The introduction of metal single atoms(SAs)and nanoparticles(NPs)are effective approaches to mod-ify electronic configuration of semiconductors,whereas recognizing the synergistic effects of metal SAs and NPs are stil...The introduction of metal single atoms(SAs)and nanoparticles(NPs)are effective approaches to mod-ify electronic configuration of semiconductors,whereas recognizing the synergistic effects of metal SAs and NPs are still challenging in photocatalytic water purification.Herein,a general strategy is achieved by subsequentially anchoring Fe SAs and Fe NPs in graphitic carbon nitride.The modification of Fe SAs and Fe NPs improves the energy band structure and constructs a gradient charge polarization,directly expanding the optical absorption range and facilitating the efficient separation and transfer of charge car-riers.With the assistance of the gradient charge polarization,pollutants are readily oxidated by h+,which strengthens the continuous reduction of O2 on Fe NPs for pollutant oxidation in water.This work rein-forces the synergistic effect of SAs and NPs on electronic configuration modulation at the atomic level,which exhibits great potential for the construction of an efficient and sustainable water purification sys-tem.展开更多
The functional properties of glasses are governed by their formation history and the complex relaxation processes they undergo.However,under extreme conditions,glass behaviors are still elusive.In this study,we employ...The functional properties of glasses are governed by their formation history and the complex relaxation processes they undergo.However,under extreme conditions,glass behaviors are still elusive.In this study,we employ simulations with varied protocols to evaluate the effectiveness of different descriptors in predicting mechanical properties across both low-and high-pressure regimes.Our findings demonstrate that conventional structural and configurational descriptors fail to correlate with the mechanical response following pressure release,whereas the activation energy descriptor exhibits robust linearity with shear modulus after correcting for pressure effects.Notably,the soft mode parameter emerges as an ideal and computationally efficient alternative for capturing this mechanical behavior.These findings provide critical insights into the influence of pressure on glassy properties,integrating the distinct features of compressed glasses into a unified theoretical framework.展开更多
In response to the issue of determining the appropriate capacity when hybrid energy storage systems(HESS)collaborate with thermal power units(TPU)in the system’s secondary frequency regulation,a configuration method ...In response to the issue of determining the appropriate capacity when hybrid energy storage systems(HESS)collaborate with thermal power units(TPU)in the system’s secondary frequency regulation,a configuration method for HESS based on the analysis of frequency regulation demand analysis is proposed.And a corresponding simulation platform is developed.Firstly,a frequency modulation demand method for reducing the frequency modulation losses of TPU is proposed.Secondly,taking into comprehensive consideration that flywheel energy storage features rapid power response and battery energy storage has the characteristic of high energy density,a coordinated control strategy for HESS considering the self-recovery of state of charge(SOC)is put forward.Then,to measure the economic and technical performance of HESS in assisting the secondary frequency modulation of TPU,an optimized configurationmodel considering the full-life-cycle economy and frequency modulation performance of TPU and HESS system is constructed.Finally,a visual simulation platform for the combined frequency modulation of TPU and HESS is developed based on Matlab Appdesigner.Theresults of calculation examples indicate that the proposed configuration method can improve the overall economic efficiency and frequency modulation performance of TPU and HESS;The control strategy can not only prolong the service life of battery energy storage but also enhance the continuous response ability of HESS;The visual simulation platform is easy to use,and the simulation results are accurate and reliable.展开更多
