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
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
Bitterness,one of the 5“basic tastes”,is usually undesired by humans.However,abundant literature reported that bitter fruits and vegetables have beneficial health effects due to their bitter contributors.This review...Bitterness,one of the 5“basic tastes”,is usually undesired by humans.However,abundant literature reported that bitter fruits and vegetables have beneficial health effects due to their bitter contributors.This review provided an updated overview of the main bitter contributors of typical bitter fruits and vegetables and their health benefits.The main bitter contributors,including phenolics,terpenoids,alkaloids,amino acids,nucleosides and purines,were summarized.The bioactivities and wide range of beneficial effects of them on anti-cancers,anti-inflammations,anti-microbes,neuroprotection,inhibiting chronic and acute injury in organs,as well as regulating behavior performance and metabolism were reported.Furthermore,not only did the bitter taste receptors(taste receptor type 2 family,T2Rs)show taste effects,but extra-oral T2Rs could also be activated by binding with bitter components,regulating physiological activities via modulating hormone secretion,immunity,metabolism,and cell proliferation.This review provided a new perspective on exploring and explaining the nutrition of bitter foods,revealing the relationship between the functions of bitter contributors from food and T2Rs.Future trends may focus on revealing the possibility of T2Rs being targets for the treatment of diseases,exploring the mechanism of T2Rs mediating the bioactivities,and making bitter foods more acceptable without getting rid of bitter contributors.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
This study investigates the heat dissipation mechanism of the insulation layer and other plane insulation layers in the polar drilling rig system.Combining the basic theory of heat transfer with the environmental requ...This study investigates the heat dissipation mechanism of the insulation layer and other plane insulation layers in the polar drilling rig system.Combining the basic theory of heat transfer with the environmental requirements of polar drilling operations and the characteristics of polar drilling processes,we analyze the factors that affect the insulation effect of the drilling rig system.These factors include the thermal conductivity of the insulation material,the thickness of the insulation layer,ambient temperature,and wind speed.We optimize the thermal insulation material of the polar drilling rig system using a steady-state method to measure solid thermal conductivity.By analyzing the distribution of temperature in space after heating,we optimize the distribution and air outlet angle of the heater using Fluent hydrodynamics software.The results demonstrate that under polar conditions,polyisocyanurate with stable thermodynamic properties is selected as the thermal insulation material.The selection of thermal insulation material and thickness significantly affects the thermal insulation effect of the system but has little effect on its heating effect.Moreover,when the air outlet angle of the heater is set to 32.5°,the heating efficiency of the system can be effectively improved.According to heat transfer equations and heat balance theory,we determine that the heating power required for the system to reach 5°C is close to numerical simulation.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
Cordyceps is treasured entomopathogenic fungi that have been used as antitumor,immunomodulating,antioxidant,and pro-sexual agent.Cordyceps,also called DongChongXiaCao in Chinese,Yartsa Gunbu(Tibetan),means winter worm...Cordyceps is treasured entomopathogenic fungi that have been used as antitumor,immunomodulating,antioxidant,and pro-sexual agent.Cordyceps,also called DongChongXiaCao in Chinese,Yartsa Gunbu(Tibetan),means winter worm-summer grass.Natural Cordyceps sinensis with parasitic hosts is difficult to be collected and the recent findings on its potential pharmacological functions,resulted in skyrocketing prices.Therefore,finding a mass-production method or an alternative for C.sinensis products is a top-priority task.In this review,we describe current status of Cordyceps research and its recent developments in Taiwan.The content and pharmacological activities of four major industrial species of Cordyceps(C.sinensis,Cordyceps militaris,Cordyceps cicadae and Cordyceps sobolifera)used in Taiwan,were reviewed.Moreover,we highlighted the effect of using different methods of fermentation and production on the morphology and chemical content of Cordyceps sp.Finally,we summarized the bottle-necks and challenges facing Cordyceps research as well as we proposed future road map for Cordyceps industry in Taiwan.展开更多
