Reinforced concrete(RC)columns are often subjected to off-central explosion due to the uncertainty of blast locations.However,few studies have focused on the dynamic response of RC columns under offcentral explosions....Reinforced concrete(RC)columns are often subjected to off-central explosion due to the uncertainty of blast locations.However,few studies have focused on the dynamic response of RC columns under offcentral explosions.A field blast experiment was conducted under close-in explosion with varying detonation offset distances(0 m,0.5 m,and 1 m),the overpressure load and dynamic responses of the full-scale RC columns were measured.Compared with the centrally detonated condition,a relative offset distance of 1.67 decreases the maximum and residual deflections of the RC column by 16.8%and 21.4%,respectively,while increasing the maximum and residual support rotations by 24.7%and 17.8%.Based on the experimental results,a theoretical model was proposed that considers the detonation location and charge mass,boundary conditions,axial compression ratio and material properties.The theoretical model exhibited good agreement with the experimental results,with prediction errors below 10%for both maximum and residual deflection.The effects of parameters were analyzed,and it indicated that an increase in offset distance results in decreased maximum and residual deflections but an increased support angle,thereby exacerbating damage.Higher axial load ratio,span-depth ratio,and longitudinal reinforcement ratio reduce both deflections and support angle.Additionally,a rapid method to predict the maximum and residual deflection of RC columns under off-central blast loading was also proposed based on the Generalized Regression Neural Network(GRNN).Eleven features which related to the RC column properties and the blast characteristics were used in the training process of GRNN,and accurate predictions were achieved with prediction errors within 20%.This study fills the gap in predicting the dynamic response of RC columns under off-central explosion,providing valuable references for blast-resistant design.展开更多
Guided by the significant theoretical principle of the“Two Integrations”and grounded in Marxist cultural theory as its methodological basis,this paper constructs a bidirectional interpretative model linking“Yellow ...Guided by the significant theoretical principle of the“Two Integrations”and grounded in Marxist cultural theory as its methodological basis,this paper constructs a bidirectional interpretative model linking“Yellow River Culture”with“Cultural Confidence”.It proposes an integrated“Objective-Content-Path-Support”framework.Through the synergy of three-dimensional objectives,adaptation of stratified content,innovation in four-dimensional pathways,and support from a three-dimensional guarantee system,this framework establishes a closed-loop operational mechanism of“Curriculum-Practice-Evaluation-Feedback”.The study focuses on core issues in integrating Yellow River culture into university education practices,such as content construction,methodological pathways,and institutional guarantees.It aims to provide a systematic reference for universities to fulfill their fundamental task of“fostering virtue and cultivating talent”and to serve the national strategies for ecological protection and high-quality development in the Yellow River Basin.展开更多
The electric double layer(EDL)at the electrochemical interface is crucial for ion transport,charge transfer,and surface reactions in aqueous rechargeable zinc batteries(ARZBs).However,Zn anodes routinely encounter per...The electric double layer(EDL)at the electrochemical interface is crucial for ion transport,charge transfer,and surface reactions in aqueous rechargeable zinc batteries(ARZBs).However,Zn anodes routinely encounter persistent dendrite growth and parasitic reactions,driven by the inhomogeneous charge distribution and water-dominated environment within the EDL.Compounding this,classical EDL theory,rooted in meanfield approximations,further fails to resolve molecular-scale interfacial dynamics under battery-operating conditions,limiting mechanistic insights.Herein,we established a multiscale theoretical calculation framework from single molecular characteristics to interfacial ion distribution,revealing the EDL’s structure and interactions between different ions and molecules,which helps us understand the parasitic processes in depth.Simulations demonstrate that water dipole and sulfate ion adsorption at the inner Helmholtz plane drives severe hydrogen evolution and by-product formation.Guided by these insights,we engineered a“water-poor and anion-expelled”EDL using 4,1’,6’-trichlorogalactosucrose(TGS)as an electrolyte additive.As a result,Zn||Zn symmetric cells with TGS exhibited stable cycling for over 4700 h under a current density of 1 mA cm^(−2),while NaV_(3)O_(8)·1.5H_(2)O-based full cells kept 90.4%of the initial specific capacity after 800 cycles at 5 A g^(−1).This work highlights the power of multiscale theoretical frameworks to unravel EDL complexities and guide high-performance ARZB design through integrated theory-experiment approaches.展开更多
Time-delayed blasting is widely utilized in engineering to mitigate induced vibration hazards and enhance fragmentation.The underlying vibration reduction principle is the decrease of the charge weight per delay,while...Time-delayed blasting is widely utilized in engineering to mitigate induced vibration hazards and enhance fragmentation.The underlying vibration reduction principle is the decrease of the charge weight per delay,while the potential for further vibration reduction remains debated,largely due to unclear underlying mechanisms.In light of the popularization of electronic detonators and the representativeness of double-hole configurationsfor multiple blastholes,it is essential to investigate the vibration characteristics induced by time-delayed double blastholes.Therefore,a series of doubleborehole experimental blasts was conducted in an underground roadway to clarify the variation in vibration from single-hole to dual-hole conditions.Based on the experimental data and inherent limitations,an exact full-fieldtheoretical model was further employed to systematically analyze the effects of delay time,charge length,and borehole inclination angle on vibrations induced by various doublehole configurations.The experimental data and theoretical analysis reveal that the general scaled distance effectively predicts vibrations in delayed blasting but does not reflectvibration reduction.Increasing delay time causes fluctuatingPPVs,which stabilize slightly above single-hole PPVs as delay times exceed a certain value.The delayed blasting primarily reduces near-fieldfrequencies.Longer charge lengths in double boreholes increase PPV levels and attenuation rates within a certain length,and the vibration behavior of combined long and short charge lengths is governed by the long blasthole.Larger blasthole inclination angles enhance vibration amplitude and reduce PPV attenuation rates.Optimizing inclination angles is more critical than adjusting delay times,and parallel boreholes offer the best vibration control.展开更多
This study proposes a framework for the concept of“new quality productive forces”in the ice and snow economy(ISE)as a strategic response to global climate change and the demands of technological and industrial trans...This study proposes a framework for the concept of“new quality productive forces”in the ice and snow economy(ISE)as a strategic response to global climate change and the demands of technological and industrial transformation for high-quality development.These new quality productive forces in the ISE have developed alongside the zonal distribution of natural resources,strictly adhere to ecological principles,and integrate value transformation mechanisms specific to ice and snow resources.Their development is projected to generate multiple benefits across ecological,economic,and social dimensions.The new quality productive forces in the ISE are characterized by technology-driven resource development,synergistic integration across the entire ice and snow industry value chain,and a focus on high-quality,green growth.Grounded in geography and economics,the new quality productive forces in the ISE link scientific innovation,the reallocation of productive factors,and industrial upgrading within the context of resource constraints.Furthermore,they expand the growth potential of the ISE by fostering new production relations through digital,intelligent,and green integration,while advancing low-carbon,sustainable development under the guiding principle that“ice and snow landscapes are also mountains of gold and silver.”For China's ISE,these new quality productive forces emphasize rigorous resource protection,balanced human-environment relationships,a resilient integrated supply chain framework,and an efficient“dual circulation”economic model.Practical strategies include integrating production factors,optimizing spatial resource allocation,fostering industrial synergy,and adapting production relations,all aimed at advancing the sustainable and high-quality development of China's ISE.展开更多
