The key-value store can provide flexibility of data types because it does not need to specify the data types to be stored in advance and can store any types of data as the value of the key-value pair.Various types of ...The key-value store can provide flexibility of data types because it does not need to specify the data types to be stored in advance and can store any types of data as the value of the key-value pair.Various types of studies have been conducted to improve the performance of the key-value store while maintaining its flexibility.However,the research efforts storing the large-scale values such as multimedia data files(e.g.,images or videos)in the key-value store were limited.In this study,we propose a new key-value store,WR-Store++aiming to store the large-scale values stably.Specifically,it provides a new design of separating data and index by working with the built-in data structure of the Windows operating system and the file system.The utilization of the built-in data structure of the Windows operating system achieves the efficiency of the key-value store and that of the file system extends the limited space of the storage significantly.We also present chunk-based memory management and parallel processing of WR-Store++to further improve its performance in the GET operation.Through the experiments,we show that WR-Store++can store at least 32.74 times larger datasets than the existing baseline key-value store,WR-Store,which has the limitation in storing large-scale data sets.Furthermore,in terms of processing efficiency,we show that WR-Store++outperforms not only WR-Store but also the other state-ofthe-art key-value stores,LevelDB,RocksDB,and BerkeleyDB,for individual key-value operations and mixed workloads.展开更多
Understanding the proton dynamic behavior in inorganic materials has long been a topic of intense fascination[1],especially in the field of electrochemical energy storage[2].One of the examples is the research of prot...Understanding the proton dynamic behavior in inorganic materials has long been a topic of intense fascination[1],especially in the field of electrochemical energy storage[2].One of the examples is the research of proton transport in transition metal oxides,which dates back to 1971[3]when RuO_(2) was discovered to be capable of storing protons via reversible redox reactions[4].In aqueous electrolytes,the thin film RuO_(2) electrode exhibits a surface pseudocapacitive behavior[5],which could be modified by the structural water in its hydrated form due to the facile Grotthuss hopping mode of protons along the established hydrogen bonds inside the bulk phase[6].Soon later,Goodenough et al.reported the capacitor-like behavior of amorphous MnO_(2)·xH_(2)O electrode in an aqueous KCl electrolyte[7],and further studies on the hydrated MnO_(2) electrodes prepared by sol-gel processes have soon discovered that the intercalation of protons from aqueous electrolytes plays an indispensable role in the charge storage mechanism[8].In recent years,the research interest on rechargeable aqueous batteries has fueled the renaissance of mechanistic study of proton transport in transition metal oxides[9],which can operate as cathodes or anodes via a topotactic insertion mechanism similar to that in Li-ion batteries[10].However,due to the challenges for experimental detection of local chemical environments of the inserted protons,a comprehensive understanding of proton dynamic behavior in these electrodes remains largely lacking.展开更多
Conversation A(in a department store)Sara:Department store directories are helpful.Sam:They are.Today,I have to buy new furniture and bedding for my apartment.They're on the sixth floor.
