Taking the Gaussian Schell-model beam as a typical example of partially coherent beams, this paper applies the simulated annealing （SA） algorithm to the design of phase plates for shaping partially coherent beams. A...Taking the Gaussian Schell-model beam as a typical example of partially coherent beams, this paper applies the simulated annealing （SA） algorithm to the design of phase plates for shaping partially coherent beams. A flow diagram is presented to illustrate the procedure of phase optimization by the SA algorithm. Numerical examples demonstrate the advantages of the SA algorithm in shaping partially coherent beams. An uniform flat-topped beam profile with maximum reconstruction error RE 〈 1.74% is achieved. A further extension of the approach is discussed.展开更多
The intensity distribution of depolarized field in the focal region of a high numerical-aperture optical system was investigated and found that the depolarization effect is tunable by the plate. The depolarization eff...The intensity distribution of depolarized field in the focal region of a high numerical-aperture optical system was investigated and found that the depolarization effect is tunable by the plate. The depolarization effect gains with the increase of the inner convergence angle of the phase plate, goes through a dramatic descent when the angle is larger than 30°, and begins to come back when the angle reaches a threshold of respectively 60°and 65° for the orthogonal diffractive field and the longitudinal diffractive fields. This reveals two convergence points where the depolarization effect is the strongest and weakest, respectively, suggesting that the pure phase plate can be a promising method for altering depolarization diffractive fields and constructing optical instruments.展开更多
We propose and demonstrate the use of random phase plates(RPPs)for high-energy sub-picosecond lasers.Contrarily to previous work related to nanosecond lasers,an RPP poses technical challenges with ultrashort-pulse las...We propose and demonstrate the use of random phase plates(RPPs)for high-energy sub-picosecond lasers.Contrarily to previous work related to nanosecond lasers,an RPP poses technical challenges with ultrashort-pulse lasers.Here,we implement the RPP near the beginning of the amplifier and image-relay it throughout the laser amplifier.With this,we obtain a uniform intensity distribution in the focus over an area 1600 times the diffraction limit.This method shows no significant drawbacks for the laser and it has been implemented at the PHELIX laser facility where it is now available for users.展开更多
A novel technique of producing azimuthal index 1>1 doughnut beam of good quality by use of multi-liquid crystal cells is presented, it has the advantages of high conversion efficiency and flexibility.
Light carrying orbital angular momentum(OAM) has a spatial distribution of intensity and phase, which attracts considerable interest regarding several potential applications in optical and quantum scenarios recently. ...Light carrying orbital angular momentum(OAM) has a spatial distribution of intensity and phase, which attracts considerable interest regarding several potential applications in optical and quantum scenarios recently. Spiral phase plates are commonly used elements for generating and analyzing OAM states. In this study, we put forward a method of directly writing binary multi-sector phase plates using the femtosecond laser. These phase plates are engraved on fused silica, which could be applied in high-intensity regimes. Different binary multi-sector phase plates were generated with high quality, which were proved by the observation of their structures, accompanied by detecting the beam patterns with the Gaussian beams. The proposed method provides a crucial basis for the rapid manufacturing of phase plates using convenient equipment, which can generate the superposition OAM states and may lead to the capability of measuring the high-dimensional entanglement.展开更多
During subduction, continental margins experience shortening along with inversion of extensional sedimentary basins. Here we explore a tectonic scenario for the inversion of two-phase extensional basin systems, where ...During subduction, continental margins experience shortening along with inversion of extensional sedimentary basins. Here we explore a tectonic scenario for the inversion of two-phase extensional basin systems, where the Early-Middle Jurassic intra-arc volcano-sedimentary Oseosan Volcanic Complex was developed on top of the Late Triassic-Early Jurassic post-collisional sequences, namely the Chungnam Basin. The basin shortening was accommodated mostly by contractional faults and related folds. In the basement, regional high-angle reverse faults as well as low-angle thrusts accommodate the overall shortening, and are compatible with those preserved in the cover. This suggests that their spatial and temporal development is strongly dependent on the initial basin geometry and inherited structures.Changes in transport direction observed along the basement-sedimentary cover interface is a characteristic structural feature, reflecting sequential kinematic evolution during basin inversion. Propagation of basement faults also enhanced shortening of the overlying sedimentary cover sequences. We constrain timing of the Late Jurassic-Early Cretaceous(ca. 158-110 Ma) inversion from altered K-feldspar 40 Ar/39 Ar ages in stacked thrust sheets and K-Ar illite ages of fault gouges, along with previously reported geochronological data from the area. This "non-magmatic phase" of the Daebo Orogeny is contemporaneous with the timing of magmatic quiescence across the Korean Peninsula. We propose the role of flat/low-angle subduction of the Paleo-Pacific Plate for the development of the "Laramide-style" basement-involved orogenic event along East Asian continental margin.展开更多
