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A regression approach for seismic first-break picking

Petroleum Science 2024年第3期21卷 1584-1596页

作者： Huan Yuan San-yi Yuan jie Wu Wen-Jing Sang Yu-He Zhao CNPC Key Laboratory of Geophysical Exploration China University of Petroleum(Beijing)Beijing 102249China Research Institute of Petroleum Exploration&Development—Northwest(NWGI) Key Laboratory of reservoir characterization of CNPCPetroChinaLanzhou 730020GansuChina

The picking efficiency of seismic first breaks(FBs)has been greatly accelerated by deep learning(DL)***,the picking accuracy and efficiency of DL methods still face huge challenges in low signal-to-noise ratio(SNR)*** address this issue,we propose a regression approach to pick FBs based on bidirectional long short-term memory(Bi LSTM)neural network by learning the implicit Eikonal equation of 3D inhomogeneous media with rugged topography in the target *** employ a regressive model that represents the relationships among the elevation of shots,offset and the elevation of receivers with their seismic traveltime to predict the unknown FBs,from common-shot gathers with sparsely distributed *** from image segmentation methods which automatically extract image features and classify FBs from seismic data,the proposed method can learn the inner relationship between field geometry and *** addition,the predicted results by the regressive model are continuous values of FBs rather than the discrete ones of the binary *** picking results of synthetic data shows that the proposed method has low dependence on label data,and can obtain reliable and similar predicted results using two types of label data with large *** picking results of9380 shots for 3D seismic data generated by vibroseis indicate that the proposed method can still accurately predict FBs in low SNR *** subsequent stacked profiles further illustrate the reliability and effectiveness of the proposed *** results of model data and field seismic data demonstrate that the proposed regression method is a robust first-break picker with high potential for field application.

关键词： First-break picking Low signal-to-noiseratio Regression BiLSTM Traveltime Geometry Noisy seismic data

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An experimental study on effects of temperature gradient on microstructure of a 308L stainless steel manufactured by directed energy deposition

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Journal of Iron and Steel Research International 2024年第8期31卷 2031-2040页

作者： Ting Dai De-yu gu Yu-wen Qiu Wei guo Hui Ding yi-wei Sun School of Materials Science and Engineering Jiangsu Key Laboratory of Advanced Metallic MaterialsSoutheast UniversityNanjing 211189JiangsuChina

The effect of spatial temperature gradient on the microstructural evolution of a 308L stainless steel during the directed energy deposition(DED)process was experimentally investigated.A novel cooling system was designed and incorporated to a DED system in order to control the temperature gradient along the deposition direction during *** deposition,the workpiece was placed on a lifting platform,and as the deposition process proceeded,the platform and workpiece were gradually lowered into cooling water so that the temperature gradient along the deposition direction could be controlled and maintained stable during the deposition *** microstructure characterization results indicated that a deposition strategy with higher G and G/R values(where G is temperature gradient and R is solidification rate)produced finer cellular grains that were better aligned with the deposition direction,while a deposition strategy with lower G and G/R values produced columnar grains with larger primary arm spacing and less aligned with the deposition direction.

关键词： Additive manufacturing Directed energy deposition Stainless steel Microstructure Temperature gradient

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Slope-climbing of cropland and its effects in China

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Journal of Mountain Science 2024年第8期21卷 2754-2769页

作者： CHEN Wanxu XIE Youping YUAN Jintao ZENG jie YANG Liyan gu Tianci LEI Fan Hubei Key Laboratory of Regional Ecology and Environmental Change School of Geography and Information EngineeringChina University of GeosciencesWuhan 430074China Key Laboratory of Natural Resources Monitoring and Supervision in Southern Hilly Region Ministry of Natural ResourcesChangsha 410118China Yunnan Key Laboratory of Plateau Geographic Processes and Environmental Changes Faculty of GeographyYunnan Normal UniversityKunming 650500China

