Monotonic Increase Research Articles

In utero, childhood, and adolescence tobacco smoke exposure, physical activity, and chronic kidney disease incidence in adulthood: evidence from a large prospective cohort study

BackgroundThe adverse effects of early-life tobacco smoke exposure on chronic kidney disease (CKD) risk remain unclear. This study aimed to investigate the associations of early-life tobacco smoke exposure with CKD incidence in adulthood, and further explore the modification effects of physical activity (PA).MethodsA total of 352,883 participants were included from the UK Biobank. The information on early-life tobacco smoke exposure was assessed by employing in utero tobacco smoke exposure and age of smoking initiation. Weekly moderate-to-vigorous physical activity (MVPA) was calculated for each individual. Cox proportional hazard regression was fitted to estimate the hazard ratio (HR) and 95% confidence interval (CI) of CKD risk, and to investigate the modification effects of MVPA.ResultsCKD incidence significantly increased in participants with in utero tobacco smoke exposure (HR: 1.08, 95% CI: 1.04, 1.12). Compared with never-smokers, we found a monotonic increase in the risk of CKD with smoking initiation across adulthood (HR: 1.21, 95% CI: 1.16, 1.27), adolescence (HR: 1.29, 95% CI: 1.24, 1.35), and childhood (HR: 1.34, 95% CI: 1.25, 1.43) (P trend < 0.001). Additionally, we identified joint cumulative effects of MVPA and early-life tobacco smoke exposure on incident CKD. Compared with never-smokers with recommended MVPA, prenatal or childhood tobacco smokers without recommended MVPA had the highest CKD risk, and the HRs (95% CIs) were 1.17 (1.10, 1.24) and 1.51 (1.36, 1.68), respectively.ConclusionsEarly-life tobacco smoke exposure may contribute to CKD incidence in adulthood, and the observed associations could be modified by MVPA. These findings provide important information on CKD prevention in the participant’s early life while urging a more rapid and powerful need for tobacco control among pregnant couples, children, and adolescents.

Creep evaluation for fiber-reinforced composites with hybrid fibers: From quantifying fiber anchorage effect to homogenization model

A general micromechanical creep model for fiber-reinforced composites with multi-type hybrid fibers is proposed from quantifying the fiber anchorage effects. An average Eshelby tensor-based homogenization method is employed to calculate the effective creep of composites with realistic-shaped (straight, hooked, and wavy) fibers. A fiber anchorage zone is introduced to depict the anchorage effects of fibers and its parameters are obtained by back analysis. The micromechanical model and fiber anchorage zones are validated by comparing with extensive creep experimental data and finite element simulation. According to the micromechanical model, the effects of fiber shapes, types, direction, anchorage zone, and fiber doping on the creep of composites are systematically explored. The results show fiber shapes and types have obvious effects on composites creep. Fiber deflection angle leads to a monotonous increase in creep. The creep with fiber doping is between the two cases without fiber doping. It indicates that the creep of fiber-reinforced composites can be tailored via proper design for these factors.

A multi-linear constitutive relation considering the temperature effect on quasi-static mode I delamination in UD/MD laminates

In this study, a multi-linear constitutive relation taking into account temperature and fiber bridging is proposed for characterizing delamination behavior in composite laminates under various temperature conditions. An approach combining analytical solution and J-integral is also established for determining the cohesive parameters in the multi-linear constitutive relation. To validate the proposed constitutive relation, mode I quasi-static delamination experiments of unidirectional (UD) and multidirectional (MD) carbon/bismaleimide laminates are carried out at 25 ℃ (room temperature), 80 °C and 130 ℃. The experimental results show that the increasing temperature resulted in a monotonic increase in the fracture toughness of the UD laminates while affect the fracture toughness of MD laminates slightly. A FE model is established with the implementation of the proposed multi-linear constitutive relation using UMAT subroutine. Good agreements between the experimental and simulated results demonstrate the validity of the proposed constitutive relation, with the relative difference of peak load between predicted and experimental values less than 8.2 % and the relative difference of initial and steady-state fracture toughness between predicted and tested results less than 15 %. This study provides the possibility to numerically study the temperature effect on the delamination behavior of laminates and has promising applications in the damage tolerance design of composite structures.

