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This paper reviews the critical contributions of MOF-based catalytic materials in CO 2 RR and HER, mainly discussing the strategies for the synthesis and modification of MOF-based catalysts, advanced characterization techniques, and the current advances, challenges and future prospects of MOF-based catalysts in CO 2 RR and HER. [Display omitted] • A prototype of future carbon–neutral energy conversion system is pointed out. • Strategies of synthesis, modification and characterization for MOF are highlighted. • Recent advances of MOF-based catalysts in CO 2 RR and HER are compiled in detail. • Challenges and prospect of MOF-based catalysts for CO 2 RR and HER are discussed. To address environmental problems and growing energy demands, reducing CO 2 emissions and developing sustainable clean energy are becoming increasingly crucial. In this context, carbon dioxide reduction reaction (CO 2 RR) and hydrogen evolution reaction (HER) are gaining significant attention as promising technologies for energy conversion utilizing renewable energy sources. However, developing advanced and highly efficient catalysts is essential to make these applications feasible. Metal-organic frameworks (MOFs), a new class of porous crystalline materials, have shown great potential in designing such catalysts for CO 2 RR and HER. Their ordered and tailorable structures, ultrahigh surface areas, and well-defined active sites make them ideal for this purpose. This review discusses the current advances, remaining challenges and future opportunities of MOF-based catalysts in CO 2 RR and HER. First, the strategies for synthesizing and modifying MOF-based catalysts are overviewed, including pristine MOFs, MOF composites and MOF derivatives. Then, the advanced characterization techniques are showcased to provide reaction mechanism insights. Moreover, the recent advances of MOF-based catalysts in both CO 2 RR and HER are compiled in detail, highlighting the structure–activity relationship of MOF materials. Finally, the challenges and outlooks of MOF-based catalysts for CO 2 RR and HER are described. This review provides a systemic and in-depth insight into MOF-based catalyst for CO 2 RR and HER, hoping that this timely and comprehensive review can shed light on the upcoming research horizons of these prosperous areas. [ABSTRACT FROM AUTHOR]

The mechanical properties and cavitation erosion-corrosion behavior of directed energy deposition (DED) and as-cast nickel-aluminum bronze (NAB) alloys in 3.5 wt% NaCl solution were investigated. The DED-produced NAB alloy showed a finer microstructure, and the content of κ phases significantly decreased, improving yield strength (increased by 27.76%) and elongation (increased by 54.89%) of NAB alloy. The DED-produced NAB exhibited a more uniform microstructure, fewer high-angle grain boundaries (HAGBs), and twin boundaries (∑3), resulting in a weakened synergistic effect between corrosion and mechanical attack. Compared with the as-cast counterpart, the mass loss rate of DED-produced NAB decreased by 74.77%. ● Nickel-Aluminum Bronze components were fabricated by directed energy deposition. ● Differences in microstructure between DNAB and the CNAB were discussed. ● Fine and uniform microstructure of DNAB enhanced its mechanical properties. ● DNAB exhibited better cavitation erosion and -corrosion resistance than CNAB. [ABSTRACT FROM AUTHOR]

• Self-breaking design of composite current collector helps improve battery safety. • Self-breaking is fulfilled by introducing oxygen when evaporating aluminum layer. • Extra oxygen forms multilayer structure containing Al oxide on the polymer core. • Short circuit path is spontaneously cut-off by the multilayer structure. • Battery will not undergo thermal runaway when being penetrated. The safety problem obstructs the large-scale application of high energy batteries. Instantaneous short circuit at millisecond triggers uncontrollable thermal runaway in high energy batteries. Herein, to shut down the short circuit at early stage, we accomplish the safety design using composite current collector that spontaneously breaks due to its heterogeneous ductility. The composite current collector has a core with high ductility (the polyethylene terephthalate base), and a skin with low ductility (multi-layer metal). Controlled oxygen is introduced when evaporating aluminum atoms onto the polyethylene terephthalate base, therefore the skin layer will be composed of aluminum and aluminum-oxide layers in staggered rows. The multi-layer skin is more susceptible to crack under the mesoscopic deformation than the plastic core, thereby preventing short circuit by cutting off the pathway of electrons. The cell assembled by the multi-layer composite current collector can pass the nail penetration test without spark, fire and explosion, while the cell with pure current collector and composite current collector with single layer skin cannot. The assembled cell has comparable electrochemical performance (88% capacity retention after 450 cycles) with the reference cell. This work affords novel ideas for the high safety structural design of high energy batteries. [ABSTRACT FROM AUTHOR]

Cutting-type structures, because of their desirable mechanical characteristics, high energy absorption capabilities and excellent guiding performance, has been extensively employed in high-speed trains. Its lightweight design and optimization problems are also the hotspot of research directions in present. This paper designed a new-type structure, i.e., magnesium alloy cutting-type energy-absorbing structure (CTEAS), taking into account its excellent properties of high lightweight level and ease of processing demonstrated through AZ31B magnesium alloy tensile mechanical test. Subsequently, experimental study on magnesium alloy CTEAS are conducted by trolley impact tests of train considering different cutting depths and different velocity levels. The results confirmed the outstanding advantages, including high lightweight level and higher absorbed energy properties, and lower demands of knives, compared with the structures with Q345 steel. In addition, the mechanism of knives cracking and melting phenomenon found in the experiment is explored by finite element analytical method. The results show that the temperature difference between the high-temperature surface and the interior during the cutting Q345 steel process is maybe the key influencing factor leading to knives damage. This research provides an effective tool for the design and analysis of excellent performance energy absorbing structure of high-speed trains. • AZ31B magnesium alloy can be used to cutting-type energy-absorbing structures. • Magnesium alloy structure has outstanding advantages in lightweight and higher SEA. • Temperature of the tools during the cutting process of Q345 steel is more than 900 °C. • Temperature of the tools is less than 800 °C when AZ31B magnesium alloy is cut. [ABSTRACT FROM AUTHOR]

To investigate the cardioprotective mechanism of exercise or exercise combined with inducible costimulatory molecules (ICOS) monoclonal antibody (mAb) therapy against isoproterenol (ISO)-induced cardiac remodeling. Totally 24 male C57BL/6J mice were randomly divided into four groups: the control group (normal saline treatment), ISO group (subcutaneous injection of isoproterenol, 10 mg/kg/day, once daily for 5 consecutive days), the exercise with subcutaneous ISO injection group (EPI), and the exercise with injected with ISO and ICOS mAb group (EPII). The mice in EPI and EPII group were trained on a small animal treadmill for 4 weeks (13 m/min, 0% grade, 60min/day). Exercise significantly attenuated CD45+, Mac-2 inflammatory cell infiltration, cardiac fibrosis and inhibited the RIPK1/RIPK3/MLKL/CaMKII and cardiomyocyte pyroptosis pathways to counter ISO-induced severe cardiac injury. The administration of the ICOS mAb may inhibit the cardioprotection of exercise against ISO-induced heart damage. Compared to those in EPI, our data showed that the increasing levels of myocardial fibrosis, the leukocyte infiltration of cardiac tissue and proteins expression of cardiac myocyte necrosis and pyroptosis signaling pathways in the EPII group. Our results demonstrated that exercise decreased leukocyte infiltration in heart, inhibited the cardiomyocyte pyroptosis and necroptosis signaling pathways, and attenuated inflammatory responses to alleviate ISO-induced cardiac fibrosis. However, the antifibrotic effects of combined treatment with exercise and ICOS mAb intervention did not exhibit synergistic enhancement. • Exercise attenuates the cardiac fibrosis induced by isoproterenol. • ICOS antibody attenuates the protective effect of exercise against isoproterenol induced cardiac injury. • Exercise preconditioning inhibited the cardiomyocyte pyroptosis and necroptosis signaling pathways by ISO-induced. [ABSTRACT FROM AUTHOR]

