The behavior of cold⁃formed steel(CFS)stud⁃to⁃sheathing connections at elevated temperatures is an important parameter for the fire resistance design and modeling of mid⁃rise CFS structures.In this paper,three kinds o...The behavior of cold⁃formed steel(CFS)stud⁃to⁃sheathing connections at elevated temperatures is an important parameter for the fire resistance design and modeling of mid⁃rise CFS structures.In this paper,three kinds of sheathings,namely,medium⁃and low⁃density calcium⁃silicate boards and oriented strand board,were selected for double⁃shear experiments on the mechanical properties of 253 screw connections at ambient and elevated temperatures.The effects of the shear direction,screw edge distance and the number of screws on the behavior of the connections were studied.The results showed that the shear direction and the screw edge distance more significantly influenced the peak deformation,while their impacts on the peak load varied with the type of sheathings.Compared with the single⁃screw connections,the peak loads of the specimens with double⁃screw connections obviously increased but did not double.Finally,a simplified load⁃displacement curve model of stud⁃to⁃sheathing connections at elevated temperature was generated first by establishing the prediction formula for characteristic parameters,such as the peak load,the peak deformation and the elastic stiffness,and then by considering whether the curves corresponded to stiffness increase phenomena.The present investigation provides basic data for future studies on the numerical modeling of CFS structures under fire conditions.展开更多
Hydrogen (H2) production from renewable biomass resources plays a significant role in solving the shortage of fossil energy;hence, there is an interest in investigating alternative, cleaner processes. This work intend...Hydrogen (H2) production from renewable biomass resources plays a significant role in solving the shortage of fossil energy;hence, there is an interest in investigating alternative, cleaner processes. This work intends to study the photocatalytic production of hydrogen from D-(+)-Glucose by using different groups of catalysts that have been prepared (M2+ = Zn, Mg and Ni) M2+/Ti4+ Al3+-LDHs (layered double hydroxides). It is then loaded Pd on the catalyst, and the effect of the composite catalyst, layered double hydroxides, is measured. After calcining, the catalyst for the conversion of Layered Double Hydroxides (LDHs) to Layered Double Oxides (LDOs) is used to produce hydrogen gas from glucose. Photocatalytic reforming of glucose-derived compounds is an efficient method for the production of hydrogen. The purpose is to study the effect of metal ions on layered double oxide (LDO) materials by loading Pd and investigate hydrogen production from glucose. The metal cations in the layer were distributed through the preparation of the catalyst process by ion and atom scale between the layers, which were dispersed systematically, as well as the controlled component catalysis. This process shows that ZnTiAl-LDO had the best effect as a catalyst in producing hydrogen compared to NiTiAl-LDO and MgTiAl-LDO.展开更多
The pore structure of porous scaffolds plays a crucial role in bone repair.The prevalent bone implant structure in clinical practice is the traditional cubic structure.However,the traditional cubic structure exhibits ...The pore structure of porous scaffolds plays a crucial role in bone repair.The prevalent bone implant structure in clinical practice is the traditional cubic structure.However,the traditional cubic structure exhibits sharp edges and junctions that are not conducive to cell adhesion or growth.In this study,a double gyroid(DG)Ti6Al4V scaffold based on a triply periodic minimal surface(TPMS)structure was devised,and the osseointegration performance of DG structural scaffolds with varying porosities was investigated.Compression tests revealed that the elastic modulus and compressive strength of DG structural scaffolds were sufficient for orthopedic implants.In vitro cellular experiments demonstrated that the DG structure significantly enhanced cell proliferation,vascularization,and osteogenic differentiation compared to the cubic structure.The DG structure with 55%porosity exhibited the most favorable outcomes.In vivo experiments in rabbits further demonstrated that DG scaffolds could promote neovascularization and bone regeneration and maturation;those with 55%porosity performed best.Comparing the surface area,specific surface area per unit volume,and internal flow distribution characteristics of gyroid and DG structure scaffolds,the latter are more conducive to cell adhesion and growth within scaffolds.This study underscored the potential of DG scaffolds based on the TPMS structure in optimizing the pore structure design of titanium scaffolds,inducing angiogenesis,and advancing the clinical application of titanium scaffolds for repairing bone defects.展开更多
Electronic auctions(e-auctions)remove the physical limitations of traditional auctions and bring this mechanism to the general public.However,most e-auction schemes involve a trusted auctioneer,which is not always cre...Electronic auctions(e-auctions)remove the physical limitations of traditional auctions and bring this mechanism to the general public.However,most e-auction schemes involve a trusted auctioneer,which is not always credible in practice.Some studies have applied cryptography tools to solve this problem by distributing trust,but they ignore the existence of collusion.In this paper,a blockchain-based Privacy-Preserving and Collusion-Resistant scheme(PPCR)for double auctions is proposed by employing both cryptography and blockchain technology,which is the first decentralized and collusion-resistant double auction scheme that guarantees bidder anonymity and bid privacy.A two-server-based auction framework is designed to support off-chain allocation with privacy preservation and on-chain dispute resolution for collusion resistance.A Dispute Resolution agreement(DR)is provided to the auctioneer to prove that they have conducted the auction correctly and the result is fair and correct.In addition,a Concise Dispute Resolution protocol(CDR)is designed to handle situations where the number of accused winners is small,significantly reducing the computation cost of dispute resolution.Extensive experimental results confirm that PPCR can indeed achieve efficient collusion resistance and verifiability of auction results with low on-chain and off-chain computational overhead.展开更多