In recent years,research focusing on synaptic device based on phototransistors has provided a new method for asso-ciative learning and neuromorphic computing.A TiO_(2)/AlGaN/GaN heterostructure-based synaptic phototra...In recent years,research focusing on synaptic device based on phototransistors has provided a new method for asso-ciative learning and neuromorphic computing.A TiO_(2)/AlGaN/GaN heterostructure-based synaptic phototransistor is fabricated and measured,integrating a TiO_(2)nanolayer gate and a two-dimensional electron gas(2DEG)channel to mimic the synaptic weight and the synaptic cleft,respectively.The maximum drain to source current is 10 nA,while the device is driven at a reverse bias not exceeding-2.5 V.A excitatory postsynaptic current(EPSC)of 200 nA can be triggered by a 365 nm UVA light spike with the duration of 1 s at light intensity of 1.35μW·cm^(-2).Multiple synaptic neuromorphic functions,including EPSC,short-term/long-term plasticity(STP/LTP)and paried-pulse facilitation(PPF),are effectively mimicked by our GaN-based het-erostructure synaptic device.In the typical Pavlov’s dog experiment,we demonstrate that the device can achieve"retraining"process to extend memory time through enhancing the intensity of synaptic weight,which is similar to the working mecha-nism of human brain.展开更多
A high-temperature and high-pressure valve is the key equipment of a wind tunnel system;it controls the generation of high-temperature and high-pressure gas.To reduce the adverse impact of high-temperature and high-pr...A high-temperature and high-pressure valve is the key equipment of a wind tunnel system;it controls the generation of high-temperature and high-pressure gas.To reduce the adverse impact of high-temperature and high-pressure gas on the strength of the valve body,a cooling structure is set on the valve seat.This can significantly reduce the temperature of the valve body and valve seat.The effects of its structure on the cooling characteristics and stress of the valve seat are studied,and six main parameters that can completely describe the geometry of the cooling structure are proposed.The central composite design method is used to select sample points,and the multi-objective genetic algorithm(MOGA)method is used for optimal structural design.A modification method according to the main parameters for the valve seat is proposed.The results show that the cooling structure weakens the pressure-bearing capability of the valve seat.Among the six main parameters of the valve seat,the distance from the end face of the lower hole to the Z-axis and the distance from the axis of the lower hole to the origin of the coordinates have the most obvious effects on the average stress of the valve seat.An optimum design value is proposed.This work can provide a reference for the design of high-temperature and high-pressure valves.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
1.Challenges Thermoacoustic instability in combustors arises from the interaction between sound waves and unsteady heat release,commonly found in systems like gas turbines and aeroengines.This instability leads to und...1.Challenges Thermoacoustic instability in combustors arises from the interaction between sound waves and unsteady heat release,commonly found in systems like gas turbines and aeroengines.This instability leads to undesirable consequences such as structural damage and performance deterioration.The challenge lies in predicting and mitigating these instabilities due to the complex interplay of various physical phenomena like acoustic propagation,turbulent flow,and combustion chemistry,which are summarized in detail in Aimee S.Morgans and Dong Yang's published article.展开更多
1.Introduction Computational Fluid Dynamics-Discrete Element Method(CFD-DEM)is a powerful tool for simulating dense gas-solid reacting flows,which is essential in combustion,metallurgy,and waste management.Traditional...1.Introduction Computational Fluid Dynamics-Discrete Element Method(CFD-DEM)is a powerful tool for simulating dense gas-solid reacting flows,which is essential in combustion,metallurgy,and waste management.Traditional methods face challenges in CFD-DEM modeling of dense gas-solid flows due to multi-scale characteristics,limiting resolution and creating simulation bottlenecks.By integrating fluid dynamics and particle behavior,it optimizes industrial processes.This review highlights advancements,applications,and challenges,emphasizing its role in sustainable engineering.展开更多
1. Introduction Research on the ground effect of rotor can be traced back to the 1930s1.However, few studies have been conducted on the aerodynamic characteristics of rotors and ducted fans when hovering near a water ...1. Introduction Research on the ground effect of rotor can be traced back to the 1930s1.However, few studies have been conducted on the aerodynamic characteristics of rotors and ducted fans when hovering near a water surface for an extended period.With the emergence of cross-media rotorcraft, rotor wakes interact violently with the water surface to generate large-scale,air–water droplet mixed flows (hereafter referred to as mixed air–water flows). Rotors operating in mixed air–water flows always have aerodynamic performances that are different from those owing to the In-Ground Effect (IGE) and Out-of Ground Effect (OGE). Accordingly, this effect is called the Near-Water Effect (NWE) of the rotor2,and it usually causes thrust loss and torque increase.展开更多