Size Effects on the Magnetic Properties of a System of ε-Fe2O3 Nanoparticles Embedded in a SiO2 Xerogel Matrix

A representative series of samples consisting of fine ε-Fe2O3 nanoparticles uniformly distributed over the SiO2 xerogel matrix with an iron oxide content of 5‒33 wt % has been synthesized and studied by mutually complementary physical methods. It has been shown by the X-ray diffractometry and high-resolution electron microscopy examination that, with increasing iron oxide concentration, the average particle size <d> increases from 4 to 11 nm. According to the X-ray diffractometry and Mӧssbauer spectroscopy data, the samples with an iron oxide content of 5–20 wt % are single-phase, while at the highest Fe2O3 concentration (33 wt %), the β-Fe2O3 and α-Fe2O3 phases arise. As the average particle size <d> increases, a monotonic increase in coercivity HC and remanent magnetization MR of the synthesized systems at room temperature is observed, which is indicative of their magnetic hysteresis. The magnetic transition known to occur in the ε–Fe2O3 oxide manifests itself in all the investigated samples as a drastic change in the HC and MR values at 150–75 K. At the same time, a thorough analysis of the temperature dependence of the real part of the ac magnetic susceptibility χ′ has shown that the particles with a size smaller than a critical value of dC ∼ 6.5 nm do not undergo the magnetic transition and have a much lower magnetic anisotropy constant as compared with coarser particles (d >dC). It has been found that, in the low-temperature region, the magnetic moments of these fine particles experience superparamagnetic blocking. It has been established that the size effects that arise in ultra-fine ε–Fe2O3 particles has a serious impact on the macroscopic magnetic properties of the highly dispersed systems based on them.

Role of particle shape in sheared granular media: Roundness and elongation

Particle shape is an intrinsic characteristic of soil particles that significantly influences mechanical responses. In this investigation, a meticulously calibrated and validated two-dimensional discrete element method (DEM) model of a biaxial shearing test was employed to simulate the shearing response of forty distinct particle shapes. The systematic evolution of particle roundness (R) and aspect ratio (AR) was achieved by utilizing idealized polygonal-shaped particles, aiming to comprehend their effects on the macro and micromechanical behaviors of granular materials. The results suggest that a reduction in R limits free rotations and enhances interlocking, thereby promoting relatively stable force transmission between particles and leading to a monotonic increase in shear strength. However, this effect diminishes as particles become more elongated. Conversely, a decrease in AR from 1.0 (increased elongation) constrains particle rotations, increases the coordination number, and enhances fabric anisotropy initially resulting in increased overall shear strength, reaching a maximum before exhibiting a decreasing trend, indicative of non-monotonic variation. For high elongations, notable fabric anisotropy impedes clear force transmission between particles thus facilitating interparticle sliding and overall strength diminishes. The extent to which AR impacts depends on the angularity feature of particles. Finally, a nonlinear equation has been proposed to predict the variation in critical state shear strength of granular samples, based on the R and AR values of the constituent particles.

Cumulative effect of lifetime smoking history on arterial stiffness and subclinical atherosclerosis in patients with arterial hypertension

