Virtual organization uses information technology to achieve a closer integration and better management of business relationships between internal and external parties. There are many emerging issues in virtual organiz...Virtual organization uses information technology to achieve a closer integration and better management of business relationships between internal and external parties. There are many emerging issues in virtual organization and one of them is knowl- edge sharing. Knowledge sharing that is the core of knowledge management plays a key role in virtual organization. However, game theoretic exploration about knowledge sharing mechanism based on virtual organization is seldom published, In this study, knowledge sharing mechanism in virtual organization enterprise is explored using game theories from two aspects based on the features of knowledge sharing in virtual organization enterprise. Fi- nally, the critical model of knowledge sharing mechanism in virtual organization also is presented based on the perspective of game analysis.展开更多
A self-organized criticality model of a thermal sandpile is formulated for the first time to simulate the dynamic process with interaction between avalanche events on the fast time scale and diffusive transports on th...A self-organized criticality model of a thermal sandpile is formulated for the first time to simulate the dynamic process with interaction between avalanche events on the fast time scale and diffusive transports on the slow time scale. The main characteristics of the model are that both particle and energy avalanches of sand grains are considered simultaneously. Properties of intermittent transport and improved confinement are analyzed in detail. The results imply that the intermittent phenomenon such as blobs in the low confinement mode as well as edge localized modes in the high confinement mode observed in tokamak experiments are not only determined by the edge plasma physics, but also affected by the core plasma dynamics.展开更多
We have made an extensive numerical study of a modified model proposed by Olami,Feder,and Christensen to describe earthquake behavior.Two situations were considered in this paper.One situation is that the energy of th...We have made an extensive numerical study of a modified model proposed by Olami,Feder,and Christensen to describe earthquake behavior.Two situations were considered in this paper.One situation is that the energy of the unstable site is redistributed to its nearest neighbors randomly not averagely and keeps itself to zero.The other situation is that the energy of the unstable site is redistributed to its nearest neighbors randomly and keeps some energy for itself instead of reset to zero.Different boundary conditions were considered as well.By analyzing the distribution of earthquake sizes,we found that self-organized criticality can be excited only in the conservative case or the approximate conservative case in the above situations.Some evidence indicated that the critical exponent of both above situations and the original OFC model tend to the same result in the conservative case.The only difference is that the avalanche size in the original model is bigger.This result may be closer to the real world,after all,every crust plate size is different.展开更多
An accurate critical heat flux（CHF） prediction method is the key factor for realizing the steady-state operation of a water-cooled divertor that works under one-sided high heating flux conditions.An improved CHF pre...An accurate critical heat flux（CHF） prediction method is the key factor for realizing the steady-state operation of a water-cooled divertor that works under one-sided high heating flux conditions.An improved CHF prediction method based on Euler＇s homogeneous model for flow boiling combined with realizable k-ε model for single-phase flow is adopted in this paper in which time relaxation coefficients are corrected by the Hertz-Knudsen formula in order to improve the calculation accuracy of vapor-liquid conversion efficiency under high heating flux conditions.Moreover,local large differences of liquid physical properties due to the extreme nonuniform heating flux on cooling wall along the circumference direction are revised by formula IAPWSIF97.Therefore,this method can improve the calculation accuracy of heat and mass transfer between liquid phase and vapor phase in a CHF prediction simulation of water-cooled divertors under the one-sided high heating condition.An experimental example is simulated based on the improved and the uncorrected methods.The simulation results,such as temperature,void fraction and heat transfer coefficient,are analyzed to achieve the CHF prediction.The results show that the maximum error of CHF based on the improved method is 23.7%,while that of CHF based on uncorrected method is up to 188%,as compared with the experiment results of Ref.[12].Finally,this method is verified by comparison with the experimental data obtained by International Thermonuclear Experimental Reactor（ITER）,with a maximum error of 6% only.This method provides an efficient tool for the CHF prediction of water-cooled divertors.展开更多
To promote the global dissemination of Chinese culture,the translation of Chinese classic literature has garnered widespread attention in the translation field.Literary translation criticism plays an essential role in...To promote the global dissemination of Chinese culture,the translation of Chinese classic literature has garnered widespread attention in the translation field.Literary translation criticism plays an essential role in the development of translation endeavors.This paper will analyze three versions of English translations of Shen Congwen’s novella Border Town using Reiss’s translation criticism model and summarize their performance in terms of formal equivalence and aesthetic effect,linguistic components,and extra-linguistic components.展开更多