The spatiotemporal distribution of soot concentration in aero-engine combustor is important for assessing its combustion performance.Here,we report experimental measurements of soot concentration in terms of Soot Volu...The spatiotemporal distribution of soot concentration in aero-engine combustor is important for assessing its combustion performance.Here,we report experimental measurements of soot concentration in terms of Soot Volume Fraction(SVF)and its spatiotemporal distribution in a single-sector dual-swirl aero-engine combustor using Two-Color Laser-Induced Incandescence(2C-LII).It is shown that soot predominantly forms in the symmetrical vortices of the primary combustion zone,exhibiting a V-type distribution with higher concentration in the lower half of the zone than the upper half,with a small amount distributed in the secondary recirculation zone.Soot emissions at the combustor outlet are relatively low under three typical operating conditions by LII experiments,which is aligned with Smoke Number(SN)from gas analysis.The effect of inlet air temperature on SVF distribution and dynamics in the primary combustion zone is studied,which suggests that the SVF level in the primary combustion zone monotonically increases with the temperature.Meanwhile,the SVF distribution becomes more symmetrical as the inlet temperature increases,although the overall SVF level in the lower half of the zone is still higher.We also investigate the influence of the inlet air pressure on the SVF distribution at the combustor outlet.The soot concentration at the combustor outlet increases with inlet pressure,mainly distributed irregularly across both sides and the center.On both sides,the distribution is continuous,while the center exhibits dot-like and linear patterns.Numerical simulations correlated SVF distribution with the flow field in the primary combustion zone,qualitatively explaining the observed SVF distribution behavior.These results under various conditions can provide valuable insights for improving the performance of this specific combustor and designing high-temperature-rise combustors in the future.展开更多
To facilitate the low-noise design of tandem lift bodies as applied in aeroengines and aircraft,the acoustic features of tandem blades are investigated by wind-tunnel experiments.This is further specialized for the ro...To facilitate the low-noise design of tandem lift bodies as applied in aeroengines and aircraft,the acoustic features of tandem blades are investigated by wind-tunnel experiments.This is further specialized for the rotating blades applied in contra-rotating open rotors under the concept of frozen-rotor.A 70-channel phased microphone array and nine high-precision free-field microphones are employed.The beamforming method,enhanced by a source filtering technique,is employed to locate noise sources,providing insights into the source patterns of blade-blade interaction noise concerning flow speed,blade spacing,and aft blade clipping.The results show the following:(A)Sources of tandem-blade noise exist in the form of concentrated source clusters,resulting in two major clusters:the mid-span interaction noise and the tip-induced noise.(B)These source clusters tend to separate as flow speed or blade spacing increases.(C)By increasing blade spacing,the band-pass filtered overall sound pressure level is reduced by 2.9 dB.(D)A two-phase noise suppression pattern is observed with blade clipping,resulting in a total reduction of 3.0 dB for the interaction noise through the removal of tip-induced noise sources and the replacement of mid-span noise sources.Based on these findings,suggestions concerning blade spacing and clipping are discussed.展开更多
It is well known that appropriate aerobic exercise can effectively alleviate fatty liver and enhance brain function.The concept of multi-organ crosstalk coordinating disease progression has become the current research...It is well known that appropriate aerobic exercise can effectively alleviate fatty liver and enhance brain function.The concept of multi-organ crosstalk coordinating disease progression has become the current research hot topic.However,there remains an urgent need to elucidate its specific mechanisms.This study aimed to explore the impact of a high-fat diet(HFD)on liver health and cognitive function,and to further uncover the regulatory effect of aerobic exercise by liver-specific activating transcription factor 3(Atf3)knockout(ATF3cKO)mice in a“liver-brain”axis mode.The 5-week-old C57BL/6 and ATF3cKO mice were fed with HFD for 32 weeks,and sequentially subjected to aerobic exercise intervention at the 20th week for another 12 consecutive weeks.Meanwhile,C57BL/6 mice were provided with a normal diet as the control group.The functional parameters of liver and brain of all mice were assessed.Cognitive capacity of all mice was assessed by the Morris water maze(MWM).Inflammatory factors in the serum and brain of mice were quantified using enzyme-linked immunosorbent assay(ELISA),and the expression of inflammasomes was detected by immunohistochemistry(IHC).Additionally,the activation of nuclear factor-κB(NF-κB)and phosphoinositide 3-kinase(PI3K)signal pathways was analyzed by Western blotting.In this study,HFD impaired hepatic and brain functions,while aerobic exercise and liver-specific Atf3 knockout suppressed inflammatory factors in the peripheral circulation through hepatoprotective mechanisms,thereby attenuating cerebral inflammation and preserving neurological integrity,as well as mitigating HFD-induced cognitive decline.展开更多
