Liquid Behavior Research Articles

Modulation of Luttinger Liquid Behavior by Multichannel Electron Transport in Aligned Multiwalled Carbon Nanotube Arrays

In the case of one-dimensional systems, Luttinger liquid states are typically anticipated, which have previously been identified primarily in nanoscopic devices fabricated from isolated bundles of single- or multi-walled carbon nanotubes. In this study, the electrical transport properties of aligned multiwalled carbon nanotube arrays were investigated. The resistance of both aligned arrays and those covered with metal Mo exhibits a strong dependence on temperature, demonstrating a power-law relationship of R~T–α below 100K. The Luttinger liquid behavior was modulated by tuning the electron-transport channels via alerting the number of walls that contribute to the conductance within the multi-walled carbon nanotubes. The exponent α, derived theoretically as a parameter that depends on the number of conducting channels, exhibits minimal variation across the arrays and declines rapidly with the tubular structure opening due to the solid-solid reaction between the magnetron-sputtered molybdenum and the carbon atoms.

Managing Solvent Complexes to Amplify Ripening Process by Covalent Interaction Driving Force Under External Field for Perovskite Photovoltaic

AbstractUp to now, post‐annealing is most commonly used to post treat the perovskite film to accelerate the ripening process. Nonetheless, the top‐down crystallization mechanism impedes the efficient desolvation of solvent complexes. Thus, residual solvent complexes tend to accumulate at the bottom of the film during the ripening process and deteriorate the device. Here, a new strategy with unique concept is promoted to amplify ripening process of perovskite film, in which a nematic thermotropic liquid crystal (LC) molecular is introduced to facilitate the conversion of solvent complexes by utilizing the liquid crystalline behavior under external field. Upon the concurrent application of thermal and force fields, the covalent interaction between LC and solvent complexes generates a driving force, which promotes upward migration of solvent complexes, thereby facilitating their engagement in the ripening process. In addition, the driving force under external fields assists the flattening of grain boundary grooves. Therefore, film quality is improved efficiently with amplified ripening process and adequately handled buried interface. Based on the positive effects, the devices achieve a champion efficiency of 25.24%, and sustained ≈75% of its initial efficiency level even after undergoing a damp heat test (85 °C/85% RH) for 1400 h.

Crystal growth and pressure effect on the transport properties in 122-type (La,Na,K)Fe2As2 superconductors

Abstract High-quality single crystals are essential for probing the intrinsic properties of unconventional superconductors. In this work, we report the successful growth of (La,Na,K)Fe2As2 single crystals, a novel 122-type iron-based superconductor, using the self-flux method. The crystal structure and chemical composition were characterized through x-ray diffraction and energy-dispersive x-ray spectroscopy. The (La,Na,K)Fe2As2 single crystals exhibit bulk superconductivity, with a critical transition temperature Tc of approximately 22 K. Magnetization measurements reveal a second peak effect and a critical current density Jc ~ 5×105 A/cm2 at 2 K in a self-field. The upper critical field anisotropy was systematically studied within the framework of the anisotropic Ginzburg–Landau theory, yielding an anisotropy value of approximately 2.6. Furthermore, we employ the diamond anvil cell technique to investigate the pressure effect on (La,Na,K)Fe2As2. Our results demonstrate that superconductivity is gradually suppressed with increasing pressure, while the normal state resistivity at low temperatures evolves from non-Fermi liquid to Fermi liquid behavior. This observation suggests that (La,Na,K)Fe2As2 may be situated on the right of the quantum critical point or, at the very least, within the over-doped region. These findings provide a critical sample platform and experimental insights for advancing the understanding of the physical properties of the newly discovered (La,Na,K)Fe2As2 superconductors.

