Motivated by the great potential of carbon nanotubes for developing nanofluidic devices, this paper presents a nonlocal elastic, Timoshenko multi-beam model with the second order of strain gradient taken into consider...Motivated by the great potential of carbon nanotubes for developing nanofluidic devices, this paper presents a nonlocal elastic, Timoshenko multi-beam model with the second order of strain gradient taken into consideration and derives the corresponding dispersion relation of flexural wave in multi-walled carbon nanotubes conveying fuids. The study shows that the moving flow reduces the phase velocity of flexural wave of the lowest branch in carbon nanotubes. The phase velocity of flexural wave of the lowest branch decreases with an increase of flow velocity. However, the effects of flow velocity on the other branches of the wave dispersion are not obvious. The effect of microstructure characterized by nonlocal elasticity on the dispersion of flexural wave becomes more and more remarkable with an increase in wave number.展开更多
Analytical solutions for the elastic properties of a variety of binary nanotubes with arbitrary chirality are obtained through the study of systematic molecular mechanics. This molecular mechanics model is first exten...Analytical solutions for the elastic properties of a variety of binary nanotubes with arbitrary chirality are obtained through the study of systematic molecular mechanics. This molecular mechanics model is first extended to chiral binary nanotubes by introducing an additional out-of-plane inversion term into the so-called stick-spiral model, which results from the polar bonds and the buckling of binary graphitic crystals. The closed-form expressions for the longitudinal and circumferential Young's modulus and Poisson's ratio of chiral binary nanotubes are derived as functions of the tube diameter. The obtained inversion force constants are negative for all types of binary nanotubes, and the predicted tube stiffness is lower than that by the former stick-spiral model without consideration of the inversion term, reflecting the softening effect of the buckling on the elastic properties of binary nanotubes. The obtained properties are shown to be comparable to available density functional theory calculated results and to be chirality and size sensitive. The developed model and explicit solutions provide a systematic understanding of the mechanical performance of binary nanotubes consisting of III-V and II-VI group elements.展开更多
We find by ab initio simulations that significant overall tensile strain can be induced by pure bending in a wide range of two-dimensional crystals perpendicular to the bending moment, just like an accordion being ben...We find by ab initio simulations that significant overall tensile strain can be induced by pure bending in a wide range of two-dimensional crystals perpendicular to the bending moment, just like an accordion being bent to open. This bending-induced tensile strain increases in a power law with bent curvature and can be over 20% in monolayered black phosphorus and transition metal dichalcogenides at a moderate curvature of but more than an order weaker in graphene and hexagon boron nitride. This accordion effect is found to be a quantum mechanical effect raised by the asymmetric response of chemical bonds and electron density to the bending curvature.展开更多
Water contains tremendous energy,which fuels the Earth’s water cycle.Technology for generating electricity directly from interaction between water and nanomaterials is referred to as hydrovoltaic technology,providing...Water contains tremendous energy,which fuels the Earth’s water cycle.Technology for generating electricity directly from interaction between water and nanomaterials is referred to as hydrovoltaic technology,providing versatile ways to harvest energy from most steps of the water cycle.Due to its attractive potential,intensive efforts have been devoted into this area,and lots of notable developments have been made during the last few years,supporting the progress of hydrovoltaics.In this article,a brief review of recent progress made in hydrovoltaic energy harvester for mechanical and environmental energy of water is presented.Following that,the future directions for hydrovoltaic energy and its potential on hydrovoltaic ecology and intelligence are envisioned.展开更多
The reliable functioning of ion channels should be closely related to their structural stability. The selectivity filter in the KcsA potassium channel possesses four stable ion binding sites that can coordinate nearly...The reliable functioning of ion channels should be closely related to their structural stability. The selectivity filter in the KcsA potassium channel possesses four stable ion binding sites that can coordinate nearly fully dehydrated ions, whereas only two of such binding sites exist in the non-selective NaK channel, and none of them is found in the NavAb sodium channel. Here we show that the stability of the selectivity filters in these tetrameric cation channels is inversely correlated with the number of stable binding sites by extensive molecular dynamics simulations. While the presence of coordinated ions is crucial for the selectivity filters of the KcsA and NaK channels to stabilize the conformations in their crystal structures, the selectivity filter of the NavAb channel shows higher stability, independent of the presence of ions. We further show that the distinct repulsive electrostatic interactions between negatively charged oxygen atoms in the selectivity filter which form the stable binding sites are responsible for the different stability of these cation channels. The hydrogen bonding networks between residues in the selectivity filter and its adjacent pore helix also play an important role in maintaining stability. Together, these results provide important mechanistic insights into the structural stability of the selectivity filters in typical cation channels.展开更多
Artificial biomaterials with dynamic mechano-responsive behaviors similar to those of biological tissues have been drawing great attention.In this study,we report a TiO_(2)-based nanowire(TiO_(2)NWs)scaffolds,which ex...Artificial biomaterials with dynamic mechano-responsive behaviors similar to those of biological tissues have been drawing great attention.In this study,we report a TiO_(2)-based nanowire(TiO_(2)NWs)scaffolds,which exhibit dynamic mechano-responsive behaviors varying with the number and amplitude of nano-deformation cycles.It is found that the elastic and adhesive forces in the TiO_(2)NWs scaffolds can increase significantly after multiple cycles of nano-deformation.Further nanofriction experiments show the triboelectric effect of increasing elastic and adhesive forces during the nano-deformation cycles of TiO_(2)NWs scaffolds.These properties allow the TiO_(2)NW scaffolds to be designed and applied as intelligent artificial biomaterials to simulate biological tissues in the future.展开更多
