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The present study investigates impact of nanodroplets on liquid films with varied film thicknesses over hydrophilic to hydrophobic surfaces via molecular dynamics simulations. A new crown pattern, hollow crown, is observed on medium liquid films for nanodroplets, whereas it is not reported for millimeter-sized droplets. Holes (or hollows) are attributed to capillary vibration of a nanometer-thick liquid film. The occurrence of holes is inhibited effectively for deep liquid films because the cavity thickness is much larger than the amplitude of capillary vibration. Surface wettability has a significant influence on thin and medium liquid films for nanodroplets, whereas it only affects thin liquid films for macrodroplets because the range of solid–liquid intermolecular forces is comparable to the size of droplets when the size of droplets reduces to the nanoscale. Subsequently, the accuracies of the existing macroscale models for predicting the time-dependent crown radius of nanodroplets are tested by simulated results. The results show that the macroscale models cannot capture the time-dependent crown radius of nanodroplets. On the basis of energetics analysis, we prove that the failure of macroscale models is attributed to the distinct difference in viscous dissipation mechanisms between macroscale and nanoscale droplets. [ABSTRACT FROM AUTHOR]

Exposure of dark-grown etiolated seedlings to light triggers the transition from skotomorphogenesis/etiolation to photomorphogenesis/de-etiolation. In the life cycle of plants, de-etiolation is essential for seedling development and plant survival. The mobilization of soluble sugars (glucose [Glc], sucrose, and fructose) derived from stored carbohydrates and lipids to target organs, including cotyledons, hypocotyls, and radicles, underpins de-etiolation. Therefore, dynamic carbohydrate biochemistry is a key feature of this phase transition. However, the molecular mechanisms coordinating carbohydrate status with the cellular machinery orchestrating de-etiolation remain largely opaque. Here, we show that the Glc sensor HEXOKINASE 1 (HXK1) interacts with GROWTH REGULATOR FACTOR5 (GRF5), a transcriptional activator and key plant growth regulator, in Arabidopsis (Arabidopsis thaliana). Subsequently, GRF5 directly binds to the promoter of phytochrome A (phyA), encoding a far-red light (FR) sensor/cotyledon greening inhibitor. We demonstrate that the status of Glc within dark-grown etiolated cotyledons determines the de-etiolation of seedlings when exposed to light irradiation by the HXK1–GRF5–phyA molecular module. Thus, following seed germination, accumulating Glc within dark-grown etiolated cotyledons stimulates a HXK1-dependent increase of GRF5 and an associated decrease of phyA, triggering the perception, amplification, and relay of HXK1-dependent Glc signaling, thereby facilitating the de-etiolation of seedlings following light irradiation. Our findings, therefore, establish how cotyledon carbohydrate signaling under subterranean darkness is sensed, amplified, and relayed, determining the phase transition from skotomorphogenesis to photomorphogenesis on exposure to light irradiation. This study reveals how sugar signaling under subterranean darkness is sensed, amplified, and relayed to determine skototophotomorphogenesis upon exposure to light irradiation. [ABSTRACT FROM AUTHOR]

This study investigates the heat transfer enhancement by electrohydrodynamic (EHD) in a rectangular channel with various geometric and operational parameters in a wide NEHD range of 0.4–5. Here, NEHD is a dimensionless number, describing the ratio of electrostatic, inertial, and viscous forces. Two working regimes in EHD are identified: inertial and electrostatic regimes. The results show that the barrier effect exists only in the inertial regime; however, the interference effect occurs in the electrostatic regime. The barrier effect relies heavily on NEHD rather than the dimensionless distance between electrodes l* and the dimensionless channel width H* because the thermal boundary layer cannot be disturbed sufficiently by a small electrostatic force; however, the interference effect depends on l* and H* rather than NEHD due to the stagnant area initiated only by a strong interaction between adjacent emitting electrodes. A new effect, the "blocking effect," is found in the electrostatic regime. The mechanism of the blocking effect is different from that of the barrier and interference effects. The blocking effect is initiated by a giant vortex, which "blocks" the airflow flowing toward the downstream channel. The average Nusselt number of channels can be reduced by at least 8%, 13%, and 5% for the barrier, interference, and blocking effects, respectively. A working spectrum of EHD-induced heat transfer enhancement in a rectangular channel is provided under NEHD and channel area coupling conditions. We believe the spectrum can help in designing EHD-induced heat transfer enhancement because it provides theoretical guidance for avoiding the three effects. [ABSTRACT FROM AUTHOR]

In this work, we investigate microscale electrohydrodynamic (EHD) conduction pumps of dielectric liquids in a wide working regime range from the Ohmic to the saturation regime. We show that the electric force of microscale EHD conduction pumps differs from that of macroscale EHD conduction pumps owing to the scale effect. We reveal that the scale effect of microscale EHD conduction pumps is triggered by the enhanced ionic diffusion. When the characteristic length of the system reduces from millimeter to micrometer, the maximum order of magnitude of α increases from O(10−5) to O(10−1), resulting in significantly enhanced ionic diffusion; however, the ionic diffusion can be neglected for macroscale EHD conduction pumps, where α denotes the ratio of ionic diffusion velocity to ionic migration velocity. We found that the existing macroscale theoretical models do not work for the microscale EHD conduction pumps due to the rough estimation of heterocharge layer thickness. We show that the heterocharge layer thickness of microscale EHD conduction pumps not only depends on ionic migration but also relies on ionic diffusion. By modifying the expression of the heterocharge layer thickness with respect to ionic migration and diffusion, we develop a theoretical model of dimensionless electric force for the microscale EHD conduction pumps. [ABSTRACT FROM AUTHOR]

Small molecule covalent drugs have proved to be desirable therapies especially on drug resistance related to point mutations. Secondary mutations of FLT3 have become the main mechanism of FLT3 inhibitors resistance which further causes the failure of treatment. Herein, a series of 4‐(4‐aminophenyl)‐6‐phenylisoxazolo[3,4‐b]pyridine‐3‐amine covalent derivatives were synthesized and optimized to overcome the common secondary resistance mutations of FLT3. Among these derivatives, compound F15 displayed potent inhibition activities against FLT3 (IC50 = 123 nM) and FLT3‐internal tandem duplication (ITD) by 80% and 26.06%, respectively, at the concentration of 1 μM. Besides, F15 exhibited potent activity against FLT3‐dependent human acute myeloid leukemia (AML) cell lines MOLM‐13 (IC50 = 253 nM) and MV4‐11 (IC50 = 91 nM), as well as BaF3 cells with variety of secondary mutations. Furthermore, cellular mechanism assays indicated that F15 inhibited phosphorylation of FLT3 and its downstream signaling factors. Notably, F15 could be considered for further development as potential drug candidate to treat AML. [ABSTRACT FROM AUTHOR]

