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Cantilever beams with axial extension and contraction functions as time-varying parameter systems have attracted extensive research due to their prevalence in engineering structures. In this paper, the dynamic characteristics of the flat-push bridge mechanism are investigated from the theoretical aspect, firstly, it is simplified into a cantilever beam model with axial motion, and the transverse vibration equations of the cantilever beam are established based on the Euler–Bernoulli beam theory and D’Alembert’s principle, and the transverse displacements of the beam are discretized using the Galerkin truncation method and solved numerically by using the Newmark-β method for the second-order vibration differential equations with variable coefficients; second-order vibration differential equations were solved numerically by the Newmark-β method; then the structural examples in the existing literature are verified numerically, and the calculation results are consistent with the literature results, indicating that the transverse vibration equations derived in this paper are solved effectively; then a parametric analysis of the speed of the cantilever beam during axial extension/contraction was done, which showed that the faster the speed of axial motion, the faster the rate of change of the dynamic characteristics of the beam and the more pronounced the vibration; finally, the power signal is decomposed in the time-frequency domain by using the Choi–Williams Distribution (CWD), and the time-frequency characteristics of the system under different speeds are analyzed, and the results show that the use of CWD technique can accurately reflect the system’s transient vibration frequency and vibration energy with the change rule of time and speed, and the axial motion speed of ±0.05m/s, the transient frequency of the theoretical prediction and the average relative deviation between the finite element modal frequencies are kept within 5% and the recognition accuracy is high. This analysis provides flexible technical guidance for vibration control in engineering structures. [ABSTRACT FROM AUTHOR]

Porphyrin‐based conjugated polymers (PCPs) have garnered significant attention due to their exceptional conjugated π‐electron system and remarkable physical/chemical properties, further endowing them with ordered mesoscopic architecture to break the intrinsic non/microporous restriction is highly desirable, but it still remains a great challenge. Herein, a facile bottom‐up approach for fabricating ordered mesoporous PCPs (mPCPs) with tunable mesoporous channels through colloid‐mediated self‐assembly are presented. The resultant orders mesoscopic architecture featuring a substantial specific surface area (99.3 m2 g−1) and polar skeleton, remarkably improved anchoring properties for iodine chloride molecule. Meanwhile, the optimized mass transport facilitated by the robust mesoporous channels, coupled with the increased accessibility of polar functional groups, renders the structures with an ideal nanoreactor for the highly synergistic stabilization of the four‐electron I+/I2/I− conversion process. Therefore, the mPCPs host exhibits a high specific capacity (321 mA h g−1 at 0.5 A g−1), excellent rate performance, and cycle stability (266 mAh g−1 at 3.0 A g−1 after 1800 cycles), underscoring its potential as an effective platform for zinc‐iodine batteries. This study will provide a new method for precise control and engineering of mesoporous structures tailored for specific functionalities and electrochemical requirements, thereby facilitating the development of advanced materials based on multi‐electron energy storage applications. [ABSTRACT FROM AUTHOR]

We report herein a series of macrocycles in which the densely π‐stacked charge‐transfer (CT) donor/acceptor with naphthalenediimides (NDIs) or perylene diimide (PDI) as acceptor moiety pairing various donor moieties are locked by covalent bond. The X‐ray crystallography of C8BDT‐NDI reveals a short intramolecular π‐stacking distance around 3.4 Å and the existence of intermolecular donor/acceptor π‐stacking (3.7 Å). The intramolecular CT is highly dependent on the electron‐donating ability of donor moiety and replacing carbazole (C8KZ) with benzo[1,2‐b:4,5‐b′]dithiophene (C8BDT) or dihydroindolo[3,2‐b]indole (C8DN) redshift CT absorption into NIR region. Notably, both C8BDT‐NDI and C8DN‐NDI demonstrate excellent photothermal performance, which is a result of the active non‐radiative pathways. Interestingly, the different molecular symmetry between donor and acceptor moiety in cyclophanes endow C8BDT‐NDI and C8DN‐NDI with intrinsic planar chirality. The enantiomeric C8BDT‐NDI shows chiral selectivity for incident light, i.e., when irradiated by left‐circularly polarized light, (R)‐C8BDT‐NDI is more sensitive and a higher maximum stable temperature is achieved. While, enantiomeric C8DN‐NDI pack with different orientations forming M‐ and P‐handedness helix, respectively, demonstrating molecular planar chirality being transferred and amplified through molecular assembly. These results provide insight into the intramolecular charge transfer in enforced D/A π‐stacks in which CT interactions and planar chirality would be engineered through structural control. [ABSTRACT FROM AUTHOR]

The response amplification technology, which enhances the efficiency of shock absorption apparatuses, has been widely applied in the field of shock absorption control for engineering structures. Researchers have proposed and verified through numerical analysis and experiments more structural forms of this technology as applicable. The functions are also more comprehensive, such as increased utilization rate of structural space and economy. The development of its theoretical foundation has progressed from constant solutions based on small deformations to solutions that reflect the time-varying characteristics of the amplification factor of the brace-damping system. Simultaneously, the influencing factors of the amplification factor have been analyzed in detail to provide better theoretical guidance for engineering practice. This paper provides a detailed discussion on the research overview of the response amplification technology and the influencing factors of the amplification factor. The conclusion introduces the significance of using this technology, comprehensively analyzes the deficiencies and limitations of existing response amplification technology, and points out the research and development direction, with the expectation of providing ideas for further development. [ABSTRACT FROM AUTHOR]

