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Geological parameters of soil exhibit spatial variability. Inverse analysis allows the acquisition of accurate spatial distributions of key geological parameters, which is crucial for structural safety assessment. In this study, an ensemble Kalman filter (EnKF) is employed in the context of data assimilation. Random fields are used as the initial input ensembles for the algorithm. The present study effectively integrates the ensemble Kalman filter with the numerical simulation software ABAQUS, enabling the inversion of parameter fields under various operating conditions. An in-house Python code script is developed to control ABAQUS for finite element computations and to obtain observations at target points. During the stepwise computation process, the algorithm can utilize newly acquired observations to accelerate the convergence of the parameter field to the true field. The effectiveness of the algorithm is validated, and the method is applied to a case study of double-tunnel excavation and a stepwise excavation analysis of a three-layered slope. The impact of the number of ensemble members and the ratio of the horizontal correlation scale to the vertical correlation scale of random fields on the effectiveness of updating the parameter field have also been investigated. [ABSTRACT FROM AUTHOR]

Liquid hydrogen storage is an important way of hydrogen storage and transportation, which greatly improves the storage and transportation efficiency due to the high energy density but at the same time brings new safety hazards. In this study, the liquid hydrogen leakage in the storage area of a hydrogen production station is numerically simulated. The effects of ambient wind direction, wind speed, leakage mass flow rate, and the mass fraction of gas phase at the leakage port on the diffusion behavior of the liquid hydrogen leakage were investigated. The results show that the ambient wind direction directly determines the direction of liquid hydrogen leakage diffusion. The wind speed significantly affects the diffusion distance. When the wind speed is 6 m/s, the diffusion distance of the flammable hydrogen cloud reaches 40.08 m, which is 2.63 times that under windless conditions. The liquid hydrogen leakage mass flow rate and the mass fraction of the gas phase have a greater effect on the volume of the flammable hydrogen cloud. As the leakage mass flow rate increased from 5.15 kg/s to 10 kg/s, the flammable hydrogen cloud volume increased from 5734.31 m3 to 10,305.5 m3. The installation of a barrier wall in front of the leakage port can limit the horizontal diffusion of the flammable hydrogen cloud, elevate the diffusion height, and effectively reduce the volume of the flammable hydrogen cloud. This study can provide theoretical support for the construction and operation of hydrogen production stations. [ABSTRACT FROM AUTHOR]

With the rapid development of hydrogen energy worldwide, the number of hydrogen energy facilities, such as hydrogen refueling stations, has grown rapidly in recent years. However, hydrogen is prone to leakage accidents during use, which could lead to hazards such as fires and explosions. Therefore, research on the safety of hydrogen energy facilities is crucial. In this paper, a study of high-pressure hydrogen jet flame accidents is conducted for a proposed integrated hydrogen production and refueling station in China. The effects of leakage direction and leakage port diameter on the jet flame characteristics are analyzed, and a risk assessment of the flame accident is conducted. The results showed that the death range perpendicular to the flame direction increased from 2.23 m to 5.5 m when the diameter of the leakage port increased from 4 mm to 10 mm. When the diameter of the leakage port is larger than 8 mm, the equipment on the scene will be within the boundaries of the damage. The consequences of fire can be effectively mitigated by a reasonable firewall setup to ensure the overall safety of the integrated station. [ABSTRACT FROM AUTHOR]

Chalcogenide cathodes with multi‐electron transfer characteristics are indispensable to aluminum‐ion batteries (AIBs). Nevertheless, their grievous capacity degradation and sluggish reaction kinetics remain fundamental challenges for the practical application. Herein, a Cu2S/Ni3S2 multiphase structure within the metal‐organic frame (MOF) derived carbon decoration layer (CNS@MC) is constructed to elevate the intrinsic electronic properties of chalcogenide cathode and realize high‐performance AIBs. The existence of outer carbon layer and strong orbital interaction at inner heterointerfaces eliminates the bandgap and arises more electrons at Fermi level, efficiently reducing the energy barrier for electron transfer and achieving high reactivity within cathodes. The CNS@MC also presents a strong electronic interaction with active solvent groups, which is beneficial to capture Al3+ and facilitate the three‐electron charge‐storage reactions. Experimental results demonstrate that the tailored CNS@MC cathode possesses superior redox kinetics due to the sufficient surface area and rapid Al‐ion diffusion during cycling. Meanwhile, the robust CNS@MC delivers ultra‐high electrochemical stability (131.1 mAh g−1 over 3500 cycles) with high coulombic efficiency and outstanding rate performance. This work offers new opportunities for optimizing the intrinsic properties of the chalcogenide electrodes based on MOF derivatives and heterostructure, providing novel thoughts for designing high‐performance AIBs. [ABSTRACT FROM AUTHOR]

