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To determine the associations of intravoxel incoherent motion (IVIM) parameters with expression of programmed cell death-1 (PD-1) and programmed cell death ligand-1 (PD-L1), and evaluate the performance of the combined model established based on IVIM and clinicopathological parameters in predicting PD-L1and PD-1 status of cervical cancer (CC) patients. Seventy-eight consecutive CC patients were enrolled prospectively and underwent magnetic resonance imaging (MRI) including IVIM. IVIM quantitative parameters were measured, compared, and correlated with PD-L1 and PD-1 expression. Independent factors related to PD-L1 and PD-1 positivity were identified and were used to establish the combined model. The combined model's diagnostic performance was evaluated using the receiver operating characteristic (ROC) analysis. The Shapley additive explanation (SHAP) algorithm was used to explain the contribution of each parameter in the combined model. The real diffusion coefficient (D) value was significantly lower in the PD-L1-positive group than in the PD-L1-negative group (0.64 ± 0.12 versus 0.72 ± 0.11, p= 0.021). The PD-1-positive and PD-1-negative groups showed similar trends (0.63 ± 0.13 versus 0.73 ± 0.09, p= 0.003). Parametrial invasion, lymph node status, pathological grade, FIGO (International Federation of Gynecology and Obstetrics) staging, and D values were independently associated with PD-L1 and PD-1expression. A combined model incorporating these parameters showed good discrimination with the sensitivity, specificity of 90.9%, 82.6% for PD-L1, and 93.5%, 72% for PD-1. According to the SHAP value, FIGO staging and pathological grade were the most influential features of the prediction model. IVIM parameters were found to correlate with PD-L1 and PD-1 expression. The combined model, incorporating parametrial invasion, lymph node status, pathological grade, FIGO staging, and D values, showed good discrimination in predicting PD-L1 and PD-1 status, providing the basis for CC immunotherapy. • D value is negatively correlated with PD-L1 and PD-1 expression. • The combined model has the best discrimination providing a basis for immunotherapy. • According to SHAP analysis, FIGO staging and pathological grade are major features. [ABSTRACT FROM AUTHOR]

A composite double-arrow auxetic structure was fabricated by using the hot mold pressing and bonding technologies, and a polyurethane foam was utilized to fill the voids of core to prepare a foam-reinforced auxetic structure. Projectile impact experiments were carried out to investigate the influence of the filling foam on the dynamic response, the failure mechanism and a negative Poisson's ratio on the composite double-arrow auxetic structure. A high-speed recording system was used to gather data on the deformation profile and failure mechanism of the composite auxetic structure during the impact loading. The foams were found to significantly reduce the local crushing and overall bending/shear deformation of the sandwich structure. This synergistic effect of the core member and foam blocks greatly enhanced the impact resistant and energy absorption capacity of the composite auxetic structure. However, filling foam would reduce the negative Poisson's ratio effect of the auxetic structure. [ABSTRACT FROM AUTHOR]

Objectives: Synthetic adrenocorticotropic hormone or tetracosactide is routinely used in the diagnosis of hypoadrenocorticism and frequently in the diagnosis and treatment of hyperadrenocorticism. There have been repeated shortages of tetracosactide in recent years in Australia. This study investigated the agreement of serum cortisol after a compounded tetracosactide (Bova Aus), compared to commercial tetracosactide (Synacthen®) in healthy dogs. Methods: Prospective crossover study using 20 dogs. Ten dogs received 5 μg/kg Synacthen® on day 1 and 5 μg/kg compounded tetracosactide on Day 2. The other 10 dogs received the reverse order. Cortisol concentrations in each dog 1 h after injection were compared for agreement, which was defined as the limits of agreement of the Bland–Altman ratio to be within a range of 0.8–1.25. Passing‐Bablok regression analysis examined for constant and proportional biases. Results: Three dogs were excluded with post‐stimulation serum cortisol concentrations markedly outside reference interval. For the remaining 17 dogs, Bland–Altman ratio analysis of cortisol concentration (tetracosactide/Synacthen®) at 1 h found virtually no constant bias (mean of ratios 1.01;95% CI 0.97–1.05) and 95% limits of agreement were 0.88 (95% CI 0.78–0.90) and 1.17 (95% CI 1.13–1.25). This met our criteria for agreement between cortisol concentrations. Bias of the Bland–Altman difference was 2.8 nmol/L (95% CI −7.2 to 12.8); 95% limits of agreement −35.2 nmol/L (95% CI −57.0 to −26.1) and 40.8 nmol/L (95% CI 31.7–62.6). Passing‐Bablok regression analysis did not identify bias. Conclusion: In healthy dogs, cortisol concentrations were in agreement after compounded tetracosactide compared to commercial tetracosactide, Synacthen®. [ABSTRACT FROM AUTHOR]

In this work, we present a framework for the analysis and reduction of plasma mechanisms by means of weighted directed graphs, in which reactions and species are both treated as nodes. The methodology consists of two distinct analyses. The first, which is qualitative, relies on graph spatializations via force-directed algorithms to discover the predominant global patterns in the chemical model. The second ranks the reactions based on their shortest paths' lengths from/to the species of interest and their relative contributions to the power balance. This quantitative investigation enables a strategy for mechanism reduction that is fully automatized, as it does not require any expert knowledge, highly effective, as it generates reduced mechanisms that are highly accurate while relying on a small number of processes, and easily interpretable, as the algorithm justifies the importance of the retained reactions by outputting their related chemical pathways. Additionally, the work proposes a methodology extension that employs ensembles of graphs to improve the robustness of the reduced mechanism to reaction parameter uncertainties. The approach, here tested for steady-state predictions of a plasma system characterizing negative hydrogen ion sources, is general and can be used in a wide variety of applications outside the particular nuclear fusion context demonstrated in this work. [ABSTRACT FROM AUTHOR]

We present the results of the neutron star X-ray binary system Cen X-3 performed by Insight -HXMT with two observations during 2017 and 2018. During these two observations, the source reached a X-ray luminosity of ∼1038 erg s−1 from 2–105 keV. The analysis of the broadband X-ray spectrum reports the presence of two cyclotron resonance scattering features (CRSFs) with the fundamental line at ∼ 28 keV and the harmonic line at ∼47 keV. The multiple lines exist by fittings with different continuum models, like the absorbed negative and positive power-law with an exponential cutoff (NPEX) model and a power-law with high energy exponential cutoff model. This is the first time that both fundamental and harmonic lines are detected in Cen X-3. We also show evidence of two cyclotron lines in the phase-resolved spectrum of Cen X-3. The CRSF and continuum spectral parameters show evolution with the pulse profile, and the two line centroid energy ratio does not change significantly and locates in a narrow value range of 1.6−1.7 over the pulse phase. The implications of the discovering two cyclotron absorption features and phase-resolved spectral properties are discussed. [ABSTRACT FROM AUTHOR]

