The calibration model for simultaneous deter-mination of chlorogenic acid and baicalin in heat-clearing and detoxicating oral liquid was built by partial least squares and near infrared spectroscopy, and the method of...The calibration model for simultaneous deter-mination of chlorogenic acid and baicalin in heat-clearing and detoxicating oral liquid was built by partial least squares and near infrared spectroscopy, and the method of spectral pre-treatment was discussed. Building model from calibration set obtained good results, and vali-dated by prediction. According to heat-clearing and detoxicating oral liquid from 30 batches of 6 factories, the correlation coefficient of chloro-genic acid and baicalin model are 0.9993 and 0.9923, The root mean square error of cross validation (RMSECV) are 0.467 and 0.480, and the standard Error of prediction (SEP) of chloro- genic acid and baicalin are 0.356 and 0.370 re-spectively. The correlation coefficients in pre-diction set are 0.9997 and 0.9969, prediction results are accurate and reliable. This method can be applied in rapid analysis of heat- clearing and detoxicating oral liquid, and it is fit for on-line detection and has a wide application prospect.展开更多
The heat transfer of hydrocarbon refrigerant across tube bundles have been widely used in refrigeration.Three-dimensional simulation model using volume of fluid(VOF) was presented to study the effects of tube shapes o...The heat transfer of hydrocarbon refrigerant across tube bundles have been widely used in refrigeration.Three-dimensional simulation model using volume of fluid(VOF) was presented to study the effects of tube shapes on flow pattern, film thickness and heat transfer of n-pentane across tube bundles, including circle, ellipse-shaped, egg-shaped and cam-shaped tube bundles. Simulation results agree well with experimental data in the literature. The liquid film thickness of sheet flow and heat transfer for different tube shapes were obtained numerically. The flow pattern transition occurs lower vapor quality for ellipse-shaped tube than other tube shapes. For sheet flow, the liquid film on circle tube and ellipseshaped tube is symmetrically distributed along the circumferential direction. However, the liquid film on egg-shaped tube at circumferential angles(θ) = 15°–60° is thicker than θ = 135°–165°. The liquid film on cam tube at θ = 15°–60° is slightly thinner than θ = 135°–165°. The liquid film thickness varies from thinner to thicker for ellipse-shaped, cam-shaped, egg-shape and circle within θ = 15°–60°. The effect of tube shape is insignificant on thin liquid film thickness. Ellipse-shaped tube has largest heat transfer coefficient for sheet flow. In practical engineering, the tube shape could be designed as ellipse to promote heat transfer.展开更多
In the present work,the turbulent mixing process of a polydisperse quartz particle flow with a plasma stream generated by a radio-frequency(RF)inductively coupled plasma torch was numerically studied.The thermobaric s...In the present work,the turbulent mixing process of a polydisperse quartz particle flow with a plasma stream generated by a radio-frequency(RF)inductively coupled plasma torch was numerically studied.The thermobaric stress in the quartz particles under dynamic heating in a heterogeneous plasma flow was determined by a two-stage approximation approach.The effect of the presence of vacuoles in natural quartz on the particle thermobaric destruction conditions was studied.It was found that the equivalent thermal and baric stresses in quartz particles may significantly increase in the presence of vacuoles within a small gas volume fraction.The influence of the regime and energetic working conditions of an RF inductively coupled plasma torch system on the particle thermobaric destruction conditions was examined,and a recommendation was given to promote the degree of thermobaric destruction of quartz particles,which is of substantial importance for improving the overall enrichment efficiency of quartz concentrates.展开更多
The agitated thin film evaporator(ATFE),which is known for its high efficiency,force the material to form a film through the scraping process of a scraper,followed by evaporation and purification.The complex shape of ...The agitated thin film evaporator(ATFE),which is known for its high efficiency,force the material to form a film through the scraping process of a scraper,followed by evaporation and purification.The complex shape of the liquid film inside the evaporator can significantly affect its evaporation capability.This work explores how change in shape of the liquid films affect the evaporation of the materials with non-Newtonian characteristics,achieved by changing the structure of the scraper.Examining the distribution of circumferential temperature,viscosity,and mass transfer of the flat liquid film shows that the film evaporates rapidly in shear-thinning region.Various wavy liquid films are developed by using shear-thinning theory,emphasizing the flow condition in the thinning area and the factors contributing to the exceptional evaporation capability.Further exploration is conducted on the spread patterns of the wavy liquid film and flat liquid film on the evaporation wall throughout the process.It is noted that breaking the wavy liquid film on the evaporating wall during evaporation is challenging due to its film-forming condition.For which the fundamental causes are demonstrated by acquiring the data regarding the flow rate and temperature of the liquid film.The definitive findings of the analysis reveal a significant improvement in the evaporation capability of the wavy liquid film.This enhancement is attributed to increasing the shear-thinning areas and maintaining the overall shape of the film throughout the entire evaporation process.展开更多
Objective:To systemically review the efficacy and safety about the method of enriching qi,activating blood circulation,clearing away dampness and heat combined with western medicine in the therapy of patients with idi...Objective:To systemically review the efficacy and safety about the method of enriching qi,activating blood circulation,clearing away dampness and heat combined with western medicine in the therapy of patients with idiopathy membranous nephropathy(IMN).Methods:We collected the randomized controlled trials(RCTs)of enriching qi,activating blood circulation,clearing away dampness and heat for the treatment of IMN from Pub Med,The Cochrane Library,Medline,China National Knowledge Infrastructure(CNKI),China Biology Medicine disc(CBM),Wanfang Data and Wiper Databases.Bias of risk of retrieval literature was evaluated according to Cochrane Collaboration standard,and Review Manager 5.3 software was used for statistical analysis.Results:Fourteen trials(836 participants)were included in the meta-analysis.This kind of traditional