A wide range of terrain features and landforms,which are exemplified by intricate geological formations and diverse rock compositions,are found in the western mountainous regions of China.These areas frequently encoun...A wide range of terrain features and landforms,which are exemplified by intricate geological formations and diverse rock compositions,are found in the western mountainous regions of China.These areas frequently encounter geological disasters.As one of the natural disasters,landslides lead to considerable loss of human life and property.Considering mitigation of the losses caused by landslide disasters,a necessary measure for disaster prevention and mitigation involves conducting detailed investigations and monitoring of landslides,which is also the cornerstone of landslide warning.This study compares and analyzes the feasibility of the magnetotelluric detection method for landslides using the results of engineering geological surveys and landslide monitoring.The study aims to address the scientific problem of the validity of using magnetotelluric methods to detect landslide development processes.The Tangjiawan landslide signal on the left side of the K94+000~K94+145 section of the Wenma Expressway is analyzed by employing engineering geological survey,magnetotelluric detection,landslide monitoring,landslide analysis,and other methods.Analysis results provide the static electrical characteristics of lithology,structure,and groundwater,as well as the dynamic electrical characteristics of landslide development.This study focuses on analyzing the relationship between the methods of magnetotelluric detection and engineering geological surveys and the results of landslide monitoring.The workflow and methods for data collection,processing,inversion,interpretation,and analysis using the magnetotelluric method to detect the dynamic development process of landslides are presented in the conclusion.Preliminary conclusions indicate a strong correlation between the dynamic changes in magnetotelluric wave impedance with the surface displacement of landslides and the dynamic changes in groundwater.The use of the magnetotelluric method for landslide detection and monitoring is a feasible example.The research results can offer certain technical references for the detection and monitoring of landslides using magnetotelluric methods and also provide references and guidance for the selection of diversified landslide monitoring methods in the future.展开更多
In this study,Mg-based composites,by the addition of ZnO,Ca_(2)ZnSi_(2)O_(7),Ca_(2)MgSi_(2)O_(7),and CaSiO_(3)as bioactive agents,were fabricated using friction stir processing.The microstructure and in vitro assessme...In this study,Mg-based composites,by the addition of ZnO,Ca_(2)ZnSi_(2)O_(7),Ca_(2)MgSi_(2)O_(7),and CaSiO_(3)as bioactive agents,were fabricated using friction stir processing.The microstructure and in vitro assessment of bioactivity,biodegradation rate,and corrosion behavior of the resultant composites were investigated in simulated body fluid(SBF).The results showed that during the immersion of composites in SBF for 28 d,due to the release of Ca^(2+)and PO_(4)^(3-)ions,hydroxyapatite(HA)crystals with cauliflower shaped morphology were deposited on the surface of composites,confirming good bioactivity of composites.In addition,due to the uniform distribution of bioceramic powders throughout Mg matrix,grain refinement of the Mg matrix,and uniform redistribution of secondary phase particles,the polarization resistance increased,and the biodegradation rate of composites significantly reduced compared to monolithic Mg matrix.The polarization corrosion resistance of Mg-ZnO increased from 0.216 to 2.499 kΩ/cm^(2)compared to monolithic Mg alloy.Additionally,Mg-ZnO composite with the weight loss of 0.0217 g after 28 d immersion showed lower weight loss compared to other samples with increasing immersion time.Moreover,Mg-ZnO composite with the biodegradation rate of 37.71 mm/a exhibited lower biodegradation rate compared to other samples with increasing immersion time.展开更多
Considering that copper mine tailings(CMTs)are commonly mixed with ordinary Portland cement,fly ash(FA),and kaolin to produce geopolymers,to make full use of CMTs,the properties of geopolymers manufactured under diffe...Considering that copper mine tailings(CMTs)are commonly mixed with ordinary Portland cement,fly ash(FA),and kaolin to produce geopolymers,to make full use of CMTs,the properties of geopolymers manufactured under different material mass ratios and curing methods(standard curing,water bath curing,and 60℃curing)are evaluated with significantly increased dosage of CMTs.Porosity and unconfined compressive strength tests,X-ray diffraction,field emission scanning electron microscopy,and energy dispersive spectroscopy are used to determine the physical and mechanical properties,microstructure,and mineral composition of geopolymers.Finally,costs and CO 2 emissions of specimens with different material mass ratios during the preparation processes are compared.The results show that during the geopolymerization of low-calcium materials,various geopolymer gels,including calcium silicate,calcium silicoaluminate,and mainly sodium silicoaluminate gels,coexist.The solid waste,cost,and carbon dioxide emission reductions can reach 100%,166.3 yuan/t,and 73.3 kg/t,respectively.Under a curing condition of 60℃,the sample with a CMTs mass fraction of 70%and an FA mass fraction of 30%meets the requirements of porosity,compressive strength.The resource utilization of CMT and FA is realized in a more economical way.展开更多
