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This paper presents a comprehensive study on the design optimization of a robotic gripper, focusing on both the gripper modeling and the optimization of its parallel mechanism structure. This study integrates the Black-winged Kite Algorithm (BKA), Finite Element Analysis (FEA), Backpropagation Neural Network (BPNN), and response surface optimization techniques. The Good Point Set (GPS), nonlinear convergence factor, and adaptive t-distribution method improve BKA, which enhances exploration and exploitation performance, convergence speed, and solution quality. Subsequently, the parallel mechanism structure is designed to minimize the total mass, total deformation, and maximum equivalent stress. The central composite design (CCD) method was used to design the FEA experiment and establish the BKA-BPNN regression prediction model. The RMSE of this model’s training set and test set are 0.001615 and 0.0029328. A response surface optimization model is constructed to determine the best design solution. The optimized design achieves a 33.12% reduction in maximum equivalent stress, a 1.47% decrease in total mass, and a 0.16% reduction in maximum total deformation. This study provides valuable insights into the design optimization process for robotic grippers, showcasing the effectiveness of the proposed methodologies in enhancing performance while reducing mass and improving structural integrity.

This research introduces an integrated optimization methodology for spindle design, combining the improved dung beetle optimization (IDBO) algorithm with finite element analysis (FEA). The IDBO algorithm, enhanced in population initialization and convergence factors, minimizes total deformation and mass, addressing a multi-objective optimization model. The obtained optimal parameters guide the construction of a finite element model, considering additional factors like stiffness and maximum stress. The ensuing FEA produces a foundation for constructing a response surface, further optimized to refine the initial design. Through the combination of the IDBO algorithm and FEA method, the mass of the spindle is reduced from 46.582 kg obtained by the IDBO algorithm solution to 28.479 kg, a total reduction of 38.86%, while meeting design requirements such as maximum total deformation. Modal analysis up to the sixth order validates the design correctness reveals dynamic spindle behavior and guarantees the design requirements. The study demonstrates the reliability and effectiveness of the proposed IDBO algorithm in conjunction with FEA, providing a versatile framework for engineering optimization. [ABSTRACT FROM AUTHOR]

Trajectory planning of robotic manipulators in complex environments involves generating smooth and collision-free paths, and key aspects to consider include dynamic environment perception, path planning, trajectory smoothing and optimization, and obstacle avoidance. This paper discusses different algorithms and finally proposes a fusion of the improved Dung Beetle Optimizer (IDBO) algorithm using chaotic mapping, sinusoidal random mutation, and nonlinear convergence strategies with the bidirectional Rapidly exploring Random Tree (RRT) algorithm to achieve manipulator trajectory planning and minimum jerk optimization trajectory. In the experiment, the IDBO algorithm was compared with other heuristic algorithms. The path obtained was shortened by 9.18% on average, and the calculation time was shortened by 33.81% on average. Then, the paper explored Cartesian coordinate space trajectory planning and joint space trajectory planning when the robot was working in 3D space, and verified the superiority of the latter. In controlling the movement of the robot, by combining the minimum angle jerk planning and the bidirectional RRT obstacle avoidance algorithm to drive the joint angle parameters obtained by the spatial trajectory planning, the trajectory of the robot manipulator can be smoother, more efficient, and avoid obstacles in complex 3D space. This research helps improve the performance, safety, and technical support of robots, and is of great research significance. [ABSTRACT FROM AUTHOR]

Engineering constructions in coastal areas not only affect existing landslides, but also induce new landslides. Variation of the water level makes the coastal area a geological hazard-prone. Prediction of the slope displacement based on monitoring data plays an important role in early warning of potential landslide and slope failure, and supports the risk management of hazards. Given the complex characteristic of the slope deformation, we proposed a prediction model using random coefficient model under the frame of panel data analysis, so as to take the correlation among monitoring points into consideration. In addition, we classified the monitoring data using Gaussian mixture model, to take the temporal-spatial characteristics into consideration. Monitoring data of Guobu slope was used to validate the model. Results indicated that the proposed model have a better performance in prediction accuracy. We also compared the proposed model with the BP neural network model and temporal – temperature model, and found that the prediction accuracy of the proposed model is better than those of the two control models. [ABSTRACT FROM AUTHOR]

