In order to investigate the application performances of the solar greenhouses with new types of backwall(greenhouse W_(2),and greenhouse W_(3))and the ordinary clay brick backwall greenhouse(greenhouse W_(1)),and prov...In order to investigate the application performances of the solar greenhouses with new types of backwall(greenhouse W_(2),and greenhouse W_(3))and the ordinary clay brick backwall greenhouse(greenhouse W_(1)),and provide a theoretical basis for the construction of solar greenhouse in Yangling Demonstration Zone,Shaanxi,China,two greenhouses with different new types of backwall were designed.The backwall of one of them was built with lightweight aggregate concrete block(greenhouse W_(2))and that of the other one was assembled with a row of sand-filled cement pipes(greenhouse W_(3)).The tested greenhouses were constructed in Yangling Demonstration Zone.Based on the data collected on typical sunny and cloudy days,the indoor temperature,inside wall temperature,and the heat flow of the greenhouses with new types of backwall were compared with those detected in the ordinary clay brick backwall solar greenhouse,and the tested results were numerically simulated.According to the comparison of the physiological indicators of tomatoes planted in the greenhouses and the construction costs,the greenhouse type with the best practicability was found.The results indicated that:The average air temperature in greenhouses W_(1),W_(2),and W_(3)and outside was 15.1℃,15.9℃,17.3℃,and−0.4℃ on the night of a sunny day,and the air temperature in W_(3)was the highest.The average air temperature in greenhouses W_(1),W_(2),and W_(3)and outside were 9.5℃,13.3℃,11.0℃,and−5.5℃ on the night of a cloudy day,the air temperature in W_(2)was the highest.In the depth of 0-330 mm from the interface of the backwalls,the walls were obviously affected by the solar radiation,and the temperature changed greatly.The wall temperature on the sunny days exhibited an ascending order of W_(1),W_(2),W_(3),while on the cloudy days was in the ascending order of W_(1),W_(3),W_(2).The wall of W_(3)absorbed the most heat during the daytime and released the most heat at night on the sunny day,while W_(2)exhibited the second most heat absorption during the daytime,however,it exhibited the highest heat release at night on the cloudy day,which were almost equaled to its heat absorption.Tomatoes in W_(3)grew well and exhibited the highest yield,and this greenhouse had the lowest construction costs.Comprehensively considering the physiological indicators of tomatoes and the corresponding construction costs of greenhouses,W_(3)has the best application performance in Yangling Demonstration Zone.展开更多
C60 High Performance Concrete (HPC) was prepared by limiting cement content and adopting compositesuperplasticizer, low-alkalinity expansive agent and high-quality line mixture. The results showed that the performance...C60 High Performance Concrete (HPC) was prepared by limiting cement content and adopting compositesuperplasticizer, low-alkalinity expansive agent and high-quality line mixture. The results showed that the performance of the prepared C60 HPC was excellent. By adopting some advanced construction techniques such as usingsecondary vibration and secondary face compaction, controlling temperature difference and paying special attentionto early curing in the construction process, the prepared C60 HPC had been successfully applied in the monolithicstructure of huge building.展开更多
Cloud computing technology is changing the development and usage patterns of IT infrastructure and applications. Virtualized and distributed systems as well as unified management and scheduling has greatly im proved c...Cloud computing technology is changing the development and usage patterns of IT infrastructure and applications. Virtualized and distributed systems as well as unified management and scheduling has greatly im proved computing and storage. Management has become easier, andOAM costs have been significantly reduced. Cloud desktop technology is develop ing rapidly. With this technology, users can flexibly and dynamically use virtual ma chine resources, companies' efficiency of using and allocating resources is greatly improved, and information security is ensured. In most existing virtual cloud desk top solutions, computing and storage are bound together, and data is stored as im age files. This limits the flexibility and expandability of systems and is insufficient for meetinz customers' requirements in different scenarios.展开更多
Using ground granulated blast furnace slag as the active stuff of high performance concrete (HPC), the C60 SHPC was prepared. The behaviour of the C60 SHPC and its application in the Car Parking Building of Beijing C...Using ground granulated blast furnace slag as the active stuff of high performance concrete (HPC), the C60 SHPC was prepared. The behaviour of the C60 SHPC and its application in the Car Parking Building of Beijing Capital International Airport were described. Also, the manufacturing techniques of reducing cement consumption, lowering hydration heat, minimizing shrinkage cracks and improving durability of the C60 SHPC were discussed. (Author abstract) 3 Refs.展开更多