Chinese method combined with western medicine in the treatment of IMN exerted statistical differences in reducing 24-hour urinary protein[WMD=-0.97,95%CI(-1.30,-0.65),Z=5.86(P<0.00001)]and elevating serum albumin[WMD=3.83,95%CI(2.10,5.57),Z=4.33,P<0.0001],lowering serum cholesterol[WMD=-0.82,95%CI(-1.08,-0.56),Z=6.18,P<0.00001],triglycerides[WMD=-0.39,95%CI(-0.67,-0.11),Z=2.77,P=0.006]and reducing the risk of adverse events[OR=0.29,95%CI[0.16,0.50],Z=4.35,P<0.0001]in the patients with IMN as compared with controls.However,there was no statistically significant difference between the method and controls when combining all trials in serum creatinine[WMD=-5.52,95%CI(-18.06,7.03),Z=0.86,P=0.39],when combining all trials in urea nitrogen[WMD=-0.90,95%CI(-2.22,0.41),Z=1.35,P=0.18].Conclusion:The method of enriching qi,activating blood circulation,clearing away dampness and heat combined with western medicine exerts certain advantages and better safety in treating patients with IMN.However,for the inferiority of the included studies,the conclusion still needs high-quality and large-sample prospective randomized controlled trials to verify.展开更多
[Objectives]To explore the effects of heat clearing and stasis resolving method on prethrombotic state,inflammatory factors and T-lymphocyte subsets in peripheral blood of unexplained recurrent miscarriage(URM)patient...[Objectives]To explore the effects of heat clearing and stasis resolving method on prethrombotic state,inflammatory factors and T-lymphocyte subsets in peripheral blood of unexplained recurrent miscarriage(URM)patients with suppressed internal heat.[Methods]Thirty cases of URM patients with suppressed internal heat and 30 normal women were collected,and characteristics of changes in peripheral serum D-dimer(D-D),fibrin degradation product(FDP),fibrinogen(FIB),IL-6,IL-10 and TNF-α,CD,CD,CD,CD,CDlevels were detected.URM patients were treated with traditional Chinese medicine for clearing heat and resolving blood stasis for 3 menstrual cycles,and the changes of indicators before and after treatment were observed.[Results]Compared with normal women,the peripheral serum levels of D-D,IL-6,TNF-αand CDin URM patients with suppressed internal heat were increased(P<0.05),while the IL-10 lymphocyte level was significantly decreased(P<0.05);compared with that before treatment,the contents of D-D,IL-6,TNF-αand CDdecreased after 3 menstrual cycles(P<0.05),while the contents of IL-10 and CDT lymphocytes increased significantly(P<0.05).[Conclusions]The heat clearing heat and stasis resolving method can effectively improve the prethrombotic state of URM,and the action mechanism may be related to the regulation of immune and peripheral blood inflammatory factors.展开更多
The non-uniformity of gas–liquid mixture is a critical issue which leads to the heat transfer deterioration of spiralwound heat exchangers(SWHEs).Two-phase mass flow rate and the content of gas are important paramete...The non-uniformity of gas–liquid mixture is a critical issue which leads to the heat transfer deterioration of spiralwound heat exchangers(SWHEs).Two-phase mass flow rate and the content of gas are important parameters as well as structural parameters which have prominent influences on flow distribution uniformity of SWHE shell side.In order to investigate the influences of these parameters,an experimental test system was built using water and air as mediums and a novel distributor named"tubes distributor"was designed.The effects of mass flow rate and the content of gas on two-phase distribution performance were analyzed,where the mass flow rate ranged from 28.4 to 171.9 kg·h-1 and the content of gas changed from 0.2 to 0.8,respectively.The results showed that the mixture mass flow rate considerably influenced the liquid distribution than that of gas phase and the larger mass flow rate exhibited the better distribution uniformity of two-phase flow.It was also found that the tubes distributor had the better two-phase uniformity when the content of gas was around 0.4.Tube diameter played an important role in the distribution of gas phase and slit width was more significant for the uniformity of liquid phase.展开更多
A high-resolution testing technique named liquid crystal thermography is used for the experimental study on jet array impingement to map out the distribution of heat transfer coefficients on the cooling surface. Effec...A high-resolution testing technique named liquid crystal thermography is used for the experimental study on jet array impingement to map out the distribution of heat transfer coefficients on the cooling surface. Effects of the impingement distance, the impinging hole arrangement and the initial crossflow on heat transfer characteristics are investigated. The thermal images show truly the features of local heat transfer for each jet impingement cooling. The applications of thermochromic liquid crystal are successful in the qualitative and quantitative measurement for heat transfer coefficients distribution.展开更多
The heat capacity of ionic liquids is an important physical property,and experimental measuring is usually used as a common method to obtain them.Owing to the huge number of ionic liquids that can be potentially synth...The heat capacity of ionic liquids is an important physical property,and experimental measuring is usually used as a common method to obtain them.Owing to the huge number of ionic liquids that can be potentially synthesized,it is desirable to acquire theoretical predictions.In this work,the Conductor-like Screening Model for Real Solvents(COSMO-RS)was used to predict the heat capacity of pure ionic liquids,and an intensive literature survey was conducted for providing a database to verify the prediction of COSMO-RS.The survey shows that the heat capacity is available for 117 ionic liquids at temperatures ranging 77.66-520 K since 2004,and the 4025 data points in total with the values from 76.37 to 1484 J·mol^(-1)·K^(-1) have been reported.The prediction of heat capacity with COSMO-RS can only be conducted at two temperatures(298 and 323 K).The comparison with the experimental data proves the prediction reliability of COSMO-RS,and the average relative deviation(ARD)is 8.54%.Based on the predictions at two temperatures,a linear equation was obtained for each ionic liquid,and the heat capacities at other temperatures were then estimated via interpolation and extrapolation.The acquired heat capacities at other temperatures were then compared with the experimental data,and the ARD is only 9.50%.This evidences that the heat capacity of a pure ionic liquid follows a linear equation within the temperature range of study,and COSMO-RS can be used to predict the heat capacity of ionic liquids reliably.展开更多