Sodium-ion batteries(SIBs)have recently gained wildly interest due to the abundance of sodium,lower production costs,and better low-temperature performance compared to lithium-ion batteries(LIBs).Among various cathode...Sodium-ion batteries(SIBs)have recently gained wildly interest due to the abundance of sodium,lower production costs,and better low-temperature performance compared to lithium-ion batteries(LIBs).Among various cathode materials of SIBs,O_(3)-type NaNi_(0.4)Fe_(0.2)Mn_(0.4)O_(2)(NFM424)demonstrates high capacity and ease of synthesis,yet suffers from structural degradation and sluggish Na^(+)kinetics caused by large ionic radius and strong electrostatic interactions.To overcome these issues,a configuration strategy combined with TiO_(2) and Co_(3)O_(4) by a simple solid-state reaction method was introduced to improve structural and electrochemical stability.XRD,SEM,TEM,and various electrochemical characterizations as well as TGA/DSC tests were conducted.The resulting NaNi_(0.4)Fe_(0.2)Mn_(0.3)Co_(0.05)Ti_(0.05)O_(2)(NFMCT)cathode mitigated Jahn-Teller distortions and Na^(+)/vacancy ordering while enhancing phase integrity and diffusion pathways.The obtained NFMCT maintained 93.7 mAh·g^(−1) after 550 cycles at 1 C,with superior rate capabilities at 2 C and 5 C.These findings deepen the understanding of configuration strategy by using multi-element oxide and highlight a practical strategy for designing high-performance SIB cathodes.展开更多
It is absolutely critical that trusted configuration management which significantly affects trust chain establishment, sealing storage and remote attestation, especially in trusted virtualization platform like Xen who...It is absolutely critical that trusted configuration management which significantly affects trust chain establishment, sealing storage and remote attestation, especially in trusted virtualization platform like Xen whose system configuration changes easily. TPM （trusted platform module） context manager is presented to carry out dynamic configuration management for virtual machine. It manages the TPM command requests and VM （virtual machine） configurations. The dynamic configuration representa- tion method based on Merkle hash tree is explicitly proposed against TCG （trusted computing group） static configuration representation. It reflects the true VM status in real time even if the configuration has changed, and it eliminates the invalidation of configuration representation, sealing storage and remote attestation. TPM context manager supports TCG storage protection, remote attestation etc, which greatly enhances the security on trusted virtualization platform.展开更多
Cold atmospheric plasma(CAP)jet has wide applications in various fields including advanced materials synthesis and modifications,biomedicine,environmental protection and energy saving,etc.Appropriate control on the vo...Cold atmospheric plasma(CAP)jet has wide applications in various fields including advanced materials synthesis and modifications,biomedicine,environmental protection and energy saving,etc.Appropriate control on the volume,temperature and chemically reactive species concentratio ns of the CAP jet is of great importance in actual applications.In this paper,an radio-frequency atmospheric-pressure glow discharge(RF-APGD)plasma generator with a hybrid cross-linear-field electrode configuration is proposed.The experimental results show that,with the aid of the copper mesh located at the downstream of the traditional co-axial-type plasma generator with a cross-field electrode configuration,a linear field between the inner powered electrode of the traditional plasma generator and the copper mesh can be established.This linerfield can,to some extent,enhance the discharges at the upstream of the copper mesh,resulting in small increments(all less than 12.5%)of the species emission intensities,electron excitation temperatures and gas temperatures by keeping other parameters being unchanged.And due to the intrinsic transparent and conducting features of the grounded copper mesh to the gas flowing,electric current and heat flux of the plasma plumes,a plasma region with higher concentrations of chemically reactive species and larger plasma plume diameters is obtained at the downstream of the grounded copper mesh on the same level of the gas temperature and electron excitation temperature compared to those of the plasma free jet.In addition,the charged particle number densities at the same downstream axial location of the grounded copper mesh decrease significantly compared to those of the plasma free jet.This means that the copper mesh is also,to some extent,helpful for separating the chemically reactive neutral species from the charged particles in side a plasma environment.The preceding results indicate that the cross-linear-field electrode configuration of the plasma generator is an effective approach for tuning the characteristics of the RF-APGD plasma jet in order to obtain an appropriate combination of the plasma jet properties with higher chemically reactive species concentrations,especially relative higher number densities of neutral species,larger plasma volumes and lower gas temperatures.展开更多
