Yolk‐shell structured nanoparticles are of immense scientific and technological interests because of their unique architecture and myriad of applications.This review summarizes recent progresses in the use of yolk‐s...Yolk‐shell structured nanoparticles are of immense scientific and technological interests because of their unique architecture and myriad of applications.This review summarizes recent progresses in the use of yolk‐shell structured nanoparticles as nanoreactors for various chemical reactions.A very brief overview of synthetic strategies is provided with emphasis on recent research progress in the last five years.Catalytic applications of these yolk‐shell structured nanoreactors are then discussed by covering photocatalysis,methane reforming and electrochemical conversion.The state of the art research and perspective in future development are also highlighted.展开更多
A highly intense green-emitting phosphor of Eu2+-doped Sr4Al14O25 (SAE:Eu2+) was synthesized by a solid state reaction. In this study, XRD, PL/PLE, QE, thermal stability and LED package tests are systematically c...A highly intense green-emitting phosphor of Eu2+-doped Sr4Al14O25 (SAE:Eu2+) was synthesized by a solid state reaction. In this study, XRD, PL/PLE, QE, thermal stability and LED package tests are systematically carried out and investigated. The optimized-composition of (Sro 92Eu0.08)4Al14025 exhibited a green emission peak at 497 nm under excitation wavelength of 400 nm, giving the chromaticity coordinates of (0.14, 0.35) with excellent quantum efficiency (98%) compared to those of other green-commodities, such as Ba2SiO4:Eu2+ (90%) and BaMgAl10O17:EU2+, Mn2+ (92%). The results demonstrated that SAE:Eu2+ could be a potential candidate as the NUV-pumping phosphor for applications in light-emitting diodes (LEDs).展开更多
Building-integrated photovoltaic(BIPV) is an important application way of solar photovoltaic power. The electric vehicle(EV) charging and parking shed of BIPV is the regeneration energy intellectual integration demons...Building-integrated photovoltaic(BIPV) is an important application way of solar photovoltaic power. The electric vehicle(EV) charging and parking shed of BIPV is the regeneration energy intellectual integration demonstration application system collection of photovoltaic(PV) grid power,PV off- grid power,EV charging and parking shed,and any part of the functions and their combination will be engaged in practical application on demand. The paper describes the PV shed system structure and design in detail with the present of its actual photos. The shed is 50 m long and 5.5 m wide and capable of parking 18 cars. Under the control of system intellectual controller,the power produced by PV from sunlight will charge the parking EV car prior to charging the storage battery,charging the storage battery prior to grid power,grid power at last,and charge the EV by utility grid when it is a cloudy or rainy day.展开更多
There is a growing awareness among industry players of reaping the benefits of mobile-cloud convergence by extending today's unmodified cloud to a decentralized two-level cloud-cloudlet architecture based on emerg...There is a growing awareness among industry players of reaping the benefits of mobile-cloud convergence by extending today's unmodified cloud to a decentralized two-level cloud-cloudlet architecture based on emerging mobile-edge computing(MEC) capabilities. In light of future 5G mobile networks moving toward decentralization based on cloudlets, intelligent base stations, and MEC, the inherent distributed processing and storage capabilities of radio-and-fiber(R&F) networks may be exploited for new applications, e.g., cognitive assistance, augmented reality, or cloud robotics. In this paper, we first revisit fiber-wireless(Fi Wi) networks in the context of conventional clouds and emerging cloudlets, thereby highlighting the limitations of conventional radio-overfiber(Ro F) networks such as China Mobile's centralized cloud radio access network(C-RAN) to meet the aforementioned trends. Furthermore, we pay close attention to the specific design challenges of data center networks and revisit our switchless arrayedwaveguide grating(AWG) based network with efficient support of east-west flows and enhanced scalability.展开更多
In the 21th century, one of the biggest problems that the world faces is energy provision. Today, the way that most countries use for energy production is not clean and continuous. The most obvious proof for that is t...In the 21th century, one of the biggest problems that the world faces is energy provision. Today, the way that most countries use for energy production is not clean and continuous. The most obvious proof for that is the change in the climate. The amount of CO2 (carbon dioxide) that is caused by fossil fuel burning increases day by day and this situation creates the greenhouse effect and change in the climate. The sun is one of the best solutions to this problem. It is not only clean and continuous, but also available anywhere, anytime. However, the efficiency of a photovoltaic system is directly related to the amount of solar energy acquired by the system which means that, it is necessary to follow the sun to have a high efficient system. There are two types of trackers that follow the sun and there are several ways to build them. In this paper, solar tracker designs are examined and a new dual axis solar tracker design is given.展开更多