A lithium(Li)vapour layer was formed around a flowing liquid Li limiter to shield against the plasma incident power and reduce limiter heat flux in the EAST tokamak.The results revealed that after a plasma operation o...A lithium(Li)vapour layer was formed around a flowing liquid Li limiter to shield against the plasma incident power and reduce limiter heat flux in the EAST tokamak.The results revealed that after a plasma operation of a few seconds,the layer became clear,which indicated a strong Li emission with a decrease in the limiter surface temperature.This emission resulted in a dense vapour around the limiter,and Li ions moved along the magnetic fleld to form a green shielding layer on the limiter.The plasma heat flux loaded on the limiter,measured by the probe installed on the limiter,was approximately 52%lower than that detected by a fast-reciprocating probe at the same radial position without the limiter in EAST.Additionally,approximately 42%of the parallel heat flux was dissipated directly with the enhanced Li radiation in the discharge with the liquid metal infused trenches(LIMIT)limiter.This observation revealed that the Li vapour layer exhibited an excellent shielding effect to liquid Li on plasma heat flux,which is a possible beneflt of liquid-plasma-facing components in future fusion devices.展开更多
The role of the Cattaneo-Christov heat flux theory in the two-dimensional laminar flow of the Jeffrey liquid is discussed with a vertical sheet. The salient feature in the energy equation is accounted due to the imple...The role of the Cattaneo-Christov heat flux theory in the two-dimensional laminar flow of the Jeffrey liquid is discussed with a vertical sheet. The salient feature in the energy equation is accounted due to the implementation of the Cattaneo-Christov heat flux. A liquid with variable thermal conductivity is considered in the Darcy-Forchheimer porous space. The mathematical expressions of momentum and energy are coupled due to the presence of mixed convection. A highly nonlinear coupled system of equations is tackled with the homotopic algorithm. The convergence of the homotopy expressions is calculated graphically and numerically. The solutions of the velocity and temperature are expressed for various values of the Deborah number, the ratio of the relaxation time to the retardation time, the porosity parameter, the mixed convective parameter, the Darcy-Forchheimer parameter, and the conductivity parameter. The results show that the velocity and temperature are higher in Fourier's law of heat conduction cases in comparison with the Cattaneo-Christov heat flux model.展开更多
Heat transfer characteristics between the immersed heater and the bed content were studied in the riser of a liquid-solid circulating fluidized bed, whose diameter and height were 0.102 m (ID) and 2.5 m, respectively....Heat transfer characteristics between the immersed heater and the bed content were studied in the riser of a liquid-solid circulating fluidized bed, whose diameter and height were 0.102 m (ID) and 2.5 m, respectively. Effects of liquid velocity, particle size, surface tension of liquid phase and solid circulation rate on the overall heat transfer coefficient were examined. The heat transfer coefficient increased with increasing particle size or solid circulation rate due to the higher potential of particles to contact with the heater surface and promote turbulence near the heater surface. The value of heat transfer coefficient increased gradually with increase in the surface tension of liquid phase, due to the slight increase of solid holdup. The heat transfer coefficient increased with the liquid velocity even in the higher range, due to the solid circulation prevented the decrease in solid holdup, in contrast to that in the conventional liquid-solid fluidized beds. The values of heat transfer coefficient were well correlated in terms of dimensionless groups as well as operating variables.展开更多
The skin friction and heat transfer occurring in the laminar boundary layerwhich caused by a vertical liquid jet impinging on a continuously moving horizontal plate werestudied. Similarity solutions for shear stress a...The skin friction and heat transfer occurring in the laminar boundary layerwhich caused by a vertical liquid jet impinging on a continuously moving horizontal plate werestudied. Similarity solutions for shear stress and heat distribution were obtained by using thehooting technique. The results show that the skin friction decreases with an increase of velocityparameter, the evolving of thermal boundary decrease with increasing in Prandtl number, but increasewith increasing of velocity parameter.展开更多
The interfacial evaporative heat transfer was included in the semi-empirical study of the heat transfer for the falling liquid film flow. The investigations showed that, the inclusion of the interfacial eveiporative h...The interfacial evaporative heat transfer was included in the semi-empirical study of the heat transfer for the falling liquid film flow. The investigations showed that, the inclusion of the interfacial eveiporative heat transfer in the turbulent model would lower the predicted convective heat transfer coefficient. Predictions of the new model resulted in a prominent deviation from that predictions of the normal model in the case of large mass flow rate and low wall heat flux. This deviation will be decreased with increasing wall heat flux, such that it will be asymptotic zero at very high wall heat flux. Predictions of the new model agreed well with the current experimental measurements. This study has verified that the Reynolds number is not the sole crucial parameter for heat transfer of falling liquid film flow, and wall heat flux will be another important independent parameter. This result is consistent with our previous studies.展开更多
The cascade model was tested using transient liquid crystal temperature measurement technology.The effects of main flow Reynolds number,blowing ratio and tip clearance height on the convective heat transfer coefficien...The cascade model was tested using transient liquid crystal temperature measurement technology.The effects of main flow Reynolds number,blowing ratio and tip clearance height on the convective heat transfer coefficient of the turbine outer ring were studied.Two feature lines were marked on the turbine outer ring corresponding to the position of the blade.The conclusions are as follows:The tip clearance leakage flow has a great influence on the convective heat transfer coefficient of the turbine outer ring.When the clearance height and the blowing ratio are kept constant,gradually increasing the main flow Reynolds number will result in an increase in the convective heat transfer coefficient of the turbine outer ring.When the clearance height and the main flow Reynolds number are kept constant and the blowing ratio is gradually increased,the convective heat transfer coefficient of the turbine outer ring is almost constant.The heat transfer coefficient of the turbine outer ring surface is little affected by the blowing ratio;The clearance height has great influence on the heat transfer characteristics of the turbine outer ring.Under the typical working condition in this paper,when the tip clearance height ratio is 1.6%,the convective heat transfer coefficient of the outer surface of the turbine is the highest.展开更多
