Precast concrete structures have gained popularity due to their advantages.However,the seismic performance of their connection joints remains an area of ongoing research and improvement.Grouted Sleeve Connection(GSC)o...Precast concrete structures have gained popularity due to their advantages.However,the seismic performance of their connection joints remains an area of ongoing research and improvement.Grouted Sleeve Connection(GSC)offers a solution for connecting reinforcements in precast components,but their vulnerability to internal defects,such as construction errors and material variability,can significantly impact performance.This article presents a finite element analysis(FEA)to evaluate the impact of internal grouting defects in GSC on the structural performance of precast reinforced concrete columns.Four finite elementmodels representing GSC with varying degrees of defects were used to investigate the effects on mechanical properties,including bearing capacity,stress-deformation behavior,and stiffness degradation.The study highlights the significant impact of internal grouting defects on the mechanical performance of GSC,with findings indicating a decrease in stiffness,increased plastic deformation,and reduced energy dissipation as the proportion of internal defects rises.The analysis reveals that the internal defects in GSC act as stress concentration points,leading to early crack formation and accelerated damage under cyclic loading.By improving construction quality and reducing the prevalence of grouting defects,the adverse effects on the performance of GSC can be mitigated.Compared to defect-free specimens,those with defects of 30%exhibited a 31.23%reduction in horizontal bearing capacity,highlighting the importance of minimizing defects in practical engineering applications.展开更多
The single-event susceptibility of three silicon carbide(SiC)metal-oxide-semiconductor field-effect transistor(MOSFET)power devices structures(planar,trench and double trench)is researched by the technology computer-a...The single-event susceptibility of three silicon carbide(SiC)metal-oxide-semiconductor field-effect transistor(MOSFET)power devices structures(planar,trench and double trench)is researched by the technology computer-aided design(TCAD)simulation.Comparative analysis of the heavy-ion irradiation effects on three device structures reveals distinct susceptibility characteristics.The gate oxide region is identified as the most sensitive position in planar devices,while trench and doubletrench structures exhibit no localized sensitive regions.Furthermore,the single-event susceptibility demonstrates strong depth dependence across all three structures,with enhanced vulnerability observed at greater ion penetration depths.展开更多
To deepen understanding of the evolution of coal char microstructural properties of coal char during the co-pyrolysis of coking coal with additives,this study incorporated two typical additives,coal tar pitch(CTP)and ...To deepen understanding of the evolution of coal char microstructural properties of coal char during the co-pyrolysis of coking coal with additives,this study incorporated two typical additives,coal tar pitch(CTP)and waste plastic(HDPE),into a blended coal sample and carried out pyrolysis experiments.The pyrolysis process and the microstructure of char were systematically characterized using various analytical techniques,including thermogravimetric analysis(TGA),X-ray diffraction(XRD)and Raman spectroscopy.Data correlation analysis was performed to reveal the mechanism of carbon structural ordering evolution within the critical temperature range(350−600℃)from colloidal layer formation to semi-coke conversion in coking coal,and to elucidate the regulatory effects of different additives on coal pyrolysis pathways.The results indicate that HDPE releases free radicals during high-temperature pyrolysis,accelerating the pyrolysis reaction and increase the yield of volatile components.Conversely,CTP facilitates pyrolysis at low temperatures through its light components,thereby delaying high-temperature reactions due to the colloidal layer’s effect.XRD results indicate that during the process of pyrolysis,there is a progressive decrease in the interlayer spacing of aromatic layers(d002),while the aromatic ring stacking height(L_(c))and lateral size(L_(a))undergo significant of carbon skeleton ordering.Further comparative reveals that CTP partially suppresses structural ordering at low temperatures,whereas HDPE promotes the condensation and alignment of aromatic clusters via a free radical mechanism.Raman spectroscopy reveals a two-stage reorganization mechanism in the microstructure of the coal char:the decrease in the I_(D)/I_(G)ratio between 350 and 550℃is primarily attributed to the cleavage of aliphatic side chains and cross-linking bonds,leading to a reduction in defective structures;whereas the increase in ID/IG between 550 and 600℃is closely associated with enhanced condensation reactions of aromatic structures.Correlation analysis further demonstrates progressive graphitization during pyrolysis,with a significant positive correlation(R^(2)>0.85)observed between d002 and the full width at half maximum of the G-band(FWHM-G).展开更多
Past investigations of the hydrodynamic forces on vertical columns have generally been based on rigid structure assumptions.The effects of structural flexibility and geometry characteristics on the hydrodynamic force ...Past investigations of the hydrodynamic forces on vertical columns have generally been based on rigid structure assumptions.The effects of structural flexibility and geometry characteristics on the hydrodynamic force distribution are not well understood.In this study,fluid-structure interaction models are developed for numerical analyses.This modeling technique is verified with an experimental test in the literature using both circular and rectangular cross-sections.A series of material elasticities that present structural properties ranging from rigid to flexible is then used to conduct analyses.This finding indicates that an increase in structural flexibility can decrease the impact force to some extent,but this effect is limited.A concrete bridge pier with fluid flow impact can be considered rigid when it is fixed at the bottom.After that,the effects of the initial downstream water height and the width of water tank on the hydrodynamic force are thoroughly investigated.The results demonstrate that the increase in the downstream water height with a constant upstream water height corresponds to a decreased force.Moreover,the vertical column results in a blockage effect on the fluid flow.The greater the blockage effect,the higher the hydrodynamic force.The blockage effect from the vertical column can be neglected when the tank width is greater than eight times the structural cross-section diameter.展开更多
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
This study proposes a new post-tensioned precast bridge column(PT-PBC)with a socket connection.Compared to conventional PBCs connected by PT tendons,the combination of the PT tendons with the socket connection can avo...This study proposes a new post-tensioned precast bridge column(PT-PBC)with a socket connection.Compared to conventional PBCs connected by PT tendons,the combination of the PT tendons with the socket connection can avoid tensioning the PT tendons on site,which further accelerates construction speed while improving construction quality and safety.In addition,compared to conventional PBCs with a socket connection,a rocking interface can avoid the formation of a plastic hinge in a column,which greatly alleviates seismic damage to that area.One specimen for quasi-static testing is used to validate the feasibility of this connection type.Subsequently,finite element models(FEM)are established to systematically predict the responses of the proposed columns under lateral cyclic loading.The accuracy of the FEM is verified through quasistatic testing.Next,the influences of the key design parameters of the PT-PBC,including the area ratio and prestress level of the PT tendons,the area ratio of energy dissipation(ED)steel rebars,and the total axial compression ratio on the seismic performances of PT-PBC are systematically investigated.The use of shape memory alloy(SMA)rods as energy dissipation devices and their performances also are investigated.The results show that increasing the area ratio and prestress level of PT tendons has an overall positive impact on the self-centering capacity of the column.The prestress level of PT tendons should be kept between 35%and 55%,depending on different conditions.The total compression axial ratio of the columns should be maintained between 0.3 and 0.4.Both ED steel rebars and SMA rods can boost the column’s energy dissipation capacity,while SMA rods can reduce residual deformation due to their inherent mechanical properties.展开更多
