We calibrate the macroscopic vortex high-order harmonic generation(HHG)obtained by the quantitative rescattering(QRS)model to compute single-atom induced dipoles against that by solving the time-dependent Schr?dinger ...We calibrate the macroscopic vortex high-order harmonic generation(HHG)obtained by the quantitative rescattering(QRS)model to compute single-atom induced dipoles against that by solving the time-dependent Schr?dinger equation(TDSE).We show that the QRS perfectly agrees with the TDSE under the favorable phase-matching condition,and the QRS can accurately predict the main features in the spatial profiles of vortex HHG if the phase-matching condition is not good.We uncover that harmonic emissions from short and long trajectories are adjusted by the phase-matching condition through the time-frequency analysis and the QRS can simulate the vortex HHG accurately only when the interference between two trajectories is absent.This work confirms that it is an efficient way to employ the QRS model in the single-atom response for precisely simulating the macroscopic vortex HHG.展开更多
Synthesis of multi-color laser pulses has been developed as a promising way to improve low conversion efficiency of high-order harmonic generation(HHG). Here we systematically study the effect of laser focus in a two-...Synthesis of multi-color laser pulses has been developed as a promising way to improve low conversion efficiency of high-order harmonic generation(HHG). Here we systematically study the effect of laser focus in a two-color waveform on generation of macroscopic HHG in soft x-rays. We find that the dependence of HHG yields on laser focus at low or high gas pressure is sensitive to the characteristics of single-atom harmonic response, in which “short”-or “long”-trajectory emissions can be selectively controlled by changing the waveform of two-color synthesized laser pulse. We uncover the phase-matching mechanism of HHG in the gas medium by examining the propagation of the two-color waveform and the evolution of time-frequency emissions of high-harmonic field. We further reveal that the nonlinear effects, such as geometric phase, atomic dispersion, and plasma defocusing, are responsible for modification of two-color waveform upon propagation. This work can be used to find better macroscopic conditions for generating soft x-ray HHG by employing two-color optimized waveforms.展开更多
The development of high-efficiency and cost-effective bifunctional electrocatalysts for overall water splitting remains a formidable challenge.Herein,FeNi-Nd_(2)O_(3) nanoparticles anchored on N-doped carbon nanotubes...The development of high-efficiency and cost-effective bifunctional electrocatalysts for overall water splitting remains a formidable challenge.Herein,FeNi-Nd_(2)O_(3) nanoparticles anchored on N-doped carbon nanotubes(FeNi-Nd_(2)O_(3)/NCN) are designed for highly effective overall water splitting via a facile two-step hydrothermal approach.The synthetic FeNi-Nd_(2)O_(3) hetero-trimers(Fe 2p-Ni 2p-Nd 3d orbital coupling)on NCN achieve excellent oxygen evolution reaction(OER) and hydrogen evolution reaction(HER) activities with overpotentials of 270 and 120 mV at 10 mA cm^(-2) in 1 M KOH solution.Moreover,a small voltage of 1.52 V at 10 mA cm^(-2) is achieved when FeNi-Nd_(2)O_(3)/NCN is assessed as bifunctional catalyst for overall water splitting,which is superior to the typically integrated Pt/C and RuO_(2) counterparts(1.54 V at 10 mA cm^(-2)).The related characterizations including X-ray absorption fine structure(XAFS)spectroscopy show that the remarkably improved activity is originated from Nd_(2)O_(3)-induced FeNi bimetallic lattice contraction.Furthermore,density functional theory(DFT) calculations indicate that the lattice contraction reduces binding energies of intermediates by downshifting the position of FeNi bimetallic d-band center relative to the Fermi level to optimize catalytic performance.Therefore,the Nd_(2)O_(3)-induced FeNi bimetallic lattice contraction may provide a new perspective for designing and synthesizing innovative catalytic systems.展开更多
Precisely reducing the size of metal-organic frameworks(MOFs)derivatives is an effective strategy to manipulate their phase engineering owing to size-dependent oxidation;however,the underlying relationship between the...Precisely reducing the size of metal-organic frameworks(MOFs)derivatives is an effective strategy to manipulate their phase engineering owing to size-dependent oxidation;however,the underlying relationship between the size of derivatives and phase engineering has not been clarified so far.Herein,a spatial confined growth strategy is proposed to encapsulate small-size MOFs derivatives into hollow carbon nanocages.It realizes that the hollow cavity shows a significant spatial confinement effect on the size of confined MOFs crystals and subsequently affects the dielectric polarization due to the phase hybridization with tunable coherent interfaces and heterojunctions owing to size-dependent oxidation motion,yielding to satisfied microwave attenuation with an optimal reflection loss of-50.6 d B and effective bandwidth of 6.6 GHz.Meanwhile,the effect of phase hybridization on dielectric polarization is deeply visualized,and the simulated calculation and electron holograms demonstrate that dielectric polarization is shown to be dominant dissipation mechanism in determining microwave absorption.This spatial confined growth strategy provides a versatile methodology for manipulating the size of MOFs derivatives and the understanding of size-dependent oxidation-induced phase hybridization offers a precise inspiration in optimizing dielectric polarization and microwave attenuation in theory.展开更多
