Roadways in deep mining are strongly affected by high in-situ stress and mining-induced stress, exhibiting characteristics of sustained large deformation failure in surrounding rock control. Mere strengthening support is insufficient to prevent the persistence of such failure. In this case, sustained rib extrusion occurred in the deep mine coal pillar recovery working face (CPRWF), leading to frequent failure of the anchored body, which remained uncontrollable even after repair support. Through geological investigation, on-site survey, and mechanism analysis, it was clarified that the superimposed stress borne by the 12.5 m-coal pillar is the root cause of inducing sustained deformation of the surrounding rock. Moreover, since the compression degree on the goaf-side of the coal pillar is significantly higher than that on the roadway-side, stress is transmitted to the coal pillar rib of the roadway, resulting in sustained coal extrusion. Based on this, a control concept of “stress source control - transmission path blocking - working environment improvement” was proposed. A pressure-relieving roadway was constructed in the 12.5 m-coal pillar, converting an entire section of wide pillar into two sections of narrow pillars, thereby directly improving the stress environment from the source and blocking stress transmission in the path. Furthermore, numerical simulation verified the effect of the pressure-relieving roadway, indicating that its optimal layout configuration is in the middle of the coal pillar, with an optimal cross-sectional size of approximately 4.0 m. Consequently, a comprehensive technical scheme was established, including advanced roadway excavation for pressure relief, double-roadway combined support, and full recovery of coal pillars. This scheme not only achieved control over sustained deformation failure but also recovered an additional 7,657 tons of coal pillar resources. Meanwhile, the double-roadway combined support method successfully prevented and controlled the sustained failure of surrounding rock. This study provides an innovative solution for blocking sustained failure through deep stress regulation by establishing pressure-relieving roadways, offering technical references for the safe and efficient recovery of deep resources.

To address the challenge of controlling large deformations in surrounding rock of deep gob-side entries, a new coordinated control technology integrating external anchoring and internal holemaking pressure relief was proposed. Based on field investigations and analysis of surrounding rock deformation characteristics, the study elucidated the full-cable control mechanism for fractured roadway sides and the fundamental principles of internal hole-making pressure relief. Laboratory test equipment simulating shallow fractured surrounding rock and deep intact surrounding rock was designed, incorporating confined lateral loading molds. Results demonstrate that full-cable support effectively enhances the strength of anchored coal masses. Through synergistic collaboration with surface-protection structures, it significantly improves the coal's selfbearing capacity and deformation resistance. By conducting 3DEC simulation experiments, this study further verifies the protective effect of full-cable support on fractured coal masses at the roadway side. A Flac3D numerical model was established to elucidate the influence of each parameter on pressure relief effectiveness and determining optimal hole-making parameters. Similarity simulation test results demonstrate that internal hole-making spaces transfer peak stress from the roadway side to deeper zones during both static and dynamic pressure stages, with an inward shift distance of 75 mm, achieving effective pressure relief in surrounding rock. Cumulative water discharge from pockets totaled 65.28 cm3, effectively reflecting contraction behavior within hole-making spaces. Complementary numerical simulations verified peak stress inward displacements of 3 m (static stage) and 4.5-6.5 m (dynamic stage), respectively. These outcomes validate both the efficacy of full-cable support combined with internal hole-making pressure relief for large-deformation coal roadways in deep mines, and the rationality of the pocket monitoring system. Collectively, this research advances control technologies for fractured surrounding rock in deep roadways.

Mine exploitation and recovery reflect environmental destruction and remediation, and mine change detection is critical to environmental sustainability and management. Numerous mines are distributed worldwide and exhibit complicated variations; thus, there is an urgent need to develop automatic detection of mine changes. This work proposes a novel three-dimensional (3D) multi-scale attention-based full convolutional neural network (FCNN), named as 3D MSA-UNet, for mine exploitation and regreenization detection. The new neural network features 3 advantages. (1) It constructs 3D filters in the FCNN of U-Net; thus, the spatial and temporal changing features can be synchronously extracted, and the mine changes during different periods can be simultaneously and automatically detected. (2) It establishes a multi-scale convolutional layer to capture abundant global and local features and achieves a good generalization ability when applying in multiple mining regions. (3) It introduces an attention mechanism of Convolutional Block Attention Module (CBAM) to learn significant and useful feature representation and to catch long-range and comprehensive feature dependency. Thus, the detection accuracy can be effectively improved. Therefore, due to the obvious advantages in spatiotemporal synchronization, multiscale useful feature learning, and good generalization, the suggested 3D MSA-UNet can relatively accurately reveal the progress of mine exploitation and regreenization. The novel network is applied to 3 large-scale mining areas, and the overall accuracy of change detection attains 97.47, 97.12, and 90.25