In recent decades,the spatio-temporal patterns of China’s croplands have been reshaped by disturbances from anthropogenic activities,with complex changes in the topographic characteristics of ***-climbing of croplands(SCCL)is an important issue that threatens sustainable agricultural *** providing land with prominent location advantages,SCCL weakens the water and fertilizer retention capacity for cropland,intensifies various geological disasters,and adversely affects the ecological environment and food yield of these *** is crucial to determine the spatio-temporal variation features and effects of SCCL in China to formulate more accurate cropland protection policies and to maintain food security;however,the current lack of relevant studies is detrimental for capturing trends in cropland resources and sustainable cropland *** this study,we constructed a multi-scale slope spectrum for cropland and total terrain to explore the spatial differences and trends of SCCL from a three-dimensional *** evaluated the natural and socioeconomic effects of SCCL in China from multiple *** indicate that the proportion of cropland with slopes below 2°,5°,and 6°in China decreased by 0.43%,0.47%,and 0.50%from 1980 to 2020,*** became apparent during 1980-1990 and 2010-2020,especially over the recent *** cropland climbing index(CCI)and upper limited slope change(ULSC)to measure the spatio-temporal pattern of SCCL were 0.99%and 1.17°,respectively,during *** the agricultural regional scale,the SCCL was also concentrated in 1980-1990 and 2010-2020,and it is more pronounced in the southern *** proportion of provinces and prefecture-level cities with high-intensity SCCL during 1980-2020 were 87.10%and 49.73%,*** was comparatively more pronounced and broader from 2010 to *** this period,17.84%of prefecture-level cities had no SCCL,and the average CCI for all prefecture-level citi

关键词： Croplands Slope spectrum Slope-climbing Three-dimensional perspective Multi-scale China

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Development and validation of a nomogram to predict allograft survival after pediatric liver transplantation

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World Journal of Pediatrics 2024年第3期20卷 239-249页

作者： guang-Xiang gu Shu-Ting Pan yi-Chen Fan Chen Chen Qiang Xia Department of Liver Surgery Renji HospitalShanghai Jiaotong University School of MedicineNo.160 Pujian RoadPudong New DistrictShanghai 200128China Department of Liver Transplantation Sun Yet-Sen Memorial HospitalSun Yat-Sen UniversityNo.107 Yanjiang West RoadGuangzhou 510080China Clinical Center for Investigation Renji HospitalShanghai Jiaotong University School of MedicineShanghaiChina Department of Anesthesiology Renji HospitalShanghai Jiaotong University School of MedicineShanghaiChina

Background Liver transplantation is the main treatment for cholestatic liver disease and some metabolic liver diseases in ***,no accurate prediction model to determine the survival probability of grafts prior to surgery *** study aimed to develop an effective prognostic model for allograft survival after pediatric liver *** This retrospective cohort study included 2032 patients who underwent pediatric liver transplantation between January 1,2006,and January 1,2020.A nomogram was developed using Cox regression and validated based on bootstrap *** and discriminatory accuracies were determined using the concordance index and visualized using calibration curves;net benefits were calculated for model *** online Shiny application was developed for easy access to the *** Multivariable analysis demonstrated that preoperative diagnosis,recipient age,body weight,graft type,preoperative total bilirubin,interleukin-1β,portal venous blood flow direction,spleen thickness,and the presence of heart disease and cholangitis were independent factors for survival,all of which were selected in the *** of the nomogram indicated that the 1-,3-,and 5-year predicted survival rates agreed with the actual survival *** concordance indices for graft survival at 1,3,and 5 years were 0.776,0.757,and 0.753,respectively,which were significantly higher than those of the Pediatric End-Stage Liver Disease and Child-Pugh scoring *** allograft dysfunction risk of a recipient could be easily predicted using the following URL:https://***/ASPELT/l Conclusion The allograft survival after pediatric liver transplantation(ASPELT)score model can effectively predict the graft survival rate after liver transplantation in children,providing a simple and convenient evaluation method for clinicians and patients.

关键词： Allograft survival Nomogram Pediatric liver transplantation

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Retinal Vessel Segmentation via Adversarial Learning and Iterative Refinement

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Journal of Shanghai Jiaotong university(Science) 2024年第1期29卷 73-80页

作者：顾闻徐奕 School of Electronic Information and Electrical Engineering Shanghai Jiao Tong UniversityShanghai 200240China

Retinal vessel segmentation is a challenging medical task owing to small size of dataset,micro blood vessels and low image *** address these issues,we introduce a novel convolutional neural network in this paper,which takes the advantage of both adversarial learning and recurrent neural *** iterative design of network with recurrent unit is performed to refine the segmentation results from input retinal image *** unit preserves high-level semantic information for feature reuse,so as to output a sufficiently refined segmentation map instead of a coarse ***,an adversarial loss is imposing the integrity and connectivity constraints on the segmented vessel regions,thus greatly reducing topology errors of *** experimental results on the DRIVE dataset show that our method achieves area under curve and sensitivity of 98.17%and 80.64%,*** method achieves superior performance in retinal vessel segmentation compared with other existing state-of-the-art methods.