This study investigated auto-ignition characteristics of ammonia-air and ammonia-hydrogen-air laminar and turbulent mixing layers by means of direct numerical simulations (DNS) under elevated pressure conditions. The results show that elevated pressure and hydrogen addition accelerate the auto-ignition process, reducing the auto-ignition delay time. Analysis of the heat release rate revealed that the first peak of the heat release rate corresponds to the increment of appearance in temperature (induction stage) and the second peak of the heat release rate corresponds to the steady maximum temperature regime (thermal runaway stage). The results found that both induction and thermal runaway stages are affected by turbulence for pure ammonia-air mixing layers, while only the thermal runaway stage is affected by turbulence for ammonia-hydrogen-air mixing layers. The auto-ignition occurs along the most reactive mixture fraction with lower scalar dissipation rate, being further reduced by elevated pressure and hydrogen addition. Three radicals (NH 2, OH, HNO) distinguish the entire auto-ignition process very well for all cases. • DNS study of auto-ignition in ammonia and ammonia-hydrogen combustion. • Elevated pressure and hydrogen addition accelerate the auto-ignition process. • Induction and thermal runaway stages are identified. • The radicals NH 2, OH, HNO distinguish the entire auto-ignition process. [ABSTRACT FROM AUTHOR]

The protection and removal efficiency of laser paint removal from an Al alloy substrate on aircraft is closely related to the energy distribution of the laser spot and material damage threshold. The change of laser incident angle will directly change the energy distribution form, material damage threshold and paint removal efficiency of the material surface. MATLAB was used to simulate the spot morphology and energy centres distribution of different angles, to study the damage threshold of a 2024-T3 Al alloy and paint at different incidence angles by reference to the ISO 11254 1-on-1 laser damage threshold fluence test method, and to analyse the two-dimensional (2-D) and three-dimensional (3-D) morphology of the single-pulse laser spot and verify the results with the simulation. The results have shown that as the laser incidence angle decreases, the spot area increases and the threshold decreases, which effectively improves the energy availability rate and paint removal efficiency. The depth of the actual single-pulse action crater in the material was not affected by the angle of incidence, but the area increases and the offset of the energy centre on the geometric centre of the spot increases. The experimental and simulated values of energy density distribution, offset and craters diameter were well correlated and the errors were explained in terms of the mechanism of laser-material action. [ABSTRACT FROM AUTHOR]

Novel red phosphors Sr7Sb2O12:Eu3+ and Sr7Sb2O12:Eu3+, M+ (M = Li, Na, K) were synthesized via a high temperature solid-state method and their luminescent properties were investigated to figure out the promising application in warm white light-emitting diodes (LED). The phase structure, crystal morphology, luminescence properties, luminescence decay lifetime, thermal stability and chromaticity coordinate of the as-synthesized phosphors were investigated in detail. Sr7Sb2O12:Eu3+ could be efficiently excited by the near-ultraviolet (UV) light and exhibited bright red emission around 612 nm. When co-doped with the charge compensation M+ (M = Li, Na, K) ions, the emission intensity of Eu3+ can be enhanced to some extent. The optimal Eu3+ doping concentration was determined to be about x = 0.2 and concentration quenching mechanism in Sr7Sb2O12:Eu3+ sample was attributed to the electric dipole–dipole interaction. The temperature-dependent spectra of Sr7Sb2O12:Eu3+ implied that this sample shows good thermal-stable properties. The decay lifetime of Sr7Sb2O12:0.2Eu3+ was about 1.44 ms. Combining with the red Sr7Sb2O12:0.20Eu3+, blue BaMgAl10O17:Eu2+, yellow (Ba,Sr)2SiO4:Eu2+ phosphor and a 395 nm near-UV LED chip, a white LED with low correlated color temperature (CCT = 4260 K) and high-color rendering index (Ra = 91.8) was fabricated. The overall work suggested that Sr7Sb2O12:Eu3+ phosphor is a promising red-emitting component applied in warm white LED. [ABSTRACT FROM AUTHOR]

Deterministic magnetization switching driven by current-induced spin–orbit torque (SOT) without an external magnetic field has potential applications in magnetic random access memory. Here, we realized the field-free magnetization switching in a T-type structure (CoFeB/W/CoFeB), where the two CoFeB layers have perpendicular magnetic anisotropy and in-plane magnetic anisotropy (IMA), respectively. We discovered that the direction of symmetry-breaking field is parallel to the magnetization of the bottom CoFeB (IMA), which cannot be explained by a stray field of this layer. In addition, by placing a 2.5-nm thick insulating layer of MgO between the bottom CoFeB and W layer (CoFeB/MgO/W/CoFeB) to block the interlayer exchange coupling and the spin current from the bottom CoFeB, the field-free SOT switching was still achieved, primarily due to the Néel orange-peel effect in our devices. By using micromagnetic simulations, the roughness of angstrom magnitude was introduced into the model to calculate the symmetry-breaking field, finding a qualitative agreement with experiments. Moreover, we obtained the spin Hall angle of CoFeB ( θ SH = −0.024) by the current-induced hysteresis loop shift method, and the contribution of the effective efficiency χ from the bottom CoFeB was accounted for about 26% of the total in the current-induced SOT switching process. These results indicated that an in-plane ferromagnet layer in the T-type structure provides not only the symmetry-breaking field but also spin current for the field-free SOT magnetization switching. [ABSTRACT FROM AUTHOR]