This paper reports the preparation of three di‑iron complexes containing a thiazole moiety.Esterification of complex[Fe_(2)(CO)_(6)(μ‑SCH_(2)CH(CH_(2)OH)S)](1)with 4‑methylthiazole‑5‑carboxylic acid gave the correspo...This paper reports the preparation of three di‑iron complexes containing a thiazole moiety.Esterification of complex[Fe_(2)(CO)_(6)(μ‑SCH_(2)CH(CH_(2)OH)S)](1)with 4‑methylthiazole‑5‑carboxylic acid gave the corresponding ester[Fe_(2)(CO)_(6)(μ‑tedt)](2),where tedt=SCH_(2)CH(CH_(2)OOC(5‑C_(3)HNSCH_(3)))S.Further reactions of complex 2 with tri(ptolyl)phosphine(tp)or tris(4‑fluorophenyl)phosphine(fp)gave the phosphine‑substituted derivatives[Fe_(2)(CO)_(5)(tp)(μ‑tedt)](3)and[Fe_(2)(CO)_(5)(fp)(μ‑tedt)](4).The structures of the newly prepared complexes were elucidated by elemental analysis,NMR,IR,and X‑ray photoelectron spectroscopy.Moreover,single‑crystal X‑ray diffraction analysis confirmed their molecular structures,showing that they contain a di‑iron core ligated by a bridged dithiolate bearing a thiazole moiety and terminal carbonyls.The electrochemical and electrocatalytic proton reduction were probed by cyclic voltammetry,revealing that three complexes can catalyze the reduction of protons to H_(2) under the electrochemical conditions.For comparison,complex 4 possessed the best efficiency with a turnover frequency of 23.5 s^(-1)at 10 mmol·L^(-1)HOAc concentration.In addition,the fungicidal activity of these complexes was also investigated in this study.CCDC:2477511,2;2477512,3;2477513,4.展开更多
Bolting steel angles at the bottom ends of columns provides a rapid and efficient method for repairing damaged structures,while also offering a viable approach to restore their potential bearing capacity.To validate t...Bolting steel angles at the bottom ends of columns provides a rapid and efficient method for repairing damaged structures,while also offering a viable approach to restore their potential bearing capacity.To validate the suitability of specific strengthening strategies,particularly the utilization of bolted steel angles,three reinforced concrete frame specimens were subjected to hysteresis testing.These specimens all featured RC columns strengthened with steel angle ends.Additionally,one control specimen without steel angle ends was included in the testing.The hysteresis effects of bolting steel angles were discussed in terms of typical failure mode,hysteresis and skeleton curves,stiffness degradation and energy dissipation.The experimental results revealed that the three specimens that had bolted steel angles exhibited ductile failure behavior.Through analysis of hysteresis and skeleton curves,it was observed that the frame demonstrated distinct plasticity,maintaining sufficient load-bearing capacity even after yielding and exhibiting superior displacement ductility performance.Considering equivalent viscous damping,the energy dissipation capacity of the RC frame increased linearly with drift and remained largely unaffected by structural damage.Therefore,bolting steel angles at specified cross-sections proved to be a viable technique for structural repair and restoration.展开更多
Nickel-rich cathodes(NRCs)hold great promise for next-generation high-energy lithium-ion batteries(LIBs)due to high specific energy and low cost.However,the higher Ni content exacerbates the instability issues associa...Nickel-rich cathodes(NRCs)hold great promise for next-generation high-energy lithium-ion batteries(LIBs)due to high specific energy and low cost.However,the higher Ni content exacerbates the instability issues associated with structural degradation and side reactions during electrochemical cycling.Herein,we demonstrate the possibility of preparing NRCs,typically Li Ni_(0.9)Co_(0.05)Mn_(0.05)O_(2)(NCM9055),with much-improved mechanical and chemical stability based on the surface coating of the hydroxide precursors.Specifically,a conformal nanoshell containing both Al^(3+)and W^(6+)was first deposited around the precursor particles,and the following high-temperature lithiation produced the targeted NCM9055 with favorable structural features,where Al3+existed as a bulk dopant to enhance the structural stability while the high-valent W^(6+)promoted the microstructural evolution into radially-architectured elongated primary particles.Such a structural engineering benefiting from the Al^(3+)/W^(6+)co-modification endowed the prepared NCM9055 cathode(NCM9055-Al W)with much-improved cycling stability,as revealed by a high-capacity retention of 98.0%after 100 cycles(tested at 0.5 C,4.3 V)as compared to only 79.0%for the pristine cathode without Al^(3+)/W^(6+).The NCM9055-15Al W cathode also showed a high-rate capability with extraordinary structural stability against mechanical failure.Our study highlighted the enormous potential of precursor multi-element treatment as an effective tool in structural refinement of NRCs to circumvent their stability challenge for their applications in high-energy LIBs.展开更多
From cracking the code of viruses to mentoring the next generation of scientists,the former president of Nankai University has contributed a lot to turning microscopic discoveries into monumental shields for global he...From cracking the code of viruses to mentoring the next generation of scientists,the former president of Nankai University has contributed a lot to turning microscopic discoveries into monumental shields for global health.OVER the past 40 years,one man has distinguished himself through a deep commitment to researching protein structures of high pathogenic viruses,and published numerous significant works in top international scientific journals.展开更多
Achieving high energy and power densities is currently a core challenge in the fabrication of energy storage materials.Although numerous high-capacity materials have been developed,conventional planar electrodes canno...Achieving high energy and power densities is currently a core challenge in the fabrication of energy storage materials.Although numerous high-capacity materials have been developed,conventional planar electrodes cannot achieve high active material loading and efficient ion/electron transport simultaneously.By contrast,three-dimensional(3D)structures have attracted increasing interest because of their capacity to enhance active material utilization,shorten ion and electron transport pathways,reduce interfacial impedance,and provide spatial accommodation for volume expansion.Additive manufacturing(AM)technology effectively fabricates energy-storage materials with 3D structures by accurately constructing complex 3D structures via layer-by-layer deposition.Recent studies have employed AM to construct ordered 3D electrodes that can optimize ion/electron transport,regulate electric field distribution,or improve the electrode-electrolyte interface,thereby contributing to enhanced kinetic performance and cycling stability.This review systematically summarizes the applications of several AM technologies in the fabrication of energy storage materials and analyzes their respective advantages and limitations.Subsequently,the advantages of AM technology in the fabrication of energy storage materials and several major optimization strategies are comprehensively discussed.Finally,the major challenges and potential applications of AM technology in energy storage material optimization are discussed.展开更多