The solar energy conversion system is very interesting alternative on supplement the electric system generation, due to the persistent cost reduction of the overall system and cleaner power generation. To obtain a sta...The solar energy conversion system is very interesting alternative on supplement the electric system generation, due to the persistent cost reduction of the overall system and cleaner power generation. To obtain a stable voltage from an input supply (PV cells) that is higher and lower than the output, a high efficiency and minimum ripple DC-DC converter required in the system for residential power production. Buck-boost converters make it possible to efficiently convert a DC voltage to either a lower or higher voltages. Buck-boost converters are especially useful for PV maximum power tracking purposes, where the objective is to draw maximum possible power from solar panels at all times, regardless of the load. This paper analyzes and describes step by step the process of designing, and simulation of high efficiency low ripple voltage buck-boost DC-DC converter for the photovoltaic solar conversion system applicable to a (typical) single family home based on battery-based systems. The input voltage can typically change from (20 V) initially, down to (5 V), and provide a regulated voltage within the range of the battery (12 V). PLECS simulation results provide strong evidences about the high efficiency, minimum ripple voltage, high accuracy, and the usefulness of the system of the proposed converter when applied to either residential or solar home applications.展开更多
The electrical new technology is a new frontier science.This kind of technology, with the development and progress of society, makes the continuous development and innovation.It is the future development trend of elec...The electrical new technology is a new frontier science.This kind of technology, with the development and progress of society, makes the continuous development and innovation.It is the future development trend of electrical engineering system,which plays a very important role in technological innovation.The principle and theoretical support for the development of electrical new technology includes Bio- electro magnetics, plasma physics, electromagnetic fluid mechanics and gas discharge physics etc.In addition, under the application of permanent magnetic materials and other new materials, the electrical new technology and obtained further development also promote the development and application of electronic power supply, strong magnetic field technology, solar photovoltaic power generation, and superconducting power technology.This paper mainly analyzes the application of electrical new technology in electromechanical integration.展开更多
The laser equipment is one of the key equipment in the production line of the solar energy. In this article, the author de-scribes the application of the laser equipment in the production line of the amorphous silicon...The laser equipment is one of the key equipment in the production line of the solar energy. In this article, the author de-scribes the application of the laser equipment in the production line of the amorphous silicon film solar cells, and points out that the stable and exactitude is the key direction of the future development of the laser scribing equipment.展开更多
The high-performance CPC-trough (compound parabolic concentrator) collector has been developed for the utility scale generation of low temperature solar steam and hot water for low temperature process heat applicati...The high-performance CPC-trough (compound parabolic concentrator) collector has been developed for the utility scale generation of low temperature solar steam and hot water for low temperature process heat applications including solar air conditioning. With an optical concentration of 7.5:1, operating temperatures over 130 ℃ may be reached. This novel design has included a FEM (finite element modeling) validation and is compatible with the standard reflectors and evacuated tubes in the market. The peak efficiencies of 35% with unshielded and more than 45% with evacuated tube receivers were obtained. This CPC-trough collector requires intermittent tracking, i.e., tilt adjustment is only once in a week for more than eight hours collection in summer and six to seven hours in winter seasons.展开更多
Uniquely structured rutile TiO2 microspheres with exposed nano-acicular single crystals have been successfully synthesized via a facile hydrothermal method. After calcination at 450 ℃ for 2 h, the futile TiO2 microsp...Uniquely structured rutile TiO2 microspheres with exposed nano-acicular single crystals have been successfully synthesized via a facile hydrothermal method. After calcination at 450 ℃ for 2 h, the futile TiO2 microspheres with a high surface area of 132 m2/g have been utilized as a light harvesting enhancement material for dye-sensitized solar cells (DSSCs). The resultant DSSCs exhibit an overall light conversion efficiency of 8.41% for TiO2 photoanodes made of futile TiO2 microspheres and anatase TiO, nanoparticles (mass ratio of 1:1), significantly higher than that of pure anatase TiO2 nanoparticle photoanodes of similar thickness (6.74%). Such a significant improvement in performance can be attributed to the enhanced light harvesting capability and synergetic electron transfer effect. This is because the photoanodes made of futile TiO2 microsphere possess high refractive index which improves the light utilisation efficiency, suitable microsphere core sizes (450-800 nm) to effectively scatter visible light, high surface area for dye loading, and synergetic electron transfer effects between nanoparticulate anatase and nano-acicular futile single crystals phases giving high electron collection efficiency.展开更多
