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Spatially modulated full polarization imaging is the method of modulating the polarization information of a target into a single interferogram, which has a good real-time feature. Since polarization modulation lenses are made of birefringent crystals, they will produce chromatic dispersion. Therefore, the interference fringes on the interferogram will become blurred, affecting the subsequent demodulation processing. It is necessary to determine the bandwidth limit of the incident light. Based on these considerations, this paper analyses the distribution of the polarization information in the frequency domain and proposes a method of determining the bandwidth limit based on the pixel size in the frequency domain. [ABSTRACT FROM AUTHOR]

Abstract: The clinical utilization of resorbable bone substitutes has been growing rapidly during the last decade, creating a rising demand for new resorbable biomaterials. An ideal resorbable bone substitute should not only function as a load-bearing material but also integrate into the local bone remodeling process. This means that these bone substitutes need to undergo controlled resorption and then be replaced by newly formed bone structures. Thus the assessment of resorbability is an important first step in predicting the in vivo clinical function of bone substitute biomaterials. Compared with in vivo assays, cell-based assays are relatively easy, reproducible, inexpensive and do not involve the suffering of animals. Moreover, the discovery of RANKL and M-CSF for osteoclastic differentiation has made the differentiation and cultivation of human osteoclasts possible and, as a result, human cell-based bone substitute resorption assays have been developed. In addition, the evolution of microscopy technology allows advanced analyses of the resorption pits on biomaterials. The aim of the current review is to give a concise update on in vitro cell-based resorption assays for analyzing bone substitute resorption. For this purpose models using different cells from different species are compared. Several popular two-dimensional and three-dimensional optical methods used for resorption assays are described. The limitations and advantages of the current ISO degradation assay in comparison with cell-based assays are discussed. [Copyright &y& Elsevier]

Abstract: Increasing evidence suggests that vascular resident endothelial progenitor cells (VR-EPCs) are present in several organs, playing an important role in postnatal neovascularization. Here, we isolated and characterized VR-EPCs from cardiac tissue in vitro, evaluating their regenerative potential in vivo. VR-EPCs showed to be highly clonogenic and expressed several stem and differentiation markers. Under endothelial differentiation conditions, cells form capillary-like structures, in contrast to osteogenic or adipogenic differentiation conditions where no functional changes were observed. After seeding in scaffolds, cells were distributed homogeneously and directly attached to the scaffold. Then, cell seeded scaffolds were used to induce dermal regeneration in a nude mice full skin defect model. The presence of VR-EPCs enhanced dermal vascularization. Histological assays showed increased vessel number (p < 0.05) and cellularization (p < 0.05) in VR-EPCs group. In order to explore possible mechanisms of vascular regeneration, in vitro experiments were performed. Results showed that pro-angiogenic environments increased the migration capacity (p < 0.001) and ability to form capillary-like structures (p < 0.05) of VR-EPC. In addition, VR-EPCs secreted several pro-angiogenic molecules including VEGF and PDGF. These results indicate that a highly clonogenic population of VR-EPCs might be established in vitro, representing a new source for therapeutic vascularization in tissue engineering and regeneration. [Copyright &y& Elsevier]

Abstract: We build a model to study the sidewall corrugation of fabricated silicon microrings and investigate its impact on the spectral response of the resonator system. From the scanning electron microscope images, the sidewall corrugation can be engineered into certain periodicity and characterized into a group of rectangular gratings, or quasi-gratings, which in turn generate mutual mode coupling between the forward- and backward-propagating modes in the ring and lead to resonance splitting. We find that the reflectivity of the quasi-gratings is proportional to the mutual coupling strength and the resonance splitting only occurs at the resonances where high reflectivity takes place. The model agrees well with the experimental measurements and provides some guideline in applying mutual mode coupling for various functions in the field of optics. [Copyright &y& Elsevier]

Terahertz (THz) waves have the advantages of being noninvasive and nonionizing because of their low radiation energy, so they have potential applications in the biomedical field, but thus far, those have been limited by the strong absorption in water and low detection sensitivity. Herein, we propose a reflective THz time-domain circular dichroism (CD) sensing system and a silicon subwavelength grating as the microstructure sensor to generate and detect the THz chiral polarization states, to realize quantitative detection of living cell numbers and qualitative identification of cell kinds in a liquid environment. Three kinds of hepatoma cell proliferation and inhibition with different concentrations of aspirin were measured by this sensing method, and the experimental results show that the sensitivities for CD resonance intensity and frequency shift can reach 3.44 dB mL/106 cells and 5.88 GHz mL/106 cells, respectively, and the minimum detection concentration is in the order of 104 cells/mL for THz detection in a liquid environment for the first time. This new THz sensing system and sensing method are expected to become a broadband, label-free, noncontact, real-time detection technology that can be used for quantitative detection and qualitative identification of cells or other active biochemical materials. [Display omitted] • THz chiral polarization state is generated and the circular dichroism is used as the sensing characterization. • Artificial dielectric grating is used as the microstructure sensor. • Strong absorption of water is avoided by the reflective THz system. • Realize the concentration sensing of HepG2 cells in a liquid culture environment. • Realize the identification of HepG2, Huh7, and H7402 cell. [ABSTRACT FROM AUTHOR]

The development of the green sea urchin (Strongylocentrotus droebachiensis) fishery in British Columbia, Canada, is presented as an example of how a precautionary approach was applied to avert collapse of a developing invertebrate fishery and to rebuild towards a sustainable fishery. We consider four components: (1) identification of the appropriate spatial scales; (2) development of scientifically-supported management strategies; (3) consideration of uncertainties; and (4) collaborations amongst scientists, fishery managers, and stakeholders. The green sea urchin fishery in British Columbia has experienced three periods: a “developing” period during which effort and landings increased, but catch per unit of effort (CPUE) declined; a “crisis” period during which effort and landings peaked and CPUE reached a minimum; and a “rebuilding to sustainable” period during which landings and effort stabilised and CPUE increased. Passive management actions (minimum size limit, seasonal closures) were introduced at the beginning of the fishery, but were unable to limit exploitation. Subsequent to the crisis period, active management measures (large area closures, quotas, and an individual quota system) were implemented based on scientific studies and appear to have stabilised the fishery. The availability of fishing logbook information from the inception of the fishery and the development of positive relationships amongst all participants in the fishery were central elements of this rebuilding process. The long time series of logbook information provided sufficient data contrasts to use two surplus production modelling techniques to develop biological reference points for management regulations. The green sea urchin fishery is now a small but important, and apparently stable, component of the dive fisheries in British Columbia. [Copyright &y& Elsevier]

This study examines the inter-layer and cross-layer fracture behavior of 3D printed short CFRP composites using both experimental and numerical methods. First, the orthotropic mechanical response of the 3D printed CFRP samples was characterized by tensile tests. The out-of-plane Young's modulus and yield strength were measured to be about 25% and 32% of the in-plane counterparts, respectively. Second, compact tension fracture tests were performed to characterize the fracture behavior of the CFRP composite samples. The crack resistance curves of inter-layer and cross-layer fracture were independently derived using the elastic-plastic fracture theory. Both cross-layer and inter-layer fracture exhibited stable crack growth with the rising crack resistance curves. Finite element simulations incorporating a cohesive zone method was used to numerically determine the critical cohesive strength and fracture toughness from the experimental results. The experimentally measured and numerically calibrated cross-layer fracture toughness was found to be three-fold of the inter-layer counterparts. In addition, fracture surface morphology and the crack-tip strain field evaluated by the digital image correlation technique revealed three important observations: (1) the cross-layer fracture resulted in a larger fracture process zone ahead of the crack tip compared to the inter-layer fracture, (2) the cross-layer fracture exhibited a fibril-bridging toughening mechanism along with fiber pull-out failure at the micro-scale, and (3) the inter-layer fracture showed a uncracked-ligament toughening mechanism arising from the locally enhanced inter-layer adhesion due to short fiber-bridging. The fracture mechanisms reported in this study provide practical strategies for designing and 3D printing CFRP composites with superior fracture-resistance. [Display omitted] [ABSTRACT FROM AUTHOR]