The waste fiuorgypsum was modified and applied as a cement retarder. The main chemical composition and mineral structure of the waste fluorgypsum were analyzed. Scanning electron microscopy (SEM) and eight-channel m...The waste fiuorgypsum was modified and applied as a cement retarder. The main chemical composition and mineral structure of the waste fluorgypsum were analyzed. Scanning electron microscopy (SEM) and eight-channel micro-calorimeter (TAM Air) were employed to analyze the changes in morphology and study the application performance of the modified fluorgypsum, respectively. Experimental results indicate that the flexural strength and compressive strength of the modified fiuorgypsurn are roughly equal to those of the natural gypsum. The morphology of the crystal of the fiuorgypsum changes from block particle into trimetric short column. The fluorgypsum crystals stagger mutually and improve the strength of the hardened body. The modified fluorgypsum as cement retarder could delay the hydration, reduce the heat of the hydration and make the setting time, volume stability, and the S03 content of the cement meet the national standards. The modified fluorgypsum is a good substitute for the natural gypsum.展开更多
As one of the most rapidly expanding materials,hydrogels have gained increasing attention in a variety of fields due to their biocompatibility,degradability and hydrophilic properties,as well as their remarkable adhes...As one of the most rapidly expanding materials,hydrogels have gained increasing attention in a variety of fields due to their biocompatibility,degradability and hydrophilic properties,as well as their remarkable adhesion and stretchability to adapt to different surfaces.Hydrogels combined with carbon-based materials possess enhanced properties and new functionalities,in particular,conductive hydrogels have become a new area of research in the field of materials science.This review aims to provide a comprehensive overview and up-to-date examination of recent developments in the synthesis,properties and applications of conductive hydrogels incorporating several typical carbon nanoparticles such as carbon nanotubes,graphene,carbon dots and carbon nanofibers.We summarize key techniques and mechanisms for synthesizing various composite hydrogels with exceptional properties,and represented applications such as wearable sensors,temperature sensors,supercapacitors and human-computer interaction reported recently.The mechanical,electrical and sensing properties of carbon nanoparticles conductive hydrogels are thoroughly analyzed to disclose the role of carbon nanoparticles in these hydrogels and key factors in the microstructure.Finally,future development of conductive hydrogels based on carbon nanoparticles is discussed including the challenges and possible solutions in terms of microstructure optimization,mechanical and other properties,and promising applications in wearable electronics and multifunctional materials.展开更多
Application launch performance is of great importance to system platform developers and vendors as it greatly affects the degree of users' satisfaction. The single most effective way to improve application launch per...Application launch performance is of great importance to system platform developers and vendors as it greatly affects the degree of users' satisfaction. The single most effective way to improve application launch performance is to replace a hard disk drive (HDD) with a solid state drive (SSD), which has recently become affordable and popular. A natural question is then whether or not to replace the traditional HDD-aware application launchers with a new SSD-aware optimizer. We address this question by analyzing the inefficiency of the HDD-aware application launchers on SSDs and then proposing a new SSD-aware application prefetching scheme, called the Fast Application STarter (FAST). The key idea of FAST is to overlap the computation (CPU) time with the SSD access (I/O) time during an application launch. FAST is composed of a set of user-level components and system debugging tools provided by Linux OS (operating system). Hence, FAST can be easily deployed in any recent Linux versions without kernel recompilation. We implement FAST on a desktop PC with an SSD running Linux 2.6.32 OS and evaluate it by launching a set of widely-used applications, demonstrating an average of 28% reduction of application launch time as compared to PC without a prefetcher.展开更多
Owing to its thickness-modulated direct energy band gap, relatively strong light–matter interaction, and unique nonlinear optical response at a long wavelength, few-layer black phosphorus, or phosphorene, becomes ver...Owing to its thickness-modulated direct energy band gap, relatively strong light–matter interaction, and unique nonlinear optical response at a long wavelength, few-layer black phosphorus, or phosphorene, becomes very attractive in ultrafast photonics applications. Herein, we synthesized a graphene/phosphorene nano-heterojunction using a liquid phase-stripping method. Tiny lattice distortions in graphene and phosphorene suggest the formation of a nano-heterojunction between graphene and phosphorene nanosheets. In addition, we systematically investigate their nonlinear optical responses at different wavelength regimes. Our experiments indicate that the combined advantages of ultrafast relaxation, broadband response in graphene, and the strong light–matter interaction in phosphorene can be combined together by nano-heterojunction. We have further fabricated two-dimensional(2D) nano-heterojunction based optical saturable absorbers and integrated them into an erbium-doped fiber laser to demonstrate the generation of a stable ultrashort pulse down to 148 fs. Our results indicate that a graphene/phosphorene nano-heterojunction can operate as a promising saturable absorber for ultrafast laser systems with ultrahigh pulse energy and ultranarrow pulse duration. We believe this work opens up a new approach to designing 2D heterointerfaces for applications in ultrafast photonics and other research.The fabrication of a 2D nano-heterojunction assembled from stacking different 2D materials, via this facile and scalable growth approach, paves the way for the formation and tuning of new 2D materials with desirable photonic properties and applications.展开更多
