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This manuscript provides insights into the characteristics of shock wave propagation and flame development mechanisms in bifurcated tubes due to accidental leakage from a high-pressure hydrogen storage unit in the energy and chemical industries. Incorporating the non-stop working process of tube plugging in gas transportation in industrial production, two types of bifurcated tubes with axial and normal blocking are designed. The experimental results indicate that, compared to straight tube, both types of blocking tube structures can effectively reduce shock wave pressure intensity at the nozzle. Under the initial burst pressure of 8 MPa, the lowest shock wave pressure at the nozzle of the axially blocking tube is just 0.47 MPa. However, the peak shock wave pressure inside the blocking tubes is higher, and the ignition critical pressure is lower. Within the axially sealed blocking tube, flame quenching is observed, offering experimental support for mitigating the development of continuous jet fires outside of high-pressure hydrogen tubes.

Due to the over-actuated characteristics, the distributed vehicle has more potential for mobility and controllability than the traditional vehicle, making it more suitable for autonomous driving. Motion control of distributed vehicles still faces significant challenges of adjusting longitudinal speed while tracking the reference trajectory and ensuring stability under complex and changeable driving maneuvers. This paper proposes a hierarchical coupling motion control method for the distributed vehicle considering vehicle posture at the handling limit. In the motion-following layer, a coupling motion controller is presented based on variable-time steps discrete linear time-varying model predictive control (VTDLTV-MPC). To improve the predictive model accuracy, the linearization reference point is updated with the predicted state and control sequence of the last moment. While performing coupling motion control, the vehicle posture is coordinated in the heading deviation to enable the reference sideslip angle tracking. By coordinated control of motion and posture, the distributed vehicle can be handled outside the stability region of the traditional vehicle. In the executive layer, a tire parameter online adaptive module (TPOAM) is proposed to update tire parameters online, which does not rely on complex and multi-parameter tire models or look-up tables. Finally, the proposed controller is verified on the hardware-in-the-loop (HIL) platform. The results show that the proposed controller can adaptively adjust the longitudinal speed and control the distributed vehicle at the friction circle boundary to fully utilize the chassis performance, while tracking the reference posture to realize the decoupling of yaw and lateral motions.

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This letter studies transmission optimization for cell-free multi-input multi-ouput (MIMO) systems over spatially-correlated Ricean fading channels, where the transmitter only has the statistical channel state information (CSI), i.e. mean and covariance matrices. The transmission covariance matrix is optimized to maximize the ergodic system capacity subject to per access point (AP) power constraints. We first present the Taylor expansion for a scalar function with Hermitian matrix variables, where the Hessian matrix of such function is derived. With it, a majorization-minimization (MM) based algorithm is then proposed to solve the problem, where a sequence of convex subproblems are created. For each subproblem, a surrogate objective function simpler than the original one is constructed so that at each iteration the closed-form solution can be derived. The proposed algorithm is able to converge to the global optimum, whose performance is also illustrated by simulation results.

Advances in artificial intelligence (AI) technology are propelling the rapid development of automotive intelligent cockpits. The active perception of driver emotions significantly impacts road traffic safety. Consequently, the development of driver emotion recognition technology is crucial for ensuring driving safety in the advanced driver assistance system (ADAS) of the automotive intelligent cockpit. The ongoing advancements in AI technology offer a compelling avenue for implementing proactive affective interaction technology. This study introduced the multimodal driver emotion recognition network (MDERNet), a dual-branch deep learning network that temporally fused driver facial expression features and driving behavior features for non-contact driver emotion recognition. The proposed model was validated on publicly available datasets such as CK+, RAVDESS, DEAP, and PPB-Emo, recognizing discrete and dimensional emotions. The results indicated that the proposed model demonstrated advanced recognition performance, and ablation experiments confirmed the significance of various model components. The proposed method serves as a fundamental reference for multimodal feature fusion in driver emotion recognition and contributes to the advancement of ADAS within automotive intelligent cockpits.