Based on a detailed analysis of differences between seismic data and well logs, we discuss the problem of matching seismic traces and well logs and present a new matching method based on event search in instantaneous ...Based on a detailed analysis of differences between seismic data and well logs, we discuss the problem of matching seismic traces and well logs and present a new matching method based on event search in instantaneous phase which greatly improves seismic resolution. The method is based on flattening events in instantaneous phase to compare the seismic traces to the well log traces with the same phase. We calculate the coefficients using the singular value decomposition method to extrapolate the well logs. As a result, the events in the seismic profile are continuous and match well with well logs. We apply this method to the Mao-2 well in Daqing Oilfield with good results.展开更多
The catalytic wet air oxidation of aniline over Ru catalysts supported on modified Ti 2 (Ti 2, Ti0.9Ce0.1O2, Ti0.9Zr0.1O2) is investigated. A series of characterization techniques are conducted to deter...The catalytic wet air oxidation of aniline over Ru catalysts supported on modified Ti 2 (Ti 2, Ti0.9Ce0.1O2, Ti0.9Zr0.1O2) is investigated. A series of characterization techniques are conducted to determine the relationship between the physico-chemical properties and the catalytic performance. As a result of the good metal dispersion and large number of surface oxygen species, the Ru/Ti0.9 Zr0.1O2 catalyst presents the best catalytic activity among the tested samples. The effects of the operating conditions on the reaction are investigated and the optimal reaction conditions are determined. Based on the relationship between the by-products concentration and the reaction time, the reaction path for the catalytic oxidation of aniline is established. Carbonaceous deposits on the surface of the support are known to be the main reason for catalyst deactivation. The catalysts maintain a constant activity even after three consecutive cycles.展开更多
Aim To establish an RP-HPLC method for the determination of scutellarin in plasma and study its pharmacokinetics in dogs. Methods Scutellarin was given to dogs by intravenous injection and determined by RP-HPLC, the m...Aim To establish an RP-HPLC method for the determination of scutellarin in plasma and study its pharmacokinetics in dogs. Methods Scutellarin was given to dogs by intravenous injection and determined by RP-HPLC, the mean plasma concentration-time curve was plotted and pharmacokinetic parameters were calculated by program 3p87. Resu;ts The concentration-time curve of scutellarin could be fitted to three-compartment model with T1/2 pi, T1/2 α and T1/2 β being 1.05 ± 0.80 min, 6.99 + 2.76 min and 51.61 + 28.78 min, respectively, Vc being 880.1 + 508.3 mL, CL being 189.6 + 53.8 mL@ min- 1, and AUC0-90 and AUC0-∞ being 574.43 + 133.95 μg@ min@ mL - 1 and 599.34 ± 132.00μg@ min@mL- 1, respectively. Conclusion The fact that the concentrations of scutellarin in plasma declined rapidly after the medication suggested that the T1/2 of scutellarin should be taken into account in drug administration and preparation development.展开更多
By studying principles and methods related to early-warning model of plant diseases and using PSO method, parameter optimization was conducted to backward propagation neural network, and a pre-warning model for plant ...By studying principles and methods related to early-warning model of plant diseases and using PSO method, parameter optimization was conducted to backward propagation neural network, and a pre-warning model for plant diseases based on particle swarm and neural network algorithm was established. The test results showed that the construction of early-warning model is effective and feasible, which will provide a via- ble model structure to establish the effective early-warning platform.展开更多
A hybrid technique is developed for the evaluation of two dimensional electromagnetic scattering from electrically large conducting bodies with cracks on their surfaces (TE case). The edge based finite element metho...A hybrid technique is developed for the evaluation of two dimensional electromagnetic scattering from electrically large conducting bodies with cracks on their surfaces (TE case). The edge based finite element method (FEM) is employed to compute the scattering from the cracks. Physical optics (PO) and physical theory of diffraction (PTD) are utilized to evaluate the scattering from the large bodies with the cracks filled with perfect conductors. These two methods are combined by an efficient coupling scheme. Some of numerical results are presented. It is shown that the hybrid technique has some advantages over other methods in regard to saving computer memory units and CPU time.展开更多
