Rock mass is fractured media. Its fracture is a nonlinear process. Theaccumulation of acoustic emission (AF) is closely related to the degree of damage. The dynamicsproblem is simply described based on the non-equilib...Rock mass is fractured media. Its fracture is a nonlinear process. Theaccumulation of acoustic emission (AF) is closely related to the degree of damage. The dynamicsproblem is simply described based on the non-equilibrium statistical theory of crack evolvement,trying to use the hybrid analysis of the statistical theory and scan electron microscopy (SEM), thecharacters of AE signals from rock damage in a mined-out area is synthetically analyzed andevaluated. These provide an evidence to reverse deduce and accurately infer the position of rockfracture for dynamical hazard control.展开更多
The study concentrates mainly on the development of failure process incomposite rock mass. By use of acoustic emission (AE), convergence inspection, pressure monitoring,level measurement techniques and the modem signa...The study concentrates mainly on the development of failure process incomposite rock mass. By use of acoustic emission (AE), convergence inspection, pressure monitoring,level measurement techniques and the modem signal analysis technology, as well as scan electronmicroscopy (SEM) experiment, various aspects of nonlinear dynamic damage of composite rock masssurrounding the transport roadway in Linglong gold mine are discussed. According to the monitoringresults, the stability of the rock mass can be synthetically evaluated, and the intrinsic relationbetween the damage and the characteristic parameters of acoustic emission can be determined. Thelocation of the damage of rock mass can also be detected based on the acoustic emission couplemonitoring signals. Finally, the key factors which influence the stability of the transport roadwaysupported by composite hard rock materials are found out.展开更多
Based on the composite modification technology of the surface of nano Silicondioxide by non-soap emulsion polymerization, it is verified that there are polymer grafted on thesurface of nano silicon dioxide. The modifi...Based on the composite modification technology of the surface of nano Silicondioxide by non-soap emulsion polymerization, it is verified that there are polymer grafted on thesurface of nano silicon dioxide. The modification mechanism and the bonding status on the surface ofnano silicon dioxide after modification were suggested via the results of the infrared spectrum,transmission electronic microscope photograph and X-ray photoelectron spectrum. The hydroxyl formedby hydrolyzing of silane coupling agent reacts with hydroxyl on the surface of nano silicon dioxideto form Si-O-Si bonds by losing water molecules and hence the double bonds are introduced onto thesurface of nano silicon dioxide. The surface of nano silicon dioxide is grafted with polymer throughfree radical polymerization between the double bonds on the surface of nano silicon dioxide andstyrene under the action of initiating agent. The dispersibility of nano silicon dioxide and thecontrollability of surface modification of nano silicon dioxide can be greatly improved by themodification process.展开更多
By simulating test and study in laboratory, the structure and performance offrothing generator were determined. The relative curves between the frothing volume and gas velocityof foaming net, supplying liquid volume a...By simulating test and study in laboratory, the structure and performance offrothing generator were determined. The relative curves between the frothing volume and gas velocityof foaming net, supplying liquid volume and the content of foaming agent were obtainedrespectively. There were an optimum gas-velocity of foaming net, an optimum supplying liquid volumeand an optimum content of foaming agent under the condition of the given material quality and shapeof foaming net and spraying form. The spraying froth is of a great assistance in collectingrespirable dust.展开更多
Four reactors of up-flow anaerobic sludge blanket (UASB) were concurrentlyoperated to examine the effects of the xonotlite secondary particles on promoting the sludgegranulation during the starting-up stage at room te...Four reactors of up-flow anaerobic sludge blanket (UASB) were concurrentlyoperated to examine the effects of the xonotlite secondary particles on promoting the sludgegranulation during the starting-up stage at room temperature. The results show that the putting ofthe xonotlite secondary particles into the UASB reactors can increase the basicity of the reactingliquid significantly. The particles can act as the media for biomass accumulation. Thus, thegranulation process of the sludge within the reactor can be largely promoted by the specialperformances of the particles both in physical and chemical aspects.展开更多