Abstract Introduction Although the effect of smoking status on blood pressure (BP) changes is well known an adverse association between cumulative smoke exposure (by pack-years) and functional and structural changes in arteries of patients with high BP has not been consistently demonstrated. Aim of the study was to explore the contributions of cumulative smoke exposure to the vascular consequences of arterial hypertension. Methods Indices of vascular function and structure including carotid-femoral pulse wave velocity (PWV), augmentation index (AIx) and carotid intima media thickness (cIMT) were measured in 485 adults aged less than 60 years old without a history of cardiovascular disease. The cohort was divided into three groups according to office systolic BP (SBP) and diastolic BP (DBP): normal (SBP &amp;lt;130 and DBP &amp;lt;85 mmHg, n=242), high normal (130≤SBP&amp;lt;140 or DBP 85≤DBP&amp;lt;90mmHg, n=96), and hypertension (SBP≥140 or DBP≥90mmHg, n=147). The cohort was subdivided according to pack-years of smoking history as never smokers (0.0 pack-years), light smokers (&amp;lt;20 pack-years), moderate smokers (20-40 pack-years), and heavy smokers (&amp;gt; 40 pack-years). Results The three BP groups had similar age and metabolic parameters (body mass index, fasting blood glucose and LDL-C). Figure shows PWV, AIx and carotid IMT by smoking exposure, stratified by BP level. The lowest PWV level was observed in never smokers with normal BP; whereas heavy smokers with hypertension exhibited the highest PWV. Also of note, heavy smokers with normal BP exhibited comparable PWV to light and never smokers with hypertension. Furthermore, in smokers with more than 20 pack-years tobacco exposure, PWV was higher among patients with high normal BP compared to subjects with normal BP (all P&amp;lt;0.01). In contrast to the monotonic increases in PWV and AIx by BP and pack-years smoking history, carotid IMT was generally similar among BP groups on the basis of cumulative exposure category. This finding may indicate a plateau in subclinical atherosclerotic burden over cumulative tobacco exposure for all BP categories. Conclusion Tobacco cumulative exposure adversely modify the effect of BP on arterial stiffness. Given that most adults who smoke start before the age 18 years, efforts to promote smoking cessation should continue to target younger adults with high BP.BP, tobacco exposure-vascular changes

Effects of fluorine and phosphorus-based flame retardants addition on the lower flammability limit of dimethyl carbonate

This study initially examines the alteration pattern of the lower flammable limit (LFL) of dimethyl carbonate (DMC), a typical electrolyte component in lithium batteries, under the influence of inhibitors, namely di(2,2,2trifluoroethyl) carbonate (DtFEC), perfluorohexanone (C6F12O), and trimethylphosphate (TMP), through experimental investigation. Additionally, the critical inhibitory concentration required for complete inhibition is investigated. Subsequently, numerical simulations and chemical kinetic path analyses reveal how these inhibitors control combustion. Results show that C6F12O and DtFEC initially decrease and then increase the LFL of DMC, while TMP causes a monotonic increase. This is due to the competition between reaction-thermal and reaction-radical effects. Reaction kinetic analysis reveal that when small amounts of C6F12O and DtFEC are added, the fluorine-containing components decomposed by the reaction undergo oxidation, thereby promoting combustion. However, with increased amounts, these components combine with H and OH radicals to form stable substances like HF, inhibiting the combustion process. In the case of TMP, the phosphorus-containing intermediate components produced by cleavage catalyze the recombination of H and OH radicals, thereby inhibiting DMC combustion. The research findings offer a theoretical foundation for the development of safer lithium batteries and provide crucial data references for enhancing battery safety and prevention measures.

Developmental Thermal Reaction Norms of Leatherback Marine Turtles at Nesting Beaches.

Accurate scientific information is critical for undertaking appropriate conservation and management practices for imperiled species. One source of concern is that research findings might vary for non-biological reasons, including experimental design and analytical methods. To illustrate, we provide detailed modern analysis of reproductive data for leatherback turtles (Dermochelys coriacea). This species exhibits significant fluctuations in nesting densities across different regions, possibly driven by local rather than global factors. Key factors influencing these changes include hatching success and sex determination, both sensitive to incubation temperatures (e.g., lower temperatures yield more males, higher temperatures yield females). This study updates the understanding of temperature-dependent sex determination (TSD) in this species using Bayesian statistics. Growth rate data from the West Pacific and Northwest Atlantic populations show a similar, monotone increase with temperature, affirming the reliability of the models used. The analysis of TSD patterns indicates that observed differences are more likely due to study methodologies and clutch-specific factors rather than regional differences. These findings challenge previous assumptions, showing that leatherback TSD does not conform to a simple on/off pattern but is influenced by multiple, interacting environmental factors. Population dynamics models must account for these complexities, recognizing that both sex ratios and hatching success are critical to understand the rapid changes observed in some leatherback populations.

