Fluctuotaxis: Nanoscale directional motion away from regions of fluctuation.

Regulating the motion of nanoscale objects on a solid surface is vital for a broad range of technologies such as nanotechnology, biotechnology, and mechanotechnology. In spite of impressive advances achieved in the field, there is still a lack of a robust mechanism which can operate under a wide range of situations and in a controllable manner. Here, we report a mechanism capable of controllably driving directed motion of any nanoobjects (e.

Experimental study on the flow structures and dynamics of turbulent Rayleigh-Bénard convection in an annular cell.

We conduct an experimental study on the flow structures and dynamics of turbulent Rayleigh-Bénard convection in an annular cell with radius ratio η≃0.5 and aspect ratio Γ≃4. The working fluid is water with a Prandtl number of Pr≃5.

Enhancing the ionic conductivity and mechanical properties of PEO-based solid electrolytes through thermal pre-stretching treatment.

Pre-stretching as a method for directing polymer crystallization offers a promising solution for addressing the limitations of solid polymer electrolytes in flexible batteries at ambient temperatures. In this study, we have investigated the ionic conductivity, mechanical behaviour, and microstructural and thermal properties of polyethylene oxide (PEO)-based polymer electrolytes with varying pre-strain levels. The results indicate that thermal stretching-induced pre-deformation can significantly increase the through-plane ionic conductivity, in-plane strength, stiffness of solid electrolytes, and cell-specific capacity.

Experimental investigation of nanofluid enhanced oil recovery by spontaneous imbibition.

Nanofluids have been recently proposed as new chemical agents for enhanced oil recovery. In this study, in order to reflect the effect of nanofluids on imbibition, the imbibition performance of manganese chloride (MnCl) solution, sodium dodecylbenzene sulfonate (SDBS) solution, and silica (SiO) nanofluids were studied by a spontaneous imbibition experiment at 25 °C and 0 MPa. The oil production from pores with different sizes and the imbibition efficiency were tested by nuclear magnetic resonance spectroscopy and metering in spontaneous imbibition.

High-accuracy positivity-preserving numerical method for Keller-Segel model.

The Keller-Segel model is a time-dependent nonlinear partial differential system, which couples a reaction-diffusion-chemotaxis equation with a reaction-diffusion equation; the former describes cell density, and the latter depicts the concentration of chemoattractants. This model plays a vital role in the simulation of the biological processes. In view of the fact that most of the proposed numerical methods for solving the model are low-accuracy in the temporal direction, we aim to derive a high-precision and stable compact difference scheme by using a finite difference method to solve this model.

Parallel Aluminum-Cobalt Oxide Nanosheet Arrays with High-Temperature Ferromagnetism.

Parallel nanomaterials possess unique properties and show potential applications in industry. Whereas, vertically aligned 2D nanomaterials have plane orientations that are generally chaotic. Simultaneous control of their growth direction and spatial orientation for parallel nanosheets remains a big challenge.

Binding kinetics study of SARS-CoV-2 main protease and potential inhibitors molecular dynamics simulations.

The pandemic COVID-19 was induced by the novel coronavirus SARS-CoV-2. The virus main protease (M) cleaves the coronavirus polyprotein translated from the viral RNA in the host cells. Because of its crucial role in virus replication, M is a potential drug target for COVID-19 treatment.

A transversely isotropic viscohyperelastic-damage model for the brain tissue with strain rate sensitivity.

Understanding the mechanical behaviors and properties of brain tissue are crucial to study the mechanisms of traumatic brain injury (TBI). Such injury may be associated with high rate loading conditions and the large deformation of brain tissue. Thus, constitutive models that consider the rate dependent large deformation of brain tissue and its possible damage initiation and evolution may help uncover the related mechanisms of TBI.

Structural basis for TRIM72 oligomerization during membrane damage repair.

