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Rock strength typically decreases when the rock is subjected to temperatures higher than 400 °C. Our previous experimental study on Sichuan Marble showed that the rock was strengthened rather than weakened in the temperature range 25–200 °C. To numerically model the thermal strengthening/weakening behavior of rock, a grain-based model integrating the thermal effects on grains and grain boundaries in an applicable temperature range 25–400 °C (thermo-GBM) is proposed. A Voronoi-tessellated thermo-GBM (GBM-1) is calibrated and verified by our experimental triaxial compressive tests equipped with real-time heating from 25 to 200 °C. The same tests are simulated on another thermo-GBM with realistic rock microstructure (GBM-2) to investigate the effects of microstructural heterogeneity. The results suggest that increasing microstructural heterogeneity leads to a higher extent of thermal strengthening. Such an effect is amplified by the application of confining pressure, but it is less dependent on the treated temperature. Then, both uniaxial compression strength (UCS) and confined strength tests are simulated on GBM-1 in a higher temperature range 250–400 °C to examine the strengthening phenomenon. Thermal strengthening takes place in all the confined test groups but not in the UCS test group. The thermal strength is enhanced by 8.1% at 250 °C as compared with that at room temperature, and decreases to the non-heated value at 350 °C. The results suggest that thermal expansion leading to a more compacted structure is the governing mechanism in strengthening effect, meanwhile the degradation of grain-boundary properties is a major competing factor to weaken the rock. [ABSTRACT FROM AUTHOR]

• Recycled waste aluminum scraps were used to fabricate S-Al0@Fe0 with high e − capacity. • S-Al0@Fe0 with a three-layer structure had higher reactivity toward Cr(VI) than S-Fe0. • Cr(VI) removal capacity of S-Al0@Fe0 was 8.2 times higher than of S-Fe0. • S-Al0@Fe0 served as an electric cell to harness persistent and selective e − transfer. • S-Al0@Fe0 is a cost-effective and environmentally-friendly alternative to S-Fe0. Massive waste aluminum scraps produced from the spent aluminum products have high electron capacity and can be recycled as an attractive alternative to materials based on zero-valent iron (Fe0) for the removal of oxidative contaminants from wastewater. This study thus proposed an approach to fabricate micron-sized sulfidated zero-valent iron-aluminum particles (S-Al0@Fe0) with high reactivity, electron selectivity and capacity using recycled waste aluminum scraps. S-Al0@Fe0 with a three-layer structure contained zero-valent aluminum (Al0) core, Fe0 middle layer and iron sulfide (FeS) shell. The rates of chromate (Cr(VI)) removal by S-Al0@Fe0 at pH 5.0‒9.0 were 1.6‒5.9 times greater than that by sulfidated zero-valent iron (S-Fe0). The Cr(VI) removal capacity of S-Al0@Fe0 was 8.2-, 11.3- and 46.9-fold greater than those of S-Fe0, zero-valent iron-aluminum (Al0-Fe0) and Fe0, respectively. The chemical cost of S-Al0@Fe0 for the equivalent Cr(VI) removal was 78.5% lower than that of S-Fe0. Negligible release of soluble aluminum during the Cr(VI) removal was observed. The significant enhancement in the reactivity and capacity of S-Al0@Fe0 was partially ascribed to the higher reactivity and electron density of the Al0 core than Fe0. More importantly, S-Al0@Fe0 served as an electric cell to harness the persistent and selective electron transfer from the Al0-Fe0 core to Cr(VI) at the surface via coupling Fe0-Fe2+-Fe3+ redox cycles, resulting in a higher electron utilization efficiency. Therefore, S-Al0@Fe0 fabricated using recycled waste aluminum scraps can be a cost-effective and environmentally-friendly alternative to S-Fe0 for the enhanced removal of oxidative contaminants in industrial wastewater. [Display omitted] [ABSTRACT FROM AUTHOR]

The poor solubility of iridium complexes severely hampers its application in the electrochemiluminescence (ECL) sensing field. The doping of an iridium complex with silica (SiO2) nanospheres provides feasible solution for this problem. Herein, one kind of water insoluble iridium complex ([Ir(dFppy)2(d(CF3)bpy)](PF6)) was doped with SiO2 nanoparticles to obtain a luminescent nanocomposite (SiO2@Ir) which could generate strong ECL signals to act as a beacon molecule. An "off–on–off" mode ECL sensor was proposed based on the competitive host–guest interactions between 2-adamantanamine (2-ADA), ferrocene (Fc) and cucurbit[7]uril (Q[7]). Fc could be used as an inhibitor to decrease the ECL signal, while Q[7] could wrap Fc to recover the ECL signal. Q[7] has a stronger binding ability with 2-ADA than Fc. As a result, 2-ADA could replace Fc from the cavity of Q[7], and the ECL signal was inhibited again. Under the optimal conditions, the ECL intensity varied linearly with 2-ADA concentration in the range of 1.0 × 10−8 to 1.0 × 10−6 mol L−1 with a detection limit of 2.5 × 10−10 mol L−1. The results not only provided a new avenue for the application of water insoluble iridium complexes in ECL sensing, but also revealed the attractive potential of host–guest interactions in the fabrication of biosensors. [ABSTRACT FROM AUTHOR]

In this paper, we propose a novel distributed algorithm based on model predictive control and alternating direction multiplier method (DMPC-ADMM) for cooperative trajectory planning of quadrotor swarms. First, a receding horizon trajectory planning optimization problem is constructed, in which the differential flatness property is used to deal with the nonlinear dynamics of quadrotors while we design a relaxed form of the discrete-time control barrier function (DCBF) constraint to balance feasibility and safety. Then, we decompose the original trajectory planning problem by ADMM and solve it in a fully distributed manner with peer-to-peer communication, which induces the quadrotors within the communication range to reach a consensus on their future trajectories to enhance safety. In addition, an event-triggered mechanism is designed to reduce the communication overhead. The simulation results verify that the trajectories generated by our method are real-time, safe, and smooth. A comprehensive comparison with the centralized strategy and several other distributed strategies in terms of real-time, safety, and feasibility verifies that our method is more suitable for the trajectory planning of large-scale quadrotor swarms. [ABSTRACT FROM AUTHOR]

• A stochastic vibro-acoustic analysis scheme is built based on the PUFEM/FEM and the direct probability integral method. • The new scheme can easily treat the propagation of uncertainties by summing the responses at each representative point. • The effects of uncertain acoustic impedance and modeling parameters on the system response are investigated. A novel stochastic response analysis scheme for 3D vibro-acoustic systems is constructed based on the PUFEM/FEM and the direct probability integral method, and the effect of uncertain acoustic impedance and modeling parameters on the system response is investigated. The proposed scheme has the capability of capturing waveform within the element, the small system matrices and easy handling acoustic impedance, also can efficiently treat the propagation of parameter uncertainties through transforming the integration of the response probability density function into the summation of the response under each representative point by partitioning the input probability space and smoothing the Dirac δ function. Numerical examples show that the mean and standard deviation of the responses computed by the proposed scheme agree well with the MCS, but the agreement of the standard deviation is slightly lower at the frequency with large response dispersion. The effect of uncertain acoustic impedance on the system response is mainly at the low frequencies, where the location and amplitude of resonance peaks fluctuate significantly. Uncertain modeling parameters synthetically modify the stiffness and mass matrix, altering the intrinsic properties and response of the system, and the response at the higher frequency is more sensitive to the uncertain modeling parameters. [ABSTRACT FROM AUTHOR]

