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Quantitative evaluation of rock dynamic disaster intensity is a challenging and difficult task in the field of earth science. In this article, the dynamic compression tests of granite under different impact velocities are carried out, and the energy evolution characteristics of the dynamic failure process of granite are analyzed. The dynamic fracture characteristics of granite were studied by using computed tomography and section scanning equipment. The results show that the energy dissipation and energy accumulation mechanism of granite under dynamic loading are fundamentally changed with the increase of impact disturbance strength, which leads to the transformation of the failure mode from the tension-type sheet crack under low-speed impact to the complex network crack coupled by tension and shear under high-speed impact. At the same time, the greater the impact velocity, the larger the macroscopic crack density, the more uneven the particle distribution on the fracture section, the greater the roughness, and the higher the rock mass fracture degree. In accordance with the results, the energy distribution ratio is proposed to quantitatively characterize the coupling effect of energy dissipation and energy accumulation in the dynamic failure process of granite and to reflect its dynamic failure intensity. The higher the energy distribution ratio, the stronger the energy coupling effect and the more intense the dynamic failure of the rock mass.

Objective The Laiwu Basin is a typical monocline fault basin in the central and southern regions of Shandong Province. It has a complex geological structure and an uneven distribution of groundwater resources within the region. Previous researchers have conducted a large number of hydrogeological and spring water protection studies, but no relevant research has been conducted on the relationship between the development laws of fissure karst and the distribution of karst groundwater. Methods In this study, karstification and groundwater enrichment characteristics were investigated in the Laiwu Basin through research methods of data collection, field geological surveys, hydrogeological drilling, and rock and mineral testing. Results Carbonate strata are concentrated in the southern part of the Laiwu Basin, with a monoclinal structure controlled by the geological structure, which is scattered sporadically in the northern and eastern regions. Karst development is affected by many factors, such as formation lithology, geological structure, groundwater dynamic conditions, and magma intrusion. The principal surface karst features are grikes and karst valleys. In addition, the principal underground karst features were dominated by dissolution fissures and holes at 400 m depth. Karst groundwater is primarily concentrated in multistage structural fault basins, hanging walls formed by water-blocking faults, groundwater pressure discharge areas, and karst development areas on the anticlinal flank of the mine. Conclusion The karst water cycle in the Laiwu Basin has a general regularity of monoclinic basins but is influenced by multiple factors, forming karst water systems of varying sizes that are relatively independent. Significant differences were observed in the development characteristics and water abundance patterns of karsts in different regions. Fault structures and geological water-blocking areas have relatively abundant karst water, whereas the shallow karst water has a strong runoff cycle. [ Significance ] This study provides scientific and technical support for the exploitation and utilization of groundwater resources in water-scarce mountainous areas of central and southern Shandong Province.

Acoustic liner is an important component to reduce engine noise. In this work, the modal sound source characteristics of the pipeline under different flow fields were calculated and used as the input boundary for the background flow field calculation and sound propagation calculation of the Actran software, thereby establishing the sound propagation model. The influences of four structural parameters on the sound absorption effect of the muffler plate hole diameter, hole spacing, honeycomb height, and muffler plate thickness in the single-DOF acoustic liner and the double-DOF acoustic liner were studied respectively. The simulation results show that both degrees of freedom acoustic liners exhibit the phenomenon that the smaller the perforation diameter, the better the sound absorption performance within a certain range of hole diameter. The effects of hole spacing, honeycomb height, and muffler thickness on the sound absorption performance are varied with frequency, the double-DOF acoustic liner above 2500 Hz has large dissipation power and good sound absorption effect. Through the contrast verification in the flow tube test, the transmission loss of the acoustic liner of different structures under different excitation sources is compared, and a reasonable and credible simulation method is obtained.

【Objective】 This paper aims to study the optimal layout of inclined pipes in sedimentation basins in attempts to improve sediment removal efficiency in the Yellow River. 【Method】 Three different layouts of inclined pipes were compared: a single layer (Fs), and two double-layer layouts (Fv1, Fv2), in a gravity-operated sedimentation basin. Sediment distribution of three typical particle sizes in the upstream (Su), middle stream (Sm), and downstream (Sd) was measured. Sediment tests were conducted under a low (Qq) and a high (Qs) flow rate to compare the impact of pipe inclination on sedimentation in the three layouts. 【Result】 The large granular sediment settled prior to entering the inclined pipes, while the fine particle sediment (

Currently, coal gangue pre-sorting is still mostly done manually, with high labor intensity, low sorting efficiency, and safety hazards. Using coal gangue sorting robots to replace manual coal gangue pre-sorting is an effective way to ensure the health and safety of workers and improve work efficiency. However, the existing coal gangue sorting robots have poor performance in situations such as low light intensity and coal gangue surface covered with coal powder. To solve the above problems, an experimental platform for coal gangue sorting robot based on image detection is proposed. This experimental platform collects coal gangue images through industrial cameras. The platform uses ResNet18-YOLOv3 deep learning algorithm to identify the coal gangue in the images. The platform uses TCP communication to provide the position information of the gangue to the coal gangue sorting module for trajectory planning, then controls the manipulator to clamp the gangue and completes the gangue sorting operation. The platform uses the Halcon calibration method for hand-eye calibration of the experimental platform, in order to achieve the conversion of camera pixel coordinates and manipulator spatial coordinates. The positioning error of the experimental platform is calibrated. For coal gangue samples with sizes above 50 mm, the positioning error should not exceed 9 mm. The experimental results show that the recognition accuracy of the experimental platform for coal gangue under strong lighting conditions is 99%. The recognition accuracy of coal gangue under weak lighting conditions is 95%. The recognition accuracy of coal gangue under pulverized coal adhesion conditions is not less than 82%. The accuracy of coal gangue sorting is 82%.