Most of the collision avoidance strategies in recent years only consider steering or braking. The dynamic and complex nature of the driving environment presents a challenge to developing robust collision avoidance algorithms in emergency scenarios. To address the complex, dynamic obstacle scene and improve lateral manoeuvrability, this paper establishes a multi-level decision-making obstacle avoidance framework that employs the safe distance model and integrates emergency steering and emergency braking to complete the obstacle avoidance process. This approach helps avoid the high-risk situation of vehicle instability that can result from the separation of steering and braking actions. In the emergency steering algorithm, we define the collision hazard moment and propose a multi-constraint dynamic collision avoidance planning method that considers the driving area. Simulation results demonstrate that the decision-making collision avoidance logic can be applied to dynamic collision avoidance scenarios in complex traffic situations and improving the safety of autonomous driving.

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Research on game-based human-machine shared driving (HMSD) has traditionally been constrained by stringent game theory assumptions, high requirements for automated steering controllers, and the need to acquire the human driver’s target trajectory. To address these issues, this paper proposes a bargaining game-based HMSD control authority allocation strategy for a steer-by-wire vehicle. First, two types of lateral path tracking controllers are developed to simulate the human driver and the automatic steering system. Then, a bargaining game-based HMSD control authority allocation strategy is created using the Nash bargaining solution. Finally, a Simulink/CARSIM co-simulation platform and a driver-in-the-loop experimental bench are utilized to verify the proposed strategy. The results show that the proposed bargaining game-based HMSD control authority allocation strategy has potential advantages over existing game-based HMSD, including decoupling of human-machine interaction, lower requirements for automated steering controllers, and feasible game modeling ability. Moreover, the proposed strategy demonstrates excellent performance in terms of shared driving, which extends the applicability of HMSD in various operating maneuvers. Both the human driver and the automatic steering system benefit from the proposed HMSD system, which could increase the acceptance and trustworthiness of the human driver with the HMSD system and reduce the human driving load to make the driver-vehicle interaction more reliable and smoother.

While tiger nut (Cyperus esculentusL.) is regarded as a new oil resource, its tubers are also rich in polysaccharides and oligosaccharides. In this study, a sequential process was first developed to isolate various carbohydrate components from the tiger nut meal. Starch polysaccharide (SP) was the most extract (yield, 27.77%), with good gelatinization stability and digestion resistance. The second was oligosaccharide (OS, 15.28%), which contained 83.47% free sucrose. Four heteropolysaccharides (0.21–1.27%), namely water-soluble polysaccharide (WSP), alkali-soluble polysaccharides extracted by Na2CO3, 1 mol/L NaOH, and 4 mol/L NaOH (ASP-N, ASP-1, and ASP-4, respectively), from cell wall and composed mainly of α-d-Glcp, β-d-Glcp, β-d-Galp, α-d-Xylp, and α-l-Araf. Cellulose polysaccharide (CP) was the final product (5.47%). Their molecular weight distribution and thermal behavior were further characterized. The results demonstrate the usefulness of the sequential extraction process and provide the preliminary structure about tiger nut carbohydrates. This study contributes valuable information to promote the comprehensive utilization of tiger nuts.