Establishing efficient synthetic pathways for microbial production of biochemicals is often hampered by competing pathways and insufficient precursor supply. Compartmentalization in cellular organelles can isolate biosynthetic pathways from competing pathways, and thus provide a more compact and conducive environment for biosynthesis. Herein, the farnesyl diphosphate biosynthetic pathway and α-bisabolene synthase were compartmentalized in the yeast Yarrowia lipolytica peroxisome to enable high-level α-bisabolene production. Along with compartmentalization of the α-bisabolene biosynthesis pathway, a systems metabolic engineering approach that comprises mediating product export with an efflux pump, optimizing the gene copy numbers of rate-limiting enzymes, balancing the distribution of the common precursor acetyl-CoA between native lipid biosynthesis and heterologous α-bisabolene production, improving ATP and acetyl-CoA supply, and dynamic regulation of peroxisomes was then employed to further enhance the bisabolene production. Consequently, the optimized engineered strain produced 3028.9 mg L−1 α-bisabolene from waste cooking oil as the sole carbon source through shake flask cultivation. Finally, fed-batch fermentation was performed to accomplish α-bisabolene production at 15.5 g L−1, the highest ever reported for α-bisabolene from an engineered microbe. Taken together, this work lays the foundation for peroxisome engineering of Y. lipolytica, towards the production of α-bisabolene in a highly sustainable manner. [ABSTRACT FROM AUTHOR]

Organic fluorophores with highly efficient luminescence in both solution and solid states have attracted significant attention due to their ability to circumvent the limitations of aggregation‐caused quenching and aggregation‐induced emission type molecules. However, their development and wide‐range applications are hampered by extremely complex synthetic methodologies and limited frameworks with dual‐state emission (DSE) structural characteristics. In sharp contrast to the reported luminogens with big and planar π systems or highly conjugated and twisted structures, we discovered novel three‐dimensional scaffolds in one molecule to achieve DSE. These molecules allowing for rapid access showed completely different molecular packing manners from those of planar conjugated molecules and exhibited excellent optoelectronic properties with diminished intermolecular π−π stacking interactions due to steric hindrance. Our findings should open new avenues for designing DSE molecules with new frameworks, which will enable more successful development of dual‐state emitters for their broad applications in the future. [ABSTRACT FROM AUTHOR]

Green‐processable printed large‐area light‐emitting diode (LED) is the crucial component of the high quality solid lighting and flat‐panel display. Accelerating the replacement from fossil‐based solvents to sustainable ecofriendly solvent is desirable for solution‐based printed organic electronics. Herein, by simple introducing methyl to the benzene groups of polydiarylfluorene‐based polymer, this work realizes the solution processing of blue polymer light‐emitting diodes (PLEDs) with a bio‐based solvent of limonene toward large‐area printed display. Film processed from this solvent exhibits satisfactory morphology and remarkable photophysical performances, even though the polymer chains show more serious aggregation in solution. What's more, devices fabricated with spin‐coated films present higher external quantum efficiency (EQE) and better spectra repeatability. Encouraged by the good film‐forming ability of this polymer in limonene, this work realizes the fabrication of printed large‐area films (5 × 5 cm2) with uniform emission and surface morphology by blade coating. Furthermore, this work develops passive matrix (PM) PLEDs arrays with 20 × 20 pixels that can dynamically display monochrome letters and numbers, demonstrating the potential application of cost‐effective printing techniques in large‐area display. [ABSTRACT FROM AUTHOR]

Innovative modes of response can greatly push forward chemical sensing processes and subsequently improve sensing performance. Classical chemical sensing modes seldom involve the transition of a delicate molecular assembly during the response. Here, we display a sensing mode for polyamine detection based on an order–order transition of iron–sulfur complexes upon their assembly. Strong validation proves that the unique order–order transition of the assemblies is the driving force of the response, in which the polyamine captures the metal ion of the iron–sulfur complex, leading it to decompose into a metal–polyamine product, accompanied by an order–order transition of the assemblies. This mechanism makes the detection process more intuitive and selective, and remarkably improves the detection efficiency, achieving excellent polyamines specificity, second-level response, convenient visual detection, and good recyclability of the sensing system. Furthermore, this paper also provides opportunities for the further application of the iron–sulfur platform in environment-related fields. Polyamine detection is of particular importance in the food industry, typically achieved via direct bonding between sensor and analyte or by indicator displacement. Here, the self-assembly of iron–sulfur complexes is shown to enable the efficient and selective detection of polyamines, driven by an order-to-order transition upon assembly. [ABSTRACT FROM AUTHOR]

Organic room-temperature phosphorescence (RTP) materials are currently the focus of research in the field of bioimaging. In comparison with the conventional imaging modalities based on organic fluorescent dyes, RTP materials with long lifetime enable time-resolved imaging to improve the imaging resolution by avoiding autofluorescence. In this review, we will start with summarizing strategies for achieving high performance RTP materials for bioimaging, including the development of RTP-compounds, host–guest doping materials, and supramolecular assemblies. We then discuss the optimization of nanonization processes to obtain RTP nanoparticles with controllable size, high dispersibility, and improved stability. The differences between top-down and bottom-up approaches are further described. Finally, we briefly introduce the emerging methods for preparing RTP materials for bioimaging. [ABSTRACT FROM AUTHOR]

This paper proposes a new optimized parameter model that enhances the pointing accuracy of moving-platform electro-optical telescopes (MPEOTs). The study begins by comprehensively analyzing the error sources, including the telescope and the platform navigation system. Next, a linear pointing correction model is established based on the target positioning process. To eliminate multicollinearity, stepwise regression is applied to obtain the optimized parameter model. The experimental results show that the MPEOT corrected by this model outperforms the mount model, with pointing errors of less than 50 arcsec for approximately 23 h. In the three tests conducted, the modified azimuth error(s) (RMS) were 14.07″, 12.71″, and 28.93″, and the elevation error(s) (RMS) were 12.94″, 12.73″, and 28.30″, respectively. [ABSTRACT FROM AUTHOR]

Background: Necrotizing fasciitis is a rapid and severe soft tissue infection that targets subcutaneous fat tissue, muscle, and fascia. This study compares the clinical outcomes of vacuum-assisted closure (VAC) versus conventional dressing on necrotizing fasciitis. Methods: We systematically searched Embase, Cochrane, and PubMed for clinical trials (published between January 1, 1995 and September 30, 2021), which compared VAC with conventional dressing for necrotizing fasciitis. The mortality rate of necrotizing fasciitis was the primary outcome of this study. The number of debridements, the total length of hospital stay, and the complication rate were secondary outcomes. A random effects model assessed all pooled data. Results: A total of 230 identified studies and seven controlled clinical trials met the inclusion criteria and were included in this analysis (n = 249 participants). Compared to the conventional dressing, patients treated with VAC had a significantly lower mortality rate [OR = 0.27, 95% CI (0.09, 0.87)] (P = 0.03). Total length of hospital stays [MD = 8.46, 95% CI (− 0.53, 17.45)] (P = 0.07), number of debridements [MD = 0.86, 95% CI (− 0.58, 2.30)] (P = 0.24), and complication rate [OR = 0.64, 95% CI (0.07, 5.94)] (P = 0.69) were not significant. These results did not show significant differences between both groups treated with VAC or conventional treatment. Conclusion: VAC could significantly decrease the death rate compared to conventional dressing. No significant impacts were found on the number of debridements, the total length of hospital stay, and the complication rate in this study. Level of evidence Level-III. Registration Research Registry (reviewregistry1246). [ABSTRACT FROM AUTHOR]

