The ever-increasing environmental/energy crisis as well as the rapid upgrading of mobile devices had stimulated intensive research attention on promising alternative energy storage and conversion devices.Among these d...The ever-increasing environmental/energy crisis as well as the rapid upgrading of mobile devices had stimulated intensive research attention on promising alternative energy storage and conversion devices.Among these devices,alkali metal ion batteries,such as lithium-ion batteries(LIBs) had attracted increasing research attention due to its several advantages including,environmental friendliness,high power density,long cycle life and excellent reversibility.It had been widely used in consumer electronics,electric vehicles,and large power grids et ac.Silicon-based(silicon and their oxides,carbides) anodes had been widely studied.Its several advantages including low cost,high theoretical capacity,natural abundance,and environmental friendliness,which shows great potential as anodes of LIBs.In this review,we summarized the recently progress in the synthetic method of silicon matrix composites.The empirical method for prelithiation of silicon-based materials were also provided.Further,we also reviewed some novel characterization methods.Finally,the new design,preparation methods and properties of these nano materials were reviewed and compared.We hoped that this review can provide a general overview of recent progress and we briefly highlighted the current challenges and prospects,and will clarify the future trend of silicon anode LIBs research.展开更多
A heuristic theoretical optimal routing algorithm （TORA） is presented to achieve the data-gathering structure of location-aided quality of service （QoS） in wireless sensor networks （WSNs）. The construction of TO...A heuristic theoretical optimal routing algorithm （TORA） is presented to achieve the data-gathering structure of location-aided quality of service （QoS） in wireless sensor networks （WSNs）. The construction of TORA is based on a kind of swarm intelligence （SI） mechanism, i. e. , ant colony optimization. Firstly, the ener- gy-efficient weight is designed based on flow distribution to divide WSNs into different functional regions, so the routing selection can self-adapt asymmetric power configurations with lower latency. Then, the designs of the novel heuristic factor and the pheromone updating rule can endow ant-like agents with the ability of detecting the local networks energy status and approaching the theoretical optimal tree, thus improving the adaptability and en- ergy-efficiency in route building. Simulation results show that compared with some classic routing algorithms, TORA can further minimize the total communication energy cost and enhance the QoS performance with low-de- lay effect under the data-gathering condition.展开更多
The influence of high energy ball milling on Al 30Si powder and ceramic particulate SiC was studied by means of SEM, XRD and DSC. The results show that Al 30Si powder and their microstructure are obviously refined aft...The influence of high energy ball milling on Al 30Si powder and ceramic particulate SiC was studied by means of SEM, XRD and DSC. The results show that Al 30Si powder and their microstructure are obviously refined after high energy ball milling process. The alloy powder and SiC p stick closely to each other without interfacial reaction. DSC results detect no reaction but relaxation of the samples. So high energy ball milling can be used as an effective method for ceramic particulate pre treatment in the fabrication of MMC.展开更多
Mechanical alloying of Mo Si (Mo 33 Si 67 ) and V Si (V 75 Si 25 ) powder mixtures was activated by high energy ball milling at ambient temperature. The metastable phase transitions in both systems during milling were...Mechanical alloying of Mo Si (Mo 33 Si 67 ) and V Si (V 75 Si 25 ) powder mixtures was activated by high energy ball milling at ambient temperature. The metastable phase transitions in both systems during milling were investigated by X ray diffraction, scanning and transmission electron microscopy. It is found that the alloying processes are closely related to the milling conditions. As far as the Mo Si system is concerned, ball milling leads to the formation of both α MoSi 2 (room temperature phase) and β MoSi 2 (high temperature phase), but lower energy milling favors the formation of β phase, while higher energy milling promotes the formation of α phase. In addition, if the milling energy is high enough, the Mo/Si reaction is governed by a self propagating high temperature process. On the other hand, two different pathways of phase transition in the V Si system were also identified depending on the milling intensity, i.e. weak milling leads to amorphous transition, whereas intensive milling causes the formation of V 3Si and V 5Si 3 intermetallic compounds. Finally, the thermodynamics and kinetics related to the different phase transitions in the two systems were discussed.展开更多
