A large amount of genome-wide association study(GWAS)panels together with quantitative-trait locus(QTL)information associated with breeding-targeted traits have been described in wheat(Triticum aestivum L.).However,th...A large amount of genome-wide association study(GWAS)panels together with quantitative-trait locus(QTL)information associated with breeding-targeted traits have been described in wheat(Triticum aestivum L.).However,the application of mapping results from a GWAS panel to conventional wheat breeding remains a challenge.In this study,we first report a general genetic map which was constructed from 44 published linkage maps.It permits the estimation of genetic distances between any two genetic loci with physical map positions,thereby unifying the linkage relationships between QTL,genes,and genomic markers from multiple genetic populations.Second,we describe QTL mapping in a wheat GWAS panel of 688 accessions,identifying 77 QTL associated with 12 yield and grain-quality traits.Because these QTL have known physical map positions,they could be mapped onto the general map.Finally,we present a design approach to wheat breeding by using known QTL information and computer simulation.Potential crosses between parents in the GWAS panel may be evaluated by the relative frequency of the target genotype,trait correlations in simulated progeny populations,and genetic gain of selected progenies.It is possible to simultaneously improve yield and grain quality by suitable parental selection,progeny population size,and progeny selection scheme.Applying the design approach will allow identifying the most promising crosses and selection schemes in advance of the field experiment,increasing predictability and efficiency in wheat breeding.展开更多
The application of computer simulation technique to electronic controlled fuel injection(EFI) engine was studied to increase the development speed and improve the overall performance of the engine and car. On the bas...The application of computer simulation technique to electronic controlled fuel injection(EFI) engine was studied to increase the development speed and improve the overall performance of the engine and car. On the basis of an EFI system developed by ourselves, the simulation model of the initial control data and engine operation points during a driving cycle and the car performance pridiction model were established. This method was applied to a mini car. The experiment showed that the simulated control data has good accuracy; and the engine test points and car performances obtained by simulation are useful for the matching of EFI system with gasoline engine and the development speed is increased.展开更多
This paper used EAM and static relaxation method to simulate the grain boundary segregation behavior of Mg in Ni-based superalloys. The results offer a better understanding in the strengthening mechanism of Mg additio...This paper used EAM and static relaxation method to simulate the grain boundary segregation behavior of Mg in Ni-based superalloys. The results offer a better understanding in the strengthening mechanism of Mg addition in superalloys. The segregation of Mg increases the grain boundary cohesive bond and the vacancy formation energy, and decreases the mobility of grain boundary dislocation. It results in the retardation of creep voids initiation and growth.展开更多
In this paper, a 3-D video encoding scheme suitable for digital TV/HDTV (high definition television) is studied through computer simulation. The encoding scheme is designed to provide a good match to human vision. Bas...In this paper, a 3-D video encoding scheme suitable for digital TV/HDTV (high definition television) is studied through computer simulation. The encoding scheme is designed to provide a good match to human vision. Basically, this involves transmission of low frequency luminance information at full frame rate for good motion rendition and transmission of high frequency luminance signal at reduced frame rate for good detail in static images.展开更多
A major motivation for this work is to investigate a method of computer simulation for compensating fixed pattern noise of the infrared focal plane arrays. A mathematical model of the output signal of focal plane arra...A major motivation for this work is to investigate a method of computer simulation for compensating fixed pattern noise of the infrared focal plane arrays. A mathematical model of the output signal of focal plane array was established; a compensating algorithm utilizing reference source was derived and simulating programs were designed. The images of compensating process verify the influence of nonuniformity of responsibility and offset on fixed pattern noise. The result show that simulating method of investigating compensation technology for focal plane arrays is feasible, the generated images and methods can be used to the study of image recognition.展开更多