This paper aims to explore the key role of the property industry in China’s low-carbon transition, and analyze the opportunities and challenges of its dual-carbon development. Firstly, the urgency of global greenhouse gas emissions and the importance of property industry in carbon emissions are introduced, then the definition and significance of carbon neutral and dual carbon goals are analyzed, and the international and domestic dual carbon policies and commitments are reviewed. Then it lists the main sources and components of carbon emissions of the property industry in detail, and evaluates the carbon footprint of the property industry. Next, it discusses the opportunities of new technology and innovation, renewable energy, carbon finance and carbon market for the dual-carbon development of the property industry. At the same time, it also discusses the challenges of technical constraints and cost pressures, the uncertainty and landing problems of policies and regulations, and the difficulty and constraints of landlord and tenant participation. Finally, the paper puts forward policy suggestions to promote the dual-carbon development of the property industry, including setting clear carbon reduction targets and schedules, providing policy support and financial incentives, and establishing industry cooperation and sharing mechanism.

This essay explores the concept of activity-based carbon neutrality as a critical component in achieving carbon emission reduction targets. With the Chinese government’s commitment to carbon sequestration by 2030 and carbon neutrality by 2060. activity-based carbon neutrality has gamed prominence as a hot topic in environmental discussions. The essay emphasizes the significance of activity-based carbon neutrality in promoting public awareness and participation in carbon reduction efforts. It highlights the existing research gap in this field and stresses the need for exploring methodologies to achieve activity-based carbon neutrality. The essay outlines the accounting standards for activity-based carbon neutrality, focusing on large-scale events and offering practical examples of carbon emission reduction measures during the preparation, execution, and conclusion phases of activities. Additionally, it introduces carbon offsetting methods such as carbon quotas and carbon credits. The article also presents a specific case study of the “Six-Five Environment Day National Event” held in Liaoning Province, which successfully achieved carbon neutrality through various initiatives. Overall, the essay encourages further investigation into activity-based carbon neutrality to enhance overall carbon reduction efforts.

For improving the test system, it needs to build measuring carrier and optimize shell design. To obtain valid and reliable test data, it needs the measurement uncertainty of test system with 3dB.But the test results show the measurement of results between the inside and outside the shell are quite different. This has great impact on the measurement results. This paper carried out cause analysis from five links of people, machine, material, method, environment for sound transmission performance of FRP housing. It found out the main reason of poor sound transmission of FRP housing, Single side vacuum adsorption molding method have been taken, good results and expected purpose have been achieved.

This paper provides an experimental study of interlanguage phonological characteristics of Chinese students learning Thai as a foreign language and the accentedness perceived by native Thai speakers. Both production and perception experiments were designed to see how Chinese students acoustically produced Thai final nasal consonants and how Thai native speakers perceived these Chinese-accented nasals. The production experiment compared the acoustic features of Thai final nasal consonants (i.e. /m/, /n/, and /[eng]/) produced by Chinese students and native Thai speakers (n = 5 in each group), who provided speech samples from a wordlist reading task, consisting of 28 words (840 tokens). Nasal acoustic properties of 840 tokens (duration, nasal murmurs, and formant transitions) were examined. The findings showed that the Chinese students produced significantly longer nasal duration and more drastic formant transitions compared to the native speakers. The perception experiment analyzed how native Thai raters (n = 10) rated speech samples concerning degrees of accentedness by using a 5-point Likert scale with 5 as the most native level. Based on this, the native Thai raters rated the Chinese students' speech as 3.22 on average, while native Thai speech was judged with an average score of 4.65, which demonstrated that native Thai raters could distinguish foreign speech from those pronounced by native speakers. To find out to what extent nasal acoustic characteristics in Chinese students' interlanguage phonology contributed to the degree of accentedness, stepwise regression analyses were utilized to discover that nasal duration was particularly important in accurately predicting accentedness in Thai with Chinese accents.

High bypass ratio aero-engine was widely used on military and civil aviation domain, as the power of larger aircraft. Fan frame unit was the main bearing frame of high bypass ratio aero-engine, which composed of strut, HUB MID BOX and external bypass parts. Resin/composite was used on external bypass parts(acoustic liner, containment ring, fan outlet guide vane and fan case skin fillets), which not only reduced the weight and manufacturing cost, but also improved the noise absorption, containment and anti-fatigue ability of engine. The design of composite was becoming a key technique for high bypass ratio aero-engine. In special test of the core engine, nitrogen cooling system was designed to cool the cavity of spool. The nitrogen pipeline passed through the inner cavity of fan frame, then inserted into NO. 3 bearing seal, so nitrogen gas was sent into the cavity of core engine spool. On high bypass ratio aero-engine, the external bypass and fan frame inner cavity were the design platform for advanced technique, such as composite and pipeline system, and also provided guarantee for reliable operation of engine.