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Mass-Spring-Damper Model with Steady State Parameters for Predicting the Movement of Liquid Column and Temperature Oscillation in Loop Heat Pipe
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作者 Ge Zhang Di Chen +1 位作者 Yingying Hong Li Liu 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2016年第5期82-89,共8页
In order to investigate the mechanism of the temperature oscillation in loop heat pipes,this paper investigated the movement of the phase interface as the changed input power by a mass-spring-damper model.The model wa... In order to investigate the mechanism of the temperature oscillation in loop heat pipes,this paper investigated the movement of the phase interface as the changed input power by a mass-spring-damper model.The model was solved with MATLAB and was used to explain the high-frequency and low-amplitude temperature oscillation.Temperature variation with the input power from 20 W to 75 W was investigated based on a LHP prototype in a literature.The model agreed well with the experimental data in the literature.The simulation results suggested that the movement of the liquid column was caused by the fluctuation of pressure difference applied on the liquid column and the stiffness coefficients of the vapor springs increasing with the input power.According to parameter analyses,the temperature oscillation at the outlet of the condenser can be weakened by increasing the mass of the liquid column and keeping the temperature at the outlet of the condenser steady. 展开更多
关键词 loop heat pipe temperature oscillation DISPLACEMENT mass-spring-damper model steady state parameters
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Visualization Investigation on Temperature Oscillation and Two-Phase Behaviors of A Flat Loop Heat Pipe
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作者 DU Sheng ZHANG Quan +3 位作者 LING Li ZOU Sikai LIU Lijun MENG Fanxi 《Journal of Thermal Science》 SCIE EI CAS CSCD 2023年第4期1536-1546,共11页
To better analyzing the temperature oscillation and the two-phase behavior inside a flat loop heat pipe,visual studies were conducted.Under the 20℃ water cooling and horizontal orientation,the effects of the filling ... To better analyzing the temperature oscillation and the two-phase behavior inside a flat loop heat pipe,visual studies were conducted.Under the 20℃ water cooling and horizontal orientation,the effects of the filling ratio and heat loads on the temperature oscillation were analyzed.Based on the experimental data,the results indicate that owing to the increased system pressure,the temperature oscillation decays as the filling ratio increases from 34%to 58%.Meanwhile,during the startup process,temperature oscillation tends to occur during the boiling and steady stages due to the more violent two-phase behavior,while the temperature curves are smooth during the slow evaporation stage.Moreover,as the heat load increases,the evaporation becomes more intense at the active zone of evaporator,leading to a faster startup process and a higher oscillation frequency.Besides,owing to the synergistic effect of two-phase flow in the compensation chamber caused by heat leak and subcooled liquid backflowing,a“breathing”oscillation behavior of the vapor-liquid interface is observed at the compensation chamber,which further leads to the unstable operation behavior of the loop heat pipe system. 展开更多
关键词 loop heat pipe temperature oscillation visualization observations two-phase flow patterns start-up characteristics vapor-liquid interface fluctuation
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LARGE EDDY SIMULATION OF THERMALLY-STRATIFIED TURBULENT CHANNEL FLOW WITH TEMPERATURE OSCILLATION ON THE BOTTOM WALL 被引量:9
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作者 DONGYu-hong LUXi-yun ZHUANGLi-xian 《Journal of Hydrodynamics》 SCIE EI CSCD 2004年第1期34-38,共5页
Thermally-stratified shear turbulent channel flow with temperatureoscillation on the bottom wall of the channel was investigated with the Large Eddy Simulation (LES)approach coupled with dynamic Sub-Grid-Scale (SGS) m... Thermally-stratified shear turbulent channel flow with temperatureoscillation on the bottom wall of the channel was investigated with the Large Eddy Simulation (LES)approach coupled with dynamic Sub-Grid-Scale (SGS) models. The effect of temperature oscillation onthe turbulent channel flow behavior was examined. The phase-averaged velocities and temperature, andflow structures at different Richardson numbers and periods of the oscillation was analyzed. 展开更多
关键词 large eddy simulation (LES) turbulent channel flow thermally-stratifiedturbulence sub-grid scale (SGS) model oscillatory heat transfer temperature oscillation
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Interpretation of living tissue's temperature oscillations by thermal wave theory 被引量:5
