Purpose–This study summarizes the overall situation of the resources of the national science and technology innovation platform in the railway industry,including the distribution of platform types,supporting institut...Purpose–This study summarizes the overall situation of the resources of the national science and technology innovation platform in the railway industry,including the distribution of platform types,supporting institutions,construction sites,professional fields,etc.,to provide a reference for the further improvement and optimization of the national science and technology innovation platform system in the railway industry.Design/methodology/approach–Through literature review,field investigation,expert consultation and other methods,this paper systematically investigates and analyzes the development status of the national science and technology innovation platform in the railway industry.Findings–Taking the national science and technology innovation platform of the railway industry as the research object,this paper investigates and analyzes the construction,development and distribution of the national science and technology innovation platform of railway industry over the years.And the National Engineering Research Center of High-speed Railway and Urban Rail Transit System Technology was taken as an example to introduce its operation effect.Originality/value–China Railway has made great development achievements,with the construction and development of national science and technology innovation platform in the railway industry.In recent years,a large number of national science and technology innovation platforms have been built in the railway industry,which play an important role in railway technological innovation,standard setting and commodification,and Railway Sciences provide strong support for railway technology development.展开更多
In recent years, with the rapid development of large-scale distributed wireless sensor systems and micro-power devices, the disadvantages of traditional chemical battery power supply mode are becoming more and more ob...In recent years, with the rapid development of large-scale distributed wireless sensor systems and micro-power devices, the disadvantages of traditional chemical battery power supply mode are becoming more and more obvious. Piezoelectric energy collector has attracted wide attention because of its simple structure, no heating, no electromagnetic interference, environmental protection and easy miniaturization. Wind energy is a reproducible resource. Wind energy harvester based on piezoelectric intelligent material can be named piezoelectric wind energy harvesting which converts wind energy into electric power and will have great application prospect. To promote the development of piezoelectric wind energy harvesting technology, research statuses on piezoelectric wind energy harvesting technology are reviewed. The existing problem and development direction about piezoelectric wind energy harvester in the future are discussed. The study will be helpful for researchers engaged in piezoelectric wind energy harvesting.展开更多
Deep condensate gas reservoirs exhibit highly complex and variable phase behaviors,making it crucial to understand the relationship between fluid phase states and flow patterns.This study conducts a comprehensive anal...Deep condensate gas reservoirs exhibit highly complex and variable phase behaviors,making it crucial to understand the relationship between fluid phase states and flow patterns.This study conducts a comprehensive analysis of the actual production process of the deep condensate gas well A1 in a certain oilfield in China.Combining phase behavior analysis and CMG software simulations,the study systematically investigates phase transitions,viscosity,and density changes in the gas and liquid phases under different pressure conditions,with a reservoir temperature of 165°C.The research covers three crucial depletion stages of the reservoir:single-phase flow,two-phase transition,and two-phase flow.The findings indicate that retrograde condensation occurs when the pressure falls below the dew point pressure,reachingmaximum condensate liquid production at around 25MPa.As pressure decreases,gas phase density and viscosity gradually decrease,while liquid phase density and viscosity show an increasing trend.In the initial single-phase flow stage,maintaining a consistent gas-oil ratio is observed when both bottom-hole and reservoir pressures are higher than the dew point pressure.However,a sudden drop in bottom-hole pressure below the dew point triggers the production of condensate oil,significantly reducing subsequent gas and oil production.In the transitional two-phase flow stage,as the bottom-hole pressure further decreases,the reservoir exhibits a complex flow regime with coexisting areas of gas and liquid.In the subsequent two-phase flow stage,when both bottom-hole and reservoir pressures are below the dew point pressure,a significant increase in the gas-oil ratio is observed.The reservoir manifests a two-phase flow regime,devoid of single-phase gas flow areas.For lowpressure conditions in deep condensate gas reservoirs,considerations include gas injection,gas lift,and cyclic gas injection and production in surrounding wells.Additionally,techniques such as hot nitrogen or CO_(2) injection can be employed to mitigate retrograde condensation damage.The implications of this study are crucial for developing targeted development strategies and enhancing the overall development of deep condensate gas reservoirs.展开更多
Purpose–High-speed maglev technology can address the issues of adhesion,friction,vibration and highspeed current collection in traditional wheel-rail systems,making it an important direction for the future developmen...Purpose–High-speed maglev technology can address the issues of adhesion,friction,vibration and highspeed current collection in traditional wheel-rail systems,making it an important direction for the future development of high-speed rail technology.Design/methodology/approach–This paper elaborates on the demand and significance of developing high-speed maglev technology worldwide and examines the current status and technological maturity of several major high-speed maglev systems globally.Findings–This paper summarizes the challenges in the development of high-speed maglev railways in China.Based on this analysis,it puts forward considerations for future research on high-speed maglev railways.Originality/value–This paper describes the development status and technical maturity of several major high-speed maglev systems in the world for the first time,summarizes the existing problems in the development of China’s high-speed maglev railway and on this basis,puts forward the thinking of the next research of China’s high-speed maglev railway.展开更多
As the bed depth increases,sintering yield increases,but the productivity decreases.To reveal the reasons for the decrease in productivity and explore targeted solutions,the bed resistance of mixtures,wet zone,and com...As the bed depth increases,sintering yield increases,but the productivity decreases.To reveal the reasons for the decrease in productivity and explore targeted solutions,the bed resistance of mixtures,wet zone,and combustion zone was analyzed in the laboratory.The results showed that the decreased porosity of mixture resulted in the increased bed resistance by 160.56%when the bed depth increased from 600 to 1000 mm.After improving porosity of 1%by adding loosening bars with optimized size and distribution,the bed resistance decreased,and the productivity increased by 5%.The increase in bed depth increased the thickness of the wet zone from 120 to 680 mm and the resistance from 1.56 to 8.83 kPa.By using a three-stage intensive mixer and pre-adding water for granulation,the moisture of mixture was reduced by 0.6%,and the sintering productivity increased by 4%.Besides,the high bed resistance is mainly caused by the increase in the thickness of the combustion zone from 31.9 to 132.7 mm,and the bed resistance increased from 0.70 to 5.62 kPa.The bed resistance of the combustion zone at 900 mm was increased by 90.51%compared to 700 mm.After optimization of the distribution of coke breeze,the thickness of combustion zone at the lower layer decreased from 132.7 to 106.84 mm and permeability improved significantly.展开更多