A computer software to simulate the phase transformation during quenching is designed based on Avrami equation and Scheil additivity principle of incubation period. The isothermal transformation diagrams of supercool...A computer software to simulate the phase transformation during quenching is designed based on Avrami equation and Scheil additivity principle of incubation period. The isothermal transformation diagrams of supercooled austenite are described by cubic spline functions. This software is possess of a good graphic interface of Windows style, can simulate the whole process in austenite decomposition during continuous cooling. If the cooling rate was given, the fraction of various microstructures transformed of austenite decomposition during continuous cooling at any temperature can be calculated. The simulation results are checked with the quenching experiment of 45 steel. The results indicate that the simulation results are comparatively close to the experimental results.展开更多
AIM：To compare accuracy,reproducibility and test duration for the Snellen and the Early Treatment Diabetic Retinopathy Study（ETDRS）charts,two main tools used to measure visual acuity（VA）.·M ETHODS：A compute...AIM：To compare accuracy,reproducibility and test duration for the Snellen and the Early Treatment Diabetic Retinopathy Study（ETDRS）charts,two main tools used to measure visual acuity（VA）.·M ETHODS：A computer simulation was programmed to run multiple virtual patients,each with a unique set of assigned parameters,including VA,false-positive and false-negative error values.For each virtual patient,assigned VA was randomly chosen along a continuous scale spanning the range between 1.0 to 0.0 log MAR units（equivalent to 20/200 to 20/20）.Each of 30 000virtual patients were run ten times on each of the two VA charts.·RESULTS：Average test duration（expressed as the total number of characters presented during the test±SD）was12.6±11.1 and 31.2±14.7 characters,for the Snellen and ETDRS,respectively.Accuracy,defined as the absolute difference（±SD）between the assigned VA and the measured VA,expressed in log MAR units,was superior in the ETDRS charts：0.12±0.14 and 0.08±0.08,for the Snellen and ETDRS charts,respectively.Reproducibility,expressed as test-retest variability,was superior in the ETDRS charts：0.23±0.17 and 0.11±0.09 log MAR units,for the Snellen and ETDRS charts,respectively.·CONCLUSION：A comparison of true（assigned）VA to measured VA,demonstrated,on average,better accuracy and reproducibility of the ETDRS chart,but at the penalty of significantly longer test duration.These differences were most pronounced in the low VA range.The reproducibility using a simulation approach is in line with reproducibility values found in several clinical studies.展开更多
The mathematical models of the kinetics of the layer growth at different ion nitriding condi- tions of armco iron.steels 45,40Cr,42CrMo and 38CrMoAl have been established.Based on these models the expression of nitrog...The mathematical models of the kinetics of the layer growth at different ion nitriding condi- tions of armco iron.steels 45,40Cr,42CrMo and 38CrMoAl have been established.Based on these models the expression of nitrogen concentration profile of ion nitrided layers have been deduced with profile simulating method.They are C_=C_(min)^+(P_4)/(ξ_1-x)+(P_5)/(ξ_(10)~2)(ξ_1-x)~2 C_(γ′)=C_(min)^(γ′)+(P_1)/(ξ_(21))(ξ_2-x)+(P_2)/(ξ_(21)~2)(ξ_2-x)~2 C_α=C_(min)~α+(C_(33))/(C_(33))/(ξ_(32))(ξ_3-x)~3 Using these models,the kinetics of layer growth and the nitrogen concentration profile of ion nitrided layers were sinulated on Apple-Ⅱ computer.Results show that the simulated curves coincide quite well with the experimental data.展开更多
The new filling system is smooth filling without gas gap. It works well in avoiding the generation of defects such as porosity and inclusion. The pouring basin, sprue, runner and the gate of the bolster casting were d...The new filling system is smooth filling without gas gap. It works well in avoiding the generation of defects such as porosity and inclusion. The pouring basin, sprue, runner and the gate of the bolster casting were designed according to the principle of the new filling system. The filling and solidifciation process of the bolster casting were also simulated. It was found that the filling process was smooth, and air entrapment and shrinkage were avoided. Finally, a further validation of the new filling system of bolster casting was carried out in a foundry.展开更多
Core filling process of cast high speed steel roll was simulated.Ductile iron was used as core material.The influences of filling parameters,such as core filling time and core filling temperature,on the filling proces...Core filling process of cast high speed steel roll was simulated.Ductile iron was used as core material.The influences of filling parameters,such as core filling time and core filling temperature,on the filling process were investigated.Based on the simulated results,optimal core filling parameters were determined.The predicted temperature fields show that the temperature at the roll shoulder is the lowest during the core filling process and usually causes binding defects there.Method for solving this problem was presented.展开更多