Hanyu Xu 1,Xuedan Song 1,*,Qing Zhang 1,Chang Yu 1,Jieshan Qiu 1,2,*1 Liaoning Key Lab for Energy Materials and Chemical Engineering,State Key Laboratory of Fine Chemicals,School of Chemical Engineering,Dalian Univers...Hanyu Xu 1,Xuedan Song 1,*,Qing Zhang 1,Chang Yu 1,Jieshan Qiu 1,2,*1 Liaoning Key Lab for Energy Materials and Chemical Engineering,State Key Laboratory of Fine Chemicals,School of Chemical Engineering,Dalian University of Technology,Dalian 116024,Liaoning Province,China.展开更多
Thermally activated delayed fluorescence(TADF)molecules have outstanding potential for applications in organic light-emitting diodes(OLEDs).Due to the lack of systematic studies on the correlation between molecular st...Thermally activated delayed fluorescence(TADF)molecules have outstanding potential for applications in organic light-emitting diodes(OLEDs).Due to the lack of systematic studies on the correlation between molecular structure and luminescence properties,TADF molecules are far from meeting the needs of practical applications in terms of variety and number.In this paper,three twisted TADF molecules are studied and their photophysical properties are theoretically predicted based on the thermal vibrational correlation function method combined with multiscale calculations.The results show that all the molecules exhibit fast reverse intersystem crossing(RISC)rates(kRISC),predicting their TADF luminescence properties.In addition,the binding of DHPAzSi as the donor unit with different acceptors can change the dihedral angle between the ground and excited states,and the planarity of the acceptors is positively correlated with the reorganization energy,a property that has a strong influence on the non-radiative process.Furthermore,a decrease in the energy of the molecular charge transfer state and an increase in the kRISC were observed in the films.This study not only provides a reliable explanation for the observed experimental results,but also offers valuable insights that can guide the design of future TADF molecules.展开更多
It has been experimentally observed that,in the perforation of metal plates by a flat-nosed projectile,there exists a plateau phenomenon where the ballistic limit increases slightly with increasing plate thickness,whi...It has been experimentally observed that,in the perforation of metal plates by a flat-nosed projectile,there exists a plateau phenomenon where the ballistic limit increases slightly with increasing plate thickness,which is related to a change in the mode of failure.No theoretical model has so far explained this phenomenon satisfactorily.This paper presents a combined numerical and theoretical study on the perforation of 2024-T351 aluminum plates struck by flat-nosed projectiles.First,numerical simulations are performed to investigate the failure mechanisms/deformation modes of the aluminum plates.Then,a theoretical model is proposed based on the numerical results and the experimental observations within a unified framework.The model takes into account the main energy absorbing mechanisms and the corresponding energies absorbed are determined analytically.In particular,a dimensionless equation is suggested to describe the relationship between global deformations and impact velocity.It transpires that the model predictions are in good agreement with the test data and the numerical results for the perforation of 2024-T351 aluminum plates struck by rigid flat-nosed projectiles in terms of residual velocity,ballistic limit,relationship between global deformations and impact velocity,and transition of failure modes.It also transpires that the present model can predict the“plateau”phenomenon,which shows a slight increase in ballistic limit as plate thickness increases.Furthermore,the energy absorption mechanisms are discussed on the basis of the theoretical analysis.展开更多
Objective:To explore the obstructive factors in the behavior of medical staff during the implementation of respiratory rehabilitation process,and to provide a basis for the rehabilitation management intervention of CO...Objective:To explore the obstructive factors in the behavior of medical staff during the implementation of respiratory rehabilitation process,and to provide a basis for the rehabilitation management intervention of COPD.Methods:A descriptive nature research method was adopted.An interview outline was formulated based on the theoretical domain framework.From October to December 2024,15 medical staff from the respiratory department of a tertiary hospital in Shaanxi Province were selected for semi-structured interviews.The interview data were analyzed using the Colaizzi 7-step analysis method.Result:The analysis of this study found that the obstructive factors for medical staff to implement respiratory rehabilitation include five theoretical domains.The problems are respectively the lack of knowledge about respiratory rehabilitation and insufficient training intensity,the insufficient self-recognition of implementing respiratory rehabilitation,the low awareness rate of patients and the low cooperation degree,the insufficient provision of instruments and facilities,the lack of rehabilitation training venues and respiratory rehabilitation clinics,and the lack of scientific and standardized respiratory rehabilitation management processes.Conclusion:There are many obstructive factors affecting the implementation of respiratory rehabilitation by medical staff.Clinical managers should take corresponding measures,continuously improve the rehabilitation management strategies for COPD,and promote the clinical application of the best evidence for respiratory rehabilitation.展开更多
Understanding and predicting droplet breakup is essential in droplet-based microfluidic systems,as it enables precise control over droplet manipulation for various applications.In this study,droplet breakup behavior i...Understanding and predicting droplet breakup is essential in droplet-based microfluidic systems,as it enables precise control over droplet manipulation for various applications.In this study,droplet breakup behavior in a T-junction microchannel is investigated under the influence of microchannel geometry using three-dimensional numerical simulations.A theoretical model is developed based on the balance between surface tension and viscous drag forces acting on the droplet,incorporating the effects of geometric parameters on droplet length.This model predicts the critical Capillary number required for breakup to occur.The theoretical predictions are validated using both previous research data and the present numerical simulations.The results show that the model accurately predicts the transition between breakup and non-breakup regimes.Specifically,an increase in sidearm length ratio inhibits droplet breakup and leads to an asymmetric breakup regime.Furthermore,increasing the outlet-to-inlet width ratio also reduces the likelihood of droplet breakup.These findings provide a predictive framework for understanding and controlling droplet dynamics in microfluidic T-junctions,with potential applications in lab-on-a-chip technologies.展开更多
The double-sided lapping process is extensively employed in the manufacturing of wafers,optical windows,and seal rings due to its high efficiency and ability to achieve precise flatness.However,limited research has ex...The double-sided lapping process is extensively employed in the manufacturing of wafers,optical windows,and seal rings due to its high efficiency and ability to achieve precise flatness.However,limited research has explored the thickness uniformity among different workpieces after double-sided lapping,and the underlying mechanism remains unclear.To address the demand for higher precision,this paper first analyzed the relative kinematic model between the workpiece and the lapping plate to clarify the causes of thickness variations among workpieces after double-sided lapping.Subsequently,a finite element method(FEM)model was developed to account for the pressure distribution on the workpiece surfaces at the initial stage of the process.The results indicate that the number of workpieces influences the final thickness variation.Then,various sets of thin copper plates with different thicknesses were lapped,and the findings revealed that five copper plates processed simultaneously exhibited more uniform thickness compared to the three plates.The experimental results align well with the theoretical analysis.Ultimately,a thickness variation of less than 6μm was achieved on five copper plates measuringΦ100×2.9 mm.This study presents a comprehensive analysis of the mechanisms influencing thickness uniformity in the double-sided lapping process and provides practical guidelines for optimizing the process to achieve stringent precision standards in industrial applications.展开更多