一、单词拼写1.Light travels much faster than___(声音).2.It's______(容易的)for us to pay online with Alipay now,3.The teacher often____(测试)his students in math.4.At that time,things could be_____(困难的)for the w...一、单词拼写1.Light travels much faster than___(声音).2.It's______(容易的)for us to pay online with Alipay now,3.The teacher often____(测试)his students in math.4.At that time,things could be_____(困难的)for the workers.5.It's said that she's__(储备)nearly one ton of potatoes at home.6.In his spare time,Dr.Yuan loves playing the piano and listening to__(音乐),especially Mozart's.展开更多
Train Mass Rapid Transit(MRT)was put into service in 1987,and has since been augmented by and linked to the Light Rapid Transit.Combined,you can often get you within walking distance of most destinations.The maps on t...Train Mass Rapid Transit(MRT)was put into service in 1987,and has since been augmented by and linked to the Light Rapid Transit.Combined,you can often get you within walking distance of most destinations.The maps on the metro system are easy to read,complete with English version.You can easily purchase an EZ-Link card or a NETS Flashpay Card(stored value cards)at all MRT stations and bus interchange.展开更多
简单的善举不仅温暖了他人,也让施助者感受到内心的充盈与喜悦,既彰显出爱的力量,更传递出分享的真谛。1 I have no idea why some stores make shelves so high that only a professional basketball player can reach them,but they d...简单的善举不仅温暖了他人,也让施助者感受到内心的充盈与喜悦,既彰显出爱的力量,更传递出分享的真谛。1 I have no idea why some stores make shelves so high that only a professional basketball player can reach them,but they do.I experienced one of them just the other day.I had just picked up some toothpaste and deodorant and was heading to the dog food section when I took a short cut through the toy section.展开更多
Boosting Tourism and Consumption.China plans to accelerate the availability of tax refund stores for eligible overseas visitors to about 10,000 shops nationwide this year,almost tripling the current number,as the coun...Boosting Tourism and Consumption.China plans to accelerate the availability of tax refund stores for eligible overseas visitors to about 10,000 shops nationwide this year,almost tripling the current number,as the country continues to boost inbound tourism and consumption,a senior official said.展开更多
In recent years, Chinese game developers have been quietly pulling off a “gold rush” in the global m a rket. Of c ou r se, eve r yone knows about mega-hits like “Genshin Impact” and “Black Myth:Wukong”,but what ...In recent years, Chinese game developers have been quietly pulling off a “gold rush” in the global m a rket. Of c ou r se, eve r yone knows about mega-hits like “Genshin Impact” and “Black Myth:Wukong”,but what about all those lesser-known Chinese games quietly taking over app stores worldwide? These games are raking in the dough, using localization that is so good that Western players are too excited to realize the game they’re obsessed with is from China. Let’s talk numbers:in 2024, Chinese-developed games made a whopping USD 18.557 billion overseas, up 13.39%from the year before.展开更多
Phillip Katuve,a landlord who owns a six-storey apartment complex in Kileleshwa,an upmarket Nairobi suburb,embraced green roofing two years ago.His building now boasts a vibrant rooftop garden with integrated solar pa...Phillip Katuve,a landlord who owns a six-storey apartment complex in Kileleshwa,an upmarket Nairobi suburb,embraced green roofing two years ago.His building now boasts a vibrant rooftop garden with integrated solar panels,supplying energy to all 24 units.“Initially,the idea sounded expensive,but the long-term benefits have been remarkable,”said Katuve.展开更多
LATEST NEWS FROM THE WORLD OF BUSINESS CHINA Beijing to Open‘4S’Store for Robots China’s capital is set to launch the world’s first“4S store”dedicated to embodied artificial intelligence robots,marking the lates...LATEST NEWS FROM THE WORLD OF BUSINESS CHINA Beijing to Open‘4S’Store for Robots China’s capital is set to launch the world’s first“4S store”dedicated to embodied artificial intelligence robots,marking the latest push to commer-cialise advanced robotics in the country.展开更多
The Chinese New Year gives a boost to“debut economy,”which has already become a driver of upgraded consumption and a higher lifestyle.XIAONIAN,or the Chinese Little New Year,is the day when preparations for the Spri...The Chinese New Year gives a boost to“debut economy,”which has already become a driver of upgraded consumption and a higher lifestyle.XIAONIAN,or the Chinese Little New Year,is the day when preparations for the Spring Festival start a week before the actual Chinese New Year.The following day on January 24,2025,Chaoyang District in Beijing saw the capital’s first MINISO LAND open,a two-storied store full of items loved by young people-plush toys,trinkets,cosmetics,badges,and internationally popular merchandise like Hello Kitty,Little Pony,and Harry Potter branded goods.展开更多
An eco-friendly label makes cultural products from recycled bottles and industrial waste to nudge young people towards a green lifestyle.IN a gift store in China’s iconic Palace Museum,also known as the Forbidden Cit...An eco-friendly label makes cultural products from recycled bottles and industrial waste to nudge young people towards a green lifestyle.IN a gift store in China’s iconic Palace Museum,also known as the Forbidden City,sustainable cultural and creative products made from recycled materials are a hit with visitors.展开更多