The main purpose of the present work is to discuss whether or not the collective flows in heavy-ion collision at the Fermi energy can be taken as a tool to investigate the cluster configuration in light nuclei. In pra...The main purpose of the present work is to discuss whether or not the collective flows in heavy-ion collision at the Fermi energy can be taken as a tool to investigate the cluster configuration in light nuclei. In practice, within an extended quantum molecular dynamics model, four a-clustering （linear chain, kite, square and tetrahedron） configurations of 16O are employed in the initialization, 16O＋16O around the Fermi energy （40-60 MeV/nucleon） with impact parameter 1-3fro are simulated, and the directed and elliptic flows are analyzed. It is found that collective flows are influenced by the different a-clustering configurations, and the directed flow of free protons is more sensitive to the initial cluster configuration than the elliptic flow. Nuclear reaction at the Fermi energy can be taken as a useful way to study cluster configuration in light nuclei.展开更多
MGa2O4（M=Zn,Ni） rods with similar crystallinity and BET surface area were prepared via a facile template-engaged reaction.The photocatalytic activities for water splitting of RuO2-loaded MGa2O4（M=Zn,Ni） were inves...MGa2O4（M=Zn,Ni） rods with similar crystallinity and BET surface area were prepared via a facile template-engaged reaction.The photocatalytic activities for water splitting of RuO2-loaded MGa2O4（M=Zn,Ni） were investigated under high-pressure Hg lamp.RuO2-loaded ZnGa2O4 catalyst exhibited much higher photocatalytic activity than RuO2-loaded NiGa2O4.Factors affecting the photocatalytic activities of RuO2-loaded MGa2O4（M=Zn,Ni） were discussed.It was suggested that the electronic structure of oxide semiconductor was a predominant factor of the photocatalytic behavior for RuO2-loaded MGa2O4（M=Zn,Ni）.展开更多
The title compound, (+)-O-phenyl cyclophosphorodiamidate (C28H33N2O2P, Mr = 460.53), has been synthesized and characterized by 31P NMR, 1H NMR and elemental analysis. X-ray diffraction analysis at 273(2) K indicates t...The title compound, (+)-O-phenyl cyclophosphorodiamidate (C28H33N2O2P, Mr = 460.53), has been synthesized and characterized by 31P NMR, 1H NMR and elemental analysis. X-ray diffraction analysis at 273(2) K indicates that it belongs to orthorhombic system, space group P212121 with a = 11.518(4), b = 13.449(4), c = 16.539(5) ? V = 2562(1) 3, Z = 4, Dc = 1.194 g/cm3, F(000) = 984 and m(MoKa) = 0.134 mm-1. The structure parameters were refined by full-matrix least-squares on F2 to R = 0.0459 and wR = 0.0640. The flack x parameter is 0.03(10), and the absolute configuration of the phosphorus atom in the title compound is S.展开更多
Bi2O2Se thin film could be one of the promising material candidates for the next-generation electronic and optoelectronic applications. However, the performance of Bi2O2Se thin film-based device is not fully explored ...Bi2O2Se thin film could be one of the promising material candidates for the next-generation electronic and optoelectronic applications. However, the performance of Bi2O2Se thin film-based device is not fully explored in the photodetecting area. Considering the fact that the electrical properties such as carrier mobility, work function, and energy band structure of Bi2O2Se are thickness-dependent, the in-plane Bi2O2Se homojunctions consisting of layers with different thicknesses are successfully synthesized by the chemical vapor deposition(CVD) method across the terraces on the mica substrates,where terraces are created in the mica surface layer peeling off process. In this way, effective internal electrical fields are built up along the Bi2O2Se homojunctions, exhibiting diode-like rectification behavior with an on/off ratio of 102, what is more, thus obtained photodetectors possess highly sensitive and ultrafast features, with a maximum photoresponsivity of 2.5 A/W and a lifetime of 4.8 μs. Comparing with the Bi2O2Se uniform thin films, the photo-electric conversion efficiency is greatly improved for the in-plane homojunctions.展开更多
Recent studies have successfully demonstrated high-Tc superconductivity in bilayer nickelate La3Ni2O7.However,research on modulating the structural and transport characteristics of La3Ni2O7 films by applying“chemical...Recent studies have successfully demonstrated high-Tc superconductivity in bilayer nickelate La3Ni2O7.However,research on modulating the structural and transport characteristics of La3Ni2O7 films by applying“chemical”compressive pressure through cation substitution is still limited.Here,we address this issue in the La_(3−x)Nd_(x)Ni_(2)O_(7)(x=0,1.0,1.5,2.0,and 2.5)thin film samples.It was found that using Nd3+with a smaller radius instead of La3+can reduce the c-axis lattice constant and shift the metal-insulator transition(MIT)temperature TMIT.To probe the origin of the MIT at cryogenic temperatures,experimental measurements of magnetoresistance were conducted,and theoretical analysis was carried out using the Kondo model,Hikami-Larkin-Nagaoka equation,and other methods.The results indicate that as Nd doping rises,the contributions of the Kondo effect and two-dimensional weak localization(WL)first decrease and then increase.The total contribution of WL and the Kondo effect in the mid-doped La_(1.5)Nd_(1.5)Ni_(2)O_(7)sample was the smallest,which to some extent explains the changes in TMIT.The Kondo effect dominates in other La_(3−x)Nd_(x)Ni_(2)O_(7)(x=0,1.0,2.0,and 2.5)samples.This work demonstrates that cation doping has a significant impact on bilayer nickelates,providing experimental evidence for understanding the physical mechanism of the MIT in bilayer nickelates.展开更多