Lower temperature waste heats less than 373 K have strong potentials to supply additional energies because of their enormous quantities and ubiquity. Accordingly, reinforcement of power generations harvesting low temp...Lower temperature waste heats less than 373 K have strong potentials to supply additional energies because of their enormous quantities and ubiquity. Accordingly, reinforcement of power generations harvesting low temperature heats is one of the urgent tasks for the current generation in order to accomplish energy sustainability in the coming decades. In this study, a liquid turbine power generator driven by lower temperature heats below 373 K was proposed in the aim of expanding selectable options for harvesting low temperature waste heats less than 373 K. The proposing system was so simply that it was mainly composed of a liquid turbine, a liquid container with a biphasic medium of water and an underlying water-insoluble low-boiling-point medium in a liquid phase, a heating section for vaporization of the liquid and a cooling section for entropy discharge outside the system. Assumed power generating steps via the proposing liquid turbine power generator were as follows: step 1: the underlying low-boiling-point medium in a liquid phase was vaporized, step 2: the surfacing vapor bubbles of low-boiling-point medium accompanied the biphasic medium in their wakes, step 3: such high momentum flux by step 2 rotated the liquid turbine (i.e. power generation), step 4: the surfacing low-boiling-point medium vapor was gradually condensed into droplets, step 5: the low-boiling-point medium droplets were submerged to the underlying medium in a liquid phase. Experiments with a prototype liquid turbine power generator proved power generations in accordance with the assumed steps at a little higher than ordinary temperature. Increasing output voltage could be obtained with an increase in the cooling temperature among tested ranging from 294 to 296 K in contrast to normal thermal engines. Further improvements of the direct current voltage from the proposing liquid turbine power generator can be expected by means of far more vigorous multiphase flow induced by adding solid powders and theoretical optimizations of heat and mass transfers.展开更多
Cu-Zn-Al slurry catalysts were prepared using a complete liquid-phase preparation technology under different heat treatment atmospheres.The catalysts were characterized using X-ray diffraction,X-ray photoelectron spec...Cu-Zn-Al slurry catalysts were prepared using a complete liquid-phase preparation technology under different heat treatment atmospheres.The catalysts were characterized using X-ray diffraction,X-ray photoelectron spectroscope,and N2 adsorption-desorption.Their application in the single-step synthesis of dimethyl ether from syngas was also investigated.The results indicate that the type of heat treatment atmosphere has an influence on the Cu species and the Cu0/Cu+ ratio on the catalyst surface.Moreover,the final Cu/Zn ratio on the catalyst surface is mainly dependent on the composition and reaction environment of the catalyst and less on the type of heat treatment atmosphere.The prepared catalysts can suppress sintering of active sites at high temperatures,and the type of heat treatment atmosphere mainly affects the capability of the catalyst for methanol synthesis.The catalysts perform best using N2 as the heat treatment atmosphere.展开更多
Liquid metal alloys(LMAs) are the potential candidates of thermal interface materials(TIMs) for electronics cooling.In the present work, buffer layers of Ag, Ti, Cu, Ni, Mo, and W were deposited on polished Cu plates ...Liquid metal alloys(LMAs) are the potential candidates of thermal interface materials(TIMs) for electronics cooling.In the present work, buffer layers of Ag, Ti, Cu, Ni, Mo, and W were deposited on polished Cu plates by DC magnetron sputtering, the contact angles of de-ionized water and diiodomethane on the buffer layers were measured by an easy drop shape analyzer and the surface free energies(SFEs) of the buffer layers were calculated by the Owens–Wendt–Kaelble equation. Samples were prepared by sandwiching the filmed Cu plates and LMAs. The thermal properties of the samples were measured by laser flash analysis method. The SFE of the buffer layer has a strong influence on the interface heat transfer, whereas the measurement temperature has no obvious effect on the thermal properties of the samples. As the SFE of the buffer layer increases, the wettability, thermal diffusivity, and thermal conductivity are enhanced, and the thermal contact resistance is decreased.展开更多
Superconducting thermal fluctuation(STF) plays an important role in both thermodynamic and transport properties in the vortex liquid phase of high Tsuperconductors.It was widely observed in the vicinity of the critica...Superconducting thermal fluctuation(STF) plays an important role in both thermodynamic and transport properties in the vortex liquid phase of high Tsuperconductors.It was widely observed in the vicinity of the critical transition temperature.In the framework of Ginz burg-Landau-La wrence-Doniach theory in magnetic field,a self-consistent analysis of STF including all Landau levels is given.Besides that,we calculate the contribution of STF to specific heat in vortex liquid phase for high Tcuprate superconductors,and the fitting results are in good agreement with experimental data.展开更多
文摘The calibration model for simultaneous deter-mination of chlorogenic acid and baicalin in heat-clearing and detoxicating oral liquid was built by partial least squares and near infrared spectroscopy, and the method of spectral pre-treatment was discussed. Building model from calibration set obtained good results, and vali-dated by prediction. According to heat-clearing and detoxicating oral liquid from 30 batches of 6 factories, the correlation coefficient of chloro-genic acid and baicalin model are 0.9993 and 0.9923, The root mean square error of cross validation (RMSECV) are 0.467 and 0.480, and the standard Error of prediction (SEP) of chloro- genic acid and baicalin are 0.356 and 0.370 re-spectively. The correlation coefficients in pre-diction set are 0.9997 and 0.9969, prediction results are accurate and reliable. This method can be applied in rapid analysis of heat- clearing and detoxicating oral liquid, and it is fit for on-line detection and has a wide application prospect.