Objective: Cisplatin (CDDP)-based chemotherapy is a first-line, drug regimen for muscle-invasive bladder cancer (BC) and metastatic bladder cancer. Clinically, resistance to CDDP restricts the clinical benefit of some bladder cancer patients. AT-rich interaction domain 1A (ARID1A) gene mutation occurs frequently in bladder cancer; however, the role of CDDP sensitivity in BC has not been studied. Methods: We established ARID1A knockout BC cell lines using CRISPR/Cas9 technology. IC50determination, flow cytometry analysis of apoptosis, and tumor xenograft assays were performed to verify changes in the CDDP sensitivity of BC cells losing ARID1A. qRT-PCR, Western blotting, RNA interference, bioinformatic analysis, and ChIP-qPCR analysis were performed to further explore the potential mechanism of ARID1A inactivation in CDDP sensitivity in BC. Results: It was found that ARID1A inactivation was associated with CDDP resistance in BC cells. Mechanically, loss of ARID1A promoted the expression of eukaryotic translation initiation factor 4A3 (EIF4A3) through epigenetic regulation. Increased expression of EIF4A3 promoted the expression of hsa_circ_0008399 (circ0008399), a novel circular RNA (circRNA) identified in our previous study, which, to some extent, showed that ARID1A deletion caused CDDP resistance through the inhibitory effect of circ0008399 on the apoptosis of BC cells. Importantly, EIF4A3-IN-2 specifically inhibited the activity of EIF4A3 to reduce circ0008399 production and restored the sensitivity of ARID1A inactivated BC cells to CDDP. Conclusion: Our research deepens the understanding of the mechanisms of CDDP resistance in BC and elucidates a potential strategy to improve the efficacy of CDDP in BC patients with ARID1A deletion through combination therapy targeting EIF4A3.

Lightning strikes are one of the major causes leading to faults in the traction power supply systems. Quick identification of the lightning shielding and backflashover failures is a complex task. In this paper a lightning strike identification model based on morphological fractal theory is constructed. A simulation model of lightning-struck tractive network faults is developed aiming at investigating the influence of the structure of the all-parallel AT tractive network on the waveform characteristics. The differences in the waveform characteristics under lightning shielding and backflashover failures are studied. Further, the fault analysis of lightning strike signals is carried out based on mathematical morphology. The influence of different structural elements and basic operations on the effect of morphological transformation is obtained. The classification effects of single- and multi-scale fractal dimensions of voltage and current waveforms are compared based on fractal theory. Moreover, a neural network framework is employed using the fractal dimensions of samples at different scales as feature vectors and the fault state as the output for establishing a lightning-strike identification model. The result shows that this method can effectively identify lightning strike faults in all-parallel AT traction power supply system with an accuracy of more than 95%.

PIWI-clade proteins harness piRNAs of 24–33 nt in length. Of great puzzles are how PIWI-clade proteins incorporate piRNAs of different sizes and whether the size matters to PIWI/piRNA function. Here we report that a PIWI-Ins module unique in PIWI-clade proteins helps define the length of piRNAs. Deletion of PIWI-Ins in Miwishifts MIWI to load with shorter piRNAs and causes spermiogenic failure in mice, demonstrating the functional importance of this regulatory module. Mechanistically, we show that longer piRNAs provide additional complementarity to target mRNAs, thereby enhancing the assembly of the MIWI/eIF3f/HuR super-complex for translational activation. Importantly, we identify a c.1108C>T (p.R370W) mutation of HIWI(human PIWIL1) in infertile men and demonstrate in Miwiknock-in mice that this genetic mutation impairs male fertility by altering the property of PIWI-Ins in selecting longer piRNAs. These findings reveal a critical role of PIWI-Ins-ensured longer piRNAs in fine-tuning MIWI/piRNA targeting capacity, proven essential for spermatid development and male fertility.

Taking full advantage of tire saturation in high sideslip drifting maneuvers can substantially improve the handling limits of autonomous vehicles. However, most singular motion control methods in conventional drifting controllers have been conducted, which cannot meet general driving needs. In this article, a hierarchical dynamic drifting controller (HDDC) is designed under both drifting maneuvers and typical cornering maneuvers to uniformly track the general path within and beyond stability limits. Specifically, the HDDC includes the path tracking layer, vehicle motion control layer, and actuator regulating layer. The first layer is designed to achieve accurate path tracking and generate the desired states, and it is algorithmically adaptable and confirmed by MPC and LQR. The second layer is proposed to integrate drifting and typical cornering control by the dynamic drifting inverse model. The third layer can achieve the steering system and wheel speed control to satisfy corresponding commands. Ultimately, the real-time performance of the controller is verified by the ECU hardware-in-the-loop platform. The results with MPC-HDDC and LQR-HDDC show that the HDDC can achieve integrated control of drifting and typical cornering maneuvers and possess high tracking accuracy.