One of the researchers' concerns in structural engineering is to control the dynamic behavior of structures efficiently. The TMD (tuned mass damper) is one of the effective methods of controlling the vibration of structures, and various numerical techniques have been proposed to find the optimal parameters of the TMD. This paper develops a new explicit formula to derive the optimal parameters of the TMD of a single degree of freedom (SDOF) structure under seismic load using a genetic algorithm (GA). In addition, the state-space model and the H2 norm function are used to identify the optimal frequency ratio and damping ratio of the TMD that minimize the overall vibration energy of the structure. The MATLAB curve fitting toolbox is used for the explicit formula proposal, and the validity of the proposed formula is verified through multidimensional performance verification technique. Finally, the TMD parameters of the SDOF structure are applied to the multi-degrees of freedom (MDOF) structure to compare and analyze with the existing research results, and the results of the explicit formula proposed in this paper are confirmed to be excellent. This paper can suggest a new direction for determining the optimal TMD parameters using a GA and can be effectively applied to vibration control problems of various structures. [ABSTRACT FROM AUTHOR]

The electrocatalytic hydrogen evolution reaction (HER) is a key technology for hydrogen production and plays a significant role in advancing sustainable energy conversion. This study successfully anchored platinum (Pt) nanoparticles onto monolayer VS 2 nanosheets via a colloidal chemistry method to enhance their HER performance under acidic conditions. The monolayer VS 2 nanosheets provide a stable substrate, with their large surface area and high in-plane electrical conductivity effectively enhancing the interfacial electron transfer and electrochemical contact of the Pt nanoparticles. The Pt/VS 2 composite material significantly reduces the energy barrier required for HER and enhances electrochemical activity, while also lowering the cost of the catalyst. At a current density of 10 mA cm−2, the composite material with Pt nanoparticles anchored onto VS 2 nanosheets achieved an overpotential of just 26 mV and exhibited a high mass activity of 23.7 A/mg Pt. Density functional theory (DFT) calculations and experimental analyses further elucidated the critical role of interfacial electronic effects and sulfur vacancy modulation in enhancing catalytic efficiency. These findings highlight the potential of interface engineering to control electronic structure and sulfur vacancies, significantly enhancing the hydrogen production efficiency and cost-effectiveness of Pt-based catalysts even at low Pt loadings under acidic conditions. By anchoring platinum (Pt) nanoparticles onto monolayer VS 2 via a two-step colloidal chemistry method, the electronic configuration was effectively modified, significantly enhancing the electrocatalytic activity and stability for hydrogen evolution reaction (HER) under acidic conditions. These modifications optimize the electronic structure, enhance interfacial electron transfer, and reduce energy barriers, contributing to the increased availability of active sites and improved charge dynamics. [Display omitted] • Monolayer VS 2 nanosheets anchored Pt nanoparticles. • The electronic interaction between Pt and VS 2 improved the electrocatalytic hydrogen precipitation performance. • The mass activity of the Pt/VS 2 composite was 23.7 A/mgPt at 70 mV overpotential. [ABSTRACT FROM AUTHOR]

Within a shared cytoplasm, filamentous actin (F-actin) plays numerous and critical roles across the cell body. Cells rely on actin-binding proteins (ABPs) to organize F-actin and to integrate its polymeric characteristics into diverse cellular processes. Yet, the multitude of ABPs that engage with and shape F-actin make studying a single ABP's influence on cellular activities a significant challenge. Moreover, without a means of manipulating actin-binding subcellularly, harnessing the F-actin cytoskeleton for synthetic biology purposes remains elusive. Here, we describe a suite of designed proteins, Controllable Actin-binding Switch Tools (CASTs), whose actin-binding behavior can be controlled with external stimuli. CASTs were developed that respond to different external inputs, providing options for turn-on kinetics and enabling orthogonality and multiplexing. Being genetically encoded, we show that CASTs can be inserted into native protein sequences to control F-actin association locally and engineered into structures to control cell and tissue shape and behavior. Numerous proteins interact with the actin cytoskeleton, convoluting their influence on cellular behaviour. Here the authors engineer actin-binding switch tools that can be activated with external stimuli to control the activity of just one protein. [ABSTRACT FROM AUTHOR]

Grouting has been commonly used for structure controlling in mining engineering. To investigate the mechanism of fracturing grouting, an experiment was conducted under constant flowing conditions. Through the real-time gathering of main parameters and reconstruction of the slurry distribution, the complete grouting process and pressure spread of the high-pressure slurry were revealed. An identification method of fracturing diffusion based on acoustic emission (AE) signals was proposed and verified. The results indicated that the intact rock showed fracturing response with a mutated pressure in a short time. For fractured ones, the grouting process can be divided into five stages: seepage flow, pressure holding, fracturing diffusion, steady flow, and pressure relief. Influenced by the hydraulic fracture and slurry infiltration, there were three states: cement diffusion, water seepage, and the unaffected zone. A calculation method of whole stages for the grouting pressure was proposed based on the Hoek–Brown strength criterion and flow model in a fracture. In addition, AE ring counting occurred during the entire slurry process but was relatively concentrated in pressure holding and fracturing diffusion stages. Considering the zonal distribution characteristics, the AE method was used to characterize the slurry diffusion range and flow paths. The slurry distribution was obtained by the three-dimensional cutting and reconstruction method to verify its feasibility. This study is expected to further clarify the grouting mechanism, and guide engineering practices. Highlights: High-pressure grouting experiment of fractured rock based on acoustic emission was carried out. The whole process of fracturing grouting shows five responses in fractured rock. The pressure calculation model for revealed whole injection process was established in inclined fracture. AE monitoring can be used to identify the splitting-diffusion range and path for fracturing grouting. [ABSTRACT FROM AUTHOR]

