From the viewpoint of interaction mechanics for solid and gas, a coupled mathematical model was presented for solid coal/rock deformation and gas leak flow in parallel deformable coal seams. Numerical solutions using ...From the viewpoint of interaction mechanics for solid and gas, a coupled mathematical model was presented for solid coal/rock deformation and gas leak flow in parallel deformable coal seams. Numerical solutions using the SIP (Strong Implicit Proce- dure) method to the coupled mathematical model for double parallel coal seams were also developed in detail. Numerical simulations for the prediction of the safety range using protection layer mining were performed with experimental data from a mine with potential danger of coal/gas outbursts. Analyses show that the numerical simulation results are consistent with the measured data in situ.展开更多
Based on the transport phenomena theory, the passive mixing of water and ethanol in different threedimensional microchannels is simulated numerically. The average variance of water volume fraction is used to index the...Based on the transport phenomena theory, the passive mixing of water and ethanol in different threedimensional microchannels is simulated numerically. The average variance of water volume fraction is used to index the mixing efficiency in the cases with different Reynolds number and different fabricated mixers. The results show that the efficiency of liquid mixing is progressively dependent on the convective transport as the Reynolds number increases. The efficiency of serpentine microchannel decreases with the increasing Reynolds number in the laminar regime. Altering the aspect ratio of channel inlet section has no significant effect on the mixing efficiency. Increasing the area of channel inlet section will cause the decrease of the mixing efficiency. The mixing in serpentine channels is the most efficient among three different mixers because of the existence of second flow introduced by its special structure.展开更多
Microstructure evolution during the homogenization heat treatment of an Al?Mg?Si?Fe?Mn(AA6xxx)alloy wasinvestigated using a combination of modelling and experimental studies.The model is based on the CALPHAD-coupledho...Microstructure evolution during the homogenization heat treatment of an Al?Mg?Si?Fe?Mn(AA6xxx)alloy wasinvestigated using a combination of modelling and experimental studies.The model is based on the CALPHAD-coupledhomogenization heat treatment model originally developed for AA3xxx alloys(i.e.,Al?Mn?Fe?Si).In this work,the model wasadapted to the more complex AA6xxx system(Al?Mg?Si?Mn?Fe)to predict the evolution of critical microstructural features suchas the spatial distribution of solute,the type and fraction of constituent particles and dispersoid number density and size distribution.Experiments were also conducted using three direct chill(DC)cast AA6xxx alloys with different Mn levels subjected to varioushomogenization treatments.The resulting microstructures were characterized using a range of techniques including scanning electronmicroscopy,electron microprobe analysis(EPMA),XRD,and electrical resistivity measurements.The model predictions werecompared with the experimental measurements,and reasonable agreement was found.展开更多
Equipment management is one of the important parts of business administra- tion of coal. Most of coal mines take no account of their equipment management, and have no comprehensive and effective evaluation index syste...Equipment management is one of the important parts of business administra- tion of coal. Most of coal mines take no account of their equipment management, and have no comprehensive and effective evaluation index system. Based on the analysis of the equipment evaluation measures of reform and the applications, the paper built up a comprehensive and effective evaluation index system of coal mine equipment, and im- proved the evaluation method with the use of fuzzy theory, analytic hierarchy process and entropy method.展开更多
By applying the aggregation operator γ-operator and introducing a new method for global data contribution, the problems of information loss and the decrease of running efficiency in FuzzyJ Toolkit, an expert system s...By applying the aggregation operator γ-operator and introducing a new method for global data contribution, the problems of information loss and the decrease of running efficiency in FuzzyJ Toolkit, an expert system shell, can be effectively solved. The example shows that the approach can overcome imprecision of max-operator and min-operator used during the process of fuzzy reasoning. Therefore, the information accuracy and the system performance can be effectively improved, which promotes the usability of FuzzyJ Toolkit.展开更多