With the increasing consumer focus on automotive safety, Autonomous Emergency Braking (AEB) systems, recognized as effective active safety technologies for collision avoidance and the mitigation of collision-related injuries, are gaining wider application in the automotive industry. To address the issues of the insufficient working reliability of AEB systems and their unsatisfactory level of accordance with the psychological expectations of drivers, this study proposes an optimized second-order Time to Collision (TTC) safety time algorithm based on the motion state of the preceding vehicle. Additionally, the study introduces a safety distance algorithm derived from an analysis of the braking process of the main vehicle. The safety time algorithm focusing on comfort and the safety distance algorithm focusing on safety are effectively integrated in the time domain and the space domain to obtain the safety time–safety distance fusion algorithm. A MATLAB/Simulink–Carsim joint simulation platform has been established to validate the AEB control strategy in terms of safety, comfort, and system responsiveness. The simulation results show that the proposed safety time–safety distance fusion algorithm consistently achieves complete collision avoidance, indicating a higher safety level for the AEB system. Furthermore, the application of active hierarchical braking minimizes the distance error, at under 0.37 m, which meets psychological expectations of drivers and improves the comfort of the AEB system. [ABSTRACT FROM AUTHOR]

Considering the requirements pertaining to the trafficability of off-road vehicles on rough roads, and since their roll stability deteriorates rapidly when turning violently or passing slant roads due to a high center of gravity (CG), an efficient anti-slip control (ASC) method with superior instantaneity and robustness, in conjunction with a rollover prevention algorithm, was proposed in this study. A nonlinear 14 DOF vehicle model was initially constructed in order to explain the dynamic coupling mechanism among the lateral motion, yaw motion and roll motion of vehicles. To acquire physical state changes and friction forces of the tires in real time, corrected LuGre tire models were utilized with the aid of resolvers and inertial sensors, and an adaptive sliding mode controller (ASMC) was designed to suppress each wheel's slip ratio. In addition, a model predictive controller (MPC) was established to forecast rollover risk and roll moment in reaction to the change in the lateral forces as well as the different ground heights of the opposite wheels. During experimentation, the mutations of tire adhesion capacity were quickly discerned and the wheel-hub drive motors (WHDM) and ASC maintained the drive efficiency under different adhesion conditions. Finally, a hardware-in-the-loop (HIL) platform made up of the vehicle dynamic model in the dSPACE software, semi-active suspension (SAS), a vehicle control unit (VCU) and driver simulator was constructed, where the prediction and moving optimization of MPC was found to enhance roll stability effectively by reducing the length of roll arm when necessary. [ABSTRACT FROM AUTHOR]

Aqueous static zinc–iodine batteries attract tremendous attention because of their abundant reserves of iodine, nonflammable electrolyte, and facile assembly. Currently, scientific challenges for static zinc–iodine batteries include self‐discharge and sluggish kinetics. Herein, a lithiation approach for the iodine host to suppress the shuttle effect and catalyze iodine conversion is reported. Through regulating the d‐ and p‐band center and lowering the I−/I0 conversion barrier, Li+ intercalation into VS2 reinforces interaction with I3− and achieves catalytic conversion of iodine, ameliorating self‐discharge, and accelerating kinetics. Zinc–iodine batteries featuring LiVS2 as the iodine host reach a high iodine utilization, high Coulombic efficiencies, and a long cyclic lifespan. Notably, the performance enhancement mechanism is the thermodynamically favorable iodine conversion reaction, inhibition of the I3− appearance, and promotion of I3− consumption due to the Li+ insertion. The findings provide fundamental insights into tackling issues of static zinc–iodine batteries. [ABSTRACT FROM AUTHOR]