Purpose–The study aims to build a high-precision longitudinal dynamics model for heavy-haul trains and validate it with line test data,present an optimization method for multi-stage cyclic brakes based on the model a...Purpose–The study aims to build a high-precision longitudinal dynamics model for heavy-haul trains and validate it with line test data,present an optimization method for multi-stage cyclic brakes based on the model and conduct a multi-objective detailed evaluation of the driver’s manipulation during cyclic braking.Design/methodology/approach–The high-precision longitudinal train dynamics model was established and verified by the cyclic braking test data of the 20,000 t heavy-haul combination train on the long and steep downgrade.Then the genetic algorithm is employed for optimization subsequent to decoupling multiple cyclic braking procedures,with due consideration of driver operation rules.For evaluation,key manipulation assessments in the scenario are prioritized,supplemented by multi-objective evaluation requirements,and the computational model is employed for detailed evaluation analysis.Findings–Based on the model,experimental data reveal that the probability of longitudinal force error being less than 64.6 kN is approximately 68%,95%for less than 129.2 kN and 99.7%for less than 193.8 kN.Upon optimizing manipulations during the cyclic braking,the maximum reduction in coupler force spans from 21%∼23.9%.Andtheevaluation scoresimply that a proper elevationof the releasingspeed favorssafety.A high electric braking force,although beneficial to some extent for energy-saving,is detrimental to reducing coupler force.Originality/value–The results will provide a theoretical basis and practical guidance for further ensuring the safety and energy-efficient operation of heavy haul trains on long downhill sections and improving the operational quality of heavy-haul trains.展开更多
Purpose–The precast concrete slab track(PST)has advantages of fewer maintenance frequencies,better smooth rides and structural stability,which has been widely applied in urban rail transit.Precise positioning of prec...Purpose–The precast concrete slab track(PST)has advantages of fewer maintenance frequencies,better smooth rides and structural stability,which has been widely applied in urban rail transit.Precise positioning of precast concrete slab(PCS)is vital for keeping the initial track regularity.However,the cast-in-place process of the self-compacting concrete(SCC)filling layer generally causes a large deformation of PCS due to the water-hammer effect of flowing SCC,even cracking of PCS.Currently,the buoyancy characteristic and influencing factors of PCS during the SCC casting process have not been thoroughly studied in urban rail transit.Design/methodology/approach–In this work,a Computational Fluid Dynamics(CFD)model is established to calculate the buoyancy of PCS caused by the flowing SCC.The main influencing factors,including the inlet speed and flowability of SCC,have been analyzed and discussed.A new structural optimization scheme has been proposed for PST to reduce the buoyancy caused by the flowing SCC.Findings–The simulation and field test results showed that the buoyancy and deformation of PCS decreased obviously after adopting the new scheme.Originality/value–The findings of this study can provide guidance for the control of the deformation of PCS during the SCC construction process.展开更多
Accurate lithofacies classification in low-permeability sandstone reservoirs remains challenging due to class imbalance in well-log data and the difficulty of the modeling vertical lithological dependencies.Traditiona...Accurate lithofacies classification in low-permeability sandstone reservoirs remains challenging due to class imbalance in well-log data and the difficulty of the modeling vertical lithological dependencies.Traditional core-based interpretation introduces subjectivity,while conventional deep learning models often fail to capture stratigraphic sequences effectively.To address these limitations,we propose a hybrid CNN–GRU framework that integrates spatial feature extraction and sequential modeling.Heat Kernel Imputation is applied to reconstruct missing log data,and Borderline SMOTE(BSMOTE)improves class balance by augmenting boundary-case minority samples.The CNN component extracts localized petrophysical features,and the GRU component captures depth-wise lithological transitions,to enable spatial-sequential feature fusion.Experiments on real-well datasets from tight sandstone reservoirs show that the proposed model achieves an average accuracy of 93.3%and a Macro F1-score of 0.934.It outperforms baseline models,including RF(87.8%),GBDT(81.8%),CNN-only(87.5%),and GRU-only(86.1%).Leave-one-well-out validation further confirms strong generalization ability.These results demonstrate that the proposed approach effectively addresses data imbalance and enhances classification robustness,offering a scalable and automated solution for lithofacies interpretation under complex geological conditions.展开更多
With brick-wall solar greenhouses in Changli area as the research object,using temperature dynamic monitoring and statistical methods,the greenhouse structure suitable for promoting early cultivation of local peach tr...With brick-wall solar greenhouses in Changli area as the research object,using temperature dynamic monitoring and statistical methods,the greenhouse structure suitable for promoting early cultivation of local peach trees was selected by studying the temperature data of the solar greenhouses during the winter solstice,and a prediction model for daily average temperature was constructed.The results showed that greenhouse Ⅰ had reasonable structural parameters and good daylight during the day.However,due to the low wall thickness and poor insulation material,the minimum temperature was significantly lower than other greenhouses.The thermal insulation performance of greenhouse Ⅱ and Ⅲ was better than that of greenhouse Ⅰ,but the depth-span ratio and the front roof lighting angle were smaller.During the winter solstice,the average temperature of the three greenhouses was between 10 and 15℃,which was suitable for early cultivation of peach trees.The prediction model of daily average temperature was obtained:Daily average temperature=1.02+0.69×Daily average temperature of the previous day+0.02×Maximum temperature of the previous day-0.01×Minimum temperature of the previous day.To sum up,the structural parameters of brick-wall solar greenhouses suitable for early cultivation of peach trees in Changli area were as follows:span 6.5-8.5 m,depth-span ratio 0.47,front roof lighting angle 30°and wall thickness greater than 55 cm.展开更多
The rapid and increasing growth in the volume and number of cyber threats from malware is not a real danger;the real threat lies in the obfuscation of these cyberattacks,as they constantly change their behavior,making...The rapid and increasing growth in the volume and number of cyber threats from malware is not a real danger;the real threat lies in the obfuscation of these cyberattacks,as they constantly change their behavior,making detection more difficult.Numerous researchers and developers have devoted considerable attention to this topic;however,the research field has not yet been fully saturated with high-quality studies that address these problems.For this reason,this paper presents a novel multi-objective Markov-enhanced adaptive whale optimization(MOMEAWO)cybersecurity model to improve the classification of binary and multi-class malware threats through the proposed MOMEAWO approach.The proposed MOMEAWO cybersecurity model aims to provide an innovative solution for analyzing,detecting,and classifying the behavior of obfuscated malware within their respective families.The proposed model includes three classification types:Binary classification and multi-class classification(e.g.,four families and 16 malware families).To evaluate the performance of this model,we used a recently published dataset called the Canadian Institute for Cybersecurity Malware Memory Analysis(CIC-MalMem-2022)that contains balanced data.The results show near-perfect accuracy in binary classification and high accuracy in multi-class classification compared with related work using the same dataset.展开更多