基金supported by National Natural Science Foundation of China (52006242)National Natural Science Foundation of China (52192623)+1 种基金Science Foundation of China University of Petroleum,Beijing (ZX20200126)Science and technology program for strategic cooperation of CNPC–China University of Petroleum (ZLZX2020-05)。
文摘The heat transfer of hydrocarbon refrigerant across tube bundles have been widely used in refrigeration.Three-dimensional simulation model using volume of fluid(VOF) was presented to study the effects of tube shapes on flow pattern, film thickness and heat transfer of n-pentane across tube bundles, including circle, ellipse-shaped, egg-shaped and cam-shaped tube bundles. Simulation results agree well with experimental data in the literature. The liquid film thickness of sheet flow and heat transfer for different tube shapes were obtained numerically. The flow pattern transition occurs lower vapor quality for ellipse-shaped tube than other tube shapes. For sheet flow, the liquid film on circle tube and ellipseshaped tube is symmetrically distributed along the circumferential direction. However, the liquid film on egg-shaped tube at circumferential angles(θ) = 15°–60° is thicker than θ = 135°–165°. The liquid film on cam tube at θ = 15°–60° is slightly thinner than θ = 135°–165°. The liquid film thickness varies from thinner to thicker for ellipse-shaped, cam-shaped, egg-shape and circle within θ = 15°–60°. The effect of tube shape is insignificant on thin liquid film thickness. Ellipse-shaped tube has largest heat transfer coefficient for sheet flow. In practical engineering, the tube shape could be designed as ellipse to promote heat transfer.
基金supported by National Natural Science Foundation of China(Nos.52202460,52177128)National Key R&D Program of China(Nos.2020YFC2201100,2021YFC2202804)+2 种基金China Postdoctoral Science Foundation(Nos.2021M690392,2021TQ0036)Science Foundation for Youth Scholars of the Beijing Institute of TechnologyAdvanced Space Propulsion Laboratory of BICE and the Beijing Engineering Research Centre of Efficient and Green Aerospace Propulsion Technology(No.LabASP-2021-04)。
文摘In the present work,the turbulent mixing process of a polydisperse quartz particle flow with a plasma stream generated by a radio-frequency(RF)inductively coupled plasma torch was numerically studied.The thermobaric stress in the quartz particles under dynamic heating in a heterogeneous plasma flow was determined by a two-stage approximation approach.The effect of the presence of vacuoles in natural quartz on the particle thermobaric destruction conditions was studied.It was found that the equivalent thermal and baric stresses in quartz particles may significantly increase in the presence of vacuoles within a small gas volume fraction.The influence of the regime and energetic working conditions of an RF inductively coupled plasma torch system on the particle thermobaric destruction conditions was examined,and a recommendation was given to promote the degree of thermobaric destruction of quartz particles,which is of substantial importance for improving the overall enrichment efficiency of quartz concentrates.
基金supported by the National Natural Science Foundation of China (Grant Nos.52375172,52075093,and 51905089).
文摘The agitated thin film evaporator(ATFE),which is known for its high efficiency,force the material to form a film through the scraping process of a scraper,followed by evaporation and purification.The complex shape of the liquid film inside the evaporator can significantly affect its evaporation capability.This work explores how change in shape of the liquid films affect the evaporation of the materials with non-Newtonian characteristics,achieved by changing the structure of the scraper.Examining the distribution of circumferential temperature,viscosity,and mass transfer of the flat liquid film shows that the film evaporates rapidly in shear-thinning region.Various wavy liquid films are developed by using shear-thinning theory,emphasizing the flow condition in the thinning area and the factors contributing to the exceptional evaporation capability.Further exploration is conducted on the spread patterns of the wavy liquid film and flat liquid film on the evaporation wall throughout the process.It is noted that breaking the wavy liquid film on the evaporating wall during evaporation is challenging due to its film-forming condition.For which the fundamental causes are demonstrated by acquiring the data regarding the flow rate and temperature of the liquid film.The definitive findings of the analysis reveal a significant improvement in the evaporation capability of the wavy liquid film.This enhancement is attributed to increasing the shear-thinning areas and maintaining the overall shape of the film throughout the entire evaporation process.