A method for determination of tool-chip contact length is theoreticallypresented in orthogonal metal machining. By using computer simulation and based on the analyses ofthe elastro-plastic deformation with lagrangian ...A method for determination of tool-chip contact length is theoreticallypresented in orthogonal metal machining. By using computer simulation and based on the analyses ofthe elastro-plastic deformation with lagrangian finite element method in the deformation zone, theaccumulated representative length of the low layer, the tool-chip contact length of the chipcontacting the tool rake are calculated, experimental studies are also carried out with 0.2 percentcarbon steel. It is shown that the tool-chip contact lengths obtained from computer simulation havea good agreement with those of measured values.展开更多
In order to study the evacuation behavior of miners during accidents,we analyzed the rational layout of a safe chamber,and improved evacuation efficiency.A visual model of evacuation was developed and used to simulate...In order to study the evacuation behavior of miners during accidents,we analyzed the rational layout of a safe chamber,and improved evacuation efficiency.A visual model of evacuation was developed and used to simulate the evacuation process of mines,given their special underground environments.In our simulation,the working faces of a coal mine and nearby tunnels were divided into 0.5 m×0.5 m grids to reflect the location of occupants and obstacles.Based on a "flow potential of the occupant",we determined the direction of movement and routes of occupants.In the model,evacuation speed changed as a function of crowd density,with an average speed of 1.30 m/s.The model also takes into account detection time of the disaster and the personnel response time.Evacuation time,exit flow rate and evacuation path were obtained by simulation.The results indicate that using simulation technology can present a more visual evacuation process and show the behavior of occupants.Our establishment of a mine safety evacuation system has merit as reference value.展开更多
Covalent organic framework （COF） is a porous material with low density and large BET （Brtmauer-Emmett-Teller） surface area. They have great potential in gas adsorption and separation. In this work, the adsorption ...Covalent organic framework （COF） is a porous material with low density and large BET （Brtmauer-Emmett-Teller） surface area. They have great potential in gas adsorption and separation. In this work, the adsorption of pure CO2 and CO2/CH4 mixture on modified COF-102 was simulated by using GCMC （grand canonical Monte Carlo）. Metal Li was incorporated into COF-102 through three doping methods, including charge exchange, O^--Li6＋ dipolar interaction and O^--Li^＋ chemical bonding. The influence of Li doping on the adsorption of CO2 was studied. The results showed that among the three methods, the dipole doping is the best way to improve CO2 adsorption performance. Further, the ligands of COF-102 were replaced by extended aromatic moieties, such as diphenyl and pyrene. The adsorption capacity of CO2 and CH4, and the selectivity of CO2/CH4 on the ligand-replaced COF-102 were studied. The capacity of CO2 and CH4 on the ligand-replaced COF-102 had obvious changes; hence the selectivity of CO2/CH4 can be adjusted accordingly.展开更多
To realize the technology of fabricating the rheologic semi-solid slurry of ZL112Y aluminum alloy via continues electromagnetic stirring process, ANSYS software was used to simulate electromagnetic force field and flu...To realize the technology of fabricating the rheologic semi-solid slurry of ZL112Y aluminum alloy via continues electromagnetic stirring process, ANSYS software was used to simulate electromagnetic force field and fluid velocity field in the alloy melt in a crucible tube in three coils. In the first section of the paper, eletromagnetic force field and fluid velocity field caused by single coil were simulated. The result of this simulation gives an average velocity of 3.2 cm/s and it is called critical velocity because a fluid velocity over it will cause a fine and spherical structure of solid primary a in a semi-solid melt. And, from this result, a reasonable temperature of semi-solid of the alloy and an electrical current intensity were established. The electrical current intensity of the result of this simulation corresponded to the current intensity used in a practice experiment, in which the primary α was obviously refined and sphericized. Based on this simulation of single coil electromagnetic stirring, in the second section of the paper, eletromagnetic force field and fluid velocity field caused by three coils were simulated. The result of the simulation shows that, 1） there is a semi-solid zone of 32 mm from bottom of the crucible tube to the upper; 2） the electrical current intensities of three coils of 400 A, 600 A, and 400 A, which were set to top range, middle range and bottom range of the tube, respectively, were the optimum parameters of electromagnetic current intensity under the condition of this investigation; and 3） under effect of these electromagnetic current intensity, the fluid velocities of the melt in the tube were 6.3 cm/s in top range, 3.75 cm/s in middle range, and 3.9 cm/s in bottom range of it, respectively.展开更多