An electronic personal dosimeter mainly uses a Si-PIN photodiode as X-and gamma-ray detectors.The photon energy response of this instrument is inconsistent in the case of no correction,which seriously affects the accu...An electronic personal dosimeter mainly uses a Si-PIN photodiode as X-and gamma-ray detectors.The photon energy response of this instrument is inconsistent in the case of no correction,which seriously affects the accurate monitoring of personal dose equivalent H_p(10)parameters for radiation workers.For this reason,in this paper we propose a method of combining composite screen detection technology,multichannel measurement technology,and the channel ratio method to achieve accurate measurement of the personal dose equivalent parameters.According to China National Standard GB/T 13161-2003 and National Verification Regulation JJG 1009-2006,the instrument was tested in the energy range between 48 keV and 1.25 MeV.The experimental results showed that the difference of energy response to ^(137)C_S corrected by the new method was almost constant within ±6.0%,which fulfilled the ±30% requirement of GB/T 13161-2003 and JJG1009-2006.Meanwhile,the method proposed obtained energy information regarding the radiation field.展开更多
Development of new vernacular dwelling of water town in the southern bank of the Yangze River is an important approach to improve rural appearance,infrastructure,quality of life,and to realize new urbanization of this...Development of new vernacular dwelling of water town in the southern bank of the Yangze River is an important approach to improve rural appearance,infrastructure,quality of life,and to realize new urbanization of this area. How would this process to inherit the quintessence of traditional local-style dwelling as well as integrate with low energy consumption technology is also an important problem due to the valuable Chinese traditional architectural culture in this area. Taking SI system as breaking point,this paper analyzes the green ecological characteristics of traditional residence in the south of the lower reaches of the Yangze River,discusses the current residential technology of low energy consumption, and proposes the low energy consumption residential technology integration system in the south of the lower reaches of the Yangze River.Based on this,this paper takes the SDC 2013 entry "solark"as a practical application case study and further expounds the prospects of this technology system.展开更多
A novel 4H-Si C trench insulated gate bipolar transistor(IGBT)with a controllable hole-extracting(CHE)path is proposed and investigated in this paper.The CHE path is controlled by metal semiconductor gate(MES gate)and...A novel 4H-Si C trench insulated gate bipolar transistor(IGBT)with a controllable hole-extracting(CHE)path is proposed and investigated in this paper.The CHE path is controlled by metal semiconductor gate(MES gate)and metal oxide semiconductor gate(MOS gate)in the p-shield region.The grounded p-shield region can significantly suppress the high electric field around gate oxide in Si C devices,but it weakens the conductivity modulation in the Si C trench IGBT by rapidly sweeping out holes.This effect can be eliminated by introducing the CHE path.The CHE path is pinched off by the high gate bias voltage at on-state to maintain high conductivity modulation and obtain a comparatively low on-state voltage(VON).During the turn-off transient,the CHE path is formed,which contributes to a decreased turn-off loss(EOFF).Based on numerical simulation,the EOFFof the proposed IGBT is reduced by 89%compared with the conventional IGBT at the same VONand the VONof the proposed IGBT is reduced by 50%compared to the grounded p-shield IGBT at the same EOFF.In addition,the average power reduction for the proposed device can be 51.0%to 81.7%and 58.2%to 72.1%with its counterparts at a wide frequency range of 500 Hz to 10 k Hz,revealing a great improvement of frequency characteristics.展开更多
The effect of Si on the growth kinetics of intermetallic compounds during the reaction of solid iron and molten aluminum was investigated with a scanning electron microscope coupled with an energy dispersive X-ray spe...The effect of Si on the growth kinetics of intermetallic compounds during the reaction of solid iron and molten aluminum was investigated with a scanning electron microscope coupled with an energy dispersive X-ray spectroscope, and hot-dip aluminized experiments. The results show that the intermetallic layer is composed of major Fe2Al5 and minor FeAl3. The Al-Fe-Si ternary phase, rl/rg, is formed in the Fe2Al5 layer. The tongue-like morphology of the Fe2Als layer becomes less distinct and disappears finally as the content of Si in aluminum bath increases. Si in the bath improves the prohibiting ability to the growth of Fe2Als and FeAl3. When the contents of Si are 0, 0.5%, 1.0%, 1.5%, 2.0% and 3.0%, the activation energies of Fe2Al5 are evaluated to be 207, 186, 169, 168, 167 and 172 kJ/mol, respectively. The reduction of the activation energy might result from the lattice distortion caused by Si atom penetrating into the Fe2Al5 phase. When Si atom occupies the vacancy site, it blocks easy diffusion path and results in the disappearance of tongue-like morphology.展开更多
