Search

Discusses the domain specifications and content representativeness of the revised value orientation inventory (VOI) for physical education teachers. VOI revision process; Disciplinary mastery; Learning process; Self-actualization; Ecological integration; Social reconstruction.

Tebuconazole is an effective but potentially carcinogenic fungicide. Tebuconazole residues in loquat and sugarcane were investigated, together with an analysis of their dietary risk. Solid-phase extraction and high-performance liquid chromatography-tandem mass spectrometry showed fortified recoveries of 87% to 98%, with standard deviations ≤ 6.4%. The tebuconazole residues were below 6.34 mg kg−1 for whole loquat and 0.80 mg kg−1 for sugarcane. Based on the final residue test, the chronic hazard index was 90.74% in whole loquat and sugarcane, while the acute hazard index ranged from 66.32% to 109.49% for loquat and 33.37% to 76.93% for sugarcane. The assessment of potential dietary risk showed that while loquats may represent an acute risk to human health, whereas sugarcane consumption was safe. A 21-day pre-harvest interval is proposed to comply with maximum residue limit regulations and the observed risks when using 430 g/L tebuconazole for treating sugarcane. These findings offer guidance for tebuconazole formulation and use. [ABSTRACT FROM AUTHOR]

Rheumatic heart disease (RHD) is an autoimmune disease caused by rheumatic fever following group A hemolytic streptococcal infection and primarily affects the mitral valve. RHD is currently a major global health problem. However, the exact pathological mechanisms associated with RHD-induced cardiac valve damage remain to be elucidated. The endothelial-mesenchymal transition (EndMT) serves a key role in a number of diseases with an important role in cardiac fibrosis and the activin/Smad2 and 3 signaling pathway is involved in regulating the EndMT. Nevertheless, there are no studies to date, to the best of the authors' knowledge, investigating the association between RHD and EndMT. Thus, the aim of the current study was to investigate the potential role of EndMT in cardiac valve damage and assess whether activin/Smad2 and 3 signaling was activated during RHD-induced valvular injury in a rat model of RHD induced by inactivated Group A streptococci and complete Freund's adjuvant. Inflammation and fibrosis were assessed by hematoxylin and eosin and Sirius red staining. Serum cytokine and rheumatoid factor levels were measured using ELISA kits. Expression levels of activin/Smad2 and 3 signaling pathway-related factors [activin A, Smad2, Smad3, phosphorylated (p-)Smad2 and p-Smad3], EndMT-related factors [lymphoid enhancer factor-1 (LEF-1), Snail1, TWIST, zinc finger E-box-binding homeobox (ZEB)1, ZEB2, α smooth muscle actin (α-SMA) and type I collagen α 1 (COL1A1)], apoptosis-related markers (BAX and cleaved caspase-3) and valvular inflammation markers (NF-κB and p-NF-κB) were detected using reverse transcription-quantitative PCR and western blot analyses. Compared with the control group, the degree of valvular inflammation and fibrosis, serum levels of IL-6, IL-17, TNF-α and expression of apoptosis-related markers (BAX and cleaved caspase-3) and valvular inflammation marker (p-NF-κB), activin/Smad2 and 3 signaling pathway-related factors (activin A, p-Smad2 and p-Smad3), EndMT-related factors (LEF-1, Snail1, TWIST, ZEB 1, ZEB2, α-SMA and COL1A1) were significantly increased in the RHD group. These results suggested that the activin/Smad2 and 3 signaling pathway was activated during the development of valvular damage caused by RHD and that the EndMT is involved in RHD-induced cardiac valve damage. [ABSTRACT FROM AUTHOR]

Organoboronates are synthetically useful and highly valuable building blocks in synthetic and medicinal chemistry. Two‐electron reactions allow for the rapid construction of organoboronates via nucleophilic 1,2‐boron shift of boron ate complexes or MIDA‐mediated 1,2‐boryl migration. Radical approaches through 1,2‐boron shift of neutral boronic esters or boron ate complexes have been demonstrated to be feasible, providing complementary methods to access these privileged scaffolds. In this Review, recent achievements are highlighted and future opportunities are discussed, with an emphasis on different operative modes of catalysis and reaction pathways. [ABSTRACT FROM AUTHOR]

The dielectric and ferroelectric properties of (1-z) (Sr0.7Bi0.2)TiO3–z(Na0.5Bi0.5)TiO3 solid solutions with z=0.65–1 are studied. High remnant polarization of ∼51 μC/cm2 with a coercive field of 50 kV/cm, and a dielectric constant of ∼1000 have been obtained at room temperature in the sample with z=0.9, indicating an application potential as a lead-free ferroelectric material. There are two dielectric anomalies in the temperature range of 150–670 K for all samples; one is the dielectric peak without significant frequency dispersion, and the other is significantly frequency dependent. The result of this work shows that the formula scheme “a ferroelectric relaxor+a ferroelectric” for solid solutions is a promising approach in the search for high performance lead-free ferroelectric materials. [ABSTRACT FROM AUTHOR]

The dielectric behavior and electrical conduction in Bi doped SrTiO3 annealed in both oxidizing (air and oxygen) and reducing atmospheres (nitrogen and “hydrogen+argon”) are studied in this letter. The dielectric constant and electrical conductivity are greatly enhanced in the sample annealed in a reducing atmosphere compared with that annealed in an oxidizing atmosphere. A Mott’s variable range hopping (VRH) conduction mechanism, σ=σ0 exp[-(T0/T)1/4], is observed in a strongly reduced sample, where a significant dielectric relaxation process is present. No direct correlation is found between the VRH conduction and the dielectric relaxation. The underlying physics of these results are briefly discussed. [ABSTRACT FROM AUTHOR]

The dielectric spectra of poly(vinylidene fluoride-trifluoroethylene) copolymers and poly(vinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene) terpolymers are studied in a wide temperature and frequency range with electric field. It is found that the dominant relaxation process displays a peculiar characteristic—a “dielectric relaxor” behavior, rather than a “ferroelectric relaxor” behavior reported in the current literature; furthermore, we show the experimental observation that the existence of nanometer scale crystals embedded in an amorphous matrix is the base of the dielectric relaxor behavior and high electroactive performance in these polymers. [ABSTRACT FROM AUTHOR]

The dc electric-field dependence of the dielectric properties of cadmium niobate Cd2Nb2O7 single crystals is studied, and characteristics of the dielectric behavior of Cd2Nb2O7 under dc bias are revealed. The temperature (Tm) where the dielectric relaxation mode occurs is independent of dc bias levels, while its intensity is greatly suppressed and finally eliminated with increasing dc bias from 0 to 15 kV/cm. The observed dielectric relaxation features of Cd2Nb2O7 can be attributed to “dielectric relaxor” behavior, rather than “ferroelectric relaxor” behavior previously designated in literature. The physical nature of the dielectric relaxor behavior is briefly discussed. [ABSTRACT FROM AUTHOR]