Ca (II) speciation and effect of Gd (III) speciation on Ca (II) speciation in human blood plasma were studied by computer simulation. [CaHCO3](-) is a predominant compound species of Ca (II). Gd (III) can compete with...Ca (II) speciation and effect of Gd (III) speciation on Ca (II) speciation in human blood plasma were studied by computer simulation. [CaHCO3](-) is a predominant compound species of Ca (II). Gd (III) can compete with Ca (II) for biological molecules. The presence of Gd (III) results in a increase of concentration of free Ca (II) and a decrease of concentration of Ca (II) compounds.展开更多
On the basis of transformation kinetics and thermodynamics, the austenite-ferrite transformation start temperature during deformation was predicted for several grades of low-carbon steels under different processing co...On the basis of transformation kinetics and thermodynamics, the austenite-ferrite transformation start temperature during deformation was predicted for several grades of low-carbon steels under different processing conditions. Results indicate that Ar3d temperature mostly depended on alloying composition and processing parameters. Ar3d increased as strain rate or strain increased for the same steel grade. In view of enhancement of deformation on transformation, the basic kinetics model was established to simulate deformation induced transformation behavior, using which the influence of the deformation stored energy and effective deformation ledge on the nucleation and growth can be considered. The simulated results are in good agreement with experiment results.展开更多
This article reports an experimental investigation on the axial impact buckling of thin metallic cylindrical shells fully filled with water. Low velocity impact tests are carried out by DHR-9401 drop hammer rig. The w...This article reports an experimental investigation on the axial impact buckling of thin metallic cylindrical shells fully filled with water. Low velocity impact tests are carried out by DHR-9401 drop hammer rig. The whole process of dynamic buckling is simulated using LS-DYNA computer code. The consistency between experimental observation and numerical simulation is quite satisfactory. The investigation indicates that quite high internal hydrodynamic pressure occurs inside the shell during the impact process. Under the combined action of the high internal pressure and axial compression plastic buckling occurs easily in the thin-walled shells and buckling modes take on regular and axisymmetric wrinkles.展开更多
In this paper, we investigate the method of computer simulation for derivative weave by adopting the way of weave differentiation with mathematical function. And on that base, we explore the way for dealing with compo...In this paper, we investigate the method of computer simulation for derivative weave by adopting the way of weave differentiation with mathematical function. And on that base, we explore the way for dealing with composed weave. It is purposed for building a simple and efficient way of computer simulation for weave.展开更多
This paper presents the use of a computer method of the ventilation process simulation for the analysis of the flow distribution of air and gases in the area of wall mining work and the adjacent goaf.In workings and g...This paper presents the use of a computer method of the ventilation process simulation for the analysis of the flow distribution of air and gases in the area of wall mining work and the adjacent goaf.In workings and goaf,the complex issue of the formation of a gaseous atmosphere under variable ventilation conditions and an existing fire hazard level,with the possibility of feeding goaf with an additional carbon dioxide flux as the inertizing agent is considered.Some examples of the simulation of feeding goaf with carbon dioxide illustrating the different patterns of the distribution of the goaf atmosphere gases concentration,said distribution patterns being gas supply place dependent,have been presented.In addition,the impact of the additional sealing of goaf on the distribution level of the concentration of gases,the said sealing made from the wall side with chemical agents has also been considered.The capabilities of the VentGoaf computer simulation program,being the basis for our calculations,enable consideration of the use of the inert gases supplied to the goaf depending on: the location of the gas feeding the pipe outlet,tightness of the fire field,fire centre location,and spatial situation of the mined wall.It has been found that fire prevention elements,such as chemical sealing agents,are of great impact on the effectiveness of fire prevention.展开更多