The Milky Way atlas for linear filaments – II. Clump rotation versus filament orientation

ABSTRACT Dense clumps distributed along filaments are the immediate medium for star formation. Kinematic properties of the clumps, such as velocity gradient and angular momentum, combined with filament orientation, provide important clues to the formation mechanism of filament-clump configurations and the role of filaments in star formation. By cross-matching the Milky Way atlas for linear filaments and the structure, excitation and dynamics of the inner Galactic interstellar medium (SEDIGISM) $^{13}$CO (2-1) data, we aim to derive the velocity gradient and its direction, the specific angular momentum ($J/M$), and the ratio ($\beta$) between the rotational energy and gravitational energy of clumps, as well as to investigate the alignment between clump rotation and filament orientation. We found a monotonic increase in $J/M$ as a function of clump size (R), following a power-law relation $J/M~\propto ~R^{1.5\pm 0.2}$. The ratio $\beta$ ranges from 1.1 $\times$ 10$^{-5}$ to 0.1, with a median value 1.0 $\times$ 10$^{-3}$, suggesting that clump rotation provides insignificant support against gravitational collapse. The distribution of the angle between clump rotation and natal filament orientation is random, indicating that the clumps’ rotational axes have no discernible correlation with the orientation of their hosting filaments. Counting only the most massive clump in each filament also finds no alignment between clump rotation and filament orientation.

Understanding AFM-IR Signal Dependence on Sample Thickness and Laser Excitation: Experimental and Theoretical Insights.

Photothermal induced resonance (PTIR), also known as atomic force microscopy-infrared (AFM-IR), enables nanoscale IR absorption spectroscopy by transducing the local photothermal expansion and contraction of a sample with the tip of an atomic force microscope. PTIR spectra enable material identification at the nanoscale and can measure sample composition at depths >1 μm. However, implementation of quantitative, multivariate, nanoscale IR analysis requires an improved understanding of PTIR signal transduction and of the intensity dependence on sample characteristics and measurement parameters. Here, PTIR spectra measured on three-dimensional printed conical structures up to 2.5 μm tall elucidate the signal dependence on sample thickness for different IR laser repetition rates and pulse lengths. Additionally, we develop a model linking sample thermal expansion dynamics to cantilever excitation amplitudes that includes samples that do not fully thermalize between consecutive pulses. Remarkable qualitative agreement between experiments and theory demonstrates a monotonic increase in the PTIR signal intensity with thickness, with decreasing sensitivities at higher repetition rates, while signal intensity is nearly unaffected by laser pulse length. Although we observe slight deviations from linearity over the entire 2.5 μm thickness range, the signal's approximate linearity for bands of sample thicknesses up to ≈500 nm suggests that samples with comparably low topographic variations are most amenable to quantitative analysis. Importantly, we measure absorptive undistorted profiles in PTIR spectra for strongly absorbing modes, up to ≈1650 nm, and >2500 nm for other modes. These insights are foundational toward quantitative nanoscale PTIR analyses and material identification, furthering their impact across many applications.

Phonon-limited mobility for electrons and holes in highly-strained silicon

Strain engineering is a widely used technique for enhancing the mobility of charge carriers in semiconductors, but its effect is not fully understood. In this work, we perform first-principles calculations to explore the variations of the mobility of electrons and holes in silicon upon deformation by uniaxial strain up to 2% in the [100] crystal direction. We compute the π11 and π12 electron piezoresistances based on the low-strain change of resistivity with temperature in the range 200 K to 400 K, in excellent agreement with experiment. We also predict them for holes which were only measured at room temperature. Remarkably, for electrons in the transverse direction, we predict a minimum room-temperature mobility about 1200 cm2 V−1 s−1 at 0.3% uniaxial tensile strain while we observe a monotonous increase of the longitudinal transport, reaching a value of 2200 cm2 V−1 s−1 at high strain. We confirm these findings experimentally using four-point bending measurements, establishing the reliability of our first-principles calculations. For holes, we find that the transport is almost unaffected by strain up to 0.3% uniaxial tensile strain and then rises significantly, more than doubling at 2% strain. Our findings open new perspectives to boost the mobility by applying a stress in the [100] direction. This is particularly interesting for holes for which shear strain was thought for a long time to be the only way to enhance the mobility.

