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广义流动中的积原理 被引量:17
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作者 程雪涛 徐向华 梁新刚 《物理学报》 SCIE EI CAS CSCD 北大核心 2011年第11期695-703,共9页
自然界发生的热量传递、分子扩散、导电等现象具有一定的相似性,它们均可被称为广义流动.文章基于这种相似性,对过增元等针对传热过程提出的理论进行了推广,定义了积、积流、积耗散等概念.针对只有一种广义流动和存在两种广义流动的系... 自然界发生的热量传递、分子扩散、导电等现象具有一定的相似性,它们均可被称为广义流动.文章基于这种相似性,对过增元等针对传热过程提出的理论进行了推广,定义了积、积流、积耗散等概念.针对只有一种广义流动和存在两种广义流动的系统,指出了在该类系统中可以发展积原理的条件,并在满足相应条件的系统中得到了积损失极小值原理、积耗散极值原理和最小广义流阻原理. 展开更多
关键词 广义流动 积损失极小值原理 积耗散极值原理
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自组织系统规格化模型序参量的形成及演化 被引量:7
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作者 蔡绍洪 苏禹 《贵州科学》 2002年第1期21-26,20,共7页
本文建立了一个规格化模型来模拟和描述在定态间跃迁的一般自组织系统的临界行为 ,并从随机理论出发导出了该系统序参量运动方程的一般形式。研究结果表明 ,对于演化形成的定态系统 ,该序参量存在一个广义势 ,由之可讨论该系统的临界标... 本文建立了一个规格化模型来模拟和描述在定态间跃迁的一般自组织系统的临界行为 ,并从随机理论出发导出了该系统序参量运动方程的一般形式。研究结果表明 ,对于演化形成的定态系统 ,该序参量存在一个广义势 ,由之可讨论该系统的临界标度性质。 展开更多
关键词 自组织系统 规模化模型 序参量 演化广义势
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UNIQUENESS OF GENERALIZED SOLUTION FOR THE CAUCHY PROBLEM OF TRANSPORTATTION EQUATIONS 被引量:6
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作者 王振 丁夏畦 《Acta Mathematica Scientia》 SCIE CSCD 1997年第3期341-352,共12页
In this paper, we prove the uniqueness of generalized solution defined by Lebesgue-Stieltjes integral for the Cauchy problem of transportation equations. Our results are based on the discussions for linear system with... In this paper, we prove the uniqueness of generalized solution defined by Lebesgue-Stieltjes integral for the Cauchy problem of transportation equations. Our results are based on the discussions for linear system with discontinuous coefficient. 展开更多
关键词 hyperbolic system generalized solution Lebesgue-Stieltjes integral generalized potential
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非完整系统相对于非惯性系的Noether理论 被引量:7
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作者 俞慧丹 张解放 许友生 《应用数学和力学》 EI CSCD 北大核心 1993年第6期499-506,共8页
本文通过构造广义惯性势,建立起非完整系统相对于非惯性系的新型Gauss型变分原理.提出并证明了非完整系统相对于非惯性系的Noether定理和逆定理.最后举例说明其应用.