The development of safe, cheap, and environmentally friendly advanced rechargeable batteries with high energy density are one of the most pressing tasks for today's energy crisis. With the advantages of low cost, abundant reserves, and high‐level safety, rechargeable aluminum ion batteries are considered ideal candidates for next‐generation energy storage batteries in the context of large‐scale energy applications. Relevant knowledge of energy storage materials and electrolytes, which possess close connection in between, is undeniably crucial for such research, while ironically, most attention is attracted to merely one element alone, especially the energy storage materials involving micro/nanomaterials. In this review, we focus on cathode materials matching with various electrolyte systems for rechargeable aluminum batteries and manage to provide new ideas for the preparation methods of high‐efficiency electrochemical energy storage materials, with future outlooks in this field. [ABSTRACT FROM AUTHOR]

The Ti3C2Tx MXene with surface functional groups complexing Mn4+ (Mn–Ti3C2Tx) was prepared for the cathode of aqueous zinc batteries. The electrode reaction is confirmed as the Zn2+/H+ co-insertion compensated by the Mn4+/Mn2+ redox. The Mn4+-loading modification boosts the Zn2+ storage due to the enhanced Zn2+ adsorption possibility. [ABSTRACT FROM AUTHOR]

The effects of laser welding parameters on the interface microstructure of AZ31B magnesium alloy and 304 stainless steel were investigated. After welding, a scanning electron microscope and ultra-depth of field microscope were used to observe the microstructure of the welded material, to analyze the effects of power on the interface morphology. The simulation of laser welding of magnesium and steel was carried out by the COMSOL software. The results showed that when the power was 15 W–20 W, the temperature did not reach the melting point of magnesium alloy, there was MgO at the welding, and the interface had poor connection strength. When the power was 35 W–50 W, the temperature reached or even exceeded the boiling point of magnesium alloy, and the interface formed hot cracks, pores, and oxides and had poor joint strength. When the power was 25 W–30 W, the temperature was between the melting point and boiling point of magnesium, and the interface had excellent connection strength. [ABSTRACT FROM AUTHOR]

Rechargeable aqueous zinc batteries (RAZBs) with high safety and low cost offer great hopes for complementing lithium-ion batteries. However, realizing practical high-safety and long-lifespan RAZBs is held back by the low coulombic efficiency and non-negligible dendrite issues in Zn anodes. Here, we report a layered TiTe2 prepared by a one-step vacuum sintering technique as the metal-free anode for RAZBs, bypassing the above challenges of Zn metal. The density functional theory (DFT) calculations with ab initio molecular dynamics (AIMD) simulations predict the Zn-storage mechanism, thermodynamic stability, and ionic mobility properties of TiTe2. The TiTe2 electrode in the half cell shows a low charging voltage (∼0.7 V vs. Zn2+/Zn), a high reversible capacity of 225 mA h g−1 at 0.1 A g−1, and stable cycling properties with a 95% capacity retention over an exceptionally long life of 30 000 cycles at 5 A g−1. As demonstrated by in situ diffraction and ex situ spectra, the sustained high reversible capacity relies on the conversion chemistry involving the ZnTe formation/dissociation process with the charge compensation by two-electron redox of Ti2+/Ti4+. In regard to practical implementation, the TiTe2‖ZnxCo3O4 pouch-type full battery displays a competitive energy density of 149 W h kg−1 on the electrode level, exceeding state-of-the-art metal-free RAZBs. A high capacity retention of 94% is achieved in the pouch cells over 5000 cycles, verifying the bright application prospects of the TiTe2 anode. [ABSTRACT FROM AUTHOR]

The kinetics of the ring-opening polymerization of ε-caprolactone with butane-1,4-diol as the initiator and 1,5,7-triazabicyclo[4.4.0]dec-5-ene as catalyst were examined. A highly efficient and controllable polymerization of ε-caprolactone occurred with an activation energy of 22.5 kJ·mol–1 , which is much lower than that observed with butan-1-ol as the initiator (39.5 kJ·mol–1). An intramolecular hydrogen-bonding-assisted mechanism is proposed to explain this lowering of the activation energy. [ABSTRACT FROM AUTHOR]