Quantitative measurement of Soot Volume Fraction (SVF) is an essential prerequisite for controlling soot particle emissions from aero-engine combustors. As an in-situ and non-intrusive optical diagnostic technique, La...Quantitative measurement of Soot Volume Fraction (SVF) is an essential prerequisite for controlling soot particle emissions from aero-engine combustors. As an in-situ and non-intrusive optical diagnostic technique, Laser-Induced Incandescence (LII) has been increasingly applied for soot concentration quantification in various combustion environments such as laminar flame, vehicle exhaust, internal combustion chamber as well as aero-engine combustor. In this work, we experimentally measured the spatial and temporal distribution of SVF using two-color LII technique at the outlet of a single-sector dual-swirl aero-engine model combustor. The effect of inlet pressure and air preheat temperature on the SVF distribution was separately investigated within a pressure range of 241–425 kPa and a temperature range of 292–500 K. The results show that soot production increases with the inlet pressure but generally decreases with the air preheat temperature. Qualitative analysis was provided to explain the above results of parametric studies. The LII experiments were also conducted under 3 designed conditions to evaluate soot emission under practical operations. Particularly, weak soot emission was detected at the outlet under the idle condition. Our experimental results provide a valuable benchmark for evaluating soot emission in the exhaust plume of this aero-engine combustor during practical operations.展开更多
This paper conducts an in-depth analysis of the theory and methods for differentiating and treating insomnia in Bu Ju Ji by Wu Cheng,a physician of the Qing Dynasty.By systematically sorting out the origin of Wu Cheng...This paper conducts an in-depth analysis of the theory and methods for differentiating and treating insomnia in Bu Ju Ji by Wu Cheng,a physician of the Qing Dynasty.By systematically sorting out the origin of Wu Cheng’s academic thoughts,this study explores his unique perspective on differentiating and treating insomnia,analyzes the compatibility rules of his core formulas and herbs,and reveals the characteristics of his medication use as well as its guiding value for later clinical practice.Research shows that Wu Cheng integrated the principles of the I Ching(Book of Changes)with medical theories to construct a theoretical system for consumptive diseases.In the differentiation and treatment of insomnia,he emphasized the dynamic balance of zang-fu organs,Qi,blood,Yin and Yang,with special attention to the impact of spleen-Yin deficiency on insomnia.He thus formed distinctive academic features,including treating both deficiency and excess,taking into account both Qi and blood,and regulating the spleen to protect the body’s defense system.In terms of medication,he was skilled in using herbs that are sweet and warm in nature for tonification,harmonizing Qi and blood,and invigorating the spleen to nourish Yin.These insights hold significant reference value for modern TCM(Traditional Chinese Medicine)in the treatment of insomnia.展开更多
Aqueous ammonium-ion batteries(AAIBs)showed great potential in large-scale energy storage systems due to their low-cost,ultrafast kinetics,plentiful resources,inherent security and environmental friendliness.Herein,th...Aqueous ammonium-ion batteries(AAIBs)showed great potential in large-scale energy storage systems due to their low-cost,ultrafast kinetics,plentiful resources,inherent security and environmental friendliness.Herein,the well-dispersed Zn_(3)V_(3)O_(8)nanorods and agglomerated MnV_(2)O_(4)nanoparticles were prepared and firstly used as anodes for AAIBs.The ultrafast reaction kinetics and NH_(4)^(+)diffusion kinetics of Zn_(3)V_(3)O_(8)were confirmed by systematically contrasting with MnV_(2)O_(4).Specifically,Zn_(3)V_(3)O_(8)delivered perfect cyclic performances with 82.6%capacity retention after 500 cycles.When coupled with theβ-MnO_(2)cathode,theβ-MnO_(2)//Zn_(3)V_(3)O_(8)full batteries submitted a maximum energy density of 86 Wh.kg^(-1)and a maximum power density of 677W.kg^(-1).The phase transformation from Zn_(3)V_(3)O_(8)to Zn_(3)(OH)_(2)V_(2)O_(7).2H_(2)O during the first charge process and the reversible building/breaking behaviors of hydrogen bonds during the NH_(4)^(+)insertion/extraction processes were discussed by ex situ technology analyses.Thus,the fresh perceptions on the phase transformation laws and the hydrogen bonds evolution mechanisms could enrich the fundamental understanding of the NH_(4)^(+)storage mechanism,and promote the development of the practical applications for Zn_(3)V_(3)O_(8)in aqueous ammonium-ion batteries.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
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.