基金Scientific Research Special Project of Capital Health Development in 2018(No.First issues 2018-1-4192)TCM Science and Technology Development Fund of Beijing in 2020(No.JJ-2020-42)。
文摘Objective:To systemically review the efficacy and safety about the method of enriching qi,activating blood circulation,clearing away dampness and heat combined with western medicine in the therapy of patients with idiopathy membranous nephropathy(IMN).Methods:We collected the randomized controlled trials(RCTs)of enriching qi,activating blood circulation,clearing away dampness and heat for the treatment of IMN from Pub Med,The Cochrane Library,Medline,China National Knowledge Infrastructure(CNKI),China Biology Medicine disc(CBM),Wanfang Data and Wiper Databases.Bias of risk of retrieval literature was evaluated according to Cochrane Collaboration standard,and Review Manager 5.3 software was used for statistical analysis.Results:Fourteen trials(836 participants)were included in the meta-analysis.This kind of traditional Chinese method combined with western medicine in the treatment of IMN exerted statistical differences in reducing 24-hour urinary protein[WMD=-0.97,95%CI(-1.30,-0.65),Z=5.86(P<0.00001)]and elevating serum albumin[WMD=3.83,95%CI(2.10,5.57),Z=4.33,P<0.0001],lowering serum cholesterol[WMD=-0.82,95%CI(-1.08,-0.56),Z=6.18,P<0.00001],triglycerides[WMD=-0.39,95%CI(-0.67,-0.11),Z=2.77,P=0.006]and reducing the risk of adverse events[OR=0.29,95%CI[0.16,0.50],Z=4.35,P<0.0001]in the patients with IMN as compared with controls.However,there was no statistically significant difference between the method and controls when combining all trials in serum creatinine[WMD=-5.52,95%CI(-18.06,7.03),Z=0.86,P=0.39],when combining all trials in urea nitrogen[WMD=-0.90,95%CI(-2.22,0.41),Z=1.35,P=0.18].Conclusion:The method of enriching qi,activating blood circulation,clearing away dampness and heat combined with western medicine exerts certain advantages and better safety in treating patients with IMN.However,for the inferiority of the included studies,the conclusion still needs high-quality and large-sample prospective randomized controlled trials to verify.
基金Supported by National Natural Science Foundation of China(81760806)Project of Traditional Chinese Medicine Administration of Gansu Province(GZK-2019-28)Innovation Ability Improvement Project of Higher Education Institutions of Gansu Province(2019B-103)。
文摘[Objectives]To explore the effects of heat clearing and stasis resolving method on prethrombotic state,inflammatory factors and T-lymphocyte subsets in peripheral blood of unexplained recurrent miscarriage(URM)patients with suppressed internal heat.[Methods]Thirty cases of URM patients with suppressed internal heat and 30 normal women were collected,and characteristics of changes in peripheral serum D-dimer(D-D),fibrin degradation product(FDP),fibrinogen(FIB),IL-6,IL-10 and TNF-α,CD,CD,CD,CD,CDlevels were detected.URM patients were treated with traditional Chinese medicine for clearing heat and resolving blood stasis for 3 menstrual cycles,and the changes of indicators before and after treatment were observed.[Results]Compared with normal women,the peripheral serum levels of D-D,IL-6,TNF-αand CDin URM patients with suppressed internal heat were increased(P<0.05),while the IL-10 lymphocyte level was significantly decreased(P<0.05);compared with that before treatment,the contents of D-D,IL-6,TNF-αand CDdecreased after 3 menstrual cycles(P<0.05),while the contents of IL-10 and CDT lymphocytes increased significantly(P<0.05).[Conclusions]The heat clearing heat and stasis resolving method can effectively improve the prethrombotic state of URM,and the action mechanism may be related to the regulation of immune and peripheral blood inflammatory factors.
基金Supported by the research funds from MIIT program on High Technology Research Program of Ship(2013K4181).
文摘The non-uniformity of gas–liquid mixture is a critical issue which leads to the heat transfer deterioration of spiralwound heat exchangers(SWHEs).Two-phase mass flow rate and the content of gas are important parameters as well as structural parameters which have prominent influences on flow distribution uniformity of SWHE shell side.In order to investigate the influences of these parameters,an experimental test system was built using water and air as mediums and a novel distributor named"tubes distributor"was designed.The effects of mass flow rate and the content of gas on two-phase distribution performance were analyzed,where the mass flow rate ranged from 28.4 to 171.9 kg·h-1 and the content of gas changed from 0.2 to 0.8,respectively.The results showed that the mixture mass flow rate considerably influenced the liquid distribution than that of gas phase and the larger mass flow rate exhibited the better distribution uniformity of two-phase flow.It was also found that the tubes distributor had the better two-phase uniformity when the content of gas was around 0.4.Tube diameter played an important role in the distribution of gas phase and slit width was more significant for the uniformity of liquid phase.
文摘A high-resolution testing technique named liquid crystal thermography is used for the experimental study on jet array impingement to map out the distribution of heat transfer coefficients on the cooling surface. Effects of the impingement distance, the impinging hole arrangement and the initial crossflow on heat transfer characteristics are investigated. The thermal images show truly the features of local heat transfer for each jet impingement cooling. The applications of thermochromic liquid crystal are successful in the qualitative and quantitative measurement for heat transfer coefficients distribution.