Fatigue properties of materials by Additive Manufacturing(AM) depend on many factors such as AM processing parameter, microstructure, residual stress, surface roughness, porosities, post-treatments, etc. Their evaluat...Fatigue properties of materials by Additive Manufacturing(AM) depend on many factors such as AM processing parameter, microstructure, residual stress, surface roughness, porosities, post-treatments, etc. Their evaluation inevitably requires these factors combined as many as possible, thus resulting in low efficiency and high cost. In recent years, their assessment by leveraging the power of Machine Learning(ML) has gained increasing attentions. A comprehensive overview on the state-of-the-art progress of applying ML strategies to predict fatigue properties of AM materials, as well as their dependence on AM processing and post-processing parameters such as laser power, scanning speed, layer height, hatch distance, built direction, post-heat temperature,etc., were presented. A few attempts in employing Feedforward Neural Network(FNN), Convolutional Neural Network(CNN), Adaptive Network-Based Fuzzy Inference System(ANFIS), Support Vector Machine(SVM) and Random Forest(RF) to predict fatigue life and RF to predict fatigue crack growth rate are summarized. The ML models for predicting AM materials' fatigue properties are found intrinsically similar to the commonly used ones, but are modified to involve AM features. Finally, an outlook for challenges(i.e., small dataset, multifarious features,overfitting, low interpretability, and unable extension from AM material data to structure life) and potential solutions for the ML prediction of AM materials' fatigue properties is provided.展开更多
The extraordinary properties of a heterostructure by stacking atom-thick van der Waals(vdW)magnets have been extensively studied.However,the magnetocaloric effect(MCE)of heterostructures that are based on monolayer ma...The extraordinary properties of a heterostructure by stacking atom-thick van der Waals(vdW)magnets have been extensively studied.However,the magnetocaloric effect(MCE)of heterostructures that are based on monolayer magnets remains to be explored.Herein,we deliberate MCE of vd W heterostructure composed of a monolayer CrI_(3)and metal atomic layers(Ag,Hf,Au,and Pb).It is revealed that heterostructure engineering by introducing metal substrate can improve MCE of CrI_(3),particularly boosting relative cooling power to 471.72μJ m^(-2)and adiabatic temperature change to 2.1 K at 5 T for CrI_(3)/Hf.This improved MCE is ascribed to the enhancement of magnetic moment and intralayer exchange coupling in CrI_(3)due to the CrI_(3)/metal heterointerface induced charge transfer.Electric field is further found to tune MCE of CrI_(3)in heterostructures and could shift the peak temperature by around 10 K in CrI_(3)/Hf,thus manipulating the working temperature window of MCE.These theoretical results could enrich the research on low-dimensional magnetocaloric materials.展开更多
Erratum to Nano Research,2023,16(7):9387-9397 htps:/oi.or/0.100/1274-023-5603-040(1)One sentence in the article was unfortunately mispresented on page 9392.Instead of As shown in Fig.S19 in the ESM,the A2/A2 values of...Erratum to Nano Research,2023,16(7):9387-9397 htps:/oi.or/0.100/1274-023-5603-040(1)One sentence in the article was unfortunately mispresented on page 9392.Instead of As shown in Fig.S19 in the ESM,the A2/A2 values of the reference,N-COF,and C-COF samples were 45.52%,44.55%,and 45.05%,respectively.展开更多
Water evaporation is a ubiquitous natural process exploiting thermal energy from ambient environment.Hydrovoltaic technologies emerged in recent years offer one prospective route to generate electricity from water eva...Water evaporation is a ubiquitous natural process exploiting thermal energy from ambient environment.Hydrovoltaic technologies emerged in recent years offer one prospective route to generate electricity from water evaporation,which has long been overlooked.Herein,we developed a hybrid hydrovoltaic generator driven by natural water evaporation,integrating an“evaporation motor”with an evaporation-electricity device and a droplet-electricity device.A rotary motion of the“evaporation motor”relies on phase change of ethanol driven by water-evaporation induced temperature gradient.This motion enables the evaporation-electricity device to work under a beneficial water-film operation mode to produce output of~4 V and~0.2μA,as well as propels the droplet-electricity device to convert mechanical energy into pulsed output of~100 V and~0.2 mA.As different types of hydrovoltaic devices require distinctive stimuli,it was challenging to make them work simultaneously,especially under one single driving force.We here for the first time empower two types of hydrovoltaic devices solely by omnipresent water evaporation.Therefore,this work presents a new pathway to exploiting water evaporation-associated ambient thermal energy and provides insights on developing hybrid hydrovoltaic generators.展开更多
Since its first discovery in 2017,evaporation-induced electricity has attracted extensive attention and shown significant advantages in green energy conversion.While the streaming potential-related electrokinetic effe...Since its first discovery in 2017,evaporation-induced electricity has attracted extensive attention and shown significant advantages in green energy conversion.While the streaming potential-related electrokinetic effect has been intensively explored and widely recognized as the underlying mechanism,the role of coupling between water molecules and charge carriers in the material remains elusive.Here we show through carefully designed experiments that the streaming potential effect indeed plays a role but can only contribute about half to the total water-evaporation-induced voltage occurring within the partially-wetted region of the carbon black film where the solid-liquid-gas three-phase interface exists.It is also shown that water evaporation from carboxyl and amino-functionalized carbon black films produces opposite voltage signals.Detailed first-principles calculations unveil that the adsorption of water molecules can lead to reversed charge transfer in the carboxyl and amino-functionalized carbon substrates.Finally,an evaporation-driven charge transport mechanism is proposed for the induced electricity mediated by the coupling between water molecules and charge carriers in the material.The results reveal the important role of direct interaction between water molecules and materials,deepening our understanding of the mechanism for evaporation-induced hydrovoltaic effect beyond streaming potential.展开更多