Lithium-ion batteries have received considerable attention as energy storage tool for modern-life equipments. However, drawbacks like low electric conductivity and volume expansion are the obstacles that hinder its application. To solve these problems, we developed a facile method using waste eggshell as hard template to reduce its particle size and change its morphology by simple hydrothermal process. Then, by utilizing waste paper, conductive paper (CP) current collector with graphene and multiwalled carbon nanotube implanted was prepared and combined with MnO2 anode material. The composite anode shows extraordinary electrochemical performances like much smaller impedance, high reversible capacity of 1767/1762 mAh/g even after 200 cycles at 100 mA/g, superior rate performance, etc. Compared with anode using metal current collectors, this composite anode will reduce weight and can be generalized to other high energy storage applications. Our environment-friendly method has far-reaching referential significance to other active materials and battery systems. A composite electrode, with δ -MnO2 as active material and conductive paper as current collector, has been synthesized and used in lithium-ion battery. Waste eggshell and waste paper were used in the synthetic process to protect environment. The electrode is much lighter and has much better electrochemical performances. This method can be generalized to other active materials and battery systems. [ABSTRACT FROM AUTHOR]

TiO2 nanocrystal (NC)-based photoreversible color switching (PCS) materials, which are capable of actively responding to external light, have significant potential for use in printable rewritable paper in the creation of sustainable technologies. Reductive TiO2 NCs with high hole-scavenging capabilities can be obtained by surface disorder or lattice distortion, but achieving an optimum balance between them is still a great challenge to enable simultaneous retention of the photoreduction performance and visible light catalytic ability of the TiO2 NCs. Here, we demonstrated solvent-controlled synthesis of interstitial Sn2+-doped TiO2 NCs and investigated the effects of solvent-induced surface disorder and doping-induced lattice distortion on the PCS properties of the TiO2 NCs. The midgap state produced by surface disorder combines with the energy level produced by the interstitial Sn2+ dopants in TiO2 NCs to become the main center for photogenerated electron transfer. Thus, efficient PCS was achieved, with the number of switching cycles greatly increased. The ethylene glycol-synthesized TiO2 NCs with a Sn2+-doping concentration of ca. 3% are the most favorable catalyst for achieving PCS performance. The process of PCS can be repeated 48 times without any rest. The results of this work suggest an approach to the design and preparation of PCS materials that exhibit excellent scalability and outstanding reversible performance by using colloidal NCs with optimized surface composition, lattice structure, and particle size as key-functional photocatalysts. [ABSTRACT FROM AUTHOR]

Effectively increasing the length of N‐heteroacenes is highly desirable because such materials could have great potential applications in organic optoelectronics. In this review we summarize the recent progress in the construction of larger N‐heteroacenes based on the use of phenazinediamine and its analogues as building blocks to react with different kinds of ortho‐diketones (or tetraketones) or ortho‐dihalides through condensation or coupling reactions. In addition, the potential applications of the corresponding N‐heteroacenes are also presented. [ABSTRACT FROM AUTHOR]

Abstract: Three novel heterocyclic compounds containing one (M1) or two (isomers M2 and M3) benzimidazole units have been synthesized and fully characterized. The isomers M2 and M3 could be easily separated by column chromatography. Studies showed that the decrease of intermolecular π‐π stackings could enhance the fluorescence intensity of target compounds obviously. The single‐site compound M1 shows the lowest fluorescent quantum yield (ΦM1=0.013) in CH2Cl2 than that of the double‐site isomers M2 (anti‐type, ΦM2=0.148) and M3 (syn‐type, ΦM3=0.053). Electroluminescent performances of M2 and M3 in organic light‐emitting diodes were studied. As expected, M2 exhibits more than 2 times higher current efficiency than M3 with M2 showing a maximum current efficiency of 7.8 cd/A as compare to 3.6 cd/A for M3. [ABSTRACT FROM AUTHOR]

Uniform magnetite mesocrystals were fabricated by solvothermal treatment of ferrous chloride in ethylene glycol in the presence of sodium hydroxide. The formation mechanism of magnetite mesocrystals in ethylene glycol was deduced by a time-dependent experiment. [ABSTRACT FROM AUTHOR]