基金the financial support provided by“Pioneer”and“Leading Goose”R&D Program of Zhejiang(2022C020122022C02078)。
文摘Bitterness,one of the 5“basic tastes”,is usually undesired by humans.However,abundant literature reported that bitter fruits and vegetables have beneficial health effects due to their bitter contributors.This review provided an updated overview of the main bitter contributors of typical bitter fruits and vegetables and their health benefits.The main bitter contributors,including phenolics,terpenoids,alkaloids,amino acids,nucleosides and purines,were summarized.The bioactivities and wide range of beneficial effects of them on anti-cancers,anti-inflammations,anti-microbes,neuroprotection,inhibiting chronic and acute injury in organs,as well as regulating behavior performance and metabolism were reported.Furthermore,not only did the bitter taste receptors(taste receptor type 2 family,T2Rs)show taste effects,but extra-oral T2Rs could also be activated by binding with bitter components,regulating physiological activities via modulating hormone secretion,immunity,metabolism,and cell proliferation.This review provided a new perspective on exploring and explaining the nutrition of bitter foods,revealing the relationship between the functions of bitter contributors from food and T2Rs.Future trends may focus on revealing the possibility of T2Rs being targets for the treatment of diseases,exploring the mechanism of T2Rs mediating the bioactivities,and making bitter foods more acceptable without getting rid of bitter contributors.
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supported by the Key-Area Research and Development Program of Guangdong Province,Research on the Method of Heat Preservation and Heating for the Drilling System of Polar Offshore Drilling Platform (No.2020B1111010001).
文摘This study investigates the heat dissipation mechanism of the insulation layer and other plane insulation layers in the polar drilling rig system.Combining the basic theory of heat transfer with the environmental requirements of polar drilling operations and the characteristics of polar drilling processes,we analyze the factors that affect the insulation effect of the drilling rig system.These factors include the thermal conductivity of the insulation material,the thickness of the insulation layer,ambient temperature,and wind speed.We optimize the thermal insulation material of the polar drilling rig system using a steady-state method to measure solid thermal conductivity.By analyzing the distribution of temperature in space after heating,we optimize the distribution and air outlet angle of the heater using Fluent hydrodynamics software.The results demonstrate that under polar conditions,polyisocyanurate with stable thermodynamic properties is selected as the thermal insulation material.The selection of thermal insulation material and thickness significantly affects the thermal insulation effect of the system but has little effect on its heating effect.Moreover,when the air outlet angle of the heater is set to 32.5°,the heating efficiency of the system can be effectively improved.According to heat transfer equations and heat balance theory,we determine that the heating power required for the system to reach 5°C is close to numerical simulation.
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.
文摘Cordyceps is treasured entomopathogenic fungi that have been used as antitumor,immunomodulating,antioxidant,and pro-sexual agent.Cordyceps,also called DongChongXiaCao in Chinese,Yartsa Gunbu(Tibetan),means winter worm-summer grass.Natural Cordyceps sinensis with parasitic hosts is difficult to be collected and the recent findings on its potential pharmacological functions,resulted in skyrocketing prices.Therefore,finding a mass-production method or an alternative for C.sinensis products is a top-priority task.In this review,we describe current status of Cordyceps research and its recent developments in Taiwan.The content and pharmacological activities of four major industrial species of Cordyceps(C.sinensis,Cordyceps militaris,Cordyceps cicadae and Cordyceps sobolifera)used in Taiwan,were reviewed.Moreover,we highlighted the effect of using different methods of fermentation and production on the morphology and chemical content of Cordyceps sp.Finally,we summarized the bottle-necks and challenges facing Cordyceps research as well as we proposed future road map for Cordyceps industry in Taiwan.
基金supported by the National Key R&D Program of China(2021YFB3601000,2021YFB3601004)the National Key R&D Program of China(2022YFB3604702)the Chinese Academy of Sciences.
文摘In recent years,research focusing on synaptic device based on phototransistors has provided a new method for asso-ciative learning and neuromorphic computing.A TiO_(2)/AlGaN/GaN heterostructure-based synaptic phototransistor is fabricated and measured,integrating a TiO_(2)nanolayer gate and a two-dimensional electron gas(2DEG)channel to mimic the synaptic weight and the synaptic cleft,respectively.The maximum drain to source current is 10 nA,while the device is driven at a reverse bias not exceeding-2.5 V.A excitatory postsynaptic current(EPSC)of 200 nA can be triggered by a 365 nm UVA light spike with the duration of 1 s at light intensity of 1.35μW·cm^(-2).Multiple synaptic neuromorphic functions,including EPSC,short-term/long-term plasticity(STP/LTP)and paried-pulse facilitation(PPF),are effectively mimicked by our GaN-based het-erostructure synaptic device.In the typical Pavlov’s dog experiment,we demonstrate that the device can achieve"retraining"process to extend memory time through enhancing the intensity of synaptic weight,which is similar to the working mecha-nism of human brain.
