检索结果-南通市图书馆

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

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effect of rare earth on primary carbides in H13 die steel and their addition method:a review

引用

Journal of Iron and Steel Research International 2024年第3期31卷 531-551页

作者： jing-feng Wang Lin-zhu Wang Chao-yi Chen Xiang Wang Fei zhao School of Materials and Metallurgy Guizhou UniversityGuiyang 550025GuizhouChina Zhengzhou Railway Vocational and Technical College Zhengzhou 450000HenanChina Guizhou Provincial University Key Laboratory of High Performance Battery Materials Guizhou UniversityGuiyang 550025GuizhouChina Shougang Guiyang Special Steel Co. Guiyang 550005GuizhouChina

Larger-sized primary carbides lead to stress concentration during the application of H13 hot-work die steel,resulting in microcracks and fatigue *** earth was usually added to modify the carbides and *** existing literature is reviewed on the effect of rare earth on primary carbides in H13 steel.A comprehensive review on the effect of rare earth on the characteristics of primary carbides,i.e.,number,size,morphology,and thermal stability in H13 steel,was *** precipitation mechanism and nucleation of primary carbides with rare earth were *** position and form of rare earth in steel and their effects on alloying elements segregation were *** addition techniques of rare earth in H13 steel were compared,and the prospects for other uncommon rare earth and emerging technology were *** on the current references,it can be known that adding rare earth facilitated refined and dispersed primary *** size of primary carbides would be reduced,and their morphology would be improved because the rare earth inclusions formed in H13 steel can act as nucleation cores forγ-Fe orδ-Fe,refining the dendritic ***,the number of primary carbides at grain boundaries would be significantly ***,rare earth had little impact on thermal *** nucleation of primary carbides tended to be inhibited due to the modification of inclusions by rare earth which were likely to be nucleation cores for primary *** earth had been reported to affect the mechanism and process of primary carbide ***,the addition of rare earth can inhibit the segregation of alloying elements and carbon diffusion by ***,laboratory experiments and theoretical calcu-lations need to be conducted to study the states and evolution of rare earth steels.

关键词： Rare earth H13 die steel Primary carbide Nucleation Dendritic structure

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Study on the occurrence and influencing factors of gastrointestinal symptoms in hemodialysis patients with uremia

引用

World Journal of Gastrointestinal Surgery 2024年第7期16卷 2157-2166页

作者： Dan Yuan Xiao-qi Wang Feng Shao jing-jing Zhou Zhong-Xin Li Department of Nephrology Beijing Luhe Hospital Affiliated to Capital Medical UniversityBeijing 101100China

BACKGROUND Gastrointestinal symptoms are common in patients with uremia undergoing hemodialysis,and these symptoms seriously affect patients'*** To assess the occurrence and factors influencing gastrointestinal symptoms in patients with uremia undergoing *** We retrospectively selected 98 patients with uremia who underwent regular hemo-dialysis treatment in the blood purification center of our hospital from December 2022 to December *** gastrointestinal symptoms and scores of each dimension were evaluated using the Gastrointestinal Symptom Grading Scale(GSRS).Patients were divided into gastrointestinal symptoms and no gastrointestinal symptom groups according to whether they had gastrointestinal *** factors that may affect gastrointestinal symptoms were identified by single-factor *** logistic regression analysis was performed to identify independent risk factors for gastrointestinal *** Gastrointestinal symptoms included indigestion,constipation,reflux,diarrhea,abdominal pain,and eating disorders,and the total average GSRS score was 1.35±*** study showed that age,number of tablets,dialysis time,glucocorticoid,parathyroid hormone(PTH),combined diabetes mellitus and C-reactive protein(CRP)were independent risk factors for gastrointestinal symptoms in patients with uremia undergoing hemodialysis,whereas body mass index(BMI),hemoglobin(Hb),and urea clearance index were independent protective factors(P<0.05).CONCLUSION Gastrointestinal symptoms are mostly mild in patients with uremia undergoing hemodialysis,most commonly including dyspepsia,eating disorders,and gastroesophageal *** independent influencing factors mainly include the BMI,age,number of pills taken,dialysis time,urea clearance index,Hb,use of glucocorticoids,and thyroid hormone ***,CRP,and diabetes are clinically related factors influencing the occurrence of gastrointestinal symptoms,and targeted prevention can be perform

关键词： Uremic hemodialysis Gastrointestinal symptoms Influencing factors Blood pressure dialysis Chronic renal failure

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Ferrihydrite transformation impacted by coprecipitation of lignin:Inhibition or facilitation?