The design and practice in supporting the cut slope of an open-pit mine wereintroduced, in which the high pressure grouting method was used in reinforcing the weak formation inthe slopes. Based on a detailed geologica...The design and practice in supporting the cut slope of an open-pit mine wereintroduced, in which the high pressure grouting method was used in reinforcing the weak formation inthe slopes. Based on a detailed geological survey of the slope, a theoretical analysis was carriedout, and the design parameters were proposed, where the Tresca or Mohr-Coulomb yield criteria wasemployed. A patent technology, named 'Technology of high pressure and multiple grouting in differentlevels within a single hole', was employed in the construction. Anchor bars were also installed asgrouting proceeds. This method combines anchoring and grouting comprehensively and was foundsuccessful in practice.展开更多
In order to get cheap and excellent PEE (Powdery Emulsion Explosives), themodel of optimizing selection on preparation of PEE was established by the Neural Net Theory (NNT).On the basis of some data in the study of PE...In order to get cheap and excellent PEE (Powdery Emulsion Explosives), themodel of optimizing selection on preparation of PEE was established by the Neural Net Theory (NNT).On the basis of some data in the study of PEE, the training, prediction and optimizing selection ofthe Neural Net (NN) model were finished by compiling procedures. The results indicate that the modelis helpful to the preparation of PEE and worthy to extend and apply broadly.展开更多
Reliable information of in--situ stress state is necessary for the design andconstruction of most important rock projects. As most rock projects are getting deeper and deeper,traditional techniques of in--situ stress ...Reliable information of in--situ stress state is necessary for the design andconstruction of most important rock projects. As most rock projects are getting deeper and deeper,traditional techniques of in--situ stress measurement are not very suitable. The current techniquesof in--situ stress measurement and their insufficiency for use at great depth are analyzed. Somebasic ideas of the development of new techniques and the improvement of current techniques for useat great depth are provided.展开更多
Ion exchange membranes with high permselectivity (the character of separatingcations from anions or anions from cations) and high selectivity (the character of separatingcations or anions of different valencies) are i...Ion exchange membranes with high permselectivity (the character of separatingcations from anions or anions from cations) and high selectivity (the character of separatingcations or anions of different valencies) are important for electrodialysis process. The Donnanequilibrium theory, based on the equilibrium of ions and no electric field, can not exactly explainthe permselectivity of ion exchange membrane for ED process, since it is impossible to set up a ionexchange equilibrium between membrane and solution and to neglect the influence of electricaldriving force on ions during ED process. A novel model named 'anti-electric potential' isestablished to interpret the permselectivity of ion exchange membrane, according to thedetermination of electric potential between membranes and the variation of elements content insolutions and membranes. The results of experiment prove that the 'anti-electric potential' reallyexists within membranes. As for the selectivity, the results reveal that electric potential andhydration energy have great influence on the concentration and mobility of ions in membranes.展开更多
An unsaturated clay slope, with various sloping angles and a thickness of 14 m, consists of backfill, slope soil and residual soil. Slide interfaces were determined by geophysical approaches and the original slope was...An unsaturated clay slope, with various sloping angles and a thickness of 14 m, consists of backfill, slope soil and residual soil. Slide interfaces were determined by geophysical approaches and the original slope was reconstructed. Sub-slope masses were classified based on the varieties of sloping angle. A force recursive principle was proposed to calculate the stability coefficient of the sub-slope masses. The influencing factors such as sloping angle, water content, hydrostatic pressure, seismic force as well as train load were analyzed. The range and correlation of the above-mentioned factors were discussed and coupled wave equations were established to reflect the relationships between unit weight, cohesion, internal frictional angle, and water content, as well as between internal frictional angle and cohesion. The sensitivity analysis of slope stability was carried out and susceptive factors were determined when the factors were taken as independent and dependent variables respectively. The results show that sloping angle, water content and earthquake are the principal susceptive factors influencing slope stability. The impact of hydrostatic pressure on slope stability is similar to the seismic force in quantity. Train load plays a small role in slope stability and its influencing only reaches the roadbed and its neighboring slope segment. If the factors are taken as independent variables, the influencing extent of water content and cohesion on slope stability can be weakened and train load can be magnified.展开更多