• A theoretical model was developed to explain how PRG bolts maintain support force after creep in the anchoring section. • Indoor experiments using Distributed Optical Sensing (DOS) technology revealed the changes in axial force distribution over time for both PR and PGR bolts during service. • The mechanical properties of PR and PGR bolts after long-term loading were evaluated through mechanical testing. As an effective solution for controlling deformation in surrounding rock, prestressed rock bolts have been increasingly adopted in transportation tunnels. However, the potential for prestress loss and anchorage failure due to creep in the anchorage material over extended service life necessitates further investigation. In response, this study investigated the long-term mechanical performance of a prestressed post-grouting resin bolt, focusing on its supporting effect and mechanical behavior after anchorage creep. We began by establishing a model that explained the mechanical mechanism of the grouting segment. This model was then used to analyze the impact of grouting material properties. Additionally, the bearing characteristics of the prestressed post-grouting resin rock bolt during reloading were assessed. Furthermore, a laboratory experiment was conducted using distributed optical fiber strain sensing (DOS) technology to evaluate the long-term behavior and mechanical performance of both prestressed resin anchor bolts (PR bolts) and prestressed post-grouting resin anchor bolts (PGR bolts) under various loading conditions. The results indicated that the PGR bolt significantly reduced prestress loss compared to the PR bolt, with reductions of 13%, 15%, and 16% at pretensions of 50 kN, 80 kN, and 110 kN, respectively. Additionally, PGR bolts can avoid stress concentration on the anchoring interface under long-term loads, reducing the risk of anchoring failure when re loaded. Taken together, the findings of the research indicate that PGR bolts can maintain higher prestress and strength in long-term support, and the theory model helps design the grouting parameters of PGR bolts. [ABSTRACT FROM AUTHOR]

Different motor learning methods (explicit or analogy learning) show different effects on motor performance stability, and reinvestment propensity plays an important role in motor performance stability. This study aimed to explore whether reinvestment propensity, that is, movement self-consciousness (MS-C) and conscious motor processing (CMP) as two dimensions, played a moderating role in the relationship between motor learning methods and motor performance stability. A total of 78 participants were randomly assigned to either the explicit or analogy learning group and their reinvestment propensity was measured. We recorded the number of golf putt goals in both the practice phase and the test phases (including a retention test and a stress test). In the moderating analysis, participants' reinvestment propensity was the moderating variable, and the dependent variable was motor performance stability (i.e., the difference between the two test phases). Results showed that motor performance was significantly different between practicing blocks, which indicated that the motor performance of learners was gradually increasing. The significant interaction between learning methods and the test phase on motor performance was detected, suggesting under stress, analogy learning was more likely to maintain the stability of motor performance, while explicit learning impaired the stability of motor performance. The CMP played a significant moderating role in the relationship between motor learning methods and motor performance stability. The result indicated that for learners with low CMP, the motor performance stability of analogy learning was better than explicit learning, while there was no significant difference in the stability of motor performance between the two learning methods for learners with high reinvestment propensity. No significant evidence was found that MS-C played a moderating role in the relationship between motor learning methods and motor performance stability. These findings expand the theoretical framework of motor skill learning and provide theoretical support for motor performance stability. • Analogy learning is more likely to maintain the stability of motor performance under stress. • CMP plays a significant moderating role in the relationship between motor learning methods and motor performance stability. • For people with low CMP, analogy learning is better than explicit learning in maintaining motor performance stability. • For people with high CMP, there is no significant difference in motor performance stability between the two learning methods. [ABSTRACT FROM AUTHOR]

• All-optical tactile sensor realized with only one fiber. • Accurate 2D location + force recognition with fine resolution. • Combines laser multimode interference with AI-enabled imaging processing. • Promising for large-area, fine-resolution yet low-cost touch pads. A 2D tactile sensor is demonstrated using a single winding fiber embedded in a soft, elastic silicone substrate of 6 mm thickness. Laser light at 1550 nm is injected from a single mode fiber into a spliced multimode fiber and causes multimode interference. The formed image is susceptible to any disturbance along the fiber path. These images at the output facet are captured during the automatic scanning/probing loops by a spring needle. The collected data are fed into a convolutional neural network for training, validation and test. Results show that with only a few hundred images, over 98% accuracy can be achieved in recognizing the probe spatial position within a 0.5 mm × 0.5 mm resolution. In addition, close to 100% accuracy is reached for force sensing in the third dimension at a resolution of 3 g. The presented technology may lead to the design of large-area, fine-resolution yet low-cost touch pads, thanks to its extremely simple structure and powerful interrogation method. [ABSTRACT FROM AUTHOR]

The use of nanomaterials with exotic mechanical and functional properties to reinforce otherwise softer and inert polymers or resins promises the development of high-performance and highly functional composite materials for advanced applications. Polymeric materials serving as matrices or substrates can translate the superior properties of different nanomaterials from nanoscale to macroscale, holding the potential to move nanomaterials from the research laboratory to tangible technological applications that revolutionize the broad plastics industry. However, even after nearly 30 years of innovative and groundbreaking research, various technical challenges still exist such as controlling the dispersion of nanomaterials in the polymer matrix during processing and the need for new synthetic concepts and processing strategies [1]. Emerging trends in 2D nanotechnology and the recent development of certain 2D materials (e.g., large-area 2D sheets and 2D heterostructures) may provide for major advancements in the field of polymer nanocomposites. The use of 2D sheets as fillers provides a means of precisely positioning nanomaterials into/onto polymer matrices/substrates with precise structural control at an atomic level, a precise control of the surface/interface layer and the distances in between the nanoinclusions, all of which are not feasible with traditional polymer nanocomposite materials. The 2D filler components have extremely high aspect ratios, which provides for maximum reinforcement at exceedingly small volume fractions. They also provide 'multifunctional property enhancement' and, for example, can contribute specific photoelectric or electronic functionality and mechanical reinforcement. This contribution reviews recent advances in 2D materials-based polymer nanocomposites. First, important synthetic techniques for 2D nanomaterials such as chemical vapor deposition growth and wet-chemistry are presented. Subsequently, strategies for the surface modification of 2D sheets with small molecules and polymers as well as processes for the manufacturing of polymer nanocomposites with aligned 2D inclusions are reviewed. The mechanisms of physical property enhancement are discussed and applications across a range of technology areas are presented. Finally, the challenges as well as opportunities for research in this emerging area of nanocomposite science and engineering are commented on. It is hoped that the unified perspective presented in this review will enable readers to make contributions to this exciting and rapidly advancing field. The recent progress of two-dimensional (2D) materials and nanotechnology offers us an unprecedented opportunity for precise control of the nanoparticle dispersion in/on polymer matrices/substrates. In this paper, we will review and prospect the emergent field of polymer nanocomposites with aligned 2D materials, particularly those with large-area, high-quality ones. Image, graphical abstract [ABSTRACT FROM AUTHOR]

This study investigates the interlaminar shear behavior of 3D printed CFRP composites fabricated by fused deposition modeling (FDM) through a combined experimental and numerical study. Short beam shear (SBS) tests were performed to quantitatively characterize interlaminar shear strength (ILSS) of 3D printed continuous and short CFRP composites. Numerical simulations incorporating the extended finite element method (XFEM) and cohesive zone model (CZM) were conducted to rationalize the experiments. Two different combinations of continuous and short carbon fiber reinforcements were studied. The first composite layup made of 48 layers of continuous CFRP filaments was used to determine the intrinsic ILSS of the fully continuous CFRP composites. The second composite layup composed of 24 layers of continuous CFRP filaments and 24 layers of short CFRP filaments was used to determine the ILSS of the continuous and short CFRP composites. The average ILSS of these two composite layups were measured to be about 40.9 MPa and 24.4 MPa, respectively. Four distinct stacking sequences were implemented to examine the effect of stacking sequence of the continuous and short CFRP layers on the ILSS. The ILSS exhibited a significant sensitivity to the stacking sequence. The ILSS tends to increase with the number of the consecutive short CFRP layers. A failure mode transition from a brittle matrix cracking of short CFRP layers to cracking in the interface between the continuous and short CFRP layers was observed. The failure mode transition is attributed to the enhanced fracture strength and toughness of the short CFRP layers due to the increase in layer thickness. [ABSTRACT FROM AUTHOR]

• This paper analyzes the tail-risk interdependence among 23 cryptocurrencies. • Significant risk spillover effect exists in cryptocurrency markets. • The degree of the total connectedness of all the sampled cryptocurrencies increases steadily over time. • Bitcoin is the largest systemic risk receiver. • Ethereum is the largest systemic risk emitter. This paper analyzes the tail-risk interdependence among 23 cryptocurrencies and identifies the systemically important cryptocurrencies using the TENET approach proposed by Fan et al. (2018) and finds that (i) significant risk spillover effect exists; (ii) the degree of the total connectedness of all the sampled cryptocurrencies increases steadily over time; (iii) Bitcoin is the largest systemic risk receiver; (iv) Ethereum is the largest systemic risk emitter. [ABSTRACT FROM AUTHOR]