Heat and mass transfer analysis in flow of Walter's B nanofluid: A numerical study of dual solutions

AbstractThis study investigates the behavior of Walter's liquid B fluid over a biaxially stretching/shrinking surface for Homann stagnation point flow, focusing on the rheological properties that are crucial for understanding physical phenomena in engineering and industrial processes. The problem is modeled using Buongiorno's model in the presence of a permeable surface subject to heat generation/absorption, Ohmic heating, and chemical reactions influenced by Arrhenius activation energy. The governing partial differential equations are solved numerically using an appropriate similarity transformation, and the results are graphically analyzed via MATLAB's bvp5c solver. The study highlights the importance of characterizing the intricate properties of viscoelastic fluids, with potential applications in biomedical engineering and materials science. The findings reveal the coexistence of two distinct flow regimes and dual solutions are obtained. It is noted that the activation energy parameter is shown to enhance mass distribution in both solutions, while chemical reactions accelerate reactant conversion but reduce mass distribution. Additionally, an increase in viscoelasticity shifts the fluid's behavior towards elasticity, creating greater resistance to shear deformation and reducing both velocity profiles.

Effect of Liquid Properties on the Non-Newtonian Rheology of Concentrated Silica Suspensions: Discontinuous Shear Thickening, Shear Jamming, and Shock Absorbance.

Concentrated particle suspensions exhibit rheological behavior, such as discontinuous shear thickening (DST) and dynamic shear jamming (SJ), which affect applications such as soft armors. Although the origin of this behavior in shear-activated particle-particle interactions has been identified, the effect of chemical factors, especially the role of liquids, on this behavior remains unexplored. Hydrogen bonding in suspensions has been proposed to be essential for frictional contacts between particles, and therefore, most studies on DST and SJ have focused on aqueous and protic organic media with a definite hydrogen bonding ability. To identify an alternative molecular mechanism, this study explored the effects of liquid polarity and an aprotic nature on the rheological behavior of concentrated suspensions of silica microparticles. Owing to their excellent particle dispersion, the DST behavior of polar liquids was observed, independent of protic and aprotic liquids. In contrast, nonpolar liquids formed particle agglomerates because of the particle-particle attraction and became a paste at a high particle fraction. The SJ behavior was confirmed for three aprotic organic liquids (propylene carbonate, 1,3-dimethyl-2-imidazolidinone, and 1,3-dimethylpropyleneurea), suggesting the hydrogen bonding ability of these aprotic liquids. The diverse mechanisms of shear-activated interactions between particles present material design possibilities for the non-Newtonian rheology of concentrated particle suspensions.

Liquid Crystal Behavior of Uniform Short Rods Made from Computationally Designed Parallel Coiled Coil Building Blocks.

Parallel, homotetrameric coiled coils were computationally designed using 29 amino acid peptides. These parallel coiled coils, called "bundlemers", have C2 symmetry, with all N-termini displayed from one end of the nanoparticle and all C-termini from the opposite end. This anisotropic display of the peptide termini allowed for the functionalization of two sets of nanoparticles with either maleimide or thiol functionality at the N-terminal region of the constituent peptides. The thiol-Michael conjugation reaction between the N-terminal end of complementary bundlemer nanoparticles formed monodisperse, rigid bundlemer dimer, called "dibundlemer", rods. The constituent, individual bundlemer nanoparticles were characterized with small-angle X-ray scattering (SAXS), Förster resonance energy transfer (FRET), and circular dichroism (CD) spectroscopy to confirm the parallel assembly of the coiled coils, consistent with the computational design. The dibundlemer rods were characterized with SAXS to reveal the uniform dibundlemer nature of the rods. Optical birefringence is observed in concentrated samples of the rods, with polarized optical microscopy (POM) revealing a nematic liquid crystalline behavior.

Validation of a phase-field approach for contact line hysteresis against a sloshing droplet case

AbstractUnderstanding liquid propellants behavior in microgravity conditions is critical for efficient spacecraft design. For a number of operations, ranging from engine restart to orbital propellant storage and transfer, insight is needed to characterize capillary-dominated flows. In such conditions, surface tension and wetting properties, including contact angle hysteresis, can greatly impact the fluid’s behavior and therefore spacecraft performance. Using experimental data from ESA Propulsion Laboratory, a contact line model for the Cahn–Hilliard phase-field method is validated. The case studied is that of a droplet confined between two oscillating plates, which aims to isolate and observe contact angle-driven physics, limiting the effect of gravity on the flow in a simple and reproducible way on ground. The contact line model allows for the prediction of contact line motion without requiring the computation of dynamic contact angles or contact line velocities, thus simplifying implementation and reducing computational overhead. For the validation, contact line pinning and motion under varying oscillation frequencies is investigated. Specifically, the length between the rear and front contact line edges, as well as the shape of the sloshing droplet are compared. The results show good agreement between simulations and experimental data, confirming the model’s accuracy in predicting contact line behavior and pinning.

