We aimed to investigate the potential pathogenic profile and antibiotic resistance of Listeria monocytogenes isolated from ready-to-eat food in China.Antimicrobial resistance was determined by broth microdilution foll...We aimed to investigate the potential pathogenic profile and antibiotic resistance of Listeria monocytogenes isolated from ready-to-eat food in China.Antimicrobial resistance was determined by broth microdilution following the Clinical and Laboratory Standards Institute protocol Molecular serotyping,virulence,and resistance genes were identified using PCR.Multi-locus展开更多
After trace Sm^3+ ions and Gd^3+ ions doping, the emission intensity of red phosphors Y2O2S: Eu^3 + was enhanced and the voltage character (relation between emission intensity and excitation voltage) was improve...After trace Sm^3+ ions and Gd^3+ ions doping, the emission intensity of red phosphors Y2O2S: Eu^3 + was enhanced and the voltage character (relation between emission intensity and excitation voltage) was improved while the other properties of physics and chemistry were not changed. The origins of enhancement and improvement are discussed. Probably the distortion and the defect of crystals are decreased by the substitution of Gd^3+ for Y^3+ instead of Eu^3+ for Y^3+ , and thus the Eu^3+ crystal field is improved, and radiationless process and energy loss resulted from crystal defect are weakened, which leads to increased luminescence intensity and voltage character improvement. The overlapping fluorescent spectra of Y2O2S: Sm^3+ emission and Y2O2S:Eu^3+ excitation as well as Eu^3 + excitation spectra transitions spectra lead to energy transfer from Sm^3 + sensitization of Sm^3+ ions fectively. containing Sm^3+ excitation the possibility of resonance ions to Eu^3+ ions, and the to Eu^3+ ions is achieved effectively.展开更多
CO_(2) flooding can significantly improve the recovery rate, effectively recover crude oil, and has the advantages of energy saving and emission reduction. At present, most domestic researches on CO_(2) flooding seepa...CO_(2) flooding can significantly improve the recovery rate, effectively recover crude oil, and has the advantages of energy saving and emission reduction. At present, most domestic researches on CO_(2) flooding seepage experiments are field tests in actual reservoirs or simulations with reservoir numerical simulators. Although targeted, the promotion is poor. For the characterization of seepage resistance, there are few studies on the variation law of seepage resistance caused by the combined action in the reservoir. To solve this problem, based on the mechanism of CO_(2), a physical simulation experiment device for CO_(2) non-miscible flooding production manner is designed. The device adopts two displacement schemes, gas-displacing water and gas-displacing oil, it mainly studies the immiscible gas flooding mechanism and oil displacement characteristics based on factors such as formation dip angle, gas injection position, and gas injection rate. It can provide a more accurate development simulation for the actual field application. By studying the variation law of crude oil viscosity and start-up pressure gradient, the characterization method of seepage resistance gradient affected by these two factors in the seepage process is proposed. The field test is carried out for the natural core of the S oilfield, and the seepage resistance is described more accurately. The results show that the advancing front of the gas drive is an arc, and the advancing speed of the gas drive oil front is slower than that of gas drive water;the greater the dip angle, the higher the displacement efficiency;the higher the gas injection rate is, the higher the early recovery rate is, and the lower the later recovery rate is;oil displacement efficiency is lower than water displacement efficiency;taking the actual core of S oilfield as an example, the mathematical representation method of core start-up pressure gradient in low permeability reservoir is established.展开更多
文摘We aimed to investigate the potential pathogenic profile and antibiotic resistance of Listeria monocytogenes isolated from ready-to-eat food in China.Antimicrobial resistance was determined by broth microdilution following the Clinical and Laboratory Standards Institute protocol Molecular serotyping,virulence,and resistance genes were identified using PCR.Multi-locus
文摘After trace Sm^3+ ions and Gd^3+ ions doping, the emission intensity of red phosphors Y2O2S: Eu^3 + was enhanced and the voltage character (relation between emission intensity and excitation voltage) was improved while the other properties of physics and chemistry were not changed. The origins of enhancement and improvement are discussed. Probably the distortion and the defect of crystals are decreased by the substitution of Gd^3+ for Y^3+ instead of Eu^3+ for Y^3+ , and thus the Eu^3+ crystal field is improved, and radiationless process and energy loss resulted from crystal defect are weakened, which leads to increased luminescence intensity and voltage character improvement. The overlapping fluorescent spectra of Y2O2S: Sm^3+ emission and Y2O2S:Eu^3+ excitation as well as Eu^3 + excitation spectra transitions spectra lead to energy transfer from Sm^3 + sensitization of Sm^3+ ions fectively. containing Sm^3+ excitation the possibility of resonance ions to Eu^3+ ions, and the to Eu^3+ ions is achieved effectively.
基金the Dongying Science Development Fund Project(Nos.DJ2022009 and DJ2020003)the Shandong Provincial Higher Education Research and Development Program(Science and Technology A Class)(No.J18KA201)+2 种基金the High-level Talent Research Start-up Fund of Shengli College of China University of Petroleum(No.KQ2019-008)the Chunhui Project of Shengli College of China University of Petroleum(No.KY2017004)the Research Cultivation Project of College of Big Data and Basic Science of Shandong Institute of Petroleum and Chemical Technology(No.XYPY2201)which supports are appreciated.
文摘CO_(2) flooding can significantly improve the recovery rate, effectively recover crude oil, and has the advantages of energy saving and emission reduction. At present, most domestic researches on CO_(2) flooding seepage experiments are field tests in actual reservoirs or simulations with reservoir numerical simulators. Although targeted, the promotion is poor. For the characterization of seepage resistance, there are few studies on the variation law of seepage resistance caused by the combined action in the reservoir. To solve this problem, based on the mechanism of CO_(2), a physical simulation experiment device for CO_(2) non-miscible flooding production manner is designed. The device adopts two displacement schemes, gas-displacing water and gas-displacing oil, it mainly studies the immiscible gas flooding mechanism and oil displacement characteristics based on factors such as formation dip angle, gas injection position, and gas injection rate. It can provide a more accurate development simulation for the actual field application. By studying the variation law of crude oil viscosity and start-up pressure gradient, the characterization method of seepage resistance gradient affected by these two factors in the seepage process is proposed. The field test is carried out for the natural core of the S oilfield, and the seepage resistance is described more accurately. The results show that the advancing front of the gas drive is an arc, and the advancing speed of the gas drive oil front is slower than that of gas drive water;the greater the dip angle, the higher the displacement efficiency;the higher the gas injection rate is, the higher the early recovery rate is, and the lower the later recovery rate is;oil displacement efficiency is lower than water displacement efficiency;taking the actual core of S oilfield as an example, the mathematical representation method of core start-up pressure gradient in low permeability reservoir is established.