[Display omitted] • Biomass-derived carbon dots with unique sp2 conjugated structure. • The synergistic effect of fragmented graphitized structures embedded in the amorphous structure of carbon dots facilitates efficient electron transfer. • CDs with excellent electronic and physicochemical properties for boosting in vitro photosynthesis. Photosynthesis by plants stores sunlight into chemicals and drives CO 2 fixation into sugars with low biomass conversion efficiency due to the unoptimized solar spectrum utilization and various chemical conversion possibilities that follow H 2 O oxidation. Expanding the solar spectrum utilization and optimizing the charge transfer pathway of photosynthesis is critical to improving the conversion efficiency. Here, a group of carbon dots (CDs) with distinct content of sp2 C C domain are prepared by one-step carbonization of natural xylose, which penetrated natural chloroplasts and integrated with the grana thylakoid to promote in vitro photosynthesis. Structural characterization and electrochemical results reveal the positive impact of graphitization degree on the electron transport capacity of CDs. Classic Hill reaction and ATP production demonstrate the enhanced photosynthetic activity resulting from the CDs-mediated electron transfer of photosystem II. In-depth studies of the structure–function relationship prove the synergistic effect of intensified biotic-abiotic interaction between CDs and chloroplast, lower charge transfer resistance, and extended light absorption. This work posts a promising method to optimize electron transport and improve natural photosynthesis using artificial interventions. [ABSTRACT FROM AUTHOR]

Damage to a belt conveyor idler will increase the downtime and maintenance cost, so it is very important to diagnose its fault. At present, the fault diagnosis of the idler of a belt conveyor is mostly based on vibration and temperature signal. However, contact fault diagnosis approaches are severely limited when sensors are inconvenient to install or when vibration and temperature signals cannot be returned. In this special case, the non-contact fault diagnosis method, represented by measuring acoustic signals, becomes a necessary means. To effectively extract mechanical state information from sound signals of belt conveyors and identify typical mechanical faults, we propose a fault detection method based on sample center distance weighted (support vector data description (SVDD)) and multi-frame fusion (Mel-frequency cepstral coefficient (MFCC)) features. Aiming at the disadvantage that single frame MFCC features and traditional SVDD are susceptible to noise, multi-frame fusion MFCC optimization features are used as samples, and the weighted SVDD model based on sample center distance is used for fault detection. Finally, the overall recognition accuracy of the experiment is greatly improved. It is proved that MFCC features of multi-frame fusion sound signal and weighted SVDD fault detection based on sample center distance can effectively determine whether there is a fault in the of belt conveyor idler. [ABSTRACT FROM AUTHOR]

Soil-available nitrogen is the main nitrogen source that plants can directly absorb for assimilation. It is of great significance to detect the concentration of soil-available nitrogen in a simple, rapid and reliable method, which is beneficial to guiding agricultural production activities. This study confirmed that Raman spectroscopy is one such approach, especially after surface enhancement; its spectral response is more sensitive. Here, we collected three types of soils (chernozem, loess and laterite) and purchased two kinds of nitrogen fertilizers (ammonium sulfate and sodium nitrate) to determine ammonium nitrogen (NH4-N) and nitrate nitrogen (NO3-N) in the soil. The spectral data were acquired using a portable Raman spectrometer. Unique Raman characteristic peaks of NH4-N and NO3-N in different soils were found at 978 cm−1 and 1044 cm−1, respectively. Meanwhile, it was found that the enhancement of the Raman spectra by silver nanoparticles (AgNPs) was greater than that of gold nanoparticles (AuNPs). Combined with soil characteristics and nitrogen concentrations, Raman peak data were analyzed by multiple linear regression. The coefficient of determination for the validation ( R p 2 ) of multiple linear regression prediction models for NH4-N and NO3-N were 0.976 and 0.937, respectively, which deeply interpreted the quantitative relationship among related physical quantities. Furthermore, all spectral data in the range of 400–2000 cm−1 were used to establish the partial least squares (PLS), back-propagation neural network (BPNN) and least squares support vector machine (LSSVM) models for quantification. After cross-validation and comparative analysis, the results showed that LSSVM optimized by particle swarm methodology had the highest accuracy and stability from an overall perspective. For all datasets of particle swarm optimization LSSVM (PSO-LSSVM), the R p 2 was above 0.99, the root mean square errors of prediction (RMSEP) were below 0.15, and the relative prediction deviation (RPD) was above 10. The ultra-portable Raman spectrometer, in combination with scatter-enhanced materials and machine learning algorithms, could be a promising solution for high-efficiency and real-time field detection of soil-available nitrogen. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to construct a nomogram to effectively predict the overall survival (OS) of patients with early-stage non-small-cell lung cancer (NSCLC).Methods: For the training and internal validation cohorts, a total of 26,941 patients with stage I and II NSCLC were obtained from the Surveillance, Epidemiology, and End Results (SEER) database. A nomogram was constructed based on the risk factors affecting prognosis using a Cox proportional hazards regression model. And 505 patients were recruited from Jiaxing First Hospital for external validation. The discrimination and calibration of the nomogram were evaluated by C-index and calibration curves.Results: A Nomogram was created after identifying independent prognostic factors using univariate and multifactorial factor analysis. The C-index of this nomogram was 0.726 (95% CI, 0.718-0.735) and 0.721 (95% CI, 0.709-0.734) in the training cohort and the internal validation cohort, respectively, and 0.758 (95% CI, 0.691-0.825) in the external validation cohort, which indicates that the model has good discrimination. Calibration curves for 1-, 3-, and 5-year OS probabilities showed good agreement between predicted and actual survival. In addition, DCA analysis showed that the net benefit of the new model was significantly higher than that of the TNM staging system.Conclusion: We developed and validated a survival prediction model for patients with non-small cell lung cancer in the early stages. This new nomogram is superior to the traditional TNM staging system and can guide clinicians to make the best clinical decisions. [ABSTRACT FROM AUTHOR]

The adhesive ability of bamboo scrimber is critical for its use in large‐scale engineering structures. Cold‐pressed bamboo scrimber with varying sanding mesh and density was made and then bonded with polyurethane resin. The adhesive was concentrated on the surface, assisting the anchoring into the material surface. The shear strength and immersion peel strength are studied as parameters to determine the glue qualities. The optimum gluing characteristics were obtained using a 120 grit sandpaper and a density of 1.15 g/cm3. The results indicated that at a density of 1.15 g/cm3, the gluing characteristics rose initially and subsequently dropped as the number of sanding meshes increased. The bonding strength improved with increasing density when 120‐mesh sanding was used. With increasing density, the bamboo fiber distribution inside the material got more compact, while the resin dispersion became more uniform. Thus, the surface porosity and roughness were decreased. [ABSTRACT FROM AUTHOR]

The efficacy of Shaoyao Decoction (SYD), a traditional Chinese medicine prescription, in treating damp-heat colitis is established, but its underlying mechanism remains to be elucidated. Our study aims to investigate the effect and mechanism of action of SYD in treating damp-heat colitis. A mouse model of damp-heat colitis was induced and treated with SYD via gavage for seven days. The therapeutic efficacy of SYD was assessed through clinical indicators and histopathological examinations. The inflammatory factors and oxidative stress parameters were detected by ELISA and biochemical kits. We also analyzed alterations in the gut microbiome via 16 S rRNA gene sequencing and quantified serum indole derivatives using targeted tryptophan metabolomics. Western blotting and immunofluorescence were used to detect the expressions of AHR, CYP1A1, STAT3 and tight junction (TJ) proteins. The ELISA kit was utilized to detect the content of antibacterial peptides (Reg3β and Reg3γ) in colon. The immunohistochemistry was employed to detect the expressions of proliferating cell nuclear antigen (PCNA) protein. SYD effectively alleviated symptoms in mice with damp-heat colitis, including body weight loss, shortened colon, elevated DAI, enlarged spleen, and damage to the intestinal mucosa. SYD notably reduced IL-6, TNF-α, IL-1β and MDA levels in colon tissues, while increasing IL-10 and T-AOC levels. Furthermore, SYD mitigated gut microbiota disturbance, restored microbial tryptophan metabolite production (such as IA, IAA, and IAld), notably increased the protein levels of AHR, CYP1A1 and p-STAT3 in colon tissue, and elevated the IL-22 level. Moreover, the expression levels of Reg3β, Reg3γ, occludin, ZO-1 and PCNA were increased in SYD group. Our study showed that SYD ameliorates damp-heat colitis by restructuring gut microbiota structure, enhancing the metabolism of tryptophan associated with gut microbiota to activate the AHR/IL-22/STAT3 pathway, thereby recovering damaged intestinal mucosa. This research offers novel insights into the therapeutic mechanisms of SYD on damp-heat colitis. [Display omitted] • SYD significantly alleviated the symptoms of damp-heat colitis mice, reduced inflammation and oxidative damage. • The gut microbiota and microbial tryptophan metabolism play a critical role in SYD improving damp-heat colitis. • The activation of AHR-IL-22-STAT3 signaling is a potential mechanism for SYD to repair the intestinal mucosal barrier. [ABSTRACT FROM AUTHOR]