关键词 非完整系统 非惯性系 NOETHER理论
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Dynamical and Thermal Problems in Vortex Development and Movement. Part II: Generalized Slantwise Vorticity Development 被引量:7
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作者 吴国雄 郑永骏 刘屹岷 《Acta meteorologica Sinica》 SCIE 2013年第1期15-25,共11页
The development of vertical vorticity under adiabatic condition is investigated by virtue of the view of potential vorticity and potential temperature (PV-θ) and from a Lagrangian perspective. A new concept of gene... The development of vertical vorticity under adiabatic condition is investigated by virtue of the view of potential vorticity and potential temperature (PV-θ) and from a Lagrangian perspective. A new concept of generalized slantwise vorticity development (GSVD) is introduced for adiabatic condition. The GSVD is a coordinate independent framework of vorticity development (VD), which includes slantwise vorticity development (SVD) when a particle is sliding down the concave slope or up the convex slope of a sharply tilting isentropic surface under stable or unstable condition. The SVD is a special VD for studying the severe weather systems with rapid development of vertical vorticity. In addition, the GSVD clarifies VD and SVD. The criteria for VD and SVD demonstrate that the demand for SVD is much more restricted than the demand for VD. When an air parcel is moving down the concave slope or up the convex slope Of a sharply tilting isentropic surface in a stable stratified atmosphere with its stability decreasing, or in an unstable atmosphere with its stability increasing, i.e., its stability θz approaches zero, its vertical vorticity can develop rapidly if its CD is decreasing. The theoretical results are employed to analyze a Tibetan Plateau (TP) vortex (TPV), which appeared over the TP, then slid down and moved eastward in late July 2008, resulting in heavy rainfall in Sichuan Province and along the middle and lower reaches of the Yangtze River. The change of PV2 contributed to the intensification of the TPV from 0000 to 0600 UTC 22 July 2008 when it slid upward on the upslope of the northeastern edge of the Sichuan basin, since the changes in both horizontal vorticity ~?~ and baroclinity Os have positive effects on the development of vertical vorticity. At 0600 UTC 22 July 2008, the criterion for SVD at 300 K isentropic surface is satisfied, meaning that SVD occurred and contributed significantly to the development of vertical vorticity. The appearance of the stronger signals concerni 展开更多
关键词 potential vorticity vorticity development slantwise vorticity development generalized slant-wise vorticity development
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社区微网主动能量管理协同与优化方法研究 被引量:7
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作者 侯媛媛 曾君 +1 位作者 罗燕 刘俊峰 《电网技术》 EI CSCD 北大核心 2023年第4期1548-1557,共10页
微电网是分布式资源与电网之间的重要桥梁,是提高可再生能源就地消纳的重要途径,是新型电力系统建设的重要组成。该文以多种可再生能源接入的社区微网为对象,研究多主体利益博弈下,微网主动能量管理和协同优化方法。首先,深入分析了社... 微电网是分布式资源与电网之间的重要桥梁,是提高可再生能源就地消纳的重要途径,是新型电力系统建设的重要组成。该文以多种可再生能源接入的社区微网为对象,研究多主体利益博弈下,微网主动能量管理和协同优化方法。首先,深入分析了社区微网能量特性与需求,提出将柔性负荷和光伏可再生能源统一起来,形成广义用户,让具有供电能力的柔性负荷和储能单元协调运行。然后再将广义用户的舒适度和经济性纳入考虑,建立广义用户的多目标优化模型。最后基于势博弈理论,分析运营商和广义用户的互动博弈模型并进行求解。仿真结果表明,所提出的方法在保证运营商和用户的自主性和自利性的基础上,有效改善柔性负荷用电曲线,提高用户用电的经济性和可再生能源就地消纳能力。 展开更多
关键词 微电网 广义用户 负荷满意度 势博弈 主动能量管理
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ON THE CAUCHY PROBLEM OF TRANSPORTATION EQUATIONS 被引量:4
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作者 王振 黄飞敏 丁夏畦 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 1997年第2期113-122,共6页
In this paper, we prove the global existence of generalized solutions of Cauchy problem for transportation equations; moreover, we construct the solution by generalized potential.
关键词 Hyperbolic system generalized solution Lebesgue-Stieltjes integral generalized potential
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非惯性系中的Lagrange方程及其应用 被引量:4
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作者 廖旭 《云南大学学报(自然科学版)》 CAS CSCD 2004年第B07期122-124,共3页
通过在非惯性系中引入一个与惯性力相对应的广义非惯性势,建立了非惯性系中力学体系的拉格朗日方程,并应用举例.