Thermodynamic re-optimisation of the CaO-FeO-Fe2O3 system integrated with experimental phase equilibria studies (Part II – Thermodynamic optimisation)

The Ca-Fe-O system is essential for understanding the chemical equilibria involved in copper production using calcium ferrite slags. It forms a core component of a complex 20-component Cu-Pb-Zn-Fe-Ca-Si-O-S-Al-Mg-Cr-Na-As-Sn-Sb-Bi-Ag-Au-Ni-Co system developed for diverse applications in ferrous and non-ferrous metallurgy. This study re-evaluates the Ca-Fe-O system using recent experimental phase equilibrium data acquired by the authors [1] through advanced equilibration, quenching, and Electron Probe X-ray Microanalysis (EPMA) techniques. Thermodynamic properties of solid phases have been revised in accordance with the recommendations for the third generation of Calphad databases. Liquid endmember heat capacities have been refined to describe glass transition behaviour in supercooled liquids. The updated properties of liquid endmembers significantly extend the applicability of the database, enabling lower-temperature applications related to toxic element leaching from amorphous and partially crystallized slags. The revised, higher melting temperature of CaO enhances predictive accuracy in multicomponent systems. Liquid slag phase has been modelled within the Modified Quasichemical Formalism to account for short-range ordering phenomena. Recent advances in modelling and optimization technique made it possible to assess experimental data within the Ca-Fe-O system as an integral part of a large multicomponent dataset, applicable for industrial conditions.

Interplay between membranes and biomolecular condensates in the regulation of membrane-associated cellular processes.

Liquid‒liquid phase separation (LLPS) has emerged as a key mechanism for organizing cellular spaces independent of membranes. Biomolecular condensates, which assemble through LLPS, exhibit distinctive liquid droplet-like behavior and can exchange constituents with their surroundings. The regulation of condensate phases, including transitions from a liquid state to gel or irreversible aggregates, is important for their physiological functions and for controlling pathological progression, as observed in neurodegenerative diseases and cancer. While early studies on biomolecular condensates focused primarily on those in fluidic environments such as the cytosol, recent discoveries have revealed their existence in close proximity to, on, or even comprising membranes. The aim of this review is to provide an overview of the properties of membrane-associated condensates in a cellular context and their biological functions in relation to membranes.

Liquid breakup and droplets behavior of free triple-impinging jets with different impinging distance

The breakup characteristics and droplet behavior of free triple-impinging jets (FTIJs) were investigated using a high-speed camera. The liquid sheet and droplets breakup mechanism, liquid sheet breakup length, width, droplet diameter and velocity, were studied under different jet velocity and horizontal impinging distance and perpendicular impinging distance. The results revealed that with increasing jet velocity from 1.42 m/s to 6.61 m/s, different breakup modes were observed: closed-rim mode, open-rim mode, rimless mode, and wave or ligament mode. At low jet velocities, increasing impinging distance delayed the development of breakup mode. Based on experimental observations, the sheet breakup mechanism is categorized into two main regimes with four subregimes. Droplet breakup occurs in two stages: growth and necking, however, at high jet velocities complete breakup was achieved. Increasing jet velocity led to an increase in liquid sheet breakup length, width, and droplet velocity but a decrease in droplet diameter. Conversely, increasing impinging distance resulted in a decrease in liquid sheet breakup width and droplet radial velocity but an increase in droplet diameter. The effect of perpendicular impinging distance on axial velocity and breakup length was found to be more significant than that of horizontal impinging distance due to the effect of perpendicular nozzle. The findings indicate that the perpendicular jet greatly enhances atomization. This study provides a theoretical basis for designing and optimizing FTIJs.