The stochastic isogeometric analysis (SIGA) based on random geometric methods plays a crucial role in structural random analysis. However, existing intrusive SIGA methods suffer from limitations of low applicability or efficiency. On the other hand, current material uncertainties are mostly limited to low dimensions and often ignore spatial correlations. Therefore, we propose an efficient and adaptive nested non-intrusive SIGA method based on Radial Basis Function Neural Network (RBFNN). This method combines quasi-Monte Carlo simulation (QMCS) to achieve a general solution for high-dimensional material uncertainty in porous functionally graded materials (PFGM) plates, including statistical quantities and probability density functions (PDFs) of random responses. Firstly, within the IGA framework, we establish a geometrically nonlinear model for PFGM plates using HSDT and Von Kármán strain-displacement relations, effectively mitigating shear locking effects. Secondly, by considering spatial correlations, we employ the Karhunen-Loève expansion to establish a high-order random field for material uncertainty. Subsequently, we propose a nested and non-intrusive response surface analysis method using RBFNN, significantly enhancing the accuracy and efficiency of SIGA in addressing high-dimensional uncertainty problems. Finally, by leveraging the efficiency of SIGA, we overcome the low convergence speed drawback of QMCS, achieving a comprehensive solution for statistical quantities and PDFs of high-dimensional uncertainty problems. The advantages of efficiency and accuracy are validated through random response analysis of high-dimensional uncertain PFGM plates. In randomly structured geometrically nonlinear PFGM plates, porosity significantly influences the response, while the gradient exponent and Young's modulus have a weaker but non-negligible impact on the response. [ABSTRACT FROM AUTHOR]

The direct C–H functionalization of tetrahydro-γ-carbolines (THγCs) at the α-position has been presented. This mild and simple strategy allows coupling of THγCs with various anilines and indoles with satisfactory to excellent yields. This two-step/one-pot method could be applied to synthesize complex compounds and is suitable for the C–H functionalization of similar biologically active structures. [ABSTRACT FROM AUTHOR]

P2-P3 series-parallel hybrid electric vehicles (HEVs) feature intricate topologies with multiple power sources and multiple working modes, posing a challenge for developing effective energy management strategies (EMSs). This paper introduces a framework that combines deep reinforcement learning (DRL) with pre-optimized energy management to address this challenge. Considering the characteristics of HEVs, the framework incorporates the pre-optimized equivalent motor and pre-optimized mode selection rule into a deep deterministic policy gradient (DDPG) loop. The pre-optimization of the equivalent motor aims to reduce the energy management task's dimensionality by equating two motors as the equivalent motor, while the pre-optimized mode selection rule systematically integrates mode selection and energy allocation into the EMS. The study assumes HEVs operate in connected urban environments and incorporates middle-horizon traffic information to enhance EMS performance. Additionally, the study integrates the frequent engine start-stop characteristics of HEVs into EMS design. Simulation results demonstrate that the fuel economy of the proposed EMSs in this study ranges from 87.2% to 90.7% of the DP-based EMS. The inclusion of an engine start-stop penalty significantly reduces the number of engine start-stops without compromising fuel economy. [Display omitted] • A pre-optimization-assisted DDPG-based EMS is designed for series-parallel HEVs. • Equivalent method regards two motors as one and reduces dimensionality of optimization. • Dynamic programming guides the pre-optimization of mode selection rule design. • Traffic information and engine start-stop events are considered in energy management. [ABSTRACT FROM AUTHOR]

[Display omitted] • This review presents the recent progress of photonic RE-MOFs creatively categorized by rare earth elements. • The inherent correlation between structure of RE-MOFs and their photonic properties are systematically and comprehensively presented. • Several key development directions of advanced photonic RE-MOFs are highlighted to guide the further design. Metal-organic frameworks (MOFs) represent an emerging category of porous crystalline materials, notable for their high porosity, adjustable pore sizes and elevated Lewis acid contents. Rare earth MOFs (RE-MOFs), a specific subset of MOFs, use rare earth ions or clusters as central metal linkers, rendering advantages of both MOFs and rare earth ions. The distinctive feature of rare earth ions with unfilled 4f electron shells endows them with elevated coordination numbers and unique photophysical characteristics. Besides, the diversity of ligands within MOF frameworks effectively channels the antenna effect to sensitize the rare earth ions, resulting in enhanced photon emission, making RE-MOFs a kind of promising material in the photonics field, including photocatalysis, fluorescent probes, light-emitting, temperature sensing, near infrared (NIR) emission and more. This review presents the recent progress of photonic RE-MOFs creatively categorized by rare earth elements to demonstrate their great potential in photonics. The inherent correlation between structure of RE-MOFs and their photonic properties are systematically and comprehensively discusssed. Moreover, we highlight several key development directions of advanced photonic RE-MOFs to guide the further design. [ABSTRACT FROM AUTHOR]

A reliable and real-time eco-driving control strategy that incorporates vehicle connectivity is crucial for enhancing the fuel economy and mobility of fuel cell hybrid vehicles (FCHVs). However, the strong coupling of dynamic traffic, vehicle dynamics, and powertrain characteristics makes eco-driving challenging in terms of effectiveness and computational efficiency for co-optimizing velocity planning and energy management. This study proposes a hierarchical eco-driving predictive control framework for connected automated FCHVs, which improves comprehensive performance and is real-time applicable by incorporating an explicit dynamic traffic model (EDTM)-based velocity planning and an equivalent consumption minimization strategy (ECMS). The EDTM predicts the ego vehicle's state of proceeding through signalized intersections in dynamic traffic scenarios. The model predictive control is employed for multi-objective velocity planning, which balances energy savings, comfort, and traffic efficiency. At the powertrain level, a multi-horizon predictive ECMS (MhP-ECMS) is designed to incorporate both the optimized velocity (short-horizon) and the EDTM-based predictive velocity (mid-horizon). Dynamic traffic Scenario- and Hardware-in-the-Loop (S/HiL) validations show that the proposed strategy can make driving smoother in vehicle-following and through signalized intersections, and markedly improve fuel economy by 5.41% compared to the baseline controller. This study helps provide valuable insight into improving the efficiency and mobility of connected vehicles. [Display omitted] • A hierarchical eco-driving strategy is proposed for co-optimization of speed and powertrain. • An explicit dynamic traffic model is developed for characterizing traffic lights influence. • A predictive ECMS incorporating multi-horizon traffic information is designed for EMS. • Scenario-/hardware-in-the loop experiments verify fuel saving and real-time feasibility. [ABSTRACT FROM AUTHOR]