Today, latent heat storage technology has advanced to allow reuse of waste heat in the middle-temperature range. This paper describes an approach to develop a latent heat storage system using middle-temperature waste ...Today, latent heat storage technology has advanced to allow reuse of waste heat in the middle-temperature range. This paper describes an approach to develop a latent heat storage system using middle-temperature waste heat (~100oC - 200oC) from factories. Direct contact melting and solidification behavior between a heat-transfer fluid (oil) and a latent heat storage material mixture were observed. The mixture consisted of mannitol and erythritol (Cm = 70 mass %, Ce = 30 mass %) as a phase-change material (PCM). The weight of the PCM was 3.0 kg and the flow rate of the oil, foil, was 1.0, 1.5, or 2.0 kg/min. To decrease the solidified height of the PCM mixture during the solidification process, a perforated partition plate was installed in the PCM region in the heat storage vessel. PCM coated oil droplets were broken by the perforated partition plate, preventing the solidified height of the PCM from increasing. The solidification and melting processes were repeated using metal fiber. It was found that installing the metal fiber was more effective than installing the perforated partition plate to prevent the flow out problem of the PCM.展开更多
This paper investigates a new vortex wave imaging approach to improve the imaging quality of small metal targets of size less than 1.5 mm.Antennas with different spiral phase plates are designed to efficiently transmi...This paper investigates a new vortex wave imaging approach to improve the imaging quality of small metal targets of size less than 1.5 mm.Antennas with different spiral phase plates are designed to efficiently transmit vortex beams with orbital angular momentums(OAMs).By analyzing the OAM spectrum of the target,it was discovered that the predominant reflection contains a particular OAM mode that carries abundant azimuthal information.This can be explained by the OAM selectivity of the target and the guidance of the vortex transmitting beam.A simple reflection vortex imaging system was designed to capture the phase information.Measurement results show that the high image contrast reaches 14.9%,which is twice as high as that of the imaging without OAM.Both of simulations and experiments demonstrate that the vortex phase imaging approach proposed in this paper can effectively improve the imaging quality at 80 GHz.This approach is suitable for other millimeter wave imaging systems and is helpful to improve the resolution in anti-terrorism security checks.展开更多
A phase contrast imaging（PCI） diagnostic has recently been developed on HL-2 A tokamak. It can diagnose plasma density fluctuations with maximum wave number of 15 cm^（-1） and wave number resolution of 2 cm^（-1）....A phase contrast imaging（PCI） diagnostic has recently been developed on HL-2 A tokamak. It can diagnose plasma density fluctuations with maximum wave number of 15 cm^（-1） and wave number resolution of 2 cm^（-1）. The time resolution reaches 2 μs. A 10.6 μm CO_2 laser is expanded to a beam with a diameter of 30 mm and injected into the plasma as an incident beam,injecting into plasma. The emerging scattered and unscattered beams are contrasted by a phase plate. The ideas of optical path design are presented in this paper, together with the parameters of the main optical components. The whole optical path of PCI is not only carefully designed, but also constructed on HL-2 A. First calibration results show the ability of this system to catch plasma turbulence in a wide frequency domain.展开更多
We present an ultrasonic method for determining the thickness of a composite consisting of a soft thin film attached to a hard plate substrate, by resonance spectra in the low frequency region, The interrogating waves...We present an ultrasonic method for determining the thickness of a composite consisting of a soft thin film attached to a hard plate substrate, by resonance spectra in the low frequency region, The interrogating waves can be incident only to the two-layered composite from the substrate side. The reflection spectra are obtained by FFT analysis of the compressive pulsed echoes from the composite, and the thicknesses of the film and the substrate are simultaneously inversed by the simulated annealing method from the resonant frequencies knowing other acoustical parameters in prior. The sensitivity of the method to individual thickness, its convergence and stability against experimental noises are studied, Experiment with interrogating wavelength 4 times larger than the film thickness in a sample of a polymer film （0.054mm） on an aluminium plate （6.24mm） verifies the validity of the method. The average relative errors in the measurement of the thicknesses of the film and the substrate are found to be -4.1% and -0.62%, respectively.展开更多