AIM： To investigate the flow and mixing at the duodenal stump after gastric resection, a computer simulation was implemented. METHODS： Using the finite element method, two different Billroth fl procedure cases （A a...AIM： To investigate the flow and mixing at the duodenal stump after gastric resection, a computer simulation was implemented. METHODS： Using the finite element method, two different Billroth fl procedure cases （A and B） were modeled. Case A was defined with a shorter and almost straight duodenal section, while case B has a much longer and curved duodenal section. Velocity, pressure and food concentration distribution were determined and the numerical results were compared with experimental observations. RESULTS： The pressure distribution obtained by numerical simulation was in the range of the recorded experimental results. Case A had a more favorable pressure distribution in comparison with case B. However, case B had better performance in terms of food transport because of more continual food distribution, as well as better emptying of the duodena section. CONCLUSION： This study offers insight into the transport process within the duodenal stump section after surgical intervention, which can be useful for future patient-specific predictions of a surgical outcome.展开更多
基金the Hainan Yazhou Bay Seed Laboratory(B21Y10209 and B22C10212)China Postdoctoral Science Foundation(2022M713433)+1 种基金National Natural Science Foundation of China(31861143003)Innovation Program of Chinese Academy of Agricultural Sciences.
文摘A large amount of genome-wide association study(GWAS)panels together with quantitative-trait locus(QTL)information associated with breeding-targeted traits have been described in wheat(Triticum aestivum L.).However,the application of mapping results from a GWAS panel to conventional wheat breeding remains a challenge.In this study,we first report a general genetic map which was constructed from 44 published linkage maps.It permits the estimation of genetic distances between any two genetic loci with physical map positions,thereby unifying the linkage relationships between QTL,genes,and genomic markers from multiple genetic populations.Second,we describe QTL mapping in a wheat GWAS panel of 688 accessions,identifying 77 QTL associated with 12 yield and grain-quality traits.Because these QTL have known physical map positions,they could be mapped onto the general map.Finally,we present a design approach to wheat breeding by using known QTL information and computer simulation.Potential crosses between parents in the GWAS panel may be evaluated by the relative frequency of the target genotype,trait correlations in simulated progeny populations,and genetic gain of selected progenies.It is possible to simultaneously improve yield and grain quality by suitable parental selection,progeny population size,and progeny selection scheme.Applying the design approach will allow identifying the most promising crosses and selection schemes in advance of the field experiment,increasing predictability and efficiency in wheat breeding.
文摘The application of computer simulation technique to electronic controlled fuel injection(EFI) engine was studied to increase the development speed and improve the overall performance of the engine and car. On the basis of an EFI system developed by ourselves, the simulation model of the initial control data and engine operation points during a driving cycle and the car performance pridiction model were established. This method was applied to a mini car. The experiment showed that the simulated control data has good accuracy; and the engine test points and car performances obtained by simulation are useful for the matching of EFI system with gasoline engine and the development speed is increased.
文摘This paper used EAM and static relaxation method to simulate the grain boundary segregation behavior of Mg in Ni-based superalloys. The results offer a better understanding in the strengthening mechanism of Mg addition in superalloys. The segregation of Mg increases the grain boundary cohesive bond and the vacancy formation energy, and decreases the mobility of grain boundary dislocation. It results in the retardation of creep voids initiation and growth.
文摘In this paper, a 3-D video encoding scheme suitable for digital TV/HDTV (high definition television) is studied through computer simulation. The encoding scheme is designed to provide a good match to human vision. Basically, this involves transmission of low frequency luminance information at full frame rate for good motion rendition and transmission of high frequency luminance signal at reduced frame rate for good detail in static images.
