Search

Flexoelectricity, a universal electromechanical coupling effect present in all dielectric materials, has garnered significant theoretical and experimental interest in recent years, particularly in ferroelectric perovskite oxides. However, nitride-based materials have received considerably less attention. In this Letter, we report the observation of direct flexoelectric effect in plasma-enhanced chemical vapor deposition silicon nitride thin film with a thickness of 200 nm. From three-point bending tests, we determined the effective flexoelectric coefficient of Si3N4 to be 1.64 ± 0.22 nC / m. Additionally, the measured flexoelectric-induced voltages are consistent with finite element computational models. This observation of the flexoelectric coupling effect could contribute to the development of silicon nitride-based micro-scale devices. [ABSTRACT FROM AUTHOR]

Primarily due to the scarce direct field evidence along a same fault, understanding the relationship between the pre‐existing off‐fault damage and coseismic slip distribution remains challenging. This study offers the first field‐based quantitative assessments of fault damage zones along the surface rupture generated by the 2008 Mw 7.9 Wenchuan earthquake in China over eight profiles with 254 outcrops. The width and mean tectonic fracture intensity of the damage zones exhibit pronounced variations along the fault strike. We introduce the damage index as a proxy to quantify the extent of pre‐existing damage. We find a statistically significant anti‐correlation between the damage index and coseismic on‐fault slip. We thus infer that pre‐existing off‐fault damage plays a significant role in dissipating rupture energy, thereby reducing coseismic on‐fault slip. This study provides a natural case for linking the long‐term fault zone evolution and the short‐term earthquake rupture dynamics. Plain Language Summary: Large earthquakes can cause significant surface ruptures, which often spatially coincide with severe seismic disasters. Therefore, understanding where large coseismic slip occurs is crucial for mitigating hazards. Off‐fault damage is an indispensable component of fault zone structure, and its impact on seismic behavior has been widely emphasized. However, unlike coseismic off‐fault damage, pre‐existing off‐fault damage cannot be easily observed through remote sensing. Investigating pre‐existing off‐fault damage and its influence on coseismic on‐fault slip is challenging yet essential for comprehending earthquake processes. To address this gap, we conducted a detailed field investigation along the surface rupture of the 2008 Mw 7.9 Wenchuan earthquake, China, characterizing the along‐strike distribution of fault damage zone. Comparing the extent of pre‐existing fault damage with the coseismic on‐fault slip profiles revealed an inverse relationship: a higher extent of pre‐existing off‐fault damage leads to smaller coseismic on‐fault slip. We propose that the dissipation of seismic energy occurring within densely fractured damage zones provides a possible explanation for this phenomenon. Our findings establish critical connections between long‐term fault zone evolution and short‐term earthquake rupture dynamics. From a disaster reduction perspective, identifying off‐fault damage along major active faults before future earthquakes may enhance fault displacement hazard assessments. Key Points: Detailed measurements of the pre‐existing off‐fault damage along the surface ruptures associated with the 2008 Mw 7.9 Wenchuan EarthquakeWe provide compelling evidence that a higher extent of pre‐existing off‐fault damage leads to smaller coseismic on‐fault slipWe discuss the seismic energy dissipation hypothesis for the mechanism of pre‐existing off‐fault damage impeding coseismic on‐fault slip [ABSTRACT FROM AUTHOR]

Intense attosecond light sources are required for investigating ultrafast electron dynamics, such as that in molecules and atoms, etc. However, so far the achievable photon energy remains at the keV level, thereby limiting their range of applications. For instance, probing intranuclear dynamics requires photon energies in the gamma-ray regime. We propose here a scheme for generating intense attosecond gamma-ray pulses by irradiating a thin solid-density foil with intense vortex laser. In the interaction, the laser driven-foil electrons are differentially accelerated within a quarter-wave field and become highly bunched. Three-dimensional particle-in-cell simulations show that they can efficiently (with ∼ 30 % energy conversion efficiency) radiate ultrashort ( ∼ 400 as), high-flux ( > 10 10 photons per pulse), and ultrabrilliant (up to 1027 photons s−1 mm−2 mrad−2 per 0.1% BW at 1 MeV photon energy) gamma rays. With an x-ray driving laser, the scheme can even produce isolated bright sub-attosecond gamma-ray pulses that are useful for time-resolved nuclear spectroscopy and many other areas. [ABSTRACT FROM AUTHOR]

Differentiable rasterization changes the standard formulation of primitive rasterization — by enabling gradient flow from a pixel to its underlying triangles — using distribution functions in different stages of rendering, creating a "soft" version of the original rasterizer. However, choosing the optimal softening function that ensures the best performance and convergence to a desired goal requires trial and error. Previous work has analyzed and compared several combinations of softening. In this work, we take it a step further and, instead of making a combinatorial choice of softening operations, parameterize the continuous space of common softening operations. We study meta‐learning tunable softness functions over a set of inverse rendering tasks (2D and 3D shape, pose and occlusion) so it generalizes to new and unseen differentiable rendering tasks with optimal softness. [ABSTRACT FROM AUTHOR]

In the process of carrying out the installation of large flue, because the thickness of the flue is thin, it is easy to deform when hoisting with wire rope, and too much deformation will affect the subsequent use of the flue, resulting in waste, so in order to reduce the deformation of the flue, the existing conditions are utilized, and the bracket is added inside the flue to play the role of support, and the deformation of the flue is reduced. Using 3D modeling and numerical simulation software, the flue structure before and after adding supports was modeled and numerically analyzed, and the two simulation results were compared, and the deformation of the flue after adding supports was analyzed to be relatively obvious under the action of hoisting. [ABSTRACT FROM AUTHOR]

Lifting is to use lifting equipment to lift components and install them to the designated position. On the main structure, lifting equipment is used to transport the flue and transport the sectional flue to the designated position. Certain deformation will occur during the lifting operation of the flue due to its force condition, but it is not known whether it is elastic deformation or plastic deformation. Therefore, this paper analyzes the stress and strain of the flue during operation by finite element method, and observes and analyzes the influence of plastic deformation on the whole flue. [ABSTRACT FROM AUTHOR]