Titanium dioxide (TiO2) thin films were grown onto Indium tin oxide (ITO) glass under atmospheric pressure by chemical va- por deposition (AP-MOCVD) using titanium tetraisopropoxide astitanium precursor. The as-...Titanium dioxide (TiO2) thin films were grown onto Indium tin oxide (ITO) glass under atmospheric pressure by chemical va- por deposition (AP-MOCVD) using titanium tetraisopropoxide astitanium precursor. The as-prepared TiOe/ITO films were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and photoelectrochemical measurements. Their photocatalytic (PC) and photoelec- trocatalytic (PEC) activities were evaluated based on the results of methyl orange dye (MO) degradation experiments in aque- ous solution. The difference between the front side (EE, electrolyte/electrode interface) and the back side (SE, sub- strate/electrode interface) illumination was evaluated in both photocurrent and MO degradation experiments. The effect of the film thickness on degradation rate by PEC under the two illumination directions was also studied. Stability of TiO2/ITO film electrode was investigated in repetitive degradation experiments. Overall, the TiO2/ITO film with thickness ranging from 321 to1440 nm deposited by MOCVD method is an effective photoelectrode for MO degradation under SE illumination in PEC reaction system.展开更多
Electrochromism refers to the persistent and reversible change of optical properties by an applied voltage pulse.Electrochromic(EC)devices have been extensively studied because of their commercial applications in smar...Electrochromism refers to the persistent and reversible change of optical properties by an applied voltage pulse.Electrochromic(EC)devices have been extensively studied because of their commercial applications in smart windows of green buildings,display devices and thermal control of equipments.In this review,a basic EC device design is presented based on useful oxides and solid-state electrolytes.We focus on the state-of-the-art research activities related to the structures of tungsten oxide(WO_3)and nickel oxide(NiO),summarizing the strategies to improve their EC performances and further applications of devices.展开更多
Research interest in ZnO nanostructures derives from their excellent luminescent properties and availability of low cost fabricating and processing,which hold promise for the development of electronic and optoelectron...Research interest in ZnO nanostructures derives from their excellent luminescent properties and availability of low cost fabricating and processing,which hold promise for the development of electronic and optoelectronic nanodevices.In this review,we focus on the progress in synthesis,properties and nanodevices of ZnO nanorod(NR)arrays and nanotetrapods(NTPs).Recent work done by the authors are also presented.After a brief introduction to the controlled fabrication methods for the highly-ordered ZnO NR arrays and NTPs,we present some aspects of the fundamental properties,especially optical performance,of ZnO NRs/NTPs.Then,we provide an overview of the applications to functional nanodevices based on individual NR and NTP of ZnO.It is demonstrated that different morphologies of ZnO nanostructures have salient effects on their properties and applications.Although much progress has been achieved in the fundamental and applied investigations of ZnO NRs/NTPs over the past decade,many obstacles still remain,hampering further development in this field.Finally,some longstanding problems that warrant further investigation are addressed.展开更多
文摘Yolk‐shell structured nanoparticles are of immense scientific and technological interests because of their unique architecture and myriad of applications.This review summarizes recent progresses in the use of yolk‐shell structured nanoparticles as nanoreactors for various chemical reactions.A very brief overview of synthetic strategies is provided with emphasis on recent research progress in the last five years.Catalytic applications of these yolk‐shell structured nanoreactors are then discussed by covering photocatalysis,methane reforming and electrochemical conversion.The state of the art research and perspective in future development are also highlighted.
文摘A highly intense green-emitting phosphor of Eu2+-doped Sr4Al14O25 (SAE:Eu2+) was synthesized by a solid state reaction. In this study, XRD, PL/PLE, QE, thermal stability and LED package tests are systematically carried out and investigated. The optimized-composition of (Sro 92Eu0.08)4Al14025 exhibited a green emission peak at 497 nm under excitation wavelength of 400 nm, giving the chromaticity coordinates of (0.14, 0.35) with excellent quantum efficiency (98%) compared to those of other green-commodities, such as Ba2SiO4:Eu2+ (90%) and BaMgAl10O17:EU2+, Mn2+ (92%). The results demonstrated that SAE:Eu2+ could be a potential candidate as the NUV-pumping phosphor for applications in light-emitting diodes (LEDs).