The electrostrictive property and dielectric behavior of the stretched poly (vinylidene fluoride–trifluoroethylene) copolymers, denoted as P(VDF–TrFE), have been studied at cryogenic temperatures. Polarization hysteresis loops and high electrostrictive performance (strain ∼1%) are obtained at room temperature. An obvious dielectric relaxation process is observed and the relaxation rate follows the Vogel–Fulcher relation with T[sub VF]=160 K, U=0.18 eV, ν[sub 0]=5.7×10[sup 12] Hz. The dielectric relaxation behavior and high strain level decrease quickly with decreasing temperature, and below 160 K only a small strain level (∼0.1%) and an “intrinsic” dielectric constant sustains. The correlation of dielectric behavior and strain activity and the physical mechanism of the quick suppression of the strain with decreasing temperature are briefly discussed. The results indicate that a high dielectric constant is critical for obtaining high electrostrictive strains in the polymers at a reasonable electric field. © 2003 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Purpose: Based on the theorized concept "Curriculum Safety Zone (CSZ)," this study was conducted to identify the factors for breaking CSZ by contrasting the experiential accounts of two pre-service teacher groups who taught within or outside of their CSZ. Method: Pre-service teachers (n = 14) from a sport-centered PETE program were trained to teach a Health-First curriculum module and their peers (n = 14) a traditional sport module. Each group taught their respective module to 14 intact 7th grade classes in 14 schools in China. A mixed-methods design was used. Quantitative data on learner knowledge gain were collected from the learners. Qualitative data included lesson observation fieldnotes, social-media posts, and interview responses and were gathered from the pre-service teachers. Results: Learners in the Health-First schools gained more knowledge than those in the Comparison schools (t26 = 2.92, p =.007, Cohen's d = 1.10). Qualitative evidence was triangulated using a Health-First vs. Comparison contrasting approach with open-, axial-, and selective-coding to generate themes. The themes were Confidence in Doubt, Lesson Plans to the Rescue, Professional Development is Necessary But..., and Student Learning Save the Day! A grounded theory was developed using the themes and interpreted using the Interconnection Model of Teacher Professional Growth. Conclusion: Breaking CSZ requires a synergistic effort with carefully designed professional development, detailed lesson plans, an effective support network, and, most important of all, a powerful curriculum that can elicit observable and measurable learner achievement. [ABSTRACT FROM AUTHOR]

Purpose: It has been acknowledged in physical education (PE) that knowledge empowers learners to develop a physically active lifestyle In this study, we consider Cognitive Load Theory (CLT) as a valuable extension of the constructivist learning theory to help articulate the role of three pivotal instructional factors, content knowledge, learners, and instructional process, in learning fitness knowledge in PE. Guided by CLT, this study was intended to identify middle school students' cognitive architecture about aerobic and anaerobic concepts and pedagogical factors that might enhance or limit scientific conceptualization. Methods: We employed a mixed-methods approach. A total of 291 students randomly drawn from the 24 schools provided data on conceptual knowledge levels via standardized test and conceptual structures of understanding via semi-structured interviews about the aerobic/anaerobic concepts. Results: Results from integrated quantitative and qualitative analyses reveal the role of task element interactivity as a function of conceptualization in the students' cognitive architecture. The students lack the understanding that aerobic and anaerobic concepts are associated with the concepts of complex metabolic systems that dictate the energy pathways experienced in physical activity. Their understandings are characterized by a tendency of overly simplifying the complex conceptions for convenient schema activation. The simplified conception is likely to prohibit their understanding from becoming consistent with the science. The findings suggest that teachers should anticipate lack of understanding of knowledge connectivity when teaching fitness concepts and establish the task element interactivity with enhanced clarity to facilitate knowledge learning. Conclusion: Consistent with the constructivist learning theory, the findings inform us that teaching complex fitness concepts require the teacher to connect prior knowledge as a prerequisite to activate relevant cognitive architecture and actively build connections between the prior knowledge and the to-be learned concepts. PE curriculum designers and teachers should anticipate the complex challenges in teaching the aerobic and anaerobic concepts because of their connections to other concepts associated with human energy systems such as intensity and oxygen supply. [ABSTRACT FROM AUTHOR]

Studies the influence of post-sintering annealing on the dielectric relaxation behavior in La-doped perovskite oxide. Peaking of dielectric permittivity with frequency dispersion; Dielectric polarization behavior; Similarity between La and Bi-doped perovskite oxide.

A flexible polyurethane elastomer (PUE) is studied, and the improved impact-resistant performance is revealed. Compressive stress–strain curves over a wide loading rate range were derived. Under static loading, the rubbery-like characteristics are demonstrated, which are flexible and hyperelastic, to process a large strain of about 60% followed by full recovery upon unloading. Under high-rate loadingcompared with the mechanical data of polyurethane elastomer (PUE) and polyurea (PUA) materials in the literature. Orderly parallel deformation bands were formed from carrying a large strain. The fibrils were found between deformation bands for enhancing the yield/plateau stress. A considerable plastic zone ahead of propagating crack with numerous crazes and microcracks was produced for realizing the dynamic strain energy absorption. This work presents a scientific innovation for developing outstanding impact-resistant polyurethane elastomers for transparent protection engineering. [ABSTRACT FROM AUTHOR]

[Display omitted] • A selection strategy for base-period images of spatio-temporal fusion was proposed. • The spatio-temporal inconsistency between field samples and images was reduced. • The estimation accuracy of grassland aboveground biomass was improved. The accurate estimation of the aboveground biomass (AGB) is crucial for the sustainable utilization and management of grassland resources. Spatio-temporal inconsistencies between field samples and satellite images are major source of error in the estimation of grassland AGB. To solve this problem, this study selected the Three Rivers Headwater Region as the study area and proposed a selection strategy for base-period images of spatio-temporal fusion that was suitable for use at a large spatial scale in which cloud-free images are difficult to obtain. The spatial and temporal adaptive reflectance fusion model (STARFM) based on the selection strategy was used to generate a synthetic Normalized Difference Vegetation Index (NDVI) dataset with high spatial-temporal resolution by using the maximum value composite of GF-1 NDVI and MODIS NDVI to enhance the spatial-temporal quality of the images for field-scale application. Three estimation models for grassland AGB were then constructed by the random forest algorithm using synthetic NDVI, MODIS NDVI, GF-1 NDVI respectively, together with ancillary data. Following this, the estimation model with the highest accuracy was used to generate a 16-m eight-day time-series AGB in the growing season. The results showed: (1) The synthetic NDVI was correlated closely with the observed GF-1 NDVI, with an average R of 0.825 and a RMSE of 0.087. The temporal trend of the synthetic NDVI for each grassland type was highly consistent with that of the MODIS NDVI in the growing season with a correlation higher than 0.9. (2) The synthetic NDVI reduced the spatial difference between field samples and images to 16-fold, and the temporal difference was controlled to within four days under ideal conditions. (3) The synthetic NDVI improved the estimation accuracy of grassland AGB by about 15.9% and 19.7% (R2), and 13.7% and 17.5% (RMSE) relative to MODIS NDVI and GF-1 NDVI, respectively. (4) The time-series AGB revealed accurately the spatial distribution of and seasonal temporal variations in the grassland biomass. The results of this study may serve as scientific guidance for timely monitoring of grassland conditions and precise management of grassland resources in China. [ABSTRACT FROM AUTHOR]