A critical porosity model is often used to calculate the dry frame elastic modulus by the rock critical porosity value which is affected by many factors. In practice it is hard for us to obtain an accurate critical po...A critical porosity model is often used to calculate the dry frame elastic modulus by the rock critical porosity value which is affected by many factors. In practice it is hard for us to obtain an accurate critical porosity value and we can generally take only an empirical critical porosity value which often causes errors. In this paper, we propose a method to obtain the rock critical porosity value by inverting P-wave velocity and applying it to predict S-wave velocity. The applications of experiment and log data both show that the critical porosity inversion method can reduce the uncertainty resulting from using an empirical value in the past and provide the accurate critical porosity value for predicting S-wave velocity which significantly improves the prediction accuracy.展开更多
In current critical area models, it is generally assumed the defect outlines are circular and the conductors to be rectangle or the merger of rectangles. However, real defects and conductors associated with optimal la...In current critical area models, it is generally assumed the defect outlines are circular and the conductors to be rectangle or the merger of rectangles. However, real defects and conductors associated with optimal layout design exhibit a great variety of shapes. Based on mathematical morphology, a new critical area model is presented, which can be used to estimate the critical area of short circuit, open circuit and pinhole. Based on the new model, the efficient validity check algorithms are explored to extract critical areas of short circuit, open circuit and pinhole from layouts. The results of experiment on an approximate layout of 4 × 4 shifts register show that the new model predicts the critical areas accurately. These results suggest that the proposed model and algorithm could provide new approaches for yield prediction.展开更多
Breaking down the entire structure of a material implies severing all the bonds between its atoms either by applying work or by heat transfer. Because bond-breaking is indifferent to either means, there is a kind of e...Breaking down the entire structure of a material implies severing all the bonds between its atoms either by applying work or by heat transfer. Because bond-breaking is indifferent to either means, there is a kind of equivalence between heat energy and strain energy. Based on this equivalence, we assume the existence of a constant maximum storage of energy that includes both the strain energy and the corresponding equivalent heat energy. A temperaturedependent fracture strength model is then developed for ultrahigh temperature ceramics （UHTCs）. Model predictions for UHTCs, HfB2, TiC and ZrB2, are presented and compared with the experimental results. These predictions are found to be largely consistent with experimental results.展开更多
Isothermal hot compression tests of as-cast high-Cr ultra-super-critical（USC） rotor steel with columnar grains perpendicular to the compression direction were carried out in the temperature range from 950 to 1250...Isothermal hot compression tests of as-cast high-Cr ultra-super-critical（USC） rotor steel with columnar grains perpendicular to the compression direction were carried out in the temperature range from 950 to 1250°C at strain rates ranging from 0.001 to 1 s^（-1）. The softening mechanism was dynamic recovery（DRV） at 950°C and the strain rate of 1 s^（-1）, whereas it was dynamic recrystallization（DRX） under the other conditions. A modified constitutive equation based on the Arrhenius model with strain compensation reasonably predicted the flow stress under various deformation conditions, and the activation energy was calculated to be 643.92 kJ ×mol^（-1）. The critical stresses of dynamic recrystallization under different conditions were determined from the work-hardening rate（θ）–flow stress（σ） and-θ/σ–σ curves. The optimum processing parameters via analysis of the processing map and the softening mechanism were determined to be a deformation temperature range from 1100 to 1200°C and a strain-rate range from 0.001 to 0.08 s^（-1）, with a power dissipation efficiency η greater than 31%.展开更多
By means of CUSP model of catastrophe theory. this paper has studied thephysics process of rockburst occured on circular chamber. The present paper has nolonly described the instability process of rockburst more deepl...By means of CUSP model of catastrophe theory. this paper has studied thephysics process of rockburst occured on circular chamber. The present paper has nolonly described the instability process of rockburst more deeply. but also got the crilicaldepth of plastic softening area of chamber that is valuable in the controlling engineering of rockburst. the chamber displacement jump and energy liberation have been derived. the influence of rock parameters on the rockburst has been discussed .展开更多
In this paper, the equilibrium properties of spin-1 Blume–Emery–Griffiths model are studied by using constant-coupling approximation. The dipolar and quadrupolar order parameters, the stable, metastable and unstable...In this paper, the equilibrium properties of spin-1 Blume–Emery–Griffiths model are studied by using constant-coupling approximation. The dipolar and quadrupolar order parameters, the stable, metastable and unstable states and free energy of the model are investigated. The states are defined in terms of local minima of the free energy of system. The numerical calculations are presented for several values of exchange interactions on the simple cubic lattice with q = 6.展开更多
Response surface methodology（RSM） is introduced into corrosion research as a tool to assess the effects of environmental factors and their interactions on corrosion behavior and establish a model for corrosion predi...Response surface methodology（RSM） is introduced into corrosion research as a tool to assess the effects of environmental factors and their interactions on corrosion behavior and establish a model for corrosion prediction in complex coupled environment（CCE）. In this study, a typical CCE, that is, the corrosion environment of pipelines in gas field is taken as an example. The effects of environmental factors such as chloride concentration, pH value and pressure as well as their interactions on critical pitting temperature（CPT） were evaluated, and a quadratic polynomial model was developed for corrosion prediction by RSM. The results showed that the model was excellent in corrosion prediction with R2= 0.9949. CPT was mostly affected by single environmental factor rather than interaction, and among the whole factors, chloride concentration was the most influential factor of CPT.展开更多
