As the demand for more efficient and adaptable power distribution systems intensifies, especially in rural areas, innovative solutions like the Capacitor-Coupled Substation with a Controllable Network Transformer (CCS...As the demand for more efficient and adaptable power distribution systems intensifies, especially in rural areas, innovative solutions like the Capacitor-Coupled Substation with a Controllable Network Transformer (CCS-CNT) are becoming increasingly critical. Traditional power distribution networks, often limited by unidirectional flow capabilities and inflexibility, struggle to meet the complex demands of modern energy systems. The CCS-CNT system offers a transformative approach by enabling bidirectional power flow between high-voltage transmission lines and local distribution networks, a feature that is essential for integrating renewable energy sources and ensuring reliable electrification in underserved regions. This paper presents a detailed mathematical representation of power flow within the CCS-CNT system, emphasizing the control of both active and reactive power through the adjustment of voltage levels and phase angles. A control algorithm is developed to dynamically manage power flow, ensuring optimal performance by minimizing losses and maintaining voltage stability across the network. The proposed CCS-CNT system demonstrates significant potential in enhancing the efficiency and reliability of power distribution, making it particularly suited for rural electrification and other applications where traditional methods fall short. The findings underscore the system's capability to adapt to varying operational conditions, offering a robust solution for modern power distribution challenges.展开更多
Carbon dioxide injection into deep saline aquifers results in a variety of strongly coupled physical and chemical processes. In this study, reactive transport simulations using a 2-D radial model were performed to inv...Carbon dioxide injection into deep saline aquifers results in a variety of strongly coupled physical and chemical processes. In this study, reactive transport simulations using a 2-D radial model were performed to investigate the fate of the injected CO2, the effect of CO2-water-rock interactions on mineral alteration, and the long-term CO2 sequestration mechanisms of the Liujiagou Formation sandstone at the Shenhua CCS（carbon capture and storage） pilot site of China. Carbon dioxide was injected at a constant rate of 0.1 Mt/year for 30 years, and the fluid flow and geochemical transport simulation was run for a period of 10 000 years by the TOUGHREACT code according to the underground conditions of the Liujiagou Formation. The results show that different trapping phases of CO2 vary with time. Sensitivity analyses indicate that plagioclase composition and chlorite presence are the most significant determinants of stable carbonate minerals and CO2 mineral trapping capacity. For arkosic arenite in the Liujiagou Formation, CO2 can be immobilized by precipitation of ankerite, magnesite, siderite, dawsonite, and calcite for different mineral compositions, with Ca（2＋）, Mg（2＋）, Fe（2＋） and Na＋ provided by dissolution of calcite, albite（or oligoclase） and chlorite. This study can provide useful insights into the geochemistry of CO2 storage in other arkosic arenite（feldspar rich sandstone） formations at other pilots or target sites.展开更多