Reconfigurable intelligent surface(RIS)is a novel meta-material which can form a smart radio environment by dynamically altering reflection directions of the impinging electromagnetic waves.In the prior literature,the...Reconfigurable intelligent surface(RIS)is a novel meta-material which can form a smart radio environment by dynamically altering reflection directions of the impinging electromagnetic waves.In the prior literature,the inter-RIS links which also contribute to the performance of the whole system are usually neglected when multiple RISs are deployed.In this paper we investigate a general double-RIS assisted multiple-input multiple-output(MIMO)wireless communication system under spatially correlated non line-of-sight propagation channels,where the cooperation of the double RISs is also considered.The design objective is to maximize the achievable ergodic rate based on full statistical channel state information(CSI).Specifically,we firstly present a closedform asymptotic expression for the achievable ergodic rate by utilizing replica method from statistical physics.Then a full statistical CSI-enabled optimal design is proposed which avoids high pilot training overhead compared to instantaneous CSI-enabled design.To further reduce the signal processing overhead and lower the complexity for practical realization,a common-phase scheme is proposed to design the double RISs.Simulation results show that the derived asymptotic ergodic rate is quite accurate even for small-sized antenna arrays.And the proposed optimization algorithm can achieve substantial gain at the expense of a low overhead and complexity.Furthermore,the cooperative double-RIS assisted MIMO framework is proven to achieve superior ergodic rate performance and high communication reliability under harsh propagation environment.展开更多
This paper aims to explore the development strategies for subject services in university libraries within the context of the“double first-class”initiative.By examining the relationship between“double first-class”c...This paper aims to explore the development strategies for subject services in university libraries within the context of the“double first-class”initiative.By examining the relationship between“double first-class”construction and university library subject services,the study analyzes the current state of subject services,including resource development,service models,and team building.Drawing on domestic and international case studies,the paper proposes a series of targeted and practical strategies to enhance the quality of subject services in university libraries,thereby providing robust support for the advancement of the“double first-class”initiative.展开更多
In response to the limitations and low computational efficiency of one-dimensional water and sediment models in representing complex hydrological conditions, this paper proposes a dual branch convolution method based ...In response to the limitations and low computational efficiency of one-dimensional water and sediment models in representing complex hydrological conditions, this paper proposes a dual branch convolution method based on deep learning. This method utilizes the ability of deep learning to extract data features and introduces a dual branch convolutional network to handle the non-stationary and nonlinear characteristics of noise and reservoir sediment transport data. This method combines permutation variant structure to preserve the original time series information, constructs a corresponding time series model, models and analyzes the changes in the outbound water and sediment sequence, and can more accurately predict the future trend of outbound sediment changes based on the current sequence changes. The experimental results show that the DCON model established in this paper has good predictive performance in monthly, bimonthly, seasonal, and semi-annual predictions, with determination coefficients of 0.891, 0.898, 0.921, and 0.931, respectively. The results can provide more reference schemes for personnel formulating reservoir scheduling plans. Although this study has shown good applicability in predicting sediment discharge, it has not been able to make timely predictions for some non-periodic events in reservoirs. Therefore, future research will gradually incorporate monitoring devices to obtain more comprehensive data, in order to further validate and expand the conclusions of this study.展开更多
Shear rheology is a fundamental property of soft matter,which can be deformed.Although the shear rheology of fluids has been well studied at the macroscopic scale,understanding the microscopic processes of rheology at...Shear rheology is a fundamental property of soft matter,which can be deformed.Although the shear rheology of fluids has been well studied at the macroscopic scale,understanding the microscopic processes of rheology at the single-particle level remains a challenging issue.Dusty plasma serves as an ideal platform for exploring microscopic dynamics of system at the individual particle level.Here,we study the shear rheology of confined double rings of strongly coupled dust particles in a dusty plasma.The outer ring is actively driven to rotate using laser illumination.Depending on the particle number,the inner ring may passively rotate following the outer ring at different angular speeds,resulting in shear rheology.The number of dust particles influences particle arrangement,which is characterized by the pair correlation function,bond-orientational order parameter,and triangle skewness.That further alters structural stability,significantly affecting the shear rheology.展开更多
ACKGROUND The hemoglobin glycation index(HGI)represents the discrepancy between the glucose management indicator(GMI)based on mean blood glucose levels and laboratory values of glycated hemoglobin(HbA1c).The HGI is a ...ACKGROUND The hemoglobin glycation index(HGI)represents the discrepancy between the glucose management indicator(GMI)based on mean blood glucose levels and laboratory values of glycated hemoglobin(HbA1c).The HGI is a promising indicator for identifying individuals with excessive glycosylation,facilitating personalized evaluation and prediction of diabetic complications.However,the factors influencing the HGI in patients with type 1 diabetes(T1D)remain unclear.Autoimmune destruction of pancreaticβcells is central in T1D pathogenesis,yet insulin resistance can also be a feature of patients with T1D and their coexistence is called“double diabetes”(DD).However,knowledge regarding the relationship between DD features and the HGI in T1D is limited.AIM To assess the association between the HGI and DD features in adults with T1D.METHODS A total of 83 patients with T1D were recruited for this cross-sectional study.Laboratory HbA1c and GMI from continuous glucose monitoring data were collected to calculate the HGI.DD features included a family history of type 2 diabetes,overweight/obesity/central adiposity,hypertension,atherogenic dyslipidemia,an abnormal percentage of body fat(PBF)and/or visceral fat area(VFA)and decreased estimated insulin sensitivity.Skin autofluorescence of advanced glycation end products(SAF-AGEs),diabetic complications,and DD features were assessed,and their association with the HGI was analyzed.RESULTS A discrepancy was observed between HbA1c and GMI among patients with T1D and DD.A higher HGI was associated with an increased number of SAF-AGEs and a higher prevalence of diabetic microangiopathy(P=0.030),particularly retinopathy(P=0.031).Patients with three or more DD features exhibited an eight-fold increased risk of having a high HGI,compared with those without DD features(adjusted odds ratio=8.12;95%confidence interval:1.52-43.47).Specifically,an elevated PBF and/or VFA and decreased estimated insulin sensitivity were associated with high HGI.Regression analysis identified estimated insulin sensitivity and VFA as factors independently associated with HGI.CONCLUSION In patients with T1D,DD features are associated with a higher HGI,which represents a trend toward excessive glycosylation and is associated with a higher prevalence of chronic diabetic complications.展开更多