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作者 刘静 任泽霈 王存诚 《Chinese Science Bulletin》 SCIE EI CAS 1995年第17期1493-1495,共3页
The fact that the temperature of living tissue may respond oscillatorily to externalheating has been a classical difficulty in the field of bioheat transfer for a long time.Roemer et al. have carefully discussed this ... The fact that the temperature of living tissue may respond oscillatorily to externalheating has been a classical difficulty in the field of bioheat transfer for a long time.Roemer et al. have carefully discussed this in their serial articles, but experiments did notsupport their conclusions, Tharp et al. have artificially made a time-delay differential equs-tion to describe this phenomenon, but their model is short of a strict theoretical founda- 展开更多
关键词 heat Interpretation of living tissue’s temperature oscillations by thermal wave theory wave
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East-west oscillation of sea temperature in the Equatorial Pacific and its modelling
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作者 Hu Zeyong and Tang Maocang Lanzhou Institute of Plateau Atmospheric physics, Academia Sinica, Lanzhou 730000, China 《Acta Oceanologica Sinica》 SCIE CAS CSCD 1993年第2期207-218,共12页
In this paper, by analyzing the data of sea temperature in the Equatorial Western Pacific (EWP), we found that the sea temperature at sensitive district (WSST) (about at 6° N, depth of 125-150 m) is correlated ne... In this paper, by analyzing the data of sea temperature in the Equatorial Western Pacific (EWP), we found that the sea temperature at sensitive district (WSST) (about at 6° N, depth of 125-150 m) is correlated negatively to the sea temperature in the Equatorial Eastern Pacific (EEP). On the basis of basic characteristics of Equatorial Pacific atmosphere and ocean, we designed a simple air-sea coupled model. Using this model,an ocean circulation was simulated. The east-west oscillation of sea temperature in Equatorial Pacific is related to this ocean circulation. 展开更多
关键词 East-west oscillation of sea temperature in the Equatorial Pacific and its modelling Nino
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The low frequency oscillations of the sea surface temperature in the Equatorial Eastern Pacific and El Nino formation
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作者 Zhou Faxiu and Yu Shenyu Ocean University of Oingdao, Qingdao, China 《Acta Oceanologica Sinica》 SCIE CAS CSCD 1989年第4期521-533,共13页
-In this paper the variations of the sea surface temperature anomalies (SSTA) in the Equatorial Eastern Pacific are analysed. The results show that there are two peaks in the spectrum. One is the low frequency oscilla... -In this paper the variations of the sea surface temperature anomalies (SSTA) in the Equatorial Eastern Pacific are analysed. The results show that there are two peaks in the spectrum. One is the low frequency oscillation with a period of 3 - 5 years, and the other is the quasi-biennial oscillation. The former shows a westward migration in the warm episode of SSTA and the latter has the opposite trend. The El Nino events will be formed while the two frquency bands are in phase in the warming stage of SSTA in the Equatorial Eastern Pacific 展开更多
关键词 Nino EI SSTA The low frequency oscillations of the sea surface temperature in the Equatorial Eastern Pacific and El Nino formation EL
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A Realistic Interpretation of Quantum Wavefunctions as Temperature Dependent Vacuum Polarization Waves
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作者 Gianpaolo Bei Roberto Li Voti 《Journal of Modern Physics》 2022年第6期892-917,共26页
We discuss in this paper a novel interpretation of Born rule as an approximated thermodynamic law which emerges from the interaction of a quantum system with a non-stationary thermal bath associated to vacuum fluctuat... We discuss in this paper a novel interpretation of Born rule as an approximated thermodynamic law which emerges from the interaction of a quantum system with a non-stationary thermal bath associated to vacuum fluctuations induced by external environment radiation. In particular we assume that vacuum polarization is a real non relativistic phenomena caused by hidden vacuum charge oscillations which diffuses heat energy in a dispersive and dissipative dielectric medium with a temperature dependent speed of propagation. We propose a model which couples vacuum wavefunctions to vacuum charge fluctuations and we deduce a temperature dependent running fine structure constant function proportional, at first approximation, to the squared of the effective electron charge and compatible with known experimental data. We interpret the vacuum symmetry breaking energy fluctuations induced in scattering experiments of particle physics and in laser assisted nuclear