Computer based automation and control systems are becoming increasingly important in smart sustainable buildings,often referred to as automated buildings(ABs),in order to automatically control,optimize and supervise a...Computer based automation and control systems are becoming increasingly important in smart sustainable buildings,often referred to as automated buildings(ABs),in order to automatically control,optimize and supervise a wide range of building performance applications over a network while minimizing energy consumption and associated green house gas emission.This technology generally refers to building automation and control systems(BACS)architecture.Instead of costly and time-consuming experiments,this paper focuses on development and design of a distributed dynamic simulation environment with the capability to represent BACS architecture in simulation by run-time coupling two or more different software tools over a network.This involves using distributed dynamic simulations as means to analyze the performance and enhance networked real-time control systems in ABs and improve the functions of real BACS technology.The application and capability of this new dynamic simulation environment are demonstrated by an experimental design,in this paper.展开更多
With the rise of online applications such as machine learning,stream processing,and interactive data-intensive applications in shared clusters,container cluster scheduling in data centers is facing new challenges.In o...With the rise of online applications such as machine learning,stream processing,and interactive data-intensive applications in shared clusters,container cluster scheduling in data centers is facing new challenges.In order to solve the problem that application performance and economic cost cannot be balanced in a container cluster deploying a hybrid application,this paper proposes a container cluster scheduling strategy based on delay decision under multi-dimensional constraints.Formal language-based application placement constraints were introduced,and a task reorder model was established based on delayed decision-making.The experiments show that this strategy improves application performance and cluster utilization.展开更多
基金This research was financially supported by the Shaanxi Provincial Key Research and Development Program(Grant No.2019TSLNY01-03)the National Natural Science Foundation of China(Grant No.31901420)the Young Scientist Promotion Project of Jiangsu Science and Technology Association(Grant No.2020-2-46).
文摘In order to investigate the application performances of the solar greenhouses with new types of backwall(greenhouse W_(2),and greenhouse W_(3))and the ordinary clay brick backwall greenhouse(greenhouse W_(1)),and provide a theoretical basis for the construction of solar greenhouse in Yangling Demonstration Zone,Shaanxi,China,two greenhouses with different new types of backwall were designed.The backwall of one of them was built with lightweight aggregate concrete block(greenhouse W_(2))and that of the other one was assembled with a row of sand-filled cement pipes(greenhouse W_(3)).The tested greenhouses were constructed in Yangling Demonstration Zone.Based on the data collected on typical sunny and cloudy days,the indoor temperature,inside wall temperature,and the heat flow of the greenhouses with new types of backwall were compared with those detected in the ordinary clay brick backwall solar greenhouse,and the tested results were numerically simulated.According to the comparison of the physiological indicators of tomatoes planted in the greenhouses and the construction costs,the greenhouse type with the best practicability was found.The results indicated that:The average air temperature in greenhouses W_(1),W_(2),and W_(3)and outside was 15.1℃,15.9℃,17.3℃,and−0.4℃ on the night of a sunny day,and the air temperature in W_(3)was the highest.The average air temperature in greenhouses W_(1),W_(2),and W_(3)and outside were 9.5℃,13.3℃,11.0℃,and−5.5℃ on the night of a cloudy day,the air temperature in W_(2)was the highest.In the depth of 0-330 mm from the interface of the backwalls,the walls were obviously affected by the solar radiation,and the temperature changed greatly.The wall temperature on the sunny days exhibited an ascending order of W_(1),W_(2),W_(3),while on the cloudy days was in the ascending order of W_(1),W_(3),W_(2).The wall of W_(3)absorbed the most heat during the daytime and released the most heat at night on the sunny day,while W_(2)exhibited the second most heat absorption during the daytime,however,it exhibited the highest heat release at night on the cloudy day,which were almost equaled to its heat absorption.Tomatoes in W_(3)grew well and exhibited the highest yield,and this greenhouse had the lowest construction costs.Comprehensively considering the physiological indicators of tomatoes and the corresponding construction costs of greenhouses,W_(3)has the best application performance in Yangling Demonstration Zone.
