Many people like to shop at a supermarket.Supermarkets are very convenient.They are open long hours,every day of the week.Everything is easy to find in a supermarket.It's always in the same place.Supermarkets ofte...Many people like to shop at a supermarket.Supermarkets are very convenient.They are open long hours,every day of the week.Everything is easy to find in a supermarket.It's always in the same place.Supermarkets often have sales.These can help you save money.展开更多
好题精选阅读下面短文,从每题所给的A、B、C、D四个选项中选出最佳选项。Born during my parents'sea voyage(航行)around the world,I always wanted to make the trip myself.At age 8,I began saving and sailing to 1 that drea...好题精选阅读下面短文,从每题所给的A、B、C、D四个选项中选出最佳选项。Born during my parents'sea voyage(航行)around the world,I always wanted to make the trip myself.At age 8,I began saving and sailing to 1 that dream.My parents weren't excited about the idea,but after talking to them about it,they became 2.展开更多
As an indispensable part of modern buildings,centralized central air conditioning systems play an important role in maintaining the comfort and air quality of the indoor environment.However,with the increasing energy ...As an indispensable part of modern buildings,centralized central air conditioning systems play an important role in maintaining the comfort and air quality of the indoor environment.However,with the increasing energy consumption,how to improve the energy efficiency ratio of air conditioning systems and reduce energy consumption has become an important issue in research and practice.The purpose of this paper is to discuss the impact of humidity control strategies on energy saving in centralized central air conditioning systems,with a view to providing a theoretical basis and practical guidance for realizing building energy efficiency.展开更多
Load-sensing systems use a centralized power source for energy supply and multiway valves for flow distribution and suffer from excessive throttling losses and low energy efficiency.Pump-controlled systems adopt volum...Load-sensing systems use a centralized power source for energy supply and multiway valves for flow distribution and suffer from excessive throttling losses and low energy efficiency.Pump-controlled systems adopt volumetric control methods to eliminate throttling losses.However,pump-controlled multi-actuator systems require excessive installed power.To address these issues,by combining the respective advantages of valve-and pump-controlled technologies,an open-closed circuit integrated pump-valve collaborative drive multi-actuator system consisting of pump-and valve-controlled units is proposed.The pump-controlled units manage the individual actuator motions,whereas the valve-controlled unit enhances the driving power of the pump-controlled units.In addition,to optimize the operation characteristics and energy consumption,a four-quadrant control strategy and an ultralow-pressure loss control strategy were proposed.Several experiments were conducted to evaluate the working performance of the proposed system and the load-sensing system under different working conditions.Experimental results demonstrated that the proposed system exhibited satisfactory velocity control characteristics.Compared with the traditional load-sensing system,the proposed system reduced throttling losses by 90.4−94.4%and energy consumption by 45.9−50.0%.Additionally,only 22.8%of the total energy consumption was attributed to the pump-controlled units,with the remainder provided by the valve-controlled unit.Compared with the traditional pump-controlled multi-actuator system,the proposed system achieved a 29.4%reduction in installed power,thereby lowering the system installed power and costs.This paper presents an electrohydraulic multi-actuator drive method that combines high energy efficiency and high power density and is suitable for electric construction machinery and other heavy equipment with multiple actuators.展开更多
Jinmao Tex(short for Chongqing Jinmao Textile Accessories Co.,Ltd.),founded in 1960,is the largest manufacturer of ring traveller and steel ring in China,and its ring traveller delivery tops in China market for more t...Jinmao Tex(short for Chongqing Jinmao Textile Accessories Co.,Ltd.),founded in 1960,is the largest manufacturer of ring traveller and steel ring in China,and its ring traveller delivery tops in China market for more than 30 consecutive years.In recent years,in order to serve the transformation and upgrading of the textile industry,Jinmao Tex invested"China Ring Traveller and Steel Ring R&D center",focused on the technological innovation of key textile accessories,developed high-performance and long-life textile accessories to assist textile mills save energy,reduce consumption,improve quality and increase efficiency.Jinmao Tex has now become a“steel ring+ring traveller”solution provider for high-speed spinning and differential fiber spinning.展开更多