Liquid crystal (LC) materials are a good candidate for active phase and polarization devices. However, they also encounter significant challenges in the lack of transparent electrodes and the difficulty of LC alignment due to the thick LC cell for sub-mm wavelength in the terahertz (THz) regime. Here, we presented a strategy to overcome these difficulties, that is, using a super-aligned carbon nanotube (CNT) film with dual functions for both transparent electrodes and the aligning layer for THz LC cell. The LC molecules are uniformly aligned along the orientation direction of the CNT film because of its surface anchoring effect. The experiment results show that the active THz polarization conversions are controlled by the bias voltage tuning from 0 to 30 V between the upper and lower CNT films, and the output polarization state is converted between linear polarization and circular polarization. This work may pave a simple and flexible path toward the development of various active THz liquid crystal devices for spatial light modulation, dynamic imaging, and wavefront control. [Display omitted] [ABSTRACT FROM AUTHOR]

• Sodium selenite had important effects on Cd tolerance of strawberry seedlings. • Low concentrations of Se had positive effects on Cd tolerance by regulating antioxidant metabolism. • Low concentrations of Se had positive effects on Cd tolerance by reducing Cd accumulation in leaves and fruits of strawberry. • Low concentrations of Se had positive effects on the contents of photosynthetic pigments, the growth and the yield and quality of fruits. This study investigated the effects of sodium selenite (Na 2 SeO 3) on the antioxidant capacity and the fruit yield and quality of cadmium-stressed strawberry. The results showed that cadmium (Cd) stress notably decreased the activities of superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT) and glutathione synthetic enzyme gamma-glutamylcysteine synthetase (γ-ECS), plant height and plant biomass, and fruit yield and quality, improved the activities of ascorbate oxidase (AO), glutathione reductase (GR) and ascorbate synthetic enzyme L-galactono-1,4-lactone dehydrogenase (GalLDH), the ratios of AsA/DHA and GSH/GSSG and the contents of malondialdehyde (MDA), hydrogen peroxide (H 2 O 2) and Cd, compared with control. Compared with Cd stress alone, 5 and 10 μM Na 2 SeO 3 notably improved the activities of above enzymes except AO, the ratios of AsA/DHA and GSH/GSSG, plant height and biomass, Se contents in leaves and fruits, average fruit weight and the contents of Vc, soluble sugar and total soluble solid in fruits. 15 μM Na 2 SeO 3 notably improved the activities of above enzymes except AO, the ratio of GSH/GSSG, plant height, Se contents in leaves and fruits, average fruit weight and Vc content in fruits. 20 μM Na 2 SeO 3 only notably improved Se contents in leaves and fruits, average fruit weight and Vc content in fruits. Meanwhile, 5, 10 and 15 μM Na 2 SeO 3 significantly reduced Cd stress-induced the contents of MDA, H 2 O 2 and Cd, 20 μM Na 2 SeO 3 only significantly reduced Cd stress-induced the contents of Cd in leaves and fruits, compared with Cd stress alone. Our findings indicated that only low concentrations of Se were effective in conferring Cd tolerance in strawberry plants by up-regulating their antioxidant capacity and reducing Cd accumulation, which further improved the fruit yield and quality of strawberry. [ABSTRACT FROM AUTHOR]

Continuous carbon fiber-reinforced polymer (CCFRP) composites are lightweight and strong materials that have been used in a wide range of applications in automotive and aerospace industries. Traditional manufacturing processes (e.g., lay-up and out of autoclave techniques) are not capable of fabricating complex composites. Additive manufacturing (AM) has been increasingly used to fabricate composites with complex geometries. In this study, CCFRP with concentric and isotropic carbon fiber infill patterns were additively manufactured using fused deposition modeling (FDM). The microstructures of CCFRP composites with both infill patterns were characterized by an optical microscope and a scanning electron microscope (SEM). The void density was characterized for infill, solid and carbon fiber regions. Four-point flexural tests and tensile tests were conducted to evaluate the effects of carbon fiber concentration and infill patterns on both tensile and flexural behaviors. A stiffness averaging method was used to model the elastic behavior of CCFRP samples with different microstructures by taking into account porosity in infill, solid and carbon fiber bundles. Experimental results have shown that the specimens with the concentric carbon fiber infill pattern exhibit better flexural strength and energy absorption capability than those with the isotropic carbon fiber infill pattern. As carbon fiber concentration and the number of fiber rings increase, the flexural strength of the CCFRP composite increases. The specimen with 48.72 wt% carbon fibers showed the highest flexural strength of 270.63 MPa. In comparison with chopped carbon fiber-reinforced polymer composites, the flexural strength of the CCFRP specimen was increased by 40%. The predicted elastic moduli are in good agreement with experimental data. [ABSTRACT FROM AUTHOR]

The magnetocaloric properties of Gd 70 Co 30- x Fe x (x = 0, 5, 10) amorphous ribbons were measured, analyzed and compared with the reported experimental data of Gd 50 Co 50- x Fe x (x = 0, 2, 5) and Gd 60 Co 40- x Fe x (x = 0, 5, 10) amorphous alloy series. The results show that the magnetocaloric effect (MCE) of Gd-(Co, Fe) amorphous alloys could be tuned on the basis of following mechanism: the magnetic transition temperature (T C) of the Gd-(Co, Fe) amorphous alloys linearly increases about 22 ± 2 K with every substitution of 5 at% Fe for Co, and the maximum magnetic entropy change |Δ S M pk| of each alloy series nearly linearly depends on the T C −2/3. Additionally, the Gd-(Co, Fe) amorphous alloys with higher Fe content exhibit the table-like MCE and higher value of exponent n (T pk) (| Δ S M p k | ∝ H n (T p k) ). • The Gd 70 Co 30- x Fe x (x = 0, 5, 10) amorphous ribbons were produced. • The adjustable magnetocaloric effect of Gd-(Co, Fe) amorphous alloys were studied. • Every 5 at% replacement of Fe may raise the Curie temperature (T C) by ∼22 ± 2 K. • The correlation of magnetic entropy change peak with T C −2/3 is nearly linear. • The table-like curves obtained in the Gd-(Co, Fe) alloys with higher Fe content. [ABSTRACT FROM AUTHOR]

• For the first time, neural networks were applied to denoise in spatial heterodyne spectroscopy, and significant results were achieved. • Four corresponding network models were constructed for denoising different brightness and noise levels. • The denoising ability of DnCNN in spatial heterodyne interferograms were comprehensively evaluated. • The reasonable selection of four neural network schemes were discussed. Spatial heterodyne spectroscopy is a hyperspectral remote sensing technology. With the continuous improvement of signal detection accuracy, new methods are urgently needed to further reduce the interference of noise on the information contained in spatial heterodyne interferograms. Convolutional neural networks, as an emerging field, have achieved good results in image denoising in recent years. This paper applies convolutional neural networks to the field of spatial heterodyne spectroscopy, constructs and trains four deep convolutional neural network models for denoising spatial heterodyne interferograms under different brightness and Gaussian noise conditions, and compares their performance with other algorithms. The results show that deep convolutional neural networks have significant advantages in denoising spatial heterodyne interferograms. Finally, a comparison of four neural networks was conducted to explore how to reasonably select network models. This work provides new ideas and effective solutions for reducing the interference of noise on spatial heterodyne spectral information and improving signal detection accuracy. [ABSTRACT FROM AUTHOR]

This article investigates the path-following control problem for autonomous underwater vehicles (AUVs) subject to external disturbances and unknown model parameters. An event-triggered model-free adaptive control (ETMFAC) method is designed with a practical experimental platform. Firstly, a line-of-sight (LOS) guidance law is employed to obtain the desired heading angle for the AUV. Secondly, an improved model-free adaptive control method is used, in which an adaptive law is introduced to compensate for the effects caused by external disturbances. Subsequently, an event-triggering mechanism that can reduce the communication and calculation burden of the control system is proposed. As for the state mutation caused by variable disturbances, an adaptive triggering threshold is designed based on the state vector of the AUV to maintain satisfactory following performance. The stability of the control system is proved by theoretical analysis. Finally, both numerical simulations and practical experiments are conducted to evaluate the efficacy and prove the superiority of the proposed method. • Adaptive law is introduced into MFAC algorithm to improve the robustness of AUV in complex environment. • The improved event triggering mechanism reduces the system channel occupancy. • A novel adaptive threshold is proposed, which can make the AUV converge to the desired domain smoothly. • The effectiveness of the algorithm in engineering is verified by practical experiments. [ABSTRACT FROM AUTHOR]

