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[Objective] This paper aims to present clarified axial stress solution formulas for epoxy steel sleeve repaired and reinforced pipelines subjected to axial forces. [Methods] A mechanical model was first established to express simplified stress characteristics of pipelines repaired with epoxy steel sleeves under axial forces. Based on this model, theoretical solution formulas were derived for determining axial stresses on the pipe and sleeve layers under axial forces, through utilizing the stress solution method and considering deformation coordination.To verify the proposed axial stress formulas, ANSYS software was employed to establish sleeve repaired pipeline models, both with and without a flange, for numerical simulations. The calculations were performed for pipelines with diameters of 219 mm, 660 mm, and 1 219 mm,respectively. A comparison between the theoretical solutions for axial stress and the numerical solutions was made to verify the proposed formulas. Additionally, the proposed calculation formulas were further verified by comparison with examples found in the available literature.[Results] The study results demonstrated the validity of the mechanically simplified models and their conservative nature in the obtained outcomes. When subject to axial forces, the discrepancies between the theoretical and numerical solutions for axial stress on the inner and outer walls of the pipe layer and sleeve layer, using both the sleeve repair models with and without a flange, remained within 5%. Similarly, in the three diameter scenarios, the differences between the theoretical and numerical solutions for axial stress did not exceed 5%. Furthermore,with an axial force of 1 500 kN, the errors between the theoretical axial stress bearing capacity proportions and the measured values from full-scale tensile experiments on epoxy steel sleeve repaired steel pipelines were all below 5%. [Conclusion] Through the comparison of the theoretical solutions with the numerical solutions and measured values, the rationality and applicability of the theoretical formulas for axial stress have been verified. These formulas can be used for safe integral structural checks. The research findings provide a reference for the design and evaluation of epoxy steel sleeve repaired and reinforced pipelines subjected to axial forces.

Temporary plugging and fracturing is an important technology for the efficient development of unconventional reservoirs. Due to the diverse physical properties of unconventional reservoirs and the complex stress environment, the evaluation of temporary plugging effect needs to consider the working conditions in the wells, and it also needs to focus on the transport and placement of temporary plugging agent in the near-well fracture region, so it is impossible to predict the effect of temporary plugging and fracturing effectively. In this paper, a numerical simulation study is carried out to investigate the transport and placement of temporary plugging agent in the near-well area, and a finite element model of “wellbore-near-well fracture” is established based on computational fluid dynamics, and numerical simulation and verification of temporary plugging and fracturing are carried out based on the fiber-optic monitoring data of temporary plugging and fracturing in Well A, as well as the optimization of some construction parameters. The results show that: as the volume concentration of temporary plugging agent increases, the temporary plugging effect is weakened and then strengthened, and the temporary plugging agent will enter into the heel cluster in advance when the concentration is small; at the initial stage, the increase in the quality of temporary plugging agent will cause some clusters to form incomplete plugging, but the quality of the plugging agent will not be changed after the quality is greater than 360kg; the temporary plugging effect is mainly reflected in the heel cluster, and the toe cluster is not obvious. This paper forms a set of temporary plugging and fracturing simulation methods based on the actual fiber-optic monitoring data in the field, which provides a reference for the optimization design of the type, particle size and dosage of temporary plugging agent during the temporary plugging construction process.

Objective To identify the key pathways and potential biomarkers with diagnotic value for the development of intrahepatic cholangiocarcinoma (ICC) by integrating bioinformatics analysis. Methods We downloaded 3 high-quality datasets of ICC gene microarray (GSE26566, GSE32879 and GSE45001) from Gene Expression Omnibus (GEO) and the high-throughput sequencing data of cholangiocarcinoma (CCA) from the Cancer Genome Atlas (TCGA) database. Differentially expressed genes (DEGs) were screened using the Limma package in R software; Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were performed with Cluster Profiler package. Protein-protein interaction (PPI) network analysis of DEGs was subsequently carried out using the Search Tool for the Retrieval of Interacting Genes (STRING) database and subsequently visualized with Cytoscape. In addition, the transcriptional expression of hub genes was further verified by Gene Expression Profiling Interactive Analysis (GEPIA), and their diagnostic value was assessed by receiver operating characteristic (ROC) curve. Finally, the methylation level of the hub genes was determined using Diseasemeth 2.0. Results In total, 382 DEGs were screened and validated, including 90 up-regulated and 292 down-regulated genes. The up-regulated genes were noticeably enriched in PI3K-Akt signaling pathway, while the down-regulated in the carbon metabolism pathway. A PPI network was constructed with 289 nodes, and 6 hub genes were identified by PPI analysis: PRSS23, LGALS1, VCAN, COL5A1, ITGB1 and EHHADH. ROC curve results showed that all the hub genes distinguished tumor tissues from non-tumorous tissues. Conclusion Six hub genes are identified by integrative bioinformatics analysis, which may be potential molecular biomarkers for early diagnosis of ICC.