Objective:To investigate the potential efficacy and safety of Lutai Danshen Baishao granules(LDBG)for treating female melasma associated with kidney deficiency and blood stasis patterns.Methods:A randomized,double-bli...Objective:To investigate the potential efficacy and safety of Lutai Danshen Baishao granules(LDBG)for treating female melasma associated with kidney deficiency and blood stasis patterns.Methods:A randomized,double-blind,placebo-controlled trial was conducted at the Third Central Hospital of Tianjin,China from March to December 2023.A total of 110 female patients with melasma linked to kidney deficiency and blood stasis were enrolled and treated with either LDBG or a placebo twice daily for 60 days.Efficacy was assessed through measures such as the total melasma area,reduced melasma area,reduction rate of melasma area,melasma color score,Melasma Area and Severity Index(MASI)score,and traditional Chinese medicine(TCM)symptom score scale.Safety assessments included routine blood and biochemical tests.Results:Participants in both groups were aged 52-63 years,with no significant differences.After the 2-month intervention,the total melasma area decreased in both groups;however,a greater reduction was observed in the test group[462.50 mm^(2)(12.81%)vs.100.00 mm2(3.11%),P<.001].Moreover,LDBG treatment significantly reduced the MASI and melasma color scores in the test group(P<.05).The total TCM symptom evaluation score significantly decreased(test group:6.00 vs.placebo group:7.00,P=.001),with significant relief in symptoms such as improvement in dark lips,nails,and waist soreness in the test group,compared with that in the placebo group(P<.05).Within-group comparisons revealed that TCM syndrome was significantly alleviated in the test group(P<.05).Conclusion:LDBG intervention shows promising effectiveness in reducing female melasma and alleviating TCM syndromes.展开更多
Photon upconversion has received substantial attention owing to its great promise in broad applications from bioimaging to other frontier fields like display,upconversion laser,information security and anticounterfeit...Photon upconversion has received substantial attention owing to its great promise in broad applications from bioimaging to other frontier fields like display,upconversion laser,information security and anticounterfeiting.A smart control and manipulation of the upconversion luminescence has always been a key topic,however,to date the most efficient mechanism for upconversion nanoparticles remains the energy transfer upconversion and recently reported energy migration mediated upconversion.Recently,we found that the interfacial energy transfer(IET)is also an efficient approach for enabling and tuning photon upconversion of lanthanide ions.Moreover,it can be used for the mechanistic understanding of the interionic interactions such as energy transfer and energy migration on the nanoscale.In this review,the recent advances of the research on the IET are summarized,the principles for designing IET process and typical examples are discussed together with its applications in both mechanistic research and frontier information security.The challenges and perspectives for future research are also commented.展开更多
Effective multiple optoelectronic feedback circuits for simultaneously suppressing low-frequency and relaxation oscillation intensity noise in a single-frequency phosphate fiber laser are demonstrated. The forward tra...Effective multiple optoelectronic feedback circuits for simultaneously suppressing low-frequency and relaxation oscillation intensity noise in a single-frequency phosphate fiber laser are demonstrated. The forward transfer function, which relates the laser output intensity to the pump modulations, is measured and analyzed. A custom two-path feedback system operating at different frequency bands is designed to adjust the pump current directly. The relative intensity noise is decreased by 20dB from 0.2 to 5kHz and over lOdB from 5 to lOkHz. The relaxation oscillation peak is suppressed by 22dB. In addition, a long term （24h） laser instability of less than 0.05% is achieved.展开更多
Efficient and low-cost recycling of spent lithium iron phosphate(LiFePO_(4),LFP)batteries has become an inevitable trend.In this study,an integrated closed-loop recycling strategy including isomorphic substitution lea...Efficient and low-cost recycling of spent lithium iron phosphate(LiFePO_(4),LFP)batteries has become an inevitable trend.In this study,an integrated closed-loop recycling strategy including isomorphic substitution leaching and solvent extraction process for spent LFP was proposed.An inexpensive FeCl_(3)was used as leaching agent to directly substitute Fe^(2+)from LFP.99%of Li can be rapidly leached in just 30 min,accompanied by 98%of FePO_(4)precipitated in lixivium.The tri-n-butyl phosphate(TBP)-sulfonated kerosene(SK)system was applied to extract Li from lixivium through a twelve-stage countercurrent process containing synchronous extraction and stepwise stripping of Li^(+)and Fe^(3+).80.81%of Li can be selectively enriched in stripping liquor containing 3.059 mol·L^(-1)of Li^(+)under optimal conditions.And the Fe stripping liquor was recovered for LFP re-leaching,of which,Fe^(2+)was oxidized to Fe^(3+)by appropriate H_(2)O_(2).Raffinate and lixivium were concentrated and entered into extraction process to accomplished closeloop recycling process.Overall,the results suggest that more than 99%of Li was recovered.FeCl_(3)holding in solution was directly regenerated without any pollutant emission.The sustainable mothed would be an alternative candidate for total element recycling of spent LFP batteries with industrial potential.展开更多
Phosphors of BaLiF3 doped with Eu or/and Ce were solvothermally prepared at 200℃ for 5 d and characterized by means of X-ray powder diffraction （XRD） and environment scanning electron microscopy （ESEM）. The excit...Phosphors of BaLiF3 doped with Eu or/and Ce were solvothermally prepared at 200℃ for 5 d and characterized by means of X-ray powder diffraction （XRD） and environment scanning electron microscopy （ESEM）. The excitation and emission spectra of the rare earth ions doped BaLiF3 were measured by fluorescence spectroscopy and the effects of Ce3＋ ions on the luminescence of Eu〉 ions were in- vestigated. In the co-doped Eu2＋ and Ce3＋ system, the emission intensity of Eu2＋ ion gradually increased with the Ce3＋ concentration increas- ing, and the enhancement of Eu2＋ fluorescence was due to efficient energy transfer from Ce3＋ to Eu2＋ in the host.展开更多
To analyze wheel wear discrepancy between motor car and trailer of an intercity train,a novel wheel wear rates calculation model was proposed,which was composed of the intercity train dynamics model,wheel-rail three-d...To analyze wheel wear discrepancy between motor car and trailer of an intercity train,a novel wheel wear rates calculation model was proposed,which was composed of the intercity train dynamics model,wheel-rail three-dimensional rolling contact FEM model and the wear model.The simulated results were contrasted with measured results in field test.The simulated results showed the motor car wheels had larger rotation rate and longitudinal creepage than the trailer wheels.Meanwhile,the motor car wheels encountered larger vertical forces and longitudinal forces from bogie because of the heavier car body and the impact of traction torque.The traction torque acting on motor car wheel could increase the slip rates in the rear part of wheel contact patch and weaken the spinning phenomenon of relative slip.Larger contact pressure and slip rates caused the higher wear rates of motor car wheel than those of trailer wheel.The overall trends of wheel wear depth in simulated and tested results were similar.And they both showed the motor car wheel encountered the more serious wear than the trailer wheel.These models can be used to study the effect of the traction characteristics curves on the wear of wheel.展开更多