关键词： medical image processing retinal image segmentation adversarial learning iterative refinement

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Additive manufacturing of NiTi lightweight porous structures bio-mimicking coral skeleton with enhanced mechanical properties and shape memory functions

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Science China(Technological Sciences) 2024年第8期67卷 2461-2474页

作者： LIU Xin gu DongDong YUAN LuHao ZHANG Han SUN JianFeng CHEN WenXin WANG jie SHI KeYu Jiangsu Provincial Research Center for Laser Additive Manufacturing of High-Performance Components College of Materials Science and TechnologyNanjing University of Aeronautics and AstronauticsNanjing 210016China

Concerning the high demand for lightweight and multifunctional properties of engineering structures, the coral skeleton-inspired sheet-based(CSS) structure, which was a novel bio-mimicking coral skeleton wall-septa architecture with a unique ability to resist wave shocks was fabricated using NiTi alloy by laser powder bed fusion(LPBF) technology. The effects of laser energy density(LED) on surface morphologies, microstructures, phase transformation behavior, and mechanical properties of LPBFfabricated CSS structures were systematically investigated. The results indicated that the size deviation was predominantly governed by powder adhesion and step effect. NiTi CSS structures with LED of 71 J·mm~(-3)possessed superior compressive modulus(~400 MPa), ultimate strength(~13 MPa), and energy absorption efficiency(~69%). The compression fracture mechanism of the LPBF-fabricated NiTi CSS structures was revealed to be predominantly brittle fracture accompanied by ductile fracture. Furthermore, the Ni_4Ti_3 nanoprecipitates induced the precipitation strengthening effect, enabling better shape memory response at LED of 71 J·mm~(-3), with a recoverable strain of 3.63% and recovery ratio of 90.8%, after heating under a pre-strain of 4%. This study highlights the importance of a bionic design strategy for enhancing the mechanical properties of NiTi components and offers the possibility to tailor its functional properties.

关键词： bioinspired structures laser powder bed fusion NiTi shape memory alloy mechanical performance

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Effect of different bottom blowing elements on stirring characteristics of molten bath in converter

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Journal of Iron and Steel Research International 2024年第2期31卷 368-376页

作者： Ming Lv Shuang-ping Chen Hong-min guo yi-jie Hao Xiang-dong Xing School of Metallurgical Engineering Xi’an University of Architecture and TechnologyXi’an710055ShaanxiChina Shaanxi Longmen Steel Company Hancheng715405ShaanxiChina

The bottom blowing element is the key equipment to ensure the bottom blowing effect of the *** types of bottom blowing elements,dispersive type(D1),double circular seam(D2)and straight cylinder type(D3),were built,and the effects of bottom blowing element type on molten bath flow,wall erosion and furnace bottom erosion were *** was found that when the bottom blowing elements of dispersive type(D1)and double circular seam(D2)were used,the dead zone area in the lower part of the molten bath was smaller,and the high-speed zone area was larger;therefore,the stirring effect on the bottom melt was *** the straight cylinder type(D3)bottom blowing element was used,the gas penetrated the molten bath at a faster rate to reach the surface of molten bath and failed to disperse in the bottom molten bath,and the wall shear stress near the nozzle outlet was *** argon was blown by three different bottom blowing elements,the area of the wall shear stress greater than 3 Pa was 4.8,5.6 and 8.7 cm2,respectively,within 0.2 m of the bottom blowing nozzle outlet.

关键词： Converter steelmaking Bottom blowing element Molten bath stirring Wall erosion

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Cytochrome P45026A1 Contributes to the Maintenance of Neuropathic Pain

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Neuroscience Bulletin 2024年第3期40卷 293-309页

作者： De-Li Cao Ling-jie Ma Bao-Chun Jiang Qiang gu Yong-Jing Gao Institute of Pain Medicine and Special Environmental Medicine Co-innovation Center of NeuroregenerationNantong UniversityNantong226019China Nantong University Medical School Nantong226001China Department of Pain Management The Affiliated Hospital of Nantong UniversityNantong226001China