Marx scientifically summarized the experience and lessons of the Paris Commune,deeply exposed the root causes of bourgeois corruption,and emphasized the purity and advancement of the construction of proletarian politi...Marx scientifically summarized the experience and lessons of the Paris Commune,deeply exposed the root causes of bourgeois corruption,and emphasized the purity and advancement of the construction of proletarian political parties and political power.The dictatorship of the proletariat puts forward the ideas of cheap government that eradicate corruption,realizes that the people are the masters of the country,implements democratic supervision of elections,simplifies the construction of institutions,lowers governance costs,and achieves higher efficiency.A deep understanding of the theoretical characteristics of Marx’s thoughts on integrity,democracy,and honor,and a profound clarification of the practical significance of Marx’s ideology on clean governance,combined with practical practice,will help promote the construction of a new system of anti-corruption and incorruption in our country,and will benefit our contemporary services.The construction of a type-oriented government system is conducive to deepening the construction of China’s national legal system.展开更多
Heterostructures of organic semi-conductors and transition metal dichalcogenides(TMDs)are viable candidates for superior optoelec-tronic devices.Photoinduced inter-facial charge transfer is crucial for the performance...Heterostructures of organic semi-conductors and transition metal dichalcogenides(TMDs)are viable candidates for superior optoelec-tronic devices.Photoinduced inter-facial charge transfer is crucial for the performance efficiency of such devices,yet the underlying mecha-nism,especially the roles of optical-ly dark triplets and spatially sepa-rated charge transfer states,is poorly understood.In the present work,we obtain the struc-tures of distinct excited states and investigate how they are involved in the charge transfer process at the Pd-octaethylporphyrin(PdOEP)and WS_(2) interface in terms of their energies and couplings.The results show that electron transfer from the triplet PdOEP formed via intersystem crossing prevails over direct electron transfer from the singlet(two orders of magnitude faster).Further analysis reveals that the relatively higher rate of triplet electron transfer compared to singlet electron transfer is mainly attributed to a smaller reorganization energy,which is dominated by the out-of-plane vibrations of the organic component.The work emphasizes the important roles of the optically dark triplets in the electron transfer of the PdOEP@WS_(2) heterostructure,and provides valuable theoretical insights for further improv-ing the optoelectronic performance of TMD-based devices.展开更多
An analytical model for describing the charged-particle transport in a wall-confined laser-induced decaying plasma is established under an external electrostatic field,focusing on the effects of the initial plasma-ele...An analytical model for describing the charged-particle transport in a wall-confined laser-induced decaying plasma is established under an external electrostatic field,focusing on the effects of the initial plasma-electrode gap(IPEG)that exists in applications such as laser isotope separation.This newly developed analytical model is validated by particle-in-cell simulations and the experimental scaling relation,and can also be reduced to its previously published counterpart that did not consider IPEGs.Based on this analytical model,the influences of different IPEG spacings on the characteristics of the whole ion extraction process are studied.The results show that the ion extraction ratios at the endpoints of the first and second stages both decrease with increasing IPEG spacing,while the corresponding time durations for the first two stages show a non-monotonous variation trend.The specific ion extraction time,defined as the ion extraction time per unit mass to comprehensively characterize the ion extraction efficiency,increases generally with the increase of IPEG spacing.This study not only provides further insight into the fundamental physical processes in a wall-bounded decaying plasma under an externally applied electrostatic field,but also offers useful theoretical guidance for optimal designs of geometrical and operating parameters in laser isotope separation processes.展开更多
Hydraulic fracture growth is significantly influenced by the minimum horizontal principal stress gradient and the fracturing fluid pressure gradient.However,these gradients are often neglected in scaled physical model...Hydraulic fracture growth is significantly influenced by the minimum horizontal principal stress gradient and the fracturing fluid pressure gradient.However,these gradients are often neglected in scaled physical modeling experiments due to difficulties in reproducing them.This study uses centrifugal hypergravity to simulate both gradients and investigate their effects on fracture propagation.Artificial mortar specimens(ϕ200 mm×400 mm)are fractured under 1g(normal gravity),50g,and 100g.Results show that compared to 1g,fractures under 50g and 100g exhibit increasingly uneven propagation,with higher g-values leading to greater asymmetry.To interpret this,a theoretical analysis based on fracture mechanics is conducted.When the fluid pressure gradient exceeds the stress gradient,a positive net gradient is generated,increasing net pressure at the lower fracture tip.This raises the stress intensity factor at the lower tip,promoting downward growth.As g increases,the disparity becomes more significant,resulting in greater fracture deviation.In conclusion,this study,for the first time,has verified and explained that the net gradient can change the propagation of hydraulic fractures,providing important guidance for wellbore placement under stress gradients.展开更多
This study investigates the intersystem crossing(ISC)mechanism in donor-acceptor(D-A)type distyryl-BODIPY photosensitizers,including previously reported M1(benzene donor),M2,M3(phenothiazine donors),and newly predicte...This study investigates the intersystem crossing(ISC)mechanism in donor-acceptor(D-A)type distyryl-BODIPY photosensitizers,including previously reported M1(benzene donor),M2,M3(phenothiazine donors),and newly predicted M4(triphenylamine donor),M5-M7(nitrogen-containing aliphatic rings with thiophene donors).Using computational chemistry,we analyzed their geometric configurations,spectral properties,spin-orbit coupling,and electron-hole orbitals.We found that S_(2) is a charge transfer singlet state(^(1)CT),T2is a locally excited triplet state(^(3)LE),and the S_(2)→T_(2)transition is the main ISC pathway in M2-M7,following the ^(1)CT→^(3)LE mechanism.M5-M7 show near-vertical dihedral angles between donor and acceptor in the S_(2) state relative to M2-M4,facilitating charge transfer.The strain energies in the nitrogen-containing rings of M5-M7 affect oxidation potentials and ISC.M5,with the highest strain energy,shows the lowest oxidation potential,smaller△_(ES2-T2),highest SOC,and fastest kisc,making it the most efficient predicted singlet oxygen producer.This research clarifies the structure-performance relationships of near-infrared D-A type distyryl-BODIPY photosensitizers and provides a theoretical foundation for developing heavy-atom-free photosensitizers with tuned fluorescence quantum yield and singlet oxygen quantum yield.展开更多
