsorption process is acknowledged as an effective option for phenolic wastewater treatment. In this work, the activated carbon （AC） samples after thermal modification were prepared by using muffle furnace. The phen...Adsorption process is acknowledged as an effective option for phenolic wastewater treatment. In this work, the activated carbon （AC） samples after thermal modification were prepared by using muffle furnace. The phenol ad- sorption kinetics and equilibrium measurements were carried out under static conditions at temperature ranging from 25 to 55 ~C. The test results show that the thermal modification can enhance phenol adsorption on AC samples. The porous structure and surface chemistry analyses indicate that the decay in pore morphology and decrease of total oxygen-containing functional groups are found for the thermal modified AC samples. Thus, it can be further inferred that the decrease of total oxygen-containing functional groups on the modified AC sam- ples is the main reason for the enhanced phenol adsorption capacity. For both the raw sample and the optimum modified AC sample at 900 ~C, the pseudo-second order kinetics and Langmuir models are found to fit the exper- imental data very well. The maximum phenol adsorption capacity of the optimum modified AC sample can reach 144,93 mg.g ~ which is higher than that of the raw sample, i.e. 119.53 mg.g 1. Adsorption thermodynamics analysis confirms that the phenol adsorption on the optimum modified AC sample is an exothermic process and mainly via physical adsorption.展开更多
The microstructure and mechanical properties of Mg-xCe-0.5Zn （x=0.5, 1.5, 2.5, molar fraction, %） alloys were examined using a nano-indentation technique. The alloys were fabricated using a vacuum induction melting ...The microstructure and mechanical properties of Mg-xCe-0.5Zn （x=0.5, 1.5, 2.5, molar fraction, %） alloys were examined using a nano-indentation technique. The alloys were fabricated using a vacuum induction melting method under an argon atmosphere The microstruetures of Mg-xCe-0.5Zn alloys mainly consist ofa-Mg and eutectic Mg12Ce phase. The volume fraction and size of the eutectic Mgl2Ce phase increase with increasing Ce contents. Nano-indentation test results show that the indentation hardness and elastic modulus of the eutectic Mg12Ce phase are higher than those of the a-Mg matrix. In addition, the mean indentation hardness and elastic modulus of the Mg-xCe-0.5Zn alloys increase with the Ce addition amount increasing.展开更多
Isothermal decomposition process of chemically transforming indium tin oxide（ITO） powders into indium（III） hydroxide powders was investigated. Two types of powders were analyzed, i.e., non-activated and mechanical...Isothermal decomposition process of chemically transforming indium tin oxide（ITO） powders into indium（III） hydroxide powders was investigated. Two types of powders were analyzed, i.e., non-activated and mechanically activated. It has been found that in the case of activated sample, shorter induction periods appear, which permits growth of smaller crystals, while in the case of non-activated sample, long induction periods appear, characterized by the growth of larger crystals. DAEM approach has shown that decomposition processes of non-activated and mechanically activated samples can be described by contracting volume model with a linear combination of two different density distribution functions of apparent activation energies（Ea）, and with first-order model, with a single symmetrical density distribution function of Ea, respectively. It was established that specific characteristics of particles not only affect the mechanism of decomposition processes, but also have the significant impact on thermodynamic properties.展开更多
Equipment manufacturing industry is an important symbol to measure the industrial strength, scientific and technological innovation ability and international competitiveness of a country or region. Firstly, this paper...Equipment manufacturing industry is an important symbol to measure the industrial strength, scientific and technological innovation ability and international competitiveness of a country or region. Firstly, this paper analyzes the development status of equipment manufacturing industry in Shanghai, and then uses DEA to analyze the efficiency of technology innovation capability of equipment manufacturing industry in Shanghai. The results show that the equipment manufacturing industry in Shanghai has stronger overall drawing ability, and besides, the technology innovation ability of the transportation equipment manufacturing industry is weak, other equipment manufacturing sub industries have relatively strong ability of technological innovation. This paper analyzes the shortcomings of the transportation equipment manufacturing industry and gives guidance and puts forward corresponding suggestions and measures.展开更多
