The small and scattered enterprise pattern in the county economy has formed numerous sporadic pollution sources, hindering the centralized treatment of the water environment, increasing the cost and difficulty of trea...The small and scattered enterprise pattern in the county economy has formed numerous sporadic pollution sources, hindering the centralized treatment of the water environment, increasing the cost and difficulty of treatment. How enterprises can make reasonable decisions on their water environment behavior based on the external environment and their own factors is of great significance for scientifically and effectively designing water environment regulation mechanisms. Based on optimal control theory, this study investigates the design of contractual mechanisms for water environmental regulation for small and medium-sized enterprises. The enterprise is regarded as an independent economic entity that can adopt optimal control strategies to maximize its own interests. Based on the participation of multiple subjects including the government, enterprises, and the public, an optimal control strategy model for enterprises under contractual water environmental regulation is constructed using optimal control theory, and a method for calculating the amount of unit pollutant penalties is derived. The water pollutant treatment cost data of a paper company is selected to conduct empirical numerical analysis on the model. The results show that the increase in the probability of government regulation and public participation, as well as the decrease in local government protection for enterprises, can achieve the same regulatory effect while reducing the number of administrative penalties per unit. Finally, the implementation process of contractual water environmental regulation for small and medium-sized enterprises is designed.展开更多
Crowdsensing,as a data collection method that uses the mobile sensing ability of many users to help the public collect and extract useful information,has received extensive attention in data collection.Since crowdsens...Crowdsensing,as a data collection method that uses the mobile sensing ability of many users to help the public collect and extract useful information,has received extensive attention in data collection.Since crowdsensing relies on user equipment to consume resources to obtain information,and the quality and distribution of user equipment are uneven,crowdsensing has problems such as low participation enthusiasm of participants and low quality of collected data,which affects the widespread use of crowdsensing.This paper proposes to apply the blockchain to crowdsensing and solve the above challenges by utilizing the characteristics of the blockchain,such as immutability and openness.An architecture for constructing a crowdsensing incentive mechanism under distributed incentives is proposed.A multi-attribute auction algorithm and a k-nearest neighbor-based sensing data quality determination algorithm are proposed to support the architecture.Participating users upload data,determine data quality according to the algorithm,update user reputation,and realize the selection of perceived data.The process of screening data and updating reputation value is realized by smart contracts,which ensures that the information cannot be tampered with,thereby encouraging more users to participate.Results of the simulation show that using two algorithms can well reflect data quality and screen out malicious data.With the help of blockchain performance,the architecture and algorithm can achieve decentralized storage and tamper-proof information,which helps to motivate more users to participate in perception tasks and improve data quality.展开更多
Nowadays manufacturers are facing fierce challenge.Apart from the products,providing customers with multiple maintenance options in the service contract becomes more popular,since it can help to improve customer satis...Nowadays manufacturers are facing fierce challenge.Apart from the products,providing customers with multiple maintenance options in the service contract becomes more popular,since it can help to improve customer satisfaction,and ultimately promote sales and maximize profit for the manufacturer.By considering the combinations of corrective maintenance and preventive maintenance,totally three types of maintenance service contracts are designed.Moreover,attractive incentive and penalty mechanisms are adopted in the contracts.On this basis,Nash non-cooperative game is applied to analyze the revenue for both the manufacturer and customers,and so as to optimize the pricing mechanism of maintenance service contract and achieve a win-win situation.Numerical experiments are conducted.The results show that by taking into account the incentive and penalty mechanisms,the revenue can be improved for both the customers and manufacturer.Moreover,with the increase of repair rate and improvement factor in the preventive maintenance,the revenue will increase gradually for both the parties.展开更多
