We reveal the ultralow friction or superlubricity of water nanodroplets containing cations and anions on graphene substrates at high ion concentration by molecular dynamics *** the ion concentration is higher than 7 w...
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We reveal the ultralow friction or superlubricity of water nanodroplets containing cations and anions on graphene substrates at high ion concentration by molecular dynamics *** 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 *** a certain ion concentration,the optimal nanodroplet diameter of 17–20 nm exists at which the friction coefficient is 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 *** results unveil the essential role of ions in achieving the superlubricity of water nanodroplets.
Recent years have seen a rising interest in distributed optimization problems because of their widespread applications in power grids, multi-robot control, and regression *** the last few decades, many distributed alg...
Recent years have seen a rising interest in distributed optimization problems because of their widespread applications in power grids, multi-robot control, and regression *** the last few decades, many distributed algorithms have been developed for tackling distributed optimization problems. In these algorithms, agents over the network only have access to their own local functions and exchange information with their neighbors.
Geckos can efficiently navigate complex terrains due to their multi-level adhesive system that is present on their *** setae are responsible for the gecko’s extraordinary adhesion and have garnered wide attention fro...
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Geckos can efficiently navigate complex terrains due to their multi-level adhesive system that is present on their *** setae are responsible for the gecko’s extraordinary adhesion and have garnered wide attention from the scientific *** majority of the reported works in the literature that have dealt with the peeling models mainly focus on the gecko hierarchical adhesive system,with limited attention given to investigating the influence of gecko toe structure on the *** these lines,to gain a deeper understanding of the rapid and effortless detachment abilities of gecko toes,the peeling behavior of gecko toes on vertical surfaces was primarily investigated in this *** specifically,the detachment time of a single toe on a smooth acrylic plate was measured to be 0.41±0.21 ***,it was observed that the toe assumed a"U"-shaped structure upon complete ***,Finite Element Analysis(FEA)models for three different types of gecko toes were developed to simulate both the displacement-peel and the moment-peel *** the segmentation of the adhesive layer led to a gradual decrease in the resultant force,as well as the normal and tangential ***,a gecko-inspired toe model was constructed and powered by Shape Memory Alloy(SMA).A systematic comparison between the vertical drag separation and the outward flip separation was also *** our analysis,it was clearly demonstrated that outward peel separation significantly necessitated the reduction of the peeling force,thus confirming the advantageous nature of the outward motion in gecko toe *** data not only contribute to a deeper understanding of the gecko detachment behavior but also offer valuable insights for the advancement of the wall-climbing robot feet.
In this paper, we study a distributed state estimation problem for Markov jump systems (MJS) over sensor networks, in which each sensor node connects with each other through wireless networks with communication delays...
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The colour-enhanced point cloud map is increasingly being employed in fields such as robotics,3D reconstruction and virtual *** authors propose ER-Mapping(Extrinsic Robust coloured Mapping system using residual evalua...
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The colour-enhanced point cloud map is increasingly being employed in fields such as robotics,3D reconstruction and virtual *** authors propose ER-Mapping(Extrinsic Robust coloured Mapping system using residual evaluation and selection).ER-Mapping consists of two components:the simultaneous localisation and mapping(SLAM)subsystem and the colouring *** SLAM subsystem reconstructs the geometric structure,where it employs a dynamic threshold-based residual selection in LiDAR-inertial odometry to improve mapping *** the other hand,the col-ouring subsystem focuses on recovering texture information from input images and innovatively utilises 3D–2D feature selection and optimisation methods,eliminating the need for strict hardware time synchronisation and highly accurate extrinsic *** were conducted in both indoor and outdoor *** results demonstrate that our system can enhance accuracy,reduce computational costs and achieve extrinsic robustness.
Our extensive nonequilibrium and equilibrium molecular dynamics simulations reveal the ion-induced interfacial friction reduction of NaCl-containing water nanoflow over *** under a normal pressure,with the increase in...
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Our extensive nonequilibrium and equilibrium molecular dynamics simulations reveal the ion-induced interfacial friction reduction of NaCl-containing water nanoflow over *** under a normal pressure,with the increase in ion concentration,the friction coefficients of water nanoflow at the water/graphene interfaces decrease,and the slip lengths and shear viscosities of water nanoflow *** interfacial friction reduction with the increase in ion concentration is mainly attributed to the decrease in interfacial hydrated ions and the weaker binding of water molecules with graphene at a higher ion *** presence of ions changes the hydrogen bond networks and structural configuration of water molecules close to the underlying graphene sheets and plays a key role in reducing the interfacial friction between water nanoflow and graphene.