Geopolymer-lightweight aggregate refractory concrete (GLARC) was prepared with geopolymer and lightweight aggregate. The mechanical property and heat-resistance (950 ℃) of GLARC were investigated. The effects of size...Geopolymer-lightweight aggregate refractory concrete (GLARC) was prepared with geopolymer and lightweight aggregate. The mechanical property and heat-resistance (950 ℃) of GLARC were investigated. The effects of size of aggregate and mass ratio of geopolymer to aggregate on mechanical and thermal properties were also studied. The results show that the highest compressive strength of the heated refractory concrete is 43.3 MPa,and the strength loss is only 42%. The mechanical property and heat-resistance are influenced by the thickness of geopolymer covered with aggregate,which can be expressed as the quantity of geopolymer on per surface area of aggregate. In order to show the relationship between the thickness of geopolymer covered with aggregate and the thermal property of concrete,equal thickness model is presented,which provides a reference for the mix design of GLARC. For the haydite sand with size of 1.18-4.75 mm,the best amount of geopolymer per surface area of aggregate should be in the range of 0.300-0.500 mg/mm2.展开更多
Graphite nanoplatelets were prepared by a novel magnetic-grinding method using self-made equipments. Under a variant magnetic field, magnetic needles collided at a high rotating speed and exfoliated pristine graphite ...Graphite nanoplatelets were prepared by a novel magnetic-grinding method using self-made equipments. Under a variant magnetic field, magnetic needles collided at a high rotating speed and exfoliated pristine graphite into graphite nanoplatelets with high efficiency. The obtained graphite nanoplatelets are highly crystalline, and the thickness is less than 10 nm. Moreover, the surface area could reached 738.1 m^2/g with a grinding time of 4 h. Silanized graphite nanoplatelets can disperse well in SG 15W-40 engine oil and serve as lubricant additive. Tribological results indicate that the friction coefficient and wear-scar of the friction pairs are lower than 76% and 41%, respectively, by adding 1.5‰(mass fraction) of silanized graphite nanoplatelets. Notably, the functionalized graphite nanoplatelets can realize large-scale production and commercial application.展开更多
Global demand for power has significantly increased, but power generation and transmission capacities have not increased proportionally with this demand. As a result, power consumers suffer from various problems, such...Global demand for power has significantly increased, but power generation and transmission capacities have not increased proportionally with this demand. As a result, power consumers suffer from various problems, such as voltage and frequency instability and power quality issues. To overcome these problems, the capacity for available power transfer of a transmission network should be enhanced. Researchers worldwide have addressed this issue by using flexible AC transmission system （FACTS） devices. We have conducted a comprehensive review of how FACTS controllers are used to enhance the avail- able transfer capability （ATC） and power transfer capability （PTC） of power system networks. This review includes a discussion of the classification of different FACTS devices according to different factors. The popularity and applications of these devices are discussed together with relevant statistics. The operating principles of six major FACTS devices and their application in increasing ATC and PTC are also presented. Finally, we evaluate the performance of FACTS devices in ATC and PTC improvement with respect to different control algorithms.展开更多
In this work, we fabricated a monodisperse nanocomposite by coating gold nanorods （AuNRs） with a layer of biocompatible, stable carbon, obtaining AuNR@Carbon core-shell nanocapsules, which without any functionalizat...In this work, we fabricated a monodisperse nanocomposite by coating gold nanorods （AuNRs） with a layer of biocompatible, stable carbon, obtaining AuNR@Carbon core-shell nanocapsules, which without any functionalization could be used as a molecule loading material due to its high surface areas. In this system, the AuNR core had a high-absorption cross section for con- version of near-infrared light to heat, which could be ex- plored for local hyperthermia. The carbon shell, which was biocompatible and stable even under concentrated acidic and alkaline conditions, was able to adsorb molecules with n-n interactions or electrostatic interactions. In comparison with AuNR@SiO2, AuNR@Carbon nanocapsules demon- strate the following merits： （1） simple and green synthesis method, （2） far more stable with respect to high-tem- perature stability and （3） larger molecule loading capacity, which indicate great potential in the biomedical applications.展开更多