Developing high-performance nanostructured materials is key to deliver the potential of hydrovoltaic technology into practical applications.As single-component materials have approached its limit in generating hydrovo...Developing high-performance nanostructured materials is key to deliver the potential of hydrovoltaic technology into practical applications.As single-component materials have approached its limit in generating hydrovoltaic electricity,the development of multi-component hydrovoltaic materials has been necessary in continuously boosting the electricity output.Here,we report a hydrovoltaic material by integrating reduced graphene oxides and polypyrrole nanoparticles(rGO/PPy),where the rGO contributes improved conductivity and large specific surface area while PPy nanoparticles enable enhanced interaction with water.The device fabricated with this material generates a short-circuit current of 6μA as well as a maximum power density of over 1μW/cm3 from natural evaporation of water.And the substantial ion-PPy interaction enables robust voltage generation from evaporation of various salt solutions.Moreover,an outstanding scaling ability is demonstrated by connecting 10 devices in series that generate a sustainable voltage of up to~2.5 V,sufficing to power many commercial devices,e.g.LED bulb and LCD screen.展开更多
Water,the source of life,contains immense energy and manifests in diverse forms.Hydrovoltaic technology enables the direct interaction between water and materials to generate electricity,a vital necessity for industry...Water,the source of life,contains immense energy and manifests in diverse forms.Hydrovoltaic technology enables the direct interaction between water and materials to generate electricity,a vital necessity for industry modernization.Due to the ubiquitous presence and easy availability of falling water,hydrovoltaic energy derived from water droplets has attracted considerable attention and shown great potential in raindrop energy harvesting.In this review,a comprehensive summary of the latest advancements in harvesting hydrovoltaic energy from water droplets is presented,with a focus on the configurations and underlying mechanisms of hydrovoltaic devices.Additionally,a brief discussion on the applications of dropletbased hydrovoltaic devices is presented,along with future prospects for this energyharvesting technology.展开更多
The Au(100)surface has been a subject of intense studies due to excellent catalytic activities and its model character for surface science.However,the spontaneous surface reconstruction buries active Au(100)plane and ...The Au(100)surface has been a subject of intense studies due to excellent catalytic activities and its model character for surface science.However,the spontaneous surface reconstruction buries active Au(100)plane and limits practical applications,how to controllably eliminate the surface reconstruction over large scale remains challenging.Here,we experimentally and theoretically demonstrate that simple decoration of the Au(100)surface by tellurium(Te)atoms can uniquely lift its reconstruction over large scale.Scanning tunneling microscopy imaging reveals that the lifting of surface reconstruction preferentially starts from the boundaries of distinct domains and then extends progressively into the domains with the reconstruction rows perpendicular to the boundaries,leaving a Au(100)-(1×1)surface behind.The Au(100)-(1×1)is saturated at~84%±2%with respect to the whole surface at a Te coverage of 0.16 monolayer.With further increasing the Te coverage to 0.25 monolayer,the Au(100)-(1×1)surface becomes reduced and overlapped by a well-ordered(2×2)-Te superstructure.No similar behavior is found for Te-decorated Au(111),Cu(111),Cu(100)surfaces,nor for the decorated Au(100)with other elements.This result may pave the way to design Au-based catalysts and,as an intermediate step,even potentially open a new route to constructing complex transition metal dichalcogenides.展开更多
Perovskite solar cells(PSCs)have attracted much attention due to their rapidly increased power conversion efficiencies,however,their inherent poor long-term stability hinders their commercialization.The degradation of...Perovskite solar cells(PSCs)have attracted much attention due to their rapidly increased power conversion efficiencies,however,their inherent poor long-term stability hinders their commercialization.The degradation of PSCs first comes from the degradation of hole transport materials(HTMs).Here,we report the construction of periodicπ-columnar arrays and ionic interfaces over the skeletons by introducing cationic covalent organic frameworks(C-COFs)to the HTM.Periodicπ-columnar arrays can optimize the charge transport ability and energy levels of the hole transport layer and suppress the degradation of HTM,and ionic interfaces over the skeletons can produce stronger electric dipole and electrostatic interactions,as well as higher charge densities.The C-COFs were designed and synthesized via Schiff base reaction by using 1,3,5-triformylphloroglucinol as a neutral knot and dimidium bromide as cationic linker.The neutral COFs(N-COFs)were also synthesized as a reference by using 3,8-diamino-6-phenylphenanthridine as neutral linker.PSCs with cationic COF exhibit the highest efficiency of 23.4%with excellent humidity and thermal stability.To the best of our knowledge,this is the highest efficiency among the meso-structured PSCs fabricated by a sequential process.展开更多
We reveal the ultralow friction or superlubricity of water nanodroplets containing cations and anions on graphene substrates at high ion concentration by molecular dynamics simulations.When the ion concentration is hi...We reveal the ultralow friction or superlubricity of water nanodroplets containing cations and anions on graphene substrates at high ion concentration by molecular dynamics simulations.When the ion concentration is higher than 7 wt.%and the nanodroplet diameter is larger than 10 nm,the friction coefficients of water nanodroplets are lower than 10−2,and can decrease to the order of 10−3 with increasing the ion concentration further.At a certain ion concentration,the optimal nanodroplet diameter of 17–20 nm exists at which the friction coefficient is the lowest.The ultralow friction behaviors of water nanodroplets containing cations and anions are mainly attributed to the opposite variation trends between the interfacial adhesion energy and surface energy of water nanodroplet with ion concentration,and the interfacial hydrophobicity sustained by high ion concentration.These results unveil the essential role of ions in achieving the superlubricity of water nanodroplets.展开更多