In the existing models of estimating the yield and critical area, the defect outline is usually assumed to be circular, but the observed real defect outlines are irregular in shape. In this paper, estimation of the yi...In the existing models of estimating the yield and critical area, the defect outline is usually assumed to be circular, but the observed real defect outlines are irregular in shape. In this paper, estimation of the yield and critical area is made using the Monte Carlo technique and the relationship between the errors of yield estimated by circular defect and the rectangle degree of the defect is analysed. The rectangular model of a real defect is presented, and the yield model is provided correspondingly. The models take into account an outline similar to that of an original defect, the characteristics of two-dimensional distribution of defects, the feature of a layout routing, and the character of yield estimation. In order to make the models practicable, the critical area computations related to rectangular defect and regular （vertical or horizontal） routing are discussed. The critical areas associated with rectangular defect and non- regular routing are developed also, based on the mathematical morphology. The experimental results show that the new yield model may predict the yield caused by real defects more accurately than the circular model. It is significant that the yield is accurately estimated using the proposed model for IC metals.展开更多
Carbonate,tight sandstone,and shale reservoirs have many pore types,and the relationship between the porosity and elastic parameters is extremely discrete due to the complex pore shape.This paper presents a method for...Carbonate,tight sandstone,and shale reservoirs have many pore types,and the relationship between the porosity and elastic parameters is extremely discrete due to the complex pore shape.This paper presents a method for predicting reservoir pore types based on pore shape substitution.The pore shape substitution allows for accurately characterizing the changes in the elastic properties of the rock with the changes in pore shape,assuming there are no changes in terms of minerals,porosity,or fl uids.By employing a multiple-porosity variable critical porosity model,the eff ective pore aspect ratio could be inverted from the velocities of the rock.To perform pore shape substitution,we could replace the eff ective pore aspect ratio with another pore aspect ratio or increase/decrease the volume content of diff erent pore shapes.The reservoir pore types could be evaluated by comparing the differences in the reservoir velocities before and after the substitution of the pore shape.The test results pertaining to the theoretical model and the well logging data indicated that the pore shape substitution method could be applied to characterize pore types in terms of separating the eff ects of the pore shapes from the eff ects of the minerals,porosity,or fl uids on the velocities.展开更多
Transgenic mice carrying mutations that cause Autism Spectrum Disorders（ASDs） continue to be valuable for determining the molecular underpinnings of the disorders. Recently, researchers have taken advantage of such ...Transgenic mice carrying mutations that cause Autism Spectrum Disorders（ASDs） continue to be valuable for determining the molecular underpinnings of the disorders. Recently, researchers have taken advantage of such models combined with Cre-lox P and similar systems to manipulate gene expression over space and time. Thus, a clearer picture is starting to emerge of the cell types, circuits, brain regions, and developmental time periods underlying ASDs. ASD-causing mutations have been restricted to or rescued speci？cally in excitatory or inhibitory neurons, different neurotransmitter systems, and cells speci？c to the forebrain or cerebellum. In addition,mutations have been induced or corrected in adult mice,providing some evidence for the plasticity and reversibility of core ASD symptoms. The limited availability of Cre lines that are highly speci？c to certain cell types or time periods provides a challenge to determining the cellular and circuitry bases of autism, but other technological advances may eventually overcome this obstacle.展开更多
A reduction in network energy consumption and the establishment of green networks have become key scientific problems in academic and industrial research.Existing energy efficiency schemes are based on a known traffic...A reduction in network energy consumption and the establishment of green networks have become key scientific problems in academic and industrial research.Existing energy efficiency schemes are based on a known traffic matrix,and acquiring a real-time traffic matrix in current complex networks is difficult.Therefore,this research investigates how to reduce network energy consumption without a real-time traffic matrix.In particular,this paper proposes an intra-domain energy-efficient routing scheme based on multipath routing.It analyzes the relationship between routing availability and energy-efficient routing and integrates the two mechanisms to satisfy the requirements of availability and energy efficiency.The main research focus is as follows:(1)A link criticality model is evaluated to quantitatively measure the importance of links in a network.(2)On the basis of the link criticality model,this paper analyzes an energy-efficient routing technology based on multipath routing to achieve the goals of availability and energy efficiency simultaneously.(3)An energy-efficient routing algorithm based on multipath routing in large-scale networks is proposed.(4)The proposed method does not require a real-time traffic matrix in the network and is thus easy to apply in practice.(5)The proposed algorithm is verified in several network topologies.Experimental results show that the algorithm can not only reduce network energy consumption but can also ensure routing availability.展开更多