To determine the latent degradation of SiC MOSFETs under single-pulse avalanche conditions, the stability of static characteristics and device capacitances is thoroughly studied by conducting Unclamped Inductive Switching (UIS) tests. No parametric shift is observed even though more than 90 % of the maximum avalanche energy is dissipated, indicating that devices fail in an abrupt mode. The avalanche failure turns out to be reaching the critical temperature. By introducing some corrections, including the temperature-dependent material properties, the aluminium layer, and the model of its melting process, the established model provides more accurate temperature results. The derived critical temperature is around 1200 K. All the devices suffer a fusion of metallization, which is considered to be the main mechanism of avalanche failure at the rated current region. With a sufficiently high current, the avalanche failure could also be accelerated by the turning-on of parasitic BJT. [ABSTRACT FROM AUTHOR]

In recent years, environmental wastewater has become an increasingly prominent problem, and photocatalytic degradation is one of the effective means to treat waste pollutants. In this study, glycine was embedded in a tubular carbon nitride material with melamine as the parent by a supramolecular self-assembly strategy to prepare carbon chains implanted tubular graphitic carbon nitride (CTCN). The introduction of carbon chains can reduce the formation of hydrogen bonds, which is beneficial to improve the carrier transport efficiency. It can also adjust the valence band position and has better reduction performance. The thin-walled tubular structure formed by supramolecular self-assembly exposes more active sites and shortens the carrier transport distance due to the size effect, which further improves the carrier separation efficiency. The synergistic effect of the two greatly contributes to the photocatalytic performance of the material. The degradation rate of 0.3% CTCN is 8.1 times higher than that of Bulk CN, and 0.3% CTCN exhibits good stability. This solution is beneficial to optimize some existing wastewater treatment methods and has a role in environmental protection. [Display omitted] • The carbon chain improves molecular polymerization and reduces the formation of hydrogen bonds. • The highly conductive carbon chain facilitates the separation of carriers in carbon nitride. • The thin-walled tubular structure improves the optoelectronic properties of the sample. [ABSTRACT FROM AUTHOR]

We develop a multi-fidelity surrogate modelling approach to replace the complex and costly physics-based computer models that are often used in the optimization of solid oxide fuel cell (SOFC) performance, or the simplified models that are used in lieu of complex models. We extend multi-fidelity stochastic collocation through a feature engineering step, and eliminate the requirement for the exact low-fidelity output at the inference stage. In contrast to previous approaches, the surrogate model we develop provides detailed spatial information, rather than one or more scalar outputs. This allows for the incorporation of such information into the objective of the optimization study, with the flexibility to choose from more than one objective, such as a minimum, maximum or average. Furthermore, the detailed spatial information can be used for general design purposes, such as ensuring uniformity in reactant and potential distributions. From the results on a 3-d SOFC model, we demonstrate highly accurate predictions of multiple spatially distributed quantities at up to spatial 250,000 locations. The results are superior to state-of-the-art multi-fidelity approaches, particularly for low numbers of high fidelity training points. We use the surrogate model to optimize the SOFC performance with respect to different objectives (including with nonlinear constraints and multiple objectives), with results that are accurate and are obtained in a fraction of the time required for the full model. [ABSTRACT FROM AUTHOR]

The sonication effect on the sorption behavior of carbon nanotubes (CNTs) with different functional groups has been poorly understood in previous studies, especially when combined with solution chemistry that may affect both the sorption and dispersion of CNTs. Our results show that sonication accelerated sorption of triclosan and increased the sorption capacities of CNTs with and without functionalizations at a neutral pH. Regardless of how sonication on CNTs was applied, the sorption decreased in the following order: pristine CNTs > CNTs-OH > CNTs-COOH. Sorption decreased with the increase of pH for all types of CNTs due to the electrostatic repulsion between triclosan and CNTs. The pH effect is greater for pristine CNTs than functionalized CNTs, while the sonication effect is greater for functionalized CNTs than pristine CNTs. Sonication increased sorption at a low pH (i.e., < 9.5) but decreased sorption at a high pH (i.e., > 9.5) for all types of CNTs, which may be due to the difference in the structure of CNTs at different pHs. Within 0.001–0.1 M NaCl, sorption increased and then decreased for all types of CNTs with and without sonication, which can be explained by the balance between the salting-out effect and electrostatic screening effect. [ABSTRACT FROM AUTHOR]

[Display omitted] • The flexural modulus and strength of the multi-material struts decrease with the increasing core-to-strut thickness ratio. • The energy absorption capacity of the multi-material struts is greater than that of the individual constituents. • Multi-material lattices with tunable in-plane compression modulus and strength are achieved. • The multi-material lattices exhibit greater energy absorption capacity compared to those of the individual constituents. Modern engineering applications require advanced materials that are stronger, tougher, and lighter. Nature offers various structural architectures to achieve superior mechanical properties. Inspired by bone with a spongy soft-core and a compact hard-shell, this study introduces architected multi-material lattices with tunable mechanical properties such as stiffness, strength, and energy absorption. The architected lattices are fabricated via multi-material fused filament fabrication. The hard polylactic acid (PLA) shell of the lattice struts maintains the stiffness, while the soft thermoplastic polyurethane (TPU) core enhances toughness and energy absorption capacity. The microstructural and mixed-mode fracture characteristics of the PLA-TPU interfaces were examined since the interfacial microstructure and adhesion are crucial to stress transfer in multi-phase composite materials. This study explores the flexural behavior of the multi-material struts and reveals two distinct failure modes depending on the volume fraction of the soft-core through 3-point bend tests. This study demonstrates the bio-inspired design on a hexagonal planar lattice with a strut thickness-to-length ratio of 0.3. Tunable stiffness, strength, and energy absorption are achieved by varying the core-to-strut thickness ratio. Compression test results show that the architected lattices exhibit an energy absorption capacity that is about 2–3 times greater than that of the constituent single-phase lattices. [ABSTRACT FROM AUTHOR]

• A novel two-stage dish solar concentrator with a fixed focus is designed. • The optical performances are determined by ray-tracing under a new sun-tracking mode. • The optimum PR rim angles are 45° and 60° for a flat and a hyperboloidal SR. • The flat SR contributes to a higher instantaneous concentration ratio. • The optical performance stability is better with a hyperboloidal SR. • An overall average concentration ratio of 2097 suns is achieved over the 35 mm-radius aperture for a flat SR. In this study, a two-stage beam-down dish solar concentrator with a fixed focus was innovatively designed, consisting of a paraboloidal primary reflector (PR), a flat secondary reflector (SR), and a receiver. A new sun-tracking mode was proposed to obtain a fixed focus. The influences of the PR rim angle, SR tilt angle, and distance from the SR to the primary focus on the concentration ratio and optical efficiency using different types of SR (flat or hyperboloidal reflectors) were comprehensively investigated. The instantaneous and overall optical performances were determined using Monte Carlo ray-tracing simulations. The results showed that the optimum SR tilt angle is equal to 38.25° as the solar altitude angle ranges from 30° to 73.5°, and the optimum PR rim angles are 45° and 60° for the two proposed concentrators adopting a flat SR (Design I) and a hyperboloidal SR (Design II). The numerical values of instantaneous and overall optical performance for Design I and Design II are almost equal, whereas the flat SR adopted in Design I is preferred in terms of manufacturing accuracy and installation. A peak solar concentration ratio of 6970 suns and an overall average of 2097 suns are achieved over the 35 mm-radius aperture of the receiver for Design I. The radiative power and overall optical efficiency are 8.089 KW and 78.9%, respectively. [ABSTRACT FROM AUTHOR]