This paper investigates the free vibration and transient response of interconnected structures including double curved beams and intermediate straight beams,which are all constructed from functionally graded porous(FG...This paper investigates the free vibration and transient response of interconnected structures including double curved beams and intermediate straight beams,which are all constructed from functionally graded porous(FGP)materials.The strain potential and kinetic energies of each beam along with the work done by the external force are calculated.Additionally,a higher-order beam element is introduced to derive stiffness and mass matrices,along with the force vector.The curved and straight beams are discretized,and their assembled stiffness,mass matrices,and force vectors,are obtained.Continuity conditions at the joints are used to derive the total matrices of the entire structure.Subsequently,the natural frequencies and transient response of the system are determined.The accuracy of the mathematical model and the self-developed computer program is validated through the comparison of the obtained results with those of the existing literature and commercial software ANSYS,demonstrating excellent agreement.Furthermore,a comprehensive study is conducted to investigate the effects of various parameters on the free vibration and transient response of the considered structure.展开更多
To investigate the wind⁃induced vibration re⁃sponse characteristics of multispan double⁃layer cable photo⁃voltaic(PV)support structures,wind tunnel tests using an aeroelastic model were carried out to obtain the wind⁃...To investigate the wind⁃induced vibration re⁃sponse characteristics of multispan double⁃layer cable photo⁃voltaic(PV)support structures,wind tunnel tests using an aeroelastic model were carried out to obtain the wind⁃induced vibration response data of a three⁃span four⁃row double⁃layer cable PV support system.The wind⁃induced vibration characteristics with different PV module tilt angles,wind speeds,and wind direction angles were analyzed.The results showed that the double⁃layer cable large⁃span flexible PV support can effectively control the wind⁃induced vibration response and prevent the occur⁃rence of flutter under strong wind conditions.The maxi⁃mum value of the wind⁃induced vibration displacement of the flexible PV support system occurs in the windward first row.The upstream module has a significant shading effect on the downstream module,with a maximum effect of 23%.The most unfavorable wind direction angles of the structure are 0°and 180°.The change of the wind direction angle in the range of 0°to 30°has little effect on the wind vi⁃bration response.The change in the tilt angle of the PV modules has a greater impact on the wind vibration in the downwind direction and a smaller impact in the upwind di⁃rection.Special attention should be paid to the structural wind⁃resistant design of such systems in the upwind side span.展开更多
Objective: This study assessed the effects of consuming acetic acid bacteria (Gluconacetobacter hansenii GK-1) for 12 weeks on fatigue induced by temporary mental stress. Methods: This randomized, double-blind, placeb...Objective: This study assessed the effects of consuming acetic acid bacteria (Gluconacetobacter hansenii GK-1) for 12 weeks on fatigue induced by temporary mental stress. Methods: This randomized, double-blind, placebo-controlled, parallel-group study included 100 healthy male and female adults aged 20 - 64 years. Participants consumed either the G. hansenii GK-1 supplement (9 × 10⁹ cells/day) or a placebo daily for 12 weeks. The impact of temporary mental stress on fatigue in G. hansenii GK-1 was assessed using a Visual Analog Scale (VAS) before the study began and after 12 weeks of supplementation. Results: Subjective fatigue measured by Visual Analog Scale (VAS) showed a significant decrease in fatigue induced by temporary mental stress after 12 weeks of consumption in the G. hansenii GK-1 group compared with the placebo group. No adverse events were attributed to G. hansenii GK-1. These findings confirm that continuous oral ingestion of G. hansenii GK-1 by healthy Japanese adults reduces feelings of fatigue caused by temporary mental stress.展开更多
We present an application of short-pulse laser-generated hard x rays for the diagnosis of indirectly driven double shell targets. Coneinserted double shell targets were imploded through an indirect drive approach on t...We present an application of short-pulse laser-generated hard x rays for the diagnosis of indirectly driven double shell targets. Coneinserted double shell targets were imploded through an indirect drive approach on the upgraded SG-II laser facility. Then, based on thepoint-projection hard x-ray radiography technique, time-resolved radiography of the double shell targets, including that of their near-peakcompression, were obtained. The backlighter source was created by the interactions of a high-intensity short pulsed laser with a metalmicrowire target. Images of the target near peak compression were obtained with an Au microwire. In addition, radiation hydrodynamicsimulations were performed, and the target evolution obtained agrees well with the experimental results. Using the radiographic images, arealdensities of the targets were evaluated.展开更多
The influence of variable viscosity and double diffusion on the convective stability of a nanofluid flow in an inclined porous channel is investigated.The DarcyBrinkman model is used to characterize the fluid flow dyn...The influence of variable viscosity and double diffusion on the convective stability of a nanofluid flow in an inclined porous channel is investigated.The DarcyBrinkman model is used to characterize the fluid flow dynamics in porous materials.The analytical solutions are obtained for the unidirectional and completely developed flow.Based on a normal mode analysis,the generalized eigenvalue problem under a perturbed state is solved.The eigenvalue problem is then solved by the spectral method.Finally,the critical Rayleigh number with the corresponding wavenumber is evaluated at the assigned values of the other flow-governing parameters.The results show that increasing the Darcy number,the Lewis number,the Dufour parameter,or the Soret parameter increases the stability of the system,whereas increasing the inclination angle of the channel destabilizes the flow.Besides,the flow is the most unstable when the channel is vertically oriented.展开更多