基金supported by the National Natural Science Foundation of China(No.52175067)the Zhejiang Key Research&Development Project(No.2021C01021)+1 种基金the Natural Science Foundation of Zhejiang Province(No.LY20E050016)the Postdoctoral Fellowship Program of China Postdoctoral Science Foundation(CPSF)(No.GZC20241478)。
文摘A high-temperature and high-pressure valve is the key equipment of a wind tunnel system;it controls the generation of high-temperature and high-pressure gas.To reduce the adverse impact of high-temperature and high-pressure gas on the strength of the valve body,a cooling structure is set on the valve seat.This can significantly reduce the temperature of the valve body and valve seat.The effects of its structure on the cooling characteristics and stress of the valve seat are studied,and six main parameters that can completely describe the geometry of the cooling structure are proposed.The central composite design method is used to select sample points,and the multi-objective genetic algorithm(MOGA)method is used for optimal structural design.A modification method according to the main parameters for the valve seat is proposed.The results show that the cooling structure weakens the pressure-bearing capability of the valve seat.Among the six main parameters of the valve seat,the distance from the end face of the lower hole to the Z-axis and the distance from the axis of the lower hole to the origin of the coordinates have the most obvious effects on the average stress of the valve seat.An optimum design value is proposed.This work can provide a reference for the design of high-temperature and high-pressure valves.
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.
文摘1.Challenges Thermoacoustic instability in combustors arises from the interaction between sound waves and unsteady heat release,commonly found in systems like gas turbines and aeroengines.This instability leads to undesirable consequences such as structural damage and performance deterioration.The challenge lies in predicting and mitigating these instabilities due to the complex interplay of various physical phenomena like acoustic propagation,turbulent flow,and combustion chemistry,which are summarized in detail in Aimee S.Morgans and Dong Yang's published article.
文摘1.Introduction Computational Fluid Dynamics-Discrete Element Method(CFD-DEM)is a powerful tool for simulating dense gas-solid reacting flows,which is essential in combustion,metallurgy,and waste management.Traditional methods face challenges in CFD-DEM modeling of dense gas-solid flows due to multi-scale characteristics,limiting resolution and creating simulation bottlenecks.By integrating fluid dynamics and particle behavior,it optimizes industrial processes.This review highlights advancements,applications,and challenges,emphasizing its role in sustainable engineering.
文摘1. Introduction Research on the ground effect of rotor can be traced back to the 1930s1.However, few studies have been conducted on the aerodynamic characteristics of rotors and ducted fans when hovering near a water surface for an extended period.With the emergence of cross-media rotorcraft, rotor wakes interact violently with the water surface to generate large-scale,air–water droplet mixed flows (hereafter referred to as mixed air–water flows). Rotors operating in mixed air–water flows always have aerodynamic performances that are different from those owing to the In-Ground Effect (IGE) and Out-of Ground Effect (OGE). Accordingly, this effect is called the Near-Water Effect (NWE) of the rotor2,and it usually causes thrust loss and torque increase.
基金support of the National Science and Technology Major Project of China(No.J2019-V-0005-0096)the National Key Research and Development Program of China(No.2020YFA0405700).
文摘The spatiotemporal distribution of soot concentration in aero-engine combustor is important for assessing its combustion performance.Here,we report experimental measurements of soot concentration in terms of Soot Volume Fraction(SVF)and its spatiotemporal distribution in a single-sector dual-swirl aero-engine combustor using Two-Color Laser-Induced Incandescence(2C-LII).It is shown that soot predominantly forms in the symmetrical vortices of the primary combustion zone,exhibiting a V-type distribution with higher concentration in the lower half of the zone than the upper half,with a small amount distributed in the secondary recirculation zone.Soot emissions at the combustor outlet are relatively low under three typical operating conditions by LII experiments,which is aligned with Smoke Number(SN)from gas analysis.The effect of inlet air temperature on SVF distribution and dynamics in the primary combustion zone is studied,which suggests that the SVF level in the primary combustion zone monotonically increases with the temperature.Meanwhile,the SVF distribution becomes more symmetrical as the inlet temperature increases,although the overall SVF level in the lower half of the zone is still higher.We also investigate the influence of the inlet air pressure on the SVF distribution at the combustor outlet.The soot concentration at the combustor outlet increases with inlet pressure,mainly distributed irregularly across both sides and the center.On both sides,the distribution is continuous,while the center exhibits dot-like and linear patterns.Numerical simulations correlated SVF distribution with the flow field in the primary combustion zone,qualitatively explaining the observed SVF distribution behavior.These results under various conditions can provide valuable insights for improving the performance of this specific combustor and designing high-temperature-rise combustors in the future.
