期刊文献+
共找到9,850篇文章
< 1 2 250 >
每页显示 20 50 100
Three-stage tectonic subsidence and its implications for the evolution of conjugate margins of the southwest subbasin,South China Sea 被引量:1
1
作者 Wenlong WANG Dongdong DONG +1 位作者 Xiujuan WANG Guangxu ZHANG 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2021年第5期1854-1870,共17页
To reveal the tectonic characteristics of the continental margins in the southwest subbasin(SWB)of the South China Sea,a long high-resolution seismic profile was studied using empty basin subsidence.We find that tecto... To reveal the tectonic characteristics of the continental margins in the southwest subbasin(SWB)of the South China Sea,a long high-resolution seismic profile was studied using empty basin subsidence.We find that tectonic subsidence features on both margins are uniformly divided into three stages:(1)slow subsidence from Tg to 18.5 Ma(synrift stage);(2)extremely slow subsidence/uplift from18.5 to 16 Ma(spreading stage);and(3)accelerated subsidence from 16 to 0 Ma(post-spreading stage).This feature differs from the classic tectonic subsidence pattern of rifted basins,which exhibits fast subsidence during synrift stage and slow subsidence during the post-rift stage.The tectonic uplift occurred during the spreading stage and the magnitude increased from the continent to the ocean,which is likely related to mantle flow during seafloor spreading.We propose that lower crustal flow played a significant role in the tectonic evolution of the continental margins of the SWB.The lower crust of the SWB margins was warmer and therefore weaker,and more prone to flow beneath the faulting center,which compensated for the upper crustal thinning caused by brittle faulting during the synrift period and thus reduced the tectonic subsidence rate.During the spreading stage,faulting attenuated rapidly,and a necking zone appeared at the continentocean transition formed by lithospheric extension.With upwelling asthenosphere,small-scale secondary mantle convection occurred under the necking zone,which raised the continental margin isotherms and increased the buoyancy.Simultaneously,secondary mantle convection lifted the overriding crust,thus the overall subsidence rate decreased sharply or even reversed to uplift.After seafloor spreading,the effect of mantle convection faded away,and sediment loading drove the lower crust to flow landward.Thermal relaxation,lower crust flow,and vanish of secondary mantle convection together led to rapid subsidence in this stage. 展开更多
关键词 tectonic subsidence lower crustal flow tectonic evolution southwest subbasin South China Sea
在线阅读 下载PDF
Three-Stage Heat Transfer Pathways in the Latent Heat Thermal Energy Storage System With Solid–Liquid Phase-Change Materials
2
作者 Qian Xu Di Yang +9 位作者 Caixia Yang Pengxiang Zhao Andrey A.Shiryaev Ruitao Zhang Gang Li Huachao Yang Haihong Wang Yiyao Ge Yong Zang Yulong Ding 《Carbon Energy》 2025年第12期40-70,共31页
The latent heat thermal energy storage system with solid-liquid phase-change material(SLPCM-LHTES)as energy storage medium provides outstanding advantages such as system simplicity,stable temperature control,and high ... The latent heat thermal energy storage system with solid-liquid phase-change material(SLPCM-LHTES)as energy storage medium provides outstanding advantages such as system simplicity,stable temperature control,and high energy storage density,showing great potential toward addressing the energy storage problems associated with decentralized,intermittent,and unstable renewable energy sources.Notably,effective heat transfer within the SLPCM-LHTES is crucial for extending its application potential.Therefore,a comprehensive understanding of the heat transfer processes in SLPCM-LHTES from a theoretical perspective is necessary.In this review,we propose a three-stage heat transfer pathway in SLPCM-LHTES,including external heating,interfacial heat transfer,and intrinsic phase transition processes.From the perspective of this three-stage pathway,the theoretical basis of heat transfer processes and typical efficiency enhancement strategies in SLPCM-LHTES are summarized.Moreover,an overview of the typical applications of SLPCM-LHTES in various fields,such as building energy efficiency,textiles and garments,and battery thermal management,is presented.Finally,the remaining challenges and possible avenues of research in this burgeoning field will also be discussed. 展开更多
关键词 heat transfer efficiency latent heat thermal energy storage phase-change material three-stage heat transfer pathway