G213.0−0.6 is a faint extended source situated in the anticentre region of the Galactic plane. It has been classified as a shell-type supernova remnant (SNR) based on its shell-like morphology, steep radio continuum spectrum, and high ratio of [S  ii ]/Hα. With new optical emission line data of Hα, [S  ii ], and [N  ii ] recently observed by the Large Sky Area Multi-Object Fiber Spectroscopic Telescope, the ratios of [S  ii ]/Hα and [N  ii ]/Hα are re-assessed. The lower values than those previously reported put G213.0−0.6 around the borderline of SNR-H  ii region classification. We decompose the steep-spectrum synchrotron and the flat-spectrum thermal free-free emission in the area of G213.0−0.6 with multi-frequency radio continuum data. G213.0−0.6 is found to show a flat spectrum, in conflict with the properties of a shell-type SNR. Such a result is further confirmed by TT-plots made between the 863-MHz, 1.4-GHz, and 4.8-GHz data. Combining the evidence extracted in both optical and radio continuum, we argue that G213.0−0.6 is possibly not an SNR, but an H  ii region instead. The V LSR pertaining to the Hα filaments places G213.0−0.6 approximately 1.9 kpc away in the Perseus Arm. [ABSTRACT FROM AUTHOR]

Cavitation erosion and corrosion-cavitation synergism behavior of CoCrFeNiMnTix (x = 0.5, 1.0, 1.5, 2.0 in atomic ratio) high entropy alloy coatings were analyzed. The sample with x = 1.0 showed the best cavitation erosion resistance due to the low weight loss and the maximum erosion rate. The protective ability of passivation film also displayed an increased first and then decreased tendency with the increase of Ti content as indicated by corrosion-cavitation synergism determined by open circuit potential method under cavitation erosion and quiescence condition. The sample with x = 1.0 displayed good re-passivation ability of passivation film according to open circuit potential behavior under cavitation erosion and quiescence condition. In general, the sample with x = 1.0 exhibited the highest cavitation erosion, the best self-repairing ability of the passivation film under the corrosion-cavitation synergism condition, which showed a great potential in the application of ocean engineering field as fluid-passing parts. [ABSTRACT FROM AUTHOR]

Hysterectomy is the most common gynaecological surgery, performed mainly for benign uterine pathologies in women. Studies have suggested that hysterectomy is associated with osteoarthritis (OA); however, the association remains controversial. This study aimed to investigate the association between hysterectomy and the risk of OA. We performed a population-based nested case–control study using the National Health Insurance programme database from 2000 to 2016 in Taiwan. All medical conditions for each case and control were categorized using the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) and ICD-10. A multiple conditional logistic regression model was applied to analyse the adjusted odds ratio (aOR) and 95% confidence interval (CI) for the association between hysterectomy and OA. Our analyses included 16 592 patients with OA and 66 368 matched controls. After adjustment for possible confounders, hysterectomy had a significant association with OA (aOR = 1.19, 95% CI = 1.09–1.30), especially knee OA (aOR = 1.25, 95% CI = 1.13–1.38). Furthermore, women who received oestrogen therapy (ET) alone and patients who underwent hysterectomy without ET showed a greater risk of OA development compared to women who did not receive ET (aOR = 1.14, 95% CI = 1.07–1.23, and aOR = 1.19, 95% CI = 1.08–1.31, respectively). Our findings indicate that hysterectomy is associated with OA, especially knee OA. We also found that women who received ET alone and patients who underwent hysterectomy without ET had an increased risk of OA. [ABSTRACT FROM AUTHOR]

According to the practical engineering application, three-dimensional modeling of electric hoist and I-beam track is carried out, and the model is simplified to determine the electric hoist load, roller acceleration and speed, and the Abaqus software is used to simulate, analyze the simulation results, observe the actual maximum load under the track stress and strain to meet the requirements, calculate the allowable stress, Observe whether it exceeds the allowable stress and whether plastic deformation occurs. If the numerical simulation results of stress and strain are within the safety requirements, the project can be implemented. [ABSTRACT FROM AUTHOR]

Ab initio calculation and Boltzmann transport equation have been integrated to find the fundamental influences of trigonal transformation on band structures and thermoelectric performances of antimony. Calculations reveal that antimony could keep its semimetal feature within the c/a range of 2.27–2.82 and that two transitions of band structures of antimony under trigonal transformation are revealed for the first time. Moreover, trigonal transformation has a significant influence on the thermoelectric performances of antimony, and the Seebeck coefficients for the electrons and holes of antimony reach the peaks at the c/a points of 2.72 and 2.57, respectively. The calculated results are in good agreement with the values from experiments in the literature and could deepen the comprehension of the intrinsic relationship between trigonal transformation, band structures, and Seebeck coefficients of antimony. [ABSTRACT FROM AUTHOR]

During the continuous casting process, the residual oxygen in the tundish can be significantly reduced by argon blowing from the tundish cover (ABTC). As a result, the effect of protective casting can be obviously improved, which helps to reduce the reoxidation of molten steel in the tundish. In the present work, numerical models for the ABTC of a six-strand continuous casting machine were established and verified by the measured oxygen mass fraction in the tundish during the ABTC. The results indicate that the best conditions for ABTC are to install the argon pipes on either side of the tundish cover holes, seal the baking holes, and keep the stopper rod holes open. The argon flow rate should be =120 m³/h during the period of empty tundish and =60 m³/h during the period of normal casting. Based on the calculation results, industrial testsof ABTC were carried out. The results indicated that the increased nitrogen content in steel(Δw[N]) decreased by 21.5% from 8.78×10-6 to 6.89×10-6, from the end of RH to tundish, and the amount of inclusions except for MnS in bloom (scanned size: 8 mm × 8 mm) decreased by 21.3% from 13.43 to 10.57, and the average size of inclusions decreased by 19.0% from 9.27 µm to 7.51 µm. [ABSTRACT FROM AUTHOR]