Holding temperature and holding thickness are main parameters for two-phase controlled rolling on plate mill. The optimization of holding temperature and holding thickness for pass schedule calculation of two-phase co...Holding temperature and holding thickness are main parameters for two-phase controlled rolling on plate mill. The optimization of holding temperature and holding thickness for pass schedule calculation of two-phase controlled rolling on plate mill was presented and its feature is as follows： （1） Determination of holding thickness can be automatically obtained based on the influence of mill safety limits, tracking zone length and holding time on holding thickness; （2） Determination of holding temperature can be automatically obtained and the holding time can be reduced as much as possible; （3） Algorithm can modify the holding temperature and thickness depending on slab size and product size.展开更多
Heat exchangers are devices in which heat is transferred from one fluid to another fluid as a result of temperature difference. Heat exchanger presented in the current paper in which inside the tubes flows water, but ...Heat exchangers are devices in which heat is transferred from one fluid to another fluid as a result of temperature difference. Heat exchanger presented in the current paper in which inside the tubes flows water, but outside the tubes flows air aims to enable cooling of circulating water, which serves to cool the engine of a machine. Such exchangers find application in the automotive industry as well as heating and cooling equipment and HVAC systems etc. The surface of the heat exchanger by the air side always tends to be much larger using surface fins in order to facilitate equalization of thermal resistance for both sides of the heat exchanger, because the rate of transmission of heat from the water side is much greater. Furthermore, the paper will present analytical and experimental studies involved for determination of performance of plate-fin heat exchanger for various flows of working fluids in order to get the highest values of performances i.e.: overall heat transfer coefficient U, efficiency of heat exchanger ε, maximal and real heat transferred, pressure drop, air velocity and Reynolds number from the air side of heat exchanger etc. The present scientific paper is based on the fact that from the experimental model made for laboratory conditions, conclusions are derived that can be used during installation of such heat exchanger on certain machines in order to predict their performance.展开更多
A thermal heat storage system with an energy content of 40 kWh and a temperature of 58°C will be presented. This storage system is suitable for supporting the use of renewable energies in buildings and for absorb...A thermal heat storage system with an energy content of 40 kWh and a temperature of 58°C will be presented. This storage system is suitable for supporting the use of renewable energies in buildings and for absorbing solar heat, heat from co-generation and heat pumps or electric heat from excess wind and solar power. The storage system is equipped with a plate heat exchanger that is so powerful that even with small temperature differences between the flow temperature and the storage temperature a high load dynamic is achieved. The storage system has a performance of 2.8 kW at 4 K and 10.6 kW at a temperature difference of 10 K. Thus, large performance variations in solar thermal systems or CHP plants can be buffered very well. Further a storage charge function Q(T, t) will be presented to characterize the performance of the storage.展开更多
A two-dimensional binary driven disk system embedded by impermeable tilted plates is investigated through nonequilibrium computer simulations. It is well known that a binary disk system in which two particle species a...A two-dimensional binary driven disk system embedded by impermeable tilted plates is investigated through nonequilibrium computer simulations. It is well known that a binary disk system in which two particle species are driven in opposite directions exhibits jammed, phase separated, disordered, and laning states. The presence of tilted plates can not only advance the formation of laning phase, but also effectively stabilize laning phase by suppressing massively drifting behavior perpendicular to the driving force. The lane width distribution can be controlled easily by the interplate distance. The collective behavior of driven particles in laning phase is guided by the funnel-shaped confinements constituted by the neighboring tilted plates. Our results provide the important clues for investigating the mechanism of laning formation in driven system.展开更多