This work investigates the retraction and bouncing dynamics of an impacting low-viscosity nanodroplet on superhydrophobic surfaces via molecular dynamics simulations, aiming to reveal the scaling laws of retraction and bouncing velocities and to establish the relationship between them. The retraction velocity, Vre, is found to scale as Vre ∼ Dmax/τc,n, where Dmax is the maximum spreading diameter, τc,n = (D0/V0)We1/2Oh1/3 is the inertial-capillary-viscous time, and We and Oh are the Weber number and Ohnesorge number, respectively. The bouncing stems from the collision of the retracting rim at the center of the nanodroplet, leading to the bouncing velocity scaling as the retraction velocity. Combining the relationship of Vre ∼ Dmax/τc,n with the scaling law of Dmax ∼ We1/2Oh1/3D0 yields both the retraction and bouncing velocities scaling as the impact velocity, indicating that both the retraction and bouncing velocities of low-viscosity nanodroplets on a superhydrophobic surface depend merely on the impact velocity. An energy analysis shows that the proportion of the surface energy at the maximum spreading state (Es,max) to the initial kinetic energy (Ek,ini) follows Es,max/Ek,ini ∼ Oh2/3, whereas the proportion of the bouncing kinetic energy (Ek,b) to the surface energy at the maximum spreading state follows Ek,b/Es,max ∼ Oh−2/3, leading to constant Ek,b/Ek,ini and also constant restitution coefficient for low-viscosity nanodroplets impacting superhydrophobic surfaces. [ABSTRACT FROM AUTHOR]

The asteroid (4) Vesta, Vesta dynamic family members and asteroids residing in their vicinity, as the important informational carriers, can supply us with abundant information on the evolution of the inner solar system, such as the collision evolution process and the solar irradiation influence on the changes of the inner belt asteroidal orbits and their spin states. There are significant prospects for investigating the spin and color properties of these asteroids through multi‐color photometric observations. We developed a long‐term observational research plan, and have carried out the first implementation of this plan by using two telescopes who are equipped with the three‐channel system and the SDSS filters. In this paper, we report the corresponding observational results and the determinations of spin pole orientations for three asteroids (556) Phyllis, (620) Drakonia, and (1152) Pawona who reside in the vicinity of Vesta family, and meanwhile estimate the color indexes of Phyllis and Pawona. [ABSTRACT FROM AUTHOR]

Purpose: We aim to identify the risk factors of PPOI in patients with CD and create a nomogram for prediction of PPOI for CD. Methods: Data on 462 patients who underwent partial intestinal resection for CD in Jin-ling Hospital between January 2019 and June 2021 were retrospectively collected. Univariate and multivariate analyses were performed to determine the risk factors for PPOI and we used the risk factors to create a nomogram. Then we used the Bootstrap-Concordance index and calibration diagrams to evaluate the performance of the Nomogram. Decision curve analysis was performed to evaluate clinical practicability of the model. Results: The incidence of PPOI was 27.7% (n of N). Course of CD ≥ 10 years, operation time ≥ 154 min, the lowest mean arterial pressure ≤ 76.2 mmHg, in–out balance per body weight ≥ 22.90 ml/kg, post-op day 1 infusion ≥ 2847 ml, post-op lowest K+ ≤ 3.75 mmol/L, and post-op day 1 procalcitonin ≥ 2.445 ng/ml were identified as the independent risk factors of PPOI in patients with CD. The nomogram we created by these risk factors presented with good discriminative ability (concordance index 0.723) and was moderately calibrated (bootstrapped concordance index 0.704). The results of decision curve analysis showed that the nomogram was clinically effective within probability thresholds in the 8 to 66% range. Conclusion: The nomogram we developed is helpful to evaluate the risk of developing PPOI after partial intestinal resection for CD. Clinicians can take more necessary measures to prevent PPOI in CD's patients or at least minimize the incidence. [ABSTRACT FROM AUTHOR]

The communication and observation spacecraft generally consists of the spacecraft body, the composite connecting beams, the working payload and the CMG/momentum wheel for integrated attitude-vibration control. When such complex space structure operates in near-Earth orbit, the sudden change in thermal load may cause a solar flux shock to the structure, which is likely to excite the flutter motion of the structure. The flutter mechanism of a rigid-flexible coupled composite space structure configured with the momentum wheel is investigated. In this study, the heat conduction equation of the composite beam appendage is derived. Then, the dynamic equations of the system influenced by the momentum wheel and composite material parameters are obtained based on the Kane's equations. Using the Routh–Hurwitz stability criterion, the stability boundaries of the flexible appendage are obtained for different composite material parameters, different operating conditions of the momentum wheel, and different attitude angular velocities. Finally, the flutter behavior is analyzed based on the dynamic response of the flexible structure and the flutter stability boundaries are verified. [ABSTRACT FROM AUTHOR]

Hungaria region locates the inner edge of asteroidal main belt with the high orbital inclination and is surrounded by several resonances, in which more small asteroids (size less than 11 km) reside. We estimate the spin states for eight fast (rotation period ≲4.3hr) rotators in this region based on the dense photometric data and discover that seven of them are in the retrograde spin state. By the analysis on the distributions of spin characteristics, 35 out of 59 Hungaria region members exhibit a tendency—their obliquities distribute in the range larger than 90∘, and especially, most of them clustering significantly in the interval of 135°−165°. Meanwhile, it is also noted that the Hungaria region asteroids with the fast spin (rotation period <4.0hr) show more significant clustering characteristic. [ABSTRACT FROM AUTHOR]

When multiple droplets impact a superhydrophobic surface, coalescence between the droplets may lead to an increased viscous dissipation rate and thus an increased contact time. In this study, the impact of double droplets on a superhydrophobic surface is studied via a lattice Boltzmann model. The morphology and contact time of the rebounding droplet are obtained for various droplet distances and Weber numbers. The simulations show that there are three kinds of rebound patterns, complete-coalescence rebound (CCR), partial-coalescence rebound (PCR), and no-coalescence rebound (NCR); and the contact time is the shortest in the PCR regime. An energy analysis is implemented to reveal the energy conversion mechanism. It is found that viscous dissipation strongly depends on the coalescence strength, and it increases monotonously from the CCR regime to the NCR regime. This result implies that the shortest contact time in the PCR regime does not arise from the reduced viscous dissipation but is attributed to the morphology of the rebounding droplet. Moreover, the simulations also show that the total kinetic energy at the rebound moment is the highest in the PCR regime; however, the restitution coefficient or the rebound velocity is lowest in this regime because a larger proportion of the total kinetic energy occurs in the transverse direction. Therefore, a shorter contact time does not imply a higher rebound velocity. [ABSTRACT FROM AUTHOR]

In this paper, a temporal instability model has been derived to explore the influence of slight multiple airflow movements for the power-law fuel annular jet. Adopting the method of linear approximation and considering two different disturbance modes, the power-law fuel jet dispersion equation has been obtained based on the initial and boundary conditions. The influence of dimensionless characteristic parameters for the annular jet is investigated. By solving the dispersion equation, it can be found that the para-sinuous mode is more likely to play a leading role. For low-speed cases, the outer crossflow gas promotes the instability of fuel annular jets more effectively, while the inner coaxial airflow has an obvious promotion impact on high-speed jets. Reducing the thickness of the fuel annular film will weaken the stable inertia of the fuel, make the fuel annular jet easier to break up, and enhance the primary breakup scale. Furthermore, increasing the outer or inner gas density can accelerate the annular spray breakup process, and also amplify the gain effect of airflows. Besides, pseudoplastic fluid annular jets are more unstable and more suitable as fuel for future use. These discussions aim for a better understanding of the power-law fuel annular jet breakup process with multiple airflows and provide theoretical guidance for practical applications. [ABSTRACT FROM AUTHOR]