A mesoporous sorption complex catalyst was prepared by pore-forming modification and evaluated by the COz reactive sorption enhanced reforming （ReSER） process, which is used to produce hydrogen from methane. Three s...A mesoporous sorption complex catalyst was prepared by pore-forming modification and evaluated by the COz reactive sorption enhanced reforming （ReSER） process, which is used to produce hydrogen from methane. Three samples of polyethylene glycol （PEG） with molecular weights between 2000 and 20 000 were added as templates into a mixed slurry to create catalysts with different pore properties by further formation and calcination. The pore characteristics determined by Brunauer- Emmett-Teller （BET） analysis showed that one of the mesoporous catalysts, named M-NiAICa-6000, had a pore size of 9.2 nm and a surface area of 70.52 m2/g and the CO2 sorption capacity of this catalyst was 44% higher than that of the catalyst without the PEG 6000 modification. The catalyst was evaluated in the ReSER process in a fixed-bed reactor system at 0.1 MPa and 600 C with an H20/CH4 molar ratio of 4. An H2 concentration of 94.2% and a CH4 conversion of 86.0% were obtained at a carbon space velocity of 1700 h 1 while CO2 was hardly detected.展开更多
基金Supported by the National Natural Science Foundation of China(51276210,50906030,31301586)the Partial Financial Grant of North China University of Water Resources and Electric Power(201012)the National Basic Research Program of China(2011CB707301)
文摘Calcium looping method has been considered as one of the efficient options to capture C02 in the combustion Ilue gas. CaO-based sorbent is the basis for application of calcium looping and should be subjected to the severe calcination condition so as to obtain the concentrated C02 stream. In this research, CaO/CaZrO3 sorbents were synthesized using the sol-gel combustion synthesis （SGCS） method with urea as fuel. The cyclic reaction performance of the synthesized sorbents was evaluated on a lab-scaled reactor system through calcination at 950 ℃ in a pure C02 atmosphere and carbonation at 650 ℃ in the 15% （by volume） C02. The mass ratio of CaO to CaZr03 as 8：2 （designated as CasZr2） was screened as the best option among all the synthesized CaO sorbents for its high CO2 capture capacity and carbonation conversion at the initial cycle. And then a gradual decay in the C02 capture capacity was observed at the following 10 successive cycles, but hereafter stabilized throughout the later cycles. Furthermore, structural evolution of the carbonated CasZr2 over the looping cycles was investigated. With increasing looping cycles, the pore peak and mean grain size of the carbonated CasZr2 sorbent shifted to the bigger direction but both the surface area （SA） ratio and surface fractal dimension Ds decreased. Finally, morphological transformation of the carbonated CasZr2 was observed. Agglomeration and edge rounding of the newly formed CaC03 grains were found as aggravated at the cyclic carbonation stage. As a result, carbonation of CasZr2 with C02 was observed only confined to the external active CaO by the fast formation of the CaC03 shell outside, which occluded the further carbonation of the unreacted CaO inside. Therefore, enough attention should be paid to the carbonation stage and more effective activation measures should be explored to ensure the unreacted active CaO fully carbonatPd river the extended Ioonin cycles.
基金Project(2006CB605203-3) supported by the National Basic Research Program of China
文摘10%(volume fraction) SiCp/Al-Mg composites with different Mg contents were successfully fabricated by semi-solid mechanical stirring technique under optimum processing conditions.Effects of Mg content on microstructure and mechanical properties were studied by scanning electron microscopy(SEM),X-ray diffractometry(XRD) and transmission electron microscopy(TEM).The results indicate that SiC particles disperse homogeneously in Al-Mg matrix and interfacial reaction between Al matrix and SiC particles is effectively controlled.Distribution of SiCp reinforcement and interfacial bonding are improved by adding Mg.Additionally,the mechanical properties of composites are remarkably improved with the Mg content increasing.
