Cu_(2)ZnSn(S,Se)_(4)(CZTSSe)is considered to be the most potential light-absorbing material to replace CuInGaSe_(2)(CIGS),but the actual photoelectric conversion efficiency of such cells is much lower than that of CIG...Cu_(2)ZnSn(S,Se)_(4)(CZTSSe)is considered to be the most potential light-absorbing material to replace CuInGaSe_(2)(CIGS),but the actual photoelectric conversion efficiency of such cells is much lower than that of CIGS.One of the reasons is the high recombination rate of carriers at the interface.In this paper,in order to reduce the carrier recombination,a new solar cell structure with double absorber layers of Al-doped ZnO(AZO)/intrinsic(i)-ZnO/CdS/CZTS_(x1)Se_(1−x1)(CZTSSe_(1))/CZTS_(x2)Se_(1−x2)(CZTSSe_(2))/Mo was proposed,and the optimal conduction band offsets(CBOs)of CdS/CZTSSe_(1) interface and CZTSSe_(1)/CZTSSe_(2) interface were determined by changing the S ratio in CZTSSe_(1) and CZTSSe_(2),and the effect of thickness of CZTSSe_(1) on the performance of the cell was studied.The efficiencies of the optimized single and double absorber layers reached 17.97%and 23.4%,respectively.Compared with the single absorber layer structure,the proposed structure with double absorber layers has better cell performance.展开更多
CO_(2)hydrogenation to value-added light olefins(C_(2-4)=)is crucial for the utilization and cycling of global carbon resource.Moderate CO_(2)activation and carbon chain growth ability are key factors for iron-based c...CO_(2)hydrogenation to value-added light olefins(C_(2-4)=)is crucial for the utilization and cycling of global carbon resource.Moderate CO_(2)activation and carbon chain growth ability are key factors for iron-based catalysts for efficient CO_(2)conversion to target C_(2-4)=products.The electronic interaction and confinement effect of electron-deficient graphene inner surface on the active phase are effective to improve surface chemical properties and enhance the catalytic performance.Here,we report a core-shell FeCo alloy catalyst with graphene layers confinement prepared by a simple sol-gel method.The electron transfer from Fe species to curved graphene inner surface modifies the surface electronic structure of the active phaseχ-(Fe_(x)Co_(1-x))_(5)C_(2)and improves CO_(2)adsorption capacity,enhancing the efficient conversion of CO_(2)and moderate C-C coupling.Therefore,the catalyst FeCoK@C exhibits C_(2-4)=selectivity of 33.0%while maintaining high CO_(2)conversion of 52.0%.The high stability without obvious deactivation for over 100 h and unprecedented C_(2-4)=space time yield(STY)up to 52.9 mmolCO_(2)·g^(-1)·h^(-1)demonstrate its potential for practical application.This work provides an efficient strategy for the development of high-performance CO_(2)hydrogenation catalysts.展开更多
The charge carrier transport and recombination dynamics in the quantum dots-based light-emitting diodes(QLEDs)featuring multiple emitting layers(M-EMLs)has a great impact on the device performance.In this work,QLEDs b...The charge carrier transport and recombination dynamics in the quantum dots-based light-emitting diodes(QLEDs)featuring multiple emitting layers(M-EMLs)has a great impact on the device performance.In this work,QLEDs based on M-EMLs separated by polyethyleneimine ethoxylated(PEIE)layer with different stacking sequences of blue(B),green(G),and red(R)QDs layer were used to intuitively explore the injection,transportation and recombination processes of the charge carriers in QLEDs by using the time-resolved electroluminescence(TrEL)spectra.From the TrEL spectra mea-surements,green and red emissions were obtained first in the QLEDs with the EMLs sequences of G/PEIE/B/PEIE/R and B/PEIE/R/PEIE/G along the direction of light emission,respectively.While the QLEDs adopt EMLs sequences of B/PEIE/G/PEIE/R,the blue,green and red emissions were obtained nearly at the same time.The above phenomenon can be attributed to different charge carrier transmission and radiation recombination process in the EMLs due to different valence band offsets and conduction band offsets between R-,G-and B-QDs by using different sequences of EMLs.White emission with coordi-nates of(0.31,0.31)and correlated color temperature(CCT)of 5916 K was obtained in the QLEDs with the EMLs se-quences of B/PEIE/G/PEIE/R,which can be attributed to the relative uniform emission of B-,G-and R-QDs due to the effec-tive injection and radiation recombination of charge carriers in each of the EMLs.The above results have great significance for further understanding and improving the performance of QLEDs with M-EMLs.展开更多
Separator modification is an effective approach to suppress dendrite growth to realize high-energy sodium metal batteries(SMBs)in practical applications,however,its success is mainly subject to surface modification.He...Separator modification is an effective approach to suppress dendrite growth to realize high-energy sodium metal batteries(SMBs)in practical applications,however,its success is mainly subject to surface modification.Herein,a separator with multifunctional layers composed of N-doped mesoporous hollow carbon spheres(HCS)as the inner layer and sodium fluoride(NaF)as the outer layer on commercial polypropylene separator(PP)is proposed(PP@HCS-NaF)to achieve stable cycling in SMB.At the molecular level,the inner HCS layer with a high content of pyrrolic-N induces the uniform Na^(+)flux as a potential Na^(+)redistributor for homogenous deposition,whereas its hollow mesoporous structure offers nanoporous buffers and ion channels to regulate Na^(+)ion distribution and uniform deposition.The outer layer(NaF)constructs the NaF-enriched robust solid electrolyte interphase layer,significantly lowering the Na^(+)ions diffusion barrier.Benefiting from these merits,higher electrochemical performances are achieved with multifunctional double-layered PP@HCS-NaF separators compared with single-layered separators(i.e.PP@HCS or PP@NaF)in SMBs.The Na‖Cu half-cell with PP@HCS-NaF offers stable cycling(280 cycles)with a high CE(99.6%),and Na‖Na symmetric cells demonstrate extended lifespans for over 6000 h at 1 mA cm^(-2)with a progressively stable overpotential of 9 mV.Remarkably,in Na‖NVP full-cells,the PP@HCS-NaF separator grants a stable capacity of~81 mA h g^(-1)after 3500 cycles at 1 C and an impressive rate capability performance(~70 mA h g^(-1)at 15 C).展开更多
The global drive for sustainable energy solutions intensified interest in anion exchange membrane water electrolysis(AEMWE),as a promising hydrogen production pathway,leveraging renewable energy sources.However,widesp...The global drive for sustainable energy solutions intensified interest in anion exchange membrane water electrolysis(AEMWE),as a promising hydrogen production pathway,leveraging renewable energy sources.However,widespread adoption is hindered by the high cost and non-optimised design of crucial components,such as porous transport layers(PTL)and flow fields.This study comprehensively investigates the interplay between structure,mechanics,and electrochemical performance of a low-cost knitted wire mesh PTL,focusing on its potential to enhance cell assembly and operation.Electrochemical characterisation was performed on a single 4 cm^(2)cell,using 1M KOH at 60℃.Knitted wire mesh PTL,characterised by approximately 70%porosity,2mm thickness,and 1.098 tortuosity,delivered a 33%improvement in current density compared to the standard cell configuration.Introducing a knitted PTL interlayer reduced cell voltage by 74 mV at 2 A cm^(−2)by improving compression force distribution across the active area,enhancing gas transport and maintaining optimal electrical and thermal conductivity.These findings highlight the significant potential of innovative PTL designs in AEMWE to improve mechanical and operational efficiency without increasing the cost.展开更多