In order to investigate the failure modes and instability mechanism of fractured rock. Uniaxial compression tests were conducted on sandstone specimens with different dip angles. Based on rock energy dissipation theory and fractal theory, the energy evolution characteristics and fragmentation fractal characteristics in the process of deformation and failure of specimens were analyzed. The results show that the peak strength and elastic modulus of fractured rock mass are lower than those of intact samples, and both show an exponential increase with the increase of fracture dip angle. The energy evolution laws of different fracture specimens are roughly similar and can be classified into four stages based on the stress–strain curve: pressure-tight, elastic, plastic, and post-destructive. The total strain energy, elastic strain energy, and dissipated strain energy of the specimen at the peak stress point increased exponentially with crack inclination, and the dissipated strain energy and compressive strength conformed to a power function growth relationship. The distribution of the fragments after the failure of the fracture sample has fractal characteristics, and the fractal dimension increases with the increase of the fracture dip angle. In addition, the higher the compressive strength of the specimen, the greater the energy dissipation, the more serious the degree of fragmentation, and the greater the fractal dimension. The data fitting further shows that there is a power function relationship between the dissipated strain energy and the fractal dimension. The research results can provide a theoretical basis for the stability of rock mass engineering and structural deformation control. [ABSTRACT FROM AUTHOR]

This document, titled "Optimal control - analysis, algorithms and applications," explores the significance of optimal control in systems and control research. It highlights key breakthroughs in the field, such as Dynamic Programming and the Maximum Principle, and emphasizes the importance of optimal control in various applications. The document includes articles that cover a range of topics, including trajectory planning for heterogeneous systems, distributed model predictive control, energy-optimal control of adaptive structures, and robust stability of moving horizon estimation. These articles provide insights into the methods and applications of optimal control, showcasing its relevance and potential for further research. [Extracted from the article]

In this paper, parametric forced tuned solid ball dampers (TSBD) are considered for vibration control of engineering structures in an untypical way. The special feature of the presented investigation is to evaluate the potential application of parametric forcing of the rolling cylindrical or spherical body in the runway for reducing the vertical vibrations of a vibration-prone main system. Typically, tuned solid ball dampers are applied to structures that are prone to horizontal vibrations only. The coupled nonlinear differential equations of motion are derived and the phenomenon of parametric resonance of the rolling body in the runway is analyzed. A criterion for avoiding parametric resonance is given to achieve the optimal damping effect of the TSBD. In the second part of the article, a method for the targeted use of parametric resonance to reduce the vertical vibrations of engineering structures is presented and verified, considering a biaxially harmonic excited pedestrian bridge. It is shown that, with a suitable choice of damper parameters, a stable vibration of the rolling body in the runway is formed over the course of the vibration despite the occurrence of parametric resonance and that the maximum vertical vibration amplitudes of the main system can be reduced up to 93%. Hence, the here presented untypical application of parametric forced TSBD for reducing the vertical forced vibrations of vibration-prone main systems could be successfully demonstrated. [ABSTRACT FROM AUTHOR]

In recent years, shape memory alloys (SMAs) have been applied in the vibration control of engineering structures due to their special properties such as super elasticity and high damping, and the study of the performance of SMA wires has been relatively comprehensive, while research on the fatigue performance of SMA bars via cyclic tensile tests has been pretty rare, and low-cycle fatigue test has not been reported. However, the damage to building structures caused by earthquakes is of high-strain, low-cycle fatigue; therefore, in order for SMA bars to be used in seismic design, low-cycle fatigue tests were conducted on SMA bars with a diameter of 14 mm in this paper. Firstly, specimens were heat treated at a constant temperature of 350 °C for 30 min; other specimens were heat treated at a constant temperature of 400 °C for 15 min, while the rests were heat treated under a constant temperature of 400 °C for 30 min. Secondly, the energy dissipation capacity and residual strain of the SMA bar specimens were determined using the low-cycle fatigue test, in which the strain amplitudes were 2.5%, 3.5% and 3.75%. Additionally, the stress–strain relationship for SMA bars under cyclic loading was given. Finally, low-cycle fatigue properties of SMA bars were numerically simulated in the comparison analysis with the experimental results to verify their feasibility. Thus, it is proved that SMA bars can be recommend for seismic design building structures. [ABSTRACT FROM AUTHOR]

The crystal structures of metal-organic frameworks (MOFs) are typically determined by the strong chemical bonds formed between the organic and inorganic building units. However, the latest generation of redox-active frameworks often rely on counterions in the pores to access specific charge states of the components. Here, we model the crystal structures of three layered MOFs based on the redox-active ligand 2,5-dihydroxybenzoquinone (dhbq): Ti2(Cl2dhbq)3, V2(Cl2dhbq)3 and Fe2(Cl2dhbq)3 with implicit and explicit counterions. Our full-potential first-principles calculations indicate that while the reported hexagonal structure is readily obtained for Ti and V, the Fe framework is stabilised only by the presence of explicit counterions. For high counterion concentrations, we observe the formation of an electride-like pocket in the pore center. An outlook is provided on the implications of solvent and counterion control for engineering the structures and properties of porous solids. [ABSTRACT FROM AUTHOR]