在线阅读 下载PDF
Effect of three-stage fusion nursing intervention the rehabilitation process and psychological stress in patients after gastric cancer surgery
3
作者 Xia Zhao 《World Journal of Gastrointestinal Surgery》 2025年第7期319-327,共9页
BACKGROUND Patients with gastric cancer often experience slow postoperative recovery and psychological stress,necessitating enhanced nursing care to improve their prognosis.AIM To analyze the impact of a timing-theory... BACKGROUND Patients with gastric cancer often experience slow postoperative recovery and psychological stress,necessitating enhanced nursing care to improve their prognosis.AIM To analyze the impact of a timing-theory-guided three-stage integrated nursing intervention(TSIN)on the postoperative recovery of patients undergoing gastric cancer surgery.METHODS Total 84 patients that underwent gastric cancer surgeries between June 2022 and June 2024 were selected and divided into a control group and an observation group based on perioperative nursing methods.The control group(n=42)received routine nursing care,whereas the observation group(n=42)received a timing-theory-guided TSIN.The psychological adjustment capabilities,psychological stress,cancer-related fatigue levels,postoperative recovery,and quality of life of the two groups were compared.RESULTS Compared to the control group,the observation group took lesser time to get out of bed,achieve gastrointestinal motility,have the first mealtime,along with a shorter hospital stay(P<0.05).Before nursing,there were no significant differences between groups’parameters or scores(P>0.05).After nursing,the scores for psychological stress and cancer-related fatigue decreased.In contrast,the scores for psychological adjustment capabilities and quality of life increased,with more significant improvements observed in the observation group,showing significant differences within and between the groups(P<0.05).CONCLUSION Timing theory-guided TSIN can improve the psychological adjustment capabilities of patients undergoing gastric cancer surgery,reduce psychological stress and cancer-related fatigue,accelerate postoperative recovery,and improve the quality of life. 展开更多
关键词 Timing theory three-stage integrated nursing Gastric cancer surgery Psychological adjustment Psychological stress Quality of life
暂未订购
CoMoNiO-S/nickel foam heterostructure composite for efficient oxygen evolution catalysis performance
4
作者 YANG Hong SHAO Shengjuan +2 位作者 LI Baoyi LU Yifan LI Na 《无机化学学报》 北大核心 2026年第1期203-215,共13页
A composite electrocatalyst,CoMoNiO-S/NF-110(NF is nickel foam),was synthesized through electrodeposition,followed by pyrolysis and then the vulcanization process.CoMoNiO-S/NF-110 exhibited a structure where Ni3S2 and... A composite electrocatalyst,CoMoNiO-S/NF-110(NF is nickel foam),was synthesized through electrodeposition,followed by pyrolysis and then the vulcanization process.CoMoNiO-S/NF-110 exhibited a structure where Ni3S2 and Mo2S3 nanoparticles were integrated at the edges of Co3O4 nanosheets,creating a rich,heterogeneous interface that enhances the synergistic effects of each component.In an alkaline electrolyte,the synthesized CoMoNiO-S/NF-110 exhibited superior electrocatalytic performance for oxygen evolution reaction(OER),achieving current densities of 100 and 200 mA·cm^(-2) with low overpotentials of 199.4 and 224.4 mV,respectively,outperforming RuO2 and several high-performance Mo and Ni-based catalysts.This excellent performance is attributed to the rich interface formed between the components and active sites exposed by the defect structure. 展开更多
关键词 oxygen evolution reaction VULCANIZATION composite electrocatalyst MoNi-based catalyst
在线阅读 下载PDF
Post-synthetic modification strategy to construct Co-MOF composites for boosting oxygen evolution reaction activity
5
作者 ZHENG Haifeng GUO Xingzhe +5 位作者 WEI Yunwei WANG Xinfang QI Huimin YAN Yuting ZHANG Jie LI Bingwen 《无机化学学报》 北大核心 2026年第1期193-202,共10页