reactions as thermal quasi-monochromatic beams produced by the decay of hidden non equilibrium massive photons propagating with a variable light speed. We suggest, exploiting an old analogy between plasmons and pseudo Goldstone bosons, to interpret heat diffusion of this non relativistic polarized vacuum as a real De Broglie electromagnetic scalar wave associated to the radiation emitted by the hidden massive photons with acceleration proportional to vacuum Unruh like temperature. We predict a temperature dependent deviation from Coulomb law and a generalized dispersive law of these hidden unstable photons that could be revealed as not stationary coloured noise in experiments on anomalous heat diffusions associated to the decay of unstable accelerated pairs produced in nuclear physics experiments. We discuss then how our proposal of a temperature dependent non relativistic vacuum polarization might be applied to deduce a dynamic generalization of Born rule based on a realistic interpretation of quantum wavefunctions as averaged electromagnetic waves of hidden massive photons. Finally we suggest to test our time asymmetric model looking for very fast oscillating polarization thermal waves emitted during the not instantaneous wavefunction collapse and revealed as not stationary bulk heating effects in experiments on accelerated conductors and nanoconductors. 展开更多
关键词 Non Relativistic Vacuum Pilot Wave Hidden temperature Dependent Vacuum Index Hidden Unstable Massive Photons Space Time Dependent Vacuum temperature oscillations temperature Dependent Running Fine Structure Constant Vacuum temperature Induced Wave Collapse Generalized Born Rule
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Frequency Switches at Transition Temperature in Voltage-Gated Ion Channel Dynamics of Neural Oscillators
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作者 Yasuomi D.Sato 《Chinese Physics Letters》 SCIE CAS CSCD 2018年第5期152-155,共4页
Understanding of the mechanisms of neural phase transitions is crucial for clarifying cognitive processes in the brain. We investigate a neural oscillator that undergoes different bifurcation transitions from the big ... Understanding of the mechanisms of neural phase transitions is crucial for clarifying cognitive processes in the brain. We investigate a neural oscillator that undergoes different bifurcation transitions from the big saddle homoclinic orbit type to the saddle node on an invariant circle type, and the saddle node on an invariant circle type to the small saddle homoclinic orbit type. The bifurcation transitions are accompanied by an increase in thermodynamic temperature that affects the voltage-gated ion channel in the neural oscillator. We show that nonlinear and thermodynamical mechanisms are responsible for different switches of the frequency in the neural oscillator. We report a dynamical role of the phase response curve in switches of the frequency, in terms of slopes of frequency-temperature curve at each bifurcation transition. Adopting the transition state theory of voltagegated ion channel dynamics, we confirm that switches of the frequency occur in the first-order phase transition temperature states and exhibit different features of their potential energy derivatives in the ion channel. Each bifurcation transition also creates a discontinuity in the Arrhenius plot used to compute the time constant of the ion channel. 展开更多
关键词 Frequency Switches at Transition temperature in Voltage-Gated Ion Channel Dynamics of Neural Oscillators
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Impact of Temperature Variation on Performance of Carbon Nanotube Field-Effect Transistor-Based on Chaotic Oscillator:A Quantum Simulation Study
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作者 Van Ha Nguyen Hanjung Song 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第3期141-144,共4页
We evaluate the impact of temperature on the output behavior of a carbon nanotube field effect transistor (CNFET) based chaotic generator. The sources cause the variations in both current-voltage characteristics of ... We evaluate the impact of temperature on the output behavior of a carbon nanotube field effect transistor (CNFET) based chaotic generator. The sources cause the variations in both current-voltage characteristics of the CNFET device and an overall chaotic circuit is pointed out. To verify the effect of temperature variation on the output dynamics of the chaotic circuit, a simulation is performed by employing the CNFET compact model of Wong et al. in HSPICE with a temperature range from -100℃ to 100℃. The obtained results with time series, frequency spectra, and bifurcation diagram from the simulation demonstrate that temperature plays a significant role in the output dynamics of the CNFET-based chaotic circuit. Thus, temperature-related issues should be taken into account while designing a high-quality chaotic generator with high stability. 展开更多
