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Approach for redefining the damping factor of railway bridges with ballast superstructure:model calibration and guidelines for practical application
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作者 Andreas Stollwitzer Samuel Loidl +1 位作者 Lara Bettinelli Josef Fink 《Railway Engineering Science》 2026年第1期97-127,共31页
To ensure the compatibility between rolling stock and infrastructure when dynamically assessing railway bridges under high-speed traffic,the damping properties considered in the calculation model significantly influen... To ensure the compatibility between rolling stock and infrastructure when dynamically assessing railway bridges under high-speed traffic,the damping properties considered in the calculation model significantly influence the predicted acceleration amplitude at resonance.However,due to the normative specifications of EN 1991-2,which are considered to be overly conservative,damping factors that are far below the actual damping have to be used when predicting vibrations of railway bridges,which means that accelerations at resonance tend to be overestimated to an uneconomical extent.Comparisons between damping factors prescribed by the standard and those identified based on in situ structure measurements always reveal a large discrepancy between reality and regulation.Given this background,this contribution presents a novel approach for defining the damping factor of railway bridges with ballasted tracks,where the damping factor for bridges is mathematically determined based on three different two-dimensional mechanical models.The basic principle of the approach for mathematically determining the damping factor is to separately define and superimpose the dissipative contributions of the supporting structure(including the substructure)and the superstructure.Using the results of a measurement campaign on 15 existing steel railway bridges in the Austrian rail network,the presented mechanical models are calibrated,and by analysing the energy dissipation in the ballasted track,guiding principles for practical application are defined.This guideline is intended to establish an alternative to the currently valid specifications of EN 1991-2,enabling the damping factor of railway bridges to be assessed in a realistic range by mathematical calculation and thus without the need for extensive in situ measurements on the individual structure.In this way,the existing potential of the infrastructure with regard to the damping properties of bridges can be utilised.This contribution focuses on steel bridges,but the mathematical approach for determining the damping factor applies equally to other bridge types(concrete,composite,or filler beam). 展开更多
关键词 Railway bridges Bridge dynamics DAMPING Track-bridge interaction Structural health monitoring Condition assessment
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Dissolution kinetics of a low-grade oxide-sulfide copper ore with high silica content:Laboratory studies and statistical modeling
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作者 Hiva Farhadi Faramarz Doulati Ardejani +5 位作者 Sied Ziaedin Shafaei Tonkaboni Soroush Maghsoudy Roya Kafi Helia Tafakori Christoph Butscher Reza Taherdangkoo 《Acta Geochimica》 2026年第1期111-131,共21页
In this study,copper extraction from low-grade oxide-sulfide ores was investigated using a leaching method combined with response surface methodology(RSM)to optimize operational conditions and assess leaching kinetics... In this study,copper extraction from low-grade oxide-sulfide ores was investigated using a leaching method combined with response surface methodology(RSM)to optimize operational conditions and assess leaching kinetics.Given copper's extensive industrial applications,sustainable recovery from low-grade ores is critical.Five key parameters-acid concentration,leaching time,particle size,temperature,and solids percentage-were identified as major influences on copper recovery.The results revealed that leaching time and solids percentage,along with interactions between temperature-time and temperature-solids percentage,had the most significant effects.Optimal conditions for 80% copper recovery while minimizing iron recovery below 3% included an acid concentration of 1.21 mol L^(-1),a leaching time of 108 min,a particle size of 438μm,a temperature of 45℃,and a solids percentage of 18.2%.Leaching kinetics were analyzed using shrinking core models,with the Dickinson model best describing the process,showing an activation energy of 32.63 kJ mol^(-1),indicative of mixed diffusion and chemical reaction control.The final kinetic model effectively predicted the influence of key parameters.These findings highlight the importance of optimizing process variables and selecting suitable kinetic models to enhance extraction efficiency,reduce costs,and improve sustainability in copper recovery. 展开更多
关键词 Oxide-sulfi de ore Response surface methodology Kinetic analysis Miduk copper mine Shrinking core model Copper leaching
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Effects of discrete fracture networks on simulating hydraulic fracturing,induced seismicity and trending transition of relative modulus in coal seams 被引量:1