The vertical stability of a magnetic tip over a superconducting material is investigated by using the critical state and the frozen image models. The analytical expressions of the stiffness and the vibration frequency...The vertical stability of a magnetic tip over a superconducting material is investigated by using the critical state and the frozen image models. The analytical expressions of the stiffness and the vibration frequency about the equilibrium position are derived in term of the geometrical parameters of the magnet/superconductor system. It is found that the stability of the system depends on the shape of the superconductor as well as its thickness.展开更多
In present paper, study of magnetization behaviour was carried out for textured bulk YBaCuO polycrystalline superconductors synthesized by MTG process. The magnetization behaviour apparently different from that of sin...In present paper, study of magnetization behaviour was carried out for textured bulk YBaCuO polycrystalline superconductors synthesized by MTG process. The magnetization behaviour apparently different from that of sintered samples was observed. Magnetization hysteresis measurements were performed for the textured YBaCuO superconductors at 77K in± 10kOe magnetic field range. Based on the results of magnetization hysteresis, the magnetic field dependence of critical current density (Jc) at 77K was evaluated for the textured YBaCuO samples. The magnetic flux penetration in textured bulk YBaCuO polycrystalline superconductors was investigated at 77K through the magnetization hysteresis measurements under various maximum applied magnetic fields (HM) and reasonable discussion for the phenomena was conducted in terms of Bean's critical state model. The enhancement of magnetic properties for textured hulk YBaCuO polycrystalline superconductors is presumably attributed to the improvement of microstructure in these samples.展开更多
A new method of system failure analysis was proposed. First, considering the relationships between the failure subsystems,the decision making trial and evaluation laboratory(DEMATEL) method was used to calculate the d...A new method of system failure analysis was proposed. First, considering the relationships between the failure subsystems,the decision making trial and evaluation laboratory(DEMATEL) method was used to calculate the degree of correlation between the failure subsystems, analyze the combined effect of related failures, and obtain the degree of correlation by using the directed graph and matrix operations. Then, the interpretative structural modeling(ISM) method was combined to intuitively show the logical relationship of many failure subsystems and their influences on each other by using multilevel hierarchical structure model and obtaining the critical subsystems. Finally, failure mode effects and criticality analysis(FMECA) was used to perform a qualitative hazard analysis of critical subsystems, determine the critical failure mode, and clarify the direction of reliability improvement.Through an example, the result demonstrates that the proposed method can be efficiently applied to system failure analysis problems.展开更多
Deep shale gas resources in the Sichuan Basin have great potential,and this is a major area for future shale gas exploration and development.Deep shale gas wells face problems with liquid loading throughout the produc...Deep shale gas resources in the Sichuan Basin have great potential,and this is a major area for future shale gas exploration and development.Deep shale gas wells face problems with liquid loading throughout the production cycle.Regarding deliquification techniques,it is necessary to consider the requirements of gas wells over the full life cycle,as well as the main form of artificial lift used at different stages,to achieve economically efficient development.This paper divides the life cycle of a deep shale gas well into two stages:early production and middle/late production.Pressure-control production is conducted in the early stage of production,whereas investigations on critical liquid-carrying models,the flow distribution in the wellbore,and the main form of artificial lift are conducted in the middle and late stages of production.A recommended scheme of deliquification techniques over the full life cycle has been developed to guide the development and enhancement of artificial lift methods in deep shale gas reservoirs.As of March 2022,in the PetroChina Southwest Oil&Gasfield Company managed-pressure production has been implemented in 14 wells in the early stage of deep shale gas production.In eight wells,plunger gas lift has been implemented in the middle and late stages of production.In seven wells,foam lift has been implemented.The abovementioned techniques are effective in increasing and stabilizing production and achieving deliquification in deep shale gas reservoirs.展开更多
基金Supported by the Natural Science Foundation of Fujian Province(2012D135)
文摘Virtual organization uses information technology to achieve a closer integration and better management of business relationships between internal and external parties. There are many emerging issues in virtual organization and one of them is knowl- edge sharing. Knowledge sharing that is the core of knowledge management plays a key role in virtual organization. However, game theoretic exploration about knowledge sharing mechanism based on virtual organization is seldom published, In this study, knowledge sharing mechanism in virtual organization enterprise is explored using game theories from two aspects based on the features of knowledge sharing in virtual organization enterprise. Fi- nally, the critical model of knowledge sharing mechanism in virtual organization also is presented based on the perspective of game analysis.