Tongguanshan copper deposit of Tongling large ore belt is one of the typicalskarn copper deposits. Based on careful observation under microscope many daughter mineralsincluding transparent ones and opaque ones have be...Tongguanshan copper deposit of Tongling large ore belt is one of the typicalskarn copper deposits. Based on careful observation under microscope many daughter mineralsincluding transparent ones and opaque ones have been distinguished in the fluid inclusions of garnetand diopside. The results of SEM/EDS (scanning electron microscope/energy dispersive spectrometer)and LRM (laser Raman microprobe) analysis show that these daughter minerals in garnet are sylvite,halite, sphalerite, chalcopyrite and carbonate. Sylvite daughter mineral is very popular in garnetand diopside. The existence of so much sylvite daughter mineral and other daughter minerals in thefluid inclusions indicates that the ore--forming fluid is of supper-high salinity and high potassiumconcentration. High potassium concentration in the fluid inclusions agrees with K-richmesotype--acid rock and K-silicate alteration that occurred widely in this area. The daughtermineral assemblage in garnet and diopside is similar to the mineral assemblage of ore-forming stagethat followed skarn stage.展开更多
An implementation scheme of the marching cubes (MC) algorithm was presented for the visualization of mineral deposits. The basic principles, processes and pitfalls of the MC algorithm were discussed. The asymptotic de...An implementation scheme of the marching cubes (MC) algorithm was presented for the visualization of mineral deposits. The basic principles, processes and pitfalls of the MC algorithm were discussed. The asymptotic decider algorithm was employed to solve the ambiguity problem associated with the MC algorithm. The implementation scheme was applied to model and reconstruct the surfaces of mineral deposits, using the geological data obtained from an iron mine in China. Experimental results demonstrate the ability of the implementation scheme to solve the ambiguity problem, and illustrate the effectiveness and efficiency of the MC algorithm in the visualization of mineral deposits.展开更多
Yima Coal Corporation is considering to adopt highwall mining method withauger machine to recover coal from north surface pit that has reached final highwall position. Themajor geomechanical issues associated with aug...Yima Coal Corporation is considering to adopt highwall mining method withauger machine to recover coal from north surface pit that has reached final highwall position. Themajor geomechanical issues associated with auger mining are highwall and pillar stability. Based onthe field investigation and laboratory test results of mechanical parameters, numerical modeling iscarried out to assess the stability of highwall and pillar. Field measurements of highwalldeformation have been used to validate and ensure the confidence for the development of realisticmodels. The results of numerical modeling show that the mining method is feasible for mining theseam of 10 m thickness in north surface coal mine.展开更多
Computer simulation was used for hydraulic lifting systems. Based on theoryof multiphase flows and their applications on the lifting systems, mathematical models for pumplifting and air lifting were built and simulati...Computer simulation was used for hydraulic lifting systems. Based on theoryof multiphase flows and their applications on the lifting systems, mathematical models for pumplifting and air lifting were built and simulative analysis programs for them were developedrespectively. Corresponding lifting behaviors and system parameters were analyzed and optimum matchof the parameters for future pilot mining tests and commercial mining production was predicted.展开更多
Nanometer-sized xonotlite fibers have great potential application in manyfields. The traditional method of preparing ultra fine xonotlite fibers uses the ultra fine andhighly active silica as the major raw materials, ...Nanometer-sized xonotlite fibers have great potential application in manyfields. The traditional method of preparing ultra fine xonotlite fibers uses the ultra fine andhighly active silica as the major raw materials, which is not only expensive but also difficult toprepare the xonotlite fibers with diameters around 100 nm. In this study, the ultra fine xonotlitefibers with diameters around 100 nm were prepared by an autoclaving method. The preparation waslow-cost oriented by using natural powder quartz and lime as the major raw materials. Theintergrowth of the fibers formed thin shell hollow balls or ellipsoids, namely the secondaryparticles. The length of the nanometer-sized xonotlite fibers was around several microns. The fibersand their secondary particles were produced at 216 deg C for 6 h with a continuous stirring of300-500 r/min. Zirconium oxychloride was used as an additive. The experiments show that zirconiumoxychloride has an enormous effect on the growing habit of xonotlite crystals and plays an importantrole in controlling the diameter of the xonotlite fibers.展开更多
Bioflotation of pyrite with bacteria Thiobacillus ferrooxidans in thepresence or absence of potassium ethyl xanthate was studied on a pure pyrite through microflotationand electrophoretic light scattering measurements...Bioflotation of pyrite with bacteria Thiobacillus ferrooxidans in thepresence or absence of potassium ethyl xanthate was studied on a pure pyrite through microflotationand electrophoretic light scattering measurements. The experimental results showed that in theabsence of xanthate, pyrite flotation is slightly enhanced by Thiobacillus ferrooxidans. However,with xanthate as a collector, pyrite flotation is strongly depressed after being exposed to thebacteria. The longer is the time when the pyrite is exposed to the bacteria, the stronger thedepression is. The mechanism of the depression might be due to the formation of the biofilms ofThiobacillus ferrooxidans on pyrite surfaces, preventing the adsorption of xanthate on pyritesurfaces in the form of dixanthogen or xanthate ions.展开更多
