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Rock blasting technology is crucial for national economic development, particularly resource extraction and infrastructure construction. This paper explores the constitutive relationships in rock blasting, proposing three evolutionary stages: constitutive relationships 1.0, 2.0, and 3.0. These stages focus on contradictory relationships, energy balance, and minimum action theory, respectively. Constitutive relationship 1.0 centers on the interaction between rock and explosive impact loads, emphasizing the offense–defense dynamic. It analyzes the dynamic mechanical response of rock materials under explosive and impact loads, highlighting the conflict and balance between the explosive force and the rock resistance. This stage provides fundamental insights into the behavior of rock materials under high-stress conditions. Constitutive relationship 2.0 approaches the problem from an energy perspective. It treats rocks with significant anisotropy, joints, fractures, bedding, and cavities as complex structural materials. This stage studies the dynamic equilibrium between load input energy and the energy required to destroy the material. By understanding the relationship between structural strength, input energy, dissipated energy, and releasable strain energy, researchers can better predict the response of complex rock structures to explosive loads and improve blasting efficiency. Constitutive relationship 3.0 examines the propagation laws of stress waves under explosive loads and their relationship with medium damage effects. This stage focuses on optimizing energy propagation paths based on the minimum action theory, aiming to maximize the effectiveness of the explosive force while minimizing unwanted damage to the surrounding rock mass. These theories not only reveal the mechanical behavior of rocks under different load conditions but also provide a theoretical basis for optimizing blasting design and improving blasting outcomes. In addition to these theoretical advancements, the integration of artificial intelligence and big data technologies offers a new approach to managing and predicting rock material performance. This paper proposes the concept of rock material engineering genes, which involves establishing a rock gene library to systematically manage the physical and mechanical parameters of rocks. By constructing performance prediction models using advanced data analytics and machine learning algorithms, this approach enhances the accuracy of predicting how different rock types will respond to various engineering applications. Such a comprehensive database has significant implications for resource extraction, geological disaster prevention, and infrastructure construction. The rock material gene library is expected to play an increasingly important role in mineral resource development, geological disaster prevention, and infrastructure construction, thereby promoting the development and application of engineering technology. Its integration with traditional blasting techniques can lead to more efficient and safer methods of rock blasting, ultimately contributing to the advancement of engineering practices and economic development of regions dependent on these technologies. This holistic approach underscores the importance of continued research and technological innovation in rock blasting and material science.

ObjectiveThis study sought to uncover the relationship between physical education courses integrated with civic education (PECICE) and prosocial behavior among university students. Additionally, we aimed to decipher the mediating roles of cultural confidence and self-esteem within this relationship.MethodsEmploying a questionnaire-based approach, we assessed the relationship among PECICE, cultural confidence, self-esteem, and prosocial behavior in university students. The instrument comprised four distinct scales: the Perceived Effectiveness Scale for PECICE, the Cultural Confidence Scale, the Self-Esteem Scale, and the Prosocial Behavior Scale. Our sample encompassed 293 Chinese college students, consisting of 137 men and 156 women, with an average age of 21.39 years (SD = 2.1).ResultsPECICE demonstrated significant positive associations with cultural confidence (r = 0.29, p < 0.001), self-esteem (r = 0.35, p < 0.001), and prosocial behavior (r = 0.40, p < 0.001). The influence of PECICE on prosocial behavior among university students was mediated through three channels: solely via cultural confidence (mediating effect value: 0.14), solely via self-esteem (mediating effect value: 0.22), and through the combined influence of both cultural confidence and self-esteem (mediating effect value: 0.2).ConclusionThe intertwined mediating roles of cultural confidence and self-esteem highlight their pivotal significance in enhancing the efficacy of PECICE. These insights offer a valuable reference for both educators and policymakers striving to augment prosocial behavior in university students.

