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Comparative analysis on pulverized coal combustion preheated by self-sustained purifying burner with coaxial and centrosymmetric air nozzle structures:Purification,combustion and NO_(x)emission characteristics
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作者 Kun Su Ziqu Ouyang +4 位作者 Hongshuai Wang Hongliang Ding Wenyu Wang Qisi Chen Shuyun Li 《Chinese Journal of Chemical Engineering》 2025年第1期102-113,共12页
To optimize secondary air nozzle structure in purifying burner,this study focused on the comparison of purification,combustion and NO_(x)emission characteristics of pulverized coal preheated by a 30 kW purifying burne... To optimize secondary air nozzle structure in purifying burner,this study focused on the comparison of purification,combustion and NO_(x)emission characteristics of pulverized coal preheated by a 30 kW purifying burner with coaxial and centrosymmetric structures.Centrosymmetric structure shifted the position of main burning region down in high-temperature reduction unit(HTRU),and the number of branches differently influenced the temperature in different regions with this structure.For reductive gas components,CO concentration with centrosymmetric structure was higher compared to coaxial structure,while the differences in H_(2)and CH_(4)concentrations were smaller.Centrosymmetric structure was more disadvantageous to improve physicochemical properties of pulverized coal compared to coaxial structure,and this structure with four branches further deteriorated its properties compared to two branches.In mild combustion unit(MCU),the temperature at top was lower with centrosymmetric structure,while was higher in the rest.Centrosymmetric structure more effectively reduced NO_(x)emission compared to coaxial structure,but with slight sacrifice of combustion efficiency(η).Moreover,both two-branch and four-branch centrosymmetric structures realized ultra-low NO_(x)emission(<50 mg·m^(-3))with high η of over 98.50%,and the former was more advantageous.With this optimal structure,η and NO_(x)emission were 99.25%and 40.42 mg·m^(-3). 展开更多
关键词 Purifying-burning NO_(x)emission Coaxial structure Centrosymmetric structure
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Advances in solid-state NMR methods for studying RNA structures and dynamics
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作者 Jinhan He Xiaole Liu Shenlin Wang 《Magnetic Resonance Letters》 2025年第1期64-74,共11页
Ribonucleic acid(RNA)structures and dynamics play a crucial role in elucidating RNA functions and facilitating the design of drugs targeting RNA and RNA-protein complexes.However,obtaining RNA structures using convent... Ribonucleic acid(RNA)structures and dynamics play a crucial role in elucidating RNA functions and facilitating the design of drugs targeting RNA and RNA-protein complexes.However,obtaining RNA structures using conventional biophysical techniques,such as Xray crystallography and solution nuclear magnetic resonance(NMR),presents challenges due to the inherent flexibility and susceptibility to degradation of RNA.In recent years,solid-state NMR(SSNMR)has rapidly emerged as a promising alternative technique for characterizing RNA structure and dynamics.SSNMR has several distinct advantages,including flexibility in sample states,the ability to capture dynamic features of RNA in solid form,and suitability to character RNAs in various sizes.Recent decade witnessed the growth of ^(1)H-detected SSNMR methods on RNA,which targeted elucidating RNA topology and base pair dynamics in solid state.They have been applied to determine the topology of RNA segment in human immunodeficiency virus(HIV)genome and the base pair dynamics of riboswitch RNA.These advancements have expanded the utility of SSNMR techniques within the RNA research field.This review provides a comprehensive discussion of recent progress in ^(1)H-detected SSNMR investigations into RNA structure and dynamics.We focus on the established ^(1)H-detected SSNMR methods,sample preparation protocols,and the implementation of rapid data acquisition approaches. 展开更多
关键词 Solid-state NMR RNA STRUCTURE DYNAMics Pulse sequences
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Enhanced dynamics of Al^(3+)/H^(+) ions in aqueous aluminum ion batteries:Construction of metastable structures in vanadium pentoxide upon oxygen vacancies
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作者 Zhibao Wang Hanqing Gu +2 位作者 Tianci Wu Wenming Zhang Zhanyu Li 《Journal of Energy Chemistry》 2025年第2期562-569,I0011,共9页