In the research field of energy storage dielectrics,the“responsivity”parameter,defined as the recyclable/recoverable energy density per unit electric field,has become critically important for a comprehensive evaluat...In the research field of energy storage dielectrics,the“responsivity”parameter,defined as the recyclable/recoverable energy density per unit electric field,has become critically important for a comprehensive evaluation of the energy storage capability of a dielectric.In this work,high recyclable energy density and responsivity,i.e.,W_(rec)=161.1 J·cm^(-3) and ξ=373.8 J·(kV·m^(2))^(-1),have been simultaneously achieved in a prototype perovskite dielectric,BaTiO_(3),which is integrated on Si at 500℃ in the form of a submicron thick film.This ferroelectric film features a multi-scale polar structure consisting of ferroelectric grains with different orientations and inner-grain ferroelastic domains.A LaNiO_(3) buffer layer is used to induce a{001}textured,columnar nanograin microstructure,while an elevated deposition temperature promotes lateral growth of the nanograins(in-plane diameter increases from~10-20 nm at lower temperatures to~30 nm).These preferably oriented and periodically regulated nanograins have resulted in a small remnant polarization and a delayed polarization saturation in the film’s P-E behavior,leading to a high recyclable energy density.Meanwhile,an improved polarizability/dielectric constant of the BaTiO_(3) film has produced a much larger maximum polarization than those deposited at lower temperatures at the same electric field,leading to a record-breaking responsivity for this simple perovskite.展开更多
基金financially supported by the International Science & Technology Cooperation Program of China under 2019YFE0100200the NSAF (Grant No. U1930113)+2 种基金the Beijing Natural Science Foundation (Grant No. L182022)the 13th Five-Year Plan of Advance Research and Sharing Techniques by the Equipment Department (41421040202)the SAST (2018-114).
文摘The ever-increasing environmental/energy crisis as well as the rapid upgrading of mobile devices had stimulated intensive research attention on promising alternative energy storage and conversion devices.Among these devices,alkali metal ion batteries,such as lithium-ion batteries(LIBs) had attracted increasing research attention due to its several advantages including,environmental friendliness,high power density,long cycle life and excellent reversibility.It had been widely used in consumer electronics,electric vehicles,and large power grids et ac.Silicon-based(silicon and their oxides,carbides) anodes had been widely studied.Its several advantages including low cost,high theoretical capacity,natural abundance,and environmental friendliness,which shows great potential as anodes of LIBs.In this review,we summarized the recently progress in the synthetic method of silicon matrix composites.The empirical method for prelithiation of silicon-based materials were also provided.Further,we also reviewed some novel characterization methods.Finally,the new design,preparation methods and properties of these nano materials were reviewed and compared.We hoped that this review can provide a general overview of recent progress and we briefly highlighted the current challenges and prospects,and will clarify the future trend of silicon anode LIBs research.
基金Supported by the Foundation of National Natural Science of China(60802005,50803016)the Science Foundation for the Excellent Youth Scholars in East China University of Science and Technology(YH0157127)the Undergraduate Innovational Experimentation Program in East China University of Science andTechnology(X1033)~~
文摘A heuristic theoretical optimal routing algorithm （TORA） is presented to achieve the data-gathering structure of location-aided quality of service （QoS） in wireless sensor networks （WSNs）. The construction of TORA is based on a kind of swarm intelligence （SI） mechanism, i. e. , ant colony optimization. Firstly, the ener- gy-efficient weight is designed based on flow distribution to divide WSNs into different functional regions, so the routing selection can self-adapt asymmetric power configurations with lower latency. Then, the designs of the novel heuristic factor and the pheromone updating rule can endow ant-like agents with the ability of detecting the local networks energy status and approaching the theoretical optimal tree, thus improving the adaptability and en- ergy-efficiency in route building. Simulation results show that compared with some classic routing algorithms, TORA can further minimize the total communication energy cost and enhance the QoS performance with low-de- lay effect under the data-gathering condition.