AbstractWith the modernization of urban development, land resources are becoming increasingly scarce. A new type of building model comprising an underground depot and a superstructure has been constructed. To study the hybrid ventilation (HV) in interlayer of the underground depot with a superstructure under monorail line section fire, full-scale numerical simulation and reduced-scale (1:50) experiment were performed. Five ventilation velocities were used under a certain heat release rate. The temperature distribution and stratification in the interlayer were examined, and the movement of the fire smoke was analyzed. The smoke layer was visualized using a laser sheet and the smoke layer thickness determined by N-percentage rule (N = 10, 20, 30) was compared with the results of visual observation. At the same time, CFD simulations were conducted to measure the height of smoke layer and the smoke front propagation. Besides, the distribution of carbon monoxide (CO) in the interlayer was also simulated. The results show that Nvalue of 30 could properly determine the smoke layer thickness in relatively stable stage of combustion. HV had a better effect on smoke control than natural ventilation (NV) did. At a ventilation velocity of 1.4 m/s, the smoke layer in the interlayer remained in a steady state until its exclusion from the building. CO could be effectively controlled and did not spread all over the interlayer in HV systems. The structure of HV system can be adjusted according to the actual conditions of the various sizes and types of buildings. Thus, the HV system shows good adaptability and can be directly applied to the design and installation of new buildings such as underground garages and depots. The results of the fire dynamic simulations and experimental tests exhibited considerable agreement.

Subcritical water-ethanol extraction (SWE) was performed to extract proanthocyanidins (PAs) from Chinese quince fruits. The extraction parameters (temperature, time, liquid-solid ratio) were optimized using response surface methodology (RSM), based on single-factor experiments. The optimal SWE conditions were: temperature, 135 °C; time, 31 min; liquid-solid ratio, 32 mL/g. The maximum PAs obtained were 22.36 ± 0.35 mg PB2/g DW, which matched predicted values. In the analysis of PAs, 7 compounds were identified: catechin, epicatechin, epicatechin gallate, epigallocatechin-3-gallate, and proanthocyanidins dimers, trimers and tetramers. Structurally, these PAs contained substantial procyanidin (PC) but little prodelphinidin (PD). The findings revealed that SWE yielded more total PA than the conventional method extraction (CME). Furthermore, compared with CME PAs, PAs obtained by SWE showed higher radical scavenging capacities (IC50: 139.32 µg/mL for DPPH; IC50: 113.11 µg/mL for ABTS) and stronger α-amylase inhibition (IC50: 88.29 µg/mL). These results indicate that SWE is an efficient method for the separation of PAs from Chinese quince. Chinese quince PAs represent a potentially valuable resource for use in functional foods and nutraceuticals.

We experimentally demonstrate an electrically tunable superconducting device capable of switching the extraordinary terahertz (THz) transmission. The planar device consists of subwavelength hole arrays with real-time control capability. The maximum transmission coefficient at 0.33 THz is 0.98 and decreases to 0.17 when the applied voltage only increases to 1.3 V. A relative intensity modulation of 82.7% is observed, making this device an efficient THz switch. Additionally, this device exhibits good narrow-bandpass characteristics within 2 THz, which can be used as a frequency-selective component. This study offers an ideal tuning method and delivers a promising approach for designing active and miniaturized devices in THz cryogenic systems.