ZnO with good lithiophilicity has widely been employed to modify the lithiophobic substrates and facilitate uniform lithium(Li)deposition.The overpotential of ZnO-derived Li anode during cycling depends on the lithiop...ZnO with good lithiophilicity has widely been employed to modify the lithiophobic substrates and facilitate uniform lithium(Li)deposition.The overpotential of ZnO-derived Li anode during cycling depends on the lithiophilicity of both LiZn and Li_(2)O products upon lithiation of ZnO.However,the striking differences in the lithiophilicity between Li_(2)O and LiZn would result in a high overpotential during cycling.In this research,the Al_(2)O_(3)/nZnO(n≥1)hybrid layers were precisely fabricated by atomic layer deposition(ALD)to regulate the lithiophilicity of ZnO phase and Li_(2)O/LiZn configuration—determining the actual Li loading amount and Li plating/stripping processes.Theoretically,the Li adsorption energy(E_(a))values of LiZn and Li_(2)O in the LiZn/Li_(2)O configuration are separately predicted as-2.789 and-3.447 eV.In comparison,the E_(a) values of LiZn,LiAlO_(2),and Li_(2)O in the LiZn/LiAlO_(2)/Li_(2)O configuration upon lithiation of Al_(2)O_(3)/8ZnO layer are calculated as-2.899,-3.089,and-3.208 eV,respectively.Importantly,a novel introduction of LiAlO_(2)into the LiZn/Li_(2)O configuration could enable the hierarchical Li plating/stripping and reduce the overpotentials during cycling.Consequently,the Al_(2)O_(3)/8ZnO-derived hybrid Li-metal anode could exhibit electrochemical performances superior to these of ZnO-derived Li anode in both symmetrical and full cells paired with a LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)(NCM622)cathode.展开更多
A hot spot is a reliability problem in photovoltaic(PV) modules where a mismatched or shaded cell heats up significantly and degrades the PV module output power performance. High PV cell temperature due to a hot spot ...A hot spot is a reliability problem in photovoltaic(PV) modules where a mismatched or shaded cell heats up significantly and degrades the PV module output power performance. High PV cell temperature due to a hot spot can damage the cell encapsulate and lead to second breakdown, which both cause permanent damage to the PV module. In present systems, bypass diodes are used to mitigate the hot spot problem. In this work, five commercial polysilicon P V modules configured with different numbers of bypass diodes are used to study the influence of bypass diodes on the reverse bias voltage of a shaded cell and the resulting hot spot phenomenon. The reverse bias voltage of the shaded cell, and the hot spot probability and severity decrease as the number of bypass diodes increases. Negative terminal voltage of a shaded cell accompanied by a switched-off bypass diode are the necessary condition for hot spot generation. In an extreme case where each cell has an individual bypass diode in a P V module, it still cannot avoid the hazards of a hot spot under the shading areas of 5-7 cm2, but the probability of a hot spot is reduced to a minimum of 0.41%.展开更多
Selecting a cost optimum subset of discrete-value dispersion compensation modules (DV-DCMs) subject to maximum module count from an available set of DV-DCMs is a NP-hard problem. We derive a novel dynamic programming ...Selecting a cost optimum subset of discrete-value dispersion compensation modules (DV-DCMs) subject to maximum module count from an available set of DV-DCMs is a NP-hard problem. We derive a novel dynamic programming algorithm with pseudo-polynomial time bound and show that DV-DCM cost re-scaling can improve the running time.展开更多
基金the National Natural Science Foundation of China(Nos.52100032 and 52350005)the Basic and Applied Basic Research Project of Guangzhou(Nos.2024A04J3679, 2024A03J0088)+2 种基金the Introduced Innovative Research and Development Team Project under the“The Pearl River Talent Recruitment Program”of Guangdong Province(No.2019ZT08L387)the Special Basic Research Fund for Central Public Research Institutes of China(No.PMzx703-202204-152)the Research Fund Program of Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology(No.2023B1212060016).
