bluuebunny/crossref_metadata_2025_split huggingface dataset:
A novel bearing weak fault diagnosis method based on rank constrained low-rank and sparse decomposition
Authors: Liang Yanping , Li Ning , Cui Li , Li Jie , Yao Xishuo 
Published: November 2024

Abstract
Addressing the challenge of diagnosing incipient bearing faults amidst significant noise, a novel diagnostic approach is introduced, leveraging a Rank Constrained Low-Rank and Sparse Decomposition (RCLRSD) model tailored for weak fault detection in bearings. Initially, we raised the Autocorrelation Function of the Square Envelope in Frequency Domain as an innovative method for the estimation of fault frequencies. Subsequently, we constructed a two-dimensional observation matrix, which is formulated independently of predefined assumptions. Then, we examine the configuration and distribution patterns of bearing fault signals, uncovering the low-rank nature of fault characteristics within a designated two-dimensional transform domain. Moreover, we found the noise signal to exhibit sparsity and an approximate Gaussian distribution. Based on this, a rank-constrained low-rank sparse decomposition model is established, and rank-constrained low-rank regular constraints for feature information and sparse regular constraints and Gaussian constraints for interference signals are constructed respectively. Ultimately, we employed the Gray Wolf Optimization algorithm to refine the model parameters, and we deduced the model’s solver via the Alternating Direction Method of Multipliers. The proposed RCLRSD model decomposes bearing fault data into three constituents: low-rank, sparse, and Gaussian components, effectively addressing the challenge of extracting weak fault signatures from bearings. The weak feature extraction capability of the RCLRSD model is verified using a multi-interference simulation model and experimental data of bearing failures under strong noise conditions; the generalization of the model is verified by the classification effect of the Support Vector Machine under two bearing failure datasets. Comparison with various algorithms confirms the superiority of the proposed algorithm.
Exploring Sb2S3 as a hole transport layer for GeSe based solar cell: a numerical simulation
Authors: Zhao Xiaojian , Yan Peipei , Liang Yan , Li Guijin , Zhou Xilin , Xiao Youpeng 
Published: November 2024

Abstract
Germanium selenide (GeSe) and antimony sulfide (Sb2S3) both are technological intriguing semiconductor material for green and economical photovoltaic devices. In this study, GeSe and Sb2S3 have been utilized as the absorber layer and hole transport layer, respectively, to constructed a heterojunction thin film solar cell consisting of FTO/TiO2/GeSe/Sb2S3/Metal. The GeSe and Sb2S3 are binary compounds and can adopt the same film deposition method, for instance, thermal evaporation, which is expected to improve process compatibility and to reduce production costs. The TiO2 (electron transport layer) and Sb2S3 can form small spike-like conduction band offset and valence band offset with the GeSe, respectively, which possesses potential to suppress carrier recombination at the heterointerfaces. Subsequently, the effects of main functional layer material parameters, heterointerface characteristics and back contact metal work function on the performance parameters of the proposed solar cell were simulated and analyzed using wxAMPS software. After numerical simulation and optimization, the proposed solar cell can reach an open circuit voltage of 0.872 V, a short circuit current of 40.72 mA·cm−2, a filling factor of 84.16%, and a conversion efficiency of 28.35%. According to the simulation results, it is anticipated that the Sb2S3 can serve as a hole transport layer for GeSe based solar cell and enable device to achieve high efficiency. Simulation analysis also provides some meaningful references for the design and preparation of heterojunction thin film solar cells.
Theoretical studies on the scattering of e± off the C2H2 molecule
Authors: Billah M Masum , Khatun M Mousumi , Khandker Mahmudul H , Haque A K F , Uddin M Alfaz 
Published: November 2024