The photosynthetic oxygen-evolving center(OEC)is a unique Mn_(4)CaO_(5)cluster catalyzing the water oxidation into electrons,protons and O_(2)through a five-intermediate state cycle(Sn,n=0,1,2,3,4).The modeling of OEC...The photosynthetic oxygen-evolving center(OEC)is a unique Mn_(4)CaO_(5)cluster catalyzing the water oxidation into electrons,protons and O_(2)through a five-intermediate state cycle(Sn,n=0,1,2,3,4).The modeling of OEC is essential for understanding the water oxidation mechanism and developing high efficient water oxidation catalysts.Recently,a series of Mn_(4)CaO_(4)model complexes have been synthesized,which have very similar structures to OEC and also show reactivity of water oxidation.In this work,we employed DFT method to investigate the stability of Mn_(4)CaO_(4)model complex in oxidative conditions,aiming to figure out whether it decomposes itself to release O_(2)during the catalytic water oxidation process.We discovered that the barrier for the O−O bond formation is quite high in the S1 and S2 states,while decreases to 40.2 kcal/mol in the S3 state,indicating the good stability in all oxidation states under normal conditions.Acetonitrile and pyridine can effectively reduce the barrier to 36.5 kcal/mol and 29.9 kcal/mol,respectively.Therefore,strong Lewis base,such as pyridine,could be harmful to the stability of Mn_(4)CaO_(4)and shall be avoided when designing such a catalytic system.Once the O−O bond is formed,Mn_(4)CaO_(4)in the S3 state can readily decompose to O_(2),solvated Ca^(2+)and Mn_(4)O_(2)complex,with the assistance of acetonitrile or pyridine.As a comparison,the O_(2)decomposition in the S2 state is kinetically hindered and thermodynamically disfavored.The S4 state Mn_(4)CaO_(4)has a much lower barrier for O-O bond formation,and is unstable.However,the S4 state Mn_(4)CaO_(4)is difficult to achieve under water oxidation condition,as evidenced by the calculated redox potential of 2.3 V for S3→S4 transition.展开更多
Steel-concrete composite beams,due to their superior mechanical properties,are widely utilized in engineering structures.This study systematically investigates the calculation methods for internal forces and load-bear...Steel-concrete composite beams,due to their superior mechanical properties,are widely utilized in engineering structures.This study systematically investigates the calculation methods for internal forces and load-bearing capacity of composite beams based on elastic theory,with a focus on the transformed section method and its application under varying neutral axis positions.By deriving the geometric characteristics of the transformed section and incorporating a reduction factor accounting for slip effects,a computational model for sectional stress and ultimate load-bearing capacity is established.The results demonstrate that the slip effect significantly influences the flexural load-bearing capacity of composite beams.The proposed reduction factor,which considers the influence of the steel beam’s top flange thickness,offers higher accuracy compared to traditional methods.These findings provide a theoretical foundation for the design and analysis of composite beams,with significant practical engineering value.展开更多
The pursuit of sustainable energy has driven a significant interest in hydrogen(H_(2))as a clean fuel alternative.A critical challenge is the efficient storage of H_(2),which this study addresses by examining the pote...The pursuit of sustainable energy has driven a significant interest in hydrogen(H_(2))as a clean fuel alternative.A critical challenge is the efficient storage of H_(2),which this study addresses by examining the potential of tricycloquinazoline-based monolayer metal-organic frameworks(MMOFs with the first“M”representing metal species).Using density functional theory,we optimized the structures of MMOFs and calculated H_(2)adsorption energies above the open metal sites,identifying ScMOF,TiMOF,NiMOF,and MgMOF for further validation of their thermodynamic stability via ab-initio molecular dynamics(AIMD)simulations.Force field parameters were fitted via the Morse potential,providing a solid foundation for subsequent grand canonical Monte Carlo simulations.These simulations revealed that the maximum of saturated excess gravimetric H_(2)uptake exceeds 14.16 wt%at 77 K,surpassing other reported MOFs,whether they possess open metal sites or not.At 298 K and 100 bar,both the planar and distorted structures derived from our AIMD simulations demonstrated comparable excess gravimetric H_(2)uptake within the range of 3.05 wt%to 3.94 wt%,once again outperforming other MOFs.Furthermore,lithium(Li)doping significantly enhanced the excess H_(2)uptake,with Li-TiMOF achieving an impressive 6.83 wt%at 298 K and 100 bar,exceeding the ultimate target set by the U.S.Department of Energy.The exceptional H_(2)adsorption capacities of these monolayer MOFs highlight their potential in H_(2)storage,contributing to the design of more efficient hydrogen storage materials and propelling the sustainable hydrogen economy forward.展开更多
During strike-slip fault dislocation,multiple fault planes are commonly observed.The resulting permanent ground deformation can lead to profound structural damage to tunnels.However,existing analytical models do not c...During strike-slip fault dislocation,multiple fault planes are commonly observed.The resulting permanent ground deformation can lead to profound structural damage to tunnels.However,existing analytical models do not consider multiple fault planes.Instead,they concentrate the entire fault displacement onto a single fault plane for analysis,thereby giving rise to notable errors in the calculated results.To address this issue,a refined nonlinear theoretical model was established to analyze the mechanical responses of the tunnels subjected to multiple strike-slip fault dislocations.The analytical model considers the number of fault planes,nonlinear soil‒tunnel interactions,geometric nonlinearity,and fault zone width,leading to a significant improvement in its range of applicability and calculation accuracy.The results of the analytical model are in agreement,both qualitatively and quantitatively,with the model test and numerical results.Then,based on the proposed theoretical model,a sensitivity analysis of parameters was conducted,focusing on the variables such as the number of fault planes,fault plane distance(d),fault displacement ratio(η),burial depth(C),crossing angle(β),tunnel diameter(D),fault zone width(Wf),and strike-slip fault displacement(Δfs).The results show that the peak shear force(Vmax),bending moment(Mmax),and axial force(Nmax)decrease with increasing d.The Vmax of the tunnel is found at the fault plane with the largest fault displacement.C,D,andΔfs contribute to the increases in Vmax,Mmax,and Nmax.Additionally,increasing the number of fault planes reduces Vmax and Mmax,whereas the variation in Nmax remains minimal.展开更多
基金financially supported by the National Natural Science Foundation of China(Grants No.12472399)。
文摘Reinforced concrete(RC)columns are often subjected to off-central explosion due to the uncertainty of blast locations.However,few studies have focused on the dynamic response of RC columns under offcentral explosions.A field blast experiment was conducted under close-in explosion with varying detonation offset distances(0 m,0.5 m,and 1 m),the overpressure load and dynamic responses of the full-scale RC columns were measured.Compared with the centrally detonated condition,a relative offset distance of 1.67 decreases the maximum and residual deflections of the RC column by 16.8%and 21.4%,respectively,while increasing the maximum and residual support rotations by 24.7%and 17.8%.Based on the experimental results,a theoretical model was proposed that considers the detonation location and charge mass,boundary conditions,axial compression ratio and material properties.The theoretical model exhibited good agreement with the experimental results,with prediction errors below 10%for both maximum and residual deflection.The effects of parameters were analyzed,and it indicated that an increase in offset distance results in decreased maximum and residual deflections but an increased support angle,thereby exacerbating damage.Higher axial load ratio,span-depth ratio,and longitudinal reinforcement ratio reduce both deflections and support angle.Additionally,a rapid method to predict the maximum and residual deflection of RC columns under off-central blast loading was also proposed based on the Generalized Regression Neural Network(GRNN).Eleven features which related to the RC column properties and the blast characteristics were used in the training process of GRNN,and accurate predictions were achieved with prediction errors within 20%.This study fills the gap in predicting the dynamic response of RC columns under off-central explosion,providing valuable references for blast-resistant design.