The rise of secondhand goods stores,both offline and online,is another way to recycle and reuse,boosting an environment-friendly lifestyle.NEAR the Forbidden City in downtown Beijing,an old subway construction site wa...The rise of secondhand goods stores,both offline and online,is another way to recycle and reuse,boosting an environment-friendly lifestyle.NEAR the Forbidden City in downtown Beijing,an old subway construction site was turned into a traditional quadrangle courtyard five years ago,becoming a cultural center for local residents to watch movies,attend band performances and go to yoga classes.展开更多
This study investigates the differences in microstructural control between cryogenic forging combined with pre-deformation(PCF)and traditional thermal forging(TTF)for 7050 aluminum forgings intended for aerospace appl...This study investigates the differences in microstructural control between cryogenic forging combined with pre-deformation(PCF)and traditional thermal forging(TTF)for 7050 aluminum forgings intended for aerospace applications.The PCF process,utilizing cryogenic deformation,significantly refines the coarse grains at the surface of the forgings,resulting in a finer and more uniform microstructure,thereby effectively addressing the issue of surface coarse grains associated with traditional methods.The findings indicate that the PCF process can accumulate higher stored energy,facilitating static recrystallization(SRX)during subsequent heat treatment and enhancing the microstructural uniformity.Utilizing various analytical techniques,including optical microscopy(OM),electron backscatter diffraction(EBSD),and transmission electron microscopy(TEM).This study reveals the superiority of the PCF process in terms of strain accumulation,dislocation density,and grain refinement.In conclusion,this method offers advantages in enhancing the performance and microstructural uniformity of 7050 aluminum forgings,presenting new opportunities for applications in the aluminum forging industry.展开更多
The majors accredited by the Engineering Education Accreditation(EEA)reflect the accreditation agency’s recognition of the school’s engineering programs.Excellent accreditation management holds significant importanc...The majors accredited by the Engineering Education Accreditation(EEA)reflect the accreditation agency’s recognition of the school’s engineering programs.Excellent accreditation management holds significant importance for the advancement of engineering education programs.However,the traditional engineering education system framework suffers from the opacity of raw education data and the difficulty for accreditation bodies to forensically examine the self-assessment reports.To solve these issues,an EEA framework based on Hyperledger Fabric blockchain technology is proposed in this work.Firstly,all relevant stakeholders and information interactions occur within the blockchain network,ensuring the authenticity of educational data and enhancing the transparency of accreditation processes.Secondly,multiple roles are abstracted into a single organization to optimize the network topology.The original data is stored off-chain,and the hash values of the data are stored on-chain to reduce on-chain storage costs.The experimental results show that the proposed framework has a high throughput and the network latency of writing data to the blockchain is reduced by at least 0.04 s.It effectively improves network performance and security,which provides new insights for EEA management.展开更多
The<001>orientation of the Goss texture aligned with the rolling direction is the most easily magnetized direction,effectively enhancing the magnetic properties of non-oriented silicon steel.In the present study...The<001>orientation of the Goss texture aligned with the rolling direction is the most easily magnetized direction,effectively enhancing the magnetic properties of non-oriented silicon steel.In the present study,an ultra-thin high-silicon sheet of 0.2 mm with a strong Goss texture was successfully fabricated using a two-stage rolling method,achieving superior magnetic properties.The combination of suitable primary rolling reduction and intermediate annealing proved beneficial in promoting the formation of Goss texture.Electron back scatter diffraction(EBSD)was used to characterize micro-shear bands within deformed grains of secondary rolled sheets.Observations revealed that the recrystallized Goss nucleus originated from the Goss substructure of shear bands within deformed{111}<112>grains during the initial stages of recrystallization.The influence of stored energy and grain size on texture evolution was thoroughly investigated using quasi-in situ EBSD during recrystallization.In the initial stages,large deformed{111}<112>and near{111}<112>grains with high stored energy facilitated nucleation and growth of Goss and near-Goss grains within shear bands and reduced grain boundary nucleation.In the later stages,large deformed grains with low stored energy underwent a strain-induced grain boundary migration mechanism to nucleate.During the recrystallization,many recrystallized Goss and near-Goss grains clustered together,with Goss grains rotating towards near-Goss orientation.The resulting annealed ultra-thin 0.2 mm sheet with a pronounced Goss texture exhibited superior magnetic properties.展开更多