基金Supported by the National Natural Science Foundation of China(41302132)Training Programmes of Innovation and Entrepreneurship for Undergraduates of Yunnan Province(Grant No.201510674042)the Introduced Talents Foundation of Kunming University of Science and Technology(KKSY201205160)
文摘Adsorption process is acknowledged as an effective option for phenolic wastewater treatment. In this work, the activated carbon （AC） samples after thermal modification were prepared by using muffle furnace. The phenol ad- sorption kinetics and equilibrium measurements were carried out under static conditions at temperature ranging from 25 to 55 ~C. The test results show that the thermal modification can enhance phenol adsorption on AC samples. The porous structure and surface chemistry analyses indicate that the decay in pore morphology and decrease of total oxygen-containing functional groups are found for the thermal modified AC samples. Thus, it can be further inferred that the decrease of total oxygen-containing functional groups on the modified AC sam- ples is the main reason for the enhanced phenol adsorption capacity. For both the raw sample and the optimum modified AC sample at 900 ~C, the pseudo-second order kinetics and Langmuir models are found to fit the exper- imental data very well. The maximum phenol adsorption capacity of the optimum modified AC sample can reach 144,93 mg.g ~ which is higher than that of the raw sample, i.e. 119.53 mg.g 1. Adsorption thermodynamics analysis confirms that the phenol adsorption on the optimum modified AC sample is an exothermic process and mainly via physical adsorption.
基金supported by a grant-in-aid for the National Core Research Center Program(No.R15-2006-022-02001-0)the Metals Bank project of the Korea Ministry of Knowledge Economy
文摘The microstructure and mechanical properties of Mg-xCe-0.5Zn （x=0.5, 1.5, 2.5, molar fraction, %） alloys were examined using a nano-indentation technique. The alloys were fabricated using a vacuum induction melting method under an argon atmosphere The microstruetures of Mg-xCe-0.5Zn alloys mainly consist ofa-Mg and eutectic Mg12Ce phase. The volume fraction and size of the eutectic Mgl2Ce phase increase with increasing Ce contents. Nano-indentation test results show that the indentation hardness and elastic modulus of the eutectic Mg12Ce phase are higher than those of the a-Mg matrix. In addition, the mean indentation hardness and elastic modulus of the Mg-xCe-0.5Zn alloys increase with the Ce addition amount increasing.
基金partially supported by the Ministry of Science and Environmental Protection of Serbia under the Project 172015
文摘Isothermal decomposition process of chemically transforming indium tin oxide（ITO） powders into indium（III） hydroxide powders was investigated. Two types of powders were analyzed, i.e., non-activated and mechanically activated. It has been found that in the case of activated sample, shorter induction periods appear, which permits growth of smaller crystals, while in the case of non-activated sample, long induction periods appear, characterized by the growth of larger crystals. DAEM approach has shown that decomposition processes of non-activated and mechanically activated samples can be described by contracting volume model with a linear combination of two different density distribution functions of apparent activation energies（Ea）, and with first-order model, with a single symmetrical density distribution function of Ea, respectively. It was established that specific characteristics of particles not only affect the mechanism of decomposition processes, but also have the significant impact on thermodynamic properties.
文摘Equipment manufacturing industry is an important symbol to measure the industrial strength, scientific and technological innovation ability and international competitiveness of a country or region. Firstly, this paper analyzes the development status of equipment manufacturing industry in Shanghai, and then uses DEA to analyze the efficiency of technology innovation capability of equipment manufacturing industry in Shanghai. The results show that the equipment manufacturing industry in Shanghai has stronger overall drawing ability, and besides, the technology innovation ability of the transportation equipment manufacturing industry is weak, other equipment manufacturing sub industries have relatively strong ability of technological innovation. This paper analyzes the shortcomings of the transportation equipment manufacturing industry and gives guidance and puts forward corresponding suggestions and measures.
基金Project(2009CB623201) supported by the National Basic Research Program of ChinaProject(G0510) supported by the Key Laboratory for Refractories and High-temperature Ceramics of Hubei Province, China
文摘Geopolymer-lightweight aggregate refractory concrete (GLARC) was prepared with geopolymer and lightweight aggregate. The mechanical property and heat-resistance (950 ℃) of GLARC were investigated. The effects of size of aggregate and mass ratio of geopolymer to aggregate on mechanical and thermal properties were also studied. The results show that the highest compressive strength of the heated refractory concrete is 43.3 MPa,and the strength loss is only 42%. The mechanical property and heat-resistance are influenced by the thickness of geopolymer covered with aggregate,which can be expressed as the quantity of geopolymer on per surface area of aggregate. In order to show the relationship between the thickness of geopolymer covered with aggregate and the thermal property of concrete,equal thickness model is presented,which provides a reference for the mix design of GLARC. For the haydite sand with size of 1.18-4.75 mm,the best amount of geopolymer per surface area of aggregate should be in the range of 0.300-0.500 mg/mm2.