Three different preparation methods including steam physical activation, catalytic carbonation and KOH chemical activation methods were used to prepare municipal solid waste- based carbon materials. The methylene blue...Three different preparation methods including steam physical activation, catalytic carbonation and KOH chemical activation methods were used to prepare municipal solid waste- based carbon materials. The methylene blue (MB) adsorption value was applied to evaluate the adsorption capabilities of the prepared carbon materials. The effects of preparation methods on adsorption capability and yield of products were investigated. The yield of carbon materials with the catalytic carbonation method is the highest, and the KOH activation method is the second level. Considering the adsorption performance, the KOH activation method is much more favorable. Among the different components of municipal solid waste-based carbon materials, the adsorption properties of the single component of paperboard, the double components of tire and paperboard, the triple components of tire, paperboard and polyvinyl chloride (PVC), and the multi-component mixtures are better than those of other single-, double-, triple- and multi-component mixtures, respectively.展开更多
Aim A simple, sensitive and rapid RP HPLC method with pre column derivatization has been developed for the determination of sulphonylurea glimepiride in dog serum. Methods The sulphonylurea glimepiride was extract...Aim A simple, sensitive and rapid RP HPLC method with pre column derivatization has been developed for the determination of sulphonylurea glimepiride in dog serum. Methods The sulphonylurea glimepiride was extracted from the dog serum using dichlromethane followed by derivatization with DNBF for 20 min at 100℃. The solvent was then evaporated at 60℃ under nitrogen, and the residue was taken up in 100 μL of mobile phase consisting of acetonitrile water (75∶30, v/v). The separation was performed on a Hypersil BDS C18 column with a flow rate of 0 8 mL·min -1 , and the ultraviolet detector wavelength was set at 350 nm. Results Extraction recovery ranged from 75.9% to 83.2%, and methodological recovery was between 96.5% and 109.3%. Within day RSD ranged from 1.5% to 6.3%, and inter day RSD was between 2 9% and 14.8%. The method showed good linearity (R=0.9998). Conclusion The method was simple, convenient and sensitive. The reaction of derivatization was reproducible.展开更多
Based on Kuo and Dai's vectorial wave-field extrapolation equations, we derive new Kirchhoff migration equations by introducing unit vectors which represent the ray directions at the imaging points of the reflected P...Based on Kuo and Dai's vectorial wave-field extrapolation equations, we derive new Kirchhoff migration equations by introducing unit vectors which represent the ray directions at the imaging points of the reflected P- and PS converted-waves. Furthermore, using the slope of the events on shot records and a ray racing procedure, mirror-image reflection points are found and the reflection data are smeared along the Fresnel zone. The migration method proposed in this paper solves two troublesome imaging problems caused by limited receiving aperture and migration artifacts resulting from wave propagation at the velocities of non original wave type. The migration method is applied successfully with model data, demonstrating that the new method is effective and correct.展开更多
Gassmann's equations are commonly used for predicting seismic wave velocity in rock physics research.However the input matrix mineral bulk modulus parameters are not accurate,which greatly influences the prediction r...Gassmann's equations are commonly used for predicting seismic wave velocity in rock physics research.However the input matrix mineral bulk modulus parameters are not accurate,which greatly influences the prediction reliability.In this paper,combining the Russell fluid factor with the Gassman-Biot-Geertsma equation and introducing the dry-rock Poisson's ratio,we propose an effective matrix mineral bulk modulus extraction method.This method can adaptively invert the equivalent matrix mineral bulk modulus to apply the Gassmann equation to fluid substitution of complex carbonate reservoirs and increase the fluid prediction reliability.The verification of the actual material fluid substitution also shows that this method is reliable,efficient,and adaptable.展开更多
The interfacial adhesive properties ofpolypropylene/stainless steel were studied by the blister test. The polypropylene film with a squared free-standing window was pressured by oil from one side of film. The correspo...The interfacial adhesive properties ofpolypropylene/stainless steel were studied by the blister test. The polypropylene film with a squared free-standing window was pressured by oil from one side of film. The corresponding deformation field was observed by a digital speckle correlation method. The experimental results show that the squared film deforms and debonds from stainless steel with the increase of pressure. The debonding of the squared film in initiates from the center of edge and extends to the comer, and then the deformation of film evolves from square to circle shape. The interfacial adhesive energy of polypropylene/stainless steel is (22.60±1.55) J/m2, which is in agreement with that measured by film with a circular window.展开更多