The combustion characteristics of ammonia and ammonia-hydrogen fuel blends under spark-ignited turbulent premixed engine-relevant conditions were investigated by means of direct numerical simulation and detailed chemistry. Several test cases were investigated for an outwardly expanding turbulent premixed flame configuration covering pure ammonia and ammonia-hydrogen fuel blends with 10% and 15% hydrogen content by volume for different equivalence ratio values of 0.9, 1.0 and 1.1. The results showed that the fuel-lean flames exhibit strong wrinkled structures at flame front compared to stoichiometric and fuel-rich flames. The heat release rate plots indicate that adding hydrogen into ammonia improves the reactivity of the flame and enhances the combustion process. The scatter plots of heat release rate versus local curvature coloured by NO formation, show that high heat release rate values occur in the concave structures and low heat release rate values occur in the convex structure, which is consistent with NO distribution. The highest turbulent burning velocity values were found for the fuel-lean cases due to more wrinkled flame front with lower effective Lewis number compared to fuel-rich cases. The results show a bending effect for the ratio between turbulent to laminar burning velocities with respect to hydrogen addition at all equivalence ratios with 10% hydrogen addition into ammonia exhibiting a highest value for the burning velocity ratio. Two distinct flame structures (concave and convex) were analysed in terms of local equivalence ratio based on the elements of N and O as well as H and O. They revealed an opposite distribution of NO formation normal to the flame front within concave and convex structures. Elementary chemical reactions involved in NO formation have shown that hydrogen addition into ammonia influences the reactivity of certain specific chemical reactions. [Display omitted] • Study of premixed ammonia and ammonia-hydrogen combustion at elevated pressures. • Adding hydrogen into ammonia improves the reactivity of the flame. • 10% hydrogen addition by volume into ammonia provides better flame conditions. • NO formation is analysed. [ABSTRACT FROM AUTHOR]

The combustion characteristics of ammonia and ammonia-hydrogen fuel blends under spark-ignited turbulent premixed engine-relevant conditions were investigated by means of direct numerical simulation and detailed chemistry. Several test cases were investigated for an outwardly expanding turbulent premixed flame configuration covering pure ammonia and ammonia-hydrogen fuel blends with 10% and 15% hydrogen content by volume for different equivalence ratio values of 0.9, 1.0 and 1.1. The results showed that the fuel-lean flames exhibit strong wrinkled structures at flame front compared to stoichiometric and fuel-rich flames. The heat release rate plots indicate that adding hydrogen into ammonia improves the reactivity of the flame and enhances the combustion process. The scatter plots of heat release rate versus local curvature coloured by NO formation, show that high heat release rate values occur in the concave structures and low heat release rate values occur in the convex structure, which is consistent with NO distribution. The highest turbulent burning velocity values were found for the fuel-lean cases due to more wrinkled flame front with lower effective Lewis number compared to fuel-rich cases. The results show a bending effect for the ratio between turbulent to laminar burning velocities with respect to hydrogen addition at all equivalence ratios with 10% hydrogen addition into ammonia exhibiting a highest value for the burning velocity ratio. Two distinct flame structures (concave and convex) were analysed in terms of local equivalence ratio based on the elements of N and O as well as H and O. They revealed an opposite distribution of NO formation normal to the flame front within concave and convex structures. Elementary chemical reactions involved in NO formation have shown that hydrogen addition into ammonia influences the reactivity of certain specific chemical reactions. [Display omitted] • Study of premixed ammonia and ammonia-hydrogen combustion at elevated pressures. • Adding hydrogen into ammonia improves the reactivity of the flame. • 10% hydrogen addition by volume into ammonia provides better flame conditions. • NO formation is analysed. [ABSTRACT FROM AUTHOR]

Blazars show extreme observational properties that are due to the beaming effect with the jet being close to the line of sight. It was found that the observed luminosity is anticorrelated with the synchrotron peak frequency but the debeamed luminosity and the frequency is positively correlated. In this work, we revisit this correlation for a large sample of 255 blazars from the fourth Fermi catalog with available Doppler factors. Our analysis comes to the following conclusions. (1) The observed radio, X-ray, Îł -ray, and synchrotron peak luminosity are all anticorrelated with the peak frequency, but the debeamed luminosity is positively correlated with the debeamed peak frequency. The anticorrelation is due to a selection effect or a beaming effect. (2) The Compton dominance parameter is correlated with both the bolometric luminosity and Doppler factor, implying that the more highly Compton-dominated sources are more luminous. (3) The bolometric luminosity can be represented by the Îł -ray luminosity for Fermi blazars. [ABSTRACT FROM AUTHOR]

We analyzed the 3 mm wavelength spectral line survey of 408 clumps from the APEX telescope large area survey of the Galaxy, focusing on the methanol maser transitions. The main goals of this study are (1) to search for new methanol masers, (2) to statistically study the relationship between class I masers and shock tracers, (3) to study the properties between methanol masers and their host clumps, also as a function of their evolutionary stages and, (4) to better constrain the physical conditions using multiple co-spatial line pairs. [ABSTRACT FROM AUTHOR]

Asthma is a respiratory disease with a clinically high incidence, and repeated attacks of asthma severely affect the quality of life and even pose a threat to health, leading to severe burdens on families and even the society. A thorough understanding of the pathogenesis of asthma is essential for the prevention and treatment of asthma. This study aimed to examine the effect of the microRNA miR-27a on asthma and its relationship with mitogen activated protein kinase 4 (MAP2K4). Patients with asthma admitted to our hospital from August 2016 to August 2018 and healthy participants in the same period were included in this prospective analysis. The mRNA expression levels of miR-27a and MAP2K4 in peripheral blood were determined. Airway smooth muscle cells (ASMCs) were used to study the effects of miR-27a and MAP2K4 on cell biological behavior. The relationship between miR-27a and MAP2K4 was verified using dual-luciferase reporter assay. miR-27a expression was increased and MAP2K4 mRNA expression was decreased in asthma (P < 0.05). Increasing miR-27a expression and inhibiting MAP2K4 expression could enhance the activity of ASMCs, whereas inhibiting miR-27a expression and increasing MAP2K4 expression had the opposite effect (P < 0.05). Dual-luciferase reporter assay results showed that the fluorescence activity of MAP2K4-wild type was inhibited by increased miR-27a expression (P < 0.05). miR-27a promotes the proliferation and invasion of ASMCs by targeting MAP2K4 and is involved in the occurrence of asthma. [ABSTRACT FROM AUTHOR]