[Display omitted] • Combining electrospinning and ion exchange technology. • Different samples were obtained by controlling the reduction time. • High Raman enhancement effect on R6G. • Harmful rust of bronze relics can be tested at trace detection. A convenient and reliable surface-enhanced Raman scattering (SERS) substrate has been developed for the surface corrosion analysis of bronze artifacts. The substrate consists of oriented alginate nanofiber membranes containing silver nanoparticles (Ag NPs), which were obtained through electrostatic spinning, ion exchange, and in-situ reduction. By controlling the reduction time, Ag/alginate nanofiber membranes with different contents, sizes, and distributions were obtained. The Ag/alginate nanofiber#20 membranes, obtained with a reduction time of 20 min, reached a detection limit of 10−12 M for R6G with an enhancement factor of 6.64 × 107. In the trace detection of bronze patina, the intensity of the characteristic peaks of harmful patina located at 513, 846, 911, and 974 cm−1 were increased by more than 500 %. This was due to the uniform loading of a large number of Ag NPs on the surface of the nanofiber membrane obtained by reduction for 20 min, and the formation of a large number of hot spots between the oriented nanofibers. This significantly improved the SERS performance of the flexible substrate layer under the joint action with the Ag NPs. These results indicate that the flexible substrate layer can greatly enhance the Raman characteristic peaks of alkali copper chloride and be effectively used for trace analysis of the surface composition of bronze artifacts. [ABSTRACT FROM AUTHOR]

BACKGROUND: In the healthy body, the fascial system maintains elasticity and coordination of movements. If these functions are destroyed, facial paraly appears. Myofascial induction therapy (MIT), a manual physical therapy method that focuses on restoring altered fascial tissue, is prevalently and widely used in clinical treatment. OBJECTIVE: The study aimed to observe the application of MIT in the rehabilitation of patients with acute facial palsy. METHODS: Sixty-eight patients with acute facial palsy were divided into control group and manual treatment group. The control group received drug treatments, such as prednisone, methylcobalamin, and vitamin B1, and instrumental physical therapy, such as semiconductor laser, shortwave therapy, and facial muscle training. In addition to these treatments, the manual treatment group received MIT. Both groups were treated for 4 weeks. The patients were assessed using the following methods: the House-Brackmann facial nerve function evaluation, Sunnybrook facial grading system, facial nerve electrophysiological examination compound muscle action potential (CMAP) amplitude, and blink reflex (BR) R1 latency. RESULTS: House-Brackmann and Sunnybrook scores and CMAP amplitude and BRR1 latencies were significantly different between the two groups (p < 0.05). Furthermore, the manual treatment group showed greater improvement than the control group (p < 0.05). CONCLUSIONS: Treatment with MIT promoted better recovery of acute facial palsy and thus may be considered a valid rehabilitation intervention that is worthy of clinical application. [ABSTRACT FROM AUTHOR]

In this paper, the nonparametric models of the vehicle and track subsystems are established separately by the nonparametric probabilistic method, in which modeling uncertainties are represented by random matrices and the dispersion level of each random matrix is controlled by a corresponding dispersion parameter. The stochastic equations of motion of the vehicle and track subsystems are obtained respectively and coupled by the wheel-rail dynamic interaction model, in which nonlinear wheel-rail contact geometry relation and wheel-rail detachment can be considered. Random responses are obtained with the prediction-based iterative method in the framework of Monte Carlo simulation (MCS). The sensitivities of the random responses to the uncertainties of coefficient matrices of vehicle and track subsystems are analyzed and the confidence intervals obtained by the nonparametric and parametric models are compared. The results show that the lateral acceleration of the car body on a straight track is most sensitive to the vehicle's mass matrix, while the wheel derailment coefficient is most sensitive to the vehicle's stiffness matrix at curve negotiation. The confidence intervals obtained by the two probabilistic models with the same dispersion level are close to each other, verifying the validity of the nonparametric model of vehicle-track coupled systems. [ABSTRACT FROM AUTHOR]

With the depletion of high-grade ores, beneficiation of valuable minerals from mineral processing tailings attracts attentions of mining companies and researchers. Recovery of valuable sulfide minerals by flotation from the tailing of an iron-copper mine in central China was investigated in this paper. The surface oxidation status of sulfide minerals is an important factor influencing their flotation properties. Electron probe microanalyzer (EPMA) equipped with wavelength dispersive X-ray spectrometer (WDS) is an effective apparatus for characterizing solid surface (interface), which can analyze the composition and element distribution on the surfaces of sulfide minerals so as to understand their oxidation status. EPMA-WDS was employed to analyze the phenomenon responsible for the low flotation recovery of chalcopyrite and pyrite in this tailing. The research methodology is a useful reference for further work in the field of sulfide mineral surface analysis. [ABSTRACT FROM AUTHOR]

The study of coupling effect (CE) within low-dimensional quantum structures is essential not only for the comprehensive understanding of quantum transport but also for improving the performances of photoelectric devices. Recently, electronically weakly coupled quantum well (QW) structures pave the way for low threshold lasing, but the related coupling mechanism has not been clarified yet. Here, we report the direct experimental evidence of compensation mechanism in the carrier migration process within weakly coupled double QWs (DQWs). It is proved that the leakage rate of charges could be modulated within the two InGaSb QWs of the DQW structure owing to CE. Compared to the single QW configuration, the dissipation of carriers from the QWs within the DQW structure is alleviated under an external field. Further, radiative recombination efficiency for the DQW structure could be enhanced to obtain a lower threshold power. Thus, it may be deduced that the carrier compensation effect between QWs profoundly impacts the multiple-QW laser performance. [ABSTRACT FROM AUTHOR]

This research study reviews a direct comparison of the loading capabilities and selectivity of 13 different ion exchange resins represented in 24 different commercial resins for the removal of Fe(III) from synthetic Ni(II) leach liquor. The use of ion-exchange resins for selectively removing high concentrations of Fe(III) from leach liquor is presented as an alternative to current Fe precipitation processes in base metal industry. Our results show that resins with aminophosphonic, iminodiacetic, a combination of phosphonic-sulfonic groups, and methyl-glucamine groups favored the Fe(III) loading over Ni(II) and obtained high percentage of metal loadings. Resins with carboxylic, amidoxime, phosphoric, and phosphinic acid groups also favored the Fe(III) loading but achieved low percentage of metal loadings. Resins with active sulfur groups containing thiourea, isothiouronium, and thiol showed compromised adsorption preferences to Fe(III), and achieved low percentage of metal loadings. Sulfonic groups showed no adsorption preferences for Fe(III) but achieved relatively high metal loadings. Contrarily, bis-picolylamine groups showed preferences for Ni(II) loading. Our results suggest that resins with methyl-glucamine and amidoxime groups have the best potential to achieve successful Fe(III) removals. Thus, the recovery of high concentrations of Fe(III) at similar Ni(II) concentrations by ion exchange resins is confirmed at laboratory scale supporting its potential to replace precipitation in the base metal purification process. Further technical and economic studies for the development and scale-up process are still required to confirm its industrial application. [ABSTRACT FROM AUTHOR]

Organoboron compounds are powerful precursors of value-added organic compounds in synthetic chemistry, and transition metal-catalysed borylation has always been dominant. To avoid toxic reagents and costs associated with metal catalysts, simpler, more economical and effective approaches for delivering organoborons are highly desirable. Here, without the use of any metal catalysts, a CH3CN-involved electrochemical borylation reaction is reported with alkenes and HBpin as substrates. The site-selectivity is realised to achieve mono- or di-functional borylation of an unsaturated bond by regulating the proportion of HBpin. In addition, the success of gram-scale experiments and versatile conversions confirms the potential applications of this strategy in industrial synthesis. The vital auxiliary role of N,N-diisopropylethylamine (DIEA) in the process of acetonitrile electrolysis is disclosed in the mechanism study. The proposed new strategy provides a generic platform for the discovery of additional challenging electrochemical systems for hydrogenation reactions. [ABSTRACT FROM AUTHOR]