Conventional Tb^(3+)-doped phosphors typically suffer from concentration quenching once the doping level exceeds a critical threshold.Consequently,the development of Tb^(3+)phosphors with intrinsic resistance to conce...Conventional Tb^(3+)-doped phosphors typically suffer from concentration quenching once the doping level exceeds a critical threshold.Consequently,the development of Tb^(3+)phosphors with intrinsic resistance to concentration quenching has become a key research focus.In this work,we successfully synthesized KBi(MoO_(4))_(2):x Tb^(3+)(x=0-100 at%)(denoted as KBM:x Tb^(3+))phosphors via a high-temperature solid-state reaction.Remarkably,no concentration quenching was observed across the entire doping range.This anti-quenching behavior originates from the large Tb^(3+)-Tb^(3+)interionic distance(>5Å)inherent to the quasi-layered crystal structure,which effectively suppresses multipole-interaction-mediated energy migration.At full Tb^(3+)substitution(x=100 at%),the material undergoes a structural phase transition from the monoclinic KBM phase to the triclinicα-KTb(MoO_(4))_(2)(α-KTM)phase.Theα-KTM phosphor exhibits excellent thermal stability(activation energy=0.6129 eV)and a single-exponential decay profile,whereas KBM:x Tb^(3+)(x<100%)display double-exponential decay behaviors,attributed to dual energy transfer pathways.These findings provide new insights into the luminescence mechanisms of high-concentration rare-earth-doped systems and offer guidance for designing nextgeneration anti-quenching phosphors.展开更多
Plastome variation,including single spontaneous nucleotide substitutions and single insertions/deletions,is the major source of leaf variegation in plants.Additionally,one recent study has showed that a simple plastom...Plastome variation,including single spontaneous nucleotide substitutions and single insertions/deletions,is the major source of leaf variegation in plants.Additionally,one recent study has showed that a simple plastome structural variation,which is induced by one pair of small inverted repeats,can also result in leaf variegation.Here we show a complex plastome structural variation caused by intermolecular and intramolecular recombination across three pairs of small inverted repeats accounts for leaf variegation in a widely cultivated shrub Heptapleurum ellipticum(Araliaceae).This plastome structural variation contains two deletions and two duplications,resulting in dramatic expansion of IRs,substantial contraction of LSC and loss of 11 genes that essential for photosynthesis.Plastome heteroplasmy was detected in both green and albino sectors of variegated leaves.Relative to green sectors,albino sectors in the variegated leaves exhibit significantly reduced expression for the 11 genes lost in the mutated plastome as well as 26 other genes,but significantly increased expression for one gene related to translation apparatus.Optical and transmission electron microscopy observations showed that mesophyll cells of albino sectors possess plastids lacking grana lamellae,which likely carry the mutated plastome and contribute to albinism.In both sectors,the first layer of spongy mesophyll cells beneath the lower epidermis contains normal chloroplasts,suggesting periclinal division of the lower epidermis during development.Our study demonstrates that multiple small repeats can collectively mediate intra-and inter-molecular recombination in plastome and offers a new mechanism accounting for leaf variegation in plants.展开更多
Transition-metal dichalcogenides hosting multiple competing structural and electronic phases are thus ideal platforms for constructing polytype heterostructures with emergent quantum properties.However,controlling pha...Transition-metal dichalcogenides hosting multiple competing structural and electronic phases are thus ideal platforms for constructing polytype heterostructures with emergent quantum properties.However,controlling phase transitions to form diverse heterostructures inside a single crystal remains challenging.In this study,we realize vertical/lateral polytype heterostructures in a hole-doped Mott insulator via thermal annealing-induced structural transitions.Raman spectroscopy,atomic force microscopy and scanning Kelvin probe force microscopy confirm the coexistence of T-H polytype heterostructures.Atomic-scale scanning tunneling microscopy/spectroscopy measurements reveal the transparent effect in 1H/1T vertical heterostructures,where positive bias voltage induces in a pronounced superposition of the√13×√13 CDW of the 1T-layer on the 1H-layer.By systematically comparing the 1T/1H and 1T/1T interfaces,we demonstrate that the metallic 1H-layer induces a Coulomb screening effect on the 1T-layer,suppressing the formation of CDW domain walls and forming more ordered electronic states.These results clarify the interfacial coupling between distinct quantum many-body phases and establish a controllable pathway for constructing two-dimensional polytype heterostructures with tunable electronic properties.展开更多
Structural variation is an important source of genetic variation in wheat and have been important in the evolution of the wheat's genome.Few studies have examined the relationship between structural variations and...Structural variation is an important source of genetic variation in wheat and have been important in the evolution of the wheat's genome.Few studies have examined the relationship between structural variations and agronomy and drought tolerance.The present study identified structural chromosome variations(SCVs)in a doubled haploid(DH)population and backcross introgression lines(BC5F3)derived from Jinmai 47 and Jinmai 84 using fluorescence in situ hybridization(FISH).There are one simple translocation,10 present/absent variations(PAVs),and one copy number variation(CNV)between Jinmai 47 and Jinmai 84,which distributed in 10 chromosomes.Eight SCVs were associated with 15 agronomic traits.A PAV recombination occurred on chromosome 2A,which was associated with grain number per spike(GNS).The 1BL/1RS translocation and PAV.2D were associated with significant reductions in plant height,deriving from the effects on LI2-LI4,LI2-LI4 and UI,respectively respectively.PAV.2D was also contributed to an increase of 3.13%for GNS,1BL/1RS significantly increased spikelet number,grain length(GL),and grain thickness(GT).The effect of PAV.4A.1 on GL,PAV.6A on spike length(SL)and thousand-grain weight(TGW),PAV.6B on SL,GT and TGW were identified and verified.PAVs on chromosomes 2A,6A,1D,2D,and a CNV on chromosome 4B were associated with the drought tolerance coefficients.Additive and interaction effects among SCVs were observed.Many previously cloned key genes and yield-related QTL were found in polymorphic regions of PAV.2B,PAV.2D,and CNV.4B.Altogether,this study confirmed the genetic effect of SCVs on agronomy and drought tolerance,and identification of these SCVs will facilitate genetic improvement of wheat through marker-assisted selection.展开更多
TMPRSS2 plays a crucial role in facilitating the entry of both the influenza virus and the SARSCoV-2 coronavirus into host cells.Recent studies have identified a guanine-rich sequence in the proximal promoter region o...TMPRSS2 plays a crucial role in facilitating the entry of both the influenza virus and the SARSCoV-2 coronavirus into host cells.Recent studies have identified a guanine-rich sequence in the proximal promoter region of the TMPRSS2 gene,which can form G-quadruplex structures(TMPRSS2-G4s)that are potential targets for small molecules to inhibit TMPRSS2 expression.However,the structural details of the major TMPRSS2-G4 and its complex with small molecules remain unknown,hindering the development of antiviral drugs targeting TMPRSS2-Gquadruplexes(G4s).This study reports the first high-resolution nuclear magnetic resonance(NMR)solution structure of the major TMPRSS2-G4,which consists of a three-tetrad core parallel-stranded G4.Both 3′and 5′flanking regions form well-defined capping structures stabilized by multiple hydrogen bonds.Importantly,we found that berberine,an antiviral alkaloid,strongly binds to the major TMPRSS2-G4 and determined its binding complex structure with TMPRSS2-G4 at a 2∶1 binding stoichiometry.Each berberine molecule recruits an adjacent flanking residue,forming a coplanar structure superimposed on two outer G-tetrads.Moreover,we demonstrated that the major TMPRSS2-G4 can stably form within a longer deoxyribonucleic acid(DNA)context and be targeted by small molecules to inhibit DNA polymerase activity.Overall,this study provides structural insights into the recognition mechanism of small molecules by the major TMPRSS2-G4 and may facilitate the development of novel antiviral therapeutics targeting TMPRSS2-G4.展开更多