Traditional numerical integration requires sufficient smoothness of the integrand to achieve high-order algebraic accuracy.If the function has a boundary layer with large gradient,the composite integration formula on ...Traditional numerical integration requires sufficient smoothness of the integrand to achieve high-order algebraic accuracy.If the function has a boundary layer with large gradient,the composite integration formula on the uniform mesh will produce very large integration errors.In this paper,we study the Newton-Cotes formula based on Lagrange interpolation functions,local L^(2) projection approximating the integrand,and Gauss integration.On the Shishkin mesh,we establish an optimal-order integration error estimate uniformly in the perturbation parameter.The convergence rate is the same as that for the smooth function.Numerical experiments confirm the sharpness of our theoretical results.展开更多
Silicon(Si)has gained popularity as a potential anodic material for Li-ion batteries(LIBs)due to its large theoretical capacity.However,low conductivity,large volume expansion,and side reactions during alloying and de...Silicon(Si)has gained popularity as a potential anodic material for Li-ion batteries(LIBs)due to its large theoretical capacity.However,low conductivity,large volume expansion,and side reactions during alloying and de-alloying lead to poor cyclic and bad high-rate performance,which has severely hindered its practical large-scale application.Herein,a novel stamen-structured Si-based anode material with a protective SiO_(x)layer and dual carbon layers(Si@SiO_(x)/C@C)is designed for high-performance LIBs.The protective SiO_(x)layer reduces side reactions and dual carbon layers enhance charge transport to improve reaction kinetics,while the unique structure provides buffering space for volume expansion.Such Si@SiO_(x)/C@C anode demonstrates impressive Li storage properties for a half-battery,including a discharge capacity of 2935 mA h g^(-1)at a current density 0.1 A g^(-1),cyclic performance(814 mA h g^(-1)at 2 A g^(-1)over 500 cycles and 988 mA h g^(-1)over 200 cycles at 1 A g^(-1))and a rate performance(609 mA h g^(-1)at 5 A g^(-1)).It also maintains a high reversible capacity of 131 mA h g^(-1)at 0.25 C after100 cycles for a full battery.This work provides insights into the novel design of multiple protective layers on Si-based anode materials for fast-charging and highly stable LIBs.展开更多
Rechargeable zinc-ion batteries have emerged as one of the most promising candidates for large-scale energy storage applications due to their high safety and low cost.However,the use of Zn metal in batteries suffers f...Rechargeable zinc-ion batteries have emerged as one of the most promising candidates for large-scale energy storage applications due to their high safety and low cost.However,the use of Zn metal in batteries suffers from many severe issues,including dendrite growth and parasitic reactions,which often lead to short cycle lives.Herein,we propose the construction of functional organic interfacial layers(OIL)on the Zn metal anodes to address these challenges.Through a well-designed organic-assist pre-construction process,a densely packed artificial layer featuring the immobilized zwitterionic molecular brush can be constructed,which can not only efficiently facilitate the smooth Zn plating and stripping,but also introduce a stable environment for battery reactions.Through density functional theory calculations and experimental characterizations,we verify that the immobilized organic propane sulfonate on Zn anodes can significantly lower the energy barrier and increase the kinetics of Zn^(2+)transport.Thus,the Zn metal anode with the functional OIL can significantly improve the cycle life of the symmetric cell to over 3500 h stable operation.When paired with the H_(2)V_(3)O_(8)cathode,the aqueous Zn-ion full cells can be continuously cycled over 7000 cycles,marking an important milestone for Zn anode development for potential industrial applications.展开更多
Synergistic interplays involving multiple active centers originating from TiO2 nanotube layers(TNT)and ruthenium(Ru)species comprising of both single atoms(SAs)and nanoparticles(NPs)augment the alkaline hydrogen evolu...Synergistic interplays involving multiple active centers originating from TiO2 nanotube layers(TNT)and ruthenium(Ru)species comprising of both single atoms(SAs)and nanoparticles(NPs)augment the alkaline hydrogen evolution reaction(HER)by enhancing Volmer kinetics from rapid water dissociation and improving Tafel kinetics from efficient H*desorption.Atomic layer deposition of Ru with 50 process cycles results in a mixture of Ru SAs and 2.8-0.4 nm NPs present on TNT layers,and it emerges with the highest HER activity among all the electrodes synthesized.A detailed study of the Ti and Ru species using different high-resolution techniques confirmed the presence of Ti^(3+)states and the coexistence of Ru SAs and NPs.With insights from literature,the role of Ti^(3+),appropriate work functions of TNT layers and Ru,and the synergistic effect of Ru SAs and Ru NPs in improving the performance of alkaline HER were elaborated and justified.The aforementioned characteristics led to a remarkable performance by having 9mV onset potentials and 33 mV dec^(-1) of Tafel slopes and a higher turnover frequency of 1.72 H2 s^(-1) at 30 mV.Besides,a notable stability from 28 h staircase chronopotentiometric measurements for TNT@Ru surpasses TNT@Pt in comparison.展开更多
Given the limited exposure of active sites and the retarded separation of photogenerated charge carriers in those developed photocata-lysts,photocatalyticCO_(2)splitting into value-added chemicals has suffered from th...Given the limited exposure of active sites and the retarded separation of photogenerated charge carriers in those developed photocata-lysts,photocatalyticCO_(2)splitting into value-added chemicals has suffered from the poor activity and remained in great challenge for real application.Herein,hydrothermally synthesized BiOCl with layered structure(BOC-NSs)was exfoliated into thickness reduced nanosheets(BOCNSs-w)and even atomic layers(BOCNSs-i)via ultrasonication in water and isopro-panol,respectively.In comparison with the pristine BOCNSs,the exfoli-ated BiOCl,especially BOCNSs-i with atomically layered structure,exhibits much improved photocatalytic activity forCO_(2)overall splitting to produce CO andO_(2) at a stoichiometric ratio of 2:1,with CO evolution rate reaching 134.8µmolg^(-1)h^(-1) under simulated solar light(1.7 suns).By surpassing the photocatalytic performances of the state-of-the-artBi_(l)O_(m)X_(n)(X:Cl,Br,I)based photocatalysts,the CO evolution rate is further increased by 99 times,reaching 13.3 mmolg^(-1)h^(-1) under concentrated solar irradiation(34 suns).This excellent photocatalytic performance achieved over BOCNSs-i should be benefited from the shortened transfer distance and the increased built-in electric field intensity,which acceler-ates the migration of photogenerated charge carriers to surface.Moreover,with oxygen vacancies(VO)introduced into the atomic layers,BOCNSs-i is exposed with the electrons enriched Bi active sites that could transfer electrons to activateCO_(2)molecules for highly efficient and selective CO production,by lowering the energy barrier of rate-determining step(RDS),*OH+*CO_(2)-→HCO_(3)-.It is also realized that theH_(2)O vapor supplied during photocatalytic reaction would exchange oxygen atoms withCO_(2),which could alter the reaction path-ways and further reduce the energy barrier of RDS,contributing to the dramatically improved photocatalytic performance forCO_(2)overall splitting to CO andO_(2).展开更多