基金financially supported by the Joint Research Fund for Overseas Chinese Scholars and Scholars in Hong Kong and Macao Young Scholars(No.21729601)the National Natural Science Foundation of China(No.21838004)+2 种基金financial support from Carl Tryggers Stiftelse foundation(No.18:175)financial support from Swedish Energy Agency(P50830-1)financial support from National Natural Science Foundation of China(No.21878143)。
文摘The heat capacity of ionic liquids is an important physical property,and experimental measuring is usually used as a common method to obtain them.Owing to the huge number of ionic liquids that can be potentially synthesized,it is desirable to acquire theoretical predictions.In this work,the Conductor-like Screening Model for Real Solvents(COSMO-RS)was used to predict the heat capacity of pure ionic liquids,and an intensive literature survey was conducted for providing a database to verify the prediction of COSMO-RS.The survey shows that the heat capacity is available for 117 ionic liquids at temperatures ranging 77.66-520 K since 2004,and the 4025 data points in total with the values from 76.37 to 1484 J·mol^(-1)·K^(-1) have been reported.The prediction of heat capacity with COSMO-RS can only be conducted at two temperatures(298 and 323 K).The comparison with the experimental data proves the prediction reliability of COSMO-RS,and the average relative deviation(ARD)is 8.54%.Based on the predictions at two temperatures,a linear equation was obtained for each ionic liquid,and the heat capacities at other temperatures were then estimated via interpolation and extrapolation.The acquired heat capacities at other temperatures were then compared with the experimental data,and the ARD is only 9.50%.This evidences that the heat capacity of a pure ionic liquid follows a linear equation within the temperature range of study,and COSMO-RS can be used to predict the heat capacity of ionic liquids reliably.
基金funded by the National Key Research and Development Program of China(No.2017YFE0301100)National Natural Science Foundation of China(Nos.11905138,11905148 and 11905254)+2 种基金the U.S.Dept.of Energy contract DE-AC02-09CH11466 and grant DESC0016553Users with Excellence Program of Hefei Science Center CAS(No.2020HSC-UE010)Interdisciplinary and Collaborative Teams of CAS。
文摘A lithium(Li)vapour layer was formed around a flowing liquid Li limiter to shield against the plasma incident power and reduce limiter heat flux in the EAST tokamak.The results revealed that after a plasma operation of a few seconds,the layer became clear,which indicated a strong Li emission with a decrease in the limiter surface temperature.This emission resulted in a dense vapour around the limiter,and Li ions moved along the magnetic fleld to form a green shielding layer on the limiter.The plasma heat flux loaded on the limiter,measured by the probe installed on the limiter,was approximately 52%lower than that detected by a fast-reciprocating probe at the same radial position without the limiter in EAST.Additionally,approximately 42%of the parallel heat flux was dissipated directly with the enhanced Li radiation in the discharge with the liquid metal infused trenches(LIMIT)limiter.This observation revealed that the Li vapour layer exhibited an excellent shielding effect to liquid Li on plasma heat flux,which is a possible beneflt of liquid-plasma-facing components in future fusion devices.
文摘The role of the Cattaneo-Christov heat flux theory in the two-dimensional laminar flow of the Jeffrey liquid is discussed with a vertical sheet. The salient feature in the energy equation is accounted due to the implementation of the Cattaneo-Christov heat flux. A liquid with variable thermal conductivity is considered in the Darcy-Forchheimer porous space. The mathematical expressions of momentum and energy are coupled due to the presence of mixed convection. A highly nonlinear coupled system of equations is tackled with the homotopic algorithm. The convergence of the homotopy expressions is calculated graphically and numerically. The solutions of the velocity and temperature are expressed for various values of the Deborah number, the ratio of the relaxation time to the retardation time, the porosity parameter, the mixed convective parameter, the Darcy-Forchheimer parameter, and the conductivity parameter. The results show that the velocity and temperature are higher in Fourier's law of heat conduction cases in comparison with the Cattaneo-Christov heat flux model.
基金Supported by Korea Institute of Energy Technology Evaluation and Planning (KETEP)GTL Technology Development Consortium (Korean National Oil Corp., Korea Gas Corp., Daelim Industrial Co. and Hyundai Engineering Co.) under "Energy Efficiency & Resources Programs" of the Ministry of Knowledge Economy, Republic of Korea
文摘Heat transfer characteristics between the immersed heater and the bed content were studied in the riser of a liquid-solid circulating fluidized bed, whose diameter and height were 0.102 m (ID) and 2.5 m, respectively. Effects of liquid velocity, particle size, surface tension of liquid phase and solid circulation rate on the overall heat transfer coefficient were examined. The heat transfer coefficient increased with increasing particle size or solid circulation rate due to the higher potential of particles to contact with the heater surface and promote turbulence near the heater surface. The value of heat transfer coefficient increased gradually with increase in the surface tension of liquid phase, due to the slight increase of solid holdup. The heat transfer coefficient increased with the liquid velocity even in the higher range, due to the solid circulation prevented the decrease in solid holdup, in contrast to that in the conventional liquid-solid fluidized beds. The values of heat transfer coefficient were well correlated in terms of dimensionless groups as well as operating variables.
基金[This work was financially supported by "973" key foundation of China (No.G 1998061510).]
文摘The skin friction and heat transfer occurring in the laminar boundary layerwhich caused by a vertical liquid jet impinging on a continuously moving horizontal plate werestudied. Similarity solutions for shear stress and heat distribution were obtained by using thehooting technique. The results show that the skin friction decreases with an increase of velocityparameter, the evolving of thermal boundary decrease with increasing in Prandtl number, but increasewith increasing of velocity parameter.
基金Supported by the National Natural Science Foundation of China (No. 59995550-3) and Science Funds from the Ministry of Education (No. 97000357).
文摘The interfacial evaporative heat transfer was included in the semi-empirical study of the heat transfer for the falling liquid film flow. The investigations showed that, the inclusion of the interfacial eveiporative heat transfer in the turbulent model would lower the predicted convective heat transfer coefficient. Predictions of the new model resulted in a prominent deviation from that predictions of the normal model in the case of large mass flow rate and low wall heat flux. This deviation will be decreased with increasing wall heat flux, such that it will be asymptotic zero at very high wall heat flux. Predictions of the new model agreed well with the current experimental measurements. This study has verified that the Reynolds number is not the sole crucial parameter for heat transfer of falling liquid film flow, and wall heat flux will be another important independent parameter. This result is consistent with our previous studies.