To evaluate the downscaling ability with respect to tropical cyclones(TCs)near China and its sensitivity to the model physics representation,the authors performed a multi-physics ensemble simulation with the regional ...To evaluate the downscaling ability with respect to tropical cyclones(TCs)near China and its sensitivity to the model physics representation,the authors performed a multi-physics ensemble simulation with the regional Climate-Weather Research and Forecasting(CWRF)model at a 30 km resolution driven by ERA-Interim reanalysis data.The ensemble consisted of 28 integrations during 1979-2016 with varying CWRF physics configurations.Both CWRF and ERA-Interim can generally capture the seasonal cycle and interannual variation of the TC number near China,but evidently underestimate them.The CWRF downscaling and its multi-physics ensemble can notably reduce the underestimation and significantly improve the simulation of the TC occurrences.The skill enhancement is especially large in terms of the interannual variation,which is most sensitive to the cumulus scheme,followed by the boundary layer,surface and radiation schemes,but weakly sensitive to the cloud and microphysics schemes.Generally,the Noah surface scheme,CAML(CAM radiation scheme as implemented by Liang together with the diagnostic cloud cover scheme of Xu and Randall(1996))radiation scheme,prognostic cloud scheme,and Thompson microphysics scheme stand out for their better performance in simulating the interannual variation of TC number.However,the Emanuel cumulus and MYNN boundary layer schemes produce severe interannual biases.Our study provides a valuable reference for CWRF application to improve the understanding and prediction of TC activity.展开更多
A field experiment was conducted to study the combined effect of nutrient andpest managements on soil biomass phospholipid contents, functional biodiversity and substrateutilization patterns of soil microbial populati...A field experiment was conducted to study the combined effect of nutrient andpest managements on soil biomass phospholipid contents, functional biodiversity and substrateutilization patterns of soil microbial populations in hybrid rice cropping system. The mineral N, Pand K fertilizers (as urea, calcium superphosphate and KCl respectively) were incorporated at 100,25, and 100 kg ha^(-1), respectively, and the various pesticides were applied at the recommendedrates. The results of the experiment demonstrated a decline in the microbial abundance and soilmicrobial biomass phospholipid contents with the advancement of crop growth, and significant changesin substrate utilization pattern of soil microbial population studied were observed with differentmanagement practices and at different growth stages. The principal component analysis (PCA) usingall 95-carbon sources (BIOLOG plates) gave good differentiation among the treatments, indicatingthat they have different patterns of carbon utilization under different habitats. The data showedthat diversity in microbial community continuously changed with the progression in crop stage,particularly at physiological maturity (PM) stage that was evident from the utilization of differentcarbon sources at various crop stages.展开更多
In complex networks, network modules play a center role, which carry out a key function. In this paper, we introduce the spatial correIation function to describe the relationships among the network modules. Our focus ...In complex networks, network modules play a center role, which carry out a key function. In this paper, we introduce the spatial correIation function to describe the relationships among the network modules. Our focus is to investigate how the network modules evolve, and what the evolution properties of the modules are. In order to test the proposed method, as the examples, we use our method to analyze and discuss the ER random network and scale-free network. Rigorous analysis of the existing data shows that the introduced correlation function is suitable for describing the evolution properties of network modules. Remarkably, the numerical simulations indicate that the ER random network and scale-free network have different evolution properties.展开更多
The tensile stress-strain curves of NiTi wires are obtained by tensile experiments under different heat treatments. A phenomenological physical model based on hysteresis element method is developed to describe the exp...The tensile stress-strain curves of NiTi wires are obtained by tensile experiments under different heat treatments. A phenomenological physical model based on hysteresis element method is developed to describe the experimentally determined stress-strain curves of shape memory alloy (SMA) wires. Numerical simulations are made. Simulation results show that:(1) a series of unusual changes on physical and mechanical properties of SMA wires occur when martensitic, especially R (rhombohedral) phase transformation emerge. The stress-strain relation of SMA wires is highly non-linear; (2) there are no notable yielding phenomena before NiTi wires are broken; (3) numerical results obtained by the physical model are in good agreement with experimental data.展开更多