Bamboo is a natural composite that has inspired the design of biomimetic composites due to its unique multi-scale struc-ture and outstanding mechanical properties.This paper first presents the structural features of b...Bamboo is a natural composite that has inspired the design of biomimetic composites due to its unique multi-scale struc-ture and outstanding mechanical properties.This paper first presents the structural features of bamboo,detailing the hydro-phobic wax and silica layer of the surface,the functionally graded vascular bundles of the wall for optimized toughness,and the hollow,multi-node architecture of the stem for overall stability and bending resistance.Subsequently,this study surveys recent sustainability and designability advances in bamboo-inspired composites.Inspiration from the bamboo sur-face has spurred the creation of materials with enhanced functionalities,such as transparent composites and high-stiffness structural materials.Imitation of the wall structure has led to the development of high-strength and tough materials,with the discussion covering examples such as hydrogels,polymer composites,and metal-matrix composites.Inspiration from the stem structure has yielded lightweight composites with excellent energy absorption and stability,exemplified by advanced linear materials like resilient yarns and tendon sutures,as well as functional structures like flexible sensors.These biomimetic designs show significant potential across numerous fields,including construction,healthcare,urban rail transit,wearable electronics,and mechanical engineering.Finally,this paper discusses the current limitations and challenges to understanding bamboo's structural characteristics towards the development of bamboo-inspired composites.Future research directions are proposed,including understanding bamboo's structure,designing novel biomimetic com-posites,and optimizing their structure to develop bamboo-inspired functional materials.展开更多
High-moisture meat analogues(HMMAs)offer sustainable protein alternatives to conventional meat and become a research hotspot in recent years.This study systematically investigated the impact of nori powder(NP)incorpor...High-moisture meat analogues(HMMAs)offer sustainable protein alternatives to conventional meat and become a research hotspot in recent years.This study systematically investigated the impact of nori powder(NP)incorporation(0.5%–2.0%)on the physicochemical and structural properties of HMMAs.Rheological analysis revealed that NP reduced the viscosity(consistency coefficient K decreased from 65.67 Pa⋅s to 16.66–19.99 Pa⋅s)and enhanced the fluidity(flow behavior index n increased from 0.25 to 0.33–0.38)of raw material.NP addition progressively decreased the redness values(a*),except for 0.5%NP level.At 1.0%NP level,HMMAs exhibited a denser microstructure with reduced water mobility,resulting in the lowest water holding capacity(2.07 g/g).Conversely,2.0%NP promoted highly oriented fibrous structures,achieving a maximal texturization degree of 1.51.Secondary structure analysis indicated NP facilitated a shift fromα-helix toβ-sheet conformations(β-sheet content increased from 26.06%to 29.92%at 2.0%NP),resulting in stabilized protein networks.These modifications were attributed to NP-induced hydrophobic interactions and polysaccharide-protein crosslinking.The study demonstrates NP's role in modulating HMMA texture and nutrition,providing critical insights for developing fiber-enhanced,nutrient-fortified HMMAs.展开更多
Wind disturbance has emerged as a potential eco-friendly method for seedling cultivation.In this study,an electromechanical device was designed and built to investigate the effects of airflow on the micro-environment ...Wind disturbance has emerged as a potential eco-friendly method for seedling cultivation.In this study,an electromechanical device was designed and built to investigate the effects of airflow on the micro-environment and physiological activities of tomato seedlings in seedbeds by controlled experiments.The results indicated that airflow could enhance CO_(2) concentration near the seedling canopy,accelerate water evaporation from the seedling substrate,and reduce fluctuations in the temperature and humidity in microclimate.The photosynthetic rates of leaves at the 4th,7th,and 10th positions in seedlings subjected to airflow increased by 25.04%,8.23%,and 8.47%,respectively,whereas the transpiration rates increased by 15.59%,22.28%,and 13.26%,respectively when compared to the control group.Additionally,the strong seedling index of seedlings treated with airflow and exogenous iron element increased by 26.02%and 31.5%,respectively.Compared to seedlings treated with exogenous iron element,the geometric mean diameter of the pith tissue cells in the stems of seedlings subjected to airflow disturbance was reduced by approximately 18.66%,while the elastic modulus and bending strength of the stems increased by 10.01%and 5.89%,respectively.Similarly,the volume of root tissue cells decreased by 19.22%,but the elastic modulus of the roots increased by 6.46%.This study confirms that airflow significantly enhances seedling resilience to abiotic stress,yielding similar or better outcomes than exogenous iron application.It provides both theoretical and practical support for using airflow disturbance as a green technology for cultivating robust seedlings.展开更多
Flexible and wearable sensors offer immense potential for rehabilitation medicine,but most rely solely on electrical signals,lacking real-time visual feedback and limiting trainee's interactivity.Inspired by the s...Flexible and wearable sensors offer immense potential for rehabilitation medicine,but most rely solely on electrical signals,lacking real-time visual feedback and limiting trainee's interactivity.Inspired by the structural coloration of Cyanocitta stelleri feathers,we developed a dual-mode sensor by utilizing black conductive polymer hydrogel(CPH)-enhanced structural color strategy.This sensor integrates a hydroxypropyl cellulose(HPC)-based structural color interface with a designed CPH sensing component.Highly visible light-absorbing CPH(absorption rate>88%)serves as the critical substrate for enhancing structural color performance.By absorbing incoherent scattered light and suppressing background interference,it significantly enhances the saturation of structural color,thereby achieving a high contrast index of 4.92.Unlike the faint and hardly visible structural colors on non-black substrates,the HPC on CPH displays vivid,highly perceptible colors and desirable mechanochromic behavior.Moreover,the CPH acts as a flexible sensing element,fortified by hydrogen and coordination bond networks,and exhibits exceptional electromechanical properties,including 867.1 kPa tensile strength,strain sensitivity(gauge factor of 4.24),and outstanding durability(over 4400 cycles).Compared to traditional single-mode sensors,the integrated sensor provides real-time visual and digital dual feedback,enhancing the accuracy and interactivity of rehabilitation assessments.This technology holds promise for advancing next-generation rehabilitation medicine.展开更多
文摘Precast concrete structures have gained popularity due to their advantages.However,the seismic performance of their connection joints remains an area of ongoing research and improvement.Grouted Sleeve Connection(GSC)offers a solution for connecting reinforcements in precast components,but their vulnerability to internal defects,such as construction errors and material variability,can significantly impact performance.This article presents a finite element analysis(FEA)to evaluate the impact of internal grouting defects in GSC on the structural performance of precast reinforced concrete columns.Four finite elementmodels representing GSC with varying degrees of defects were used to investigate the effects on mechanical properties,including bearing capacity,stress-deformation behavior,and stiffness degradation.The study highlights the significant impact of internal grouting defects on the mechanical performance of GSC,with findings indicating a decrease in stiffness,increased plastic deformation,and reduced energy dissipation as the proportion of internal defects rises.The analysis reveals that the internal defects in GSC act as stress concentration points,leading to early crack formation and accelerated damage under cyclic loading.By improving construction quality and reducing the prevalence of grouting defects,the adverse effects on the performance of GSC can be mitigated.Compared to defect-free specimens,those with defects of 30%exhibited a 31.23%reduction in horizontal bearing capacity,highlighting the importance of minimizing defects in practical engineering applications.