The authors propose a complete software and hardware framework for a novel spherical robot to cope with exploration in harsh and unknown *** proposed robot is driven by a heavy pendulum covered by a fully enclosed sph...
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The authors propose a complete software and hardware framework for a novel spherical robot to cope with exploration in harsh and unknown *** proposed robot is driven by a heavy pendulum covered by a fully enclosed spherical shell,which is strongly protected,amphibious,anti-overturn and has a *** for location and perception,planning and motion control are comprehensively *** the one hand,the authors fully consider the kinematic model of a spherical robot,propose a positioning algorithm that fuses data from inertial measurement units,motor encoder and Global Navigation Satellite System,improve global path planning algorithm based on Hybrid A*and design an instruction planning controller based on model predictive control(MPC).On the other hand,the dynamic model is built,linear MPC and robust servo linear quadratic regulator algorithm is improved,and a speed controller and a direction controller are *** addition,based on the pose and motion charac-teristics of a spherical robot,a visual obstacle perception algorithm and an electronic image stabilisation algorithm are ***,the authors build physical systems to verify the effectiveness of the above algorithms through experiments.
Fixed-time synchronization(FTS)of delayed memristor-based neural networks(MNNs)with discontinuous activations is studied in this *** continuous and discontinuous activations are considered *** the mixed delays which a...
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Fixed-time synchronization(FTS)of delayed memristor-based neural networks(MNNs)with discontinuous activations is studied in this *** continuous and discontinuous activations are considered *** the mixed delays which are closer to reality are taken into the ***,two kinds of control schemes are proposed,including feedback and adaptive control *** on some lemmas,mathematical inequalities and the designed controllers,a few synchronization criteria are ***,the upper bound of settling time(ST)which is independent of the initial values is ***,the feasibility of our theory is attested by simulation examples.
With the development of imaging and measurement technologies,scanning near-field optical microscopy(SNOM)has achieved high signal-to-noise *** resolution of a fibre probe-based SNOM system is capable of reaching 10 **...
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With the development of imaging and measurement technologies,scanning near-field optical microscopy(SNOM)has achieved high signal-to-noise *** resolution of a fibre probe-based SNOM system is capable of reaching 10 ***,SNOM applications are presently constrained to the measurement of near-field optical information to relatively straightforward structures,including quantum dots,carbon nanotubes,graphene,and so *** geometry of conventional fibre probes,with tips at an angle of 30°-60°,presents a challenge for accurately imaging complex surface *** paper proposes a carbon nanotube composite fibre probe(CNT-FP)with a large aspect *** key point is that a carbon nanotube bundle is composited at the tip of conventional surface plasmon polaritons fibre probes(SPPs-FP),which are the fibre probes coated with gold film to excite the *** coupling,propagation,and focusing effects of SPPs on the carbon nanotube bundle are ***-FPs have been fabricated and applied to measure a grating with the depth of 400 nm and the width of 400 *** experimental results show that the measurement accuracy and imaging quality of CNT-FP are nearly one order of magnitude higher than that of conventional SPPs-FP,as evidenced by evaluation criteria such as line roughness and volatility ***,it achieves an optical resolution of 72.1 nm in the measurements of a nano structure with large aspect *** provides an effective solution of measuring structures with larger aspect ratios.
Network localization serves as a fundamental component for enabling various position based operations in multi-agent systems,facilitating tasks like target searching and formation control by providing accurate positio...
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Network localization serves as a fundamental component for enabling various position based operations in multi-agent systems,facilitating tasks like target searching and formation control by providing accurate position information for all nodes in the *** localization focuses on the challenge of determining the positions of nodes within a network,relying on the known positions of anchor nodes and internode relative *** the past few decades,distributed network localization has garnered significant attention from *** paper aims to provide a review of main results and advancements in the field of distributed network localization,with a particular focus on the perspective of graph *** to its favorable characteristics,graph Laplacian unifies various network localization,even when dealing with diverse types of internode relative measurements,into a unified protocol framework,which can be constructed by a linear method and ensure the global convergence.
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