Recently, the synthesis of new elements above Z = 118 has been a hot topic in nuclear physics. Meanwhile, the α-decay chain is expected to be the unique tool to identify these heaviest nuclei. We have systematically ...Recently, the synthesis of new elements above Z = 118 has been a hot topic in nuclear physics. Meanwhile, the α-decay chain is expected to be the unique tool to identify these heaviest nuclei. We have systematically calculated the α-decay energies and half-lives on the same footing for superheavy nuclei (SHN) within the cluster model along with a slightly modified Woods-Saxon (W.S.) potential as the nuclear potential. Based on the available experimental data, the key radius parameter (R) in the α-core potential is determined via the systematic trend from the α-decay and isotopic chains. The α-decay energy (Qα) values and half-lives are then obtained simultaneously for those unknown SHN in the range of 117 ≤ Z ≤ 120, during which the decay width is obtained using a new treatment for the asymptotic behavior of the α-core wave function. The theoretical values and experimental data are found to be in excellent agreement for the nuclei ^(293,294)117 and ^(294)118 regardless of the method used to determine the R parameter. Predicting the α-decay chains for new elements Z = 119 and Z = 120 can be useful in ongoing or forthcoming experiments.展开更多
As a fundamental thermodynamic variable, pressure can alter the bonding patterns and drive phase transitions leading to the creation of new high-pressure phases with exotic properties that are inaccessible at ambient ...As a fundamental thermodynamic variable, pressure can alter the bonding patterns and drive phase transitions leading to the creation of new high-pressure phases with exotic properties that are inaccessible at ambient pressure. Using the swarm intelligence structural prediction method, the phase transition of TiF_(3), from R-3c to the Pnma phase, was predicted at high pressure, accompanied by the destruction of TiF_6 octahedra and formation of TiF_8 square antiprismatic units. The Pnma phase of TiF_(3), formed using the laser-heated diamond-anvil-cell technique was confirmed via high-pressure x-ray diffraction experiments. Furthermore, the in situ electrical measurements indicate that the newly found Pnma phase has a semiconducting character, which is also consistent with the electronic band structure calculations. Finally, it was shown that this pressure-induced phase transition is a general phenomenon in ScF_(3), VF_(3), CrF_(3), and MnF_(3), offering valuable insights into the high-pressure phases of transition metal trifluorides.展开更多
The contradiction between classical and quantum physics can be identified through quantum contextuality, which does not need composite systems or spacelike separation. Contextuality is proven either by a logical contr...The contradiction between classical and quantum physics can be identified through quantum contextuality, which does not need composite systems or spacelike separation. Contextuality is proven either by a logical contradiction between the noncontextuality hidden variable predictions and those of quantum mechanics or by the violation of noncontextual inequality. We propose an experimental scheme of state-independent contextual inequality derived from the Mermin proof of the Kochen–Specker(KS) theorem in eight-dimensional Hilbert space, which could be observed either in an individual system or in a composite system. We also show how to resolve the compatibility problems. Our scheme can be implemented in optical systems with current experiment techniques.展开更多
Attosecond transient absorption(ATA)has been developed as an all-optical technique for probing electron dynamics in matter.Here we present a scheme that can modify the laserinduced state and the corresponding ATA spec...Attosecond transient absorption(ATA)has been developed as an all-optical technique for probing electron dynamics in matter.Here we present a scheme that can modify the laserinduced state and the corresponding ATA spectrum via excitation by a pair of XUV attosecond pulses and by a time-delayed mid-infrared(MIR)laser probe.Different from the scheme of the electronic excitation by a single XUV attosecond pulse,the application of a pair of XUV pulses provides extra degrees of freedom,such as the time delay and the intensity ratio between two XUV pulses,which make it possible to adjust the pump process,resulting in the modification of the ATA spectrum.We show that by varying the time delay between the two XUV pulses,the population of the dark state and the ATA spectrum of the laser-induced state have periodic modulations.We also demonstrate that the peak of the ATA spectrum of the laser-induced state appears at a fixed time delay between the XUV pair and the MIR laser when the intensity ratio is large,and it changes with the time delay when the intensity ratio is small,which can be related to either one of two peaks in the population of the dark state.展开更多
In addition to the Coulomb displacement energy,the residual differences between the binding energies of mirror nuclei(a pair of nuclei with the same mass number plus interchanged proton and neutron numbers)contribute ...In addition to the Coulomb displacement energy,the residual differences between the binding energies of mirror nuclei(a pair of nuclei with the same mass number plus interchanged proton and neutron numbers)contribute to the shell effect via the valence scheme in this study.To this end,one linear combining type of valence nucleon number,namely,αNp+βNn,is chosen to tackle this shell correction,in which Npand Nnare the valence proton and neutron numbers with respect to the nearest shell closure,respectively.The mass differences of mirror nuclei,as the sum of the empirical Coulomb displacement energy and shell effect correction,are then used to obtain the binding energies of proton-rich nuclei through the available data of their mirror partners to explore the proton dripline of the nuclear chart.展开更多
Quantum error correction is essential for achieving reliable quantum information processing tasks,as it can mitigate the detrimental effects of noise by encoding single-qubit information into a larger quantum system.H...Quantum error correction is essential for achieving reliable quantum information processing tasks,as it can mitigate the detrimental effects of noise by encoding single-qubit information into a larger quantum system.However,the generation of distributed entanglement between logical qubits located within two spatially separated nodes presents a significant resource-intensive challenge that has yet to be overcome.Here we present a heralded protocol for generating distributed entanglement between two nonlocal error-protected logical qubits.A high-dimensional single photon can evolve physical qubits into a logical qubit that entangles with the photon and then converts logical qubit-photon entanglement into entanglement between two logical qubits,when the photon state is properly tuned and an effective photon-spin interface between single photons and individual spins is exploited.Furthermore,the success of the entanglement generation is heralded by the detection of the photon,and the corresponding efficiency can,in principle,approach unity.These distinguished features make our protocol highly appealing for future large-scale quantum technologies.展开更多