[Objectives]This study was conducted to improve the seed production efficiency of water-saving and drought-resistant hybrid millet in production.[Methods]A high-efficiency seed production technology for water-saving a...[Objectives]This study was conducted to improve the seed production efficiency of water-saving and drought-resistant hybrid millet in production.[Methods]A high-efficiency seed production technology for water-saving and drought-resistant hybrid millet varieties was developed by integrating aspects such as parental line sources,botanical characteristics,biological traits,seed production yield structure,key technical points of seed production,and suitable planting regions.[Results]Under standardized pre-sowing preparation and field management,both parents are simultaneously sown around May 20 with a planting row ratio of 2:6(female:male),a row spacing of 20 cm and plant spacing of 10 cm for the female parent,and a row spacing of 35 cm and plant spacing of 15 cm for the male parent.Both parents are fertilized simultaneously with 375 kg/hm^(2) of urea at the booting stage combined with intertillage or rainfall,and 225 kg/hm^(2) of urea at the grain-filling stage combined with irrigation.Strict hybrid removal,proper pollination and timely harvesting can significantly increase the yield of seed production.[Conclusions]This technology can be fully applied to large-scale seed production of water-saving and drought-resistant hybrid millet,providing seed supply support for cultivation in arid and semi-arid regions.It helps alleviate issues such as excessive groundwater extraction and water scarcity while enhancing planting efficiency,increasing yield,and boosting increase of farmers income.展开更多
The advancement of sophisticated smart windows exhibiting superior thermoregulation capabilities in both solar spectrum and long-wave infrared range maintains a prominent objective for researchers in this field.In thi...The advancement of sophisticated smart windows exhibiting superior thermoregulation capabilities in both solar spectrum and long-wave infrared range maintains a prominent objective for researchers in this field.In this study,a Janus window is proposed and prepared based on polymer-stabilized liquid-crystal films/thermochromic materials.It can achieve switchable front long-wave infrared emissivity(ε_(Front))and solar modulation ability(ΔT_(sol))through dynamic flipping,making it suitable for different seasonal energy-saving requirements.Outdoor experiments show that under daytime illumination,the indoor temperature decreases by 8℃,and the nighttime temperature drops by 5℃.MATLAB simulation calculations indicate that the daytime cooling power is 93 W m^(-2),while the nighttime cooling power reaches 142 W m^(-2).Interestingly,by modifying the conductive layer,it can effectively shield electromagnetic radiation(within the X-band frequency range(8.2-12.4)GHz).Energy simulation reveals the substantial superiority of this device in energy savings compared with single-layer polymer-stabilized liquid crystal,poly(N-isopropyl acrylamide),and normal glass when applied in different climate zones.This research presents a compelling opportunity for the development of sophisticated smart windows characterized by exceptional thermoregulation capabilities.展开更多
This study analyzes the energy impact of applying green roofs on flat roofs of existing buildings,assessing their potential to reduce the demand for non-renewable primary energy for heating and cooling.Through dynamic...This study analyzes the energy impact of applying green roofs on flat roofs of existing buildings,assessing their potential to reduce the demand for non-renewable primary energy for heating and cooling.Through dynamic numerical simulations conducted on two real buildings located near Florence,Italy,and modeled in 130 different European locations,with a particular focus on the Mediterranean climate,it was possible to quantify the energy benefits derived from the application of green roofs on existing structures.The results show that,while the effect on heating is limited,with an average reduction in energy demand of only a few percentage points,the impact on cooling is significantly more pronounced,with average savings of 20%in non-renewable primary energy,particularly in Mediterranean climates with high CDD(cooling degree days)values.The study confirms that green roofs can be an effective solution to improve the energy efficiency of existing buildings with flat roofs in the Mediterranean climate,in line with European goals for reducing CO₂emissions and promoting renewable energy.展开更多
BACKGROUND Conventional reusable endoscopes have high disinfection costs because of their large size.In this study,we compared the effectiveness,safety,and operation performance of the portable disposable large-channe...BACKGROUND Conventional reusable endoscopes have high disinfection costs because of their large size.In this study,we compared the effectiveness,safety,and operation performance of the portable disposable large-channel endoscope that we developed with those of a conventional gastroscope in endoscopic submucosal dissection(ESD).AIM To compare two gastroscopes in ESD for effectiveness and safety.METHODS Ten Bama pigs were subjected to gastroscopy and ESD after general anesthesia.The experiment was completed by four experienced endoscopists.First,two endoscopists randomly selected the portable disposable large-channel or conventional gastroscope to complete gastroscopy procedures.The other two endoscopists assessed the quality of endoscopic images.After endoscopy,all of the