引用

Journal of Environmental Sciences 2024年第5期139卷 23-33页

作者： Lin Liu Zhihui Yang Weichun Yang Wen Jiang qi Liao Mengying Si Feiping zhao School of Metallurgy and Environment Central South UniversityChangsha 410083China Chinese National Engineering Research Center for Control&Treatment of Heavy Metal Pollution(CNERC-CTHMP) Changsha 410083China

Lignin is a common soil organic matter that is present in soils,but its effect on the transformation of ferrihydrite(Fh)remains *** matter is generally assumed to inhibit Fh ***,lignin can reduce Fh to Fe(Ⅱ),in which Fe(Ⅱ)-catalyzed Fh transformation ***,the effects of lignin on Fh transformation were investigated at 75℃ as a function of the lignin/Fh mass ratio(0-0.2),pH(4-8)and aging time(0-96 hr).The results of Fh-lignin samples(mass ratios=0.1)aged at different pH values showed that for Fh-lignin the time of Fh transformation into secondary crystalline minerals was significantly shortened at pH 6 when compared with pure Fh,and the Fe(Ⅱ)-accelerated transformation of Fh was strongly dependent on *** pH 6,at low lignin/Fh mass ratios(0.05-0.1),the time of secondary mineral formation decreased with increasing lignin *** high lignosulfonate-content material(lignin:Fh=0.2),Fh did not transform into secondary minerals,indicating that lignin content plays a major role in Fh *** addition,lignin affected the pathway of Fh transformation by inhibiting goethite formation and facilitating hematite *** effect of coprecipitation of lignin on Fh transformation should be useful in understanding the complex iron and carbon cycles in a soil environment.

关键词： Ferrihydrite transformation Lignin Hematite Goethite Fe(Ⅱ)-catalyzed Reactive Fe(Ⅲ)species

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Tube Model Predictive Control Based Cyber-attack-resilient Optimal Voltage Control Strategy in Wind Farms

引用

CSEE Journal of Power and Energy Systems 2024年第2期10卷 530-538页

作者： Zhenming Li Minghao Wang Yunfeng Yan Donglian qi zhao Xu Jianliang Zhang Zezhou Wang College of Electrical Electronic Engineering Zhejiang UniversityHangzhou 310058China Department of Electrical Engineering The Hong Kong Polytechnic UniversityKowloonHong KongChina Haiyan power supply company of State Grid Zhejiang Electric Power Co. LtdHangzhouChina

Optimal voltage controls have been widely applied in wind farms to maintain voltage stability of power *** order to achieve optimal voltage operation,authentic grid information is widely needed in the sensing and actuating ***,this may induce system vulnerable to malicious *** this end,a tube model predictive control-based cyber-attack-resilient optimal voltage control method is proposed to achieve voltage stability against malicious *** proposed method consists of two cascaded model predictive controllers(MPC),which outperform other peer control methods in effective alleviation of adverse effects from cyber-attacks on actuators and sensors of the ***,efficiency of the proposed method is evaluated in sensor and actuator cyber-attack cases based on a modified IEEE 14 buses system and IEEE 118 buses *** Terms-Attack-resilient control,optimal voltage control,tube-based model predictive control,wind farm-connected power system.

关键词： Attack-resilient control optimal voltage control tube-based model predictive control wind farm-connected power system

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Investigation of the Corrosion and Passive Behavior of HP-13Cr Stainless Steel in Formate Annulus Protection Fluid

引用

Acta Metallurgica Sinica(English Letters) 2024年第6期37卷 1087-1103页

作者： Jidong Wang Tengfei Yin Wenlong qi Xuanpeng Li Yang zhao Tao Zhang Fuhui Wang Shenyang National Laboratory for Materials Science Northeastern UniversityShenyang110819China State Key Laboratory of Performance and Structural Safety for Petroleum Tubular Goods and Equipment Materials Tubular Goods Research InstituteCNPCXi’an710077China