文摘The influence of high energy ball milling on Al 30Si powder and ceramic particulate SiC was studied by means of SEM, XRD and DSC. The results show that Al 30Si powder and their microstructure are obviously refined after high energy ball milling process. The alloy powder and SiC p stick closely to each other without interfacial reaction. DSC results detect no reaction but relaxation of the samples. So high energy ball milling can be used as an effective method for ceramic particulate pre treatment in the fabrication of MMC.
文摘Mechanical alloying of Mo Si (Mo 33 Si 67 ) and V Si (V 75 Si 25 ) powder mixtures was activated by high energy ball milling at ambient temperature. The metastable phase transitions in both systems during milling were investigated by X ray diffraction, scanning and transmission electron microscopy. It is found that the alloying processes are closely related to the milling conditions. As far as the Mo Si system is concerned, ball milling leads to the formation of both α MoSi 2 (room temperature phase) and β MoSi 2 (high temperature phase), but lower energy milling favors the formation of β phase, while higher energy milling promotes the formation of α phase. In addition, if the milling energy is high enough, the Mo/Si reaction is governed by a self propagating high temperature process. On the other hand, two different pathways of phase transition in the V Si system were also identified depending on the milling intensity, i.e. weak milling leads to amorphous transition, whereas intensive milling causes the formation of V 3Si and V 5Si 3 intermetallic compounds. Finally, the thermodynamics and kinetics related to the different phase transitions in the two systems were discussed.
基金supported by the National Key Scientific Instruments To Develop Dedicated(2013YQ090811)
文摘An electronic personal dosimeter mainly uses a Si-PIN photodiode as X-and gamma-ray detectors.The photon energy response of this instrument is inconsistent in the case of no correction,which seriously affects the accurate monitoring of personal dose equivalent H_p(10)parameters for radiation workers.For this reason,in this paper we propose a method of combining composite screen detection technology,multichannel measurement technology,and the channel ratio method to achieve accurate measurement of the personal dose equivalent parameters.According to China National Standard GB/T 13161-2003 and National Verification Regulation JJG 1009-2006,the instrument was tested in the energy range between 48 keV and 1.25 MeV.The experimental results showed that the difference of energy response to ^(137)C_S corrected by the new method was almost constant within ±6.0%,which fulfilled the ±30% requirement of GB/T 13161-2003 and JJG1009-2006.Meanwhile,the method proposed obtained energy information regarding the radiation field.
基金Sponsored by the Chinese Nature Science Foundation(Grant No.51278110)the Fundamental Research Funds for the Central Universities+1 种基金the Research Funds of Graduate Student Innovation Planning Program for Jiangsu Province's University(Grant No.KYLX-0143)the Fundamental Research Fundsof Southeast University
文摘Development of new vernacular dwelling of water town in the southern bank of the Yangze River is an important approach to improve rural appearance,infrastructure,quality of life,and to realize new urbanization of this area. How would this process to inherit the quintessence of traditional local-style dwelling as well as integrate with low energy consumption technology is also an important problem due to the valuable Chinese traditional architectural culture in this area. Taking SI system as breaking point,this paper analyzes the green ecological characteristics of traditional residence in the south of the lower reaches of the Yangze River,discusses the current residential technology of low energy consumption, and proposes the low energy consumption residential technology integration system in the south of the lower reaches of the Yangze River.Based on this,this paper takes the SDC 2013 entry "solark"as a practical application case study and further expounds the prospects of this technology system.