文摘The introduction of metal single atoms(SAs)and nanoparticles(NPs)are effective approaches to mod-ify electronic configuration of semiconductors,whereas recognizing the synergistic effects of metal SAs and NPs are still challenging in photocatalytic water purification.Herein,a general strategy is achieved by subsequentially anchoring Fe SAs and Fe NPs in graphitic carbon nitride.The modification of Fe SAs and Fe NPs improves the energy band structure and constructs a gradient charge polarization,directly expanding the optical absorption range and facilitating the efficient separation and transfer of charge car-riers.With the assistance of the gradient charge polarization,pollutants are readily oxidated by h+,which strengthens the continuous reduction of O2 on Fe NPs for pollutant oxidation in water.This work rein-forces the synergistic effect of SAs and NPs on electronic configuration modulation at the atomic level,which exhibits great potential for the construction of an efficient and sustainable water purification sys-tem.
基金supported by the National Natural Science Foundation of China (Grant Nos.T2325004 and 52161160330)the National Natural Science Foundation of China (Grants No.12504233)+2 种基金Advanced MaterialsNational Science and Technology Major Project (Grant No.2024ZD0606900)the Talent Hub for “AI+New Materials” Basic Researchthe Key Research and Development Program of Ningbo (Grant No.2025Z088)。
文摘The functional properties of glasses are governed by their formation history and the complex relaxation processes they undergo.However,under extreme conditions,glass behaviors are still elusive.In this study,we employ simulations with varied protocols to evaluate the effectiveness of different descriptors in predicting mechanical properties across both low-and high-pressure regimes.Our findings demonstrate that conventional structural and configurational descriptors fail to correlate with the mechanical response following pressure release,whereas the activation energy descriptor exhibits robust linearity with shear modulus after correcting for pressure effects.Notably,the soft mode parameter emerges as an ideal and computationally efficient alternative for capturing this mechanical behavior.These findings provide critical insights into the influence of pressure on glassy properties,integrating the distinct features of compressed glasses into a unified theoretical framework.
基金supported by a Key Project of the National Natural Science Foundation of China under Grant 52337004.
文摘In response to the issue of determining the appropriate capacity when hybrid energy storage systems(HESS)collaborate with thermal power units(TPU)in the system’s secondary frequency regulation,a configuration method for HESS based on the analysis of frequency regulation demand analysis is proposed.And a corresponding simulation platform is developed.Firstly,a frequency modulation demand method for reducing the frequency modulation losses of TPU is proposed.Secondly,taking into comprehensive consideration that flywheel energy storage features rapid power response and battery energy storage has the characteristic of high energy density,a coordinated control strategy for HESS considering the self-recovery of state of charge(SOC)is put forward.Then,to measure the economic and technical performance of HESS in assisting the secondary frequency modulation of TPU,an optimized configurationmodel considering the full-life-cycle economy and frequency modulation performance of TPU and HESS system is constructed.Finally,a visual simulation platform for the combined frequency modulation of TPU and HESS is developed based on Matlab Appdesigner.Theresults of calculation examples indicate that the proposed configuration method can improve the overall economic efficiency and frequency modulation performance of TPU and HESS;The control strategy can not only prolong the service life of battery energy storage but also enhance the continuous response ability of HESS;The visual simulation platform is easy to use,and the simulation results are accurate and reliable.
基金funded by the National Natural Science Foundation of China(Grants 21701083 and 22179054)Jiangsu Provincial Key Research and Development Program(BZ2023010)2023 Jiangsu Government Scholarship for Overseas Studies.