文摘A major motivation for this work is to investigate a method of computer simulation for compensating fixed pattern noise of the infrared focal plane arrays. A mathematical model of the output signal of focal plane array was established; a compensating algorithm utilizing reference source was derived and simulating programs were designed. The images of compensating process verify the influence of nonuniformity of responsibility and offset on fixed pattern noise. The result show that simulating method of investigating compensation technology for focal plane arrays is feasible, the generated images and methods can be used to the study of image recognition.
文摘A computer software to simulate the phase transformation during quenching is designed based on Avrami equation and Scheil additivity principle of incubation period. The isothermal transformation diagrams of supercooled austenite are described by cubic spline functions. This software is possess of a good graphic interface of Windows style, can simulate the whole process in austenite decomposition during continuous cooling. If the cooling rate was given, the fraction of various microstructures transformed of austenite decomposition during continuous cooling at any temperature can be calculated. The simulation results are checked with the quenching experiment of 45 steel. The results indicate that the simulation results are comparatively close to the experimental results.
文摘AIM：To compare accuracy,reproducibility and test duration for the Snellen and the Early Treatment Diabetic Retinopathy Study（ETDRS）charts,two main tools used to measure visual acuity（VA）.·M ETHODS：A computer simulation was programmed to run multiple virtual patients,each with a unique set of assigned parameters,including VA,false-positive and false-negative error values.For each virtual patient,assigned VA was randomly chosen along a continuous scale spanning the range between 1.0 to 0.0 log MAR units（equivalent to 20/200 to 20/20）.Each of 30 000virtual patients were run ten times on each of the two VA charts.·RESULTS：Average test duration（expressed as the total number of characters presented during the test±SD）was12.6±11.1 and 31.2±14.7 characters,for the Snellen and ETDRS,respectively.Accuracy,defined as the absolute difference（±SD）between the assigned VA and the measured VA,expressed in log MAR units,was superior in the ETDRS charts：0.12±0.14 and 0.08±0.08,for the Snellen and ETDRS charts,respectively.Reproducibility,expressed as test-retest variability,was superior in the ETDRS charts：0.23±0.17 and 0.11±0.09 log MAR units,for the Snellen and ETDRS charts,respectively.·CONCLUSION：A comparison of true（assigned）VA to measured VA,demonstrated,on average,better accuracy and reproducibility of the ETDRS chart,but at the penalty of significantly longer test duration.These differences were most pronounced in the low VA range.The reproducibility using a simulation approach is in line with reproducibility values found in several clinical studies.
文摘The mathematical models of the kinetics of the layer growth at different ion nitriding condi- tions of armco iron.steels 45,40Cr,42CrMo and 38CrMoAl have been established.Based on these models the expression of nitrogen concentration profile of ion nitrided layers have been deduced with profile simulating method.They are C_=C_(min)^+(P_4)/(ξ_1-x)+(P_5)/(ξ_(10)~2)(ξ_1-x)~2 C_(γ′)=C_(min)^(γ′)+(P_1)/(ξ_(21))(ξ_2-x)+(P_2)/(ξ_(21)~2)(ξ_2-x)~2 C_α=C_(min)~α+(C_(33))/(C_(33))/(ξ_(32))(ξ_3-x)~3 Using these models,the kinetics of layer growth and the nitrogen concentration profile of ion nitrided layers were sinulated on Apple-Ⅱ computer.Results show that the simulated curves coincide quite well with the experimental data.
基金supported by the Natural Science Foundation of Liaoning Province (20092061)
文摘The new filling system is smooth filling without gas gap. It works well in avoiding the generation of defects such as porosity and inclusion. The pouring basin, sprue, runner and the gate of the bolster casting were designed according to the principle of the new filling system. The filling and solidifciation process of the bolster casting were also simulated. It was found that the filling process was smooth, and air entrapment and shrinkage were avoided. Finally, a further validation of the new filling system of bolster casting was carried out in a foundry.
文摘Core filling process of cast high speed steel roll was simulated.Ductile iron was used as core material.The influences of filling parameters,such as core filling time and core filling temperature,on the filling process were investigated.Based on the simulated results,optimal core filling parameters were determined.The predicted temperature fields show that the temperature at the roll shoulder is the lowest during the core filling process and usually causes binding defects there.Method for solving this problem was presented.