1 M-P神经元模型的工作原理和几何意义
1943年,MoCulloch和Pitts[1]根据神经元传递规律,第一次提出了神经元的数学模型.M-P神经元模型一直沿用至今,它对神经网络的发展起到了奠基性的作用.每个神经元的状态由M-P方程决定:S=f(∑W X -θ)...1 M-P神经元模型的工作原理和几何意义
1943年,MoCulloch和Pitts[1]根据神经元传递规律,第一次提出了神经元的数学模型.M-P神经元模型一直沿用至今,它对神经网络的发展起到了奠基性的作用.每个神经元的状态由M-P方程决定:S=f(∑W X -θ),θ为阈值,f为激励函数,一般取符号函数.令:它代表了n维空间中,以X为坐标变量,以W为坐标系数,θ为常数项的一个超平面.当样本点X落入超平面的正半区,即I(X)>0时,有f(I)＝1;当样本点X落入超平面的负半区,即I(X)<0时,有f(I)＝0.从分类的角度看,一个神经元按输入将样本划分成为两类(0和1).现在广泛使用的BP模型采用Sigmoid函数作为激励函数,但是它没有改变神经元分类的本质.神经网络实际上就是多个神经元组织起来的一种网状结构.展开更多
考虑碳交易价格、燃料价格、投资成本及政府补贴等不确定性因素,基于实物期权理论构建了燃煤电站碳捕获与储存(carbon capture and storage,CCS)投资决策的四叉树模型,通过算例分析了模型的求解过程,证实了实物期权方法比传统的净现值(N...考虑碳交易价格、燃料价格、投资成本及政府补贴等不确定性因素,基于实物期权理论构建了燃煤电站碳捕获与储存(carbon capture and storage,CCS)投资决策的四叉树模型,通过算例分析了模型的求解过程,证实了实物期权方法比传统的净现值(NPV)方法能更准确地评估CCS的投资价值;进一步研究了政策补贴对CCS投资决策的影响,并计算出不同政策补贴系数下碳交易价格的投资临界值。结果表明,政策补贴越高则碳价格临界值越低,当政府提供全额补贴和不提供补贴时,碳交易临界价格分别为103.56元/t和217.95元/t。这意味着在当前市场环境下,电站CCS投资会导致亏损。上述结论对燃煤电站的CCS投资决策提供了理论依据。展开更多
软件动态行为可信度量是可信计算必须要解决的关键问题之一.对该问题的关键一环,软件动态行为建模理论和方法,进行了研究:以系统调用为建模对象,从软件行为学的观点出发,将软件动态行为刻画为进程代数CCS(calculus of communication sys...软件动态行为可信度量是可信计算必须要解决的关键问题之一.对该问题的关键一环,软件动态行为建模理论和方法,进行了研究:以系统调用为建模对象,从软件行为学的观点出发,将软件动态行为刻画为进程代数CCS(calculus of communication system)动作的形式.在此基础上,提出了软件动态行为模型的形式化表达DBMS={SCSS,E},其中,SCSS是整个系统的系统调用序列,E是一套基于CCS的行为变换操作符,结合SCSS和E,能够表达系统内任意软件的任意行为.进一步地,提出了一种分布式软件动态行为度量架构,利用该架构能够增强软件动态行为度量的准确性,并提高度量效率.展开更多
利用通信系统演算CCS(Calculus of Communicating Systems),对用来解决进程间通信问题的信号量给出了形式化建模和验证的方法,并利用该方法对以信号量机制解决生产者—消费者问题和哲学家进餐问题进行建模、逻辑说明和验证。该方法具有...利用通信系统演算CCS(Calculus of Communicating Systems),对用来解决进程间通信问题的信号量给出了形式化建模和验证的方法,并利用该方法对以信号量机制解决生产者—消费者问题和哲学家进餐问题进行建模、逻辑说明和验证。该方法具有一定通用性,并可将其推广到其他通过信号量机制解决进程通信的问题当中。展开更多
文摘As the demand for more efficient and adaptable power distribution systems intensifies, especially in rural areas, innovative solutions like the Capacitor-Coupled Substation with a Controllable Network Transformer (CCS-CNT) are becoming increasingly critical. Traditional power distribution networks, often limited by unidirectional flow capabilities and inflexibility, struggle to meet the complex demands of modern energy systems. The CCS-CNT system offers a transformative approach by enabling bidirectional power flow between high-voltage transmission lines and local distribution networks, a feature that is essential for integrating renewable energy sources and ensuring reliable electrification in underserved regions. This paper presents a detailed mathematical representation of power flow within the CCS-CNT system, emphasizing the control of both active and reactive power through the adjustment of voltage levels and phase angles. A control algorithm is developed to dynamically manage power flow, ensuring optimal performance by minimizing losses and maintaining voltage stability across the network. The proposed CCS-CNT system demonstrates significant potential in enhancing the efficiency and reliability of power distribution, making it particularly suited for rural electrification and other applications where traditional methods fall short. The findings underscore the system's capability to adapt to varying operational conditions, offering a robust solution for modern power distribution challenges.