Circular RNAs (circRNAs) are believed to regulate the progression of various cancers including colorectal cancer (CRC). However, the role and mechanism of circ_0124554 in regulating the sensitivity of CRC to radiation remain unknown. The RNA levels of circ_0124554, LIM and SH3 protein 1 (LASP1), and methyltransferase 3, N6-adenosine-methyltransferase complex catalytic subunit (METTL3) were detected by quantitative real-time polymerase chain reaction. Protein expression was checked by western blot. Cell proliferation, apoptosis, migration, and invasion were investigated by 5-Ethynyl-2′-deoxyuridine (EdU) assay, flow cytometry analysis, and transwell assay, respectively. The sensitivity of CRC cells to radiation was analyzed by cell colony formation assay. Xenograft mouse model assay was conducted to disclose the role of circ_0001023 in the sensitivity of tumors to radiation in vivo. The binding relationships among circ_0124554, miR-1184 and LASP1 were confirmed by a dual-luciferase reporter assay. m6A RNA immunoprecipitation assay was performed to identify the association of METTL3 with circ_0124554. Circ_0124554 expression was upregulated in CRC tissues and cells in comparison with normal colorectal tissues and cells. Circ_0124554 knockdown inhibited proliferation, migration and invasion and promoted apoptosis and radiosensitivity of CRC cells. Moreover, circ_0124554 depletion inhibited tumor formation and improved radiosensitivity in vivo. MiR-1184 was identified as a target miRNA of circ_0124554 and targeted LASP1. Additionally, LASP1 overexpression rescued circ_0124554 knockdown-mediated effects in CRC cells. METTL3 mediated m6A methylation of circ_0124554. Further, circ_0124554 overexpression attenuated METTL3 depletion-induced effects in CRC cells. m6A-modified circ_0124554 promoted CRC progression and radioresistance by inducing LASP1 expression through interaction with miR-1184. • Circ_0124554 expression was upregulated in CRC tissues and cells. • Circ_0124554 silencing inhibited CRC cell malignancy and promoted radiosensitivity. • Circ_0124554 silencing inhibited LASP1 expression by interacting with miR-1184. • METTL3 mediated m6A methylation of circ_0124554. • Circ_0124554 overexpression attenuated METTL3 depletion-mediated effects in CRC cells. [ABSTRACT FROM AUTHOR]

• PIV and the PCA are used to measure simultaneously the surface velocity field and pollutant concentration. • DBM D2Q16 and LBM D2Q5 are used to simulate the velocity and concentration fields. • Effects of the vegetation's density on water depth, velocity field and pollutant transport are discussed. Transport phenomena are crucial components of the biological and chemical processes that govern fluvial environments. The presence of vegetation along rivers plays a significant role in affecting the flow velocity, which becomes unevenly distributed, and consequently is an important factor that can affect longitudinal and transversal dispersion and mixing of pollutants. Therefore, in this study, to provide a better understanding and further insights of the velocity field and the pollutant dispersion in open channels partially covered by sparse vegetation and dense vegetation, an experimental campaign is presented to compare them with the no-vegetation scenario. Novel datasets are produced by applying the Particle Image Velocity (PIV) and the Planar Concentration Analysis (PCA) technologies, which were used to measure simultaneously the surface velocity field and pollutant concentration map within the open channel tested. Results obtained have been used to calibrate and validate a numerical model designed to simulate velocity fields (via Discrete Boltzmann Model D2Q16) and pollutant concentration maps (via the Lattice Boltzmann model D2Q9). Results have shown that as the density of vegetation increases, the flow velocity in the vegetation zone decreases while the velocity in the no-vegetation zone increases. So, the velocity gradient in the transition zone increases accordingly. Besides, the water surface difference between inlet and outlet is higher as the density increases. Finally, the simulated results have been compared with corresponding experimental data and good agreements have been achieved, which indicates that the model developed can accurately predict features that were observed and measured within the experimental facility. [ABSTRACT FROM AUTHOR]

• Ultrasound combined with Baicalin can effectively treat traumatic brain injury. • Functional magnetic resonance imaging was used to evaluate the brain damage. • The Nissl staining was used to quantify brain injury histologically. • Compared with ultrasound, Baicalin is more effective in the treatment of brain edema. • Compared with Baicalin, ultrasound is more effective in the treatment of fiber injury. Low-intensity transcranial ultrasound stimulation (LITUS) can improve the inflammatory reaction after traumatic brain injury (TBI), and Baicalin also has a good protective effect on TBI. The purpose of this study was to observe the neuroprotective effect of LITUS combined with Baicalin intervention in the TBI rats. Sprague Dawley (SD) rats were randomly divided into 5 groups (n = 15) which were Sham control group, TBI group, LITUS group, Baicalin group, LITUS combined with Baicalin group (L B group). The rats were scanned with 3.0 T magnetic resonance imager, and the apparent diffusion coefficient (ADC) and the fractional anisotropy (FA) of the brain injury cortical area were determined at 3 h, 1, 3, 7 and 10 d after TBI. The ADC value, FA value, neurological function score and Nissl staining were used to assess the level of brain damage of rats. The results showed that on the 10th day after TBI, the ADC values of the TBI group, the LITUS group and the Baicalin group were remarkable greater than that of the L-B group (all adjusted P < 0.05), FA values were remarkable smaller than that of the L-B group (all adjusted P < 0.05), neurological function scores were remarkable greater than that of the L-B group (all adjusted P < 0.05), and Nissl body loss rates were remarkable greater than that of the L-B group (all adjusted P < 0.001). This study indicated that compared with the LITUS group and the Baicalin group, the L-B group can more effectively reduce level of brain damage after TBI, and the method of LITUS combined with Baicalin intervention was a more effective neuroprotection for brain injury. [ABSTRACT FROM AUTHOR]

We aimed to analyze the association of estimated glomerular filtration rate (eGFR) levels of hospitalized patients with treatment decisions and clinical outcomes in Chinese patients with acute coronary syndrome (ACS). This was a secondary analysis study from CPACS-2 Program which was a trial of a quality improvement intervention in China and recruited 15,141 patients from 75 hospitals between October 2007 and August 2010. All patients were divided into three groups by the eGFR level on admission. The primary outcomes were several key performance indicators (KPIs) reflecting the management of ACS and the secondary outcomes were clinical outcomes. A total of 14,437 ACS patients were enrolled in this analysis. Among patients with reduced eGFR levels, fewer patients received appropriate medical therapy (p for trend <0.001) and fewer high-risk patients received coronary angiography (p for trend <0.001) compared to patients with a normal eGFR. Furthermore, 436 cases of death, 357 cases of cardiac death, 686 cases of major adverse cardiovascular events, and 198 cases of major bleeding episodes were reported. Patients with a worse eGFR level had significantly higher rates of death (p for trend <0.001), cardiac death (p for trend <0.001), major adverse cardiovascular events (p for trend <0.001) and major bleeding episodes (p for trend <0.001). Among Chinese ACS patients, those with renal insufficiency have a lower percentage of adherence to guideline-recommended treatments and worse clinical prognosis. Renal insufficiency is an important factor affecting guideline implementation in Chinese ACS patients. http://www.anzctr.org.au/default.aspx. Unique identifier: ACTRN12609000491268. • In reduced eGFR levels more patients had a longer length of hospitalization stay. • In reduced eGFR levels less patients received appropriate medical therapy. • In reduced eGFR levels and less high-risk patients received coronary angiography. • Patients with worse eGFR level had significant worse clinical outcomes. • Renal insufficiency is important to guideline implementation in ACS in China. [ABSTRACT FROM AUTHOR]