Investigating natural-inspired applications is a perennially appealing subject for scientists. The current increase in the speed of natural-origin structure growth may be linked to their superior mechanical properties...Investigating natural-inspired applications is a perennially appealing subject for scientists. The current increase in the speed of natural-origin structure growth may be linked to their superior mechanical properties and environmental resilience. Biological composite structures with helicoidal schemes and designs have remarkable capacities to absorb impact energy and withstand damage. However, there is a dearth of extensive study on the influence of fiber redirection and reorientation inside the matrix of a helicoid structure on its mechanical performance and reactivity. The present study aimed to explore the static and transient responses of a bio-inspired helicoid laminated composite(B-iHLC) shell under the influence of an explosive load using an isomorphic method. The structural integrity of the shell is maintained by a viscoelastic basis known as the Pasternak foundation, which encompasses two coefficients of stiffness and one coefficient of damping. The equilibrium equations governing shell dynamics are obtained by using Hamilton's principle and including the modified first-order shear theory,therefore obviating the need to employ a shear correction factor. The paper's model and approach are validated by doing numerical comparisons with respected publications. The findings of this study may be used in the construction of military and civilian infrastructure in situations when the structure is subjected to severe stresses that might potentially result in catastrophic collapse. The findings of this paper serve as the foundation for several other issues, including geometric optimization and the dynamic response of similar mechanical structures.展开更多
Modulating metal-organic framework’s(MOF)crystallinity and size using a polymer,in conjunction with a high surface area of layered double hydroxide,yields an effective strategy for concurrently enhancing the electroc...Modulating metal-organic framework’s(MOF)crystallinity and size using a polymer,in conjunction with a high surface area of layered double hydroxide,yields an effective strategy for concurrently enhancing the electrochemical and photocatalytic performance.In this study,we present the development of an optimized nanocomposite,denoted as 0.5PVP/ZIF-67,developed on AZ31 magnesium alloy,serving as an efficient and durable multifunctional coating.This novel strategy aims to enhance the overall performance of the porous coating through the integration of microarc oxidation(MAO),ZnFe LDH backbone,and ZIF-67 formation facilitated by the addition of polyvinylpyrrolidone(PVP),resulting in a three-dimensional,highly efficient,and multifunctional material.The incorporation of 0.5 g of PVP proved to be effective in the size modulation of ZIF-67,which formed a corrosion-resistant top layer,improving the total polarization resistance(R_(p)=8.20×10^(8)).The dual functionality exhibited by this hybrid architecture positions it as a promising candidate for mitigating environmental pollution,degrading 97.93%of Rhodamine B dye in 45 min.Moreover,the sample displayed exceptional degradation efficiency(96.17%)after 5 cycles.This study illuminates the potential of nanocomposites as electrochemically stable and photocatalytically active materials,laying the foundation for the advancements of next-generation multifunctional frameworks.展开更多
BACKGROUND Gastric cancer(GC)is the most common malignant tumor and ranks third for cancer-related deaths among the worldwide.The disease poses a serious public health problem in China,ranking fifth for incidence and ...BACKGROUND Gastric cancer(GC)is the most common malignant tumor and ranks third for cancer-related deaths among the worldwide.The disease poses a serious public health problem in China,ranking fifth for incidence and third for mortality.Knowledge of the invasive depth of the tumor is vital to treatment decisions.AIM To evaluate the diagnostic performance of double contrast-enhanced ultrasonography(DCEUS)for preoperative T staging in patients with GC by comparing with multi-detector computed tomography(MDCT).METHODS This single prospective study enrolled patients with GC confirmed by preoperative gastroscopy from July 2021 to March 2023.Patients underwent DCEUS,including ultrasonography(US)and intravenous contrast-enhanced ultrasonography(CEUS),and MDCT examinations for the assessment of preoperative T staging.Features of GC were identified on DCEUS and criteria developed to evaluate T staging according to the 8th edition of AJCC cancer staging manual.The diagnostic performance of DCEUS was evaluated by comparing it with that of MDCT and surgical-pathological findings were considered as the gold standard.RESULTS A total of 229 patients with GC(80 T1,33 T2,59 T3 and 57 T4)were included.Overall accuracies were 86.9%for DCEUS and 61.1%for MDCT(P<0.001).DCEUS was superior to MDCT for T1(92.5%vs 70.0%,P<0.001),T2(72.7%vs 51.5%,P=0.041),T3(86.4%vs 45.8%,P<0.001)and T4(87.7%vs 70.2%,P=0.022)staging of GC.CONCLUSION DCEUS improved the diagnostic accuracy of preoperative T staging in patients with GC compared with MDCT,and constitutes a promising imaging modality for preoperative evaluation of GC to aid individualized treatment decision-making.展开更多
The double casing warhead with sandwiched charge is a novel fragmentation warhead that can produce two groups of fragments with different velocity,and the previous work has presented a calculation formula to determine...The double casing warhead with sandwiched charge is a novel fragmentation warhead that can produce two groups of fragments with different velocity,and the previous work has presented a calculation formula to determine the maximum fragment velocity.The current work builds on the published formula to further develop a formula for calculating the axial distribution characteristics of the fragment velocity.For this type of warhead,the simulation of the dispersion characteristics of the detonation products at different positions shows that the detonation products at the ends have a much larger axial velocity than those in the middle,and the detonation products have a greater axial dispersion velocity when they are closer to the central axis.The loading process and the fragment velocity vary with the axial position for both casing layers,and the total velocity of the fragments is the vector sum of the radial velocity and the axial velocity.At the same axial position,the acceleration time of the inner casing is greater than that of the outer casing.For the same casing,the fragments generated at the ends have a longer acceleration time than the fragments from the middle.The proposed formula is validated with the X-ray radiography results of the four warheads previously tested experimentally and the 3D smoothedparticle hydrodynamics numerical simulation results of several series of new warheads with different configurations.The formula can accurately and reliably calculate the fragment velocity when the lengthto-diameter ratio of the charge is greater than 1.5 and the thickness of the casing is less than 20%its inner radius.This work thus provides a key reference for the theoretical analysis and the design of warheads with multiple casings.展开更多
基金the National Natural Science Foundation of China(Grant No.51978655)the Natural Science Foundation of Jiangsu Province of China(Grant No.BK20201347)+1 种基金the Xuzhou Science and Technology Project(Grant No.KC20175)the China Postdoctoral Science Foundation Funded Project(Grant No.2019M652007).