In recent years,aqueous aluminum ion batteries have been widely studied owing to their abundant energy storage and high theo retical capacity.An in-depth study of vanadium oxide materials is necessary to address the p... In recent years,aqueous aluminum ion batteries have been widely studied owing to their abundant energy storage and high theo retical capacity.An in-depth study of vanadium oxide materials is necessary to address the precipitation of insoluble products covered cathode surface and the slow reaction kinetics.Therefore,a method using a simple one-step hydrothermal preparation and oxalic acid to regulate oxygen vacancies has been reported.A high starting capacity(400 mAh g^(-1))can be achieved by Ov-V2O5,and it is capable of undergoing 200 cycles at 0.4 A g^(-1),with a termination discharge capacity of103 mAh g^(-1).Mechanism analysis demonstrated that metastable structures(AlxV2O5and HxV2O5)were constructed through the insertion of Al^(3+)/H^(+)during discharging,which existed in the lattice intercalation with V2O5.The incorporation of oxygen vacancies lowers the reaction energy barrier while improving the ion transport efficiency.In addition,the metastable structure allows the electrostatic interaction between Al3+and the main backbone to establish protection and optimize the transport channel.In parallel,this work exploits ex-situ characterization and DFT to obtain a profound insight into the instrumental effect of oxygen vacancies in the construction of metastable structures during in-situ electrochemical activation,with a view to better understanding the mechanism of the synergistic participation of Al3+and H+in the reaction.This work not only reports a method for cathode materials to modulate oxygen vacancies,but also lays the foundation for a deeper understanding of the metastable structure of vanadium oxides. 展开更多
关键词 Vanadium pentoxide Oxygen vacancies Electrochemical activation Metastable structure
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Derivation of 3D Dynamics for Rigid Floating Structures under Directional Wave Excitation
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作者 Shengzhe Wang 《Sustainable Marine Structures》 2025年第1期35-51,共17页
Modularfiloating structures(MFS)offer a sustainable pathway towards the expansion of coastal cities in adaptation tofilooding and sea level rise driven by climate change.It is therefore necessary to develop analytical... Modularfiloating structures(MFS)offer a sustainable pathway towards the expansion of coastal cities in adaptation tofilooding and sea level rise driven by climate change.It is therefore necessary to develop analytical methods easily accessible to architects or structural engineers for the rapid prototyping of MFS designs.This work develops novel closed‑form expressions describing the rigid body dynamics of symmetrically loaded rectangular pontoons across all six degrees of freedom(DOF)excited by surface waves approaching from any arbitrary direction.The derivations were based on Airy wave theory assuming frequency‑independent added mass and damping.When benchmarked against numerical solutions from ANSYS/AQWA for two MFS prototypes,the analytical approach proved capable of predicting the response amplitude operators(RAO)across all DOFs,wave directions,and structural confiigurations.However,while the response of mass‑dominated DOFs(surge,sway,and yaw)were well captured,the damping ratio for stiffness‑dominated DOFs(heave,roll,and pitch)must be judiciously selected to yield accurate RAO results.A parametric investigation further elucidated the contribution of structural geometry and wave directionality on the critical accelerations experienced by an idealizedfiloating structure founded upon a square pontoon under realistic sea states.It was discovered that the largest accelerations were triggered by waves approaching orthogonally to the pontoon.Ultimately,this work facilitates a more streamlined approach for the dynamic analysis of compliantfiloating bodies to supplement detailed modeling efforts via numerical methods. 展开更多
关键词 Floating Structure Airy Waves PONTOON RAO DAMPING Climate Adaptation
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Dynamic Characteristics of Different Pantograph Structures for Heavy-Duty Trucks Considering Road Excitation
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作者 Yan Xu Dietmar Gohlich +4 位作者 Sangyoung Park William Zhendong Liu Ziwei Zhou Haiyang Qu Weidong Zhu 《Computer Modeling in Engineering & Sciences》 2025年第8期1655-1676,共22页
The emissions from traditional fossil heavy-duty trucks have become a conspicuous issue worldwide.The electrical road system(ERS)can offer a viable solution for achieving zero CO_(2) emissions and has high energy effi... The emissions from traditional fossil heavy-duty trucks have become a conspicuous issue worldwide.The electrical road system(ERS)can offer a viable solution for achieving zero CO_(2) emissions and has high energy efficiency in long-distance road cargo transport.While many kinds of pantograph structures have been developed for the ERS,their corresponding pantograph-catenary dynamic characteristics under different road conditions have not been investigated.This work performs a numerical study on the dynamics of the pantograph-catenary interaction of an ERS considering different pantograph structures.First,a pantograph-catenary-truck-road model is proposed.The reduced catenary model and reduced-plate model transmission method are used to minimize model scale.Three different types of ERS pantograph structures are considered in the model.After validation,the pantograph-catenary dynamics under the influence of truck-road interactions with complex road roughness and different pantographs are studied and compared.The corresponding vibration transmission mechanism is further focused.The results show that the truck-road interaction has a significant effect on the pantograph-catenary interaction,but the pantograph with only one lower and upper armcan isolate the roll vibrationmotion transmission fromthe truck to the collector head,which has the best dynamic performance and is suggested for use in the ERS. 展开更多