A multi-step isothermal forging and subsequent multipass rolling was used to produce one kind of two phase titanium alloy plate with thickness of 2.2 mm. Tensile properties at ambient temperature and at two kinds of h...A multi-step isothermal forging and subsequent multipass rolling was used to produce one kind of two phase titanium alloy plate with thickness of 2.2 mm. Tensile properties at ambient temperature and at two kinds of high temperatures were investigated for the plate with submicrocrystalline (SMC) structure in present work. Microstructures and fractographies of the alloy plate before and after tensile tests were also observed by scanning electron microscope. The results indicated that the alloy possesses favorite integrated tensile properties at ambient temperature, the average UTS and elongation for the longitudinal sample is 1070 MPa and 20%, while which for the transverse sample is 1103 MPa and 15%. The tensile elongation of the alloy plate is as high as 1078% at 780°C with a primary strain rate of 1.7 × 10<sup>-3</sup> s<sup>-1</sup>. The microstructure is fine for the alloy plate solutioned at 700°C for 1 h, AC, and the grain size after tensile test is 2 μm and 3 μm for the longitudinal and transverse plates. Fractography for the as-annealed plate is composed of a large number of dimples and voids after tensile test at ambient temperature.展开更多
A new type of umbrella plate scrubber was developed to address the pollution due to the dust,dioxide sulfur and other harmful gases,which were emitted from coal-burning boilers.The performance of the new device was st...A new type of umbrella plate scrubber was developed to address the pollution due to the dust,dioxide sulfur and other harmful gases,which were emitted from coal-burning boilers.The performance of the new device was studied through computational fluid dynamics(CFD)simulation and experiment methods.Initial work included experimental measurement of inlet-velocity,and gas phase simulation using Reynolds stress model(RSM).After gas phase was converged,particles were injected from the inlet of the new device.Discrete phase model(DPM)was used for particle trajectories determination.The pressure drop and the collection efficiency of the new device were predicted through simulation.The simulation results show that the pressure drop of the new devices is 230?250 Pa and the efficiency is 84%-86%,with the inlet velocity equal to 10.6 m/s and the dust concentration ranging from 2 to 22 g/m 3 .The CFD simulation results of the new device show good agreement with experimental data.The relative error of the pressure drop and the efficiency is approximately 4%and 10%respectively.The results obtained both from the numerical simulation and from the experiment demonstrate that CFD simulation is an effective method for this type of study.展开更多
Dual-plate structure is very effective in the protection of space vehicle from hypervelocity im- pact.The experiments of A1 projectile impacting A1 dual targets at the velocity ranging over 2.5—7.0 km/s were systemat...Dual-plate structure is very effective in the protection of space vehicle from hypervelocity im- pact.The experiments of A1 projectile impacting A1 dual targets at the velocity ranging over 2.5—7.0 km/s were systematically conducted.The damage effects were examined,including the perforation of the shield, the development of debris cloud and the general damage characteristics of the subplate.Many valuable experi- mental data and phenomena have been obtained展开更多
A dynamic solution is presented for the propagation of waves in an electric-magneto-elastic plate composed of piezoelectric, piezomagnetic materials and elastic matrix. The electric-magneto-elastic plate is polarized ...A dynamic solution is presented for the propagation of waves in an electric-magneto-elastic plate composed of piezoelectric, piezomagnetic materials and elastic matrix. The electric-magneto-elastic plate is polarized along the thickness direction. The generalized displacements are expressed as the sum of the gradient of a scalar (dilatation wave) and the curl of a vector (shear wave). With the help of dynamic equilibrium equations and geometric equations, we can obtain dynamic equations of the dilatation wave and the shear wave. The conclusion that the types of the dilatation waves and the shear waves remain unchanged after being reflected by the boundary can be obtained through the analysis of these kinetic equations. The dispersion properties and phase velocity surface of the dilatation and shear wave can be obtained by solutions of dynamic equilibrium equations. Influences of the piezoelectric and piezomagnetic parameters on wave characteristics are discussed.展开更多
基金supported by the National Natural Science Foundation of China (Grant No 10574097)
文摘Taking the Gaussian Schell-model beam as a typical example of partially coherent beams, this paper applies the simulated annealing （SA） algorithm to the design of phase plates for shaping partially coherent beams. A flow diagram is presented to illustrate the procedure of phase optimization by the SA algorithm. Numerical examples demonstrate the advantages of the SA algorithm in shaping partially coherent beams. An uniform flat-topped beam profile with maximum reconstruction error RE 〈 1.74% is achieved. A further extension of the approach is discussed.