The poor electrical conductivity of metal-organic frameworks(MOFs)limits their electrocatalytic performance in the oxygen evolution reaction(OER).In this study,a Py@Co-MOF composite material based on pyrene(Py)molecul... The poor electrical conductivity of metal-organic frameworks(MOFs)limits their electrocatalytic performance in the oxygen evolution reaction(OER).In this study,a Py@Co-MOF composite material based on pyrene(Py)molecules and{[Co2(BINDI)(DMA)_(2)]·DMA}_(n)(Co-MOF,H4BINDI=N,N'-bis(5-isophthalic acid)naphthalenediimide,DMA=N,N-dimethylacetamide)was synthesized via a one-pot method,leveragingπ-πinteractions between pyrene and Co-MOF to modulate electrical conductivity.Results demonstrate that the Py@Co-MOF catalyst exhibited significantly enhanced OER performance compared to pure Co-MOF or pyrene-based electrodes,achieving an overpotential of 246 mV at a current density of 10 mA·cm^(-2) along with excellent stability.Density functional theory(DFT)calculations reveal that the formation of O*in the second step is the rate-determining step(RDS)during the OER process on Co-MOF,with an energy barrier of 0.85 eV due to the weak adsorption affinity of the OH*intermediate for Co sites.CCDC:2419276. 展开更多
关键词 PYRENE metal-organic frameworks composite catalyst oxygen evolution reaction density functional theory
在线阅读 下载PDF
S-scheme unidirectional transmission of CdS-CuO heterojunction benefits for superior photocatalytic hydrogen evolution efficiency
6
作者 ZHAO Haiting YAN Zheng +2 位作者 LIU Yang JIANG Longde LUAN Jingde 《燃料化学学报(中英文)》 北大核心 2026年第1期1-14,共14页
The efficiency and stability of catalysts for photocatalytic hydrogen evolution(PHE)are largely governed by the charge transfer behaviors across the heterojunction interfaces.In this study,CuO,a typical semiconductor ... The efficiency and stability of catalysts for photocatalytic hydrogen evolution(PHE)are largely governed by the charge transfer behaviors across the heterojunction interfaces.In this study,CuO,a typical semiconductor featuring a broad spectral absorption range,is successfully employed as the electron acceptor to combine with CdS for constructing a S-scheme heterojunction.The optimized photocatalyst(CdSCuO2∶1)delivers an exceptional hydrogen evolution rate of 18.89 mmol/(g·h),4.15-fold higher compared with bare CdS.X-ray photoelectron spectroscopy(XPS)and ultraviolet-visible diffuse reflection absorption spectroscopy(UV-vis DRS)confirmed the S-scheme band structure of the composites.Moreover,the surface photovoltage(SPV)and electron paramagnetic resonance(EPR)indicated that the photogenerated electrons and photogenerated holes of CdS-CuO2∶1 were respectively transferred to the conduction band(CB)of CdS with a higher reduction potential and the valence band(VB)of CuO with a higher oxidation potential under illumination,as expected for the S-scheme mechanism.Density-functional-theory calculations of the electron density difference(EDD)disclose an interfacial electric field oriented from CdS to CuO.This built-in field suppresses charge recombination and accelerates carrier migration,rationalizing the markedly enhanced PHE activity.This study offers a novel strategy for designing S-scheme heterojunctions with high light harvesting and charge utilization toward sustainable solar-tohydrogen conversion. 展开更多
关键词 photocatalytic hydrogen evolution CdS-CuO S-scheme heterojunction electron directional transmission interfacial electric field DFT calculation
在线阅读 下载PDF
Synergistic Oxygen Vacancy and Ru-N Coordination in RuO_(2)@NCC for Enhanced Acidic Oxygen Evolution Reaction
7
作者 Mi Luo Linyao Huang +2 位作者 Chen Shen Tianhua Yang Chenguang Wang 《Carbon Energy》 2026年第1期115-125,共11页
Developing efficient and durable electrocatalysts for acidic oxygen evolution reaction(OER)is pivotal for advancing proton exchange membrane water electrolysis(PEMWEs),yet balancing activity and stability remains a fo... Developing efficient and durable electrocatalysts for acidic oxygen evolution reaction(OER)is pivotal for advancing proton exchange membrane water electrolysis(PEMWEs),yet balancing activity and stability remains a formidable challenge.Herein,we propose a dual-engineering strategy to stabilize Ru-based catalysts by synergizing the oxygen vacancy site-synergized mechanism-lattice oxygen mechanism(OVSM-LOM)with Ru-N bond stabilization.The engineered RuO_(2)@NCC catalyst exhibits exceptional OER performance in 0.5 M H2SO4,achieving an ultralow overpotential of 215 mV at 10 mA cm^(-2) and prolonged stability for over 327 h.The catalyst delivers 300 h of continuous operation at 1 A cm^(-2),with a negligible degradation rate of only 0.067 mV h-1,further demonstrating its potential for practical application.Oxygen vacancies unlock the OVSM-LOM pathway,bypassing the sluggish adsorbate evolution mechanism(AEM)and accelerating reaction kinetics,while the Ru-N bonds suppress Ru dissolution by anchoring low-valent Ru centers.Quasi-in situ X-ray photoelectron spectroscopy(XPS),X-ray absorption spectroscopy(XAS),and isotopic labeling experiments confirm the lattice oxygen participation with *O formation as the rate-determining step.The Ru-N bonds reinforce the structural integrity by stabilizing low-valent Ru centers and inhibiting overoxidation.Theoretical calculations further verify that the synergistic interaction between OVs and Ru-O(N)active sites optimizes the Ru d-band center and stabilizes intermediates,while Ru-N coordination enhances structural integrity.This study establishes a novel paradigm for designing robust acidic OER catalysts through defect and coordination engineering,bridging the gap between activity and stability for sustainable energy technologies. 展开更多
