期刊文献+
共找到20篇文章
< 1 >
每页显示 20 50 100
基于单片机数字式智能电子热量称的设计 被引量:3
1
作者 江杭军 朱型存 +1 位作者 施烨凯 张丽萍 《电子世界》 2013年第17期138-138,共1页
为了在不增加成本的前提下,开发电子称新功能,设计数字式电子热量称。采用STC89C52单片机为主控芯片,在软硬件控制下实现智能化称重,并根据输入热量参数换算出食物热量,并显示称重和换算结果,指导人们健康生活。设计经过仿真和实验测试... 为了在不增加成本的前提下,开发电子称新功能,设计数字式电子热量称。采用STC89C52单片机为主控芯片,在软硬件控制下实现智能化称重,并根据输入热量参数换算出食物热量,并显示称重和换算结果,指导人们健康生活。设计经过仿真和实验测试,准确度高,稳定性好,通过单片机技术,为电子称开辟新的应用道路,成为现代家庭都买得起的必备电子产品。 展开更多
关键词 电子 热量称 单片机
下载PDF
Perturbation of Symmetries and Hojman Adiabatic Invariants for Mechanical Systems with Unilateral Holonomic Constraints 被引量:4
2
作者 ZHANG Yi FAN Cun-Xin 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第4期607-610,共4页
The perturbation of symmetries and adiabatic invariants for mechanical systems with unilateral holonomic constraints are studied. The exact invariant in the form of Hojman led by special Lie symmetries for an undistur... The perturbation of symmetries and adiabatic invariants for mechanical systems with unilateral holonomic constraints are studied. The exact invariant in the form of Hojman led by special Lie symmetries for an undisturbed system with unilateral constraints is given. Based on the concept of high-order adiabatic invariant of mechanical systems, the perturbation of Lie symmetries for the system under the action of small disturbance is investigated, and a new adiabatic invariant for the system with unilateral holonomic constraints is obtained, which can be called Hojman adiabatic invariant. In the end of the paper, an example is given to illustrate the application of the results. 展开更多
关键词 unilateral constraint Lie symmetry PERTURBATION exact invariant adiabatic invariant
下载PDF
Mei Adiabatic Invariants Induced by Perturbation of Mei Symmetry for Nonholonomic Controllable Mechanical Systems 被引量:2
3
作者 丁宁 方建会 《Communications in Theoretical Physics》 SCIE CAS CSCD 2010年第11期785-791,共7页
Two types of Mei adiabatic invariants induced by perturbation of Mei symmetry for nonholonomic controllablemechanical systems are reported.Criterion and restriction equations determining Mei symmetry after beingdistur... Two types of Mei adiabatic invariants induced by perturbation of Mei symmetry for nonholonomic controllablemechanical systems are reported.Criterion and restriction equations determining Mei symmetry after beingdisturbed of the system are established.Form and existence condition of Mei adiabatic invariants are obtained. 展开更多
关键词 nonholonomic controllable mechanical system Mei symmetry PERTURBATION Mei adiabatic invariant
下载PDF
Perturbation to Unified Symmetry and Adiabatic Invariants for Relativistic Hamilton Systems 被引量:1
4
作者 ZHANG Ming-Jiang FANG Jian-Hui LU Kai PANG Ting LIN Peng 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第6期961-966,共6页
Based on the concept of adiabatic invariant, the perturbation to unified symmetry and adiabatic invariants for relativistic Hamilton systems are studied. The definition of the perturbation to unified symmetry for the ... Based on the concept of adiabatic invariant, the perturbation to unified symmetry and adiabatic invariants for relativistic Hamilton systems are studied. The definition of the perturbation to unified symmetry for the system is presented, and the criterion of the perturbation to unified symmetry is given. Meanwhile, the Noether adiabatic invariants, the generalized Hojman adiabatic invariants, and the Mei adiabatic invariants for the perturbed system are obtained. 展开更多
关键词 unified symmetry PERTURBATION adiabatic invariant relativistic Hamilton system
下载PDF
Lie Symmetrical Perturbation and Adiabatic Invariants of Generalized Hojman Type for Relativistic Birkhoffian Systems 被引量:4
5
作者 LUO Shao-Kai GUO Yong-Xin 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第1期25-30,共6页