基金supported by grants from the National Natural Science Foundation of China(Nos.12102451,12072186)the National Science and Technology Major Project,China(No.J2019-II-0006-0026)AVIC Aerodynamics Research Institute,China(No.XFX20220201).
文摘To facilitate the low-noise design of tandem lift bodies as applied in aeroengines and aircraft,the acoustic features of tandem blades are investigated by wind-tunnel experiments.This is further specialized for the rotating blades applied in contra-rotating open rotors under the concept of frozen-rotor.A 70-channel phased microphone array and nine high-precision free-field microphones are employed.The beamforming method,enhanced by a source filtering technique,is employed to locate noise sources,providing insights into the source patterns of blade-blade interaction noise concerning flow speed,blade spacing,and aft blade clipping.The results show the following:(A)Sources of tandem-blade noise exist in the form of concentrated source clusters,resulting in two major clusters:the mid-span interaction noise and the tip-induced noise.(B)These source clusters tend to separate as flow speed or blade spacing increases.(C)By increasing blade spacing,the band-pass filtered overall sound pressure level is reduced by 2.9 dB.(D)A two-phase noise suppression pattern is observed with blade clipping,resulting in a total reduction of 3.0 dB for the interaction noise through the removal of tip-induced noise sources and the replacement of mid-span noise sources.Based on these findings,suggestions concerning blade spacing and clipping are discussed.
基金supported by the National Natural Science Foundation of China(32471186 and 31771318)the 14th Five-Year-Plan Advantageous and Characteristic Disciplines(Groups)of Colleges and Universities in Hubei Province for Exercise and Brain Science+1 种基金as well as the Leading Talent Program and Innovative Start-up Foundation from Wuhan Sports University to Ning Chensupported by the Hubei Natural Science Foundation(2022CFB929)and China Postdoctoral Science Foundation(2023M732727)to Tong Wu.
文摘It is well known that appropriate aerobic exercise can effectively alleviate fatty liver and enhance brain function.The concept of multi-organ crosstalk coordinating disease progression has become the current research hot topic.However,there remains an urgent need to elucidate its specific mechanisms.This study aimed to explore the impact of a high-fat diet(HFD)on liver health and cognitive function,and to further uncover the regulatory effect of aerobic exercise by liver-specific activating transcription factor 3(Atf3)knockout(ATF3cKO)mice in a“liver-brain”axis mode.The 5-week-old C57BL/6 and ATF3cKO mice were fed with HFD for 32 weeks,and sequentially subjected to aerobic exercise intervention at the 20th week for another 12 consecutive weeks.Meanwhile,C57BL/6 mice were provided with a normal diet as the control group.The functional parameters of liver and brain of all mice were assessed.Cognitive capacity of all mice was assessed by the Morris water maze(MWM).Inflammatory factors in the serum and brain of mice were quantified using enzyme-linked immunosorbent assay(ELISA),and the expression of inflammasomes was detected by immunohistochemistry(IHC).Additionally,the activation of nuclear factor-κB(NF-κB)and phosphoinositide 3-kinase(PI3K)signal pathways was analyzed by Western blotting.In this study,HFD impaired hepatic and brain functions,while aerobic exercise and liver-specific Atf3 knockout suppressed inflammatory factors in the peripheral circulation through hepatoprotective mechanisms,thereby attenuating cerebral inflammation and preserving neurological integrity,as well as mitigating HFD-induced cognitive decline.
基金supported by the National Key Research and Development Program of China(No.2020YFA0405700).