Toward understanding the solid-liquid equilibrium behavior of dinotefuran by thermodynamic analysis and molecular dynamic simulation

Dinotefuran is a third-generation nicotinic insecticide with a wide insecticidal spectrum and low toxicity to humans and other mammals, which has a huge potential market. The insight into the solid–liquid equilibrium behavior of dinotefuran in various solvents could further guide the design, development, and refinement of the further crystallization process. However, the complexity and variability of the dissolution process make it very challenging to study. In this research, the solid–liquid equilibrium of dinotefuran in both mono-solvents and mixed solvents was systematically investigated through a combined approach of the experimentation and molecular dynamics simulation. Firstly, the solubility of dinotefuran in a range of solvents was ascertained using the laser dynamic monitoring method over spanning temperatures from 278.15 to 318.15 K. The results showed that the solubility of dinotefuran in mono-solvents increase with the temperature increasing, while the solubility in mixed solvents exhibited an initial increase followed by a decrease with the organic solvent molar fraction increasing. Then the experimental data were fitted using five thermodynamic models. The NRTL model has the lowest 102ARD and 104RMSD values, indicating the best correlation, validity and fit. The dissolution behavior of dinotefuran was explored by calculating the thermodynamic properties. The results indicated that dinotefuran dissolution was a spontaneous, disorder degree increase process, and dissolution an exothermic process except the isopropanol + water mixed solvents. Additionally, the influence of the physicochemical properties of the solvent on the dinotefuran dissolution process was investigated, with a particular focus on the critical role of solvent polarity. Hansen solubility and the preferred solvation parameters of dinotefuran in the solvents were also further calculated to analyze the dissolution process. For the studied mixed solvents, when the ratios of methanol, ethanol, isopropanol, and acetone reached 0.85, 0.75, 0.50, and 0.70, respectively, dinotefuran molecules turned to be preferentially solvated by the water molecules. Finally, molecular dynamics simulation was performed to reveal the mechanisms of dinotefuran dissolution, suggesting the greater solute–solvent interaction, the easier dissolution. The solid–liquid equilibrium data might provide a guidance for the development of environment-friendly and efficient formulation.

Forecasting Market Activity and Aggregate Demand in China Using Time Series Models

The purpose of this study was to forecast market activity and aggregate demand in China using time series models. Forecasts of market activity (MA) and aggregate demand (AD) provide insights into consumer behavior and economic trends, which are crucial for policymakers and businesses alike. In order to forecast the MA and AD in China, this study uses the time series model, especially the exponential smoothing model. Based on the increase rates of M1 and M2 money supply, respectively, and the difference in increase rates between them. These indicators are necessary to assess MA and AD and reflect changes in money liquidity and people's spending behavior. The results suggest that people will be less willing to spend and more inclined to save in the coming years. This finding suggests that MA may decline as consumers become more cautious and prioritize saving over spending. This trend could be attributed to a variety of factors, including economic uncertainty or changes in monetary policy. The implications of this research are significant because it provides a forecasting framework that can help policymakers and businesses anticipate changes in consumer demand and adjust their strategies accordingly. Understanding these trends can lead to more informed decisions in economic planning and financial forecasting.

A QSPR Model for Henry's Law Constants of Organic Compounds in Water and Ethanol for Distilled Spirits.

Henry's law describes the vapor-liquid equilibrium for dilute gases dissolved in a liquid solvent phase. Descriptions of vapor-liquid equilibrium allow the design of improved separations in the food and beverage industry. The consumer experience of taste and odor are greatly affected by the liquid and vapor phase behavior of organic compounds. This study presents a machine learning (ML) based model that allows quick, accurate predictions of Henry's law constants (kH) for many common organic compounds. Users input only a Simplified Molecular-Input Line-Entry System (SMILES) string or a common English name, and the model returns Henry's law estimates for compounds in water and ethanol. Training was performed on 5,690 compounds. Training data were gathered from an existing database and were supplemented with quantum mechanical (QM) calculations. An extra trees regression model was generated that predicts kH with a mean absolute error of 1.3 in log space and an R2 of 0.98. The model is applied to common flavor and odor compounds in bourbon whiskey as a test case for food and beverage applications.