基金Supported by the National Natural Science Foundation of China under Grant No 11275061the National Magnetic Confinement Fusion Science Program under Grant No 2014GB108002
文摘A self-organized criticality model of a thermal sandpile is formulated for the first time to simulate the dynamic process with interaction between avalanche events on the fast time scale and diffusive transports on the slow time scale. The main characteristics of the model are that both particle and energy avalanches of sand grains are considered simultaneously. Properties of intermittent transport and improved confinement are analyzed in detail. The results imply that the intermittent phenomenon such as blobs in the low confinement mode as well as edge localized modes in the high confinement mode observed in tokamak experiments are not only determined by the edge plasma physics, but also affected by the core plasma dynamics.
基金Supported by National Natural Science Foundation of China under Grant Nos.11675096 and 11305098the Fundamental Research Funds for the Central Universities under Grant No.GK201702001+1 种基金FPALAB-SNNU under Grant No.16QNGG007Interdisciplinary Incubation Project of SNU under Grant No.5
文摘We have made an extensive numerical study of a modified model proposed by Olami,Feder,and Christensen to describe earthquake behavior.Two situations were considered in this paper.One situation is that the energy of the unstable site is redistributed to its nearest neighbors randomly not averagely and keeps itself to zero.The other situation is that the energy of the unstable site is redistributed to its nearest neighbors randomly and keeps some energy for itself instead of reset to zero.Different boundary conditions were considered as well.By analyzing the distribution of earthquake sizes,we found that self-organized criticality can be excited only in the conservative case or the approximate conservative case in the above situations.Some evidence indicated that the critical exponent of both above situations and the original OFC model tend to the same result in the conservative case.The only difference is that the avalanche size in the original model is bigger.This result may be closer to the real world,after all,every crust plate size is different.
基金supported by the National Magnetic Confinement Fusion Science Program of China(No.2010GB104005)National Natural Science Foundation of China(No.51406085)
文摘An accurate critical heat flux（CHF） prediction method is the key factor for realizing the steady-state operation of a water-cooled divertor that works under one-sided high heating flux conditions.An improved CHF prediction method based on Euler＇s homogeneous model for flow boiling combined with realizable k-ε model for single-phase flow is adopted in this paper in which time relaxation coefficients are corrected by the Hertz-Knudsen formula in order to improve the calculation accuracy of vapor-liquid conversion efficiency under high heating flux conditions.Moreover,local large differences of liquid physical properties due to the extreme nonuniform heating flux on cooling wall along the circumference direction are revised by formula IAPWSIF97.Therefore,this method can improve the calculation accuracy of heat and mass transfer between liquid phase and vapor phase in a CHF prediction simulation of water-cooled divertors under the one-sided high heating condition.An experimental example is simulated based on the improved and the uncorrected methods.The simulation results,such as temperature,void fraction and heat transfer coefficient,are analyzed to achieve the CHF prediction.The results show that the maximum error of CHF based on the improved method is 23.7%,while that of CHF based on uncorrected method is up to 188%,as compared with the experiment results of Ref.[12].Finally,this method is verified by comparison with the experimental data obtained by International Thermonuclear Experimental Reactor（ITER）,with a maximum error of 6% only.This method provides an efficient tool for the CHF prediction of water-cooled divertors.