The power industry plays a crucial role in achieving the carbon reduction objectives and facilitating the transition towards a low-carbon economy and society. This study employed the IPCC carbon emission coefficient method to calculate the carbon emissions of the power industry in Fujian Province from 2001 to 2021. To predict the carbon emissions of the power industry in Fujian Province from 2022 to 2030, this article established a STIRPAT model based on ridge regression. Empirical research was carried out in this study to investigate the timing of carbon peaking and peak carbon emissions in the power industry of Fujian Province, considering various scenarios. The calculation of carbon emissions indicates that the overall carbon emissions in the electricity industry in Fujian Province showed an upward trend from 2001 to 2021. By 2021, the emissions reached 9.646×107 tons, and the carbon emissions peak has not been reached. Scenario simulation analysis shows that under the energy-saving scenario, the electricity industry in Fujian Province is projected to reach its carbon emissions peak in 2025, with a peak value of 9.687×107 tons. However, in the baseline and ideal scenarios, the carbon emissions in the electricity industry in Fujian Province are projected to not peak before 2030. By 2030, the emissions are estimated to be 9.853×107 tons and 1.067×108 tons, respectively. The article concludes by presenting a comprehensive analysis of the most effective approach towards achieving carbon peaking in the power industry within Fujian Province. This is accomplished by examining the issue from various angles, including government planning, power generation structure, industrial structure, and public awareness.

Accurate identification of ECG signals is the key to intelligent diagnosis of ECG monitoring systems. In order to improve the classification accuracy of ECG signals, an improved ECG signal classification algorithm based on BP neural network was studied. Firstly, statistical analysis was performed on the MIT-BIH Arrhythmia Database sample experts. The normal heart beat, ventricular premature beat, left bundle branch block heart beat and right bundle branch block heart beat were selected as neural network recognition targets, and extracted by principal component analysis. 25 heart beat features are used as sample vectors. The simulation results show that the improved BP neural network has better classification and recognition ability, and the accuracy of the whole sample classification is 98.4%. The algorithm has fast convergence speed and high classification accuracy, which is helpful for detecting and diagnosing heart diseases.

Based on the generating theory of the pinion of spiral bevel gears and the relative motion theory,the tooth flank equation with the work head setting high order modification formula is established. According to the manufacturing parameters of the working gear flank of a spiral bevel gear set,a program is written on the platform of Matlab to calculate the modified tooth flank coordinates. Through constructing tooth flank form error figures and computing contact zones of the calculated tooth flank,the effects of work head setting high order modification on tooth flank form and contact zone of spiral bevel gears are analyzed,which can provide theoretical basis and valuable reference to facilitate the control of tooth flank form and contact zone of spiral bevel gear.

The principle of double- flank gear measuring is usually adopted by gear screening equipment in workshop. The real quality of gear transmission cannot be obtained because of the test result containing manufacture error in both sides of tooth. To solve this problem,a new type of gear comprehensive roll testing method is studied,combining the gear double meshing gear radial comprehensive deviation detection with the single meshing vibration noise detection,the quality of gear transmission can be comprehensively evaluated. The key techniques,such as automatically aligning tooth,automatic backlash adjust,electric closed coupling loading,measuring and analysis are solved. The complement software is developed,which is applied on YKZ9932 machine manufactured by Tianjin No. 1 Machine Tool Works. According to the test result,the gear transmission quality is reflected more systematically by using this new method.