Paternal age, de novo mutations, and offspring health? New directions for an ageing problem.

This Directions article examines the mechanisms by which a father's age impacts the health and wellbeing of his children. Such impacts are significant and include adverse birth outcomes, dominant genetic conditions, neuropsychiatric disorders, and a variety of congenital developmental defects. As well as age, a wide variety of environmental and lifestyle factors are also known to impact offspring health via changes mediated by the male germ line. This picture of a dynamic germ line responsive to a wide range of intrinsic and extrinsic factors contrasts with the results of trio studies indicating that the incidence of mutations in the male germ line is low and exhibits a linear, monotonic increase with paternal age (∼two new mutations per year). While the traditional explanation for this pattern of mutation has been the metronomic plod of replication errors, an alternative model pivots around the 'faulty male' hypothesis. According to this concept, the genetic integrity of the male germ line can be dynamically impacted by age and a variety of other factors, and it is the aberrant repair of such damage that drives mutagenesis. Fortunately, DNA proofreading during spermatogenesis is extremely effective and these mutant cells are either repaired or deleted by apoptosis/ferroptosis. There appear to be only two mechanisms by which mutant germ cells can escape this apoptotic fate: (i) if the germ cells acquire a mutation that by enhancing proliferation or suppressing apoptosis, permits their clonal expansion (selfish selection hypothesis) or (ii) if a genetically damaged spermatozoon manages to fertilize an oocyte, which then fixes the damage as a mutation (or epimutation) as a result of defective DNA repair (oocyte collusion hypothesis). Exploration of these proposed mechanisms should not only help us better understand the aetiology of paternal age effects but also inform potential avenues of remediation.

Thermodynamics and kinetics of evaporation and thermal decomposition of 1-ethyl- and 1-butyl-3-methylimidazolium methanesulfonate ionic liquids: Experimental and computational study

Knudsen cell mass spectrometry was used to study the evaporation of two ionic liquids, 1-ethyl-3-methylimidazolium methanesulfonate ([EtMIm][MS], MS = CH3SO3) and 1-butyl-3-methylimidazolium methanesulfonate ([BuMIm][MS]), accompanied by thermal decomposition (thermolysis). The independent occurrence of evaporation and thermolysis reactions made it possible to determine their thermodynamic and kinetic characteristics under identical experimental conditions. The saturated vapor pressures were measured and the standard enthalpies of vaporization of [EtMIm][MS](l) and [BuMIm][MS](l) were obtained. The standard thermodynamic functions of formation in the liquid and gaseous states at 298.15 K were estimated from the available experimental data and the results of quantum chemical calculations. The gaseous decomposition products of ionic liquids were identified and the pressures of the thermolysis products of [EtMIm][MS](l) were determined. According to the experimental data and quantum chemical calculations, the thermolysis of [EtMIm][MS](l) occurs through heterogeneous reactions far from the equilibrium state. The kinetics of the reactions is described in two ways. When the degree of sample conversion is used as a variable, the constant reaction rates at the initial stage of thermolysis correspond to a pseudo-zero order reaction with a monotonic increase in the degree of conversion. In the proposed alternative approach, the reaction rates are estimated from the fluxes of thermolysis products and are expressed in terms of ionic liquid concentration.

Effect of charge inversion on the electrokinetic transport of nanoconfined multivalent ionic solutions