文摘To promote the global dissemination of Chinese culture,the translation of Chinese classic literature has garnered widespread attention in the translation field.Literary translation criticism plays an essential role in the development of translation endeavors.This paper will analyze three versions of English translations of Shen Congwen’s novella Border Town using Reiss’s translation criticism model and summarize their performance in terms of formal equivalence and aesthetic effect,linguistic components,and extra-linguistic components.
基金sponsored by Important National Science and Technology Specifi c Projects of China (No.2011ZX05001)
文摘A critical porosity model is often used to calculate the dry frame elastic modulus by the rock critical porosity value which is affected by many factors. In practice it is hard for us to obtain an accurate critical porosity value and we can generally take only an empirical critical porosity value which often causes errors. In this paper, we propose a method to obtain the rock critical porosity value by inverting P-wave velocity and applying it to predict S-wave velocity. The applications of experiment and log data both show that the critical porosity inversion method can reduce the uncertainty resulting from using an empirical value in the past and provide the accurate critical porosity value for predicting S-wave velocity which significantly improves the prediction accuracy.
文摘In current critical area models, it is generally assumed the defect outlines are circular and the conductors to be rectangle or the merger of rectangles. However, real defects and conductors associated with optimal layout design exhibit a great variety of shapes. Based on mathematical morphology, a new critical area model is presented, which can be used to estimate the critical area of short circuit, open circuit and pinhole. Based on the new model, the efficient validity check algorithms are explored to extract critical areas of short circuit, open circuit and pinhole from layouts. The results of experiment on an approximate layout of 4 × 4 shifts register show that the new model predicts the critical areas accurately. These results suggest that the proposed model and algorithm could provide new approaches for yield prediction.
基金The project was supported by the National Natural Science Foundation of China （90505015 and 10702035）.
文摘Breaking down the entire structure of a material implies severing all the bonds between its atoms either by applying work or by heat transfer. Because bond-breaking is indifferent to either means, there is a kind of equivalence between heat energy and strain energy. Based on this equivalence, we assume the existence of a constant maximum storage of energy that includes both the strain energy and the corresponding equivalent heat energy. A temperaturedependent fracture strength model is then developed for ultrahigh temperature ceramics （UHTCs）. Model predictions for UHTCs, HfB2, TiC and ZrB2, are presented and compared with the experimental results. These predictions are found to be largely consistent with experimental results.
基金supported by the Major State Basic Research Development Program of China (No.2011CB012900)the National Natural Science Foundation of China (No.51374144)the Shanghai Rising-Star Program (No.14QA1402300)
文摘Isothermal hot compression tests of as-cast high-Cr ultra-super-critical（USC） rotor steel with columnar grains perpendicular to the compression direction were carried out in the temperature range from 950 to 1250°C at strain rates ranging from 0.001 to 1 s^（-1）. The softening mechanism was dynamic recovery（DRV） at 950°C and the strain rate of 1 s^（-1）, whereas it was dynamic recrystallization（DRX） under the other conditions. A modified constitutive equation based on the Arrhenius model with strain compensation reasonably predicted the flow stress under various deformation conditions, and the activation energy was calculated to be 643.92 kJ ×mol^（-1）. The critical stresses of dynamic recrystallization under different conditions were determined from the work-hardening rate（θ）–flow stress（σ） and-θ/σ–σ curves. The optimum processing parameters via analysis of the processing map and the softening mechanism were determined to be a deformation temperature range from 1100 to 1200°C and a strain-rate range from 0.001 to 0.08 s^（-1）, with a power dissipation efficiency η greater than 31%.
文摘By means of CUSP model of catastrophe theory. this paper has studied thephysics process of rockburst occured on circular chamber. The present paper has nolonly described the instability process of rockburst more deeply. but also got the crilicaldepth of plastic softening area of chamber that is valuable in the controlling engineering of rockburst. the chamber displacement jump and energy liberation have been derived. the influence of rock parameters on the rockburst has been discussed .
文摘In this paper, the equilibrium properties of spin-1 Blume–Emery–Griffiths model are studied by using constant-coupling approximation. The dipolar and quadrupolar order parameters, the stable, metastable and unstable states and free energy of the model are investigated. The states are defined in terms of local minima of the free energy of system. The numerical calculations are presented for several values of exchange interactions on the simple cubic lattice with q = 6.