文摘Sodium-ion batteries(SIBs)have recently gained wildly interest due to the abundance of sodium,lower production costs,and better low-temperature performance compared to lithium-ion batteries(LIBs).Among various cathode materials of SIBs,O_(3)-type NaNi_(0.4)Fe_(0.2)Mn_(0.4)O_(2)(NFM424)demonstrates high capacity and ease of synthesis,yet suffers from structural degradation and sluggish Na^(+)kinetics caused by large ionic radius and strong electrostatic interactions.To overcome these issues,a configuration strategy combined with TiO_(2) and Co_(3)O_(4) by a simple solid-state reaction method was introduced to improve structural and electrochemical stability.XRD,SEM,TEM,and various electrochemical characterizations as well as TGA/DSC tests were conducted.The resulting NaNi_(0.4)Fe_(0.2)Mn_(0.3)Co_(0.05)Ti_(0.05)O_(2)(NFMCT)cathode mitigated Jahn-Teller distortions and Na^(+)/vacancy ordering while enhancing phase integrity and diffusion pathways.The obtained NFMCT maintained 93.7 mAh·g^(−1) after 550 cycles at 1 C,with superior rate capabilities at 2 C and 5 C.These findings deepen the understanding of configuration strategy by using multi-element oxide and highlight a practical strategy for designing high-performance SIB cathodes.
基金the National High Technology Research and Development Program of China (2007AA01Z412)
文摘It is absolutely critical that trusted configuration management which significantly affects trust chain establishment, sealing storage and remote attestation, especially in trusted virtualization platform like Xen whose system configuration changes easily. TPM （trusted platform module） context manager is presented to carry out dynamic configuration management for virtual machine. It manages the TPM command requests and VM （virtual machine） configurations. The dynamic configuration representa- tion method based on Merkle hash tree is explicitly proposed against TCG （trusted computing group） static configuration representation. It reflects the true VM status in real time even if the configuration has changed, and it eliminates the invalidation of configuration representation, sealing storage and remote attestation. TPM context manager supports TCG storage protection, remote attestation etc, which greatly enhances the security on trusted virtualization platform.
基金supported by National Natural Science Foundation of China(Nos.11475103,21627812)the National Key Research and Development Program of China(No.2016YFD0102106)Tsinghua University Initiative Scientific Program(20161080108)
文摘Cold atmospheric plasma(CAP)jet has wide applications in various fields including advanced materials synthesis and modifications,biomedicine,environmental protection and energy saving,etc.Appropriate control on the volume,temperature and chemically reactive species concentratio ns of the CAP jet is of great importance in actual applications.In this paper,an radio-frequency atmospheric-pressure glow discharge(RF-APGD)plasma generator with a hybrid cross-linear-field electrode configuration is proposed.The experimental results show that,with the aid of the copper mesh located at the downstream of the traditional co-axial-type plasma generator with a cross-field electrode configuration,a linear field between the inner powered electrode of the traditional plasma generator and the copper mesh can be established.This linerfield can,to some extent,enhance the discharges at the upstream of the copper mesh,resulting in small increments(all less than 12.5%)of the species emission intensities,electron excitation temperatures and gas temperatures by keeping other parameters being unchanged.And due to the intrinsic transparent and conducting features of the grounded copper mesh to the gas flowing,electric current and heat flux of the plasma plumes,a plasma region with higher concentrations of chemically reactive species and larger plasma plume diameters is obtained at the downstream of the grounded copper mesh on the same level of the gas temperature and electron excitation temperature compared to those of the plasma free jet.In addition,the charged particle number densities at the same downstream axial location of the grounded copper mesh decrease significantly compared to those of the plasma free jet.This means that the copper mesh is also,to some extent,helpful for separating the chemically reactive neutral species from the charged particles in side a plasma environment.The preceding results indicate that the cross-linear-field electrode configuration of the plasma generator is an effective approach for tuning the characteristics of the RF-APGD plasma jet in order to obtain an appropriate combination of the plasma jet properties with higher chemically reactive species concentrations,especially relative higher number densities of neutral species,larger plasma volumes and lower gas temperatures.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11421505,11220101005,11305239 and 11605270the Major State Basic Research Development Program of China under Grant No 2014CB845401+1 种基金the Key Research Program of Frontier Sciences of the Chinese Academy of Sciences under Grant No QYZDJ-SSW-SLH002the China Postdoctoral Science Foundation under Grant No 2016M591730
文摘The main purpose of the present work is to discuss whether or not the collective flows in heavy-ion collision at the Fermi energy can be taken as a tool to investigate the cluster configuration in light nuclei. In practice, within an extended quantum molecular dynamics model, four a-clustering （linear chain, kite, square and tetrahedron） configurations of 16O are employed in the initialization, 16O＋16O around the Fermi energy （40-60 MeV/nucleon） with impact parameter 1-3fro are simulated, and the directed and elliptic flows are analyzed. It is found that collective flows are influenced by the different a-clustering configurations, and the directed flow of free protons is more sensitive to the initial cluster configuration than the elliptic flow. Nuclear reaction at the Fermi energy can be taken as a useful way to study cluster configuration in light nuclei.