The last decade has witnessed the emergence of hydrovoltaic technology,which can harvest electricity from different forms of water movement,such as raindrops,waves,flows,moisture,and natural evaporation.In particular,...The last decade has witnessed the emergence of hydrovoltaic technology,which can harvest electricity from different forms of water movement,such as raindrops,waves,flows,moisture,and natural evaporation.In particular,the evaporation-induced hydrovoltaic effect received great attention since its discovery in 2017 due to its negative heat emission property.Nevertheless,the influence of electrode reactions in evaporation-induced power generation is not negligible due to the chemical reaction between active metal electrodes and water,which leads to“exceptional”power generation.Herein,we designed a series of experiments based on air-laid paper devices with electrodes of different activities as the top and bottom electrodes.To verify the contribution of electrodes,we compared the output performance of different electrode combinations when the device was partially-wetted and fully-wetted.The device hydrophilicity,salt concentration,and acidity or basicity of solutions were also comprehensively investigated.It is demonstrated that the chemical reaction of active metals(Zn,Cu,Ag,etc.)with different aqueous solutions can generate considerable electrical energy and significantly distort the device performance,especially for Zn electrodes with an output voltage from~1.26 to~1.52 V and current from~1.24 to~75.69μA.To promote the long-term development of hydrovoltaic technology,we recommend use of inert electrodes in hydrovoltaic studies,such as Au and Pt,especially in water and moisture environment.展开更多
Pseudo-ferroelectric transistors have attracted particular interest owing to their applications in the non-volatile memories and neuromorphic circuits;however,it remains to be explored in the limit of few-layer device...Pseudo-ferroelectric transistors have attracted particular interest owing to their applications in the non-volatile memories and neuromorphic circuits;however,it remains to be explored in the limit of few-layer devices.Here we reveal a pseudo-ferroelectric phenomenon in the ultrathin graphene/black phosphorene(G/BP)heterostructure by first-principles calculations.Putting forward an excitation-assisted mechanism,the ferroelectric-like hysteresis loop can be explained by a combined effect of the external electric fields dependent bipolarity and anisotropy in the G/BP heterostructure.Considering the build-in electric field,the bipolar behavior results in the multistate effect of the G/BP heterostructure when modulating the applied electric field.The anisotropic hybridization caused by the susceptible Dirac electrons in graphene and the large in-plane anisotropy in BP provides the interfacial states,which trap excitations and stabilize the multistate.The pseudo-ferroelectric behavior should be useful for interpreting transport experiments in gated G/BP devices and exploring its applications in memories or synaptic devices.展开更多
Chitosan oligosaccharides(COSs)are the main degradation products from chitosan or chitin and have been reported to induce resistance to diseases in herbaceous plants like cucumber and Arabidopsis.Concomitantly,pine wi...Chitosan oligosaccharides(COSs)are the main degradation products from chitosan or chitin and have been reported to induce resistance to diseases in herbaceous plants like cucumber and Arabidopsis.Concomitantly,pine wilt disease(PWD)is a devastating disease of conifer tree species.Here,we hypothesized that COSs induce plant resistance gene(PRG)expression in the woody plant Masson pine,Pinus massoniana.COSs were inoculated into P.massoniana seedlings and the BGISEQ-500 platform was used to generate transcriptomes from COSs-treated P.massoniana and control seedlings.A total of 501 differentially expressed genes(DEGs)were identified by comparing the treatment and control groups.A total of 251(50.1%)DEGs were up-regulated in the treatment relative to the control seedlings and 250(49.9%)were down-regulated.Inoculation of COSs induced the expression of 31 PRGs in P.massoniana seedlings and the relative expression levels of six of the PRGs were verified by RT-qPCR.This is the first study to demonstrate that COS induces the expression of PRGs in a tree species.These results provide important insights into the function of COSs and further the prospects of developing a COS-based immune inducer for controlling PWD.展开更多
基金supported in part by the National Natural Science Foundation of China (No10702026)
文摘Motivated by the great potential of carbon nanotubes for developing nanofluidic devices, this paper presents a nonlocal elastic, Timoshenko multi-beam model with the second order of strain gradient taken into consideration and derives the corresponding dispersion relation of flexural wave in multi-walled carbon nanotubes conveying fuids. The study shows that the moving flow reduces the phase velocity of flexural wave of the lowest branch in carbon nanotubes. The phase velocity of flexural wave of the lowest branch decreases with an increase of flow velocity. However, the effects of flow velocity on the other branches of the wave dispersion are not obvious. The effect of microstructure characterized by nonlocal elasticity on the dispersion of flexural wave becomes more and more remarkable with an increase in wave number.
基金supported by the 973 Program (Grants 2013CB932604, 2012CB933403)a project funded by the Priority Academic Program Development of Jiangsu Higher Education InstitutionsJiangsu Innovation Program for Graduate Education (Grant CXZZ12_0140)
文摘Analytical solutions for the elastic properties of a variety of binary nanotubes with arbitrary chirality are obtained through the study of systematic molecular mechanics. This molecular mechanics model is first extended to chiral binary nanotubes by introducing an additional out-of-plane inversion term into the so-called stick-spiral model, which results from the polar bonds and the buckling of binary graphitic crystals. The closed-form expressions for the longitudinal and circumferential Young's modulus and Poisson's ratio of chiral binary nanotubes are derived as functions of the tube diameter. The obtained inversion force constants are negative for all types of binary nanotubes, and the predicted tube stiffness is lower than that by the former stick-spiral model without consideration of the inversion term, reflecting the softening effect of the buckling on the elastic properties of binary nanotubes. The obtained properties are shown to be comparable to available density functional theory calculated results and to be chirality and size sensitive. The developed model and explicit solutions provide a systematic understanding of the mechanical performance of binary nanotubes consisting of III-V and II-VI group elements.
