According with control theory of variable-speed and constant-frequency (VSCF) pitch-controlled wi... more According with control theory of variable-speed and constant-frequency (VSCF) pitch-controlled wind turbine, neural network algorithm is adopted to predict pitch angle at real-time working condition, and to obtain more accurate pitch angle reference value. It enhances control precision of the entire pitch-controlled system.
Nitrate nitrogen and nitrite nitrogen concentration of surface water and groundwater samples in t... more Nitrate nitrogen and nitrite nitrogen concentration of surface water and groundwater samples in the Jiantan River in the Three Gorges Reservoir area were measured and analyzed to depict the spatial discrepancy of nitrate and nitrite pollution in the study basin. This study analyzed the correlativity of nitrate nitrogen, nitrite nitrogen, and the ratio of nitrate nitrogen and nitrite nitrogen with the altitude of surface water and groundwater sample sites, then revealed the spatial evolvement characteristics, resources and influence factors of nitrate nitrogen and nitrite nitrogen of the surface water and groundwater bodies in the study basin. The results show the transfer times of the surface water bodies and land use styles influence the correlativity of nitrate and nitrite nitrogen in the surface water bodies with the altitude of the sample sites. While the storage conditions of the groundwater bodies and the sources of the nitrogen influence the correlativity of nitrate and nitrite nitrogen in the groundwater bodies with the altitude of the sample sites. In the surface water bodies, nitrite is the intermediate product from ammonia to nitrate under the nitrification process, thus the nitrite nitrogen concentration offer quite a large quantity to the surface water bodies with the ongoing reaction. While the nitrogen pollution in the groundwater bodies is mainly nitrate nitrogen because of the more complete nitrification of nitrogen pollution in the groundwater conditions, leading to higher nitrate nitrogen level than the nitrite nitrogen.
Frontiers of Mechanical Engineering in China, 2007
Owing to a lack of practical methods and software tools in the existing researches on green manuf... more Owing to a lack of practical methods and software tools in the existing researches on green manufacturing (GM), process planning support system for green manufacturing (GMPPSS) was developed to deal with the problems in optimization of environment-benign process planning. The GMPPSS consisted mainly of three function modules and related model repositories including: selection of process elements, optimization of process courses, and evaluation of process projects for GM. The database of the GMPPSS was used to provide plentiful information on resources consumption and environmental impact in manufacturing processes, which consisted of process attribute database, inventory database, machine database, tool database, and the cutting fluid database. Raw materials, secondary material consumption, energy consumption, and environment impacts of process planning were optimized to improve the green attribute of process planning of parts with the supports of the databases and model repositories. The gear processing in the machining tool factory was presented to verify the system’s applicability.
Four images of 1991 AVHRR, 2003 and 2007 MODIS were used to extract waterlogging inundated water ... more Four images of 1991 AVHRR, 2003 and 2007 MODIS were used to extract waterlogging inundated water of three years, and three inundated water maps were overlaid to estimate waterlogging affected frequency. Based on waterlogging affected frequency, waterlogging hazard of pixel scale was assessed. According to the weighed score of area percentage of different waterlogging affected frequency in 13 counties/cities of Lixiahe region, waterlogging hazard rank of every county/city was assessed. Waterlogging affected frequency map and 1km×1km grid landuse map were used to assess waterlogging risk of pixel scale; and then waterlogging risk rank of every county/city was assessed by the similar method by which waterlogging hazard rank of every county/city was assessed. High risk region is located mainly in core zone of Lixiahe hinterland, medium risk region is adjacent to high risk region, and low risk region is located in the most outlying area of risk zone and mainly in south to middle part of Lixiahe region. Xinghua and Gaoyou belong to high risk city, Jiangyan belongs to medium risk city, and the other counties/cities have low or lower waterlogging risk. The method of assessing waterlogging risk in this paper is simple and applicable. This paper can provide guidance for the waterlogging risk analysis in broader area of Huaihe River Basin.