基金Funded by the Natural Science Foundation of China under the Grant No. 60608009.
文摘The intensity distribution of depolarized field in the focal region of a high numerical-aperture optical system was investigated and found that the depolarization effect is tunable by the plate. The depolarization effect gains with the increase of the inner convergence angle of the phase plate, goes through a dramatic descent when the angle is larger than 30°, and begins to come back when the angle reaches a threshold of respectively 60°and 65° for the orthogonal diffractive field and the longitudinal diffractive fields. This reveals two convergence points where the depolarization effect is the strongest and weakest, respectively, suggesting that the pure phase plate can be a promising method for altering depolarization diffractive fields and constructing optical instruments.
基金European Union’s Horizon 2020 research and innovation program under grant agreement number 633053。
文摘We propose and demonstrate the use of random phase plates(RPPs)for high-energy sub-picosecond lasers.Contrarily to previous work related to nanosecond lasers,an RPP poses technical challenges with ultrashort-pulse lasers.Here,we implement the RPP near the beginning of the amplifier and image-relay it throughout the laser amplifier.With this,we obtain a uniform intensity distribution in the focus over an area 1600 times the diffraction limit.This method shows no significant drawbacks for the laser and it has been implemented at the PHELIX laser facility where it is now available for users.
文摘A novel technique of producing azimuthal index 1>1 doughnut beam of good quality by use of multi-liquid crystal cells is presented, it has the advantages of high conversion efficiency and flexibility.
基金the financial support by the Youth Innovation Promotion Association, Chinese Academy of Sciences
文摘Light carrying orbital angular momentum(OAM) has a spatial distribution of intensity and phase, which attracts considerable interest regarding several potential applications in optical and quantum scenarios recently. Spiral phase plates are commonly used elements for generating and analyzing OAM states. In this study, we put forward a method of directly writing binary multi-sector phase plates using the femtosecond laser. These phase plates are engraved on fused silica, which could be applied in high-intensity regimes. Different binary multi-sector phase plates were generated with high quality, which were proved by the observation of their structures, accompanied by detecting the beam patterns with the Gaussian beams. The proposed method provides a crucial basis for the rapid manufacturing of phase plates using convenient equipment, which can generate the superposition OAM states and may lead to the capability of measuring the high-dimensional entanglement.