In order to apply physical simulation results to natural gas hydrate reservoir parameters to provide a theoretical framework for the design of a development plan,an analytical equation method was used to obtain the si...In order to apply physical simulation results to natural gas hydrate reservoir parameters to provide a theoretical framework for the design of a development plan,an analytical equation method was used to obtain the similarity criteria of natural gas hydrate reservoir development by physical simulation,based on a mathematical model of natural gas hydrate development.Given the approach of numerical simulation,a sensitivity analysis for all parameters was carried out,which specifically demonstrated that initial temperature is the most important parameter.Parameters of thermal conductivity coefficients are not necessary for conducting the NGH dissociation process,which will fundamentally simplify the design and establishment of the model.The analysis provides a sound theoretical basis and design principles for particular similarity.展开更多
This paper introduces a new type machine for polyblends with excellent mixing capabilities of internal mixer and continuous molding character of extruder.The machine includes two functions - mixing and extrusion moldi...This paper introduces a new type machine for polyblends with excellent mixing capabilities of internal mixer and continuous molding character of extruder.The machine includes two functions - mixing and extrusion molding that have been composed together by rational design,so a tandem production mode - "batch + continuous" are opened up.The mathematical model of continuous mixing molding was established and verified availably by experimental research.The main physical mechanical property of vulcanizate,which had met national waterproof material standard,verified the machine practicability.The essential difference from other similar type machines is that this machine is not only suitable in producing granular and powder rubbers but also lumpish rubbers.展开更多
Using the mass of time-varying length balance rope focused on the hoisting conveyance, the coupling longi- tudinal-transverse model of mine friction hoist was established by using of the Hamilton's principle. The mod...Using the mass of time-varying length balance rope focused on the hoisting conveyance, the coupling longi- tudinal-transverse model of mine friction hoist was established by using of the Hamilton's principle. The modified Galerkin's method was used to discretize partial differential Eqs. The mine hoisting system was used to the example to analysis the relation between the load, velocity and transverse vibration of rope. The in situ tests were illustrated to evaluate the proposed mathematical model. The results showed that the modeling method can well represent the transverse vibration of rope.展开更多
The alternative productions, increasingly importance, are based on the rational utilization of the resources, on agreement with the environment and the use of autochthonous breeds that many cases are found in danger o...The alternative productions, increasingly importance, are based on the rational utilization of the resources, on agreement with the environment and the use of autochthonous breeds that many cases are found in danger of disappearance, due to the tact that their suckling is not economically profitable. A way of predicting and knowing the growth of the animals is using mathematical models. This work presented the results of the estimate of the growth according to the Gompertz-Laird model of males of the atttochthonous breed Serrana Soriana and Charolais. The weight to the birth of the breed calfs Charolais (45.14 kg), was superior to those of Serrana Soriana (40.13 kg), and presented a greater relative growth (9.9%) before the inflection point of the growth curve: furthermore it ~as also superior to the maximum decline relative after this point (6%), Serrana Soriana reached 7 days after the maximum growth point but with a smaller weight (315.05 kg vs 384.76 kg). It was calculated a weight to the maturity of 1 ,(176.91) kg for Charolais and 856.40 kg for Serrana Soriana.展开更多
Traditional fractal pattern design has some disadvantages such as inability to effectively reflect the characteristics of real scenery and texture. We propose a novel pattern design technique combining fractal geometr...Traditional fractal pattern design has some disadvantages such as inability to effectively reflect the characteristics of real scenery and texture. We propose a novel pattern design technique combining fractal geometry and image texture synthesis to solve these problems. We have improved Wei and Levoy (2000)’s texture synthesis algorithm by first using two-dimensional autocorrelation function to analyze the structure and distribution of textures, and then determining the size of L neighborhood. Several special fractal sets were adopted and HSL (Hue, Saturation, and Light) color space was chosen. The fractal structure was used to manipulate the texture synthesis in HSL color space where the pattern’s color can be adjusted conveniently. Experiments showed that patterns with different styles and different color characteristics can be more efficiently generated using the new technique.展开更多