基金China Southern Power Grid New Energy Experimental Project(No.03HC0901578)
文摘Building-integrated photovoltaic(BIPV) is an important application way of solar photovoltaic power. The electric vehicle(EV) charging and parking shed of BIPV is the regeneration energy intellectual integration demonstration application system collection of photovoltaic(PV) grid power,PV off- grid power,EV charging and parking shed,and any part of the functions and their combination will be engaged in practical application on demand. The paper describes the PV shed system structure and design in detail with the present of its actual photos. The shed is 50 m long and 5.5 m wide and capable of parking 18 cars. Under the control of system intellectual controller,the power produced by PV from sunlight will charge the parking EV car prior to charging the storage battery,charging the storage battery prior to grid power,grid power at last,and charge the EV by utility grid when it is a cloudy or rainy day.
文摘There is a growing awareness among industry players of reaping the benefits of mobile-cloud convergence by extending today's unmodified cloud to a decentralized two-level cloud-cloudlet architecture based on emerging mobile-edge computing(MEC) capabilities. In light of future 5G mobile networks moving toward decentralization based on cloudlets, intelligent base stations, and MEC, the inherent distributed processing and storage capabilities of radio-and-fiber(R&F) networks may be exploited for new applications, e.g., cognitive assistance, augmented reality, or cloud robotics. In this paper, we first revisit fiber-wireless(Fi Wi) networks in the context of conventional clouds and emerging cloudlets, thereby highlighting the limitations of conventional radio-overfiber(Ro F) networks such as China Mobile's centralized cloud radio access network(C-RAN) to meet the aforementioned trends. Furthermore, we pay close attention to the specific design challenges of data center networks and revisit our switchless arrayedwaveguide grating(AWG) based network with efficient support of east-west flows and enhanced scalability.
文摘In the 21th century, one of the biggest problems that the world faces is energy provision. Today, the way that most countries use for energy production is not clean and continuous. The most obvious proof for that is the change in the climate. The amount of CO2 (carbon dioxide) that is caused by fossil fuel burning increases day by day and this situation creates the greenhouse effect and change in the climate. The sun is one of the best solutions to this problem. It is not only clean and continuous, but also available anywhere, anytime. However, the efficiency of a photovoltaic system is directly related to the amount of solar energy acquired by the system which means that, it is necessary to follow the sun to have a high efficient system. There are two types of trackers that follow the sun and there are several ways to build them. In this paper, solar tracker designs are examined and a new dual axis solar tracker design is given.
文摘The solar energy conversion system is very interesting alternative on supplement the electric system generation, due to the persistent cost reduction of the overall system and cleaner power generation. To obtain a stable voltage from an input supply (PV cells) that is higher and lower than the output, a high efficiency and minimum ripple DC-DC converter required in the system for residential power production. Buck-boost converters make it possible to efficiently convert a DC voltage to either a lower or higher voltages. Buck-boost converters are especially useful for PV maximum power tracking purposes, where the objective is to draw maximum possible power from solar panels at all times, regardless of the load. This paper analyzes and describes step by step the process of designing, and simulation of high efficiency low ripple voltage buck-boost DC-DC converter for the photovoltaic solar conversion system applicable to a (typical) single family home based on battery-based systems. The input voltage can typically change from (20 V) initially, down to (5 V), and provide a regulated voltage within the range of the battery (12 V). PLECS simulation results provide strong evidences about the high efficiency, minimum ripple voltage, high accuracy, and the usefulness of the system of the proposed converter when applied to either residential or solar home applications.
文摘The electrical new technology is a new frontier science.This kind of technology, with the development and progress of society, makes the continuous development and innovation.It is the future development trend of electrical engineering system,which plays a very important role in technological innovation.The principle and theoretical support for the development of electrical new technology includes Bio- electro magnetics, plasma physics, electromagnetic fluid mechanics and gas discharge physics etc.In addition, under the application of permanent magnetic materials and other new materials, the electrical new technology and obtained further development also promote the development and application of electronic power supply, strong magnetic field technology, solar photovoltaic power generation, and superconducting power technology.This paper mainly analyzes the application of electrical new technology in electromechanical integration.
文摘The laser equipment is one of the key equipment in the production line of the solar energy. In this article, the author de-scribes the application of the laser equipment in the production line of the amorphous silicon film solar cells, and points out that the stable and exactitude is the key direction of the future development of the laser scribing equipment.