endoscopists randomly used the portable disposable large-channel endoscope or the conventional gastroscope for ESD.Endoscopic operation performance,submucosal dissection time,total procedure time,total submucosal injection volume,specimen size,success rate of en bloc resection,muscular injury rate,and complications were compared between the endoscopes.RESULTS No significant differences in gastroscopy duration or in the integrity,sharpness,saturation,and brightness of the gastroscopic images were observed between the gastroscopes.For ESD,no significant differences in endoscopic operation performance,incision time,submucosal dissection time,total procedure time,total submucosal injection volume,specimen size,or success rate of en bloc resection were observed between the gastroscopes.Neither gastroscope caused muscular injury or treatment-related complica-tions.CONCLUSION The portable disposable large-channel endoscope can be used safely and effectively for gastroscopy and treatment.展开更多
The permeability of the sintering process can be significantly improved by the pellet sintering,but the excessive permeability will impact the heat accumulation of the sinter bed.Thus,it is very essential to clarify t...The permeability of the sintering process can be significantly improved by the pellet sintering,but the excessive permeability will impact the heat accumulation of the sinter bed.Thus,it is very essential to clarify the influence of the pellet particle size on the heat transfer process of sintering.Therefore,pilot-scale sinter pot tests of pellet sintering with manganese ore fines of different particle sizes were conducted,and traditional sintering was compared to reveal the heat transfer process of sintering and its impact on the microstructure of sintered ore.The results indicate that under suitable pellet sizes(8-12 mm),the heat transfer efficiency and the heat accumulation effect between the layers of sinter bed are strengthened by the pellet sintering,as well as the highest temperature in the combustion zone and the duration of high-temperature zone.This also leads to the further growth of ferrotephroite or hausmannite in liquid phase and its more reasonable crystal distribution.Ultimately,compared with the traditional sintering process,the total solid fuel consumption can be reduced by 20%-30%,and the productivity can be increased by 11.71%-16.21%.展开更多
Lightweight structures for gears enable a reduction in material usage while maintaining the technical function of the gear.Previous approaches have pursued the strategy of lightweight structures in the gear wheel body...Lightweight structures for gears enable a reduction in material usage while maintaining the technical function of the gear.Previous approaches have pursued the strategy of lightweight structures in the gear wheel body.By taking inspiration from biological models and utilizing material savings in the gear rim,new design approaches for the lightweight design of gears can be realized.For this reason,a holistic biological design approach for spur gears is presented.In addition to the method of topology optimization,a biologically inspired approach based on diatoms is introduced,which achieves a weight reduction of over 50%compared to conventional solid gears.Diatom structures are extracted from the oceans,digitally modelled,and adapted to the load conditions of a reference gear by parametric design and simulation optimization.For the experimental validation of the design,a manufactured gear is statically loaded in the nominal load range and analyzed using a tactile geometry gear measurement.The measurement results of selected standard gear parameters show that the gear does not exhibit any plastic deformation for the nominal load capacity of 383 Nm,validating the presented design approach.展开更多
Passive daytime radiative cooling has great potential for energy conservation and sustainable development.Polymer-based radiative cooling materials have received much attention due to their excellent cooling performan...Passive daytime radiative cooling has great potential for energy conservation and sustainable development.Polymer-based radiative cooling materials have received much attention due to their excellent cooling performance and scalable potential.However,the use of large amounts of organic solvents,the long cycle time,and the complexity of the preparation process have limited their development.Herein,we report a two-step cold-press sintering method for the preparation of a polymer radiative cooler,which is free of organic solvents.For demonstration,a polyvinylidene fluoride-hexafluoropropylene copolymer(PVDF-HFP)coating with a solar reflectance of 97.4%and an emissivity of 0.969 within the atmospheric window is prepared,which can achieve a sub-ambient cooling phenomenon with a temperature reduction of 4.8℃.Besides,the maximal radiative cooling power of 50.2 W/m^(2)is also obtained under sunlight.After the implementation of the proposed sintered PVDF-HFP coating in buildings,more than 10%of annual energy consumption can be saved in China.This work proposes a simple,environmentally friendly,and scalable processing method for the preparation of radiative cooling materials,facilitating the large-scale application of radiative cooling technology.展开更多