When the stress wave propagates through rock mass with different wave impedances on two sides. It shows different reflection tendencies compared with the traditional study of wave propagation. A characteristic line method combined with the displacement discontinuity model was proposed to study the wave reflection through such rock mass. The effects of incident frequency, joint stiffness and wave impedance ratio on the reflection coefficient were discussed. The results show that the reflection coefficient increases as the wave impedance ratio increases. The traditional study of wave reflection can be regarded as a special case of the present study when the wave impedance ratio equals 1.0. Moreover, the difference of reflection coefficients decreases as the incident frequency increases, while increases as the joint stiffness and wave impedance ratio increase when the wave impedance ratio is larger than 1.0. When the wave impedance ratio is smaller than 1.0, the difference of reflection coefficients increases firstly and then decreases with the increase of incident frequency and joint stiffness, while decreases as the wave impedance ratio increases. For the cases of large incident frequency or small joint stiffness, the effects of wave impedance ratio can be neglected for the approximated prediction of wave reflection. [ABSTRACT FROM AUTHOR]

This paper investigates the mechanical behaviour of a bi-layered panel containing many particles in one layer and demonstrates the size effect of particles on the deflection. The inclusion-based boundary element method (iBEM) considers a fully bounded bi-material system. The fundamental solution for two-jointed half spaces has been used to acquire elastic fields resulting from source fields over inclusions and boundary-avoiding multi-domain integral along the interface. Eshelby's equivalent inclusion method is used to simulate the material mismatch with a continuously distributed eigenstrain field over the equivalent inclusion. The eigenstrain is expanded at the centre of the inclusion, which provides tailorable accuracy based on the order of the polynomial of the eigenstrain. As a single-domain approach, the iBEM algorithm is particularly suitable for conducting virtual experiments of bi-layered composites with many defects or reinforcements for both local analysis and homogenization purposes. The maximum deflection of solar panel coupons is studied under uniform vertical loading merged with inhomogeneities of different material properties, dimensions and volume fractions. The size of defects or reinforcements plays a significant role in the deflection of the panel, even with the same volume fraction, as the substrate is relatively thin. [ABSTRACT FROM AUTHOR]

Short fiber–reinforced composites (SFRCs) are high-performance engineering materials for lightweight structural applications in the automotive and electronics industries. Typically, SFRC structures are manufactured by injection molding, which induces heterogeneous microstructures, and the resulting nonlinear anisotropic behaviors are challenging to predict by conventional micromechanical analyses. In this work, we present a machine learning–based multiscale method by integrating injection molding–induced microstructures, material homogenization, and deep material network (DMN) in the finite-element simulation software LS-DYNA for structural analysis of SFRC. DMN is a physics-embedded machine learning model that learns the microscale material morphologies hidden in representative volume elements of composites through offline training. By coupling DMN with finite elements, we have developed a highly accurate and efficient data-driven approach that predicts nonlinear behaviors of composite materials and structures at a computational speed orders of magnitude faster than the high-fidelity direct numerical simulation. To model industrial-scale SFRC products, transfer learning is utilized to generate a unified DMN database, which effectively captures the effects of injection molding–induced fiber orientations and volume fractions on the overall composite properties. Numerical examples are presented to demonstrate the promising performance of this LS-DYNA machine learning–based multiscale method for SFRC modeling. [ABSTRACT FROM AUTHOR]

In order to explore the effect of exogenous 24-epibrassinolide (EBR, 0.1 µM) application on photosynthetic parameters in response to different light intensities and CO2 concentrations in maize seedlings under NaCl stress (180 mM), this study investigated the light response curve, CO2 response curve, and diurnal variation of photosynthesis of maize seedlings under NaCl stress. Maize cv. Jinlai 318 was used as the material, and the leaves were sprayed with 0.1 µM EBR. Net photosynthetic rate (PN), stomatal conductance (gs), intercellular CO2 concentration (Ci), and transpiration rate (E) were determined. The results showed that the light response curve, CO2 response curve, and diurnal variation trend under the four treatments (180 mM NaCl, 0.1 µM EBR, 180 mM NaCl with 0.1 µM EBR, pure water) were similar. The light saturation point of the leaves under NaCl stress was the lowest (about 1 031 mol m-2 s-1), and that in the control group (without stress) was the highest (about 1 344 mol m-2 s-1). When the light saturation point was reached (1 030 -1 350 mol m-2 s-1), the maximum PN under NaCl stress was the lowest (about 15.15 µmol m-2 s-1), while that under EBR treatment, it was the highest (about 19.86 µmol m-2 s-1). NaCl stress significantly reduced chlorophyll a, chlorophyll b, and carotenoid content and chlorophyll a/b ratio, while chlorophyll content significantly increased after EBR treatment. These results showed that exogenous EBR could effectively alleviate the damage to maize seedlings under NaCl stress, delay the light saturation phenomenon, and improve the photosynthetic capacity of maize. [ABSTRACT FROM AUTHOR]

The compound of fucosterol (C29H48O), an active phytosterol present in many edible marine algae, has been characterized by X-ray diffraction and extensive nuclear magnetic resonance spectroscopy. Its stereo configuration is (E,E)-24-ethylcholest-5,24(28)-dien-3β-ol. It crystallizes in the monoclinic system and sp. gr. P21. There are four C29H48O molecules and two CH3OH molecules in the asymmetric part of the unit cell. They are stacked into a special laminated structure due to hydrogen bonds and Van der Waals forces. Crystallographic data are reported for the first time. [ABSTRACT FROM AUTHOR]

In order to overcome the low recognition rate of road traffic status and low evaluation accuracy in road traffic safety assessment in different time periods, a road traffic safety assessment method in different time periods based on deep neural network was proposed. Firstly, build a road traffic safety assessment index system at different time periods. Then, combined with the bat algorithm, the support vector machine is improved to identify the road traffic status in different time periods. Finally, a deep neural network is used to construct a probability function with the identified traffic state as input, and output the safety assessment result, so as to realize the road traffic safety assessment result in different time periods. The experimental results show that the minimum recognition rate of road traffic state in different periods is 96.31%, the average recognition time is 0.59s, and the minimum evaluation accuracy rate is 96%. It has the advantages of rapid and accurate recognition of road traffic state in different periods and high evaluation accuracy. [ABSTRACT FROM AUTHOR]