Evidences indicate that,due to the limited caching capacity or inaccurate estimation on users’preferences,the requested files may not be fully cached in the network edge.The transmissions of the un-cached files will ...Evidences indicate that,due to the limited caching capacity or inaccurate estimation on users’preferences,the requested files may not be fully cached in the network edge.The transmissions of the un-cached files will also lead to duplicated transmissions on backhaul channels.Buffer-aided relay has been proposed to improve the transmission performance of the un-cached files.Because of the limited buffer capacity and the information asymmetric environment,how to allocate the limited buffer capacity and how to incentivize users in participating buffer-aided relay have become critical issues.In this work,an incentive scheme based on the contract theory is proposed.Specifically,the backlog violation probability,i.e.,the buffer overflow probability,is provided based on the martingale theory.Next,based on the backlog violation probability,the utility functions of the relay node and users are constructed.With the purpose to maximize the utility of the relay node,the optimal contract problem is formulated.Then,the feasibility of the contract is also demonstrated,and the optimal solution can be obtained by the interior point method.Finally,numerical results are presented to demonstrate effectiveness of the proposed contract theory scheme.展开更多
Kinetics and mechanism of oxidation induced contraction of MgAl2O4 spinel carbon composites reinforced by Al4C3 in situ reaction were researched in air using vertical high temperature thermal dilatometer from 25℃to 1...Kinetics and mechanism of oxidation induced contraction of MgAl2O4 spinel carbon composites reinforced by Al4C3 in situ reaction were researched in air using vertical high temperature thermal dilatometer from 25℃to 1400℃.It is shown that oxidation induced contraction of MgAl2O4 spinel carbon composites reinforced Al4C3 in situ reaction is the common logarithm of oxidation time t and the oxygen partial pressure P inside MgAl2O4 spinel carbon composites reinforced by Al4C3 in situ reaction in air at 1400℃is as follows:P=F(-2.75×10^-4A+2.13×10^-3)lnt.The nonsteady diffusion kinetic equation of O2 at 1400℃inside the composites is as follows:J=De lnt.Acceleration of the total diffusional?flux of oxygen inside the composites at 1400℃is in inverse proportion to the oxidation time.The nonsteady state effective diffusion coefficient De of O2(g)inside the composites decreases in direct proportional to the increase of the amount of metallic aluminium.The method of preventing the oxidation induced contraction of MgAl2O4 spinel carbon composites reinforced by Al4C3 in situ reaction is to increase the amount of Al.The slag erosion index of MgO-Al2O3 spinel carbon composite reinforced by Al4C3 in situ reaction is 0.47 times that of MgO-CaO brick used in the lining above slag line area of a VOD stainless steel-making vessel.HMOR of MgO-Al2O3 spinel carbon composite reinforced by Al4C3 in situ reaction is 26.7 MPa,HMOR of the composite is 3.6 times the same as that of MgO-CaO brick used in the lining above slag line area of a VOD vessel.Its service life is two times as many as that of MgO-CaO brick.展开更多
In today's management of the teaching staff of public security colleges and universities, the research on the Psychological Contract problem is not only beneficial to the management and estimation of the teachers, bu...In today's management of the teaching staff of public security colleges and universities, the research on the Psychological Contract problem is not only beneficial to the management and estimation of the teachers, but also has an important role in the coordination and stability of the whole system of public security colleges and universities. Based on the theory of Psychological Contract, this paper expounds the basic understanding and research value of Psychological Contract, and puts forward the measures to cultivate teachers' good character and understanding, and as well as coordinate teachers' needs, effectively change teachers' attitude and actively promote the establishment of good interpersonal relationship to explain the research on the Management Mechanism of Teachers in Public Security Colleges and Universities from the Perspective of Psychological Contract.展开更多
Considering participators' risk bias,which is measured by the method of value at risk,the risk constraints in a two-echelon supply chain coordination under buy-back contract is equal to giving the order of an uppe...Considering participators' risk bias,which is measured by the method of value at risk,the risk constraints in a two-echelon supply chain coordination under buy-back contract is equal to giving the order of an upper bound.With a risk-averse dominant enterprise(M)and a risk-neutral non-dominant one(R),the coordination which optimizes the supply chain under the risk constraints is achieved by a penalty mechanism L to reduce R's order.With risk-neutral M and risk-averse R,M can motivate R to increase his order by providing a risk subsidy K,and two cases are discussed.If the risk constraints of R cannot satisfy M's participation constraint to offer K,M will prefer to accept R's order to obtain a sub-optimization solution of the supply chain.Or else,with M's K,R's optimal order just coordinates the supply chain,which is equal to the case without risk bias,and in this situation R's risk bias only affects the profit distribution between the participators.展开更多
The forced lengthening of an activated skeletal muscle has been termed an eccentric contraction(EC).This review highlights the mechanically unique nature of the EC and focuses on the specific disruption of proteins wi...The forced lengthening of an activated skeletal muscle has been termed an eccentric contraction(EC).This review highlights the mechanically unique nature of the EC and focuses on the specific disruption of proteins within the cell known as cytoskeletal proteins.The major intermediate filament cytoskeletal protein,desmin,has been the focus of work in this area because changes to desmin occur within minutes of ECs and because desmin has been shown to play both a mechanical and biologic role in a muscle's response to EC.It is hoped that these types of studies will assist in decreasing the incidence of muscle injury in athletes and facilitating the development of new therapies to treat muscle injuries.展开更多