The empirical models for wavenumber-frequency spectra of wall pressure are broadly used in the fast prediction of aerodynamic and hydrodynamic noise.However,it needs to fit the parameter using massive data and is only...The empirical models for wavenumber-frequency spectra of wall pressure are broadly used in the fast prediction of aerodynamic and hydrodynamic noise.However,it needs to fit the parameter using massive data and is only used for limited cases.In this letter,we propose Kolmogorov-Arnold networks(KAN)base models for wavenumber-frequency spectra of pressure fluctuations under turbulent boundary layers.The results are compared with DNS results.In turbulent channel flows,it is found that the KAN base model leads to a smooth wavenumber-frequency spectrum with sparse samples.In the turbulent flow over an axisymmetric body of revolution,the KAN base model captures the wavenumber-frequency spectra near the convective peak.展开更多
Surface oxide layers play a significant role in forming secondary oxidation inclusions during the casting process.In this study,three typical Mg-RE alloys(Mg-3Nd(NZ30K),Mg-3Nd-3Gd(EV33)and Mg-3Nd-4Y(WE43A))are selecte...Surface oxide layers play a significant role in forming secondary oxidation inclusions during the casting process.In this study,three typical Mg-RE alloys(Mg-3Nd(NZ30K),Mg-3Nd-3Gd(EV33)and Mg-3Nd-4Y(WE43A))are selected.Their surface oxide layers formed during the solidification are characterized in detail,and the corresponding oxidation mechanisms are discussed.The results reveal that RE elements obviously influence the characteristics of surface oxide layers,which depends on their ability to purify the formed MgO in the melt via the reaction(2RE+3MgO=3Mg+RE_(2)O_(3)).On the one hand,as Nd and Gd do not easily displace MgO already formed in the melt,the loose oxide layers in NZ30K and EV33 alloys are mainly composed of MgO matrix with embedded RE-rich oxide particles.On the other hand,due to the strong ability of Y to purify MgO in the melt,the oxide layer of WE43A alloy becomes a denser and thinner Y_(2)O_(3) oxide layer.Note that the differences in surface oxide layers well explain the different secondary inclusions that occur in three typical Mg-RE alloys during the casting process.展开更多
Synchrotron method of resonant X-ray reflectivity 2D mapping has been applied to study ultrathin epitaxial layers of WS_(2)grown by pulsed laser deposition on Al_(2)O_(3)(0001)substrates.The measurements were carried ...Synchrotron method of resonant X-ray reflectivity 2D mapping has been applied to study ultrathin epitaxial layers of WS_(2)grown by pulsed laser deposition on Al_(2)O_(3)(0001)substrates.The measurements were carried out across the L absorption edge of tungsten to perform depth-dependent element-selective analysis sensitive to potential chemical modification of the WS_(2)layer in ambient conditions.Despite the few monolayer thickness of the studied film,the experimentally measured maps of reflectance as a function of incident angle and photon energy turned out to be quite informative showing well-pronounced interference effects near W absorption edge at 10210 eV.The synchrotron studies were complemented with conventional non-resonant reflectance measurements carried out in the laboratory at a fixed photon energy corresponding to Cu Kαemission.The reconstruction of the depth and energy dependent scattering length density within the studied multilayers was carried out using the OpenCL empowered fitting software utilizing spectral shaping algorithm which does not rely on the pre-measured reference absorption spectra.A thin WO_(x) layer has been revealed at the surface of the WS_(2)layer pointing out to the effect of water assisted photo-oxidation reported in a number of works related to ultrathin layers of transition metal dichalcogenides.展开更多
Promising aqueous zinc metal batteries(AZMBs)continue to face significant challenges regarding zinc anode reversibility due to detrimental reactions including hydrogen evolution and corrosion.Herein,the d-band center ...Promising aqueous zinc metal batteries(AZMBs)continue to face significant challenges regarding zinc anode reversibility due to detrimental reactions including hydrogen evolution and corrosion.Herein,the d-band center is used as an“intuitive descriptor”to compare the hydrogen evolution activity of zinc-based transition bimetallic oxides(ZTBOs)of fourth-period transition metal elements,and the advantages of ZnTi_(3)O_(7)(ZTO)functional protective layer in inhibiting hydrogen evolution and extending the lifespan of the zinc anode are selectively identified.展开更多
We present the results of two ground-based radio-echo-sounding（RES） and GPS surveys performed in the vicinity of new Chinese Taishan station,Princess Elizabeth Land,East Antarctica,obtained in two austral summers du...We present the results of two ground-based radio-echo-sounding（RES） and GPS surveys performed in the vicinity of new Chinese Taishan station,Princess Elizabeth Land,East Antarctica,obtained in two austral summers during CHINARE 21（2004/2005） and CHINARE 29（2012/2013）.The radar surveys measured ice thickness and internal layers using 60- and 150-MHz radar systems,and GPS measurements showed smooth surface slopes around the station with altitudes of 2607-2636 m above sea level（a.s.l.）.Radar profiles indicate an average ice thickness of 1900 m,with a maximum of 1949 m and a minimum of 1856 m,within a square area measuring approximately 2 km × 2 km in the vicinity of the station.The ice thickness beneath the station site is 1870 m.The subglacial landscape beneath the station is quiet sharp and ranges from 662 to 770 m a.s.l.,revealing part of a mountainous topography.The ice volume in the grid is estimated to be 7.6 km^3.Along a 60-MHz radar profile with a length of 17.6 km at the region covering the station site,some disturbed internal layers are identified and traced;the geometry of internal layers within the englacial stratigraphy may imply a complex depositional process in the area.展开更多
Mn-based layered oxides are widely recognized as cathode materials for potassium-ion batteries(KIBs)due to their high specific capacity derived from their low molar mass.However,the structural instability caused by th...Mn-based layered oxides are widely recognized as cathode materials for potassium-ion batteries(KIBs)due to their high specific capacity derived from their low molar mass.However,the structural instability caused by the Jahn-Teller effect of Mn^(3+)and the large ionic radius of K+results in poor electrochemical performance.Herein,we propose an effective structural stabilization strategy for P2-type Mn-based layered oxide cathodes of KIBs through Li-incorporation into the transition metal layer.Using the firstprinciples calculations and experiments,we demonstrate that the P2-K_(0.48)[Li_(0.1)Mn_(0.9)]O_(2)(P2-KLMO)delivers improved electrochemical performance,specific capacity and average discharge voltage of~124.4 m A h g^(-1)and~2.7 V(vs.K^(+)/K)at 0.05C(1C=260 mA g^(-1)),outperforming P2-K_(0.5)MnO_(2).Operando X-ray diffraction analysis confirms the P2-OP4 phase transition and Mn^(3+)-induced Jahn-Teller distortion are significantly suppressed in P2-KLMO.These improvements are attributed to the lithium introduction into transition metal layers,leading to strengthened structural stability and enhanced K+diffusion kinetics.Moreover,synthetic accessibility through the conventional solid-state method provides an additional advantage for practical application of Li-incorporated Mn-based P2-type cathodes in KIBs.We believe our study offers a simple yet effective strategy for designing highperformance and practical cathode materials for KIBs.展开更多