Tripartite Motif Protein 72 (TRIM72, also named MG53) mediates membrane damage repair through membrane fusion and exocytosis. During injury, TRIM72 molecules form intermolecular disulfide bonds in response to the oxidative environment and TRIM72 oligomers are proposed to connect vesicles to the plasma membrane and promote membrane fusion in conjunction with other partners like dysferlin and caveolin. However, the detailed mechanism of TRIM72 oligomerization and action remains unclear.

Effects of basilar-membrane lesions on dynamic responses of the middle ear.

Background: Numerical simulations can reflect the changes in physiological properties caused by various factors in the cochlea.

Aims/objective: To analyze the influence of lesions of the basilar membrane (BM) on the dynamic response of the middle ear.

Method: Based on healthy human ear CT scan images, use PATRAN software to build a three-dimensional finite element model of the human ear, then apply NASTRAN software to conduct analysis of solid-fluid coupled frequency response.

Behavioral characteristics in sensing mechanism of the Corti.

Some experiments can't be realized because the cochlea's Corti is the most delicate and complex sensory organ. In this paper, some typical and special behavioral characteristics in the process of sensation were found in medical clinic. Based on the interdisciplinary principles of medicine, physics and biology, a real numerical simulation model of Corti is established.

Competing mechanisms in fracture of staggered mineralized collagen fibril arrays.

Mineralized collagen fibril (MCF) arrays are important structural elements involved in inelastic deformation and fracture process of bone. Recent experiments have shown that MCF breakage has an influence on toughening of bone. Motivated by the experiments, we carry out the analyses of fracture in staggered MCF arrays.

Modeling the damage-induced softening behavior of brain white matter using a coupled hyperelasticty-damage model.

White matter in the brain is structurally anisotropic consisting of large bundle of aligned axonal fibers. Hyperelastic, transversely isotropic constitutive models are typically used in the modeling and simulation of such tissues. However, most studies constrain the material models to describe the mechanical behavior of white matter in the limit of small deformation, without considering the experimentally observed damage initiation and damage-induced material softening in large strain regime.

Modulation of thermal conductivity of single-walled carbon nanotubes by fullerene encapsulation: the effect of vacancy defects.

Single-walled carbon nanotubes (SWCNTs) possess extremely high thermal conductivity that benefits their application in high-performance electronic devices. The characteristic hollow configuration of SWCNTs is not favorable for the buckling stability of the structure, which is typically resolved by fullerene encapsulation in practice. To investigate the fullerene encapsulation effect on thermal conductivity, we perform molecular dynamics simulations to comparatively study the thermal conductivity of pure SWCNTs and fullerene encapsulated SWCNTs.

Development of an Assessment Model for the Effect of the Replacement of Minimal Artificial Ossicles on Hearing in the Inner Ear.

Due to ethical issues and the nature of the ear, it is difficult to directly perform experimental measurements on living body elements of the human ear. Therefore, a numerical model has been developed to effectively assess the effect of the replacement of artificial ossicles on hearing in the inner ear. A healthy volunteer's right ear was scanned to obtain CT data, which were digitalized through the use of a self-compiling program and coalescent Patran-Nastran software to establish a 3D numerical model of the whole ear, and a frequency response of a healthy human ear was analyzed.

Mechanical Properties of Internally Hierarchical Multiphase Lattices Inspired by Precipitation Strengthening Mechanisms.

In metal metallurgy, precipitation strengthening is widely used to increase material strength by utilizing the impediment effect of the second-phase particles on dislocation movements. Inspired by this mechanism, in this paper, novel multiphase heterogeneous lattice materials are developed with enhanced mechanical properties utilizing a similar hindering effect of second-phase lattice cells on the shear band propagation. For this purpose, biphase and triphase lattice samples are fabricated using high-speed multi jet fusion (MJF) and digital light processing (DLP) additive manufacturing techniques, and a parametric study is carried out to investigate their mechanical properties.

Polarization Doping in a GaN-InN System-Ab Initio Simulation.

Polarization doping in a GaN-InN system with a graded composition layer was studied using ab initio simulations. The electric charge volume density in the graded concentration part was determined by spatial potential dependence. The emerging graded polarization charge was determined to show that it could be obtained from a polarization difference and the concentration slope.