关键词 非惯性系 LAGRANGE方程 广义势 动力学方程
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A Generalized Statement of Highest-Entropy Principle for Stable Equilibrium and Non-Equilibrium in Many-Particle Systems
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作者 Pierfrancesco Palazzo 《Journal of Modern Physics》 2016年第3期344-357,共14页
Among all statements of Second Law, the existence and uniqueness of stable equilibrium, for each given value of energy content and composition of constituents of any system, have been adopted to define thermodynamic e... Among all statements of Second Law, the existence and uniqueness of stable equilibrium, for each given value of energy content and composition of constituents of any system, have been adopted to define thermodynamic entropy by means of the impossibility of Perpetual Motion Machine of the Second Kind (PMM2) which is a consequence of the Second Law. Equality of temperature, chemical potential and pressure in many-particle systems are proved to be necessary conditions for the stable equilibrium. The proofs assume the stable equilibrium and derive, by means of the Highest-Entropy Principle, equality of temperature, chemical potential and pressure as a consequence. A first novelty of the present research is to demonstrate that equality is also a sufficient condition, in addition to necessity, for stable equilibrium implying that stable equilibrium is a condition also necessary, in addition to sufficiency, for equality of temperature potential and pressure addressed to as generalized potential. The second novelty is that the proof of sufficiency of equality, or necessity of stable equilibrium, is achieved by means of a generalization of entropy property, derived from a generalized definition of exergy, both being state and additive properties accounting for heat, mass and work interactions of the system underpinning the definition of Highest-Generalized-Entropy Principle adopted in the proof. 展开更多
关键词 Many-Particle Systems Stable Equilibrium NON-EQUILIBRIUM Second Law generalized potential generalized Reservoir generalized Exergy generalized Entropy Highest-generalized-Entropy Principle
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Theorem of Necessity and Sufficiency of Stable Equilibrium for Generalized Potential Equality between System and Reservoir
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作者 Pierfrancesco Palazzo 《Journal of Modern Physics》 2014年第18期2003-2011,共9页
The literature reports that equality of temperature, equality of potential and equality of pressure between a system and a reservoir are necessary conditions for the stable equilibrium of the system-reservoir composit... The literature reports that equality of temperature, equality of potential and equality of pressure between a system and a reservoir are necessary conditions for the stable equilibrium of the system-reservoir composite or, in the opposite and equivalent logical inference, that stable equilibrium is a sufficient condition for equality. The aim and the first novelty of the present study is to prove that equality of temperature, potential and pressure is also a sufficient condition for stable equilibrium, in addition to necessity, implying that stable equilibrium is a condition also necessary, in addition to sufficiency, for equality. The second novelty is that the proof of the sufficiency of equality (or the necessity of stable equilibrium) is attained by means of the generalization of the entropy property, derived from the generalization of exergy property, which is used to demonstrate that stable equilibrium is a logical consequence of equality of generalized potential. This proof is underpinned by the Second Law statement and the Maximum-Entropy Principle based on generalized entropy which depends on temperature, potential and pressure of the reservoir. The conclusion, based on these two novel concepts, consists of the theorem of necessity and sufficiency of stable equilibrium for equality of generalized potentials within a composite constituted by a system and a reservoir. 展开更多
关键词 Available Energy Second Law Stable EQUILIBRIUM NONEQUILIBRIUM generalized EXERGY generalized Entropy generalized potential