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Full drive-by-wire electric vehicles (FDWEV) equipped with X-by-wire technology can enable independent driving, braking, and steering of each wheel, making them an ideal platform for developing autonomous driving technology. However, designing a robust control algorithm that comprehensively integrates vehicle path planning in a complex and unstructured scenario is a challenging task for FDWEV. To address this issue, this paper (1) proposes the artificial potential field (APF) method for path planning in the prescribed park with different static obstacles to generate the reference path information, where speed planning is incorporated considering kinematics and dynamic constraints; (2) designs curvature calculation (CC-based) and model predictive control (MPC-based) tracking methods with the lateral dynamics model to track the desired path under different driving conditions, in which a forward-looking behavior model of the driver with variable preview distance is designed based on the fuzzy control theory; (3) conducts CarSim-AMESim-Simulink co-simulation with the existence of obstacles. The simulation results show that the proposed two control approaches are practical for classical driving scenarios. Especially the MPC-based path-tracking controller enhances dynamic tracking performance and ensures good maneuverability under high-dynamic driving conditions.

The high-energy photon source (HEPS) is the first fourth-generation synchrotron light source facility in China. The HEPS injector consists of a linear accelerator (Linac) and a full energy booster. The booster captures the electron beam from the Linac and increases its energy to the value required for the storage ring. The full-energy beam could be injected to the storage ring directly or after “high-energy accumulation.” On November 17, 2023, the key booster parameters successfully reached their corresponding target values. These milestone results were achieved based on numerous contributions, including nearly a decade of physical design, years of equipment development and installation, and months of beam commissioning. As measured at the extraction energy of 6 GeV, the averaged beam current and emittance reached 8.57 mA with 5 bunches and 30.37 nm rad with a single-bunch charge of 5.58 nC, compared with the corresponding target values of 6.6 mA and 35 nm rad, respectively. This paper presents the physical design, equipment development, installation, and commissioning process of the HEPS booster.

Fine tuning of the metal site coordination environment of a single-atom catalyst (SAC) to boost its catalytic activity for oxygen reduction reaction (ORR) is of significance but challenging. Herein, we report a new SAC bearing Fe–N3C–N sites with asymmetric in-plane coordinated Fe–N3C and axial coordinated N atom for ORR, which was obtained by pyrolysis of an iron isoporphyrin on polyvinylimidazole (PVI) coated carbon black. The C@PVI-(NCTPP)Fe-800 catalyst exhibited significantly improved ORR activity (E1/2= 0.89 V vs RHE) than the counterpart SAC with Fe–N4-N sites in 0.1 M KOH. Significantly, the Zn-air batteries equipped with the C@PVI-(NCTPP)Fe-800 catalyst demonstrated an open-circuit voltage (OCV) of 1.45 V and a peak power density (Pmax) of 130 mW/cm2, outperforming the commercial Pt/C catalyst (OCV = 1.42 V; Pmax= 119 mW/cm2). The density functional theory (DFT) calculations revealed that the d-band center of the asymmetric Fe–N3C–N structure shifted upward, which enhances its electron-donating ability, favors O2adsorption, and supports O–O bond activation, thus leading to significantly promoted catalytic activity. This research presents an intriguing strategy for the designing of the active site architecture in metal SACs with a structure–function controlled approach, significantly enhancing their catalytic efficiency for the ORR and offering promising prospects in energy-conversion technologies.

Maintaining both path-tracking accuracy and yaw stability of distributed drive electric vehicles (DDEVs) under various driving conditions presents a significant challenge in the field of vehicle control. To address this limitation, a coordinated control strategy that integrates adaptive model predictive control (AMPC) path-tracking control and direct yaw moment control (DYC) is proposed for DDEVs. The proposed strategy, inspired by a hierarchical framework, is coordinated by the upper layer of path-tracking control and the lower layer of direct yaw moment control. Based on the linear time-varying model predictive control (LTV MPC) algorithm, the effects of prediction horizon and weight coefficients on the path-tracking accuracy and yaw stability of the vehicle are compared and analyzed first. According to the aforementioned analysis, an AMPC path-tracking controller with variable prediction horizon and weight coefficients is designed considering the change of vehicle speed in the upper layer. The lower layer involves DYC based on the linear quadratic regulator (LQR) technique. Specifically, the intervention rule of DYC is determined by the threshold of the yaw rate error and the phase diagram of the sideslip angle. Extensive simulation experiments are conducted to evaluate the proposed coordinated control strategy under different driving conditions. The results show that, under variable speed and low adhesion conditions, the vehicle yaw stability and path-tracking accuracy have been improved by 21.58% and 14.43%, respectively, compared to AMPC. Similarly, under high speed and low adhesion conditions, the vehicle yaw stability and path-tracking accuracy have been improved by 44.30% and 14.25%, respectively, compared to the coordination of LTV MPC and DYC. The results indicate that the proposed adaptive path-tracking controller is effective across different speeds. Furthermore, the proposed coordinated control strategy successfully enhances the vehicle stability while maintaining good path-tracking accuracy even under extreme conditions.