The continuous large deformation of the surrounding rock during gob-side entry driving in a 1000-m-deep mine requires frequent renovation of the mining roadway, seriously restricting the normal mining operations at the coal face. Taking 11,216 headgate of a coal mine as the engineering background, this paper expounds that the large deformation factors of the gob-side entry driving of a 1000-m-deep mine are stress-field factors dominated by high in-situ stress, side abutment pressure, front abutment pressure and tectonic stress, and stress-related factors dominated by coal body crushing, unreasonable support, large section size and broken narrow coal pillar. The two-stage pressurization of the surrounding rock of the section roadway of the mine is governed by the following fundamental law: After pressurization, the peak area of the original abutment pressure of the roadway transfers to the lower parts of the surrounding rock, resulting in an increased stress in the surrounding rock at the side of the roadway. A targeted cooperative control involving external anchor-internal unloading of the surrounding rock of the roadway during gob-side entry driving is proposed, and the pressure relief mechanism in the surrounding rock during the static and dynamic pressure stages of the hole-making process is elucidated: the hole-making space transfers the peak stress to the deep during the static pressure stage, and it transfers the high stress to the deep during the dynamic pressure stage. The pressure relief laws of the surrounding rock were analyzed for different hole-making parameters during the static and dynamic pressure stages of deep gob-side entry driving, the hole-making parameters of the 11,216 headgate were as follows: the hole-making depth, length, and spacing were 8, 4, and 3.2 m. A “four-in-one” double space monitoring method was developed to evaluate the control effect of the support structure on the surrounding rock. The results indicated that the surrounding rock deformation remained within a controllable range, the support structure did not experience any breakage or detachment throughout the service period, and the hole-making space played a pressure relief role. The successful application of this technology to control the large deformations in the surrounding rock of coal roadways in deep mines via gob-side entry driving is of great scientific significance.

The landslide susceptibility map estimates the quantitative relationship between known landslides and control factors, and it has been used for site selection of infrastructures and geo-disaster management. As landslides and rockfalls occur frequently in mountainous areas in Hebei Province, China, due to road construction, the managing government needs to evaluate the vulnerability of geo-disasters in the road slopes to avoid unfavorable site selection for subsequent road constructions. Some typical collector road slopes were used as the study area in Pingshan County, Hebei Province. By analyzing the landslide triggering factors, we determined classification criteria and proposed a comprehensive method for determining the weighting. The respective weighting was calculated by the AHP and CRITIC method, and the combination weighting was determined by the game theory method. The landslide susceptibility of collector roads was evaluated and mapped using the ArcGIS platform. The susceptibility map was validated using landslide field investigation. The validation results show the effectiveness of the susceptibility methods, given the good number of correctly classified landslides. The landslide susceptibility map could have a significant impact on reducing the vulnerability of infrastructure to landslides in Hebei Province, China.

AbstractThis paper summarizes the typical landslide characteristics and main triggering factors by statistically analyzing the detailed investigation data of 51 landslides in Hebei Province, among which rainfall-induced cover-type landslides are the most typical form of landslides. In order to study the destabilizing and destructive mechanism of high steep cover type slope under the action of rainfall infiltration, taking a cover type slope as an example, based on the theory of unsaturated seepage and shear strength, the changing rules of seepage field, displacement field, plasticity zone, and sliding cracking surface of the cover type slope under the condition of intermittent rainfall were analyzed by using the slip surface stress method, and the safety coefficient of the slope under the action of rainfall was calculated. The results show that: after the rainfall starts, because the shallow soil layer of the slope is mainly coarse gravel soil and gravel soil, with relatively strong permeability, the rainwater on the slope surface infiltrates into the interior of the slope body and softens the soil body along the soil-rock interface, and the soil body of the slope body produces displacement at the leading and trailing edges, and shallow sliding is formed in the slope; with the continuation of the rainfall, the slope produces a through plastic zone, and the soil body of the leading edge pulls the central pile body to produce traction slip, and the trailing edge of the soil body produces traction slip, and the trailing edge of the soil body produces traction slip. As the rainfall continues, the slope produces through plastic zone, the leading edge soil body pulls the central pile body to produce traction slip, the trailing edge soil body pushes the central pile body to produce nudging slip, and the deformation gradually develops from the surface to the depth, from the leading edge to the trailing edge.