Unlike previous theories with velocity and/or elastic modulus averaging, we use a three-phase porous rock physics model developed by Santos for analyzing the seismic response of two immiscible fluids in saturated poro...Unlike previous theories with velocity and/or elastic modulus averaging, we use a three-phase porous rock physics model developed by Santos for analyzing the seismic response of two immiscible fluids in saturated porous media. Considering reservoir reference pressure and coupling drag of two fluids in pores, the effects of frequency, porosity, and gas saturation on the phase velocities of the P-and S-waves are discussed in detail under field conditions. The effects of porosity and gas saturation on Vp/Vs are also provided. The data for our numerical experiments are from a sample of deep volcanic rock from Daqing. The numerical results show that the frequency dispersion effect can be ignored for deep volcanic rocks with low porosity and low permeability. It is concluded that for deep volcanic rocks the effect of gas content in pores on Vp/Vs is negligible but the effect of porosity is significant when there is a certain amount of water contained in the pores. The accurate estimate of lithology and porosity in this case is relatively more important.展开更多
In order to improve the bio-oxidation efficiency of Axi refractory gold concentrate, a two-step process including a high temperature chemical oxidation and a subsequent bio-oxidation, combined with p H control during ...In order to improve the bio-oxidation efficiency of Axi refractory gold concentrate, a two-step process including a high temperature chemical oxidation and a subsequent bio-oxidation, combined with p H control during the bio-oxidation step was used. The results revealed that the optimum mode was to maintain solution p H at 1.0-1.2 during the biological oxidation stage. Under this condition, the activity of mixed culture could be sustained and the formation of jarosite could be diminished, thus the oxidation efficiency was improved. The oxidation levels of iron and sulfur were improved by 12.50% and 15.49%, and the gold recovery was increased by 21.02%. Therefore, the two-step process combined with p H control is an effective method for oxidizing the biohydrometallurgical process of Axi gold concentrate, and it will have a broad prospect of application in dealing with complex refractory gold concentrate.展开更多
基金supported by the Construction S&T Project of Department of Transportation of Sichuan Province(Grant No.2023A02,No.2024A04,No.2020A01)the Sichuan Science and Technology Program(Grant No.2022YFG0141)+3 种基金the Research Project of Sichuan Highway Planning,Survey,Design,and Research Institute Ltd.(Grant No.KYXM2021000049,No.KYXM2022000038,No.KYXM2023000056)the National Natural Science Foundation of China(41630640)the National Science Foundation of Innovation Research Group(41521002)the National Natural Science Foundation of China(41790445).
文摘A wide range of terrain features and landforms,which are exemplified by intricate geological formations and diverse rock compositions,are found in the western mountainous regions of China.These areas frequently encounter geological disasters.As one of the natural disasters,landslides lead to considerable loss of human life and property.Considering mitigation of the losses caused by landslide disasters,a necessary measure for disaster prevention and mitigation involves conducting detailed investigations and monitoring of landslides,which is also the cornerstone of landslide warning.This study compares and analyzes the feasibility of the magnetotelluric detection method for landslides using the results of engineering geological surveys and landslide monitoring.The study aims to address the scientific problem of the validity of using magnetotelluric methods to detect landslide development processes.The Tangjiawan landslide signal on the left side of the K94+000~K94+145 section of the Wenma Expressway is analyzed by employing engineering geological survey,magnetotelluric detection,landslide monitoring,landslide analysis,and other methods.Analysis results provide the static electrical characteristics of lithology,structure,and groundwater,as well as the dynamic electrical characteristics of landslide development.This study focuses on analyzing the relationship between the methods of magnetotelluric detection and engineering geological surveys and the results of landslide monitoring.The workflow and methods for data collection,processing,inversion,interpretation,and analysis using the magnetotelluric method to detect the dynamic development process of landslides are presented in the conclusion.Preliminary conclusions indicate a strong correlation between the dynamic changes in magnetotelluric wave impedance with the surface displacement of landslides and the dynamic changes in groundwater.The use of the magnetotelluric method for landslide detection and monitoring is a feasible example.The research results can offer certain technical references for the detection and monitoring of landslides using magnetotelluric methods and also provide references and guidance for the selection of diversified landslide monitoring methods in the future.