The metal-to-core charge transfer (MCCT) transition in sensitized titanium-oxo clusters is an important process for photoinduced electron injection in photovoltaic conversion. This process resembles most closely the Type II photoinjection in dye-sensitized solar cells. Herein we report the synthesis and photophysical and photoelectrochemical (PEC) properties of the phosphonate-stabilized titanium-oxo clusters containing the ferrocenecarboxylate ligands. These ferrocene-containing clusters exhibit intense visible absorption extended up to 600 nm along with low optical band gaps of ∼2.2 eV. The low-energy transitions of these clusters were systematically investigated by UV–vis spectroscopy and DFT/TDDFT calculations. The combined experimental and computational studies suggest that the ferrocenecarboxylate-substituted titanium-oxo clusters form a donor–acceptor (D–A) system. The low-energy transition of these clusters primarily involves the MCCT from the iron center to TiO cluster core. The TiO core structure and phosphonate ligands both have great influence on the PEC properties of the clusters. This work provides valuable examples for the sensitized titanium-oxo clusters in which electron injection takes place via MCCT transition.

The conversion efficiency and product selectivity of the electroreduction of carbon dioxide have been largely limited by the low CO2solubility in aqueous solution. To relieve this problem, Cu3(BTC)2(Cu-MOF) as CO2capture agent was introduced into a carbon paper based gas diffusion electrode (GDE) in this study. The faradaic efficiencies (FEs) of CH4on GDE with Cu-MOF weight ratio in the range of 7.5–10% are 2–3-fold higher than that of GDE without Cu-MOF addition under negative potentials (−2.3 to −2.5 V vs SCE), and the FE of the competitive hydrogen evolution reaction (HER) is reduced to 30%. This work paves the way to develop GDE with high catalytic activity for ERC.

A series of geminal diethynylethene (gem-DEE) bridged diferrocenyl compounds with varying pendant substituents at the side chain, including xanthene, thioxanthene, dibenzo[a,d]cycloheptene, and fluorene, is reported with the aim of exploring electronic interactions in the cross-conjugated system. The compounds 9-[bis(ferrocenylethynyl)methylene]-9H-xanthene (1), 9-[bis(ferrocenylethynyl)methylene]-9H-thioxanthene (2), 5-[bis(ferrocenylethynyl)methylene]-5H-dibenzo[a,d]cycloheptene (3), and 9-[bis(ferrocenylethynyl)methylene]-9H-fluorene (4) were synthesized and characterized by using spectroscopic methods and single-crystal X-ray diffraction analyses. Electrochemical measurements using the weakly coordinating electrolyte Na[B{C6H3(3,5-CF3)2}4] reveal the moderate electronic coupling between the ferrocenyl (Fc) termini. Hush analysis of the intervalence charge-transfer (IVCT) bands for the monocation species is suggestive of the weakly coupled Robin–Day class II mixed-valence compounds. DFT and TDDFT calculations suggest that the low-energy transitions of these compounds mainly involve a metal to ligand charge transfer (MLCT) transition from the iron center of ferrocenyl termini to the pendant substituent.