基金National Key Research and Development Program of China(2023YFA1609000)National Natural Science Foundation of China(62474190,U22B2043,U2267210)。
文摘The single-event susceptibility of three silicon carbide(SiC)metal-oxide-semiconductor field-effect transistor(MOSFET)power devices structures(planar,trench and double trench)is researched by the technology computer-aided design(TCAD)simulation.Comparative analysis of the heavy-ion irradiation effects on three device structures reveals distinct susceptibility characteristics.The gate oxide region is identified as the most sensitive position in planar devices,while trench and doubletrench structures exhibit no localized sensitive regions.Furthermore,the single-event susceptibility demonstrates strong depth dependence across all three structures,with enhanced vulnerability observed at greater ion penetration depths.
基金Supported by National Natural Science Foundation of China(22378180,22078141)Education Department Foundation of Liaoning Province(JYTMS20230960)。
文摘To deepen understanding of the evolution of coal char microstructural properties of coal char during the co-pyrolysis of coking coal with additives,this study incorporated two typical additives,coal tar pitch(CTP)and waste plastic(HDPE),into a blended coal sample and carried out pyrolysis experiments.The pyrolysis process and the microstructure of char were systematically characterized using various analytical techniques,including thermogravimetric analysis(TGA),X-ray diffraction(XRD)and Raman spectroscopy.Data correlation analysis was performed to reveal the mechanism of carbon structural ordering evolution within the critical temperature range(350−600℃)from colloidal layer formation to semi-coke conversion in coking coal,and to elucidate the regulatory effects of different additives on coal pyrolysis pathways.The results indicate that HDPE releases free radicals during high-temperature pyrolysis,accelerating the pyrolysis reaction and increase the yield of volatile components.Conversely,CTP facilitates pyrolysis at low temperatures through its light components,thereby delaying high-temperature reactions due to the colloidal layer’s effect.XRD results indicate that during the process of pyrolysis,there is a progressive decrease in the interlayer spacing of aromatic layers(d002),while the aromatic ring stacking height(L_(c))and lateral size(L_(a))undergo significant of carbon skeleton ordering.Further comparative reveals that CTP partially suppresses structural ordering at low temperatures,whereas HDPE promotes the condensation and alignment of aromatic clusters via a free radical mechanism.Raman spectroscopy reveals a two-stage reorganization mechanism in the microstructure of the coal char:the decrease in the I_(D)/I_(G)ratio between 350 and 550℃is primarily attributed to the cleavage of aliphatic side chains and cross-linking bonds,leading to a reduction in defective structures;whereas the increase in ID/IG between 550 and 600℃is closely associated with enhanced condensation reactions of aromatic structures.Correlation analysis further demonstrates progressive graphitization during pyrolysis,with a significant positive correlation(R^(2)>0.85)observed between d002 and the full width at half maximum of the G-band(FWHM-G).
基金The National Natural Science Foundation of China(No.52222804,U21A20154).
文摘Past investigations of the hydrodynamic forces on vertical columns have generally been based on rigid structure assumptions.The effects of structural flexibility and geometry characteristics on the hydrodynamic force distribution are not well understood.In this study,fluid-structure interaction models are developed for numerical analyses.This modeling technique is verified with an experimental test in the literature using both circular and rectangular cross-sections.A series of material elasticities that present structural properties ranging from rigid to flexible is then used to conduct analyses.This finding indicates that an increase in structural flexibility can decrease the impact force to some extent,but this effect is limited.A concrete bridge pier with fluid flow impact can be considered rigid when it is fixed at the bottom.After that,the effects of the initial downstream water height and the width of water tank on the hydrodynamic force are thoroughly investigated.The results demonstrate that the increase in the downstream water height with a constant upstream water height corresponds to a decreased force.Moreover,the vertical column results in a blockage effect on the fluid flow.The greater the blockage effect,the higher the hydrodynamic force.The blockage effect from the vertical column can be neglected when the tank width is greater than eight times the structural cross-section diameter.
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Natural Science Foundation of China under Grant No.52178449,the Beijing Natural Science Foundation under Grant No.8234060the Innovation Center of Beijing Association for Science and Technology。
文摘This study proposes a new post-tensioned precast bridge column(PT-PBC)with a socket connection.Compared to conventional PBCs connected by PT tendons,the combination of the PT tendons with the socket connection can avoid tensioning the PT tendons on site,which further accelerates construction speed while improving construction quality and safety.In addition,compared to conventional PBCs with a socket connection,a rocking interface can avoid the formation of a plastic hinge in a column,which greatly alleviates seismic damage to that area.One specimen for quasi-static testing is used to validate the feasibility of this connection type.Subsequently,finite element models(FEM)are established to systematically predict the responses of the proposed columns under lateral cyclic loading.The accuracy of the FEM is verified through quasistatic testing.Next,the influences of the key design parameters of the PT-PBC,including the area ratio and prestress level of the PT tendons,the area ratio of energy dissipation(ED)steel rebars,and the total axial compression ratio on the seismic performances of PT-PBC are systematically investigated.The use of shape memory alloy(SMA)rods as energy dissipation devices and their performances also are investigated.The results show that increasing the area ratio and prestress level of PT tendons has an overall positive impact on the self-centering capacity of the column.The prestress level of PT tendons should be kept between 35%and 55%,depending on different conditions.The total compression axial ratio of the columns should be maintained between 0.3 and 0.4.Both ED steel rebars and SMA rods can boost the column’s energy dissipation capacity,while SMA rods can reduce residual deformation due to their inherent mechanical properties.