基金This project is supported by Provincial Natural Science Foundation of Heilongjiang(No.A9809).
文摘A method for determination of tool-chip contact length is theoreticallypresented in orthogonal metal machining. By using computer simulation and based on the analyses ofthe elastro-plastic deformation with lagrangian finite element method in the deformation zone, theaccumulated representative length of the low layer, the tool-chip contact length of the chipcontacting the tool rake are calculated, experimental studies are also carried out with 0.2 percentcarbon steel. It is shown that the tool-chip contact lengths obtained from computer simulation havea good agreement with those of measured values.
文摘In order to study the evacuation behavior of miners during accidents,we analyzed the rational layout of a safe chamber,and improved evacuation efficiency.A visual model of evacuation was developed and used to simulate the evacuation process of mines,given their special underground environments.In our simulation,the working faces of a coal mine and nearby tunnels were divided into 0.5 m×0.5 m grids to reflect the location of occupants and obstacles.Based on a "flow potential of the occupant",we determined the direction of movement and routes of occupants.In the model,evacuation speed changed as a function of crowd density,with an average speed of 1.30 m/s.The model also takes into account detection time of the disaster and the personnel response time.Evacuation time,exit flow rate and evacuation path were obtained by simulation.The results indicate that using simulation technology can present a more visual evacuation process and show the behavior of occupants.Our establishment of a mine safety evacuation system has merit as reference value.
基金Supported by the National Natural Science Foundation of China （20736002）, the National High Technology Research and Development Program of China （2008AA062302） and Program for Changjiang Scholars and Innovative Research Team in University of China （IRT0721）.
文摘Covalent organic framework （COF） is a porous material with low density and large BET （Brtmauer-Emmett-Teller） surface area. They have great potential in gas adsorption and separation. In this work, the adsorption of pure CO2 and CO2/CH4 mixture on modified COF-102 was simulated by using GCMC （grand canonical Monte Carlo）. Metal Li was incorporated into COF-102 through three doping methods, including charge exchange, O^--Li6＋ dipolar interaction and O^--Li^＋ chemical bonding. The influence of Li doping on the adsorption of CO2 was studied. The results showed that among the three methods, the dipole doping is the best way to improve CO2 adsorption performance. Further, the ligands of COF-102 were replaced by extended aromatic moieties, such as diphenyl and pyrene. The adsorption capacity of CO2 and CH4, and the selectivity of CO2/CH4 on the ligand-replaced COF-102 were studied. The capacity of CO2 and CH4 on the ligand-replaced COF-102 had obvious changes; hence the selectivity of CO2/CH4 can be adjusted accordingly.
文摘To realize the technology of fabricating the rheologic semi-solid slurry of ZL112Y aluminum alloy via continues electromagnetic stirring process, ANSYS software was used to simulate electromagnetic force field and fluid velocity field in the alloy melt in a crucible tube in three coils. In the first section of the paper, eletromagnetic force field and fluid velocity field caused by single coil were simulated. The result of this simulation gives an average velocity of 3.2 cm/s and it is called critical velocity because a fluid velocity over it will cause a fine and spherical structure of solid primary a in a semi-solid melt. And, from this result, a reasonable temperature of semi-solid of the alloy and an electrical current intensity were established. The electrical current intensity of the result of this simulation corresponded to the current intensity used in a practice experiment, in which the primary α was obviously refined and sphericized. Based on this simulation of single coil electromagnetic stirring, in the second section of the paper, eletromagnetic force field and fluid velocity field caused by three coils were simulated. The result of the simulation shows that, 1） there is a semi-solid zone of 32 mm from bottom of the crucible tube to the upper; 2） the electrical current intensities of three coils of 400 A, 600 A, and 400 A, which were set to top range, middle range and bottom range of the tube, respectively, were the optimum parameters of electromagnetic current intensity under the condition of this investigation; and 3） under effect of these electromagnetic current intensity, the fluid velocities of the melt in the tube were 6.3 cm/s in top range, 3.75 cm/s in middle range, and 3.9 cm/s in bottom range of it, respectively.