Abstract Drilling and blasting methods have been used as a common driving technique for shallow-hole driving and blasting in rock roadways. With the advent of digital electronic detonators and the need for increased production efficiency, the traditional blasting design is no longer suitable for deep hole blasting. In this paper, a disperse charge cut blasting method was proposed to address the issues of low excavation depth and high block rate in deep hole undercut blasting. First, a blasting model was used to illustrate the mechanism of the deep hole dispersive charge cut blasting process. Then, continuous charge and dispersed charge blasting models were developed using the smooth particle hydrodynamics-finite element method (SPH-FEM). The cutting parameters were determined theoretically, and the cutting efficiency was introduced to evaluate the cutting effect. The blasting effects of the two charging models were analyzed utilizing the evolution law of rock damage, the number of rock particles thrown, and the cutting efficiency. The results show that using a dispersed charge improves the cutting efficiency by about 20% and the rock breakage for the deep hole cut blasting compared to the traditional continuous charge. In addition, important parameters such as cutting hole spacing, cutting hole depth and upper charge proportion also have a significant impact on the cutting effect. Finally, the deep hole dispersed charge cut blasting technology is combined with the digital electronic detonator through the field engineering practice. It provides a reference for the subsequent deep hole cutting blasting and the use of electronic detonators in rock roadways.

PurposeDepression disorder is the most commonly diagnosed type of mental illness among youths. Although a plethora of evidence suggests a positive relationship between exercise and lower levels of depression in youths, the findings regarding the variation in magnitude of this relationship are inconclusive with respect to the preventive and therapeutic effects of different types of exercise. This network meta-analysis aimed to determine the best type of exercise for the treatment and prevention of depression in youths.MethodsA comprehensive search of databases, including PubMed, EMBASE, The Cochrane Library, Web of Science, PsychINFO, ProQuest, Wanfang, and CNKI, was conducted to identify relevant research on exercise interventions for depression in youth populations. The risk of bias in the included studies was evaluated using Cochrane Review Manager 5.4 according to the Cochrane Handbook 5.1.0 Methodological Quality Evaluation Criteria. The network meta-analysis was performed using STATA 15.1 to calculate the standardized mean difference (SMD) of all concerned outcomes. The node-splitting method was used to test the local inconsistency of the network meta-analysis. Funnel plots were used to evaluate the potential impact of bias in this study.ResultUtilizing data extracted from 58 studies (10 countries, 4,887 participants), we found that for depressed youths, exercise is significantly better than usual care in reducing anxiety (SMD = −0.98, 95% CI [-1.50, −0.45]). For non-depressed youths, exercise is significantly better than usual care in reducing anxiety (SMD = −0.47, 95% CI [ −0.66, −0.29]). In the treatment of depression, resistance exercise (SMD = −1.30, 95% CI [ −1.96, −0.64]), aerobic exercise (SMD = −0.83, 95% CI [-1.10 −0.72]), mixed exercise (SMD = −0.67, 95% CI [−0.99, −0.35]), and mind-body exercise (SMD = −0.61, 95% CI [−0.84, −0.38]) all showed significant efficacy over usual care. For the prevention of depression, resistance exercise (SMD = −1.18, 95% CI [-1.65, −0.71]), aerobic exercise (SMD = −0.72, 95% CI [−0.98, −0.47]), mind-body exercise (SMD = −0.59, 95% CI [-0.93, −0.26]), and mixed exercise (SMD = −1.06, 95% CI [−1.37 to −0.75]) were all significantly effective compared to usual care. According to the test of the surface under the cumulative ranking score (SUCRA), the ranking of exercises for the treatment of depression in depressed youths is as follows: resistance exercise (94.9%) > aerobic exercise (75.1%) > mixed exercise (43.8%) > mind-body exercise (36.2%) > usual care (0%). For the prevention of depression in non-depressed youths, resistance exercise (90.3%) > mixed exercise (81.6%) > aerobic exercise (45.5%) > mind-body exercise (32.6%) > usual care (0%). Resistance exercise thus had the best comprehensive effect on both the treatment and prevention of depression in youths (clusterank value = 1914.04). Subgroup analyses show that a frequency of 3–4 times per week, a duration of 30–60 min, and a length of more than 6 weeks were found to be the most effective interventions for depression (P > 0.001).ConclusionThis study provides compelling evidence that exercise is a viable intervention for improving depression and anxiety in young individuals. In addition, the study emphasizes the importance of selecting the appropriate type of exercise to optimize treatment and prevention. Specifically, the results suggest that resistance exercise, performed 3–4 times per week, with sessions lasting 30–60 min and a length of more than 6 weeks, yields optimal results for the treatment and prevention of depression in young individuals. These findings have significant implications for clinical practice, particularly given the challenges associated with implementing effective interventions and the economic burden of treating and preventing depression in young people. However, it is worth noting that additional head-to-head studies are necessary to confirm these findings and strengthen the evidence base. Nevertheless, this study provides valuable insights into the role of exercise as a potential treatment and preventative measure for depression in young people.Systematic review registrationhttps://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=374154, identifier: 374154.