Surface and Structural Characterization of PVTMS Films Treated by Elemental Fluorine in Liquid Perfluorodecalin.

Poly(vinyl trimethylsilane) (PVTMS) films were subjected to direct surface fluorination in liquid medium (perfluorodecalin). The samples were investigated using several techniques: SEM-XEDS, XPS, ATR-IR, and contact angle measurement. The methods used allowed us to estimate chemical changes occurring because of the treatment.

On the configuration of the graphene/carbon nanotube/graphene van der Waals heterostructure.

The graphene/carbon nanotube/graphene (GCG) van der Waals heterostructure is a promising candidate for application in electronics and optical devices, for which the configuration and mechanical properties are of great importance. We perform molecular dynamics simulations to investigate the configuration of the GCG structure, which is successfully interpreted by the mechanic model based on the competition between the bending energy and the adhesion energy. It is found that the cross-section of the nanotube is compressed into an ellipse by the graphene layers, and the eccentricity increases with the increase of the nanotube's diameter.

Study of fatigue damage to the cochlea.

In order to explore the hearing loss resulting from exposure to continuous or intermittent loud noise. A three-dimensional liquid-solid coupling finite element model of spiral cochlea was established. The reliability of the model was verified, and the stress and amplitude of the basilar membrane of the pivotal structure in cochlea were analyzed.

An Improved Experiment for Measuring Lithium Concentration-Dependent Material Properties of Graphite Composite Electrodes.

The in situ curvature measurement of bilayer beam electrodes is widely used to measure the lithium concentration-dependent material properties of lithium-ion battery electrodes, and further understand the mechano-electrochemical coupling behaviors during electrochemical cycling. The application of this method relies on the basic assumption that lithium is uniformly distributed along the length and thickness of the curved active composite layer. However, when the electrode undergoes large bending deformation, the distribution of lithium concentration in the electrolyte and active composite layer challenges the reliability of the experimental measurements.

Unraveling the Defect-Dominated Broadband Emission Mechanisms in (001)-Preferred Two-Dimensional Layered Antimony-Halide Perovskite Film.

By adding molar-controlled SbCl in a CsSbCl precursor, we employed a low-temperature solution-processed approach to prepare high-quality (001)-preferred CsSbCl thin film, which demonstrates a stable defect-dominated broadband emission at room temperature. Density functional theory calculations reveal that the defect emission originates from the donor-acceptor pair (DAP) recombination between chlorine vacancy (V) and cesium vacancy (V). Furthermore, V + V DAP is more stable on the (001) surface.

Three-dimensional finite element analysis on cochlear implantation electrode insertion.

Studying the insertion process of cochlear implant (CI) electrode array (EA) is important to ensure successful, sufficient, and safe implantation. A three-dimensional finite element (FE) model was developed to simulate the insertion process. The cochlear structures were reconstructed from an average statistical shape model (SSM) of human cochlea.

Hydrophobic-Hydrophilic Properties and Characterization of PIM-1 Films Treated by Elemental Fluorine in Liquid Perfluorodecalin.

A direct fluorination technique was applied for the surface treatment of PIM-1 films in a liquid phase (perfluorodecalin). The fluorinated samples were analyzed by various instrumental techniques. ATR-IR spectroscopy showed that the fluorination predominantly takes place in methylene- and methyl-groups.

Mechanical Constraint Effect on DNA Persistence Length.

Persistence length is a significant criterion to characterize the semi-flexibility of DNA molecules. The mechanical constraints applied on DNA chains in new single-molecule experiments play a complex role in measuring DNA persistence length; however, there is a difficulty in quantitatively characterizing the mechanical constraint effects due to their complex interactions with electrostatic repulsions and thermal fluctuations. In this work, the classical buckling theory of Euler beam and Manning's statistical theories of electrostatic force and thermal fluctuation force are combined for an isolated DNA fragment to formulate a quantitative model, which interprets the relationship between DNA persistence length and critical buckling length.