BACKGROUND The inclusion of race in equations to estimate the glomerular filtration rate (GFR) has become controversial. Alternative equations that can be used to achieve similar accuracy without the use of race are needed. METHODS In a large national study involving adults with chronic kidney disease, we conducted cross-sectional analyses of baseline data from 1248 participants for whom data, including the following, had been collected: race as reported by the participant, genetic ancestry markers, and the serum creatinine, serum cystatin C, and 24-hour urinary creatinine levels. RESULTS Using current formulations of GFR estimating equations, we found that in participants who identified as Black, a model that omitted race resulted in more underestimation of the GFR (median difference between measured and estimated GFR, 3.99 ml per minute per 1.73 m² of body-surface area; 95% confidence interval [CI], 2.17 to 5.62) and lower accuracy (percent of estimated GFR within 10% of measured GFR [P10], 31%; 95% CI, 24 to 39) than models that included race (median difference, 1.11 ml per minute per 1.73 m²; 95% CI, -0.29 to 2.54; P10, 42%; 95% CI, 34 to 50). The incorporation of genetic ancestry data instead of race resulted in similar estimates of the GFR (median difference, 1.33 ml per minute per 1.73 m²; 95% CI, -0.12 to 2.33; P10, 42%; 95% CI, 34 to 50). The inclusion of non-GFR determinants of the serum creatinine level (e.g., body-composition metrics and urinary excretion of creatinine) that differed according to race reported by the participants and genetic ancestry did not eliminate the misclassification introduced by removing race (or ancestry) from serum creatinine-based GFR estimating equations. In contrast, the incorporation of race or ancestry was not necessary to achieve similarly statistically unbiased (median difference, 0.33 ml per minute per 1.73 m²; 95% CI, -1.43 to 1.92) and accurate (P10, 41%; 95% CI, 34 to 49) estimates in Black participants when GFR was estimated with the use of cystatin C. CONCLUSIONS The use of the serum creatinine level to estimate the GFR without race (or genetic ancestry) introduced systematic misclassification that could not be eliminated even when numerous non-GFR determinants of the serum creatinine level were accounted for. The estimation of GFR with the use of cystatin C generated similar results while eliminating the negative consequences of the current race-based approaches. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases and others.) [ABSTRACT FROM AUTHOR]

Summary: The dominance effect is a kind of non‐additive effect due to the interaction between alleles at the same locus. Quantitative traits such as growth traits in farm animals have been found to be influenced by dominance effects. However, dominance effects are usually ignored in the genome‐wide association study (GWAS) of complex traits for farm animals. In this study, we performed GWAS and genetic parameters estimation for the two traits age at 100 kg (AGE) and backfat thickness at 100 kg (BF) of 3572 Large White pigs. The pigs were from three breeding farms of China and were genotyped by an in‐house designed 50k SNP chip. Our results showed significant non‐zero variance for the dominance effect of AGE, while the dominance effect of BF was not significant. Using a GWAS model accounting for both additive and dominance effects, we identified three additive and two dominance significant SNPs for the trait AGE. For the trait BF, three genome‐wide significant additive SNPs were detected, but no significant SNP was found for the dominance effect. In total, six important functional genes (NPAS3, USP16, PARN, ARL15, GPC3, ABHD4) near significant SNPs were identified as candidate genes associated with AGE or BF. Notably, ARL15 and PARN were associated with AGE near the dominance association signals. Overall, the newly detected SNPs and newly identified candidate genes in our study added new information about the genetic architectures of growth and fatness traits in pigs, and have the potential to be applied to the pig breeding program in the future. [ABSTRACT FROM AUTHOR]

Background: Mechano-electro-chemical coupling during the ion diffusion process is a core factor to determine the electrochemical performance of electrodes. However, relationship between the mechanics and the electrochemistry has not been clarified by experiments. Objective: In this work, we conduct an in situ, visual, comprehensive characterization of strain field and Li concentration distribution to further explore the mechano-electro-chemical relationship. Methods: The digital image correlation characterized by fluorescent speckle and active optical imaging is developed. Combined with electrochromic-based Li concentration detection, the spatiotemporal evolution of in-plane strain and Li concentration of a graphite electrode during the lithiation and delithiation processes are measured and displayed visually via a dual optical path acquisition system. Results: The visual results show that in-plane strain and Li concentration possess a spatially non-uniform gradient distribution along the radial direction (i.e., diffusion path) with large values outside and small values inside, and that both present obvious temporal segmentation. And mechano-electro-chemical coupling analysis reveals that the in-plane strain is not always linearly related to the concentration and infers that a high strain limits the diffusion and lithiation. The strain–concentration evolution exhibits obvious asymmetric differences between lithiation and delithiation, wherein three equations are fitted to approximately represent the evolution process between in-plane strain and concentration during the lithiation and delithiation processes Conclusions: This work overcomes the difficulties of fine strain measurements and collaborative concentration characterization during the electrochemical process, and provides an effective experimental method and data support for further exploration of mechano-electro-chemical coupling. [ABSTRACT FROM AUTHOR]

Change impact evaluation of complex product plays an important role in controlling change cost and improving change efficiency of engineering change enterprises. In order to improve the accuracy of engineering change impact evaluation, this paper introduces three-parameter interval grey number to evaluate complex products according to the data characteristics. The linear combination of BWM and Gini coefficient method is used to improve the three-parameter interval grey number correlation model. It is applied to the impact evaluation of complex product engineering change. This paper firstly constructs a multi-stage complex network for complex product engineering change. Then the engineering change impact evaluation index system is determined. Finally, a case analysis was carried out with the permanent magnet synchronous centrifugal compressor in a large permanent magnet synchronous centrifugal unit to verify the effectiveness of the proposed method. [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]

Boson peaks (BP) have been observed from phonon specific heats in 10 studied amorphous alloys. Two Einstein-type vibration modes were proposed in this work and all data can be fitted well. By measuring and analyzing local atomic structures of studied amorphous alloys and 56 reported amorphous alloys, it is found that (a) the BP originates from local harmonic vibration modes associated with the lengths of short-range order (SRO) and medium-range order (MRO) in amorphous alloys, and (b) the atomic packing in amorphous alloys follows a universal scaling law, i.e., the ratios of SRO and MRO lengths to solvent atomic diameter are 3 and 7, respectively, which exact match with length ratios of BP vibration frequencies to Debye frequency for the studied amorphous alloys. This finding provides a new perspective for atomic packing in amorphous materials, and has significant implications for quantitative description of the local atomic orders and understanding the structure-property relationship. [ABSTRACT FROM AUTHOR]

Reservoir computing (RC) is a recently introduced bio-inspired computational framework capable of excellent performances in the temporal data processing, owing to its derivation from the recurrent neural network (RNN). It is well-known for the fast and effective training scheme, as well as the ease of the hardware implementation, but also the problematic sensitivity of its performance to the optimizable architecture parameters. In this article, a particular time-delayed RC with a single clamped–clamped silicon beam resonator that exhibits a classical Duffing nonlinearity is presented and its optimization problem is studied. Specifically, we numerically analyze the nonlinear response of the resonator and find a quasi-linear bifurcation point shift of the driving voltage with the driving frequency sweeping, which is called Bifurcation Point Frequency Modulation (BPFM). Furthermore, we first proposed that this method can be used to find the optimal driving frequency of RC with a Duffing mechanical resonator for a given task, and then put forward a comprehensive optimization process. The high performance of RC presented on four typical tasks proves the feasibility of this optimization method. Finally, we envision the potential application of the method based on the BPFM in our future work to implement the RC with other mechanical oscillators. [ABSTRACT FROM AUTHOR]