Rainfall is the primary influencing factor of cliff landslide water content and stability, which is the focus of geological disaster prevention and control. Taking the Nangaojiayu landslide in Jingxing County, the eastern foot of Taihang Mountain, as the research object, the development characteristics of the steep cliff landslide were discussed, and the relationship between rainfall and geological disaster was analyzed by combining the regional geological environment data and survey results. Based on this, the professional monitoring data were systematically combed, the relationship between water content, time, and rainfall was analyzed, and the stability of rainfall on landslides was studied. The results showed that: (1) Under the action of tectonic movement and external force, the spatial difference of a collapse, residual, and colluvial cliff landslide with a high content of large stone in the middle and rear parts and a high content of small cohesive soil in the front part was formed. (2) The change curve of water content in the shallow surface of the cliff landslide under the action of rainfall was in a normal distribution, which reflected the characteristics of rapid infiltration of groundwater in the middle and rear of the landslide and slow dissipation in the front, which was not conducive to the stability of the shallow layer of the landslide. Based on this, the mode of change in the relationship between water content and time was summarized. (3) The function equations of water content, time, and rainfall were established by using the Extremes function curve and Boltzmann function curve, which were basically applicable to the calculation and stability analysis of the water content of a cliff landslide. (4) When the rainfall intensity was less than 150 mm/d, the shallow sliding of the landslide was induced, and the impact on the overall stability was small, which provided a reference for the early warning and prediction of the landslide.27

Mountain mudslides have emerged as one of the main geological dangers in the Yanshan region of China as a result of excessive rains. In light of this, a multi-step debris flow hazard assessment method combining optimal weights and a topological object metamodel is proposed based on game theory ideas. First of all, based on the geological environment research in Yanshan area, this paper determines the mudslide danger evaluation indexes according to the field investigation and remote sensing image data, then combines them with the theory of topological object element evaluation, utilizes the idea of game theory, and carries out the optimal combination of the weight coefficients derived from hierarchical analysis and the CRITIC method to obtain the final comprehensive weights of the indexes, and forms the combination-assigning topological object element of the mudslide danger topological model. The results suggest that improved weight coefficients can increase topological evaluation precision, which is more in line with objective reality than the traditional method and has some application utility.

Heavy rainfall induces shallow landslides in the mountainous areas of China. There is a need for regional slope stability prediction to reduce the damage to infrastructure, residents, and the economy. This study attempts to demarcate areas prone to rainfall-induced shallow landslides using the transient rainfall infiltration and grid-based slope stability (TRIGRS) model under different rainfall conditions. After inputting the engineering geological and geotechnical characteristic data of the area in China, the slope stability was simulated and verified by a deformation monitoring landslide. The slope stability gradually declined under the influence of precipitation from 5–8 July 2021. Slope stability gradually decreased under the predicted rainfall intensity of 60 mm/d for 6 days. The percentage of the slope area with a factor of safety (FS) less than 1.0 increased from 0.00% (1 d) to 3.18% (6 d). The study results could be used for hazards mitigation in this region.

Routine serried drilling (slotting) technology ruins the coal mass and support architecture of the anchorage ring during stress relief, and cannot resolve the conflict between stress relief and anchorage. Therefore, a novel powerful anchorage and stress relief technology was proposed in this study to balance the conflict. The numerical simulation analysis was conducted on the main stress difference (MSD) of stress relief in large-hole fabrication to acquire the first-best stress relief parameters. 1) When the distance between the starting site of the large-hole fabrication and the roadway wall ( L h ), is small, the stress-crest region near the roadway cannot be effectively shifted far from the roadway. When L h ≥12 m, the stress data curve of the roadway rib exhibits a double high crest distribution. When L h is 10 m, the new crest site of MSD of the roadway rib shifted far from the roadway is 7.5 m without ruining the anchorage function of the superficial part of the anchor cable. 2) The increase in the large-hole fabrication length does not lead to a change in the shape and size of the MSD between the starting site of the large-hole fabrication and the roadway wall. With the increase in the large-hole fabrication length, the migration degree of the crest site of the second MSD is larger than the degree of the crest size of the second MSD. 3) When the large-hole fabrication spacing is >5 m, the high MSD between neighboring large holes appears, resulting in invalid stress relief between neighboring large holes. When the large-hole fabrication spacing is ≤4 m, the small regions of the MSD produced by each large hole are connected, forming a continuous stress relief region in the deep part of the roadway rib. The engineering application results reveal that this powerful anchorage and stress relief technology can effectively control the deformation of the surrounding rock in a deep roadway.