基金Philosophy and Social Sciences Research Project of Shandong Higher Education Institutions:“Research on the Double Helix Mechanism of Yellow River Culture Empowering Ideological and Political Education in Universities from the Perspective of Cultural Confidence Cultivation”(2025ZSYB077)Youth Key Project of Shandong Humanities and Social Sciences Research Project,“Research on Integrating Yellow River Culture into the Cultivation of University Students’Cultural Confidence”Shandong Higher Education Institutions Young Innovation Team Program:“Yellow River Delta Ecological Protection and Governance Innovation Team”(2023RW036).
文摘Guided by the significant theoretical principle of the“Two Integrations”and grounded in Marxist cultural theory as its methodological basis,this paper constructs a bidirectional interpretative model linking“Yellow River Culture”with“Cultural Confidence”.It proposes an integrated“Objective-Content-Path-Support”framework.Through the synergy of three-dimensional objectives,adaptation of stratified content,innovation in four-dimensional pathways,and support from a three-dimensional guarantee system,this framework establishes a closed-loop operational mechanism of“Curriculum-Practice-Evaluation-Feedback”.The study focuses on core issues in integrating Yellow River culture into university education practices,such as content construction,methodological pathways,and institutional guarantees.It aims to provide a systematic reference for universities to fulfill their fundamental task of“fostering virtue and cultivating talent”and to serve the national strategies for ecological protection and high-quality development in the Yellow River Basin.
基金supported by the National Natural Science Foundation of China(52471240)the Natural Science Foundation of Zhejiang Province(LZ23B030003)+2 种基金the Fundamental Research Funds for the Central Universities(226-2024-00075)support from the Engineering and Physical Sciences Research Council(EPSRC,UK)RiR grant-RIR18221018-1EU COST CA23155。
文摘The electric double layer(EDL)at the electrochemical interface is crucial for ion transport,charge transfer,and surface reactions in aqueous rechargeable zinc batteries(ARZBs).However,Zn anodes routinely encounter persistent dendrite growth and parasitic reactions,driven by the inhomogeneous charge distribution and water-dominated environment within the EDL.Compounding this,classical EDL theory,rooted in meanfield approximations,further fails to resolve molecular-scale interfacial dynamics under battery-operating conditions,limiting mechanistic insights.Herein,we established a multiscale theoretical calculation framework from single molecular characteristics to interfacial ion distribution,revealing the EDL’s structure and interactions between different ions and molecules,which helps us understand the parasitic processes in depth.Simulations demonstrate that water dipole and sulfate ion adsorption at the inner Helmholtz plane drives severe hydrogen evolution and by-product formation.Guided by these insights,we engineered a“water-poor and anion-expelled”EDL using 4,1’,6’-trichlorogalactosucrose(TGS)as an electrolyte additive.As a result,Zn||Zn symmetric cells with TGS exhibited stable cycling for over 4700 h under a current density of 1 mA cm^(−2),while NaV_(3)O_(8)·1.5H_(2)O-based full cells kept 90.4%of the initial specific capacity after 800 cycles at 5 A g^(−1).This work highlights the power of multiscale theoretical frameworks to unravel EDL complexities and guide high-performance ARZB design through integrated theory-experiment approaches.
基金supported by the National Natural Science Foundation of China(Grant Nos.42407267 and 52374152)the Natural Science Foundation of Jiangsu Province,China(Grant No.BK20220975).
文摘Time-delayed blasting is widely utilized in engineering to mitigate induced vibration hazards and enhance fragmentation.The underlying vibration reduction principle is the decrease of the charge weight per delay,while the potential for further vibration reduction remains debated,largely due to unclear underlying mechanisms.In light of the popularization of electronic detonators and the representativeness of double-hole configurationsfor multiple blastholes,it is essential to investigate the vibration characteristics induced by time-delayed double blastholes.Therefore,a series of doubleborehole experimental blasts was conducted in an underground roadway to clarify the variation in vibration from single-hole to dual-hole conditions.Based on the experimental data and inherent limitations,an exact full-fieldtheoretical model was further employed to systematically analyze the effects of delay time,charge length,and borehole inclination angle on vibrations induced by various doublehole configurations.The experimental data and theoretical analysis reveal that the general scaled distance effectively predicts vibrations in delayed blasting but does not reflectvibration reduction.Increasing delay time causes fluctuatingPPVs,which stabilize slightly above single-hole PPVs as delay times exceed a certain value.The delayed blasting primarily reduces near-fieldfrequencies.Longer charge lengths in double boreholes increase PPV levels and attenuation rates within a certain length,and the vibration behavior of combined long and short charge lengths is governed by the long blasthole.Larger blasthole inclination angles enhance vibration amplitude and reduce PPV attenuation rates.Optimizing inclination angles is more critical than adjusting delay times,and parallel boreholes offer the best vibration control.