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On the Generalized Ertel-Rossby Invariant
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作者 高守亭 许鹏程 +1 位作者 冉令坤 李娜 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2012年第4期690-694,共5页
A new invariant called the generalized Ertel Rossby invariant (GER) was developed in this study. The new invariant is given by the dot product of the generalized vorticity and the generalized velocity. The generaliz... A new invariant called the generalized Ertel Rossby invariant (GER) was developed in this study. The new invariant is given by the dot product of the generalized vorticity and the generalized velocity. The generalized vortieity is the absolute vorticity minus the cross product of the gradient of Lagrangian--time integrated temperature and the gradient of entropy. The generalized velocity is the absolute velocity minus the sum of the gradient of Lagrangian-time integrated kinetic potential and the Lagrangian time integrated temperature multiplied by the gradient of entropy. In addition to the traditional potential vorticity, the GER invariant may provide another useful tool to study the atmospheric dynamic processes for weather phenomena ranging from large scales to small scales. 展开更多
关键词 potential vorticity generalized Ertel-Rossby invariant generalized vorticity generalized velocity
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p-wave resonances in the exponential cosine screened Coulomb potential
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作者 Yuan-Cheng Wang Li Guang Jiao +2 位作者 Aihua Liu Yew Kam Ho Stephan Fritzsche 《Communications in Theoretical Physics》 SCIE CAS CSCD 2024年第7期105-113,共9页
We perform benchmark calculations of the p-wave resonances in the exponentially cosine screened Coulomb potential using the uniform complex-scaling generalized pseudo-spectral method.The present results show significa... We perform benchmark calculations of the p-wave resonances in the exponentially cosine screened Coulomb potential using the uniform complex-scaling generalized pseudo-spectral method.The present results show significant improvement in calculation accuracy compared to previous predictions and correct the misidentification of resonance electron configuration in previous works.It is found that the resonance states approximately follow an n^(2)-scaling law which is similar to the bound counterparts.The birth of a new resonance would distort the trajectory of an adjacent higher-lying resonance. 展开更多
关键词 complex-scaling method shape resonance generalized pseudospectral method exponential cosine screened Coulomb potential
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Performance of a two-state quantum engine improved by the superposition effect 被引量:4
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作者 OU CongJie HUANG ZhiFu +1 位作者 LIN BiHong CHEN JinCan 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2013年第10期1815-1821,共7页
The performance of a two-state quantum engine under different conditions is analyzed. It is shown that the efficiency of the quantum engine can be enhanced by superposing the eigenstates at the beginning of the cycle.... The performance of a two-state quantum engine under different conditions is analyzed. It is shown that the efficiency of the quantum engine can be enhanced by superposing the eigenstates at the beginning of the cycle. By employing the finite-time movement of the potential wall, the power output of the quantum engine as well as the efficiency at the maximum power out- put (EMP) can be obtained. A generalized potential is adopted to describe a class of two-level quantum engines in a unified way. The results obtained show clearly that the performances of these engines depend on the external potential, the geometric configuration of the quantum engines, and the superposition effect. Moreow^r, it is found that the superposition effect will en- large the optimally operating region of quantum engines. 展开更多
关键词 quantum engine superposition effect generalized potential
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岩石结构超塑性损伤本构理论及热力学框架 被引量:3
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作者 郭璇 张顶立 +3 位作者 赵成刚 张晓新 王梦恕 祝瑛 《岩石力学与工程学报》 EI CAS CSCD 北大核心 2016年第4期658-669,共12页
