According to physiological and biochemical characteristics of Leptospirillum ferriphilum, a strain of object bacteria was isolated successfully. Bacteria were enriched by selective liquid medium and plated on designed...According to physiological and biochemical characteristics of Leptospirillum ferriphilum, a strain of object bacteria was isolated successfully. Bacteria were enriched by selective liquid medium and plated on designed single-layered agar solid medium. Colony was cultured and bacteria were collected. The morphologies of the object bacteria were observed using crystal violet staining, scanning electron microscope（SEM） and transmission electron microscope （TEM）. The result of 16S rDNA identification shows that this bacterium belongs to Leptospirillum ferriphilum and it is named as Leptospirillum ferriphilum strain D1. These results indicate that this new single-layered agar solid medium is efficient and physiological-biochemical characteristics show that the optimum simple for isolation of Leptospirillum ferriphilum. Additionally, initial pH value and its growth temperature are 1.68 and 40℃.展开更多
The highly-efficient dry separation technique using a gas-solid fluidized bed is very beneficial for increasing coal grade and optimizing the utilization of coal resources.The size distribution of the solid medium(e.g...The highly-efficient dry separation technique using a gas-solid fluidized bed is very beneficial for increasing coal grade and optimizing the utilization of coal resources.The size distribution of the solid medium(e.g.,magnetite powder) used in this technique is one of key factors that influences fluidization and separation performance.It is,therefore,urgent to prepare medium in a way that operates at low cost and high efficiency.Grinding experiments were performed using a planetary ball mill equipped with a frequency converter.The effect of fed mass,rotation frequency of the mill,grinding time and the ball-size ratio on grinding performance was investigated.The grinding parameters were optimized by numerical calculations using Artificial Neural Network(ANN) in Matlab.A regression equation for predicting the yield of the desired product(i.e.,0.3～0.15 mm magnetite powder) is proposed.The maximum yield of 0.3～0.15 mm particles was 47.24%.This lays a foundation for the industrial-scale production of the solid medium required for separation with a magnetite-powder fluidized bed.展开更多
In this paper, the Adomian’s decomposition method has been developed to yield approximate solution of bacterial chemotaxis model of fractional order in a semi-solid medium. The fractional derivatives are described in...In this paper, the Adomian’s decomposition method has been developed to yield approximate solution of bacterial chemotaxis model of fractional order in a semi-solid medium. The fractional derivatives are described in the Caputo sense. The method introduces a promising tool for solving many linear and nonlinear fractional differential equations.展开更多
Certain non-metallic granules （NMG） were selected as the research object. It was proposed to conduct the volume compression experiments as well as those on the NMG physical properties at high stress levels. Then, no...Certain non-metallic granules （NMG） were selected as the research object. It was proposed to conduct the volume compression experiments as well as those on the NMG physical properties at high stress levels. Then, not only the volume compression ratio curve but also the extended Drucker-Prager linear model were obtained. In addition, through the friction strength tests, parameters of the Mohr-Coulomb model were gained, which proved in basic agreement with those of the extended Drucker-Prager linear model. Additionally, curves of the friction coefficients between the NMG and the sheet metal trader different pressures were also obtained. Based on the material performance experiments, numerical analysis in respect of flexible-die forming process with solid granule medium （SGM） was conducted. The die and device for experiments of solid granule medium forming （SGMF） on sheet metal were designed and manufactured. Typical parabolic parts were successfully trial-produced. The tests and simulation results show that the sheet formability is significantly improved for the extraordinary friction performance during interaction between the SGM and the sheet metal surface. The process control and die structure are simple, and the shaped work-pieces enjoy many advantages, such as satisfactory surface quality and favorable die fitability, which offers a brand-new method and means for processing and preparation of sheet metals.展开更多
