Numerical simulation on the flow fields near the dimpled and the smooth revolution bodies are performed and compared by using SST k-ω turbulence model, to explain the reasons of friction and base drag reductions on t...Numerical simulation on the flow fields near the dimpled and the smooth revolution bodies are performed and compared by using SST k-ω turbulence model, to explain the reasons of friction and base drag reductions on the bionic dimpled surface and the control behaviors of dimpled surface to boundary layer near wall of the revolution body. The simulation results show that the dimpled surface reduces the skin friction drag through reducing the velocity gradient and turbulent intensity, and reduces the base drag through weakening the pumping action on the flow behind the revolution body caused by the external flow; the low speed rotating vortexes in the dimples segregate the external flow and the revolution body; and the low speed rotating vortexes forming in the bottom of dimples can produce negative skin friction.展开更多
Based on the discovery of the SSW stress field of the Earth and Mars, the authors proposed that each of the celestial bodies in the Solar System possesses a consistent stress field along the revolution axis relative t...Based on the discovery of the SSW stress field of the Earth and Mars, the authors proposed that each of the celestial bodies in the Solar System possesses a consistent stress field along the revolution axis relative to their own obliquity of the ecliptic ( ε ).This paper describes a deep going study on the control role of the stress field on the formation of the Tibet plateau.1\ Discovery of the stress filed along the revolution axis of the Earth and Mars (1)Discovery of the four tridimensional tectonic systems in the global SSW stress field [1] :In West China, under the action of this stress field, the alternative WNW\|trending belts of fault uplifts and fault depressions intersect the alternative belts of ENE\|trending sinistral and NNW\|trending dextral conjugate shear\|compressive uplifts and depressions,and then combine with the NNE\|trending tensile fault belt, to form the “uplift on uplift" ,the “third\|order overlapped uplift" ,the“depression in depression” ,the “third\|order sunk depression", and also the composite fault uplifts and fault depressions composed of four or more fault groups. They are produced simultaneously and form the rivers, lakes, basins, mountains and plateaus and show the mirror symmetry in section. This tectonic framework can be observed not only in the Qinghai—Tibet plateau but also in all over China and even on the entire Earth. Therefore, the SSW principal compressive stress is the unified global stress field and its model has already been constructed [1] .展开更多
Revolutions,typical cases of crucial social transformations,cannot be realized successfully without a large number of activists.Therefore,creating conditions favorable for acquiring enough participants should be an im...Revolutions,typical cases of crucial social transformations,cannot be realized successfully without a large number of activists.Therefore,creating conditions favorable for acquiring enough participants should be an important topic of Marxist social science.In particular,this problem includes the “free-ride,” because the benefits of revolutionaries’ activities are gained not only by the activists but also by all other members.The paper analyzes problems such as this one,applying non-cooperative game theory to social dilemma problems.This leads to some interesting results.In this research,the problem of the workers’ choice between unity or freeride is first defined using numerical examples of the gain structure.It is defined again in a more generalized form using other parameters.In so doing,we express both the cost of participating in the movement and the gains from the concession of the ruling class.Because this analysis focuses on the importance of the number of participants,the concession of the ruling class is framed as a function of the number of participants.The results of this analysis revealed that the economic base and superstructure accurately correspond in some game structures but not in others.In other words,the social dilemma presents either as a case of prisoners’ dilemma or as a chicken game.Furthermore,this paper analyzes the influence of group size,and it was revealed that groups with a large number of members,such as a ruled class,find it particularly difficult to unite.This phenomenon is called the “large group dilemma.” In these ways,this research shows that the aforementioned type of game theory can be used to analyze the difficulties and possibilities of social movements.展开更多
The process of modernization accelerates the decline of the rural areas in China pausing malignant changes of the rural culture,such as lack of education and religious chaos and so on.Such cultural crisis in rural are...The process of modernization accelerates the decline of the rural areas in China pausing malignant changes of the rural culture,such as lack of education and religious chaos and so on.Such cultural crisis in rural areas results in incredibility of the public power.As a social class farmers are marginalized.On the contrary,the decline of the rural culture provides the possibility of the rooting of the revolutionary ideas.Led and influenced by the Communist Party of China farmers become the principal part of modernization and revolution and the major driving force and hard core of the new- democratic revolution,having great effect upon the direction of China's modern history.展开更多