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作者 Xin Zhang Guangyao Si +3 位作者 Qingsheng Bai Joung Oh Biao Jiao Wu Cai 《International Journal of Coal Science & Technology》 2025年第1期263-278,共16页
Discrete fracture network(DFN)commonly existing in natural rock masses plays an important role in geological complexity which can influence rock fracturing behaviour during fluid injection.This paper simulated the hyd... Discrete fracture network(DFN)commonly existing in natural rock masses plays an important role in geological complexity which can influence rock fracturing behaviour during fluid injection.This paper simulated the hydraulic fracturing process in lab-scale coal samples with DFNs and the induced seismic activities by the discrete element method(DEM).The effects of DFNs on hydraulic fracturing,induced seismicity and elastic property changes have been concluded.Denser DFNs can comprehensively decrease the peak injection pressure and injection duration.The proportion of strong seismic events increases first and then decreases with increasing DFN density.In addition,the relative modulus of the rock mass is derived innovatively from breakdown pressure,breakdown fracture length and the related initiation time.Increasing DFN densities among large(35–60 degrees)and small(0–30 degrees)fracture dip angles show opposite evolution trends in relative modulus.The transitional point(dip angle)for the opposite trends is also proportionally affected by the friction angle of the rock mass.The modelling results have much practical meaning to infer the density and geometry of pre-existing fractures and the elastic property of rock mass in the field,simply based on the hydraulic fracturing and induced seismicity monitoring data. 展开更多
关键词 Discrete fracture network Hydraulic fracturing Discrete element method Induced seismicity Relative modulus
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Efficacy of Wee1 G2 Checkpoint Kinase and Mouse Double Minute 2 Homolog Inhibitors in Gastrointestinal Stromal Tumors Determined by p53 Status
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作者 Chiao-Ping Chen Yan-Jei Tang +7 位作者 You-Yan Cai Yi-Ru Pan Chun-Nan Yeh Wen-Kuan Huang Chih-Hong Lo Yu-Tien Hsiao Hsuan-Jen Shih Chiao-En Wu 《Oncology Research》 2025年第11期3429-3446,共18页
Background:KIT proto-oncogene,receptor tyrosine kinase(KIT,CD117)and platelet-derived growth factor-alpha(PDGFRA)are key drivers of gastrointestinal stromal tumors(GIST),but resistance to targeted therapy often arises... Background:KIT proto-oncogene,receptor tyrosine kinase(KIT,CD117)and platelet-derived growth factor-alpha(PDGFRA)are key drivers of gastrointestinal stromal tumors(GIST),but resistance to targeted therapy often arises from tumor protein p53(p53)alterations and loss of cell cycle control.However,the role of p53 status in GIST therapeutic potential has rarely been studied,so this study aimed to employ both wild-type andmutant p53 GIST models to investigate how p53 dysfunction influences the efficacy of p53 pathway-targeted therapies.Methods:The efficacy of the mouse double minute 2 homolog(MDM2)inhibitor(HDM201)and the Wee1 G2 checkpoint kinase(Wee1)inhibitor(adavosertib)was confirmed in both p53 wild-type(p53 WT)and p53 mutant(p53 MT)GIST cells.The anti-proliferative effects were assessed using the Cell Counting Kit-8(CCK-8)assay.Flow cytometry(FACS)and immunoblotting were employed to evaluate apoptosis and the expression of proteins related to drug efficacy.These findings were further validated in a xenograft model.Results:HDM201 selectively inhibited growth and triggered apoptosis in p53WT GIST cells,while adavosertib was effective mainly in p53 MT cells.Western blot analysis revealed thatHDM201 increased p53 and p21 levels in p53WT cells,and adavosertib affectedWee1 and phospho-cdc2 expression in both p53WT and p53 MT cells.In a xenograft mouse model,HDM201 significantly reduced the tumor volume and weight in p53WTGIST cells,whereas p53MT tumors showed only a moderate size reduction with adavosertib,without significant changes.Conclusions:Our results highlight the importance of p53 status in guiding GIST treatment.p53 WT tumors respond toMDM2 inhibitors,while p53 MTtumors show greater sensitivity toWee1 inhibitors,supporting p53 pathway targeting as a promising strategy for GIST patients. 展开更多
关键词 Tumor proteinp53(p53) Wee1G2 checkpoint kinase(Wee1) mouse double minute 2 homolog(MDM2) gastrointestinal stromal tumors(GIST) mouse double minute 2 homolog inhibitor(HDM201) adavosertib
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Strain rate effects on mechanical properties,microstructural evolution,and deformation mechanisms of high manganese steels 被引量:1
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作者 Dong Liu Dapeng Yang +3 位作者 Yong Hou Yunjie Li Guodong Wang Hongliang Yi 《Journal of Materials Science & Technology》 2025年第34期219-255,共37页