In this paper, a general model on sound reflection from a layered solid medium with rigid and slip interfaces is proposed by using matrix method. Analytical expressions for reflection coefficients of both longitudinal...In this paper, a general model on sound reflection from a layered solid medium with rigid and slip interfaces is proposed by using matrix method. Analytical expressions for reflection coefficients of both longitudinal and transverse waves from the layered solid medium with one or two slip interfaces are derived. Numerical results of sound reflection coefficients from some typical adhesive joints with slip and rigid interfaces are presented, which may be useful for correct choice of technical parameters in ultrasonic evaluation of their interface properties.展开更多
The transient acoustic field radiated by a piezoelectric thickness-mode transducer into a solid medium is theoretically analysed. It is proved that the field consists of the direct wave, the longitudinal edge waves, t...The transient acoustic field radiated by a piezoelectric thickness-mode transducer into a solid medium is theoretically analysed. It is proved that the field consists of the direct wave, the longitudinal edge waves, the shear edge.waves, the head wave and the surface waves. The wavefront approximations of all these waves are given which result in a clear physical picture which is not only simple but also cotains the main features of the field. The theoretical result well describes the experiment.展开更多
The Rayleigh waves in a layered solid medium is dispersive. Using the 'spring' model for a weak interface between two solids, the characteristic equation for the quasi-Rayleigh waves in an isotropic layered so...The Rayleigh waves in a layered solid medium is dispersive. Using the 'spring' model for a weak interface between two solids, the characteristic equation for the quasi-Rayleigh waves in an isotropic layered solid medium with a weak interface is presented. The numerical results for the typical coating structure with the rigid, slip and weak interface are shown. The influence of the interface stiffness constants on the velocity of the quasi-Rayleigh waves is considered. The numerical results show that the interface characteristics of the coating structure can be nondestructively evaluated by employing the quasi-Rayleigh waves in the low frequency band.展开更多
The experimental die apparatus of the solid granules medium forming on sheet metal was designed and manufactured.Typical parts,such as conical,parabolic,cylindrical and square-box-shaped components,were successfully t...The experimental die apparatus of the solid granules medium forming on sheet metal was designed and manufactured.Typical parts,such as conical,parabolic,cylindrical and square-box-shaped components,were successfully trial-produced as well.According to the analysis of the changing trends of the cross-section shape and the wall thickness during the process,it can be found that the shape of the free deformation zone of the sheet metal,which is the most critical thinning area,can be described as an approximately spherical cap.According to this forming feature,back pressure deep drawing technology with solid granules medium on sheet metal was proposed to restrain drastic thinning at the bottom of the part through the joint friction effect of solid granules medium,the back pressure tringle and the sheet metal.Therefore,the deep drawing limit of the sheet metal is significantly improved.In order to fabricate thin-walled rotary parts with great drawing ratio and complex cross-sections,a finite element model based on the material property test of the solid granules medium was established to optimize the scheme of the back pressure deep drawing.The effects on the forming performance of sheet metal from back pressure load and the approach of blank holding control were analyzed through this model.展开更多
In this paper,microwave sterilization craft of solid culture medium in fungus growth is studied.The results show that microwave not only can be used to sterilize the micro-organisms which is useless for fungus growth ...In this paper,microwave sterilization craft of solid culture medium in fungus growth is studied.The results show that microwave not only can be used to sterilize the micro-organisms which is useless for fungus growth in the solid culture medium,but also has positive effect on fungus growth;and the sterilization process is featured with shorter time and higher efficiency compared with the traditional method.展开更多