Higher alcohols synthesis (HAS) from syngas (CO/H 2) has attracted widespread attention, while the low selectivity and poor stability of the catalysts mainly stumbled its industrial application. In the work, Ni–Co alloy nanoparticles (NPs) derived from Co 1-x Ni x Al 2 O 4 loaded on the SiO 2 with large specific surface area were prepared; and during reaction, the highly dispersed Ni–Co alloys were self-optimized to Ni–Co alloy@Co–Co 2 C. Importantly, Ni–Co alloy@Co–Co 2 C can be regenerated through oxidation - reduction - self-optimization process. Characteristic results indicated that the structural liberalization during the reaction process inhibited the loss of Ni, regulated and balanced the dual active sites of the catalyst and the Ni–Co alloys were regenerated after the re-oxidation and re-reduction process. The optimized catalyst exhibited excellent catalytic performance, including a high total selectivity to alcohols of 39.3% and an excellent catalytic stability at 250 °C, 3.5 MPa (H 2 /CO = 2) and a space velocity of 6000 mL (g cat h)−1. In addition, the Ni–Co alloy@Co–Co 2 C catalyst after stability test could recover its original catalytic performance after re-oxidation and re-reduction. The renewable characteristics and superior catalytic performance of Ni–Co alloy@Co–Co 2 C made the catalyst to be one of the potential industrial catalysts for HAS. [Display omitted] • The interaction between Ni–Co inhibited the sintering of the active components. • The formation of Co–Co 2 C on the surface suppressed the loss of active components. • Ni–Co alloys were regenerated after the re-oxidation and re-reduction process. • Renewable catalyst could recover its original catalytic performance. [ABSTRACT FROM AUTHOR]

• A fully flexible THz sensor: both the metasurface sensor on PI film and the detected samples in the PVA film form a fully flexible thin film. • THz polarization sensing technology: Polarization characteristic parameters are characterized more information of the samples. • Trace and highly sensitive detection: the lowest measured sample is 35 µg, and the sensitivity is 1.5 times that of the traditional resonance sensing. • Quantitatively detect the sample concentration and qualitatively distinguish different saccharide isomers. Terahertz (THz) biochemical sensing still faces challenges in low sensing sensitivity and strong absorption, especially in aqueous solutions. In this work, the THz polarization sensing method with an ultra-thin fully flexible metasurface sensor has been proposed. The saccharides solutions of different concentrations were prepared as the polyvinyl alcohol (PVA) films of only 2.3 µm thickness on the flexible metasurface of the 100 µm polyimide (PI) film. On the micron scale of the film surface, THz waves were enhanced locally by the metasurface and had very low absorption due to the ultra-thin thickness, which improved the sensing sensitivity. Two polarization characteristic parameters (i.e. the polarization ellipticity and polarization rotation angle) were applied to characterize the information of the samples. The experimental results showed that a trace amount of sample on the surface of the sensor can be detected, the actual lowest measured value was 35 µg, and the sensitivity could reach 1.43 GHz/(µg/cm2) or 0.57°/(µg/cm2), which was 1.5 times that of the traditional resonance sensing. This method also qualitatively distinguished different saccharide isomers, which also had higher accuracy than that of the traditional resonance method. Therefore, this THz fully flexible sensor and polarization sensing have a important application prospect in the future's biophilic, stretchable, attachable, and wearable sensing fields. [ABSTRACT FROM AUTHOR]

• Practical solar spectrum measured by an integrated optical chip. • Solar radiation is coupled to a fiber and transmits flexibly over 50 m to the lab. • The observed O 2 (687.7 nm, 761.9 nm) and H 2 O (718.4 nm) absorption lines are in good agreement with the literature. • This work proves feasibility of chip-based instrument for atmospheric observation, climatology, and exoplanet exploration. We demonstrate solar spectrum measurement in the visible-near-infrared region by integrated waveguide spectral lens (WSL). Light through the chip is dispersed and focused on a camera placed at the designed distance without any free-space lens. Commercial polymer materials with low propagation loss near visible region are chosen for wafer-scale fabrication. The solar radiation is coupled to a fiber via a home-made setup and the captured light is transmitted over ∼ 50 m to the lab, where the spectrum is examined by two WSL chips for broadband and fine analysis, respectively. The observed O 2 (687.7 nm, 761.9 nm) and H 2 O (718.4 nm) absorption lines are in good agreement with the results from a commercial optical spectral analyzer and the literature. This experiment proves the feasibility of using planar WSL chips as low-cost and versatile components for the development of compact and portable spectrometer equipment. [ABSTRACT FROM AUTHOR]

• Achieved arbitrary power ratio splitter with only 4 microheaters on a multimode waveguide. • Construct a nonlinear equivalent neural network to represent the thermally controlled multimode interference device. • Using "offline" inverse design to achieve splitting functions without tedious numerical simulations. A 3-port beam splitter with arbitrary power ratio is developed on a multimode waveguide by effectively manipulating the multimode interference through 4 locally placed microheaters. For matched interference, different light powers are coupled to the three output waveguides but the sum does not undergo extra loss, whereas the splitter integrates also the variable attenuation function, from zero to maximum, to any of the outputs. Different from the conventional design approach using extensive simulations, an equivalent neural network is established to represent such a multimode waveguide system based on experimental data only. From this neural network, an optimization program is developed to inverse the output and input. For a target power splitting ratio, the required heater currents can be readily calculated on a computer and then loaded onto the waveguide chip. The experimental results match well with the targets. This work demonstrates that the nonlinear activation is inherently integrated in the thermally controlled multimode waveguide though the optical material itself is linear. This feature can be used to construct complex deep learning networks. It may lead to the development of advanced integrated optical switches and computing networks. [ABSTRACT FROM AUTHOR]

• Uniform PB/ITO composite films are prepared by an in-situ replacement method. • The process is completed under atmospheric pressure without requests of sealed spaces. • The films achieve 59.9% transmittance modulation within 12 s. • After 1200 bleaching/coloring cycles, 77% of transmittance modulation ability remained. • This method is friendly to large-areal and scale-up fabrication. As an attractive electrochromic (EC) material, Prussian blue (PB) holds many praiseworthy merits such as environmental benignity, low cost, proper redox potential, and fast electrochemical kinetics, thanks to their unique open framework structure consisting of common elements. However, restricted by the available synthetic methods and the formation of crystallographic imperfects, facile fabrication of large areal and high performance PB EC layers is still challenging. In this article, we establish a simple yet effective protocol to prepare PB EC layers with the assistance of ITO nanoparticle (ITO-np). This preparation method involves just an interfacial precipitation reaction between Fe(CN) 6 4- from the electrolyte and Fe3+ from the acid-etched sacrifice layers. The ITO-np, as a transparent conductive additive, is used to enhance not only electrical conductivity but also adhesion strength of the prepared PB EC layers. The whole processes can be completed under atmospheric pressure without requests of any sealed reaction spaces, and thus should be very friendly to scale up fabrication. The as-prepared PB layers demonstrate decent EC performances with a transmittance modulation of 59.9% at 633 nm, a bleaching/coloring time of 12 s/8s, a cycling lifetime with 77% transmittance modulating ability remained after 1200 cycles, along with a remarkable charge storage/release ability. This work provides an alternative approach for the facile preparation of PB-based films for applications of both EC devices and smart-supercapatteries. [ABSTRACT FROM AUTHOR]

Scalloped (Sd) is transcription factor that regulates cell proliferation and organ growth in the Hippo pathway. In the present research, LmSd was identified and characterized, and found to encode an N-terminal TEA domain and a C-terminal YBD domain. qRT-PCR showed that the LmSd transcription level was highest in the fifth-instar nymphs and very little was expressed in embryos. Tissue-specific analyses showed that LmSd was highly expressed in the wing. Immunohistochemistry indicated that LmSd was highly abundant in the head, prothorax, and legs during embryonic development. LmSd dsRNA injection resulted in significantly down-regulated transcription and protein expression levels compared with dsGFP injection. Gene silencing of LmSd resulted in deformed wings that were curved, wrinkled, and failed to fully expand. Approximately 40% of the nymphs had wing pads that were not able to close normally during molting from fifth-instar nymphs into adults. After silencing of LmSd , the transcription levels of cell division genes were suppressed and the expression levels of apoptosis genes were significantly up-regulated. Our results reveal that LmSd plays an important role in wing formation and development by controlling cell proliferation and inhibiting apoptosis. [ABSTRACT FROM AUTHOR]