Light-assisted N 2 fixation to NH 3 under mild conditions is attracting massive attention to circumvent energy crisis and global warming. Herein, highly dispersed Cs-decorated Ru sub-nanometric clusters supported on ZrO 2 NPs have been prepared by means of MOF-templated transformation method. The obtained catalyst exhibited N 2 hydrogenation activity of 1.6 mmol NH3 g cat −1 h−1 in the dark (350 °C, 0.1 MPa). Remarkably this value increased by over 300 %, reaching 5.1 mmol NH3 g cat −1 h−1 (204 mmol NH3 g Ru −1 h−1) under 1 Sun power illumination (1080 W/m2) The influence of the incident light wavelength has been evaluated, revealing 81 % and 213 % enhancement in the NIR and visible region, respectively. DFT calculations were carried out to understand the static adsorption states of Ru sub-nanoclusters. Mechanistic studies have confirmed the co-existence of a photothermal and a nonthermal-hot electron mechanism. XPS, PXRD and FTIR analysis have determined that the Cs species block surface Zr4+ acidity, increasing the basicity of the ZrO 2 support. Moreover, partially reduced Csδ+ (0 <δ < 1) species surrounding the Ru active sites are donating electron density to the adjacent Ru sites, favoring N 2 adsorption and subsequent activation. Finally, this photocatalyst has shown an extended stability for 100 h irradiation under continuous flow. Highly dispersed Cs-decorated Ru clusters supported on ZrO 2 has demonstrated an outstanding catalytic activity for light-assisted N 2 fixation to NH 3. This material has been obtained through UiO-66 MOF templated method. More than 90 % of the spectral response is located in the visible and NIR region. Mechanistic studies revealed the co-existence of photothermal and non-thermal hot-electron injection mechanisms. [Display omitted] • UiO-66 containing Ru was used to obtain fine Ru nanoparticles supported on ZrO 2. • Ru/ZrO 2 promoted by Cs is a photocatalyst for N 2 hydrogenation reaching 5 mmol NH3 g−1h−1. • The apparent quantum efficiency of the process is 39 %. • A large percentage of photocatalytic NH 3 formation is due photons in the visible region. • The Cs-Ru/ZrO2 is stable for a 100 h irradiation run. [ABSTRACT FROM AUTHOR]

• Parameterize the shape of the proposed origami structure. • Propose an origami design to improve the initial peak force of thin-walled energy absorption structure for high speed train. • Parametric studies are performed to evaluate the effects of design variables on collision responses. • Response surface models are established to formulate the mathematical relationship between the crashworthiness responses and proposed structure dimensions. • The optimized design is validated and the IPCF decreases by 29.36% comparing with the initial design without reducing the energy absorption. The initial peak crushing force usually causes catastrophic harm to the passengers once vehicle collision accidents happen. In this study, an origami design is introduced and optimized to improve the initial peak crushing force (IPCF) of a thin-walled energy absorption structure. First, by analyzing the basic idea of origami structure, this paper decides twist angle (φ) , height (h) and thickness (t) as the control variables. Then, the crashing characteristics of the thin-walled structure are under study and the FE model is validated by an impact test. Further, parametric analysis on the relationships between design variables and target responses (energy absorption and IPCF) is studied. It is found that the twist angle has a negative influence of IPCF and EA , while the t has a positive influence on the impact responses. Particularly, the increase of h cause the increase of IPCF but a decrease of EA. In further, to minimize the IPCF but do not affect the EA , optimization technology with NSGA-II algorithm is employed. The optimization results (i.e., φ = 3.24°, h = 30 mm, t = 4 mm, IPCF = 934.28 kN, EA = 269.90 kJ) manifest that IPCF reduces by 29.36% without reducing the ability of energy absorption. For the point of train collision safety, the proposed origami inspired structure is introduced successfully and the optimal structure is of great advantages in improving the IPCF for the energy absorption structure. [ABSTRACT FROM AUTHOR]

Dissimilar metals of Ti-6Al-4V and T2 Cu were successfully welded by vacuum electron beam. Forming and tensile fracture characteristics of the joints were studied in the paper. Wettability and tensile tests were introduced to reveal the weldability of Ti-Cu joints, meanwhile, OM, SEM, EDS, XRD and TEM were applied to assess the microstructure and fracture mechanism. The results shows that Cu can wet the surface of Ti alloy well, but not the opposite. Thus, shifting the electron beam on Cu sheet is helpful to improve appearance quality and bonding strength. Average tensile strength of Ti-Cu joints could reach 147 MPa, i.e. 63% of that of T2 Cu substrate when the electron beam was shifted to the copper side with an offset of 1.4 mm. The micro analysis demonstrate that there is a thin IMCs layer at the fusion zone. Which consists of a variety of Ti-Cu intermetallic compounds, e.g., Ti 2 Cu, TiCu, Ti 3 Cu 4 , βTiCu 4 , etc. Fracture morphologies indicate that it belongs to quasi-cleavage fracture and fracture occurred at the IMCs layer. • Dissimilar metals of Ti-6Al-4V and T2 Cu were successfully welded by vacuum electron beam. • Average tensile strength of Ti-Cu joints could reach 147 MPa, i.e. 63% of that of T2 Cu substrate. • Detailed investigation of microstructures and fracture mechanism were presented. [ABSTRACT FROM AUTHOR]

The rational design and in deep understanding of efficient, affordable and stable materials to promote the light-assisted production of fuels and commodity chemicals is very appealing for energy crisis and climate change amelioration. Herein, we have prepared a series of Co-doped hydroxyapatite (HAP) catalysts with different Co content. The materials structure has been widely investigated by XRD, FT-IR, HRTEM, XPS, XAS, as well as computational simulations based on Density Functional Theory (DFT) with PBE functional. At low Co loading, there is a partial substitution of Ca cations in the HAP structure, while higher loadings promote the precipitation of small (∼ 2 nm) Co nanoparticles on the HAP surface. For the optimal Co content, a constant CO rate of 62 mmol·g−1·h−1 at 1 sun illumination and 400 °C, with the material being stable for 90 h. Visible and NIR photons have been determined responsible of the light-assisted activity enhanced. Mechanistic studies based on both experimental and DFT simulations show that H 2 preferentially adsorbs to metallic Co, while CO 2 adsorbs to the HAP surface oxygen. Moreover, both direct photo- and plasmon-driven contributions have been separated in order to study their mechanisms independently. [Display omitted] • A series of Co-doped hydroxyapatite (CoHAP) at various Co loadings (3.46–11.38%) have been prepared. • Characterization indicates that Co2+ replaces Ca2+ in the HAP lattice up to 5.88%. • At higher loading Co2+ migrates outside the HAP lattice and forms small Co 3 O 4 nanoparticles. • Under continuous flow at 400 °C, the optimal CoHAP produces 62 mmol CO·g−1·h−1. • The material is stable for at least 90 h without activity decay [ABSTRACT FROM AUTHOR]

• A collision scene of high-speed train-moose collision was applied to the study. • A full finite element model of the moose was developed and validated. • Considering the impact on the pantograph after the obstacle was hit. • The collision force and trajectory of the moose after being hit were analyzed. Collisions between trains and moose that cross a track are common occurrences according to rail accident statistics. A moose lying on a track after a crash may increase the risk of train derailment. In addition, a moose thrown into the air during a collision may also hit and damage the pantograph, which prevents a train from running. This paper developed a finite element (FE) model of moose and is aimed at investigating the train crash safety and moose motion trajectory in train-moose collisions for different moose crossing scenarios using the FE method. Material biomechanics tests were conducted to obtain the mechanical property parameters of moose. Drop hammer impact tests were performed to validate the constitutive models of different moose segments. The whole moose FE model was verified against previous vehicle-moose crash tests. The numerical impact scenes of moose crossing the rail at different collision positions were established in LS-DYNA. The results showed that the impact force depends on the contact area between the train and the moose. A larger contact area corresponded to a larger impact force. The moose would be pushed away by the V-shaped locomotive and would not cause a derailment, and the height of the moose thrown into the air cannot reach the height of the pantograph, which would prevent damage to the pantograph of a bullet train. [ABSTRACT FROM AUTHOR]