Wide-size-range medium-solids are used in a modularized coal beneficiation demonstration system with a gas-solid fluidized bed. The characteristics of fluidization and dry-beneficiation of the medium solids were studi...Wide-size-range medium-solids are used in a modularized coal beneficiation demonstration system with a gas-solid fluidized bed. The characteristics of fluidization and dry-beneficiation of the medium solids were studied. The numerical simulation results show that 0.15–0.06 mm fine magnetite powder can decrease the disturbances caused by the bubbles. This is beneficial to the uniformity of the gas-solid interactions and thus to the uniformity and stability of the bed density and height. The experimental results show that, with an increase in the fine coal content in medium solids, both the fluidization quality and the beneficiation performance of the bed decreased gradually. When the fine coal content was no more than 13%, a relatively high superficial gas velocity increased the beneficiation efficiency. When the content was more than 13%, part of the fine coal was separated, leading to product layers. The separation efficiency was therefore gradually decreased. The models for predicting the bed density standard deviation and the probable error, E, value were both proposed. The E value can reach to 0.04–0.07 g/cm^3 under the optimized experimental parameters. This work provides a foundation for the adjustment of the bed density and the separation performance of the modularized 40–60 ton per hour dry coalbeneficiation industrial system.展开更多
The effect of the solid matrix and porosity of the porous medium are first introduced to the study of power-law nanofluids, and the Marangoni boundary layer flow with heat generation is investigated. Two cases of soli...The effect of the solid matrix and porosity of the porous medium are first introduced to the study of power-law nanofluids, and the Marangoni boundary layer flow with heat generation is investigated. Two cases of solid matrix of porous medium including glass balls and aluminum foam are considered. The governing partial differential equations are simplified by dimensionless variables and similarity transformations, and are solved numerically by using a shooting method with the fourth-fifth-order Runge-Kutta integration technique. It is indicated that the increase of the porosity leads to the enhancement of heat transfer in the surface of the Marangoni boundary layer flow.展开更多
For the production of low ash content clean coal, separation at low density is required for some raw coals.Based on analyzing the fluidizing characteristics of magnetic-pearls with a specific size clistribution and fo...For the production of low ash content clean coal, separation at low density is required for some raw coals.Based on analyzing the fluidizing characteristics of magnetic-pearls with a specific size clistribution and formation mechanism of a microbubble fluidized bed, optimal technological and operating parameters suitable for low density coal separation were determined. The experimental results show that an air dense medium fluidized bed with low den-sity can be formed using magnetic pearls as medium solids, which can efficiently beneficiate coal of 6-50 mm size with a probable error Ep value of 0.05 at a separating density of 1.44 g/cm^3.展开更多
Based on composite materials, the equivalent elastic-plastic constitutive equations of multiphase solid are researched. According to the suggested definition of. constitutive equivalence it is demonstrated that the mu...Based on composite materials, the equivalent elastic-plastic constitutive equations of multiphase solid are researched. According to the suggested definition of. constitutive equivalence it is demonstrated that the multiphase solid, composed of several kinds of homogeneous elastic-plastic media that conform to the generalized normality rule, has the same type of constitutive equations as its constituents have that also conform to the generalized normality rule.展开更多
基金Projects(50374075, 50321402) supported by the National Natural Science Foundation of ChinaProject(2004CB619204) supported by the National Basic Research and Development Program of China+1 种基金Project(200549) supported by the Specialized Research Fund of the NationalExcellent PhD Thesis
文摘According to physiological and biochemical characteristics of Leptospirillum ferriphilum, a strain of object bacteria was isolated successfully. Bacteria were enriched by selective liquid medium and plated on designed single-layered agar solid medium. Colony was cultured and bacteria were collected. The morphologies of the object bacteria were observed using crystal violet staining, scanning electron microscope（SEM） and transmission electron microscope （TEM）. The result of 16S rDNA identification shows that this bacterium belongs to Leptospirillum ferriphilum and it is named as Leptospirillum ferriphilum strain D1. These results indicate that this new single-layered agar solid medium is efficient and physiological-biochemical characteristics show that the optimum simple for isolation of Leptospirillum ferriphilum. Additionally, initial pH value and its growth temperature are 1.68 and 40℃.