文摘C60 High Performance Concrete (HPC) was prepared by limiting cement content and adopting compositesuperplasticizer, low-alkalinity expansive agent and high-quality line mixture. The results showed that the performance of the prepared C60 HPC was excellent. By adopting some advanced construction techniques such as usingsecondary vibration and secondary face compaction, controlling temperature difference and paying special attentionto early curing in the construction process, the prepared C60 HPC had been successfully applied in the monolithicstructure of huge building.
文摘Cloud computing technology is changing the development and usage patterns of IT infrastructure and applications. Virtualized and distributed systems as well as unified management and scheduling has greatly im proved computing and storage. Management has become easier, andOAM costs have been significantly reduced. Cloud desktop technology is develop ing rapidly. With this technology, users can flexibly and dynamically use virtual ma chine resources, companies' efficiency of using and allocating resources is greatly improved, and information security is ensured. In most existing virtual cloud desk top solutions, computing and storage are bound together, and data is stored as im age files. This limits the flexibility and expandability of systems and is insufficient for meetinz customers' requirements in different scenarios.
文摘Using ground granulated blast furnace slag as the active stuff of high performance concrete (HPC), the C60 SHPC was prepared. The behaviour of the C60 SHPC and its application in the Car Parking Building of Beijing Capital International Airport were described. Also, the manufacturing techniques of reducing cement consumption, lowering hydration heat, minimizing shrinkage cracks and improving durability of the C60 SHPC were discussed. (Author abstract) 3 Refs.
基金Project(21003014) supported by the National Natural Science Foundation of ChinaProject(2010FJ3167) supported by the Hunan Provincial Science and Technology Program,ChinaProject(K1104029-11) supported by the Changsha IT Project
文摘The waste fiuorgypsum was modified and applied as a cement retarder. The main chemical composition and mineral structure of the waste fluorgypsum were analyzed. Scanning electron microscopy (SEM) and eight-channel micro-calorimeter (TAM Air) were employed to analyze the changes in morphology and study the application performance of the modified fluorgypsum, respectively. Experimental results indicate that the flexural strength and compressive strength of the modified fiuorgypsurn are roughly equal to those of the natural gypsum. The morphology of the crystal of the fiuorgypsum changes from block particle into trimetric short column. The fluorgypsum crystals stagger mutually and improve the strength of the hardened body. The modified fluorgypsum as cement retarder could delay the hydration, reduce the heat of the hydration and make the setting time, volume stability, and the S03 content of the cement meet the national standards. The modified fluorgypsum is a good substitute for the natural gypsum.
基金This work was supported by the National Key R&D Program of China(grant No.2020YFA0210702)National Natural Science Foundation of China(grant No.51872267)+2 种基金the Natural Science Foundation of Henan Province,China(grant No.202300410371)Program for Science&Technology Innovation Talents in Universities of Henan Province(grant No.21HASTIT017)Foundation of Henan Province Educational Committee(grant No.23A140005).
文摘As one of the most rapidly expanding materials,hydrogels have gained increasing attention in a variety of fields due to their biocompatibility,degradability and hydrophilic properties,as well as their remarkable adhesion and stretchability to adapt to different surfaces.Hydrogels combined with carbon-based materials possess enhanced properties and new functionalities,in particular,conductive hydrogels have become a new area of research in the field of materials science.This review aims to provide a comprehensive overview and up-to-date examination of recent developments in the synthesis,properties and applications of conductive hydrogels incorporating several typical carbon nanoparticles such as carbon nanotubes,graphene,carbon dots and carbon nanofibers.We summarize key techniques and mechanisms for synthesizing various composite hydrogels with exceptional properties,and represented applications such as wearable sensors,temperature sensors,supercapacitors and human-computer interaction reported recently.The mechanical,electrical and sensing properties of carbon nanoparticles conductive hydrogels are thoroughly analyzed to disclose the role of carbon nanoparticles in these hydrogels and key factors in the microstructure.Finally,future development of conductive hydrogels based on carbon nanoparticles is discussed including the challenges and possible solutions in terms of microstructure optimization,mechanical and other properties,and promising applications in wearable electronics and multifunctional materials.