The demand of hydrogen in oil refinery is increasing as market forces and environmental legislation, so hydrogen network management is becoming increasingly important in refineries. Most studies focused on single-obje...The demand of hydrogen in oil refinery is increasing as market forces and environmental legislation, so hydrogen network management is becoming increasingly important in refineries. Most studies focused on single-objective optimization problem for the hydrogen network, but few account for the multi-objective optimization problem. This paper presents a novel approach for modeling and multi-objective optimization for hydrogen network in refineries. An improved multi-objective optimization model is proposed based on the concept of superstructure. The optimization includes minimization of operating cost and minimization of investment cost of equipment. The proposed methodology for the multi-objective optimization of hydrogen network takes into account flow rate constraints, pressure constraints, purity constraints, impurity constraints, payback period, etc. The method considers all the feasible connections and subjects this to mixed-integer nonlinear programming (MINLP). A deterministic optimization method is applied to solve this multi-objective optimization problem. Finally, a real case study is intro-duced to illustrate the applicability of the approach.展开更多
The main methods of the second phase quantitative analysis in current material science researches are manual recognition and extracting by using software such as Image Tool and Nano Measurer. The weaknesses such as hi...The main methods of the second phase quantitative analysis in current material science researches are manual recognition and extracting by using software such as Image Tool and Nano Measurer. The weaknesses such as high labor intensity and low accuracy statistic results exist in these methods. In order to overcome the shortcomings of the current methods, the Ω phase in A1-Cu-Mg-Ag alloy is taken as the research object and an algorithm based on the digital image processing and pattern recognition is proposed and implemented to do the A1 alloy TEM (transmission electron microscope) digital images process and recognize and extract the information of the second phase in the result image automatically. The top-hat transformation of the mathematical morphology, as well as several imaging processing technologies has been used in the proposed algorithm. Thereinto, top-hat transformation is used for elimination of asymmetric illumination and doing Multi-layer filtering to segment Ω phase in the TEM image. The testing results are satisfied, which indicate that the Ω phase with unclear boundary or small size can be recognized by using this method. The omission of these two kinds of Ω phase can be avoided or significantly reduced. More Ω phases would be recognized (growing rate minimum to 2% and maximum to 400% in samples), accuracy of recognition and statistics results would be greatly improved by using this method. And the manual error can be eliminated. The procedure recognizing and making quantitative analysis of information in this method is automatically completed by the software. It can process one image, including recognition and quantitative analysis in 30 min, but the manual method such as using Image Tool or Nano Measurer need 2 h or more. The labor intensity is effectively reduced and the working efficiency is greatly improved.展开更多
Coal and gas outburst is one of the most serious natural calamities in collieries. And protective layer mining is an effective regional method for preventing and controlling coal outburst. However, how to rationally d...Coal and gas outburst is one of the most serious natural calamities in collieries. And protective layer mining is an effective regional method for preventing and controlling coal outburst. However, how to rationally determine the mining safety range in coal mining of protective layer with quantitative analysis is a difficult problem in rock mechanics and mining engineering so far. Then in this paper applied solid gas interaction mechanics for gas leakage flow, the solid gas interaction analysis for the safety range of up protective layer mining has been achieved with the results of experimental research and in situ measurements so that the result of numerical simulation for the difficult problem is closer to reality. Furthermore, the safety range of up protective layer mining can be determined with time dependent based on the result of numerical simulation.展开更多
A novel fusion algorithm was given based on fuzzy similarity and fuzzy integral theory. First, it calculated the fuzzy similarity among a certain sensor's measurement values and the multiple sensors' objective predi...A novel fusion algorithm was given based on fuzzy similarity and fuzzy integral theory. First, it calculated the fuzzy similarity among a certain sensor's measurement values and the multiple sensors' objective prediction values to determine the importance weight of each sensor and realize multi-sensor data fusion. Then according to the determined importance weight, an intelligent fusion system based on fuzzy integral theory was given, which can solve FEI-DEO and DEI-DEO fusion problems and realize the decision fusion. Simulation results were proved that fuzzy integral algorithm has enhanced the capability of handling the uncertain information and improved the intelligence degrees展开更多