基金supported by the National Natural Science Foundation of China (Nos.50921002 and 90510002)the National High Technology Research and Development Program of China (No.2007AA05Z318)
文摘The highly-efficient dry separation technique using a gas-solid fluidized bed is very beneficial for increasing coal grade and optimizing the utilization of coal resources.The size distribution of the solid medium(e.g.,magnetite powder) used in this technique is one of key factors that influences fluidization and separation performance.It is,therefore,urgent to prepare medium in a way that operates at low cost and high efficiency.Grinding experiments were performed using a planetary ball mill equipped with a frequency converter.The effect of fed mass,rotation frequency of the mill,grinding time and the ball-size ratio on grinding performance was investigated.The grinding parameters were optimized by numerical calculations using Artificial Neural Network(ANN) in Matlab.A regression equation for predicting the yield of the desired product(i.e.,0.3～0.15 mm magnetite powder) is proposed.The maximum yield of 0.3～0.15 mm particles was 47.24%.This lays a foundation for the industrial-scale production of the solid medium required for separation with a magnetite-powder fluidized bed.
文摘In this paper, the Adomian’s decomposition method has been developed to yield approximate solution of bacterial chemotaxis model of fractional order in a semi-solid medium. The fractional derivatives are described in the Caputo sense. The method introduces a promising tool for solving many linear and nonlinear fractional differential equations.
基金Project(50775197)supported by the National Natural Science Foundation of China
文摘Certain non-metallic granules （NMG） were selected as the research object. It was proposed to conduct the volume compression experiments as well as those on the NMG physical properties at high stress levels. Then, not only the volume compression ratio curve but also the extended Drucker-Prager linear model were obtained. In addition, through the friction strength tests, parameters of the Mohr-Coulomb model were gained, which proved in basic agreement with those of the extended Drucker-Prager linear model. Additionally, curves of the friction coefficients between the NMG and the sheet metal trader different pressures were also obtained. Based on the material performance experiments, numerical analysis in respect of flexible-die forming process with solid granule medium （SGM） was conducted. The die and device for experiments of solid granule medium forming （SGMF） on sheet metal were designed and manufactured. Typical parabolic parts were successfully trial-produced. The tests and simulation results show that the sheet formability is significantly improved for the extraordinary friction performance during interaction between the SGM and the sheet metal surface. The process control and die structure are simple, and the shaped work-pieces enjoy many advantages, such as satisfactory surface quality and favorable die fitability, which offers a brand-new method and means for processing and preparation of sheet metals.
文摘In this paper, a general model on sound reflection from a layered solid medium with rigid and slip interfaces is proposed by using matrix method. Analytical expressions for reflection coefficients of both longitudinal and transverse waves from the layered solid medium with one or two slip interfaces are derived. Numerical results of sound reflection coefficients from some typical adhesive joints with slip and rigid interfaces are presented, which may be useful for correct choice of technical parameters in ultrasonic evaluation of their interface properties.
文摘The transient acoustic field radiated by a piezoelectric thickness-mode transducer into a solid medium is theoretically analysed. It is proved that the field consists of the direct wave, the longitudinal edge waves, the shear edge.waves, the head wave and the surface waves. The wavefront approximations of all these waves are given which result in a clear physical picture which is not only simple but also cotains the main features of the field. The theoretical result well describes the experiment.
基金the National Natural Science Foundation of China.
文摘The Rayleigh waves in a layered solid medium is dispersive. Using the 'spring' model for a weak interface between two solids, the characteristic equation for the quasi-Rayleigh waves in an isotropic layered solid medium with a weak interface is presented. The numerical results for the typical coating structure with the rigid, slip and weak interface are shown. The influence of the interface stiffness constants on the velocity of the quasi-Rayleigh waves is considered. The numerical results show that the interface characteristics of the coating structure can be nondestructively evaluated by employing the quasi-Rayleigh waves in the low frequency band.