基金supported by Basic Science Research Program through National Research Foundation of Korea funded by the Ministry of Education, Science and Technology (2018R1C 186003851)to S.-I. Park and 2015RIDlAIA09058914 and NRF2019R1A2C1002211 to S. Kwonsupported by the 2017RlA6A1A07015374(Multidisciplinary study forassessment of large earthquake potentials in the Korean Peninsula) through the National Research Foundation of Korea(NRF)funded by the Ministry of Science and ICT, Korea to S.K
文摘During subduction, continental margins experience shortening along with inversion of extensional sedimentary basins. Here we explore a tectonic scenario for the inversion of two-phase extensional basin systems, where the Early-Middle Jurassic intra-arc volcano-sedimentary Oseosan Volcanic Complex was developed on top of the Late Triassic-Early Jurassic post-collisional sequences, namely the Chungnam Basin. The basin shortening was accommodated mostly by contractional faults and related folds. In the basement, regional high-angle reverse faults as well as low-angle thrusts accommodate the overall shortening, and are compatible with those preserved in the cover. This suggests that their spatial and temporal development is strongly dependent on the initial basin geometry and inherited structures.Changes in transport direction observed along the basement-sedimentary cover interface is a characteristic structural feature, reflecting sequential kinematic evolution during basin inversion. Propagation of basement faults also enhanced shortening of the overlying sedimentary cover sequences. We constrain timing of the Late Jurassic-Early Cretaceous(ca. 158-110 Ma) inversion from altered K-feldspar 40 Ar/39 Ar ages in stacked thrust sheets and K-Ar illite ages of fault gouges, along with previously reported geochronological data from the area. This "non-magmatic phase" of the Daebo Orogeny is contemporaneous with the timing of magmatic quiescence across the Korean Peninsula. We propose the role of flat/low-angle subduction of the Paleo-Pacific Plate for the development of the "Laramide-style" basement-involved orogenic event along East Asian continental margin.
文摘Today, latent heat storage technology has advanced to allow reuse of waste heat in the middle-temperature range. This paper describes an approach to develop a latent heat storage system using middle-temperature waste heat (~100oC - 200oC) from factories. Direct contact melting and solidification behavior between a heat-transfer fluid (oil) and a latent heat storage material mixture were observed. The mixture consisted of mannitol and erythritol (Cm = 70 mass %, Ce = 30 mass %) as a phase-change material (PCM). The weight of the PCM was 3.0 kg and the flow rate of the oil, foil, was 1.0, 1.5, or 2.0 kg/min. To decrease the solidified height of the PCM mixture during the solidification process, a perforated partition plate was installed in the PCM region in the heat storage vessel. PCM coated oil droplets were broken by the perforated partition plate, preventing the solidified height of the PCM from increasing. The solidification and melting processes were repeated using metal fiber. It was found that installing the metal fiber was more effective than installing the perforated partition plate to prevent the flow out problem of the PCM.
基金Science,Technology and Innovation Project of Xiongan New Area (Grant No.2022XAGG0181)LiaoNing Revitalization Talents Program (Grant No.XLYC2007074)+1 种基金Shenyang Young and Middle-aged Science and Technology Innovation Talent Support Program (Grant No.RC220523)Natural Science Foundation of Liaoning Province of China (Grant Nos.2022-YGJC-03 and 2022-MS-034)to provide fund for conducting experiments。
文摘This paper investigates a new vortex wave imaging approach to improve the imaging quality of small metal targets of size less than 1.5 mm.Antennas with different spiral phase plates are designed to efficiently transmit vortex beams with orbital angular momentums(OAMs).By analyzing the OAM spectrum of the target,it was discovered that the predominant reflection contains a particular OAM mode that carries abundant azimuthal information.This can be explained by the OAM selectivity of the target and the guidance of the vortex transmitting beam.A simple reflection vortex imaging system was designed to capture the phase information.Measurement results show that the high image contrast reaches 14.9%,which is twice as high as that of the imaging without OAM.Both of simulations and experiments demonstrate that the vortex phase imaging approach proposed in this paper can effectively improve the imaging quality at 80 GHz.This approach is suitable for other millimeter wave imaging systems and is helpful to improve the resolution in anti-terrorism security checks.