基金the NSFC for financial support of this work (Project Nos.29890280, 29971029).
文摘Ca (II) speciation and effect of Gd (III) speciation on Ca (II) speciation in human blood plasma were studied by computer simulation. [CaHCO3](-) is a predominant compound species of Ca (II). Gd (III) can compete with Ca (II) for biological molecules. The presence of Gd (III) results in a increase of concentration of free Ca (II) and a decrease of concentration of Ca (II) compounds.
基金This work was financially supported by the High Technology Development Program(No.2001AA339030)the National Nat ural Science Foundation of China(No.50100404).
文摘On the basis of transformation kinetics and thermodynamics, the austenite-ferrite transformation start temperature during deformation was predicted for several grades of low-carbon steels under different processing conditions. Results indicate that Ar3d temperature mostly depended on alloying composition and processing parameters. Ar3d increased as strain rate or strain increased for the same steel grade. In view of enhancement of deformation on transformation, the basic kinetics model was established to simulate deformation induced transformation behavior, using which the influence of the deformation stored energy and effective deformation ledge on the nucleation and growth can be considered. The simulated results are in good agreement with experiment results.
基金the National Natural Science Foundation of China(19672039)the Shanxi Foundation for Returned Scholars from Abroad
文摘This article reports an experimental investigation on the axial impact buckling of thin metallic cylindrical shells fully filled with water. Low velocity impact tests are carried out by DHR-9401 drop hammer rig. The whole process of dynamic buckling is simulated using LS-DYNA computer code. The consistency between experimental observation and numerical simulation is quite satisfactory. The investigation indicates that quite high internal hydrodynamic pressure occurs inside the shell during the impact process. Under the combined action of the high internal pressure and axial compression plastic buckling occurs easily in the thin-walled shells and buckling modes take on regular and axisymmetric wrinkles.
文摘In this paper, we investigate the method of computer simulation for derivative weave by adopting the way of weave differentiation with mathematical function. And on that base, we explore the way for dealing with composed weave. It is purposed for building a simple and efficient way of computer simulation for weave.
基金a part of research projects(NN524 368237)Financed by the Ministry of Science and Higher Education
文摘This paper presents the use of a computer method of the ventilation process simulation for the analysis of the flow distribution of air and gases in the area of wall mining work and the adjacent goaf.In workings and goaf,the complex issue of the formation of a gaseous atmosphere under variable ventilation conditions and an existing fire hazard level,with the possibility of feeding goaf with an additional carbon dioxide flux as the inertizing agent is considered.Some examples of the simulation of feeding goaf with carbon dioxide illustrating the different patterns of the distribution of the goaf atmosphere gases concentration,said distribution patterns being gas supply place dependent,have been presented.In addition,the impact of the additional sealing of goaf on the distribution level of the concentration of gases,the said sealing made from the wall side with chemical agents has also been considered.The capabilities of the VentGoaf computer simulation program,being the basis for our calculations,enable consideration of the use of the inert gases supplied to the goaf depending on: the location of the gas feeding the pipe outlet,tightness of the fire field,fire centre location,and spatial situation of the mined wall.It has been found that fire prevention elements,such as chemical sealing agents,are of great impact on the effectiveness of fire prevention.
基金Supported by The Ministry of Science of Serbia with the grants OI144028 and TR12007
文摘AIM： To investigate the flow and mixing at the duodenal stump after gastric resection, a computer simulation was implemented. METHODS： Using the finite element method, two different Billroth fl procedure cases （A and B） were modeled. Case A was defined with a shorter and almost straight duodenal section, while case B has a much longer and curved duodenal section. Velocity, pressure and food concentration distribution were determined and the numerical results were compared with experimental observations. RESULTS： The pressure distribution obtained by numerical simulation was in the range of the recorded experimental results. Case A had a more favorable pressure distribution in comparison with case B. However, case B had better performance in terms of food transport because of more continual food distribution, as well as better emptying of the duodena section. CONCLUSION： This study offers insight into the transport process within the duodenal stump section after surgical intervention, which can be useful for future patient-specific predictions of a surgical outcome.