The practical engineering of satellite tracking telemetry and command(TT&C)is often disturbed by unpredictable external factors,including the temporary rise in a significant quantity of satellite TT&C tasks,te...The practical engineering of satellite tracking telemetry and command(TT&C)is often disturbed by unpredictable external factors,including the temporary rise in a significant quantity of satellite TT&C tasks,temporary failures and failures of some TT&C resources,and so on.To improve the adaptability and robustness of satellite TT&C systems when faced with uncertain dynamic disturbances,a hierarchical disturbance propagation mechanism and an improved contract network dynamic scheduling method for satellite TT&C resources were designed to address the dynamic scheduling problem of satellite TT&C resources.Firstly,the characteristics of the dynamic scheduling problem of satellite TT&C resources are analyzed,and a mathematical model is established with the weighted optimization objectives of maximizing the revenue from task completion and minimizing the degree of plan disturbance.Then,a bottom-up distributed dynamic collaborative scheduling framework for satellite TT&C resources is proposed,which includes a task layer,a resource layer,a central internal collaboration layer,and a central external collaboration layer.Dynamic disturbances are propagated layer by layer from the task layer to the central external collaboration layer in a bottom-up manner,using efficient heuristic strategies in the task layer and the resource layer,respectively.We use improved contract network algorithms in the center internal collaboration layer and the center external collaboration layer,the original scheduling plan is quickly adjusted to minimize the impact of disturbances while effectively completing dynamic task requirements.Finally,a large number of simulation experiments were carried out and compared with various comparative algorithms.The results show that the proposed algorithm can effectively improve the solution effect of satellite TT&C resource dynamic scheduling problems,and has good application prospects.展开更多
Introduction: The 12-lead electrocardiogram (ECG) is the most widely-used tool for the detection and diagnosis of cardiac conditions including myocardial infarction and ischemia. It has therefore been a focus of cardi...Introduction: The 12-lead electrocardiogram (ECG) is the most widely-used tool for the detection and diagnosis of cardiac conditions including myocardial infarction and ischemia. It has therefore been a focus of cardiac modeling. However, the most contemporary in silico ECG investigations of the intact heart have assumed a static heart and ignored the mechanical contraction that is an essential component of cardiac function. The aim of this study was to utilize electromechanically coupled human ventricle models to explore the consequences of ventricular mechanical contraction on the ECG profiles. Methods and Results: Biophysically detailed human ventricular cell models incorporating contractile activity and a stretchactivated current (Isac) were incorporated into a 3D human ventricular model within a human torso, from which 12-lead ECGs were computed at a stimulation rate of 1 Hz. Compared to the static model, ventricular contraction without Isac had little effect on the QRS complex, but shifted the T-wave peak leftwards and reduced its peak amplitude. With Isac, ventricular mechanical contraction increased the QRS duration by 23% and QT interval by 5%. Conclusion: Mechanical contraction of the heart has a significant effect on the morphology and characteristics of the ECG particularly on the T-wave. The alteration of the cell membrane kinetics by stretch via Isac further exacerbates these effects. Our simulation data suggest that mechanical contraction should be considered in the interpretation of ECGs in pathological conditions, especially those in which mechanical contraction of the heart is impaired.展开更多
To research the operating mechanisms of rural financial reform, through setting up a contract model, the constraint roles of reputation and legal intervention on the default risk arising in the operating of the credit...To research the operating mechanisms of rural financial reform, through setting up a contract model, the constraint roles of reputation and legal intervention on the default risk arising in the operating of the credit union funds are inspected. Analysis indicates that the increase in reputation cost can reduce the probability of union member default behavior and the probability of turning to the law for the credit union funds. Meanwhile, the amount of loans and the interest rates can increase the probability of turning to the law for the credit union funds. Below the marginal values, the penalty mechanisms can reduce the balancing probabilities of member default behavior and turning to the law for the credit union funds, namely, the penalty has some "substitution effect" for turning to the law for the credit union funds.展开更多