AbstractThis study proposed a hybrid ventilation mode for underground subway depot with superstructures and described the construction of a calculation model for estimating the smoke-exhaust efficiency of ventilation systems in such buildings. The hybrid ventilation system consisted of natural ventilation, a flow deflector, and mechanical fans. The smoke-layer height, smoke temperature, gas-flow routes, and velocity distribution under the ceiling were recorded, and the smoke-exhaust efficiencies of the three ventilation modes were calculated and compared. The results revealed a lower ceiling temperature in hybrid ventilation than in mechanical ventilation or natural ventilation systems, with no smoke accumulation in the bottom layer or interlayer. Therefore, the thickness and stability of the smoke layer was determined to be more desirable in hybrid ventilation than in the other two ventilation systems. Gas-flow routes demonstrated that air from outside flowed in through the side window along the ceiling of the bottom layer to the exhaust fan. The dispersion of hot smoke was thus impeded, and smoke was entrained into the fan. The smoke-exhaust efficiencies of hybrid ventilation and mechanical ventilation systems were similar, and both were higher than that of natural ventilation.

Direct N-glycosylation between glycals and amides/amines was achieved with exclusive stereoselectivity in moderate to high yields. Various amides, amines, and 3,4-O-carbonate-glycals were tolerated, and unique β-N-glycosides were obtained. The strategy was based on palladium-catalyzed decarboxylative allylation, and the high 1,4-cis-selectivity was proposed because of the hydrogen bonding effect. Notably, all the synthesized products were subjected to preliminary bioactivity studies, revealing that three compounds were cytotoxic to tumor cells and nontoxic to normal human cells.

Identifying surface-active sites and reaction pathways is of great significance in heterogeneous catalysis. However, even for the simplest catalytic reaction, there could exist a myriad of possible active sites and reaction intermediates, rending exhaustive computational and experimental investigations of all possible reaction pathways difficult. For the oxychlorination of C3H8over CeO2catalyst, electron affinity and Brønsted basicity of a variety of surface sites and reaction intermediates have been calculated using density functional theory (DFT), and a diagram of the corresponding energy levels is used to help identify the relevant reaction sites and intermediates. It is found that surface Cl•radicals that are generated from Cl–oxidation by peroxide at oxygen vacancies play an important role in the C–H activation of alkanes. The formation of C3H7Cl and C3H5Cl intermediates regulates reaction channels and prohibits overoxidation. We show that thermodynamic analysis based on energy levels is useful to elucidate reaction sites and mechanisms for oxidative dehydrogenation.

Steer-by-wire (SBW) system with dual steering actuator motors is a novel and potential type of steering system by means of hardware fault tolerant redundancy to enhance the driving safety. The basic control strategy "road feel feedback and steering angle control" has been carried out. Aiming at the non-synchronous appearance of dual steering actuator motors, dual-motor synchronous control employing differential negative feedback method has been proposed to reduce the adverse influence of "servo fight" non-synchronous issue. In addition, considering the existence of unavoidable backlash impact, dual-motor anti-backlash control adopting variable bias compensation current method has been developed to abate the negative effect caused by backlash factors for SBW system, so that the precision of steering implementation for SBW system can be enhanced. The results of simulations and hardware-in-loop experiments are analysed and then the conclusion has been drawn that the proposed control strategy is effective and feasible.

AbstractFreehand sketching has traditionally been considered as an essential part of the design process. However, despite extensive literature on the subject, the roles that sketching play in design are still not fully understood. Therefore, the aim of this PhD study is to identify and understand the roles sketching plays in supporting creative design work and to develop means to enhance the creative performance of designers. The research methodology is composed of three phases. Hypotheses first emerged from the review of the literature, which then led to three descriptive studies, a pilot study and two surveys with design students and professionals respectively. Data collected from these studies will be used to test and verify the hypotheses. An id-Sketching Toolkit will be developed and tested during the prescriptive study to facilitate the effective use of sketching in design.