Inerters have significantly uplifted the cost‐effectiveness of structural control technologies. A recently proposed tuned mass damper‐clutching inerter (TMDCI) takes advantage of both mass amplification effect and energy absorption capacity of inerter which is more effective and practical than its predecessors. However, the existing study only provided numerical demonstrations while experimental evidence and analytical explanation are still lacking for in‐depth understanding of the dynamic properties and working principles of TMDCIs. In this study, the mathematical descriptions of TMDCIs are first developed and experimentally validated on a three‐story structure. The validated model is then used to analyze the influences of inerter arrangement and total inertance in inerter‐enhanced devices. With an appropriate inerter arrangement and inertance, the TMDCI shows excellent control performance regardless of the changes in the structural frequency. The reason for the strong robustness of TMDCIs is then revealed via analytical investigation of standalone TMDCIs; the harmonically forced steady‐state responses manifest that the TMDCI can be linearized as equivalent tuned mass damper‐inerters with variable parameters whose natural frequency increases with the increase of excitation frequency. Based on the analytical findings, a design method with robustness consideration is subsequently proposed and draws satisfactory TMDCI designs for both single‐degree‐of‐freedom and multi‐degree‐of‐freedom structures. The designed TMDCI outperforms the comparable devices for both impulsive and seismic response mitigation. The study provides analytical insight into the control capacity of TMDCIs and lays the groundwork for practical design of TMDCIs as an effective and robust control strategy for engineering structures. [ABSTRACT FROM AUTHOR]

Flexoelectric effect can be used to design actuators to control engineering structures including beams, plates, and shells. Multiple flexoelectric actuators method has the advantage of less stress concentration and better control effect, but the mode-dependent optimal actuator locations could influence the flexoelectric actuation effect significantly. In this work, a neural network model is established to study the optimal combinations of multiple flexoelectric actuators on a rectangular plate. In the physical model, an atomic force microscope (AFM) probe was employed to generate an electric field gradient in the flexoelectric patch, so that flexoelectric control force and moment can be obtained. Multiple flexoelectric actuators on the plate was considered. Case studies showed that the flexoelectricity induced stress mainly concentrate near the probe, the size and shape of the flexoelectric patch have limited effect on the actuation, hence, only the actuator positions were choosing as the input of the ANN model. Using the prediction of the neural network model, the driving effect of a large number of actuators at different positions can be quickly obtained, and the optimal position of the actuator can be analyzed more accurately. [ABSTRACT FROM AUTHOR]

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Boulders mixed with debris flows roll downstream under interactions with debris flow slurry, which poses a great threat to the people, houses, bridges, and other infrastructure encountered during their movement. The catastrophic debris flow in Zhouqu County, which occurred on 7 August 2010, was used as an example to study the motion and accumulation characteristics of boulders in debris flows. In this study, a fluid–solid coupling model utilizing the general moving objects collision model and the renormalization group turbulent model was used in the FLOW-3D software, treating boulders with different shapes in the Zhouqu debris flow as rigid bodies and the debris flow as a viscous flow. Numerical simulation results show that this method can be used to determine the motion parameters of boulders submerged in debris flows at different times, such as the centroid velocity, angular velocity, kinetic energy, and motion coordinates. The research method employed herein can provide a reference for studying debris flow movement mechanisms, impact force calculations, and aid in designing engineering control structures. [ABSTRACT FROM AUTHOR]

This paper focuses on the design of Adaptive-Neural Interval Type-2 Fuzzy Logic Controller (AN-IT2FLC) in an active tuned mass damper to reduce the response of building under seismic excitation. One of the main shortcomings of Interval Type-2 Fuzzy Logic Controller (IT2FLC) is its need to adjust in any earthquake. This is whilst the AN-IT2FLC can solve this problem using the training process. In this research, four inputs are used for designing and training of AN-IT2FLC as controlled displacement and velocity of roof level with IT2FLC, acceleration of the implemented earthquakes and the control force of IT2FLC. AN-IT2FLC training performed based on the eight earthquake records of El Centro, Hachinohe, Kobe, Northridge, Loma Prieta, Tabas, Morgan Hill and Erizkan with various seismic characteristics. In order to investigate the effectiveness of the proposed controller, an 11-story building with ATMD on its top floor analyzed under another four ground accelerations of Chi-Chi, Kern-county, Coalinga and Coyote-lake records. The results revealed that ATMD with AN-IT2FLC is able to achieve more response reduction with higher speed and accuracy rather than that of the IT2FLC. [ABSTRACT FROM AUTHOR]