Along the ancient Tea-Horse Road of thousands of miles between Sichuan and Xizang in Southwest China lies a centuries old courtyard.Commonly called the"Jiang Family Compound"or"Yu Xing Tea Store",t...Along the ancient Tea-Horse Road of thousands of miles between Sichuan and Xizang in Southwest China lies a centuries old courtyard.Commonly called the"Jiang Family Compound"or"Yu Xing Tea Store",this architecture situated in the old downtown area of Yingjing County in Ya'an City,Sichuan Province,was once the residence of the local tea merchants-the Jiang family.展开更多
To evaluate the accuracy of rockburst tendency classification in coal-bearing sandstone strata,this study conducted uniaxial compression loading and unloading tests on sandstone samples with four distinct grain sizes....To evaluate the accuracy of rockburst tendency classification in coal-bearing sandstone strata,this study conducted uniaxial compression loading and unloading tests on sandstone samples with four distinct grain sizes.The tests involved loading the samples to 60%,70%,and 80%of their uniaxial compressive strength,followed by unloading and reloading until failure.Key parameters such as the elastic energy index and linear elasticity criteria were derived from these tests.Additionally,rock fragments were collected to calculate their initial ejection kinetic energy,serving as a measure of rockburst tendency.The classification of rockburst tendency was conducted using grading methods based on burst energy index(WET),pre-peak stored elastic energy(PES)and experimental observations.Multi-class classification and regression analyses were applied to machine learning models using experimental data to predict rockburst tendency levels.A comparative analysis of models from two libraries revealed that the Random Forest model achieved the highest accuracy in classification,while the Ada Boost Regressor model excelled in regression predictions.This study highlights that on a laboratory scale,integrating ejection kinetic energy with the unloading ratio,failure load,W_(ET)and PES through machine learning offers a highly accurate and reliable approach for determining rockburst tendency levels.展开更多
This research is focused on the singularity analysis for single-gimbal control moment gyros systems （SCMGs） which include two types, with constant speed （CSCMG） or variable speed （VSCMG） rotors. Through angular ...This research is focused on the singularity analysis for single-gimbal control moment gyros systems （SCMGs） which include two types, with constant speed （CSCMG） or variable speed （VSCMG） rotors. Through angular momentum hypersurfaces of singular states, the passable and impassable singular points are discriminated easily, meanwhile the information about how much the angular momentum workspace as well as the steering capability available is provided directly. It is obvious that the null motions of steering laws are more effective for the five pyramid configuration（FPC） than for the pyramid configuration（PC） from the singular plots. The possible degenerate hyperbolic singular points of the preceding configurations are calculated and the distinctness of them is denoted by the Gaussian curvature. Furthermore, failure problems to steer integrated power and attitude control system （IPACS） are also analyzed. A sufficient condition of choosing configurations of VSCMGs to guarantee the IPACS steering is given. The angular momentum envelops of VSCMGs, in a given energy and a limited range of rotor speeds, are plotted. The connection and distinctness between CSCMGs and VSCMGs are obtained from the point of view of envelops.展开更多
文摘The key-value store can provide flexibility of data types because it does not need to specify the data types to be stored in advance and can store any types of data as the value of the key-value pair.Various types of studies have been conducted to improve the performance of the key-value store while maintaining its flexibility.However,the research efforts storing the large-scale values such as multimedia data files(e.g.,images or videos)in the key-value store were limited.In this study,we propose a new key-value store,WR-Store++aiming to store the large-scale values stably.Specifically,it provides a new design of separating data and index by working with the built-in data structure of the Windows operating system and the file system.The utilization of the built-in data structure of the Windows operating system achieves the efficiency of the key-value store and that of the file system extends the limited space of the storage significantly.We also present chunk-based memory management and parallel processing of WR-Store++to further improve its performance in the GET operation.Through the experiments,we show that WR-Store++can store at least 32.74 times larger datasets than the existing baseline key-value store,WR-Store,which has the limitation in storing large-scale data sets.Furthermore,in terms of processing efficiency,we show that WR-Store++outperforms not only WR-Store but also the other state-ofthe-art key-value stores,LevelDB,RocksDB,and BerkeleyDB,for individual key-value operations and mixed workloads.