A common but easily overlooked affective overlap problem has not been received enough attention in electroencephalogram (EEG)-based emotion recognition research. In real life, affective overlap refers to the current emotional state of human being is sometimes influenced easily by his/her historical mood. In stimulus-evoked EEG collection experiment, due to the short rest interval in consecutive trials, the inner mechanisms of neural responses make subjects cannot switch their emotion state easily and quickly, which might lead to the affective overlap. For example, we might be still in sad state to some extent even if we are watching a comedy because we just saw a tragedy before. In pattern recognition, affective overlap usually means that there exists the feature-label inconsistency in EEG data. To alleviate the impact of inconsistent EEG data, we introduce a variable to adaptively explore the sample inconsistency in emotion recognition model development. Then, we propose a semi-supervised emotion recognition model for joint sample inconsistency and feature importance exploration (SIFIAE). Accordingly, an efficient optimization method to SIFIAE model is proposed. Extensive experiments on the SEED-V dataset demonstrate the effectiveness of SIFIAE. Specifically, SIFIAE achieves 69.10%, 67.01%, 71.50%, 73.26%, 72.07% and 71.35% average accuracies in six cross-session emotion recognition tasks. The results illustrated that the sample weights have a rising trend in the beginning of most trials, which coincides with the affective overlap hypothesis. The feature importance factor indicated the critical bands and channels are more obvious compared with some models without considering EEG feature-label inconsistency. • Affective overlap problem was considered in emotion recognition. • Feature-label inconsistency and feature importance were utilized jointly. • SIFIAE obtained a significant improvement in cross-session emotion recognition. • Obtained sample inconsistency demonstrated affective overlap hypothesis. • Affective activation pattern could be adaptively obtained in our model. [ABSTRACT FROM AUTHOR]

Abstract The thermionic electron gun is one of essential parts of electron accelerators and vacuum tubes. For electron beam generation it is basically configured by cathode, anode and it can have control electrode. In common electron guns, beam current is typically controlled by the bias voltage on the Wehnelt electrode. To deeply study the control mechanism of electron beam current, a three-dimensional model of a 60 kV/6 kW thermionic electron gun is established and the simulation of electric field distribution with CST software is shown in this paper. The particle tracking model is used to track the movement of emitted electrons and the quantitative relationship between beam current and bias voltage is established. Results show that electron beam current is inversely proportional to the bias voltage within a certain range. As the bias voltage increases, the electric field distribution in electron gun changes and the equipotential line of accelerating voltage moves towards the emitting surface of cathode, therefore the Effective Emitting Area (EEA) of cathode decreases and, accordingly, the beam current also decreases. Besides, when the bias voltage is fixed, fluctuations of the accelerating voltage cause fluctuations of the beam current, which is especially severe when the beam current is small. Graphical abstract Image 1 Highlights • Beam current control mechanism in the thermionic electron gun is simulated. • Beam current is inversely proportional to the bias voltage within a certain range. • The bias voltage adjusts beam current by changing the effective emitting surface. • Beam current with small value is more affected by high voltage fluctuations. [ABSTRACT FROM AUTHOR]

The mechanical responses and crystallographic texture evolution of four representative aluminum alloy sheets (2xxx, 5xxx, 6xxx and 7xxx series), commonly used in the transportation industry, are studied under reverse shear loading in this work. The monotonic and forward-reverse simple shear tests are carried out to obtain the stress-strain response. The initial and after-deformation crystallographic texture are experimentally measured. The deformations are simulated using a dislocation theory-related hardening model incorporated in the Visco-Plastic Self-Consistent (VPSC) framework. The simulation results are in good agreement with the experiments in both the mechanical response and texture evolution. Furthermore, the changes of texture components during shear and reverse shear deformation are contrastively discussed as well as the influence of initial texture on the evolution. The cube component, as the primary initial orientation, transforms into other orientations as the applied shear deformation progresses. The rate of change is dependent on the initial texture intensity. Although the loading direction reverses once, the intensity variation of the orientation components showed two inflection points. [ABSTRACT FROM AUTHOR]

Abstract Based on the Simplified Super Folding Element (SSFE) theory, the theoretical prediction of average crushing force (F avg) for multi-cell thin-walled structures is inferred and a combined five-cell thin-walled structure used in high speed train is proposed and investigated in this paper. The finite element model of the proposed structure and the theoretical prediction are validated by a full scaled impact experiment. Then, parametric studies are performed to evaluate the effects of design variables, including the thickness (t) and the side length (a) of the orthohexagonal cell, on collision responses based on the validated FE model and theoretical prediction. It is found that both specific energy absorption (SEA) and the maximum initial force (F max) are obviously affected by the design parameters. Particularly, the effect of parameter t on crushing performance is greater than that of parameter a. In further, to minimize the F max and maximum SEA under the constraint of F avg , a multi-objective robust optimization methodology is adopted. The Optimal Latin Hypercube Design (OLHD) and orthogonal design are combined to perform Design of Experiment (DoE) and dual response surface models (DRSM) are constructed for the optimization. The optimal results of deterministic optimization indicate that the F max decreases by 11.07% compared with the original design while the robust optimization optimal result of F max decreases by 10.01%. However, the robust optimization optimal design is more acceptable considering the robustness, which means the robust optimization is more attractive than deterministic optimization in practical engineering application. Highlights • Infers the theoretical prediction of average crushing force for multi-cell thin-walled structures. • Proposes a combined multi-cell thin-walled structure for high speed train. • Parametric studies are performed to evaluate the effects of design variables on collision responses. • RS models are established to describe the relationship between crashworthiness responses and proposed structure dimensions. • The multi-objective robust optimization parameters of a combined five-cell thin-walled structure is obtained. [ABSTRACT FROM AUTHOR]

Abstract The aim of the present work was to study the synergistic reinforcement, by short and continuous carbon fibers, of polyamide-based composites. The three-phase composites were obtained by the fused filament fabrication process where short fiber reinforced polyamide was deposited/printed along with continuous carbon fibers in a layered structure. The properties of the continuous carbon fiber tows and short carbon fiber reinforced polyamide tows were first evaluated by means of morphological, thermal and mechanical tests. The effects of stacking sequence of laminates as well as the effects of both short and continuous fibers' contents, on the mechanical properties of laminated composites, were carefully analyzed by considering several layering configuration. The results showed that the synergistic reinforcement of laminates by both short and continuous carbon fibers was indeed superior to the individual carbon fiber reinforcement for the tensile strength but not for the elastic modulus. The tensile properties of the laminated composites were higher when the stacked continuous carbon fiber reinforced layers (CCFRLs) were separated. Laminated composites with more interfaces between short carbon fiber reinforced layers (SCFRLs) and SCFRL/CCFRL interfaces showed higher mechanical performance due to the stronger adhesion of these interfaces compared to the interfaces between CCFRLs. The mechanical properties of laminated composites tended to be higher with increasing continuous carbon fiber content. The rule of mixture was used to estimate the mechanical behaviors of short and continuous fiber reinforced composites. All the experimental data was comprised between the upper bound and the lower bound estimates. However, the experimental results were rather close to the upper bound due to the alignment of the continuous carbon fibers. [ABSTRACT FROM AUTHOR]