文摘This paper reports the preparation of three di‑iron complexes containing a thiazole moiety.Esterification of complex[Fe_(2)(CO)_(6)(μ‑SCH_(2)CH(CH_(2)OH)S)](1)with 4‑methylthiazole‑5‑carboxylic acid gave the corresponding ester[Fe_(2)(CO)_(6)(μ‑tedt)](2),where tedt=SCH_(2)CH(CH_(2)OOC(5‑C_(3)HNSCH_(3)))S.Further reactions of complex 2 with tri(ptolyl)phosphine(tp)or tris(4‑fluorophenyl)phosphine(fp)gave the phosphine‑substituted derivatives[Fe_(2)(CO)_(5)(tp)(μ‑tedt)](3)and[Fe_(2)(CO)_(5)(fp)(μ‑tedt)](4).The structures of the newly prepared complexes were elucidated by elemental analysis,NMR,IR,and X‑ray photoelectron spectroscopy.Moreover,single‑crystal X‑ray diffraction analysis confirmed their molecular structures,showing that they contain a di‑iron core ligated by a bridged dithiolate bearing a thiazole moiety and terminal carbonyls.The electrochemical and electrocatalytic proton reduction were probed by cyclic voltammetry,revealing that three complexes can catalyze the reduction of protons to H_(2) under the electrochemical conditions.For comparison,complex 4 possessed the best efficiency with a turnover frequency of 23.5 s^(-1)at 10 mmol·L^(-1)HOAc concentration.In addition,the fungicidal activity of these complexes was also investigated in this study.CCDC:2477511,2;2477512,3;2477513,4.
基金National Key R&D Program of China under Grant No.2023YFC3805100Technologies R&D Project of China Construction First Group Corporation Limited under Grant No.PT-2022-09National Natural Science Foundation of China under Grant No.52178126。
文摘Bolting steel angles at the bottom ends of columns provides a rapid and efficient method for repairing damaged structures,while also offering a viable approach to restore their potential bearing capacity.To validate the suitability of specific strengthening strategies,particularly the utilization of bolted steel angles,three reinforced concrete frame specimens were subjected to hysteresis testing.These specimens all featured RC columns strengthened with steel angle ends.Additionally,one control specimen without steel angle ends was included in the testing.The hysteresis effects of bolting steel angles were discussed in terms of typical failure mode,hysteresis and skeleton curves,stiffness degradation and energy dissipation.The experimental results revealed that the three specimens that had bolted steel angles exhibited ductile failure behavior.Through analysis of hysteresis and skeleton curves,it was observed that the frame demonstrated distinct plasticity,maintaining sufficient load-bearing capacity even after yielding and exhibiting superior displacement ductility performance.Considering equivalent viscous damping,the energy dissipation capacity of the RC frame increased linearly with drift and remained largely unaffected by structural damage.Therefore,bolting steel angles at specified cross-sections proved to be a viable technique for structural repair and restoration.
基金supported by the National Key R&D Program of China(Grant No.2022YFB2404402)the National Natural Science Foundation of China(Grant Nos.22025507,22421001,and 22409200)+1 种基金the Strategic Priority Research Program of the Chinese Academy of SciencesGrant No.XDB 1040200。
文摘Nickel-rich cathodes(NRCs)hold great promise for next-generation high-energy lithium-ion batteries(LIBs)due to high specific energy and low cost.However,the higher Ni content exacerbates the instability issues associated with structural degradation and side reactions during electrochemical cycling.Herein,we demonstrate the possibility of preparing NRCs,typically Li Ni_(0.9)Co_(0.05)Mn_(0.05)O_(2)(NCM9055),with much-improved mechanical and chemical stability based on the surface coating of the hydroxide precursors.Specifically,a conformal nanoshell containing both Al^(3+)and W^(6+)was first deposited around the precursor particles,and the following high-temperature lithiation produced the targeted NCM9055 with favorable structural features,where Al3+existed as a bulk dopant to enhance the structural stability while the high-valent W^(6+)promoted the microstructural evolution into radially-architectured elongated primary particles.Such a structural engineering benefiting from the Al^(3+)/W^(6+)co-modification endowed the prepared NCM9055 cathode(NCM9055-Al W)with much-improved cycling stability,as revealed by a high-capacity retention of 98.0%after 100 cycles(tested at 0.5 C,4.3 V)as compared to only 79.0%for the pristine cathode without Al^(3+)/W^(6+).The NCM9055-15Al W cathode also showed a high-rate capability with extraordinary structural stability against mechanical failure.Our study highlighted the enormous potential of precursor multi-element treatment as an effective tool in structural refinement of NRCs to circumvent their stability challenge for their applications in high-energy LIBs.
文摘From cracking the code of viruses to mentoring the next generation of scientists,the former president of Nankai University has contributed a lot to turning microscopic discoveries into monumental shields for global health.OVER the past 40 years,one man has distinguished himself through a deep commitment to researching protein structures of high pathogenic viruses,and published numerous significant works in top international scientific journals.
基金support of the National Natural Science Foundation of China(No.52574411)Beijing Natural Science Foundation(No.2242043).
文摘Achieving high energy and power densities is currently a core challenge in the fabrication of energy storage materials.Although numerous high-capacity materials have been developed,conventional planar electrodes cannot achieve high active material loading and efficient ion/electron transport simultaneously.By contrast,three-dimensional(3D)structures have attracted increasing interest because of their capacity to enhance active material utilization,shorten ion and electron transport pathways,reduce interfacial impedance,and provide spatial accommodation for volume expansion.Additive manufacturing(AM)technology effectively fabricates energy-storage materials with 3D structures by accurately constructing complex 3D structures via layer-by-layer deposition.Recent studies have employed AM to construct ordered 3D electrodes that can optimize ion/electron transport,regulate electric field distribution,or improve the electrode-electrolyte interface,thereby contributing to enhanced kinetic performance and cycling stability.This review systematically summarizes the applications of several AM technologies in the fabrication of energy storage materials and analyzes their respective advantages and limitations.Subsequently,the advantages of AM technology in the fabrication of energy storage materials and several major optimization strategies are comprehensively discussed.Finally,the major challenges and potential applications of AM technology in energy storage material optimization are discussed.
基金supported by the Natural Science Research Project of Anhui Province Education Department for Excellent Young Scholars(Grant No.2024AH030007)the National Natural Science Foundation of China(Grant No.52202001)。
文摘Conventional Tb^(3+)-doped phosphors typically suffer from concentration quenching once the doping level exceeds a critical threshold.Consequently,the development of Tb^(3+)phosphors with intrinsic resistance to concentration quenching has become a key research focus.In this work,we successfully synthesized KBi(MoO_(4))_(2):x Tb^(3+)(x=0-100 at%)(denoted as KBM:x Tb^(3+))phosphors via a high-temperature solid-state reaction.Remarkably,no concentration quenching was observed across the entire doping range.This anti-quenching behavior originates from the large Tb^(3+)-Tb^(3+)interionic distance(>5Å)inherent to the quasi-layered crystal structure,which effectively suppresses multipole-interaction-mediated energy migration.At full Tb^(3+)substitution(x=100 at%),the material undergoes a structural phase transition from the monoclinic KBM phase to the triclinicα-KTb(MoO_(4))_(2)(α-KTM)phase.Theα-KTM phosphor exhibits excellent thermal stability(activation energy=0.6129 eV)and a single-exponential decay profile,whereas KBM:x Tb^(3+)(x<100%)display double-exponential decay behaviors,attributed to dual energy transfer pathways.These findings provide new insights into the luminescence mechanisms of high-concentration rare-earth-doped systems and offer guidance for designing nextgeneration anti-quenching phosphors.
基金supported financially by the National Natural Science Foundation of China(31811530297 and 32170217).