Abstract
By employing previous models [1, 2], we report the differential, integrated elastic, inelastic, total (elastic+inelastic), viscosity and momentum transfer cross sections of e± − C2H2 collision dynamics, for the energy range of 1 eV−1 MeV. This report also incorporates Sherman spin polarization function and total ionization cross section. This work provides the first comprehensive study of electron/positron scattering from C2H2 over such a wide energy range. A complex optical model potential (OMP) has been used to represent the projectile-atom interaction. Relativistic Dirac equation has been solved, to get phase-shifts, needed for the calculations of scattering observables, using OMP. Our results are compared with the existing experimental data and theoretical calculations.
D̅arkRayNet: emulation of cosmic-ray antideuteron fluxes from dark matter
Authors: Heisig Jan , Korsmeier Michael , Krämer Michael , Nippel Kathrin , Rathmann Lena 
Published: November 2024

Abstract
Cosmic-ray antimatter, particularly low-energy antideuterons, serves as a sensitive probe of dark matter annihilating in our Galaxy. We study this smoking-gun signature and explore its complementarity with indirect dark matter searches using cosmic-ray antiprotons. To this end, we develop the neural network emulator D̅arkRayNet, enabling a fast prediction of propagated antideuteron energy spectra for a wide range of annihilation channels and their combinations. We revisit the Monte Carlo simulation of antideuteron coalescence and cosmic-ray propagation, allowing us to explore the uncertainties of both processes. In particular, we take into account uncertainties from the Λ
b
production rate and consider two distinctly different propagation models. Requiring consistency with cosmic-ray antiproton limits, we find that AMS-02 shows sensitivity to a few windows of dark matter masses only, most prominently below 20 GeV. This region can be probed independently by the upcoming GAPS experiment. The program package D̅arkRayNet is available on GitHub, https://github.com/kathrinnp/DarkRayNet.
QED effects on Kerr-Newman black hole shadows*
Authors: Yuan 元 Shao-bing 绍冰 , Luo 罗 Chang-kai 昶恺 , Hu 胡 Ze-zhou 泽州 , Zhang 张 Zhen-yu 震宇 , Chen 陈 Bin 斌 
Published: November 2024

Abstract
By incorporating first-order QED effects, we explored the shadows of Kerr-Newman black holes with a magnetic charge through the numerical backward ray-tracing method. Our investigation encompassed both the direct influence of the electromagnetic field on light rays and the distortion of the background spacetime metric due to QED corrections. We found that the area of the shadow increases with the QED effect, mainly owing to the fact that the photons travel more slowly in the effective medium, making them more susceptible to being trapped by the black hole.
Research on The Accumulation Law and Treatment Measures of Low-pressure Wet Gas Pipeline Network in A Certain Gas Field
Authors: Hao Baolin , Bian Zhong , Bu Lu , Yang Xue , Gao Liyan , Wang Tong 
Published: November 2024

Abstract
With the increasing development and utilization of natural gas resources, the operational problems of low-pressure wet gas pipelines are gradually becoming prominent, especially in low-pressure wet gas pipelines where changes in gas pressure and temperature are often accompanied by the precipitation of free water and the formation of accumulated liquid. Liquid accumulation not only increases pipeline friction and reduces transportation efficiency, but may also cause a series of safety issues such as corrosion and hydrate freezing, seriously threatening the stable operation of the pipeline network and the efficient supply of natural gas. Therefore, in-depth research and exploration of the accumulation law of low-pressure wet gas pipeline network and corresponding treatment measures have important practical significance and application value for ensuring the safety production of gas fields, improving transportation efficiency, and extending pipeline life. This article selects a low-pressure wet gas pipeline network in a certain gas field as the research object. Through a detailed analysis of its structural characteristics, wet gas transportation process, and the mechanism of liquid accumulation, the impact of liquid accumulation on the pipeline network system is deeply explored. The study analyzed the structural characteristics of the pipeline network, moisture transportation technology, and the mechanism of liquid accumulation. A numerical simulation model was established using advanced OLGA software, and detailed simulation analysis was conducted on the phenomenon of liquid accumulation under different production conditions. The research results show that changes in pipeline throughput and shutdowns and restarts can have an impact on liquid accumulation, especially an increase in start-up throughput can effectively shorten the equilibrium time of liquid accumulation and increase the liquid flow rate at the pipeline outlet. On this basis, this study further explores the best practices for pipeline cleaning operations, proposes a series of suggestions, and explores reasonable cleaning cycles. The optimization of cleaning operations can not only reduce the accumulation of liquid, but also help improve the operational efficiency and safety of the pipeline network. This study not only provides theoretical guidance for the safe and stable operation of low-pressure wet gas pipelines, but also provides strong technical support for related engineering practices. By deeply understanding the law of liquid accumulation and taking corresponding treatment measures, the frictional resistance along the pipeline can be effectively reduced, and accidents such as corrosion and hydrate freezing can be reduced, thereby ensuring the long-term, efficient, and safe production of the gas field.
Application of Constant Pressure Explosive Floating Casing Technology in Large Displacement Horizontal Wells
Authors: Feng Qiang , Wang Huaijing , Ding Keyu , Zhan Hongyun , Wu Jie 
Published: November 2024