A linear mass-spring system model of a tractor-semitrailer together withdriver body parts and sprung seat is presented. Natural frequencies of the system are calculated andresponse of components in the system to road ...A linear mass-spring system model of a tractor-semitrailer together withdriver body parts and sprung seat is presented. Natural frequencies of the system are calculated andresponse of components in the system to road roughness is completed by means of computer simulationand power spectral density (PSD) approach in all of road conditions and loading cases. The resultsshow that the severest situation of response of the system occurs when the road in rough conditionand vehicle unladen. The most sensitive frequency to human body parts is around 0.9 Hz, and modeltypes of a human body seem to be not significant to the response of a heavy tractor-semitrailersystem, including to the response of the driver himself.展开更多
A novel way for electrification of mineral particles by electronbeam irradiation was proposed. The effect of irradiation dose oncharge/mass ratio was investigated experimentally. The charge/massratio of electrified mi...A novel way for electrification of mineral particles by electronbeam irradiation was proposed. The effect of irradiation dose oncharge/mass ratio was investigated experimentally. The charge/massratio of electrified mineral powders after irradiation was meas- uredby an instrument based on the principle of electrostatic induction.The experimental results showed that the charge/mass ratio is lar-gely dependent on radiation dose and electric physical properties ofminerals. The mechanism of electrification by electron beam irradi-ation is discussed. it is suggested that the essential ofelectrification by electron beam irradiation is a process ofretardation and charge deposition of incident electrons in materials.展开更多
Based on the technology of titanium dioxide grafting modification withpolystyrene (PS), the modification mechanisms are studied and the polystyrene-grafting states on thesurface of titanium dioxide have been set up. U...Based on the technology of titanium dioxide grafting modification withpolystyrene (PS), the modification mechanisms are studied and the polystyrene-grafting states on thesurface of titanium dioxide have been set up. Under the synergistic actions of mechanical force,chemistry and heat, macromolecular free radicals of PS are created, at the same time, the O-O bondsof titanium dioxide are broken and the oxide free radicals produced, and the numbers of oxygen atomare increased and crystal lattice defects rich electrons are formed on the surface of titaniumdioxide. The radical polymerization is the main reaction between PS and titanium dioxide and C-Obonds form in the process of modification. Multi-sites chemical adsorption also exists besidesgrafting between PS and titanium dioxide.展开更多
The feasibility for modifying the wettability and floatability of sulfideminerals by electron beam irradiation has been studied experimentally. The wettability ofcrystalline pyrite and floatability of some sulfide as ...The feasibility for modifying the wettability and floatability of sulfideminerals by electron beam irradiation has been studied experimentally. The wettability ofcrystalline pyrite and floatability of some sulfide as pyrite, arsenopyrite, chalcopyrite andmarmatite after irradiation were examined by flotation in a modified Hallimond tube. Experimentalresults show that the hydrophobicity of crystalline pyrite enhances with the increase of irradiationdose in a low dose range. And the flotation responses of sulfide minerals on irradiation dose varywith the mineral species and particle size. The floatability of minerals can be regulated byaltering irradiation dose. An explanation for the mechanism has been suggested based on theprinciple of radiation chemistry.展开更多
基金This work was financially supported by the Natural Science Foundation of Shannxi Province (No.2003E_213 )the Doctoral Foundation of the Ministry of Education of China (No.20020008021)the National Natural Science Foundation of China (No.50074002)
文摘Rock mass is fractured media. Its fracture is a nonlinear process. Theaccumulation of acoustic emission (AF) is closely related to the degree of damage. The dynamicsproblem is simply described based on the non-equilibrium statistical theory of crack evolvement,trying to use the hybrid analysis of the statistical theory and scan electron microscopy (SEM), thecharacters of AE signals from rock damage in a mined-out area is synthetically analyzed andevaluated. These provide an evidence to reverse deduce and accurately infer the position of rockfracture for dynamical hazard control.
基金This work was financially supported by the National Natural Science Foundation of China, No.50074002.