关键词 OVSM-LOM oxygen evolution reaction oxygen vacancy Ru-N XAFS
在线阅读 下载PDF
Ternary metal NiRuPt partition synergistic relay promotes pHuniversal hydrogen evolution
8
作者 Miaoyang Yu Qiao Ye +7 位作者 Feng Wang Abdukader Abdukayum Nianpeng Li Lei Zhang Chuan Zuo Weiping Liu Xue Zhao Guangzhi Hu 《Nano Research》 2026年第1期244-252,共9页
Hydrogen production by electrolysis of water is a key technology to achieve green hydrogen energy economy,but it relies on advanced catalyst materials with high efficiency,stability,and wide pH adaptability.In this st... Hydrogen production by electrolysis of water is a key technology to achieve green hydrogen energy economy,but it relies on advanced catalyst materials with high efficiency,stability,and wide pH adaptability.In this study,Ni,Ru,and Pt ternary metals were embedded into nitrogen-doped hollow carbon spheres(NHCSs)by hydrothermal tandem heat treatment to form ternary supported metal nanoparticles with high dispersion and ultra-small particle size(~1.3 nm),which realized efficient hydrogen evolution from multi-scenario electrocatalytic water splitting.In the whole pH range,the performance of NiRuPt/NHCSs is better than that of commercial Pt/C catalyst,and the overpotentials under alkaline,neutral,and acidic conditions are as low as 15.5,20.0,and 29.5 mV,respectively.Under industrial conditions,NiRuPt/NHCSs also have excellent hydrogen evolution reaction(HER)performance,achieving efficient electrolysis of seawater for hydrogen production,and achieving Ampere-level hydrogen production at low voltage(~1.76 V)on integrated membrane electrode assemblies.Density functional theory(DFT)calculations show that in the NiRuPt ternary metal,the Pt site is conducive to promoting the desorption of*H to form H_(2),the Ru site is conducive to promoting the capture of H_(2)O,and the Ni site is conducive to promoting the dissociation of H_(2)O.Therefore,the formed NiRuPt ternary metal synergistically promotes multi-scenario efficient electrolysis of water to produce hydrogen.This study provides a new idea for the design of multi-component metal/carbon-based composite catalysts,and promotes the development of non-noble metal/noble metal composite catalysts in hydrogen production by electrolysis of water. 展开更多
关键词 hydrogen evolution reaction trimetallic nanohybrids synergistic catalysis seawater electrolysis
原文传递
The historical evolution of the Serbisütherapy in traditional Mongolian medicine,from its origins to contemporary practice
9
作者 Mei-Ri Na Manda Manda +1 位作者 Temuqile Temuqile De-Zhi Yang 《History and Philosophy of Medicine》 2026年第1期43-48,共6页
Serbisütherapy(ST)is a distinctive external treatment modality within traditional Mongolian medicine(TMM),historically developed within a nomadic cultural framework.This study presents a comprehensive philologica... Serbisütherapy(ST)is a distinctive external treatment modality within traditional Mongolian medicine(TMM),historically developed within a nomadic cultural framework.This study presents a comprehensive philological and historical analysis of ST,tracing its evolution from early battlefield applications to contemporary clinical use.By critically examining classical Mongolian medical texts alongside modern case studies,we aim to systematize ST’s therapeutic methods,indications,and limitations,while exploring its mechanisms of action through both traditional theory and modern biomedical perspectives.ST has undergone significant transformation,shifting from whole-body cavity immersion in the 13th century to targeted,organ-specific applications in modern practice.Its four primary methods–Covering,Mounted,Organ Placement,and Suction–demonstrate efficacy in treating cold-natured diseases,musculoskeletal disorders,gynecological conditions,and certain emergencies.ST embodies the core principles of TMM,particularly the balance of the“Three Roots”and the correction of cold-induced pathologies through heat.Despite challenges related to standardization,cultural translation,and regulatory acceptance,ST holds translational potential for integrative medicine.Future research should prioritize mechanistic validation,clinical standardization,and the development of biocompatible thermal technologies to bridge traditional practice with modern healthcare systems. 展开更多
