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Balancing stress wave attenuation with structural integrity is recognized as a critical challenge for protective materials in underground defense systems. A novel high-titanium slag (HTS) concrete featuring multiscale pores is proposed to address this dilemma. Large-particle porous HTS aggregates are embedded into cement mortar, enabling mechanical robustness comparable to conventional concrete alongside significant stress wave dissipation. Wave scattering and gas–solid interfacial reflections are induced by the multiscale pore architecture, effectively attenuating energy propagation. A dense interface transition zone between HTS aggregates and the cement mortar is confirmed through microscopic characterization, ensuring structural coherence. Wave attenuation is revealed by Split Hopkinson Pressure Bar tests to primarily originate from pore-driven reflections rather than impedance mismatch. A groundbreaking strategy is offered for designing blast-resistant materials that harmonize dynamic energy dissipation with structural durability, advancing the development of resilient underground infrastructure.

The Laoheba Phosphate Mine Area in the Sichuan Basin stands as one of China’s primary locations for phosphate extraction, boasting a diverse array of rock types and complex rock layers. In recent years, frequent geological disasters, notably landslides, have occurred in the mining area. The safe extraction of phosphate rock faces significant challenges, necessitating an in-depth exploration of the physical and mechanical properties of the rocks within the mining area. This study employs nuclear magnetic resonance (NMR) and X-ray diffractometer (XRD) testing on six typical rock specimens, contrasting and analyzing their physical traits, thus unveiling the impact of rock composition and microstructure on their mechanical properties. The MTS815 Flex Test GT rock mechanics testing system was employed to perform uniaxial compression, triaxial compression, Brazilian disk splitting, and triaxial penetration tests. The study systematically examined the mechanical characteristics of typical rocks in the mining area. The correctness of the experiments was mutually validated by four types of tests. Finally, an analysis of rock failure modes and patterns was conducted. Research suggests that phosphate ore exhibits the highest porosity and permeability. Phosphate ore exhibits significant development of original joints and cracks internally, along with numerous defects, leading to its minimal compressive and tensile strength. Phosphate ore is typically situated in regions of weakened rock mass strength. Real-time monitoring of confining pressure is essential during mining operations to prevent the collapse of surrounding rock formations. The findings of this study offer theoretical backing for secure mining operations in the Laoheba Mining Area of the Sichuan Basin while also furnishing fundamental physical and mechanical parameters for regional geomechanical analysis.

Unmanned aerial vehicle (UAV)-enabled integrated sensing and communication (ISAC) systems have been widely applied in various scenarios recently. This paper aims to maximize the total secure communication rate (SCR) of multiple users while ensuring the minimum beamforming gain towards sensing targets under the surveillance of multiple UAV warden swarms. To reduce the risk of detection, a novel type of artificial noise (AN) is introduced to interfere with swarm wardens. We conduct an analysis of the detection error probability (DEP) of these wardens and subsequently establish a mathematical model. In this model, the SCR is maximized subject to power, trajectory, sensing performance, and secure communication constraints. Since the problem is non-convex and the variables to be optimized are numerous and complex, we decompose the problem into three sub-problems. Then, an overall algorithm is proposed to solve these sub-problems separately. Simulation results demonstrate that the proposed scheme leads to a significant increase in the SCR. Moreover, the system exhibits highly stable performance in both communication and sensing tasks over time, indicating its robustness and reliability. Additionally, communication fairness among users is ensured, and energy efficiency is enhanced.

The electric vehicle (EV) market is expanding rapidly, highlighting the need for enhanced customer perceived value to foster loyalty and competitive differentiation. This study investigates how experience management tools can improve customer experience management in the EV sector with an emphasis on sustainable business practices and environmental sustainability. The research explores existing customer experience management methods, the necessary functions of these tools, and their effectiveness in enhancing management capabilities from the perspective of customer perceived value. A thorough literature review and empirical analysis were conducted to design and evaluate tailored experience management tools. The findings suggest that these tools can enhance customer satisfaction and loyalty by addressing key elements of perceived value, such as price perception, quality perception, and brand image. Additionally, improved customer experience management may encourage sustainable consumer behaviors by making eco-friendly EVs more appealing, supporting environmental sustainability. This research aims to bridge the gap between customer perceived value theory and its practical application in the EV industry. It offers insights for manufacturers and marketers seeking to create more engaging and sustainable customer experiences. The implications extend beyond the EV market, providing a potential framework for various industries to enhance customer perceived value through effective and sustainable experience management.