The northern Batinah occupies approximately 12,150 km2 in the north of Oman Quaternary deposits and Neogene's upper Fats form the aquifer units. MODFLOW compatible MT3D was used for simulation development of the area...The northern Batinah occupies approximately 12,150 km2 in the north of Oman Quaternary deposits and Neogene's upper Fats form the aquifer units. MODFLOW compatible MT3D was used for simulation development of the area. It can be concluded that: (1) The groundwater in the Batinah area generally flows from the south-west to the gulf of Oman in the north-east; (2) Recharge takes place through direct recharge from rainfall and wadi flow by about 902 ×10^3 ma/day; (3) The hydraulic conductivity attains a relatively wide range between 0.02 m/day and 78 m/day and 0.02 m/day and 60 m/day for the Quaternary and Fars respectively; (4) There is probably less potential for groundwater abstraction in the northern part of the area; (5) The water level decreased by about 6 m over 24 years and (6) The increase of salinity most likely due to a contribution of sea water intrusion from the gulf along the coast. It is recommended that: (1) automatic well control system should be installed to accurate measurements of abstraction; (2) further analysis under different future scenarios should be made and (3) formulate an integrated management plan for the basin.展开更多
文摘From the viewpoint of interaction mechanics for solid and gas, a coupled mathematical model was presented for solid coal/rock deformation and gas leak flow in parallel deformable coal seams. Numerical solutions using the SIP (Strong Implicit Proce- dure) method to the coupled mathematical model for double parallel coal seams were also developed in detail. Numerical simulations for the prediction of the safety range using protection layer mining were performed with experimental data from a mine with potential danger of coal/gas outbursts. Analyses show that the numerical simulation results are consistent with the measured data in situ.
基金Supported by the National Natural Science Foundation of China (No. 20299030).
文摘Based on the transport phenomena theory, the passive mixing of water and ethanol in different threedimensional microchannels is simulated numerically. The average variance of water volume fraction is used to index the mixing efficiency in the cases with different Reynolds number and different fabricated mixers. The results show that the efficiency of liquid mixing is progressively dependent on the convective transport as the Reynolds number increases. The efficiency of serpentine microchannel decreases with the increasing Reynolds number in the laminar regime. Altering the aspect ratio of channel inlet section has no significant effect on the mixing efficiency. Increasing the area of channel inlet section will cause the decrease of the mixing efficiency. The mixing in serpentine channels is the most efficient among three different mixers because of the existence of second flow introduced by its special structure.
基金support from Rio Tinto AluminiumNSERC are gratefully acknowledged
文摘Microstructure evolution during the homogenization heat treatment of an Al?Mg?Si?Fe?Mn(AA6xxx)alloy wasinvestigated using a combination of modelling and experimental studies.The model is based on the CALPHAD-coupledhomogenization heat treatment model originally developed for AA3xxx alloys(i.e.,Al?Mn?Fe?Si).In this work,the model wasadapted to the more complex AA6xxx system(Al?Mg?Si?Mn?Fe)to predict the evolution of critical microstructural features suchas the spatial distribution of solute,the type and fraction of constituent particles and dispersoid number density and size distribution.Experiments were also conducted using three direct chill(DC)cast AA6xxx alloys with different Mn levels subjected to varioushomogenization treatments.The resulting microstructures were characterized using a range of techniques including scanning electronmicroscopy,electron microprobe analysis(EPMA),XRD,and electrical resistivity measurements.The model predictions werecompared with the experimental measurements,and reasonable agreement was found.
文摘Equipment management is one of the important parts of business administra- tion of coal. Most of coal mines take no account of their equipment management, and have no comprehensive and effective evaluation index system. Based on the analysis of the equipment evaluation measures of reform and the applications, the paper built up a comprehensive and effective evaluation index system of coal mine equipment, and im- proved the evaluation method with the use of fuzzy theory, analytic hierarchy process and entropy method.
文摘By applying the aggregation operator γ-operator and introducing a new method for global data contribution, the problems of information loss and the decrease of running efficiency in FuzzyJ Toolkit, an expert system shell, can be effectively solved. The example shows that the approach can overcome imprecision of max-operator and min-operator used during the process of fuzzy reasoning. Therefore, the information accuracy and the system performance can be effectively improved, which promotes the usability of FuzzyJ Toolkit.