Impact dynamics of nanodroplets has recently gained extensive attention because of its potential applications in nanoscale inkjet printing, nanodroplet spray cooling, and nanocoating. In this study, a nanodroplet impacting unheated, flat, smooth, and hydrophobic surfaces is investigated via molecular dynamics simulations. The emphasis is placed on spreading and retraction kinetics, i.e., time-dependent wetting radius or r–τ relation, where r and τ are the normalized wetting radius and time. On the basis of an energy conservation approach, an analytical model of r–τ kinetics is developed for impacting nanodroplets. Hypotheses of cylinder droplet and extensional flow are employed to calculate the transient kinetic energy and viscous dissipation rate, which are found to be the most appropriate for impacting nanodroplets. The model is tested in a range of Weber numbers from We = 15 to 60, Reynolds numbers from Re = 11.07 to 22.19, and surface wettability θ0 = 105° and 125°. The tests show that the mean relative deviation ranges from 2.22% to 5.47%, and hence, the developed model captures the spreading and retraction kinetics of a nanodroplet impacting hydrophobic surfaces with satisfactory accuracy. Furthermore, it is found that the model can also be extended to predict the retraction kinetics of nanodroplets on hydrophilic surfaces for high Weber numbers. [ABSTRACT FROM AUTHOR]

Butterfly white etching area (WEA) formed at subsurface inclusions under rolling contact fatigue (RCF) of bearing steel was investigated by using the Scanning Electronic Microscopy and Transmission Electron Microscopy. Two kinds of butterfly WEAs with different orientations were observed at non-metallic inclusions: largely sheared and narrow band morphologies. Both involve body-centered-cubic (bcc) to face-centered-cubic (fcc) transformation, which is opposed to the previously reported butterfly WEAs consisting of only ferrite nanocrystallines. The largely sheared WEA is composed of nanocrystallines with the grain size of 15 nm averagely. In contrast, apart from the nanocrystallines, the narrow band WEA also includes well-developed equiaxed dynamic recrystallization grains with the grain size ten times larger than the nanocrystallines. This indicates that the WEA involves not only grain refinement, which is commonly reported, but grain growth as well due to dynamic recrystallization. It was suggested that the bcc to fcc phase transformation in nanocrystallines is mechanically controlled, while the phase transformation in equiaxed dynamic recrystallization grains is governed by thermally-assisted plastic deformation. • New microstructure is observed in the butterfly WEA. • Phase transformation from BCC to FCC occurs in the butterfly WEA. • Equiaxed dynamic recrystallization grains are formed in the butterfly WEA. • Butterfly WEA involves grain growth apart from grain refinement. [ABSTRACT FROM AUTHOR]

Highlights • A double droplet impact on a moving liquid film in studied numerically. • Impact velocity, film thickness, and separate spacing of the droplets are examined. • Asymmetric flow and heat transfer characteristics are analyzed. • The asymmetry becomes more significant for larger film moving velocities. Abstract In this work, a coupled level-set and volume of fluid method is employed to investigate a two-dimensional double droplet impact on a moving liquid film. The flow and heat transfer characteristics are analyzed for various film moving velocities, horizontal spacings between the two droplets, impact velocities, and film thicknesses. The results show that four small jets occur near the neck at the contact regions between the droplet and film at the initial impact stage. Subsequently, the two peripheral jets expand outward and form a crown, while two inner jets merge into a central uprising jet. The largest local wall heat flux appears in the two impact regions; however, three extra peaks are observed in the jet regions due to the enhanced convection heat transfer. As compared with impact on the stationary film, the peripheral and central jets for impact on the moving film exhibit an asymmetric feature due to shearing effect of the film, leading to an asymmetric and enhanced local wall heat flux. The asymmetry becomes more significant for larger film moving velocities. The heat transfer enhancement in the impact region is more remarkable for a smaller spacing between the two droplets, a higher impact velocity, or a thinner film thickness based on the present simulation conditions. [ABSTRACT FROM AUTHOR]

Least-squares migration (LSM) is applied to image subsurface structures and lithology by minimizing the objective function of the observed seismic and reverse-time migration residual data of various underground reflectivity models. LSM reduces the migration artifacts, enhances the spatial resolution of the migrated images, and yields a more accurate subsurface reflectivity distribution than that of standard migration. The introduction of regularization constraints effectively improves the stability of the least-squares offset. The commonly used regularization terms are based on the L2-norm, which smooths the migration results, e.g., by smearing the reflectivities, while providing stability. However, in exploration geophysics, reflection structures based on velocity and density are generally observed to be discontinuous in depth, illustrating sparse reflectance. To obtain a sparse migration profile, we propose the super-resolution least-squares Kirchhoff prestack depth migration by solving the L0-norm-constrained optimization problem. Additionally, we introduce a two-stage iterative soft and hard thresholding algorithm to retrieve the super-resolution reflectivity distribution. Further, the proposed algorithm is applied to complex synthetic data. Furthermore, the sensitivity of the proposed algorithm to noise and the dominant frequency of the source wavelet was evaluated. Finally, we conclude that the proposed method improves the spatial resolution and achieves impulse-like reflectivity distribution and can be applied to structural interpretations and complex subsurface imaging. [ABSTRACT FROM AUTHOR]

Surface charge accumulated on insulators plays an important role in flashover process in vacuum, which has not yet been fully understood. In this paper, charging behaviors on insulator surface were experimentally examined under negative DC and impulse voltage. For the case of DC voltage, two charging stages were observed, i.e., the area near cathode was at first negatively charged under lower voltage (stage I) and then followed by a positively charged cathode-anode surface (stage II). Surface charging at stage I is considered to be caused by Schottky injection of homo-charges from electrode into sample surface layer. While at stage II secondary electron emission (SEE) process is responsible to the positively charged anode-cathode surface. However, charging at stage I is quite sensitive to pre-stress process, as well as the electrode-insulator interface conditions. The ongoing injection of electrons from cathode can lead to gradually decreasing in surface charge accumulation as the voltage duration increases. For the case of impulse voltage, Schottky injection of homo-charges has little influence on surface charging as the time is too short for charge injection and migration in surface layer. The SEE process will govern surface charging due to its extremely fast establishment process. A good linear relationship is obtained between saturated surface charge density and applied voltage, which is generally consistent with the numerical calculation result based on secondary electron emission avalanche theory. At last, it is confirmed that the ionization of desorbed gas from insulator surface and subsequent neutralization of electrons with positive surface charge is the main cause to eliminate surface charge in flashover. [ABSTRACT FROM AUTHOR]

The micro-geometry of three-dimensional (3D) braided tubular preform is more complex than that of rectangular one, especially for the interfaces between yarns. The yarn interfaces are difficult to analyze theoretically, and if two sides of the interfaces do not fit perfectly in the model, the final result will contain overlapped yarns, which is bad for finite element calculation. This paper focuses on the microstructure of 3D four-directional braided tubular composites and presents a modelling approach based on Free Form Deformation (FFD) theory. First, the planar and spatial yarn paths are analyzed and three geometrical mapping equations from rectangular unit-cell to tubular sub unit-cell are derived. The modelling approach was then developed to establish the sub unit-cell model. Finally, the established models are compared with micro computed tomography (μ-CT) scans of a dry specimen of the circular braided preform. The model not only solves the yarn-overlapping problem, but also accurately describes the key characteristics of the preform. [ABSTRACT FROM AUTHOR]