Ultrasonic guided waves (UGWs) in water-filled pipes are subject to more severe dispersion and attenuation than vacant pipes, posing significant challenges for defect identification and localization. To this end, a novel sparse signal decomposition method called orthogonal matching pursuit based on dispersion and multi-mode (DMOMP) was proposed, which utilizes the second-order asymptotic solution of dispersion curves and the conversion characteristics of asymmetric UGWs in the defect contact stage to reconstruct the dispersive signals and converts the time-domain dispersive signals to distance-domain non-dispersive signals by dispersion compensated time-distance mapping. The synthesized simulation results indicate that DMOMP not only exhibits higher reconstruction accuracy compared to OMP, but also reveals more accurate and stable mode recognition and localization compared to DOMP, which only considers the dispersion under perturbation and noise. In addition, the UGW testing experimental results of water-filled pipes verify the effectiveness of DMOMP, the localization accuracies of three feature signals (defct 1, defct 2 and end echo) with DMOMP are 99.10%, 98.72% and 98.36%, respectively, and the average localization accuracy of DMOMP is as high as 98.73%. [ABSTRACT FROM AUTHOR]

Inhibition of CYP enzymes is thought to be the most common cause of drug–drug and/or herb–drug interactions. To characterize the inhibition of CYP enzymes activities by chemicals, enzyme inhibition kinetic experiments are usually carried out. The purpose of this letter is to call attention to evaluate the enzyme inhibition kinetics in drug–drug interactions. [ABSTRACT FROM AUTHOR]

Oridonin (ORI), the major pharmacological component extracted from a traditional Chinese medicine, possesses a beneficial effect on myocardial ischemia/reperfusion (I/R) injury. However, the underlying molecular mechanism by which ORI effects take place is not completely known. Thus, whether ORI works via downregulating oxidative stress and nod-like receptor protein-3 (NLRP3) inflammasome pathway was investigated in this study. Mice underwent surgery to induce myocardial I/R injury, and some were administered ORI (10 mg/kg/day) pretreatment, while others were not. The myocardial enzymes' levels, infarct area, and inflammatory injury were measured. The activation situation of oxidative stress and NLRP3 inflammasome was also detected. We found that ORI pretreatment significantly alleviated CK-MB and cTnI levels and infarct size induced by I/R. ORI mitigated the inflammatory injury by decreasing the pathological damage and lowering TNF-α, IL-1β, and IL-18 levels. Moreover, the SOD1 and eNOS levels were significantly increased by ORI, while MDA and iNOS levels were relatively decreased. The oxidative stress was reversed using ORI pretreatment. Importantly, NLRP3 inflammasome pathway was also inhibited by ORI, as reflected by the lower protein levels of NLRP3, caspase-1, and IL-1β. In conclusion, ORI alleviates myocardial injury induced by I/R via inhibiting the oxidative stress and NLRP3 inflammasome pathway. [ABSTRACT FROM AUTHOR]

• The inhibition risk of shikonin on UGT enzymes was firstly investigated. • Shikonin significantly inhibited UGT1A1, UGT1A3, UGT1A9/PROG, and UGT2B7/AZTG activities in human and rat liver microsomes. • Shikonin exhibited no time-dependent inhibition on UGT activities. • Shikonin displayed competitive inhibition on UGT isoforms. Shikonin, a natural red colorant, is widely used for food garnishment and cosmetic ingredient in the world. Shikonin also possesses a variety of pharmacological actions, including anti-inflammation and anti-cancer activities. However, little is known about its effects on the UDP-glucuronosyltransferases (UGT) activity. Therefore, the aim of this study was to evaluate the effect of shikonin on the UGT1A1, UGT1A3, UGT1A6, UGT1A9 and UGT2B7 activities via the human and rat liver microsomal assay and cocktail approach. The results showed shikonin inhibited human and rat liver microsomal UGT activity only in a dose-dependent manner. The further enzyme kinetic studies demonstrated that shikonin was not only a competitive inhibitor of human UGT1A1, UGT1A9, and UGT2B7, but also presented competitive inhibition on rat UGT1A1 and AZTG reactions. In conclusion, shikonin as a reversible inhibitor of UGT enzyme has a high-risk potential to cause the possible toxicity, especially drug-drug or food-drug interactions. [ABSTRACT FROM AUTHOR]

The increasing frequency of global drought events poses a significant threat to the stability of grassland ecosystems' functionality. The Inner Mongolian grasslands stand out as one of the world's most drought-prone regions, facing elevated drought risks compared to other biomes. An in-depth comprehension of the impact of drought on grassland ecosystems is paramount for their long-term sustainability. Using the Standardized Precipitation Evapotranspiration Index (SPEI) from 1982 to 2018, this study identified various drought events within the Inner Mongolian grasslands, encompassing moderate drought, severe drought, and extreme drought. The resistance of the vegetation to the different drought conditions, assessed through net primary productivity (NPP) as a metric (reflecting its capacity to maintain its original level during drought periods), was examined. The research findings indicated that the period from 2001 to 2018 witnessed a substantial increase in both the frequency and the extent of drought events compared to the period from 1982 to 2000, particularly concerning severe and extreme droughts. The areas most severely impacted by extreme drought were the Xilingol League and the Alxa League. From 1982–2000 to 2001–2018, under moderate drought conditions, vegetation resistance exhibited a minor decrease in the central and eastern regions but experienced a slight increase in the western region. In contrast, under severe drought conditions, the western region saw a significant decrease in vegetation resistance. Remarkably, under extreme drought conditions, the western region showed a substantial increase in vegetation resistance, while the central and eastern regions experienced a slight decrease. Across all three drought conditions, as precipitation levels declined, the resistance of the meadow–steppe–desert ecosystems demonstrated a high–low–high distribution pattern. The temperate desert steppe exhibited a minimal vulnerability to drought, boasting resistance levels exceeding 0.9. Notably, extreme drought had the most pronounced impact on the temperate meadow steppe, temperate steppe, and temperate desert steppe, particularly within the temperate meadow steppe category. Given these findings, the authorities responsible for grassland management should prioritize regions characterized by frequent drought occurrences and low drought resistance, such as Ulanqab City, the Xilingol League, and the western part of Hulun Buir City. Safeguarding steppe ecosystems is of paramount importance for stabilizing vegetation productivity and land carbon sinks, especially under the anticipated exacerbation of climate conditions in the future. [ABSTRACT FROM AUTHOR]