文摘The behavior of cold⁃formed steel(CFS)stud⁃to⁃sheathing connections at elevated temperatures is an important parameter for the fire resistance design and modeling of mid⁃rise CFS structures.In this paper,three kinds of sheathings,namely,medium⁃and low⁃density calcium⁃silicate boards and oriented strand board,were selected for double⁃shear experiments on the mechanical properties of 253 screw connections at ambient and elevated temperatures.The effects of the shear direction,screw edge distance and the number of screws on the behavior of the connections were studied.The results showed that the shear direction and the screw edge distance more significantly influenced the peak deformation,while their impacts on the peak load varied with the type of sheathings.Compared with the single⁃screw connections,the peak loads of the specimens with double⁃screw connections obviously increased but did not double.Finally,a simplified load⁃displacement curve model of stud⁃to⁃sheathing connections at elevated temperature was generated first by establishing the prediction formula for characteristic parameters,such as the peak load,the peak deformation and the elastic stiffness,and then by considering whether the curves corresponded to stiffness increase phenomena.The present investigation provides basic data for future studies on the numerical modeling of CFS structures under fire conditions.
文摘Hydrogen (H2) production from renewable biomass resources plays a significant role in solving the shortage of fossil energy;hence, there is an interest in investigating alternative, cleaner processes. This work intends to study the photocatalytic production of hydrogen from D-(+)-Glucose by using different groups of catalysts that have been prepared (M2+ = Zn, Mg and Ni) M2+/Ti4+ Al3+-LDHs (layered double hydroxides). It is then loaded Pd on the catalyst, and the effect of the composite catalyst, layered double hydroxides, is measured. After calcining, the catalyst for the conversion of Layered Double Hydroxides (LDHs) to Layered Double Oxides (LDOs) is used to produce hydrogen gas from glucose. Photocatalytic reforming of glucose-derived compounds is an efficient method for the production of hydrogen. The purpose is to study the effect of metal ions on layered double oxide (LDO) materials by loading Pd and investigate hydrogen production from glucose. The metal cations in the layer were distributed through the preparation of the catalyst process by ion and atom scale between the layers, which were dispersed systematically, as well as the controlled component catalysis. This process shows that ZnTiAl-LDO had the best effect as a catalyst in producing hydrogen compared to NiTiAl-LDO and MgTiAl-LDO.
基金supported bythe National Natural Science Foundation of China(Nos.U23A20523,82272504,and 82072456)the Department of Science and Technology of Jilin Province,China(Nos.20210101439JC,20210101321JC,20220204119YY,202201ZYTS131,202201ZYTS129,20230204114YY,YDZJ202201ZYTS505,and YDZJ202301ZYTS076)+4 种基金the Special Program for Science and Technology Personnel of Changchun(No.ZKICKJJ2023015)the Key Training Plan for Outstanding Youth of Jilin University(No.419070623036)the Research Fund of the First Hospital of Jilin University(No.2021-zl-01)the Graduate Innovation Fund of Jilin University(No.2024CX125)the Foun-dation of National Center for Translational Medicine(Shanghai)SHU Branch,China(No.SUITM-202405).
文摘The pore structure of porous scaffolds plays a crucial role in bone repair.The prevalent bone implant structure in clinical practice is the traditional cubic structure.However,the traditional cubic structure exhibits sharp edges and junctions that are not conducive to cell adhesion or growth.In this study,a double gyroid(DG)Ti6Al4V scaffold based on a triply periodic minimal surface(TPMS)structure was devised,and the osseointegration performance of DG structural scaffolds with varying porosities was investigated.Compression tests revealed that the elastic modulus and compressive strength of DG structural scaffolds were sufficient for orthopedic implants.In vitro cellular experiments demonstrated that the DG structure significantly enhanced cell proliferation,vascularization,and osteogenic differentiation compared to the cubic structure.The DG structure with 55%porosity exhibited the most favorable outcomes.In vivo experiments in rabbits further demonstrated that DG scaffolds could promote neovascularization and bone regeneration and maturation;those with 55%porosity performed best.Comparing the surface area,specific surface area per unit volume,and internal flow distribution characteristics of gyroid and DG structure scaffolds,the latter are more conducive to cell adhesion and growth within scaffolds.This study underscored the potential of DG scaffolds based on the TPMS structure in optimizing the pore structure design of titanium scaffolds,inducing angiogenesis,and advancing the clinical application of titanium scaffolds for repairing bone defects.
基金supported by the National Key R&D Program of China (No.2020YFB1005500)the Leading-edge Technology Program of Jiangsu Natural Science Foundation (No.BK20202001)+1 种基金the Fundamental Research Funds for the Central Universities (No.XJSJ23040)the Postdoctoral Science Foundation of Jiangsu Province (No.2021K596C)。
文摘Electronic auctions(e-auctions)remove the physical limitations of traditional auctions and bring this mechanism to the general public.However,most e-auction schemes involve a trusted auctioneer,which is not always credible in practice.Some studies have applied cryptography tools to solve this problem by distributing trust,but they ignore the existence of collusion.In this paper,a blockchain-based Privacy-Preserving and Collusion-Resistant scheme(PPCR)for double auctions is proposed by employing both cryptography and blockchain technology,which is the first decentralized and collusion-resistant double auction scheme that guarantees bidder anonymity and bid privacy.A two-server-based auction framework is designed to support off-chain allocation with privacy preservation and on-chain dispute resolution for collusion resistance.A Dispute Resolution agreement(DR)is provided to the auctioneer to prove that they have conducted the auction correctly and the result is fair and correct.In addition,a Concise Dispute Resolution protocol(CDR)is designed to handle situations where the number of accused winners is small,significantly reducing the computation cost of dispute resolution.Extensive experimental results confirm that PPCR can indeed achieve efficient collusion resistance and verifiability of auction results with low on-chain and off-chain computational overhead.