The Market Revolution took place in America during the first half of the 19th century,and the new trend of development promoted the transition from a traditional rural society to a market society.The influences brough...The Market Revolution took place in America during the first half of the 19th century,and the new trend of development promoted the transition from a traditional rural society to a market society.The influences brought by the Market Revolution are as follows:the status of the rural women has been improved;the ideas of market and the sense of competition have been strengthened;American economy developed rapidly,and both the domestic and international markets have been broadened.The experiences of the transition from rural society to market society include:government supported the development of commercial agriculture;all sectors of society paid attention to agriculture;the quality of agriculture products was guaranteed;however,the development of agriculture damaged the environment.展开更多
In the travel process of urban residents,travelers will take a series of activities such as imitation and exclusion by observing other people’s travel modes,which affects their following trips.This process can be see...In the travel process of urban residents,travelers will take a series of activities such as imitation and exclusion by observing other people’s travel modes,which affects their following trips.This process can be seen as a repeated game between members of the travelers.Based on the analysis of this game and its evolution trend,a multi-dimensional game model of low-carbon travel for residents is established.The two dimensional game strategies include whether to accept the low-carbon concept and whether to choose low-carbon travel.Combined with evolutionary game theory,the low-carbon travel choices of residents in different cities are simulated,and the evolutionary stability strategies are obtained.Finally,the influences of the main parameters of the model on the evolution process and stability strategies are discussed.The results show that travelers would develop towards two trends.Cities with more developed public traffic system have a higher proportion of receiving low-carbon concept and choosing low-carbon travel.Cities with underdeveloped public transport system could increase this proportion by some measures such as encouraging residents to choose slow transport and increasing the propaganda of low-carbon travel,but the positive effects of the measures like propaganda have a limited impact on the proportion.展开更多
In order to investigate the regularity of metal magnetic signals of ferromagnetic materials under the effect of applied load, the static tensile test of Q235 steel and 18CrNiWA steel plate specimens were conducted and...In order to investigate the regularity of metal magnetic signals of ferromagnetic materials under the effect of applied load, the static tensile test of Q235 steel and 18CrNiWA steel plate specimens were conducted and metal magnetic memory signals of specimens were measured during the test process. The influencing factors of metal magnetic memory signals and the relationship between axial applied load and signals were analyzed. The fracture and microstructure of the specimens were observed. The results show that the magnetic signals corresponding to the measured points change linearly approximately with increasing axial load. The microstructure of Q235 steel is ferrite and perlite, whereas that of 18CrNiWA steel is bainite and low-carbon martensite. The fracture of these two kinds of specimens is ductile rupture; carbon content of specimen materials and dislocation glide give much contribution to the characteristics of magnetic curves.展开更多
In this study,a modeling method for investigating the dynamic characteristics of a hydraulically driven shell manipulator with revolute clearance joints is presented.This model accounts for the effect of the clearance...In this study,a modeling method for investigating the dynamic characteristics of a hydraulically driven shell manipulator with revolute clearance joints is presented.This model accounts for the effect of the clearance,the flexibility of the rotating beam,and the coupled dynamic characteristics of the hydraulic cylinder.A modified contact force model was developed to simulate the physical properties of realistic revolute joints with small clearances,heavy loads,and variable contact stiffnesses and damping coefficients with variations of the indentations.Considering the strong coupling relationship between the hydraulic cylinder and the flexible beam,a system equation of motion combining the state variables of the hydraulic cylinder and mechanical system was established.The complex nonlinear friction force of the hydraulic cylinder motion was constructed using a modified Lu Gre model,and the parameters of the friction model were identified using intelligent identification algorithms.Moreover,a test system for the shell manipulator was established to achieve experimental validation.Finally,the effects of the clearance size and the stiffness of the cylinder support on the dynamic response were investigated.展开更多
Full scale experimental study on nitrogen removal for low-carbon wastewater was conducted in reversed A2/O process in Jiguanshi waste water treatment plant in Chongqing,in order to aid the operation and maintenance of...Full scale experimental study on nitrogen removal for low-carbon wastewater was conducted in reversed A2/O process in Jiguanshi waste water treatment plant in Chongqing,in order to aid the operation and maintenance of similar WWTP. When the proposed measures,such as using 0.1% (volume fraction of wastewater) landfill leachate,shortening HRT by 2/3 in the primary sedimentation tank and controlling DO at 0.5 mg/L in the 3rd section of aerobic zone,are applied,15% of the carbon source can be complemented,the favorable property of activated sludge is achieved,and the nitrogen removal effect is significantly improved. The effluent NH3-N is 2 mg/L and the removal rate is 90%. The effluent TN is 17 mg/L and the removal rate is 54%. The up-to-standard discharge of the effluent is achieved. And after the optimization,the unit electricity consumption also reaches 0.21 kW/h and saves 20%.展开更多