Understanding the effects of phenomena occurring at electrically charged interfaces, such as charge inversion (CI), is crucial for enabling electroosmosis as an efficient transport mechanism in nanodevices. Here, we employ molecular dynamics (MD) simulations to systematically analyze the effect of CI on the electrokinetic transport of multivalent ionic solutions confined in amorphous silica nanochannels. We employ mixtures of monovalent and multivalent counterions while fixing the total ionic concentration to establish correlations between observed phenomena and the amount of multivalent ionic species in the electrolyte solution. The results show that the development of CI is related to a decrease in the mobility of the fluid layers adjacent to the charged surface. In addition, we observe that interfacial overcharging disrupts the water molecular orientation in the fluid layers adjacent to the channel walls. From the non-equilibrium MD simulations of electro-osmotic flow, we disclose the influence of phenomena related to the presence of CI. In particular, flow reversal occurs in scenarios involving CI due to increased local viscosity and a higher concentration of coions within the hydrodynamically mobile and electrokinetically active region of the charged interface. We also find that the magnitude of the wall zeta (ζ) potential displays a monotonic increase with the development of CI in the system. Moreover, we explain why positioning the wall ζ potential at an imaginary (slip) plane, which separates the hydrodynamically mobile and immobile fluid, is misleading.

New Analytical Solutions for Constant Rate Pumping in Two‐Zone Double‐Porosity Confined Aquifer: A New Source Term Reflecting Effects of Well Skin and Wellbore Storage

AbstractThis study develops two new analytical models for constant rate pumping at a partially penetrating well in a double‐porosity confined aquifer, considering skin and formation zones. One model, referred to as the two‐zone model, incorporates a flow equation to depict the flow in the skin around the well. The other model, named the source‐term model, introduces a novel source term at the outer rim of the skin to reflect the effects of both the skin and wellbore storage. The analytical solutions for both models are derived by the Laplace transform and finite Fourier cosine transform. Additionally, a finite element solution for the source‐term model is presented. Results suggest the source‐term model is suitable to most wells when the width of the skin is less than 1 m and the radius of influence exceeds the outer rim of the skin. Temporal drawdown distribution for a negative skin exhibits a triple‐humped shape with two flat stages, while that for a positive skin shows monotonous increase. The source‐term model enables orthogonal 5 × 5 nodes for finite element approximation to discretize a well and its adjacent skin. The finite element solution aligns with early drawdown data measured at an observation well under the effects observed in two field constant rate pumping tests. In conclusion, this study introduces a novel approach to modeling two‐zone flow, which may find practical utility in field applications.

The species diversity and phylogenetic structure patterns of desert plant communities in the Turpan-Hami region, Xinjiang

Desert plant communities play a crucial role in enhancing desert ecosystem productivity and stability but are highly susceptible to environmental changes owing to their limited resilience and resistance to disturbances, making it essential to understand the factors influencing their diversity patterns and community structure, particularly under the threat of climate change and intensifying droughts. This study focused on the Turpan-Hami desert region, a typical desert ecosystem in which diversity patterns and community structures remain unclear. We established 101 sampling sites ranging from elevations of -134 to 2056m and recorded community information, including species composition, height, coverage, and density, using the sample plot method. The diversity patterns were analyzed using regression analysis, and the phylogenetic structure was assessed. Additionally, Canonical Correspondence Analysis, Mantel tests, and General Linear Models were used to identify the key factors affecting community structure. Our results demonstrated that the species richness and phylogenetic diversity of plant communities exhibited a monotonic increase with elevation, and the phylogenetic structure exhibited low clustering and high dispersion along the elevational gradient. The annual mean temperature emerged as the most significant factor influencing diversity patterns, with soil nutrients, such as total potassium and available phosphorus, also affecting the spatial distribution of diversity. Notably, no significant correlations were found between community phylogenetic structure and abiotic factors, highlighting the complex interactions that drive diversity in the Turpan-Hami region. This study offers valuable insights into the mechanisms shaping desert plant community diversity and is essential for biodiversity conservation efforts in fragile desert ecosystems amid climate change.

Are Parameterized Entrainment Rates as Scale‐Dependent as Those Estimated From Cloud Resolving Model Simulations?

AbstractEntrainment rates at varying horizontal grid spacing were diagnosed and analyzed based on Large Eddy Model (LES) and Cloud Resolving Model (CRM) simulations of shallow and deep convection. Results show the estimated entrainment rates increase with increasing resolution, and the growth rate is roughly power‐law related to resolution. However, all commonly used parameterizations except for the buoyancy sorting scheme fail to reproduce the monotonic increase of entrainment with resolution, but rather a slight decrease instead. For these schemes, it is suggested the power‐law fitting formula derived from LES/CRM simulations can be used as a scaling function for high‐resolution entrainment correction. Preliminary tests show that the application of entrainment scaling largely reduces the parcel buoyancy and thus the convective available potential energy, favoring the reduction of parameterized convection at high resolution.