High manganese steels(HMS),known for their exceptional strength-ductility balance,are increasingly utilized in dynamic loading applications.This review examines the effects of strain rate on their mechanical propertie... High manganese steels(HMS),known for their exceptional strength-ductility balance,are increasingly utilized in dynamic loading applications.This review examines the effects of strain rate on their mechanical properties and microstructural evolution,focusing on strain rate hardening,adiabatic heating softening,and dynamic strain aging(DSA).The influence of strain rate on yield strength,ultimate tensile strength,strain hardening,and ductility is discussed,highlighting both positive and negative sensitivities across different alloy compositions and strain rate regimes.The strain rate response of various deformation mechanisms,including deformation twinning,dislocation slip,and phase transformation,is examined alongside their influence on microstructural evolution,alloy design,and industrial applications.The intricate role of DSA is also analyzed,emphasizing its contribution to strain rate sensitivity.To optimize HMS for dynamic environments,future research should focus on advanced modeling and processing techniques,in-situ characterization methods,and a deeper understanding of thermally activated processes and stacking fault energy-controlled mechanisms.This review provides insights into strain rate effects,guiding alloy design,and technological advancements of the new HMS. 展开更多
关键词 High manganese steels Strain rate sensitivity Yield strength Strain hardening Deformation mechanisms Microstructural evolution Dynamic strain aging
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Fabricating Core-Shell WC@C/Pt Structures and its Enhanced Performance for Methanol Electrooxidation 被引量:1
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作者 陈赵扬 段隆发 +3 位作者 褚有群 盛江峰 林文锋 马淳安 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2017年第4期450-456,I0002,共8页
The spray-dried spheres within a W/Pt multi-separation can be used to prepare discrete core-shell WC@C/Pt catalysts through a typical carburization production mechanism at 800 ℃. In contrast with previous studies of ... The spray-dried spheres within a W/Pt multi-separation can be used to prepare discrete core-shell WC@C/Pt catalysts through a typical carburization production mechanism at 800 ℃. In contrast with previous studies of the WC/Pt synthesis, the reaction observed here proceeds through an indirect annealing thereby resulting in core-shell structure, and mechanism at 600℃ wherein species diffuse, Pt nanoparticles were successfully dispersed in size/shape and randomly scattered across the in situ produced C spheres. Through direct carburization or at higher initial hydrochloroplatiuic acid concentrations, however, complete reaction with core-shell spheres was not observed. Indirect carburization reduces the strain felt by the bonds featuring the larger WC WC and Pt nanoparticles to be reserved, stability toward methanol oxidation. particles and allows the motion of carbon around influencing the eleetrocatalytic performance and 展开更多
关键词 Self-disperse Core-shell structure Carbon-resist Tungsten carbide Methanol oxidation
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Tailoring microstructure and performance of WE43MEO magnesium alloy via multi-pass hot rolling and finishing heat treatment towards foils for biomedical support structures
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作者 Franziska Ueberschär Simon Schmidt +4 位作者 Kristina Kittner Simon Pöstges Madlen Ullmann Alexander Kopp Ulrich Prahl 《Journal of Magnesium and Alloys》 2025年第10期4966-4984,共19页
WE43MEO magnesium foils(thickness≤200μm)were successfully produced via hot rolling.The initially extruded material was heat treated at 450℃for 2 h to achieve a more homogenous microstructure.Afterwards the sheets w... WE43MEO magnesium foils(thickness≤200μm)were successfully produced via hot rolling.The initially extruded material was heat treated at 450℃for 2 h to achieve a more homogenous microstructure.Afterwards the sheets were hot rolled at 480℃in two to five rolling passes to achieve a uniform thickness of less than 200μm and finally heat treated(T5 and T6 heat treatment).After foil rolling and final heat treatment the microstructural und texture evolution as well as resulting mechanical properties were investigated.Therefore,the samples were quenched directly after foil rolling and the final heat treatment.The foil rolling led either to a deformation microstructure(two and three passes)or globular grains(four and five passes)depending on the number of rolling passes.As main recrystallisation mechanisms continuous dynamic recrystallisation(CDRX)and twinning induced dynamic recrystallisation(TDRX)were identified.The resulting textures revealed the activation of non-basal slip of<c+a>-dislocations during prior foil rolling.As a result of the rolling,the strength increased and the elongation decreased compared to the extruded and heat-treated state.Furthermore,it was found that a T6 temper increased corrosion resistance of the tested WE43MEO foils. 展开更多
关键词 WE43MEO BIOABSORBABLE Heat treatment Foil rolling Degradation MICROSTRUCTURE
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Flexible nanogenerators for intelligent robotics:design,manufacturing,and applications
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作者 Hongfa Zhao Liguang Ruan +6 位作者 Zihan Wang Mingrui Shu Chuqiao Lyu Bulathsinghala Rameesh Lakshan Dharmasena Ishara Changsheng Wu Wenbo Ding 《International Journal of Extreme Manufacturing》 2025年第2期418-457,共40页