基金supported by the National Climate Center of China under Grants 2211011816501。
文摘To evaluate the downscaling ability with respect to tropical cyclones(TCs)near China and its sensitivity to the model physics representation,the authors performed a multi-physics ensemble simulation with the regional Climate-Weather Research and Forecasting(CWRF)model at a 30 km resolution driven by ERA-Interim reanalysis data.The ensemble consisted of 28 integrations during 1979-2016 with varying CWRF physics configurations.Both CWRF and ERA-Interim can generally capture the seasonal cycle and interannual variation of the TC number near China,but evidently underestimate them.The CWRF downscaling and its multi-physics ensemble can notably reduce the underestimation and significantly improve the simulation of the TC occurrences.The skill enhancement is especially large in terms of the interannual variation,which is most sensitive to the cumulus scheme,followed by the boundary layer,surface and radiation schemes,but weakly sensitive to the cloud and microphysics schemes.Generally,the Noah surface scheme,CAML(CAM radiation scheme as implemented by Liang together with the diagnostic cloud cover scheme of Xu and Randall(1996))radiation scheme,prognostic cloud scheme,and Thompson microphysics scheme stand out for their better performance in simulating the interannual variation of TC number.However,the Emanuel cumulus and MYNN boundary layer schemes produce severe interannual biases.Our study provides a valuable reference for CWRF application to improve the understanding and prediction of TC activity.
基金the National Natural Science Foundation of China.
文摘A field experiment was conducted to study the combined effect of nutrient andpest managements on soil biomass phospholipid contents, functional biodiversity and substrateutilization patterns of soil microbial populations in hybrid rice cropping system. The mineral N, Pand K fertilizers (as urea, calcium superphosphate and KCl respectively) were incorporated at 100,25, and 100 kg ha^(-1), respectively, and the various pesticides were applied at the recommendedrates. The results of the experiment demonstrated a decline in the microbial abundance and soilmicrobial biomass phospholipid contents with the advancement of crop growth, and significant changesin substrate utilization pattern of soil microbial population studied were observed with differentmanagement practices and at different growth stages. The principal component analysis (PCA) usingall 95-carbon sources (BIOLOG plates) gave good differentiation among the treatments, indicatingthat they have different patterns of carbon utilization under different habitats. The data showedthat diversity in microbial community continuously changed with the progression in crop stage,particularly at physiological maturity (PM) stage that was evident from the utilization of differentcarbon sources at various crop stages.
基金National Natural Science Foundation of China under Grant Nos.60634010 and 60776829New Century Excellent Talents in Universities under Grant No.NCET-06-0074the Key Project of the Ministry of Education of China under Grant No.107007
文摘In complex networks, network modules play a center role, which carry out a key function. In this paper, we introduce the spatial correIation function to describe the relationships among the network modules. Our focus is to investigate how the network modules evolve, and what the evolution properties of the modules are. In order to test the proposed method, as the examples, we use our method to analyze and discuss the ER random network and scale-free network. Rigorous analysis of the existing data shows that the introduced correlation function is suitable for describing the evolution properties of network modules. Remarkably, the numerical simulations indicate that the ER random network and scale-free network have different evolution properties.
文摘The tensile stress-strain curves of NiTi wires are obtained by tensile experiments under different heat treatments. A phenomenological physical model based on hysteresis element method is developed to describe the experimentally determined stress-strain curves of shape memory alloy (SMA) wires. Numerical simulations are made. Simulation results show that:(1) a series of unusual changes on physical and mechanical properties of SMA wires occur when martensitic, especially R (rhombohedral) phase transformation emerge. The stress-strain relation of SMA wires is highly non-linear; (2) there are no notable yielding phenomena before NiTi wires are broken; (3) numerical results obtained by the physical model are in good agreement with experimental data.