The use of precision technology is increasingly seen as an option to improve productivity, animal welfare, resource use efficiency, and workplace features on dairy farms. There is limited research related to longitudinal adoption patterns of precision dairy technologies and reasons for any patterns. The aim of this analysis was to investigate trends in technology adoption regarding both the amount (number of farms with a technology) and intensity (number of technologies per farm) of adoption. Surveys of parlor technology adoption were conducted on New Zealand dairy farms in 2008, 2013, and 2018, with 532, 500, and 500 respondents, respectively. Technologies were grouped into labor-saving (LS, such as automatic cluster removers) or data-capture (DC, such as in-line milk meters) categories. Trends were examined for farms that had only LS, only DC, or LS+DC technologies. Technology adoption increased over time; the likelihood of technology adoption in 2018 (and 2013 in parentheses) increased by 21 (22), 7 (68), and 378% (165) for LS, DC, and LS+DC technology groups, respectively, compared to 2008. Farms with LS+DC technologies also had a greater proportion of LS technologies compared to non-LS+DC farms, although this relationship declined over the 10-yr period. The use of a rotary versus herringbone parlor was estimated to be associated with 356 and 470% increase in the likelihood of adopting LS technologies and LS+DC, respectively, from 2008 to 2018. Regional differences in adoption were also found, with the likelihood of adopting DC and LS+DC technologies found to be 46 and 59% greater, respectively, in the South Island of New Zealand, compared to the base region of Waikato. The results highlight the importance of understanding spatial and temporal farm characteristics when considering future effect and adoption of precision dairy technologies. For example, the analysis indicates the occurrence of 2 trajectories to technology investment on farms, where larger farms are able to take advantage of technology opportunities, but smaller farms may be constrained by factors such as lack of economies of scale, limited capital to invest, and inability to retrofit technology into aging parlor infrastructure. [ABSTRACT FROM AUTHOR]

To evaluate the efficacy and safety of concomitant chemoradiotherapy with nab-paclitaxel and cisplatin in patients with locally advanced non-small cell lung cancer (NSCLC). This study (NCT04284215) is a prospective, phase II, randomized controlled study, and the patients are enrolled in a ratio of 1:1 in the study with patients treat-naïve locally advanced stage III non-small cell lung cancer.in comparison with paclitaxel plus cisplatin, the regimen of nab-paclitaxel plus cisplatin was use in the treatment of DT:69 Gy/46f.Nab-paclitaxel 40mg/m2/week (4-6 weeks in total) and cisplatin 75mg/m2 for 2 cycles. Control arm: paclitaxel 175mg/m2 d1, cisplatin 75mg/m2 for 2 cycles. The primary endpoints are ORR and treatment-induced toxicity of concurrent chemoradiotherapy, and the secondary endpoints are PFS and OS. A total of 68 patients (1:1) were randomized from March 3, 2019 to August 23, 2021.Sixty-five patients received concomitant chemoradiotherapy according to the study protocol, including 32 patients in the nab-paclitaxel group and 33 patients in the paclitaxel group. There was no significant difference in ORR between the two groups (84.4% vs. 73.7%, p = 0.411).There was no difference in median PFS between the two groups (14 months (95% CI 14.60-22.93) vs. 12 months (95% CI 13.15-22.74), P = 0.521).The incidence of grade III-IV leukopenia and neutropenia, fatigue, nausea, vomiting and other toxic and adverse reactions in the nab-paclitaxel group were significantly lower than those in the paclitaxel group (P<0.006, P<0.000, 0.016, 0.021, 0.019) Compared with paclitaxel plus cisplatin regimen, the combination of nab-paclitaxel plus cisplatin regimen has no significant difference in ORR and PFS, but significantly reduces the incidence of grade III-IV granulocytopenia and gastrointestinal reactions. [ABSTRACT FROM AUTHOR]

The Fe/Ni-based coatings fabricated by high power diode laser (HPDL) cladding (expressed as laser clad layers) were used as the renovated or modified layers formed on a 4Cr5MoSiV1 steel substrate. The laser clad layers with high strength ceramic particles were prepared on the steel by means of an industrial set up so as to improve the mechanical and tribological properties of the metal substrate. The microstructure and phase constituents, as well as microhardness and wear properties of the laser clad layers were analysed in detail. The carbides or ceramic phases were dispersed within grains for Fe/Ni based clad layer. Especially, the two kinds of Ni/Fe based clad layers containing WC particles present excellent properties combined with a high hardness and a good dry friction wear and impact abrasive wear resistance, greatly prolonging the service life of metal components. These laser clad layers were widely used in electric power industry, such as steam turbines, hydroturbine, boiler tube, valve body in power station. In addition, the laser clad layers have been used for the metal component in the coal and mining industries. [ABSTRACT FROM AUTHOR]

Material compressibility and entropy is of great significance for inertial confinement fusion research. Preheat induced degradation on material compression under double shock compression is studied on ShenGuang series laser facility. The deviations on rear surface expansion and multiple shock timing are contrasted under different picket power. The measured preheat besides shocks could provide more physical boundaries and benchmarks from experiment. 1% silicon dopants is mandatory to keep ablator/fuel interface stable with and in a double-shock compression. While pure GDP ablator is applicable to. This study demonstrates a new testbed to provide in-situ preheat evaluation for implosion experiment. It aims to validate the preheat level and effects on material compression for a double shock, low convergence ratio design. It could also provide valuable information for target dopant design and upcoming shock tuning process. [ABSTRACT FROM AUTHOR]