Construction engineering plays a vital role in urban development,especially as the pace of modern progress continues to accelerate.The widespread use of energy-saving and green environmental protection building materi...Construction engineering plays a vital role in urban development,especially as the pace of modern progress continues to accelerate.The widespread use of energy-saving and green environmental protection building materials in this field not only brings convenience to daily life but also promotes the scientific,sustainable,and stable development of construction projects.These materials significantly extend the service life of buildings while supporting environmental protection efforts.This paper explores the practical application value of energy-saving and environmentally friendly building materials in construction engineering,outlines the key application principles,and analyzes their specific types and usage requirements.The aim is to provide a valuable reference for future research and practical implementation.展开更多
At the forthcoming IGATEX textile machinery exhibition inKarachi,Pakistan,from April 24-26,Monforts will highlight thebenefits of its latest Universal Energy Tower.This stand-aloneair/air heat exchanger module enables...At the forthcoming IGATEX textile machinery exhibition inKarachi,Pakistan,from April 24-26,Monforts will highlight thebenefits of its latest Universal Energy Tower.This stand-aloneair/air heat exchanger module enables recovery of the heatfrom the exhaust air flow of thermal systems such as existingstenters and THERMEX dyeing ranges with infrared predriers,resulting in energy savings of up to 25%,depending on the ex-haust air volume and operating temperature.展开更多
Dynamic wake field information is vital for the optimized design and control of wind farms.Combined with sparse measurement data from light detection and ranging(LiDAR),the physics-informed neural network(PINN)framewo...Dynamic wake field information is vital for the optimized design and control of wind farms.Combined with sparse measurement data from light detection and ranging(LiDAR),the physics-informed neural network(PINN)frameworks have recently been employed for forecasting freestream wind and wake fields.However,these PINN frameworks face challenges of low prediction accuracy and long training times.Therefore,this paper constructed a PINN framework for dynamic wake field prediction by integrating two accuracy improvement strategies and a step-by-step training time saving strategy.The results showed that the different performance improvement routes significantly improved the overall performance of the PINN.The accuracy and efficiency of the PINN with spatiotemporal improvement strategies were validated via LiDAR-measured data from a wind farm in Shandong province,China.This paper sheds light on load reduction,efficiency improvement,intelligent operation and maintenance of wind farms.展开更多
This year summarizes the experience of industrialization of vacuum glazing in the past twenty years.A series of technical difficulties have been solved to start the first global mass production of high-quality vacuum ...This year summarizes the experience of industrialization of vacuum glazing in the past twenty years.A series of technical difficulties have been solved to start the first global mass production of high-quality vacuum glass.High quality means high performance and long life which are interrelated.A mass production line must be able to achieve these two requirements if it is to produce vacuum glazing products that can be accepted by the society.With a U-value of 0.4 W/m²·K based on Low-E(low emissivity)with an emissivity of 0.03 the door is wide open for further solutions.Time,gradually to improve costs,maximizes output and develops innovative solutions of advanced window and façade systems combining complete new features like smart glasses,intelligent lamella systems in hybrid VG-IG solutions changing the building world towards“Energy plus Houses”.Market demand will rapidly increase with completely new options.Cost saving means to balance additional advantages for savings against system costs of window or façade elements.Due to promotion of energy saving and emission reduction,both,subjective and objective conditions for industrialization of vacuum glasses are perfect;the building world is waiting for it,since long.There is a lot to investigate and to gain for business success.展开更多
In May,dimly lit footage posted by a dubious Russian blog,English Russia,showing a Chinese office equipped with 10,000 phones,confirmed what many in tech mediahave warned about for years:Views and rankings all overthe...In May,dimly lit footage posted by a dubious Russian blog,English Russia,showing a Chinese office equipped with 10,000 phones,confirmed what many in tech mediahave warned about for years:Views and rankings all overthe internet are being manipulated by'click farms.'The high ratings of many apps on Android展开更多
文摘Many people like to shop at a supermarket.Supermarkets are very convenient.They are open long hours,every day of the week.Everything is easy to find in a supermarket.It's always in the same place.Supermarkets often have sales.These can help you save money.