基金financial support from the National Natural Science Foundation of China(22109003)the Basic and Applied Basic Research Foundation of Guangdong Province(2023A1515011391)+1 种基金Soft Science Research Project of Guangdong Province(No.2017B030301013)the Major Science and Technology Infrastructure Project of Material Genome Big-science Facilities Platform supported by Municipal Development and Reform Commission of Shenzhen.
文摘Understanding the proton dynamic behavior in inorganic materials has long been a topic of intense fascination[1],especially in the field of electrochemical energy storage[2].One of the examples is the research of proton transport in transition metal oxides,which dates back to 1971[3]when RuO_(2) was discovered to be capable of storing protons via reversible redox reactions[4].In aqueous electrolytes,the thin film RuO_(2) electrode exhibits a surface pseudocapacitive behavior[5],which could be modified by the structural water in its hydrated form due to the facile Grotthuss hopping mode of protons along the established hydrogen bonds inside the bulk phase[6].Soon later,Goodenough et al.reported the capacitor-like behavior of amorphous MnO_(2)·xH_(2)O electrode in an aqueous KCl electrolyte[7],and further studies on the hydrated MnO_(2) electrodes prepared by sol-gel processes have soon discovered that the intercalation of protons from aqueous electrolytes plays an indispensable role in the charge storage mechanism[8].In recent years,the research interest on rechargeable aqueous batteries has fueled the renaissance of mechanistic study of proton transport in transition metal oxides[9],which can operate as cathodes or anodes via a topotactic insertion mechanism similar to that in Li-ion batteries[10].However,due to the challenges for experimental detection of local chemical environments of the inserted protons,a comprehensive understanding of proton dynamic behavior in these electrodes remains largely lacking.
文摘Conversation A(in a department store)Sara:Department store directories are helpful.Sam:They are.Today,I have to buy new furniture and bedding for my apartment.They're on the sixth floor.
文摘一、单词拼写1.Light travels much faster than___(声音).2.It's______(容易的)for us to pay online with Alipay now,3.The teacher often____(测试)his students in math.4.At that time,things could be_____(困难的)for the workers.5.It's said that she's__(储备)nearly one ton of potatoes at home.6.In his spare time,Dr.Yuan loves playing the piano and listening to__(音乐),especially Mozart's.
文摘Train Mass Rapid Transit(MRT)was put into service in 1987,and has since been augmented by and linked to the Light Rapid Transit.Combined,you can often get you within walking distance of most destinations.The maps on the metro system are easy to read,complete with English version.You can easily purchase an EZ-Link card or a NETS Flashpay Card(stored value cards)at all MRT stations and bus interchange.
文摘简单的善举不仅温暖了他人,也让施助者感受到内心的充盈与喜悦,既彰显出爱的力量,更传递出分享的真谛。1 I have no idea why some stores make shelves so high that only a professional basketball player can reach them,but they do.I experienced one of them just the other day.I had just picked up some toothpaste and deodorant and was heading to the dog food section when I took a short cut through the toy section.
文摘Boosting Tourism and Consumption.China plans to accelerate the availability of tax refund stores for eligible overseas visitors to about 10,000 shops nationwide this year,almost tripling the current number,as the country continues to boost inbound tourism and consumption,a senior official said.
文摘In recent years, Chinese game developers have been quietly pulling off a “gold rush” in the global m a rket. Of c ou r se, eve r yone knows about mega-hits like “Genshin Impact” and “Black Myth:Wukong”,but what about all those lesser-known Chinese games quietly taking over app stores worldwide? These games are raking in the dough, using localization that is so good that Western players are too excited to realize the game they’re obsessed with is from China. Let’s talk numbers:in 2024, Chinese-developed games made a whopping USD 18.557 billion overseas, up 13.39%from the year before.
文摘Phillip Katuve,a landlord who owns a six-storey apartment complex in Kileleshwa,an upmarket Nairobi suburb,embraced green roofing two years ago.His building now boasts a vibrant rooftop garden with integrated solar panels,supplying energy to all 24 units.“Initially,the idea sounded expensive,but the long-term benefits have been remarkable,”said Katuve.
文摘LATEST NEWS FROM THE WORLD OF BUSINESS CHINA Beijing to Open‘4S’Store for Robots China’s capital is set to launch the world’s first“4S store”dedicated to embodied artificial intelligence robots,marking the latest push to commer-cialise advanced robotics in the country.
