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Studies regarding the reuse of a gob‐side roadway formed by the N00 longwall mining method are scarce. To investigate the mine pressure behavior characteristics during roadway reuse, the anchor cable force, roof‐to‐floor deformation, and working resistance of the hydraulic support obtained from the verification working face were analyzed. Test results show that the influence range of the mining‐induced pressure was 0‐90 m in front of the working face. The ratios of the first and periodic weighting steps between the entry‐retaining and non‐roof‐cutting sides were 20.25 and 1.94, respectively. However, the ratios of the ground pressure strengths at the two sides were 1.07 and 1.31, respectively. The results indicate that the monitored roadway can be classified into three deformation zones based on the severity of the mine pressure behavior: large, intermediate, and creep. The main roof between the adjacent working faces exhibited a failure type comprising the “O‐X” and “O‐Y” states, which resulted in an unconventional mine pressure behavior. This study provides insights into the N00 longwall mining method as well as important guidance for tackling similar geological conditions when using this mining method. The mine pressure behavior characteristics of a gob‐side roadway formed by the N00 longwall mining method in the stage of reusing are analyzed based on a field test. The automatically formed roadway can be divided into three deformation zones according to the severity of the mine pressure behavior: large, intermediate, and creep. The fracture form of the main roof above the adjacent working faces during the reusing stage is the composite state of “O‐X” and “O‐Y,” resulting in an unconventional phenomenon of mine pressure behavior.

The deformation of Muzhailing deep tunnel is about 2.3 m in the process of construction, which is difficult to be controlled by the traditional “anchor-grouting integration” support system. This paper deeply analyzes the geological characteristics, rock mechanics characteristics, and surrounding rock failure characteristics of Muzhailing tunnel. The deformation mechanism and the failure of the support system are analyzed through the numerical simulation, theoretical analysis, and field test. The authors propose support measures suitable for Muzhailing tunnel based on the analysis results. The maximum buried depth is 600 m, and the engineering rock mass at the depth has nonlinear physical and mechanical phenomenon. The maximum principal stress of Muzhailing tunnel is 25.7 MPa, which belongs to high-stress joint swelling soft rock tunnel. The NPR cable can achieve large deformation under the condition of constant support resistance. The authors put forward the coupling support mode of “NPR cable + steel arch frame + concrete,” which is based on the idea of transforming the composite deformation mechanism to a single type. The stress concentration appears in the range of 12 m in the surrounding rock circle, and the lateral and vertical stress distributions are relatively symmetrical after the improved support. The circumferential strain of the surrounding rock is greatly reduced, and the range of strain is reduced by 10%. The field monitoring results show that the new support system can well control the large soft rock deformation of Muzhailing tunnel (0.5 m). The support strategy proposed can effectively control the large deformation and promote the formation of new support concept for deep tunnel.

Affected by high in-situ stress and mining activities, In the original support scheme, entry of guotun coal mine is seriously deformed. The side of the head entry bulges out seriously and the roof sinks seriously. In order to solve the problem of large deformation of roadway, guotun coal mine adopts the technology of a nonpillar mining method with entry automatically retained in 4306 mining face. First, taking method of theoretical analysis, the stress model of blasthole under the deep condition is established, the mechanical conditions of crack propagation under the action of directional detonation wave and high surrounding rock binding force are obtained theoretically. Next, the mechanical model of roof cutting and pressure relief is established. Afterwards, The mechanical model of directional blasting under the condition of stress constraint is established by using LS-DYNA numerical calculation software, the evolution characteristics of effective stress and the law of crack growth are analyzed. In the end, the field test was carried out in 4306 mining face, and the blasting effect was observed by drilling peep, and the deformation of the head entry before and after pressure relief was monitored and analyzed. The results show that directional fracture blasting can produce a continuous crack, and the effect of pressure relief is remarkable, effectively controlling the deformation of surrounding rock under high in-situ stress.