The rationality and scientific nature of the emission trading mechanism is the key to the effective implementation of environmental and economic policies.As far as China is concerned,there are phenomena such as inform...The rationality and scientific nature of the emission trading mechanism is the key to the effective implementation of environmental and economic policies.As far as China is concerned,there are phenomena such as information asymmetry,low supervision efficiency,and alienation of government and enterprise behaviors caused by the incomplete mechanism of emission trading in the practice of different pilots.The introduction of blockchain technology can innovate the traditional transaction model and form a decentralized peer-to-peer transaction and a trusted emission trading market.To this end,based on the current emission trading mechanism and the characteristics of blockchain technology,this paper couples the core technologies of blockchain with the functional requirements of application scenarios.Then,an innovative application framework is built based on the consortium blockchain Fabric from three aspects:emission trading supervision,secondary trading market construction,as well as emission trading incentive and punishment mechanisms.Technologies such as the consensus mechanism,smart contract,Merkle tree and asymmetric encryption are comprehensively applied in this process.In the construction of the blockchain framework of the secondary market for emission trading,institutional changes and innovations brought about by the blockchain at various levels are analyzed in terms of participants,transaction processes and the transaction scope.At the same time,smart contract functions and algorithms are designed for the purchase,transfer-out and trading of emission rights,and the operation business logic of the smart contract is analyzed.On the whole,this paper explores the application framework of blockchain technology in the field of emission trading at the macro level,and analyzes the application mechanism of the corresponding technologies of blockchain at each coupling point in the framework at the micro level.The collaborative analysis at the two levels shows that blockchain technology and the requirements of emission trading mechanism can be effectively coupled,and the application of blockchain technology can promote the effective supervision of enterprises'emission behavior,making the processes of the purchase,transfer and transaction of emission rights intelligent and automated,and providing technical support for cross regional emission trading to reduce transaction costs and management complexity.In addition,the issuance of emission credits based on smart contract will be a new incentive for companies to actively participate in transactions.Based on the above analysis,this paper believes that the innovative application of blockchain technology is of great significance in the promotion of the market-based allocation of element of emission trading and the rational allocation of environmental resources.It will lead to a major breakthrough in the traditional trading system in terms of trading modes,forming a value transmission network of environmental resources between the government and polluters.展开更多
To compare the formation mechanisms of He and Ar atmospheric pressure plasma jets(APPJs),an intensified charge-coupled device(ICCD)are utilized to observe the dynamic process of APPJ.The experimental results show that...To compare the formation mechanisms of He and Ar atmospheric pressure plasma jets(APPJs),an intensified charge-coupled device(ICCD)are utilized to observe the dynamic process of APPJ.The experimental results show that,He APPJ is first ignited,which is independent of the dielectric barrier discharge(DBD)between the two wrapped electrodes when the high voltage placed at the downstream.The intensity and APPJ length under positive discharge pulses are bigger than that under negative discharge pulses due to the space charge effect.The He APPJ is formed by the DBD development when the high-voltage electrode placed at the upstream side of tube.However,the plasma plume in Ar APPJ is formed by the propagation of DBD whatever the high-voltage electrode is arranged on upstream or downstream side of ground electrode.The difference in formation mechanism between He and Ar APPJs is mainly caused by the gas properties.Moreover,during the discharges,Ar tends to lead to thermal instability and electron Maxwellian instability.展开更多
The construction process of modern project is distributed across teams, departments, or systems, each of which is corresponding to a particular project unit. Conflicts often occur in construction project organization ...The construction process of modern project is distributed across teams, departments, or systems, each of which is corresponding to a particular project unit. Conflicts often occur in construction project organization because of the improper coordination amongbetween these project units. The primary reason for coordination puzzle in project organization is generally the diversification of culture and technology. In order to enhance the organization’s performance efficiency, good and effective coordination mechanism aimed at diversification of culture and technology is needed. The relationship amongbetween parties and project units is defined and expressed through contract, so construction project organization usually relies on various contracts to deal with its cooperative partner relationship. However, the contractual mode is a defensive method which is more prone to conflicts than the conglomerate of diversification, especially evaluated from the aspects of culture and value. By culture integration—a more flexible way to make up the shortage of contractual mode, a harmonious atmosphere in which organization members can exert their potential ability can be created to help project administrators mitigate organization conflicts and achieve the common goals of project organization. Based on arbitration theory, moreover, this paper puts forward a combined coordination mechanism-hierarchical coordination and nonhierarchical coordination—to resolve the conflicts resulted from diversification of technology. The introduction of intelligent agents system has the advantage of a more systematic and organizational method in reality without causing unnecessary emotional and the behavioural side effects is an effective instrument to utilize this coordination mechanism and realizes its established goals.展开更多