The development of high-performance direct-Z Scheme heterojunctions as photocatalysts is the focus of current research, and it is also an effective way to improve the performance of photocatalysts. Based on this, we use density functional theory (DFT) to predict two-dimensional (2D) XSe2/SiH (X = Zr, Sn) van der Waals (vdW) heterojunction as a potential direct Z-scheme heterojunction photocatalyst. The results indicate that both heterojunctions exhibit a typical Type-II band edge arrangement. Furthermore, the small band gap and built-in electric field of the heterojunctions facilitate electronic transitions between the valence band (VB) and conduction band (CB), thereby increasing the probability of interlayer electron–hole (e−-h+) recombination within the heterojunction. This process is beneficial for the formation of direct-Z Scheme heterojunctions. In addition, the XSe2/SiH (X = Zr, Sn) heterojunction exhibits remarkable photogenerated electron and hole driving forces, along with exceptional light-trapping capabilities. Therefore, XSe2/SiH (X = Zr, Sn) heterojunction is a potential new photocatalyst. [ABSTRACT FROM AUTHOR]

Objective: The pedicle screw technique has been widely used in adolescent idiopathic scoliosis orthopedic surgery, but misplacement of screws may damage important structures such as blood vessels and nerves around the pedicle, resulting in serious consequences. Therefore, our research team has independently developed a surgical tool to assist in the placement of pedicle screws. This study aims to investigate the safety and accuracy of postural awareness tool assisted nail placement in orthopedic surgery for adolescent idiopathic scoliosis. Method: A retrospective analysis was performed on 24 adolescent patients with idiopathic scoliosis admitted to our hospital from July 2019 to July 2022, including 10 males and 14 females, with an average age of 14.88 ± 2.36 years (10–19 years). The mean follow‐up was 15.67 ± 2.20 months (12–20 months). We divided the patients into postural awareness group (n = 12) and C‐arm group (n = 12) according to whether the postural awareness surgical tool was used during the operation. All patients were treated with posterior spinal orthopedic surgery. The postural awareness group was assisted by pedicle screw placement with a postural awareness surgical tool, while the C‐arm group was given a pedicle screw placement with freehand technique. The operative time, intraoperative blood loss, intraoperative fluoroscopy times, nail placement related complications, nail placement accuracy, and scoliosis correction rate were recorded and compared between the two groups. Results: The operative time, intraoperative blood loss and fluoroscopy times in the postural awareness group were significantly lower than those in the C‐arm group, with statistical significance (p < 0.05). The postural awareness group implanted 163 screws with an accuracy rate of 91.41%, while the C‐arm group implanted 159 screws with an accuracy rate of 83.02%. The accuracy rate of screw placement in the postural awareness group was higher than that in the C‐arm group, with a statistically significant difference (p = 0.024). According to the imaging of the patients, there was no significant difference between the Cobb Angle of the main bend measured at three time points before surgery, 1 week after surgery and the last follow‐up between the two groups. Similarly, there was no significant difference in the rate of lateral curvature correction between the two groups. Conclusion: The application of postural awareness surgical tool in posterior orthopedic surgery for adolescent idiopathic scoliosis can improve screw placement accuracy, shorten screw placement time, and make auxiliary screw placement safer and more accurate. [ABSTRACT FROM AUTHOR]

Environmental noise has a significant negative impact on acoustic communication in most situations, as it influences the production, transmission, and reception of acoustic signals. However, how animals respond to conspecific sounds when there is interference from environmental noise, and whether males and females display convergent behavioral responses in the face of noise masking remain poorly understood. In this study, we investigated the effects of conspecific male advertisement calls with different signal-to-noise ratios on male–male competition and female choice in the Anhui tree frog Rhacophorus zhoukaiyae using playback and phonotaxis experiments, respectively. The results showed that (1) female Anhui tree frogs preferentially selected the conspecific calls with higher SNR compared to calls with lower SNR; (2) males preferentially responded vocally to the conspecific calls with higher SNR compared to calls with lower SNR; and (3) males' competitive strategies were flexible in the face of noise interference. These results suggest that preferences of both sexes converge in outcome, and that male competitive strategies may depend on predictable female preferences. This study will provide an important basis for further research on decision-making in animals. [ABSTRACT FROM AUTHOR]