A dynamic caustics test system was used, and different moving cracks were analysed to study the interaction between the crack growth rate, stress intensity factor, and curvature of the elliptical end of a moving crack under impact loading. Based on the linear elastic fracture mechanics theory, linearly fitting of the crack tip stress intensity factor and the elliptical curvature were employed to obtain the specific functional expressions. ABAQUS software was used to numerically simulate the moving crack fracture process passing through different elliptical curvatures. The crack tip stress intensity factor was calculated by the stress extrapolation method. The stress intensity factor obtained from the numerical calculation and the caustics test was consistent. The test and numerical simulation results showed that the direction of moving cracks entering and passing through the elliptical defects shows a certain regularity. As the ellipse curvature increased, the moving crack stress intensity factor passing through the ellipse gradually decreased, and the moving crack also passed easily through oval defects.

Crack defects make it difficult to predict the dynamic fracture of tunnel specimens under an impact load. To study the impact of the velocity and crack location on a roadway under dynamic load, specimens with tunnel-type voids were made using polymethyl methacrylate. The split-Hopkinson bar was used as the loading method, and a digital laser dynamic caustics system was used to observe the fracture process of the specimens. The dynamic fracture process was evaluated by the crack propagation velocity, displacement, and dynamic stress intensity factor. To predict and verify the test results, ABAQUS was used to simulate the test process. It was found that the results of the simulated combinations of the crack propagation path and initial fracture toughness change law are consistent with the test results. The initial fracture toughness and the peak value of the crack propagation velocity increased with the increase of the impact velocity. The crack propagation law and trajectory were affected by the location of the prefabricated cracks.

Objective: This study sought to uncover the relationship between physical education courses integrated with civic education (PECICE) and prosocial behavior among university students. Additionally, we aimed to decipher the mediating roles of cultural confidence and self-esteem within this relationship. Methods: Employing a questionnaire-based approach, we assessed the relationship among PECICE, cultural confidence, self-esteem, and prosocial behavior in university students. The instrument comprised four distinct scales: the Perceived Effectiveness Scale for PECICE, the Cultural Confidence Scale, the Self-Esteem Scale, and the Prosocial Behavior Scale. Our sample encompassed 293 Chinese college students, consisting of 137 men and 156 women, with an average age of 21.39 years (SD = 2.1). Results: PECICE demonstrated significant positive associations with cultural confidence (r = 0.29, p < 0.001), self-esteem (r = 0.35, p < 0.001), and prosocial behavior (r = 0.40, p < 0.001). The influence of PECICE on prosocial behavior among university students was mediated through three channels: solely via cultural confidence (mediating effect value: 0.14), solely via selfesteem (mediating effect value: 0.22), and through the combined influence of both cultural confidence and self-esteem (mediating effect value: 0.2). Conclusion: The intertwined mediating roles of cultural confidence and selfesteem highlight their pivotal significance in enhancing the efficacy of PECICE. These insights offer a valuable reference for both educators and policymakers striving to augment prosocial behavior in university students. [ABSTRACT FROM AUTHOR]