Shale gas reservoirs have large burial depths,thin thickness,and low resistance,which lead to problems with weak surface observation,abnormal information,and multiple inversion solutions.The traditional electromagneti...Shale gas reservoirs have large burial depths,thin thickness,and low resistance,which lead to problems with weak surface observation,abnormal information,and multiple inversion solutions.The traditional electromagnetic method cannot effectively identify information from deep,low-resistance thin layers in terms of detection depth and accuracy.Wide field electromagnetic method(WFEM)with large depth and high precision has become the main method for deep earth exploration.This method has been widely used in the exploration of deep oil and gas energy,as well as mineral resources.However,an in-depth analysis of the various factors that affect the deep detection ability of WFEM is lacking.Therefore,the analysis of system parameters has significant theoretical importance and practical value for studying the effectiveness of WFEM in deep-layer identification.In this study,a multilayer geoelectric model is established in this study using the measured well data.The influence characteristics of different observation system parameters on the resolution of specific deep-seated targets under the WFEM_E-Ex mode are analyzed in detail through forward modeling and inversion.Results show that the resolution ability of WFEM for deep,low-resistance thin layers is affected by factors such as transceiver distance,target layer thickness,and resistivity difference between the target body and the surrounding rock,but the influence range differs.This study analyzes the influence characteristics of various system parameters.It provides targeted work scheme design and feasibility analysis for deep shale gas exploration.It also offers an important theoretical basis for optimizing construction schemes and improving the recognition ability of WFEM for deep,low-resistance targets.展开更多
A sparsely introduced basal intrinsic 2-type stacking fault(I_(2)-SF)with a dense segregation of clusters(cluster-arranged layer;CAL)inα-Mg exerts a sufficient strengthening effect with a reduced content of additive ...A sparsely introduced basal intrinsic 2-type stacking fault(I_(2)-SF)with a dense segregation of clusters(cluster-arranged layer;CAL)inα-Mg exerts a sufficient strengthening effect with a reduced content of additive elements.Moreover,the dynamic nucleation and growth of CALs during deformation largely improves the creep resistance.This paper analyzes the cosegregation behaviors of yttrium(Y)and zinc(Zn)atoms at an I_(2)-SF in bulk and at basal edge dislocations using density functional theory calculations.We also study the modification of the generalized stacking-fault energy(GSFE)curves associated with the cosegregation.The segregation energies of Y and Zn atoms in the I_(2)-SF are relatively small during the initial segregation of a cluster,but increases stepwise as the cluster grows.After introducing Y and Zn atoms in the I_(2)-SF in an energetically stable order,we obtain an L1_(2)-type cluster resembling that reported in the literature.Small structural changes driven by vacancy diffusion produce an exact L1_(2)-type cluster.Meanwhile,the core of the Shockley partial dislocation generates sufficient segregation energy for cluster nucleation.Migration of the Shockley partial dislocation and expansion of the I_(2)-SF part are observed at a specific cluster size.The migration is triggered by a large modification of the GSFE curve and destabilization of the hexagonal close-packed stacking(hcp)by the segregated atoms.At this point,the cluster has reached sufficient size and continues to follow the growth in the I_(2)-SF part.According to our findings,the CAL at elevated temperature is formed through repeated synchronized behavior of cluster nucleation at the Shockley partial dislocation,dislocation migration triggered by the destabilized hcp stacking,and following of cluster growth in the I_(2)-SF part of the dislocation.展开更多
The E_(s) layer is a thin layer that concentrates metallic ions in the mesosphere and lower thermosphere(MLT)region.When it occurs,it can affect the performance of the Global Navigation Satellite System and high/very ...The E_(s) layer is a thin layer that concentrates metallic ions in the mesosphere and lower thermosphere(MLT)region.When it occurs,it can affect the performance of the Global Navigation Satellite System and high/very high frequency(HF/VHF)radio communications.Previous studies mainly focused on the one-dimensional structure of E_(s) layer in the vertical direction.However,due to the limitation of observations,the horizontal structure of E_(s) layers is not yet fully understood.This study investigated the horizontal structure of E_(s) layers using amateur radio data in the European sector during the summer of 2020.Statistical analysis shows that the horizontal structure of E_(s) layer is mainly elongated in the east-west direction.In addition,we investigated the dynamics of the E_(s) layers,which primarily propagates in the northeast-southwest direction with a speed of 50-200 m/s.The results provide us a way for obtaining the horizontal structure and dynamic features of E_(s) layers,which can help improve our understanding of the formation and evolution of E_(s) layers.展开更多
Self-assembled monolayers(SAMs)have been commonly employed as hole-selective layers(HSLs)in inverted(p-i-n)perovskite solar cells(PSCs),and typically only a single-component SAM is applied,which plays limited role in ...Self-assembled monolayers(SAMs)have been commonly employed as hole-selective layers(HSLs)in inverted(p-i-n)perovskite solar cells(PSCs),and typically only a single-component SAM is applied,which plays limited role in selective hole transport.Herein,we synthesize a novel SAM,(4-(3,11-dibro mo-7H-dibenzo[c,g]carbazol-7-yl)butyl)phosphonic acid(Br-4PADBC),and apply it as a complementary component to the commonly used[2-(3,6-dimeth oxy-9H-carbazol-9-yl)ethyl]phosphonic acid(MeO-2PACz)SAM,accomplishing boosted hole transport in inverted PSCs.A series of characterizations and theoretical calculations are employed to unravel the roles of each components within the binary SAM(bi-SAM).The involvements of the non-planar dibenzo[c,g]carbazole unit and electron-withdrawing Br atoms induce larger dipole moment of Br-4PADBC than MeO-2PACz,resulting in much deeper work function of ITO and consequently improved alignment with the valence band energy level of perovskite.Besides,the introduced Br atoms improve the quality of perovskite crystals and help passivate defects of perovskite.On the other hand,the existence of the conventional MeO-2PACz SAM ensures the considerable conductivity of the bi-SAM and thus efficient hole extraction from the perovskite layer.As a result,inverted PSC devices based on bi-SAM HSL deliver a decent power conversion efficiency(PCE)of 24.52%as well as dramatically improved thermal and operational stabilities.展开更多
基金supported by the Science and Technology Innovation Development Program(No.70304901).