The embodied artificial intelligence(EAI)is driving a significant transformation in robotics,enhancing their autonomy,efficiency and evolution ability.In this rapidly evolving technological landscape,robots need numer... The embodied artificial intelligence(EAI)is driving a significant transformation in robotics,enhancing their autonomy,efficiency and evolution ability.In this rapidly evolving technological landscape,robots need numerous sensors to realize high levels of perception,precision,safety,adaptability,and intelligence.Triboelectric and piezoelectric sensors address these needs by providing high sensitivity,flexibility,and the capability of self-powered sensing,leveraging the revolutionary nature of nanogenerators to convert mechanical energy into electrical energy on basis of Maxwell’s displacement current.These sensors surpass externally powered passive sensors by offering continuous operation,reduced maintenance,and the capability to function in remote or harsh environments.The integration of EAI with advanced nanogenerators sensors could position robotics to perform autonomously,efficiently,and safely,paving the way for innovative applications in various domains such as industrial automation,environmental monitoring,healthcare,and smart homes.In this paper,the fundamental theories,design,manufacturing,and applications of nanogenerators are comprehensively reviewed as afoundation of the advanced sensors for intelligent robotics in the new era,with three major application fields:sensing(including human–robot interaction,exteroceptive sensing and proprioceptive sensing),computing and actuating.Perspectives are addressed for nanogenerators systems in future development. 展开更多
关键词 triboelectric/piezoelectric nanogenerators ROBOTICS MANUFACTURING
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Study on the characteristics of crack initiation in deep dense shale containing circular hole under varying stress conditions
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作者 XIE Hong-qiang FENG Gan +4 位作者 LIU Huai-zhong HE Qiang XIAO Ming-li PEI Jian-liang TAHERDANGKOO Reza 《Journal of Central South University》 2025年第1期244-261,共18页
The evolution of cracks in shale directly affects the efficient production of shale gas.However,there is a lack of research on the characteristics of crack initiation in deep dense shale under different stress conditi... The evolution of cracks in shale directly affects the efficient production of shale gas.However,there is a lack of research on the characteristics of crack initiation in deep dense shale under different stress conditions.In this work,considering the different combinations of confining pressure and bedding plane inclination angle(α),biaxial mechanical loading experiments were conducted on shale containing circular holes.The research results indicate that the confining pressure and inclination angle of the bedding planes significantly influence the failure patterns of shale containing circular holes.The instability of shale containing circular holes can be classified into five types:tensile failure along the bedding planes,tensile failure through the bedding planes,shear slip along the bedding planes,shear failure through the bedding planes,and block instability failure.Furthermore,the evolution of strain and stress fields around the circular holes was found to be the fundamental cause of variations in the initiation characteristics and locations of shale cracks.The crack initiation criterion for shale containing circular hole was established,providing a new method for evaluating the trajectory of shale hole wall fractures.This study holds significant importance for evaluating the evolution and stability of fracture networks within shale reservoirs. 展开更多
关键词 shale gas deep dense shale crack initiate characteristics failure modes
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Wave-Driven Energy Harvesting from Frequency-Increasing Floating Structures
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作者 Mir Mohammad Ettefagh Alireza Hesari +1 位作者 Reza Fathi Sina Akhbari 《哈尔滨工程大学学报(英文版)》 2025年第5期1075-1085,共11页
This study focuses on wave energy harvesting by leveraging the impact-induced frequency of sea waves.It introduces a novel double-buoyed model based on the existing single-buoyed system to address the shortcomings of ... This study focuses on wave energy harvesting by leveraging the impact-induced frequency of sea waves.It introduces a novel double-buoyed model based on the existing single-buoyed system to address the shortcomings of previous systems.Notably,the traditional single-buoyed system,which is characterized by a long beam extending to the sea floor,proves impractical in deep-sea environments,especially in distant offshore regions.The proposed double-buoyed model replaces the long beam with a second buoy to increase energy harvesting efficiency.A parametric analysis that included the density and height of the first buoy and wave period was conducted to enhance the proposed model further.Results indicated that with the selection of optimal parameters,the power output of the double-buoyed system increased by approximately 13-fold,thereby enhancing the viability and efficiency of wave energy harvesting. 展开更多
关键词 Energy harvesting Sea wave BUOY PIEZOELECTRICITY Impact
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Confined seepage analysis of saturated soils using fuzzy fields