This paper presents an adaptive stochastic isogeometric method to incorporate material uncertainties in the nonlinear bending analysis of thin functionally graded material (FGM) shells. The gradient index is modeled as a second-order random field to describe the spatial randomness of material properties. An adaptive, nested, and non-intrusive Chebyshev interpolation process based on Leja sequences is formulated to approximate the response surface concerning random inputs, in which the discrete responses are parallelly obtained and incrementally augmented to save computational effort. The response surface is taken as a surrogate model to promote the efficiency of the stochastic analysis. In particular, a new probabilistic post-processing technique is proposed to accelerate the evaluation of the probability characteristics of the response. Isogeometric analysis is applied to solve the discrete responses of FGM shells, eliminating geometric errors and simplifying the implementation. Through three examples with different computational costs, the effectiveness of the present method is demonstrated by comparing it with two forms of Monte Carlo simulation methods. The influence of the statistical characteristics of the gradient index field on the response surface analysis and the random response is investigated. • We present an adaptive SSIGA method for stochastic nonlinear analysis of FGM shells. • Leja sequences are introduced to form an efficient Chebyshev interpolation process. • A probabilistic post-processing technique shows precision and efficiency advantages. • Effects of material uncertainties on analyses and responses are investigated. [ABSTRACT FROM AUTHOR]

A novel ECL sensor for the detection of PMD based on the quenching effect of GDY on Ru(bpy) 3 2+ ECL and the competitive host–guest interaction between Q[8], PMD and Fc. Strong anodic Ru(bpy) 3 2+ ECL was obtained at a Q[8] modified electrode. Fc terminated DNA could be used to immobilize GDY onto the electrode through the host–guest interaction between Q[8] and Fc, leading to the decrease of anodic ECL. PMD could replace Fc from the cavity of Q[8] and release GDY from the electrode, leading to the recovery of ECL intensity. As a result, an "on–off-on" mode ECL sensor was designed. [Display omitted] • Graphdiyne exhibited apparent inhibiting effect on Ru(bpy) 3 2+ ECL. • The competitive interaction between Fc, PMD, and Q[8] could bring signal variation. • PMD could be sensitively detected based on inhibiting effect and host–guest interaction. Graphdiyne (GDY) is considered as another promising carbon material in biosensing field. However, the application of GDY in ECL sensing is in its infancy stage, and different roles of GDY are urgent to be discovered. In this work, strong anodic Ru(bpy) 3 2+ electrochemiluminescence (ECL) was obtained at a cucurbit[8]uril (Q[8]) modified electrode. Although GDY exhibited electrocatalytic effect on the oxidation of Ru(bpy) 3 2+, an apparent inhibiting effect of GDY on the ECL signal was observed due to the energy transfer. An "on-off-on" mode ECL sensor was fabricated to detect pancuronium (PMD) based on the competitive host–guest interaction between ferrocene (Fc), PMD and Q[8]. Fc modified single-stranded DNA was immobilized onto the surface of GDY, which could be attached onto the electrode through the interaction between Fc and Q[8]. The quenching effect of GDY could apparently decrease ECL signal. PMD exhibited stronger combining ability with Q[8] than Fc, and could replace Fc from the cavity of Q[8], leading to the recovery of ECL signal. The variation of ECL intensity changed linearly with the PMD concentration in the range of 10 nM to 50 μM with a detection limit of 5 nM (3σ). The proposed sensor has high sensitivity, outstanding specificity and accuracy, indicating that GDY has promising potential application in ECL sensing field based on its inhibiting effect. [ABSTRACT FROM AUTHOR]

[Display omitted] • N-doped hollow carbon nanospheres anchored Pd catalysts (Pd/HCAFR-X) were synthesized. • The ethylbenzene yield in acetophenone HDO was close to 99% under mild conditions. • Nitrogen doping regulates the degree of defects on the surface of the carrier. • Defects offer stable anchor points for Pd loading, increasing the active sites of the reaction. • N modulates the electron distribution and guarantees that Pd0 remains at a high level. Hydrodeoxygenation (HDO) is a promising approach for the synthesis of renewable fuels and chemicals, while the design and preparation of high-performance catalysts in this field remain a challenge. Herein, a series of hollow carbon nanospheres anchored Pd nanoparticles (NPs) catalysts with different nitrogen doping contents (Pd/HCAFR-X, X=0.3, 0.6, 0.9) were prepared for the selective HDO of bio-models compound under mild conditions. Notably, the Pd/HCAFR-0.6 catalyst exhibited excellent catalytic performance for the acetophenone (APh) HDO in polymethylhydrosiloxane (PMHS) at 50 °C for 3 h, and the yield of ethylbenzene was close to 99%. The good catalytic results can be mainly attributed to the unique hollow carbon nanospheres with abundant defects provided by appropriate nitrogen doping content. The large surface area and hierarchical porous structure of the hollow carbon framework offered more active sites, which promoted the transportation of species on the catalyst. In addition, the nitrogen doping amount can adjust the defect degree of the hollow carbon nanospheres, stabilize the dispersion and anchoring of Pd NPs, and then induce the transfer of local electrons. Furthermore, the Pd/HCAFR-0.6 catalyst showed good catalytic performance for bio-models compound HDO after 5 cycles. [ABSTRACT FROM AUTHOR]

This article deals with the sensitivity analysis of dynamic response and optimal size design of complex built-up systems in the mid-frequency range. A complex built-up system may be fabricated from many components which often differ greatly in materials and sizes. It may be subjected to many different wavelength structural deformations and may typically exhibit mixed mid-frequency behaviour which is very sensitive to uncertainties at higher frequencies. To perform optimization on the mid-frequency vibration of complex built-up systems, the hybrid finite element (FE)–statistical energy analysis (SEA) method, in which the deterministic and statistical subsystem are respectively modelled using FE and SEA, is implemented in this work. In this context, an efficient direct differentiation method for sensitivity analysis is derived. Two numerical examples illustrate the efficiency and effectiveness of the proposed optimization model. [ABSTRACT FROM AUTHOR]

In this paper, the development of railway vehicles random analysis procedure (RVRAP) based on the pseudo-excitation theory is described in detail; the procedure helps predict the structural random response of railway vehicle. As traditional finite element method (FEM)-based random vibration analyses are too complex, and time consuming to be carried out by engineer, limited studies have been conducted in the related field. By using the pseudo excitation method (PEM), a stochastic vibration analysis of the railway vehicle system is conducted while the vehicle is modelled by FEM and its mode results are stored as substructures. With the primary and secondary suspension system, the FE-based vehicle configuration is assembled, a structural random vibration analysis is conducted, and the running quality and fatigue life is predicted accurately. Experimental results are compared with the those of a railway vehicle numerical simulation; the accuracy of the random vibration vehicle system is tested and the reliability of the PVRAP is verified. [ABSTRACT FROM AUTHOR]

Guo, Q.; Zhang, Y.; Zhou, Z., and Zhao, Y., 2020. Saltwater transport under the influence of sea-level rise in coastal multilayered aquifers. Journal of Coastal Research, 36(5), 1040–1049. Coconut Creek (Florida), ISSN 0749-0208. The dynamic behavior of groundwater flow and salt transport in coastal multilayered aquifers is affected by sea-level rise (SLR). Two sets of laboratory experiments were completed that took into account SLR (seawater rising from 85 to 105 cm for scenario 1 and inland head decreasing from 100 to 80 cm for scenario 2). Groundwater flow and salt transport in the multilayered aquifers were observed during the experiment. SEAWAT software was used to validate the processes of seawater transport in the coastal multilayered aquifer under the influence of SLR. The hydrogeological parameters were identified by fitting the observed values of groundwater level and salinity in the model. The influences of aquifer heterogeneity, SLR, and boundary condition on solute mixing of saltwater and freshwater were described. Results showed that the transient toe penetration xtoe and area of the seawater wedge increased initially and then tended to stabilize as the seawater level increased in each stage of both scenarios. The spreading rate of the seawater wedge during the process of releasing water in scenario 2 was faster than that of storing water in scenario 1, although the difference between sea level and inland boundary head was the same in the two scenarios. Sensitivity analysis indicated that the estimated parameters were reasonable. Moreover, the variation of the seawater wedge could not be reproduced well when the hydraulic conductivities and saltwater density of the upper and lower layers were increased or decreased. The analysis provided insights into how SLR and inland water head influence seawater intrusion rate and area. [ABSTRACT FROM AUTHOR]