Basing on the consistent couple stress theory (CCST), we develop a unified size-dependent shear deformation theory to analyze the free vibration characteristics of simply supported, porous functionally graded (FG) piezoelectric microplates which resting on the Winkler-Pasternak foundation are subjected to electric voltages. Various CCST-based shear deformation theories can be reproduced by incorporating their corresponding shape functions, which characterize the through-thickness distributions of the shear deformations, into the unified size-dependent theory. The reproduced CCST-based plate theories include the classical plate theory (CPT), the first-order shear deformation plate theory (SDPT), Reddy's refined SDPT, the sinusoidal SDPT, the exponential SDPT, and the hyperbolic SDPT. The unified size-dependent theory is subsequently used to determine the natural frequencies of simply supported, porous FG piezoelectric microplates and their corresponding vibration mode shapes. The effects of the material length scale parameter, the length-to-thickness ratio, the material-property gradient index, different values of the applied voltages, the porosity parameter, different porosity distribution patterns, the Winkler spring coefficient, and the shear modulus of the surrounding medium on the natural frequencies of the porous FG piezoelectric microplates are examined and appear to be significant. [ABSTRACT FROM AUTHOR]

For the most advanced multi-frame camera in the world, the shortest response time between two frames is no shorter than 1.5 ns. Thus, there is no effective way to diagnose the ultrafast sub-nanosecond dynamic of a microwave-driven plasma discharge in a single pulse. Different-length multi-sub-beam optical fibers, together with a spectrometer and an EMICCD camera, are proposed and designed to detect the nanosecond discharge spectra in a single pulse, like a real-time multi-frame spectral camera. This novel method could realize a time interval between two consecutive frames shorter than 0.1 ns by a length difference of 2 cm for sub-fibers, achieving the measurement of ultrafast plasma dynamics. Temporal evolution of electron density as well as energy of electrons and ions during nanosecond microwave discharge is further studied by de-convolving the Stark broadening and thermal Doppler broadening and by calculating the ratio of emission coefficients. [ABSTRACT FROM AUTHOR]

In this paper, a bicycle light-emitting diode (LED) headlamp is design for the purpose of meeting the regulation and removing the unwanted reflection of some specific parts. In addition to the optical design of the headlamp, a three-dimensional mask is designed to block the LED light source to remove the specific unwanted light on the front tyre of the bicycle and then reduce the glare effect to the rider. The experimental results show that the 3D mask can effectively eliminate 97.7% of the unwanted light on the wheel of the bicycle and keeps 98.6% of the original illuminance at the A point of the K-mark regulation. The proposed mask approach will be helpful to the design by using LED as a light source. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to investigate women's adherence patterns to pelvic floor muscle exercises (PFME), their associated factors and within-pattern changes.Methods: This was a secondary analysis using data collected from 647 women aged 55 years and older in the USA. Women were randomly assigned to either a 2-h class group or an equivalent content 20-min DVD group to receive PFME complemented with adherence enhancement strategies. Adherence was assessed at 3, 12 and 24 months using three self-reported items matching PFME parameters. The k-mean clustering and multinomial logistic regression were used to investigate adherence patterns and their associated factors, respectively. Descriptive statistics were used for within-pattern changes over time.Results: Four adherence patterns, A, B, C and D, were identified. Women who displayed optimal adherence to all three aforementioned items, i.e. adherence pattern A, constituted 49.1%, 38.2% and 37.2% of women at 3, 12 and 24 months, respectively. Women with income > US$100,000 were more likely to display adherence pattern A within 12 months. Of women who had adherence pattern A at 3 months, 63.9% and 49.2% continued in this pattern at 12 and 24 months.Conclusions: Fewer than half of women displayed adherence pattern A for 2 years. Early optimal adherence predicted women's subsequent optimal adherence. [ABSTRACT FROM AUTHOR]

Aim: To assess the predictive value of major adverse cardiac events (MACEs) in patients with acute myocardial infarction (AMI) by T2-mapping texture analysis (TA) of the myocardial remote zone.Materials and Methods: Data from 155 patients, who were diagnosed with AMI and were treated with primary percutaneous coronary intervention (PPCI), and 32 healthy controls who underwent cardiac magnetic resonance imaging (CMRI) were analysed retrospectively. T2-mapping TA of the myocardial remote zone was conducted accordingly. The patients were divided into two subgroups according to the occurrence of MACEs. The primary outcome was a composite of MACEs.Results: Among 155 patients, 32 (20.6%) patients suffered MACEs, and the most common event was non-sustained ventricular tachycardia (84.3%). Five independent texture features on T2-mapping were selected: Perc.50%, S(4,-4)AngScMom, S(1,1)InvDfMom, S(0,2)DifEntrp, and Horzl_LngREmph. Among them, the mean value of Horzl_LngREmph in the myocardial remote zone among all patients, MACEsnegative, and MACEs-positive was 21.64, 19.12, and 34.52, respectively. Horzl_LngREmph provided the highest area under the receiver operating characteristic (ROC) curve (AUC) value, which enabled two subgroups to be distinguished (AUC = 0.914, p<0.05). According to the results of the univariate analysis, combined with late gadolinium enhancement (LGE) extent and the presence of left ventricular hypertrophy, Horzl_LngREmph, was strongly associated with the occurrence of MACEs (p<0.05, hazard ratio: 1.64, 95% confidence interval: 1.10-4.51).Conclusion: Together with LGE extent, Horzl_LngREmph, a texture feature obtained from T2-mapping TA of the myocardial remote zone, could predict the occurrence of MACEs in AMI patients. [ABSTRACT FROM AUTHOR]

Molecular dynamics simulations were performed to characterize the ablation process induced by a picosecond infrared laser (PIRL) operating in the regime of desorption by impulsive vibrational excitation (DIVE) of a model peptide (lysozyme)/counter-ion system in aqueous solution. The simulations were performed for ablation under typical experimental conditions found within a time-of-flight mass spectrometer (TOF-MS), that is in vacuum with an applied electric field (E = ± 107 V/m), for up to 2 ns post-ablation and compared to the standard PIRL-DIVE ablation condition (E = 0 V/m). Further, a simulation of ablation under an extreme field condition (E = 1010 V/m) was performed for comparison to extend the effective dynamic range of the effect of the field on charge separation. The results show that the plume dynamics were retained under a typical TOF-MS condition within the first 1 ns of ablation. Efficient desorption was observed with more than 90% of water molecules interacting with lysozyme stripped off within 1 ns post-ablation. The processes of ablation and desolvation of analytes were shown to be independent of the applied electric field and thus decoupled from the ion separation process. Unlike under the extreme field conditions, the electric field inside a typical TOF-MS was shown to modify the ions' motion over a longer time and in a soft manner with no enhancement to fragmentation observed as compared to the standard PIRL-DIVE. The study indicates that the PIRL-DIVE ablation mechanism could be used as a new, intrinsically versatile, and highly sensitive ion source for quantitative mass spectrometry. [ABSTRACT FROM AUTHOR]

