Guangxi University of Science and Technology

Cui Y., Zhu J., Knoll A.

Liu D., You H., Zhang S., Pan J., Dong W., Li W.

Du X., Yin L., Guo X., Chen Y., Li L., Zhang D., Chen S.

The frequency and buckling characteristics of functional gradient (FG) beams with asymmetric material distribution in the temperature field are analyzed in this paper. Generally, the asymmetrical material distribution of FG beams results in a non-zero neutral axis and non-zero thermal moment. However, some previous studies adopted the treatment of homogeneous beams in which the neutral axis and thermal moment were set as zero. To this end, a comprehensive FG beam model with thermal effect is developed based on the absolute nodal coordinate formulation, in which Euler–Bernoulli beam theory, Lagrangian strain, exact curvature, thermally induced strain, and neutral axis position are considered. For the convenience of comparisons, the presented model can be simplified into three models which do not consider the neutral axis or thermal moment. The numerical results indicate that the influence of the neutral axis on the thermal axial force is minimal while that on the thermal moment is significant. In the case of the high temperature difference, frequency, critical temperature difference, unstable state, and the buckling type of the FG beams are misjudged when the neutral axis or thermal moment is ignored.

Yang Z., Chen R., Lin C.

Wang Y., Li J., Liang P., Ye R.

Abstract In response to elderly individuals and stroke patients with weakened lower limb muscle strength, this study proposes a multi-joint soft lower limb assistive exoskeleton designed to assist hip and knee joint flexion and extension during human walking. To achieve smooth control of the flexible exoskeleton, a hardware control system based on STM32 is constructed. The study establishes the theoretical dynamics model and motion characteristic equations for the soft exoskeleton. To minimize assistive errors, a control strategy is designed based on the proportional derivative iterative learning control methods, and control algorithm simulations are performed. For precise assistance of the soft exoskeleton, a mean prediction method is employed to forecast the gait cycle of the human body. To validate the correctness of the dynamic model and the practicality of the soft exoskeleton, tracking experiments with a dummy and walking assistance experiments with human subjects are conducted separately. The dummy tracking experiment results indicate that the percentage errors of peak assistive values for hip and knee joint flexion are 4.77% and 5.81%, respectively, while for extension, the percentage errors are 8.94% and 9.13%. The human walking assistance experiment results show that the peak assistive values provided by the soft exoskeleton for hip joint flexion and extension reach 152.46 N and 150.26 N, respectively, while for knee joint flexion and extension, the peak assistive values are 107.64 N and 106.13 N, respectively.

He X., Huang S., Jiang Q., Huang C., Huang W., Liang W.

Abstract Background Recent clinical trials have shown that inhibitors targeting programmed cell death protein 1 (PD-1) or its ligand (programmed cell death-ligand 1 [PD-L1]) provide significant efficacy and clinical benefit in the treatment of advanced or metastatic urothelial carcinoma. This systematic review and meta-analysis aimed to compare the effectiveness and safety of PD-1/PD-L1 inhibitors in combination with chemotherapy or PD-1/PD-L1 inhibitor monotherapy versus platinum-based chemotherapy as a first-line treatment for advanced urothelial carcinoma. Materials and methods From the beginning of the database construction to February 4, 2024, a combination of MeSH and free-text words was searched using the population intervention comparison outcome study design framework. The PubMed, Cochrane Library, Embase, and Web of Science electronic databases were searched. Meta-analyses of progression-free survival, overall survival, objective response rate (ORR), complete remission rate, duration of remission, and grade ≥3 adverse events were performed. Results Four studies were included in the meta-analysis. The PD-1/PD-L1 inhibitors plus chemotherapy therapy is associated with significantly better ORR rate compared with chemotherapy. Unfortunately, there were no significant differences between PD-1/PD-L1 inhibitor monotherapy and chemotherapy in terms of ORR, duration of remission, or overall survival. Conclusions Our findings indicate that PD-1/PD-L1 inhibitors plus chemotherapy therapy provides more oncological advantages than standard chemotherapy and should be recommended as a first-line treatment for advanced or metastatic urothelial carcinoma. Attention must also be paid to the adverse effects of the combination of PD-1/PD-L1 inhibitors and chemotherapy.