文摘好题精选阅读下面短文,从每题所给的A、B、C、D四个选项中选出最佳选项。Born during my parents'sea voyage(航行)around the world,I always wanted to make the trip myself.At age 8,I began saving and sailing to 1 that dream.My parents weren't excited about the idea,but after talking to them about it,they became 2.
文摘As an indispensable part of modern buildings,centralized central air conditioning systems play an important role in maintaining the comfort and air quality of the indoor environment.However,with the increasing energy consumption,how to improve the energy efficiency ratio of air conditioning systems and reduce energy consumption has become an important issue in research and practice.The purpose of this paper is to discuss the impact of humidity control strategies on energy saving in centralized central air conditioning systems,with a view to providing a theoretical basis and practical guidance for realizing building energy efficiency.
基金Supported by National Natural Science Foundation of China(Grant No.52075358).
文摘Load-sensing systems use a centralized power source for energy supply and multiway valves for flow distribution and suffer from excessive throttling losses and low energy efficiency.Pump-controlled systems adopt volumetric control methods to eliminate throttling losses.However,pump-controlled multi-actuator systems require excessive installed power.To address these issues,by combining the respective advantages of valve-and pump-controlled technologies,an open-closed circuit integrated pump-valve collaborative drive multi-actuator system consisting of pump-and valve-controlled units is proposed.The pump-controlled units manage the individual actuator motions,whereas the valve-controlled unit enhances the driving power of the pump-controlled units.In addition,to optimize the operation characteristics and energy consumption,a four-quadrant control strategy and an ultralow-pressure loss control strategy were proposed.Several experiments were conducted to evaluate the working performance of the proposed system and the load-sensing system under different working conditions.Experimental results demonstrated that the proposed system exhibited satisfactory velocity control characteristics.Compared with the traditional load-sensing system,the proposed system reduced throttling losses by 90.4−94.4%and energy consumption by 45.9−50.0%.Additionally,only 22.8%of the total energy consumption was attributed to the pump-controlled units,with the remainder provided by the valve-controlled unit.Compared with the traditional pump-controlled multi-actuator system,the proposed system achieved a 29.4%reduction in installed power,thereby lowering the system installed power and costs.This paper presents an electrohydraulic multi-actuator drive method that combines high energy efficiency and high power density and is suitable for electric construction machinery and other heavy equipment with multiple actuators.
文摘Jinmao Tex(short for Chongqing Jinmao Textile Accessories Co.,Ltd.),founded in 1960,is the largest manufacturer of ring traveller and steel ring in China,and its ring traveller delivery tops in China market for more than 30 consecutive years.In recent years,in order to serve the transformation and upgrading of the textile industry,Jinmao Tex invested"China Ring Traveller and Steel Ring R&D center",focused on the technological innovation of key textile accessories,developed high-performance and long-life textile accessories to assist textile mills save energy,reduce consumption,improve quality and increase efficiency.Jinmao Tex has now become a“steel ring+ring traveller”solution provider for high-speed spinning and differential fiber spinning.