Dissolved organic matter(DOM)plays a vital role in promoting carbon and nutrient cycling.It is a food source for organisms and controls the migration and transformation of trace metals and other contaminants in aquati...Dissolved organic matter(DOM)plays a vital role in promoting carbon and nutrient cycling.It is a food source for organisms and controls the migration and transformation of trace metals and other contaminants in aquatic systems.The contributions of aquatic DOM to the environment and ecology of a system are closely related to its abundance and chemical structure.In this study,the chemical composition and binding properties of DOM in a hypersaline lake watershed were investigated for the fi rst time using dissolved organic carbon(DOC)analysis,absorption spectroscopy,Fourier transform infrared spectroscopy,pyrolysis-GC-MS(Py-GC-MS),and fl uorescence parallel factor(PARAFAC)analysis combined with Pb(II)titration techniques.The results showed that DOM from the tributaries that fl owed into the lake had a lower DOC content,higher molecular weight,and higher specifi c UV absorbance than the DOM in lake water.Protein-like fl uorophores were mainly found in tributary and lake surface water DOM(LSDOM)and humic-like substances were abundant in lake groundwater DOM(LGDOM).Using this multi-methodological approach,we found that the DOM from the hypersaline lake watershed was mainly from microbial origins,and consisted of aromatics,carbohydrates,and aliphatics.The results from quantitative analysis showed that DOM from the infl owing tributaries contained more aromatics,lower carbohydrates,and lower aliphatics than DOM in the lake.Monocyclic aromatic hydrocarbons and carbohydrates were more abundant in LSDOM than LGDOM.The results from the Pb(II)titration technique coupled with PARAFAC analysis suggested that PARAFAC-derived components had relatively low condition stability constants(log K_(M)<2).Of the two types of lake DOM,the LGDOM had a higher Pb(II)binding potential than the LSDOM.From this study we have improved our understanding of how DOM within a hypersaline lake watershed varies in its composition and potential to bind with metals.展开更多
Purpose–This study aims to analyze the development direction of train speed,density and weight in China.Design/methodology/approach–The development of China’s railway in the past 40 years can be divided into 3 stag...Purpose–This study aims to analyze the development direction of train speed,density and weight in China.Design/methodology/approach–The development of China’s railway in the past 40 years can be divided into 3 stages.At the stage of potential tapping and capacity expansion,it is important to improve the train weight and density by upgrading the existing lines,and improving transportation capacity rapidly.At the stage of railway speed increase,the first priority is to increase train speed,reduce the travel time of passenger train,and synchronously take into account the increase of train density and weight.At the stage of developing high-speed railway,train speed,density and weight are co-developing on demand.Findings–The train speed of high-speed railway will be 400 km h1,the interval time of train tracking will be 3 min,and the traffic density will be more than 190 pairs per day.The running speed of high-speed freight EMU will reach 200 km h1 and above.The maximum speed of passenger train on mixed passenger and freight railway can reach 200 km h1.The minimum interval time of train tracking can be compressed to 5 min.The freight train weight of 850 m series arrival-departure track railway can be increased to 4,500–5,000 t and that of 1,050 m series to 5,500–6,400 t.EMU trains should gradually replace ordinary passenger trains to improve the quality of railway passenger service.Small formation trains will operate more in intercity railway,suburban railway and short-distance passenger transportation.Originality/value–The research can provide new connotations and requirements of railway train speed,density and weight in the new railway stage.展开更多
The regeneration of fluidized catalytic cracking(FCC)catalysts is an essential process in petroleum processing.The current study focused the regeneration reaction characteristics of spent fluidized catalytic cracking ...The regeneration of fluidized catalytic cracking(FCC)catalysts is an essential process in petroleum processing.The current study focused the regeneration reaction characteristics of spent fluidized catalytic cracking catalyst(SFCC)at different atmospheres with influences on pore evolution and activity,for a potential way to reduce emission,produce moderate chemical product(CO),and maintain catalyst activity.The results show that regeneration in air indicates a satisfaction on removing coke on the catalyst surface while giving a poor effect on eliminating the coke inside micropores.This is attributed that the combustion in air led to a higher temperature and further transformed kaolinite phase to silicaaluminum spinel crystals,which tended to collapse and block small pores or expand large pores,with similar results observed in pure O_(2)atmosphere.Nevertheless,catalysts regenerated in O_(2)/CO_(2)diminished the combustion damage to the pore structure,of which the micro porosity after regeneration increased by 32.4% and the total acid volume rose to 27.1%.The regeneration in pure CO_(2)displayed low conversion rate due to the endothermic reaction and low reactivity.The coexistence of gasification and partial oxidation can promote regeneration and maintain the original structure and good reactivity.Finally,a mechanism of the regeneration reaction at different atmospheres was revealed.展开更多
Radiant syngas cooler(RSC)is widely used as a waste heat recovery equipment in industrial gasification.In this work,an RSC with radiation screens is established and the impact of gaseous radiative property models,gas ...Radiant syngas cooler(RSC)is widely used as a waste heat recovery equipment in industrial gasification.In this work,an RSC with radiation screens is established and the impact of gaseous radiative property models,gas components,and ash particles on heat transfer is investigated by the numerical simulation method.Considering the syngas components and the pressure environment of the RSC,a modified weighted-sum-of-gray-gases model was developed.The modified model shows high accuracy in validation.In computational fluid dynamics simulation,the calculated steam production is only 0.63%in error with the industrial data.Compared with Smith's model,the temperature decay along the axial direction calculated by the modified model is faster.Syngas components are of great significance to heat recovery capacity,especially when the absorbing gas fraction is less than 10%.After considering the influence of particles,the outlet temperature and the proportion of radiative heat transfer are less affected,but the difference in steam output reaches 2.7 t·h^(-1).The particle deposition on the wall greatly reduces the heat recovery performance of an RSC.展开更多
文摘Purpose–This study summarizes the overall situation of the resources of the national science and technology innovation platform in the railway industry,including the distribution of platform types,supporting institutions,construction sites,professional fields,etc.,to provide a reference for the further improvement and optimization of the national science and technology innovation platform system in the railway industry.Design/methodology/approach–Through literature review,field investigation,expert consultation and other methods,this paper systematically investigates and analyzes the development status of the national science and technology innovation platform in the railway industry.Findings–Taking the national science and technology innovation platform of the railway industry as the research object,this paper investigates and analyzes the construction,development and distribution of the national science and technology innovation platform of railway industry over the years.And the National Engineering Research Center of High-speed Railway and Urban Rail Transit System Technology was taken as an example to introduce its operation effect.Originality/value–China Railway has made great development achievements,with the construction and development of national science and technology innovation platform in the railway industry.In recent years,a large number of national science and technology innovation platforms have been built in the railway industry,which play an important role in railway technological innovation,standard setting and commodification,and Railway Sciences provide strong support for railway technology development.