文摘The small and scattered enterprise pattern in the county economy has formed numerous sporadic pollution sources, hindering the centralized treatment of the water environment, increasing the cost and difficulty of treatment. How enterprises can make reasonable decisions on their water environment behavior based on the external environment and their own factors is of great significance for scientifically and effectively designing water environment regulation mechanisms. Based on optimal control theory, this study investigates the design of contractual mechanisms for water environmental regulation for small and medium-sized enterprises. The enterprise is regarded as an independent economic entity that can adopt optimal control strategies to maximize its own interests. Based on the participation of multiple subjects including the government, enterprises, and the public, an optimal control strategy model for enterprises under contractual water environmental regulation is constructed using optimal control theory, and a method for calculating the amount of unit pollutant penalties is derived. The water pollutant treatment cost data of a paper company is selected to conduct empirical numerical analysis on the model. The results show that the increase in the probability of government regulation and public participation, as well as the decrease in local government protection for enterprises, can achieve the same regulatory effect while reducing the number of administrative penalties per unit. Finally, the implementation process of contractual water environmental regulation for small and medium-sized enterprises is designed.
基金supported by National Key R&D Program of China(2020YFB1807800).
文摘Crowdsensing,as a data collection method that uses the mobile sensing ability of many users to help the public collect and extract useful information,has received extensive attention in data collection.Since crowdsensing relies on user equipment to consume resources to obtain information,and the quality and distribution of user equipment are uneven,crowdsensing has problems such as low participation enthusiasm of participants and low quality of collected data,which affects the widespread use of crowdsensing.This paper proposes to apply the blockchain to crowdsensing and solve the above challenges by utilizing the characteristics of the blockchain,such as immutability and openness.An architecture for constructing a crowdsensing incentive mechanism under distributed incentives is proposed.A multi-attribute auction algorithm and a k-nearest neighbor-based sensing data quality determination algorithm are proposed to support the architecture.Participating users upload data,determine data quality according to the algorithm,update user reputation,and realize the selection of perceived data.The process of screening data and updating reputation value is realized by smart contracts,which ensures that the information cannot be tampered with,thereby encouraging more users to participate.Results of the simulation show that using two algorithms can well reflect data quality and screen out malicious data.With the help of blockchain performance,the architecture and algorithm can achieve decentralized storage and tamper-proof information,which helps to motivate more users to participate in perception tasks and improve data quality.
基金supported by the National Natural Science Foundation of China(71671035)。
文摘Nowadays manufacturers are facing fierce challenge.Apart from the products,providing customers with multiple maintenance options in the service contract becomes more popular,since it can help to improve customer satisfaction,and ultimately promote sales and maximize profit for the manufacturer.By considering the combinations of corrective maintenance and preventive maintenance,totally three types of maintenance service contracts are designed.Moreover,attractive incentive and penalty mechanisms are adopted in the contracts.On this basis,Nash non-cooperative game is applied to analyze the revenue for both the manufacturer and customers,and so as to optimize the pricing mechanism of maintenance service contract and achieve a win-win situation.Numerical experiments are conducted.The results show that by taking into account the incentive and penalty mechanisms,the revenue can be improved for both the customers and manufacturer.Moreover,with the increase of repair rate and improvement factor in the preventive maintenance,the revenue will increase gradually for both the parties.
基金the National Natural Science Foundation of China(No.61702258)the Key Projects of Natural Science Research in Colleges and Universities of Jiangsu Province(No.19KJA410001)the Foundation of Jiangsu Advanced Numerical Control Technology Key Laboratory(No.SYKJ201901).