基金Supported by National Modern Agricultural Industry Technology System(CARS-06-14.5-A7)Hebei Provincial Agricultural Science and Technology Achievement Transformation Fund Project("Zhangzagu 19"Pilot Test and Demonstration).
文摘[Objectives]This study was conducted to improve the seed production efficiency of water-saving and drought-resistant hybrid millet in production.[Methods]A high-efficiency seed production technology for water-saving and drought-resistant hybrid millet varieties was developed by integrating aspects such as parental line sources,botanical characteristics,biological traits,seed production yield structure,key technical points of seed production,and suitable planting regions.[Results]Under standardized pre-sowing preparation and field management,both parents are simultaneously sown around May 20 with a planting row ratio of 2:6(female:male),a row spacing of 20 cm and plant spacing of 10 cm for the female parent,and a row spacing of 35 cm and plant spacing of 15 cm for the male parent.Both parents are fertilized simultaneously with 375 kg/hm^(2) of urea at the booting stage combined with intertillage or rainfall,and 225 kg/hm^(2) of urea at the grain-filling stage combined with irrigation.Strict hybrid removal,proper pollination and timely harvesting can significantly increase the yield of seed production.[Conclusions]This technology can be fully applied to large-scale seed production of water-saving and drought-resistant hybrid millet,providing seed supply support for cultivation in arid and semi-arid regions.It helps alleviate issues such as excessive groundwater extraction and water scarcity while enhancing planting efficiency,increasing yield,and boosting increase of farmers income.
基金supported by the National Natural Science Foundation of China(52372279,52103071,52203322,52473289,52303220)the Interdisciplinary Research Project for Young Teachers of USTB(Fundamental Research Funds for the Central Universities in China,FRF-IDRY-GD22-001)。
文摘The advancement of sophisticated smart windows exhibiting superior thermoregulation capabilities in both solar spectrum and long-wave infrared range maintains a prominent objective for researchers in this field.In this study,a Janus window is proposed and prepared based on polymer-stabilized liquid-crystal films/thermochromic materials.It can achieve switchable front long-wave infrared emissivity(ε_(Front))and solar modulation ability(ΔT_(sol))through dynamic flipping,making it suitable for different seasonal energy-saving requirements.Outdoor experiments show that under daytime illumination,the indoor temperature decreases by 8℃,and the nighttime temperature drops by 5℃.MATLAB simulation calculations indicate that the daytime cooling power is 93 W m^(-2),while the nighttime cooling power reaches 142 W m^(-2).Interestingly,by modifying the conductive layer,it can effectively shield electromagnetic radiation(within the X-band frequency range(8.2-12.4)GHz).Energy simulation reveals the substantial superiority of this device in energy savings compared with single-layer polymer-stabilized liquid crystal,poly(N-isopropyl acrylamide),and normal glass when applied in different climate zones.This research presents a compelling opportunity for the development of sophisticated smart windows characterized by exceptional thermoregulation capabilities.
文摘This study analyzes the energy impact of applying green roofs on flat roofs of existing buildings,assessing their potential to reduce the demand for non-renewable primary energy for heating and cooling.Through dynamic numerical simulations conducted on two real buildings located near Florence,Italy,and modeled in 130 different European locations,with a particular focus on the Mediterranean climate,it was possible to quantify the energy benefits derived from the application of green roofs on existing structures.The results show that,while the effect on heating is limited,with an average reduction in energy demand of only a few percentage points,the impact on cooling is significantly more pronounced,with average savings of 20%in non-renewable primary energy,particularly in Mediterranean climates with high CDD(cooling degree days)values.The study confirms that green roofs can be an effective solution to improve the energy efficiency of existing buildings with flat roofs in the Mediterranean climate,in line with European goals for reducing CO₂emissions and promoting renewable energy.