In this study, a sump in the Xingdong coal mine (buried at a depth of over 1200 m) was used to analyze the surrounding rock's stability and control technology. Under the combined influences of various complex conditions, such as the burial depth of over 1200 m, ultra-high ground stress, and location under the goaf, the sump support became extremely difficult, severely restricting the efficient production of the mine. The overall pressure-relief mechanisms and degree of the sump surrounding the rock environment under the goaf were studied, and the rationality of the sump location was verified through numerical simulations and field tests. A more effective support scheme was proposed based on the deformation characteristics and failure mechanisms of the temporary sump-surrounding rock under the supporting conditions. The combined control technology employed the lengthened strong anchor bolts (cables), full-section concrete-filled steel tubular supports, and pouring full-section reinforced concrete and full-section long-hole grouting reinforcement. The field test results showed that after adopting the new support scheme, the sump-surrounding rock tended to be stable after three months. The sump roof subsidence amount, floor heave amount, and convergence of the two sidewalls of the sump were 17.2–19.2 mm, 13.9–16.5 mm, and 23.2–27.9 mm, respectively, thus satisfying the application requirements. This study provides an essential reference for deep-mine roadway support under a complex high-ground-stress environment.

Previous studies have shown that the influence of deep dynamic pressure on the surrounding rock control of a coal roadway is one of the difficulties in mine roadway support. Based on the investigation of the headgate 11231 in a coal mine, this study analyzes the damage characteristics of coal roadway surrounding rock affected by deep dynamic pressure, expounds on the difficulties of controlling the roadway surrounding rock, and creatively proposes a cooperative control technology of external anchor–internal unloading for regulating large deformation of roadways. The vertical stress distribution and transfer law of surrounding rock with different hole-making depths, spacing, and lengths after roadway excavation were simulated and studied, and an appropriate parameter range of hole-making space in the stage without dynamic pressure influence was obtained. Considering the influence of mining dynamic pressure, the surrounding rock pressure relief effect of each optimized hole-making parameter was analyzed. In addition, the optimal hole-making parameters (the hole-making depth, spacing, and length were 8 m, 3.2 m, and 3 m, respectively) that can effectively reduce the high stress of roadway shallow surrounding rock in two stages (without and with dynamic pressure) and ensure integrity of the shallow surrounding rock were obtained. The actual field application shows that the new technology can reduce the higher rib deformation by approximately 850 mm and achieve a good surrounding rock control effect. The research and practice show that the pressure relief control for soft coal roadways with deep, violent mining and large deformation has achieved success, providing technical support for the maintenance of the same type of roadway.

The royal chicken was used as animal model.All chickens were fed under the same raising condition for 13 weeks.The tenderness,water content,crude protein,crude fat,crude ash and amino acids of the breast muscle were determinated.The result showed that the average tenderness was 1.490.The content of water,crude protein,crude fat and crude ash was 73.357% 、23.132% 、1.466% and 1.788% respectively.The breast muscle of the royal chicken had rich amino acids.There were 16 kinds of amino acid,in which 7 types were essential to man.And the 7 kinds of the essential amino acids were 39.59% of the total amino acid.

In the present study, chromosome specimens were prepared by culture of peripheral blood lymphocytes, and karyotypes were analyzed routinely from different varieties of Mediterranean buffalo (M), F1 of Mediterranean buffalo x Murrah buffalo (MM), F1 of Mediterranean buffalo x Nili-Ravi buffalo (MN) and F1 of Mediterranean buffalox Guangxi native swamp buffalo (MG). The results were shown that the chromosomes of M, MM and MN are 2n=50, which are in consistence with those of river buffaloes of Murrah and Nili-Ravi reported by other researchers. However, the chromosomes of MG are 2n = 49, which are disagree with 2n=48 of swamp buffalo and 2n=50 of riverine buffalo. These results confirmed that Mediterranean buffalo belongs to the riverine subspecies as the same as Murrah and Nili-Ravi instead of the swamp subspecies as the Guangxi native buffalo.

