An experimental study on intensifying osmotic dehydration was carried out ina state of nature and with acoustic cavitation of different cavitating intensity (0.5A, 0.7A and0.9A) respectively, in which the material is ...An experimental study on intensifying osmotic dehydration was carried out ina state of nature and with acoustic cavitation of different cavitating intensity (0.5A, 0.7A and0.9A) respectively, in which the material is apple slice of 5mm thickness. The result showed thatacoustic cavitation remarkably enhanced the osmotic dehydration, and the water loss was acceleratedwith the increase of cavitating intensity. The water diffusivity coefficients ranged from1.8x10^(-10)m^2·s^(-1) at 0.5A to 2.6x10^(-10)m^2·s^(-1) at 0.9A, and solute diffusivitycoefficients ranged from 3.5x10^(-11) m^2·s^(-1) at 0.5A to 4.6X10^(-11)m^2·s^(-1) at 0.9A. On thebasis of experiments, a mathematical model was established about mass transfer during osmoticdehydration, and the numerical simulation was carried out. The calculated results agree well withexperimental data, and represent the rule of mass transfer during osmotic dehydration intensified byacoustic cavitation.展开更多
A 40-60 t/h modularized dry coal beneficiation process with a novel method to control the bed was designed around a gas-solid fluidized bed separator. Furthermore, the hydrodynamics of medium-solids consisting of wide...A 40-60 t/h modularized dry coal beneficiation process with a novel method to control the bed was designed around a gas-solid fluidized bed separator. Furthermore, the hydrodynamics of medium-solids consisting of wide-size-range magnetite powder (0.3-0.06 ram) and 〈1 mm fine coal were numerically studied. The simulation results show that the fluidization performance of the wide-size-range medium-solid bed is good. The separation performance of the modularized system was then investigated in detail using a mixture of 〈0.3 mm magnetite powder (mass fraction of 0.3-0.06 mm particles is 91.38 %) and 〈1 mm fine coal as solid media. The experimental results show that at separation densities of 1.33 g/cm^3 or 1.61 g/cm^3, 50-6 mm coal can be separated effectively with probable error, E, values of 0.05 g/cm^3 and 0.06 g/cm^3, respectively. This technique is beneficial for saving water resources and for the clean utilization of coal.展开更多
The current separator with air dense medium fluidized bed can only turn out two products at the same time with a single separating density. The double density fluidized bed means that two separating areas with differe...The current separator with air dense medium fluidized bed can only turn out two products at the same time with a single separating density. The double density fluidized bed means that two separating areas with different densities are formed in a fluidized cascade. In each separating area, the bed density is uniform and meets the technical requirement of coal preparation respectively. Therefore, the processed materials can be separated into three products according to density. In this paper, the fluidized behaviors of binary dense media were experimentally studied and the distribution characteristics of particle concentration and bed density in different bed structure were discussed. The segregation and mixing mechanisms of binary dense media were analyzed. It was testified that the pyramidal part designed in the bed structure played a key role in the formation of double density fluidized bed. The pyramidal part intensified the segregation of binary particles between two separating areas and strengthened the mixing in the low density area, which made for the density uniform of the area.展开更多
In order to compensate for the deficiency of present methods of monitoring plane displacement in similarity model tests,such as inadequate real-time monitoring and more manual intervention,an effective monitoring meth...In order to compensate for the deficiency of present methods of monitoring plane displacement in similarity model tests,such as inadequate real-time monitoring and more manual intervention,an effective monitoring method was proposed in this study,and the major steps of the monitoring method include:firstly,time-series images of the similarity model in the test were obtained by a camera,and secondly,measuring points marked as artificial targets were automatically tracked and recognized from time-series images.Finally,the real-time plane displacement field was calculated by the fixed magnification between objects and images under the specific conditions.And then the application device of the method was designed and tested.At the same time,a sub-pixel location method and a distortion error model were used to improve the measuring accuracy.The results indicate that this method may record the entire test,especially the detailed non-uniform deformation and sudden deformation.Compared with traditional methods this method has a number of advantages,such as greater measurement accuracy and reliability,less manual intervention,higher automation,strong practical properties,much more measurement information and so on.展开更多
In this paper, the authors point out that the Creativity is an inevitable request in solving engineering and technological problems and that the coal beneficiation technology with air dense medium fluidized bed is a r...In this paper, the authors point out that the Creativity is an inevitable request in solving engineering and technological problems and that the coal beneficiation technology with air dense medium fluidized bed is a result of reversal thinking, and its forming mechanism is the use of other things for reference and the transplantation.展开更多
Cost, the effect on the environment, and health issues are relevant when considering the choice of a lubricant and application system in a modern metal cutting process. This paper provided a general introduction to me...Cost, the effect on the environment, and health issues are relevant when considering the choice of a lubricant and application system in a modern metal cutting process. This paper provided a general introduction to metalworking fluids, reviewed the benefits and negative effects attributed to the production of mist during cutting processes. Due to the increasing concern over workers exposed to cutting fluid mist, and to achieve the recommended exposure limit, much attention was focused on how to minimize or prevent the mist formation. Different proposed techniques were analyzed, each of them has its advantages and limitations. Finally, the benefits of minimum quantity of lubrication (MQL) technique over all other techniques were studied.展开更多