For a relativistic Birkhoffian system, the Lie symmetrical perturbation and adiabatic invariants of generalized Bojman type are studied under general infinitesimal transformations. On the basis of the invariance of re... For a relativistic Birkhoffian system, the Lie symmetrical perturbation and adiabatic invariants of generalized Bojman type are studied under general infinitesimal transformations. On the basis of the invariance of relativistic Birkhotfian equations under general infinitesimal transformations,Lie symmetrical transformations of the system are constructed, which only depend on the Birkhoffian variables. The exact invariants in the form of generalized Hojman conserved quantities led by the Lie symmetries of relativistic Birkhoffian system without perturbations are given. Based on the definition of higher-order adiabatic invariants of a mechanical system, the perturbation of Lie symmetries for relativistic Birkhoffian system with the action of small disturbance is investigated, and a new type of adiabatic invariants of the system is obtained. In the end of the paper, an example is given to illustrate the application of the results. 展开更多
关键词 relativity BirkhofIian system Lie symmetrical perturbation exact invariant adiabatic invariant of generalized Hojman type
下载PDF
Perturbation and Adiabatic Invariants of Mei Symmetry for Nonholonomic Mechanical Systems 被引量:2
6
作者 DING Ning FANG Jian-Hui WANG Peng 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第4期594-596,共3页
Based on the concept of adiabatic invariant, the perturbation and adiabatic invariants of the Mei symmetry for nonholonomic mechanical systems are studied. The exact invariants of the Mei symmetry for the system witho... Based on the concept of adiabatic invariant, the perturbation and adiabatic invariants of the Mei symmetry for nonholonomic mechanical systems are studied. The exact invariants of the Mei symmetry for the system without perturbation are given. The perturbation to the Mei symmetry is discussed and the adiabatic invariants of the Mei symmetry for the perturbed system are obtained. 展开更多
关键词 Mei symmetry PERTURBATION adiabatic invariant nonholonomic mechanical system
下载PDF
Perturbation to Noether-Mei Symmetry and Adiabatic Invariants for Nonholonomic Mechanical Systems in Phase Space 被引量:1
7
作者 ZHANG Ming-Jiang FANG Jian-Hui LU Kai 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第4期600-604,共5页
Based on the concept of adiabatic invariant, the perturbation to Noether Mei symmetry and adiabatic invariants for nonholonomie mechanical systems in phase space are studied. The definition of the perturbation to Noet... Based on the concept of adiabatic invariant, the perturbation to Noether Mei symmetry and adiabatic invariants for nonholonomie mechanical systems in phase space are studied. The definition of the perturbation to Noether-Mei symmetry for the system is presented, and the criterion of the perturbation to Noether-Mei symmetry is given. Meanwhile, the Noether adiabatic invariants and the Mei adiabatic invariants for the perturbed system are obtained. 展开更多
关键词 Noether-Mei symmetry PERTURBATION adiabatic invariant nonholonomic mechanical system phase space
下载PDF
Cornwall-Jackiw-Tomboulis Effective Potential for Quark Propagator in Real-Time Thermal Field Theory and Landau Gauge
8
作者 ZHOU Bang-Rong 《Communications in Theoretical Physics》 SCIE CAS CSCD 2005年第5X期879-882,共4页
We complete the derivation of the Cornwall-Jackiw-Tomboulis effective potentiM for quark propagator at finite temperature and finite quark chemical potential in the real-time formalism of thermal field theory and in L... We complete the derivation of the Cornwall-Jackiw-Tomboulis effective potentiM for quark propagator at finite temperature and finite quark chemical potential in the real-time formalism of thermal field theory and in Landau gauge. In the approximation that the function A(p^2) in inverse quark propagator is replaced by unity, by means of the running gauge coupling and the quark mass function invariant under the renormalization group in zero temperature Quantum Chromadynamics (QCD), we obtain a calculable expression for the thermal effective potential, which will be a useful means to research chiral phase transition in QCD in the real-time formalism. 展开更多