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作者 Nataly A.Manque Kok-Kwang Phoon +2 位作者 Yong Liu Marcos A.Valdebenito Matthias G.R.Faes 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第3期1302-1320,共19页
Seepage refers to the flow of water through porous materials.This phenomenon has a crucial role in dam,slope,excavation,tunnel,and well design.Performing seepage analysis usually is a challenging task,as one must cope... Seepage refers to the flow of water through porous materials.This phenomenon has a crucial role in dam,slope,excavation,tunnel,and well design.Performing seepage analysis usually is a challenging task,as one must cope with the uncertainty associated with the parameters such as the hydraulic conductivity in the horizontal and vertical directions that drive this phenomenon.However,at the same time,the data on horizontal and vertical hydraulic conductivities are typically scarce in spatial resolution.In this context,so-called non-traditional approaches for uncertainty quantification(such as intervals and fuzzy variables)offer an interesting alternative to classical probabilistic methods,since they have been shown to be quite effective when limited information on the governing parameters of a phenomenon is available.Therefore,the main contribution of this study is the development of a framework for conducting seepage analysis in saturated soils,where uncertainty associated with hydraulic conductivity is characterized using fuzzy fields.This method to characterize uncertainty extends interval fields towards the domain of fuzzy numbers.In fact,it is illustrated that fuzzy fields are an effective tool for capturing uncertainties with a spatial component,since they allow one to account for available physical measurements.A case study in confined saturated soil shows that with the proposed framework,it is possible to quantify the uncertainty associated with seepage flow,exit gradient,and uplift force effectively. 展开更多
关键词 Fuzzy fields Interval fields Seepage analysis Hydraulic conductivity Spatial uncertainty
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A Comparison among Different Machine Learning Algorithms in Land Cover Classification Based on the Google Earth Engine Platform: The Case Study of Hung Yen Province, Vietnam
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作者 Le Thi Lan Tran Quoc Vinh Phạm Quy Giang 《Journal of Environmental & Earth Sciences》 2025年第1期132-139,共8页
Based on the Google Earth Engine cloud computing data platform,this study employed three algorithms including Support Vector Machine,Random Forest,and Classification and Regression Tree to classify the current status ... Based on the Google Earth Engine cloud computing data platform,this study employed three algorithms including Support Vector Machine,Random Forest,and Classification and Regression Tree to classify the current status of land covers in Hung Yen province of Vietnam using Landsat 8 OLI satellite images,a free data source with reasonable spatial and temporal resolution.The results of the study show that all three algorithms presented good classification for five basic types of land cover including Rice land,Water bodies,Perennial vegetation,Annual vegetation,Built-up areas as their overall accuracy and Kappa coefficient were greater than 80%and 0.8,respectively.Among the three algorithms,SVM achieved the highest accuracy as its overall accuracy was 86%and the Kappa coefficient was 0.88.Land cover classification based on the SVM algorithm shows that Built-up areas cover the largest area with nearly 31,495 ha,accounting for more than 33.8%of the total natural area,followed by Rice land and Perennial vegetation which cover an area of over 30,767 ha(33%)and 15,637 ha(16.8%),respectively.Water bodies and Annual vegetation cover the smallest areas with 8,820(9.5%)ha and 6,302 ha(6.8%),respectively.The results of this study can be used for land use management and planning as well as other natural resource and environmental management purposes in the province. 展开更多
关键词 Google Earth Engine Land Cover LANDSAT Machine Learning Algorithm
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Impact of Zener-Hollomon parameter on substructure and texture evolution during thermomechanical treatment of iron-containing wrought aluminium alloys 被引量:5
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作者 Evgenii ARYSHENSKII Jürgen HIRSCH +2 位作者 Vladimir BAZHIN Rudolf KAWALLA Ulrich PRAL 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2019年第5期893-906,共14页
The objective of the investigation is to evaluate the influence of the Zener-Hollomon parameter on substructure and texture evolution in iron-containing wrought aluminium alloys (type AA8011). Methods applied are X-ra... The objective of the investigation is to evaluate the influence of the Zener-Hollomon parameter on substructure and texture evolution in iron-containing wrought aluminium alloys (type AA8011). Methods applied are X-ray texture analysis, electron backscatter diffraction (EBSD) and optical microscopy. The results show a serious impact of the Zener-Hollomon parameter on cube texture evolution during the thermomechanical treatment in iron-containing aluminium alloys. An increase in the Zener-Hollomon parameter reduces the survivability of cube texture during hot deformation and reinforces particle-stimulated nucleation (PSN) during the annealing process. However, thermomechanical treatment at low temperatures leads to active precipitation and as a result fine-dispersed participles tend to block all nuclei except for those producing large cube-oriented grains. It is concluded that in iron-containing wrought aluminium alloys, the general correlation between the Zener-Hollomon parameter and subgrain size is similar to that observed in 3xxx series alloys and can be described by the specific set of equations derived. 展开更多