Abstract The objective of this study is to investigate the fracture behaviors of windshield laminated glass for high-speed trains. For this purpose, tempered glass specimens sampled from constituent components of polyvinyl butyral (PVB) laminated windshield panes were tested using the following tests: flexural strength test, quasi-static uniaxial tensile test, low strain rate compression test and dynamic compressive test with split Hopkinson pressure bar (SHPB). Together with simulations, the testing results were used to determine the constitutive constants of the Johnson-Holmquist ceramic (JHC) model, including the equation of state, the strength criterion and the strain-rate effect. To validate the JHC model, it is used to simulate a safety hammer impact test on PVB-Laminated tempered glass (PVB-LTG). The simulation results showed that the JHC model with tempered material constants for PVB-LTG successfully predicted the impact response of windshields. The practical implications of fragmentation and cracking are also discussed. [ABSTRACT FROM AUTHOR]

Abstract The achievement of compact and defect-free film structure is crucial for the application of b -oriented MFI zeolite film. In this work, a novel heat treatment technique was used to treat zeolite seeded substrates prior to secondary growth. The influence of the heat treatment parameters such as treat temperature and time on the final film morphology were systematically investigated. The relationship between film compactness and the parameters was established. Under the optimized treat temperature of 120 °C and treat time of 1 h, compact and uniform b -oriented MFI zeolite film was achieved. The applicability of the optimum heat treatment condition was validated by employing various film substrates. [ABSTRACT FROM AUTHOR]

The objective of the present study is to predict brain injuries and injury severities from realworld traffic accidents via in-depth investigation of head impact responses, injuries and brain injury tolerances. Firstly, a total of 43 passenger car versus adult pedestrian accidents were selected from two databases of the In-depth Investigation of Vehicle Accidents in Changsha of China (IVAC) and the German In-Depth Accident Study (GIDAS). In a previous study the 43 accidents were reconstructed by using the multi-body system (MBS) model ( Peng et al., 2013a ) for determining the initial conditions of the head-windscreen impact in each accident. Then, a study of the head injuries and injury mechanisms is carried out via 43 finite element (FE) modelings of a head strike to a windscreen, in which the boundary and loading conditions are defined according to results from accident reconstructions, including impact velocity, position and orientation of the head FE model. The brain dynamic responses were calculated for the physical parameters of the coup/countercoup pressure, von Mises and maximum shear stresses at the cerebrum, the callosum, the cerebellum and the brain stem. In addition, head injury criteria, including the cumulative strain damage measure (CSDM) (with tissue level strain threshold 0.20) and the dilatational damage measure (DDM), were developed in order to predict the diffuse axonal injury (DAI) and contusions, respectively. The correlations between calculated parameters and brain injuries were determined via comparing the simulation results with the observed injuries in accident data. The regression models were developed for predicting the injury risks in terms of the brain dynamic responses and the calculated CSDM and DDM values. The results indicate that the predicted values of 50% probability causing head injuries in the Abbreviated Injury Scale (AIS) 2+ correspond to coup pressure 167 kPa, countercoup pressure −117 kPa, von Mises 16.3 kPa and shear stress 7.9 kPa respectively, and causing AIS 3+ head injuries were 227 kPa, −169 kPa, 24.2 kPa and 12.2 kPa respectively. The results also suggest that a 50% probability of contusions corresponds to CSDM value of 48% at strain levels of 0.2, and the 50% probability of contusions corresponds to a DDM value of 6.7%. [ABSTRACT FROM AUTHOR]

Current reported cellular metastructures can either achieve only tailorable thermal expansion or obtain only tunable Poisson's ratio. By contrast, here, we develop a kind of lightweight cellular metastructure which incorporates coupled tailorable thermal expansion and tunable Poisson's ratio. That is a wide range of positive, zero and especially negative values of both thermal expansion and Poisson's ratio can be simultaneously obtained. The ranges and constraints of the geometrical parameters are revealed, and the relative densities are only about 2%, indicating excellent lightweight character. Besides, analytical expressions for coefficient of thermal expansion (CTE) and Poisson's ratio (PR) are theoretically established and numerically simulated. Parameter analysis confirms that the range of tailorable CTE can be enhanced through rationally selecting large values of CTE ratio, first geometrical angle and height ratio. By adjusting the second and third geometrical angles, Poisson's ratio also can be tuned to be large negative, near zero and positive values. Particularly, the metastructure can give paired negative CTE and negative PR. Different combinations of paired characteristics including positive CTE + negative PR, positive CTE + positive PR and negative CTE + positive PR are also flexibly available. Moreover, CTE and PR are found to be highly coupled. To simultaneously obtain specific CTE and PR, design parameters should be selected with consideration of the coupling effect. The results here are expected to contribute feasibility to structures with both temperature and mechanical sensitivities. [ABSTRACT FROM AUTHOR]

Ionic liquids (ILs) are gradually concerned due to their potential environmental and health risks. In this work, the chronic effects of imidazolium-based ILs, using [C 14 mim]Br as a representative, were evaluated using model animal Caenorhabditis elegans . Our results show that prolonged exposure (72 h) of ILs to the nematodes at concentrations of 5 and 10 mg/L induced adverse effects on the growth, locomotive behaviors and development. To explore the toxicity mechanism, lipofuscin content, ROS level and the expressions of five superoxide dismutase (SOD) genes were determined after the prolonged exposure. The lipofuscin content, ROS level and expressions of SOD genes did not show significant changes except that the expression of sod-5 was reduced by 2.7-fold following the treatment of 10 mg/L of [C 14 mim]Br. These results suggest that oxidative stress may not be responsible for the adverse physiological effects induced by relatively low concentrations of imidazolium-based ILs. We further determined the gene expressions of phase I detoxification enzyme cytochrome P450 (CYP), phase II detoxification enzyme UDP-glucuronosyltransferase (UGT) and ATP-binding cassette (ABC) transporter P-glycoprotein (PGP). The results demonstrate that CYP, UGT and PGP may be involved in the detoxification of ILs. Our findings will aid in understanding the mechanisms of both toxicity and detoxification of imidazolium-based ILs in animals. [ABSTRACT FROM AUTHOR]

Inspired by the nature material, a crosslinked network structure of polyurethane/epoxy resin composite material was built through Diels-Alder (DA) reversible covalent bond reaction between the dienes and dienophile group on the side chain of epoxy resin and polyurethane respectively. The synthesized composite material combined the advantages of polyurethane and epoxy resin. The hard segments of polyurethane and epoxy resin were closely combined through the DA reaction and high density hydrogen bonding. The strength, hardness and toughness of the composite material were greatly enhanced. DA covalent bonds can be reversible with varying the temperature, which led to the heat reprocessing ability of the synthesized composite material. The well-established structure-property relationship shown in this paper could further provide guidance for fabrication of high performance recyclable material with precisely controllable microstructures and behaviors. [ABSTRACT FROM AUTHOR]

It is becoming increasingly difficult to improve tensile strength of dissimilar metals by controlling the formation of intermetallic compounds (IMCs) in the welding of Ti and Al alloys. In this study, a novel laser welding process based on welding-brazing process is proposed, referred to as local remelting process. Metallurgical bonding of incompatible Ti-6Al-4V and Al-Mg-Si alloys was successfully achieved and sound joint with well appearance was obtained. Tensile strength of the joint reached up to 78.6% that of Al substrate, typically the strength is lower than 70%. In order to reveal the effects of local remelting process on the microstructure and tensile strength, SEM, EDS and XRD were applied for the analysis and tensile strength was tested. In addition, FEM simulation was conducted to improve the comprehension of microstructural evolution involved in the process. The results indicate that the joint realized the metallurgical bonding by direct irradiation on aluminum sheet and heat conduction formed by welding on titanium sheet promoted the joining in the interface. Original ordered phase structure was destroyed and a thinner IMCs layer was formed. Both joints present brittle fracture characteristics, but for the joint of remelting process, parts of fracture surface were featured by dimples. [ABSTRACT FROM AUTHOR]