关键词 CJT effective potential real-time thermal field theory QCD quark propagator Landau gauge
下载PDF
Indexes of Indoor Thermal Environment with Asymmetrical Radiant Field
9
作者 钟珂 刘加平 亢燕铭 《Journal of Donghua University(English Edition)》 EI CAS 2004年第1期63-67,共5页
The main features of top-flcor rooms with natural ventilation are identified by investigating indoor thermal environment in summer season. One is high indoor air temperature, for this reason the indoor climate is far ... The main features of top-flcor rooms with natural ventilation are identified by investigating indoor thermal environment in summer season. One is high indoor air temperature, for this reason the indoor climate is far beyond the thermal comfort standard; the other is the inhomogeneons temperature distribution of the inner wall surfaces, and high temperature of the inner surface of the roof causes much scorching to the head of occupant. This is the characteristic of such rooms. Both features mentioned above should be considered comprehensively for the evaluation of indoor thermal environment of the top-floor rooms with asymmetric radiant field. In order to characterize the indoor thermal environment of the rooms, the heat stress index, HSI and radiant heat flux reaching human head, Q_R should be introduced simultaneously as thermal indexes for the indoor climate evaluation. The application of the indexes to a topfloor room is presented and analyzed. 展开更多
关键词 thermal index asymmetrical radiant field top-floor room natural ventilation
下载PDF
Perturbation to Lie-Mei Symmetry and Adiabatic Invariants for Birkhoffian Systems
10
作者 ZHANG Ming-Jiang FANG Jian-Hui LU Kai PANG Ting LIN Peng 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第7期1-6,共6页
Based on the concept of adiabatic invariant,the perturbation to Lie-Mei symmetry and adiabatic invariantsfor Birkhoffian systems are studied.The definition of the perturbation to Lie-Mei symmetry for the system is pre... Based on the concept of adiabatic invariant,the perturbation to Lie-Mei symmetry and adiabatic invariantsfor Birkhoffian systems are studied.The definition of the perturbation to Lie-Mei symmetry for the system is presented,and the criterion of the perturbation to Lie-Mei symmetry is given.Meanwhile,the Hojman adiabatic invariants andthe Mei adiabatic invariants for the perturbed system are obtained. 展开更多
关键词 Lie Mei symmetry PERTURBATION adiabatic invariant Birkhoffian system
下载PDF
Perturbation of Symmetries and Mei Adiabatic Invariants of Nonholonomic Systems with Servoconstraints
11
作者 XIA Li-Li LI Yuan-Cheng ZHAO Xian-Lin 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第10期855-860,共6页
The perturbation of symmetries and Mei adiabatic invariants of nonholonomic systems with servoconstraints are studied. The exact invariants in the form of Mei conserved quantities introduced by the Mei symmetry of non... The perturbation of symmetries and Mei adiabatic invariants of nonholonomic systems with servoconstraints are studied. The exact invariants in the form of Mei conserved quantities introduced by the Mei symmetry of nonholonomic systems with servoconstraints without perturbations are given. Based on the definition of higher-order adiabatic invariants of mechanical systems, the perturbation of Mei symmetries for nonholonomic .systems with servoconstraints under the action of small disturbance is investigated, and Mei adiabatic invatiants of the system are obtained. An example is given to illustrate the application of the results. 展开更多
关键词 nonholonomic systems servoconstraints Mei symmetry PERTURBATIONS adiabatic invariants
下载PDF
Analysis Theory of Asymmetric dc SQUID Driven by Thermal Noises
12
作者 LǖHai-Feng JIAYa HUANGXin-Tang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2004年第5期707-714,共8页