基金financially supported by the Hundred Talents Program of Chinese Academy of Sciencesthe National Natural Science Foundation of China (No. U1460202)the Key Laboratory of Superlight Material and Surface Technology (Harbin Engineering University), Ministry of Education
文摘Response surface methodology（RSM） is introduced into corrosion research as a tool to assess the effects of environmental factors and their interactions on corrosion behavior and establish a model for corrosion prediction in complex coupled environment（CCE）. In this study, a typical CCE, that is, the corrosion environment of pipelines in gas field is taken as an example. The effects of environmental factors such as chloride concentration, pH value and pressure as well as their interactions on critical pitting temperature（CPT） were evaluated, and a quadratic polynomial model was developed for corrosion prediction by RSM. The results showed that the model was excellent in corrosion prediction with R2= 0.9949. CPT was mostly affected by single environmental factor rather than interaction, and among the whole factors, chloride concentration was the most influential factor of CPT.
文摘In the existing models of estimating the yield and critical area, the defect outline is usually assumed to be circular, but the observed real defect outlines are irregular in shape. In this paper, estimation of the yield and critical area is made using the Monte Carlo technique and the relationship between the errors of yield estimated by circular defect and the rectangle degree of the defect is analysed. The rectangular model of a real defect is presented, and the yield model is provided correspondingly. The models take into account an outline similar to that of an original defect, the characteristics of two-dimensional distribution of defects, the feature of a layout routing, and the character of yield estimation. In order to make the models practicable, the critical area computations related to rectangular defect and regular （vertical or horizontal） routing are discussed. The critical areas associated with rectangular defect and non- regular routing are developed also, based on the mathematical morphology. The experimental results show that the new yield model may predict the yield caused by real defects more accurately than the circular model. It is significant that the yield is accurately estimated using the proposed model for IC metals.
基金the National Natural Science Foundation of China(Nos.42074136,41674130)National Key S&T Special Project of China(No.2016ZX05027-004-001)the Fundamental Research Funds for the Central University(No.18CX02061A).
文摘Carbonate,tight sandstone,and shale reservoirs have many pore types,and the relationship between the porosity and elastic parameters is extremely discrete due to the complex pore shape.This paper presents a method for predicting reservoir pore types based on pore shape substitution.The pore shape substitution allows for accurately characterizing the changes in the elastic properties of the rock with the changes in pore shape,assuming there are no changes in terms of minerals,porosity,or fl uids.By employing a multiple-porosity variable critical porosity model,the eff ective pore aspect ratio could be inverted from the velocities of the rock.To perform pore shape substitution,we could replace the eff ective pore aspect ratio with another pore aspect ratio or increase/decrease the volume content of diff erent pore shapes.The reservoir pore types could be evaluated by comparing the differences in the reservoir velocities before and after the substitution of the pore shape.The test results pertaining to the theoretical model and the well logging data indicated that the pore shape substitution method could be applied to characterize pore types in terms of separating the eff ects of the pore shapes from the eff ects of the minerals,porosity,or fl uids on the velocities.
基金supported by a Weatherstone Predoctoral Fellowship from Autism Speakssupported by NIH Grants 5R01MH098114-03,1R21-HD077197-01,and 1R21-MH104316-01
文摘Transgenic mice carrying mutations that cause Autism Spectrum Disorders（ASDs） continue to be valuable for determining the molecular underpinnings of the disorders. Recently, researchers have taken advantage of such models combined with Cre-lox P and similar systems to manipulate gene expression over space and time. Thus, a clearer picture is starting to emerge of the cell types, circuits, brain regions, and developmental time periods underlying ASDs. ASD-causing mutations have been restricted to or rescued speci？cally in excitatory or inhibitory neurons, different neurotransmitter systems, and cells speci？c to the forebrain or cerebellum. In addition,mutations have been induced or corrected in adult mice,providing some evidence for the plasticity and reversibility of core ASD symptoms. The limited availability of Cre lines that are highly speci？c to certain cell types or time periods provides a challenge to determining the cellular and circuitry bases of autism, but other technological advances may eventually overcome this obstacle.
基金supported by the Program of Hainan Association for Science and Technology Plans to Youth R&D Innovation(QCXM201910)the National Natural Science Foundation of China(Nos.61702315,61802092)+1 种基金the Applied Basic Research Plan of Shanxi Province(No.2201901D211168)the Key R&D Program(International Science and Technology Cooperation Project)of Shanxi Province China(No.201903D421003).