基金supported by the National Magnetic Confinement Fusion Energy Research Project(Grant Nos.2015GB120002,2013GB107000,2012GB101001)National Natural Science Foundation of China(Grant Nos.11375053,11535013)the Natural Science Foundation of Anhui Province(Grant No.1608085MA08)
文摘A phase contrast imaging（PCI） diagnostic has recently been developed on HL-2 A tokamak. It can diagnose plasma density fluctuations with maximum wave number of 15 cm^（-1） and wave number resolution of 2 cm^（-1）. The time resolution reaches 2 μs. A 10.6 μm CO_2 laser is expanded to a beam with a diameter of 30 mm and injected into the plasma as an incident beam,injecting into plasma. The emerging scattered and unscattered beams are contrasted by a phase plate. The ideas of optical path design are presented in this paper, together with the parameters of the main optical components. The whole optical path of PCI is not only carefully designed, but also constructed on HL-2 A. First calibration results show the ability of this system to catch plasma turbulence in a wide frequency domain.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10474113 and 10234060.
文摘We present an ultrasonic method for determining the thickness of a composite consisting of a soft thin film attached to a hard plate substrate, by resonance spectra in the low frequency region, The interrogating waves can be incident only to the two-layered composite from the substrate side. The reflection spectra are obtained by FFT analysis of the compressive pulsed echoes from the composite, and the thicknesses of the film and the substrate are simultaneously inversed by the simulated annealing method from the resonant frequencies knowing other acoustical parameters in prior. The sensitivity of the method to individual thickness, its convergence and stability against experimental noises are studied, Experiment with interrogating wavelength 4 times larger than the film thickness in a sample of a polymer film （0.054mm） on an aluminium plate （6.24mm） verifies the validity of the method. The average relative errors in the measurement of the thicknesses of the film and the substrate are found to be -4.1% and -0.62%, respectively.
文摘Holding temperature and holding thickness are main parameters for two-phase controlled rolling on plate mill. The optimization of holding temperature and holding thickness for pass schedule calculation of two-phase controlled rolling on plate mill was presented and its feature is as follows： （1） Determination of holding thickness can be automatically obtained based on the influence of mill safety limits, tracking zone length and holding time on holding thickness; （2） Determination of holding temperature can be automatically obtained and the holding time can be reduced as much as possible; （3） Algorithm can modify the holding temperature and thickness depending on slab size and product size.
文摘Heat exchangers are devices in which heat is transferred from one fluid to another fluid as a result of temperature difference. Heat exchanger presented in the current paper in which inside the tubes flows water, but outside the tubes flows air aims to enable cooling of circulating water, which serves to cool the engine of a machine. Such exchangers find application in the automotive industry as well as heating and cooling equipment and HVAC systems etc. The surface of the heat exchanger by the air side always tends to be much larger using surface fins in order to facilitate equalization of thermal resistance for both sides of the heat exchanger, because the rate of transmission of heat from the water side is much greater. Furthermore, the paper will present analytical and experimental studies involved for determination of performance of plate-fin heat exchanger for various flows of working fluids in order to get the highest values of performances i.e.: overall heat transfer coefficient U, efficiency of heat exchanger ε, maximal and real heat transferred, pressure drop, air velocity and Reynolds number from the air side of heat exchanger etc. The present scientific paper is based on the fact that from the experimental model made for laboratory conditions, conclusions are derived that can be used during installation of such heat exchanger on certain machines in order to predict their performance.
文摘A thermal heat storage system with an energy content of 40 kWh and a temperature of 58°C will be presented. This storage system is suitable for supporting the use of renewable energies in buildings and for absorbing solar heat, heat from co-generation and heat pumps or electric heat from excess wind and solar power. The storage system is equipped with a plate heat exchanger that is so powerful that even with small temperature differences between the flow temperature and the storage temperature a high load dynamic is achieved. The storage system has a performance of 2.8 kW at 4 K and 10.6 kW at a temperature difference of 10 K. Thus, large performance variations in solar thermal systems or CHP plants can be buffered very well. Further a storage charge function Q(T, t) will be presented to characterize the performance of the storage.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.21873082,21674082,and 21674096)the Natural Science Foundation of Zhejiang Province,China(Grant No.LY19B040006)
文摘A two-dimensional binary driven disk system embedded by impermeable tilted plates is investigated through nonequilibrium computer simulations. It is well known that a binary disk system in which two particle species are driven in opposite directions exhibits jammed, phase separated, disordered, and laning states. The presence of tilted plates can not only advance the formation of laning phase, but also effectively stabilize laning phase by suppressing massively drifting behavior perpendicular to the driving force. The lane width distribution can be controlled easily by the interplate distance. The collective behavior of driven particles in laning phase is guided by the funnel-shaped confinements constituted by the neighboring tilted plates. Our results provide the important clues for investigating the mechanism of laning formation in driven system.