In order to meet the demand for infrared stealth materials in the military field, conjugated polymers containing Schiff base moieties were designed and prepared. Various dialdehyde monomers were introduced and their effect on the comprehensive properties were systematically characterized. The resulted polymers could be cast in solution to prepare polymer coatings. The coatings exhibited high thermal stability up to 400 °C at 5% weight loss, and excellent mechanical performance with high Young's modulus and hardness. The infrared emissivity values varied from 0.587 to 0.627 at wavelength of 8–14 µm and ranged from 0.595 to 0.609 at wavelength of 2–22 µm. Specifically, it was found that the ATTPAL structure with carbazole moieties had a lower band gap and better electrical conductivity by photoelectric test and DFT theoretical analysis. Meanwhile, the infrared emissivity value of ATTPAL coating was the lowest compared with p-phenyl and pyridyl containing analogues, suggesting it was potential material for the future development of infrared stealth technology. The combined results showed that reducing the band gap and improving the electrical conductivity of the structure were both beneficial to the reduction of infrared emissivity. It would positively provide new ideas for the design of infrared stealth materials. [ABSTRACT FROM AUTHOR]

Nanodroplet impacts have attracted significant attention, while the effect of surface wettability on contact time is evaluated poorly. Utilizing molecular dynamics simulations, the current work with a special focus on the contact time studies nanodroplets impacting solid surfaces in a wide range of static contact angles (θ0 = 105°–175°) and the Weber number (We = 0.1–200). The complete trends in contact time and restitution coefficient with surface wettability are analyzed and reported for the first time. For surfaces with θ0 > 160°, four different regimes are identified for the contact time and restitution coefficient as a function of the Weber number. For surfaces with 110° < θ0 < 160°, the fourth regime is not observed. The restitution coefficient is employed to analyze the contact time of distinct rebound patterns in the individual wettability range. Intriguingly, surface wettability has a remarkable influence on the contact time of nanodroplets even for superhydrophobic surfaces. The main reason for the difference between the macroscale and nanoscale is attributed to the significantly enhanced viscous effect and interfacial effect of the nanoscale impact. Considering the different effects of surface wettability on spreading and retraction dynamics, the theoretical models for the maximum spreading factor, spreading velocity, and retraction velocity are established. Finally, scaling laws of the spreading time τspr ∼ (R0/Vi)We2/3Re−1/3 and retraction time τret ∼ (R0/Vi)We2/3Re−1/3(1 − cos θ0)−1/2 are proposed. An excellent agreement with both the current data sources and the results in the literature verifies the universality of the current scaling law from hydrophobic to superhydrophobic surfaces. [ABSTRACT FROM AUTHOR]

Efficient droplet shedding from surfaces is fundamentally interesting and important due to its promising potential in numerous applications, such as anti-erosion, anti-icing, and self-cleaning. In this work, the bouncing dynamics of the head-on impact of two nanodroplets on superhydrophobic surfaces are investigated through molecular dynamics simulations. Three bouncing patterns, including regular-coalescence-bouncing, coalescence-hole-bouncing, and ring-bouncing, are identified at a wide range of impacting Weber numbers. For three bouncing patterns, the time evolutions of the spreading factors and the vertical velocity components are employed to analyze the particular dynamic behaviors and elucidate the underlying physics. As a counter-intuitive bouncing pattern, the ring-bouncing that two impact nanodroplets coalesce, spread, and then leave the surface in a ring shape without retracting exhibits a remarkable reduction in contact time by up to 60%. Considering four typical states for the ring-bouncing pattern, the comparison of the velocity distribution within the droplet clearly reveals that the ring-shaped droplet reshapes interfaces, which leads to a special hydrodynamics distribution. As a result, the internal flows at the inner and outer edges along the opposite direction collide with each other, leading to a sudden increase in the upward velocity. Combining the largely decreased contact area between solid and liquid with the small surface adhesion, the ring-shaped droplet rapidly bounces off the surface at the maximum spreading state. Finally, it is significantly highlighted that the ring-bouncing pattern offers a new avenue to break the contact time limit for efficient droplet shedding. [ABSTRACT FROM AUTHOR]

The Arabidopsis AINTEGUMENTA (ANT) gene, which encodes an APETALA2 (AP2)-like transcription factor, controls plant organ cell number and organ size throughout shoot development. ANT is thus a key factor in the development of plant shoots. Here, we have found that ANT plays an essential role in conferring salt tolerance in Arabidopsis. ant-knockout mutants presented a salt-tolerant phenotype, whereas transgenic plants expressing ANT under the 35S promoter (35S:ANT) exhibited more sensitive phenotypes under high salt stress. Further analysis indicated that ANT functions mainly in the shoot response to salt toxicity. Target gene analysis revealed that ANT bound to the promoter of SOS3-LIKE CALCIUM BINDING PROTEIN 8 (SCABP8), which encodes a putative Ca2+ sensor, thereby inhibiting expression of SCABP8 (also known as CBL10). It has been reported that the salt sensitivity of scabp8 is more prominent in shoot tissues. Genetic experiments indicated that the mutation of SCABP8 suppresses the ant-knockout salt-tolerant phenotype, implying that ANT functions as a negative transcriptional regulator of SCABP8 upon salt stress. Taken together, the above results reveal that ANT is a novel regulator of salt stress and that ANT binds to the SCABP8 promoter, mediating salt tolerance. [ABSTRACT FROM AUTHOR]

Two new triterpenoids, 3β,6β-dihydroxy-12-oxo-13Hα-olean-28,19β-olide (1) and 3-oxo-olean-11,13(18)-dien-28,19β-olide (2) were isolated from the resin ofStyrax tonkinensis(Pier.) Craib. The structures of both triterpenoids were determined by physicochemical and spectroscopic methods. Compound1is the second triterpene found withcis-fused C/D ring from the resin, which is rarely observed in oleanane-type triterpenes. [ABSTRACT FROM PUBLISHER]

• Retraction of nanodroplets on hydrophilic to hydrophobic surfaces is studied. • Inertial and capillary regimes are distinguished. • Models of retraction velocities in the two regimes are developed. Because of scale effects, the impact of nanodroplets shows different spreading and retraction dynamics from millimeter-sized droplets, which remains poorly understood. This work investigates the retraction dynamics of low-viscosity water nanodroplets on hydrophobic to hydrophilic surfaces via molecular dynamics (MD) simulations. Two retraction regimes, inertial and capillary regimes, are defined based on whether an obvious rim can be observed in retraction processes. The two retraction regimes successively take place on hydrophobic surfaces, whereas only the capillary regime is observed on hydrophilic surfaces. In the inertial regime, the inertial force in the rim and the viscous forces near the rim entrance and the central film both dominate the retraction. The former makes the retraction velocity scale as We −1/2, whereas the latter causes the scaling of Oh −1/3. Moreover, the spreading factor in the inertial regime decreases from its maximum value to equilibrium value in the same interval of time. Based on these dynamics, an expression for retraction velocity in the inertial regime is proposed. In the capillary regime, the retraction slows down because inertial force weakens significantly. The retraction velocity depends only on the impact velocity and surface wettability. The proposed two expressions of retraction velocities are validated by MD simulations for the impact of nanodroplets on hydrophobic to hydrophilic surfaces at various impact velocities, showing good agreement between them. Furthermore, using the present retraction dynamics, a model of contact time for nanodroplets impacting hydrophobic surfaces is also developed. [ABSTRACT FROM AUTHOR]