文摘BACKGROUND Conventional reusable endoscopes have high disinfection costs because of their large size.In this study,we compared the effectiveness,safety,and operation performance of the portable disposable large-channel endoscope that we developed with those of a conventional gastroscope in endoscopic submucosal dissection(ESD).AIM To compare two gastroscopes in ESD for effectiveness and safety.METHODS Ten Bama pigs were subjected to gastroscopy and ESD after general anesthesia.The experiment was completed by four experienced endoscopists.First,two endoscopists randomly selected the portable disposable large-channel or conventional gastroscope to complete gastroscopy procedures.The other two endoscopists assessed the quality of endoscopic images.After endoscopy,all of the endoscopists randomly used the portable disposable large-channel endoscope or the conventional gastroscope for ESD.Endoscopic operation performance,submucosal dissection time,total procedure time,total submucosal injection volume,specimen size,success rate of en bloc resection,muscular injury rate,and complications were compared between the endoscopes.RESULTS No significant differences in gastroscopy duration or in the integrity,sharpness,saturation,and brightness of the gastroscopic images were observed between the gastroscopes.For ESD,no significant differences in endoscopic operation performance,incision time,submucosal dissection time,total procedure time,total submucosal injection volume,specimen size,or success rate of en bloc resection were observed between the gastroscopes.Neither gastroscope caused muscular injury or treatment-related complica-tions.CONCLUSION The portable disposable large-channel endoscope can be used safely and effectively for gastroscopy and treatment.
基金supports from the National Science Foundation of China under Grant number of No.52174329China Baowu Low Carbon Metallurgy Innovation Foundation(BWLCF202216).
文摘The permeability of the sintering process can be significantly improved by the pellet sintering,but the excessive permeability will impact the heat accumulation of the sinter bed.Thus,it is very essential to clarify the influence of the pellet particle size on the heat transfer process of sintering.Therefore,pilot-scale sinter pot tests of pellet sintering with manganese ore fines of different particle sizes were conducted,and traditional sintering was compared to reveal the heat transfer process of sintering and its impact on the microstructure of sintered ore.The results indicate that under suitable pellet sizes(8-12 mm),the heat transfer efficiency and the heat accumulation effect between the layers of sinter bed are strengthened by the pellet sintering,as well as the highest temperature in the combustion zone and the duration of high-temperature zone.This also leads to the further growth of ferrotephroite or hausmannite in liquid phase and its more reasonable crystal distribution.Ultimately,compared with the traditional sintering process,the total solid fuel consumption can be reduced by 20%-30%,and the productivity can be increased by 11.71%-16.21%.
基金funded by the Federal Ministry for Economic Affairs and Climate Action as part of the Technology Transfer Program Lightweight Construction(Grant no.03LB1000A).
文摘Lightweight structures for gears enable a reduction in material usage while maintaining the technical function of the gear.Previous approaches have pursued the strategy of lightweight structures in the gear wheel body.By taking inspiration from biological models and utilizing material savings in the gear rim,new design approaches for the lightweight design of gears can be realized.For this reason,a holistic biological design approach for spur gears is presented.In addition to the method of topology optimization,a biologically inspired approach based on diatoms is introduced,which achieves a weight reduction of over 50%compared to conventional solid gears.Diatom structures are extracted from the oceans,digitally modelled,and adapted to the load conditions of a reference gear by parametric design and simulation optimization.For the experimental validation of the design,a manufactured gear is statically loaded in the nominal load range and analyzed using a tactile geometry gear measurement.The measurement results of selected standard gear parameters show that the gear does not exhibit any plastic deformation for the nominal load capacity of 383 Nm,validating the presented design approach.