• Establish a vibroacoustic analysis model of a cavity-plate system with connecting nonlinear oscillators (CNOs). • Find that the vibroacoustic responses of the plate-cavity system with CNOs can be accurately predicted by the Lagrange method. • Find that the multi-line spectrum linear and non-linear broadband control modes of CNOs. • The multi-line spectrum non-linear broadband control mode of CNOs motivates multiple frequency components and the targeted energy transfer. • The worsening reason for the vibration control effectiveness of the passive plate of the plate-cavity system with CNOs is found. Nonlinear oscillators have been found to control the vibration of engineering structures. Unfortunately, the studies related to nonlinear vibroacoustic control of the plate-cavity systems by employing nonlinear oscillators are limited, harming the engineering application of nonlinear oscillators in controlling the vibrion and noise of plate-cavity systems. To study the potential application of connecting nonlinear oscillators (CNOs) in the vibroacoustic control of the plate-cavity system, a vibroacoustic analysis model of the plate-cavity system with CNOs is established. According to this work, the vibroacoustic responses of the plate-cavity system with CNOs can be accurately gained by the Lagrange method. The working states of CNOs can be divided into the multi-line spectrum linear and non-linear broadband control modes. Under the above two control modes, the vibration and noise of the plate-cavity system can be both effectively controlled. Especially, the multi-line spectrum non-linear broadband control mode of CNOs can motivate multiple frequency components and the targeted energy transfer phenomenon of the plate-cavity system. There is no doubt that the variation of key parameters of CNOs in a sensitive region can effectively change their working states. Importantly, the introduction of CNOs establishes an additional energy transfer pathway of the plate-cavity system, where an unsuitable parameter combination of CNOs will worsen the vibration control effectiveness of the passive plate. Overall, the application of CNOs can simultaneously suppress the vibration and noise of the plate-cavity system, where a suitable working state of CNOs will strengthen the control effectiveness. [ABSTRACT FROM AUTHOR]

Damping cementitious materials have been widely used in engineering structures for vibration control. However, achieving a balance between the mechanical strength and damping capacity of cementitious materials remains a challenge. Herein, we utilized an initiator (APS) to initiate the self-crosslinking reaction of PVA molecules in C 3 S paste, then successfully introduced the viscoelastic PVA membranes into C-S-H gel to enhance its energy dissipation capacity. Results showed that the self-crosslinking PVA (scPVA) increased the loss modulus (E ′ ′) of C-S-H gel by about 158 %, increased loss tangent (tan δ) by 85 % and increased the compressive strength by 24 %. Nano-microscopic tests and molecular dynamics (MD) simulation confirmed that scPVA was introduced into C-S-H gel via the hydrogen-bonding interaction, and then formed the viscoelastic PVA membranes, which promoted C 3 S hydration, reduced the pore size of C-S-H gel and increased the mean chain length (MCL) of C-S-H gel. This study proposes a novel approach for designing high-damping cementitious materials. [Display omitted] [ABSTRACT FROM AUTHOR]

• Magnetorheological fluid concentrations affect mutual inductance between coils. • The frequency response characteristic exists in coil mutual inductance. • The coil mutual inductance exhibits a linear correlation with the concentration. • Multiplexed excitation coils for in-use dampers are practical for health monitoring. Magnetorheological (MR) fluid-based applications have accelerated new approaches for vibration and shock control in civil engineering structures and automobile suspensions. The sedimentation phenomenon happens once the MR fluid keeps static, which limits practical realizations of commercial products. Most existing methods of sedimentation evaluation are still at the laboratory stage, which is helpless in the face of the severe operating conditions of the real damper. Based on the twin-tube MR damper, a mutual inductance-based MR fluids monitoring scheme for in-use dampers was proposed in this paper, meanwhile, being compatible with the MR damper magnetic circuit. It is identified that the scheme effectively measures the concentration of MR fluid from 0% to 45 vol%, without any additional electro-sensitive components inside the cylinder. Also, online sedimentation monitoring experiments have been successfully carried out with MR fluid(10 vol% and 30 vol%) [ABSTRACT FROM AUTHOR]

The flutter response of a rectangular cylinder model with an aspect ratio of 5 is investigated by direct numerical simulation for various Reynolds numbers (Re) and flow angles of attack (α). The results show that the lower α and Re , the larger the torsional amplitude at the critical reduced flow velocity (Ur) corresponding to the occurrence of flutter. High-order Koopman mode analysis method (HOKM) was developed to synchronously capture the inherent flow and structural modes. The element-mode-based energy transfer between cylinders and flow modes was used to reveal the underlying mechanism. HOKM analysis shows that only odd-order modes contribute to the occurrence of flutter, with an augmentation in Ur enhancing this phenomenon. By analyzing the work done in odd-order modes, it is found that the primary mode always occupies the main contribution to the work done. The leading-edge endpoint portion is always where the maximum work is done. An escalation in Re and α notably influences both the spatially relevant part (W Φ) and the temporally relevant part (W c), while an increase in Ur predominantly impacts W Φ. This study offers universal guidance on the safety and protection of ocean engineering structures and flow control strategies. [Display omitted] • High-order Koopman mode analysis method (HOKM) was proposed to synchronously capture the inherent flow and structural modes. • HOKM analysis shows that only odd-order modes contribute to the occurrence of flutter. • An escalation in Re and α notably influences both the W Φ and the W c of work done. [ABSTRACT FROM AUTHOR]

[Display omitted] • This study introduces positive charge to seed surfaces for controlled growth of silica rods. • Positively charged seeds promote strong adhesion of PVP, leading to high yields of decorated particles. • Tailoring seed surface chemistry allows precise control over final particle morphology. • This method enables decoration of complex materials like magnetic core-multishell particles with silica rods. • Surface charge engineering offers a new strategy for precise control of silica rod growth on seed particles. In this study, the effect of surface modification and the resulting surface charge of colloidal silica seeds on the growth of silica rods during an emulsion droplet-based process is investigated. Through electrostatic interactions between negatively charged poly(vinylpyrrolidone) (PVP) and seed surfaces, significant PVP adsorption occurs as the seed surfaces are modified with positively charged cationic substances and then aged with PVP. This surface charge-enhanced PVP adsorption promotes the anchoring of water emulsion droplets, serving as the starting point for the growth of silica rods on the seed surfaces and leading to a high yield of silica rod-decorated particles during emulsion droplet-based growth. The surface properties, including surface charge and hydrophobicity, can be further modified by applying different cationic modifiers, which influence the morphology, structural architecture, and yield of the final product. We further demonstrated the versatility of this approach by successfully generating silica rod-decorated magnetic core (Fe 3 O 4)–multishell (silica/polystyrene/titania) particles. The findings of this study highlight the critical role of surface charge engineering in controlling the structure and morphology of silica rod-decorated silica particles as well as their integration into complex multicomponent systems. [ABSTRACT FROM AUTHOR]