基金supported by the Global Climate and Energy Project(No.2384638-43106-A)the National Natural Science Foundation of China(No.41072180)+1 种基金the Special Scientific Research Fund of Public Welfare Profession of the Ministry of Land and Resources of China(No.201211063)a bilateral project of China Australia Geological Storage of CO2 Project Phase 2(CAGS2)
文摘Carbon dioxide injection into deep saline aquifers results in a variety of strongly coupled physical and chemical processes. In this study, reactive transport simulations using a 2-D radial model were performed to investigate the fate of the injected CO2, the effect of CO2-water-rock interactions on mineral alteration, and the long-term CO2 sequestration mechanisms of the Liujiagou Formation sandstone at the Shenhua CCS（carbon capture and storage） pilot site of China. Carbon dioxide was injected at a constant rate of 0.1 Mt/year for 30 years, and the fluid flow and geochemical transport simulation was run for a period of 10 000 years by the TOUGHREACT code according to the underground conditions of the Liujiagou Formation. The results show that different trapping phases of CO2 vary with time. Sensitivity analyses indicate that plagioclase composition and chlorite presence are the most significant determinants of stable carbonate minerals and CO2 mineral trapping capacity. For arkosic arenite in the Liujiagou Formation, CO2 can be immobilized by precipitation of ankerite, magnesite, siderite, dawsonite, and calcite for different mineral compositions, with Ca（2＋）, Mg（2＋）, Fe（2＋） and Na＋ provided by dissolution of calcite, albite（or oligoclase） and chlorite. This study can provide useful insights into the geochemistry of CO2 storage in other arkosic arenite（feldspar rich sandstone） formations at other pilots or target sites.
文摘1 M-P神经元模型的工作原理和几何意义
1943年,MoCulloch和Pitts[1]根据神经元传递规律,第一次提出了神经元的数学模型.M-P神经元模型一直沿用至今,它对神经网络的发展起到了奠基性的作用.每个神经元的状态由M-P方程决定:S=f(∑W X -θ),θ为阈值,f为激励函数,一般取符号函数.令:它代表了n维空间中,以X为坐标变量,以W为坐标系数,θ为常数项的一个超平面.当样本点X落入超平面的正半区,即I(X)>0时,有f(I)＝1;当样本点X落入超平面的负半区,即I(X)<0时,有f(I)＝0.从分类的角度看,一个神经元按输入将样本划分成为两类(0和1).现在广泛使用的BP模型采用Sigmoid函数作为激励函数,但是它没有改变神经元分类的本质.神经网络实际上就是多个神经元组织起来的一种网状结构.
文摘考虑碳交易价格、燃料价格、投资成本及政府补贴等不确定性因素,基于实物期权理论构建了燃煤电站碳捕获与储存(carbon capture and storage,CCS)投资决策的四叉树模型,通过算例分析了模型的求解过程,证实了实物期权方法比传统的净现值(NPV)方法能更准确地评估CCS的投资价值;进一步研究了政策补贴对CCS投资决策的影响,并计算出不同政策补贴系数下碳交易价格的投资临界值。结果表明,政策补贴越高则碳价格临界值越低,当政府提供全额补贴和不提供补贴时,碳交易临界价格分别为103.56元/t和217.95元/t。这意味着在当前市场环境下,电站CCS投资会导致亏损。上述结论对燃煤电站的CCS投资决策提供了理论依据。
文摘软件动态行为可信度量是可信计算必须要解决的关键问题之一.对该问题的关键一环,软件动态行为建模理论和方法,进行了研究:以系统调用为建模对象,从软件行为学的观点出发,将软件动态行为刻画为进程代数CCS(calculus of communication system)动作的形式.在此基础上,提出了软件动态行为模型的形式化表达DBMS={SCSS,E},其中,SCSS是整个系统的系统调用序列,E是一套基于CCS的行为变换操作符,结合SCSS和E,能够表达系统内任意软件的任意行为.进一步地,提出了一种分布式软件动态行为度量架构,利用该架构能够增强软件动态行为度量的准确性,并提高度量效率.
文摘利用通信系统演算CCS(Calculus of Communicating Systems),对用来解决进程间通信问题的信号量给出了形式化建模和验证的方法,并利用该方法对以信号量机制解决生产者—消费者问题和哲学家进餐问题进行建模、逻辑说明和验证。该方法具有一定通用性,并可将其推广到其他通过信号量机制解决进程通信的问题当中。