基金The Third Scientific Expedition Project in Xinjiang,No.2022xjkk0905Project Commissioned by the General Administration of Sport of ChinaProject Commissioned by the Ministry of Culture and Tourism of the People’s Republic of China。
文摘This study proposes a framework for the concept of“new quality productive forces”in the ice and snow economy(ISE)as a strategic response to global climate change and the demands of technological and industrial transformation for high-quality development.These new quality productive forces in the ISE have developed alongside the zonal distribution of natural resources,strictly adhere to ecological principles,and integrate value transformation mechanisms specific to ice and snow resources.Their development is projected to generate multiple benefits across ecological,economic,and social dimensions.The new quality productive forces in the ISE are characterized by technology-driven resource development,synergistic integration across the entire ice and snow industry value chain,and a focus on high-quality,green growth.Grounded in geography and economics,the new quality productive forces in the ISE link scientific innovation,the reallocation of productive factors,and industrial upgrading within the context of resource constraints.Furthermore,they expand the growth potential of the ISE by fostering new production relations through digital,intelligent,and green integration,while advancing low-carbon,sustainable development under the guiding principle that“ice and snow landscapes are also mountains of gold and silver.”For China's ISE,these new quality productive forces emphasize rigorous resource protection,balanced human-environment relationships,a resilient integrated supply chain framework,and an efficient“dual circulation”economic model.Practical strategies include integrating production factors,optimizing spatial resource allocation,fostering industrial synergy,and adapting production relations,all aimed at advancing the sustainable and high-quality development of China's ISE.
文摘Hanyu Xu 1,Xuedan Song 1,*,Qing Zhang 1,Chang Yu 1,Jieshan Qiu 1,2,*1 Liaoning Key Lab for Energy Materials and Chemical Engineering,State Key Laboratory of Fine Chemicals,School of Chemical Engineering,Dalian University of Technology,Dalian 116024,Liaoning Province,China.
文摘Thermally activated delayed fluorescence(TADF)molecules have outstanding potential for applications in organic light-emitting diodes(OLEDs).Due to the lack of systematic studies on the correlation between molecular structure and luminescence properties,TADF molecules are far from meeting the needs of practical applications in terms of variety and number.In this paper,three twisted TADF molecules are studied and their photophysical properties are theoretically predicted based on the thermal vibrational correlation function method combined with multiscale calculations.The results show that all the molecules exhibit fast reverse intersystem crossing(RISC)rates(kRISC),predicting their TADF luminescence properties.In addition,the binding of DHPAzSi as the donor unit with different acceptors can change the dihedral angle between the ground and excited states,and the planarity of the acceptors is positively correlated with the reorganization energy,a property that has a strong influence on the non-radiative process.Furthermore,a decrease in the energy of the molecular charge transfer state and an increase in the kRISC were observed in the films.This study not only provides a reliable explanation for the observed experimental results,but also offers valuable insights that can guide the design of future TADF molecules.
文摘It has been experimentally observed that,in the perforation of metal plates by a flat-nosed projectile,there exists a plateau phenomenon where the ballistic limit increases slightly with increasing plate thickness,which is related to a change in the mode of failure.No theoretical model has so far explained this phenomenon satisfactorily.This paper presents a combined numerical and theoretical study on the perforation of 2024-T351 aluminum plates struck by flat-nosed projectiles.First,numerical simulations are performed to investigate the failure mechanisms/deformation modes of the aluminum plates.Then,a theoretical model is proposed based on the numerical results and the experimental observations within a unified framework.The model takes into account the main energy absorbing mechanisms and the corresponding energies absorbed are determined analytically.In particular,a dimensionless equation is suggested to describe the relationship between global deformations and impact velocity.It transpires that the model predictions are in good agreement with the test data and the numerical results for the perforation of 2024-T351 aluminum plates struck by rigid flat-nosed projectiles in terms of residual velocity,ballistic limit,relationship between global deformations and impact velocity,and transition of failure modes.It also transpires that the present model can predict the“plateau”phenomenon,which shows a slight increase in ballistic limit as plate thickness increases.Furthermore,the energy absorption mechanisms are discussed on the basis of the theoretical analysis.
基金Shaanxi Provincial People’s Hospital Science and Technology Development Incubation Fund Program 2023(Project No.:2023HL-12)。
文摘Objective:To explore the obstructive factors in the behavior of medical staff during the implementation of respiratory rehabilitation process,and to provide a basis for the rehabilitation management intervention of COPD.Methods:A descriptive nature research method was adopted.An interview outline was formulated based on the theoretical domain framework.From October to December 2024,15 medical staff from the respiratory department of a tertiary hospital in Shaanxi Province were selected for semi-structured interviews.The interview data were analyzed using the Colaizzi 7-step analysis method.Result:The analysis of this study found that the obstructive factors for medical staff to implement respiratory rehabilitation include five theoretical domains.The problems are respectively the lack of knowledge about respiratory rehabilitation and insufficient training intensity,the insufficient self-recognition of implementing respiratory rehabilitation,the low awareness rate of patients and the low cooperation degree,the insufficient provision of instruments and facilities,the lack of rehabilitation training venues and respiratory rehabilitation clinics,and the lack of scientific and standardized respiratory rehabilitation management processes.Conclusion:There are many obstructive factors affecting the implementation of respiratory rehabilitation by medical staff.Clinical managers should take corresponding measures,continuously improve the rehabilitation management strategies for COPD,and promote the clinical application of the best evidence for respiratory rehabilitation.
基金funded by the Master,Ph D Scholarship Programme of Vingroup Innovation Foundation(VINIF),code VINIF.2023.Th S.118。
文摘Understanding and predicting droplet breakup is essential in droplet-based microfluidic systems,as it enables precise control over droplet manipulation for various applications.In this study,droplet breakup behavior in a T-junction microchannel is investigated under the influence of microchannel geometry using three-dimensional numerical simulations.A theoretical model is developed based on the balance between surface tension and viscous drag forces acting on the droplet,incorporating the effects of geometric parameters on droplet length.This model predicts the critical Capillary number required for breakup to occur.The theoretical predictions are validated using both previous research data and the present numerical simulations.The results show that the model accurately predicts the transition between breakup and non-breakup regimes.Specifically,an increase in sidearm length ratio inhibits droplet breakup and leads to an asymmetric breakup regime.Furthermore,increasing the outlet-to-inlet width ratio also reduces the likelihood of droplet breakup.These findings provide a predictive framework for understanding and controlling droplet dynamics in microfluidic T-junctions,with potential applications in lab-on-a-chip technologies.
基金Supported by the Liaoning Provincial Natural Science Foundation(Grant No.2023-MSBA-008)Unveiling and Commanding Program of Liaoning Province(Grant No.2022JH1/10800080)the Fundamental Research Funds for the Central Universities(Grant No.DUT24MS008).