文摘Cu_(2)ZnSn(S,Se)_(4)(CZTSSe)is considered to be the most potential light-absorbing material to replace CuInGaSe_(2)(CIGS),but the actual photoelectric conversion efficiency of such cells is much lower than that of CIGS.One of the reasons is the high recombination rate of carriers at the interface.In this paper,in order to reduce the carrier recombination,a new solar cell structure with double absorber layers of Al-doped ZnO(AZO)/intrinsic(i)-ZnO/CdS/CZTS_(x1)Se_(1−x1)(CZTSSe_(1))/CZTS_(x2)Se_(1−x2)(CZTSSe_(2))/Mo was proposed,and the optimal conduction band offsets(CBOs)of CdS/CZTSSe_(1) interface and CZTSSe_(1)/CZTSSe_(2) interface were determined by changing the S ratio in CZTSSe_(1) and CZTSSe_(2),and the effect of thickness of CZTSSe_(1) on the performance of the cell was studied.The efficiencies of the optimized single and double absorber layers reached 17.97%and 23.4%,respectively.Compared with the single absorber layer structure,the proposed structure with double absorber layers has better cell performance.
文摘CO_(2)hydrogenation to value-added light olefins(C_(2-4)=)is crucial for the utilization and cycling of global carbon resource.Moderate CO_(2)activation and carbon chain growth ability are key factors for iron-based catalysts for efficient CO_(2)conversion to target C_(2-4)=products.The electronic interaction and confinement effect of electron-deficient graphene inner surface on the active phase are effective to improve surface chemical properties and enhance the catalytic performance.Here,we report a core-shell FeCo alloy catalyst with graphene layers confinement prepared by a simple sol-gel method.The electron transfer from Fe species to curved graphene inner surface modifies the surface electronic structure of the active phaseχ-(Fe_(x)Co_(1-x))_(5)C_(2)and improves CO_(2)adsorption capacity,enhancing the efficient conversion of CO_(2)and moderate C-C coupling.Therefore,the catalyst FeCoK@C exhibits C_(2-4)=selectivity of 33.0%while maintaining high CO_(2)conversion of 52.0%.The high stability without obvious deactivation for over 100 h and unprecedented C_(2-4)=space time yield(STY)up to 52.9 mmolCO_(2)·g^(-1)·h^(-1)demonstrate its potential for practical application.This work provides an efficient strategy for the development of high-performance CO_(2)hydrogenation catalysts.
文摘The charge carrier transport and recombination dynamics in the quantum dots-based light-emitting diodes(QLEDs)featuring multiple emitting layers(M-EMLs)has a great impact on the device performance.In this work,QLEDs based on M-EMLs separated by polyethyleneimine ethoxylated(PEIE)layer with different stacking sequences of blue(B),green(G),and red(R)QDs layer were used to intuitively explore the injection,transportation and recombination processes of the charge carriers in QLEDs by using the time-resolved electroluminescence(TrEL)spectra.From the TrEL spectra mea-surements,green and red emissions were obtained first in the QLEDs with the EMLs sequences of G/PEIE/B/PEIE/R and B/PEIE/R/PEIE/G along the direction of light emission,respectively.While the QLEDs adopt EMLs sequences of B/PEIE/G/PEIE/R,the blue,green and red emissions were obtained nearly at the same time.The above phenomenon can be attributed to different charge carrier transmission and radiation recombination process in the EMLs due to different valence band offsets and conduction band offsets between R-,G-and B-QDs by using different sequences of EMLs.White emission with coordi-nates of(0.31,0.31)and correlated color temperature(CCT)of 5916 K was obtained in the QLEDs with the EMLs se-quences of B/PEIE/G/PEIE/R,which can be attributed to the relative uniform emission of B-,G-and R-QDs due to the effec-tive injection and radiation recombination of charge carriers in each of the EMLs.The above results have great significance for further understanding and improving the performance of QLEDs with M-EMLs.
基金supported by the National Natural Science Foundation of China(Grant Number 22350410379)Zhejiang Provincial Natural Science Foundation of China(LZ23B030003)+1 种基金the Fundamental Research Funds for the Central Universities(226-202400075)Ten Thousand Talent Program of Zhejiang Province.
文摘Separator modification is an effective approach to suppress dendrite growth to realize high-energy sodium metal batteries(SMBs)in practical applications,however,its success is mainly subject to surface modification.Herein,a separator with multifunctional layers composed of N-doped mesoporous hollow carbon spheres(HCS)as the inner layer and sodium fluoride(NaF)as the outer layer on commercial polypropylene separator(PP)is proposed(PP@HCS-NaF)to achieve stable cycling in SMB.At the molecular level,the inner HCS layer with a high content of pyrrolic-N induces the uniform Na^(+)flux as a potential Na^(+)redistributor for homogenous deposition,whereas its hollow mesoporous structure offers nanoporous buffers and ion channels to regulate Na^(+)ion distribution and uniform deposition.The outer layer(NaF)constructs the NaF-enriched robust solid electrolyte interphase layer,significantly lowering the Na^(+)ions diffusion barrier.Benefiting from these merits,higher electrochemical performances are achieved with multifunctional double-layered PP@HCS-NaF separators compared with single-layered separators(i.e.PP@HCS or PP@NaF)in SMBs.The Na‖Cu half-cell with PP@HCS-NaF offers stable cycling(280 cycles)with a high CE(99.6%),and Na‖Na symmetric cells demonstrate extended lifespans for over 6000 h at 1 mA cm^(-2)with a progressively stable overpotential of 9 mV.Remarkably,in Na‖NVP full-cells,the PP@HCS-NaF separator grants a stable capacity of~81 mA h g^(-1)after 3500 cycles at 1 C and an impressive rate capability performance(~70 mA h g^(-1)at 15 C).
基金supported by the European Union and the Clean Hydrogen Joint Undertaking(Grant no.101112055).
文摘The global drive for sustainable energy solutions intensified interest in anion exchange membrane water electrolysis(AEMWE),as a promising hydrogen production pathway,leveraging renewable energy sources.However,widespread adoption is hindered by the high cost and non-optimised design of crucial components,such as porous transport layers(PTL)and flow fields.This study comprehensively investigates the interplay between structure,mechanics,and electrochemical performance of a low-cost knitted wire mesh PTL,focusing on its potential to enhance cell assembly and operation.Electrochemical characterisation was performed on a single 4 cm^(2)cell,using 1M KOH at 60℃.Knitted wire mesh PTL,characterised by approximately 70%porosity,2mm thickness,and 1.098 tortuosity,delivered a 33%improvement in current density compared to the standard cell configuration.Introducing a knitted PTL interlayer reduced cell voltage by 74 mV at 2 A cm^(−2)by improving compression force distribution across the active area,enhancing gas transport and maintaining optimal electrical and thermal conductivity.These findings highlight the significant potential of innovative PTL designs in AEMWE to improve mechanical and operational efficiency without increasing the cost.
