Based on ECMWF objective analysis data, and with use of Batterworth bandpass-filtered skill and diagnostic analysis method, the interaction characteristics of low frequency wave and mean flow in midlatitudes during t...Based on ECMWF objective analysis data, and with use of Batterworth bandpass-filtered skill and diagnostic analysis method, the interaction characteristics of low frequency wave and mean flow in midlatitudes during the winter years of 1983 / 1984 and 1986 / 1987 have been studied in this paper. The main results point out the important role of the tropical convective activity on the above mentioned interaction process.展开更多
The prediction of slug frequency has important significance on gas-liquid two-phase flow. A hydrody-namic modei was put forward to evaluate slug frequency for horizontal two-phase flow, based on the dependence of slug...The prediction of slug frequency has important significance on gas-liquid two-phase flow. A hydrody-namic modei was put forward to evaluate slug frequency for horizontal two-phase flow, based on the dependence of slug frequency on the frequency of unstable interfacial wave. Using air and water, experimental verification of the modei was carried out in a large range of flow parameters. Six electrical probes were installed at different positions of a horizontal plexiglass pipe to detect slug frequency development. The pipe is 30m long and its inner diameter is 24 mm. It is observed experimentally that the interfacial wave frequency at the inlet is about l to 3 times the frequency of stable slug. The slug frequencies predicted by the modei fit well with Tronconi (1990) modei and the experimental data. The combination of the hydrodynamic modei and the experimental data results in a conclusion that the frequency of equilibrium liquid slug is approximately half the miniraum frequency of interfacial wave.展开更多
Surface wave dynamics of falling film on the surface of periodic rectangular wall under monochromatic-frequency flowrate forcing disturbances is studied via numerical simulation. Waveforms formed on the periodic recta...Surface wave dynamics of falling film on the surface of periodic rectangular wall under monochromatic-frequency flowrate forcing disturbances is studied via numerical simulation. Waveforms formed on the periodic rectangular wall are different from those on the flat plate. At low frequency, the perturbation introduced at the inlet first undergoes a steady flow region and then develops into solitary waves. When the frequency becomes higher, solitary waves disappear. Film deformations in the steady flow region and characteristics of solitary waves are studied as the film travels down. There are circulations at the depression of periodic wall which are dependent on the local film characteristics and geometry of the corrugation. Moreover, the flow rate and geometry of the corrugations can also affect the evolvement of the monochromatic perturbation.展开更多
Purpose of the study is to identify the reason for the formation of the resistive factors in blood flow: inertial flow and turbulence in large arteries and increasing viscosity in the venous blood. Methods and Materia...Purpose of the study is to identify the reason for the formation of the resistive factors in blood flow: inertial flow and turbulence in large arteries and increasing viscosity in the venous blood. Methods and Materials: Blood flow velocities were studied in the different sites of the large vessels in 35 normal adults (15 men, 20 women, age 21 - 49 years) with the use of Magnetic Resonance Angiography. Blood radiodensity (HU) was measured by the CT scanner. Blood flow pulsatility, resistivity indexes were carried out with the Duplex US. Results: Resistive and pulsatility indexes for the ascending aorta are 0.96 ± 0.07 and 3.14. ± 1.7, abdominal aorta 0.91 ± 0.07 and 2.7 ± 1.3, carotid artery 0.74 ± 0.07 and 2.04 ± 0.53, pulmonary trunk 0.74 ± 0.11 and 1.49 ± 0.37, inferior vena cava 0.32 ± 0.21 and 0.69 ± 0.37. Blood radio density (in HU) in the ascending aorta is 57.3 ± 3.5, distal thoracic aorta 25.7 ± 3.1, and inferior vena cava 59.3 ± 3.3. Pulsation of the peak velocity is expressed at the external wall of the isthmus of aorta at the end of systole. Conclusion: Heart energy is stored in the elastic deformation of the blood cells and arterial walls, in kinetic energy of the blood flow, entropy of the system. Inertial blood flow due to the frequency dispersion in the arteries, transforms to the flow with the high fluidity in capillaries. Gibbs free energy increases, enabling spontaneous chemical reaction to proceed across the cell membrane. Process is altered in the venous blood. Changes in resistance express transformation of the energy in the substance.展开更多
The tokamak plasma flows induced by the local radio frequency （RF） forces in the core region are analyzed. The effective components of local RF forces are composed of the momentum absorption term and the resonant pa...The tokamak plasma flows induced by the local radio frequency （RF） forces in the core region are analyzed. The effective components of local RF forces are composed of the momentum absorption term and the resonant parallel momentum transport term （i.e. the parallel component of the resonant ponderomotive forces）. Different momentum balance relations are em- ployed to calculate the plasma flows depending on different assumptions of momentum transport. With the RF fields solved from RF simulation codes, the toroidal and poloidal flows by these forces under the lower hybrid current drive and the mode conversion ion cyclotron resonance heating on EAST-like plasmas are evaluated.展开更多