Nanoporous silver (NPS) and copper (NPC) obtained by dealloying AgAl and CuAl alloys, respectivel... more Nanoporous silver (NPS) and copper (NPC) obtained by dealloying AgAl and CuAl alloys, respectively, were used as both three-dimensional templates and reducing agents for the fabrication of nanoporous PtAg (NPS-Pt) and PtCu (NPC-Pt) alloys with hollow ligaments by a simple galvanic replacement reaction with H2PtCl6. Electron microscopy and X-ray diffraction characterizations demonstrate that NPS and NPC with similar ligament sizes (30–50 nm) have different effects on the formed hollow nanostructures. For NPS-Pt, the shell of the hollow ligament is seamless. However, the shell of NPC-Pt is comprised of small pores and alloy nanoparticles with a size of ∼3 nm. The as-prepared NPS-Pt and NPC-Pt exhibit remarkably improved electrocatalytic activities towards the oxidation of ethanol and H2O2 compared with state-of-the-art Pt/C catalyst, and can be used for sensitive electrochemical sensing applications. The hierarchical nanoporous structure also provides a good microenvironment for enzymes. After immobilization of glucose oxidase (GOx), the enzyme modified nanoporous electrode can sensitively detect glucose in a wide linear range (0.6–20 mM).► Nanoporous PtAg and PtCu alloy with hollow ligaments are fabricated using nanoporous Ag and Cu as both templates and reducing agents. ► The shell of the nanoporous PtAg ligaments is seamless, while that of nanoporous PtCu is comprised of small pores and alloy nanoparticles. ► Nanoporous PtAg exhibits enhanced electrocatalytic activity and sensing performance compared with nanoporous PtCu.
At present, Permanent Magnet Synchronous Motor (PMSM) AC servo system based on vector control has... more At present, Permanent Magnet Synchronous Motor (PMSM) AC servo system based on vector control has attracted more and more attentions and the research on it must be a kind of inevitable development trend and focus in the future. This paper is based on DSP TMS320F2812, which is designed for special-purpose on motor control by TI Company, and designs a set of hardware control system for PMSM. The software is written by C2000 assembly language, which realized the speed, current and position loop control. The flow chart of interrupt service routine is available. The simulation results show the excellent performance of DSP control.
Through experimental analysis of peroxidase isozyme in the leaves of sugar beets, it has been ver... more Through experimental analysis of peroxidase isozyme in the leaves of sugar beets, it has been verified that the enzyme activity of dry sugar beet seeds is closely connected with the doses of N+ ion implanted, and that low dosage implantation helps to bring about enzyme activation. Meanwhile, new enzyme bands appear, and the growing quantrty and trend of sugar beets increase distinctly. The best result can be obtained when the dose of ion implantation is 4x1016N+/cm2 and the number of pulse is 60 times.
ABSTRACTMonolaurin (M) is a potential natural antimicrobial agent used in foods. It is considered... more ABSTRACTMonolaurin (M) is a potential natural antimicrobial agent used in foods. It is considered to have an antimicrobial activity against gram-positive bacteria. A monolaurin microemulsion (MME) system inhibited the growth of Bacillus subtilis, Escherichia coli, Aspergillus niger and Penicillium digitatum. Microemulsions (MEs) are transparent, isotropic solutions of oil, surfactant, cosurfactant and water, which are thermodynamically stable and have been much studied in terms of pharmaceutical and cosmetic applications. The growth of B. subtilis was inhibited more strongly by MME than by M. A similar pattern was observed for E. coli, A. niger and P. digitatum, although an enhanced inhibition by MME system over that obtained in comparable M alone was not observed.Monolaurin (M) is a potential natural antimicrobial agent used in foods. It is considered to have an antimicrobial activity against gram-positive bacteria. A monolaurin microemulsion (MME) system inhibited the growth of Bacillus subtilis, Escherichia coli, Aspergillus niger and Penicillium digitatum. Microemulsions (MEs) are transparent, isotropic solutions of oil, surfactant, cosurfactant and water, which are thermodynamically stable and have been much studied in terms of pharmaceutical and cosmetic applications. The growth of B. subtilis was inhibited more strongly by MME than by M. A similar pattern was observed for E. coli, A. niger and P. digitatum, although an enhanced inhibition by MME system over that obtained in comparable M alone was not observed.PRACTICAL APPLICATIONSMonolaurin is considered to have an antimicrobial activity against gram-positive bacteria but not against gram-negative bacteria. A monolaurin microemulsion system inhibited the growth of Bacillus subtilis, Escherichia coli, Aspergillus niger and Penicillium digitatum, and will be regarded as a “natural” antimicrobial preservative.Monolaurin is considered to have an antimicrobial activity against gram-positive bacteria but not against gram-negative bacteria. A monolaurin microemulsion system inhibited the growth of Bacillus subtilis, Escherichia coli, Aspergillus niger and Penicillium digitatum, and will be regarded as a “natural” antimicrobial preservative.