文摘A reduction in network energy consumption and the establishment of green networks have become key scientific problems in academic and industrial research.Existing energy efficiency schemes are based on a known traffic matrix,and acquiring a real-time traffic matrix in current complex networks is difficult.Therefore,this research investigates how to reduce network energy consumption without a real-time traffic matrix.In particular,this paper proposes an intra-domain energy-efficient routing scheme based on multipath routing.It analyzes the relationship between routing availability and energy-efficient routing and integrates the two mechanisms to satisfy the requirements of availability and energy efficiency.The main research focus is as follows:(1)A link criticality model is evaluated to quantitatively measure the importance of links in a network.(2)On the basis of the link criticality model,this paper analyzes an energy-efficient routing technology based on multipath routing to achieve the goals of availability and energy efficiency simultaneously.(3)An energy-efficient routing algorithm based on multipath routing in large-scale networks is proposed.(4)The proposed method does not require a real-time traffic matrix in the network and is thus easy to apply in practice.(5)The proposed algorithm is verified in several network topologies.Experimental results show that the algorithm can not only reduce network energy consumption but can also ensure routing availability.
文摘The vertical stability of a magnetic tip over a superconducting material is investigated by using the critical state and the frozen image models. The analytical expressions of the stiffness and the vibration frequency about the equilibrium position are derived in term of the geometrical parameters of the magnet/superconductor system. It is found that the stability of the system depends on the shape of the superconductor as well as its thickness.
文摘In present paper, study of magnetization behaviour was carried out for textured bulk YBaCuO polycrystalline superconductors synthesized by MTG process. The magnetization behaviour apparently different from that of sintered samples was observed. Magnetization hysteresis measurements were performed for the textured YBaCuO superconductors at 77K in± 10kOe magnetic field range. Based on the results of magnetization hysteresis, the magnetic field dependence of critical current density (Jc) at 77K was evaluated for the textured YBaCuO samples. The magnetic flux penetration in textured bulk YBaCuO polycrystalline superconductors was investigated at 77K through the magnetization hysteresis measurements under various maximum applied magnetic fields (HM) and reasonable discussion for the phenomena was conducted in terms of Bean's critical state model. The enhancement of magnetic properties for textured hulk YBaCuO polycrystalline superconductors is presumably attributed to the improvement of microstructure in these samples.
基金Project(51275205)supported by the National Natural Science Foundation of China
文摘A new method of system failure analysis was proposed. First, considering the relationships between the failure subsystems,the decision making trial and evaluation laboratory(DEMATEL) method was used to calculate the degree of correlation between the failure subsystems, analyze the combined effect of related failures, and obtain the degree of correlation by using the directed graph and matrix operations. Then, the interpretative structural modeling(ISM) method was combined to intuitively show the logical relationship of many failure subsystems and their influences on each other by using multilevel hierarchical structure model and obtaining the critical subsystems. Finally, failure mode effects and criticality analysis(FMECA) was used to perform a qualitative hazard analysis of critical subsystems, determine the critical failure mode, and clarify the direction of reliability improvement.Through an example, the result demonstrates that the proposed method can be efficiently applied to system failure analysis problems.
文摘Deep shale gas resources in the Sichuan Basin have great potential,and this is a major area for future shale gas exploration and development.Deep shale gas wells face problems with liquid loading throughout the production cycle.Regarding deliquification techniques,it is necessary to consider the requirements of gas wells over the full life cycle,as well as the main form of artificial lift used at different stages,to achieve economically efficient development.This paper divides the life cycle of a deep shale gas well into two stages:early production and middle/late production.Pressure-control production is conducted in the early stage of production,whereas investigations on critical liquid-carrying models,the flow distribution in the wellbore,and the main form of artificial lift are conducted in the middle and late stages of production.A recommended scheme of deliquification techniques over the full life cycle has been developed to guide the development and enhancement of artificial lift methods in deep shale gas reservoirs.As of March 2022,in the PetroChina Southwest Oil&Gasfield Company managed-pressure production has been implemented in 14 wells in the early stage of deep shale gas production.In eight wells,plunger gas lift has been implemented in the middle and late stages of production.In seven wells,foam lift has been implemented.The abovementioned techniques are effective in increasing and stabilizing production and achieving deliquification in deep shale gas reservoirs.