文摘Quantitative measurement of Soot Volume Fraction (SVF) is an essential prerequisite for controlling soot particle emissions from aero-engine combustors. As an in-situ and non-intrusive optical diagnostic technique, Laser-Induced Incandescence (LII) has been increasingly applied for soot concentration quantification in various combustion environments such as laminar flame, vehicle exhaust, internal combustion chamber as well as aero-engine combustor. In this work, we experimentally measured the spatial and temporal distribution of SVF using two-color LII technique at the outlet of a single-sector dual-swirl aero-engine model combustor. The effect of inlet pressure and air preheat temperature on the SVF distribution was separately investigated within a pressure range of 241–425 kPa and a temperature range of 292–500 K. The results show that soot production increases with the inlet pressure but generally decreases with the air preheat temperature. Qualitative analysis was provided to explain the above results of parametric studies. The LII experiments were also conducted under 3 designed conditions to evaluate soot emission under practical operations. Particularly, weak soot emission was detected at the outlet under the idle condition. Our experimental results provide a valuable benchmark for evaluating soot emission in the exhaust plume of this aero-engine combustor during practical operations.
基金Key Scientific Research Project of Anhui Provincial Department of Education in 2021,“Literature Collation of Insomnia Syndrome in Xin’an Medical Classics and Analysis of Its Related Academic Thoughts”(Project No.:KJ2021A1282)Wanjiang Pilot Zone Project in 2021,“Modern Apprenticeship System for TCM(Traditional Chinese Medicine)Mentorship Education”(Project No.:WJ-RCPY-037)2023 Anhui Provincial-Level High-Level Vocational Colleges and High-Level Professional Groups,TCM Professional Group(Project No.:Wan Jiao Mi Gao[2023]No.5)。
文摘This paper conducts an in-depth analysis of the theory and methods for differentiating and treating insomnia in Bu Ju Ji by Wu Cheng,a physician of the Qing Dynasty.By systematically sorting out the origin of Wu Cheng’s academic thoughts,this study explores his unique perspective on differentiating and treating insomnia,analyzes the compatibility rules of his core formulas and herbs,and reveals the characteristics of his medication use as well as its guiding value for later clinical practice.Research shows that Wu Cheng integrated the principles of the I Ching(Book of Changes)with medical theories to construct a theoretical system for consumptive diseases.In the differentiation and treatment of insomnia,he emphasized the dynamic balance of zang-fu organs,Qi,blood,Yin and Yang,with special attention to the impact of spleen-Yin deficiency on insomnia.He thus formed distinctive academic features,including treating both deficiency and excess,taking into account both Qi and blood,and regulating the spleen to protect the body’s defense system.In terms of medication,he was skilled in using herbs that are sweet and warm in nature for tonification,harmonizing Qi and blood,and invigorating the spleen to nourish Yin.These insights hold significant reference value for modern TCM(Traditional Chinese Medicine)in the treatment of insomnia.
基金financially supported by the National Nature Science Foundation of China(Nos.52171200 and52371211)Changsha Special Project(No.kh2301006)+2 种基金Hunan Provincial Innovation Foundation for Postgraduate(No.CX20211073)Natural Science Foundation of Hunan Province(No.2024JJ7145)the National Sustainable Development Innovation Demonstration Zone project(No.2022sfq09)。
文摘Aqueous ammonium-ion batteries(AAIBs)showed great potential in large-scale energy storage systems due to their low-cost,ultrafast kinetics,plentiful resources,inherent security and environmental friendliness.Herein,the well-dispersed Zn_(3)V_(3)O_(8)nanorods and agglomerated MnV_(2)O_(4)nanoparticles were prepared and firstly used as anodes for AAIBs.The ultrafast reaction kinetics and NH_(4)^(+)diffusion kinetics of Zn_(3)V_(3)O_(8)were confirmed by systematically contrasting with MnV_(2)O_(4).Specifically,Zn_(3)V_(3)O_(8)delivered perfect cyclic performances with 82.6%capacity retention after 500 cycles.When coupled with theβ-MnO_(2)cathode,theβ-MnO_(2)//Zn_(3)V_(3)O_(8)full batteries submitted a maximum energy density of 86 Wh.kg^(-1)and a maximum power density of 677W.kg^(-1).The phase transformation from Zn_(3)V_(3)O_(8)to Zn_(3)(OH)_(2)V_(2)O_(7).2H_(2)O during the first charge process and the reversible building/breaking behaviors of hydrogen bonds during the NH_(4)^(+)insertion/extraction processes were discussed by ex situ technology analyses.Thus,the fresh perceptions on the phase transformation laws and the hydrogen bonds evolution mechanisms could enrich the fundamental understanding of the NH_(4)^(+)storage mechanism,and promote the development of the practical applications for Zn_(3)V_(3)O_(8)in aqueous ammonium-ion batteries.
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.