基金supported by the National Natural Science Foundation of China(NSFC 52130601 and 52106276)the Young Elite Scientists Sponsorship Program by CAST(2023QNRC001)+1 种基金the University of Science and Technology of China-Southwest University of Science and Technology Counterpart Cooperation and Development Joint Fund(24LHJJ09)the USTC Center for Micro and Nanoscale Research and Fabrication。
文摘Passive daytime radiative cooling has great potential for energy conservation and sustainable development.Polymer-based radiative cooling materials have received much attention due to their excellent cooling performance and scalable potential.However,the use of large amounts of organic solvents,the long cycle time,and the complexity of the preparation process have limited their development.Herein,we report a two-step cold-press sintering method for the preparation of a polymer radiative cooler,which is free of organic solvents.For demonstration,a polyvinylidene fluoride-hexafluoropropylene copolymer(PVDF-HFP)coating with a solar reflectance of 97.4%and an emissivity of 0.969 within the atmospheric window is prepared,which can achieve a sub-ambient cooling phenomenon with a temperature reduction of 4.8℃.Besides,the maximal radiative cooling power of 50.2 W/m^(2)is also obtained under sunlight.After the implementation of the proposed sintered PVDF-HFP coating in buildings,more than 10%of annual energy consumption can be saved in China.This work proposes a simple,environmentally friendly,and scalable processing method for the preparation of radiative cooling materials,facilitating the large-scale application of radiative cooling technology.
文摘Construction engineering plays a vital role in urban development,especially as the pace of modern progress continues to accelerate.The widespread use of energy-saving and green environmental protection building materials in this field not only brings convenience to daily life but also promotes the scientific,sustainable,and stable development of construction projects.These materials significantly extend the service life of buildings while supporting environmental protection efforts.This paper explores the practical application value of energy-saving and environmentally friendly building materials in construction engineering,outlines the key application principles,and analyzes their specific types and usage requirements.The aim is to provide a valuable reference for future research and practical implementation.
文摘At the forthcoming IGATEX textile machinery exhibition inKarachi,Pakistan,from April 24-26,Monforts will highlight thebenefits of its latest Universal Energy Tower.This stand-aloneair/air heat exchanger module enables recovery of the heatfrom the exhaust air flow of thermal systems such as existingstenters and THERMEX dyeing ranges with infrared predriers,resulting in energy savings of up to 25%,depending on the ex-haust air volume and operating temperature.
基金supported by the National Natural Science Foundation of China(Grant Nos.12072105,11932006,and 52308498)the Natural Science Foundation of Jiangsu Province,China(Grant No.BK20220976).
文摘Dynamic wake field information is vital for the optimized design and control of wind farms.Combined with sparse measurement data from light detection and ranging(LiDAR),the physics-informed neural network(PINN)frameworks have recently been employed for forecasting freestream wind and wake fields.However,these PINN frameworks face challenges of low prediction accuracy and long training times.Therefore,this paper constructed a PINN framework for dynamic wake field prediction by integrating two accuracy improvement strategies and a step-by-step training time saving strategy.The results showed that the different performance improvement routes significantly improved the overall performance of the PINN.The accuracy and efficiency of the PINN with spatiotemporal improvement strategies were validated via LiDAR-measured data from a wind farm in Shandong province,China.This paper sheds light on load reduction,efficiency improvement,intelligent operation and maintenance of wind farms.
文摘This year summarizes the experience of industrialization of vacuum glazing in the past twenty years.A series of technical difficulties have been solved to start the first global mass production of high-quality vacuum glass.High quality means high performance and long life which are interrelated.A mass production line must be able to achieve these two requirements if it is to produce vacuum glazing products that can be accepted by the society.With a U-value of 0.4 W/m²·K based on Low-E(low emissivity)with an emissivity of 0.03 the door is wide open for further solutions.Time,gradually to improve costs,maximizes output and develops innovative solutions of advanced window and façade systems combining complete new features like smart glasses,intelligent lamella systems in hybrid VG-IG solutions changing the building world towards“Energy plus Houses”.Market demand will rapidly increase with completely new options.Cost saving means to balance additional advantages for savings against system costs of window or façade elements.Due to promotion of energy saving and emission reduction,both,subjective and objective conditions for industrialization of vacuum glasses are perfect;the building world is waiting for it,since long.There is a lot to investigate and to gain for business success.
文摘In May,dimly lit footage posted by a dubious Russian blog,English Russia,showing a Chinese office equipped with 10,000 phones,confirmed what many in tech mediahave warned about for years:Views and rankings all overthe internet are being manipulated by'click farms.'The high ratings of many apps on Android