Abstract
Large displacement horizontal wells are commonly employed to enhance unconventional resource recovery. However, during the field process, challenges often arise, particularly in cases where the casing string cannot reach the designated position. This issue is particularly prominent in the development of shallow wells with long horizontal segments. Currently, widely adopted traditional floating casing methods fall into two main categories: mechanical and rupture disc types. Mechanical methods faces the challenge that after casing running, the mechanical separation structure remains in the wellbore, adding difficulties to subsequent operations. Rupture disc methods face the challenge of pressure misalignment due to factors such as excitement pressure in the liquid column, potentially leading to premature opening during descent. This paper presents a constant pressure explosive floating casing method, characterized by large reliability and the elimination of the need for additional drilling to remove the barrier structure after casing lowered.
This paper focuses on two main aspects: firstly, the design of two-stage initiation mechanisms, corresponding to the initiation pressure of the exciting device and the crushing pressure of the rupture disc. This design ensures precise initiation at low pressure levels while maintaining pressure integrity. Secondly, for different well conditions, varying initiation pressures can be selected, allowing for targeted optimization of initiation and crushing pressures while keeping the pressure difference consistently within a safe range, preventing inadvertent opening and failure during the descent process.
In field application, the constant pressure explosive floating casing technology has been successfully applied in over 100 wells, with the longest floating segment reaching 3270m. In all cases, the casing descended smoothly to the designated position, offering convenient, safe operations without the need for repeated plugging. This technology guarantees the attainment of the design-required opening pressure and ensures full wellbore diameter and sealing integrity.
The technology effectively avoids the complexities associated with casing installation in long horizontal, large-displacement wells, reducing the difficulties in subsequent operations such as cementing and completion.
Preparation and Interfacial Behavior of Mg-based Nanosheets
Authors: Wu Zhiming , Yang Yang , Ye Shuangxiang , Liang Kesheng , Yang Jieyuan 
Published: November 2024

Abstract
Two-dimensional nanosheets have attracted considerable attention as oil displacement agent due to their unique interfacial properties. But the high cost limits the application of traditional nanosheets. In this study, a hydrophilic magnesium-based nanosheet (HMN) was synthesized and modified to obtain the amphiphilic magnesium-based nanosheets(AMN). The influences of reaction time, reaction temperature, stirring rate and raw materials ratio of product were studied and the optical reaction condition were summed up as follows: reaction time was 27 h, reaction temperature was 50 °C, stirring rate was 100 rpm, magnesium source: synthetic agent was 0.5:1. Though AFM, SEM and TEM, it was confirmed that nanosheets were two-dimensional sheet-like with 100-300 nm of plane size and 4-20 nm of thickness size. FTIR confirmed the successful modification of AMN from HMN. AMN had good interfacial properties, 0.05wt% AMN could reduce the oil-water interfacial tension from 34.67 mN/m to 1.08 mN/m, and make the oil wet glass into a neutral wetting. Furthermore, emulsion could be formed by AMN with an ultralow concentration (10 mg/L), while a stable interfacial film could be formed at higher concentrations(500mg/L). The low cost and simple synthesis of AMN make it a unique oil displacement agent with great interfacial properties and promise when compared to traditional nanosheets.
Determination method and application of variable T2 cutoff value in nuclear magnetic logging
Authors: Shen Zhong-shan , Fu Bin , Dai Ming-duo , Liu Min , Fu Yan , Li Yi-xiao 
Published: November 2024