关键词 aluminium alloy TEXTURE Zener-Hollomon parameter SUBSTRUCTURE hot rolling
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Tuning the interfacial reaction environment via pH-dependent and induced ions to understand C–N bonds coupling performance in NO_(3)-integrated CO_(2)reduction to carbon and nitrogen compounds over dual Cu-based N-doped carbon catalyst
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作者 Tianhang Zhou Chen Shen +2 位作者 Zhenghao Wu Xingying Lan Yi Xiao 《Journal of Energy Chemistry》 2025年第1期273-285,共13页
Dual atomic catalysts(DAC),particularly copper(Cu_(2))-based nitrogen(N)doped graphene,show great potential to effectively convert CO_(2)and nitrate(NO_(3)-)into important industrial chemicals such as ethylene,glycol,... Dual atomic catalysts(DAC),particularly copper(Cu_(2))-based nitrogen(N)doped graphene,show great potential to effectively convert CO_(2)and nitrate(NO_(3)-)into important industrial chemicals such as ethylene,glycol,acetamide,and urea through an efficient catalytical process that involves C–C and C–N coupling.However,the origin of the coupling activity remained unclear,which substantially hinders the rational design of Cu-based catalysts for the N-integrated CO_(2)reduction reaction(CO_(2)RR).To address this challenge,this work performed advanced density functional theory calculations incorporating explicit solvation based on a Cu_(2)-based N-doped carbon(Cu_(2)N_(6)C_(10))catalyst for CO_(2)RR.These calculations are aimed to gain insight into the reaction mechanisms for the synthesis of ethylene,acetamide,and urea via coupling in the interfacial reaction micro-environment.Due to the sluggishness of CO_(2),the formation of a solvation electric layer by anions(F^(-),Cl^(-),Br^(-),and I^(-))and cations(Na+,Mg^(2+),K+,and Ca^(2+))leads to electron transfer towards the Cu surface.This process significantly accelerates the reduction of CO_(2).These results reveal that*CO intermediates play a pivotal role in N-integrated CO_(2)RR.Remarkably,the Cu_(2)-based N-doped carbon catalyst examined in this study has demonstrated the most potential for C–N coupling to date.Our findings reveal that through the process of a condensation reaction between*CO and NH_(2)OH for urea synthesis,*NO_(3)-is reduced to*NH_(3),and*CO_(2)to*CCO at dual Cu atom sites.This dual-site reduction facilitates the synthesis of acetamide through a nucleophilic reaction between NH_(3)and the ketene intermediate.Furthermore,we found that the I-and Mg^(2+)ions,influenced by pH,were highly effective for acetamide and ammonia synthesis,except when F-and Ca^(2+)were present.Furthermore,the mechanisms of C–N bond formation were investigated via ab-initio molecular dynamics simulations,and we found that adjusting the micro-environment can change the dominant side reaction,shifting from hydrogen production in acidic conditions to water reduction in alkaline ones.This study introduces a novel approach using ion-H_(2)O cages to significantly enhance the efficiency of C–N coupling reactions. 展开更多
关键词 pH-dependent micro-environments C-N coupling N-integrated CO_(2)RR Dual Cu-based nitrogen carbon catalysts Explicit solvation model lon stabilizer AIMD
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Development of nonlinear disturbance observer based control and nonlinear PID: A personal note 被引量:2
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作者 Wen-Hua CHEN 《Control Theory and Technology》 EI CSCD 2018年第4期284-300,共17页
This paper gives an overview of early development of nonlinear disturbance observer design technique and the disturbance observer based control (DOBC) design. Some critical points raised in the development of the me... This paper gives an overview of early development of nonlinear disturbance observer design technique and the disturbance observer based control (DOBC) design. Some critical points raised in the development of the methods have been reviewed and discussed which are still relevant for many researchers or practitioners who are interested in this method. The review is followed by the development of a new type of nonlinear PID controller for a robotic manipulator and its experimental tests. It is shown that, under a number of assumptions, the DOBC consisting of a predictive control method and a nonlinear disturbance observer could reduce to a nonlinear PID with special features. Experimental results show that, compared with the predictive control method, the developed controller significantly improves performance robustness against uncertainty and friction. This paper may trigger further research and interests in the development of DOBC and related methods, and building up more understanding between this group of control methods with comparable ones (particularly control methods with integral action). 展开更多