• A new Co-based coating with excellent thermal-fatigue resistance was prepared. • The martensitic transformation only occurred in single cladding during TF process. • Boundaries of grain and γ/ε phase acted as the weak region for the crack initiation. The Co-based coating by laser deposition could improve the thermal-fatigue (TF) resistance of hot working dies but the effect of technology on properties remained to be studied further. This work investigated the influence of the microstructure and γ/ε transformation on the TF life of the Co-based coating of the AISI H13 hot work die steel. Direct laser deposition (DLD) layers were prepared on the steel surface using modified Co-based alloys, which increased the contents of Cr, W, and Ni. The single and duplex layers were made under precise conditions, and the difference in the TF test life was significant. Meanwhile, the hardness of the duplex layer coating was much higher than that of the single one in the TF process consistently. Various detection methods were adopted to characterize the Co-based coating structures and crack propagation during the TF test. The microstructure of the two deposition coatings uniformly included the γ-Co phase and M 23 C 6 crystalline phase. Moreover, after the TF experiment, the γ/ε transformation only occurred in the single layer as observed by transmission electron microscopy and electron backscattered diffraction. This indicated that the dilution of the base metal element distribution played a key role in reducing the stability of the γ-Co phase, which resulted in relatively low stacking fault (SF) energies, micro-hardness, a high fraction of the precipitate, and an early crack generation of the coating. This research was beneficial for understanding the microstructure, grain growth, γ/ε transformation, and crack propagation behavior in the DLD layers and TF test. [ABSTRACT FROM AUTHOR]

• LaNi 1- x Pt x O 3 /SiO 2 were prepared by a facile method of citrate acid complexation combined with impregnation. • Pt/LaNiO 3 loaded on SiO 2 was obtained by reducing LaNi 1- x Pt x O 3 /SiO 2. • Pt atoms were highly dispersed on a support by using a perovskite-type oxide as the precursor. • Pt/LaNiO 3 /SiO 2 showed excellent activity and stability for CO oxidation. A new facile method for preparing highly dispersed precious metal catalysts was proposed in this work. Highly dispersed Pt supported on LaNiO 3 /SiO 2 were prepared by using LaNi 1- x Pt x O 3 perovskite as precursors. The catalytic performances of CO oxidation over the prepared catalytsts were investigated. The structural features of the catalysts were characterized by N 2 adsorption-desorption, XRD, H 2 -TPR, TEM, EXAFS, CO-TPD and O 2 -TPD techniques. The result indicated that nanocrystalline of LaNi 1- x Pt x O 3 was supported on SiO 2. Reducing LaNi 1- x Pt x O 3 /SiO 2 could make Pt from the interior of the perovskite crystal lattice onto the surface and then form highly dispersed Pt on the support of LaNiO 3 /SiO 2. As the platinum content was 0.5% or less, platinum atoms could distribute highly even maybe in single atoms. The catalytic test revealed that LaNi 0.95 Pt 0.05 O 3 /SiO 2 exhibited a significant activity and stability for CO oxidation, as well as excellent performance in the presence of both 15 vol.% H 2 O and 12.5 vol.% CO 2. It has been demonstrated that the highly dispersed Pt, the easy reducibility, and sufficient surface oxygen species were responsible for the high catalytic activity of LaNi 0.95 Pt 0.05 O 3 /SiO 2 catalyst. [ABSTRACT FROM AUTHOR]

• Effective stress-strain relationship for the grouted sleeve connections is presented. • Transverse pressure influence coefficient exerted by the sleeve coupler was modeled. • The performance of prefabricated piers under cyclic loading was tested. • The proposed model was verified by using the connection test and pier test. • The proposed model can be implemented in 1D, 2D, and 3D finite element analysis. This paper describes the development of an effective stress-strain relationship model for grouted sleeve connections. The transverse pressure influence has been calibrated by using the local bond stress-slip experiment including the effect of the initial construction error of the reinforcing bar. Then, the proposed effective stress-strain model was presented by solving the governing equation of the bond stress-slip behavior for the long-bonded grouted sleeve connection. The grouted sleeve connection can be equivalent to a reinforcing bar with a higher elastic modulus and yielding strength. The equivalent elastic modulus decreases with the increase in the initial construction error, and can be calculated by using the proposed model. The experiments on the long-bonded grouted sleeve connection and prefabricated concrete piers were carried out to verify the proposed model. The tested effective stress-strain relationship of the grouted sleeve connection, the maximum slip of the reinforcing bar embedded in this connection, and the strain distribution of the sleeve coupler were successfully predicted. Moreover, the performance of prefabricated concrete piers under cyclic loading was successfully simulated by using the proposed model. [ABSTRACT FROM AUTHOR]

Hyperspectral imaging techniques are widely used for rapid, efficient, and non-destructive identification of wheat varieties. However, the interference of noise in hyperspectral images and the underutilization of spatial information by most methods are two challenging issues in identifying wheat varieties. In this paper, we present a new approach called Cost-sensitive K-Nearest Neighbor using Hyperspectral imaging (CSKNN) to address these issues. First, we fuse 128 bands acquired by hyperspectral imaging equipment to obtain hyperspectral images of wheat grains, and employ a central regionalization strategy to extract the region of interest. We then use a smoothing denoising strategy to remove noise from the hyperspectral images and improve the saliency of the object grains. Furthermore, we consider the characteristics of different bands and use linear discriminant analysis to compress features, reducing intra-class differences and increasing inter-class differences. Finally, we propose a Cost-sensitive KNN for training and testing of wheat varieties. Our experiments on different strains and varieties of wheat datasets in the same region show that our CSKNN achieves high classification accuracies of 98.09% and 97.45%, outperforming state-of-the-art methods. [ABSTRACT FROM AUTHOR]

Hyperspectral image (HSI) based methods are widely used in identifying seeds varieties with high accuracy. However, the excessive spectral bands in HSI may contain redundant information and degrade the model performance. To address this challenge, we propose a novel feature extraction method called low rank tensor approximation (LRTA). Unlike traditional methods, LRTA extracts joint discriminative information of all wheat seeds from hyperspectral images in a 3-order tensor form, preserving intrinsic information. Our model has three key steps: extracting the region of interest from hyperspectral images and presenting average spectral information in tensor form, using LRTA to extract jointly discriminative information, and feeding this information into a classifier to identify seeds varieties. Experiments on our proposed dataset show that the proposed method has 4% improved to the conventional methods on average. Our method shows promise for improving the accuracy of seeds identification while reducing the dimensionality of HSI. [ABSTRACT FROM AUTHOR]

• Strain field evolution and crack coalescence mechanism of composite strength rock-like specimens with sawtooth interface were investigated. • As the inclination of the interface increases, the peak strength of the specimen first decreases and then increases, reaching the maximum value of 28.29 MPa at the 90° interface. • The failure mode of specimen is greatly related to the strength of rock layer and the inclination of the interface. • The failure modes of the specimen are classified as single weak rock layer failure, oblique failure through rock layer interface, slip failure along the interface and axisymmetric failure along the interface. • The sawtooth parameters have an important influence on the type and location of cracks developed along the interface. The mechanical behaviors of composite rock masses containing a complex interface widely distributed in nature are significantly different from those of monolithic rock masses. The objective of this study is to perform a series of uniaxial compression tests to study the influence of sawtooth interface parameters on the fracture behavior of rock-like composite specimens. Meantimes, the acoustic emission (AE) and digital image correlation (DIC) technique were used to classify damage stages and record strain field evolution, respectively. The results of this study demonstrate that stress–strain curves of composite rock-like specimens with different sawtooth interfaces display characteristics of plastic failure, friction failure characteristics and two different brittle failure characteristics in the post-peak phase. The peak strength of the specimen first decreases and then increases as the inclination of the interface increases, achieving the maximum value of 28.29 MPa at the inclined interface of 90°. The strain concentration zone is mainly generated and expanded around the interface. The parameters of the sawtooth have a significant influence on the type and location of cracks developed along the interface. In addition, there is a strong relationship between the mode of failure of the specimen and the strength of the rock layer and the inclination of the interface. According to the relative positional relationship between the coalescence path of the specimen and the interface, the failure modes of the specimen are classified as single weak rock layer failure (S-AB-0, S-AB-15), oblique failure through rock layer interface (S-AB-30, S-AB-45), slip failure along the interface (S-AB-60, S-AB-75) and axisymmetric failure along the interface (S-AB-90). This result is of great importance for a thorough understanding of the crack coalescence mechanism and strain field evolution of rock-like composite specimens. [ABSTRACT FROM AUTHOR]