The efficiency of photocatalytic CO_(2) reduction reaction(PCRR)is restricted by the low solubility and mobility of CO_(2) in water,poor CO_(2) adsorption capacity of catalyst,and competition with hydrogen evolution r...The efficiency of photocatalytic CO_(2) reduction reaction(PCRR)is restricted by the low solubility and mobility of CO_(2) in water,poor CO_(2) adsorption capacity of catalyst,and competition with hydrogen evolution reaction(HER).Recently,hydrophobic modification of the catalyst surface has been proposed as a potential solution to induce the formation of triple-phase contact points(TPCPs)of CO_(2)(gas phase),H_(2) O(liquid phase),and catalysts(solid phase)near the surface of the catalyst,enabling direct delivery of highly concentrated CO_(2) molecules to the active reaction sites,resulting in higher CO_(2) and lower H+surface concentrations.The TPCPs thus act as the ideal reaction points with enhanced PCRR and suppressed HER.However,the initial synthesis of triple-phase photocatalysts tends to possess a lower bulk density of TPCPs due to the simple structure leading to limited active points and CO_(2) adsorption sites.Here,based on constructing a hydrophobic hierarchical porous TiO_(2)(o-HPT)with interconnected macropores and mesopores structure,we have significantly increased the density of TPCPs in a unit volume of the photocatalyst.Compared with hydrophobic macroporous TiO_(2)(o-MacPT)or mesoporous TiO_(2)(o-MesPT),the o-HPT with increased TPCP density leads to enhanced photoactivity,enabling a high methanol production rate with 1111.5μmol g^(−1) h^(−1) from PCRR.These results emphasize the significance of high-density TPCPs design and propose a potential path for developing efficient PCRR systems.展开更多
The overall photocatalytic CO_(2) reduction reaction(OPCRR)that can directly convert CO_(2) and H_(2)O into fuels represents a promising renewable energy conversion technology.As a typical redox reaction,the OPCRR inv...The overall photocatalytic CO_(2) reduction reaction(OPCRR)that can directly convert CO_(2) and H_(2)O into fuels represents a promising renewable energy conversion technology.As a typical redox reaction,the OPCRR involves two half-reactions:the CO_(2) reduction half-reaction(CRHR)and the water oxidation half-reaction(WOHR).Generally,both half-reactions can be promoted by adjusting the wettability of catalysts.However,there is a contradiction in wettability requirements for the two half-reactions.Specifically,CRHR prefers a hydrophobic surface that can accumulate more CO_(2) molecules on the active sites,ensuring the appropriate ratio of gas-phase(CO_(2))to liquid-phase(H_(2)O)reactants.Conversely,the WOHR prefers a hydrophilic surface that can promote the departure of the gaseous product(O_(2))from the catalyst surface,preventing isolation between active sites and the reactant(H_(2)O).Here,we successfully reconciled the contradictory wettability requirements for the CRHR and WOHR by creating an alternately hydrophobic catalyst.This was achieved through a selectively hydrophobic modification method and a charge-transfer-control strategy.Consequently,the collaboratively promoted CRHR and WOHR led to a significantly enhanced OPCRR with a solar-to-fuel conversion efficiency of 0.186%.Notably,in ethanol production,the catalyst exhibited a 10.64-fold increase in generation rate(271.44μmol g^(-1)h~(-1))and a 4-fold increase in selectivity(55.77%)compared to the benchmark catalyst.This innovative approach holds great potential for application in universal overall reactions involving gas participation.展开更多
The propagating of laser-generated ultrasonic waves in K9 glass was investigated. Many methods have been developed to detect the laser ultrasound since laser ultrasonic waves can be used to measure material parameters...The propagating of laser-generated ultrasonic waves in K9 glass was investigated. Many methods have been developed to detect the laser ultrasound since laser ultrasonic waves can be used to measure material parameters or characterize materials properties. In order to reduce the measuring time, a Mach–Zehnder interferometer, a full field measuring tool,was preferred in this paper. The ultrasonic wave was produced on the K9 glass surface by a Q-switched Nd:YAG laser absorbed in a liquid layer. The interferograms were then taken at various delay times by a CCD camera after single pulse induced laser ultrasonic waves. Ultrasonic waves in the K9 glass can be observed from interferogram images. The results provide an understanding of laser ultrasound propagation in K9 glass in the lifetime.展开更多
Photocatalytic hydrogen generation represents a promising strategy for the establishment of a sustainable and environmentally friendly energy reservoir.However,the current solar-to-hydrogen conversion efficiency is no...Photocatalytic hydrogen generation represents a promising strategy for the establishment of a sustainable and environmentally friendly energy reservoir.However,the current solar-to-hydrogen conversion efficiency is not yet sufficient for practical hydrogen production,highlighting the need for further research and development.Here,we report the synthesis of a Sn-doped TiO_(2)continuous homojunction hollow sphere,achieved through controlled calcination time.The incorporation of a gradient doping profile has been demonstrated to generate a gradient in the band edge energy,facilitating carrier orientation migration.Furthermore,the hollow sphere’s outer and inner sides provide spatially separated reaction sites allowing for the separate acceptance of holes and electrons,which enables the rapid utilization of carriers after separation.As a result,the hollow sphere TiO_(2)with gradient Sn doping exhibits a significantly increased hydrogen production rate of 20.1 mmol·g^(−1)·h^(−1).This study offers a compelling and effective approach to the designing and fabricating highly efficient nanostructured photocatalysts for solar energy conversion applications.展开更多