Tunnel lining falling blocks can cause great threats to traffic safety, resulting in traffic interruptions or speed limits and endangering operational safety. Traditional lining disease remediation measures have low efficiency and high costs and are time consuming. Combining the research methods used in the literature, indoor testing, and model experiments, a very normal material, namely, polyurea spray film material, is proposed as a means by which to remediate the lining falling block disease in tunnels. A 1 : 1 tunnel lining structure model was established at the site, and four experimental conditions were tested. The experiments revealed that the tensile stress was less than the tensile strength and that no tensile fracture occurred in the polyurea spray film material under the joint action of the block's self-weight and aerodynamic loads. Factors such as side seam treatment, surface sanding, and spray temperature may influence the bond strength of the polyurea spray film material. In order to remediate the issue of lining blocks falling, we recommended increasing the bond strength between the spray film material and the concrete or increasing the thickness of the polyurea spray film material. [ABSTRACT FROM AUTHOR]

This paper presents a new topology optimization technique for the design of compliant mechanisms that are efficient in transferring motion, force, or energy while being sufficiently strong to resist yield or fatigue failure. Generally, flexure hinges are efficient in transferring motion, force, or energy but are weak in resisting yield or fatigue failure while slender beams are relatively inefficient but strong. Thus, our philosophy is that a compliant mechanism may benefit from the above complimentary properties of flexure hinges and slender beams if they are connected and sized in a rational way. This requires a design approach with both flexure hinges and beams as constructional elements, and the design approach should include criteria on both efficiency and strength. Therefore, in the proposed technique, a mixed mesh of flexure hinges and beams was employed to discretize the design domain, and their connectivity, locations, and sizes were simultaneously determined to fulfill both the so-called stiffness-flexibility criterion (for efficiency) and a newly proposed input stroke criterion (for strength). The input stroke of a compliant mechanism, defined per the von-Mises yield criterion, is inversely proportional to the maximum stress per input displacement and represents the mechanism's maximum input displacement before yield failure. Both theoretical explorations and design examples demonstrate that the strength of compliant mechanisms can be significantly improved without compromising the efficiency, and trade-off designs that are better balanced between strength and efficiency can be obtained. [ABSTRACT FROM AUTHOR]

Cell-in-cell structure is prevalent in human cancer, and associated with several specific pathophysiological phenomena. Although cell membrane adhesion molecules were found critical for cell-in-cell formation, the roles of other membrane components, such as lipids, remain to be explored. In this study, we attempted to investigate the effects of cholesterol and phospholipids on the formation of cell-in-cell structures by utilizing liposome as a vector. We found that Lipofectamine-2000, the reagent commonly used for routine transfection, could significantly reduce entotic cell-in-cell formation in a cell-specific manner, which is correlated with suppressed actomyosin contraction as indicated by reduced β-actin expression and myosin light chain phosphorylation. The influence on cell-in-cell formation was likely dictated by specific liposome components as some liposomes affected cell-in-cell formation while some others didn't. Screening on a limited number of lipids, the major components of liposome, identified phosphatidylethanolamine (PE), stearamide (SA), lysophosphatidic acid (LPA) and cholesterol (CHOL) as the inhibitors of cell-in-cell formation. Importantly, cholesterol treatment significantly inhibited myosin light chain phosphorylation, which resembles the effect of Lipofectamine-2000, suggesting cholesterol might be partially responsible for liposomes' effects on cell-in-cell formation. Together, our findings supporting a role of membrane lipids and cholesterol in cell-in-cell formation probably via regulating actomyosin contraction. [ABSTRACT FROM AUTHOR]

Presents the findings of a study which investigated high school students' primary emotional responses to physical education, focusing on students perceptions of class membership and its relations to perceived meaning and interest in physical education. Details on the study's findings; What the results of the study suggested.

An innovative morphing scheme, i.e., dynamical chordwise retracting and stretching, has been proposed for flapping wings. Its aerodynamic effects have been investigated based on a plunging two-dimensional flat wing. The conclusive results suggest that the novel morphing scheme can help to enhance the power utilization efficiency of flapping wings in forward motions. Plunging wings equipped with the novel morphing scheme can generate more thrust for a given power consumption or consume less power for a given thrust generation compared with their non-morphing counterparts. Moreover, the morphing scheme tends to function more positively as the defined morphing amplitude increases. In the currently covered parameter spaces, the largest peak propulsive efficiency improvements induced by the morphing scheme are 12.3% at Re = 15 × 104 and 10.8% at Re = 5 × 104, respectively. Examination of the flow structures around the plunging wings reveals that dynamical chordwise retracting and stretching of the wing can ameliorate the vortex distribution, which could account for the propulsive property changes caused by the morphing scheme. The current study may have yielded an inspiring and prospective scheme for enhancing the propulsive capacity of micro-flapping-wing aerial and underwater robots. [ABSTRACT FROM AUTHOR]

• Light-scattering angular spectrum is proposed for high-resolution particle sizing. • A compacted and lens-free optical system is designed for LSAS sampling. • The particle size distribution is inversed with high accuracy (D KL < 0.05). • The sensor is low-cost and portable for in-situ aerosol contamination measurement. In the study of aerosols, great concern has been focused on the particle size distribution (PSD) as a crucial factor of the physical and chemical properties of the aerosols. There are strong and growing demands for on-line and in-situ aerosol analysis technologies, but existing portable aerosol sensors can hardly provide high-resolution and accurate PSD measurement with limited volume and cost. To address this challenge, we introduce the concept of a new optical aerosol sensing method using light-scattering angular spectrum (LSAS), which describes the angular dependence of the scattering light intensity. The key novelty is a compacted LSAS sampling module for collecting the scattering light up to the observing angles. According to the wide-range LSAS sampled by our sensor, high-resolution PSD is predicted by non-negative regularization inversion algorithm. To validate the performance of our sensor, monodisperse di-ethyl-hexyl-sebacate aerosols (DEHS) samples of different sizes and smokes of smoldering cotton rope were tested. The maximum relative error (RE) of LSAS was smaller than 12.02%, while the Kullback-Leibler Divergence (D KL) between inversed and reference PSDs were smaller than 0.05. Without using any particulate pre-separation module and optical lens, we build a novel low-cost and miniaturized sensor only composed of a mirror, a linear charge coupled device (CCD) and a semiconductor laser, which has significant potential for high-resolution aerosol sizing in routine field measurements outside a laboratory. [ABSTRACT FROM AUTHOR]