The corrosion and passive behavior of HP-13Cr stainless steel(HP-13Cr SS)in formate annulus protection fluid was ***-13Cr SS exhibited good passive behavior in clean formate annulus protection fluid,which was attributed to a thinner and more dense passive film mainly composed of Cr_(2)O_(3).In the formation water solution,the passive film was composed of metastable Cr(OH)3,which was explained by the isoelectric point theory,resulting in the deterioration of the passive behavior of HP-13Cr *** the formation water penetrated the formate annulus protection fluid,a large number of loose FeCO_(3)particles formed in the corrosion scales,thus HP-13Cr SS suffered severe ***,avoiding formation water penetrating the formate annulus protection fluid is conducive to improving the service life of HP-13Cr SS oil tubes in extremely aggressive environment.

关键词： HP-13Cr SS Passive behavior Formate annulus protection fluid Isoelectric point

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Interpreting Larix principis-rupprechtii radial growth in northern China based on the Vaganov-Shashkin model

引用

Journal of Forestry Research 2024年第3期35卷 99-110页

作者： Jiachuan Wang Shuheng Li qiang Li Yili Guo Yijie Han qi Liu Yiqi zhao College of Urban and Environmental Sciences Northwest UniversityXi'an 710127People's Republic of China Institute of Global Environmental Change Xi'an Jiaotong UniversityXi'an 710049People's Republic of China Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity Northwest UniversityXi'an 710127People's Republic of China State Key Laboratory of Loess and Quaternary Geology Institute of Earth EnvironmentChinese Academy of SciencesXi'an 710061People's Republic of China

Changes in annual radial growth is an important indication of climate change. Dendroclimatology studies in northern China have focused on linear statistical analysis,but lacking studies based on the process of ring formation to clarify the radial growth of trees. Tree-ring width standard chronology(STD) was established using samples of Larix principis-rupprechtii collected at 2303 m altitude on Luya Mountain. Using the Vaganov-Shashkin(VS) model to simulate growth and development, the internal physiological mechanism of radial growth is identified. It was concluded that:(1) the growing season of L. principis-rupprechtii was May to September;(2) soil moisture was a significant factor in the early and late growing seasons, and temperature was the dominant factor in its main growth period;and(3) formation of narrow ring widths was closely related to drought stress, the development of wide ring widths will be restricted by increasing future temperatures. The VS model is applicable for radial growth simulation of subalpine coniferous forests and for guiding the cultivation of local tree species in the future.

关键词： Vaganov-Shashkin model Larix principis-rupprechti Tree-ring width Annual growth

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Synergy between CSST galaxy survey and gravitational-wave observation: Inferring the Hubble constant from dark standard sirens

引用

Science China(Physics,Mechanics & Astronomy) 2024年第3期67卷 7-19页

作者： Ji-Yu Song Ling-Feng Wang Yichao Li Ze-Wei zhao jing-Fei Zhang Wen zhao Xin Zhang Key Laboratory of Cosmology and Astrophysics(Liaoning)&College of Sciences Northeastern UniversityShenyang 110819China CAS Key Laboratory for Researches in Galaxies and Cosmology Department of AstronomyUniversity of Science and Technology of ChinaChinese Academy of SciencesHefei 230026China School of Astronomy and Space Sciences University of Science and Technology of ChinaHefei 230026China National Frontiers Science Center for Industrial Intelligence and Systems Optimization Northeastern UniversityShenyang 110819China Key Laboratory of Data Analytics and Optimization for Smart Industry(Ministry of Education) Northeastern Universty Shenyang 110819China

Gravitational waves(GWs) from compact binary coalescences encode the absolute luminosity distances of GW sources. Once the redshifts of GW sources are known, one can use the distance-redshift relation to constrain cosmological parameters. One way to obtain the redshifts is to localize GW sources by GW observations and then use galaxy catalogs to determine redshifts from a statistical analysis of redshift information of the potential host galaxies, commonly referred to as the dark siren method. The third-generation(3G) GW detectors are planned to work in the 2030s and will observe numerous compact binary *** these GW events as dark sirens requires high-quality galaxy catalogs from future sky survey projects. The China Space Station Telescope(CSST) will be launched in 2024 and will observe billions of galaxies within a 17500 deg^(2) survey area with redshift up to z ~ 4, providing photometric and spectroscopic galaxy catalogs. In this work, we simulate the CSST galaxy catalogs and the 5-year GW data from the 3G GW detectors and combine them to infer the Hubble constant(H_(0)). Our results show that the measurement precision of H0could reach the sub-percent level, meeting the standard of precision cosmology. We conclude that the synergy between CSST and the 3G GW detectors is of great significance in measuring the Hubble constant.