基金supported by the China Petroleum and Chemical Corporation (No.P06070)the National Natural Science Foundation of China (No.50404003)
文摘In order to apply physical simulation results to natural gas hydrate reservoir parameters to provide a theoretical framework for the design of a development plan,an analytical equation method was used to obtain the similarity criteria of natural gas hydrate reservoir development by physical simulation,based on a mathematical model of natural gas hydrate development.Given the approach of numerical simulation,a sensitivity analysis for all parameters was carried out,which specifically demonstrated that initial temperature is the most important parameter.Parameters of thermal conductivity coefficients are not necessary for conducting the NGH dissociation process,which will fundamentally simplify the design and establishment of the model.The analysis provides a sound theoretical basis and design principles for particular similarity.
基金National Natural Science Foundation of China(No.50375075)
文摘This paper introduces a new type machine for polyblends with excellent mixing capabilities of internal mixer and continuous molding character of extruder.The machine includes two functions - mixing and extrusion molding that have been composed together by rational design,so a tandem production mode - "batch + continuous" are opened up.The mathematical model of continuous mixing molding was established and verified availably by experimental research.The main physical mechanical property of vulcanizate,which had met national waterproof material standard,verified the machine practicability.The essential difference from other similar type machines is that this machine is not only suitable in producing granular and powder rubbers but also lumpish rubbers.
文摘Using the mass of time-varying length balance rope focused on the hoisting conveyance, the coupling longi- tudinal-transverse model of mine friction hoist was established by using of the Hamilton's principle. The modified Galerkin's method was used to discretize partial differential Eqs. The mine hoisting system was used to the example to analysis the relation between the load, velocity and transverse vibration of rope. The in situ tests were illustrated to evaluate the proposed mathematical model. The results showed that the modeling method can well represent the transverse vibration of rope.
文摘The alternative productions, increasingly importance, are based on the rational utilization of the resources, on agreement with the environment and the use of autochthonous breeds that many cases are found in danger of disappearance, due to the tact that their suckling is not economically profitable. A way of predicting and knowing the growth of the animals is using mathematical models. This work presented the results of the estimate of the growth according to the Gompertz-Laird model of males of the atttochthonous breed Serrana Soriana and Charolais. The weight to the birth of the breed calfs Charolais (45.14 kg), was superior to those of Serrana Soriana (40.13 kg), and presented a greater relative growth (9.9%) before the inflection point of the growth curve: furthermore it ~as also superior to the maximum decline relative after this point (6%), Serrana Soriana reached 7 days after the maximum growth point but with a smaller weight (315.05 kg vs 384.76 kg). It was calculated a weight to the maturity of 1 ,(176.91) kg for Charolais and 856.40 kg for Serrana Soriana.
基金Project supported by the Natural Science Foundation of Zhejiang Province (No. M603228), Zhejiang Science and Technology Plan Project, and Ningbo Science Foundation for Doctor, China
文摘Traditional fractal pattern design has some disadvantages such as inability to effectively reflect the characteristics of real scenery and texture. We propose a novel pattern design technique combining fractal geometry and image texture synthesis to solve these problems. We have improved Wei and Levoy (2000)’s texture synthesis algorithm by first using two-dimensional autocorrelation function to analyze the structure and distribution of textures, and then determining the size of L neighborhood. Several special fractal sets were adopted and HSL (Hue, Saturation, and Light) color space was chosen. The fractal structure was used to manipulate the texture synthesis in HSL color space where the pattern’s color can be adjusted conveniently. Experiments showed that patterns with different styles and different color characteristics can be more efficiently generated using the new technique.
基金Supported by the National High Technology Research and Development Program of China (2008AA042902, 2009AA04Z162), the Program of Introducing Talents of Discipline to University (B07031) and the National Natural Science Foundation of China (21106129).
文摘The demand of hydrogen in oil refinery is increasing as market forces and environmental legislation, so hydrogen network management is becoming increasingly important in refineries. Most studies focused on single-objective optimization problem for the hydrogen network, but few account for the multi-objective optimization problem. This paper presents a novel approach for modeling and multi-objective optimization for hydrogen network in refineries. An improved multi-objective optimization model is proposed based on the concept of superstructure. The optimization includes minimization of operating cost and minimization of investment cost of equipment. The proposed methodology for the multi-objective optimization of hydrogen network takes into account flow rate constraints, pressure constraints, purity constraints, impurity constraints, payback period, etc. The method considers all the feasible connections and subjects this to mixed-integer nonlinear programming (MINLP). A deterministic optimization method is applied to solve this multi-objective optimization problem. Finally, a real case study is intro-duced to illustrate the applicability of the approach.