基金Project(50775197) supported by the National Natural Science Foundation of China
文摘The experimental die apparatus of the solid granules medium forming on sheet metal was designed and manufactured.Typical parts,such as conical,parabolic,cylindrical and square-box-shaped components,were successfully trial-produced as well.According to the analysis of the changing trends of the cross-section shape and the wall thickness during the process,it can be found that the shape of the free deformation zone of the sheet metal,which is the most critical thinning area,can be described as an approximately spherical cap.According to this forming feature,back pressure deep drawing technology with solid granules medium on sheet metal was proposed to restrain drastic thinning at the bottom of the part through the joint friction effect of solid granules medium,the back pressure tringle and the sheet metal.Therefore,the deep drawing limit of the sheet metal is significantly improved.In order to fabricate thin-walled rotary parts with great drawing ratio and complex cross-sections,a finite element model based on the material property test of the solid granules medium was established to optimize the scheme of the back pressure deep drawing.The effects on the forming performance of sheet metal from back pressure load and the approach of blank holding control were analyzed through this model.
基金Supported by the Natural Science Research Project of the Education Department of Henan Province(No.2009B210023)~~
文摘In this paper,microwave sterilization craft of solid culture medium in fungus growth is studied.The results show that microwave not only can be used to sterilize the micro-organisms which is useless for fungus growth in the solid culture medium,but also has positive effect on fungus growth;and the sterilization process is featured with shorter time and higher efficiency compared with the traditional method.
基金financially supported by the National Program on Key Basic Research Project of China (No.2012CB214904)the National Natural Science Foundation of China (Nos.51221462,51134022 and 51174203)
文摘Wide-size-range medium-solids are used in a modularized coal beneficiation demonstration system with a gas-solid fluidized bed. The characteristics of fluidization and dry-beneficiation of the medium solids were studied. The numerical simulation results show that 0.15–0.06 mm fine magnetite powder can decrease the disturbances caused by the bubbles. This is beneficial to the uniformity of the gas-solid interactions and thus to the uniformity and stability of the bed density and height. The experimental results show that, with an increase in the fine coal content in medium solids, both the fluidization quality and the beneficiation performance of the bed decreased gradually. When the fine coal content was no more than 13%, a relatively high superficial gas velocity increased the beneficiation efficiency. When the content was more than 13%, part of the fine coal was separated, leading to product layers. The separation efficiency was therefore gradually decreased. The models for predicting the bed density standard deviation and the probable error, E, value were both proposed. The E value can reach to 0.04–0.07 g/cm^3 under the optimized experimental parameters. This work provides a foundation for the adjustment of the bed density and the separation performance of the modularized 40–60 ton per hour dry coalbeneficiation industrial system.
基金Supported by the National Natural Science Foundation of China under Grant No 51305080
文摘The effect of the solid matrix and porosity of the porous medium are first introduced to the study of power-law nanofluids, and the Marangoni boundary layer flow with heat generation is investigated. Two cases of solid matrix of porous medium including glass balls and aluminum foam are considered. The governing partial differential equations are simplified by dimensionless variables and similarity transformations, and are solved numerically by using a shooting method with the fourth-fifth-order Runge-Kutta integration technique. It is indicated that the increase of the porosity leads to the enhancement of heat transfer in the surface of the Marangoni boundary layer flow.
基金Projects 90510002, 90210035 supported by the National Natural Science Foundation of China306008 by the Science and Technology Research of Ministry of Education of China
文摘For the production of low ash content clean coal, separation at low density is required for some raw coals.Based on analyzing the fluidizing characteristics of magnetic-pearls with a specific size clistribution and formation mechanism of a microbubble fluidized bed, optimal technological and operating parameters suitable for low density coal separation were determined. The experimental results show that an air dense medium fluidized bed with low den-sity can be formed using magnetic pearls as medium solids, which can efficiently beneficiate coal of 6-50 mm size with a probable error Ep value of 0.05 at a separating density of 1.44 g/cm^3.
文摘Based on composite materials, the equivalent elastic-plastic constitutive equations of multiphase solid are researched. According to the suggested definition of. constitutive equivalence it is demonstrated that the multiphase solid, composed of several kinds of homogeneous elastic-plastic media that conform to the generalized normality rule, has the same type of constitutive equations as its constituents have that also conform to the generalized normality rule.