文摘Evidences indicate that,due to the limited caching capacity or inaccurate estimation on users’preferences,the requested files may not be fully cached in the network edge.The transmissions of the un-cached files will also lead to duplicated transmissions on backhaul channels.Buffer-aided relay has been proposed to improve the transmission performance of the un-cached files.Because of the limited buffer capacity and the information asymmetric environment,how to allocate the limited buffer capacity and how to incentivize users in participating buffer-aided relay have become critical issues.In this work,an incentive scheme based on the contract theory is proposed.Specifically,the backlog violation probability,i.e.,the buffer overflow probability,is provided based on the martingale theory.Next,based on the backlog violation probability,the utility functions of the relay node and users are constructed.With the purpose to maximize the utility of the relay node,the optimal contract problem is formulated.Then,the feasibility of the contract is also demonstrated,and the optimal solution can be obtained by the interior point method.Finally,numerical results are presented to demonstrate effectiveness of the proposed contract theory scheme.
基金Funded by the National Torch Plan of China(No.2005EB031110)the National Scientific and Technique Program of Ninth-five Year Plan(96-22-01-19)。
文摘Kinetics and mechanism of oxidation induced contraction of MgAl2O4 spinel carbon composites reinforced by Al4C3 in situ reaction were researched in air using vertical high temperature thermal dilatometer from 25℃to 1400℃.It is shown that oxidation induced contraction of MgAl2O4 spinel carbon composites reinforced Al4C3 in situ reaction is the common logarithm of oxidation time t and the oxygen partial pressure P inside MgAl2O4 spinel carbon composites reinforced by Al4C3 in situ reaction in air at 1400℃is as follows:P=F(-2.75×10^-4A+2.13×10^-3)lnt.The nonsteady diffusion kinetic equation of O2 at 1400℃inside the composites is as follows:J=De lnt.Acceleration of the total diffusional?flux of oxygen inside the composites at 1400℃is in inverse proportion to the oxidation time.The nonsteady state effective diffusion coefficient De of O2(g)inside the composites decreases in direct proportional to the increase of the amount of metallic aluminium.The method of preventing the oxidation induced contraction of MgAl2O4 spinel carbon composites reinforced by Al4C3 in situ reaction is to increase the amount of Al.The slag erosion index of MgO-Al2O3 spinel carbon composite reinforced by Al4C3 in situ reaction is 0.47 times that of MgO-CaO brick used in the lining above slag line area of a VOD stainless steel-making vessel.HMOR of MgO-Al2O3 spinel carbon composite reinforced by Al4C3 in situ reaction is 26.7 MPa,HMOR of the composite is 3.6 times the same as that of MgO-CaO brick used in the lining above slag line area of a VOD vessel.Its service life is two times as many as that of MgO-CaO brick.
文摘In today's management of the teaching staff of public security colleges and universities, the research on the Psychological Contract problem is not only beneficial to the management and estimation of the teachers, but also has an important role in the coordination and stability of the whole system of public security colleges and universities. Based on the theory of Psychological Contract, this paper expounds the basic understanding and research value of Psychological Contract, and puts forward the measures to cultivate teachers' good character and understanding, and as well as coordinate teachers' needs, effectively change teachers' attitude and actively promote the establishment of good interpersonal relationship to explain the research on the Management Mechanism of Teachers in Public Security Colleges and Universities from the Perspective of Psychological Contract.
基金The National Natural Science Foundation of China(No.70671025)the National Key Technology R&D Program of China during the 11th Five-Year Plan Period(No.2006BAH02A06)
文摘Considering participators' risk bias,which is measured by the method of value at risk,the risk constraints in a two-echelon supply chain coordination under buy-back contract is equal to giving the order of an upper bound.With a risk-averse dominant enterprise(M)and a risk-neutral non-dominant one(R),the coordination which optimizes the supply chain under the risk constraints is achieved by a penalty mechanism L to reduce R's order.With risk-neutral M and risk-averse R,M can motivate R to increase his order by providing a risk subsidy K,and two cases are discussed.If the risk constraints of R cannot satisfy M's participation constraint to offer K,M will prefer to accept R's order to obtain a sub-optimization solution of the supply chain.Or else,with M's K,R's optimal order just coordinates the supply chain,which is equal to the case without risk bias,and in this situation R's risk bias only affects the profit distribution between the participators.