文摘Plastome variation,including single spontaneous nucleotide substitutions and single insertions/deletions,is the major source of leaf variegation in plants.Additionally,one recent study has showed that a simple plastome structural variation,which is induced by one pair of small inverted repeats,can also result in leaf variegation.Here we show a complex plastome structural variation caused by intermolecular and intramolecular recombination across three pairs of small inverted repeats accounts for leaf variegation in a widely cultivated shrub Heptapleurum ellipticum(Araliaceae).This plastome structural variation contains two deletions and two duplications,resulting in dramatic expansion of IRs,substantial contraction of LSC and loss of 11 genes that essential for photosynthesis.Plastome heteroplasmy was detected in both green and albino sectors of variegated leaves.Relative to green sectors,albino sectors in the variegated leaves exhibit significantly reduced expression for the 11 genes lost in the mutated plastome as well as 26 other genes,but significantly increased expression for one gene related to translation apparatus.Optical and transmission electron microscopy observations showed that mesophyll cells of albino sectors possess plastids lacking grana lamellae,which likely carry the mutated plastome and contribute to albinism.In both sectors,the first layer of spongy mesophyll cells beneath the lower epidermis contains normal chloroplasts,suggesting periclinal division of the lower epidermis during development.Our study demonstrates that multiple small repeats can collectively mediate intra-and inter-molecular recombination in plastome and offers a new mechanism accounting for leaf variegation in plants.
基金supported by the National Natural Science Foundation of China (Grant Nos.92477128,92580137,92477205,12374200,11604063,11974422,and 12104504)the National Key R&D Program of China (MOST) (Grant No.2023YFA1406500)+3 种基金the Strategic Priority Research Program (Chinese Academy of Sciences,CAS) (Grant No.XDB30000000)the Fundamental Research Funds for the Central Universities and Research Funds of Renmin University of China (Grant No.21XNLG27)supported by the Outstanding Innovative Talents Cultivation Funded Programs 2023 of the Renmin University of Chinaan outcome of “Two-dimensional anisotropic series of materials FePd2+xTe2:a structural modulation study from the atomic scale to the mesoscopic scale” (RUC25QSDL128),funded by the “Qiushi Academic-Dongliang” Talent Cultivation Project at Renmin University of China in 2025。
文摘Transition-metal dichalcogenides hosting multiple competing structural and electronic phases are thus ideal platforms for constructing polytype heterostructures with emergent quantum properties.However,controlling phase transitions to form diverse heterostructures inside a single crystal remains challenging.In this study,we realize vertical/lateral polytype heterostructures in a hole-doped Mott insulator via thermal annealing-induced structural transitions.Raman spectroscopy,atomic force microscopy and scanning Kelvin probe force microscopy confirm the coexistence of T-H polytype heterostructures.Atomic-scale scanning tunneling microscopy/spectroscopy measurements reveal the transparent effect in 1H/1T vertical heterostructures,where positive bias voltage induces in a pronounced superposition of the√13×√13 CDW of the 1T-layer on the 1H-layer.By systematically comparing the 1T/1H and 1T/1T interfaces,we demonstrate that the metallic 1H-layer induces a Coulomb screening effect on the 1T-layer,suppressing the formation of CDW domain walls and forming more ordered electronic states.These results clarify the interfacial coupling between distinct quantum many-body phases and establish a controllable pathway for constructing two-dimensional polytype heterostructures with tunable electronic properties.
基金supported by the Science and Technology Major Project of Shanxi Province,China(202201140601025-2,202302140601001)the Agricultural Science Research Project of Shanxi Agricultural University,China(2023BQ108)+1 种基金the Senior Foreign Experts Introducing Project,China(G202204011L)the Science and Technology Innovation Young Talent Team of Shanxi Province,China(202204051001019)。
文摘Structural variation is an important source of genetic variation in wheat and have been important in the evolution of the wheat's genome.Few studies have examined the relationship between structural variations and agronomy and drought tolerance.The present study identified structural chromosome variations(SCVs)in a doubled haploid(DH)population and backcross introgression lines(BC5F3)derived from Jinmai 47 and Jinmai 84 using fluorescence in situ hybridization(FISH).There are one simple translocation,10 present/absent variations(PAVs),and one copy number variation(CNV)between Jinmai 47 and Jinmai 84,which distributed in 10 chromosomes.Eight SCVs were associated with 15 agronomic traits.A PAV recombination occurred on chromosome 2A,which was associated with grain number per spike(GNS).The 1BL/1RS translocation and PAV.2D were associated with significant reductions in plant height,deriving from the effects on LI2-LI4,LI2-LI4 and UI,respectively respectively.PAV.2D was also contributed to an increase of 3.13%for GNS,1BL/1RS significantly increased spikelet number,grain length(GL),and grain thickness(GT).The effect of PAV.4A.1 on GL,PAV.6A on spike length(SL)and thousand-grain weight(TGW),PAV.6B on SL,GT and TGW were identified and verified.PAVs on chromosomes 2A,6A,1D,2D,and a CNV on chromosome 4B were associated with the drought tolerance coefficients.Additive and interaction effects among SCVs were observed.Many previously cloned key genes and yield-related QTL were found in polymorphic regions of PAV.2B,PAV.2D,and CNV.4B.Altogether,this study confirmed the genetic effect of SCVs on agronomy and drought tolerance,and identification of these SCVs will facilitate genetic improvement of wheat through marker-assisted selection.
基金supported by the National Natural Science Foundation of China (Nos.82322065,82173707,and 82204241)the Innovation and Entrepreneurship (Shuangchuang) Program of Jiang-su Province (2024)+3 种基金the Natural Science Foundation of Jiangsu Province (No.BK20221039)the Project Program of State Key Laboratory of Natural Medicines (China Pharmaceutical University,No.SKLNMZZ2024JS12)the Fundamental Research Funds for the Central Universities (No.2632025ZD06)the Scientific Research Foundation for High-level Faculty,China Pharmaceutical University (No.3150020065)
文摘TMPRSS2 plays a crucial role in facilitating the entry of both the influenza virus and the SARSCoV-2 coronavirus into host cells.Recent studies have identified a guanine-rich sequence in the proximal promoter region of the TMPRSS2 gene,which can form G-quadruplex structures(TMPRSS2-G4s)that are potential targets for small molecules to inhibit TMPRSS2 expression.However,the structural details of the major TMPRSS2-G4 and its complex with small molecules remain unknown,hindering the development of antiviral drugs targeting TMPRSS2-Gquadruplexes(G4s).This study reports the first high-resolution nuclear magnetic resonance(NMR)solution structure of the major TMPRSS2-G4,which consists of a three-tetrad core parallel-stranded G4.Both 3′and 5′flanking regions form well-defined capping structures stabilized by multiple hydrogen bonds.Importantly,we found that berberine,an antiviral alkaloid,strongly binds to the major TMPRSS2-G4 and determined its binding complex structure with TMPRSS2-G4 at a 2∶1 binding stoichiometry.Each berberine molecule recruits an adjacent flanking residue,forming a coplanar structure superimposed on two outer G-tetrads.Moreover,we demonstrated that the major TMPRSS2-G4 can stably form within a longer deoxyribonucleic acid(DNA)context and be targeted by small molecules to inhibit DNA polymerase activity.Overall,this study provides structural insights into the recognition mechanism of small molecules by the major TMPRSS2-G4 and may facilitate the development of novel antiviral therapeutics targeting TMPRSS2-G4.