基金supported by the 973 program (Grants 2012CB937500, 2013CB932604)the National Natural Science Foundation of China (Grants 51535005, 51472117, 11021262, 11172303, 11132011)the Fundamental Research Funds for the Central Universities (Grant NP2013309)
文摘We find by ab initio simulations that significant overall tensile strain can be induced by pure bending in a wide range of two-dimensional crystals perpendicular to the bending moment, just like an accordion being bent to open. This bending-induced tensile strain increases in a power law with bent curvature and can be over 20% in monolayered black phosphorus and transition metal dichalcogenides at a moderate curvature of but more than an order weaker in graphene and hexagon boron nitride. This accordion effect is found to be a quantum mechanical effect raised by the asymmetric response of chemical bonds and electron density to the bending curvature.
基金The authors acknowledge the support of Project supported by recommend international advanced agricultural science and technology plan of Ministry of Agriculture of China (Grant No. 2010-Z18), and the National Natural Science Foundation of China (Grant No. 51275249).
基金National Key Research and Development Program of China(Grant No.2019YFA0705400)the National Natural Science Foundation of China(Grant No.51535005)+2 种基金the Research Fund of State Key Laboratory of Mechanics and Control of Mechanical Structures(Grant Nos.MCMS-I-0418K01 and MCMS-I-0419K01)the Fundamental Research Funds for the Central Universities(Grant Nos.NC2018001,NP2019301 and NJ2019002)the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘Water contains tremendous energy,which fuels the Earth’s water cycle.Technology for generating electricity directly from interaction between water and nanomaterials is referred to as hydrovoltaic technology,providing versatile ways to harvest energy from most steps of the water cycle.Due to its attractive potential,intensive efforts have been devoted into this area,and lots of notable developments have been made during the last few years,supporting the progress of hydrovoltaics.In this article,a brief review of recent progress made in hydrovoltaic energy harvester for mechanical and environmental energy of water is presented.Following that,the future directions for hydrovoltaic energy and its potential on hydrovoltaic ecology and intelligence are envisioned.
文摘The reliable functioning of ion channels should be closely related to their structural stability. The selectivity filter in the KcsA potassium channel possesses four stable ion binding sites that can coordinate nearly fully dehydrated ions, whereas only two of such binding sites exist in the non-selective NaK channel, and none of them is found in the NavAb sodium channel. Here we show that the stability of the selectivity filters in these tetrameric cation channels is inversely correlated with the number of stable binding sites by extensive molecular dynamics simulations. While the presence of coordinated ions is crucial for the selectivity filters of the KcsA and NaK channels to stabilize the conformations in their crystal structures, the selectivity filter of the NavAb channel shows higher stability, independent of the presence of ions. We further show that the distinct repulsive electrostatic interactions between negatively charged oxygen atoms in the selectivity filter which form the stable binding sites are responsible for the different stability of these cation channels. The hydrogen bonding networks between residues in the selectivity filter and its adjacent pore helix also play an important role in maintaining stability. Together, these results provide important mechanistic insights into the structural stability of the selectivity filters in typical cation channels.
基金supported by the National Natural Science Foundation of China(No.52205198)the Ningbo Natural Science Foundation(No.202003N4091)Ministry of Education of Key Laboratory of Impact and Safety Engineering at Ningbo University(No.CJ202108).
文摘Artificial biomaterials with dynamic mechano-responsive behaviors similar to those of biological tissues have been drawing great attention.In this study,we report a TiO_(2)-based nanowire(TiO_(2)NWs)scaffolds,which exhibit dynamic mechano-responsive behaviors varying with the number and amplitude of nano-deformation cycles.It is found that the elastic and adhesive forces in the TiO_(2)NWs scaffolds can increase significantly after multiple cycles of nano-deformation.Further nanofriction experiments show the triboelectric effect of increasing elastic and adhesive forces during the nano-deformation cycles of TiO_(2)NWs scaffolds.These properties allow the TiO_(2)NW scaffolds to be designed and applied as intelligent artificial biomaterials to simulate biological tissues in the future.
基金the support from the National Science and Technology Major Project, China (No. J2019IV-0014-0082)the National Key Research and Development Program of China (No. 2022YFB4600700)+1 种基金the National Overseas Youth Talents Program, China, the Research Fund of State Key Laboratory of Mechanics and Control for Aerospace Structures, China (No. MCMS-I-0422K01)a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions, China。
文摘Fatigue properties of materials by Additive Manufacturing(AM) depend on many factors such as AM processing parameter, microstructure, residual stress, surface roughness, porosities, post-treatments, etc. Their evaluation inevitably requires these factors combined as many as possible, thus resulting in low efficiency and high cost. In recent years, their assessment by leveraging the power of Machine Learning(ML) has gained increasing attentions. A comprehensive overview on the state-of-the-art progress of applying ML strategies to predict fatigue properties of AM materials, as well as their dependence on AM processing and post-processing parameters such as laser power, scanning speed, layer height, hatch distance, built direction, post-heat temperature,etc., were presented. A few attempts in employing Feedforward Neural Network(FNN), Convolutional Neural Network(CNN), Adaptive Network-Based Fuzzy Inference System(ANFIS), Support Vector Machine(SVM) and Random Forest(RF) to predict fatigue life and RF to predict fatigue crack growth rate are summarized. The ML models for predicting AM materials' fatigue properties are found intrinsically similar to the commonly used ones, but are modified to involve AM features. Finally, an outlook for challenges(i.e., small dataset, multifarious features,overfitting, low interpretability, and unable extension from AM material data to structure life) and potential solutions for the ML prediction of AM materials' fatigue properties is provided.