Basing on geological model of Hefeng landslide and using finite difference method to analyze the interaction of landside mass and retaining wall under condition of reservoir water, we can get satisfying results. Under the condition of reservoir water, the results show:. Local tensile stress appears in the wall heel of retaining wall;. The increment of shearing strain process developed (">" development mode) from backwall to metope along retaining wall and "weak contact face" in stone head;. The landside mass and retaining wall have same deformation tendency, and the upper deformation is larger than the under-part; The isolines of displacement are parallel to each other, and the retaining wall is bedded destroyed because of shallow landslide;. The landslide is shallow slippage, and the stability of landside and retaining wall go down. In the end, the paper points out that drift index can be used to evaluate anti-slide stability and anti-tipping stability and determine critical width of retaining wall under the conditions of reservoir water; and then the stability of landslide and retaining wall can be improved for the optimization design of retaining wall. All of these will provide theoretical guiding for geologic hazard control and engineering design.

Tengchong volcanic geothermal area is located at the active arc zone of the subduction and collision of the Indian plate and Eurasian plates,and is considered as one of the most potentially active volcanic eruption areas in China.In order to study the spatial distribution and activity of the underground magma chamber,MODIS LST(Land Surface Temperature) data were used to identify the geothermal anomalies that may be created by the heating from the underground magma chamber.The monthly night MODIS LST data from Mar.2000 to Mar.2011 of the study area were collected and analyzed.The 132 month average LST map was derived and three geothermal anomalies were identified.In the light of the previous studies in this area,it can be deduced that there are three magma chambers beneath the three thermal anomalies.The first one is located along Wuhe-Xinhua-Puchuan-Tuantian with the most significant geothermal anomaly,and covers 537km2.The second one is situated in the Langpu-Rehai-Maanshan area with a significant geothermal anomaly and an area of 226km2.The third one is located between Mazhan and Qushi with an obvious geothermal anomaly and a coverage of 28km2.It is also found that the patterns of the monthly LST variation of the three thermal anomalies are similar,with 2 temperature peaks occurring in May,June and August,September,which is different from that of the local temperature of the same period.The 10-year annual LST of the geothermal anomaly in Langpu-Rehai-Maanshan area shows the greatest variations among the three,which suggests the active convective exchange of heat between the underground magma chamber and the surface water,and can be inferred that the beneath this magma chamber is the most active among the three.The findings of this study agree well with the results from seismology,GPS-based deformation detection,He isotopic emission and relative geothermal gradient measurements.It demonstrates the effectiveness and potential of thermal infrared remote sensing in geothermal studies.

This experiment was to study the effects of different dietary protein sources on gastrointestinal development in early-weaning calves. Fifteen neonatal healthy Holstein calves from 2~8 weeks of age were randomly allotted to three treatments and were fed milk replacers, of which the ratios of protein from milk and plant were 80 : 20, 50:50 and 20 : 80, and were labeled as S20, S50 and S80, respectively. The results showed that protein sources of milk replacers affected the ratio of gastrointestinal tract to body weight in early-weaning calves, and rumen-reticulum proportion was increased (P0.05) while abomasum (P0. 05), liver and pancreas proportions were decreased (P0. 05) with the increase of plant protein. The increase of plant protein improved the development of rumen-reticulum in which the rumen papilla height was higher, the shape of which showed ligule or cylinder and the color of epithelium in treatment S80 was deeper than that in other treatments, indicating that plant protein might improve digestive function of rumen in early-weaned calves. Dietary protein sources affected villous morphological but did not affect the ratio of villous height to crypt depth (P0. 05), which was between 3.0-4. 7 in small intestine. It was concluded that the rumen development was improved to some extent and there was not negative effects on intestinal villous by feeding plant protein diet.

The two sided mutual anchoring thin retaining wall is a new type of structure, the action mechanism is very complicated. It has aroused the widespread concern of the engineering community how to properly select the main filling materials of high embankment. The effect law of the index of elastic modulus on the stress of tensive bar and the lateral earth pressure are obtained based on the finite element analysis ANSYS software combining an engineering sample. Variation of elastic modulus index of main filling materials will have bigger influence on lateral earth pressure and the stress of tensive bar. These results in this paper indicate that enhances elastic modulus of main filling material can improve mechanical properties and provides the basis for the main filling materials of high filling embankment structure.

There are many secondary metabolites in the mature leaves of kenaf in photosynthesis fastigium,which bring many difficulties to the DNA extraction.CTAB is an effective method to get rid of the impurity of polysaccharide.But the common CTAB method does not fit DNA extraction of kenaf.We improved method developed by us could be effectively used in the DNA extraction of kenaf,which could get rid of most impurities through pretreatment and reduce the difficulties in the following work.We studied the cell fragmentation degree that ground in liquid nitrogen in order to know whether the pretreatment could lose DNA.We also discussed some other correlative question about the DNA extraction.