关键词： CSST galaxy survey galaxy catalogs gravitational waves dark sirens the Hubble constant

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Privacy-Preserving Multi-Keyword Fuzzy Adjacency Search Strategy for Encrypted Graph in Cloud Environment

引用

Computers, Materials & Continua 2024年第3期78卷 3177-3194页

作者： Bin Wu Xianyi Chen Jinzhou Huang Caicai Zhang jing Wang jing Yu Zhiqiang zhao Zhuolin Mei School of Computer and Big Data Science Jiujiang UniversityJiujiang332005China Jiujiang Key Laboratory of Network and Information Security Jiujiang332005China School of Computer and Software Nanjing University of Information Science&TechnologyNanjing210044China School of Computer Engineering Hubei University of Arts and ScienceXiangyang441053China School of Modern Information Technology Zhejiang Institute of Mechanical and Electrical EngineeringHangzhou310053China Information Center Jiangxi Changjiang Chemical Co.Ltd.Jiujiang332005China School of Mathematics and Computer Science Ningxia Normal UniversityGuyuan756099China

In a cloud environment,outsourced graph data is widely used in companies,enterprises,medical institutions,and so *** owners and users can save costs and improve efficiency by storing large amounts of graph data on cloud *** on cloud platforms usually have some subjective or objective attacks,which make the outsourced graph data in an insecure *** issue of privacy data protection has become an important obstacle to data sharing and *** to query outsourcing graph data safely and effectively has become the focus of *** query is a basic and frequently used operation in graph,and it will effectively promote the query range and query ability if multi-keyword fuzzy search can be supported at the same *** work proposes to protect the privacy information of outsourcing graph data by encryption,mainly studies the problem of multi-keyword fuzzy adjacency query,and puts forward a *** our scheme,we use the Bloom filter and encryption mechanism to build a secure index and query token,and adjacency queries are implemented through indexes and query tokens on the cloud *** proposed scheme is proved by formal analysis,and the performance and effectiveness of the scheme are illustrated by experimental *** research results of this work will provide solid theoretical and technical support for the further popularization and application of encrypted graph data processing technology.

关键词： Privacy-preserving adjacency query multi-keyword fuzzy search encrypted graph

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Ultrafast laser-induced decomposition for selective activation of GaAs

引用

Light(Advanced Manufacturing) 2024年第2期5卷 87-94页

作者： Ke-Mi Xu Chao Liu Lei Wang Feng-Chun Pang Xin-jing zhao Xian-Bin Li qi-Dai Chen Wei-qian zhao MIIT Key Laboratory of Complex-field Intelligent Exploration School of Optics and PhotonicsBeijing Institute of TechnologyBeijing100081China State Key Laboratory of Integrated Optoelectronics College of Electronic Science and EngineeringJilin University2699 Qianjin StreetChangchun 130012China

The manipulation of micro/nanostructures to customise their inherent material characteristics has garnered considerable *** this study,we present the selective activation of gallium arsenide(GaAs)via ultrafast laser-induced decomposition,which correlates with the emergence of ripples on the *** instigated a pronounced enrichment in the arsenic(As)concentration around the surface while inducing a depletion of gallium(Ga)at the structural *** simulations based on first principles exhibited a robust inclination towards the phase separation of GaAs,with the gasification of As-As pairs proving more facile than that of Ga-Ga pairs,particularly above the melting point of *** an illustrative application,a metal-semiconductor hybrid surface was confirmed,showing surface chemical bonding and surface-enhanced Raman scattering(SERS)through the reduction of silver ions on the laser-activated *** laser-induced selective activation holds promise for broader applications,including the controlled growth of Pd and the development of Au/Ag alloy-based platforms,and thereby opens innovative avenues for advancements in semiconductors,solar cell technologies,precision sensing,and detection methodologies.

关键词： Laser-induced activation Decomposition Laser-induced ripples Reduction SERS

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：