文摘In this study,Mg-based composites,by the addition of ZnO,Ca_(2)ZnSi_(2)O_(7),Ca_(2)MgSi_(2)O_(7),and CaSiO_(3)as bioactive agents,were fabricated using friction stir processing.The microstructure and in vitro assessment of bioactivity,biodegradation rate,and corrosion behavior of the resultant composites were investigated in simulated body fluid(SBF).The results showed that during the immersion of composites in SBF for 28 d,due to the release of Ca^(2+)and PO_(4)^(3-)ions,hydroxyapatite(HA)crystals with cauliflower shaped morphology were deposited on the surface of composites,confirming good bioactivity of composites.In addition,due to the uniform distribution of bioceramic powders throughout Mg matrix,grain refinement of the Mg matrix,and uniform redistribution of secondary phase particles,the polarization resistance increased,and the biodegradation rate of composites significantly reduced compared to monolithic Mg matrix.The polarization corrosion resistance of Mg-ZnO increased from 0.216 to 2.499 kΩ/cm^(2)compared to monolithic Mg alloy.Additionally,Mg-ZnO composite with the weight loss of 0.0217 g after 28 d immersion showed lower weight loss compared to other samples with increasing immersion time.Moreover,Mg-ZnO composite with the biodegradation rate of 37.71 mm/a exhibited lower biodegradation rate compared to other samples with increasing immersion time.
基金The National Natural Science Foundation of China(No.41877240)Scientific Research Foundation of Graduate School of Southeast University(No.YBPY1930).
文摘Considering that copper mine tailings(CMTs)are commonly mixed with ordinary Portland cement,fly ash(FA),and kaolin to produce geopolymers,to make full use of CMTs,the properties of geopolymers manufactured under different material mass ratios and curing methods(standard curing,water bath curing,and 60℃curing)are evaluated with significantly increased dosage of CMTs.Porosity and unconfined compressive strength tests,X-ray diffraction,field emission scanning electron microscopy,and energy dispersive spectroscopy are used to determine the physical and mechanical properties,microstructure,and mineral composition of geopolymers.Finally,costs and CO 2 emissions of specimens with different material mass ratios during the preparation processes are compared.The results show that during the geopolymerization of low-calcium materials,various geopolymer gels,including calcium silicate,calcium silicoaluminate,and mainly sodium silicoaluminate gels,coexist.The solid waste,cost,and carbon dioxide emission reductions can reach 100%,166.3 yuan/t,and 73.3 kg/t,respectively.Under a curing condition of 60℃,the sample with a CMTs mass fraction of 70%and an FA mass fraction of 30%meets the requirements of porosity,compressive strength.The resource utilization of CMT and FA is realized in a more economical way.
基金supported by National Natural Science Foundation of China (Grant No. 40674072)National Hi-techResearch and Development Program of China (863 Program) (Grant No. 2006AA09A102-08)+1 种基金National Basic ResearchProgram of China (the 973 Program. Grant No. 007CB209603) the Opening fund of State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences (GPMR200633)
文摘Based on a detailed analysis of differences between seismic data and well logs, we discuss the problem of matching seismic traces and well logs and present a new matching method based on event search in instantaneous phase which greatly improves seismic resolution. The method is based on flattening events in instantaneous phase to compare the seismic traces to the well log traces with the same phase. We calculate the coefficients using the singular value decomposition method to extrapolate the well logs. As a result, the events in the seismic profile are continuous and match well with well logs. We apply this method to the Mao-2 well in Daqing Oilfield with good results.
基金supported by the National Natural Science Foundation of China(21333003,21577034)National Basic Research Program of China(2013CB933200)+1 种基金National High Technology Research and Development Program of China(2015AA034603)the Fundamental Research Funds for the Central Universities(WJ1514020)~~
文摘The catalytic wet air oxidation of aniline over Ru catalysts supported on modified Ti 2 (Ti 2, Ti0.9Ce0.1O2, Ti0.9Zr0.1O2) is investigated. A series of characterization techniques are conducted to determine the relationship between the physico-chemical properties and the catalytic performance. As a result of the good metal dispersion and large number of surface oxygen species, the Ru/Ti0.9 Zr0.1O2 catalyst presents the best catalytic activity among the tested samples. The effects of the operating conditions on the reaction are investigated and the optimal reaction conditions are determined. Based on the relationship between the by-products concentration and the reaction time, the reaction path for the catalytic oxidation of aniline is established. Carbonaceous deposits on the surface of the support are known to be the main reason for catalyst deactivation. The catalysts maintain a constant activity even after three consecutive cycles.