A photonic-crystal slab can support bound states in the continuum (BICs) that have infinite lifetimes but are embedded into the continuous spectrum of optical modes in free space. The formation of BICs requires a total internal reflection (TIR) condition at both interfaces between the slab and the free space. Here, we show that the TIR of Bloch waves can be directly obtained based on the generalized Fresnel equations proposed. If each of these Bloch waves picks up a phase with integer multiples of 2π for traveling a round trip, light can be perfectly guided in the slab, namely forming a BIC. A BIC solver with low computational complexity and fast convergence speed is developed, which can also work efficiently at high frequencies beyond the diffraction limit where multiple radiation channels exist. Two examples of multi-channel BICs are shown and their topological nature in momentum space is also revealed. Both can be attributed to the coincidence of the topological charges of far-field radiations from different radiation channels. The concept of the generalized TIR and the TIR-based BIC solver developed offer highly effective approaches for explorations of BICs that could have many potential applications in guided-wave optics and enhanced light–matter interactions. [ABSTRACT FROM AUTHOR]

The direct-current (dc) electric-field dependence of dielectric constant around paraelectric-ferroelectric transition in Cd[sub 2]Nb[sub 2]O[sub 7] has been studied. The results show significant suppression of the dielectric constant by the application of dc bias. The electric-field dependence of the dielectric constant at the temperature around paraelectric-ferroelectric phase transition can be well described by the modified Devenshire relation including a cluster term, i.e., ε(E)=ε[sub 1]-ε[sub 2]E[sup 2]+ε[sub 3]E[sup 4]+(Px/ε[sub 0])[cosh(Ex)][sup -2]. The fit parameters indicate that the polar-cluster carries polarization P=∼0.5-2.5 mC/m[sup 2] with the cluster size of L=∼11-15 nm. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

A phenolic resin cross-linked nonionic polyacrylamide (NPAM) gel used for in-depth profile control was systematically analyzed. Long gelation time and strong gel strength of the gel system was obtained by adjusting NPAM or cross-linker concentration. An increase in temperature and salt concentration accelerated the gelation process and improved the gel strength. Although shearing brings a negative effect on gel performance, the gel system still had strong gel strength which could make it long-term stability in in-depth formation. Differential scanning calorimetry determined that this gel system should be used for oilfield application at temperatures below 143 °C. A compact three-dimensional network structure was formed in the bulk gel system and in porous media which contributed to long-term gel stability in the formation. Sand-pack flow experiments showed that the NPAM gel had a good plugging capacity and could selectively plug high permeability zones. By retention, adsorption, and bridging across the pore throats, the gel systems effectively reduced the permeability of porous media in high permeability zones and diverted fluid into low permeability zones, and thus improved the formation profile. Furthermore, this gel system for in-depth profile control treatment was successfully used in the Xinjiang oilfield of China which provided a reference for other similar high water cut oilfields for water control worldwide. [ABSTRACT FROM AUTHOR]

Riverine wetlands provide important habitats and travel corridors for resident and transient species, playing a key role in maintaining the diversity of entire landscapes. This paper assessed a long-term (1990–2013) landscape changes and avifauna community dynamics in the Yellow River wetland natural reserves, China. Remote sensing information was combined with field surveys to collect critical data on land use and avifaunal populations. The results reveal that land use has dramatic changes during 1990–2013. Utilized water features have significantly decreased over 20 years, whereas artificial land features such as paddy, dry field and built-up area have shown a steady increasing trend in the three riverine wetlands. The spatial landscape patterns of the three wetlands have become fragmented and notably heterogeneous as results of rapid economic development. With the changes of utilized water features, avifauna data show that some overwintering and transient species are becoming permanent residents. Though there is an abundant and diverse array of bird species utilizing the wetlands, migrating traits of these avifauna species have changed. This study can provide basic information for making effective and sustainable conservation plans for the entire Yellow River wetland natural reserves. [ABSTRACT FROM AUTHOR]

Presents information on the findings of a study which was conducted to elicit interpretations of boredom perceived by high school students repeating their required physical education course. Study's examination of the resistance model; Methods used in the study.

Magnetostrictive patch transducers (MPT) are widely used in non-destructive testing for flexibility, reputability, and durability. Based on the theory of magnetostriction, we developed a method for the design and optimization of axial magnetized MPTs for the transduction of L(0,2) ultrasonic guided waves. To get the optimum static bias magnetic field, we conducted experiments with different magnetostrictive patch aspect ratios, which were based on the theory of demagnetization. Furthermore, we analyzed the variations in solenoid coil parameters with changes in the dynamic alternating magnetic field and induced voltage via simulations and experiments. An optimized MPT was obtained, with its performance improved by 2.79 times compared with those of transducers without magnetostrictive patch. [ABSTRACT FROM AUTHOR]

This study firstly investigated the effects of cucurbitacin E (CuE), a tetracyclic triterpene compound from Cucurbitaceae, on the pharmacokinetics ( PK) and pharmacodynamics ( PD) of warfarin, a model CYP2C probe substrate, in the rat. In PK studies, the concentration of warfarin in blood samples was determined by HPLC- DAD, and the PK parameters were analysed using non-compartmental methods. In PD studies, the prothrombin time ( PT) in blood plasma at each sample point was measured via thromboplastin reagents. CuE treatment (50, 100 and 200 μg/kg, i.p.) decreased warfarin clearance (28-32%), increased the area under the curve ( AUC0-∞; 55-62%) and prolonged plasma half-life ( t1/2; 58-72%). At the same time, the anticoagulation effect of warfarin ( PTmax) was also significantly increased in the presence of CuE. These data demonstrated that CuE affected the PK and PD of warfarin, and these effects may be due to the inhibition of CYP2C activity by CuE. Hence, careful monitoring should be carried out during concomitant use of herbal products containing CuE with drugs that are metabolized by CYP2C enzymes. [ABSTRACT FROM AUTHOR]

This study analyzed the responses of two types of neutron detector in mixed gamma-ray and neutron radiation fields around a 150-MeV electron linear accelerator (LINAC). The detectors were self-assembled, high efficiency, and designed in two configurations: (1) a conventional moderated-type neutron detector based on a large cylindrical He-3 proportional counter; and (2) an extended-range version with an embedded layer of lead in the moderator to increase the detector’s sensitivity to high-energy neutrons. Two sets of the detectors were used to measure neutrons at the downstream and lateral locations simultaneously, where the radiation fields differed considerably in intensities and spectra of gamma rays and neutrons. Analyzing the detector responses through a comparison between calculations and measurements indicated that not only neutrons but also high-energy gamma rays (>5 MeV) triggered the detectors because of photoneutrons produced in the detector materials. In the lateral direction, the contribution of photoneutrons to both detectors was negligible. Downstream of the LINAC, where high-energy photons were abundant, photoneutrons contributed approximately 6% of the response of the conventional neutron detector; however, almost 50% of the registered counts of the extended-range neutron detector were from photoneutrons because of the presence of the detector rather than the effect of the neutron field. Dose readings delivered by extended-range neutron detectors should be interpreted cautiously when used in radiation fields containing a mixture of neutrons and high-energy gamma rays. [ABSTRACT FROM AUTHOR]