文摘The high-performance CPC-trough (compound parabolic concentrator) collector has been developed for the utility scale generation of low temperature solar steam and hot water for low temperature process heat applications including solar air conditioning. With an optical concentration of 7.5:1, operating temperatures over 130 ℃ may be reached. This novel design has included a FEM (finite element modeling) validation and is compatible with the standard reflectors and evacuated tubes in the market. The peak efficiencies of 35% with unshielded and more than 45% with evacuated tube receivers were obtained. This CPC-trough collector requires intermittent tracking, i.e., tilt adjustment is only once in a week for more than eight hours collection in summer and six to seven hours in winter seasons.
文摘Uniquely structured rutile TiO2 microspheres with exposed nano-acicular single crystals have been successfully synthesized via a facile hydrothermal method. After calcination at 450 ℃ for 2 h, the futile TiO2 microspheres with a high surface area of 132 m2/g have been utilized as a light harvesting enhancement material for dye-sensitized solar cells (DSSCs). The resultant DSSCs exhibit an overall light conversion efficiency of 8.41% for TiO2 photoanodes made of futile TiO2 microspheres and anatase TiO, nanoparticles (mass ratio of 1:1), significantly higher than that of pure anatase TiO2 nanoparticle photoanodes of similar thickness (6.74%). Such a significant improvement in performance can be attributed to the enhanced light harvesting capability and synergetic electron transfer effect. This is because the photoanodes made of futile TiO2 microsphere possess high refractive index which improves the light utilisation efficiency, suitable microsphere core sizes (450-800 nm) to effectively scatter visible light, high surface area for dye loading, and synergetic electron transfer effects between nanoparticulate anatase and nano-acicular futile single crystals phases giving high electron collection efficiency.
基金financial support to this study by the National Natural Science Foundation of China (21076188, 20836008, 20976158, 20990221and 21076189)the Key Innovation Team for Science and Technology of Zhejiang Province of China (2009R50047)
文摘Titanium dioxide (TiO2) thin films were grown onto Indium tin oxide (ITO) glass under atmospheric pressure by chemical va- por deposition (AP-MOCVD) using titanium tetraisopropoxide astitanium precursor. The as-prepared TiOe/ITO films were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and photoelectrochemical measurements. Their photocatalytic (PC) and photoelec- trocatalytic (PEC) activities were evaluated based on the results of methyl orange dye (MO) degradation experiments in aque- ous solution. The difference between the front side (EE, electrolyte/electrode interface) and the back side (SE, sub- strate/electrode interface) illumination was evaluated in both photocurrent and MO degradation experiments. The effect of the film thickness on degradation rate by PEC under the two illumination directions was also studied. Stability of TiO2/ITO film electrode was investigated in repetitive degradation experiments. Overall, the TiO2/ITO film with thickness ranging from 321 to1440 nm deposited by MOCVD method is an effective photoelectrode for MO degradation under SE illumination in PEC reaction system.
基金Program for Innovative Research Team in University of Ministry of Education of China (IRT13037)
文摘Electrochromism refers to the persistent and reversible change of optical properties by an applied voltage pulse.Electrochromic(EC)devices have been extensively studied because of their commercial applications in smart windows of green buildings,display devices and thermal control of equipments.In this review,a basic EC device design is presented based on useful oxides and solid-state electrolytes.We focus on the state-of-the-art research activities related to the structures of tungsten oxide(WO_3)and nickel oxide(NiO),summarizing the strategies to improve their EC performances and further applications of devices.
基金supported by the National Natural Science Foundation of China(Grant Nos.10334060,90406022,90921012,50702002,50772055,50871060 and 60807016)Ministry of Science and Technology of China(Grant Nos.2005CB623602,2006CB932401,2006AA03Z350,2010CB832905 and 2012CB932302)
文摘Research interest in ZnO nanostructures derives from their excellent luminescent properties and availability of low cost fabricating and processing,which hold promise for the development of electronic and optoelectronic nanodevices.In this review,we focus on the progress in synthesis,properties and nanodevices of ZnO nanorod(NR)arrays and nanotetrapods(NTPs).Recent work done by the authors are also presented.After a brief introduction to the controlled fabrication methods for the highly-ordered ZnO NR arrays and NTPs,we present some aspects of the fundamental properties,especially optical performance,of ZnO NRs/NTPs.Then,we provide an overview of the applications to functional nanodevices based on individual NR and NTP of ZnO.It is demonstrated that different morphologies of ZnO nanostructures have salient effects on their properties and applications.Although much progress has been achieved in the fundamental and applied investigations of ZnO NRs/NTPs over the past decade,many obstacles still remain,hampering further development in this field.Finally,some longstanding problems that warrant further investigation are addressed.