关键词 Serbisütherapy traditional Mongolian medicine THERMOTHERAPY historical evolution integrative medicine
暂未订购
Efficient oxygen evolution in acidic electrolysis of water using copper loaded with iridium nanoclusters
10
作者 Yanan Song Bingxin Zhang +5 位作者 Tai Xiang Huabin Wang Yong Zhang Xiaoning Tang Lin Tian Rui Xu 《Journal of Environmental Sciences》 2026年第1期120-129,共10页
Oxygen evolution reaction(OER)is a key step in hydrogen production by water electrolysis technology.How-ever,developing efficient,stable,and low-cost OER electrocatalysts is still challenging.This article presents the... Oxygen evolution reaction(OER)is a key step in hydrogen production by water electrolysis technology.How-ever,developing efficient,stable,and low-cost OER electrocatalysts is still challenging.This article presents the preparation of a series of novel copper iridium nanocatalysts with heterostructures and low iridium content for OER.The electrochemical tests revealed higher OER of Cu@Ir_(0.3) catalyst under acidic conditions with a generated current density of 10 mA/cm^(2) at only 284 mV overpotential.The corresponding OER mass activity was estimated to be 1.057 A/mgIr,a value 8.39-fold higher than that of the commercial IrO_(2).After 50 h of endurance testing,the Cu@Ir_(0.3) catalyst preserved excellent catalytic activity with a negligible rise in overpotential and maintained a good heterostructures.Cu@Ir_(0.3) The excellent OER activity can be attributed to its heterostructure,as con-firmed by density functional theory(DFT)calculations,indicating that Cu@Ir The coupling between isoquanta causes charge redistribution,optimizing the adsorption energy of unsaturated Ir sites for oxygen intermediates and reducing the energy barrier of OER free energy determining the rate step.In summary,this method provides a new approach for designing efficient,stable,and low iridium content OER catalysts. 展开更多
关键词 Heterostructure Oxygen evolution reaction(OER) ELECTROCATALYSIS Density functional theory(DFT)
原文传递
Advances in oxygen evolution reaction electrocatalysts via direct oxygen-oxygen coupling pathway:Recent progress,challenges,and perspectives
11
作者 Xinying Yang Zhengda Chen +4 位作者 Guoxin Zhang Yuping Sun Jiangbo Lu Haiping Lin Xing Fan 《Nano Research》 2026年第1期23-49,共27页
Deep insights into electrocatalytic mechanisms are vital for the rational design of catalysts for oxygen evolution reaction(OER).Mechanistically,the OER driven by adsorbate evolution mechanism(AEM)is limited by the li... Deep insights into electrocatalytic mechanisms are vital for the rational design of catalysts for oxygen evolution reaction(OER).Mechanistically,the OER driven by adsorbate evolution mechanism(AEM)is limited by the linear scaling relationship,thereby exhibiting large overpotentials.In the lattice oxygen mechanism(LOM),the OER can be enhanced by enabling direct O_(2)formation.However,this enhancement is accompanied by the generation of oxygen vacancies,which presents a significant challenge to the long-term stability of LOMOER,particularly when operating at high current densities.Recently,the*O-*O coupling mechanism(OCM)has emerged as a promising alternative;it not only breaks the linear scaling relationship but also ensures catalytic stability.This review encapsulates the cutting-edge advancements in electrocatalysts that are grounded in the OCM,offering a detailed interpretation on the foundational principles guiding the design of OCM-OER catalysts.It also highlights recent theoretical investigations combining machine learning(ML)with density functional theory(DFT)calculations to reveal OER mechanisms.At the end of this review,the challenges and opportunities associated with OCM-OER electrocatalysts are discussed. 展开更多
关键词 oxygen evolution reaction *O-*O coupling mechanism dual-atom catalysts machine learning
原文传递
Microstructure evolution and corrosion behavior of refill friction stir spot welding joint for dissimilar Al alloys
12
作者 Fang-yuan JIANG Da ZHANG +3 位作者 Yan-kun MA Jiang-tao XIONG Wei GUO Jing-long LI 《Transactions of Nonferrous Metals Society of China》 2026年第1期80-95,共16页