The increasing use of bridges in high-speed railway (HSR) lines raises the possibility of train derailment on bridges under seismic excitations. In this paper, the influence of random multi-point earthquakes on the safe running of a train on a long-span bridge is studied in terms of the dynamic reliability, considering spatial seismic effects, and randomness of ground motions and train locations. The equations of motion for the train and the track/bridge as time-invariant subsystems under earthquakes are established, separately. The two subsystems are connected via the wheel–rail interface, for which a nonlinear contact model and detachment are considered. The time-history samples of nonstationary multi-point random earthquakes considering wave passage effects and incoherence effects are generated by the autoregressive moving average (ARMA) model. The ground motions are imposed on the bridge support points in terms of displacement and velocity. The train location at the time of earthquake is considered a uniformly distributed random variable. The running safety reliability of a train moving on a long-span bridge under earthquakes is determined by combining subset simulation (SS) with a prediction-based iterative solution method. Under different seismic components, train speeds, apparent seismic wave velocities and seismic intensities, the most unfavorable train location intervals are determined, which provides a reference for the safety performance assessment of trains traveling on bridges under earthquakes. Numerical results show that the influence of the lateral seismic component on the wheel derailment coefficient (WDC) is greater than the vertical seismic component, and the earthquake that occurs before the train's arrival at 70% length of the bridge will significantly reduce its running safety. [ABSTRACT FROM AUTHOR]

Growth and connection of preexisting fractures have been recognized as the driving mechanism of rock fracturing. This paper aims at throwing light on the geological implications of the fracturing behavior in pre‐cracked rock observed in rock mechanics‐oriented experiments, by numerical interpretation on the interaction of en echelon fractures. To properly simulate grain crushing involved in cataclastic deformation of nonporous rocks, a sophisticated numerical scheme incorporating rock morphology and crystallography into the grain‐based model is proposed. In line with a previous experimental study, seven grain‐based models with different configurations of en echelon flaws are numerically tested under uniaxial compression. The key results are (1) evaluation of the influences of preexisting flaws on mechanical properties and damage degree of the host rock, (2) visualization of the microfracture process zone into visible cracks, and (3) generalization of three different patterns of major fracture formation from en echelon fractures, during which the ratio of the number of intergranular to intragranular microcracks is used for evaluation of the cataclastic deformation process and the stress level. Based on the numerical results, we provide valuable interpretation on (1) the field occurrence of strike‐slip fault system with typical fracturing features, focusing on the effects of the sense of left or right stepping and the degrees of separation/overlap of the master fractures, and (2) three different mechanisms of fault formation from preexisting fractures. As an initial attempt to relate rock fracturing observed in laboratory experiments with the field occurrence, capabilities and limitations of this study are also presented. Key Points: A modified grain‐based model (GBM) for simulation of fracturing of nonporous rocks is proposedWe throw light on the geological implications of laboratory studies of fracturing in rock with preexisting cracksThe strike‐slip en echelon fault system is recognized from mesoscale simulations [ABSTRACT FROM AUTHOR]

This paper documents an energy-based analysis of temperature oscillation during cyclic stress-induced phase transformation in shape memory alloys (SMAs). The conversion of total hysteresis work into dissipated heat and stored energy in SMAs is discussed, and the temperature oscillation at the shakedown state in cyclically loaded SMAs is modeled. To validate the theoretical model, both strain and stress-controlled tensile tests on pseudoelastic NiTi wires are performed under cyclic loading and an infrared camera is used to record the surface temperature of the wire. The results show that depending of the loading type, strain or stress-controlled loading, the amplitude of temperature oscillation during cyclic stress-induced phase transformation evolves differently with the frequency: The amplitude of the temperature oscillation under strain-controlled loading gradually reaches a saturated value independent of the frequency; however, for stress-controlled loading, the saturated temperature amplitude is frequency-dependent since it reduces significantly if the frequency is increased. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel fatigue response spectrum method is proposed for high-cycle fatigue. • The quasi-static response is introduced to modify the modal truncation error. • The complete SRSS rule is adopted to reduce the cost of cross-correlation analysis. • The impact factors of modal truncation error in fatigue assessment are investigated. In this paper, a more accurate and efficient format of the fatigue response spectrum method is further proposed considering modal truncation error. Firstly, the quasi-static response of higher-order modes is taken into account to modify the modal truncation error. Then, an analytical description of the cross-correlation between the modal responses as well as quasi-static response is developed by two coefficients associated with the natural frequency and modal damping ratio. Finally, the expected damage rate is transformed into a summation of modal damage responses strictly, resulting in a dual improvement in accuracy and efficiency. In numerical examples, the correctness and efficiency are verified and the influences of load spectrum and material fatigue properties on the modal truncation error are further investigated. [ABSTRACT FROM AUTHOR]

Strong and stable anodic ECL was obtained from iridium complex doped ZnO nanocomposites (Ir@ZnO). A sensitive ECL sensor for the detection of phenylalanie (Phe) was proposed via the host–guest recognition of cucurbit[8]uril (Q[8]) and Phe with Ir@ZnO nanocomposites as a signal probe. This work provided a new avenue for the application of water insoluble Ir complexes in ECL sensing field. [Display omitted] • Iridium complex doped ZnO nanocomposites were synthesized. • Strong and stable ECL of Ir@ZnO nanocomposites was obtained. • The host–guest recognition between Q[8] and phenylalanine was adopted to fabricate ECL sensor. Iridium complexes have been considered as potential promising electrochemiluminescent (ECL) reagents in recent years. However, the instability of ECL signal and easy leaching from the electrode severely limit their applications. In this work, iridium complex doped zinc oxide (ZnO) nanocomposites (Ir@ZnO) were synthesized, which could not only increase the loading amount of iridium complex, but also improve the stability of ECL signal. A sensitive ECL sensor for the detection of phenylalanie (Phe) was proposed via the host–guest recognition of cucurbit[8]uril (Q[8]) and Phe with Ir@ZnO nanocomposites as a signal probe. Q[8] was combined with Ir@ZnO nanocomposites via coordinate bond between carbonyl group of Q[8] and Ir and Zn atoms, which could quench the ECL intensity due to the accommodating ability of Q[8] for dissolved oxygen. In the presence of Phe, Q[8] could be released from the electrode surface through the strong host–guest interaction, and the ECL intensity was restored. The ECL system performed high sensitivity and low detection limit, indicating that the proposed ECL strategy was suitable for the detection of amino acids. Moreover, this work provided a new avenue for the application of water insoluble Ir complexes in ECL sensing field. [ABSTRACT FROM AUTHOR]

A symplectic wave-based method is proposed in this paper for the forced vibration analysis of thin cross-ply laminated cylindrical shells with arbitrary boundary conditions. Firstly, based on Kirchhoff–Love's shell theory, the unified governing equation of thin cross-ply laminated cylindrical shells in the symplectic duality system is established by selecting an appropriate state vector, which leads to the transformation of the vibration analysis of cylindrical shells from two-dimensional to one-dimensional. Then, the response of laminated cylindrical shells can be described in terms of wave shapes in the symplectic duality system. The relationship between incident and reflected waves at a boundary is established to analytically describe the boundary condition, which allows the present method to deal with arbitrary boundary conditions and has high computational accuracy. Finally, the displacement and internal force responses can be simultaneously and explicitly calculated by using the adjoint symplectic orthogonal relation of wave shapes in the symplectic duality system, which ensures that the present method has high computational efficiency. The present method has truncation errors only in the circumferential direction, and is analytical in the axial direction, which can lead to a high accuracy and convergence rate. Several examples demonstrate the effectiveness, convergence and accuracy of the present method, as well as its ability to handle arbitrary boundary conditions. • A unified governing equation of laminated cylindrical shells is derived. • The analytical incident-reflection relationship of waves at a boundary is established. • The directly excited waves can be explicitly calculated using the present method. [ABSTRACT FROM AUTHOR]