关键词 Disturbance observer nonlinear control PID controller disturbance observer based contro
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Application of the cumulative rainfall departure method in determination of deep groundwater recharge in Soc Trang Province,Vietnam
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作者 Tran Vu Long Nguyen Bach Thao +7 位作者 Dao Duc Bang Kieu Thi Van Anh Vu Thu Hien Duong Thi Thanh Thuy Tran Quang Tuan Nguyen Van Hoang Doan Anh Tuan Dang Tran Trung 《Journal of Groundwater Science and Engineering》 2025年第2期180-192,共13页
Groundwater(GW)is a vital freshwater resource extensively exploited in the Vietnamese Mekong Delta,especially during the dry seasons.This study applies the Cumulative Rainfall Departure(CRD)method to estimate GW recha... Groundwater(GW)is a vital freshwater resource extensively exploited in the Vietnamese Mekong Delta,especially during the dry seasons.This study applies the Cumulative Rainfall Departure(CRD)method to estimate GW recharge in deep aquifers of Soc Trang Province,located in the southernmost region of Vietnam under a tropical climate.Monthly rainfall records and daily GW level data of the aquifers from 2010 to 2020 were used.The Pearson correlation between observed GW levels and CDR model GW levels exceeds 0.995,indicating high model accuracy.The analysis reveals that the CRD fractions for the Upper Pleistocene(qp3),Middle Pleistocene(qp2-3),Lower Pleistocene(qp1),and Middle Pliocene(n22)aquifers are 0.085%,0.104%,0.130%,and 0.180%,respectively,totaling approximately 0.5%of the annual rainfall.This corresponds to an annual GW recharge of 25.86 million m3,or 70,850 m3/day,equivalent to 70%of the current GW abstraction rate of 101,000 m3/day.Given the critical role of GW as a freshwater source,implementing an enhanced GW recharge program using surface water and rainwater is strongly recommended.Additionally,the analysis suggests that the decline in GW levels due to abstraction corresponds to 0.85 times the mean annual precipitation,a finding that warrants further investigation. 展开更多
关键词 Mekong delta Tropical climate Groundwater(GW)level Mean precipitation Pearson correlation
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Radiation exposure in flexible ureteroscopy with a flexible and navigable suction ureteral access sheath:A European Association of Urologye-Endourology multicenter study
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作者 Vineet Gauhar Olivier Traxer +13 位作者 Thomas R.W.Herrmann Daniele Castellani Hatem Kamkoum Wissam Kamal Tzevat Tefik Heng Chin Tiong Mehmet Ilker Gökce Michael Y.C.Wong Khi Yung Fong Ben Hall Chew Manoj Monga Vincent de Connick Bhaskar Kumar Somani Steffi Kar Kei Yuen 《Asian Journal of Urology》 2025年第3期385-392,共8页
Objective:We aimed to study the effect of flexible ureteroscopy(FURS)for renal stones using a flexible and navigable suction ureteral access sheath(FANS)on intraoperative radiation dose and time.Methods:This was a mul... Objective:We aimed to study the effect of flexible ureteroscopy(FURS)for renal stones using a flexible and navigable suction ureteral access sheath(FANS)on intraoperative radiation dose and time.Methods:This was a multicenter study of adults who underwent FURS with FANS.The correlation analysis was done to identify factors affecting radiation dose and time measured by the C-arm fluoroscopy intraoperatively.Results:We analyzed 110 patients,with a median age of 50 years.Of them,72%were pre-stented prior to the procedure.The median stone volume was 1503 mm3 and the median operative time was 39 min.The median radiation dose was 7.4 mSv and median radiation time was 0.6 min.Totally,91%of patients achieved stone-free status(Grade A or B)on the non-contrast CT scan within 30 days postoperatively.There were no cases of postoperative sepsis.Body mass index,stone volume,and total operation time were associated with a higher radiation dose.Procedures performed under general anesthesia had a lower radiation dose and time than those performed under spinal anesthesia.Disposable scopes were associated with higher radiation time than reusable scopes but not dose.A low-power holmium laser had longer radiation time than other laser sources,but only the thulium fiber laser was associated with a significantly lower radiation dose.Conclusion:Our study is the first to highlight the multitude of factors affecting radiation exposure in FURS with FANS.Although not a direct measure of surgeons'actual exposure,it has important implications for the As Low As Reasonably Achievable principle which is commonly used to minimize radiation exposure to patients and operating room staff. 展开更多
关键词 Flexible ureteroscopy Suction device UROLITHIASIS FLUOROSCOPY Radiation
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The mechanisms of varying doses of metal ion implantation(Ag, Ti and Zr) on microstructure and properties of pure magnesium
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作者 Tao He Xu-Hui Liu +10 位作者 Zi-Jin Xiao Yi-Long Dai Yu-Chen Dou Jia She Li-Wei Lu Yi Yang Li-Fei Wang Nie Zhao Wen-Wen Wei Fu-Gang Qi Xiao-Ping Ouyang 《Rare Metals》 2025年第9期6730-6747,共18页