基金supported in part by the Xi’an Jiaotong-Liverpool University(XJTLU)Research Development Fund(2024–2027)under Grant RDF-23-02-010supported in part by the Guangdong Basic and Applied Basic Research Foundation under Grant 2023A1515110732+5 种基金supported in part by the National Natural Science Foundation of China(NSFC)under Grant 62071247supported in part by the Science and Technology Development Fund,Macao,China SAR under Grants 0087/2022/AFJ and 001/2024/SKLin part by the National Natural Science Foundation of China under Grant 62261160650in part by the Research Committee of University of Macao,Macao SAR,China under Grants MYRG-GRG2023-00116-FST-UMDF and MYRG2020-00095-FSTsupported in part by the NSFC under Grant 62261160576 and 62301148in part by the Fundamental Research Funds for the Central Universities under Grant 2242023K5003.
文摘Reconfigurable intelligent surface(RIS)is a novel meta-material which can form a smart radio environment by dynamically altering reflection directions of the impinging electromagnetic waves.In the prior literature,the inter-RIS links which also contribute to the performance of the whole system are usually neglected when multiple RISs are deployed.In this paper we investigate a general double-RIS assisted multiple-input multiple-output(MIMO)wireless communication system under spatially correlated non line-of-sight propagation channels,where the cooperation of the double RISs is also considered.The design objective is to maximize the achievable ergodic rate based on full statistical channel state information(CSI).Specifically,we firstly present a closedform asymptotic expression for the achievable ergodic rate by utilizing replica method from statistical physics.Then a full statistical CSI-enabled optimal design is proposed which avoids high pilot training overhead compared to instantaneous CSI-enabled design.To further reduce the signal processing overhead and lower the complexity for practical realization,a common-phase scheme is proposed to design the double RISs.Simulation results show that the derived asymptotic ergodic rate is quite accurate even for small-sized antenna arrays.And the proposed optimization algorithm can achieve substantial gain at the expense of a low overhead and complexity.Furthermore,the cooperative double-RIS assisted MIMO framework is proven to achieve superior ergodic rate performance and high communication reliability under harsh propagation environment.
基金Heilongjiang Provincial Library Work Committee Project“Double First-Class Construction Research on the Development Strategy of Subject Services in University Libraries”(2024-016-B)。
文摘This paper aims to explore the development strategies for subject services in university libraries within the context of the“double first-class”initiative.By examining the relationship between“double first-class”construction and university library subject services,the study analyzes the current state of subject services,including resource development,service models,and team building.Drawing on domestic and international case studies,the paper proposes a series of targeted and practical strategies to enhance the quality of subject services in university libraries,thereby providing robust support for the advancement of the“double first-class”initiative.
基金NationalNatural Science Foundation of China(U2243236,51879115,U2243215),Recipients of funds:Xinjie Li,URL:https://www.nsfc.gov.cn/(accessed on 25 November 2024).
文摘In response to the limitations and low computational efficiency of one-dimensional water and sediment models in representing complex hydrological conditions, this paper proposes a dual branch convolution method based on deep learning. This method utilizes the ability of deep learning to extract data features and introduces a dual branch convolutional network to handle the non-stationary and nonlinear characteristics of noise and reservoir sediment transport data. This method combines permutation variant structure to preserve the original time series information, constructs a corresponding time series model, models and analyzes the changes in the outbound water and sediment sequence, and can more accurately predict the future trend of outbound sediment changes based on the current sequence changes. The experimental results show that the DCON model established in this paper has good predictive performance in monthly, bimonthly, seasonal, and semi-annual predictions, with determination coefficients of 0.891, 0.898, 0.921, and 0.931, respectively. The results can provide more reference schemes for personnel formulating reservoir scheduling plans. Although this study has shown good applicability in predicting sediment discharge, it has not been able to make timely predictions for some non-periodic events in reservoirs. Therefore, future research will gradually incorporate monitoring devices to obtain more comprehensive data, in order to further validate and expand the conclusions of this study.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12275064 and 12475203)the Natural Science Foundation of Hebei Province,China(Grant No.A2024201020)+2 种基金the Regional Key Projects of the National Natural Science Foundation of China(Grant No.U23A20678)the Scientific Research and Innovation Team Project of Hebei University(Grant No.IT2023B03)the Post-graduate’s Innovation Fund Project of Hebei University(Grant No.HBU2024BS007)。
文摘Shear rheology is a fundamental property of soft matter,which can be deformed.Although the shear rheology of fluids has been well studied at the macroscopic scale,understanding the microscopic processes of rheology at the single-particle level remains a challenging issue.Dusty plasma serves as an ideal platform for exploring microscopic dynamics of system at the individual particle level.Here,we study the shear rheology of confined double rings of strongly coupled dust particles in a dusty plasma.The outer ring is actively driven to rotate using laser illumination.Depending on the particle number,the inner ring may passively rotate following the outer ring at different angular speeds,resulting in shear rheology.The number of dust particles influences particle arrangement,which is characterized by the pair correlation function,bond-orientational order parameter,and triangle skewness.That further alters structural stability,significantly affecting the shear rheology.
基金Supported by the National Key R D Program of China,No.2022YFC2010102Natural Science Foundation of Hunan Province,No.2021JC0003+1 种基金National Natural Science Foundation of China,No.82070812the Sinocare Diabetes Foundation,No.LYF2022039.