基金Supported by the National Natural Science Foundation of China(11801396)Natural Science Foundation of Jiangsu Province(BK20170374)+1 种基金Qing Lan Project of Jiangsu UniversityGraduate Student Scientific Research Innovation Projects of Jiangsu Province(KYCX24_3407)。
文摘Traditional numerical integration requires sufficient smoothness of the integrand to achieve high-order algebraic accuracy.If the function has a boundary layer with large gradient,the composite integration formula on the uniform mesh will produce very large integration errors.In this paper,we study the Newton-Cotes formula based on Lagrange interpolation functions,local L^(2) projection approximating the integrand,and Gauss integration.On the Shishkin mesh,we establish an optimal-order integration error estimate uniformly in the perturbation parameter.The convergence rate is the same as that for the smooth function.Numerical experiments confirm the sharpness of our theoretical results.
基金supported by the National Key R&D Program of China(2021YFE0115800)the National Natural Science Foundation of China(22275142,22293022,U22B6011,52103285)+1 种基金the 111 National Project(Grant No.B20002)the Fundamental Research Funds for the Central Universities(2020-YB-005)。
文摘Silicon(Si)has gained popularity as a potential anodic material for Li-ion batteries(LIBs)due to its large theoretical capacity.However,low conductivity,large volume expansion,and side reactions during alloying and de-alloying lead to poor cyclic and bad high-rate performance,which has severely hindered its practical large-scale application.Herein,a novel stamen-structured Si-based anode material with a protective SiO_(x)layer and dual carbon layers(Si@SiO_(x)/C@C)is designed for high-performance LIBs.The protective SiO_(x)layer reduces side reactions and dual carbon layers enhance charge transport to improve reaction kinetics,while the unique structure provides buffering space for volume expansion.Such Si@SiO_(x)/C@C anode demonstrates impressive Li storage properties for a half-battery,including a discharge capacity of 2935 mA h g^(-1)at a current density 0.1 A g^(-1),cyclic performance(814 mA h g^(-1)at 2 A g^(-1)over 500 cycles and 988 mA h g^(-1)over 200 cycles at 1 A g^(-1))and a rate performance(609 mA h g^(-1)at 5 A g^(-1)).It also maintains a high reversible capacity of 131 mA h g^(-1)at 0.25 C after100 cycles for a full battery.This work provides insights into the novel design of multiple protective layers on Si-based anode materials for fast-charging and highly stable LIBs.
基金supported by the Australian Research Council (FT180100705, DP230101579, DE240100868)CSIRO “International Hydrogen Research Collaboration ProgramRESEARCH FELLOWSHIPS”+2 种基金the National Natural Science Foundation of China (22209103)support from the “Joint International Laboratory on Environmental and Energy Frontier Materials”the “Innovation Research Team of High-Level Local Universities in Shanghai”
文摘Rechargeable zinc-ion batteries have emerged as one of the most promising candidates for large-scale energy storage applications due to their high safety and low cost.However,the use of Zn metal in batteries suffers from many severe issues,including dendrite growth and parasitic reactions,which often lead to short cycle lives.Herein,we propose the construction of functional organic interfacial layers(OIL)on the Zn metal anodes to address these challenges.Through a well-designed organic-assist pre-construction process,a densely packed artificial layer featuring the immobilized zwitterionic molecular brush can be constructed,which can not only efficiently facilitate the smooth Zn plating and stripping,but also introduce a stable environment for battery reactions.Through density functional theory calculations and experimental characterizations,we verify that the immobilized organic propane sulfonate on Zn anodes can significantly lower the energy barrier and increase the kinetics of Zn^(2+)transport.Thus,the Zn metal anode with the functional OIL can significantly improve the cycle life of the symmetric cell to over 3500 h stable operation.When paired with the H_(2)V_(3)O_(8)cathode,the aqueous Zn-ion full cells can be continuously cycled over 7000 cycles,marking an important milestone for Zn anode development for potential industrial applications.
基金support from the European Union Horizon 2020 program(project HERMES,nr.952184)the Ministry of Education,Youth and Sports of the Czech Republic for supporting CEMNAT(LM2023037)+1 种基金Czech-NanoLab(LM2023051)infrastructures for providing ALD,SEM,EDX,XPS,TEM,and XRDCzech Science Foundation(project 23-08019X,EXPRO).
文摘Synergistic interplays involving multiple active centers originating from TiO2 nanotube layers(TNT)and ruthenium(Ru)species comprising of both single atoms(SAs)and nanoparticles(NPs)augment the alkaline hydrogen evolution reaction(HER)by enhancing Volmer kinetics from rapid water dissociation and improving Tafel kinetics from efficient H*desorption.Atomic layer deposition of Ru with 50 process cycles results in a mixture of Ru SAs and 2.8-0.4 nm NPs present on TNT layers,and it emerges with the highest HER activity among all the electrodes synthesized.A detailed study of the Ti and Ru species using different high-resolution techniques confirmed the presence of Ti^(3+)states and the coexistence of Ru SAs and NPs.With insights from literature,the role of Ti^(3+),appropriate work functions of TNT layers and Ru,and the synergistic effect of Ru SAs and Ru NPs in improving the performance of alkaline HER were elaborated and justified.The aforementioned characteristics led to a remarkable performance by having 9mV onset potentials and 33 mV dec^(-1) of Tafel slopes and a higher turnover frequency of 1.72 H2 s^(-1) at 30 mV.Besides,a notable stability from 28 h staircase chronopotentiometric measurements for TNT@Ru surpasses TNT@Pt in comparison.
基金the financial support from the National Key R&D Program of China(2024YFF0506100)the National Natural Science Foundation of China(52225606 and 52488201).
文摘Given the limited exposure of active sites and the retarded separation of photogenerated charge carriers in those developed photocata-lysts,photocatalyticCO_(2)splitting into value-added chemicals has suffered from the poor activity and remained in great challenge for real application.Herein,hydrothermally synthesized BiOCl with layered structure(BOC-NSs)was exfoliated into thickness reduced nanosheets(BOCNSs-w)and even atomic layers(BOCNSs-i)via ultrasonication in water and isopro-panol,respectively.In comparison with the pristine BOCNSs,the exfoli-ated BiOCl,especially BOCNSs-i with atomically layered structure,exhibits much improved photocatalytic activity forCO_(2)overall splitting to produce CO andO_(2) at a stoichiometric ratio of 2:1,with CO evolution rate reaching 134.8µmolg^(-1)h^(-1) under simulated solar light(1.7 suns).By surpassing the photocatalytic performances of the state-of-the-artBi_(l)O_(m)X_(n)(X:Cl,Br,I)based photocatalysts,the CO evolution rate is further increased by 99 times,reaching 13.3 mmolg^(-1)h^(-1) under concentrated solar irradiation(34 suns).This excellent photocatalytic performance achieved over BOCNSs-i should be benefited from the shortened transfer distance and the increased built-in electric field intensity,which acceler-ates the migration of photogenerated charge carriers to surface.Moreover,with oxygen vacancies(VO)introduced into the atomic layers,BOCNSs-i is exposed with the electrons enriched Bi active sites that could transfer electrons to activateCO_(2)molecules for highly efficient and selective CO production,by lowering the energy barrier of rate-determining step(RDS),*OH+*CO_(2)-→HCO_(3)-.It is also realized that theH_(2)O vapor supplied during photocatalytic reaction would exchange oxygen atoms withCO_(2),which could alter the reaction path-ways and further reduce the energy barrier of RDS,contributing to the dramatically improved photocatalytic performance forCO_(2)overall splitting to CO andO_(2).