Materials Science and Engineering B-advanced Functional Solid-state Materials, 2006
The PZT/polyvinyl chloride (PVC) composites are prepared by hot-pressing technique using a novel ... more The PZT/polyvinyl chloride (PVC) composites are prepared by hot-pressing technique using a novel nanocrystalline PVC. The d33 value observed in this work for the 0.5PZT/0.5PVC composite is close to the 0.5PZT/0.5PVDF composite reported in the literature, but PVC is much cheaper than PVDF. The three-phase fgC/0.5PZT/(0.5 − fg)PVC composites are obtained by adding a small content of graphite particles to the 0.5PZT/0.5PVC composite. The measured dielectric properties demonstrate that a percolation transition occurs in the three-phase composites as in normal two-phase metal–insulator continuum media. An optimum piezoelectric property is obtained by adding fg = 0.005 before the percolation threshold in the fgC/0.5PZT/(0.5 − fg)PVC composites, which is 50% higher than that of the 0.5PZT/0.5PVC composite. X-ray powder diffraction (XRD) patterns show domain rotation is easy in this three-phase composite, and P–E hysteresis loops conform that a small amount of graphite particles adding in the composite break the polymer seclusion, and considerably decrease coercive field of the composite.
Eu2+, Dy3+ co-doped strontium aluminate (SrAl2O4) phosphor nanometer powders with high brightness... more Eu2+, Dy3+ co-doped strontium aluminate (SrAl2O4) phosphor nanometer powders with high brightness and long afterglow were prepared by heating the precursor gel (resulted from sol–gel method) at 900 °C and a reductive atmosphere of active carbon. The average particle size of the SrAl2O4:Eu, Dy phosphor powders was 59±7 nm and its optical properties have been studied systematically. The broad band UV excited luminescence of the SrAl2O4:Eu, Dy was observed at λmax=506 nm due to transitions from the 4f65d1 to the 4f7 configuration of the Eu2+ ion. The results indicated that the main peaks in the emission and excitation spectrum shifted to the short wavelength compared with phosphor obtained by the solid-state reaction synthesis method. The decay speed of the afterglow for nanometer phosphors was faster than that obtained by the solid-state reaction method.
According with control theory of variable-speed and constant-frequency (VSCF) pitch-controlled wi... more According with control theory of variable-speed and constant-frequency (VSCF) pitch-controlled wind turbine, neural network algorithm is adopted to predict pitch angle at real-time working condition, and to obtain more accurate pitch angle reference value. It enhances control precision of the entire pitch-controlled system.
Nitrate nitrogen and nitrite nitrogen concentration of surface water and groundwater samples in t... more Nitrate nitrogen and nitrite nitrogen concentration of surface water and groundwater samples in the Jiantan River in the Three Gorges Reservoir area were measured and analyzed to depict the spatial discrepancy of nitrate and nitrite pollution in the study basin. This study analyzed the correlativity of nitrate nitrogen, nitrite nitrogen, and the ratio of nitrate nitrogen and nitrite nitrogen with the altitude of surface water and groundwater sample sites, then revealed the spatial evolvement characteristics, resources and influence factors of nitrate nitrogen and nitrite nitrogen of the surface water and groundwater bodies in the study basin. The results show the transfer times of the surface water bodies and land use styles influence the correlativity of nitrate and nitrite nitrogen in the surface water bodies with the altitude of the sample sites. While the storage conditions of the groundwater bodies and the sources of the nitrogen influence the correlativity of nitrate and nitrite nitrogen in the groundwater bodies with the altitude of the sample sites. In the surface water bodies, nitrite is the intermediate product from ammonia to nitrate under the nitrification process, thus the nitrite nitrogen concentration offer quite a large quantity to the surface water bodies with the ongoing reaction. While the nitrogen pollution in the groundwater bodies is mainly nitrate nitrogen because of the more complete nitrification of nitrogen pollution in the groundwater conditions, leading to higher nitrate nitrogen level than the nitrite nitrogen.