文摘The cascade model was tested using transient liquid crystal temperature measurement technology.The effects of main flow Reynolds number,blowing ratio and tip clearance height on the convective heat transfer coefficient of the turbine outer ring were studied.Two feature lines were marked on the turbine outer ring corresponding to the position of the blade.The conclusions are as follows:The tip clearance leakage flow has a great influence on the convective heat transfer coefficient of the turbine outer ring.When the clearance height and the blowing ratio are kept constant,gradually increasing the main flow Reynolds number will result in an increase in the convective heat transfer coefficient of the turbine outer ring.When the clearance height and the main flow Reynolds number are kept constant and the blowing ratio is gradually increased,the convective heat transfer coefficient of the turbine outer ring is almost constant.The heat transfer coefficient of the turbine outer ring surface is little affected by the blowing ratio;The clearance height has great influence on the heat transfer characteristics of the turbine outer ring.Under the typical working condition in this paper,when the tip clearance height ratio is 1.6%,the convective heat transfer coefficient of the outer surface of the turbine is the highest.
文摘Lower temperature waste heats less than 373 K have strong potentials to supply additional energies because of their enormous quantities and ubiquity. Accordingly, reinforcement of power generations harvesting low temperature heats is one of the urgent tasks for the current generation in order to accomplish energy sustainability in the coming decades. In this study, a liquid turbine power generator driven by lower temperature heats below 373 K was proposed in the aim of expanding selectable options for harvesting low temperature waste heats less than 373 K. The proposing system was so simply that it was mainly composed of a liquid turbine, a liquid container with a biphasic medium of water and an underlying water-insoluble low-boiling-point medium in a liquid phase, a heating section for vaporization of the liquid and a cooling section for entropy discharge outside the system. Assumed power generating steps via the proposing liquid turbine power generator were as follows: step 1: the underlying low-boiling-point medium in a liquid phase was vaporized, step 2: the surfacing vapor bubbles of low-boiling-point medium accompanied the biphasic medium in their wakes, step 3: such high momentum flux by step 2 rotated the liquid turbine (i.e. power generation), step 4: the surfacing low-boiling-point medium vapor was gradually condensed into droplets, step 5: the low-boiling-point medium droplets were submerged to the underlying medium in a liquid phase. Experiments with a prototype liquid turbine power generator proved power generations in accordance with the assumed steps at a little higher than ordinary temperature. Increasing output voltage could be obtained with an increase in the cooling temperature among tested ranging from 294 to 296 K in contrast to normal thermal engines. Further improvements of the direct current voltage from the proposing liquid turbine power generator can be expected by means of far more vigorous multiphase flow induced by adding solid powders and theoretical optimizations of heat and mass transfers.
基金supported by the National Natural Science Foundation of China(No.20706039)the National Basic Research Program(973 Program) of China (No.2005CB221204)+1 种基金the Program for the Top Young Academic Leaders of Higher Learning Institutions of Shanxi of China in 2010the Young Scientific and the Technical Fund of Shanxi of China (No.2006021010)
文摘Cu-Zn-Al slurry catalysts were prepared using a complete liquid-phase preparation technology under different heat treatment atmospheres.The catalysts were characterized using X-ray diffraction,X-ray photoelectron spectroscope,and N2 adsorption-desorption.Their application in the single-step synthesis of dimethyl ether from syngas was also investigated.The results indicate that the type of heat treatment atmosphere has an influence on the Cu species and the Cu0/Cu+ ratio on the catalyst surface.Moreover,the final Cu/Zn ratio on the catalyst surface is mainly dependent on the composition and reaction environment of the catalyst and less on the type of heat treatment atmosphere.The prepared catalysts can suppress sintering of active sites at high temperatures,and the type of heat treatment atmosphere mainly affects the capability of the catalyst for methanol synthesis.The catalysts perform best using N2 as the heat treatment atmosphere.
基金Project supported by the National Natural Science Foundation of China(Grant No.11874191)the Natural Science Foundation of Shandong Province,China(Grant No.ZR2016FM38)
文摘Liquid metal alloys(LMAs) are the potential candidates of thermal interface materials(TIMs) for electronics cooling.In the present work, buffer layers of Ag, Ti, Cu, Ni, Mo, and W were deposited on polished Cu plates by DC magnetron sputtering, the contact angles of de-ionized water and diiodomethane on the buffer layers were measured by an easy drop shape analyzer and the surface free energies(SFEs) of the buffer layers were calculated by the Owens–Wendt–Kaelble equation. Samples were prepared by sandwiching the filmed Cu plates and LMAs. The thermal properties of the samples were measured by laser flash analysis method. The SFE of the buffer layer has a strong influence on the interface heat transfer, whereas the measurement temperature has no obvious effect on the thermal properties of the samples. As the SFE of the buffer layer increases, the wettability, thermal diffusivity, and thermal conductivity are enhanced, and the thermal contact resistance is decreased.
基金supported by the National Natural Science Foundation of China(Grant No.11274018)
文摘Superconducting thermal fluctuation(STF) plays an important role in both thermodynamic and transport properties in the vortex liquid phase of high Tsuperconductors.It was widely observed in the vicinity of the critical transition temperature.In the framework of Ginz burg-Landau-La wrence-Doniach theory in magnetic field,a self-consistent analysis of STF including all Landau levels is given.Besides that,we calculate the contribution of STF to specific heat in vortex liquid phase for high Tcuprate superconductors,and the fitting results are in good agreement with experimental data.