基于热力学势函数引入损伤理论,建立适用于深部岩体的新结构超塑性损伤本构框架。通过定义新内变量对:应变(损伤积累应变,结构重排应变)及相应广义应力、温度和熵,用4种热力学能量函数:内能,Helmholtz自由能,焓和Gibbs自由能描述岩石结... 基于热力学势函数引入损伤理论,建立适用于深部岩体的新结构超塑性损伤本构框架。通过定义新内变量对:应变(损伤积累应变,结构重排应变)及相应广义应力、温度和熵,用4种热力学能量函数:内能,Helmholtz自由能,焓和Gibbs自由能描述岩石结构超塑性本构关系。本理论框架即能满足热力学定律具有严格物理意义又能对结构性进行较合理考虑。通过Legendre变换建立各能量形式间的转换。利用运动内变量参数及其共轭变量(广义应力)引出耗散势。给出承压变温条件下深部岩体的塑形耗散函数或屈服函数形式,可反映损伤并考虑结构重排的体变行为,两者通过Legendre变换的退化特例进行联系。构建适用深部岩体热力学本构理论框架下具体的应力–应变增量本征关系及其新应用实例,并提供应用性的判断依据。该理论对深部地下工程实践中岩石的力学分析具有借鉴意义。 展开更多
关键词 岩石力学 广义热力学 损伤 结构超塑性 能量势 耗散势 屈服函数 应力–应变本构关系
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Boundary Conditions for Sturm-Liouville Equation with Transition Regions and Barriers or Wells 被引量:1
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作者 Alfred Wünsche 《Advances in Pure Mathematics》 2021年第4期254-295,共42页
By means of expansions of rapidly in infinity decreasing functions in delta functions and their derivatives, we derive generalized boundary conditions of the Sturm-Liouville equation for transitions and barriers or we... By means of expansions of rapidly in infinity decreasing functions in delta functions and their derivatives, we derive generalized boundary conditions of the Sturm-Liouville equation for transitions and barriers or wells between two asymptotic potentials for which the solutions are supposed as known. We call such expansions “moment series” because the coefficients are determined by moments of the function. An infinite system of boundary conditions is obtained and it is shown how by truncation it can be reduced to approximations of a different order (explicitly made up to third order). Reflection and refraction problems are considered with such approximations and also discrete bound states possible in nonsymmetric and symmetric potential wells are dealt with. This is applicable for large wavelengths compared with characteristic lengths of potential changes. In Appendices we represent the corresponding foundations of Generalized functions and apply them to barriers and wells and to transition functions. The Sturm-Liouville equation is not only interesting because some important second-order differential equations can be reduced to it but also because it is easier to demonstrates some details of the derivations for this one-dimensional equation than for the full three-dimensional vectorial equations of electrodynamics of media. The article continues a paper that was made long ago. 展开更多
关键词 Schrödinger Equation Drude Approximation Transition Layer potential Barrier potential Well Reflection REFRACTION Moment Series generalized Functions Delta Function and Its Derivatives Discrete or Bound Eigenstates
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四川盆地西部两次极端暴雨的广义湿位涡诊断分析 被引量:2
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作者 郭云云 邓莲堂 蒋伊蓉 《高原山地气象研究》 2022年第1期45-50,共6页
利用ERA50.25°×0.25°再分析资料、MICAPS4的常规资料以及四川加密自动站逐时降水观测资料,对2020年8月11~13日和15~18日发生在四川盆地西部的两次极端暴雨过程的广义位温和广义湿位涡进行诊断分析。结果表明:两次暴雨过... 利用ERA50.25°×0.25°再分析资料、MICAPS4的常规资料以及四川加密自动站逐时降水观测资料,对2020年8月11~13日和15~18日发生在四川盆地西部的两次极端暴雨过程的广义位温和广义湿位涡进行诊断分析。结果表明:两次暴雨过程均属于500 hPa“东高西低”型暴雨,中高层南亚高压、高空急流、西风槽和低层切变线、低涡等天气系统是两次暴雨有利的动力条件,低空急流则是暴雨区良好的水汽条件。两次过程暴雨区上空均存在强广义位温梯度区和强广义湿位涡异常区,“8.11”暴雨出现高度为800~900 hPa,“8.15”暴雨出现高度为700~800 hPa,这种分布与低层相对湿度含量密切相关,即相对湿度越高,广义位温垂直梯度越强,广义湿位涡异常区中心值越高。两次暴雨的强降水站点广义位温和广义湿位涡的时空演变和降水的时间演变均有较好的对应关系,但广义湿位涡强度与小时雨强并不存在明显的正相关关系。 展开更多
关键词 广义位温 广义湿位涡 极端暴雨
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UNIQUENESS ON ZERO PRESSURE GAS DYNAMICS
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作者 黄飞敏 王振 《Acta Mathematica Scientia》 SCIE CSCD 2001年第2期145-151,共7页
By introducing a new idea, the authors prove the uniqueness of weak solution of pressureless gases with the large initial data. In particular, uniqueness theorem is obtained in the same functional space as the existen... By introducing a new idea, the authors prove the uniqueness of weak solution of pressureless gases with the large initial data. In particular, uniqueness theorem is obtained in the same functional space as the existence theorem. 展开更多
关键词 Pressureless gases generalized potential generalized characteristic measure-value solution
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Compressed H3S: Fits to the Empirical Hc2(T) Data and a Discussion of the Meissner Effect