One variety of ferroelectricity that results from lateral relative movements between the adjacent atomic layers is referred to as sliding ferroelectricity,which generates an interfacial charge transfer and hence a pol...One variety of ferroelectricity that results from lateral relative movements between the adjacent atomic layers is referred to as sliding ferroelectricity,which generates an interfacial charge transfer and hence a polarization reversal.The mechanism of sliding ferroelectricity existent in van der Waals crystals is quite distinct from the conventional ferroelectric switching mechanisms mediated by ion displacement.It creates new possibilities for the design of two-dimensional(2D)ferroelectrics since it can be achieved even in non-polar systems.Before 2D ferroelectrics can be widely employed for practical implementations,however,there is still significant work to be done on several fronts,such as exploring ferroelectricity possibly in more potential 2D systems.Here,we report the experimental observation of room-temperature robust vertical ferroelectricity in layered semiconducting rhenium diselenide(ReSe_(2)),a representative member of the transition metal dichalcogenides material family,based on a combined research of nanoscale piezoresponse and second harmonic generation measurements.While no such ferroelectric behavior was seen in 1L ReSe_(2),2L ReSe_(2)exhibits vertical ferroelectricity at ambient environment.Based on density-functional theory calculations,we deduce that the microscopic origin of ferroelectricity for ReSe_(2)is uncompensated vertical charge transfer that is dependent on in-plane translation and switchable upon interlayer sliding.Our findings have important ramifications for the ongoing development of sliding ferroelectricity since the semiconducting properties and low switching barrier of ReSe2 open up the fascinating potential for functional nanoelectronics applications.展开更多
Nonadiabatic dynamics around an avoided crossing or a conical intersection play a crucial role in the photoinduced processes of most polyatomic molecules.The present work shows that the topological phase in conical in...Nonadiabatic dynamics around an avoided crossing or a conical intersection play a crucial role in the photoinduced processes of most polyatomic molecules.The present work shows that the topological phase in conical intersection makes the behavior of pump-probe high-order harmonic signals different from the case of avoided crossing.The coherence built up when the system crosses the avoided crossing will lead to the oscillatory behavior of the spectrum,while the geometric phase erodes these oscillations in the case of conical intersection.Additionally,the dynamical blueshift and the splitting of the time-resolved spectrum allow capturing the snapshot dynamics with the sub-femtosecond resolution.展开更多
Multiparty quantum communication is an important branch of quantum networks.It enables private information transmission with information-theoretic security among legitimate parties.We propose a sender-controlled measu...Multiparty quantum communication is an important branch of quantum networks.It enables private information transmission with information-theoretic security among legitimate parties.We propose a sender-controlled measurement-device-independent multiparty quantum communication protocol.The sender Alice divides a private message into several parts and delivers them to different receivers for secret sharing with imperfect measurement devices and untrusted ancillary nodes.Furthermore,Alice acts as an active controller and checks the security of quantum channels and the reliability of each receiver before she encodes her private message for secret sharing,which makes the protocol convenient for multiparity quantum communication.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos.12274230,91950102,and 11834004)the Funding of Nanjing University of Science and Technology (Grant No.TSXK2022D005)the Postgraduate Research&Practice Innovation Program of Jiangsu Province of China (Grant No.KYCX230443)。
文摘We calibrate the macroscopic vortex high-order harmonic generation(HHG)obtained by the quantitative rescattering(QRS)model to compute single-atom induced dipoles against that by solving the time-dependent Schr?dinger equation(TDSE).We show that the QRS perfectly agrees with the TDSE under the favorable phase-matching condition,and the QRS can accurately predict the main features in the spatial profiles of vortex HHG if the phase-matching condition is not good.We uncover that harmonic emissions from short and long trajectories are adjusted by the phase-matching condition through the time-frequency analysis and the QRS can simulate the vortex HHG accurately only when the interference between two trajectories is absent.This work confirms that it is an efficient way to employ the QRS model in the single-atom response for precisely simulating the macroscopic vortex HHG.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.91950102,12274230,and 11834004)the Funding of Nanjing University of Science and Technology (Grant No.TSXK2022D005)。
文摘Synthesis of multi-color laser pulses has been developed as a promising way to improve low conversion efficiency of high-order harmonic generation(HHG). Here we systematically study the effect of laser focus in a two-color waveform on generation of macroscopic HHG in soft x-rays. We find that the dependence of HHG yields on laser focus at low or high gas pressure is sensitive to the characteristics of single-atom harmonic response, in which “short”-or “long”-trajectory emissions can be selectively controlled by changing the waveform of two-color synthesized laser pulse. We uncover the phase-matching mechanism of HHG in the gas medium by examining the propagation of the two-color waveform and the evolution of time-frequency emissions of high-harmonic field. We further reveal that the nonlinear effects, such as geometric phase, atomic dispersion, and plasma defocusing, are responsible for modification of two-color waveform upon propagation. This work can be used to find better macroscopic conditions for generating soft x-ray HHG by employing two-color optimized waveforms.