基金supported by the National Natural Science Foundation of China Basic Science Center Program for“Multiscale Problems in Nonlinear Mechanics”(Grant No.11988102)the National Natural Science Foundation of China(Grant Nos.92252203,12102439,and 12425207)+1 种基金the Chinese Academy of Sciences Project for Young Scientists in Basic Research(Grant No.YSBR-087)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB0620102).
文摘The empirical models for wavenumber-frequency spectra of wall pressure are broadly used in the fast prediction of aerodynamic and hydrodynamic noise.However,it needs to fit the parameter using massive data and is only used for limited cases.In this letter,we propose Kolmogorov-Arnold networks(KAN)base models for wavenumber-frequency spectra of pressure fluctuations under turbulent boundary layers.The results are compared with DNS results.In turbulent channel flows,it is found that the KAN base model leads to a smooth wavenumber-frequency spectrum with sparse samples.In the turbulent flow over an axisymmetric body of revolution,the KAN base model captures the wavenumber-frequency spectra near the convective peak.
基金supported by the National Natural Science Foundation of China(Nos.U2037601 and 51821001)Major Scientific and Technological Innovation Projects in Luoyang(No.2201029A)the Research Program of Joint Research Center of Advanced Spaceflight Technologies(Nos.USCAST2020–14 and USCAST2020–31).
文摘Surface oxide layers play a significant role in forming secondary oxidation inclusions during the casting process.In this study,three typical Mg-RE alloys(Mg-3Nd(NZ30K),Mg-3Nd-3Gd(EV33)and Mg-3Nd-4Y(WE43A))are selected.Their surface oxide layers formed during the solidification are characterized in detail,and the corresponding oxidation mechanisms are discussed.The results reveal that RE elements obviously influence the characteristics of surface oxide layers,which depends on their ability to purify the formed MgO in the melt via the reaction(2RE+3MgO=3Mg+RE_(2)O_(3)).On the one hand,as Nd and Gd do not easily displace MgO already formed in the melt,the loose oxide layers in NZ30K and EV33 alloys are mainly composed of MgO matrix with embedded RE-rich oxide particles.On the other hand,due to the strong ability of Y to purify MgO in the melt,the oxide layer of WE43A alloy becomes a denser and thinner Y_(2)O_(3) oxide layer.Note that the differences in surface oxide layers well explain the different secondary inclusions that occur in three typical Mg-RE alloys during the casting process.
基金supported by the Ministry of Science and Higher Education of the Russian Federation(agreement No.075-15-2021-1349)。
文摘Synchrotron method of resonant X-ray reflectivity 2D mapping has been applied to study ultrathin epitaxial layers of WS_(2)grown by pulsed laser deposition on Al_(2)O_(3)(0001)substrates.The measurements were carried out across the L absorption edge of tungsten to perform depth-dependent element-selective analysis sensitive to potential chemical modification of the WS_(2)layer in ambient conditions.Despite the few monolayer thickness of the studied film,the experimentally measured maps of reflectance as a function of incident angle and photon energy turned out to be quite informative showing well-pronounced interference effects near W absorption edge at 10210 eV.The synchrotron studies were complemented with conventional non-resonant reflectance measurements carried out in the laboratory at a fixed photon energy corresponding to Cu Kαemission.The reconstruction of the depth and energy dependent scattering length density within the studied multilayers was carried out using the OpenCL empowered fitting software utilizing spectral shaping algorithm which does not rely on the pre-measured reference absorption spectra.A thin WO_(x) layer has been revealed at the surface of the WS_(2)layer pointing out to the effect of water assisted photo-oxidation reported in a number of works related to ultrathin layers of transition metal dichalcogenides.
基金support from National Natural Science Foundation of China(52272198 and 22109163)。
文摘Promising aqueous zinc metal batteries(AZMBs)continue to face significant challenges regarding zinc anode reversibility due to detrimental reactions including hydrogen evolution and corrosion.Herein,the d-band center is used as an“intuitive descriptor”to compare the hydrogen evolution activity of zinc-based transition bimetallic oxides(ZTBOs)of fourth-period transition metal elements,and the advantages of ZnTi_(3)O_(7)(ZTO)functional protective layer in inhibiting hydrogen evolution and extending the lifespan of the zinc anode are selectively identified.
基金financially supported by the National Natural Science Foundation of China(Grant No.41376192,40906101)the National Basic Research Program of China(973 Program)(Grant No.2013CBA01804 and 2012CB957702)+2 种基金the Foreign Cooperation Support Program of Chinese Arctic and Antarctic Administration,SOA,China(Grand No.IC201214)the Natural Science Foundation of Shanghai,China(Grand No.13ZR1445300)the Chinese Polar Environment Comprehensive Investigation&Assessment Programmes(CHINARE2014-01-01)
文摘We present the results of two ground-based radio-echo-sounding（RES） and GPS surveys performed in the vicinity of new Chinese Taishan station,Princess Elizabeth Land,East Antarctica,obtained in two austral summers during CHINARE 21（2004/2005） and CHINARE 29（2012/2013）.The radar surveys measured ice thickness and internal layers using 60- and 150-MHz radar systems,and GPS measurements showed smooth surface slopes around the station with altitudes of 2607-2636 m above sea level（a.s.l.）.Radar profiles indicate an average ice thickness of 1900 m,with a maximum of 1949 m and a minimum of 1856 m,within a square area measuring approximately 2 km × 2 km in the vicinity of the station.The ice thickness beneath the station site is 1870 m.The subglacial landscape beneath the station is quiet sharp and ranges from 662 to 770 m a.s.l.,revealing part of a mountainous topography.The ice volume in the grid is estimated to be 7.6 km^3.Along a 60-MHz radar profile with a length of 17.6 km at the region covering the station site,some disturbed internal layers are identified and traced;the geometry of internal layers within the englacial stratigraphy may imply a complex depositional process in the area.
基金supported by the National Research Foundation of Korea funded by the Ministry of Science and ICT of Korea(RS-2024-00408156)。
文摘Mn-based layered oxides are widely recognized as cathode materials for potassium-ion batteries(KIBs)due to their high specific capacity derived from their low molar mass.However,the structural instability caused by the Jahn-Teller effect of Mn^(3+)and the large ionic radius of K+results in poor electrochemical performance.Herein,we propose an effective structural stabilization strategy for P2-type Mn-based layered oxide cathodes of KIBs through Li-incorporation into the transition metal layer.Using the firstprinciples calculations and experiments,we demonstrate that the P2-K_(0.48)[Li_(0.1)Mn_(0.9)]O_(2)(P2-KLMO)delivers improved electrochemical performance,specific capacity and average discharge voltage of~124.4 m A h g^(-1)and~2.7 V(vs.K^(+)/K)at 0.05C(1C=260 mA g^(-1)),outperforming P2-K_(0.5)MnO_(2).Operando X-ray diffraction analysis confirms the P2-OP4 phase transition and Mn^(3+)-induced Jahn-Teller distortion are significantly suppressed in P2-KLMO.These improvements are attributed to the lithium introduction into transition metal layers,leading to strengthened structural stability and enhanced K+diffusion kinetics.Moreover,synthetic accessibility through the conventional solid-state method provides an additional advantage for practical application of Li-incorporated Mn-based P2-type cathodes in KIBs.We believe our study offers a simple yet effective strategy for designing highperformance and practical cathode materials for KIBs.