文摘In recent years, with the rapid development of large-scale distributed wireless sensor systems and micro-power devices, the disadvantages of traditional chemical battery power supply mode are becoming more and more obvious. Piezoelectric energy collector has attracted wide attention because of its simple structure, no heating, no electromagnetic interference, environmental protection and easy miniaturization. Wind energy is a reproducible resource. Wind energy harvester based on piezoelectric intelligent material can be named piezoelectric wind energy harvesting which converts wind energy into electric power and will have great application prospect. To promote the development of piezoelectric wind energy harvesting technology, research statuses on piezoelectric wind energy harvesting technology are reviewed. The existing problem and development direction about piezoelectric wind energy harvester in the future are discussed. The study will be helpful for researchers engaged in piezoelectric wind energy harvesting.
基金funding from the Key Research Project of Tarim Oilfield Company of Petrochina(671023060003)for this study.
文摘Deep condensate gas reservoirs exhibit highly complex and variable phase behaviors,making it crucial to understand the relationship between fluid phase states and flow patterns.This study conducts a comprehensive analysis of the actual production process of the deep condensate gas well A1 in a certain oilfield in China.Combining phase behavior analysis and CMG software simulations,the study systematically investigates phase transitions,viscosity,and density changes in the gas and liquid phases under different pressure conditions,with a reservoir temperature of 165°C.The research covers three crucial depletion stages of the reservoir:single-phase flow,two-phase transition,and two-phase flow.The findings indicate that retrograde condensation occurs when the pressure falls below the dew point pressure,reachingmaximum condensate liquid production at around 25MPa.As pressure decreases,gas phase density and viscosity gradually decrease,while liquid phase density and viscosity show an increasing trend.In the initial single-phase flow stage,maintaining a consistent gas-oil ratio is observed when both bottom-hole and reservoir pressures are higher than the dew point pressure.However,a sudden drop in bottom-hole pressure below the dew point triggers the production of condensate oil,significantly reducing subsequent gas and oil production.In the transitional two-phase flow stage,as the bottom-hole pressure further decreases,the reservoir exhibits a complex flow regime with coexisting areas of gas and liquid.In the subsequent two-phase flow stage,when both bottom-hole and reservoir pressures are below the dew point pressure,a significant increase in the gas-oil ratio is observed.The reservoir manifests a two-phase flow regime,devoid of single-phase gas flow areas.For lowpressure conditions in deep condensate gas reservoirs,considerations include gas injection,gas lift,and cyclic gas injection and production in surrounding wells.Additionally,techniques such as hot nitrogen or CO_(2) injection can be employed to mitigate retrograde condensation damage.The implications of this study are crucial for developing targeted development strategies and enhancing the overall development of deep condensate gas reservoirs.
基金This paper was supported by the funding of Strategic research and consulting project of Chinese Academy of Engineering(Grant No.2022-XBZD-20).
文摘Purpose–High-speed maglev technology can address the issues of adhesion,friction,vibration and highspeed current collection in traditional wheel-rail systems,making it an important direction for the future development of high-speed rail technology.Design/methodology/approach–This paper elaborates on the demand and significance of developing high-speed maglev technology worldwide and examines the current status and technological maturity of several major high-speed maglev systems globally.Findings–This paper summarizes the challenges in the development of high-speed maglev railways in China.Based on this analysis,it puts forward considerations for future research on high-speed maglev railways.Originality/value–This paper describes the development status and technical maturity of several major high-speed maglev systems in the world for the first time,summarizes the existing problems in the development of China’s high-speed maglev railway and on this basis,puts forward the thinking of the next research of China’s high-speed maglev railway.
基金supported by the Basic Science Center Project for the National Natural Science Foundation of China(No.72088101)the S&T Program of Hebei(No.23564101D).
文摘As the bed depth increases,sintering yield increases,but the productivity decreases.To reveal the reasons for the decrease in productivity and explore targeted solutions,the bed resistance of mixtures,wet zone,and combustion zone was analyzed in the laboratory.The results showed that the decreased porosity of mixture resulted in the increased bed resistance by 160.56%when the bed depth increased from 600 to 1000 mm.After improving porosity of 1%by adding loosening bars with optimized size and distribution,the bed resistance decreased,and the productivity increased by 5%.The increase in bed depth increased the thickness of the wet zone from 120 to 680 mm and the resistance from 1.56 to 8.83 kPa.By using a three-stage intensive mixer and pre-adding water for granulation,the moisture of mixture was reduced by 0.6%,and the sintering productivity increased by 4%.Besides,the high bed resistance is mainly caused by the increase in the thickness of the combustion zone from 31.9 to 132.7 mm,and the bed resistance increased from 0.70 to 5.62 kPa.The bed resistance of the combustion zone at 900 mm was increased by 90.51%compared to 700 mm.After optimization of the distribution of coke breeze,the thickness of combustion zone at the lower layer decreased from 132.7 to 106.84 mm and permeability improved significantly.