Designing the core-shell structure and controlling defect engineering are desirable for improving the performance and stability of semiconductor photocatalysts. Herein, CdS nanorods covered with ultra-thin ZnIn 2 S 4 nanosheets, named as CdS@ZnIn 2 S 4 -S V (CdS@ZIS-S V), was synthesized through the strategy of constructing core-shell structure and regulating vacancies. The core-shell structure can confine Cd2+ and S2− locally around CdS instead of rapidly diffusing into the solution, thereby inhibiting photo-corrosion. The abundant S vacancies can capture photogenerated electrons and promote the separation of electron-hole pairs, thereby preventing the oxidation of S2− by the holes. In addition, Z-Scheme heterojunction structure helps the effective separation of electron-hole pairs. Notably, the hydrogen production rate of CdS@ZIS-S V reached 18.06 mmol g−1 h−1, which was 16.9 and 19.6 times than pristine CdS (1.16 mmol g−1 h−1) and ZIS (0.92 mmol g−1 h−1), respectively. Photoelectric Characterization (PEC), Scanning Kelvin Probe (SKP), UV–vis diffuse reflectance spectra (UV–Vis DRS), Finite-Difference Time-Domain (FDTD) explain the electron transfer mechanism and the reason for the enhanced photocatalytic activity. This work has guiding significance for the preparation of photo-catalysts with high activity and inhibiting photo-corrosion by adjusting S vacancies. CdS nanorods covered with ultra-thin ZnIn 2 S 4 nanosheets has been synthesized through the strategy of constructing core-shell structure and regulating vacancies to form the heterojunction of CdS@ZIS with S Vacancies. CdS@ZIS-S V has high photocatalytic activity and excellent stability. UV–Vis, SKP, FDTD simulation and PEC explored the photocatalytic mechanism. [Display omitted] • Synthesis of CdS@ZIS core-shell structures containing S vacancies by hydrothermal method. • The core-shell structure and S vacancies can inhibit the photocorrosion of CdS and ZIS, respectively. • The charge carrier transfer between CdS and ZIS follows the Z-scheme route. • CdS@ZIS-Sv exhibits excellent photocatalytic activity and cycling stability. [ABSTRACT FROM AUTHOR]

This article presents a controlled motion investigation of viscoelastic/fiber-reinforced/magnetostrictive/sandwich plates supported via visco-Pasternak foundations. The core of the plate is modeled as a Kelvin-Voigt viscoelastic model. The governing dynamic system is derived using Hamilton's principle according to simple sinusoidal shear deformation plate theory. A simple feedback control system is utilized to control the structural vibration. Navier's type solution of the system is obtained to study the influence of significant parameters, especially, the effect of the general thickness ratios, aspect ratio, the thickness ratio of the magnetostrictive layer to viscoelastic layer, sequence staking, foundations, viscoelastic structural damping coefficient, the magnitude of the feedback coefficient, and location of magnetostrictive layers on the vibrational behavior of studied sandwich plate. A comparison with previous studies is performed for validation of the corresponding numerical results and present formulation. Numerical outcomes indicate that increasing the thickness ratio of the viscoelastic layer to the magnetostrictive layer leads to improvement of the system vibration control, as well as the damping coefficient, grows and the damped natural frequency decreases with the increase of viscoelastic structural damping coefficient. The study maybe helps the designers and engineers in development of structural control systems in several applied fields. [ABSTRACT FROM AUTHOR]

In recent years, the application of structural control strategies to attenuate the dynamic response of civil engineering structures subjected to human-induced and environmental loads has once again received much attention. The hardware involved in providing effective control, the stochastic nature of the dynamic excitation, the number of distinct variables required to determine the dissipating forces, and the nature of the control approach are a few of the parameters involved in determining the efficacy of structural control systems. However, the primary parameter to determine the overall performance of a smart adaptive structure is the implementation of a control algorithm that would conveniently counteract the external known and/or unknown excitation by providing additional force input through control devices. The control algorithm to be adopted should be robust, multi-purpose, and simple to design and implement. Moreover, the control algorithm should provide the flexibility in selecting performance objectives for a holistically effective response reduction. This paper focuses on providing a comprehensive review of control algorithms implemented in structural control engineering. This article first provides an overview of the fundamental concepts pertaining to the vibration control of structures subjected to dynamic excitations. Next, an exhaustive review of different types of control algorithms that feed the input signal to active-type control devices is conducted. Thereafter, important benchmark applications in the field of structural control in civil engineering are presented. Finally, conclusions are presented on the advantages and drawbacks of each control strategy and recommendations are presented for further research in this area. [ABSTRACT FROM AUTHOR]