The dissipation and residue levels of thiacloprid, spirotetramat and its four metabolites residues in cowpeas were investigated under field conditions. The QuEChERS technique with high-performance liquid chromatography tandem mass spectrometry (HPLC–MS/MS) was used to detect thiacloprid, spirotetramat and its four metabolites residues content in cowpeas. The recoveries were 81.3–95.1% at a spike level of 0.005–0.5 mg/kg, the relative standard deviations (RSDs) were 2.1–9.5%. The dissipation kinetics data showed that thiacloprid and spirotetramat in cowpeas were degraded with the half-lives of 1.14–1.54 days and 1.25–2.79 days. The terminal residues of thiacloprid and spirotetramat were 0.0255–0.4570 mg kg−1 and 0.0314–0.3070 mg kg−1 after application 2 times with a pre-harvest interval (PHI) of 3 days under the designed dosages. The chronic and acute dietary exposure assessment risk quotient (RQ) values of thiacloprid in cowpeas for different consumers were 2.44–4.41% and 8.72–15.78%, respectively, and those of spirotetramat were 1.03–1.87% and 0.18–0.32%, respectively, all of the RQ values were lower than 100%. The dietary risk of thiacloprid through cowpeas to consumers was higher than spirotetramat. The results from this study are important reference for Chinese governments to develop criteria for the safe and rational use of thiacloprid and spirotetramat, setting maximum residue levels (MRLs), monitoring the quality safety of agricultural products and protecting consumer health. [ABSTRACT FROM AUTHOR]

Aboveground biomass (AGB) in grasslands directly reflects the net primary productivity, making it a sensitive indicator of grassland resource quality and ecological degradation. Accurately estimating AGB over large regions to reveal long-term AGB evolution trends remains a formidable challenge. In this study, we divided Inner Mongolia Autonomous Region (IMAR) grasslands into three study regions based on their spatial distribution of grassland types. We combined remote sensing data with ground-based sample data collected over the past 19 years from 6114 field plots using the Google Earth Engine platform. We constructed random forest (RF) and traditional regression AGB inversion models for each region and selected the best-performing model through accuracy assessment to estimate IMAR grassland AGB for the period 2000–2022. We also examined the trends in AGB changes and identified the driving forces affecting IMAR grasslands through the application of Theil-Sen estimation, Mann-Kendall trend analysis, and the Geodetector model. The main findings are as follows: (1) Compared with the univariate parametric traditional regression model, the AGB monitoring accuracy of the multivariate non-parametric RF model in the three study regions increased by 5.94%, 5.08% and 19.14%, respectively. (2) The average AGB per unit area of IMAR grasslands from 2000 to 2022 was 731.41 kg/hm2, with alpine meadow having the highest average AGB (1271.70 kg/hm2) and temperate grassland desertification having the lowest (469.06 kg/hm2). IMAR grasslands exhibited an overall increasing trend in AGB over the past 23 years (6.01 kg/hm2•yr), with the increasing trend covering 83.52% of the grassland area and the decreasing trend covering 16.48%. (3) Spatially, IMAR grassland AGB showed a gradual decline from northeast to southwest and exhibited an increasing trend with increasing longitude (45.423 kg/hm2 per degree) and latitude (71.9 kg/hm2 per degree). (4) Meteorological factors were the most significant factors affecting IMAR grassland AGB, with precipitation (five-year average q value of 0.61) being the most prominent. In the western part of IMAR, where precipitation is consistently limited throughout the year, the primary drivers of influence were human activities, with particular emphasis on the number of livestock (with a five-year average q value of 0.44). It is evident that reducing human activity disturbance and pressure in fragile grassland areas or implementing near-natural restoration measures will be beneficial for the sustainable development of grassland ecosystems. The results of this research hold substantial reference importance for the protection and restoration of grasslands, the supervision and administration of grassland resources, as well as the development of policies related to grassland management. [Display omitted] • The aboveground biomass (AGB) of grasslands in IMAR increased over the past 23 years. • IMAR grassland AGB shows an upward trend with increasing longitude and latitude. • Precipitation is the main factor affecting grassland AGB in IMAR. • Human activities have a greater impact on the grassland AGB in western IMAR. [ABSTRACT FROM AUTHOR]

BACKGROUND: Thiamethoxam is widely used to control pests in Chinese kale, popularly consumed leafy vegetables. The potential risk to the environment and human health has aroused much public concern. Therefore, it is important to investigate the degradation behavior, residue distribution and dietary risk assessment of thiamethoxam in Chinese kale. RESULTS: A sensitive analytical method for determination of thiamethoxam and its metabolite clothianidin residue in Chinese kale was established and validated through a quick, easy, cheap, effective, rugged, and safe (QuEChERS) technique with ultra‐performance liquid chromatography tandem mass spectrometry (UPLC–MS/MS). The recoveries were 85.4–101.2% for thiamethoxam and 79.5–108.1% for clothianidin, with the relative standard deviations (RSDs) of 0.9–10.2% and 1.8–6.0%, respectively. For the dissipation kinetics, the data showed that thiamethoxam in Chinese kale was degraded with the half‐lives of 4.1 to 4.5 days. In the terminal residue experiments, the residues of thiamethoxam were 0.017–0.357 mg kg−1 after application 2–3 times with a preharvest interval (PHI) of 7 days under the designed dosages. The chronic and acute dietary exposure assessment risk quotient (RQ) values of thiamethoxam in Chinese kale for different Chinese consumers were 0.08–0.19% and 0.05–0.12%, respectively, and those of clothianidin were 0.01–0.04% and 0.02–0.04%, respectively, all of the RQ values were lower than 100%. CONCLUSION: Thiamethoxam in Chinese kale was rapidly degraded following first‐order kinetics models. The dietary risk of thiamethoxam and clothianidin through Chinese kale was negligible to consumers. The results from this study are important reference for Chinese governments to developing criteria for the safe and rational use of thiamethoxam, setting maximum residue levels (MRLs), monitoring the quality safety of agricultural products and protecting consumer health. © 2021 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Purpose: It is argued that the constructivist physical education has the potential to overcome socioeconomic (SES) constraints and promote learning. The purpose of this study was to determine the extent to which school SES-related class environmental factors influenced student learning in a constructivist physical education context. Methods: Students in 8th grade (N = 1,256) from 10 middle schools with varied SES were tested on exercise knowledge before and after a constructivist physical education intervention. School SES was determined using free and reduced meal ratio (FARM) and physical education related factors. Data on lesson frequency, length, facilities, equipment, and class size were collected from teachers. Results: Hierarchical linear model analyses reveal that SES is not predictive of intervention induced learning ( γ = 0.73, t =.91, p =.37). Lesson frequency ( γ 02 =.52, t =.31, p =.06), length ( γ 03 = −.03, t = −1.82, p =.07), facilities ( γ 04 = −.11, t = −.49, p =.63), equipment ( γ 05 = −.36, t = −1.36, p =.18), and class size ( γ 06 = −.05, t = −1.36, p =.18) are not predictive of learning. Student prior knowledge ( γ = −.59, t = −18.37, p <.001) and teacher factor ( γ =.04, t = 3.72, p <.001) are predictive of learning. Conclusion: The findings suggest that school SES's detrimental impact on learning in physical education could be overcome by the power of a constructivist curriculum. [ABSTRACT FROM AUTHOR]