文摘Aim To establish an RP-HPLC method for the determination of scutellarin in plasma and study its pharmacokinetics in dogs. Methods Scutellarin was given to dogs by intravenous injection and determined by RP-HPLC, the mean plasma concentration-time curve was plotted and pharmacokinetic parameters were calculated by program 3p87. Resu;ts The concentration-time curve of scutellarin could be fitted to three-compartment model with T1/2 pi, T1/2 α and T1/2 β being 1.05 ± 0.80 min, 6.99 + 2.76 min and 51.61 + 28.78 min, respectively, Vc being 880.1 + 508.3 mL, CL being 189.6 + 53.8 mL@ min- 1, and AUC0-90 and AUC0-∞ being 574.43 + 133.95 μg@ min@ mL - 1 and 599.34 ± 132.00μg@ min@mL- 1, respectively. Conclusion The fact that the concentrations of scutellarin in plasma declined rapidly after the medication suggested that the T1/2 of scutellarin should be taken into account in drug administration and preparation development.
基金Supported by a Grant from the Science and Technology Project ofYunnan Province(2006NG02)~~
文摘By studying principles and methods related to early-warning model of plant diseases and using PSO method, parameter optimization was conducted to backward propagation neural network, and a pre-warning model for plant diseases based on particle swarm and neural network algorithm was established. The test results showed that the construction of early-warning model is effective and feasible, which will provide a via- ble model structure to establish the effective early-warning platform.
文摘A hybrid technique is developed for the evaluation of two dimensional electromagnetic scattering from electrically large conducting bodies with cracks on their surfaces (TE case). The edge based finite element method (FEM) is employed to compute the scattering from the cracks. Physical optics (PO) and physical theory of diffraction (PTD) are utilized to evaluate the scattering from the large bodies with the cracks filled with perfect conductors. These two methods are combined by an efficient coupling scheme. Some of numerical results are presented. It is shown that the hybrid technique has some advantages over other methods in regard to saving computer memory units and CPU time.
基金The National Natural Science Foundation of China(No.51576048)the Environmental Protection Subject Foundation of Jiangsu Province(No.2015013)+3 种基金the Industry,Education and Research Prospective Project of Jiangsu Province(No.BY2015060-04)the Fok Ying Tong Education Foundation(No.142026)the Fundamental Research Funds for the Central UniversitiesProgram for New Century Excellent Talents in University(No.NCET-12-0118)
文摘Three different preparation methods including steam physical activation, catalytic carbonation and KOH chemical activation methods were used to prepare municipal solid waste- based carbon materials. The methylene blue (MB) adsorption value was applied to evaluate the adsorption capabilities of the prepared carbon materials. The effects of preparation methods on adsorption capability and yield of products were investigated. The yield of carbon materials with the catalytic carbonation method is the highest, and the KOH activation method is the second level. Considering the adsorption performance, the KOH activation method is much more favorable. Among the different components of municipal solid waste-based carbon materials, the adsorption properties of the single component of paperboard, the double components of tire and paperboard, the triple components of tire, paperboard and polyvinyl chloride (PVC), and the multi-component mixtures are better than those of other single-, double-, triple- and multi-component mixtures, respectively.
文摘Aim A simple, sensitive and rapid RP HPLC method with pre column derivatization has been developed for the determination of sulphonylurea glimepiride in dog serum. Methods The sulphonylurea glimepiride was extracted from the dog serum using dichlromethane followed by derivatization with DNBF for 20 min at 100℃. The solvent was then evaporated at 60℃ under nitrogen, and the residue was taken up in 100 μL of mobile phase consisting of acetonitrile water (75∶30, v/v). The separation was performed on a Hypersil BDS C18 column with a flow rate of 0 8 mL·min -1 , and the ultraviolet detector wavelength was set at 350 nm. Results Extraction recovery ranged from 75.9% to 83.2%, and methodological recovery was between 96.5% and 109.3%. Within day RSD ranged from 1.5% to 6.3%, and inter day RSD was between 2 9% and 14.8%. The method showed good linearity (R=0.9998). Conclusion The method was simple, convenient and sensitive. The reaction of derivatization was reproducible.