Passive negative stiffness dampers (NSDs) possess significant advantages and promising application prospects in the field of structural vibration control. NSDs with high energy dissipation capability are desired to satisfy the vibration mitigation requirements for large-scale engineering structures, such as high-rise buildings and long-span bridges. However, in practical applications, due to the constraints of mounting space and additional weight, the negative stiffness and damping coefficient of existing NSDs are generally not very large and with poor adjustability. To overcome these limitations, this study develops a novel magnetic negative stiffness eddy-current damper (MNSECD) with enhanced overall performance. This damper consists of a magnetic negative stiffness system (MNSS), a multi-layer-plate-type eddy-current damping system (ECDS) in parallel, and a bidirectional ball screw transmission system. Firstly, different magnetic arrays are designed to optimize the magnetic fields of the MNSECD, and to enhance its magnetic negative stiffness and eddy-current damping without adding extra dimensions and weight. Subsequently, the electromagnetic finite-element models (FEMs) of the MNSECD are established to precisely simulate its magnetic negative stiffness and eddy-current damping forces, and these models are further utilized to elucidate the enhancement mechanism of different magnetic arrays. Finally, based on the numerical simulation results, the best performing magnetic array is selected respectively for the ECDS and MNSS systems to carry out experimental studies on a small-scale prototype. Numerical and experimental results indicate that the selected magnetic array for the MNSS proves highly effective in enhancing the magnetic negative stiffness of the MNSECD, while the selected magnetic array for the ECDS also demonstrates superior effectiveness in enhancing the eddy-current damping of the damper. These findings suggest that the novel MNSECD can be readily used in the vibration control of large-scale engineering structures. [ABSTRACT FROM AUTHOR]

Developing highly efficient, durable and noble-metal-free electrocatalysts for hydrogen evolution reaction (HER) in a wide pH range is the key to achieve sustainable energy cycle. Modulating the electronic characteristics of catalysts is of great important to enhance their electrocatalytic performance. Herein, we successfully design a self-supported multi-element transition metal phosphide (V-CoP/Ni 2 P/NF) electrocatalyst by V-doping and interface engineering. According to DFT calculations, V dopants and the synergistic effect between CoP and Ni 2 P can bring optimal hydrogen/water adsorption free energies. Meanwhile, the 3D cross-linked network structure could expose abundant active sites and facilitate ions diffusion/electron transfer. As a result, the V-CoP/Ni 2 P/NF catalysts exhibit superior electrocatalytic activities with extremely low overpotentials of 20, 58 and 79 mV to deliver a current density of 10 mA cm−2 for HER in alkaline, neutral and acidic electrolytes, respectively. Moreover, they also display outstanding long-term stability. This electronic modulation strategy provides a promising pathway for energy-related catalysis processes. A self-supported V-CoP/Ni 2 P/NF was designed by electronic structure modulation control engineering for efficient hydrogen evolution reaction. [Display omitted] • A self-supported V-CoP/Ni 2 P/NF was designed by electronic structure modulation control engineering. • The 3D cross-linked network structure is beneficial to expose abundant active sites. • Electrocatalysts exhibit remarkable HER under wide pH range conditions. • V-doping and the synergistic effect between CoP and Ni 2 P bring optimalΔG H ∗/ΔG H2O ∗. [ABSTRACT FROM AUTHOR]

This review presents an up-to-date account of research in multi-hazard assessment and vibration control of engineering structures. A general discussion of the importance of multi-hazard consideration in structural engineering, as well as recent advances in this area, is presented as a background. In terms of performance assessment and vibration control, various hazards are considered with an emphasis on seismic and wind loads. Although multi-hazard problems in civil engineering structures are generally discussed to some extent, the emphasis is placed on buildings, bridges, and wind turbine towers. The scientific literature in this area is vast with rapidly growing innovations. The literature is, therefore, classified by the structure type, and then, subsequently, by the hazard. Main contributions and conclusions from the reported studies are presented in summarized tables intended to provide readers with a quick reference and convenient navigation to related publications for further research. Finally, a summary of the literature review is provided with some insights on knowledge gaps and research needs. [ABSTRACT FROM AUTHOR]

The development of efficient and highly durable materials for renewable energy conversion devices is crucial to the future of clean energy demand. Herein, cage‐like quasihexagonal structured platinum nanodendrites decorated over the transition metal chalcogenide core (CoS2)‐N‐doped graphene oxide (PtNDs@CoS2‐NrGO) through optimized shape engineering and structural control technology are fabricated. The prepared electrocatalyst of PtNDs@CoS2‐NrGO is effectively used as anodic catalyst for alcohol oxidation in direct liquid alcohol fuel cells. Notably, the prepared PtNDs@CoS2‐NrGO exhibits superior electrocatalytic performance toward alcohol oxidation with higher oxidation peak current densities of 491.31, 440.25, and 438.12 mA mgpt–1 for (methanol) C1, (ethylene glycol) C2, and (glycerol) C3 fuel electrolytes, respectively, as compared to state‐of‐the‐art Pt‐C in acidic medium. The electro‐oxidation durability of PtNDs@CoS2‐NrGO is investigated through cyclic voltammetry and chronoamperometry tests, which demonstrate excellent stability of the electrocatalyst toward various alcohols. Furthermore, the surface and adsorption energies of PtNDs and CoS2 are calculated using density functional theory along with the detailed bonding analysis. Overall, the obtained results emphasize the advances in effective precious material utilization and fabricating techniques of active electrocatalysts for direct alcohol oxidation fuel cell applications. [ABSTRACT FROM AUTHOR]

