Abstract: Brass is widely used in the manufacturing of various components due to its excellent mechanical properties, corrosion resistance, and good machinability. However, with increasingly complex working environments, the friction and wear performance of brass components has become insufficient to meet practical demands. In this study, precision ultraviolet laser machining technology was employed to fabricate four types of micro-textures—scale, rhombus, ellipse, and line—on the surface of H59 brass. The effects of micro-texture shape, diameter, depth, and area density on the friction and wear properties of brass under dry and abrasive wet friction conditions were systematically investigated. The results showed that elliptical micro-textures with a major axis of 200 μm, a minor axis of 100 μm, a depth of 125 μm, and an area density of 10% reduced the friction coefficient from 0.22 to 0.12 under dry friction conditions, with a wear rate reduction of 17.3%. Under abrasive wet friction conditions, the friction coefficient decreased from 0.52 to 0.23, with a wear rate reduction of 28.9%. The results demonstrate that elliptical micro-textures significantly enhance the wear resistance of brass components. Read More

Abstract: In the process of enterprise software development, traditional development and operations models face challenges such as low release efficiency and poor stability. This research explores the application of DevOps theory in enterprise management software development and project management. Through literature review and case analysis, the core principles and practices of DevOps are systematically explained, with a focus on the implementation strategies of key components such as continuous integration, automated testing, and monitoring feedback. The study finds that DevOps can effectively improve software delivery efficiency and enhance system stability. Using an e-commerce platform as a case study, the implementation of DevOps significantly improved release efficiency and system availability. The results provide a theoretical basis and practical reference for enterprises to implement DevOps transformation. Read More

Abstract: This study proposes a load frequency control (LFC) scheme that leverages virtual synchronous generator technology (VSG) to address the challenge of reduced power system inertia resulting from the integration of energy resources into the power grid. Firstly, a multi-area VSG-LFC model considering delay under the context of unreliable network transmission is developed. Secondly, this paper proposes an adaptive event-triggered mechanism (BAETM) based on the relative bandwidth occupation ratio, which dynamically regulates thresholds by considering the bandwidth state occupation ratio and system output state. The introduced mechanism effectively reduces data transmission and optimizes the utilization of limited network resources. Read More

Abstract: This paper presents the development of a virtual simulation teaching platform for measuring equipment in the mechanical industry, aimed at improving students' learning effectiveness and operational skills. Traditional teaching methods relying on physical hardware are costly and pose safety risks, while the virtual simulation platform offers a safe, repetitive, and resource-efficient learning environment. The platform is divided into four modules: measuring tool cognition, measuring tool experiment, measuring tool evaluation, and user management. Each module is meticulously designed to meet specific teaching and evaluation needs, covering everything from basic knowledge learning to practical skill development. By achieving the outlined objectives, this platform will contribute to the technological advancement and talent cultivation in the mechanical manufacturing industry, promoting the sustainable development of the industry. Read More

Abstract: The control point of cubic B-spline interpolation surface is calculated inversely and the back cutter face is fitted according to the given profile value points. The movement coordinates of each axis of the five-axis grinding machine after the grinding wheel grinding are calculated. Using MATLAB software to draw the given original data, then calculate the μ-direction and ω-direction control points through the B-spline difference, and then generate the standard B-spline surface. According to the grinding principle of the five-axis grinding machine, coordinate changes are made, and finally the grinding track of the grinding wheel is calculated and visualized. Read More

Abstract: Ultrasonic assisted milling technology has shown significant effects in improving the quality of machined surfaces. During ultrasonic milling, while maintaining the same cutting time, changes in the axial ultrasonic vibration amplitude of the tool can cause changes in the height of the surface microstructure contour, which in turn affects the microstructure. Based on the above reasons, different machining surface microstructures can be obtained by changing the axial ultrasonic amplitude of the tool. This article mainly uses surface morphology, hardness, and surface roughness as key indicators to evaluate the integrity of the machined surface. It systematically analyzes the trends and laws of the influence of ultrasonic amplitude and feed rate per tooth on surface morphology, surface hardness, and surface roughness in the process of ultrasonic vibration milling SLM forming TA15 titanium alloy. Read More

Abstract: Ultrasonic assisted milling technology has shown significant effects in improving the quality of machined surfaces, but its specific mechanism of action on the surface and near surface of the workpiece when applied to SLM forming TA15 titanium alloy still needs to be further explored. Under the premise of keeping other cutting conditions constant, as the feed rate of each tooth increases, the machining area covered by the tool expands accordingly, which has a direct impact on the formation of surface microstructure. Based on the above reasons, different microstructures of the machined surface can be obtained by changing the feed rate of each tooth. This article mainly uses surface morphology, roughness, and hardness as key indicators to evaluate the integrity of the machined surface. It systematically analyzes the trend and law of the influence of each tooth feed rate on surface morphology, roughness, and surface hardness during ultrasonic vibration milling of SLM formed TA15 titanium alloy. Read More

Abstract: This paper focuses on the prevention and control of coal and gas outbursts in high-gas, high-stress, and low-permeability coal seams. Through numerical simulation methods, the crack propagation mechanism and engineering application of cross-strata directional hydraulic fracturing technology are studied. Based on the RFPA (Rock Failure Process Analysis) system, a two-dimensional plane strain model is established to analyze the influence of in-situ stress, injection pressure, and coal seam gas pressure on the initiation and propagation of fractures. The research results show that the coal seam gas pressure significantly weakens the effect of high-pressure water injection. The higher the gas pressure, the greater the difficulty of coal body fracture and the higher the initiation pressure, and the injection pressure needs to be increased to optimize the fracturing effect. The directional hydraulic fracturing technology can effectively control the crack propagation along the preset path by arranging guide holes, forming a penetrating crack network, and avoiding the stress concentration and disordered crack problems caused by single-hole fracturing. The simulation shows that the directional fracturing technology has achieved the improvement of coal body pressure relief and gas drainage efficiency in the field application of Chengzhuang Mine, providing a safe and efficient permeability enhancement and pressure relief method for areas without protective layer mining conditions. This technology, by optimizing the crack direction and propagation behavior, has the dual advantages of improving oil and gas recovery efficiency and reducing environmental risks, and has significant engineering value for the development of unconventional reservoirs. Read More