Due to the significant difference of dynamic properties between the fluid medium and the structure, when a vibro-acoustic system is subjected to a higher frequency excitation, it may typically exhibit mid-frequency behavior which involves different wavelength deformations and is very sensitive to the uncertainties of the system. This paper deals with optimized distribution of a sound absorbing layer for the mid-frequency vibration of vibro-acoustic systems by using hybrid boundary element analysis and statistical energy analysis. Based on the solid isotropic material with penalization approach, an artificial sound absorbing material model is suggested and the relative densities of the sound absorbing material are taken as design variables. The sound pressure level at a specified point in the acoustic cavity is to be minimized by distributing a given amount of sound absorbing material. An efficient direct differentiation scheme for the response sensitivity analysis is proposed. Then, the optimization problem is solved by using the method of moving asymptotes. A numerical example illustrates the validity and effectiveness of the present optimization model. Impact of the excitation frequency on optimized topology is also discussed. [ABSTRACT FROM AUTHOR]

Abstract In this paper, a multiscale investigation of fatigue crack initiation in shape memory alloys (SMAs) based on Transformation Induced Plasticity (TRIP) is presented. A mechanism for fatigue crack initiation during cyclic stress-induced phase transformation along with theoretical model is proposed. To validate the TRIP-based model, quasi-static tests at different ambient temperatures, 40 ∘ C , 52 ∘ C and 65 ∘ C , and strain and stress controlled low-cycle fatigue tests at different frequencies ranging from 0.16 Hz to 5 Hz on pseudoelastic NiTi wires are carried out. The results show that, (i) TRIP appearing on phase transformation interfaces is the key factor that drives the fatigue crack initiation during cyclic stress-induced phase transformation in SMAs; (ii) maximum temperature during phase transformation is a relevant indicator to predict low-cycle fatigue of SMAs and, (iii) within the range of pseudoelasticity and below the plastic yield, low-cycle fatigue of SMAs is not directly correlated with the mechanical loads applied at macro-scale, in the sense that, if the maximum temperature reached during loading cycles is kept constant, the fatigue lifetime remains unchanged whatever the amplitude of the mechanical loading is. Based on the findings, a new criterion for pseudoelastic low-cycle fatigue of SMAs as well as fatigue-isolines diagram are proposed and validated experimentally. Highlights • A mechanism of fatigue crack initiation during cyclic loading in SMAs is modeled and experimentally validated. • TRIP appearing in A-M interfaces is the key factor that drives fatigue crack initiation during cyclic loading in SMAs. • Maximum temperature during phase transformation can be used as an indicator to predict low-cycle fatigue of SMAs. • In the pseudo-elastic domain, if the maximum temperature is kept constant the fatigue lifetime remains unchanged. • Fatigue failure almost always occurs at one of the martensite front at the end of the forward phase transformation. [ABSTRACT FROM AUTHOR]

Abstract This paper investigates the degradation of the recoverable strain during full transformation cycling in shape memory alloys. Results show that such degradation occurs due to: (i) untransformed austenite during full transformation, (ii) residual martensite after complete unloading, and (iii) plastic strain produced in the latest reverse transformation. Particularly, the plastic strain tends to zero when the stabilized state is reached. Furthermore, the degradation is frequency-dependent in the sense that a higher loading frequency results in a larger degradation of the recoverable strain. Finally, it is shown that fatigue lifetime decreases when transformation degradation increases. Graphical Abstract [ABSTRACT FROM AUTHOR]

Highlights • An uncertain model is presented for the random vibration of a subsea pipeline. • The spatial variation of ground motions is considered. • The unilateral contact relationship between the pipeline and seabed is considered. • Propagations of the randomness and modelling uncertainties are investigated. Abstract Based on a nonparametric modelling approach, this paper presents a random vibration analysis of a subsea pipeline subjected to spatially varying ground motions. The earthquake-induced ground motions are modelled as nonstationary random processes and their spatial variations are considered. The modelling uncertainties of the subsea pipeline are taken into account using a random matrix theory, while the unilateral contact relationship between the pipeline and seabed is also considered. Thus, an uncertain computational model for the subsea pipeline subjected to a random earthquake is established, and the corresponding solutions are calculated using Monte Carlo simulation (MCS). In order to highlight the contribution of the unilateral contact effect to random responses of pipelines, comparative studies are performed between the unilateral and permanent contact models. In numerical examples, the possible convergence problems in the present computational model are firstly studied to determine the optimal numbers of reduced modes and MCS samples. Then influences of the randomness in the earthquake and modelling uncertainties in the pipeline are investigated qualitatively through three representative cases. The different propagations of randomness and modelling uncertainties in the unilateral and permanent models are also examined and discussed. It is concluded that the randomness of the earthquake and modelling uncertainties of the pipeline have significant influences on the statistical characteristics of earthquake responses of the pipeline. [ABSTRACT FROM AUTHOR]

Reliable prediction of the rock fracturing process is a challenging issue in exploitation of deep earth resources in which artificial creation of complex fracture networks is employed. The grain‐based modeling (GBM) approach is a promising numerical technique for its unique capability to simulate the fracturing behavior of crystalline rocks. An extended grain‐based model is developed to improve the traditional Voronoi GBM from two aspects. First, digital image processing technique is presented to incorporate actual rock microstructures into the numerical model. Second, the effect of initial microcracks is considered by integrating a statistical discrete fracture network model into GBM. By simulating semicircular bending tests on 16 extended GBMs and 3 Voronoi GBMs, the effects of rock microstructures and initial microcracks on microcracking behavior and mechanical properties are analyzed. Cracking patterns are classified into four types for the first time with respect to fracture toughness and crack initiation threshold. The results indicate that the use of a statistical structure or a purely deterministic GBM without consideration of initial microcracks cannot realistically describe grain‐scale discontinuities, which likely leads to biased evaluations of the rock failure process. Key Points: An extended grain‐based model (EGBM) is developed for realistic simulation of crystalline rocksDigital image processing (DIP) technique is used for extracting grain boundariesInitial microcracks are incorporation by a discrete fracture network (DFN) [ABSTRACT FROM AUTHOR]

Organic functional materials, including conjugated molecules and fluorescent dyes, have been intensely developed in recent years because they can be applied in many fields, such as solar cells, biosensing and bioimaging, and medical adjuvant therapy. Organic functional materials with aggregation‐induced emission or aggregation‐enhanced emission (AIE/AEE) characteristics have increasingly attracted attention due to their high quantum efficiency in the aggregated or solid state. A large variety of AIE/AEE materials have been designed and applied during the exponential growth of research interest in the abovementioned fields. Multiphenyl‐substituted 1,3‐butadiene (MPB), as a core structure that includes tetraphenyl‐1,3‐butadiene, hexaphenyl‐1,3‐butadiene and their derivatives, show a typical AIE/AEE feature and can be potentially used in all the above‐mentioned fields. This review summarizes the design principles, the corresponding syntheses, and the structure–property relationships of MPBs, as well as their excellent innovative functionalities and applications. This review will be useful for scientists conducting chemistry, materials, and biomedical research in AIE/AEE‐related fields. Over the rainbow: Multiphenyl‐substituted 1,3‐butadiene derivatives (MPBs) with AIE/AEE characteristics show different fluorescence intensities and emission wavelengths in different states (solution, aggregated states, and solid state). The rich conformation of MPBs provides more possibilities to tailor functionalities of advanced materials in AIE/AEE‐related fields. This minireview has summarized their structural design, properties and potential applications of these MPBs. [ABSTRACT FROM AUTHOR]