基金supported by the Natural Science Foundation of Fujian Province (No. 2009J05025)the Educational Commission of Fujian province (No. JA09051)
文摘MGa2O4（M=Zn,Ni） rods with similar crystallinity and BET surface area were prepared via a facile template-engaged reaction.The photocatalytic activities for water splitting of RuO2-loaded MGa2O4（M=Zn,Ni） were investigated under high-pressure Hg lamp.RuO2-loaded ZnGa2O4 catalyst exhibited much higher photocatalytic activity than RuO2-loaded NiGa2O4.Factors affecting the photocatalytic activities of RuO2-loaded MGa2O4（M=Zn,Ni） were discussed.It was suggested that the electronic structure of oxide semiconductor was a predominant factor of the photocatalytic behavior for RuO2-loaded MGa2O4（M=Zn,Ni）.
基金Financially supported by the National Natural Science Foundation of China (No.20272025) and Ph.D. Programs Foundation of Ministry of Education of China
文摘The title compound, (+)-O-phenyl cyclophosphorodiamidate (C28H33N2O2P, Mr = 460.53), has been synthesized and characterized by 31P NMR, 1H NMR and elemental analysis. X-ray diffraction analysis at 273(2) K indicates that it belongs to orthorhombic system, space group P212121 with a = 11.518(4), b = 13.449(4), c = 16.539(5) ? V = 2562(1) 3, Z = 4, Dc = 1.194 g/cm3, F(000) = 984 and m(MoKa) = 0.134 mm-1. The structure parameters were refined by full-matrix least-squares on F2 to R = 0.0459 and wR = 0.0640. The flack x parameter is 0.03(10), and the absolute configuration of the phosphorus atom in the title compound is S.
基金Project supported by the National Natural Science Foundation of China(Grant No.61705066)the Open Fund of State Key Laboratory of Information Photonics and Optical Communications(Beijing University of Posts and Telecommunications),China(Grant No.IPOC2018B004)the National Key Research and Development Program,China(Grant No.2016YFA0202401)
文摘Bi2O2Se thin film could be one of the promising material candidates for the next-generation electronic and optoelectronic applications. However, the performance of Bi2O2Se thin film-based device is not fully explored in the photodetecting area. Considering the fact that the electrical properties such as carrier mobility, work function, and energy band structure of Bi2O2Se are thickness-dependent, the in-plane Bi2O2Se homojunctions consisting of layers with different thicknesses are successfully synthesized by the chemical vapor deposition(CVD) method across the terraces on the mica substrates,where terraces are created in the mica surface layer peeling off process. In this way, effective internal electrical fields are built up along the Bi2O2Se homojunctions, exhibiting diode-like rectification behavior with an on/off ratio of 102, what is more, thus obtained photodetectors possess highly sensitive and ultrafast features, with a maximum photoresponsivity of 2.5 A/W and a lifetime of 4.8 μs. Comparing with the Bi2O2Se uniform thin films, the photo-electric conversion efficiency is greatly improved for the in-plane homojunctions.