文摘The Chinese New Year gives a boost to“debut economy,”which has already become a driver of upgraded consumption and a higher lifestyle.XIAONIAN,or the Chinese Little New Year,is the day when preparations for the Spring Festival start a week before the actual Chinese New Year.The following day on January 24,2025,Chaoyang District in Beijing saw the capital’s first MINISO LAND open,a two-storied store full of items loved by young people-plush toys,trinkets,cosmetics,badges,and internationally popular merchandise like Hello Kitty,Little Pony,and Harry Potter branded goods.
文摘An eco-friendly label makes cultural products from recycled bottles and industrial waste to nudge young people towards a green lifestyle.IN a gift store in China’s iconic Palace Museum,also known as the Forbidden City,sustainable cultural and creative products made from recycled materials are a hit with visitors.
文摘The rise of secondhand goods stores,both offline and online,is another way to recycle and reuse,boosting an environment-friendly lifestyle.NEAR the Forbidden City in downtown Beijing,an old subway construction site was turned into a traditional quadrangle courtyard five years ago,becoming a cultural center for local residents to watch movies,attend band performances and go to yoga classes.
基金Project(2021GK1040) supported by the Major Projects of Scientific and Technology Innovation of Hunan Province,ChinaProjects(52375398,52171018) supported by the National Natural Science Foundation of China+1 种基金Project(Kfkt2023-09) supported by the Open Research Fund of State Key Laboratory of Precision Manufacturing for Extreme Service Performance,Central South University,ChinaProject(E2021203059) supported by the Natural Science Foundation of Hebei Province,China。
文摘This study investigates the differences in microstructural control between cryogenic forging combined with pre-deformation(PCF)and traditional thermal forging(TTF)for 7050 aluminum forgings intended for aerospace applications.The PCF process,utilizing cryogenic deformation,significantly refines the coarse grains at the surface of the forgings,resulting in a finer and more uniform microstructure,thereby effectively addressing the issue of surface coarse grains associated with traditional methods.The findings indicate that the PCF process can accumulate higher stored energy,facilitating static recrystallization(SRX)during subsequent heat treatment and enhancing the microstructural uniformity.Utilizing various analytical techniques,including optical microscopy(OM),electron backscatter diffraction(EBSD),and transmission electron microscopy(TEM).This study reveals the superiority of the PCF process in terms of strain accumulation,dislocation density,and grain refinement.In conclusion,this method offers advantages in enhancing the performance and microstructural uniformity of 7050 aluminum forgings,presenting new opportunities for applications in the aluminum forging industry.
基金supported by the National Natural Science Foundation of China under Grant 62462009the Guangxi Science and Technology Projects under Grant GuiKeAD24010047+4 种基金the Guangxi Natural Science Foundation under Grant 2022GXNSFFA035028Research Fund of Guangxi Normal University under Grant 2021JC006the AI+Education Research Project of Guangxi Humanities Society Science Development Research Center under Grant ZXZJ202205the Guangxi New Engineering and Technical Disciplines Research and Practice Projects under Grant XGK2022005the 2021 New Engineering and Technical Disciplines Research and Practice Project of Guangxi Normal University.
文摘The majors accredited by the Engineering Education Accreditation(EEA)reflect the accreditation agency’s recognition of the school’s engineering programs.Excellent accreditation management holds significant importance for the advancement of engineering education programs.However,the traditional engineering education system framework suffers from the opacity of raw education data and the difficulty for accreditation bodies to forensically examine the self-assessment reports.To solve these issues,an EEA framework based on Hyperledger Fabric blockchain technology is proposed in this work.Firstly,all relevant stakeholders and information interactions occur within the blockchain network,ensuring the authenticity of educational data and enhancing the transparency of accreditation processes.Secondly,multiple roles are abstracted into a single organization to optimize the network topology.The original data is stored off-chain,and the hash values of the data are stored on-chain to reduce on-chain storage costs.The experimental results show that the proposed framework has a high throughput and the network latency of writing data to the blockchain is reduced by at least 0.04 s.It effectively improves network performance and security,which provides new insights for EEA management.