Based on the trace of origin and development process of low-carbon economy, the paper defined the concept of low- carbon agriculture. As a case, the development of low-carbon advantage and disadvantage of agriculture ...Based on the trace of origin and development process of low-carbon economy, the paper defined the concept of low- carbon agriculture. As a case, the development of low-carbon advantage and disadvantage of agriculture in Heilongjiang Province made a systematic analysis of factors; it based on the empirical and comparative analysis of low-carbon development in Heilongjiang Province and put forward countermeasures and suggestions of agriculture. At last, the low-carbon agriculture was prospected in the future.展开更多
Grey cast iron’s welding itself is a complex proble m.So proper welding materials must be selected,complex welding techniques such as preheating before weldingslow cooling after welding etc,should be taken. However t...Grey cast iron’s welding itself is a complex proble m.So proper welding materials must be selected,complex welding techniques such as preheating before weldingslow cooling after welding etc,should be taken. However the carbon component in low-carbon steel is comparatively low,the carbo n of welded joint will diffuse to the low-carbon steel when it is welded with gr ey cast iron,which will cause the component of carbon greatly increased at the low-carbon steel side in HAZ,high carbon martensite and cracks will occur.If p reheating before weldingslow cooling after welding and other welding procedure are taken,the grey cast iron side can probably be qualified.But the carbon wi ll diffuse to HAZ of the low-carbon steel side more easily.Therefore after stud ying the weldabilities of grey cast iron and low-carbon steel,the author develo ped a new type of cast iron electrode considering the demands of factories’prac tices,and the welding technology test of grey cast iron and low-carbon steel ar e carried out. In this paper,a new type of grey cast iron electrode is developed based on the practices in factories,its ingredients and properties are introduced.The w elding tests of grey cast iron and low-carbon steel are practiced.The joint str ucture of the dissimilar metal and the appearance of weld are observed.The hard ness distribution of the welded joint is tested.The results show that the elect rode can meet the welding requirements of the grey cast iron and low-carbon stee l.There are no cracksgas pores and other defects of metallurgy in welded join t,the appearance of welded joint are good.展开更多
基金Sponsored by the National Natural Science Foundation of China (50635030)the Technology Development Plan of Jilin Province ( 20096032)+1 种基金the Major Program of Science and Technology Development of Jilin Province (09ZDGG001)the Youth Research Start-up Fund of Agriculture Department of Jilin University ( 4305050102K7)
文摘Numerical simulation on the flow fields near the dimpled and the smooth revolution bodies are performed and compared by using SST k-ω turbulence model, to explain the reasons of friction and base drag reductions on the bionic dimpled surface and the control behaviors of dimpled surface to boundary layer near wall of the revolution body. The simulation results show that the dimpled surface reduces the skin friction drag through reducing the velocity gradient and turbulent intensity, and reduces the base drag through weakening the pumping action on the flow behind the revolution body caused by the external flow; the low speed rotating vortexes in the dimples segregate the external flow and the revolution body; and the low speed rotating vortexes forming in the bottom of dimples can produce negative skin friction.
文摘Based on the discovery of the SSW stress field of the Earth and Mars, the authors proposed that each of the celestial bodies in the Solar System possesses a consistent stress field along the revolution axis relative to their own obliquity of the ecliptic ( ε ).This paper describes a deep going study on the control role of the stress field on the formation of the Tibet plateau.1\ Discovery of the stress filed along the revolution axis of the Earth and Mars (1)Discovery of the four tridimensional tectonic systems in the global SSW stress field [1] :In West China, under the action of this stress field, the alternative WNW\|trending belts of fault uplifts and fault depressions intersect the alternative belts of ENE\|trending sinistral and NNW\|trending dextral conjugate shear\|compressive uplifts and depressions,and then combine with the NNE\|trending tensile fault belt, to form the “uplift on uplift" ,the “third\|order overlapped uplift" ,the“depression in depression” ,the “third\|order sunk depression", and also the composite fault uplifts and fault depressions composed of four or more fault groups. They are produced simultaneously and form the rivers, lakes, basins, mountains and plateaus and show the mirror symmetry in section. This tectonic framework can be observed not only in the Qinghai—Tibet plateau but also in all over China and even on the entire Earth. Therefore, the SSW principal compressive stress is the unified global stress field and its model has already been constructed [1] .