ABSTRACTAs a kind of medicinal plant, Peucedanum praeruptorumDunn has been over-harvested in the wild population, which leads to its artificial cultivation. The present study aims to analyze the effects of different plant growth-promoting rhizobacteria (PGPR) on the growth and physiological characteristics of P. Praeruptorumleaves. Compared with the CK, the content of malondialdehyde (MDA) was drastically reduced in the leaves of P. Praeruptorumin different treatment groups (P < 0.05), and with S6 showing the most significant reduction in MDA content (content was only about 1/3 that of the CK). The indicators of leaf area, length and width were found to be the highest in group S9, reaching a level that is 3.75, 3.08 and 1.48 times higher than those in group CK, respectively. Group S8 has the largest plant height, which is 1.22 times higher than that in group CK. S2 has the largest stem diameter, which is 1.69 times higher than that in group CK. Group S1 has the largest petiole length, which is 1.74 times higher than that in group CK. Group S6 has the largest chlorophyll content, which is 1.63 times higher than that in group CK. Group S2 has the highest content of soluble sugar and soluble protein, which are 2.02 times and 3.82 times higher than those in group CK. Group S9 exhibits the strongest CAT activity, which is 3.71 times higher than that in group CK. S5 exhibits the strongest SOD activity, which is 2.32 times higher than group CK. Group S1 exhibits the strongest POD activity, which is 5.94 times higher than that in group CK. In conclusion, the inoculation with PGPR is effective in improving the growth of P. Praeruptorumleaves and their physiological indicators, which provides guidance on the application of PGPR to achieve the high quality and yield of P. Praeruptorum.

Suppression of high-pressure hydrogen spontaneous combustion is essential for the sustainable development of hydrogen energy. Previous studies have shown that suppressing hydrogen spontaneous combustion by reducing the area of the leak port is a feasible method. However, the effect of some factors, such as tube length, on this suppression method has not received attention. Therefore, the effect of leakage port areas of 10 mm, 8 mm, 6.6 mm, and 4.5 mm on the suppression of hydrogen spontaneous combustion was investigated experimentally and simulated for different pipe lengths. The results show that reducing the leak port area increases the hydrogen-air mixing path, which raises the combustible concentration. However, by reducing the leak port area, the intensity of shock waves and the maximum temperature in the tube decreased significantly, and the possibility of hydrogen spontaneous combustion decreased. This indicates that reducing the leak port area can inhibit hydrogen spontaneous combustion. In addition, within a certain leak area, increasing the tube length weakens the performance of this inhibition method. However, the effect of tube length on this method disappears as the leak area decreases. Finally, the leakage port area is reduced, changing the flow field at the nozzle, so that the spontaneous combustion flame in the near field of the nozzle undergoes extinguishment and re-ignition. The results show that reducing the area of the leakage port can effectively inhibit hydrogen self-ignition and is not affected by the length of the tube, providing a way to inhibit hydrogen self-ignition.

With the rapid development of new energy vehicles, the safety of lithium-ion batteries (LIBs) is of increasing concern. Currently, the widely used carbonate-based organic electrolytes have a low ignition point, so it is important to develop high-safety LIBs electrolytes. In this work, a new electrolyte system was configured using commercial carbonate-based organic solvents mixed with [BMP]TFSI pyrrole-type ionic liquids in different proportions. It was experimentally verified that the newly configured electrolyte system led to a significant reduction in the flammability of the battery and even improved the electrochemical performance of the battery, while ensuring the proper function of the electrolyte. As the [BMP]TFSI content increases, the electrolyte self-extinguishing time decreases and the thermal stability increases. In particular, electrolytes with 30 wt% [BMP]TFSI addition exhibit the best balance of flame retardancy and electrochemical performance. The electrolyte system at this addition level has a high thermal stability and a significantly higher oxidation potential, which facilitates stable Li+embedding and detaching and improves the stability of the SEI film. The assembled cells show a capacity retention of 99.58 % and a coulombic efficiency close to 100 % even after 200 cycles. The excellent cycle performance and high safety indicate that [BMP]TFSI has great prospects for application in the LIBs market. This is a guideline for the development of high-safety and high-capacity LIBs.