基金Project supported by the Hunan Provincial Natural Science Foundation of China(Grant No.2021JJ30738)Scientific Research Fund of Hunan Provincial Education Department(Grant No.19K001)Hunan Provincial Key Laboratory of Flexible Electronic Materials Genome Engineering’s Open Fund Project-2020(Grant No.202016)。
文摘A novel 4H-Si C trench insulated gate bipolar transistor(IGBT)with a controllable hole-extracting(CHE)path is proposed and investigated in this paper.The CHE path is controlled by metal semiconductor gate(MES gate)and metal oxide semiconductor gate(MOS gate)in the p-shield region.The grounded p-shield region can significantly suppress the high electric field around gate oxide in Si C devices,but it weakens the conductivity modulation in the Si C trench IGBT by rapidly sweeping out holes.This effect can be eliminated by introducing the CHE path.The CHE path is pinched off by the high gate bias voltage at on-state to maintain high conductivity modulation and obtain a comparatively low on-state voltage(VON).During the turn-off transient,the CHE path is formed,which contributes to a decreased turn-off loss(EOFF).Based on numerical simulation,the EOFFof the proposed IGBT is reduced by 89%compared with the conventional IGBT at the same VONand the VONof the proposed IGBT is reduced by 50%compared to the grounded p-shield IGBT at the same EOFF.In addition,the average power reduction for the proposed device can be 51.0%to 81.7%and 58.2%to 72.1%with its counterparts at a wide frequency range of 500 Hz to 10 k Hz,revealing a great improvement of frequency characteristics.
基金Project (51071135) supported by the National Natural Science Foundation of ChinaProject (20114301110005) supported by the Ph. D.Programs Foundation of Ministry of Education of ChinaProject (10XZX15) supported by the Science Foundation of Xiangtan University,China
文摘The effect of Si on the growth kinetics of intermetallic compounds during the reaction of solid iron and molten aluminum was investigated with a scanning electron microscope coupled with an energy dispersive X-ray spectroscope, and hot-dip aluminized experiments. The results show that the intermetallic layer is composed of major Fe2Al5 and minor FeAl3. The Al-Fe-Si ternary phase, rl/rg, is formed in the Fe2Al5 layer. The tongue-like morphology of the Fe2Als layer becomes less distinct and disappears finally as the content of Si in aluminum bath increases. Si in the bath improves the prohibiting ability to the growth of Fe2Als and FeAl3. When the contents of Si are 0, 0.5%, 1.0%, 1.5%, 2.0% and 3.0%, the activation energies of Fe2Al5 are evaluated to be 207, 186, 169, 168, 167 and 172 kJ/mol, respectively. The reduction of the activation energy might result from the lattice distortion caused by Si atom penetrating into the Fe2Al5 phase. When Si atom occupies the vacancy site, it blocks easy diffusion path and results in the disappearance of tongue-like morphology.
基金the National Natural Science Foundation of China(Grant Nos.51772175 and 52002192)Natural Science Foundation of Shandong Province(Grant Nos.ZR2022ZD39,ZR2022ME075,ZR2020QE042,ZR2022ME031,and ZR2022QB138)+3 种基金the Science,Education and Industry Integration Pilot Projects of Qilu University of Technology(Shandong Academy of Sciences)(Grant Nos.2022GH018 and 2022PY055)the Jinan City Science and Technology Bureau(Grant No.2021GXRC055)the Education Department of Hunan Province/Xiangtan University(Grant No.KZ0807969)funding for top talents at Qilu University of Technology(Shandong Academy of Sciences).
文摘In the research field of energy storage dielectrics,the“responsivity”parameter,defined as the recyclable/recoverable energy density per unit electric field,has become critically important for a comprehensive evaluation of the energy storage capability of a dielectric.In this work,high recyclable energy density and responsivity,i.e.,W_(rec)=161.1 J·cm^(-3) and ξ=373.8 J·(kV·m^(2))^(-1),have been simultaneously achieved in a prototype perovskite dielectric,BaTiO_(3),which is integrated on Si at 500℃ in the form of a submicron thick film.This ferroelectric film features a multi-scale polar structure consisting of ferroelectric grains with different orientations and inner-grain ferroelastic domains.A LaNiO_(3) buffer layer is used to induce a{001}textured,columnar nanograin microstructure,while an elevated deposition temperature promotes lateral growth of the nanograins(in-plane diameter increases from~10-20 nm at lower temperatures to~30 nm).These preferably oriented and periodically regulated nanograins have resulted in a small remnant polarization and a delayed polarization saturation in the film’s P-E behavior,leading to a high recyclable energy density.Meanwhile,an improved polarizability/dielectric constant of the BaTiO_(3) film has produced a much larger maximum polarization than those deposited at lower temperatures at the same electric field,leading to a record-breaking responsivity for this simple perovskite.