文摘The study concentrates mainly on the development of failure process incomposite rock mass. By use of acoustic emission (AE), convergence inspection, pressure monitoring,level measurement techniques and the modem signal analysis technology, as well as scan electronmicroscopy (SEM) experiment, various aspects of nonlinear dynamic damage of composite rock masssurrounding the transport roadway in Linglong gold mine are discussed. According to the monitoringresults, the stability of the rock mass can be synthetically evaluated, and the intrinsic relationbetween the damage and the characteristic parameters of acoustic emission can be determined. Thelocation of the damage of rock mass can also be detected based on the acoustic emission couplemonitoring signals. Finally, the key factors which influence the stability of the transport roadwaysupported by composite hard rock materials are found out.
文摘Based on the composite modification technology of the surface of nano Silicondioxide by non-soap emulsion polymerization, it is verified that there are polymer grafted on thesurface of nano silicon dioxide. The modification mechanism and the bonding status on the surface ofnano silicon dioxide after modification were suggested via the results of the infrared spectrum,transmission electronic microscope photograph and X-ray photoelectron spectrum. The hydroxyl formedby hydrolyzing of silane coupling agent reacts with hydroxyl on the surface of nano silicon dioxideto form Si-O-Si bonds by losing water molecules and hence the double bonds are introduced onto thesurface of nano silicon dioxide. The surface of nano silicon dioxide is grafted with polymer throughfree radical polymerization between the double bonds on the surface of nano silicon dioxide andstyrene under the action of initiating agent. The dispersibility of nano silicon dioxide and thecontrollability of surface modification of nano silicon dioxide can be greatly improved by themodification process.
基金This work was financially supported by the National Natural Science Foundation of China, No.50174004
文摘By simulating test and study in laboratory, the structure and performance offrothing generator were determined. The relative curves between the frothing volume and gas velocityof foaming net, supplying liquid volume and the content of foaming agent were obtainedrespectively. There were an optimum gas-velocity of foaming net, an optimum supplying liquid volumeand an optimum content of foaming agent under the condition of the given material quality and shapeof foaming net and spraying form. The spraying froth is of a great assistance in collectingrespirable dust.
基金This work was supported by the National Natural Science Foundation of China (No.50172009).
文摘Four reactors of up-flow anaerobic sludge blanket (UASB) were concurrentlyoperated to examine the effects of the xonotlite secondary particles on promoting the sludgegranulation during the starting-up stage at room temperature. The results show that the putting ofthe xonotlite secondary particles into the UASB reactors can increase the basicity of the reactingliquid significantly. The particles can act as the media for biomass accumulation. Thus, thegranulation process of the sludge within the reactor can be largely promoted by the specialperformances of the particles both in physical and chemical aspects.
文摘The design and practice in supporting the cut slope of an open-pit mine wereintroduced, in which the high pressure grouting method was used in reinforcing the weak formation inthe slopes. Based on a detailed geological survey of the slope, a theoretical analysis was carriedout, and the design parameters were proposed, where the Tresca or Mohr-Coulomb yield criteria wasemployed. A patent technology, named 'Technology of high pressure and multiple grouting in differentlevels within a single hole', was employed in the construction. Anchor bars were also installed asgrouting proceeds. This method combines anchoring and grouting comprehensively and was foundsuccessful in practice.
基金This work was financially supported by the National Natural Science Foundation of China (No.50174008).
文摘In order to get cheap and excellent PEE (Powdery Emulsion Explosives), themodel of optimizing selection on preparation of PEE was established by the Neural Net Theory (NNT).On the basis of some data in the study of PEE, the training, prediction and optimizing selection ofthe Neural Net (NN) model were finished by compiling procedures. The results indicate that the modelis helpful to the preparation of PEE and worthy to extend and apply broadly.
文摘Reliable information of in--situ stress state is necessary for the design andconstruction of most important rock projects. As most rock projects are getting deeper and deeper,traditional techniques of in--situ stress measurement are not very suitable. The current techniquesof in--situ stress measurement and their insufficiency for use at great depth are analyzed. Somebasic ideas of the development of new techniques and the improvement of current techniques for useat great depth are provided.