Wang R., Lin C., Li Y.

Garg A., Li L., Belarbi M., Zheng W., Raman R.

The present work aims to quantify the influence of uncertainties in the ply orientation of multi-layered bio-inspired helicoidal laminated composite conical, hemispherical, and toroidal shells under thermal conditions. Any change in the ply orientation affects the free vibration behavior of the laminates. The present investigation focuses on the different levels of uncertainties in the ply orientation on the free vibration behavior of the shell. Moreover, the study also focuses on the sensitivity of the uncertainties in ply orientations on the free vibration behavior of the shells, which is also quantified. To quantify the stochastic free vibration behavior of the shells, the Gaussian process regression (GPR) machine learning algorithm-based surrogate model is developed to predict the frequencies of the shells. The surrogate is created in the framework of higher-order shear deformation theory. The uncertainties in the ply orientations are introduced using bootstrapping. The present results are compared with the stochastic frequencies obtained using Monte Carlo simulations (MCS) to determine the model’s accuracy. The study highlights the influence of the temperature, type of shell, and end conditions on the stochastic free vibration behavior of bio-inspired laminated shells.

Tan G., Jin Y.

Semantic segmentation, as a critical technology in intelligent transportation and autonomous driving, plays a significant role in accurately parsing scene information and enhancing environmental perception capabilities. However, the complexity of road environments poses challenges to the robustness and real-time performance of existing algorithms. Although PIDNet achieves a certain balance between performance and efficiency, it still falls short in fine-grained object segmentation and multi-scale feature fusion. To address these issues, this paper proposes an improved algorithm based on PIDNet. The proposed method includes the following: (1) introducing a multi-branch high-resolution feature extraction module to reduce information loss; (2) adopting a dense atrous spatial pyramid pooling module to enhance multi-scale feature fusion capabilities; and (3) incorporating cross-attention mechanisms into the Bag module to optimize feature interaction. Experimental results on the CityScapes dataset show that the improved algorithm increases the mean intersection-over-union (MIoU) from 78.6% to 81.1%, demonstrating higher segmentation accuracy and robustness in complex scenarios while maintaining real-time performance, thereby validating the effectiveness of the approach.

Song Y., Gu Y., Ren A., Li X., Wu S., Gong Y., Luo Y.

This study investigated the microencapsulation process of natural taro essence and characterized its physicochemical properties. The effects of core-to-wall ratio, T-20/β-CD mass ratio, and ultrasonic time on encapsulation efficiency were systematically investigated. Optimal conditions, identified through orthogonal experiments, included a core-to-wall ratio of 1:10, a T-20/β-CD mass ratio of 1.6:1, and an ultrasonic time of 40 min, resulting in an encapsulation efficiency of 56.10%. The characterization of the microcapsules revealed satisfactory physical properties, including low moisture content, suitable solubility, appropriate bulk density, and good flowability. Particle size distribution analysis showed consistency, and zeta potential measurements indicated stability against agglomeration. Thermal analysis demonstrated enhanced thermal stability, and FT-IR spectroscopy confirmed successful encapsulation through significant interactions between taro essence and β-CD. SEM imaging revealed a heterogeneous morphology, while XRD patterns validated the formation of stable inclusion complexes. An analysis of volatile components indicated the effective encapsulation of key alkanes, with PCA and heatmap clustering analyses confirming the stability of these components during storage. In conclusion, the optimized microencapsulation process significantly enhances the encapsulation efficiency, stability, and thermal properties of natural taro essence microcapsules.

Zhu Q., Sun W., Zhou H., Mao D.