Frontiers of Mechanical Engineering in China, 2007
Owing to a lack of practical methods and software tools in the existing researches on green manuf... more Owing to a lack of practical methods and software tools in the existing researches on green manufacturing (GM), process planning support system for green manufacturing (GMPPSS) was developed to deal with the problems in optimization of environment-benign process planning. The GMPPSS consisted mainly of three function modules and related model repositories including: selection of process elements, optimization of process courses, and evaluation of process projects for GM. The database of the GMPPSS was used to provide plentiful information on resources consumption and environmental impact in manufacturing processes, which consisted of process attribute database, inventory database, machine database, tool database, and the cutting fluid database. Raw materials, secondary material consumption, energy consumption, and environment impacts of process planning were optimized to improve the green attribute of process planning of parts with the supports of the databases and model repositories. The gear processing in the machining tool factory was presented to verify the system’s applicability.
Four images of 1991 AVHRR, 2003 and 2007 MODIS were used to extract waterlogging inundated water ... more Four images of 1991 AVHRR, 2003 and 2007 MODIS were used to extract waterlogging inundated water of three years, and three inundated water maps were overlaid to estimate waterlogging affected frequency. Based on waterlogging affected frequency, waterlogging hazard of pixel scale was assessed. According to the weighed score of area percentage of different waterlogging affected frequency in 13 counties/cities of Lixiahe region, waterlogging hazard rank of every county/city was assessed. Waterlogging affected frequency map and 1km×1km grid landuse map were used to assess waterlogging risk of pixel scale; and then waterlogging risk rank of every county/city was assessed by the similar method by which waterlogging hazard rank of every county/city was assessed. High risk region is located mainly in core zone of Lixiahe hinterland, medium risk region is adjacent to high risk region, and low risk region is located in the most outlying area of risk zone and mainly in south to middle part of Lixiahe region. Xinghua and Gaoyou belong to high risk city, Jiangyan belongs to medium risk city, and the other counties/cities have low or lower waterlogging risk. The method of assessing waterlogging risk in this paper is simple and applicable. This paper can provide guidance for the waterlogging risk analysis in broader area of Huaihe River Basin.
Nanoporous silver (NPS) and copper (NPC) obtained by dealloying AgAl and CuAl alloys, respectivel... more Nanoporous silver (NPS) and copper (NPC) obtained by dealloying AgAl and CuAl alloys, respectively, were used as both three-dimensional templates and reducing agents for the fabrication of nanoporous PtAg (NPS-Pt) and PtCu (NPC-Pt) alloys with hollow ligaments by a simple galvanic replacement reaction with H2PtCl6. Electron microscopy and X-ray diffraction characterizations demonstrate that NPS and NPC with similar ligament sizes (30–50 nm) have different effects on the formed hollow nanostructures. For NPS-Pt, the shell of the hollow ligament is seamless. However, the shell of NPC-Pt is comprised of small pores and alloy nanoparticles with a size of ∼3 nm. The as-prepared NPS-Pt and NPC-Pt exhibit remarkably improved electrocatalytic activities towards the oxidation of ethanol and H2O2 compared with state-of-the-art Pt/C catalyst, and can be used for sensitive electrochemical sensing applications. The hierarchical nanoporous structure also provides a good microenvironment for enzymes. After immobilization of glucose oxidase (GOx), the enzyme modified nanoporous electrode can sensitively detect glucose in a wide linear range (0.6–20 mM).► Nanoporous PtAg and PtCu alloy with hollow ligaments are fabricated using nanoporous Ag and Cu as both templates and reducing agents. ► The shell of the nanoporous PtAg ligaments is seamless, while that of nanoporous PtCu is comprised of small pores and alloy nanoparticles. ► Nanoporous PtAg exhibits enhanced electrocatalytic activity and sensing performance compared with nanoporous PtCu.
At present, Permanent Magnet Synchronous Motor (PMSM) AC servo system based on vector control has... more At present, Permanent Magnet Synchronous Motor (PMSM) AC servo system based on vector control has attracted more and more attentions and the research on it must be a kind of inevitable development trend and focus in the future. This paper is based on DSP TMS320F2812, which is designed for special-purpose on motor control by TI Company, and designs a set of hardware control system for PMSM. The software is written by C2000 assembly language, which realized the speed, current and position loop control. The flow chart of interrupt service routine is available. The simulation results show the excellent performance of DSP control.
Through experimental analysis of peroxidase isozyme in the leaves of sugar beets, it has been ver... more Through experimental analysis of peroxidase isozyme in the leaves of sugar beets, it has been verified that the enzyme activity of dry sugar beet seeds is closely connected with the doses of N+ ion implanted, and that low dosage implantation helps to bring about enzyme activation. Meanwhile, new enzyme bands appear, and the growing quantrty and trend of sugar beets increase distinctly. The best result can be obtained when the dose of ion implantation is 4x1016N+/cm2 and the number of pulse is 60 times.