基金supported by the National Natural Science Foundation of China (NSFC) (52171206, 51762013)the Key Project of Hebei Natural Science Foundation (E20202201030)+5 种基金the BeijingTianjin-Hebei Collaborative Innovation Community Construction Project (21344301D)The Second Batch of Young Talent of Hebei Province (70280016160250, 70280011808)the Key Fund in Hebei Province Department of Education China (ZD2021014)The Central Government Guide Local Funding Projects for Scientific and Technological Development (216Z4404G, 206Z4402G)the Interdisciplinary Research Program of Natural Science of Hebei University (DXK202107)the China Postdoctoral Science Foundation (No. 2021M701718)。
文摘The development of high-efficiency and cost-effective bifunctional electrocatalysts for overall water splitting remains a formidable challenge.Herein,FeNi-Nd_(2)O_(3) nanoparticles anchored on N-doped carbon nanotubes(FeNi-Nd_(2)O_(3)/NCN) are designed for highly effective overall water splitting via a facile two-step hydrothermal approach.The synthetic FeNi-Nd_(2)O_(3) hetero-trimers(Fe 2p-Ni 2p-Nd 3d orbital coupling)on NCN achieve excellent oxygen evolution reaction(OER) and hydrogen evolution reaction(HER) activities with overpotentials of 270 and 120 mV at 10 mA cm^(-2) in 1 M KOH solution.Moreover,a small voltage of 1.52 V at 10 mA cm^(-2) is achieved when FeNi-Nd_(2)O_(3)/NCN is assessed as bifunctional catalyst for overall water splitting,which is superior to the typically integrated Pt/C and RuO_(2) counterparts(1.54 V at 10 mA cm^(-2)).The related characterizations including X-ray absorption fine structure(XAFS)spectroscopy show that the remarkably improved activity is originated from Nd_(2)O_(3)-induced FeNi bimetallic lattice contraction.Furthermore,density functional theory(DFT) calculations indicate that the lattice contraction reduces binding energies of intermediates by downshifting the position of FeNi bimetallic d-band center relative to the Fermi level to optimize catalytic performance.Therefore,the Nd_(2)O_(3)-induced FeNi bimetallic lattice contraction may provide a new perspective for designing and synthesizing innovative catalytic systems.
基金This work was financially supported by the National Natural Science Foundation of China(U21A2093 and 52102370)the Natural Science Foundation of Shaanxi Province(2022JM-260)+2 种基金the Shanghai Key Laboratory of R&D for Metallic Functional Materials(2021-01)and Open Fund of Key Laboratory for Advanced Technology in Environmental Protection of Jiangsu Province(JBGS014)Open access funding provided by Shanghai Jiao Tong University
文摘Precisely reducing the size of metal-organic frameworks(MOFs)derivatives is an effective strategy to manipulate their phase engineering owing to size-dependent oxidation;however,the underlying relationship between the size of derivatives and phase engineering has not been clarified so far.Herein,a spatial confined growth strategy is proposed to encapsulate small-size MOFs derivatives into hollow carbon nanocages.It realizes that the hollow cavity shows a significant spatial confinement effect on the size of confined MOFs crystals and subsequently affects the dielectric polarization due to the phase hybridization with tunable coherent interfaces and heterojunctions owing to size-dependent oxidation motion,yielding to satisfied microwave attenuation with an optimal reflection loss of-50.6 d B and effective bandwidth of 6.6 GHz.Meanwhile,the effect of phase hybridization on dielectric polarization is deeply visualized,and the simulated calculation and electron holograms demonstrate that dielectric polarization is shown to be dominant dissipation mechanism in determining microwave absorption.This spatial confined growth strategy provides a versatile methodology for manipulating the size of MOFs derivatives and the understanding of size-dependent oxidation-induced phase hybridization offers a precise inspiration in optimizing dielectric polarization and microwave attenuation in theory.