• The higher the order of BDFS is, the better the crashworthiness performance will be. • Structures with regular polygonal wall are better than circular with the same ribs. • The SEA, PCF and ULC of any structure are not all the best. • BDFS with six ribs and 3rd-order parting have the best comprehensive performance. • A hybrid multi-stage optimization decision system, i.e., MCDM-MOP-MCDM, is proposed. Rail vehicles offer the characteristics of large carrying capacity and high running speed. Train accidents usually result in substantial personal casualties and economic losses. Energy-absorbing structures can efficiently and quickly absorb and disperse the energy generated during collisions. In this paper, the performances with different cross-sections and partings of the bionic dendritic furcal structure (BDFS) inspired by the furcal branch and bifurcation structure of neurons are analyzed and compared by numerical simulation. The simplified super folding element theory and experiments verify that the finite element models are effective. A hybrid multi-stage optimization decision system, i.e., multi-criteria decision-making (MCDM)- multi-objective optimization (MOP)- MCDM, which integrates the VlseKriterijumska Optimizacija I Kompromisno Resenje (VIKOR) method, the multiple objective particle swarm optimization-crowding distance (MOPSO-CD) evolutionary algorithm and repetitive VIKOR method, is proposed to find the optimal structure and obtain the optimal parameter alternative of the structure. Comparisons and analyses of experiments and simulations are carried out to verify the effectiveness of the proposed method. The results show that BDFS with six furcal ribs and 3rd-order parting display the best comprehensive crashworthiness under the working condition of 10 m/s specified in EN15227 standard. When the single target requirement is considered, specific energy absorption (SEA) can be increased by 16.18%, peak crushing force (PCF) can be decreased by 67.07%, and undulation of the load-carrying capacity (ULC) can be decreased by 14.02%. This study provides an effective tool for the analysis and optimization of energy-absorbing structures. [Display omitted] [ABSTRACT FROM AUTHOR]

The wire-arc additive manufacturing (WAAM) was used to develop Ni-Al bronze (NAB) alloys for naval application. Compared with as-cast NAB, the microstructure of as-fabricated NAB is finer, the precipitation of the κ Ⅰ is suppressed, more uniform distribution of elements, and most β′-phase transformates to α + κ Ⅲ eutectic structures. Additively manufactured sample reveals a lower corrosion current (0.0149 ± 0.0014 mA·cm−2) than the counterpart (0.0162 ± 0.004 mA·cm−2). After immersion for 30 days, since the film formed on the additively manufactured NAB contains more Al 2 O 3 and Ni, the mass loss of WAAM-produced NAB alloys decreased by 35.21% compared to the cast samples. • Nickel-Aluminum Bronze components were fabricated by wire-arc additive manufacturing. • Differences in κ-phases formation between WAAM-produced NAB and cast was discussed. • WAAM-produced samples showed fine microstructure and uniform element distribution. • The more Al 2 O 3 and Ni in the oxide film formed on the WAAM-produced samples. • WAAM-produced NAB exhibited lower corrosion rate and better corrosion resistance. [ABSTRACT FROM AUTHOR]

Tailoring thermal expansion of structures is in urgent need in engineering applications where the structures are susceptible to suffer large temperature fluctuation. Here, a method to reconstruct 3D truss structures is developed to obtain large positive, zero and even negative coefficient of thermal expansion (CTE). As the basis, theoretical analysis and numerical verification of the bi-material pyramid and tetrahedron lattice cells explicitly reveal that with thick members, the influence of the cross section on the CTEs should be well considered, and the CTEs should be accurately calculated by the solid model. Furthermore, two kinds of 3D lattice structures with isotropic tailorable CTEs are originally devised. Moreover, bi-pyramid and bi-tetrahedron units are devised, and a reconstruction method, which can reconstruct an arbitrary 3D truss structures to obtain specific target CTE, is originally developed. Typical supporting structure and platform used in satellites are reconstructed by the proposed method, and near zero thermal expansion, which is urgent needed in satellite, can be flexibly obtained. The analysis and proposal of three dimensional lattice structures and reconstruction method provide a new approach to develop structures with light weight and tailorable CTEs. [ABSTRACT FROM AUTHOR]

SrTiO 3 -based films doped with different Al-precursors were prepared by sol-gel methods and the dielectric strengths and leakage currents of the materials were investigated. The best performance was found in SrTiO 3 films doped with Al 2 O 3 nanoparticles (nano-Al 2 O 3 ). When 5 mol% of nano-Al 2 O 3 was added to SrTiO 3 films with Al electrodes, the dielectric strength was enhanced to 506.9 MV/m compared with a value of 233.5 MV/m for SrTiO 3 films. The energy density of the 5 mol% nano-Al 2 O 3 doped SrTiO 3 films was 19.3 J/cm 3 , which was also far higher than that of the SrTiO 3 films (3.2 J/cm 3 ). These results were attributed to interfacial anodic oxidation reactions, which were experimentally confirmed by cross-sectional transmission electron microscope studies and theoretically modelled based on Faraday's laws. The films with added nano-Al 2 O 3 featured many conducting paths at the interfaces between the host phase and the guest nano-Al 2 O 3 , which promoted ion transport and contributed to the strong anodic oxidation reaction capability of the 5 mol% nano-Al 2 O 3 doped SrTiO 3 films. [ABSTRACT FROM AUTHOR]

Extreme learning machine (ELM) is an emerging learning algorithm for the generalized single hidden layer feedforward neural networks in which the parameters of hidden units are randomly generated and thus the output weights can be analytically calculated. From the hidden to output layer, ELM essentially learns the output weight matrix based on the least squares regression formula that can be used for both classification/regression and dimensionality reduction. In this paper, we impose the orthogonal constraint on the output weight matrix and then formulate an orthogonal extreme learning machine (OELM) model, which produces orthogonal basis functions and can have more locality preserving power from ELM feature space to output layer than ELM. Since the locality preserving ability is potentially related to the discriminating power, the OELM is expect to have more discriminating power than ELM. Considering the case that the number of hidden units is usually greater than the number of classes, we propose an effective method to optimize the OELM objective by solving an orthogonal procrustes problem. Experiments by pairwisely comparing OELM with ELM on three widely used image data sets show the effectiveness of learning orthogonal mapping especially when given only limited training samples. [ABSTRACT FROM AUTHOR]

This study proposes a cutting-style energy absorbing structure to improve the crashing performance of subway vehicles through experiment and numerical simulations. The structure consists of an anti-creeper device, energy absorption tube, cutting knife and clamp. A finite element ( FE ) model of a cutting-style energy absorbing structure is created and validated by full-scale experimental data. Based on the validated simulation model, the influence of the design parameters, which include the cutting depth ( d ), the cutting edge angle ( CEA ) and the chip central angle ( CCA ), on the impact performance is analyzed. The parametric study found that the design parameters influence the peak cutting force ( F p ) and energy absorption ( EA ). In addition, the structure has prominent advantage in lowering the peak interface force. Finally, the response surface method ( RSM ) is adopted to achieve maximum EA and minimum F p simultaneously. The optimized results show that the objectives compete with each other, and the weighting factors are of considerable significance to the most satisfactory Pareto fronts solutions. In this paper, the minimum distance selection method ( TMDSM ) is adopted to determine the most satisfactory solution. It can be concluded that when CCA = 18.18°, CEA = 23.87°, and d = 2.87 mm, the structure shows the best impact performance and EA = 275.9 kJ and F p = 887.2 kN. [ABSTRACT FROM AUTHOR]