The issue of dynamic event-triggered trajectory tracking control of autonomous underwater vehicles (AUVs) in the Trans-Atlantic Geotraverse (TAG) active mound is addressed. Concretely, a novel adaptive event-triggered disturbance observer along with auxiliary functions is constructed to handle with actuator faults and ocean current in the TAG active mound. By using rotation matrices, a new tracking error system involving position and attitude is developed such that potential singularities caused by the large pitch will be sufficiently avoided. By deep combination with model parameters, a sliding mode manifold based on additional velocity errors is established to promote robustness and convergence. Following the detailed analysis, sufficient conditions for the input-to-state practical stability in mean square are given to ensure the tracking performance. An adaptive dynamic event-trigger method is applied to reduce the communication frequency between the embedded PC module and actuators. Finally, the applications of an AUV tracking system in the near-bottom hydrothermal mound are carried out to verify the efficiency of the presented method. • A event-triggered disturbance observer with auxiliary functions is constructed. • A sliding mode manifold with additional velocity errors is established. • The AUV's rotation-matrix dynamic event-triggered tracking sysytem is verified. • With the modeling trajectory, the impacts of the TAG mound is considered. [ABSTRACT FROM AUTHOR]

• Phytoremediation plant waste was disposed via pyrolysis. • PTMs were more sensitive to leaching time in low-temperature biochar. • High-temperature pyrolysis was beneficial for PTMs and biochar stabilization. Thermal conversion of phytoremediation plant waste into biochar was performed as a safe approach for organic waste management. In this work, a promising phytoremediation plant― Silphium perfoliatum L. was pyrolyzed for biochar production at 350, 550 and 750 °C. The long-term leaching risk of potentially toxic metals (PTMs) in the derived biochars and the oxidation resistance of the biochars were investigated. The results showed that PTMs in the biochar could transform into more stable and less toxic forms with the elevated pyrolysis temperature. PTMs leaching behavior in the 350 °C biochar was considerably sensitive to the leaching while that in the 750 °C biochar was not affected. The biochar produced at a higher temperature possessed a greater oxidation resistance with little amount of C loss, and the stronger oxidation resistance would prevent the release of metals bound to the organic matter. The findings of this study demonstrated that high-temperature pyrolysis was able to reduce the potential risk of PTMs and ensure carbon stability. [ABSTRACT FROM AUTHOR]

Abstract: Phytoremediation is regarded as one of the most cost-effective and environmentally friendly strategies for potentially toxic metals (PTMs) contaminated soil remediation. However, uncertainties still existed about the contribution of foliar litter on metal accumulation and mobility in phytoremediation sites. Thus, in this study, fallen leaves, decomposed leaves, and soils at different depths (i.e., 0–5 and 5–10 cm) were collected from a phytoremediation site near a Zn smelter factory. Metals content and mobility were evaluated. Results indicated that upper-layer soils (0–5 cm) were higher in the electrical conductivity (EC) and soil organic matter (SOM) content than the deeper-layer soils (5–10 cm). However, the pH was relatively lower in the upper-layer soils. Fallen leaves were sources of metals in the phytoremediation site, and significantly high amounts of Cd (16.08 ± 0.21 mg kg−1) and Zn (1130.30 ± 60.10 mg kg−1) were found in the decomposed leaves. Metals in the upper-layer soils demonstrated higher accumulation and mobility than the deeper-layer soils. Moreover, the accumulated metals in leaves would gradually return to the soil as the contents of extractable metals increased with the rising decomposition degree of leaves (i.e., cold-water extraction < 80 °C hot water extraction < 1 M HCl extraction). Results from this research are helpful for the guidance of phytoremediation site management. Graphical abstract Image 1008210 Highlights • Effects of foliar litters on PTMs circulation in phytoremediation sites were firstly investigated. • Release of metals from plant leaves elevated metal contents and their mobility in soils. • Metal contents reduced as decomposed leaves > upper-layer soils > deep-layer soils. • Removal of plant leaves is necessary for the management of phytoremediation site. [ABSTRACT FROM AUTHOR]

Defect engineering on transition metal dichalcogenides has been regarded as an effective method to improve electrochemical properties in terms of generating active sites and enhancing the intrinsic conductivity. This study reports a new high-performance electrochemical supercapacitor made of reduced CoNi 2 S 4 (r-CoNi 2 S 4 ) nanosheets, which are synthesized via a facile moderate-reduction process. The sulfur-deficient r-CoNi 2 S 4 nanosheets exhibit significantly enhanced conductivity which is induced by abundant sulfur vacancies formed in the reduction reaction. Compared with the pristine CoNi 2 S 4 nanosheets, the r-CoNi 2 S 4 nanosheets are characterized with a higher specific capacity (1117C g −1 at current density of 2 A g −1 ) as well as excellent rate capability and stable cycling performance. First-principle analysis confirms that the sulfur vacancies originating from the reduction lead to improve hybridization between the Ni and Co d states and the S p states close to the fermi level, and consequently enhance conductivity with the CoNi 2 S 4 nanostructure. Moreover, an ultrahigh energy density of 55.4 Wh kg −1 at the power density of 8 kW kg −1 is obtained in an asymmetric supercapacitor configuration, and 80% capacitance of the supercapacitor remains even after 10000 cycles. [ABSTRACT FROM AUTHOR]

Sepsis is a systemic inflammatory response to infection, where sepsis-associated acute kidney injury (AKI) is a common morbid disease with a high morbidity and mortality, and however at present no effective therapy exists. Increasing evidence have shown that mitochondrial damage and inflammatory response are important initiating factors in pathogenesis of septic AKI. Natural flavonoid pectolinarigenin exerted anti-inflammatory properties in previous studies, while its role in septic AKI remains unknown. In the study, pectolinarigenin administration significantly ameliorated the dramatic rise of serum creatinine and blood urea nitrogen in lipopolysaccharide (LPS)- and cecal ligation/puncture (CLP)-induced septic mice, respectively. Consistently, LPS/CLP-induced renal damage as implied by histopathological score and the increased injury markers NGAL and KIM-1, which was attenuated by pectolinarigenin. Meanwhile, LPS/CLP triggered proinflammatory cytokine production and inflammation related proteins in the kidneys. However, pectolinarigenin inhibited renal expression of IL-6, IL-1β, TNF-α, and MCP-1 to improve inflammatory response. Furthermore, pectolinarigenin upregulated Bcl-2 protein expression and suppressed apoptotic protein of BAX and cleaved caspase-3 in the kidneys of CLP-induced septic AKI. Mechanistically, LPS could induce the high expression of IL-6 and trigger the phosphorylation of Jak2 and Stat3, while pectolinarigenin remarkably reduced their corresponding levels. Notably, CLP-induced kidney injury of mice significantly reduced the expression of PGC-1α, OPA1 and increased the expression of Drp1, Cyt-C, where pectolinarigenin pretreatment significantly restored their corresponding expression in mice. In summary, pectolinarigenin improved septic AKI via inhibiting JAK2/STAT3 signaling and mitochondria dysfunction. [Display omitted] • Pectolinarigenin (PEC) is a natural flavonoid with anti-inflammatory properties. • PEC alleviated kidney injury against LPS/CLP-induced septic AKI mice. • PEC improved inflammation and apoptosis in kidneys of septic mice. • PEC inhibited JAK2/STAT3 and mitochondria dysfunction in kidneys of septic mice. [ABSTRACT FROM AUTHOR]

As the value of TiO 2 in environmental protection continues to be explored, it has broad potential for stone building protection. However, the hydrophilicity of TiO 2 makes it challenging to keep stable on the exterior of buildings and hydroxyl radicals generated under UV irradiation may be harmful to substrates. Herein, TiO 2 was wrapped with the SiO 2 shell by a modified Stöber method and superhydrophobic TiO 2 was obtained by grafting methyl groups on the SiO 2 shell. The TiO 2 @Si–Me core-shell system were dispersed in Paraloid B72 and applied on marble surfaces to investigate the self-cleaning effect of TiO 2 on the substrate. The results showed that the superhydrophobic TiO 2 nanoparticles significantly enhanced the surface roughness, which was beneficial to transform the acrylic resin coating from hydrophilic to hydrophobic and retain the original vapor permeability. The adsorption rate and degradation efficiency of methylene blue of TiO 2 @Si–Me core-shell system were 2.19 and 1.45 times higher than that of pure TiO 2. Furthermore, the superhydrophobic TiO 2 did not change the color of the stone after UV aging, which contributed to maintaining the appearance of buildings. These findings will help to understand the role of photocatalytic nanomaterials in developing protective layers for stone construction and expand the application in the self-cleaning of the architectural environment. Graphical abstract illustrates the preparation process and superhydrophobic mechanism of TiO 2 @Si and TiO 2 @Si–Me. [Display omitted] • Superhydrophobic TiO 2 @Si–Me were prepared and applied to the Paraloid B72 coating. • The composite coating exhibits more efficient adsorption and photocatalytic activity. • TiO 2 @Si–Me increases the contact angle on marble from 69.87° to 147.61°. • The methyl provides an efficient pathway for the transfer of photogenerated electrons. • The color of the coating on stone was not changed after UV aging. [ABSTRACT FROM AUTHOR]