A dynamic disturbance will induce cracks around the tunnel in tunnel blasting or shield construction. To investigate the overall stability of cracks with various angles during a fixed borehole (round hole explosion) blasting, models containing an individual crack with different angles were introduced for simulation research. The research set up a thin sheet model with a length of 350 mm and a width of 150 mm, with a 7 mm diameter hole and a pre-existing crack of 75 mm and 5 mm in the middle. The evolution of the stress wave propagation model and the crack propagation model were simulated using the AUTODYN software. And in this study, the theory of stress wave is used to creatively explain the dynamic load under the action of formation and reasons for the danger zone. The results indicate that pre-existing cracks from different angles will have an impact on the blast hole and the new cracks generated around itself. At 45–90°, pre-existing cracks will direct reflected stress waves to promote some cracks around the hole to have faster growth rates than others, and these special cracks with faster growths and longer lengths will more easily connect with the free surface or other cracks, resulting in overall instability. And these conditions are consistent with the prediction made by the stress wave propagation simulation study. The research results have certain guiding significance for the stability analysis and hazardous area prediction of tunnel blasting with existing cracks.

To study the characteristics of rock fracture in deep underground under blast loads, some numerical models were established in AUTODYN code. Weibull distribution was used to characterize the inhomogeneity of rock, and a linear equation of state was applied to describe the relation of pressure and volume of granite elements. A new stress initialization method based on explicit dynamic calculation was developed to get an accurate stress distribution near the borehole. Two types of in situ stress conditions were considered. The effect of heterogeneous characteristics of material on blast-induced granite fracture was investigated. The difference between 2D models and 3D models was discussed. Based on the numerical results, it can be concluded that the increase of the magnitude of initial pressure can change the mechanism of shear failure near the borehole and suppress radial cracks propagation. When initial lateral pressure is invariable, with initial vertical pressure rising, radial cracks along the acting direction of vertical pressure will be promoted, and radial cracks in other directions will be prevented. Heterogeneous characteristics of material have an obvious influence on the shear failure zones around the borehole.

With growing demands for improved blast resistance in concrete protective structures, developing new concrete materials that combine high toughness, impact resistance, and efficient energy dissipation is essential. This study replaces conventional aggregates with titanium slag and prepares three specimen groups: pure cement mortar (control), cement mortar with large titanium slag particles, and an optimized mix with titanium slag aggregates. Using Split Hopkinson Pressure Bar (SHPB) tests and AUTODYN finite difference simulations, stress-wave absorption and attenuation performance were systematically investigated. Results show that, under identical impact loading rates, the large-particle titanium slag group increased energy absorption by 23.5% compared with the control, while the optimized mix improved by 19.2%. Both groups maintained stable absorption efficiencies across different loading rates. Numerical simulations reveal that the porous titanium slag model attenuated stress waves by approximately 67.9% after passing through three slag layers, significantly higher than the 51.4% attenuation in the non-porous model. This improvement is attributed to multiple wave reflections and interferences caused by a two-order-magnitude difference in the elastic modulus between the slag and air interfaces, creating ring-shaped stress concentrations that disrupt wave propagation and dissipate impact energy. This research provides experimental support and mechanistic insights for titanium slag application in novel blast-resistant concrete.

With the consolidation of the Internet of Things (IoT), the unmanned aerial vehicle- (UAV-) based IoT has attracted much attention in recent years. In the IoT, cognitive UAV can not only overcome the problem of spectrum scarcity but also improve the communication quality of the edge nodes. However, due to the generation of massive and redundant IoT data, it is difficult to realize the mutual understanding between UAV and ground nodes. At the same time, the performance of the UAV is severely limited by its battery capacity. In order to form an autonomous and energy-efficient IoT system, we investigate semantically driven cognitive UAV networks to maximize the energy efficiency (EE). The semantic device model for cognitive UAV-assisted IoT communication is constructed. And the sensing time, the flight speed of UAV, and the coverage range of UAV communication are jointly optimized to maximize the EE. Then, an efficient alternative algorithm is proposed to solve the optimization problem. Finally, we provide computer simulations to validate the proposed algorithm. The performance of the joint optimization scheme based on the proposed algorithm is compared to some benchmark schemes. And the simulation results show that the proposed scheme can obtain the optimal system parameters and can significantly improve the EE.

Blasting is a prevalent technique in deep rock excavation, with the state of rock fragmentation under high in-situ stress conditions being distinct from that under low in-situ stress conditions. A new material point method framework utilizing the generalized interpolated material point and convective particle domain interpolation functions was implemented to simulate the single-hole blasting process, analyze the stress distribution around the blasting hole, and elucidate the mechanism of how ground stress influences the expansion of blasting cracks through the interaction with the blasting load. In addition, the dynamic relaxation method realizes the stress’s initialization. It was concluded that the in-situ stress can increase the compressive stress induced by blasting load, whereas it decreases the caused tensile stress. With the increase in the ground stress, the scale of the cracks decreases. Under the non-isobaric condition, the blast-induced cracks preferentially expand along the high stress with the increase in the stress difference between the horizontal direction and the vertical direction, and the blast-induced cracks are suppressed to the greatest extent in the direction of the minimum ground stress.