文摘The forced lengthening of an activated skeletal muscle has been termed an eccentric contraction(EC).This review highlights the mechanically unique nature of the EC and focuses on the specific disruption of proteins within the cell known as cytoskeletal proteins.The major intermediate filament cytoskeletal protein,desmin,has been the focus of work in this area because changes to desmin occur within minutes of ECs and because desmin has been shown to play both a mechanical and biologic role in a muscle's response to EC.It is hoped that these types of studies will assist in decreasing the incidence of muscle injury in athletes and facilitating the development of new therapies to treat muscle injuries.
基金This work was supported in part by the National Natural Science Foundation of China(No.62373380).
文摘The practical engineering of satellite tracking telemetry and command(TT&C)is often disturbed by unpredictable external factors,including the temporary rise in a significant quantity of satellite TT&C tasks,temporary failures and failures of some TT&C resources,and so on.To improve the adaptability and robustness of satellite TT&C systems when faced with uncertain dynamic disturbances,a hierarchical disturbance propagation mechanism and an improved contract network dynamic scheduling method for satellite TT&C resources were designed to address the dynamic scheduling problem of satellite TT&C resources.Firstly,the characteristics of the dynamic scheduling problem of satellite TT&C resources are analyzed,and a mathematical model is established with the weighted optimization objectives of maximizing the revenue from task completion and minimizing the degree of plan disturbance.Then,a bottom-up distributed dynamic collaborative scheduling framework for satellite TT&C resources is proposed,which includes a task layer,a resource layer,a central internal collaboration layer,and a central external collaboration layer.Dynamic disturbances are propagated layer by layer from the task layer to the central external collaboration layer in a bottom-up manner,using efficient heuristic strategies in the task layer and the resource layer,respectively.We use improved contract network algorithms in the center internal collaboration layer and the center external collaboration layer,the original scheduling plan is quickly adjusted to minimize the impact of disturbances while effectively completing dynamic task requirements.Finally,a large number of simulation experiments were carried out and compared with various comparative algorithms.The results show that the proposed algorithm can effectively improve the solution effect of satellite TT&C resource dynamic scheduling problems,and has good application prospects.
文摘Introduction: The 12-lead electrocardiogram (ECG) is the most widely-used tool for the detection and diagnosis of cardiac conditions including myocardial infarction and ischemia. It has therefore been a focus of cardiac modeling. However, the most contemporary in silico ECG investigations of the intact heart have assumed a static heart and ignored the mechanical contraction that is an essential component of cardiac function. The aim of this study was to utilize electromechanically coupled human ventricle models to explore the consequences of ventricular mechanical contraction on the ECG profiles. Methods and Results: Biophysically detailed human ventricular cell models incorporating contractile activity and a stretchactivated current (Isac) were incorporated into a 3D human ventricular model within a human torso, from which 12-lead ECGs were computed at a stimulation rate of 1 Hz. Compared to the static model, ventricular contraction without Isac had little effect on the QRS complex, but shifted the T-wave peak leftwards and reduced its peak amplitude. With Isac, ventricular mechanical contraction increased the QRS duration by 23% and QT interval by 5%. Conclusion: Mechanical contraction of the heart has a significant effect on the morphology and characteristics of the ECG particularly on the T-wave. The alteration of the cell membrane kinetics by stretch via Isac further exacerbates these effects. Our simulation data suggest that mechanical contraction should be considered in the interpretation of ECGs in pathological conditions, especially those in which mechanical contraction of the heart is impaired.
基金The Philosophy and Social Sciences Program of Guangdong during the 11th Five-Year Plan Period for 2007(No.07D02)the Major Tender of Guangdong for 2007(No.KT005)
文摘To research the operating mechanisms of rural financial reform, through setting up a contract model, the constraint roles of reputation and legal intervention on the default risk arising in the operating of the credit union funds are inspected. Analysis indicates that the increase in reputation cost can reduce the probability of union member default behavior and the probability of turning to the law for the credit union funds. Meanwhile, the amount of loans and the interest rates can increase the probability of turning to the law for the credit union funds. Below the marginal values, the penalty mechanisms can reduce the balancing probabilities of member default behavior and turning to the law for the credit union funds, namely, the penalty has some "substitution effect" for turning to the law for the credit union funds.