基金supported by the Jingdezhen Science and Technology Plan Project(No.20234SF005)the Jingdezhen University Science and Technology Project(No.2023xjkt-02).
文摘Shale gas reservoirs have large burial depths,thin thickness,and low resistance,which lead to problems with weak surface observation,abnormal information,and multiple inversion solutions.The traditional electromagnetic method cannot effectively identify information from deep,low-resistance thin layers in terms of detection depth and accuracy.Wide field electromagnetic method(WFEM)with large depth and high precision has become the main method for deep earth exploration.This method has been widely used in the exploration of deep oil and gas energy,as well as mineral resources.However,an in-depth analysis of the various factors that affect the deep detection ability of WFEM is lacking.Therefore,the analysis of system parameters has significant theoretical importance and practical value for studying the effectiveness of WFEM in deep-layer identification.In this study,a multilayer geoelectric model is established in this study using the measured well data.The influence characteristics of different observation system parameters on the resolution of specific deep-seated targets under the WFEM_E-Ex mode are analyzed in detail through forward modeling and inversion.Results show that the resolution ability of WFEM for deep,low-resistance thin layers is affected by factors such as transceiver distance,target layer thickness,and resistivity difference between the target body and the surrounding rock,but the influence range differs.This study analyzes the influence characteristics of various system parameters.It provides targeted work scheme design and feasibility analysis for deep shale gas exploration.It also offers an important theoretical basis for optimizing construction schemes and improving the recognition ability of WFEM for deep,low-resistance targets.
基金supported by the Japan Science and Technology Agency(JST),CREST(grant number JapanJPR2094)。
文摘A sparsely introduced basal intrinsic 2-type stacking fault(I_(2)-SF)with a dense segregation of clusters(cluster-arranged layer;CAL)inα-Mg exerts a sufficient strengthening effect with a reduced content of additive elements.Moreover,the dynamic nucleation and growth of CALs during deformation largely improves the creep resistance.This paper analyzes the cosegregation behaviors of yttrium(Y)and zinc(Zn)atoms at an I_(2)-SF in bulk and at basal edge dislocations using density functional theory calculations.We also study the modification of the generalized stacking-fault energy(GSFE)curves associated with the cosegregation.The segregation energies of Y and Zn atoms in the I_(2)-SF are relatively small during the initial segregation of a cluster,but increases stepwise as the cluster grows.After introducing Y and Zn atoms in the I_(2)-SF in an energetically stable order,we obtain an L1_(2)-type cluster resembling that reported in the literature.Small structural changes driven by vacancy diffusion produce an exact L1_(2)-type cluster.Meanwhile,the core of the Shockley partial dislocation generates sufficient segregation energy for cluster nucleation.Migration of the Shockley partial dislocation and expansion of the I_(2)-SF part are observed at a specific cluster size.The migration is triggered by a large modification of the GSFE curve and destabilization of the hexagonal close-packed stacking(hcp)by the segregated atoms.At this point,the cluster has reached sufficient size and continues to follow the growth in the I_(2)-SF part.According to our findings,the CAL at elevated temperature is formed through repeated synchronized behavior of cluster nucleation at the Shockley partial dislocation,dislocation migration triggered by the destabilized hcp stacking,and following of cluster growth in the I_(2)-SF part of the dislocation.
基金supported by the National Natural Science Foundation of China(42230207,42104165).
文摘The E_(s) layer is a thin layer that concentrates metallic ions in the mesosphere and lower thermosphere(MLT)region.When it occurs,it can affect the performance of the Global Navigation Satellite System and high/very high frequency(HF/VHF)radio communications.Previous studies mainly focused on the one-dimensional structure of E_(s) layer in the vertical direction.However,due to the limitation of observations,the horizontal structure of E_(s) layers is not yet fully understood.This study investigated the horizontal structure of E_(s) layers using amateur radio data in the European sector during the summer of 2020.Statistical analysis shows that the horizontal structure of E_(s) layer is mainly elongated in the east-west direction.In addition,we investigated the dynamics of the E_(s) layers,which primarily propagates in the northeast-southwest direction with a speed of 50-200 m/s.The results provide us a way for obtaining the horizontal structure and dynamic features of E_(s) layers,which can help improve our understanding of the formation and evolution of E_(s) layers.
基金the National Natural Science Foundation of China(51925206,U1932214,52302052)the National Natural Science Foundation of China(52322318)+6 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0450301)the Fundamental Research Funds for the Central Universities(WK2060000051,20720220009)the National Key Research and Development Program of China(No.2023YFB3809700)the Innovation and Technology Fund(GHP/100/20SZ,GHP/102/20GD,MRP/040/21X,ITS/147/22FP)the Research Grants Council of Hong Kong Grant(N_City U102/23,C4005-22Y,C1055-23G,11306521)the Green Tech Fund(GTF202020164)the Science Technology and Innovation Committee of Shenzhen Municipality(SGDX20210823104002015,JCYJ20220818101018038)。
文摘Self-assembled monolayers(SAMs)have been commonly employed as hole-selective layers(HSLs)in inverted(p-i-n)perovskite solar cells(PSCs),and typically only a single-component SAM is applied,which plays limited role in selective hole transport.Herein,we synthesize a novel SAM,(4-(3,11-dibro mo-7H-dibenzo[c,g]carbazol-7-yl)butyl)phosphonic acid(Br-4PADBC),and apply it as a complementary component to the commonly used[2-(3,6-dimeth oxy-9H-carbazol-9-yl)ethyl]phosphonic acid(MeO-2PACz)SAM,accomplishing boosted hole transport in inverted PSCs.A series of characterizations and theoretical calculations are employed to unravel the roles of each components within the binary SAM(bi-SAM).The involvements of the non-planar dibenzo[c,g]carbazole unit and electron-withdrawing Br atoms induce larger dipole moment of Br-4PADBC than MeO-2PACz,resulting in much deeper work function of ITO and consequently improved alignment with the valence band energy level of perovskite.Besides,the introduced Br atoms improve the quality of perovskite crystals and help passivate defects of perovskite.On the other hand,the existence of the conventional MeO-2PACz SAM ensures the considerable conductivity of the bi-SAM and thus efficient hole extraction from the perovskite layer.As a result,inverted PSC devices based on bi-SAM HSL deliver a decent power conversion efficiency(PCE)of 24.52%as well as dramatically improved thermal and operational stabilities.