• A waveguide chip that disperses light and focuses it directly onto a camera without any free-space elements. • Fine spectral resolution (0.42nm) and a large focal depth (>4mm) for precise spectral analysis with relaxed system alignment. • No need for customized detectors and electronic circuits. • The chip can be easily mounted to any commercial camera for fiber spectrum analysis. We propose and experimentally demonstrate a fiber spectrum analyzer based on a planar waveguide chip butt-coupled with an input fiber and aligned to a standard camera without any free-space optical elements. The chip consists of a single-mode waveguide to connect with the fiber, a beam broadening area, and a waveguide array in which the lengths of the waveguides are designed for both wavelength separation and beam focusing. The facet of the chip is diced open so that the outputs of the array form a near-field emitter. The far field are calculated by the Rayleigh-Sommerfeld diffraction integral. We show that the chip can provide a focal depth on the millimeter scale, allowing relaxed alignment to the camera without any fine-positioning stage. Two devices with 120 and 220 waveguides are fabricated on the polymer waveguide platform. The measured spectral width are 0.63 nm and 0.42 nm, respectively. This simple and practical approach may lead to the development of a spectrum analyzer for fiber that is easily mountable to any commercial camera, thereby avoiding the complication for customized detectors as well as electronic circuits afterwards. [ABSTRACT FROM AUTHOR]

Since its inception as the cornerstone of the ultrafast pulse laser, semiconductor saturable absorber mirrors (SESAMs) have attracted considerable interest. Meanwhile, low-dimensional (LD) materials based saturable absorbers (SAs) are gaining popularity in pulsed laser applications due to their high nonlinearity, strong light-matter interaction, and low cost. Here, high-quality LD-SAs have been created by transferring 2 H-TaS 2 onto gold mirrors and covered with plasma-enhanced chemical vapor deposition (PECVD) SiO 2 layers. The non-linear transmission of SiO 2 passivated TaS 2 -SAM was measured using a balanced dual-detector technology. The modulation depth and saturated intensity were ~8.4% and 0.86 MW·cm−2. Based on the SiO 2 passivated TaS 2 -SAM, Q-switched and mode-locked Erbium-doped (Er3+-doped) fiber pulse lasers have been successfully achieved. Stable soliton pulses are obtained in erbium-doped fiber lasers (EDFLs) with pulse width of 1.8 ps, repetition rate of 3.4 MHz and a center wavelength of 1560.6 nm. Moreover, the mode-locking laser exhibited long-term stability with high signal-to-noise ratio of 63 dB. This study serves as a standard for low-dimensional materials research in photonics applications, and the results reveal that TaS 2 -SAM has a wide range of applications in multifunctional all-fiber lasers. [ABSTRACT FROM AUTHOR]

• A multi-parameter high-order extended state observer is designed to estimate lumped uncertainties. • A fixed-time fault-tolerant adaptive trajectory tracking controller is presented. • The desired trajectory is constructed by interpolating the path. • The simulation topography is built according to the TAG active mound. This paper investigates the fixed-time trajectory tracking problem of small autonomous underwater vehicles (S-AUVs) in the Trans-Atlantic Geotraverse (TAG) active mound with ocean current, unknown disturbances, model uncertainties, actuator faults, and input saturations. First, the effect of the near-bottom environment of the mound on S-AUVs is analyzed in detail from three issues. Without the upper bound and gradient of lumped uncertainties, a high-order adaptive extended state observer (ESO) is designed. Then, a continuous fixed-time sliding mode manifold is applied to obtain fast convergence performance. In order to realize the fixed-time convergence of tracking errors, an adaptive fault-tolerant trajectory tracking control law with an auxiliary dynamic system (ADS) is proposed. In addition, the simulated topography of the TAG mound is constructed and the trajectory based on path points is modeled by cubic spline interpolation. The effectiveness and superiority of the proposed algorithm are validated by comprehensive simulations. [ABSTRACT FROM AUTHOR]

Poly (L -lactic acid) microparticles (PLLAms) loaded with growth factors were prepared through the modified (ethanol as the modifier) solution enhanced dispersion by supercritical CO 2 (SEDS) for controlling release rate while maintaining bioactivity. Trypsin was used to explore operational parameters and their influence on release. Results showed that the optimized flow rate of polymer solution was 1.0 mL/min. Release rate of trypsin-PLLAms was regulated by molecular weight of PLLA and Polyethylene glycol (PEG) ratio. Bone morphogenetic protein (BMP-2), fibroblast growth factor-2 (FGF-2), and vascular endothelial growth factor (VEGF) was loaded into PLLAms. Encapsulation efficiency was 65.9%, 63.9%, and 64.3%, cumulative release rate was 63.2%, 74.8% and 84.1% for 7 days, respectively. BMP-2, VEGF and FGF-2 released from PLLAms significantly promoted cell proliferation and differentiation. Therefore, the modified SEDS effectively maintained drug bioactivity, which could be used to fabricate carriers for controlled bioactive drugs release. [Display omitted] • Solution enhanced dispersion by supercritical CO 2 (SEDS) was modified. • Polymeric microparticles loaded bioactive drugs were prepared by modified SEDS. • Bioactive drugs release was controlled by molecular weight and ratio of polymers. • Modified SEDS effectively maintained bioactivity of growth factors. [ABSTRACT FROM AUTHOR]

Targeted design of metal defects in photocatalysts helps to realize stable and efficient wastewater treatment. Herein, a novel spinel Cu 1-x Co 2-y O 4-z with bimetal defects is precisely designed by a simple temperature programmed reduction method in hydrogen atmosphere. The co-existence of metallic defects leads to defects distortion forming polarization effect, which can significantly accelerate the separation of photogenerated carriers. By optimizing the band structure, Cu 1-x Co 2-y O 4-z induced in-situ H 2 O 2 production (190 μmol L−1·h−1 with sacrificial agent and 78 μmol L−1·h−1 without sacrificial agent) to boost the generation of hydroxyl radical, and the photodegradation activity was 7.8 and 8.4 times for MB and Cr(VI) as that of CuCo 2 O 4 , respectively. Bimetal defects achieve high performance through in-situ production of H 2 O 2 and purification of contaminants, providing novel strategies for the applications of spinel photocatalysts in environmental purification. Graphical abstract illustrates the photocatalytic mechanism on contaminants of Cu 1-x Co 2-y O 4-z. [Display omitted] • Bimetal defects initiate the in-situ effect of H 2 O 2 production to boost.•OH. • Bimetal defects induce a polarization effect to boost the separation of e−-h+. • Electric field derived from bimetal defects assists efficient photodegradation. • Cu 1-x Co 2-y O 4-z can activate. • O 2 − to attain prominent photocatalytic activity for Cr (Ⅵ). [ABSTRACT FROM AUTHOR]

The rapid development of electric vehicles significantly aggravates the demand for ternary cathode materials. However, spent lithium-ion batteries (LIBs) from portable applications, generally composed of LiCoO 2 , dominate the volume for recycling. Besides, slow leaching kinetics and low leaching capacities are crucial factors that hinder the commercialization of hydrometallurgical recycling. Here, an economically feasible process for the regeneration of LiNi 0.6 Co 0.2 Mn 0.2 O 2 (NCM622) from spent portable electronics batteries is proposed. By introducing oxygen nano-bubbles (O 2 NBs) into the leaching solution, faster leaching kinetics and 2.5 times higher leaching capacities are obtained compared with those without O 2 NBs. The regenerated NCM622 cathode material demonstrates a well-ordered layered hexagonal structure with a low degree of Li+/Ni2+ mixing ratio, which facilitates the reliable reversible capacity, low polarization, high rate capabilities, and capacity retention ratio. By adopting thermodynamic and the first-principles calculations, the mechanism for the regeneration process is revealed. [Display omitted] • Oxygen nano-bubbles are first introduced into the leaching system. • 2.5 times leaching capacities are obtained compared with the previous report. • Thermodynamic and DFT calculations are used to interpret the regeneration mechanism. • Regenerated LiNi 0.6 Co 0.2 Mn 0.2 O 2 demonstrates excellent electrochemical properties. [ABSTRACT FROM AUTHOR]