The incorporation of lower hybrid (LH) wave spectrum broadening in the poloidal wavenumber ( k θ ) space at the last close field surface (LCFS) is reported to lead to better agreement of the modeled LH wave current profile with the experimental results [Baek et al., Nucl. Fusion 61, 106034 (2021)]. To further understand its underlying mechanism and find the possible influence factors, effects of wave scattering caused by drift-wave type density fluctuation on the probability distribution of the LH wave polar refractive index ( N θ) at the LCFS are studied under density parameters in the scrape-off-layer. According to a scattering model [P. T. Bonoli and E. Ott, Phys Fluids 25(2), 359–375 (1982)], scattering probability and scattering angle distribution are two main factors that determine the degree of spectral broadening. Studies presented here show that the total scattering probability increases first and then decreases as the wave propagates toward a smaller normalized radius of poloidal magnetic flux (ρ). The degree of spectral broadening is found to depend on the density and density fluctuation together by changing the intensity and a proportion of the geometrical optics approximation term and the E × B drift term in the scattering model. Furthermore, the fluctuation correlation length can significantly modify the probability distribution of N θ at the LCFS, which is found to significantly change the LH wave current profile. [ABSTRACT FROM AUTHOR]

Stress-Induced Leakage Current (SILC) behavior during the dielectric degradation of ultra-porous SiOCH low-k materials was investigated. Under high voltage stress, SILC increases to a critical value before final hard breakdown. This SILC increase rate is mainly driven by the injected charges and is negligibly influenced by temperature and voltage. SILC is found to be transient and shows a t-1 relaxation behavior, where t is the storage time at low voltages. This t-1 transient behavior, described by the tunneling front model, is caused by both electron charging of neutral defects in the dielectric close to the cathode interface and discharging of donor defects close to the anode interface. These defects have a uniform density distribution within the probed depth range, which is confirmed by the observed flat band voltage shift results collected during the low voltage storage. By applying an additional discharging step after the low voltage storage, the trap energies and spatial distributions are derived. In a highly degraded low-k dielectric, the majority of defects have a trap depth between 3.4 eV and 3.6 eV and a density level of 1×1018 eV-1 cm-3. The relation between the defect density N and the total amount of the injected charges Q is measured to be sub-linear, N~Q0.45±0.07. The physical nature of these stress-induced defects is suggested to be caused by the degradation of the Si- O based skeleton in the low-k dielectric. [ABSTRACT FROM AUTHOR]

FeCoCr-50%Al coatings were clad with a high power diode laser (HPDL) on to the surface of S355 structural steel at the different cladding speeds. The effects of laser cladding speed on the tribo-corrosive in 3.5% NaCl solution were analysed using a ball-on-disc wear tester and the electrochemical performance was investigated using an electrochemical workstation. The results show that the average coefficient of frictions (COFs) of the laser clad FeCoCr-50%Al coatings fabricated with laser cladding speeds of 3, 5 and 7 mm/s were 0.586, 0.704, and 0.763, respectively; and the corresponding wear rates were 0.363, 1.015 and 0.454 mm3/Nm, respectively. The wear mechanisms were found to be adhesion wear, abrasive wear and corrosion wear. The polarization curves of the laser clad FeCoCr-50%Al coatings shifted positively than the S355 structural steel substrate. The electrochemical resistance of the laser clad FeCoCr-50%Al coating deposited at the laser cladding speed of 7 mm/s was the highest of the three speeds studied. [ABSTRACT FROM AUTHOR]

Scalable preparation of flexible, porous, and microstructure membrane for triboelectric nanogenerators (TENGs) with controllable thickness and high contact surface area using cost-effective methods is still a great challenge. Herein, we developed a novel, cost-effective, and scalable fabrication procedure for the preparation of a lightweight, flexible, thin, and porous polyurethane (PU) membrane for a TENG device. Importantly, the thickness and pore size of the PU membrane can be tuned easily. The PU-based TENG device fabricated with a porous PU membrane of 5 μm thickness and 15 μm pore size (PU-5-15) generated a maximum peak to peak output voltage was 58.5 V with a corresponding peak to peak current was 1.37 μA at 4 N and power density of 9.7 mW/m². The device was systematically used to energize 24 green commercial lightemitting diodes (LEDs) in brighter condition connected in series and to turn on the LCD of a portable timer clock within 51 s and glow for 1 s after 187 taps. The developed TENG device also exhibited stable cyclic charging and discharging property that is very important for real applications. Furthermore, the energy-harvesting performance of the device was also tested with human body movements. The developed industrially compatible method is very easy and convenient, and mass production is possible. Compared to other studies, in this novel study, we achieved a higher electrical performance at the desired lower thickness for the porous PU membrane-based TENG device. The developed fabrication method will pave the way for the facile and scalable industrial processing of PU membranes for energy-harvesting applications. [ABSTRACT FROM AUTHOR]

A physical model is presented for the study of parametric instabilities in inertial confinement fusion (ICF), which considers the coupling of the incident and scattered electromagnetic waves with plasma electrons and ions. Specially, this model is solved numerically with the particle-mesh method, where the plasma is represented by macro-particles both for electrons and ions, and the velocity and position of each macro-particle are numerically updated by using the particle-mesh method. The developed particle-mesh code in one-dimensional geometry (PM1D) is utilized to study the development of parametric instabilities at the nonlinear stages, where electron plasma wave breaking, particle trapping, hot electron generation and density cavity formation can occur. Particle-in-cell (PIC) simulations are carried out to verify this PM1D code. By comparison, it is found that this PM1D code is able to capture the kinetic effects and precisely describe the developments of parametric instabilities at nonlinear stages as the PIC simulations while saving the computation time obviously. Furthermore, a test simulation of the stimulated Raman scattering evolution up to 200 ps verifies the robustness of this PM1D code. [ABSTRACT FROM AUTHOR]