基金supported by the National Natural Science Foundation of China(Grant Nos.12272173,12302134,and 11902150)the Fundamental Research Funds for the Central Universities(Grant No.NS2023054)+4 种基金the National Overseas Youth Talents Programthe Research Fund of State Key Laboratory of Mechanics and Control for Aerospace Structures(Grant Nos.MCMS-I-0419G01,and MCMS-I-0421K01)the Priority Academic Program Development of Jiangsu Higher Education Institutionsthe Interdisciplinary Innovation Fund for Doctoral Students of Nanjing University of Aeronautics and Astronautics(Grant No.KXKCXJJ202306)partially supported by the High Performance Computing Platform of Nanjing University of Aeronautics and Astronautics。
文摘The extraordinary properties of a heterostructure by stacking atom-thick van der Waals(vdW)magnets have been extensively studied.However,the magnetocaloric effect(MCE)of heterostructures that are based on monolayer magnets remains to be explored.Herein,we deliberate MCE of vd W heterostructure composed of a monolayer CrI_(3)and metal atomic layers(Ag,Hf,Au,and Pb).It is revealed that heterostructure engineering by introducing metal substrate can improve MCE of CrI_(3),particularly boosting relative cooling power to 471.72μJ m^(-2)and adiabatic temperature change to 2.1 K at 5 T for CrI_(3)/Hf.This improved MCE is ascribed to the enhancement of magnetic moment and intralayer exchange coupling in CrI_(3)due to the CrI_(3)/metal heterointerface induced charge transfer.Electric field is further found to tune MCE of CrI_(3)in heterostructures and could shift the peak temperature by around 10 K in CrI_(3)/Hf,thus manipulating the working temperature window of MCE.These theoretical results could enrich the research on low-dimensional magnetocaloric materials.
文摘Erratum to Nano Research,2023,16(7):9387-9397 htps:/oi.or/0.100/1274-023-5603-040(1)One sentence in the article was unfortunately mispresented on page 9392.Instead of As shown in Fig.S19 in the ESM,the A2/A2 values of the reference,N-COF,and C-COF samples were 45.52%,44.55%,and 45.05%,respectively.
基金the National Natural Science Foundation of China(Nos.T2293691,12172176,12272181,12311530052,and 12150002)the National Key Research and Development Program of China(No.2019YFA0705400)+3 种基金Natural Science Foundation of Jiangsu Province(Nos.BK20220074,BK20211191,and BK20212008)the Research Fund of State Key Laboratory of Mechanics and Control for Aerospace Structures(MCMS-I-0421G01 and MCMS-I-0422K01)the Fundamental Research Funds for the Central Universities(NE2023003,NC2023001,NJ2023002,and NJ2022002)the Fund of Prospective Layout of Scientific Research for NUAA(Nanjing University of Aeronautics and Astronautics).
文摘Water evaporation is a ubiquitous natural process exploiting thermal energy from ambient environment.Hydrovoltaic technologies emerged in recent years offer one prospective route to generate electricity from water evaporation,which has long been overlooked.Herein,we developed a hybrid hydrovoltaic generator driven by natural water evaporation,integrating an“evaporation motor”with an evaporation-electricity device and a droplet-electricity device.A rotary motion of the“evaporation motor”relies on phase change of ethanol driven by water-evaporation induced temperature gradient.This motion enables the evaporation-electricity device to work under a beneficial water-film operation mode to produce output of~4 V and~0.2μA,as well as propels the droplet-electricity device to convert mechanical energy into pulsed output of~100 V and~0.2 mA.As different types of hydrovoltaic devices require distinctive stimuli,it was challenging to make them work simultaneously,especially under one single driving force.We here for the first time empower two types of hydrovoltaic devices solely by omnipresent water evaporation.Therefore,this work presents a new pathway to exploiting water evaporation-associated ambient thermal energy and provides insights on developing hybrid hydrovoltaic generators.
基金the National and Jiangsu Province NSF(T2293691,BK20212008)of ChinaNational Key Research and Development Program of China(2019YFA0705400)+2 种基金the Research Fund of State Key Laboratory of Mechanics and Control of Mechanical Structures(MCMS-I-0422K01)the Fundamental Research Funds for the Central Universities(NJ2022002)the Fund of Prospective Layout of Scientific Research for NUAA(Nanjing University of Aeronautics and Astronautics).
文摘Since its first discovery in 2017,evaporation-induced electricity has attracted extensive attention and shown significant advantages in green energy conversion.While the streaming potential-related electrokinetic effect has been intensively explored and widely recognized as the underlying mechanism,the role of coupling between water molecules and charge carriers in the material remains elusive.Here we show through carefully designed experiments that the streaming potential effect indeed plays a role but can only contribute about half to the total water-evaporation-induced voltage occurring within the partially-wetted region of the carbon black film where the solid-liquid-gas three-phase interface exists.It is also shown that water evaporation from carboxyl and amino-functionalized carbon black films produces opposite voltage signals.Detailed first-principles calculations unveil that the adsorption of water molecules can lead to reversed charge transfer in the carboxyl and amino-functionalized carbon substrates.Finally,an evaporation-driven charge transport mechanism is proposed for the induced electricity mediated by the coupling between water molecules and charge carriers in the material.The results reveal the important role of direct interaction between water molecules and materials,deepening our understanding of the mechanism for evaporation-induced hydrovoltaic effect beyond streaming potential.