文摘Purpose–The study aims to build a high-precision longitudinal dynamics model for heavy-haul trains and validate it with line test data,present an optimization method for multi-stage cyclic brakes based on the model and conduct a multi-objective detailed evaluation of the driver’s manipulation during cyclic braking.Design/methodology/approach–The high-precision longitudinal train dynamics model was established and verified by the cyclic braking test data of the 20,000 t heavy-haul combination train on the long and steep downgrade.Then the genetic algorithm is employed for optimization subsequent to decoupling multiple cyclic braking procedures,with due consideration of driver operation rules.For evaluation,key manipulation assessments in the scenario are prioritized,supplemented by multi-objective evaluation requirements,and the computational model is employed for detailed evaluation analysis.Findings–Based on the model,experimental data reveal that the probability of longitudinal force error being less than 64.6 kN is approximately 68%,95%for less than 129.2 kN and 99.7%for less than 193.8 kN.Upon optimizing manipulations during the cyclic braking,the maximum reduction in coupler force spans from 21%∼23.9%.Andtheevaluation scoresimply that a proper elevationof the releasingspeed favorssafety.A high electric braking force,although beneficial to some extent for energy-saving,is detrimental to reducing coupler force.Originality/value–The results will provide a theoretical basis and practical guidance for further ensuring the safety and energy-efficient operation of heavy haul trains on long downhill sections and improving the operational quality of heavy-haul trains.
文摘Purpose–The precast concrete slab track(PST)has advantages of fewer maintenance frequencies,better smooth rides and structural stability,which has been widely applied in urban rail transit.Precise positioning of precast concrete slab(PCS)is vital for keeping the initial track regularity.However,the cast-in-place process of the self-compacting concrete(SCC)filling layer generally causes a large deformation of PCS due to the water-hammer effect of flowing SCC,even cracking of PCS.Currently,the buoyancy characteristic and influencing factors of PCS during the SCC casting process have not been thoroughly studied in urban rail transit.Design/methodology/approach–In this work,a Computational Fluid Dynamics(CFD)model is established to calculate the buoyancy of PCS caused by the flowing SCC.The main influencing factors,including the inlet speed and flowability of SCC,have been analyzed and discussed.A new structural optimization scheme has been proposed for PST to reduce the buoyancy caused by the flowing SCC.Findings–The simulation and field test results showed that the buoyancy and deformation of PCS decreased obviously after adopting the new scheme.Originality/value–The findings of this study can provide guidance for the control of the deformation of PCS during the SCC construction process.
基金supported by the Langfang Science and Technology Program with self-raised funds under the project“Application of Deep Learning-Based Joint Well-Seismic Analysis in Lithology Prediction”(Project No.2024011013)the Science and Technology Innovation Program for Postgraduate students in IDP subsidized by Fundamental Research Funds for the Central Universities,under the project“Research on CNN Algorithm Enhanced by Physical Information for Lithofacies Prediction in Tight Sandstone Reservoirs”(Project No.ZY20250328).
文摘Accurate lithofacies classification in low-permeability sandstone reservoirs remains challenging due to class imbalance in well-log data and the difficulty of the modeling vertical lithological dependencies.Traditional core-based interpretation introduces subjectivity,while conventional deep learning models often fail to capture stratigraphic sequences effectively.To address these limitations,we propose a hybrid CNN–GRU framework that integrates spatial feature extraction and sequential modeling.Heat Kernel Imputation is applied to reconstruct missing log data,and Borderline SMOTE(BSMOTE)improves class balance by augmenting boundary-case minority samples.The CNN component extracts localized petrophysical features,and the GRU component captures depth-wise lithological transitions,to enable spatial-sequential feature fusion.Experiments on real-well datasets from tight sandstone reservoirs show that the proposed model achieves an average accuracy of 93.3%and a Macro F1-score of 0.934.It outperforms baseline models,including RF(87.8%),GBDT(81.8%),CNN-only(87.5%),and GRU-only(86.1%).Leave-one-well-out validation further confirms strong generalization ability.These results demonstrate that the proposed approach effectively addresses data imbalance and enhances classification robustness,offering a scalable and automated solution for lithofacies interpretation under complex geological conditions.
基金Supported by Modern Agricultural Industry Technology System Innovation Team Construction in Hebei Province(HBCT2023130404).
文摘With brick-wall solar greenhouses in Changli area as the research object,using temperature dynamic monitoring and statistical methods,the greenhouse structure suitable for promoting early cultivation of local peach trees was selected by studying the temperature data of the solar greenhouses during the winter solstice,and a prediction model for daily average temperature was constructed.The results showed that greenhouse Ⅰ had reasonable structural parameters and good daylight during the day.However,due to the low wall thickness and poor insulation material,the minimum temperature was significantly lower than other greenhouses.The thermal insulation performance of greenhouse Ⅱ and Ⅲ was better than that of greenhouse Ⅰ,but the depth-span ratio and the front roof lighting angle were smaller.During the winter solstice,the average temperature of the three greenhouses was between 10 and 15℃,which was suitable for early cultivation of peach trees.The prediction model of daily average temperature was obtained:Daily average temperature=1.02+0.69×Daily average temperature of the previous day+0.02×Maximum temperature of the previous day-0.01×Minimum temperature of the previous day.To sum up,the structural parameters of brick-wall solar greenhouses suitable for early cultivation of peach trees in Changli area were as follows:span 6.5-8.5 m,depth-span ratio 0.47,front roof lighting angle 30°and wall thickness greater than 55 cm.
文摘The rapid and increasing growth in the volume and number of cyber threats from malware is not a real danger;the real threat lies in the obfuscation of these cyberattacks,as they constantly change their behavior,making detection more difficult.Numerous researchers and developers have devoted considerable attention to this topic;however,the research field has not yet been fully saturated with high-quality studies that address these problems.For this reason,this paper presents a novel multi-objective Markov-enhanced adaptive whale optimization(MOMEAWO)cybersecurity model to improve the classification of binary and multi-class malware threats through the proposed MOMEAWO approach.The proposed MOMEAWO cybersecurity model aims to provide an innovative solution for analyzing,detecting,and classifying the behavior of obfuscated malware within their respective families.The proposed model includes three classification types:Binary classification and multi-class classification(e.g.,four families and 16 malware families).To evaluate the performance of this model,we used a recently published dataset called the Canadian Institute for Cybersecurity Malware Memory Analysis(CIC-MalMem-2022)that contains balanced data.The results show near-perfect accuracy in binary classification and high accuracy in multi-class classification compared with related work using the same dataset.
基金funded by the National Key Research and Development Plan of the Traditional Chinese Medicine Modernization Research Key Project(2018YFC1706800).