Based on a sample of some real earthquakes,we have suggested in previous papers that there is a density-tectonic stress wave with ultra-low frequency which is emitted from the epicenter region for months before earthq...Based on a sample of some real earthquakes,we have suggested in previous papers that there is a density-tectonic stress wave with ultra-low frequency which is emitted from the epicenter region for months before earthquakes,and a micro-fracture wave 1 ～ 10 days before earthquakes. The former has been observed by different kinds of measurements and the latter has been observed by a few chance observations which consists of electromagnetic,gravitational and sonic fluctuations. We show real observational results that depict the two waves and they have very different frequencies,which are not difficult to discriminate. The classical elastic-rebound model is one of the most influential theories on earthquakes,and the thermodynamic elastic-rebound model has amended the classical framework. Considering the two waves above,we attempt to further modify the elasticrebound model,and the new framework could be called the "micro-fracture elasticrebound model". We infer that tectonic earthquakes could have three special phases: the accumulation of tectonic stress,micro-fracture,and main-fracture. Accordingly,there would be three waves which come from the epicenter of a tectonic earthquake,i. e. ,the tectonic stress wave with ultra-low frequency a few months before the earthquake,the micro-fracture wave about 1 ～ 10 days before the earthquake and the main-fracture wave (common earthquake wave).展开更多
Through a simple review of low-frequency variation of blocking pattern and diagnoses of observational data and combining some experience in forecast practice,we put forward some thought about the mechanism of formatio...Through a simple review of low-frequency variation of blocking pattern and diagnoses of observational data and combining some experience in forecast practice,we put forward some thought about the mechanism of formation and maintenance of the blocking flow pattern from the synoptic/climatological point of view,It is emphasized that eastward moving and deepening of troughs in the upstream of the blocking high,the SST anomalies and topography effect are the main factors of impelling the variation of the blocking high.During the maintenance of Ural blocking high wave-flow interactions are studied through disposition of baroclinic trough(transient wave)and the blocking flow.This study will offer a primary basis for the further theoretical study on the formation mechanism of the blocking high.展开更多
文摘Based on ECMWF objective analysis data, and with use of Batterworth bandpass-filtered skill and diagnostic analysis method, the interaction characteristics of low frequency wave and mean flow in midlatitudes during the winter years of 1983 / 1984 and 1986 / 1987 have been studied in this paper. The main results point out the important role of the tropical convective activity on the above mentioned interaction process.
基金National Natural Science Foundation of China(No.50206016)
文摘The prediction of slug frequency has important significance on gas-liquid two-phase flow. A hydrody-namic modei was put forward to evaluate slug frequency for horizontal two-phase flow, based on the dependence of slug frequency on the frequency of unstable interfacial wave. Using air and water, experimental verification of the modei was carried out in a large range of flow parameters. Six electrical probes were installed at different positions of a horizontal plexiglass pipe to detect slug frequency development. The pipe is 30m long and its inner diameter is 24 mm. It is observed experimentally that the interfacial wave frequency at the inlet is about l to 3 times the frequency of stable slug. The slug frequencies predicted by the modei fit well with Tronconi (1990) modei and the experimental data. The combination of the hydrodynamic modei and the experimental data results in a conclusion that the frequency of equilibrium liquid slug is approximately half the miniraum frequency of interfacial wave.
基金Supported by National Natural Science Foundation of China (No. 20976118)
文摘Surface wave dynamics of falling film on the surface of periodic rectangular wall under monochromatic-frequency flowrate forcing disturbances is studied via numerical simulation. Waveforms formed on the periodic rectangular wall are different from those on the flat plate. At low frequency, the perturbation introduced at the inlet first undergoes a steady flow region and then develops into solitary waves. When the frequency becomes higher, solitary waves disappear. Film deformations in the steady flow region and characteristics of solitary waves are studied as the film travels down. There are circulations at the depression of periodic wall which are dependent on the local film characteristics and geometry of the corrugation. Moreover, the flow rate and geometry of the corrugations can also affect the evolvement of the monochromatic perturbation.