Lithium–sulfur batteries (LSBs) are considered candidates for next-generation energy storage systems due to their high theoretical energy density and low cost. However, their practical applications are constrained by the shuttle effect, lithium dendrites, low conductivity, and volume expansion of sulfur. Metal–organic frameworks (MOFs) have emerged as promising materials for addressing these challenges, owing to their exceptional adsorption and catalysis capabilities, coupled with a readily adjustable form-factor design. This review provides a broader perspective by comprehensively examining the applications of MOFs in LSBs, covering their roles in cathodes, separators, and electrolytes from multiple dimensions, including their reaction mechanisms, the development potential of MOFs as cathode materials, and the positive impacts on LSBs’ performance achieved through the preparation of MOFs and modifications of intermediate, separator, and electrolyte. Finally, we provide perspectives on future development directions in this field.

Wang S., Zhang Q., Luo H., Lin Z.

AbstractThe Jinping Underground Laboratory is the deepest and largest underground laboratory in the world, with a maximum buried depth of approximately 2400 m. The objective is to study the brittle‐ductile transition of marble through a combination of experimental research and constitutive modeling. Triaxial compression and triaxial cyclic loading tests are initially conducted to explore the accumulation of pre‐peak plastic strain and the deterioration of stiffness of the marble. Then, a specific constitutive model is developed to accurately reflect the pre‐peak plastic hardening and post‐peak strain softening behaviors based on the deformation and failure mechanism of the marble. The incremental constitutive relationship of the proposed model is subsequently derived in detail, and the model parameters are calibrated using data obtained from the test results. Finally, the effectiveness of the proposed model is assessed by comparing its results with the experimental results of the marble. The findings show that the proposed model accurately predicts the behavior of the marble, and its results are in good agreement with the test data.

Fan X., Li T., Huang Q., Qin W., Min L., Gao Y.

Ma J., Pan M., Guan W., Zhang Z., Zhou J., Ye N., Qin H., Li L., Man X.

Nowadays, there is an increasing focus on enhancing the economy of hybrid electric vehicles (HEVs). This study builds a framework model for the parameter optimization of hybrid powertrains in user driving cycles. Unlike the optimization under standard driving cycles, the applied user driving cycle incarnates realistic driving situations, and the optimization results are more realistic. Firstly, the user driving cycle with high accuracy is constructed based on actual driving data, which provides a basis for the performance analysis of HEV. Secondly, the HEV model with good power and economy is constructed under user driving cycles. Finally, a multi-strategy improved whale optimization algorithm (MIWOA) is proposed, which can guarantee better economy of HEV compared with the original whale optimization algorithm (WOA). The economy optimization of HEV is completed by MIWOA under user driving cycles, and the hybrid vehicle economy parameters that are more in line with the user’s actual driving conditions are obtained. After optimization, the 100 km equivalent fuel consumption (EFC) of HEV is reduced by 5.20%, which effectively improves the vehicle’s economy. This study demonstrates the effectiveness of the MIWOA method in improving economy and contributes a fresh thought and method for the economic optimization of the hybrid powertrain.

He Z., Xu J., Cao F., Cheng Y., He H., Li Y., Qin J.

ABSTRACTTwo‐phase titanium alloy, pivotal in ultrasonic scalpels, exhibits working dynamics similar to fatigue behavior under axial vibration loading (R = −1) exceeding 20 kHz, with its ultra‐high‐cycle fatigue (UHCF) performance being crucial for clinical applications. This study investigates the UHCF properties of the Ti6Al4V alloy by evaluating microstructure variations and provides insights into the mechanism of nanograin formation and expansion in the internal crack initiation sites. Key findings indicate that a partially recrystallized microstructure (annealed at 650°C) exhibits the highest fatigue life, with enhanced resistance to crack initiation attributed to elongated α grains, moderate texture intensity, and optimal basal slip activation. Internal small‐scale inclusions, which precede deformed α grains, can also serve as initiation sites for cracks in the UHCF regime. The formation of nanograins at crack initiation sites is primarily driven by the slip of basal <a> dislocations, with their subsequent growth influenced by the type of surrounding grain boundaries. This study provides a profound understanding of the relationship between dislocation motion and internal crack initiation in Ti6Al4V alloy, offering valuable insights for optimizing the microstructural design of ultrasonic scalpels to enhance clinical durability.