文摘The rationality and scientific nature of the emission trading mechanism is the key to the effective implementation of environmental and economic policies.As far as China is concerned,there are phenomena such as information asymmetry,low supervision efficiency,and alienation of government and enterprise behaviors caused by the incomplete mechanism of emission trading in the practice of different pilots.The introduction of blockchain technology can innovate the traditional transaction model and form a decentralized peer-to-peer transaction and a trusted emission trading market.To this end,based on the current emission trading mechanism and the characteristics of blockchain technology,this paper couples the core technologies of blockchain with the functional requirements of application scenarios.Then,an innovative application framework is built based on the consortium blockchain Fabric from three aspects:emission trading supervision,secondary trading market construction,as well as emission trading incentive and punishment mechanisms.Technologies such as the consensus mechanism,smart contract,Merkle tree and asymmetric encryption are comprehensively applied in this process.In the construction of the blockchain framework of the secondary market for emission trading,institutional changes and innovations brought about by the blockchain at various levels are analyzed in terms of participants,transaction processes and the transaction scope.At the same time,smart contract functions and algorithms are designed for the purchase,transfer-out and trading of emission rights,and the operation business logic of the smart contract is analyzed.On the whole,this paper explores the application framework of blockchain technology in the field of emission trading at the macro level,and analyzes the application mechanism of the corresponding technologies of blockchain at each coupling point in the framework at the micro level.The collaborative analysis at the two levels shows that blockchain technology and the requirements of emission trading mechanism can be effectively coupled,and the application of blockchain technology can promote the effective supervision of enterprises'emission behavior,making the processes of the purchase,transfer and transaction of emission rights intelligent and automated,and providing technical support for cross regional emission trading to reduce transaction costs and management complexity.In addition,the issuance of emission credits based on smart contract will be a new incentive for companies to actively participate in transactions.Based on the above analysis,this paper believes that the innovative application of blockchain technology is of great significance in the promotion of the market-based allocation of element of emission trading and the rational allocation of environmental resources.It will lead to a major breakthrough in the traditional trading system in terms of trading modes,forming a value transmission network of environmental resources between the government and polluters.
基金Project supported by China National Fund for Distinguished Young Scientists(51125029)
文摘To compare the formation mechanisms of He and Ar atmospheric pressure plasma jets(APPJs),an intensified charge-coupled device(ICCD)are utilized to observe the dynamic process of APPJ.The experimental results show that,He APPJ is first ignited,which is independent of the dielectric barrier discharge(DBD)between the two wrapped electrodes when the high voltage placed at the downstream.The intensity and APPJ length under positive discharge pulses are bigger than that under negative discharge pulses due to the space charge effect.The He APPJ is formed by the DBD development when the high-voltage electrode placed at the upstream side of tube.However,the plasma plume in Ar APPJ is formed by the propagation of DBD whatever the high-voltage electrode is arranged on upstream or downstream side of ground electrode.The difference in formation mechanism between He and Ar APPJs is mainly caused by the gas properties.Moreover,during the discharges,Ar tends to lead to thermal instability and electron Maxwellian instability.
基金The National Natural Science Foundation of China (No.:60272048) ,Natural Science Foundation ofJiangsu Education Department(No.04kjb510057) and China Scholarship Council
文摘The construction process of modern project is distributed across teams, departments, or systems, each of which is corresponding to a particular project unit. Conflicts often occur in construction project organization because of the improper coordination amongbetween these project units. The primary reason for coordination puzzle in project organization is generally the diversification of culture and technology. In order to enhance the organization’s performance efficiency, good and effective coordination mechanism aimed at diversification of culture and technology is needed. The relationship amongbetween parties and project units is defined and expressed through contract, so construction project organization usually relies on various contracts to deal with its cooperative partner relationship. However, the contractual mode is a defensive method which is more prone to conflicts than the conglomerate of diversification, especially evaluated from the aspects of culture and value. By culture integration—a more flexible way to make up the shortage of contractual mode, a harmonious atmosphere in which organization members can exert their potential ability can be created to help project administrators mitigate organization conflicts and achieve the common goals of project organization. Based on arbitration theory, moreover, this paper puts forward a combined coordination mechanism-hierarchical coordination and nonhierarchical coordination—to resolve the conflicts resulted from diversification of technology. The introduction of intelligent agents system has the advantage of a more systematic and organizational method in reality without causing unnecessary emotional and the behavioural side effects is an effective instrument to utilize this coordination mechanism and realizes its established goals.