文摘Ion exchange membranes with high permselectivity (the character of separatingcations from anions or anions from cations) and high selectivity (the character of separatingcations or anions of different valencies) are important for electrodialysis process. The Donnanequilibrium theory, based on the equilibrium of ions and no electric field, can not exactly explainthe permselectivity of ion exchange membrane for ED process, since it is impossible to set up a ionexchange equilibrium between membrane and solution and to neglect the influence of electricaldriving force on ions during ED process. A novel model named 'anti-electric potential' isestablished to interpret the permselectivity of ion exchange membrane, according to thedetermination of electric potential between membranes and the variation of elements content insolutions and membranes. The results of experiment prove that the 'anti-electric potential' reallyexists within membranes. As for the selectivity, the results reveal that electric potential andhydration energy have great influence on the concentration and mobility of ions in membranes.
基金This work was financially supported by the National Natural Science Foundation of China (No. 50490271).
文摘An unsaturated clay slope, with various sloping angles and a thickness of 14 m, consists of backfill, slope soil and residual soil. Slide interfaces were determined by geophysical approaches and the original slope was reconstructed. Sub-slope masses were classified based on the varieties of sloping angle. A force recursive principle was proposed to calculate the stability coefficient of the sub-slope masses. The influencing factors such as sloping angle, water content, hydrostatic pressure, seismic force as well as train load were analyzed. The range and correlation of the above-mentioned factors were discussed and coupled wave equations were established to reflect the relationships between unit weight, cohesion, internal frictional angle, and water content, as well as between internal frictional angle and cohesion. The sensitivity analysis of slope stability was carried out and susceptive factors were determined when the factors were taken as independent and dependent variables respectively. The results show that sloping angle, water content and earthquake are the principal susceptive factors influencing slope stability. The impact of hydrostatic pressure on slope stability is similar to the seismic force in quantity. Train load plays a small role in slope stability and its influencing only reaches the roadbed and its neighboring slope segment. If the factors are taken as independent variables, the influencing extent of water content and cohesion on slope stability can be weakened and train load can be magnified.
文摘Tongguanshan copper deposit of Tongling large ore belt is one of the typicalskarn copper deposits. Based on careful observation under microscope many daughter mineralsincluding transparent ones and opaque ones have been distinguished in the fluid inclusions of garnetand diopside. The results of SEM/EDS (scanning electron microscope/energy dispersive spectrometer)and LRM (laser Raman microprobe) analysis show that these daughter minerals in garnet are sylvite,halite, sphalerite, chalcopyrite and carbonate. Sylvite daughter mineral is very popular in garnetand diopside. The existence of so much sylvite daughter mineral and other daughter minerals in thefluid inclusions indicates that the ore--forming fluid is of supper-high salinity and high potassiumconcentration. High potassium concentration in the fluid inclusions agrees with K-richmesotype--acid rock and K-silicate alteration that occurred widely in this area. The daughtermineral assemblage in garnet and diopside is similar to the mineral assemblage of ore-forming stagethat followed skarn stage.
基金This study is financially supported by the Ph.D. Programs Foundation of the Ministry of Education of China (No. 20020008006).
文摘An implementation scheme of the marching cubes (MC) algorithm was presented for the visualization of mineral deposits. The basic principles, processes and pitfalls of the MC algorithm were discussed. The asymptotic decider algorithm was employed to solve the ambiguity problem associated with the MC algorithm. The implementation scheme was applied to model and reconstruct the surfaces of mineral deposits, using the geological data obtained from an iron mine in China. Experimental results demonstrate the ability of the implementation scheme to solve the ambiguity problem, and illustrate the effectiveness and efficiency of the MC algorithm in the visualization of mineral deposits.
文摘Yima Coal Corporation is considering to adopt highwall mining method withauger machine to recover coal from north surface pit that has reached final highwall position. Themajor geomechanical issues associated with auger mining are highwall and pillar stability. Based onthe field investigation and laboratory test results of mechanical parameters, numerical modeling iscarried out to assess the stability of highwall and pillar. Field measurements of highwalldeformation have been used to validate and ensure the confidence for the development of realisticmodels. The results of numerical modeling show that the mining method is feasible for mining theseam of 10 m thickness in north surface coal mine.
文摘Computer simulation was used for hydraulic lifting systems. Based on theoryof multiphase flows and their applications on the lifting systems, mathematical models for pumplifting and air lifting were built and simulative analysis programs for them were developedrespectively. Corresponding lifting behaviors and system parameters were analyzed and optimum matchof the parameters for future pilot mining tests and commercial mining production was predicted.