基金Project(ZR2011BL005)supported by the Natural Science Foundation of Shandong Province,China
文摘Graphite nanoplatelets were prepared by a novel magnetic-grinding method using self-made equipments. Under a variant magnetic field, magnetic needles collided at a high rotating speed and exfoliated pristine graphite into graphite nanoplatelets with high efficiency. The obtained graphite nanoplatelets are highly crystalline, and the thickness is less than 10 nm. Moreover, the surface area could reached 738.1 m^2/g with a grinding time of 4 h. Silanized graphite nanoplatelets can disperse well in SG 15W-40 engine oil and serve as lubricant additive. Tribological results indicate that the friction coefficient and wear-scar of the friction pairs are lower than 76% and 41%, respectively, by adding 1.5‰(mass fraction) of silanized graphite nanoplatelets. Notably, the functionalized graphite nanoplatelets can realize large-scale production and commercial application.
基金supported by the Ministry of Higher Education of Malaysia and University of Malaya under the E-Science Fund Research Grant(No.SF005-2013)the UMRG Project RP015D-13AET
文摘Global demand for power has significantly increased, but power generation and transmission capacities have not increased proportionally with this demand. As a result, power consumers suffer from various problems, such as voltage and frequency instability and power quality issues. To overcome these problems, the capacity for available power transfer of a transmission network should be enhanced. Researchers worldwide have addressed this issue by using flexible AC transmission system （FACTS） devices. We have conducted a comprehensive review of how FACTS controllers are used to enhance the avail- able transfer capability （ATC） and power transfer capability （PTC） of power system networks. This review includes a discussion of the classification of different FACTS devices according to different factors. The popularity and applications of these devices are discussed together with relevant statistics. The operating principles of six major FACTS devices and their application in increasing ATC and PTC are also presented. Finally, we evaluate the performance of FACTS devices in ATC and PTC improvement with respect to different control algorithms.
基金supported by the National Basic Research Program of China(2013CB932702)the Program on National Key Scientific Instruments and Equipment Development(2011YQ0301241402)+1 种基金the Science and Technology Development Fund of Macao S.A.R(FDCT,067/2014/A)the Hunan Innovation and Entrepreneurship Program
文摘In this work, we fabricated a monodisperse nanocomposite by coating gold nanorods （AuNRs） with a layer of biocompatible, stable carbon, obtaining AuNR@Carbon core-shell nanocapsules, which without any functionalization could be used as a molecule loading material due to its high surface areas. In this system, the AuNR core had a high-absorption cross section for con- version of near-infrared light to heat, which could be ex- plored for local hyperthermia. The carbon shell, which was biocompatible and stable even under concentrated acidic and alkaline conditions, was able to adsorb molecules with n-n interactions or electrostatic interactions. In comparison with AuNR@SiO2, AuNR@Carbon nanocapsules demon- strate the following merits： （1） simple and green synthesis method, （2） far more stable with respect to high-tem- perature stability and （3） larger molecule loading capacity, which indicate great potential in the biomedical applications.
基金Project(No.20876142) supported by the National Natural Science Foundation of China
文摘A mesoporous sorption complex catalyst was prepared by pore-forming modification and evaluated by the COz reactive sorption enhanced reforming （ReSER） process, which is used to produce hydrogen from methane. Three samples of polyethylene glycol （PEG） with molecular weights between 2000 and 20 000 were added as templates into a mixed slurry to create catalysts with different pore properties by further formation and calcination. The pore characteristics determined by Brunauer- Emmett-Teller （BET） analysis showed that one of the mesoporous catalysts, named M-NiAICa-6000, had a pore size of 9.2 nm and a surface area of 70.52 m2/g and the CO2 sorption capacity of this catalyst was 44% higher than that of the catalyst without the PEG 6000 modification. The catalyst was evaluated in the ReSER process in a fixed-bed reactor system at 0.1 MPa and 600 C with an H20/CH4 molar ratio of 4. An H2 concentration of 94.2% and a CH4 conversion of 86.0% were obtained at a carbon space velocity of 1700 h 1 while CO2 was hardly detected.