关键词 CN Impact of temperature Variation on Performance of Carbon Nanotube Field-Effect Transistor-Based on Chaotic Oscillator:A Quantum Simulation Study HSPICE MOSFET
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Planck’s Oscillators at Low Temperatures and Haken’s Perturbation Approach to the Quantum Oscillators Reconsidered
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作者 Stanisław Olszewski 《Journal of Modern Physics》 2021年第12期1721-1728,共8页
In the first step the extremal values of the vibrational specific heat and entropy represented by the Planck oscillators at the low temperatures could be calculated. The positions of the extrema are defined by the dim... In the first step the extremal values of the vibrational specific heat and entropy represented by the Planck oscillators at the low temperatures could be calculated. The positions of the extrema are defined by the dimensionless ratios between the quanta of the vibrational energy and products of the actual temperature multiplied by the Boltzmann constant. It became evident that position of a local maximum obtained for the Planck’s average energy of a vibration mode and position of a local maximum of entropy are the same. In the next step the Haken’s time-dependent perturbation approach to the pair of quantum non-degenerate Schr<span style="white-space:nowrap;">?</span>dinger eigenstates of energy is re-examined. An averaging process done on the time variable leads to a very simple formula for the coefficients entering the perturbation terms. 展开更多
关键词 Planck’s Quantum Oscillators at Low temperatures Calculation of the Extremal Specific Heat of the Oscillator Energy and Extremal Entropy Simplified Haken’s Time-Dependent Approach to the Perturbation Energy of a Non-Degenerate Quantum State
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Causes of seasonal sea level anomalies in the coastal region of the East China Sea 被引量:2
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作者 WANG Hui LIU Kexiu +4 位作者 QI Dongmei GAO Zhigang FAN Wenjing ZHANG Zengjian WANG Guosong 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2016年第3期21-29,共9页
Based on the analysis of sea level, air temperature, sea surface temperature(SST), air pressure and wind data during 1980-2013, the causes of seasonal sea level anomalies in the coastal region of the East China Sea... Based on the analysis of sea level, air temperature, sea surface temperature(SST), air pressure and wind data during 1980-2013, the causes of seasonal sea level anomalies in the coastal region of the East China Sea(ECS) are investigated. The research results show:(1) sea level along the coastal region of the ECS takes on strong seasonal variation. The annual range is 30-45 cm, larger in the north than in the south. From north to south, the phase of sea level changes from 140° to 231°, with a difference of nearly 3 months.(2) Monthly mean sea level(MSL)anomalies often occur from August to next February along the coast region of the ECS. The number of sea level anomalies is at most from January to February and from August to October, showing a growing trend in recent years.(3) Anomalous wind field is an important factor to affect the sea level variation in the coastal region of the ECS. Monthly MSL anomaly is closely related to wind field anomaly and air pressure field anomaly. Wind-driven current is essentially consistent with sea surface height. In August 2012, the sea surface heights at the coastal stations driven by wind field have contributed 50%-80% of MSL anomalies.(4) The annual variations for sea level,SST and air temperature along the coastal region of the ECS are mainly caused by solar radiation with a period of12 months. But the correlation coefficients of sea level anomalies with SST anomalies and air temperature anomalies are all less than 0.1.(5) Seasonal sea level variations contain the long-term trends and all kinds of periodic changes. Sea level oscillations vary in different seasons in the coastal region of the ECS. In winter and spring, the oscillation of 4-7 a related to El Ni?o is stronger and its amplitude exceeds 2 cm. In summer and autumn, the oscillations of 2-3 a and quasi 9 a are most significant, and their amplitudes also exceed 2 cm. The height of sea level is lifted up when the different oscillations superposed. On the other hand, the height of sea level is fallen down. 展开更多
关键词 sea level anomalies ECS wind air pressure SST air temperature oscillations
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New design of high-precision oven controlled crystal oscillator 被引量:1
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作者 董绍锋 杜保强 周渭 《Journal of Beijing Institute of Technology》 EI CAS 2012年第3期362-369,共8页