The dissimilar 2B06 and 7B04 Al alloy joints were prepared by refill friction stir spot welding(RFSSW),and the microstructural evolution and corrosion behavior of the joints were investigated.Based on microstructural ... The dissimilar 2B06 and 7B04 Al alloy joints were prepared by refill friction stir spot welding(RFSSW),and the microstructural evolution and corrosion behavior of the joints were investigated.Based on microstructural analysis,the welded joints exhibit distinct microstructural zones,including the stir zone(SZ),thermomechanically affected zone(TMAZ),and heat-affected zone(HAZ).The grain size of each zone is in the order of HAZ>TMAZ>SZ.Notably,the TMAZ and HAZ contain significantly larger secondary-phase particles compared to the SZ,with particle size in the HAZ increasing at higher rotational speeds.Electrochemical tests indicate that corrosion susceptibility follows the sequence of HAZ>TMAZ>SZ>BM,with greater sensitivity observed at increased rotational speeds.Post-corrosion mechanical performance degradation primarily arises from crevice corrosion at joint overlaps,but not from the changes in the microstructure. 展开更多
关键词 refill friction stir spot welding high strength Al alloy dissimilar joint microstructure evolution corrosion behavior
在线阅读 下载PDF
Operando structural evolution of octahedral SnS_(2)/SnO_(2)heterojunctions enabling efficient CO_(2)-to-formate conversion over a broad potential window
13
作者 Taojiang Deng Chengyu Qin +5 位作者 Liming Sun Li-Xia Liu Wenwen Zhan Guilin Zhuang Jingyi Jia Xiguang Han 《Nano Research》 2026年第1期224-232,共9页
Heterostructure engineering has emerged as a promising strategy to enhance the electrochemical CO_(2)reduction reaction(CO_(2)RR)by optimizing interfacial electron transfer.Herein,we report a novel octahedral SnS_(2)/... Heterostructure engineering has emerged as a promising strategy to enhance the electrochemical CO_(2)reduction reaction(CO_(2)RR)by optimizing interfacial electron transfer.Herein,we report a novel octahedral SnS_(2)/SnO_(2)heterojunction catalyst synthesized via an ion-exchange vulcanization method,which achieves exceptional activity and selectivity for CO_(2)-toformate conversion.Through in-situ Raman spectroscopy,ex-situ X-ray diffraction(XRD),and X-ray photoelectron spectroscopy(XPS),we demonstrate that the octahedral SnS_(2)/SnO_(2)heterojunction dynamically restructures into a sulfur-doped Sn/SnO_(2)(Sn(S)/SnO_(2))heterostructure under operating conditions.Density functional theory(DFT)calculations reveal that the Sn(S)/SnO_(2)interface facilitates electron transfer from SnO_(2)to metallic Sn(S),generating a built-in electric field that stabilizes Sn^(4+)in SnO_(2)and accelerates proton-coupled electron transfer to*OCHO intermediates.Consequently,the catalyst achieves a formate Faradaic efficiency exceeding 90% over a broad potential window(-0.6 to -1.0 V vs.reversible hydrogen electrode(RHE))with a high partial current density of -280 mA·cm^(-2),surpassing most reported Sn-based catalysts.This work elucidates the structural dynamics and interfacial enhancement mechanisms of heterojunction catalysts,offering a rational design principle for advanced CO_(2)RR electrocatalysts. 展开更多
关键词 CO_(2)reduction SnS_(2)/SnO_(2) heterojunction structure evolution reaction mechanisms
原文传递
Investigation on seismic response of a three-stage soil slope supported by anchor frame structure 被引量:8
14
作者 LIN Yu-liang LI Ying-xin +1 位作者 ZHAO Lian-heng YANG T Y 《Journal of Central South University》 SCIE EI CAS CSCD 2020年第4期1290-1305,共16页
Based on a typical prototype of a soil slope in engineering practice, a numerical model of a three-stage soil slope supported by the anchor frame structure was established by means of FLAC3D code. The dynamic response... Based on a typical prototype of a soil slope in engineering practice, a numerical model of a three-stage soil slope supported by the anchor frame structure was established by means of FLAC3D code. The dynamic responses of three-stage soil slope and frame structure were studied by performing a series of bidirectional Wenchuan motions in terms of the failure mode of three-stage structure, the acceleration of soil slope, the displacement of frame structure, and the anchor stress of frame structure. The response accelerations in both horizontal and vertical directions are the most largely amplified at the slope top of each stage subjected to different shaking cases. The platforms among the stages reduce the amplification effect of response acceleration. The residual displacement of frame structure increases significantly as the intensity of shaking case increases. The frame structure at each stage presents a combined displacement mode consisting of a translation and a rotation around the vertex. The anchor stress of frame structure is mainly increased by the first intense pulse of Wenchuan seismic wave, and it is sensitive to the intensity of shaking case. The anchor stress of frame structure at the first stage is the most considerably enlarged by earthquake loading. 展开更多