Expectancy-Value Questionnaire (EVQ) measures student expectancy beliefs and task values of the domain content (Eccles & Wigfield, 1995).In this study the authors examine measurement invariance of EVQ in the domain of physical education between elementary and middle-school students. Participants included 811 students (3rd–5th grades) from 13 elementary and 903 (6th–8th grades) from 13 middle schools. Students completed the EVQ in their physical education classes within the same semester. A series of hierarchical steps for testing the measurement invariance were conducted based on means and covariance structures. The results suggest that the questionnaire possesses configural and metric invariance, but noninvariant item intercepts between these two groups of students (∆CFI > .05). EVQ can be used to measure expectancy-value constructs in physical education for both middle-school and elementary students. Yet the noninvariant item intercepts posted questions on how the measured construct difference should be interpreted. [ABSTRACT FROM AUTHOR]

Abstract: Students'' different perceptions of task values influence their learning experience and achievement in physical education. Framed using the subjective task value construct, this study was conducted to determine the extent to which male and female Chinese middle schoolers with different body sizes differed in their perception of the task values. A second goal of the study was to identify the extent to which the task values along with gender and body size predicted students'' performance on knowledge and physical skill tests. Data from a random sample of students (N =860) from eight Chinese middle schools revealed that the boys appreciated intrinsic (p =.001) and utility values (p =02); both boys and girls, however, equally appreciated the attainment value (p =.73). The boys performed better in physical skill tests than the girls (p =.001), whereas the girls scored higher in knowledge tests than the boys (p =.04). Regression analyses revealed that gender is the only predictor for performance on both knowledge and skill tests. Utility value and body size were predictors for skill, not for knowledge. These findings indicate that Chinese middle school boys and girls differed in valuing and achieving in physical education. The findings imply that Chinese boys need to strengthen cognitive learning and girls need to strengthen psychomotor skill development in physical education. [Copyright &y& Elsevier]

Background: Curriculum fidelity describes the extent to which a curriculum is implemented faithfully as planned. Curriculum fidelity issues may arise when teachers implement the curriculum inconsistently due to differences in philosophy, barriers in the setting, or other local concerns. Purpose: The study examined challenges that a teacher faced in implementing a constructivist physical education curriculum that had fidelity implications. Research design: Ethnographic case study design was employed in the research. Participants and setting: One physical education teacher, 'Daniel', and his students in the third, fourth, and fifth grades participated in the study as they were involved in a curriculum intervention in a large urban school district in the US. Daniel's school was randomly assigned to an experimental group to implement a physical education curriculum based on health/fitness-related science. Data collection: The researchers observed 75 lessons taught by Daniel using non-participant observation techniques and conducted two structured interviews with Daniel and eight interviews with his students. Data analysis: Constant comparison with open and axial coding was used to analyze the observation and interview data. Findings: Two thematic challenges emerged: (1) school contextual constraints that limited the fitness science learning environment in physical education, and (2) Daniel's personal values and preference for a recreational rather than a science-based physical education program. These challenges impacted Daniel's decisions when teaching the curriculum. [ABSTRACT FROM AUTHOR]

• Residue levels of eighteen pesticides during Chinese Baijiu production were assessed. • Pesticide residues were obviously removed in steeping and steaming step. • Fermentation reduced pesticide residues by 39.8–74.2% owing to microbial degradation. • Distillation step was proved to be effective for decreasing pesticide residues. • PFs of eighteen pesticides were clarified during Chinese Baijiu production. The fate of eighteen pesticides in field-collected rice samples during Chinese Baijiu production was systematically studied. The results indicated that steeping decreased flonicamid residue by 73.2% due to its high water-solubility and low octanol/water partition coefficient. The steaming step reduced pesticide residues by 32.0%–75.3% through evaporation or thermal degradation. After steaming, the pesticide residues were further reduced by 39.8–74.2% in fermentation which might be caused by biological degradation. In addition, distillation was shown to be most effective, responsible for greater than 90% losses of the remaining pesticide residues. The processing factors (PFs) were generally lower than 1 for different processes and the whole procedure. These results revealed that the procedure of Chinese Baijiu production could dramatically decrease residues of all the eighteen pesticides. Overall, this study provide important references for monitoring pesticide residue levels during the production of Chinese Baijiu from rice, and ensuring proper risk assessment from pesticide contamination. [ABSTRACT FROM AUTHOR]

Ceramic samples with the nominal composition (1− x) BaTiO3+ x Ba3Ti2YO8.5 ( x=0−0.535) were prepared by the mixed oxide method. X-ray diffraction (XRD) analysis shows that the materials are of single phase with a cubic symmetry as x≤0.16. The compositions of the solid solutions ( x≤0.16) can be expressed equivalently as Ba(Ti1− yY y)O3−δ ( y≤0.122, y= x/(1+2 x)). For x>0.16, the materials are diphasic composites consisting of Ba(Ti1− yY y)O3 ( y=0.122) and Ba3Ti2YO8.5. The microstructure observation by scanning electron microscopy supports the XRD result. The dielectric behavior and phase transitions of the solid solutions ( x≤0.16) vary with different Y concentrations. The dielectric constant of the composites ( x>0.16) follows approximately the Lichteneker relation in a wide temperature range. [ABSTRACT FROM AUTHOR]