基金This work was financially supported by the National Natural Science Foundation of China (No.50172009)
文摘Nanometer-sized xonotlite fibers have great potential application in manyfields. The traditional method of preparing ultra fine xonotlite fibers uses the ultra fine andhighly active silica as the major raw materials, which is not only expensive but also difficult toprepare the xonotlite fibers with diameters around 100 nm. In this study, the ultra fine xonotlitefibers with diameters around 100 nm were prepared by an autoclaving method. The preparation waslow-cost oriented by using natural powder quartz and lime as the major raw materials. Theintergrowth of the fibers formed thin shell hollow balls or ellipsoids, namely the secondaryparticles. The length of the nanometer-sized xonotlite fibers was around several microns. The fibersand their secondary particles were produced at 216 deg C for 6 h with a continuous stirring of300-500 r/min. Zirconium oxychloride was used as an additive. The experiments show that zirconiumoxychloride has an enormous effect on the growing habit of xonotlite crystals and plays an importantrole in controlling the diameter of the xonotlite fibers.
文摘Bioflotation of pyrite with bacteria Thiobacillus ferrooxidans in thepresence or absence of potassium ethyl xanthate was studied on a pure pyrite through microflotationand electrophoretic light scattering measurements. The experimental results showed that in theabsence of xanthate, pyrite flotation is slightly enhanced by Thiobacillus ferrooxidans. However,with xanthate as a collector, pyrite flotation is strongly depressed after being exposed to thebacteria. The longer is the time when the pyrite is exposed to the bacteria, the stronger thedepression is. The mechanism of the depression might be due to the formation of the biofilms ofThiobacillus ferrooxidans on pyrite surfaces, preventing the adsorption of xanthate on pyritesurfaces in the form of dixanthogen or xanthate ions.
文摘A linear mass-spring system model of a tractor-semitrailer together withdriver body parts and sprung seat is presented. Natural frequencies of the system are calculated andresponse of components in the system to road roughness is completed by means of computer simulationand power spectral density (PSD) approach in all of road conditions and loading cases. The resultsshow that the severest situation of response of the system occurs when the road in rough conditionand vehicle unladen. The most sensitive frequency to human body parts is around 0.9 Hz, and modeltypes of a human body seem to be not significant to the response of a heavy tractor-semitrailersystem, including to the response of the driver himself.
基金[This work was financial supported by the National Natural Science Foundation of China (No.59874002).]
文摘A novel way for electrification of mineral particles by electronbeam irradiation was proposed. The effect of irradiation dose oncharge/mass ratio was investigated experimentally. The charge/massratio of electrified mineral powders after irradiation was meas- uredby an instrument based on the principle of electrostatic induction.The experimental results showed that the charge/mass ratio is lar-gely dependent on radiation dose and electric physical properties ofminerals. The mechanism of electrification by electron beam irradi-ation is discussed. it is suggested that the essential ofelectrification by electron beam irradiation is a process ofretardation and charge deposition of incident electrons in materials.
文摘Based on the technology of titanium dioxide grafting modification withpolystyrene (PS), the modification mechanisms are studied and the polystyrene-grafting states on thesurface of titanium dioxide have been set up. Under the synergistic actions of mechanical force,chemistry and heat, macromolecular free radicals of PS are created, at the same time, the O-O bondsof titanium dioxide are broken and the oxide free radicals produced, and the numbers of oxygen atomare increased and crystal lattice defects rich electrons are formed on the surface of titaniumdioxide. The radical polymerization is the main reaction between PS and titanium dioxide and C-Obonds form in the process of modification. Multi-sites chemical adsorption also exists besidesgrafting between PS and titanium dioxide.
基金the National Natural Science Foundation of China (No.59874002).
文摘The feasibility for modifying the wettability and floatability of sulfideminerals by electron beam irradiation has been studied experimentally. The wettability ofcrystalline pyrite and floatability of some sulfide as pyrite, arsenopyrite, chalcopyrite andmarmatite after irradiation were examined by flotation in a modified Hallimond tube. Experimentalresults show that the hydrophobicity of crystalline pyrite enhances with the increase of irradiationdose in a low dose range. And the flotation responses of sulfide minerals on irradiation dose varywith the mineral species and particle size. The floatability of minerals can be regulated byaltering irradiation dose. An explanation for the mechanism has been suggested based on theprinciple of radiation chemistry.