基金financially supported by the project for the full-time introduction of national high-level innovative technological talents in Hebei province(No.2024HBQZY CXY039)the Funds for Creative Research Groups of China(No.51921001)the Key R&D Program of Jiangxi Province of China(No.20212BBE51019)。
文摘The<001>orientation of the Goss texture aligned with the rolling direction is the most easily magnetized direction,effectively enhancing the magnetic properties of non-oriented silicon steel.In the present study,an ultra-thin high-silicon sheet of 0.2 mm with a strong Goss texture was successfully fabricated using a two-stage rolling method,achieving superior magnetic properties.The combination of suitable primary rolling reduction and intermediate annealing proved beneficial in promoting the formation of Goss texture.Electron back scatter diffraction(EBSD)was used to characterize micro-shear bands within deformed grains of secondary rolled sheets.Observations revealed that the recrystallized Goss nucleus originated from the Goss substructure of shear bands within deformed{111}<112>grains during the initial stages of recrystallization.The influence of stored energy and grain size on texture evolution was thoroughly investigated using quasi-in situ EBSD during recrystallization.In the initial stages,large deformed{111}<112>and near{111}<112>grains with high stored energy facilitated nucleation and growth of Goss and near-Goss grains within shear bands and reduced grain boundary nucleation.In the later stages,large deformed grains with low stored energy underwent a strain-induced grain boundary migration mechanism to nucleate.During the recrystallization,many recrystallized Goss and near-Goss grains clustered together,with Goss grains rotating towards near-Goss orientation.The resulting annealed ultra-thin 0.2 mm sheet with a pronounced Goss texture exhibited superior magnetic properties.
文摘Along the ancient Tea-Horse Road of thousands of miles between Sichuan and Xizang in Southwest China lies a centuries old courtyard.Commonly called the"Jiang Family Compound"or"Yu Xing Tea Store",this architecture situated in the old downtown area of Yingjing County in Ya'an City,Sichuan Province,was once the residence of the local tea merchants-the Jiang family.
基金financial support for this work provided by the National Natural Science Foundation of China (No.52227901)。
文摘To evaluate the accuracy of rockburst tendency classification in coal-bearing sandstone strata,this study conducted uniaxial compression loading and unloading tests on sandstone samples with four distinct grain sizes.The tests involved loading the samples to 60%,70%,and 80%of their uniaxial compressive strength,followed by unloading and reloading until failure.Key parameters such as the elastic energy index and linear elasticity criteria were derived from these tests.Additionally,rock fragments were collected to calculate their initial ejection kinetic energy,serving as a measure of rockburst tendency.The classification of rockburst tendency was conducted using grading methods based on burst energy index(WET),pre-peak stored elastic energy(PES)and experimental observations.Multi-class classification and regression analyses were applied to machine learning models using experimental data to predict rockburst tendency levels.A comparative analysis of models from two libraries revealed that the Random Forest model achieved the highest accuracy in classification,while the Ada Boost Regressor model excelled in regression predictions.This study highlights that on a laboratory scale,integrating ejection kinetic energy with the unloading ratio,failure load,W_(ET)and PES through machine learning offers a highly accurate and reliable approach for determining rockburst tendency levels.
文摘This research is focused on the singularity analysis for single-gimbal control moment gyros systems （SCMGs） which include two types, with constant speed （CSCMG） or variable speed （VSCMG） rotors. Through angular momentum hypersurfaces of singular states, the passable and impassable singular points are discriminated easily, meanwhile the information about how much the angular momentum workspace as well as the steering capability available is provided directly. It is obvious that the null motions of steering laws are more effective for the five pyramid configuration（FPC） than for the pyramid configuration（PC） from the singular plots. The possible degenerate hyperbolic singular points of the preceding configurations are calculated and the distinctness of them is denoted by the Gaussian curvature. Furthermore, failure problems to steer integrated power and attitude control system （IPACS） are also analyzed. A sufficient condition of choosing configurations of VSCMGs to guarantee the IPACS steering is given. The angular momentum envelops of VSCMGs, in a given energy and a limited range of rotor speeds, are plotted. The connection and distinctness between CSCMGs and VSCMGs are obtained from the point of view of envelops.