文摘A multi-step isothermal forging and subsequent multipass rolling was used to produce one kind of two phase titanium alloy plate with thickness of 2.2 mm. Tensile properties at ambient temperature and at two kinds of high temperatures were investigated for the plate with submicrocrystalline (SMC) structure in present work. Microstructures and fractographies of the alloy plate before and after tensile tests were also observed by scanning electron microscope. The results indicated that the alloy possesses favorite integrated tensile properties at ambient temperature, the average UTS and elongation for the longitudinal sample is 1070 MPa and 20%, while which for the transverse sample is 1103 MPa and 15%. The tensile elongation of the alloy plate is as high as 1078% at 780°C with a primary strain rate of 1.7 × 10<sup>-3</sup> s<sup>-1</sup>. The microstructure is fine for the alloy plate solutioned at 700°C for 1 h, AC, and the grain size after tensile test is 2 μm and 3 μm for the longitudinal and transverse plates. Fractography for the as-annealed plate is composed of a large number of dimples and voids after tensile test at ambient temperature.
基金Project(03JJY2002)supported by the Key Project of Natural Science Foundation of Hunan Province,ChinaProject(NCET-04-0769)supported by the Program for New Century Excellent Talents in University,ChinaProject(105126)supported by the Key Project ofMinistry of Education of China
文摘A new type of umbrella plate scrubber was developed to address the pollution due to the dust,dioxide sulfur and other harmful gases,which were emitted from coal-burning boilers.The performance of the new device was studied through computational fluid dynamics(CFD)simulation and experiment methods.Initial work included experimental measurement of inlet-velocity,and gas phase simulation using Reynolds stress model(RSM).After gas phase was converged,particles were injected from the inlet of the new device.Discrete phase model(DPM)was used for particle trajectories determination.The pressure drop and the collection efficiency of the new device were predicted through simulation.The simulation results show that the pressure drop of the new devices is 230?250 Pa and the efficiency is 84%-86%,with the inlet velocity equal to 10.6 m/s and the dust concentration ranging from 2 to 22 g/m 3 .The CFD simulation results of the new device show good agreement with experimental data.The relative error of the pressure drop and the efficiency is approximately 4%and 10%respectively.The results obtained both from the numerical simulation and from the experiment demonstrate that CFD simulation is an effective method for this type of study.
文摘Dual-plate structure is very effective in the protection of space vehicle from hypervelocity im- pact.The experiments of A1 projectile impacting A1 dual targets at the velocity ranging over 2.5—7.0 km/s were systematically conducted.The damage effects were examined,including the perforation of the shield, the development of debris cloud and the general damage characteristics of the subplate.Many valuable experi- mental data and phenomena have been obtained
文摘A dynamic solution is presented for the propagation of waves in an electric-magneto-elastic plate composed of piezoelectric, piezomagnetic materials and elastic matrix. The electric-magneto-elastic plate is polarized along the thickness direction. The generalized displacements are expressed as the sum of the gradient of a scalar (dilatation wave) and the curl of a vector (shear wave). With the help of dynamic equilibrium equations and geometric equations, we can obtain dynamic equations of the dilatation wave and the shear wave. The conclusion that the types of the dilatation waves and the shear waves remain unchanged after being reflected by the boundary can be obtained through the analysis of these kinetic equations. The dispersion properties and phase velocity surface of the dilatation and shear wave can be obtained by solutions of dynamic equilibrium equations. Influences of the piezoelectric and piezomagnetic parameters on wave characteristics are discussed.