This paper studies the effects of internal and external environments on the strategic decision-making of diversification using the cross-sectional data of China's 1 033 non-financial listed companies in Shenzhen and ...This paper studies the effects of internal and external environments on the strategic decision-making of diversification using the cross-sectional data of China's 1 033 non-financial listed companies in Shenzhen and Shanghai Exchange. Corporate external-environment is substituted by index of marketization and market concentrative rate, and internal-environment is substituted by governance framework and financial status. The multi-regression analysis shows that the strategic decision-making of diversification is prominently affected by external factors such as index of marketization and market concentrative rate, and is significantly negative related to the proportion of state-owned shares and corporate shares. There is no correlation between diversification and whether directors hold concurrently, or manager compensation, cash flow, and debt ratio.展开更多
In the non-linear microwave drying process, the incremental improved back-propagation (BP) neural network and response surface methodology (RSM) were used to build a predictive model of the combined effects of ind...In the non-linear microwave drying process, the incremental improved back-propagation (BP) neural network and response surface methodology (RSM) were used to build a predictive model of the combined effects of independent variables (the microwave power, the acting time and the rotational frequency) for microwave drying of selenium-rich slag. The optimum operating conditions obtained from the quadratic form of the RSM are: the microwave power of 14.97 kW, the acting time of 89.58 min, the rotational frequency of 10.94 Hz, and the temperature of 136.407 ℃. The relative dehydration rate of 97.1895% is obtained. Under the optimum operating conditions, the incremental improved BP neural network prediction model can predict the drying process results and different effects on the results of the independent variables. The verification experiments demonstrate the prediction accuracy of the network, and the mean squared error is 0.16. The optimized results indicate that RSM can optimize the experimental conditions within much more broad range by considering the combination of factors and the neural network model can predict the results effectively and provide the theoretical guidance for the follow-up production process.展开更多
Monophasic mullite gel with composition 3Al2O3·2SiO2 was prepared by the sol-gel method using aluminium nitrate nonahydrate, aluminium-tri-isopropoxide, and tetraethylorthosili-cate as reagents. Gels with differe...Monophasic mullite gel with composition 3Al2O3·2SiO2 was prepared by the sol-gel method using aluminium nitrate nonahydrate, aluminium-tri-isopropoxide, and tetraethylorthosili-cate as reagents. Gels with different drying control chemical additives(DCCAs) and polyvinylpyrrolidone(PVP) as spinning assistant were dried at several temperatures. The influences of temperature, DCCAs and PVP in the drying process were investigated. N,N-dimethylformamide(DMF) was the optimum DCCA at 70℃ in the drying process. PVP decreased the solvent volatilization speed and prevented gel crack to a certain extent. FTIR results revealed that free water, ethanol, and isopropanol were completely removed by the drying procedure.展开更多
文摘An experimental study on intensifying osmotic dehydration was carried out ina state of nature and with acoustic cavitation of different cavitating intensity (0.5A, 0.7A and0.9A) respectively, in which the material is apple slice of 5mm thickness. The result showed thatacoustic cavitation remarkably enhanced the osmotic dehydration, and the water loss was acceleratedwith the increase of cavitating intensity. The water diffusivity coefficients ranged from1.8x10^(-10)m^2·s^(-1) at 0.5A to 2.6x10^(-10)m^2·s^(-1) at 0.9A, and solute diffusivitycoefficients ranged from 3.5x10^(-11) m^2·s^(-1) at 0.5A to 4.6X10^(-11)m^2·s^(-1) at 0.9A. On thebasis of experiments, a mathematical model was established about mass transfer during osmoticdehydration, and the numerical simulation was carried out. The calculated results agree well withexperimental data, and represent the rule of mass transfer during osmotic dehydration intensified byacoustic cavitation.
基金Projects(50921002, 50774084) supported by the National Natural Science Foundation of ChinaProject(2007AA05Z318) supported by the National High-tech Research and Development Program of China+1 种基金Project(BK2010002) supported by the Natural Science Foundation of Jiangsu Province of ChinaProject(20100480473) supported by the China Postdoctoral Science Foundation
文摘A 40-60 t/h modularized dry coal beneficiation process with a novel method to control the bed was designed around a gas-solid fluidized bed separator. Furthermore, the hydrodynamics of medium-solids consisting of wide-size-range magnetite powder (0.3-0.06 ram) and 〈1 mm fine coal were numerically studied. The simulation results show that the fluidization performance of the wide-size-range medium-solid bed is good. The separation performance of the modularized system was then investigated in detail using a mixture of 〈0.3 mm magnetite powder (mass fraction of 0.3-0.06 mm particles is 91.38 %) and 〈1 mm fine coal as solid media. The experimental results show that at separation densities of 1.33 g/cm^3 or 1.61 g/cm^3, 50-6 mm coal can be separated effectively with probable error, E, values of 0.05 g/cm^3 and 0.06 g/cm^3, respectively. This technique is beneficial for saving water resources and for the clean utilization of coal.