Evidence for nematic fluctuations in FeSe superconductor: a 57Fe Mössbauer spectroscopy study

There has been controversy about the driving force of the nematic order in the FeSe superconductor. Here, we present a detailed study of the57Fe Mössbauer spectra of FeSe single-crystal powders, focusing on the temperature dependences of the hyperfine parameters in the vicinity of the nematic transition temperature,Ts∼ 90 K. The nematicity-induced splitting ofdxzanddyzbands, obtained from the anomalous increase in quadrupole splitting nearTs, starts at 143 K. The temperature evolution of the lattice dynamics, deduced from the recoilless fractions and second-order Doppler shifts, is found to undergo successively two segments of phonon-softening (160 K-105 K) and phonon-hardening (105 K-90 K), related to the appearance of local orthorhombic distortions aboveTsand the establishing way of the associated nematic correlations. Analysis of the linewidths shows that spin fluctuations occur not only below 70 K but also acrossTs(105 K-70 K), accompanied by the non-Fermi liquid behavior of the electrons. The results demonstrate the strong interactions between lattice, spin, and electron degrees of freedom in the vicinity ofTsand that the lattice degrees of freedom may play an essential role in driving the nematic order for FeSe.

Disassembling one-dimensional chains in molybdenum oxides

Abstract The dimensionality of quantum materials strongly affects their physical properties. Although many emergent phenomena, such as charge-density wave and Luttinger liquid behavior, are well understood in one-dimensional (1D) systems, the generalization to explore them in higher dimensional systems is still a challenging task. In this study, we aim to bridge this gap by systematically investigating the crystal and electronic structures of molybdenum-oxide family compounds, where the contexture of 1D chains facilitates rich emergent properties. While the quasi-1D chains in these materials share general similarities, such as the motifs made up of MoO6 octahedrons, they exhibit vast complexity and remarkable tunability. We disassemble the 1D chains in molybdenum oxides with different dimensions and construct effective models to excellently fit their low-energy electronic structures obtained by ab initio calculations. Furthermore, we discuss the implications of such chains on other physical properties of the materials and the practical significance of the effective models. Our work establishes the molybdenum oxides as simple and tunable model systems for studying and manipulating the dimensionality in quantum systems.

Time-resolved counterpropagating edge transport in the topological insulating phase

We have investigated the time-resolved low-energy charge dynamics in counterpropagating edge channels formed in the quantum Hall regime of an electron-hole bilayer system in band-inverted InAs/InGaSb composite quantum wells. In the studied magnetic field range, the system remains in the topological phase where an equal number of counterpropagating electronlike and holelike edge channels exist in the bulk energy gap, analogous to the helical edge channels in a quantum spin Hall insulator. When the Fermi level was set in the conduction band, the injected charge pulses propagated unidirectionally as chiral edge magnetoplasmon (EMP) wave packets. In contrast, in the nonchiral regime with the Fermi level set in the band gap, the injected charge pulses propagated identically in both directions with significantly reduced velocity. In addition, as the channel length increased, we observed a sharp crossover from EMP transport to diffusive transport, manifested as pronounced waveform broadening and dissipation. Simulations using a distributed capacitance model including interchannel tunneling well reproduced the observed behavior in both chiral and nonchiral regimes, revealing that interchannel charge transfer between counterpropagating channels plays a crucial role. The slow EMP transport in the nonchiral regime and its crossover to diffusive transport are consequences of the strong interchannel interaction and interchannel tunneling, respectively. Our results will thus provide insights into charge dynamics and scattering mechanism in analogous one-dimensional systems, including a quantum spin Hall insulator with helical edge modes and its expected Tomonaga-Luttinger liquid behavior. Published by the American Physical Society 2024

3DDA: A Novel Python Toolkit to Analyze 3D‐Dynamic Contact Angles from Molecular Dynamics Simulations