Abstract: The portfolio of compounds approved for inhalation therapy has expanded rapidly for treatment of lung diseases. To assess the efficacy and safety of inhaled medicines, a better understanding of their fate in the lungs is essential; especially in diseased lungs where changes in anatomical structure, ventilation parameters and breathing pattern may occur. In this article, the impact of lung pathophysiology factors on the fate of inhaled medicines is reviewed, and discussed in the context of aerosol deposition, dissolution, absorption and clearance. Special emphasis is given to computational modeling of aerosol deposition and clearance taking disease factors into consideration. In silico modeling can be used as a valuable tool to characterize the biopharmaceutics and pharmacodynamics of inhaled medicines, or assess risks associated with inhaled environmental pollutants for patients with pulmonary diseases. The deposition pattern of aerosol particles is greatly altered by different lung diseases based on both experimental data and model simulation. The fate of inhaled medicines after deposition primarily depends on the site of aerosol deposition. Therefore, when developing inhalation products for treatment of lung diseases, the dosing regimen, safety and pharmacokinetic studies should be conducted on patients with lung diseases, in addition to healthy subjects. [Copyright &y& Elsevier]

In convergent beam electron diffraction (CBED) on two-dimensional (2D) materials, the intensity distributions within the individual CBED spots map the local atomic arrangements within the probed region. In this study we demonstrate that the average intensities within the CBED spots essentially depend on the scattering parameters by a single atom, thus, offering the possibility of the direct measurement of such parameters. Scattering potential of an individual atom can be approximated by the Gaussian function and its parameters, the standard deviation and the maximal phase shift, can be recovered from the ratio of the intensities in the zero- and higher orders spots in CBED pattern. In order to demonstrate this, we simulated CBED patterns and extracted the atomic scattering parameters from such patterns. In the simulated examples, no weak phase object approximation is applied and the proposed method provides accurate results even for materials with large phase shifts up to 1.5 rad, as for example tungsten. The scattering parameters recovered from the experimental CBED patterns of graphene and twisted graphene-hBN structure show good agreement with the theoretically obtained values. [Display omitted] [ABSTRACT FROM AUTHOR]

The core-shell structure is crucial for enhancing the electrochemical and electrocatalytic performance of supercapacitor electrode materials. To maximize the potential of NiCo 2 O 4 as an electrode material, this study combines NiCo 2 O 4 with CoFe-LDH. Forming a NiCo 2 O 4 @CoFe LDH core-shell structured electrode material. Using NF as the substrate, NiCo 2 O 4 @CoFe-LDH electrode materials are prepared via a hydrothermal method. The phase structure and microstructure of the electrode material are investigated through X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), and transmission electron microscope (TEM) analyses. The electrode materials undergo electrochemical and electrocatalytic tests using an electrochemical workstation. This study shows that the NiCo 2 O 4 @CoFe-LDH achieves a specific capacitance of 5384.47 mF cm−2 at 1 mA cm−2. After assembling the NiCo 2 O 4 @CoFe-LDH electrode material into a supercapacitor, it exhibits an excellent energy density. Both the power density and the energy density are 758.17 μW cm−2 and 55.81 μWh cm−2, respectively. As an electrocatalyst, the NiCo 2 O 4 @CoFe-LDH electrode material also demonstrates excellent performance. The overpotential is 183 mV at 20 mA cm−2 in Hydrogen Evolution Reaction (HER). Furthermore, the NiCo 2 O 4 @CoFe-LDH electrode material demonstrates outstanding performance in overall water splitting. The voltage is 1.7 V at 25 mA cm−2, which shows strong cyclic stability. This material provides a reliable guarantee for the continuous and stable operation of various application scenarios. • The NiCo 2 O 4 @CoFe-LDH composite electrode is synthesized via hydrothermal-calcination method. • The NiCo 2 O 4 @CoFe-LDH achieves a high specific capacitance of 5384.47 mF cm−2 at 1 mA cm−2. • The capacitance retention of the assembled NiCo 2 O 4 @CoFe-LDH//AC after 10,000 cycles is close to 70%. • Performing HER testing on NiCo 2 O 4 @CoFe-LDH. The overpotential is 183 mV at 20 mA cm−2. [ABSTRACT FROM AUTHOR]

Purpose: Inhalation of low-density porous particles enables deep lung delivery with less dependence on device design and patient inspiration. The purpose of this study was to implement Thin Film Freezing (TFF) to investigate a novel approach to dry powder inhalation. Methods: Powders produced by TFF were evaluated for aerodynamic and geometric particle size by cascade impaction and laser light scattering, respectively. Density measurements were conducted according to USP methods and calculated using data from particle size measurements. Excipient inclusion and its effect on moisture sorption was measured by Dynamic Vapor Sorption (DVS). Results: TFF-produced brittle matrix powders were sheared apart into respirable microparticles using a passive DPI device, producing fine particle fractions (FPF) up to 69% and mass median aerodynamic diameters (MMAD) as low as 2.6 μm. Particles had a mean geometric diameter ranging from 25 μm to 50 μm and mass densities of approximately 0.01 g/cm. Powders were susceptible to moisture-induced matrix collapse, capillary forces and electrostatic charging; although formulations containing mannitol or no sugar excipient proved to be more robust. Conclusions: Aerosolized brittle matrices produced by TFF may prove to be a useful platform for highly efficient pulmonary delivery of thermally labile, highly potent, and poorly soluble drugs. [ABSTRACT FROM AUTHOR]

One of the common characteristics of the electrothermal breakdown in an underwater discharge acoustic source (UDAS) is the existence of a pre-breakdown-heating phase. In our experiment, two phenomena were observed: (1) the breakdown time that takes on high randomicity and obeys a "double-peak" stochastic distribution; (2) the higher salt concentration that reduces the residual voltage and causes 100% non-breakdown. The mechanism of electrothermal breakdown is analysed. To specify the end of the pre-breakdown-heating phase, a "border boiling" assumption is proposed, in which the breakdown time is assumed to be the time needed to heat the border water around the initial arc to 773 K. Based on this 'border boiling' assumption, the numerical simulation is performed to evaluate the effects of two heating mechanisms: the Joule heating from the ionic current, and the radiation heating from the initial arc. The simulation results verify the theoretical explanations to these two experiment phenomena: (1) the stochastic distribution of the radius of the initial arc results in the randomicity of the breakdown time; (2) the difference in efficiency between the radiation heating and the Joule heating determines that, in the case of higher salt concentration, more energy will be consumed in the pre-breakdown-heating phase. [ABSTRACT FROM AUTHOR]

The breakdown of water in underwater discharge acoustic source (UDAS) is usually in the mode of electrothermal breakdown. The prominent characteristic of the electrothermal breakdown is the existence of prebreakdown-heating phase. In our experiment, the influences of salt concentration and water temperature on breakdown are tested. Three phenomena are observed: 1) The breakdown time obeys a “double peak” stochastic distribution; 2) the higher salt concentration in water leads to higher probability of nonbreakdown; and 3) the higher temperature of salty water also results in higher probability of nonbreakdown. In this paper, the mechanism of electrothermal breakdown is theoretically analyzed, and two conditions to realize electrothermal breakdown are concluded: 1) enough energy deposited to the gap to ensure “border boiling” and 2) enough remaining voltage on the gap at the moment of “border boiling.” Focused on the water temperature and gap voltage, a semiempirical model for prebreakdown-heating process is proposed. When two heating effects of both ionic current and radiation from the initial arc are taken into account, this semiempirical model provides preliminary explanations to the three phenomena observed in our experiment. Based on this model, a simulation code (CPH ) is developed which can numerically simulate the evolution of the gap voltage in prebreakdown-heating phase. The simulation reproduces the experimental phenomena under the same initial conditions. [ABSTRACT FROM PUBLISHER]