文摘Objective:To investigate the potential efficacy and safety of Lutai Danshen Baishao granules(LDBG)for treating female melasma associated with kidney deficiency and blood stasis patterns.Methods:A randomized,double-blind,placebo-controlled trial was conducted at the Third Central Hospital of Tianjin,China from March to December 2023.A total of 110 female patients with melasma linked to kidney deficiency and blood stasis were enrolled and treated with either LDBG or a placebo twice daily for 60 days.Efficacy was assessed through measures such as the total melasma area,reduced melasma area,reduction rate of melasma area,melasma color score,Melasma Area and Severity Index(MASI)score,and traditional Chinese medicine(TCM)symptom score scale.Safety assessments included routine blood and biochemical tests.Results:Participants in both groups were aged 52-63 years,with no significant differences.After the 2-month intervention,the total melasma area decreased in both groups;however,a greater reduction was observed in the test group[462.50 mm^(2)(12.81%)vs.100.00 mm2(3.11%),P<.001].Moreover,LDBG treatment significantly reduced the MASI and melasma color scores in the test group(P<.05).The total TCM symptom evaluation score significantly decreased(test group:6.00 vs.placebo group:7.00,P=.001),with significant relief in symptoms such as improvement in dark lips,nails,and waist soreness in the test group,compared with that in the placebo group(P<.05).Within-group comparisons revealed that TCM syndrome was significantly alleviated in the test group(P<.05).Conclusion:LDBG intervention shows promising effectiveness in reducing female melasma and alleviating TCM syndromes.
基金Project supported by the National Natural Science Foundation of China(51702101,51972119,51472088)the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(2017BT01X137)。
文摘Photon upconversion has received substantial attention owing to its great promise in broad applications from bioimaging to other frontier fields like display,upconversion laser,information security and anticounterfeiting.A smart control and manipulation of the upconversion luminescence has always been a key topic,however,to date the most efficient mechanism for upconversion nanoparticles remains the energy transfer upconversion and recently reported energy migration mediated upconversion.Recently,we found that the interfacial energy transfer(IET)is also an efficient approach for enabling and tuning photon upconversion of lanthanide ions.Moreover,it can be used for the mechanistic understanding of the interionic interactions such as energy transfer and energy migration on the nanoscale.In this review,the recent advances of the research on the IET are summarized,the principles for designing IET process and typical examples are discussed together with its applications in both mechanistic research and frontier information security.The challenges and perspectives for future research are also commented.
基金Supported by the National High-Technology Research and Development Program of China under Grant Nos 2013AA031502 and 2014AA041902the National Natural Science Foundation of China under Grant Nos 11174085,51132004,and 51302086+3 种基金the Guangdong Natural Science Foundation under Grant Nos S2011030001349 and S20120011380the China National Funds for Distinguished Young Scientists under Grant No 61325024the Science and Technology Project of Guangdong Province under Grant No 2013B090500028the’Cross and Cooperative’Science and Technology Innovation Team Project of Chinese Academy of Sciences under Grant No 2012-119
文摘Effective multiple optoelectronic feedback circuits for simultaneously suppressing low-frequency and relaxation oscillation intensity noise in a single-frequency phosphate fiber laser are demonstrated. The forward transfer function, which relates the laser output intensity to the pump modulations, is measured and analyzed. A custom two-path feedback system operating at different frequency bands is designed to adjust the pump current directly. The relative intensity noise is decreased by 20dB from 0.2 to 5kHz and over lOdB from 5 to lOkHz. The relaxation oscillation peak is suppressed by 22dB. In addition, a long term （24h） laser instability of less than 0.05% is achieved.
基金financially supported by the National Natural Science Foundation of China(U1707601)project of Youth Innovation Promotion Association,Chinese Academy of Sciences(2021430)+1 种基金project of Innovation Academy for Green Manufacture,Chinese Academy of Sciences(IAGM2020C26)project of Bureau of International Cooperation,Chinese Academy of Sciences(122363KYSB20190033)。
文摘Efficient and low-cost recycling of spent lithium iron phosphate(LiFePO_(4),LFP)batteries has become an inevitable trend.In this study,an integrated closed-loop recycling strategy including isomorphic substitution leaching and solvent extraction process for spent LFP was proposed.An inexpensive FeCl_(3)was used as leaching agent to directly substitute Fe^(2+)from LFP.99%of Li can be rapidly leached in just 30 min,accompanied by 98%of FePO_(4)precipitated in lixivium.The tri-n-butyl phosphate(TBP)-sulfonated kerosene(SK)system was applied to extract Li from lixivium through a twelve-stage countercurrent process containing synchronous extraction and stepwise stripping of Li^(+)and Fe^(3+).80.81%of Li can be selectively enriched in stripping liquor containing 3.059 mol·L^(-1)of Li^(+)under optimal conditions.And the Fe stripping liquor was recovered for LFP re-leaching,of which,Fe^(2+)was oxidized to Fe^(3+)by appropriate H_(2)O_(2).Raffinate and lixivium were concentrated and entered into extraction process to accomplished closeloop recycling process.Overall,the results suggest that more than 99%of Li was recovered.FeCl_(3)holding in solution was directly regenerated without any pollutant emission.The sustainable mothed would be an alternative candidate for total element recycling of spent LFP batteries with industrial potential.
基金Project supported by National Natural Science Foundation of China (U0734005, 20906037)the Fundamental Research Funds for the Central Universities (21610102)the Doctor Special Foundation of Zhanjiang Normal University (ZL1104)
文摘Phosphors of BaLiF3 doped with Eu or/and Ce were solvothermally prepared at 200℃ for 5 d and characterized by means of X-ray powder diffraction （XRD） and environment scanning electron microscopy （ESEM）. The excitation and emission spectra of the rare earth ions doped BaLiF3 were measured by fluorescence spectroscopy and the effects of Ce3＋ ions on the luminescence of Eu〉 ions were in- vestigated. In the co-doped Eu2＋ and Ce3＋ system, the emission intensity of Eu2＋ ion gradually increased with the Ce3＋ concentration increas- ing, and the enhancement of Eu2＋ fluorescence was due to efficient energy transfer from Ce3＋ to Eu2＋ in the host.