文摘The current separator with air dense medium fluidized bed can only turn out two products at the same time with a single separating density. The double density fluidized bed means that two separating areas with different densities are formed in a fluidized cascade. In each separating area, the bed density is uniform and meets the technical requirement of coal preparation respectively. Therefore, the processed materials can be separated into three products according to density. In this paper, the fluidized behaviors of binary dense media were experimentally studied and the distribution characteristics of particle concentration and bed density in different bed structure were discussed. The segregation and mixing mechanisms of binary dense media were analyzed. It was testified that the pyramidal part designed in the bed structure played a key role in the formation of double density fluidized bed. The pyramidal part intensified the segregation of binary particles between two separating areas and strengthened the mixing in the low density area, which made for the density uniform of the area.
基金provided by the Program for New Century Excellent Talents in University (No. NCET-06-0477)the Independent Research Project of the State Key Laboratory of Coal Resources and Mine Safety of China University of Mining and Technology (No. SKLCRSM09X01)the Fundamental Research Funds for the Central Universities
文摘In order to compensate for the deficiency of present methods of monitoring plane displacement in similarity model tests,such as inadequate real-time monitoring and more manual intervention,an effective monitoring method was proposed in this study,and the major steps of the monitoring method include:firstly,time-series images of the similarity model in the test were obtained by a camera,and secondly,measuring points marked as artificial targets were automatically tracked and recognized from time-series images.Finally,the real-time plane displacement field was calculated by the fixed magnification between objects and images under the specific conditions.And then the application device of the method was designed and tested.At the same time,a sub-pixel location method and a distortion error model were used to improve the measuring accuracy.The results indicate that this method may record the entire test,especially the detailed non-uniform deformation and sudden deformation.Compared with traditional methods this method has a number of advantages,such as greater measurement accuracy and reliability,less manual intervention,higher automation,strong practical properties,much more measurement information and so on.
文摘In this paper, the authors point out that the Creativity is an inevitable request in solving engineering and technological problems and that the coal beneficiation technology with air dense medium fluidized bed is a result of reversal thinking, and its forming mechanism is the use of other things for reference and the transplantation.
文摘Cost, the effect on the environment, and health issues are relevant when considering the choice of a lubricant and application system in a modern metal cutting process. This paper provided a general introduction to metalworking fluids, reviewed the benefits and negative effects attributed to the production of mist during cutting processes. Due to the increasing concern over workers exposed to cutting fluid mist, and to achieve the recommended exposure limit, much attention was focused on how to minimize or prevent the mist formation. Different proposed techniques were analyzed, each of them has its advantages and limitations. Finally, the benefits of minimum quantity of lubrication (MQL) technique over all other techniques were studied.
文摘This paper studies the effects of internal and external environments on the strategic decision-making of diversification using the cross-sectional data of China's 1 033 non-financial listed companies in Shenzhen and Shanghai Exchange. Corporate external-environment is substituted by index of marketization and market concentrative rate, and internal-environment is substituted by governance framework and financial status. The multi-regression analysis shows that the strategic decision-making of diversification is prominently affected by external factors such as index of marketization and market concentrative rate, and is significantly negative related to the proportion of state-owned shares and corporate shares. There is no correlation between diversification and whether directors hold concurrently, or manager compensation, cash flow, and debt ratio.
基金Project(50734007) supported by the National Natural Science Foundation of China
文摘In the non-linear microwave drying process, the incremental improved back-propagation (BP) neural network and response surface methodology (RSM) were used to build a predictive model of the combined effects of independent variables (the microwave power, the acting time and the rotational frequency) for microwave drying of selenium-rich slag. The optimum operating conditions obtained from the quadratic form of the RSM are: the microwave power of 14.97 kW, the acting time of 89.58 min, the rotational frequency of 10.94 Hz, and the temperature of 136.407 ℃. The relative dehydration rate of 97.1895% is obtained. Under the optimum operating conditions, the incremental improved BP neural network prediction model can predict the drying process results and different effects on the results of the independent variables. The verification experiments demonstrate the prediction accuracy of the network, and the mean squared error is 0.16. The optimized results indicate that RSM can optimize the experimental conditions within much more broad range by considering the combination of factors and the neural network model can predict the results effectively and provide the theoretical guidance for the follow-up production process.
文摘Monophasic mullite gel with composition 3Al2O3·2SiO2 was prepared by the sol-gel method using aluminium nitrate nonahydrate, aluminium-tri-isopropoxide, and tetraethylorthosili-cate as reagents. Gels with different drying control chemical additives(DCCAs) and polyvinylpyrrolidone(PVP) as spinning assistant were dried at several temperatures. The influences of temperature, DCCAs and PVP in the drying process were investigated. N,N-dimethylformamide(DMF) was the optimum DCCA at 70℃ in the drying process. PVP decreased the solvent volatilization speed and prevented gel crack to a certain extent. FTIR results revealed that free water, ethanol, and isopropanol were completely removed by the drying procedure.