Abstract: The aromatized chromophore (Chr) of C-1027 with selective DNA-cleaving ability, which is stabilized and delivered by the apoprotein (Apo) in vitro, is not released until the holoprotein (Apo+Chr) penetrates into the cultured cancer cells. As a drug delivery system, the holoprotein has gained much attention in clinical application. However, the Chr-releasing mechanism is ambiguous so far. In this paper, the releasing pathway is investigated using conventional molecular dynamics (MD), essential dynamics (ED), essential dynamics sampling and steered molecular dynamics (SMD) simulations. The results indicate that the releasing paths are related to the local motions of three loops: L3 (Val39–Gln42), L7 (Thr75–Thr79) and L9 (Asn97–Leu100). The major obstacles to Chr releasing come from steric hindrance, direct hydrogen bonds and hydrophobic interactions formed by the three loops, and Ser98 is an important residue in the releasing process. The most favorable direction of releasing is almost parallel to the connection between L7 and L3. Releasing from the direction, Chr only needs to break three hydrogen bonds from Ser98 and Pro76 and the weakest steric hindrance. [ABSTRACT FROM AUTHOR]

The bouncing dynamics of a nanodroplet impacting a superhydrophobic surface under a perpendicular electric field is studied through molecular dynamics (MD) simulations. Using the electric field strength as a parameter, two bouncing regimes are identified: an inertial force rebounding (IFR) regime (E < 0.08 V Å−1) and an electric field force rebounding (EFFR) regime (E > 0.08 V Å−1). In the IFR regime, the restitution coefficient, ε b , is the same as but the contact time, τ c , is shorter than that without an electric field. In the EFFR regime, ε b is proportional to the electric field strength, whereas τ c decreases with an increase in the electric field strength. On the boundary separating the two regimes (around 0.08 V Å−1), both ε b and τ c increase sharply due to the droplet deformation. The droplet bounces off the surface in the shape of a sphere in the IFR regime and as a long strip in the EFFR regime. A new criterion for the bouncing of nanodroplets subjected to a perpendicular electric field is proposed based on the restitution coefficient, Weber number, characteristic length, and factor Φ. The criterion demonstrates that imposing an electric field can help the bouncing of nanodroplets. [Display omitted] • The bouncing of nanodroplets subjected to perpendicular electric fields is studied. • Two bouncing regimes are discovered based on the field strength. • Restitution coefficient and contact time are measured in the two regimes. • A criterion is developed to predict bouncing in the presence of the electric field. [ABSTRACT FROM AUTHOR]

Because electric fields can significantly modify the morphology of impacting droplets, the impact dynamics of droplets subjected to external electric fields have attracted extensive attention in recent years. Owing to the enhanced viscous effect and the altered viscous dissipation mechanisms, nanodroplets show distinctly different impact behaviors from macroscale droplets. However, it is not clear how electric fields affect the impact dynamics of nanodroplets, especially when the field direction is changed. In this study, molecular dynamics (MD) simulations were performed to reveal the bouncing dynamics of a nanodroplet impacting a hydrophobic surface under electric fields with various field strengths and directions. As compared with the case without an electric field, the bouncing dynamics of the nanodroplet were significantly modified in the presence of the electric fields with tilt angles of α = 0°, 30°, 45°, 60°, and 90°, especially when the field strength was higher than 0.08 V Å−1. The restitution coefficient, ε b , was enhanced by the electric fields at a non-zero α with strengths larger than 0.08 V Å−1. Applying an electric field with α = 60° and ≥ 0.08 V Å−1 would lead to the maximum bouncing velocity. The contact time was stretched by a perpendicular electric field when E ≥ 0.08 V Å−1. When the impact velocity was not sufficient to make a droplet bounce off, an electric field with all directions was capable to cause the opposite. [Display omitted] • Bouncing dynamics of nanodroplets subjected to an electric field are studied. • Applying an electric field promotes bouncing. • The electric field with a tilt angle of 60° yields the best bouncing. • A vertical electric field increases the contact time. [ABSTRACT FROM AUTHOR]

[Display omitted] • The effect of Mn doping size over Al 2 O 3 on NO oxidation activity were elucidated. • Mn SACs/Cs -Al 2 O 3 exhibits a superior NO-NO 2 capacity compared with Mn NPs -Al 2 O 3. • The coordination environment of Mn species significantly affects the mobility of O sur. • Reducing Mn size from NPs to SACs/Cs promotes labile nitrate species formation. The exploitation of transitional metal catalysts for high-efficient conversion of NO to NO 2 still persists as an imperative issue due to the high cost of currently used Pt–based catalysts. Herein, we report a TEA-modification strategy to anchor Mn single atoms/clusters on Al 2 O 3 (Mn/Al 2 O 3 -T) for NO oxidation. Activity tests show that Mn/Al 2 O 3 -T (T 83 = 275 °C) displays a superior NO-to-NO 2 capacity compared with the unmodified Mn nanoparticle on Al 2 O 3 (Mn/Al 2 O 3 -B, T 66 = 300 °C) and Pt/Al 2 O 3 (T 43 = 350 °C) counterparts. Comprehensive characterization and DFT calculations discover that the effective adjustment of TEA can promote the generation of coordination unsaturated Mn sites with elongated Mn-O bonds, which can improve the mobility of surface lattice oxygen and facilitate the activation of molecular oxygen. Additionally, reducing Mn size from nanoparticles to single atoms/clusters favors the formation of labile nitrate species and facile desorption of NO 2 , thereby regenerating active sites and accelerating overall NO oxidation reaction. [ABSTRACT FROM AUTHOR]

Abstract: The structures of thiophene–hydrogen halide (HX) complexes are examined at the second-order Møller-Plesset (MP2) level to understand hydrogen bonding and intermolecular interactions of a heteroaromatic ring as the hydrogen bond acceptor. In contrast with the previous results on similar furan complexes, only the face-on geometry type is observed for the thiophene complexes. Variations in complex geometry can be accounted for by the differences in the electrostatic potential on the aromatic ring. A decomposition of interaction energy reveals that thiophene–hydrogen halide is bounded largely by orbital and electrostatic energy contributions. [Copyright &y& Elsevier]

Abstract: Three new polynuclear lanthanide coordination polymers [Ln5(μ3-OH)(oba)7(H2O)2] n ·0.5nH2O (Ln=Eu (1), Ho (2)) and [Yb6(oba)9(H2O)] n (3) (H2oba=4,4′-oxybis(benzoic acid)), were prepared by hydrothermal reactions. 1 and 2 are isomorphous and exhibit complicated three-dimensional structures based on [Ln5(μ3-OH)(oba)7(H2O)2] building blocks. In the asymmetric unit, there are five different coordination environments of Ln(III) ions, including a trinuclear hydroxo core. Complex 3 is a three-dimensional coordination polymer built up from a hexanuclear building block. In 3, Yb(III) ions have six different chemical environments and are in a regular arrangement, resulting in pseudohexagonal prisms along the a-axis. The luminescent property of 1 and magnetic behaviors of 2 and 3 have also been studied. [Copyright &y& Elsevier]