基金Supported by the National Natural Science Foundation of China (12075121),the Natural Science Foundation of Jiangsu Province (BK20190067),and the Fundamental Research Funds for the Central Universities (30922010312)。
文摘Recently, the synthesis of new elements above Z = 118 has been a hot topic in nuclear physics. Meanwhile, the α-decay chain is expected to be the unique tool to identify these heaviest nuclei. We have systematically calculated the α-decay energies and half-lives on the same footing for superheavy nuclei (SHN) within the cluster model along with a slightly modified Woods-Saxon (W.S.) potential as the nuclear potential. Based on the available experimental data, the key radius parameter (R) in the α-core potential is determined via the systematic trend from the α-decay and isotopic chains. The α-decay energy (Qα) values and half-lives are then obtained simultaneously for those unknown SHN in the range of 117 ≤ Z ≤ 120, during which the decay width is obtained using a new treatment for the asymptotic behavior of the α-core wave function. The theoretical values and experimental data are found to be in excellent agreement for the nuclei ^(293,294)117 and ^(294)118 regardless of the method used to determine the R parameter. Predicting the α-decay chains for new elements Z = 119 and Z = 120 can be useful in ongoing or forthcoming experiments.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 12034009, 91961204, and 11974134)。
文摘As a fundamental thermodynamic variable, pressure can alter the bonding patterns and drive phase transitions leading to the creation of new high-pressure phases with exotic properties that are inaccessible at ambient pressure. Using the swarm intelligence structural prediction method, the phase transition of TiF_(3), from R-3c to the Pnma phase, was predicted at high pressure, accompanied by the destruction of TiF_6 octahedra and formation of TiF_8 square antiprismatic units. The Pnma phase of TiF_(3), formed using the laser-heated diamond-anvil-cell technique was confirmed via high-pressure x-ray diffraction experiments. Furthermore, the in situ electrical measurements indicate that the newly found Pnma phase has a semiconducting character, which is also consistent with the electronic band structure calculations. Finally, it was shown that this pressure-induced phase transition is a general phenomenon in ScF_(3), VF_(3), CrF_(3), and MnF_(3), offering valuable insights into the high-pressure phases of transition metal trifluorides.
基金Project supported by the National Natural Science Foundation of China (Grant No. U1930402)support from the Project Funded by China Postdoctoral Science Foundation (Grant Nos. 2020M680006 and 2021T140045)+1 种基金support from the National Natural Science Foundation of China (Grant No. 12004184)the Natural Science Foundation of Jiangsu Province, China (Grants No. BK20190428)。
文摘The contradiction between classical and quantum physics can be identified through quantum contextuality, which does not need composite systems or spacelike separation. Contextuality is proven either by a logical contradiction between the noncontextuality hidden variable predictions and those of quantum mechanics or by the violation of noncontextual inequality. We propose an experimental scheme of state-independent contextual inequality derived from the Mermin proof of the Kochen–Specker(KS) theorem in eight-dimensional Hilbert space, which could be observed either in an individual system or in a composite system. We also show how to resolve the compatibility problems. Our scheme can be implemented in optical systems with current experiment techniques.
基金supported by the National Natural Science Foundation of China(Grant Nos.91950102 and 11834004)the Natural Science Foundation of Jiangsu Province(Grant No.BK20220925)the Funding of Nanjing University of Science and Technology(NJUST)(Grant No.TSXK2022D005)
文摘Attosecond transient absorption(ATA)has been developed as an all-optical technique for probing electron dynamics in matter.Here we present a scheme that can modify the laserinduced state and the corresponding ATA spectrum via excitation by a pair of XUV attosecond pulses and by a time-delayed mid-infrared(MIR)laser probe.Different from the scheme of the electronic excitation by a single XUV attosecond pulse,the application of a pair of XUV pulses provides extra degrees of freedom,such as the time delay and the intensity ratio between two XUV pulses,which make it possible to adjust the pump process,resulting in the modification of the ATA spectrum.We show that by varying the time delay between the two XUV pulses,the population of the dark state and the ATA spectrum of the laser-induced state have periodic modulations.We also demonstrate that the peak of the ATA spectrum of the laser-induced state appears at a fixed time delay between the XUV pair and the MIR laser when the intensity ratio is large,and it changes with the time delay when the intensity ratio is small,which can be related to either one of two peaks in the population of the dark state.
基金Supported by the National Natural Science Foundation of China(12075121 and 11605089)by the Natural Science Foundation of Jiangsu Province(BK20190067 and BK20150762)。
文摘In addition to the Coulomb displacement energy,the residual differences between the binding energies of mirror nuclei(a pair of nuclei with the same mass number plus interchanged proton and neutron numbers)contribute to the shell effect via the valence scheme in this study.To this end,one linear combining type of valence nucleon number,namely,αNp+βNn,is chosen to tackle this shell correction,in which Npand Nnare the valence proton and neutron numbers with respect to the nearest shell closure,respectively.The mass differences of mirror nuclei,as the sum of the empirical Coulomb displacement energy and shell effect correction,are then used to obtain the binding energies of proton-rich nuclei through the available data of their mirror partners to explore the proton dripline of the nuclear chart.