基金Project(51805374)supported by the National Natural Science Foundation of ChinaProject(208YFB1201603-08)supported by the Key R&D Program of Ministry of Science and Technology,China。
文摘To analyze wheel wear discrepancy between motor car and trailer of an intercity train,a novel wheel wear rates calculation model was proposed,which was composed of the intercity train dynamics model,wheel-rail three-dimensional rolling contact FEM model and the wear model.The simulated results were contrasted with measured results in field test.The simulated results showed the motor car wheels had larger rotation rate and longitudinal creepage than the trailer wheels.Meanwhile,the motor car wheels encountered larger vertical forces and longitudinal forces from bogie because of the heavier car body and the impact of traction torque.The traction torque acting on motor car wheel could increase the slip rates in the rear part of wheel contact patch and weaken the spinning phenomenon of relative slip.Larger contact pressure and slip rates caused the higher wear rates of motor car wheel than those of trailer wheel.The overall trends of wheel wear depth in simulated and tested results were similar.And they both showed the motor car wheel encountered the more serious wear than the trailer wheel.These models can be used to study the effect of the traction characteristics curves on the wear of wheel.
基金Supported by the Natural Science Foundation of Qinghai Province(Nos.2020-ZJ-940Q,2014-ZJ-937Q)the West Light Foundation of the Chinese Academy of Sciences(No.E010GC09)the Youth Innovation Promotion Association CAS(No.E010GC15)。
文摘Dissolved organic matter(DOM)plays a vital role in promoting carbon and nutrient cycling.It is a food source for organisms and controls the migration and transformation of trace metals and other contaminants in aquatic systems.The contributions of aquatic DOM to the environment and ecology of a system are closely related to its abundance and chemical structure.In this study,the chemical composition and binding properties of DOM in a hypersaline lake watershed were investigated for the fi rst time using dissolved organic carbon(DOC)analysis,absorption spectroscopy,Fourier transform infrared spectroscopy,pyrolysis-GC-MS(Py-GC-MS),and fl uorescence parallel factor(PARAFAC)analysis combined with Pb(II)titration techniques.The results showed that DOM from the tributaries that fl owed into the lake had a lower DOC content,higher molecular weight,and higher specifi c UV absorbance than the DOM in lake water.Protein-like fl uorophores were mainly found in tributary and lake surface water DOM(LSDOM)and humic-like substances were abundant in lake groundwater DOM(LGDOM).Using this multi-methodological approach,we found that the DOM from the hypersaline lake watershed was mainly from microbial origins,and consisted of aromatics,carbohydrates,and aliphatics.The results from quantitative analysis showed that DOM from the infl owing tributaries contained more aromatics,lower carbohydrates,and lower aliphatics than DOM in the lake.Monocyclic aromatic hydrocarbons and carbohydrates were more abundant in LSDOM than LGDOM.The results from the Pb(II)titration technique coupled with PARAFAC analysis suggested that PARAFAC-derived components had relatively low condition stability constants(log K_(M)<2).Of the two types of lake DOM,the LGDOM had a higher Pb(II)binding potential than the LSDOM.From this study we have improved our understanding of how DOM within a hypersaline lake watershed varies in its composition and potential to bind with metals.
基金The study was funded by the National Key R&D Program of China[2018YFB1201403]Science and Technology R&D Program of China State Railway Group Co.,Ltd[J2021X007].
文摘Purpose–This study aims to analyze the development direction of train speed,density and weight in China.Design/methodology/approach–The development of China’s railway in the past 40 years can be divided into 3 stages.At the stage of potential tapping and capacity expansion,it is important to improve the train weight and density by upgrading the existing lines,and improving transportation capacity rapidly.At the stage of railway speed increase,the first priority is to increase train speed,reduce the travel time of passenger train,and synchronously take into account the increase of train density and weight.At the stage of developing high-speed railway,train speed,density and weight are co-developing on demand.Findings–The train speed of high-speed railway will be 400 km h1,the interval time of train tracking will be 3 min,and the traffic density will be more than 190 pairs per day.The running speed of high-speed freight EMU will reach 200 km h1 and above.The maximum speed of passenger train on mixed passenger and freight railway can reach 200 km h1.The minimum interval time of train tracking can be compressed to 5 min.The freight train weight of 850 m series arrival-departure track railway can be increased to 4,500–5,000 t and that of 1,050 m series to 5,500–6,400 t.EMU trains should gradually replace ordinary passenger trains to improve the quality of railway passenger service.Small formation trains will operate more in intercity railway,suburban railway and short-distance passenger transportation.Originality/value–The research can provide new connotations and requirements of railway train speed,density and weight in the new railway stage.
基金supported by the National Natural Science Foundation of China(21908063)the Shanghai Pujiang Program(21PJ1402300)the Fundamental Research Funds of the Central Universities(JKB01211715 and JKB01221677)。
文摘The regeneration of fluidized catalytic cracking(FCC)catalysts is an essential process in petroleum processing.The current study focused the regeneration reaction characteristics of spent fluidized catalytic cracking catalyst(SFCC)at different atmospheres with influences on pore evolution and activity,for a potential way to reduce emission,produce moderate chemical product(CO),and maintain catalyst activity.The results show that regeneration in air indicates a satisfaction on removing coke on the catalyst surface while giving a poor effect on eliminating the coke inside micropores.This is attributed that the combustion in air led to a higher temperature and further transformed kaolinite phase to silicaaluminum spinel crystals,which tended to collapse and block small pores or expand large pores,with similar results observed in pure O_(2)atmosphere.Nevertheless,catalysts regenerated in O_(2)/CO_(2)diminished the combustion damage to the pore structure,of which the micro porosity after regeneration increased by 32.4% and the total acid volume rose to 27.1%.The regeneration in pure CO_(2)displayed low conversion rate due to the endothermic reaction and low reactivity.The coexistence of gasification and partial oxidation can promote regeneration and maintain the original structure and good reactivity.Finally,a mechanism of the regeneration reaction at different atmospheres was revealed.
基金supported by the National Natural Science Foundation of China(21878082).
文摘Radiant syngas cooler(RSC)is widely used as a waste heat recovery equipment in industrial gasification.In this work,an RSC with radiation screens is established and the impact of gaseous radiative property models,gas components,and ash particles on heat transfer is investigated by the numerical simulation method.Considering the syngas components and the pressure environment of the RSC,a modified weighted-sum-of-gray-gases model was developed.The modified model shows high accuracy in validation.In computational fluid dynamics simulation,the calculated steam production is only 0.63%in error with the industrial data.Compared with Smith's model,the temperature decay along the axial direction calculated by the modified model is faster.Syngas components are of great significance to heat recovery capacity,especially when the absorbing gas fraction is less than 10%.After considering the influence of particles,the outlet temperature and the proportion of radiative heat transfer are less affected,but the difference in steam output reaches 2.7 t·h^(-1).The particle deposition on the wall greatly reduces the heat recovery performance of an RSC.