文摘ACKGROUND The hemoglobin glycation index(HGI)represents the discrepancy between the glucose management indicator(GMI)based on mean blood glucose levels and laboratory values of glycated hemoglobin(HbA1c).The HGI is a promising indicator for identifying individuals with excessive glycosylation,facilitating personalized evaluation and prediction of diabetic complications.However,the factors influencing the HGI in patients with type 1 diabetes(T1D)remain unclear.Autoimmune destruction of pancreaticβcells is central in T1D pathogenesis,yet insulin resistance can also be a feature of patients with T1D and their coexistence is called“double diabetes”(DD).However,knowledge regarding the relationship between DD features and the HGI in T1D is limited.AIM To assess the association between the HGI and DD features in adults with T1D.METHODS A total of 83 patients with T1D were recruited for this cross-sectional study.Laboratory HbA1c and GMI from continuous glucose monitoring data were collected to calculate the HGI.DD features included a family history of type 2 diabetes,overweight/obesity/central adiposity,hypertension,atherogenic dyslipidemia,an abnormal percentage of body fat(PBF)and/or visceral fat area(VFA)and decreased estimated insulin sensitivity.Skin autofluorescence of advanced glycation end products(SAF-AGEs),diabetic complications,and DD features were assessed,and their association with the HGI was analyzed.RESULTS A discrepancy was observed between HbA1c and GMI among patients with T1D and DD.A higher HGI was associated with an increased number of SAF-AGEs and a higher prevalence of diabetic microangiopathy(P=0.030),particularly retinopathy(P=0.031).Patients with three or more DD features exhibited an eight-fold increased risk of having a high HGI,compared with those without DD features(adjusted odds ratio=8.12;95%confidence interval:1.52-43.47).Specifically,an elevated PBF and/or VFA and decreased estimated insulin sensitivity were associated with high HGI.Regression analysis identified estimated insulin sensitivity and VFA as factors independently associated with HGI.CONCLUSION In patients with T1D,DD features are associated with a higher HGI,which represents a trend toward excessive glycosylation and is associated with a higher prevalence of chronic diabetic complications.
文摘This paper investigates the free vibration and transient response of interconnected structures including double curved beams and intermediate straight beams,which are all constructed from functionally graded porous(FGP)materials.The strain potential and kinetic energies of each beam along with the work done by the external force are calculated.Additionally,a higher-order beam element is introduced to derive stiffness and mass matrices,along with the force vector.The curved and straight beams are discretized,and their assembled stiffness,mass matrices,and force vectors,are obtained.Continuity conditions at the joints are used to derive the total matrices of the entire structure.Subsequently,the natural frequencies and transient response of the system are determined.The accuracy of the mathematical model and the self-developed computer program is validated through the comparison of the obtained results with those of the existing literature and commercial software ANSYS,demonstrating excellent agreement.Furthermore,a comprehensive study is conducted to investigate the effects of various parameters on the free vibration and transient response of the considered structure.
基金The National Natural Science Foundation of China(No.52338011).
文摘To investigate the wind⁃induced vibration re⁃sponse characteristics of multispan double⁃layer cable photo⁃voltaic(PV)support structures,wind tunnel tests using an aeroelastic model were carried out to obtain the wind⁃induced vibration response data of a three⁃span four⁃row double⁃layer cable PV support system.The wind⁃induced vibration characteristics with different PV module tilt angles,wind speeds,and wind direction angles were analyzed.The results showed that the double⁃layer cable large⁃span flexible PV support can effectively control the wind⁃induced vibration response and prevent the occur⁃rence of flutter under strong wind conditions.The maxi⁃mum value of the wind⁃induced vibration displacement of the flexible PV support system occurs in the windward first row.The upstream module has a significant shading effect on the downstream module,with a maximum effect of 23%.The most unfavorable wind direction angles of the structure are 0°and 180°.The change of the wind direction angle in the range of 0°to 30°has little effect on the wind vi⁃bration response.The change in the tilt angle of the PV modules has a greater impact on the wind vibration in the downwind direction and a smaller impact in the upwind di⁃rection.Special attention should be paid to the structural wind⁃resistant design of such systems in the upwind side span.
文摘Objective: This study assessed the effects of consuming acetic acid bacteria (Gluconacetobacter hansenii GK-1) for 12 weeks on fatigue induced by temporary mental stress. Methods: This randomized, double-blind, placebo-controlled, parallel-group study included 100 healthy male and female adults aged 20 - 64 years. Participants consumed either the G. hansenii GK-1 supplement (9 × 10⁹ cells/day) or a placebo daily for 12 weeks. The impact of temporary mental stress on fatigue in G. hansenii GK-1 was assessed using a Visual Analog Scale (VAS) before the study began and after 12 weeks of supplementation. Results: Subjective fatigue measured by Visual Analog Scale (VAS) showed a significant decrease in fatigue induced by temporary mental stress after 12 weeks of consumption in the G. hansenii GK-1 group compared with the placebo group. No adverse events were attributed to G. hansenii GK-1. These findings confirm that continuous oral ingestion of G. hansenii GK-1 by healthy Japanese adults reduces feelings of fatigue caused by temporary mental stress.
基金supported by the National Key R&D Program of China(Grant Nos.2022YFA1603300 and 2022YFA1603200)the Science Challenge Project(Grant No.TZ2018005)in China+1 种基金the National Natural Science Foundation of China(Grant Nos.11805188 and 12175209)the Laser Fusion Research Center Funds for Young Talents(Grant No.RCFPD6-2022-1).
文摘We present an application of short-pulse laser-generated hard x rays for the diagnosis of indirectly driven double shell targets. Coneinserted double shell targets were imploded through an indirect drive approach on the upgraded SG-II laser facility. Then, based on thepoint-projection hard x-ray radiography technique, time-resolved radiography of the double shell targets, including that of their near-peakcompression, were obtained. The backlighter source was created by the interactions of a high-intensity short pulsed laser with a metalmicrowire target. Images of the target near peak compression were obtained with an Au microwire. In addition, radiation hydrodynamicsimulations were performed, and the target evolution obtained agrees well with the experimental results. Using the radiographic images, arealdensities of the targets were evaluated.
文摘The influence of variable viscosity and double diffusion on the convective stability of a nanofluid flow in an inclined porous channel is investigated.The DarcyBrinkman model is used to characterize the fluid flow dynamics in porous materials.The analytical solutions are obtained for the unidirectional and completely developed flow.Based on a normal mode analysis,the generalized eigenvalue problem under a perturbed state is solved.The eigenvalue problem is then solved by the spectral method.Finally,the critical Rayleigh number with the corresponding wavenumber is evaluated at the assigned values of the other flow-governing parameters.The results show that increasing the Darcy number,the Lewis number,the Dufour parameter,or the Soret parameter increases the stability of the system,whereas increasing the inclination angle of the channel destabilizes the flow.Besides,the flow is the most unstable when the channel is vertically oriented.