From infrastructure to national defense construction, concrete has been a key enabler in human history. While as the main binding material, ordinary Portland cement production indirectly threatens the human health due to the CO2 emissions contributing to the greenhouse effect. Alkali-activated materials show great promise to be one type of feasible alternative binder. Blast furnace slag (BFS) is one of the commonly used precursors that used to preparation alkali-activated slag (AAS) due to the higher content of glassy components. Accelerating the wide application of AAS requires the reaction behavior of BFS to be clearly understood. Such reaction behavior is strongly related to the BFS structure. Thus, it is crucial to identify and decipher how the basic structure of BFS control their engineering properties. Here, we review some of the recent efforts in this direction. In the present review, we report how the BFS structure controls the reaction kinetics and reaction products as well as the mechanical properties of AAS. We also envisage a perspective in which the BFS reaction behavior can be investigated and interpreted by combining topology constraint theory, machine learning and atomic simulation. [ABSTRACT FROM AUTHOR]

To better control engineering structures subjected to external disturbances, such as earthquakes of varying magnitudes, a smart compound damper is developed and its performance is investigated in this paper. Unlike devices for passive control systems without adjustable control force, the dynamic responses of the engineering structure can be more effectively suppressed under seismic excitation by using devices for active control systems that feature active input to the actuators. A compound damper designed in this vein consists of shape memory alloy (SMA) wires and a variable-friction damper that can provide an adjustable control force according to the level of ground motion by changing the voltage of piezoelectric ceramic (PZC) actuators. Numerical simulations of a seismically excited two-storey steel frame structure were implemented to evaluate the performance of the proposed SMA/PZC compound damper. A back-propagation neural network model was developed using experimentally obtained data to describe the hysteretic behaviour of the SMA wires. A Takagi–Sugeno (T-S) fuzzy controller was used to determine the command voltage of the PZC actuators, such that the compound damper could perform well when applied to structural control. The resulting solution, hybrid control modulated with a T-S fuzzy control strategy, was found to be more effective than passive control. [ABSTRACT FROM AUTHOR]

The optimization of piezoelectric actuator placement has been widely investigated in connection with active vibration control. In this paper, a modified optimization criterion considering the control spillover effect is proposed based on modal controllability. A coupled model of a stiffened plate and piezoelectric stack actuators (PSAs) is designed. By the combination of a genetic algorithm and pattern search algorithm, a hybrid optimization method is developed to obtain the optimal installation locations of PSAs. Furthermore, an active control system is designed by multichannel filtered-x least-mean-square (FxLMS) algorithm to suppress the vibration responses of the stiffened plate subjected to broadband random excitation. Using the optimized placements of PSAs, active vibration control experiments are performed to validate the effectiveness of the proposed optimization criterion. The experimental results show that the vibration responses of the first three modes of the system can be suppressed effectively. Furthermore, compared with the traditional optimization criterion, the use of the proposed optimization criterion can limit the undesirable effects of active control on residual modes. This study demonstrates that the proposed methodology could achieve improvement in active control performance, which can be applied to the vibration control of engineering structures under broadband random loads. [ABSTRACT FROM AUTHOR]

Summary: Recently, many kinds of tuned inerter‐based dampers (TIDs) have been developed due to the mass amplification property of inerters. These devices normally present better control performances compared with the conventional tuned mass damper (TMD). For a single TID installed on a main structure, similar to the single TMD system, its control behavior is sensitive to the changes in the parameters of the main structure, and mistuning may occur. The control effectiveness can then be significantly reduced. To solve this problem, multiple TMD (MTMD) system has been developed. Similar to the MTMD system, this paper proposes a multiple TID (MTID) system for seismic induced vibration control of engineering structures. Four types of MTIDs, depending on the connection configuration of the dashpot, spring, and inerter elements, are considered. The optimum design parameters of the MTID systems are firstly obtained with the assumption of a white‐noise excitation. The distribution of the optimum design parameters, the control performance, the stroke of each TID, and the robustness of the control system are then systematically investigated. Moreover, the control effectiveness of the optimized MTIDs is also examined under natural ground motions, and comparisons among the four types of MTIDs as well as the conventional MTMD are conducted. The analytical results show that among these control schemes, two types of MTIDs, that is, (a) the parallel connection of the spring and dashpot with the series connection of the inerter and (b) the parallel connection of the inerter and dashpot with the series connection of the spring, have pronounced control performances to suppress the displacement and absolute acceleration responses of the main structure. [ABSTRACT FROM AUTHOR]

An accurate and efficient calculation method for the transversely isotropic thermoelastic plates plays an important role in exact design and quality control of the engineering structures. In this study, the three-dimensional (3D) thermal stress field of transversely isotropic plates under arbitrary heat source is obtained using Green's function method. To achieve the purpose, the 3D Green's function solutions of transversely isotropic plate under a point heat source are firstly derived based on the general solutions which are presented in potential functions. The concise harmonic potential functions are constructed in simple functions with undetermined constants by mirror image principle. Then, the Green's functions are achieved by substituting the harmonic functions into the general solution. All temperature and stress components can be analytically expressed using simple functions which are convenient to use. The present method without simplifying assumption of dimensions has the applicability and reliability to analysis plate structures with arbitrarily thickness. Numerical calculations show the good convergence and high efficiency of the method. This study presents a high precision and efficiency predesign method for the thermos elastic plate structures. The numerical results provide theoretical guideline for the accurate design and quality control of plate structures. [ABSTRACT FROM AUTHOR]