基金supported by the Natural Science Foundation of Guangdong Province of China(Grant No.2025A1515011071)the National Natural Science Foundation of China(Grant Nos.92065110,11974048,and 12074334)the Beijing Municipal Natural Science Foundation Key Research Topics(Grant No.Z230006)。
文摘Recent studies have successfully demonstrated high-Tc superconductivity in bilayer nickelate La3Ni2O7.However,research on modulating the structural and transport characteristics of La3Ni2O7 films by applying“chemical”compressive pressure through cation substitution is still limited.Here,we address this issue in the La_(3−x)Nd_(x)Ni_(2)O_(7)(x=0,1.0,1.5,2.0,and 2.5)thin film samples.It was found that using Nd3+with a smaller radius instead of La3+can reduce the c-axis lattice constant and shift the metal-insulator transition(MIT)temperature TMIT.To probe the origin of the MIT at cryogenic temperatures,experimental measurements of magnetoresistance were conducted,and theoretical analysis was carried out using the Kondo model,Hikami-Larkin-Nagaoka equation,and other methods.The results indicate that as Nd doping rises,the contributions of the Kondo effect and two-dimensional weak localization(WL)first decrease and then increase.The total contribution of WL and the Kondo effect in the mid-doped La_(1.5)Nd_(1.5)Ni_(2)O_(7)sample was the smallest,which to some extent explains the changes in TMIT.The Kondo effect dominates in other La_(3−x)Nd_(x)Ni_(2)O_(7)(x=0,1.0,2.0,and 2.5)samples.This work demonstrates that cation doping has a significant impact on bilayer nickelates,providing experimental evidence for understanding the physical mechanism of the MIT in bilayer nickelates.
基金supported by the National Key Research and Development Program of China(2021YFB2400202)the National Natural Science Foundation of China(52104313)+1 种基金the Key Research and Development Plan of Shaanxi(2024GH-YBXM-11)the Foshan Science and Technology Innovation Team Project(1920001004098).
文摘ZnO with good lithiophilicity has widely been employed to modify the lithiophobic substrates and facilitate uniform lithium(Li)deposition.The overpotential of ZnO-derived Li anode during cycling depends on the lithiophilicity of both LiZn and Li_(2)O products upon lithiation of ZnO.However,the striking differences in the lithiophilicity between Li_(2)O and LiZn would result in a high overpotential during cycling.In this research,the Al_(2)O_(3)/nZnO(n≥1)hybrid layers were precisely fabricated by atomic layer deposition(ALD)to regulate the lithiophilicity of ZnO phase and Li_(2)O/LiZn configuration—determining the actual Li loading amount and Li plating/stripping processes.Theoretically,the Li adsorption energy(E_(a))values of LiZn and Li_(2)O in the LiZn/Li_(2)O configuration are separately predicted as-2.789 and-3.447 eV.In comparison,the E_(a) values of LiZn,LiAlO_(2),and Li_(2)O in the LiZn/LiAlO_(2)/Li_(2)O configuration upon lithiation of Al_(2)O_(3)/8ZnO layer are calculated as-2.899,-3.089,and-3.208 eV,respectively.Importantly,a novel introduction of LiAlO_(2)into the LiZn/Li_(2)O configuration could enable the hierarchical Li plating/stripping and reduce the overpotentials during cycling.Consequently,the Al_(2)O_(3)/8ZnO-derived hybrid Li-metal anode could exhibit electrochemical performances superior to these of ZnO-derived Li anode in both symmetrical and full cells paired with a LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)(NCM622)cathode.
基金Project supported by the National Natural Science Foundation of China(No.61504139,61275040)Chinese Academy of Sciences(No.Y072051002)
文摘A hot spot is a reliability problem in photovoltaic(PV) modules where a mismatched or shaded cell heats up significantly and degrades the PV module output power performance. High PV cell temperature due to a hot spot can damage the cell encapsulate and lead to second breakdown, which both cause permanent damage to the PV module. In present systems, bypass diodes are used to mitigate the hot spot problem. In this work, five commercial polysilicon P V modules configured with different numbers of bypass diodes are used to study the influence of bypass diodes on the reverse bias voltage of a shaded cell and the resulting hot spot phenomenon. The reverse bias voltage of the shaded cell, and the hot spot probability and severity decrease as the number of bypass diodes increases. Negative terminal voltage of a shaded cell accompanied by a switched-off bypass diode are the necessary condition for hot spot generation. In an extreme case where each cell has an individual bypass diode in a P V module, it still cannot avoid the hazards of a hot spot under the shading areas of 5-7 cm2, but the probability of a hot spot is reduced to a minimum of 0.41%.
文摘Selecting a cost optimum subset of discrete-value dispersion compensation modules (DV-DCMs) subject to maximum module count from an available set of DV-DCMs is a NP-hard problem. We derive a novel dynamic programming algorithm with pseudo-polynomial time bound and show that DV-DCM cost re-scaling can improve the running time.