ABSTRACTMonolaurin (M) is a potential natural antimicrobial agent used in foods. It is considered... more ABSTRACTMonolaurin (M) is a potential natural antimicrobial agent used in foods. It is considered to have an antimicrobial activity against gram-positive bacteria. A monolaurin microemulsion (MME) system inhibited the growth of Bacillus subtilis, Escherichia coli, Aspergillus niger and Penicillium digitatum. Microemulsions (MEs) are transparent, isotropic solutions of oil, surfactant, cosurfactant and water, which are thermodynamically stable and have been much studied in terms of pharmaceutical and cosmetic applications. The growth of B. subtilis was inhibited more strongly by MME than by M. A similar pattern was observed for E. coli, A. niger and P. digitatum, although an enhanced inhibition by MME system over that obtained in comparable M alone was not observed.Monolaurin (M) is a potential natural antimicrobial agent used in foods. It is considered to have an antimicrobial activity against gram-positive bacteria. A monolaurin microemulsion (MME) system inhibited the growth of Bacillus subtilis, Escherichia coli, Aspergillus niger and Penicillium digitatum. Microemulsions (MEs) are transparent, isotropic solutions of oil, surfactant, cosurfactant and water, which are thermodynamically stable and have been much studied in terms of pharmaceutical and cosmetic applications. The growth of B. subtilis was inhibited more strongly by MME than by M. A similar pattern was observed for E. coli, A. niger and P. digitatum, although an enhanced inhibition by MME system over that obtained in comparable M alone was not observed.PRACTICAL APPLICATIONSMonolaurin is considered to have an antimicrobial activity against gram-positive bacteria but not against gram-negative bacteria. A monolaurin microemulsion system inhibited the growth of Bacillus subtilis, Escherichia coli, Aspergillus niger and Penicillium digitatum, and will be regarded as a “natural” antimicrobial preservative.Monolaurin is considered to have an antimicrobial activity against gram-positive bacteria but not against gram-negative bacteria. A monolaurin microemulsion system inhibited the growth of Bacillus subtilis, Escherichia coli, Aspergillus niger and Penicillium digitatum, and will be regarded as a “natural” antimicrobial preservative.
Materials Science and Engineering B-advanced Functional Solid-state Materials, 2006
The PZT/polyvinyl chloride (PVC) composites are prepared by hot-pressing technique using a novel ... more The PZT/polyvinyl chloride (PVC) composites are prepared by hot-pressing technique using a novel nanocrystalline PVC. The d33 value observed in this work for the 0.5PZT/0.5PVC composite is close to the 0.5PZT/0.5PVDF composite reported in the literature, but PVC is much cheaper than PVDF. The three-phase fgC/0.5PZT/(0.5 − fg)PVC composites are obtained by adding a small content of graphite particles to the 0.5PZT/0.5PVC composite. The measured dielectric properties demonstrate that a percolation transition occurs in the three-phase composites as in normal two-phase metal–insulator continuum media. An optimum piezoelectric property is obtained by adding fg = 0.005 before the percolation threshold in the fgC/0.5PZT/(0.5 − fg)PVC composites, which is 50% higher than that of the 0.5PZT/0.5PVC composite. X-ray powder diffraction (XRD) patterns show domain rotation is easy in this three-phase composite, and P–E hysteresis loops conform that a small amount of graphite particles adding in the composite break the polymer seclusion, and considerably decrease coercive field of the composite.
Eu2+, Dy3+ co-doped strontium aluminate (SrAl2O4) phosphor nanometer powders with high brightness... more Eu2+, Dy3+ co-doped strontium aluminate (SrAl2O4) phosphor nanometer powders with high brightness and long afterglow were prepared by heating the precursor gel (resulted from sol–gel method) at 900 °C and a reductive atmosphere of active carbon. The average particle size of the SrAl2O4:Eu, Dy phosphor powders was 59±7 nm and its optical properties have been studied systematically. The broad band UV excited luminescence of the SrAl2O4:Eu, Dy was observed at λmax=506 nm due to transitions from the 4f65d1 to the 4f7 configuration of the Eu2+ ion. The results indicated that the main peaks in the emission and excitation spectrum shifted to the short wavelength compared with phosphor obtained by the solid-state reaction synthesis method. The decay speed of the afterglow for nanometer phosphors was faster than that obtained by the solid-state reaction method.
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