The impact behavior and energy absorption of two types of composite tubes, fabricated from carbon fabrics by the resin transfer molding and from carbon prepregs by the lay-up method, were investigated experimentally and numerically. In impact tests, outward-splaying crush caps with different fillet radii were used. Different types of crushing behavior of the tubes were simulated by the finite-element analysis, including a progressive failure function and considering the possibility of delamination. A comparison with experimental results confirmed that, the finite-element analysis was able to well predict the crushing behavior of the composite tubes, showing that the specific energy absorption of the prepreg composite tubes was always about 20% lower than that of the braided ones. [ABSTRACT FROM AUTHOR]

The spectrum change of the lower hybrid (LH) waves caused by a low-frequency density fluctuation in the scrape-off-layer is studied by applying the wave scattering model developed by Bonoli and Ott [Phys. Fluids 25, 359 (1982)] via a Monte Carlo method. Due to the influence of the density fluctuation, the perpendicular component of the LH wave-vector can be rotated in the 2D perpendicular space, which will further change the ray trajectory of the LH wave. A ray-tracing model specific to this purpose is developed to evaluate the probability distribution of both the poloidal refractive index (N θ) and the parallel refractive index ( N ∥ ) of the LH wave at the last closed flux surface (LCFS). The scattering probability and the rotation scattering angle are determined by the combined effect from the geometric optics approximation term and the E × B drift term in the LH tensor elements. The probability distributions of N ∥ and N θ at the LCFS are studied using the EAST parameters as a function of wave frequency, the initial N ∥ , and the polar injection position, which may influence the lower hybrid current drive efficiency. [ABSTRACT FROM AUTHOR]

Four new fundamental nonlocal quantum computing diagonal operator-state relations are derived which model the interaction between two adjacent atoms of an entangled atomic chain. Each atom possesses four eigen-states. These relations lead to four momentum-space cyclic transformations and are used as the computation states in one-dimensional cellular automaton. Four interacting half-observable periodic planar states appear with the same Poincare cycle. Due to the space-time rotational symmetry of these operator-state relations, a new type of periodic spherical state can be constructed consisting of eight finite space-time quadrants as the special quantum computing result. [ABSTRACT FROM AUTHOR]

The Smith–Watson–Topper model based on the critical plane method was constructed to predict the fretting fatigue characteristics at the riveting hole, which permits of improving the fretting fatigue performance of the riveted joint of fiber metal laminates. The effect of four design parameters, plate width, hole-to-end distance, pretightening force, and friction coefficient, on the fretting fatigue characteristics of laminate-steel single-lap rivet joint is analyzed. A four-factor three-level quadratic orthogonal combination test is carried out to find the optimal design parameters so that the riveted joint has the smallest model fatigue damage value. The lightweight design of riveted joints is also realized by adjusting the lay-ups of the laminate. The highest model value is revealed at the contact edge of the rivet and laminate. An increase in the above design parameters contributes to the reduction of model values; under a constant load, the smallest model value is obtained, which is 47% less than that before optimization; considering such factors as weight and critical line loads, a satisfactory lightweight design can be obtained. [ABSTRACT FROM AUTHOR]

The study presents new on/off switchable nanofiber membranes with high sensitivity for detecting Co2+ and Cu2+ ions. The nanofiber membranes were fabricated by electrospinning (ES) the poly[(2-hydroxyethylmethacrylate-co-N-methylolacrylamide)] [poly(HEMA-co-NMA)] copolymer with different quantities of 2,2'-bipyridine-3,3'-diol (BPDO). Poly (HEMA-co-NMA) random copolymers with various molar ratios of the HEMA and NMA monomers were synthesized by free radical polymerization. The HEMA and NMA moieties were specifically selected to promote hydrophilicity and crosslinking reactions, which ultimately support a mechanically stable structure in aqueous media. ES nanofiber membranes S1-0.5, with a HEMA:NMA molar ratio of 77:23 and 0.5 wt% of BPDO showed strong photoluminescence quenching upon exposure to Co2+ and Cu2+ ions at concentrations ranging from 10-7 to 10-4 M. Moreover, the nanofiber membranes exhibited reversibile on/off fluorescence emission properties upon the sequential addition of Cu2+ ions and ethylenediaminetetraacetic acid (EDTA). These results demonstrate a simple fabrication strategy for nanofiber membranes that have the potential to be effective for the real-time sensing of metal ions. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the effect of graded inclusion of almond hulls on growth performance, body composition, digestive tract weight, and liver antioxidant capacity of broilers. A total of 420 one-day-old Cobb male chicks was randomly allocated to 5 experimental treatments with 6 replicates of 14 birds each for 19 d of age. The five dietary treatments consisted of a corn-soybean meal control diet and 4 almond hull treatments containing 2.5, 5, 7.5, and 10% of almond hulls with 97.5, 95, 92.5, and 90% of the control diet, respectively. Feeding almond hulls at 10% reduced broiler body weight gain (P # 0.048) and increased feed conversion ratio (FCR; P, 0.01) at 0 to 7 and 0 to 14 d compared to the control group. Inclusion of almond hulls showed a quadratic effect (P = 0.044) on body weight gain and linear effect (P = 0.045) on FCR during 0 to 19 d of age. The numerically highest body weight gain was achieved when broilers were fed the diet containing 5% of almond hulls at 19 d of age. As the almond hull inclusion level increased, a linear (P = 0.035) effect was observed on the relative whole intestine weight, whereas a quadratic (P = 0.086) trend was observed on the relative gizzard weight at 19 d of age. Inclusion of almond hulls showed a quadratic (P # 0.011) effect on broiler body fat weight and fat percentage. Broilers fed the diet containing almond hulls at 5% had a lower body fat weight (P = 0.011) and fat percentage (P, 0.01) compared to the control group. Inclusion of almond hulls also showed a quadratic (P = 0.075) trend on broiler body mineral content. Hepatic superoxidative dismutase linearly (P, 0.01) increased as the level of almond hulls in the diet increased. In summary, inclusion of almond hull showed a beneficial effect on intestinal development and liver antioxidant capacity. Moreover, broilers fed the diet containing 5% almond hull showed an optimum body weight gain with lower body fat weight and fat percentage, whereas inclusion of up to 7.5% of almond hulls did not show any negative effects on growth performance. [ABSTRACT FROM AUTHOR]