To explore the influence of abandoned roadways on the technology of gob side entry retaining formed by roof cutting and pressure release, theoretical analyses, numerical simulations, and field engineering experiments are adopted to study the mining pressure distribution law, plastic zone evolution characteristics and surrounding rock control measures when the working face crosses an abandoned roadway. Mining to the vicinity of the abandoned roadway is equivalent to the process of recovering coal pillars. During the mining process, the width of the coal pillar decreases. Under the influence of mining pressure, the coal pillar will gradually lose its bearing capacity. The overburden rock gravity originally borne by the coal pillar will transfer to the retaining roadway and the coal seam in front of the abandoned roadway. Therefore, it is necessary to strengthen the support of the retaining roadway to prevent large deformations due to the sudden increase in pressure. Within 20 m near the abandoned roadway, based on the original NPR constant resistance large deformation cable (CRLD cable) support scheme, the second row of the CRLD cables is densely arranged, and the cable spacing is encrypted from 2400 to 800 mm. The successful application of these research results in actual engineering applications can provide a useful reference for working faces under similar geological condition.

Roadway safety is related to the high productivity and efficiency of coal mining, roof cutting and pressure releasing technology is one of the effective measures for roadway stability control. Under deep mining conditions,the stress condition around the blasthole is complex, and the expansion of directional crack will be affected by high ground stress. In this paper, Based on the engineering background of the roof Cutting and Pressure Relief Technology of Non-pillar Automatic Roadway Formation in guotun coal mine, the crack propagation mechanism and propagation evolution of deep rock under directional tension blasting were investigated. Based on the stress model of blasthole under the deep condition, the mechanical conditions of crack propagation under the action of directional detonation wave and high surrounding rock binding force are obtained theoretically; The mechanical model of directional blasting under the condition of stress constraint is established by using LS-DYNA numerical calculation software, the evolution characteristics of effective stress and the law of crack growth are analyzed; Finally, through the drilling peep and other technical means, the field measurement of the presplitting effect is carried out, which verifies the previous research results and puts forward the appropriate roof presplitting scheme. The results show that when the deep roof strata of Guotun coal mine adopt four hole continuous blasting and per blasthole charge of 2800g, the roof strata can form a continuous seam, and the Roof presplitting effect is the best.

Field experience shows that horizontal well multi-stage fracturing technology can transform the volumetric pressure crack network in the formation and has been widely used in unconventional oil and gas resource exploitation. According to the requirements of horizontal well fracturing operations, this paper simulates the law of horizontal well fracturing in low-porosity and low-permeability sand-shale formation by large-mold fracturing tests and analyzes crack initiation and extension. The two completion methods of open-hole completion and casing perforation completion are considered, and the maximum and minimum horizontal principal stress difference is 10 and 4 MPa. The horizontal wellbore azimuth angle changes from 0° to 90°. The test results show that the principal stress difference has a great influence on fracture initiation. The smaller the stress difference, the higher the fracture initiation pressure and the more complicated the fracture initiation and extension. The fracture propagates along the axial direction of the wellbore, and then at both ends of the wellbore the fracture turns to the direction perpendicular to the direction of the minimum horizontal principal stress. The horizontal wellbore can form a transverse fracture by drilling along the direction of the minimum horizontal principal stress. This study is of great significance for understanding the fracture initiation and propagation law of horizontal well fracturing and can provide guidance for multi-stage fracturing operations of horizontal wells in unconventional reservoirs.

Most advances in medical image recognition supporting clinical auxiliary diagnosis meet challenges due to the low-resource situation in the medical field, where annotations are highly expensive and professional. This low-resource problem can be alleviated by leveraging the transferable representations of large-scale pre-trained vision-language models via relevant medical text prompts. However, existing pre-trained vision-language models require domain experts to carefully design the medical prompts, which greatly increases the burden on clinicians. To address this problem, we propose a weakly supervised prompt learning method MedPrompt to automatically generate medical prompts, which includes an unsupervised pre-trained vision-language model and a weakly supervised prompt learning model. The unsupervised pre-trained vision-language model utilizes the natural correlation between medical images and corresponding medical texts for pre-training, without any manual annotations. The weakly supervised prompt learning model only utilizes the classes of images in the dataset to guide the learning of the specific class vector in the prompt, while the learning of other context vectors in the prompt requires no manual annotations for guidance. To the best of our knowledge, this is the first model to automatically generate medical prompts. With these prompts, the pre-trained vision-language model can be freed from the strong expert dependency of manual annotation and manual prompt design. Experimental results show that the model using our automatically generated prompts outperforms its full-shot learning hand-crafted prompts counterparts with only a minimal number of labeled samples for few-shot learning, and reaches superior or comparable accuracy on zero-shot image classification. The proposed prompt generator is lightweight and therefore can be embedded into any network architecture.