文摘The double-sided lapping process is extensively employed in the manufacturing of wafers,optical windows,and seal rings due to its high efficiency and ability to achieve precise flatness.However,limited research has explored the thickness uniformity among different workpieces after double-sided lapping,and the underlying mechanism remains unclear.To address the demand for higher precision,this paper first analyzed the relative kinematic model between the workpiece and the lapping plate to clarify the causes of thickness variations among workpieces after double-sided lapping.Subsequently,a finite element method(FEM)model was developed to account for the pressure distribution on the workpiece surfaces at the initial stage of the process.The results indicate that the number of workpieces influences the final thickness variation.Then,various sets of thin copper plates with different thicknesses were lapped,and the findings revealed that five copper plates processed simultaneously exhibited more uniform thickness compared to the three plates.The experimental results align well with the theoretical analysis.Ultimately,a thickness variation of less than 6μm was achieved on five copper plates measuringΦ100×2.9 mm.This study presents a comprehensive analysis of the mechanisms influencing thickness uniformity in the double-sided lapping process and provides practical guidelines for optimizing the process to achieve stringent precision standards in industrial applications.
基金Chongqing Social Science Planning Project“Research on the Practical Path of Leading and Cultivating Youth Responsibility and Commitment with the Spirit of Struggle”(2021YBCS24)。
文摘Marx scientifically summarized the experience and lessons of the Paris Commune,deeply exposed the root causes of bourgeois corruption,and emphasized the purity and advancement of the construction of proletarian political parties and political power.The dictatorship of the proletariat puts forward the ideas of cheap government that eradicate corruption,realizes that the people are the masters of the country,implements democratic supervision of elections,simplifies the construction of institutions,lowers governance costs,and achieves higher efficiency.A deep understanding of the theoretical characteristics of Marx’s thoughts on integrity,democracy,and honor,and a profound clarification of the practical significance of Marx’s ideology on clean governance,combined with practical practice,will help promote the construction of a new system of anti-corruption and incorruption in our country,and will benefit our contemporary services.The construction of a type-oriented government system is conducive to deepening the construction of China’s national legal system.
基金supported by the Fundamental Re-search Funds for the Central Universities(Ganglong Cui)and National Key Research and Development Pro-gram of China(No.2021YFA1500703 to Ganglong Cui)National Natural Science Foundation of China(No.22103067 to Xiao-Ying Xie)and Natural Science Foundation of Shandong Province(No.ZR2021QB105 to Xiao-Ying Xie).
文摘Heterostructures of organic semi-conductors and transition metal dichalcogenides(TMDs)are viable candidates for superior optoelec-tronic devices.Photoinduced inter-facial charge transfer is crucial for the performance efficiency of such devices,yet the underlying mecha-nism,especially the roles of optical-ly dark triplets and spatially sepa-rated charge transfer states,is poorly understood.In the present work,we obtain the struc-tures of distinct excited states and investigate how they are involved in the charge transfer process at the Pd-octaethylporphyrin(PdOEP)and WS_(2) interface in terms of their energies and couplings.The results show that electron transfer from the triplet PdOEP formed via intersystem crossing prevails over direct electron transfer from the singlet(two orders of magnitude faster).Further analysis reveals that the relatively higher rate of triplet electron transfer compared to singlet electron transfer is mainly attributed to a smaller reorganization energy,which is dominated by the out-of-plane vibrations of the organic component.The work emphasizes the important roles of the optically dark triplets in the electron transfer of the PdOEP@WS_(2) heterostructure,and provides valuable theoretical insights for further improv-ing the optoelectronic performance of TMD-based devices.
基金supported by the National Key Laboratory of Particle Transport and Separation Technology(Grant No.WZKF-2024-2).
文摘An analytical model for describing the charged-particle transport in a wall-confined laser-induced decaying plasma is established under an external electrostatic field,focusing on the effects of the initial plasma-electrode gap(IPEG)that exists in applications such as laser isotope separation.This newly developed analytical model is validated by particle-in-cell simulations and the experimental scaling relation,and can also be reduced to its previously published counterpart that did not consider IPEGs.Based on this analytical model,the influences of different IPEG spacings on the characteristics of the whole ion extraction process are studied.The results show that the ion extraction ratios at the endpoints of the first and second stages both decrease with increasing IPEG spacing,while the corresponding time durations for the first two stages show a non-monotonous variation trend.The specific ion extraction time,defined as the ion extraction time per unit mass to comprehensively characterize the ion extraction efficiency,increases generally with the increase of IPEG spacing.This study not only provides further insight into the fundamental physical processes in a wall-bounded decaying plasma under an externally applied electrostatic field,but also offers useful theoretical guidance for optimal designs of geometrical and operating parameters in laser isotope separation processes.
基金supports of Basic Science Center Program for Multiphase Evolution in Hyper-gravity of the National Natural Science Foundation of China(No.51988101)National Natural Science Foundation of China(Nos.52109138 and 52122403)Young Elite Scientists Sponsorship Program by CAST(No.2023QNRC001).
文摘Hydraulic fracture growth is significantly influenced by the minimum horizontal principal stress gradient and the fracturing fluid pressure gradient.However,these gradients are often neglected in scaled physical modeling experiments due to difficulties in reproducing them.This study uses centrifugal hypergravity to simulate both gradients and investigate their effects on fracture propagation.Artificial mortar specimens(ϕ200 mm×400 mm)are fractured under 1g(normal gravity),50g,and 100g.Results show that compared to 1g,fractures under 50g and 100g exhibit increasingly uneven propagation,with higher g-values leading to greater asymmetry.To interpret this,a theoretical analysis based on fracture mechanics is conducted.When the fluid pressure gradient exceeds the stress gradient,a positive net gradient is generated,increasing net pressure at the lower fracture tip.This raises the stress intensity factor at the lower tip,promoting downward growth.As g increases,the disparity becomes more significant,resulting in greater fracture deviation.In conclusion,this study,for the first time,has verified and explained that the net gradient can change the propagation of hydraulic fractures,providing important guidance for wellbore placement under stress gradients.