In order to seek non-propagation method to train generalized single-hidden layer feed forward neural networks, extreme learning machine was proposed, which has been proven to be an effective and efficient model for both multi-class classification and regression. Different from most of existing studies which consider extreme learning machine as a classifier, we make improvements on it to let it become a feature extraction model in this paper. Specifically, a discriminative extreme learning machine with supervised sparsity preserving (SPELM) model is proposed. From the hidden layer to output layer, SPELM performs as a subspace learning method by considering the discriminative as well as sparsity information of data. The sparsity information of data is identified by solving a supervised sparse representation objective. Experiments are conducted on four widely used image benchmark data sets and the classification results demonstrate the effectiveness of the proposed SPELM model. [ABSTRACT FROM AUTHOR]

Lattice core sandwich panels, fabricated from metal or resin matrix composites, can not be used under high temperature. Here, we devise a novel pyramidal lattice core sandwich panel fabricated from ceramic matrix C/SiC composite which can be used up to 1600 °C. We evaluate the high temperature mechanical properties through experiments, theoretical analysis, and finite element analysis. Under room temperature, 1200 °C and 1600 °C, the compressive strengths are as high as 12.70, 5.35 and 2.45 MPa, and the modulus are 630, 260 and 120 MPa, respectively. The specific bending strengths are up to 260.7, 168.7 and 152.1 MPa / ( g · cm 3 ) . We also exclusively reveal that with increasing temperature, the critical relative density for the failure models shows significant reduction, indicating service temperature increment enables the original fracture failure to transfer to the buckling of the core bars. Moreover, we develop a finite element analysis model which can well calculate the damage evolution, failure mechanism and models observed in experiments. The failure model under compression is the fracture of the core bars while the bending failure is shear failure of the core bars. These results indicate that the C/SiC sandwich panel integrates high temperature resistance, lightweight characteristic and robust mechanical properties. [ABSTRACT FROM AUTHOR]

Micromagnetic structure and coercivity were systematically investigated by electron holography and micromagnetic simulation. The experimental data show that the distribution of magnetic flux lines of FeCo-rich (α1) phase is different from that of AlNi-rich (α2) phase. Quantitative analysis based on the measurement of electron holography show that the magnetizations and coercivities of α1 phases for 36Co and 40Co are calculated to be 11.0 kG and 8.5 kG, 1848 Oe and 3029 Oe, respectively. Further micromagnetic simulations reveal that the decrease of α1 phase diameters and the weakened exchange coupling (increased distance) between adjacent phases are critical factors to increase the coercivities of AlNiCO magnets, well matching with the measured results from electron holography. [ABSTRACT FROM AUTHOR]

The distillation of azeotropic mixtures is commonly and widely performed in the pharmaceutical, petroleum, and chemical industries. Deep eutectic solvents (DESs) are environmentally-friendly entrainers that have many properties similar to ionic liquids (ILs) but are also simple in preparation and cheap in price. Also, the ethanol/water system is a typical industrial azeotropic mixture. In this work, the relative volatility of ethanol and water at the azeotropic point was increased from 1.00 to 4.70 with 0–51.0 mass % ChCl/urea (1:2, mol/mol), with ChCl/urea showing a remarkable entrainer performance in this separation. Isobaric vapor–liquid equilibrium (VLE) data of four systems, water + ethanol, water + ChCl/urea, ethanol + ChCl/urea, and water + ethanol + ChCl/urea (at 10, 20, and 30 mass%), were determined using a modified Othmer equilibrium still at 101.32 kPa. After addition of ChCl/urea, the ethanol + water mixture’s azeotropic point was eliminated. The parameters of the nonrandom two-liquid (NRTL) model for these systems were calculated and the predicted values for these systems were found to fit the experimental VLE data quite well. [ABSTRACT FROM AUTHOR]

Lightweight design of high temperature ceramic is in urgent need, as their engineering application requires higher payload. Current approach to design lightweight ceramic is either porous ceramics or ceramic foams. Here, as a new approach, ZrO 2 ceramic corrugated core sandwich panel is proposed for lightweight design. The high temperature mechanical behaviors are systematically obtained through experimental measurements, theoretical analysis and numerical simulation. Under room temperature and 1000 °C, the compressive strength are as high as 11.8 and 8.5 MPa, and the stiffness are 375.9 and 340.9 MPa, which agree well with the analytical predictions. The specific bending strengths are 124.3 MPa/(g/cm 3 ) under room temperature and 114.6 MPa/(g/cm 3 ) under 1000 °C, which are twice higher than that of the ZrO 2 bulk ceramic. We reveal that with increasing temperature up to 1000 °C, the critical relative density for the failure models under compression shows significant change, while the failure model boundaries under three point bending display small difference. Moreover, the finite element analysis reveals that distinguished stress peaks are as high as 748 MPa in compression and 710 MPa in bending. The peak stresses locate at the connections between the facesheets and core sheets, and illustrate the failure mechanism of the experimentally observed failure models. [ABSTRACT FROM AUTHOR]

Continuous fiber reinforced composite lightweight structures (CFRSs) are widely applied to aerospace, automobile, marine and other fields due to their high specific strength and modulus, low density and fatigue resistance. Innovations in the additive manufacturing technique of continuous fiber reinforced composites (CFRC) opened new perspectives for the integrated design and fabrication of composite lightweight structures with customized performance and acceptable cost. This paper reviewed the state-of-the-art 3D printing CFRSs and elaborated their future perspectives and potential applications. Specifically, different existing CFRSs printing techniques were reviewed, and the limitations of current processing methods were discussed in details. Then, the CFRSs including 2D and 3D types were discussed in terms of path planning, structural design and optimization methods. Further, the mechanical properties and novel applications in shape morphing and self-monitoring of CFRSs were presented. Finally, this paper concluded with an outlook on future research opportunities on 3D printing CFRSs from design, fabrication to final applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • Nose temperature of σ and Cr 2 N phases of 0.7- wt%-nitrogen sample is around 900 °C. • The segregation of Cr/Mo, along with the oxide inclusions, promotes the σ phase formation. • The AM-HNS0.99 material is more sensitive to the σ phase than the Cr 2 N phase. • Rapid interdendritic ferrite decomposition occurs as Inter-F → σ + Cr 2 N + γ 2. Wire and arc additive manufacturing (WAAM) technology is a promising method for fabricating high-performance protective materials and structural parts from high-nitrogen steel (HNS). However, owing to the complicated thermal fields generated by the process, it may produce some undesirable precipitates, such as the intermetallic σ phase or chromate nitrides, especially when the fabricated part is large. This study focused on the precipitation features of WAAM-produced high-nitrogen Cr-Mn steel containing 0.7 wt% nitrogen. When the isothermal post-heat treatment was conducted at approximately 900 °C, the σ phase dominated the original inter-dendritic ferrite (Inter-F) region. And, there were some secondary austenite precipitates (γ 2) along with a small amount of Cr 2 N. The oxide inclusions (especially the MnO particles) provided excellent nucleation sites for the σ phase in the Inter-F region or at the Inter-F and γ matrix interface due to the high interface energy and lattice matching index. Further, when aging above 1000 °C, no σ phase was found, and the decomposition of the Inter-F to γ matrix was dominated by element diffusion. With the precipitation of the σ phase, a typical brittle fracture was observed in the samples aged at low temperatures of 800 °C and 900 °C. [ABSTRACT FROM AUTHOR]

The present work aimed to study the penetration behaviors of 3D printed continuous ramie yarn reinforced polylactic acid (PLA) based woven-like and non-woven-like biocomposites. The architectures were produced by in-situ impregnated 3D printing process according to a novel interweaved and a conventional printing path (unidirectional and orthogonal). The quasi-static penetration test (QSPT) was conducted to evaluate the effect of 3D printed architecture, support span to indenter diameter ratios (SIRs) and fiber reinforcement on the penetration property of biocomposites. The backlight method was adopted to real-time capture the damage process of the biocomposites under QSPT. The results showed that the penetration property and energy absorption capability of the 3D printed samples increased with decreasing SIR and with the addition of continuous ramie yarn. The energy absorption and maximum penetration force of the 3D printed biocomposites with woven-like architecture increased by 31.2 %, and 18.0 % compared with non-woven-like architecture (unidirectional) at SIR = 5. The structure-penetration property relationship of 3D printed woven-like architectured biocomposite was revealed through the analysis of multiscale failure features and penetration damage mechanisms. [ABSTRACT FROM AUTHOR]