The degradation and breakdown mechanisms of a SiOCH low-k material with k=2.3 (25% porosity) and thicknesses ranging from 90 nm to 20 nm were investigated. By combining the time dependent dielectric breakdown data at positive/negative bias stress with the thickness scaling results, dielectric failure is proven to be intrinsic and not influenced by copper drift or metal barrier deposition induced dielectric damage. It is shown that stress induced leakage current (SILC) can be used as a measure of dielectric degradation. Therefore, low field lifetimes can be safely estimated using SILC extrapolation. Based on our results, both the impact damage model and the power law model have a good accuracy for low field lifetime prediction. Recovery and anneal experiments are used to study the physical nature causing the observed negative flatband voltage shifts in our metal-insulator-semiconductor planar capacitor structures, where hydrogen induced unstable fast and slow donor type interface states are hypothesized to be the root cause of the observed shifts. We suggest that atomic hydrogen is released from the dielectric during electron injection and migrates to the interfacial region. Our model is further supported by an observed irreversible SILC change during the recovery and anneal studies. The degradation mechanism proposed in this work, supported by the low field lifetime data, provides a feasible explanation for intrinsic low-k dielectric failure. [ABSTRACT FROM AUTHOR]

We outline the procedure of extending the Thévenin equivalence principle for classical electric circuits to reducing Aharonov-Bohm-based quantum networks into equivalent models. With examples, we show from first principles how the requirements are related to the electron band structure's Fermi level and the lattice spacing of the network. Quantum networks of varying degrees of coupling strength from four basic classifications of single and double entangled loops sharing symmetry and highly correlated band structures are used to demonstrate the concept. We show the limitations of how the principle may be applied. Several classes of examples are given and their equivalent forms are shown. [ABSTRACT FROM AUTHOR]

The results of the growth of thin (~3 nm) InGaN/GaN single quantum wells (SQWs) with emission wavelengths in the green region by plasma-assisted molecular beam epitaxy are present. An improved two-step growth method using a high growth temperature up to 650 °C is developed to increase the In content of the InGaN SQW to 30% while maintaining a strong luminescence intensity near a wavelength of 506 nm. The indium composition in InGaN/GaN SQW grown under group-III-rich condition increases with increasing growth temperature following the growth model of liquid phase epitaxy. Further increase in the growth temperature to 670 °C does not improve the photoluminescence property of the material due to rapid loss of indium from the surface and, under certain growth conditions, the onset of phase separation. [ABSTRACT FROM AUTHOR]

1. The liver is the major site of fatty acid synthesis in chickens. Lipid metabolism in the liver correlates with the deposition of triglycerides in adipose tissue. Northeast Agricultural University broilers lines divergently selected for abdominal fat content (NEAUHLF) provide a unique model to study the mechanisms of fat deposition. 2. In previous studies, differentially expressed genes (DEGs) in the livers of fat and lean broilers were evaluated across different developmental stages. Whether protein expression differences exist between the livers of fat and lean broilers is largely unknown. The current experiment used 2D fluorescence difference gel electrophoresis (2D-DIGE) to screen expressed protein (DEP) spots in the liver tissues of NEAUHLF at one, four and seven weeks of age. 3. Twenty-two DEPs were identified by MALDI-TOF-MS that were involved in lipid, energy, protein and amino acid metabolism, oxidative stress, cytoskeleton, and transport. 4. These data furthered the understanding of the fat and lean phenotypes of broiler chickens. [ABSTRACT FROM AUTHOR]

The packing patterns have close correlation with the thermoelastic properties of DNA adsorption films and the relevant detection signals of microcantilevers. In this paper, we investigate the influence of packing patterns on the thermoelastic properties of DNA adsorption films, the detection signals of microcantilevers and their temperature dependence. First, the Parsegian's empirical potential based on a mesoscopic liquid crystal theory is employed to describe the interaction energy among coarse-grained DNA cylinders; then, the thought experiment method and the force balance method of nonlinear elastic network nodes are combined to characterize the elastic modulus, prestress and thermal expansion coefficient of DNA adsorption films; finally, based on an effective macroscopic continuum model for DNA microbeam deformation, we study the microcantilever resonance frequency shifts caused by DNA adsorptions and the temperature effect on the microcantilever static deflections, respectively. Results show that, compared with the convex-packaged, the re-entrant honeycomb packing pattern endows DNA adsorption films with a larger adjustable range of the elastic modulus and prestress, so as to make DNA-microcantilevers having an enhanced dynamic detection signal whereas a weaker response to temperature variation. These results are expected to provide a new option for the regulation design of DNA composite materials and microbeam sensors. Packing patterns play a key role in thermoelastic properties of DNA adsorption films and detection signals of microcantilevers. By constructing multiscale relations between DNA mesoscopic free energy and continuum microcantilever deformation, resonant frequency shift, the influence of packing patterns on thermoelastic properties of DNA adsorption films and detection signals of microcantilevers is investigated. Compared with the convex-packaged DNA adsorption film, the concave-packaged one endows a stronger dynamic biodetection signal, whereas a weaker response to ambient temperature variation due to a larger adjustable range of thermoelastic property. [ABSTRACT FROM AUTHOR]

The electrical signals generated by an electromechanical coupling mechanism in biomaterials have significant potential applications in the field of biomedical engineering. For example, the piezoelectric- or flexoelectric-induced electrical signals in bone biomaterials play an important role in facilitating self-repair, remodeling, and reshaping processes. Polyetheretherketone (PEEK) has been found to possess excellent mechanical properties and biocompatibility with bone, making it an outstanding choice as an implantable polymer material. It is particularly important to investigate the electromechanical response performance of PEEK materials. In this study, we experimentally examine the flexoelectricity of PEEK and evaluate its effective out-of-plane direct and converse flexoelectric coefficients. Using the piezoresponse force microscopy module of atomic force microscopy, we observe a clear converse flexoelectric effect in a PEEK disk-shaped sample. The effective out-of-plane converse flexoelectric coefficient of the PEEK disk-shaped sample is about μ 3333 eff = 0.21 ± 0.02 nN / V. The effective out-of-plane direct flexoelectric coefficient, determined through the bending experiment of a PEEK cantilever, is f 3113 eff = 17.61 nC/m, which is larger than that of polyvinylidene fluoride and is nearly two orders of magnitude superior over other biomaterials such as bone and hydroxyapatite. This indicates that PEEK materials have even greater potential for development and research in biomedical engineering applications such as intervertebral fusion, bone joint replacement, bone rehabilitation and regeneration, etc. [ABSTRACT FROM AUTHOR]