基金supported by the National Natural Science Foundation of China(Grant Nos.11904171,and 62221004)the Fundamental Research Funds for the Central Universities(Grant No.30922010807)。
文摘Quantum error correction is essential for achieving reliable quantum information processing tasks,as it can mitigate the detrimental effects of noise by encoding single-qubit information into a larger quantum system.However,the generation of distributed entanglement between logical qubits located within two spatially separated nodes presents a significant resource-intensive challenge that has yet to be overcome.Here we present a heralded protocol for generating distributed entanglement between two nonlocal error-protected logical qubits.A high-dimensional single photon can evolve physical qubits into a logical qubit that entangles with the photon and then converts logical qubit-photon entanglement into entanglement between two logical qubits,when the photon state is properly tuned and an effective photon-spin interface between single photons and individual spins is exploited.Furthermore,the success of the entanglement generation is heralded by the detection of the photon,and the corresponding efficiency can,in principle,approach unity.These distinguished features make our protocol highly appealing for future large-scale quantum technologies.
基金National Natural Science Foundation of China(Nos.22008121,11774173,51790492)the National Outstanding Youth Science Fund Project of National Natural Science Foundation of China(No.T2125004)+2 种基金the Fundamental Research Funds for the Central Universities(Nos.30920032204,30920041115)the Foundation of State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering(No.2022-K12)Funding of NJUST(No.TSXK2022D002)for financial support.
文摘The efficiency of photocatalytic CO_(2) reduction reaction(PCRR)is restricted by the low solubility and mobility of CO_(2) in water,poor CO_(2) adsorption capacity of catalyst,and competition with hydrogen evolution reaction(HER).Recently,hydrophobic modification of the catalyst surface has been proposed as a potential solution to induce the formation of triple-phase contact points(TPCPs)of CO_(2)(gas phase),H_(2) O(liquid phase),and catalysts(solid phase)near the surface of the catalyst,enabling direct delivery of highly concentrated CO_(2) molecules to the active reaction sites,resulting in higher CO_(2) and lower H+surface concentrations.The TPCPs thus act as the ideal reaction points with enhanced PCRR and suppressed HER.However,the initial synthesis of triple-phase photocatalysts tends to possess a lower bulk density of TPCPs due to the simple structure leading to limited active points and CO_(2) adsorption sites.Here,based on constructing a hydrophobic hierarchical porous TiO_(2)(o-HPT)with interconnected macropores and mesopores structure,we have significantly increased the density of TPCPs in a unit volume of the photocatalyst.Compared with hydrophobic macroporous TiO_(2)(o-MacPT)or mesoporous TiO_(2)(o-MesPT),the o-HPT with increased TPCP density leads to enhanced photoactivity,enabling a high methanol production rate with 1111.5μmol g^(−1) h^(−1) from PCRR.These results emphasize the significance of high-density TPCPs design and propose a potential path for developing efficient PCRR systems.
基金financially supported by the National Natural Science Foundation of China(22378204,22008121,51790492)the National Outstanding Youth Science Fund Project of National Natural Science Foundation of China(T2125004)+1 种基金the Funding of NJUST(No.TSXK2022D002)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX23_0454)。
文摘The overall photocatalytic CO_(2) reduction reaction(OPCRR)that can directly convert CO_(2) and H_(2)O into fuels represents a promising renewable energy conversion technology.As a typical redox reaction,the OPCRR involves two half-reactions:the CO_(2) reduction half-reaction(CRHR)and the water oxidation half-reaction(WOHR).Generally,both half-reactions can be promoted by adjusting the wettability of catalysts.However,there is a contradiction in wettability requirements for the two half-reactions.Specifically,CRHR prefers a hydrophobic surface that can accumulate more CO_(2) molecules on the active sites,ensuring the appropriate ratio of gas-phase(CO_(2))to liquid-phase(H_(2)O)reactants.Conversely,the WOHR prefers a hydrophilic surface that can promote the departure of the gaseous product(O_(2))from the catalyst surface,preventing isolation between active sites and the reactant(H_(2)O).Here,we successfully reconciled the contradictory wettability requirements for the CRHR and WOHR by creating an alternately hydrophobic catalyst.This was achieved through a selectively hydrophobic modification method and a charge-transfer-control strategy.Consequently,the collaboratively promoted CRHR and WOHR led to a significantly enhanced OPCRR with a solar-to-fuel conversion efficiency of 0.186%.Notably,in ethanol production,the catalyst exhibited a 10.64-fold increase in generation rate(271.44μmol g^(-1)h~(-1))and a 4-fold increase in selectivity(55.77%)compared to the benchmark catalyst.This innovative approach holds great potential for application in universal overall reactions involving gas participation.
基金This work was supported by the National Natural Science Foundation of China(NNSFC)(Nos.61975080 and 11774176).