Obtaining fast and reliable contact angles in molecular dynamics simulations is crucial for screening surface wettability. Traditional methods rely on bidimensional density profile analysis to localize the liquid/vapor interface, which may not be optimal at the nanoscale, especially for nonsymmetrical droplets. Herein, 3DDA, a Python‐based code that uses the 3D droplet geometry to determine contact angles and analyze dynamic changes during spreading processes at the nanoscale, is presented. The 3D density profile of liquid molecules is enveloped using the Euclidean 3D convex hull algorithm to locate the contact line at the solid‐, liquid‐, and vapor‐phase boundaries. By fitting a general ellipsoidal function and optimizing it with the limited‐memory Broyden–Fletcher–Goldfarb–Shanno method, the best candidate function is analytically obtained, describing the interface. The angle derived from the ellipsoidal function and the solid boundary is used to gather a collection of contant angles, which are then fed into a kernel density estimator to determine the most probable angle along the contact line during the spreading process. This methodology is tested on systems such as liquid water and metals, demonstrating its efficacy and reliability. Herein, valuable insights are provided into the behavior of liquids, considering droplet asphericity induced by liquid/solid interactions.

Instantaneous Tiltmeter Triggered by Dynamic Wetting Behavior.

A novel instantaneous tiltmeter with dynamic and static monitoring functions is reported that is based on liquid metal dynamic wetting behavior in a bio-fabricated anisotropic microchannel. The proposed system achieves instantaneous tiltmeter functionality, offering a broad detection range (-90°-90°) with high precision (0.05°), a rapid reaction time (0.11 s), and enhanced durability. Moreover, a seamless integration has enabled water wave detection, language programming, and human limb monitoring. Especially, the integration of tiltmeter and a t3D motion platform results in a surface structure scanning system capable of effectively performing large area (>200 cm2) and height difference scanning functions. This innovative approach holds great potential for transformative changes in the fields of advanced manufacturing, flexible robotics, and the flexible sensing, further facilitating widespread adoption.

Isothermal compressibility and water self-diffusion coefficient in supercooled salt aqueous solutions using the Madrid-2019 model

The isothermal compressibility and self-diffusion coefficient of water in Li + , Na + , K + , Mg 2 + and Ca 2 + chloride and sulfate salts aqueous solutions is calculated by means of molecular simulations using the Madrid-2019 force-field, that uses TIP4P/2005 model for water and assigns scaled charges for ions. Our simulations predict that the isothermal compressibilities of these salts retain the anomalous behaviour of water, i.e. compressibility increases as temperature decreases, contrary to the behaviour of normal liquids. A maximum in the isothermal compressibility, analogous to that of pure water, is observed for some of the salt solutions. For the 1 m NaCl solution, simulations are performed at several pressures up to 1000 bar to estimate the location of the second critical point. We estimate that the liquid-liquid critical point is located at 190 K and 1000 bar, i.e. it is shifted to slightly higher temperatures and lower pressures with respect to the most accurate estimation of its location in pure TIP4P/2005 water (172 K and 1861 bar). Regarding the self-diffusion of water, all salts increase water mobility in the very supercooled regime (at temperatures within 200–230 K), with K 2 SO 4 producing the largest increase in water mobility, while MgCl 2 and MgSO 4 are the least effective in enhancing the self-diffusion coefficient of water.

Quasi-one-dimensional bismuth chains with topological properties

One-dimensional (1D) systems have received a lot of attention due to their exotic physical phenomena such as quantization of conductance, Peierls instability, and Luttinger liquid behavior. Here, we present the synthesis of self-assembled quasi-1D bismuth (Bi) chains on an Au(111) substrate, highlighting their topological properties. Scanning tunneling microscopy and spectroscopy measurements reveal that the high-quality large area array is composed of Bi atomic chains with a bandgap of 0.5 eV. Density functional theory (DFT) calculations confirm the experimental observation and reveal the topological properties of the system, providing evidence of the spin texture of the Bi atomic chains. Our DFT results predict that a single Bi chain hosts exotic topological properties. The atomically precise synthesis of Bi atomic chains overcomes the limitation of the top-down approach toward integration of devices. The work sheds light on the realization of 1D system, providing a platform for further investigation into the intriguing physics in 1D systems.