基金financially supported by the Fundamental Research Funds for the Central Universities(No.DUT20RC(3)076)Natural Science Foundation of Liaoning Province(No.2020-MS293)。
文摘This study investigates the intersystem crossing(ISC)mechanism in donor-acceptor(D-A)type distyryl-BODIPY photosensitizers,including previously reported M1(benzene donor),M2,M3(phenothiazine donors),and newly predicted M4(triphenylamine donor),M5-M7(nitrogen-containing aliphatic rings with thiophene donors).Using computational chemistry,we analyzed their geometric configurations,spectral properties,spin-orbit coupling,and electron-hole orbitals.We found that S_(2) is a charge transfer singlet state(^(1)CT),T2is a locally excited triplet state(^(3)LE),and the S_(2)→T_(2)transition is the main ISC pathway in M2-M7,following the ^(1)CT→^(3)LE mechanism.M5-M7 show near-vertical dihedral angles between donor and acceptor in the S_(2) state relative to M2-M4,facilitating charge transfer.The strain energies in the nitrogen-containing rings of M5-M7 affect oxidation potentials and ISC.M5,with the highest strain energy,shows the lowest oxidation potential,smaller△_(ES2-T2),highest SOC,and fastest kisc,making it the most efficient predicted singlet oxygen producer.This research clarifies the structure-performance relationships of near-infrared D-A type distyryl-BODIPY photosensitizers and provides a theoretical foundation for developing heavy-atom-free photosensitizers with tuned fluorescence quantum yield and singlet oxygen quantum yield.
基金supported by the National Natural Science Foundation of China(No.92061114)Chinese Academy of Sciences(XDB17010000)。
文摘The photosynthetic oxygen-evolving center(OEC)is a unique Mn_(4)CaO_(5)cluster catalyzing the water oxidation into electrons,protons and O_(2)through a five-intermediate state cycle(Sn,n=0,1,2,3,4).The modeling of OEC is essential for understanding the water oxidation mechanism and developing high efficient water oxidation catalysts.Recently,a series of Mn_(4)CaO_(4)model complexes have been synthesized,which have very similar structures to OEC and also show reactivity of water oxidation.In this work,we employed DFT method to investigate the stability of Mn_(4)CaO_(4)model complex in oxidative conditions,aiming to figure out whether it decomposes itself to release O_(2)during the catalytic water oxidation process.We discovered that the barrier for the O−O bond formation is quite high in the S1 and S2 states,while decreases to 40.2 kcal/mol in the S3 state,indicating the good stability in all oxidation states under normal conditions.Acetonitrile and pyridine can effectively reduce the barrier to 36.5 kcal/mol and 29.9 kcal/mol,respectively.Therefore,strong Lewis base,such as pyridine,could be harmful to the stability of Mn_(4)CaO_(4)and shall be avoided when designing such a catalytic system.Once the O−O bond is formed,Mn_(4)CaO_(4)in the S3 state can readily decompose to O_(2),solvated Ca^(2+)and Mn_(4)O_(2)complex,with the assistance of acetonitrile or pyridine.As a comparison,the O_(2)decomposition in the S2 state is kinetically hindered and thermodynamically disfavored.The S4 state Mn_(4)CaO_(4)has a much lower barrier for O-O bond formation,and is unstable.However,the S4 state Mn_(4)CaO_(4)is difficult to achieve under water oxidation condition,as evidenced by the calculated redox potential of 2.3 V for S3→S4 transition.
文摘Steel-concrete composite beams,due to their superior mechanical properties,are widely utilized in engineering structures.This study systematically investigates the calculation methods for internal forces and load-bearing capacity of composite beams based on elastic theory,with a focus on the transformed section method and its application under varying neutral axis positions.By deriving the geometric characteristics of the transformed section and incorporating a reduction factor accounting for slip effects,a computational model for sectional stress and ultimate load-bearing capacity is established.The results demonstrate that the slip effect significantly influences the flexural load-bearing capacity of composite beams.The proposed reduction factor,which considers the influence of the steel beam’s top flange thickness,offers higher accuracy compared to traditional methods.These findings provide a theoretical foundation for the design and analysis of composite beams,with significant practical engineering value.
基金supported by National Natural Science Foundation of China(Grant No.12104237)Scientific Research Foundation of Nanjing University of Posts and Telecommunications(No.NY219031).
文摘The pursuit of sustainable energy has driven a significant interest in hydrogen(H_(2))as a clean fuel alternative.A critical challenge is the efficient storage of H_(2),which this study addresses by examining the potential of tricycloquinazoline-based monolayer metal-organic frameworks(MMOFs with the first“M”representing metal species).Using density functional theory,we optimized the structures of MMOFs and calculated H_(2)adsorption energies above the open metal sites,identifying ScMOF,TiMOF,NiMOF,and MgMOF for further validation of their thermodynamic stability via ab-initio molecular dynamics(AIMD)simulations.Force field parameters were fitted via the Morse potential,providing a solid foundation for subsequent grand canonical Monte Carlo simulations.These simulations revealed that the maximum of saturated excess gravimetric H_(2)uptake exceeds 14.16 wt%at 77 K,surpassing other reported MOFs,whether they possess open metal sites or not.At 298 K and 100 bar,both the planar and distorted structures derived from our AIMD simulations demonstrated comparable excess gravimetric H_(2)uptake within the range of 3.05 wt%to 3.94 wt%,once again outperforming other MOFs.Furthermore,lithium(Li)doping significantly enhanced the excess H_(2)uptake,with Li-TiMOF achieving an impressive 6.83 wt%at 298 K and 100 bar,exceeding the ultimate target set by the U.S.Department of Energy.The exceptional H_(2)adsorption capacities of these monolayer MOFs highlight their potential in H_(2)storage,contributing to the design of more efficient hydrogen storage materials and propelling the sustainable hydrogen economy forward.
基金support from the National Natural Science Foundation of China(Grant Nos.52378411,52208404)China National Railway Group Limited Science and Technology Research and Development Program(Grant No.K2023G041).
文摘During strike-slip fault dislocation,multiple fault planes are commonly observed.The resulting permanent ground deformation can lead to profound structural damage to tunnels.However,existing analytical models do not consider multiple fault planes.Instead,they concentrate the entire fault displacement onto a single fault plane for analysis,thereby giving rise to notable errors in the calculated results.To address this issue,a refined nonlinear theoretical model was established to analyze the mechanical responses of the tunnels subjected to multiple strike-slip fault dislocations.The analytical model considers the number of fault planes,nonlinear soil‒tunnel interactions,geometric nonlinearity,and fault zone width,leading to a significant improvement in its range of applicability and calculation accuracy.The results of the analytical model are in agreement,both qualitatively and quantitatively,with the model test and numerical results.Then,based on the proposed theoretical model,a sensitivity analysis of parameters was conducted,focusing on the variables such as the number of fault planes,fault plane distance(d),fault displacement ratio(η),burial depth(C),crossing angle(β),tunnel diameter(D),fault zone width(Wf),and strike-slip fault displacement(Δfs).The results show that the peak shear force(Vmax),bending moment(Mmax),and axial force(Nmax)decrease with increasing d.The Vmax of the tunnel is found at the fault plane with the largest fault displacement.C,D,andΔfs contribute to the increases in Vmax,Mmax,and Nmax.Additionally,increasing the number of fault planes reduces Vmax and Mmax,whereas the variation in Nmax remains minimal.