Abstract
Nuclear magnetic resonance logging (NMR) is a new logging technology. By inversion of relaxation time T2 spectrum, pore characteristics can be directly measured, independent of the influence of rock skeleton minerals, and parameters such as effective porosity, movable fluid porosity, bound water porosity, pore size distribution and permeability can be calculated. The key parameter for calculating fine pore structure is the critical relaxation time of bound water and mobile fluid, namely the T2 cutoff value. The current T2 cutoff value is a fixed value based on the T2 mean value corresponding to the flowable porosity (permeability contribution porosity) in the mercury injection experimental data. However, according to the analysis of mercury injection data, there are differences in the flowable porosity of cores with the same porosity and permeability under the same pressure difference. Based on the synchronous data of nuclear magnetic logging and core mercury injection experiment, this paper establishes a variable T2 cutoff value determination method, which significantly improves the interpretation accuracy of nuclear magnetic logging and lays a foundation for the important application of nuclear magnetic logging in reservoir fine description.
Dessert Lithofacies Study of Fengxi Tight Oil in Qaidam Basin
Authors: Guo Delong , Zhang Li , Ma Bin , Wan Qingyang , Gao Xuejiang , He Jinpeng 
Published: November 2024

Abstract
Two kinds of sweet spots were deposited in the shallow-semi-deep lake subfacies during N1-N21 in Fengxi area of Qaidam Basin, but it is not clear which kind of sweet spots are dessert targets. The lithofacies of Fengxi tight oil sweet spot is analyzed from geological and engineering angles, and the optimal target of exploration and development is obtained. From the source rock quality, lithology characteristics, reservoir property, oil content and so on, the geological sweet spot analysis is carried out. The engineering dessert mainly adopts triaxial compression experiment to obtain rock mechanics parameters. Through fracturing physical model experiment, the fracture growth morphology under different geological and engineering conditions is simulated, and the law of hydraulic fracture growth is explored. The structure of algal limestone is dominated by clumps, complex fabric, poor stratification, and high fracture complexity after fracturing. The stratification of laminar lime-dolomite rock is strong, the fracture is easy to spread along the bedding after fracturing, and the fracture complexity is low. Considering the pore structure and post-compaction complexity of the reservoir, it is suggested that algae limestone should be selected as the sweet rock for exploration and development in the Fengxi tight oil area.
Application of Seismic Attribute Clustering Method Based on PCA-SOM in Identification of Paleochannels
Authors: Bian Burong 
Published: November 2024