文摘The propagating of laser-generated ultrasonic waves in K9 glass was investigated. Many methods have been developed to detect the laser ultrasound since laser ultrasonic waves can be used to measure material parameters or characterize materials properties. In order to reduce the measuring time, a Mach–Zehnder interferometer, a full field measuring tool,was preferred in this paper. The ultrasonic wave was produced on the K9 glass surface by a Q-switched Nd:YAG laser absorbed in a liquid layer. The interferograms were then taken at various delay times by a CCD camera after single pulse induced laser ultrasonic waves. Ultrasonic waves in the K9 glass can be observed from interferogram images. The results provide an understanding of laser ultrasound propagation in K9 glass in the lifetime.
基金the National Natural Science Foundation of China(Nos.22008121,11774173,and 51790492)the National Outstanding Youth Science Fund Project of National Natural Science Foundation of China(No.T2125004)+2 种基金the Fundamental Research Funds for the Central Universities(Nos.30920032204,30920021307,and 30920041115)the Foundation of State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering(No.2022-K12)the Funding of NJUST(No.TSXK2022D002)for financial support.
文摘Photocatalytic hydrogen generation represents a promising strategy for the establishment of a sustainable and environmentally friendly energy reservoir.However,the current solar-to-hydrogen conversion efficiency is not yet sufficient for practical hydrogen production,highlighting the need for further research and development.Here,we report the synthesis of a Sn-doped TiO_(2)continuous homojunction hollow sphere,achieved through controlled calcination time.The incorporation of a gradient doping profile has been demonstrated to generate a gradient in the band edge energy,facilitating carrier orientation migration.Furthermore,the hollow sphere’s outer and inner sides provide spatially separated reaction sites allowing for the separate acceptance of holes and electrons,which enables the rapid utilization of carriers after separation.As a result,the hollow sphere TiO_(2)with gradient Sn doping exhibits a significantly increased hydrogen production rate of 20.1 mmol·g^(−1)·h^(−1).This study offers a compelling and effective approach to the designing and fabricating highly efficient nanostructured photocatalysts for solar energy conversion applications.
基金supported by the Eational Eatural Science Foundation of China(Nos.12004182 and T2125004)Jiangsu Province Science Foundation(No.BK20200481)the China Postdoctoral Science Foundation(No.2021M691587).
文摘One variety of ferroelectricity that results from lateral relative movements between the adjacent atomic layers is referred to as sliding ferroelectricity,which generates an interfacial charge transfer and hence a polarization reversal.The mechanism of sliding ferroelectricity existent in van der Waals crystals is quite distinct from the conventional ferroelectric switching mechanisms mediated by ion displacement.It creates new possibilities for the design of two-dimensional(2D)ferroelectrics since it can be achieved even in non-polar systems.Before 2D ferroelectrics can be widely employed for practical implementations,however,there is still significant work to be done on several fronts,such as exploring ferroelectricity possibly in more potential 2D systems.Here,we report the experimental observation of room-temperature robust vertical ferroelectricity in layered semiconducting rhenium diselenide(ReSe_(2)),a representative member of the transition metal dichalcogenides material family,based on a combined research of nanoscale piezoresponse and second harmonic generation measurements.While no such ferroelectric behavior was seen in 1L ReSe_(2),2L ReSe_(2)exhibits vertical ferroelectricity at ambient environment.Based on density-functional theory calculations,we deduce that the microscopic origin of ferroelectricity for ReSe_(2)is uncompensated vertical charge transfer that is dependent on in-plane translation and switchable upon interlayer sliding.Our findings have important ramifications for the ongoing development of sliding ferroelectricity since the semiconducting properties and low switching barrier of ReSe2 open up the fascinating potential for functional nanoelectronics applications.
基金supported by the National Key Research and Development Program of China (Grant No.2022YFA1604301)the National Natural Science Foundation of China (Grant Nos.12074124 and 11974185)+1 种基金Zijiang Endowed Young Scholar Fund,East China Normal University,and Overseas Expertise Introduction Project for Discipline Innovation (B12024)support by the start-up funding from East China Normal University.
文摘Nonadiabatic dynamics around an avoided crossing or a conical intersection play a crucial role in the photoinduced processes of most polyatomic molecules.The present work shows that the topological phase in conical intersection makes the behavior of pump-probe high-order harmonic signals different from the case of avoided crossing.The coherence built up when the system crosses the avoided crossing will lead to the oscillatory behavior of the spectrum,while the geometric phase erodes these oscillations in the case of conical intersection.Additionally,the dynamical blueshift and the splitting of the time-resolved spectrum allow capturing the snapshot dynamics with the sub-femtosecond resolution.
基金supported by the National Natural Science Foundation of China(Grant No.11904171)the Natural Science Foundation of Jiangsu Province(Grant No.BK20180461).
文摘Multiparty quantum communication is an important branch of quantum networks.It enables private information transmission with information-theoretic security among legitimate parties.We propose a sender-controlled measurement-device-independent multiparty quantum communication protocol.The sender Alice divides a private message into several parts and delivers them to different receivers for secret sharing with imperfect measurement devices and untrusted ancillary nodes.Furthermore,Alice acts as an active controller and checks the security of quantum channels and the reliability of each receiver before she encodes her private message for secret sharing,which makes the protocol convenient for multiparity quantum communication.