关键词 three-stage soil slope anchor frame structure ACCELERATION DISPLACEMENT anchor stress
在线阅读 下载PDF
Estimating regional coal resource efficiency in China using three-stage DEA and bootstrap DEA models 被引量:10
15
作者 Cui Yijia Huang Guoliang Yin Ziyong 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2015年第5期861-864,共4页
Based on three-stage data envelopment analysis(DEA) model estimates of resource utilization efficiency of coal,we selected 29 provinces from China's 2012 input-output data and used the bootstrap DEA model to corre... Based on three-stage data envelopment analysis(DEA) model estimates of resource utilization efficiency of coal,we selected 29 provinces from China's 2012 input-output data and used the bootstrap DEA model to correct the bias.The results show that the mean overall technical efficiency,pure technical efficiency,and scale efficiency was 0.833,0.998,and 0.711 in 2012,respectively.Moreover,the comprehensive technical efficiency score indicates that the scale is invalid.Area utilization efficiencies for the eastern,central,and western regions were 0.917,0.731,and 0.629,respectively.The results prove that there are significant differences in the distribution of coal resources utilization efficiency across regions. 展开更多
关键词 Coal resource efficiency three-stage DEA Bootstrap DEA Technical efficiency
在线阅读 下载PDF
Production Efficiency of Two-Oriented Agriculture Based on Three-Stage DEA Model 被引量:10
16
作者 ZHAI Huan-huan HE Zheng-chu ZHANG Rui 《Agricultural Science & Technology》 CAS 2010年第4期159-163,共5页
Two-oriented agriculture was a complex organism coupling production,economics,society and ecology.Its development process was affected by various factors such as producers,nature,society,etc.In order to overcome measu... Two-oriented agriculture was a complex organism coupling production,economics,society and ecology.Its development process was affected by various factors such as producers,nature,society,etc.In order to overcome measurement error of traditional data envelopment analysis caused by ignoring random,three-stage DEA model was studied to remove environmental factors and random effects.On the foundation of this model was two-oriented agriculture comprehensive production efficiency of 14 cities were estimated in Hunan Province in 2008,and brown forth corresponding policy proposals to promote agricultural development. 展开更多
关键词 Two-oriented agriculture three-stage DEA model Technical efficiency Scale efficiency
在线阅读 下载PDF
An Analysis of Operational Efficiency of Agricultural Insurance Agency:Based on Three-Stage DEA Model 被引量:2
17
作者 Xuan CHEN Wenhuan WEI 《Asian Agricultural Research》 2016年第12期12-16,共5页
From the perspective of agricultural insurance agency,this paper focuses on the study of operational efficiency of agricultural insurance agency,and analyzes the operational efficiency of agricultural insurance agency... From the perspective of agricultural insurance agency,this paper focuses on the study of operational efficiency of agricultural insurance agency,and analyzes the operational efficiency of agricultural insurance agency and its influencing factors,in order to improve the operational efficiency of agricultural insurance agency,better supply agricultural insurance and achieve the policy effect of agricultural insurance.The results of this paper are as follows:( i) Either comprehensive operational efficiency or scale efficiency of Chinese-funded agency is higher than that of foreign-funded agency,but its pure technical efficiency is lower than that of foreign-funded agency,indicating that the managerial decision ability of Chinese-funded agency is weaker than that of foreign-funded agency,and needs to be improved;( ii) The operational efficiency of professional agricultural insurance agency is higher than that of comprehensive agricultural insurance agency,and the agricultural insurance agency is greatly affected by environmental factors;( iii) The operating time of agricultural insurance agency is proportional to its operational efficiency;( iv) The quality of employees is positively correlated with the capital and cost input difference,but negatively correlated with the difference in the number of employees. Therefore,it is necessary to pay attention to the improvement of employees' working efficiency while laying emphasis on employees' quality. 展开更多