This paper proposes a new quantitative and systematic design methodology for high-speed interpolation/ averaging ADCs. The methodology consists of a new mathematical BW/gain model derived from the pre-amps arrays static model and new small-signal model, a new offset modeling mechanism that can accurately estimate and help to reduce the offset, and hence a new systematic design flow . The methodology enables a quantitative and systematic analysis, conducts iterative and accurate calculation realized in MATLAB, and finally leads to an optimized ADC design that reaches a guaranteed optimum full-chip performance with given specs (i.e., resolution, speed, input range, power, input CM, etc.). The methodology shows significant advantage over the traditional trial-and-error ADC design approach with respect to performance and design efficiency, and is much more reliable in nanometer technologies. The proposed methodology was fully validated in silicon: a 4-bit 5GSps interpolation/averaging ADC is fabricated in a 65 nm CMOS technology and the measurement results show that our ADC has indeed achieved an outstanding and comparable overall performance compared to reported state-of-the art ADCs. [ABSTRACT FROM AUTHOR]

Accurate estimation of reference evapotranspiration (ET 0 ) is essential to agricultural water management. The present study developed two artificial intelligence models for daily ET 0 estimation only with temperature data, including extreme learning machine (ELM) and generalized regression neural network (GRNN) in 6 meteorological stations of Sichuan basin, southwest China, and compared the proposed ELM and GRNN with the corresponding temperature-based Hargreaves (HG) model and its calibrated version considering FAO-56 Penman-Monteith ET 0 as benchmark. Two data management scenarios were evaluated for estimation of ET 0 : (1) the models were trained/calibrated and tested using the local data of each station; and (2) the models were trained/calibrated using the pooled data from all the stations and tested in each station. In the first scenario, the results showed that the temperature-based ELM model provided the better estimation than the GRNN, HG and calibrated HG models, with average relative root mean square error (RRMSE) of 0.198, mean absolute error (MAE) of 0.267 mm/d and Nash-Sutcliffe coefficient (NS) of 0.891, respectively. In the second scenario, GRNN model provided the most accurate results among the considered models, with average RRMSE of 0.194, MAE of 0.263 mm/d and NS of 0.895, respectively. Both of the temperature-based GRNN and ELM performed much better than the HG and calibrated HG models for the two scenarios, and the temperature-based GRNN and ELM models are appropriate alternatives for accurate estimation of ET 0 for Sichuan basin of southwest China, which is very helpful for farmers or irrigation system operators to improve their irrigation scheduling. [ABSTRACT FROM AUTHOR]

Backgrounds The relation between serum total bilirubin (TBi) and mortality in patients with established coronary artery disease (CAD) remains undefined. We try to investigate the role of the subtypes of CAD in the association. Methods A total of 3013 patients with angiographically obstructive CAD were enrolled. A retrospective analysis was conducted. Patients were divided into 3 groups as follows: stable CAD (SCAD), unstable angina pectoris (UAP) and acute myocardial infarction (AMI). The predictive values of TBi for 30-day and long-term mortality were assessed using logistic and Cox regression, respectively. Results Higher initial serum TBi levels were significantly associated with increased risk of short-term mortality (OR 2.35, 95% CI 1.15–4.77) in AMI group. However, the association was absent among patients with SCAD and UAP. Serum TBi was able to independently predict the long-term mortality in SCAD (HR 0.34, 95% CI 0.16–0.70) and UAP (HR 0.49, 95% CI 0.31–0.78) groups. However, there was no significant relation between TBi and long-term mortality in AMI groups. Conclusion The different subtypes of CAD affected the relation between serum TBi and clinical prognosis. Initial serum TBi was positively correlated with short-term mortality of AMI patients, and negatively correlated with long-term mortality in SCAD or UAP patients. [ABSTRACT FROM AUTHOR]

Interest matching is an important data-filtering mechanism for a large-scale distributed virtual environment. Many of the existing algorithms perform interest matching at discrete timesteps. Thus, they may suffer the missing-event problem: failing to report the events between two consecutive timesteps. Some algorithms solve this problem, by setting short timesteps, but they have a low computing efficiency. Additionally, these algorithms cannot capture all events, and some spurious events may also be reported. In this paper, we present an accurate interest matching algorithm called the predictive interest matching algorithm, which is able to capture the missing events between discrete timesteps. The PIM algorithm exploits the polynomial functions to model the movements of virtual entities, and predict the time intervals of region overlaps associated with the entities accurately. Based on the prediction of the space–time intersection of regions, our algorithm can capture all missing events and does not report the spurious events at the same time. To improve the runtime performance, a technique called region pruning is proposed and used in our algorithm. In experiments, we compare the new algorithm with the frequent interest matching algorithm and the space–time interest matching algorithm on the HLA/RTI distributed infrastructure. The results prove that although an additional matching effort is required in the new algorithm, it outperforms the baselines in terms of event-capturing ability, redundant matching avoidance, runtime efficiency and scalability. [ABSTRACT FROM AUTHOR]

Background There is a controversy surrounding the correlation between fibrinogen (Fib) level and prognosis of coronary artery disease (CAD). We try to investigate the role of the subtypes of CAD in this controversy. Methods A retrospective analysis was conducted from a single center CAD registered database. 3020 consecutive patients with CAD confirmed by coronary angiography were enrolled. The end points were all-cause mortality. Results The mean follow-up time was 27.2 ± 13.1 months and death events occurred in 258 cases. Mortality rates for patients with CAD and those in the stable coronary artery disease (SCAD) and unstable angina pectoris (UAP) groups exhibited an overall rising trend as Fib levels increased (log rank test, all p < 0.05). However, similar trends were not detected in patients with acute myocardial infarction (AMI). The results of a Cox proportional-hazards regression analysis showed that Fib level was independently correlated with the risk of death in patients with CAD as well as those in the SCAD and UAP groups (CAD, HR 1.40, CI 1.16–1.68; SCAD, HR 1.86, CI 1.24–2.79; UAP, HR 1.42, CI 1.06–1.90). In the AMI group, however, no independent correlation was observed between Fib level and mortality. Conclusion The different proportions of subtypes of CAD affected the correlation between Fib level and the clinical prognosis of patients with CAD. This is maybe a clue to explain the controversy. [ABSTRACT FROM AUTHOR]

In the present study, we used Caenorhabditis elegans assay system to investigate in hormetic effects of imidazolium-based bromide Ionic Liquids (ILs) and explored the possible underlying mechanism. Firstly, C. elegans was treated with ILs with different alkyl chain lengths at different concentrations. We found that exposure to ILs at 0.01 mg/L extended the mean lifespan of C. elegans and the ILs with longer alkyl chain showed more obvious effects. To investigate the possible mechanism, the nematodes were exposed to the three ILs at 0.01 mg/L for 2, 5, 7, 9 and 11 days. The levels of reactive oxygen species (ROS) in C. elegans increased significantly when treated for 2 days and then declined gradually compared to those of respective controls as time went on. After exposure for 11 days, the ROS levels and liposuscin accumulation were significantly lower in the treated groups than those of control group. Meanwhile, the expression of aging-related genes sod-5 and daf-16 were both massively up-regulated for the three ILs examined. Our results show that low concentration of ILs exert hormetic effect on C. elegans . ROS generation and expression of aging-related genes may play important roles in the IL-induced hormetic effect on C. elegans . [ABSTRACT FROM AUTHOR]