基金The work was supported by the Fundamental Research Funds for the Central Universities[NJ2022002]National Key Research and Development Program of China[2019YFA0705400]+1 种基金National NSF of China[1221101035,12225205,22073048]Research Fund of State Key Laboratory of Mechanics and Control of Mechanical Structures[MCMS-I-0422K01].
文摘Developing high-performance nanostructured materials is key to deliver the potential of hydrovoltaic technology into practical applications.As single-component materials have approached its limit in generating hydrovoltaic electricity,the development of multi-component hydrovoltaic materials has been necessary in continuously boosting the electricity output.Here,we report a hydrovoltaic material by integrating reduced graphene oxides and polypyrrole nanoparticles(rGO/PPy),where the rGO contributes improved conductivity and large specific surface area while PPy nanoparticles enable enhanced interaction with water.The device fabricated with this material generates a short-circuit current of 6μA as well as a maximum power density of over 1μW/cm3 from natural evaporation of water.And the substantial ion-PPy interaction enables robust voltage generation from evaporation of various salt solutions.Moreover,an outstanding scaling ability is demonstrated by connecting 10 devices in series that generate a sustainable voltage of up to~2.5 V,sufficing to power many commercial devices,e.g.LED bulb and LCD screen.
基金National Natural Science Foundation of China,Grant/Award Numbers:12150002,12172176,12272181National Key Research and Development Program of China,Grant/Award Number:2019YFA0705400+3 种基金Natural Science Foundation of Jiangsu Province,Grant/Award Numbers:T2293691,BK20220074,BK20212008,BK20211191Research Fund of State Key Laboratory of Mechanics and Control for Aerospace Structures,Grant/Award Numbers:MCMS‐I‐0421G01,MCMS‐I‐0421K01,MCMS‐I‐0422K01Fundamental Research Funds for the Central Universities,Grant/Award Numbers:NE2023003,NJ2022002,NC2023001,NJ2023002Fund of Prospective Layout of Scientific Research for NUAA(Nanjing University of Aeronautics and Astronautics)。
文摘Water,the source of life,contains immense energy and manifests in diverse forms.Hydrovoltaic technology enables the direct interaction between water and materials to generate electricity,a vital necessity for industry modernization.Due to the ubiquitous presence and easy availability of falling water,hydrovoltaic energy derived from water droplets has attracted considerable attention and shown great potential in raindrop energy harvesting.In this review,a comprehensive summary of the latest advancements in harvesting hydrovoltaic energy from water droplets is presented,with a focus on the configurations and underlying mechanisms of hydrovoltaic devices.Additionally,a brief discussion on the applications of dropletbased hydrovoltaic devices is presented,along with future prospects for this energyharvesting technology.
基金the National Natural Science Foundation of China(No.1210040808)the Natural Science Foundation of Jiangsu Province(Nos.BK20210312 and BK20212008)+3 种基金the National Key Research and Development Program of China(No.2019YFA0705400)the Fundamental Research Funds for the Central Universities(Nos.NJ2022002,NZ2020001,and NS2022014)the Program for Innovative Talents and Entrepreneur in Jiangsu,Research Fund of State Key Laboratory of Mechanics and Control of Mechanical Structures(Nos.MCMS-I-0419G02 and MCMS-I-0421K01)a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘The Au(100)surface has been a subject of intense studies due to excellent catalytic activities and its model character for surface science.However,the spontaneous surface reconstruction buries active Au(100)plane and limits practical applications,how to controllably eliminate the surface reconstruction over large scale remains challenging.Here,we experimentally and theoretically demonstrate that simple decoration of the Au(100)surface by tellurium(Te)atoms can uniquely lift its reconstruction over large scale.Scanning tunneling microscopy imaging reveals that the lifting of surface reconstruction preferentially starts from the boundaries of distinct domains and then extends progressively into the domains with the reconstruction rows perpendicular to the boundaries,leaving a Au(100)-(1×1)surface behind.The Au(100)-(1×1)is saturated at~84%±2%with respect to the whole surface at a Te coverage of 0.16 monolayer.With further increasing the Te coverage to 0.25 monolayer,the Au(100)-(1×1)surface becomes reduced and overlapped by a well-ordered(2×2)-Te superstructure.No similar behavior is found for Te-decorated Au(111),Cu(111),Cu(100)surfaces,nor for the decorated Au(100)with other elements.This result may pave the way to design Au-based catalysts and,as an intermediate step,even potentially open a new route to constructing complex transition metal dichalcogenides.
基金This work was supported by the National Natural Science Foundation of China(No.52203359)Fundamental Research Funds for the Central Universities(No.NS2022092)+5 种基金National Key Research and Development Program of China(No.2019YFA0705400)Natural Science Foundation of Jiangsu Province(No.BK20212008)the Research Fund of State Key Laboratory of Mechanics and Control of Mechanical Structures(Nos.MCMS-I-0421K01 and MCMS-I-0422K01)the Fundamental Research Funds for the Central Universities(No.NJ2022002)the National Natural Science Foundation of China(Nos.52073119 and 21774040)A Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘Perovskite solar cells(PSCs)have attracted much attention due to their rapidly increased power conversion efficiencies,however,their inherent poor long-term stability hinders their commercialization.The degradation of PSCs first comes from the degradation of hole transport materials(HTMs).Here,we report the construction of periodicπ-columnar arrays and ionic interfaces over the skeletons by introducing cationic covalent organic frameworks(C-COFs)to the HTM.Periodicπ-columnar arrays can optimize the charge transport ability and energy levels of the hole transport layer and suppress the degradation of HTM,and ionic interfaces over the skeletons can produce stronger electric dipole and electrostatic interactions,as well as higher charge densities.The C-COFs were designed and synthesized via Schiff base reaction by using 1,3,5-triformylphloroglucinol as a neutral knot and dimidium bromide as cationic linker.The neutral COFs(N-COFs)were also synthesized as a reference by using 3,8-diamino-6-phenylphenanthridine as neutral linker.PSCs with cationic COF exhibit the highest efficiency of 23.4%with excellent humidity and thermal stability.To the best of our knowledge,this is the highest efficiency among the meso-structured PSCs fabricated by a sequential process.