Abstract
Paleochannels are crucial reservoir types in continental oil and gas fields. The P oil layer in the Sanzhao Depression of the Songliao Basin is a typical example of river-controlled delta-phase deposition. The underwater diversion channel is highly developed and serves as the primary unit of the oil and gas reservoir. The stacking of the river channel creates a complex relationship. Identifying river channels has always been a challenging aspect of predicting sweet spot reservoirs due to the thinness of the sand, fault cutting, seismic acquisition and processing noise, low-resolution constraints, and other factors. This paper proposes a method for identifying river channels by combining principal component analysis (PCA) and self-organised mapping network (SOM) with seismic attribute clustering. The aim is to address the issue of difficult identification of paleochannels. The seismic attribute set, which contains multiple types of attributes, is first dimensionality reduced using principal component analysis. Then, a few principal components that can characterise the attribute set are extracted and used as inputs to the self-organising map (SOM). This reduces the dimensionality of the training sample set and simplifies the network structure. The self-organising neural network structure is designed based on the input sample features. Training is then carried out, and the network weights are updated. Attribute clustering is performed to obtain the river identification results. The effectiveness of this method for paleochannel recognition is verified by the clear morphology of the recognised paleochannels in the Songliao Basin, their conformity to geological understanding, and their matching with drilling information.
Application of vertical seismic profile multi-component data to tight sandstone gas reservoirs
Authors: Li Qin , Li Ge , Kun Luo , Yuanzhong Chen , Jian Tang 
Published: November 2024

Abstract
Given the complex geological characteristics of the tight gas sandstone in the Shaximiao Formation of the Jurassic in the central Sichuan Basin, including its wide distribution, narrow width, and thin thickness, conventional surface seismic methods face significant challenges in reservoir delineation. To address this challenge, a vertical seismic profile (VSP) survey was conducted in the region in 2022, along with the simultaneous collection of 3D3C surface seismic data. This article mainly elaborates on a case study of using multi-component VSP technology to delineate tight sandstone gas reservoirs. By comparing the processed VSP imaging volume with the surface seismic imaging volume, it was discovered that the frequency width of the VSP image was 8 to 12 Hz higher than that of the surface seismic image. Utilizing the multi-component information in VSP data, it is feasible to more precisely delineate tight gas sandstones, thereby reducing the uncertainty of data interpretation. Based on the conventional data interpretation of these images, an innovative application suggests using the centroid frequency ratio of PSv to PP waves as an indicator for tight sandstone. The results show that this attribute has high sensitivity to this type of reservoir. Combining geological, drilling, and logging data, an interpretation template was established based on VSP data to interpret 3D3C surface seismic data and propose new drilling well locations. The conclusion is that the successful application of VSP technology cannot be achieved without the integration of multiple disciplines. The combined exploration technology of multi-component VSP and 3D3C surface seismic has been demonstrated to have high application value through practical application, significantly improving the success rate of gas wells and providing effective support for the exploration and development of tight sandstone gas reservoirs.
Technical Status and Development Trends of Difficult Throttles Treatment Technology in Gas Wells
Authors: Wang Sifan 
Published: November 2024

Abstract
In order to promote the development of treatment technology for difficult throttles in gas wells and assist in solving the problem of gas well shutdown caused by the failure of difficult throttle treatment, this paper delves into the structural principles of preset throttles and slip-type throttles, introducing various types such as preset wire deployment and fishable throttles, preset non-wire deployment and fishable throttles, mechanical slip-type throttles, and electric throttles. It systematically analyzes the difficulties in retrieving difficult throttles, including wire breakage, fishing head breakage, deformation and breakage of slips, eccentric fishing head, non-release of inflated rubber cylinder, jamming, sand burial, scaling, fluid accumulation, falling objects underground, tubing deformation, and complex production tubing strings. Furthermore, it sequentially introduces weighted steel wire fishing treatment, coiled tubing fishing treatment technology, milling and fishing stuck throttles treatment, snubbing operation treatment technology, and well killing and workover treatment technology, which encompass punching holes in the tubing treatment technology, tubing cutting technology under pressure and sand flushing technology. The shortcomings of each treatment technique are also highlighted. Taking into account the current challenges faced in the treatment of difficult throttles, such as high cost and low efficiency in low-pressure gas wells, poor technical adaptability, and high risk of operational failure, it is pointed out that future difficult throttle processing technology should focus on two key directions. Firstly, it should aim for non-well-killing and low-cost development. Secondly, it should strive to reduce the occurrence and treatment difficulty of difficult throttles from the source design. And it provides technical references and ideas for the design of the next generation throttles.