An analysis expression for the stationary probability distribution of asymmetric superconducting quantum interference device with two Josephson junctions (dc SQUID) driven by thermal noise is derived from two-dimensio... An analysis expression for the stationary probability distribution of asymmetric superconducting quantum interference device with two Josephson junctions (dc SQUID) driven by thermal noise is derived from two-dimensional Fokker-Planck equation, where the potential condition is satisfied. Two of the three asymmetric parameters, inductance asymmetric parameter η and critical current asymmetric parameter α, can be changed in this condition, but resistance asymmetric parameter ρ cannot be changed. The 'ripple' phenomenon of circulating current can disappear with the change of coefficient α. The effects of asymmetric parameters on current-voltage relationship and transfer function of dc SQUID system are also represented. 展开更多
关键词 noise Fkker-Planck equation superconducting quantum interference device
下载PDF
Perturbation to Lie Symmetry and Hojman Exact and Adiabatic Invariants of Generalized Raitzin Canonical Equation of Motion
13
作者 WANG Peng FANG Jian-Hui DING Ning ZHANG Xiao-Ni 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第4X期615-618,共4页
In this paper, firstly, we get the Hojman exact invariants by Lie symmetry for an undisturbed generalized Raitzin equation of motion. Secondly, we study the perturbation to Lie symmetry of generalized Raitzin canonica... In this paper, firstly, we get the Hojman exact invariants by Lie symmetry for an undisturbed generalized Raitzin equation of motion. Secondly, we study the perturbation to Lie symmetry of generalized Raitzin canonical equation of motion and get Hojman adiabatic invariants. Lastly, an example is given to illustrate the application of the results. 展开更多
关键词 generalized mechanics SYMMETRY Raitzin canonical equation PERTURBATION adiabatic invariant
下载PDF
Theoretical solution of a spherically isotropic hollow sphere for dynamic thermoelastic problems
14
作者 王惠明 丁皓江 陈伟球 《Journal of Zhejiang University Science》 EI CSCD 2003年第1期8-12,共5页
The separation of variables method was successfully used to resolve the spherically symmetric dynamic thermoelastic problem for a spherically isotropic elastic hollow sphere. Use of the integral transform can be avoid... The separation of variables method was successfully used to resolve the spherically symmetric dynamic thermoelastic problem for a spherically isotropic elastic hollow sphere. Use of the integral transform can be avoided by means of this method, which is also appropriate for an arbitrary thickness hollow sphere subjected to arbitrary thermal and mechanical loads. Numerical results are presented to show the dynamic stress responses in the uniformly heated hollow spheres. 展开更多
关键词 Separation of variables method Spherically symmetric THERMOELASTIC Hollow sphere
下载PDF
Perturbation to Mei Symmetry and Adiabatic Invariants for Nonholonomic Systems in Terms of Quasi-Coordinates
15
作者 PANG Ting FANG Jian-Hui ZHANG Ming-Jiang LIN Peng LU Kai 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第11期779-783,共5页
Abstract Based on the concept of adiabatic invariant, the perturbation to Mei symmetry and adiabatic invariants for nonholonomic mechanical systems in terms of quasi-coordinates are studied. The definition of the pert... Abstract Based on the concept of adiabatic invariant, the perturbation to Mei symmetry and adiabatic invariants for nonholonomic mechanical systems in terms of quasi-coordinates are studied. The definition of the perturbation to Mei symmetry for the system is presented, and the criterion of the perturbation to Mei symmetry is given. Meanwhile, the Mei adiabatic invariants for the perturbed system are obtained. 展开更多
关键词 Mei symmetry PERTURBATION nonholonomic mechanical system quasi-coordinates
下载PDF
A New Type of Mei Adiabatic Invariant Induced by Perturbation to Mei Symmetry of Hamiltonian Systems
16
作者 DING Ning FANG Jian-Hui 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第7期12-16,共5页
Considering full perturbation to infinitesimal generators in the Mei structure equation,a new type of Meiadiabatic invariant induced by perturbation to Mei symmetry for Hamiltonian system was reported.