The presence of atmospheric haze severely compromises image clarity, contrast, and detail, leading to perceptual confusion for humans and adversely affecting the performance and accuracy of computer vision systems. The challenges lie in the difficulty of enhancing the generality and robustness of methods in complex environments. We propose a haze removal algorithm based on gradient response and bright region transmission rate adjustment, specifically addressing the following issues. In contrast to previous methods, we introduce a novel multi-scale fusion technique. Firstly, with the help of Laplace operator, the dark channel gradient matrix at different scales is obtained. By analyzing the image edges and the different degrees of feature changes, we successfully captured the thresholds of strong and weak gradient changes. Using the thresholds as boundaries, we extracted the key scales with significant changes in image features, inverted their gradient strengths and mapped them to fusion weights, which enhanced the details while maintaining the image integrity. Additionally, we present a completely independent adjustment algorithm for transmission rates, effectively avoiding inaccuracies associated with traditional estimation methods. To evaluate the performance of our proposed approach, we employ nine quantitative evaluation metrics on five benchmark datasets. The results demonstrate the outstanding performance and robustness of our method across various complex environments. Its significantly high lower bound further facilitates achieving higher scientific standards.

Background Identification of loci for grain yield (GY) and related traits, and dissection of the genetic architecture are important for yield improvement through marker-assisted selection (MAS). Two genome-wide association study (GWAS) methods were used on a diverse panel of 166 elite wheat varieties from the Yellow and Huai River Valleys Wheat Zone (YHRVWD) of China to detect stable loci and analyze relationships among GY and related traits. Results A total of 326,570 single nucleotide polymorphism (SNP) markers from the wheat 90 K and 660 K SNP arrays were chosen for GWAS of GY and related traits, generating a physical distance of 14,064.8 Mb. One hundred and twenty common loci were detected using SNP-GWAS and Haplotype-GWAS, among which two were potentially functional genes underpinning kernel weight and plant height (PH), eight were at similar locations to the quantitative trait loci (QTL) identified in recombinant inbred line (RIL) populations in a previous study, and 78 were potentially new. Twelve pleiotropic loci were detected on eight chromosomes; among these the interval 714.4–725.8 Mb on chromosome 3A was significantly associated with GY, kernel number per spike (KNS), kernel width (KW), spike dry weight (SDW), PH, uppermost internode length (UIL), and flag leaf length (FLL). GY shared five loci with thousand kernel weight (TKW) and PH, indicating significantly affected by two traits. Compared with the total number of loci for each trait in the diverse panel, the average number of alleles for increasing phenotypic values of GY, TKW, kernel length (KL), KW, and flag leaf width (FLW) were higher, whereas the numbers for PH, UIL and FLL were lower. There were significant additive effects for each trait when favorable alleles were combined. UIL and FLL can be directly used for selecting high-yielding varieties, whereas FLW can be used to select spike number per unit area (SN) and KNS. Conclusions The loci and significant SNP markers identified in the present study can be used for pyramiding favorable alleles in developing high-yielding varieties. Our study proved that both GWAS methods and high-density genetic markers are reliable means of identifying loci for GY and related traits, and provided new insight to the genetic architecture of GY.

The occupational profiling system driven by the traditional survey method has some shortcomings such as lag in updating, time consumption and laborious revision. It is necessary to refine and improve the traditional occupational portrait system through dynamic occupational information. Under the circumstances of big data, this paper showed the feasibility of vocational portraits driven by job advertisements with data analysis and processing engineering technicians (DAPET) as an example. First, according to the description of occupation in the Chinese Occupation Classification Grand Dictionary, a text similarity algorithm was used to preliminarily choose recruitment data with high similarity. Second, Convolutional Neural Networks for Sentence Classification (TextCNN) was used to further classify the preliminary corpus to obtain a precise occupational dataset. Third, the specialty and skill were taken as named entities that were automatically extracted by the named entity recognition technology. Finally, putting the extracted entities into the occupational dataset, the occupation characteristics of multiple dimensions were depicted to form a profile of the vocation.