Objective: Electroconvulsive therapy (ECT) is commonly used to treat patients with treatment‐resistant depression. We aimed to investigate whether combining an antidepressant agent with ECT might enhance therapeutic efficacy and prevent early relapse. Method: During the acute ECT phase, patients (N = 97) with treatment‐resistant depression were randomized to receive ECT plus agomelatine 50 mg/day (n = 48) or ECT plus placebo (n = 49). Symptom severity measures, including the 17‐item Hamilton Depression Rating Scale (HAMD‐17) and other scales, functional impairment, quality of life, neuropsychological tests, adverse events and attitudes toward ECT, were assessed regularly. Remission was defined as a HAMD‐17 score ≤7. If patients achieved post‐ECT remission, they were prescribed agomelatine 50 mg/day and participated in a 12‐week follow‐up trial. HAMD‐17 was rated at 4‐week intervals. Relapse was defined as a HAMD‐17 score ≥14, or rehospitalization for a psychiatric reason. Results: The two treatment groups were comparable at (i) baseline variables; (ii) score changes in all symptom measures, functional impairment, quality of life, and neuropsychological tests; (iii) frequency of adverse events and attitudes toward ECT; and (iv) post‐ECT response/remission rates. There were no statistically significant differences following ECT in relapse rates and time to relapse between these two groups. Conclusion: Adding agomelatine to ECT yielded comparable response/remission rates to ECT without agomelatine in the acute ECT phase. Starting agomelatine in combination with ECT did not seem to be more efficacious in preventing relapse than starting agomelatine after the acute ECT course. More research is needed to guide clinical recommendations. [ABSTRACT FROM AUTHOR]

In the present work, the structure, magnetic, and dielectric characteristics of Nd2NiMnO6 and Sm2NiMnO6 have been investigated with comparison to those for La2NiMnO6. The magnetic and dielectric properties of the present ceramics vary with decreasing lanthanide ionic radius (RLn). Both Nd2NiMnO6 and Sm2NiMnO6 are ferromagnetism with the monoclinic symmetry (space group P21/n). The Curie temperature TC of Nd2NiMnO6 and Sm2NiMnO6 is 194 K and 156 K, respectively, and it decreases with decreasing bond angle which depends on RLn. Meanwhile, the dielectric constant [variant_greek_epsilon]′ monotonically decreases with decreasing RLn. The similar variation tendency of magnetic and dielectric characteristics with RLn indicates that the structural origins for the magnetic and dielectric response should be closely linked with each other. [ABSTRACT FROM AUTHOR]

NdBCO seed crystals and high-performance GdBCO bulk superconductors were prepared successfully by a modified top-seeded melt-textured growth (TSMG) process and by Gd + 011 top-seeded infiltration growth (TSIG) process. The modified TSMG process used a new composition powder (NCP, 0.9 Nd2O3 + 2.4 BaCuO2 + CuO) instead of the conventional composition powder (CCP, NdBa2Cu3O7-x + 0.4 Nd2BaCuO5), the GdBCO bulk superconductor seeded by the self-made NdBCO seed crystal. In the whole procedure above, only one precursor powder (BaCuO2) needs to be sintered, three kinds of powder and three pellets are required, so time and energy consumption were greatly reduced. The results of thermal analysis and X-ray diffraction (XRD) patterns revealed the reaction mechanism of the modified TSMG process. Superconductivity properties of the GdBCO sample were measured employing a levitation force measurement system and a vibrating-sample magnetometer (VSM); the maximum value of the levitation force of the GdBCO sample was 44.78 N (77 k, 0.5 T); the onset superconductivity transition temperature (Tc) was approximately 93.7 K; the transition width was 6.2 K, and the maximum value of critical current density (Jc) was 1.5 × 105 A∙cm−2 (0 T, 77 K). These results indicate that, by combing the modified TSMG process and Gd + 011 TSIG process, a practical processing method for preparing the NdBCO seed crystals and the high-performance single-domain GdBCO bulk superconductors was developed. [ABSTRACT FROM AUTHOR]

A spallation target is one of the key components of the accelerator driven system. A liquid metal windowless target is an advanced type of a spallation target and has great application prospects. In this study, the free surface flow behavior and development in a scaled-down liquid metal windowless target are investigated in experiments and simulations. The experiments are carried out based on a liquid gallium experimental loop. The CFD simulations are performed based on a three-dimensional target model by using ANSYS CFX. The main working parameters of the target are measured through experiments and then set as the boundary conditions for simulations. The simulated values of the free surface height are in good agreement with the experimental data. The free surface height gradually decreases with an increase in the inlet flow rate and with a decrease in the outlet pressure. The simulation results reveal that a flow stagnation zone presenting large eddies and a reverse flow are formed below the outlet of the inner tube. [ABSTRACT FROM AUTHOR]

Background: Definitive chemoradiation therapy (dCRT) is the standard treatment for patients with nonsurgical esophageal squamous cell carcinoma (ESCC), yet patients have demonstrated great variations in their responses to dCRT and inevitably progressed following treatment. Methods: To identify prognostic biomarkers, we performed targeted next‐generation sequencing of 416 cancer‐related genes on primary tumors from 47 nonsurgical ESCC patients prior to dCRT treatment. The association between genetic alterations and patients' local recurrence‐free survival (LRFS), progression‐free survival (PFS), and overall survival (OS) was analyzed. Results: TP53 (78% of patients), NOTCH1 (32%), ARID1A (13%), FAT1 (13%), and CDKN2A (13%) were commonly mutated in ESCC patients, while gene amplifications frequently occurred in MCL1 (36%), FGF19 (34%), MYC (32%), CCND1 (27%), ZNF217 (15%), CDKN2A (13%), and YAP1 (11%). Univariate and multivariate analyses of clinical factors and genetic alterations indicated that sex is an independent prognostic factor, with males tending to have better LRFS (hazard ratio [HR], 0.25; 95%CI, 0.08‐0.77, P =.015) and progression‐free survival (PFS) (HR, 0.35; 95%CI, 0.13‐0.93, P =.030) following dCRT. Meanwhile, YAP1 amplification (n = 7) was an adverse prognostic factor, and patients with this alteration demonstrated a tendency toward worse outcomes with shorter LRFS (HR, 4.06; 95%CI, 1.26‐13.14, P =.019) and OS (HR, 2.78; 95%CI, 0.95‐8.17, P =.062). In a subgroup analysis, while sex and M‐stage were controlled, a much stronger negative effect of YAP1 amplification vs wild‐type in LRFS was observed (log‐rank P =.0067). Conclusion: The results suggested that YAP1 amplification is a potentially useful biomarker for predicting treatment outcomes and identifying patients with a high risk of relapse who should be closely monitored. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the effects of the inclusion levels of different types of rapeseed meal (RSM) on performance, organ weight, and serum biochemical parameters in Cherry Valley ducks in the starter period and grower-finisher period. In Exp. 1, a total of 750 seven-day-old male ducklings were divided into 5 dietary treatments with 6 replicate pens of 25 birds per pen. The starter diets with the inclusion of 0, 5, 10, 15, or 20% of double-low RSM contained 0, 1.37, 2.15, 3.46, or 5.31 µmol glucosinolates (GLS)/g in the finished feed (from day 7 to 21). In Exp. 2, a total of 900 fifteen-day-old male ducklings were divided into 6 dietary treatments with 6 replicate pens of 25 birds per pen. The grower-finisher diets with the inclusion of 0, 5, 10, 15, 20, or 25% of Indian RSM contained 0, 7.67, 15.34, 24.66, 31.21, or 38.44 µmol GLS/g in the finished feed (from day 15 to 42). For ducklings in the starter period (Exp. 1), body weight gain and feed intake decreased linearly as the dietary double-low RSM inclusion level increased at day 7 to 14, while growth rate was not influenced by dietary double-low RSM inclusion levels at day 15 to 21 and day 7 to 21. For ducks in the grower-finisher period (Exp. 2), growth performance decreased linearly as the dietary RSM inclusion level increased from 5 to 20%. In addition, dietary RSM inclusion levels induced liver enlargement in ducklings at day 21 (5 to 20% double-low RSM with 1.37 to 5.31 µmol/g GLS) and thyroid enlargement accompanied by increased serum AST and ALP activities in ducks at day 42 (5 to 15% Indian RSM with 7.67 to 23.66 µmol/g GLS). Therefore, our results indicated that the upper limit of using RSM sources in feed formulation should consider the anti-nutritional factor of GLS content at different stages of duck growth. [ABSTRACT FROM AUTHOR]