关键词 three-stage DEA Operational efficiency Influencing factors
在线阅读 下载PDF
Contribution to the Optimization of the Transient Stability of an Electric Power Transmission Network Using a Universal Power Flow Compensator Controlled by a Three-Stage Inverter 被引量:2
18
作者 Koko Koko Joseph Nneme Nneme Léandre Ndjakomo Essiane Salomé 《World Journal of Engineering and Technology》 2020年第4期675-688,共14页
The use of an electrical network as close as possible to its limits can lead to its instability in the event of a high amplitude disturbance. The damping of system oscillations can be achieved by conventional means of... The use of an electrical network as close as possible to its limits can lead to its instability in the event of a high amplitude disturbance. The damping of system oscillations can be achieved by conventional means of voltage and speed regulation but also by FACTS (Flexible AC Transmission Systems) devices, which are increasingly used in power networks. In this work, optimal control coordination between a hybrid power flow controller and a three-level inverter was used to improve the transient stability of a transmission line. The UPFC is a combination of a serial compensator (SSSC) and a parallel compensator (STATCOM) both connected to a DC-LINK DC bus. The SSSC acts as a voltage source for the network and injects a voltage that can be adjusted in phase and amplitude in addition to the network voltage;the STATCOM acts as a current source. The approach used is tested in the Matlab Simulink environment on a single machine network. Optimal controller tuning gives a better transient stability improvement by reducing the transport angle oscillations from 248.17% to 9.85%. 展开更多
关键词 FACTS UPFC three-stage Inverter PI Power Transit Transient Stability
在线阅读 下载PDF
Numerical Simulation of Enhanced Oil-Water Separation in a Three-Stage Double-Stirring Extraction Tank 被引量:3
19
作者 Lü Chao Zhang Zimu +3 位作者 Zhao Qiuyue Wang Shuchan Zhang Ting'an Liu Yan 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2015年第4期121-126,共6页
Numerical simulation of enhanced fluid flow characteristics in a three-stage double-stirring extraction tank was conducted with the coupling of an Eulerian multiphase flow model and a Morsi-Alexander interphase drag f... Numerical simulation of enhanced fluid flow characteristics in a three-stage double-stirring extraction tank was conducted with the coupling of an Eulerian multiphase flow model and a Morsi-Alexander interphase drag force model. Results show that the addition of a stirring device into the settler can efficiently reduce the volume fraction of out-of-phase impurity in the outlet, and accelerate the settling separation of oil-water mixture. Such addition can also effectively break down the oil-water-wrapped liquid droplets coming from the mixer, inhibit reflux from the outlet, and improve the oil-water separation. The addition of a stirring device induces ignorable power consumption compared with that by the mixer, and can thus facilitate the commercialized promotion of this novel equipment. 展开更多
关键词 three-stage extraction tank double-stirring numerical simulation flow characteristics power
在线阅读 下载PDF
Improving Bandwidth of Three-Stage Electro-Hydraulic Servo Valve Based on Speed-Feedback 被引量:1
20
作者 刘小初 何景峰 +2 位作者 叶正茂 丛大成 韩俊伟 《Journal of Donghua University(English Edition)》 EI CAS 2009年第5期494-498,共5页
In order to improve the dynamic response bandwidth of three-stage electro-hydraulic servo valve,a new method,speed-feedback control is presented in this paper.The construction and principle of three-stage electro-hydr... In order to improve the dynamic response bandwidth of three-stage electro-hydraulic servo valve,a new method,speed-feedback control is presented in this paper.The construction and principle of three-stage electro-hydraulic servo valve are explained,and the mathematical model of three-stage electro-hydraulic servo valve is built in frequency domain.Experimental and simulation results show that the bandwidth compared with proportional control is improved under speed-feedback control.Moreover,the research results play an important role in developing high performance three-stage electro-hydraulic servo valve. 展开更多
关键词 three-stage electro-hydraulic serw walve BANDWIDTH speed-feedback construction PRINCIPLE model simulation experimental test
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部