Bimetallic AgCo Nanoparticle Synthesis via Combinatorial Nanosecond Laser‐Induced Dewetting of Thin Films

Herein, a combinatorial approach is developed to conduct high‐throughput studies on the nanosecond pulsed laser‐induced dewetting phenomenon of bilayer Ag–Co metallic thin films. Laser irradiation results in the spontaneous rupture of these films in nanosecond timescale, forming bimetallic nanoparticles (NPs) through intermediate stages of hole formation and bicontinuous nanostructures. This approach utilizes bilayer thin films with thickness gradients in both Ag and Co layers (referred to as bigradient samples) while maintaining a constant overall thickness. The laser irradiation on such bigradient bilayer films facilitates control on Ag and Co ratio in the thin films, thus enabling material libraries of Ag–Co NPs covering a large compositional variation. The evolution of NPs with a correlation between NP diameter and interparticle spacings is further studied. The study reveals monotonic increase in NP size and interparticle spacing in Co/Ag bilayer arrangement, while an increase and subsequent decrease in the NP size is observed at 50% Ag in Ag/Co bigradient films. A transition from intermediate stage hole formation to bicontinuous nanostructures with changing composition is also observed. These changes in intermediate stage morphologies and dewetting mechanism are attributed to variation of the free energy of the bilayer system dominated by intermolecular interaction forces.

A PDMS/Silicon Adhesion Control Method at Millimeter‐Scale Based on Microvibration

Switchable surface adhesion at a small scale is crucial for robot end‐effector design, allowing the manipulation of small objects such as semiconductors, optical lenses, and precision mechanical parts. In this work, a detailed characterization of a millimeter‐scale (1–5 mm) adhesion modulation method is performed, demonstrating its effectiveness for switching adhesion on small, lightweight objects with smooth surfaces. This modulation phenomenon arises from the viscoelastic behavior when PDMS interacts with a rigid surface and is controlled via microvibration. A maximum apparent adhesion enhancement of 2400% and a reduction of 50% are achieved with a 1 mm‐diameter PDMS hemisphere vibrating at a 30 μm amplitude and a 700 Hz frequency. The effects of different parameters, including size, actuation amplitude/frequency, surface roughness, and material properties, on adhesion performance are carefully measured and analyzed. A monotonic increase in maximum adhesion is observed with increased device size and surface smoothness, while nonlinear relationships of other factors are generalized with a numerical model. A long working lifespan and high endurance are also observed during the characterization. This work serves as a practical reference for the further design of small‐scale soft grippers, highlighting its continuous, large modulation range, simple structure, and flexible control.

Stress-dependent Magnetization Processes in Co based Amorphous Microwires

Soft magnetic materials with high magnetic susceptibility are sensitive to changing magnetic fields and generate electrical voltage signals whose spectra contain higher harmonics. Magnetic susceptibility and saturation field are largely determined by magnetoelastic interactions in amorphous ferromagnets, respectively, the amplitudes of higher harmonics should depend on external mechanical stresses. In this work, we study the processes of magnetization reversal in amorphous microwires of two compositions: Co71Fe5B11Si10Cr3 and Co66.6Fe4.28B11.51Si14.48Ni1.44Mo1.69 under the action of external tensile stresses. For the first composition, mechanical stresses exceeding a certain limit (more than 350 MPa) lead to the transformation of the magnetic hysteresis from a bistable type to an inclined one. In this case, a sharp change of the harmonic spectrum is observed. In microwires of the second composition with an initially inclined loop, external stresses cause a monotonous increase in the slope of the hysteresis loop (a decrease in susceptibility). In this case, the amplitudes of higher harmonics change significantly at low stresses, less than 100 MPa. The results were obtained by remagnetization of microwire samples using a system of flat coils, which demonstrates the potential of using these materials as wireless sensors of mechanical stresses with remote reading.