Combining oven controlled technique,digital compensation,high-resolution frequency difference measurement and self-calibration technique,a new design method of precise oven controlled crystal oscillator(OCXO) is pro... Combining oven controlled technique,digital compensation,high-resolution frequency difference measurement and self-calibration technique,a new design method of precise oven controlled crystal oscillator(OCXO) is proposed.Fine compensation is made in the vicinity of the crystal temperature inflection point by using the non-real-time temperature compensation strategy,and self-calibration system is integrated in the crystal.The method improves the digital compensated phase noise,simplifies the traditional OCXO development system,reduces the cost and shortens the developing cycle.Experiment results show that with a standard reference signal and self-calibration updated data,the oscillator can work stable and achieve its best performence.The performance index of crystal oscillator had an improvement with one to two orders of magnitude on the basis of original technical index.The method is widely used in the improvement of high-end crystal oscillator and atomic clock. 展开更多
关键词 crystal oscillator temperature compensation non-real-time control frequency difference measurement self-calibration
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An Asymmetric Spatiotemporal Connection between the Euro-Atlantic Blocking within the NAO Life Cycle and European Climates 被引量:1
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作者 Yao YAO Dehai LUO 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2018年第7期796-812,共17页
This paper examines an asymmetric spatiotemporal connection and climatic impact between the winter atmospheric blocking activity in the Euro-Atlantic sector and the life cycle of the North Atlantic Oscillation(NAO) ... This paper examines an asymmetric spatiotemporal connection and climatic impact between the winter atmospheric blocking activity in the Euro-Atlantic sector and the life cycle of the North Atlantic Oscillation(NAO) during the period 1950–2012. Results show that, for positive NAO(NAO+) events, the instantaneous blocking(IB) frequency exhibits an enhancement along the southwest–northeast(SW–NE) direction from the eastern Atlantic to northeastern Europe(SW–NE pattern, hereafter), which is particularly evident during the NAO+decaying stage. By contrast, for negative NAO(NAO-)events, the IB frequency exhibits a spatially asymmetric southeast–northwest(SE–NW) distribution from central Europe to the North Atlantic and Greenland(SE–NW pattern, hereafter). Moreover, for NAO-(NAO+) events, the most marked decrease(increase) in the surface air temperature(SAT) in winter over northern Europe is in the decaying stage. For NAO+events, the dominant positive temperature and precipitation anomalies exhibit the SW–NE-oriented distribution from western to northeastern Europe, which is parallel to the NAO+-related blocking frequency distribution. For NAO-events, the dominant negative temperature anomaly is in northern and central Europe, whereas the dominant positive precipitation anomaly is distributed over southern Europe along the SW–NE direction. In addition, the downward infrared radiation controlled by the NAO's circulation plays a crucial role in the SAT anomaly distribution. It is further shown that the NAO's phase can act as an asymmetric impact on the European climate through producing this asymmetric spatiotemporal connection with the Euro-Atlantic IB frequency. 展开更多
关键词 North Atlantic oscillation blocking temperature precipitation asymmetry
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ON 3.5-YEAR COUPLED OSCILLATION BETWEEN NORTHERN OSCILLATION AND SEA SURFACE TEMPERATURE OF THE EQUATORIAL PACIFIC
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作者 陈烈庭 《Acta meteorologica Sinica》 SCIE 1989年第3期366-374,共9页
In this paper, we have analyzed the processes of temporal and spatial development in the interaction be- tween the Northern Oscillation and the sea surface temperature of the cquatorial Pacific. It is revealed that be... In this paper, we have analyzed the processes of temporal and spatial development in the interaction be- tween the Northern Oscillation and the sea surface temperature of the cquatorial Pacific. It is revealed that between them there is a closed negative feedback process and the whole period including their influence, feedback and adjustment to each other is about 3.5 years. Furthermore, we have discussed the physical processes responsible for various links between the Northern Oscillation and the sea surface temperature of the equatorial Pacific. A physical model on 3.5-year coupled oscillation caused by the air-sea interaction in the tropical Pacific is postulated. 展开更多
关键词 SST over ON 3.5-YEAR COUPLED oscillation BETWEEN NORTHERN oscillation AND SEA SURFACE temperature OF THE EQUATORIAL PACIFIC SEA
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