The cytochrome P450 proteins(CYP450s)have been implicated in catalyzing numerous important biological reactions and contribute to a variety of ***26A1,a member of the CYP450 family,carries out the oxidative metabolism of retinoic acid(RA),the active metabolite of vitamin *** we report that CYP26A1 was dramatically upregulated in the spinal cord after spinal nerve ligation(SNL).CYP26A1 was mainly expressed in spinal neurons and *** analysis displayed that the content of all-trans-RA(at-RA),the substrate of CYP26A1,was reduced in the spinal cord on day 7 after *** of CYP26A1 by siRNA or inhibition of CYP26A1-mediated at-RA catabolism by talarozole relieved the SNL-induced mechanical allodynia during the maintenance phase of neuropathic *** also reduced SNL-induced glial activation and proinflammatory cytokine production but increased anti-inflammatory cytokine(IL-10)*** RA receptors RARα,RXRβ,and RXRγwere expressed in spinal neurons and glial *** promoter of Il-10 has several binding sites for RA receptors,and at-RA directly increased Il-10 mRNA expression in ***,intrathecal IL-10 attenuated SNL-induced neuropathic pain and reduced the activation of astrocytes and ***,the inhibition of CYP26A1-mediated at-RA catabolism alleviates SNL-induced neuropathic pain by promoting the expression of IL-10 and suppressing glial ***26A1 may be a potential therapeutic target for the treatment of neuropathic pain.

关键词： CYP26A1 Microglia Astrocytes ERK P38 IL-10 Neuropathic pain

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Monitoring Surface Deformation Using Distributed Scatterers InSAR

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Journal of Geodesy and Geoinformation Science 2024年第1期7卷 42-58页

作者： LI Haocheng DONG jie WANG yi’an LIAO Mingsheng State Key Laboratory of Information Engineering in Surveying Mapping and Remote SensingWuhan UniversityWuhan 430079China School of Remote Sensing and Information Engineering Wuhan UniversityWuhan 430079China

In the past two decades,extensive and in-depth research has been conducted on Time Series InSAR technology with the advancement of high-performance SAR satellites and the accumulation of big SAR *** introduction of distributed scatterers in Distributed Scatterers InSAR(DS-InSAR)has significantly expanded the application scenarios of InSAR geodetic measurement by increasing the number of measurement *** study traces the history of DS-InSAR,presents the definition and characteristics of distributed scatterers,and focuses on exploring the relationships and distinctions among proposed algorithms in two crucial steps:statistically homogeneous pixel selection and phase ***,the latest research progress in this field is tracked and the possible development direction in the future is *** simulation experiments and two real InSAR case studies,the proposed algorithms are compared and verified,and the advantages of DS-InSAR in deformation measurement practice are *** work not only offers insights into current trends and focal points for theoretical research on DS-InSAR but also provides practical cases and guidance for applied research.

关键词： InSAR permanent scatterers distributed scatterers statistically homogeneous pixel selection phase optimization

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Subsurface multi-physical characterization of mountain excavation and city construction in loess plateau with a fiber-optic sensing system

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第8期16卷 2935-2946页

作者： jie Liu Bin Shi Kai gu Meng-Ya Sun Jun-Cheng Yao He-Ming Han School of Earth Sciences and Engineering Nanjing UniversityNanjingJiangsu210023China Frontiers Science Center for Critical Earth Material Cycling Nanjing UniversityNanjing210023China School of Earth Sciences and Engineering Hohai UniversityNanjing210098China

Mountain excavation and city construction(MECC)projects being launched in the Loess Plateau in China involve the creation of large-scale artificial *** the subsurface evolution characteristics of the artificial land is essential,yet ***,we use an improved fiber-optic monitoring system for its subsurface multi-physical *** system enables us to gather spatiotemporal distribution of various parameters,including strata deformation,temperature,and ***’an New District was selected as a case study to conduct refined in-situ monitoring through a 77 m-deep borehole and a 30 m-long *** reveal that the ground settlement involves both the deformation of the filling loess and the underlying intact ***,the filling loess exhibits a stronger creep capability compared to underlying intact *** deformation along the profile is unevenly distributed,with a positive correlation with soil *** accumulation has been observed at the interface between the filling loess and the underlying intact loess,leading to a significant ***,the temperature and moisture in the filling loess have reached a new equilibrium state,with their depths influenced by atmospheric conditions measuring at 31 m and 26 m,*** refined investigation allows us to identify critical layers that matter the sustainable development of newly created urban areas,and provide improved insights into the evolution mechanisms of land creation.

关键词： Mountain excavation and city construction Fiber-optic monitoring Multi-physical characterization Compacted loess

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