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作者 Gulshan Prakash Malik Vijaya Shankar Varma 《World Journal of Condensed Matter Physics》 2023年第4期111-127,共17页
Based on μ-, T- and H-dependent pairing and number equations and the premise that μ(T) is predominantly the cause of the variation of the upper critical field H<sub>c</sub><sub>2</sub>(T), wh... Based on μ-, T- and H-dependent pairing and number equations and the premise that μ(T) is predominantly the cause of the variation of the upper critical field H<sub>c</sub><sub>2</sub>(T), where μ, T and H denote the chemical potential, temperature and the applied field, respectively, we provide in this paper fits to the empirical H<sub>c</sub><sub>2</sub>(T) data of H<sub>3</sub>S reported by Mozaffari, et al. (2019) and deal with the issue of whether or not H<sub>3</sub>S exhibits the Meissner effect. Employing a variant of the template given by Dogan and Cohen (2021), we examine in detail the results of Hirsch and Marsiglio (2022) who have claimed that H<sub>3</sub>S does not exhibit the Meissner effect and Minkov, et al. (2023) who have claimed that it does. We are thus led to suggest that monitoring the chemical potential (equivalently, the number density of Cooper pairs N<sub>s</sub> at T = T<sub>c</sub>) should shed new light on the issue being addressed. 展开更多
关键词 Compressed H3S Upper and Lower Critical Fields Chemical potential generalized Pairing and Number Equations Coherence Length Penetration Depth Meissner Effect
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A Brief Report of Graphic Explanations for Generalized Potential Temperature in the Non-Uniformly Saturated Atmosphere 被引量:2
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作者 CAO Jie ZHOU Yu-Shu GAO Shou-Ting 《Atmospheric and Oceanic Science Letters》 2011年第3期162-167,共6页
Compared to potential temperature (θ) in the dry atmosphere and equivalent potential temperature (θc) in the saturated atmosphere, generalized potential tem- perature (θ") has already proven a better thermod... Compared to potential temperature (θ) in the dry atmosphere and equivalent potential temperature (θc) in the saturated atmosphere, generalized potential tem- perature (θ") has already proven a better thermodynamic parameter in describing the non-uniformly saturated real atmosphere. To add otherwise absent graphic explanations, this paper first presents the physical definition of θ through a tephigram. Then, the utility of the measurement in identifying and forecasting the locations of precipita- tion maxima and heat wave areas with diagnostic com- parison studies and traditionally used thermodynamic parameters is shown. 展开更多
关键词 generalized potential temperature physicalgraph thermodynamic parameters
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Generalized Available Potential Energy 被引量:2
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作者 Yong.L.McHall 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1990年第4期395-408,共14页
The kinetic energy generation in either the dry or moist atmosphere may be estimated by the same relationships if we introduce the new concept of generalized available potential energy. The largest magnitude of genera... The kinetic energy generation in either the dry or moist atmosphere may be estimated by the same relationships if we introduce the new concept of generalized available potential energy. The largest magnitude of generalized available potential energy and corresponding reference state of either dry or moist atmosphere are calculated in terms of the mitial conditions and entropy variation of the atmosphere. The obtained relationships are applicable for the statically unstable atmosphere as well. The generalized available potential energy associated with reversible processes reaches the maximum with respect to same initial state. While the generation of kinetic energy in irreversible processes is characterized by sudden changes. When the reference state is assumed to be saturated, we may predict the final temperature and moisture fields corresponding to provided initial state and entropy variation. 展开更多
关键词 generalized Available potential Energy THAN AS
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