Abstract: Three new lanthanide coordination polymers with 1,2,4,5-benzenetetracarboxylic acid, Pr2(betc)2(4,4′-bpyH2)·0.25H2O (1), Ln2(betc)2(4,4′-bpyH2) (Ln=Eu (2), Gd (3)) were hydrothermally prepared. The crystallographic data of 1–3 show that they are isostructural, and possess 3D framework with 1D rhomboid channels, where the 4,4′-bipyridine molecules exist steadily via hydrogen bonds. Meanwhile, a supramolecular structure of (4,4′-bpyH2)2(betc) (4) was also obtained by hydrothermal reaction. The results of 1–4 indicate that 4,4′-bipyridine molecule acting as a template plays an important role in the formation of complexes 1–3, and thus has a synergistic action in the construction of 3D framework with large channels. [Copyright &y& Elsevier]

First examples of lanthanide coordination polymers with 4,4′-biphenyldicarboxylic acid (4,4′-H2bpdc), Ln(4,4′-Hbpdc)(4,4′-bpdc)(H2O)2 (Ln=Pr(1), Eu(2), Gd(3)) and Er(4,4′-bpdc)1.5(H2O)2 (4) were prepared by the solvothermal synthesis. Crystallographic data show that complexes 1–3 are isostructural and each lanthanide(III) ion is coordinated to six 4,4′-Hbpdc ligands, and display 3D sandwich structure with lanthanide ion layers and organic ligand layers alternately linking up with each other. Complex 4 shows different coordination modes of 4,4′-bpdc ligands from 1–3 and each Er(III) ion is attached to four 4,4′-bpdc ligands to construct 3D sandwich structure. The emission spectrum of 2 shows one Eu3+ ion site, which is consistent with the results of the X-ray crystal structure analysis. [Copyright &y& Elsevier]

• The linear temporal instability of power-law fuel jets under crossflow is studied. • The transverse motion of gas phase could effectively accelerate the liquid breakup. • Gas density enhance the aerodynamic force and weaken the influence of crossflow. • The effects of co-current airflow and crossflow on jet instability are compared. A theoretical model is presented for the effect of a slight gas crossflow on the instability of the power-law fuel jet in this paper. Based on a linear approximation, the dispersion equation was deduced theoretically with axisymmetric disturbance. The influence of various dimensionless factors for jet instability is studied. Theoretical calculation results of temporal mode show that the transverse motion of gas phase could effectively accelerate the power-law fuel breakup. With the increase of transverse gaseous velocity, power-law fuel jets would become more susceptible to be broken up. Increasing gas-liquid density ratio could enhance the aerodynamic forces in the axial and vertical directions and promote fuel fragmentation. Simultaneously, a huge gas density could weaken the influence of transverse airflow. With the increase of the transvers airflow, Weber number has a weakening effect on the fuel breakup, but it has a significant positive effect on the primary breakup scale. However, with gas crossflow, the liquid viscous force also takes strong disadvantage of development of surface wave. Besides, the effects of crossflow and co-current airflow environments on the instability of power-law liquid jet are studied. For the generalized Reynolds number and power law exponent, the fuel jet under cross-flow conditions is more unstable, but the jet under the co-current flow condition is smaller on the fracture scale. These issues are beneficial to understand the disintegration of the power-law fuel jet with gas crossflow, and supply reference for the application of power-law liquids in real engineering technologies. [ABSTRACT FROM AUTHOR]

The impact dynamics of water nanodroplets on flat solid surfaces was studied by molecular dynamics simulations over a wide range of Weber numbers (We) and surface wettability (θ0), where θ0 is the Young contact angle. A phase diagram in the parameter space of We vs θ0 was established accommodating eight impact outcomes noted in the final stage of impact, with three of them, holes rebound, partial-rebound splash, and rebound splash, for the first time being identified and reported. The eight impact outcomes were classified into three categories, i.e., non-bouncing, bouncing, and splash. The results show that the splash is triggered only when Wecr > 140. The boundaries separating bouncing from non-bouncing were determined based on the phase diagram. When θ0 > 160°, the boundary is described as Wecr = a ≪ 1; when 110° < θ0 < 160°, the boundary depends on both We and θ0, with a larger We required to trigger bouncing on a less hydrophobic surface, expressed as Wecr = b + ccosθ0; when θ0 < 110°, bouncing never takes place, and hence, the boundary is determined only by the critical contact angle, expressed as θ0,cr = 110°. Here, a, b, and c are constants. [ABSTRACT FROM AUTHOR]

For turbine blade internal cooling, the performance of turbulent flow and convective heat transfer in the cooling channel is numerically investigated via the computational fluid dynamics method, where the cooling channel adopts the combination of transverse rib arrangements and round-edged rib configurations or the combination of oblique rib arrangements and round-edged rib configurations. Under these two combination conditions, the simulation result shows that in the wide Reynolds number range of Re = 20 000–80 000, the heat transfer enhancement and the flow loss reduction, such as the larger normalized Nusselt number of Nu/Nu0 and smaller normalized friction factor of f/f0, are simultaneously realized by the oblique rather than transverse rib arrangement. In the oblique rib channel, the relationship between turbulent flow and convective heat transfer is for the first time revealed by the relationship between secondary vortices and turbulent kinetic energies. Based on the relation between secondary vortices and turbulent kinetic energies, the overall performance of turbulent flow and convective heat transfer for the oblique rib channel is first optimized by various normalized rib height, e/Dh, and rib spacing, p/e, and then evaluated by both overall performance factors of OPT1 and OPT2. Both OPT1 and OPT2 are larger at e/Dh = 0.062 and p/e = 15.00 in the wide range of e/Dh = 0.047–0.101 and p/e = 10.00–15.00. As a result of the comprehensive evaluation of OPT1 and OPT2, the combination of e/Dh = 0.062 and p/e = 15.00 is eventually employed by the oblique rib channel. [ABSTRACT FROM AUTHOR]

Coalescence-induced droplet jumping on superhydrophobic surfaces has been observed at microscale and even nanoscale. The enhancement in jumping velocity of coalescing droplets is crucial for condensation heat transfer enhancement, anti-icing, self-cleaning, and so forth. However, the research on how to acquire a higher jumping velocity is really very limited. In this paper, we use molecular dynamics simulations to study the coalescence-induced jumping of two equally sized nanodroplets on chemically heterogeneous surfaces composed of alternating stripes with different hydrophobicity. We show that the jumping velocity is closely related to the stripe width and wettability contrast, and it can even exceed that on an ideal superhydrophobic surface with 180° contact angle when the striped surfaces are properly designed. We also demonstrate that there is always an optimal stripe width yielding the maximum jumping velocity, whereas its value is independent of the wettability contrast. We reveal that the dominant factor to determine the jumping velocity is the apparent contact angle of equilibrated droplets over heterogeneous surfaces for small stripe widths; it changes to the time of liquid bridges impacting surfaces for moderate stripe widths and to the contact area between equilibrated droplets and relatively hydrophobic stripes for large stripe widths. We believe the present simulations can provide useful guidance to design self-jumping superhydrophobic surfaces. [ABSTRACT FROM AUTHOR]