基金The 2024 First class discipline-shuishan teacher research start up fund of the Nanjing Forestry university,163,020,447,Shanyu Han.
文摘Bamboo is a natural composite that has inspired the design of biomimetic composites due to its unique multi-scale struc-ture and outstanding mechanical properties.This paper first presents the structural features of bamboo,detailing the hydro-phobic wax and silica layer of the surface,the functionally graded vascular bundles of the wall for optimized toughness,and the hollow,multi-node architecture of the stem for overall stability and bending resistance.Subsequently,this study surveys recent sustainability and designability advances in bamboo-inspired composites.Inspiration from the bamboo sur-face has spurred the creation of materials with enhanced functionalities,such as transparent composites and high-stiffness structural materials.Imitation of the wall structure has led to the development of high-strength and tough materials,with the discussion covering examples such as hydrogels,polymer composites,and metal-matrix composites.Inspiration from the stem structure has yielded lightweight composites with excellent energy absorption and stability,exemplified by advanced linear materials like resilient yarns and tendon sutures,as well as functional structures like flexible sensors.These biomimetic designs show significant potential across numerous fields,including construction,healthcare,urban rail transit,wearable electronics,and mechanical engineering.Finally,this paper discusses the current limitations and challenges to understanding bamboo's structural characteristics towards the development of bamboo-inspired composites.Future research directions are proposed,including understanding bamboo's structure,designing novel biomimetic com-posites,and optimizing their structure to develop bamboo-inspired functional materials.
基金funded by The Science Foundation of Henan University of Technology(2021BS038)The Open Project Program of National Engineering Re-search Center of Wheat and Corn Further Processing(NL2022014)Henan Province Science and Technology R&D Program Joint Fund(Application Research and De-velopment Category)(242103810082).
文摘High-moisture meat analogues(HMMAs)offer sustainable protein alternatives to conventional meat and become a research hotspot in recent years.This study systematically investigated the impact of nori powder(NP)incorporation(0.5%–2.0%)on the physicochemical and structural properties of HMMAs.Rheological analysis revealed that NP reduced the viscosity(consistency coefficient K decreased from 65.67 Pa⋅s to 16.66–19.99 Pa⋅s)and enhanced the fluidity(flow behavior index n increased from 0.25 to 0.33–0.38)of raw material.NP addition progressively decreased the redness values(a*),except for 0.5%NP level.At 1.0%NP level,HMMAs exhibited a denser microstructure with reduced water mobility,resulting in the lowest water holding capacity(2.07 g/g).Conversely,2.0%NP promoted highly oriented fibrous structures,achieving a maximal texturization degree of 1.51.Secondary structure analysis indicated NP facilitated a shift fromα-helix toβ-sheet conformations(β-sheet content increased from 26.06%to 29.92%at 2.0%NP),resulting in stabilized protein networks.These modifications were attributed to NP-induced hydrophobic interactions and polysaccharide-protein crosslinking.The study demonstrates NP's role in modulating HMMA texture and nutrition,providing critical insights for developing fiber-enhanced,nutrient-fortified HMMAs.
基金supported by an International Cooperation Key Plan of Shaanxi Province(Grant No.2022KWZ-12)an Agricultural Science Innovation and Transformation Project of Shaanxi Province[Grant No.NYKJ-2022-YL(XN)12]a High-End Foreign Expert Recruitment Program(Grant No.G2022172006L).
文摘Wind disturbance has emerged as a potential eco-friendly method for seedling cultivation.In this study,an electromechanical device was designed and built to investigate the effects of airflow on the micro-environment and physiological activities of tomato seedlings in seedbeds by controlled experiments.The results indicated that airflow could enhance CO_(2) concentration near the seedling canopy,accelerate water evaporation from the seedling substrate,and reduce fluctuations in the temperature and humidity in microclimate.The photosynthetic rates of leaves at the 4th,7th,and 10th positions in seedlings subjected to airflow increased by 25.04%,8.23%,and 8.47%,respectively,whereas the transpiration rates increased by 15.59%,22.28%,and 13.26%,respectively when compared to the control group.Additionally,the strong seedling index of seedlings treated with airflow and exogenous iron element increased by 26.02%and 31.5%,respectively.Compared to seedlings treated with exogenous iron element,the geometric mean diameter of the pith tissue cells in the stems of seedlings subjected to airflow disturbance was reduced by approximately 18.66%,while the elastic modulus and bending strength of the stems increased by 10.01%and 5.89%,respectively.Similarly,the volume of root tissue cells decreased by 19.22%,but the elastic modulus of the roots increased by 6.46%.This study confirms that airflow significantly enhances seedling resilience to abiotic stress,yielding similar or better outcomes than exogenous iron application.It provides both theoretical and practical support for using airflow disturbance as a green technology for cultivating robust seedlings.
基金supported by the Science and Technology Development Fund,Macao SAR(0065/2023/AFJ,0116/2022/A3)the National Natural Science Foundation of China(52402166)+4 种基金the Natural Science Foundation of Guangdong Province(2025A1515011120)the Australian Research Council(DE220100154)the financial support from the Science and Technology Development Fund(FDCT),Macao SAR(No.0149/2022/A),and(No.0046/2024/AFJ)Guangdong Science and Technology Department(2023QN10C305)for this workthe financial support from the National Natural Science Foundation of China(Grant No.22305185)。
文摘Flexible and wearable sensors offer immense potential for rehabilitation medicine,but most rely solely on electrical signals,lacking real-time visual feedback and limiting trainee's interactivity.Inspired by the structural coloration of Cyanocitta stelleri feathers,we developed a dual-mode sensor by utilizing black conductive polymer hydrogel(CPH)-enhanced structural color strategy.This sensor integrates a hydroxypropyl cellulose(HPC)-based structural color interface with a designed CPH sensing component.Highly visible light-absorbing CPH(absorption rate>88%)serves as the critical substrate for enhancing structural color performance.By absorbing incoherent scattered light and suppressing background interference,it significantly enhances the saturation of structural color,thereby achieving a high contrast index of 4.92.Unlike the faint and hardly visible structural colors on non-black substrates,the HPC on CPH displays vivid,highly perceptible colors and desirable mechanochromic behavior.Moreover,the CPH acts as a flexible sensing element,fortified by hydrogen and coordination bond networks,and exhibits exceptional electromechanical properties,including 867.1 kPa tensile strength,strain sensitivity(gauge factor of 4.24),and outstanding durability(over 4400 cycles).Compared to traditional single-mode sensors,the integrated sensor provides real-time visual and digital dual feedback,enhancing the accuracy and interactivity of rehabilitation assessments.This technology holds promise for advancing next-generation rehabilitation medicine.