基金supported by National High-Tech Research and Development Program of China (Grant No. 2006AA06Z202)Open Fund of the Key Laboratory of Geophysical Exploration of CNPC (Grant No. GPKL0802)+2 种基金CNPC Young Innovation Fund (Grant No. 05E7028) graduate student Innovation Fund of China University of Petroleum(East China) (Grant No. S2008-1)the Program for New Century Excellent Talents in University (Grant No. NCET-07-0845).
文摘Based on Kuo and Dai's vectorial wave-field extrapolation equations, we derive new Kirchhoff migration equations by introducing unit vectors which represent the ray directions at the imaging points of the reflected P- and PS converted-waves. Furthermore, using the slope of the events on shot records and a ray racing procedure, mirror-image reflection points are found and the reflection data are smeared along the Fresnel zone. The migration method proposed in this paper solves two troublesome imaging problems caused by limited receiving aperture and migration artifacts resulting from wave propagation at the velocities of non original wave type. The migration method is applied successfully with model data, demonstrating that the new method is effective and correct.
基金sponsored by National Natural Science Foundation of China(Grant No.40904035)
文摘Gassmann's equations are commonly used for predicting seismic wave velocity in rock physics research.However the input matrix mineral bulk modulus parameters are not accurate,which greatly influences the prediction reliability.In this paper,combining the Russell fluid factor with the Gassman-Biot-Geertsma equation and introducing the dry-rock Poisson's ratio,we propose an effective matrix mineral bulk modulus extraction method.This method can adaptively invert the equivalent matrix mineral bulk modulus to apply the Gassmann equation to fluid substitution of complex carbonate reservoirs and increase the fluid prediction reliability.The verification of the actual material fluid substitution also shows that this method is reliable,efficient,and adaptable.
基金Projects(11102176,11172258,10828205)supported by the National Natural Science Foundation of China
文摘The interfacial adhesive properties ofpolypropylene/stainless steel were studied by the blister test. The polypropylene film with a squared free-standing window was pressured by oil from one side of film. The corresponding deformation field was observed by a digital speckle correlation method. The experimental results show that the squared film deforms and debonds from stainless steel with the increase of pressure. The debonding of the squared film in initiates from the center of edge and extends to the comer, and then the deformation of film evolves from square to circle shape. The interfacial adhesive energy of polypropylene/stainless steel is (22.60±1.55) J/m2, which is in agreement with that measured by film with a circular window.
文摘Unlike previous theories with velocity and/or elastic modulus averaging, we use a three-phase porous rock physics model developed by Santos for analyzing the seismic response of two immiscible fluids in saturated porous media. Considering reservoir reference pressure and coupling drag of two fluids in pores, the effects of frequency, porosity, and gas saturation on the phase velocities of the P-and S-waves are discussed in detail under field conditions. The effects of porosity and gas saturation on Vp/Vs are also provided. The data for our numerical experiments are from a sample of deep volcanic rock from Daqing. The numerical results show that the frequency dispersion effect can be ignored for deep volcanic rocks with low porosity and low permeability. It is concluded that for deep volcanic rocks the effect of gas content in pores on Vp/Vs is negligible but the effect of porosity is significant when there is a certain amount of water contained in the pores. The accurate estimate of lithology and porosity in this case is relatively more important.
基金Project(2010CB630901)supported by the National Basic Research Program of ChinaProject(2013M531814)supported by the 53rd China Postdoctoral Science Foundation
文摘In order to improve the bio-oxidation efficiency of Axi refractory gold concentrate, a two-step process including a high temperature chemical oxidation and a subsequent bio-oxidation, combined with p H control during the bio-oxidation step was used. The results revealed that the optimum mode was to maintain solution p H at 1.0-1.2 during the biological oxidation stage. Under this condition, the activity of mixed culture could be sustained and the formation of jarosite could be diminished, thus the oxidation efficiency was improved. The oxidation levels of iron and sulfur were improved by 12.50% and 15.49%, and the gold recovery was increased by 21.02%. Therefore, the two-step process combined with p H control is an effective method for oxidizing the biohydrometallurgical process of Axi gold concentrate, and it will have a broad prospect of application in dealing with complex refractory gold concentrate.