文摘Revolutions,typical cases of crucial social transformations,cannot be realized successfully without a large number of activists.Therefore,creating conditions favorable for acquiring enough participants should be an important topic of Marxist social science.In particular,this problem includes the “free-ride,” because the benefits of revolutionaries’ activities are gained not only by the activists but also by all other members.The paper analyzes problems such as this one,applying non-cooperative game theory to social dilemma problems.This leads to some interesting results.In this research,the problem of the workers’ choice between unity or freeride is first defined using numerical examples of the gain structure.It is defined again in a more generalized form using other parameters.In so doing,we express both the cost of participating in the movement and the gains from the concession of the ruling class.Because this analysis focuses on the importance of the number of participants,the concession of the ruling class is framed as a function of the number of participants.The results of this analysis revealed that the economic base and superstructure accurately correspond in some game structures but not in others.In other words,the social dilemma presents either as a case of prisoners’ dilemma or as a chicken game.Furthermore,this paper analyzes the influence of group size,and it was revealed that groups with a large number of members,such as a ruled class,find it particularly difficult to unite.This phenomenon is called the “large group dilemma.” In these ways,this research shows that the aforementioned type of game theory can be used to analyze the difficulties and possibilities of social movements.
文摘The process of modernization accelerates the decline of the rural areas in China pausing malignant changes of the rural culture,such as lack of education and religious chaos and so on.Such cultural crisis in rural areas results in incredibility of the public power.As a social class farmers are marginalized.On the contrary,the decline of the rural culture provides the possibility of the rooting of the revolutionary ideas.Led and influenced by the Communist Party of China farmers become the principal part of modernization and revolution and the major driving force and hard core of the new- democratic revolution,having great effect upon the direction of China's modern history.
基金This paper is a phase achievement of the PhD startup scientific research project of Guizhou Normal University
文摘The Market Revolution took place in America during the first half of the 19th century,and the new trend of development promoted the transition from a traditional rural society to a market society.The influences brought by the Market Revolution are as follows:the status of the rural women has been improved;the ideas of market and the sense of competition have been strengthened;American economy developed rapidly,and both the domestic and international markets have been broadened.The experiences of the transition from rural society to market society include:government supported the development of commercial agriculture;all sectors of society paid attention to agriculture;the quality of agriculture products was guaranteed;however,the development of agriculture damaged the environment.
基金Project(BK20160512)supported by the Natural Science Foundation of Jiangsu Province,ChinaProject(16YJCZH027)supported by the Humanity and Social Science Youth Foundation of Ministry of Education of ChinaProject(15GLC004)supported by the Social Science Foundation of Jiangsu Province,China
文摘In the travel process of urban residents,travelers will take a series of activities such as imitation and exclusion by observing other people’s travel modes,which affects their following trips.This process can be seen as a repeated game between members of the travelers.Based on the analysis of this game and its evolution trend,a multi-dimensional game model of low-carbon travel for residents is established.The two dimensional game strategies include whether to accept the low-carbon concept and whether to choose low-carbon travel.Combined with evolutionary game theory,the low-carbon travel choices of residents in different cities are simulated,and the evolutionary stability strategies are obtained.Finally,the influences of the main parameters of the model on the evolution process and stability strategies are discussed.The results show that travelers would develop towards two trends.Cities with more developed public traffic system have a higher proportion of receiving low-carbon concept and choosing low-carbon travel.Cities with underdeveloped public transport system could increase this proportion by some measures such as encouraging residents to choose slow transport and increasing the propaganda of low-carbon travel,but the positive effects of the measures like propaganda have a limited impact on the proportion.
基金Projects(50235030, 50505052) supported by the National Natural Science Foundation of China
文摘In order to investigate the regularity of metal magnetic signals of ferromagnetic materials under the effect of applied load, the static tensile test of Q235 steel and 18CrNiWA steel plate specimens were conducted and metal magnetic memory signals of specimens were measured during the test process. The influencing factors of metal magnetic memory signals and the relationship between axial applied load and signals were analyzed. The fracture and microstructure of the specimens were observed. The results show that the magnetic signals corresponding to the measured points change linearly approximately with increasing axial load. The microstructure of Q235 steel is ferrite and perlite, whereas that of 18CrNiWA steel is bainite and low-carbon martensite. The fracture of these two kinds of specimens is ductile rupture; carbon content of specimen materials and dislocation glide give much contribution to the characteristics of magnetic curves.