基金This work is supported by the National Natural Science Foundation of China(Nos.11972186,11890674,and 51921003)the Western Light Project of the Chinese Academy of Sciences(CAS)(No.xbzg-zdsys-202118)a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘We reveal the ultralow friction or superlubricity of water nanodroplets containing cations and anions on graphene substrates at high ion concentration by molecular dynamics simulations.When the ion concentration is higher than 7 wt.%and the nanodroplet diameter is larger than 10 nm,the friction coefficients of water nanodroplets are lower than 10−2,and can decrease to the order of 10−3 with increasing the ion concentration further.At a certain ion concentration,the optimal nanodroplet diameter of 17–20 nm exists at which the friction coefficient is the lowest.The ultralow friction behaviors of water nanodroplets containing cations and anions are mainly attributed to the opposite variation trends between the interfacial adhesion energy and surface energy of water nanodroplet with ion concentration,and the interfacial hydrophobicity sustained by high ion concentration.These results unveil the essential role of ions in achieving the superlubricity of water nanodroplets.
基金supported by the National and Jiangsu Province NSF(Nos.T2293691 and BK20212008)of ChinaNational Key Research and Development Program of China(No.2019YFA0705400)+2 种基金the Research Fund of State Key Laboratory of Mechanics and Control of Mechanical Structures(No.MCMS-I-0422K01)the Fundamental Research Funds for the Central Universities(No.NJ2022002)the Fund of Prospective Layout of Scientific Research for NUAA(Nanjing University of Aeronautics and Astronautics).
文摘The last decade has witnessed the emergence of hydrovoltaic technology,which can harvest electricity from different forms of water movement,such as raindrops,waves,flows,moisture,and natural evaporation.In particular,the evaporation-induced hydrovoltaic effect received great attention since its discovery in 2017 due to its negative heat emission property.Nevertheless,the influence of electrode reactions in evaporation-induced power generation is not negligible due to the chemical reaction between active metal electrodes and water,which leads to“exceptional”power generation.Herein,we designed a series of experiments based on air-laid paper devices with electrodes of different activities as the top and bottom electrodes.To verify the contribution of electrodes,we compared the output performance of different electrode combinations when the device was partially-wetted and fully-wetted.The device hydrophilicity,salt concentration,and acidity or basicity of solutions were also comprehensively investigated.It is demonstrated that the chemical reaction of active metals(Zn,Cu,Ag,etc.)with different aqueous solutions can generate considerable electrical energy and significantly distort the device performance,especially for Zn electrodes with an output voltage from~1.26 to~1.52 V and current from~1.24 to~75.69μA.To promote the long-term development of hydrovoltaic technology,we recommend use of inert electrodes in hydrovoltaic studies,such as Au and Pt,especially in water and moisture environment.
基金supported by the National Key Research and Development Program of China(No.2019YFA0705400)the Natural Science Foundation of Jiangsu Province(No.BK20212008)+2 种基金the Research Fund of State Key Laboratory of Mechanics and Control of Mechanical Structures(Nos.MCMS-I-0421K01 and MCMS-I-0422K01)the Fundamental Research Funds for the Central Universities(No.NJ2022002)the Fund of Prospective Layout of Scientific Research for NUAA(Nanjing University of Aeronautics and Astronautics).
文摘Pseudo-ferroelectric transistors have attracted particular interest owing to their applications in the non-volatile memories and neuromorphic circuits;however,it remains to be explored in the limit of few-layer devices.Here we reveal a pseudo-ferroelectric phenomenon in the ultrathin graphene/black phosphorene(G/BP)heterostructure by first-principles calculations.Putting forward an excitation-assisted mechanism,the ferroelectric-like hysteresis loop can be explained by a combined effect of the external electric fields dependent bipolarity and anisotropy in the G/BP heterostructure.Considering the build-in electric field,the bipolar behavior results in the multistate effect of the G/BP heterostructure when modulating the applied electric field.The anisotropic hybridization caused by the susceptible Dirac electrons in graphene and the large in-plane anisotropy in BP provides the interfacial states,which trap excitations and stabilize the multistate.The pseudo-ferroelectric behavior should be useful for interpreting transport experiments in gated G/BP devices and exploring its applications in memories or synaptic devices.
文摘Chitosan oligosaccharides(COSs)are the main degradation products from chitosan or chitin and have been reported to induce resistance to diseases in herbaceous plants like cucumber and Arabidopsis.Concomitantly,pine wilt disease(PWD)is a devastating disease of conifer tree species.Here,we hypothesized that COSs induce plant resistance gene(PRG)expression in the woody plant Masson pine,Pinus massoniana.COSs were inoculated into P.massoniana seedlings and the BGISEQ-500 platform was used to generate transcriptomes from COSs-treated P.massoniana and control seedlings.A total of 501 differentially expressed genes(DEGs)were identified by comparing the treatment and control groups.A total of 251(50.1%)DEGs were up-regulated in the treatment relative to the control seedlings and 250(49.9%)were down-regulated.Inoculation of COSs induced the expression of 31 PRGs in P.massoniana seedlings and the relative expression levels of six of the PRGs were verified by RT-qPCR.This is the first study to demonstrate that COS induces the expression of PRGs in a tree species.These results provide important insights into the function of COSs and further the prospects of developing a COS-based immune inducer for controlling PWD.