基金Project(51171209)supported by the National Natural Science Foundation of China
文摘The main methods of the second phase quantitative analysis in current material science researches are manual recognition and extracting by using software such as Image Tool and Nano Measurer. The weaknesses such as high labor intensity and low accuracy statistic results exist in these methods. In order to overcome the shortcomings of the current methods, the Ω phase in A1-Cu-Mg-Ag alloy is taken as the research object and an algorithm based on the digital image processing and pattern recognition is proposed and implemented to do the A1 alloy TEM (transmission electron microscope) digital images process and recognize and extract the information of the second phase in the result image automatically. The top-hat transformation of the mathematical morphology, as well as several imaging processing technologies has been used in the proposed algorithm. Thereinto, top-hat transformation is used for elimination of asymmetric illumination and doing Multi-layer filtering to segment Ω phase in the TEM image. The testing results are satisfied, which indicate that the Ω phase with unclear boundary or small size can be recognized by using this method. The omission of these two kinds of Ω phase can be avoided or significantly reduced. More Ω phases would be recognized (growing rate minimum to 2% and maximum to 400% in samples), accuracy of recognition and statistics results would be greatly improved by using this method. And the manual error can be eliminated. The procedure recognizing and making quantitative analysis of information in this method is automatically completed by the software. It can process one image, including recognition and quantitative analysis in 30 min, but the manual method such as using Image Tool or Nano Measurer need 2 h or more. The labor intensity is effectively reduced and the working efficiency is greatly improved.
文摘Coal and gas outburst is one of the most serious natural calamities in collieries. And protective layer mining is an effective regional method for preventing and controlling coal outburst. However, how to rationally determine the mining safety range in coal mining of protective layer with quantitative analysis is a difficult problem in rock mechanics and mining engineering so far. Then in this paper applied solid gas interaction mechanics for gas leakage flow, the solid gas interaction analysis for the safety range of up protective layer mining has been achieved with the results of experimental research and in situ measurements so that the result of numerical simulation for the difficult problem is closer to reality. Furthermore, the safety range of up protective layer mining can be determined with time dependent based on the result of numerical simulation.
基金Supported by the National Natural Science Foundation of China (50874059, 70971059) the Research Fund for the Doctoral Program of Higher Educa- tion of China (200801470003)
文摘A novel fusion algorithm was given based on fuzzy similarity and fuzzy integral theory. First, it calculated the fuzzy similarity among a certain sensor's measurement values and the multiple sensors' objective prediction values to determine the importance weight of each sensor and realize multi-sensor data fusion. Then according to the determined importance weight, an intelligent fusion system based on fuzzy integral theory was given, which can solve FEI-DEO and DEI-DEO fusion problems and realize the decision fusion. Simulation results were proved that fuzzy integral algorithm has enhanced the capability of handling the uncertain information and improved the intelligence degrees
文摘The northern Batinah occupies approximately 12,150 km2 in the north of Oman Quaternary deposits and Neogene's upper Fats form the aquifer units. MODFLOW compatible MT3D was used for simulation development of the area. It can be concluded that: (1) The groundwater in the Batinah area generally flows from the south-west to the gulf of Oman in the north-east; (2) Recharge takes place through direct recharge from rainfall and wadi flow by about 902 ×10^3 ma/day; (3) The hydraulic conductivity attains a relatively wide range between 0.02 m/day and 78 m/day and 0.02 m/day and 60 m/day for the Quaternary and Fars respectively; (4) There is probably less potential for groundwater abstraction in the northern part of the area; (5) The water level decreased by about 6 m over 24 years and (6) The increase of salinity most likely due to a contribution of sea water intrusion from the gulf along the coast. It is recommended that: (1) automatic well control system should be installed to accurate measurements of abstraction; (2) further analysis under different future scenarios should be made and (3) formulate an integrated management plan for the basin.