关键词 Mei symmetry PERTURBATION Mei adiabatic invariant Hamiltonian system
下载PDF
Combustion characteristics of Methanol-base fuel (MBF) made by coal 被引量:1
17
作者 ZHANG Quan ZHAO Cong-cong LIU Yang 《Journal of Coal Science & Engineering(China)》 2011年第4期431-433,共3页
Profound experimental research was made on Methanol-base fuel (MBF) mainly consisting of methanol, and the results were compared with that of diesel oil. Their respective combustion characteristics of caloric value,... Profound experimental research was made on Methanol-base fuel (MBF) mainly consisting of methanol, and the results were compared with that of diesel oil. Their respective combustion characteristics of caloric value, combustion efficiency and components of smoke were synthetically analyzed by employing the electronic weighing devices, the rotor flow-meter, intelligent flue gas analyzer, advanced bomb calorimeter, etc., referring to the feasibility of taking it as a fuel for general use. Experiment results show that Methanol-base fuel not only has superiorities on combustion characteristics but also bears energy saving and environmental protection advantages. 展开更多
关键词 combustion characteristics METHANOL new energy low carbon
下载PDF
Thermoelastic Stress Analysis of a Finite Structure Containing an Asymmetrical-Oriented, Arbitrarily-Shaped Hole
18
作者 S. Kurunthottikkal Philip R. E. Rowlands 《Journal of Mechanics Engineering and Automation》 2017年第3期145-159,共15页
Stresses, particularly those at geometric discontinuities, influence the structural integrity of engineering components. Motivated by the prevalence of complicated-shaped perforated components, the objective of this p... Stresses, particularly those at geometric discontinuities, influence the structural integrity of engineering components. Motivated by the prevalence of complicated-shaped perforated components, the objective of this paper is to demonstrate the ability to stress analyze loaded finite members containing asymmetrical, irregularly-shaped cutouts. Recognizing the difficulties in obtaining purely theoretical or numerical solutions for these situations, the paper presents an expeditious means of experimentally stress analyzing such structures. Processing the load-induced temperature information with a series representation of a stress function provides the independent stress components reliably full-field, including on the edge of a hole. The stresses satisfy equilibrium and strains satisfy compatibility. In addition to being able to stress analyze complicated shapes using real, rather than complex variables, the technique is significant in which it smooths the recorded thermal information, is widely applicable, and requires neither differentiating the measured data nor knowing the elastic properties or external boundary conditions. The latter is extremely important since the external loading is often unknown in practice. That the approach provides the independent stresses is also significant since fatigue analyses and strength criteria typically necessitate knowing the individual components of stress. Present results are supported by those from a finite element analysis, strain gage measurements and load equilibrium. 展开更多
关键词 Irregular cutouts stresses thermoelastic stress analysis finite structure.
下载PDF
Adiabatic approximation in PT-symmetric quantum mechanics 被引量:3
19
作者 GUO ZhiHua CAO HuaiXin LU Ling 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2014年第10期1835-1839,共5页
In this paper, we present a quantitative sufficient condition for adiabatic approximation in PT-symmetric quantum mechanics,which yields that a state of the PT-symmetric quantum system at any time will remain approxim... In this paper, we present a quantitative sufficient condition for adiabatic approximation in PT-symmetric quantum mechanics,which yields that a state of the PT-symmetric quantum system at any time will remain approximately in the m-th eigenstate up to a multiplicative phase factor whenever it is initially in the m-th eigenstate of the Hamiltonian. In addition, we estimate the approximation errors by the distance and the fidelity between the exact solution and the adiabatic approximate solution to the time evolution equation, respectively. 展开更多
关键词 PT-SYMMETRY time evolution equation adiabatic approximation error estimation
原文传递
Characteristics and mechanisms of the annual asymmetry of thermospheric mass density 被引量:1
20
作者 MA RuiPing XU JiYao +5 位作者 WANG WenBin CHEN GuangMing YUAN Wei LEI JiuHou Alan G BURNS JIANG GuoYing 《Science China Earth Sciences》 SCIE EI CAS CSCD 2015年第4期540-550,共11页
In this paper, globally-averaged, thermospheric total mass density, derived from the orbits of -5000 objects at 250, 400, and 550 km that were tracked from 1967 to 2006, has been used to quantitatively study the annua... In this paper, globally-averaged, thermospheric total mass density, derived from the orbits of -5000 objects at 250, 400, and 550 km that were tracked from 1967 to 2006, has been used to quantitatively study the annual asymmetry of thermospheric mass density and its mechanism(s). The results show that thermospheric mass density had a significant annual asymmetry, which changed from year to year. The annual asymmetry at the three altitudes varied synchronously and its absolute value increased with altitudes. The results suggest that there is an annual asymmetry in solar EUV radiation that is caused by the difference in the Sun-Earth distance between the two solstices and the random variation of solar activity within a year. This change in radiation results in an annual change in the thermospheric temperature and thus the scale height of the neutral gas, and is the main cause of the annual asymmetry of thermospheric mass density. The annual asymmetry of mass density increases with altitude because of the accumulating effect of the changes in neutral temperature and scale height in the vertical direction. 展开更多
关键词 annual asymmetry of thermospheric mass density solar EUV radiation Sun-Earth distance
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部