基金supported by the National Natural Science Foundation of China [grant number 11472137]the Fundamental Research Funds for the Central Universities [grant numbers 309181A8801,30919011204]。
文摘In this study,a modeling method for investigating the dynamic characteristics of a hydraulically driven shell manipulator with revolute clearance joints is presented.This model accounts for the effect of the clearance,the flexibility of the rotating beam,and the coupled dynamic characteristics of the hydraulic cylinder.A modified contact force model was developed to simulate the physical properties of realistic revolute joints with small clearances,heavy loads,and variable contact stiffnesses and damping coefficients with variations of the indentations.Considering the strong coupling relationship between the hydraulic cylinder and the flexible beam,a system equation of motion combining the state variables of the hydraulic cylinder and mechanical system was established.The complex nonlinear friction force of the hydraulic cylinder motion was constructed using a modified Lu Gre model,and the parameters of the friction model were identified using intelligent identification algorithms.Moreover,a test system for the shell manipulator was established to achieve experimental validation.Finally,the effects of the clearance size and the stiffness of the cylinder support on the dynamic response were investigated.
基金Project (2009ZX07315-002-01) supported by Water Pollution Control and Management of Major Special Science and Technology
文摘Full scale experimental study on nitrogen removal for low-carbon wastewater was conducted in reversed A2/O process in Jiguanshi waste water treatment plant in Chongqing,in order to aid the operation and maintenance of similar WWTP. When the proposed measures,such as using 0.1% (volume fraction of wastewater) landfill leachate,shortening HRT by 2/3 in the primary sedimentation tank and controlling DO at 0.5 mg/L in the 3rd section of aerobic zone,are applied,15% of the carbon source can be complemented,the favorable property of activated sludge is achieved,and the nitrogen removal effect is significantly improved. The effluent NH3-N is 2 mg/L and the removal rate is 90%. The effluent TN is 17 mg/L and the removal rate is 54%. The up-to-standard discharge of the effluent is achieved. And after the optimization,the unit electricity consumption also reaches 0.21 kW/h and saves 20%.
基金Supported by National Natural Science Foundation (71173035)Scientific and Technological Projects in Heilongjiang Province (GC10D206)Humanities and Social Science Project in Heilongjiang Province Department of Education (12514049)
文摘Based on the trace of origin and development process of low-carbon economy, the paper defined the concept of low- carbon agriculture. As a case, the development of low-carbon advantage and disadvantage of agriculture in Heilongjiang Province made a systematic analysis of factors; it based on the empirical and comparative analysis of low-carbon development in Heilongjiang Province and put forward countermeasures and suggestions of agriculture. At last, the low-carbon agriculture was prospected in the future.
文摘Grey cast iron’s welding itself is a complex proble m.So proper welding materials must be selected,complex welding techniques such as preheating before weldingslow cooling after welding etc,should be taken. However the carbon component in low-carbon steel is comparatively low,the carbo n of welded joint will diffuse to the low-carbon steel when it is welded with gr ey cast iron,which will cause the component of carbon greatly increased at the low-carbon steel side in HAZ,high carbon martensite and cracks will occur.If p reheating before weldingslow cooling after welding and other welding procedure are taken,the grey cast iron side can probably be qualified.But the carbon wi ll diffuse to HAZ of the low-carbon steel side more easily.Therefore after stud ying the weldabilities of grey cast iron and low-carbon steel,the author develo ped a new type of cast iron electrode considering the demands of factories’prac tices,and the welding technology test of grey cast iron and low-carbon steel ar e carried out. In this paper,a new type of grey cast iron electrode is developed based on the practices in factories,its ingredients and properties are introduced.The w elding tests of grey cast iron and low-carbon steel are practiced.The joint str ucture of the dissimilar metal and the appearance of weld are observed.The hard ness distribution of the welded joint is tested.The results show that the elect rode can meet the welding requirements of the grey cast iron and low-carbon stee l.There are no cracksgas pores and other defects of metallurgy in welded join t,the appearance of welded joint are good.