Ion implantation technology is a crucial strategy for modulating the degradation behavior of biomedical magnesium alloys.In this study,Ag,Ti,and Zr ions were implanted into the surface of pure Mg at varying doses to i... Ion implantation technology is a crucial strategy for modulating the degradation behavior of biomedical magnesium alloys.In this study,Ag,Ti,and Zr ions were implanted into the surface of pure Mg at varying doses to investigate their effects on the microstructure and properties of pure Mg.The results revealed that differences in the affinities of Mg and the implanted elements for reacting with oxygen led to the formation of implanted layers with distinct compositions and structures.Specifically,Ag ion implantation resulted in a layer predominantly composed of elemental silver,while Ti and Zr ion implantation promoted the formation of a denser layer containing Mg,MgO,the implanted elements,and their respective oxides.This layer significantly enhanced the corrosion resistance of pure Mg by reducing its susceptibility to corrosive media.Electrochemical assessments showed a substantial reduction in corrosion current density following Ti and Zr ion implantation.However,increasing doses of Ag ions induced heightened susceptibility to galvanic corrosion due to the electrode potential differences between Ag and Mg,thereby accelerating the degradation of the pure Mg substrate.Additionally,first-principles calculations of the work functions for both the (0001) basal plane and the(101 0) prism plane of Mg corroborated the observed electrochemical trends. 展开更多
关键词 MAGNESIUM Ion implantation Corrosion resistance First-principles calculations
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Creativity in ArchitecturemA Review on Effective Parameters Correlated with Creativity in Architectural Design 被引量:1
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作者 Alireza Mahdizadeh Hakak Nimish Biloria Armaghan Ahmadi Venhari 《Journal of Civil Engineering and Architecture》 2014年第11期1371-1379,共9页
Human civilization can be ameliorated by human creativity. Innovation and progress of human civilization result from a change in our thinking patterns, thus, potentially transforming the present into a creative future... Human civilization can be ameliorated by human creativity. Innovation and progress of human civilization result from a change in our thinking patterns, thus, potentially transforming the present into a creative future. Accentuating the role of creativity in design even more than other disciplines pushes one to underpin the understanding of creativity as a key role player in architecture. Furthermore, by identifying the basic principles of our ingenuity/creativity, researchers might be able to enhance this ability in the future. A key point in "creativity" is the role of previously gained experiences, which cause expanding the inventory of experiences. According to accepted def'mition in different disciplines, creativity is no more than new combinations of previous ideas. The paper explores different effectual parameters correlated with creativity in architectural design including notion of conceptual blending, improbabilist and impossibilist creativity, tolerance of ambiguity and its correlation with creativity and creativity aided tools and interfaces. At the end, we suggest necessary experiments to obtain empirical results for some speculations that are discussed in the paper. Also, practical approaches will be suggested to apply the results in pedagogy of architecture. 展开更多
关键词 Virtual environment experience CREATIVITY conceptual blending tolerance of ambiguity.
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Deep Learning and Improved Particle Swarm Optimization Based Multimodal Brain Tumor Classicatio 被引量:1
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作者 Ayesha Bin T.Tahir Muhamamd Attique Khan +4 位作者 Majed Alhaisoni Junaid Ali Khan Yunyoung Nam Shui-Hua Wang Kashif Javed 《Computers, Materials & Continua》 SCIE EI 2021年第7期1099-1116,共18页
Background:A brain tumor reects abnormal cell growth.Challenges:Surgery,radiation therapy,and chemotherapy are used to treat brain tumors,but these procedures are painful and costly.Magnetic resonance imaging(MRI)is a... Background:A brain tumor reects abnormal cell growth.Challenges:Surgery,radiation therapy,and chemotherapy are used to treat brain tumors,but these procedures are painful and costly.Magnetic resonance imaging(MRI)is a non-invasive modality for diagnosing tumors,but scans must be interpretated by an expert radiologist.Methodology:We used deep learning and improved particle swarm optimization(IPSO)to automate brain tumor classication.MRI scan contrast is enhanced by ant colony optimization(ACO);the scans are then used to further train a pretrained deep learning model,via transfer learning(TL),and to extract features from two dense layers.We fused the features of both layers into a single,more informative vector.An IPSO algorithm selected the optimal features,which were classied using a support vector machine.Results:We analyzed high-and low-grade glioma images from the BRATS 2018 dataset;the identication accuracies were 99.9%and 99.3%,respectively.Impact:The accuracy of our method is signicantly higher than existing techniques;thus,it will help radiologists to make diagnoses,by providing a“second opinion.” 展开更多
关键词 Brain tumor contrast enhancement deep learning feature selection classication
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