The popular method of calculating the noncovalent interaction energies at the coupled‐cluster single‐, double‐, and perturbative triple‐excitations [CCSD(T)] theory level in the complete basis set (CBS) limit was to add a CCSD(T) correction term to the CBS second‐order Møller‐Plesset perturbation theory (MP2). The CCSD(T) correction term is the difference between the CCSD(T) and MP2 interaction energies evaluated in a medium basis set. However, the CCSD(T) calculations with the medium basis sets are still very expensive for systems with more than 30 atoms. Comparatively, the domain‐based local pair natural orbital coupled‐cluster method [DLPNO‐CCSD(T)] can be applied to large systems with over 1,000 atoms. Considering both the computational accuracy and efficiency, in this work, we propose a new scheme to calculate the CCSD(T)/CBS interaction energies. In this scheme, the MP2/CBS term keeps intact and the CCSD(T) correction term is replaced by a DLPNO‐CCSD(T) correction term which is the difference between the DLPNO‐CCSD(T) and DLPNO‐MP2 interaction energies evaluated in a medium basis set. The interaction energies of the noncovalent systems in the S22, HSG, HBC6, NBC10, and S66 databases were recalculated employing this new scheme. The consistent and tight settings of the truncation parameters for DLPNO‐CCSD(T) and DLPNO‐MP2 in this noncanonical CCSD(T)/CBS calculations lead to the maximum absolute deviation and root‐mean‐square deviation from the canonical CCSD(T)/CBS interaction energies of less than or equal to 0.28 kcal/mol and 0.09 kcal/mol, respectively. The high accuracy and low cost of this new computational scheme make it an excellent candidate for the study of large noncovalent systems. [ABSTRACT FROM AUTHOR]

The flow of electric current through the conductor has a far‐reaching effect on its corrosion behavior. In this paper, the effect of current on the corrosion behavior of Cu is investigated. The accelerated corrosion test of Cu with various external currents from 1 A to 5 A are carried out in 5% NaCl neutral salt spray environment. The results show that the samples with external current exhibit a faster corrosion rate than those without current. The corrosion kinetics and underlying mechanism are also discussed in this paper. [ABSTRACT FROM AUTHOR]

As a kind of non-Newtonian fluid with special rheological features, the study of the breakup of power-law liquid jets has drawn more interest due to its extensive engineering applications. This paper investigated the effect of gas media confinement and asymmetry on the instability of power-law plane jets by linear instability analysis. The gas asymmetric conditions mainly result from unequal gas media thickness and aerodynamic forces on both sides of a liquid jet. The results show a limited gas space will strengthen the interaction between gas and liquid and destabilize the power-law liquid jet. Power-law fluid is easier to disintegrate into droplets in asymmetric gas medium than that in the symmetric case. The aerodynamic asymmetry destabilizes para-sinuous mode, whereas stabilizes para-varicose mode. For a large Weber number, the aerodynamic asymmetry plays a more significant role on jet instability compared with boundary asymmetry. The para-sinuous mode is always responsible for the jet breakup in the asymmetric gas media. With a larger gas density or higher liquid velocity, the aerodynamic asymmetry could dramatically promote liquid disintegration. Finally, the influence of two asymmetry distributions on the unstable range was analyzed and the critical curves were obtained to distinguish unstable regimes and stable regimes. [ABSTRACT FROM AUTHOR]

[Display omitted] • The influence of the surface structure features on the bouncing dynamics is revealed. • The phase diagrams of the bouncing patterns are constructed. • Theoretical models are developed to unravel the mechanisms of pancake bouncing of impacting nanodroplets on nanopillared surfaces. • The critical Weber number for triggering the pancake bouncing is proposed. Superhydrophobic surfaces that promote rapid droplet detachment in a pattern of pancake bouncing are fundamentally interesting and important in substantial applications, such as self-cleaning, anti-corrosion, and anti-icing. However, the accurate modeling of the trigger conditions and the underlying dynamic mechanism for the pancake bouncing have yet to be completed. Here, using molecular dynamics simulations, the bouncing dynamics of impacting water nanodroplets on superhydrophobic Pt surfaces with nanopillar arrays are comprehensively studied considering a wide range in the impact Weber number, solid fraction (the pillar width w is kept constant), and pillar height. Correspondingly, the phase diagrams of the bouncing patterns are constructed in the parameter space of the Weber number against the solid fraction. It has been found that there are critical values of the solid fraction and pillar height to induce the pancake bouncing at the moderate Weber number. Furthermore, a theoretical model is developed and quantitatively proclaims the dependence of nanostructure features and the critical Weber number on the pancake bouncing. This work provides rational design principles for attaining a controllable pancake bouncing on structured superhydrophobic surfaces for a wide range of applications. [ABSTRACT FROM AUTHOR]

• Waste plastic film recovery program of Old for New was investigated in northwest China. • Theory of planned behavior (TPB) was extended to explain farmers' participation. • The attitude was as a key factor influencing the intention of recycling behavior. • Plastic film usage & household characteristics evidently affected recycling behavior. • Role of TPB-based compulsory environmental education was highlighted in program. This study aims to address the lack of relevant researches in the field of waste recycling using the Theory of Planned Behavior (TPB). A village-scale social survey was conducted to investigate the degree of farmers' participation in a waste plastic film program, i.e. Old for New in northwest China. The program required farmers to recycle plastic film residues in exchange for new films. Survey results showed that 67.5% of farmers accepted the program, yet only 14.5% of them actually participated. Logistic regression analysis was used to analyze questionnaire data and identify the factors that significantly affected farmers' recycling behavior. Principal component and weight analysis further showed that farmers' participation was mainly influenced by their attitudes (p < 0.01), with a relative weight (RW) of 46.3%. Yet, subjective norms (p < 0.1) and perceived behavior control (p < 0.1) had less effect on the degree of participation, and their RWs were 4.2% and 4.1% only, respectively. Moreover, the RW of plastic film usage characteristics and household characteristics reached up to 13.2% and 6.4%, respectively. Interestingly, environmental awareness (β = 0.083) and compulsory environmental education (β = 0.130) as surface factors strongly affected the farmers' adoption and response, with the RW of 25.7%. As such, the extended TPB model was established to analyze the participation behavior of farmers for stronger explanatory power. This study highlighted a promising strategy based on TPB for waste plastic film recycling and similar environmental management practices. [ABSTRACT FROM AUTHOR]

The performance optimization of electrohydrodynamics (EHD) induced heat transfer enhancement has attracted much interest in recent decades. Although various EHD device designs have been proposed, coupling optimization based on comprehensive parameters, including Reynolds number, voltage, and electrode spacing, is still absent, and the overall heat transfer efficiency is rarely considered. In this study, the heat transfer efficiency of a wire-to-plate EHD device in a wide range of secondary flow intensity NEHD = 0.4–5 is investigated. Here, NEHD is a dimensionless parameter that integrates Reynolds number, voltage, electrode radius, etc. The average Nusselt number Nu rather than the enhancement rate ER is selected for optimization. It is demonstrated that NEHD = 2 is the optimal secondary flow intensity in both single-electrode and multiple-electrode configurations. The too-weak or too-strong secondary flow will lead to a decrease in the heat transfer efficiency. The underlying physics is revealed by the barrier effect and oversize vortex. An optimal electrode spacing of l > 0.014 m is proposed in the multiple-electrode configuration. A strong interaction between adjacent vortices will significantly decrease the heat transfer efficiency when l < 0.0014 m. A new design criterion for EHD devices is proposed: make sure that the secondary flow intensity NEHD = 2.0 and the electrode spacing l > 0.014 m, then arrange as many electrodes as possible in the channel. [ABSTRACT FROM AUTHOR]