文摘Purpose of the study is to identify the reason for the formation of the resistive factors in blood flow: inertial flow and turbulence in large arteries and increasing viscosity in the venous blood. Methods and Materials: Blood flow velocities were studied in the different sites of the large vessels in 35 normal adults (15 men, 20 women, age 21 - 49 years) with the use of Magnetic Resonance Angiography. Blood radiodensity (HU) was measured by the CT scanner. Blood flow pulsatility, resistivity indexes were carried out with the Duplex US. Results: Resistive and pulsatility indexes for the ascending aorta are 0.96 ± 0.07 and 3.14. ± 1.7, abdominal aorta 0.91 ± 0.07 and 2.7 ± 1.3, carotid artery 0.74 ± 0.07 and 2.04 ± 0.53, pulmonary trunk 0.74 ± 0.11 and 1.49 ± 0.37, inferior vena cava 0.32 ± 0.21 and 0.69 ± 0.37. Blood radio density (in HU) in the ascending aorta is 57.3 ± 3.5, distal thoracic aorta 25.7 ± 3.1, and inferior vena cava 59.3 ± 3.3. Pulsation of the peak velocity is expressed at the external wall of the isthmus of aorta at the end of systole. Conclusion: Heart energy is stored in the elastic deformation of the blood cells and arterial walls, in kinetic energy of the blood flow, entropy of the system. Inertial blood flow due to the frequency dispersion in the arteries, transforms to the flow with the high fluidity in capillaries. Gibbs free energy increases, enabling spontaneous chemical reaction to proceed across the cell membrane. Process is altered in the venous blood. Changes in resistance express transformation of the energy in the substance.
基金supported by National Natural Science Foundation of China(Nos.11405218,11325524,11375235 and 11261140327)in part by the National Magnetic Confinement Fusion Science Program of China(Nos.2013GB111002,2013GB112001 and 2013GB112010)the Program of Fusion Reactor Physics and Digital Tokamak with the CAS"One-Three-Five"Strategic Planning
文摘The tokamak plasma flows induced by the local radio frequency （RF） forces in the core region are analyzed. The effective components of local RF forces are composed of the momentum absorption term and the resonant parallel momentum transport term （i.e. the parallel component of the resonant ponderomotive forces）. Different momentum balance relations are em- ployed to calculate the plasma flows depending on different assumptions of momentum transport. With the RF fields solved from RF simulation codes, the toroidal and poloidal flows by these forces under the lower hybrid current drive and the mode conversion ion cyclotron resonance heating on EAST-like plasmas are evaluated.
文摘Based on a sample of some real earthquakes,we have suggested in previous papers that there is a density-tectonic stress wave with ultra-low frequency which is emitted from the epicenter region for months before earthquakes,and a micro-fracture wave 1 ～ 10 days before earthquakes. The former has been observed by different kinds of measurements and the latter has been observed by a few chance observations which consists of electromagnetic,gravitational and sonic fluctuations. We show real observational results that depict the two waves and they have very different frequencies,which are not difficult to discriminate. The classical elastic-rebound model is one of the most influential theories on earthquakes,and the thermodynamic elastic-rebound model has amended the classical framework. Considering the two waves above,we attempt to further modify the elasticrebound model,and the new framework could be called the "micro-fracture elasticrebound model". We infer that tectonic earthquakes could have three special phases: the accumulation of tectonic stress,micro-fracture,and main-fracture. Accordingly,there would be three waves which come from the epicenter of a tectonic earthquake,i. e. ,the tectonic stress wave with ultra-low frequency a few months before the earthquake,the micro-fracture wave about 1 ～ 10 days before the earthquake and the main-fracture wave (common earthquake wave).
基金National Natural Science Foundation of China under Grant No.49675257.
文摘Through a simple review of low-frequency variation of blocking pattern and diagnoses of observational data and combining some experience in forecast practice,we put forward some thought about the mechanism of formation and maintenance of the blocking flow pattern from the synoptic/climatological point of view,It is emphasized that eastward moving and deepening of troughs in the upstream of the blocking high,the SST anomalies and topography effect are the main factors of impelling the variation of the blocking high.During the maintenance of Ural blocking high wave-flow interactions are studied through disposition of baroclinic trough(transient wave)and the blocking flow.This study will offer a primary basis for the further theoretical study on the formation mechanism of the blocking high.