The microstructure and mechanical properties of hypereutectic Al−Si alloys containing 16 wt.%, 21 wt.% and 30 wt.% Si (AlSi16, AlSi21 and AlSi30) have been investigated in "as‐cast" and "annealed at the liquid‐solid region". The results show that the morphologies of primary Silicon in AlSi30 changed hardly after being annealed at 587 °C for different time. The morphology of eutectic silicon in all Al−Si alloys changed from flake‐like to granular after being annealed at 587 °C for 5 min to 15 min. With the increase of silicon content, the average size of the granular eutectic silicon decreased. The spheroidized effect for the eutectic silicon in AlSi21 was the best. After being annealed for 15 min, the tensile strength of AlSi16, AlSi21 and AlSi30 alloys decreased by 10.4 %, 11.7 % and 11.5 %, respectively. Their elongation increased 61.1 %, 50.0 % and 33.3 %, respectively. The comprehensive mechanical properties of AlSi16 and AlSi21 alloys were improved markedly after being annealed at 587 °C for 15 min. [ABSTRACT FROM AUTHOR]

Scalable growth of SiC quasi-aligned nanoarrays on SiC wafer substrate was reported through the pyrolysis of polymer precursor by using Au as the catalysts. Differently to the conventional one-dimensional nanostructures often with cylindrical shape, the as-grown SiC nanowires possessed tapered configurations with sharp tips, enabling their desired formation with typical nanoneedle morphology. Their turn-on fields manifested a decline from 3.4 to 1.4 V/ μ m, when the temperatures were adjusted from room temperature to 400 °C, evidencing their excellent field emission performance. Furthermore, they behaved a high stability with no obvious current emission degradation when subjected to high temperature of 200 °C over 10 h, representing their promising applications in vacuum electronics with robust stability under high-temperature harsh conditions. [ABSTRACT FROM AUTHOR]

Since driving behaviour has a close relationship with driving safety, forming good driving habits and avoiding unsafe driving activities are important for drivers to keep away from traffic accidents. However, abnormal driving behaviour detection system seldom appears on vehicles because of detection accuracy and many other reasons. In this paper, a novel method based on Kinect sensor is proposed to detect abnormal driving behaviour in real time. The kernel of the method is two-fold. A Kinect sensor is used to capture thejoints information of the monitoring driver. Only 6joints information are captured to form a driving behaviour descriptor. Then, an SVM is used to classify the behaviour into right driving behaviour or abnormal driving behaviour. We built a simplified car cockpit and test our method on a popular computer game, "Need for speed 11", the experiment results show that the proposed method can effectively detect abnormal driving behaviour in real time. [ABSTRACT FROM AUTHOR]

This paper addresses the problem of adaptive fuzzy tracking control for a class of nonlinearly parameterized systems with unknown control directions. In this paper, the nonlinearly parameterized functions are lumped into the unknown continuous functions which can be approximated by using the fuzzy logic systems (FLS) in Mamdani type. Then, the Nussbaum-type function is used to detect the unknown control direction and based on the backstepping technique, the adaptive fuzzy controller is designed. The main advantages of this paper are that (1) in the existing results the separation principle is used to deal with the nonlinearly parameterized functions, unlike them in this paper, the FLS are applied to approximate the nonlinearly parameterized functions, (2) by using the minimal learning parameters (MLP) algorithm, only one parameter needs to be adjusted online in the controller design procedure, which reduces the online computation burden greatly, (3) the Nussbaum-gain technique is introduced to resolve the unknown control direction problems. It is proven that the proposed control scheme renders the closed-loop system stable in the sense of semiglobal uniformly ultimately bounded (UUB). Finally, simulation results are provided to show the effectiveness of the proposed approach. [ABSTRACT FROM AUTHOR]

Temporal and spatial variations of phytoplankton community in Lake Erhai were investigated from May 2010 to April 2011. A total of 124 species belonging to 8 phyla and 72 genera were recorded, among which Chlorophyta (74) ranked the first, followed by Bacillariophyta (24) and Cyanophyta (17). Total phytoplankton density ranged from 27.7 × 105 to 442.1 × 105 cells/L, with annual average value of 196.3 × 105 cells/L. The range of total phytoplankton biomass was between 0.68 mg/L and 3.25 mg/L, with annual average value of 2.31mg/L. In winter and spring, the dominant species were Fragilaria capucina and Aulacoseira granulata, while it changed into Cyclotella meneghiniana, Microcystis (M. aeruginosa, M. wesenbergii and M. viridis) and Psephonema aenigmaticum in summer and autumn. Phytoplankton biomass in the southern zone of the lake was significantly higher than those in the northern and middle zones of the lake. Two-way ANOVA showed that the influences of temporal (F = 43.75, P < 0.001), spatial variability (F = 14.85, P < 0.001), and their interaction (F = 2.74, P < 0.001) on phytoplankton biomass in Lake Erhai were all significant. Redundancy analysis revealed that water temperature, transparency, nutrient concentration and crustacean zooplankton were main environmental factors affecting phytoplankton community structure. [ABSTRACT FROM AUTHOR]