The direct Z-scheme van der Waals (vdW) heterojunctions based on biomimetic artificial photosynthesis are a promising strategy for enhancing photocatalytic activity. Therefore, the search for superior direct Z-scheme photocatalysts is an urgent task. Herein, we predicted the WSeTe/Zr2CO2 heterostructure as a potential direct Z-scheme photocatalyst based on density functional theory (DFT). The bands of the WSeTe/Zr2CO2 heterojunction follow a typical Type-II arrangement, where the interlayer band gap is smaller than that of the individual molecular layers, and staggered alignment of the large band-edge creates conditions that allow for a direct Z-scheme. The position of the Fermi energy levels of the two monolayers determines the formation of the built-in electric field pointing from WSeTe to Zr2CO2, promoting the desired interlayer electron–hole (e−–h+) recombination and suppressing the undesired carrier recombination. Finally, in-plane biaxial strain can effectively modulate the optoelectronic properties of the catalyst, while compressive strain has a more pronounced effect on the overpotential driving force of the material. Therefore, the WSeTe/Zr2CO2 heterojunction is an effective new photocatalyst satisfying the direct Z-scheme charge transfer mechanism with its specific application. [ABSTRACT FROM AUTHOR]

In the field of photocatalytic water splitting, the direct Z-scheme heterostructure is regarded as a promising photocatalyst configuration. In this paper, we use density functional theory to predict the Ti2CO2/CrSSe heterostructure as a potential direct Z-scheme heterojunction photocatalyst and investigate its electronic, optical, and heterojunction interface properties. The results show that the Ti2CO2/CrSSe heterojunction has a strong electrostatic attraction between the electrons in the conduction band of Ti2CO2 and the holes in the valence band of CrSSe due to the small interlayer band gap, which can realize the rapid interlayer electron-hole (e−–h+) recombination. The redistribution of charge results in a built-in electric field that prevents unwanted electron and hole migration. In addition, the Ti2CO2/CrSSe van der Waals (vdW) heterojunction exhibits excellent light absorption, and its redox ability has been improved. These properties indicate that Ti2CO2/CrSSe heterostructure is a promising photocatalyst. [ABSTRACT FROM AUTHOR]

BACKGROUND Epithelioid sarcoma is rare, represents less than 1% of all sarcomas, usually occurs in the extremities, and rarely presents as a primary sarcoma of the spine. Publications are usually single reports or case series. We aimed to undertake a systematic review of publications of cases of primary epithelioid sarcoma of the spine to evaluate clinical presentation, diagnosis, management, and patient outcomes. MATERIAL AND METHODS We searched studies on spinal epithelioid sarcoma in the PubMed database. Only studies with secondary epithelioid sarcoma or without effective data for analysis were excluded. Cases in which epithelioid sarcoma first invaded other sites and then affected the spine were also excluded. RESULTS Twenty-three patients from 13 studies were included in the study, aged between 14 and 65 years, and the sex ratio of female to male was 1: 2.29. The survival time was 18.7±13.8 months. The survival time of males was longer than that of females (22.9±14.4 vs 9.0±4.6, P=0.027). The onset age was linearly correlated with the size of the lesion (size=-0.161*age+11.841).The lesions located in lumbar vertebra had the worst prognosis. Postoperative radiotherapy had a statistically significant effect on survival time (P=0.040). CONCLUSIONS This systematic review identified 23 published cases of primary epithelioid sarcoma of the spine. Pain was the main presenting symptom, and tumor size increased with patient age. Female sex and primary location in the lumbar spine were associated with poor survival. Although surgery was the first-line treatment, postoperative radiotherapy and chemotherapy may improve clinical outcomes.