The Expected Improvement (EI) method, proposed by Jones, Schonlau, andWelch, is a widely used Bayesian optimization method, which makes use of a fitted Gaussian process model for efficient black-box optimization. However, one key drawback of EI is that it is overly greedy in exploiting the fitted Gaussian process model for optimization, which results in suboptimal solutions even with large sample sizes. To address this, we propose a new hierarchical EI (HEI) framework, which makes use of a hierarchical Gaussian process model. HEI preserves a closed-form acquisition function, and corrects the over-greediness of EI by encouraging exploration of the optimization space. We then introduce hyperparameter estimation methods which allow HEI to mimic a fully Bayesian optimization procedure, while avoiding expensive Markov-chain Monte Carlo sampling steps. We prove the global convergence of HEI over a broad function space, and establish near-minimax convergence rates under certain prior specifications. Numerical experiments show the improvement of HEI over existing Bayesian optimization methods, for synthetic functions and a semiconductor manufacturing optimization problem. for this article are available online. [ABSTRACT FROM AUTHOR]

In this work, we attempt to show the differences between traditional qubit-based spintronic methodology for quantum computation and the possible ballistic quantum network implementations. Flux qubits can be considered topologically similar to the persistent currents possessed as the angular momentum in Aharonov-Bohm loops, which can be coupled and thus entangled together. Since entanglement is guaranteed for coupled quantum networks, starting from a point-contacted situation, we first investigate how varying the degree of entanglement strength can affect the superposition of the four possible states for two isolated flux qubits being brought together. In general, the superposition is destroyed once the degree of entanglement is altered from the point-contact situation. However, we show that for a specific network with maximum entanglement, a Bell state situation can be produced. We then examine the effects of varying the external perturbation strength on the readout capability in quantum networks by changing the coupling strength through the cross-sectional area ratio. From the analysis of our results, we are persuaded to believe that two universally accepted components for quantum computing are not valid in the quantum network approach: the need of a weak perturbation for measurement of computational results and the requirement of fixed entanglement among qubits. We show there is an interplay between the strength of the entanglement and that of the external perturbation for high-fidelity classical readouts. [ABSTRACT FROM AUTHOR]

The average amplitude and pitch of surface ripples after solidification are exploratorily interpreted from scale analysis and numerical computation of transport variables and free surface deformation in a molten pool. Rippling influences welding, additively manufacturing and nano-technologies. By accounting for solid speed and oscillation of fluid velocity, the results find that amplitude is proportional to the difference in surface pressures and mechanical energy losses between edge and centre regions. Pitch is determined by the product of solid speed with timescale for surface displacement. The ratios between solid speed and liquid velocity near the central and pool edge regions, respectively, determine amplitude and pitch. Rather than pitch, oscillating flow is insensitive to amplitude. Transport fields solved by COMSOL code confirm scaled results. [ABSTRACT FROM AUTHOR]

Mechanical soft reduction (MSR) is an effective method for elimination of the centerline segregation and porosity of the continuous casting steel slab, and the reduction amount is a key parameter that determines whether the MSR could be applied successfully. In the present work, a 2D heat transfer model was developed for predicting the non-uniform solidification of the wide-thick slab. The measured shell thickness by nail shooting experiment and the measured slab surface temperature by infrared camera were applied to validate the 2D heat transfer model. A new calculation method of theoretical reduction amount that could consider the influence of non-uniform solidification of the wide-thick slab was then derived. Based on the predicted temperature field by the 2D heat transfer model and the newly-proposed calculation method, the required theoretical reduction amount and reduction gradient/rate for the wide-thick slab were calculated and discussed. The difference between the newly-proposed method and the previous method, the influence of the casting speed and slab thickness on the required theoretical reduction amount and reduction gradient/rate were also investigated. [ABSTRACT FROM AUTHOR]

We give the results of parameter fitting of the magnetic clouds (MCs) observed by the Wind spacecraft for the three year period – 2004 to the end of 2006 (the "Present period") using the force-free MC model of Lepping, Jones, and Burlaga (J. Geophys. Res.95, 11957, 1990). There were 19 MCs identified in the Present period, which was mainly in the declining phase of the solar cycle. The long-term occurrence rate of MCs is 10.3/year (1995-2015), whereas the occurrence rate for the Present period is only 6.3/year, similar to that for the period 2007-2009. Hence, the MC occurrence rate has had an appreciable decrease for the six years 2004-2009. The MC modeling gives such basic MC quantities as size, axial orientation, field handedness, axial magnetic field strength, center time, and closest approach vector. A statistically based modification of the modeled field intensity is tested. Also calculated are derived quantities, such as axial magnetic flux, axial current density, and axial current. Quality ( Q 0 ) estimates are assigned representing excellent (1), good/fair (2), and poor (3). We provide error estimates on the specific fit parameters for the individual MCs for the Q 0 = 1 , 2 cases, and give a distribution of MC types (i.e. N ⇒ S, S ⇒ N, All N, All S, etc., ten categories in all). There is an inordinately large percentage of the N ⇒ S type in the Present period (32%). The Present period basic model fitting results are compared to the results of the full Wind mission and other 3-year periods. First, we notice that during the Present period the MCs are, on average, significantly faster (by 21%), distinctly stronger in axial magnetic field (by 37%), and smaller in diameter (by 5.5%), than those in the Long-term period. The quality of the MCs in the Present period is significantly better than that of the Long-term period, where the ratio N (Q 0 = 1 , 2) / N (Q 0 = 1 , 2 , 3) for each is 0.79 and 0.58, respectively. The Present period is quite different from the Long-term period (1995-2015), it is from the other three 3-year periods between 2006 and the end of 2015. In the Present period upstream shocks occur for the first 12 MCs of the 19 cases (63%); for comparison the Long-term rate is 56%. [ABSTRACT FROM AUTHOR]