In the present work, the effects of Ti-substitution for Mn upon the structure, magnetic and dielectric properties in La2NiMnO6 ceramics have been investigated. Ti-substitution for Mn strongly affects the crystallographic, magnetic, and dielectric properties of La2NiMnO6 double perovskite ceramics. Refinements of the x-ray diffraction data show that all compositions investigated here have the monoclinic perovskite structure in space group P21/n with a partially ordered arrangement of Ni and Mn/Ti cations. The magnetic nature of the present ceramics with x up to 0.8 is ferromagnetic (FM), while that is antiferromagnetic for La2NiTiO6. The Curie temperature and the spontaneous magnetization, or FM component, decrease with increasing x. These ferromagnetic states are attributed to the Ni2+-O-Mn4+ superexchange interaction. The dielectric constant monotonically decreases and the relaxor-like behavior is suppressed with x. The similar variation tendency of magnetic and dielectric properties with increasing x can be explained simply by the dilution effect. [ABSTRACT FROM AUTHOR]

The dielectric response and conductivity have been measured in (Bi1-xNdx)FeO3 (x = 0.0 and 0.05) ceramics as functions of temperature and frequency. A one-dimensional across-barrier model with intrinsic barriers, B (in temperature units), every lattice constant, a, and extrinsic barriers, B + Δ, every distance, d, is introduced to describe the dielectric response and conductivity. The across-barrier hopping is responsible for the high-temperature conductivity and step-like dielectric relaxation in the region of 500-800 K. Good qualitative fits of dielectric dispersion and conductivity are obtained with d = 20-30 nm, B = 8400-8700 K (∼0.72-0.75 eV), and Δ = 2500 K (∼0.215 eV). The resistivity plot of scaled ρ" versus ρ' indicates a contribution of grain boundaries or internal defects to the conductivity. [ABSTRACT FROM AUTHOR]

We report on the optical properties of high-quanlity ZnCdO/ZnO single quantum well (SQW) grown on c-sapphire substrates by pulsed laser deposition. The temperature dependent photoluminescence (PL) of ZnO/ZnCdO SQWs exhibits an inconspicuous S-shaped property due to the weak carrier localization effect, as a consequence of the slightly inhomogeneous Cd distribution in the well layer as well as the smooth interfaces. The integrated PL intensity of the higher Cd SQW decreases faster than that of the lower sample with increasing temperature, indicating the presence of interface barrier in high Cd content SQWs. [ABSTRACT FROM AUTHOR]

Dielectric properties of La2CuTiO6 ceramics were investigated in a broad frequency and temperature range. There is only one dielectric relaxation in the curve of temperature dependence of dielectric properties for La2CuTiO6 ceramics. This dielectric relaxation is a thermal activated process. The bulk and grain boundary resistances can be obtained from results of the least-mean-square fitting on impedance spectra. The conduction mechanism of the present ceramics is also a thermal activated process. The activation energy of dielectric relaxation is almost same as that of electrical conductivity and this indicates the closely correlation between the dielectric relaxation and electrical conductivity. The dielectric relaxation in the present ceramics should be attributed to the mixed-valent structure (Cu+/Cu2+ and Ti3+/Ti4+), which is induced from the oxygen vacancy. [ABSTRACT FROM AUTHOR]

Microstructure and polarization degradation are observed under cyclic electric loadings for [001]-oriented Pb(Mg1/3Nb2/3)O3–PbTiO3 single crystals. Microcracking and phase transition are found to bear effect for polarization degradation. Upon cyclic electric loading with a comparatively low field magnitude, phase transition does not occur but the propagation of microcracks significantly reduces the polarization. When electric loading is cycled under a high field magnitude, the single crystal transforms from a rhombohedral phase to a monoclinic one. Both microcracking and phase transition hinder ferroelectric domain switching and reduce the number of electric dipoles that may switch under cyclic electric field. The phase transition degrades the polarization to a greater degree than the microcracks. The results imply that the polydomain state of a ferroelectric rhombohedral phase enhances the electromechanical properties. [ABSTRACT FROM AUTHOR]

We present an effective medium theory based on the Maxwell-Garnett [J. C. Maxwell Garnett, Philos. Trans. R. Soc. London, Ser. A 203, 385 (1904); ibid. 205, 237 (1906)] and Bruggeman [D. A. G. Bruggeman, Ann. Phys. (Leipzig) 24, 636 (1935)] approximations, to investigate the effective mass density of binary and ternary liquid composites. Excellent agreement between our experiment and theory is shown. The results are well interpreted in terms of intermolecular interactions, which affect the miscibility between liquid components. Thus, it becomes possible to theoretically predict the effective mass density of liquid composites. [ABSTRACT FROM AUTHOR]

Deformation and molecular chain evolution under combined electrical and mechanical loads are characterized for poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] copolymer films with 55 and 68 mol % VDF content [termed P(VDF-TrFE) 55/45 and P(VDF-TrFE) 68/32, respectively]. In both copolymer films, the direction of the applied electric field with respect to the stress field direction has significant influence on the stress-strain behavior and the evolution of molecular chain structure. When the electric field is applied parallel to the tension direction, the molecular chains have the tendency to convolute, which prevents the films from acquiring a more oriented fibrillar structure compared with film structures under pure mechanical tensile stress. Consequently, the yield strength is enhanced while the fracture strain is reduced. When the electric field is applied along the film thickness direction, it causes randomly oriented dipoles in the films to orient preferentially along the direction of the external electric field. The combination of the mechanical tensile load and the electric field in the film thickness direction contributes to a well aligned and closely packed molecular chain structure, and consequently both UTS and fracture strain are increased. The VDF content dependence on the stress-strain behavior is discussed. [ABSTRACT FROM AUTHOR]

Electric fatigue under cyclic loading was characterized for poly(vinylidene fluoride-trifluoroethylene) 68/32 copolymer films prepared under two processing conditions. For the copolymer films prepared by solution casting and then annealing (termed as unstretched films), the remanent polarization (Pr) decreases while the coercive field (Ec) increases as the field cycles. For the copolymer films prepared by stretching the solution-cast films and then annealing (termed as stretched films), both Pr and Ec decrease as the cycle number increases. Scanning electron microscopy observation and x-ray diffraction analysis were carried out to examine the morphology and microstructure changes during the electric field cycling. The differences in the polarization and electric fatigue behavior between the unstretched and the stretched copolymer films can be mainly attributed to the change of the crystallinity, the orientation degree of the polymer chains and electric dipoles, as well as the interfacial layer effects. [ABSTRACT FROM AUTHOR]