We used mixed methods to identify middle school students' conceptions and misconceptions of energy in the domain of health and fitness. We selected a total of 24 middle schools from six school districts in a Southeastern state of the U. S. through stratified sampling. Students were first given a standardized knowledge test to establish their knowledge level membership in the domain of health and fitness. A sample of 291 students was selected from the 24 schools for semi-structured interviews on their understanding of energy sources for physical activities and consequences of energy surplus. Analysis of the interview data identified a variety of misconceptions on energy by grade and knowledge levels. Different conceptual change theories were adopted to form four themes to explain the identified misconceptions. We discussed pedagogical implications that may help address the misconceptions in and beyond the domain of health and fitness. [ABSTRACT FROM AUTHOR]

[Display omitted] The novel phenomena in nanophotonic materials, such as the angle-dependent reflection and negative refraction effect, are closely related to the photonic dispersions E (p). E (p) describes the relation between energy E and momentum p of photonic eigenmodes, and essentially determines the optical properties of materials. As E (p) is defined in momentum space (k -space), the experimental method to detect the energy distribution, that is the spectrum, in a momentum-resolved manner is highly required. In this review, the momentum-space imaging spectroscopy (MSIS) system is presented, which can directly study the spectral information in momentum space. Using the MSIS system, the photonic dispersion can be captured in one shot with high energy and momentum resolution. From the experimental momentum-resolved spectrum data, other key features of photonic eigenmodes, such as quality factors and polarization states, can also be extracted through the post-processing algorithm based on the coupled mode theory. In addition, the interference configurations of the MSIS system enable the measurement of coherence properties and phase information of nanophotonic materials, which is important for the study of light-matter interaction and beam shaping with nanostructures. The MSIS system can give the comprehensive information of nanophotonic materials, and is greatly useful for the study of novel photonic phenomena and the development of nanophotonic technologies. [ABSTRACT FROM AUTHOR]

[Display omitted] • The northwest area of the BTSSCP suffered severe dust-affected zones based on the dust flow trajectory. • The ESs in severe dust-affected areas were relatively poor. • ESs and the dust flow trajectory were integrated to identify ecological governance zones. • Governance suggestions were proposed for the ecological management zone combined with the driving forces. Achieving ecological conservation and governance based on ecosystem services (ESs) can balance regional ecological protection and development, which is of great significance for sustainable development. Existing research has mainly focused on the extraction of priority ecological conservation areas, thereby neglecting to consider the classification and management of ecological engineering areas. To improve regional ecological governance, we combine ESs and dust movement trajectory, using the Beijing-Tianjin Sandstorm Source Control Project (BTSSCP) as the research object to generate watersheds' ecological governance zones. Six ESs were assessed to determine ecological zones. Trajectory simulation of dust movement, using the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model and potential source contribution function, was used to determined zones affected by dust. By combining these two aspects, five main ecological governance clusters were identified. We found that: (1) the area with low ESs in the northwest of the BTSSCP suffered from severe dust impacts; (2) slight dust-affected zones were mainly distributed in the eastern of the BTSSCP, and in the area, ESs gradually decreased from south to north; (3) ESs in the region was primarily influenced by natural factors and the influencing factors of ESs vary among different zones. These findings will not only contribute to the overall planning and governance of the BTSSCP, but can offer general guidance for the formulation of targeted ecological protection and restoration measures in other areas. [ABSTRACT FROM AUTHOR]

A stripline-fed tightly coupled array antenna with compact size, large scan volume and low cross-polarization characteristics is proposed for ultrawideband (UWB) applications. Simple impedance-matching process is realized by using parallel dual dipoles. Meanwhile, the parallel symmetrical radiating structures minimize the cross-polarization field components dramatically. The mitigation of various undesired resonances is studied in detail. An infinite array is designed to achieve 3:1 bandwidth (6−18 GHz) when scanning ±60 ∘ in the E-/D-planes (VSWR < 2.5) and H-plane (VSWR < 3.5). The cross-polarization levels remain below −29 dB at broadside. A 16 × 16 prototype is fabricated to demonstrate the design. The measured results are consistent well with the simulated ones. The overall size of the prototype at the lowest operating frequency is 3 × 3 × 0.4 λ 0 3 ( 15 × 15 × 2 cm 3 ). Due to its wide bandwidth, good electronic scan performance and compact size, the proposed antenna array is a good candidate for modern wireless platforms. [ABSTRACT FROM AUTHOR]

In this paper, a transmission‐type graphene plasmonic modulator by introducing off‐resonant Au structure is theoretically and experimentally investigated. It is found that the modulation efficiency and bandwidth could be dramatically enhanced compared with bare graphene plasmonic structure. The validity of this proposed method is verified both in the 1D and 2D graphene plasmonic structures: ribbons and holes. This work will open up a new path to design the high‐efficiency modulators, switches, and multispectral detectors. [ABSTRACT FROM AUTHOR]

In this work, a tribological performance analysis is numerically conducted for a surface‐textured ring‐deformed liner conjunction. In the analysis, three different distribution patterns of surface texture are designed and machined on the surface of ring. To evaluate the frictional properties of the textured rings under mixed lubrication regime, a transient lubrication model considering the oil film thermal effect is developed. Meanwhile, to evaluate the oil film consumption and the transition of lubrication condition in an engine cycle, an oil transport model is built to determine the boundary positions of lubrication zone. Based on the models, the oil consumption, MOFT (minimum oil film thickness), friction force, power loss, and FMEP (friction mean effective pressure) value of the textured ring are studied under different oil supplies. The frictional characteristics of the rings with various distribution patterns of surface texture are also analyzed and compared. The results show that the edge‐textured ring can improve the tribological performance significantly, and the improvement varies with the oil supply. [ABSTRACT FROM AUTHOR]

Nowadays 3D bioprinting, due to its high structural reconstruction and low cost, has been a promising technology and gained expectation in the treatment of vascular diseases. Although some studies have reported that 3D printing of large-sized blood vessels in the human body has been achieved, there are still some problems to be solved urgently, such as the unfulfilled microvascular simulation and inferior biocompatibility and mechanical strength of scaffold materials. In this paper, the hybrid bioink prepared with gelatin, sodium alginate and carbon nanotubes were manufactured into cylindrical scaffolds through the collaboration between the vertical directional extrusion of printing nozzle and axial rotation of stepper motor module. Mouse epidermal fibroblasts were inoculated into the inner and outer walls of hollow tubular scaffolds to fabricate engineered blood vessels. The internal diameters of the bionic circular tubes printed in batches were 3 mm with an average wall thickness of 0.5 mm and a length of 7–10 cm. Results demonstrated that the proper doping of carbon nanotubes could effectively increase the mechanical properties of the composite scaffolds. Also, quantitative experiments proved that a small amount of doping of carbon nanotubes had little effect on cytotoxicity, and the constructs could meet the requirements of biomimetic vascular. Schematic illustration of the synthesis and 3D printing of the gelatin-based alginate/carbon nanotubes vessel constructs. Unlabelled Image [ABSTRACT FROM AUTHOR]