基金supported by RP-Grant 2010 of Ewha Womans University
文摘Application launch performance is of great importance to system platform developers and vendors as it greatly affects the degree of users' satisfaction. The single most effective way to improve application launch performance is to replace a hard disk drive (HDD) with a solid state drive (SSD), which has recently become affordable and popular. A natural question is then whether or not to replace the traditional HDD-aware application launchers with a new SSD-aware optimizer. We address this question by analyzing the inefficiency of the HDD-aware application launchers on SSDs and then proposing a new SSD-aware application prefetching scheme, called the Fast Application STarter (FAST). The key idea of FAST is to overlap the computation (CPU) time with the SSD access (I/O) time during an application launch. FAST is composed of a set of user-level components and system debugging tools provided by Linux OS (operating system). Hence, FAST can be easily deployed in any recent Linux versions without kernel recompilation. We implement FAST on a desktop PC with an SSD running Linux 2.6.32 OS and evaluate it by launching a set of widely-used applications, demonstrating an average of 28% reduction of application launch time as compared to PC without a prefetcher.
基金National Natural Science Foundation of China(NSFC)(61435010,61575089)Shenzhen-Hong Kong Innovation Cooperation Project(SGLH20150205162842428)+3 种基金Science and Technology Innovation Commission of Shenzhen JCYJ20150625103619275,JCYJ20170302153540973,JCYJ20170412111625378,KQTD2015032416270385)Science and Technology Planning Project of Guangdong Province(2016B050501005)Educational Commission ofGuangdong Province 2016KCXTD006)Student Innovation Development Fund of Shenzhen University(PIDFPZR2017002)
文摘Owing to its thickness-modulated direct energy band gap, relatively strong light–matter interaction, and unique nonlinear optical response at a long wavelength, few-layer black phosphorus, or phosphorene, becomes very attractive in ultrafast photonics applications. Herein, we synthesized a graphene/phosphorene nano-heterojunction using a liquid phase-stripping method. Tiny lattice distortions in graphene and phosphorene suggest the formation of a nano-heterojunction between graphene and phosphorene nanosheets. In addition, we systematically investigate their nonlinear optical responses at different wavelength regimes. Our experiments indicate that the combined advantages of ultrafast relaxation, broadband response in graphene, and the strong light–matter interaction in phosphorene can be combined together by nano-heterojunction. We have further fabricated two-dimensional(2D) nano-heterojunction based optical saturable absorbers and integrated them into an erbium-doped fiber laser to demonstrate the generation of a stable ultrashort pulse down to 148 fs. Our results indicate that a graphene/phosphorene nano-heterojunction can operate as a promising saturable absorber for ultrafast laser systems with ultrahigh pulse energy and ultranarrow pulse duration. We believe this work opens up a new approach to designing 2D heterointerfaces for applications in ultrafast photonics and other research.The fabrication of a 2D nano-heterojunction assembled from stacking different 2D materials, via this facile and scalable growth approach, paves the way for the formation and tuning of new 2D materials with desirable photonic properties and applications.
文摘Computer based automation and control systems are becoming increasingly important in smart sustainable buildings,often referred to as automated buildings(ABs),in order to automatically control,optimize and supervise a wide range of building performance applications over a network while minimizing energy consumption and associated green house gas emission.This technology generally refers to building automation and control systems(BACS)architecture.Instead of costly and time-consuming experiments,this paper focuses on development and design of a distributed dynamic simulation environment with the capability to represent BACS architecture in simulation by run-time coupling two or more different software tools over a network.This involves using distributed dynamic simulations as means to analyze the performance and enhance networked real-time control systems in ABs and improve the functions of real BACS technology.The application and capability of this new dynamic simulation environment are demonstrated by an experimental design,in this paper.
基金the Natural Science Foundation of China(No.61762008)the Guangxi Natural Science Foundation Project(No.2017GXNSFAA198141)the National Key Research and Development Project of China(No.2018YFB1404404).
文摘With the rise of online applications such as machine learning,stream processing,and interactive data-intensive applications in shared clusters,container cluster scheduling in data centers is facing new challenges.In order to solve the problem that application performance and economic cost cannot be balanced in a container cluster deploying a hybrid application,this paper proposes a container cluster scheduling strategy based on delay decision under multi-dimensional constraints.Formal language-based application placement constraints were introduced,and a task reorder model was established based on delayed decision-making.The experiments show that this strategy improves application performance and cluster utilization.