文摘Investigating natural-inspired applications is a perennially appealing subject for scientists. The current increase in the speed of natural-origin structure growth may be linked to their superior mechanical properties and environmental resilience. Biological composite structures with helicoidal schemes and designs have remarkable capacities to absorb impact energy and withstand damage. However, there is a dearth of extensive study on the influence of fiber redirection and reorientation inside the matrix of a helicoid structure on its mechanical performance and reactivity. The present study aimed to explore the static and transient responses of a bio-inspired helicoid laminated composite(B-iHLC) shell under the influence of an explosive load using an isomorphic method. The structural integrity of the shell is maintained by a viscoelastic basis known as the Pasternak foundation, which encompasses two coefficients of stiffness and one coefficient of damping. The equilibrium equations governing shell dynamics are obtained by using Hamilton's principle and including the modified first-order shear theory,therefore obviating the need to employ a shear correction factor. The paper's model and approach are validated by doing numerical comparisons with respected publications. The findings of this study may be used in the construction of military and civilian infrastructure in situations when the structure is subjected to severe stresses that might potentially result in catastrophic collapse. The findings of this paper serve as the foundation for several other issues, including geometric optimization and the dynamic response of similar mechanical structures.
基金supported by the National Research Foundation of Korea(NRF)funded by the Korean government(MSIT)(No.2022R1A2C1006743).
文摘Modulating metal-organic framework’s(MOF)crystallinity and size using a polymer,in conjunction with a high surface area of layered double hydroxide,yields an effective strategy for concurrently enhancing the electrochemical and photocatalytic performance.In this study,we present the development of an optimized nanocomposite,denoted as 0.5PVP/ZIF-67,developed on AZ31 magnesium alloy,serving as an efficient and durable multifunctional coating.This novel strategy aims to enhance the overall performance of the porous coating through the integration of microarc oxidation(MAO),ZnFe LDH backbone,and ZIF-67 formation facilitated by the addition of polyvinylpyrrolidone(PVP),resulting in a three-dimensional,highly efficient,and multifunctional material.The incorporation of 0.5 g of PVP proved to be effective in the size modulation of ZIF-67,which formed a corrosion-resistant top layer,improving the total polarization resistance(R_(p)=8.20×10^(8)).The dual functionality exhibited by this hybrid architecture positions it as a promising candidate for mitigating environmental pollution,degrading 97.93%of Rhodamine B dye in 45 min.Moreover,the sample displayed exceptional degradation efficiency(96.17%)after 5 cycles.This study illuminates the potential of nanocomposites as electrochemically stable and photocatalytically active materials,laying the foundation for the advancements of next-generation multifunctional frameworks.
基金This study was reviewed and approved by the Ethics Committee of Sun Yat-sen University Cancer Center(Approval No.B2023-219-03).
文摘BACKGROUND Gastric cancer(GC)is the most common malignant tumor and ranks third for cancer-related deaths among the worldwide.The disease poses a serious public health problem in China,ranking fifth for incidence and third for mortality.Knowledge of the invasive depth of the tumor is vital to treatment decisions.AIM To evaluate the diagnostic performance of double contrast-enhanced ultrasonography(DCEUS)for preoperative T staging in patients with GC by comparing with multi-detector computed tomography(MDCT).METHODS This single prospective study enrolled patients with GC confirmed by preoperative gastroscopy from July 2021 to March 2023.Patients underwent DCEUS,including ultrasonography(US)and intravenous contrast-enhanced ultrasonography(CEUS),and MDCT examinations for the assessment of preoperative T staging.Features of GC were identified on DCEUS and criteria developed to evaluate T staging according to the 8th edition of AJCC cancer staging manual.The diagnostic performance of DCEUS was evaluated by comparing it with that of MDCT and surgical-pathological findings were considered as the gold standard.RESULTS A total of 229 patients with GC(80 T1,33 T2,59 T3 and 57 T4)were included.Overall accuracies were 86.9%for DCEUS and 61.1%for MDCT(P<0.001).DCEUS was superior to MDCT for T1(92.5%vs 70.0%,P<0.001),T2(72.7%vs 51.5%,P=0.041),T3(86.4%vs 45.8%,P<0.001)and T4(87.7%vs 70.2%,P=0.022)staging of GC.CONCLUSION DCEUS improved the diagnostic accuracy of preoperative T staging in patients with GC compared with MDCT,and constitutes a promising imaging modality for preoperative evaluation of GC to aid individualized treatment decision-making.
基金supported by the National Natural Science Foundation of China(Grant No.11872121)。
文摘The double casing warhead with sandwiched charge is a novel fragmentation warhead that can produce two groups of fragments with different velocity,and the previous work has presented a calculation formula to determine the maximum fragment velocity.The current work builds on the published formula to further develop a formula for calculating the axial distribution characteristics of the fragment velocity.For this type of warhead,the simulation of the dispersion characteristics of the detonation products at different positions shows that the detonation products at the ends have a much larger axial velocity than those in the middle,and the detonation products have a greater axial dispersion velocity when they are closer to the central axis.The loading process and the fragment velocity vary with the axial position for both casing layers,and the total velocity of the fragments is the vector sum of the radial velocity and the axial velocity.At the same axial position,the acceleration time of the inner casing is greater than that of the outer casing.For the same casing,the fragments generated at the ends have a longer acceleration time than the fragments from the middle.The proposed formula is validated with the X-ray radiography results of the four warheads previously tested experimentally and the 3D smoothedparticle hydrodynamics numerical simulation results of several series of new warheads with different configurations.The formula can accurately and reliably calculate the fragment velocity when the lengthto-diameter ratio of the charge is greater than 1.5 and the thickness of the casing is less than 20%its inner radius.This work thus provides a key reference for the theoretical analysis and the design of warheads with multiple casings.