关键词 Heavy-duty truck pantograph-catenary system pantograph structure dynamic performance road roughness
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Microwave-assisted heating on sandstone subjected to liquid nitrogen freeze-thaw:Pore structures and temperature characteristics
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作者 Zairong Yang Chaolin Wang +1 位作者 Yu Zhao Jing Bi 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第9期5615-5630,共16页
Liquid nitrogen(LN_(2))and microwave are the alternative methods for reservoir fracturing,which are rarely combined.To investigate the combined effects,sandstone is frozen with LN_(2)before microwave heating(MI),and n... Liquid nitrogen(LN_(2))and microwave are the alternative methods for reservoir fracturing,which are rarely combined.To investigate the combined effects,sandstone is frozen with LN_(2)before microwave heating(MI),and nuclear magnetic resonance(NMR),ultrasonic wave,and infrared thermal imaging(ITI)are used to understand the pore structures,moisture change,and surface temperature of the sandstone samples.With the heating time,the average surface temperature of the combining-treatment samples firstly increases from the room temperature(25℃)to 144.7℃(65 s)fast,and then increases slowly to 176.6℃(95 s).For the individual MI,the temperature increases to 146.7℃at 65 s.As 30 min of LN_(2)freezing,the samples perform well in removing pore water during heating.The NMR results show that after LN_(2)freezing,the seepage pores and total pores increase by 2.93%and 4.11%,respectively,and the pore connectivity enhances.However,the individual MI performs weak in enhancing the pore structures,forming a high vapor pressure(0.428 MPa at 65 s)and causing burst after 65 s.Due to the improved pore connectivity,the vapor pressure(0.378 MPa)and temperature are small at 65 s,and burst can be avoided.After freezing,the wave velocity decreases by 13.48%and the damage variable reaches 0.251.The velocity attenuation rates and damage variable gradually increase with heating time;under the same duration,the two variables of the combining treatments are greater than that of the individual treatments.This can prove a reference for gas production in sandstone reservoirs. 展开更多
关键词 Sandstone gas Liquid nitrogen(LN_(2)) MICROWAVE Pore structures
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Novel integration of PSO-enhanced damage mechanics and finite element method for predicting medium-low-cycle fatigue life in perforated structures
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作者 Qianyu XIA Zhixin ZHAN +3 位作者 Yue MEI Yanjun ZHANG Weiping HU Qingchun MENG 《Chinese Journal of Aeronautics》 2025年第2期128-142,共15页
In this research,we introduce an innovative approach that combines the Continuum Damage Mechanics-Finite Element Method(CDM-FEM)with the Particle Swarm Optimization(PSO)-based technique,to predict the Medium-Low-Cycle... In this research,we introduce an innovative approach that combines the Continuum Damage Mechanics-Finite Element Method(CDM-FEM)with the Particle Swarm Optimization(PSO)-based technique,to predict the Medium-Low-Cycle Fatigue(MLCF)life of perforated structures.First,fatigue tests are carried out on three center-perforated structures,aiming to assess their fatigue life under various strengthening conditions.These tests reveal significant variations in fatigue life,accompanied by an examination of crack initiation through the analysis of fatigue fracture surfaces.Second,an innovative fatigue life prediction methodology is applied to perforated structures,which not only forecasts the initiation of fatigue cracks but also traces the progression of damage within these structures.It leverages an elastoplastic constitutive model integrated with damage and a damage evolution model under cyclic loads.The accuracy of this approach is validated by comparison with test results,falling within the three times error band.Finally,we explore the impact of various strengthening techniques,including cross-sectional reinforcement and cold expansion,on the fatigue life and damage evolution of these structures.This is achieved through an in-depth comparative analysis of both experimental data and computational predictions,which provides valuable insights into the behavior of perforated structures under fatigue conditions in practical applications. 展开更多
关键词 Continuum damage mechanics Medium-low-cycle fatigue Particle swarm optimization Life prediction Perforated structures
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Analysis of the electromechanical coupling characteristics of piezoelectric semiconductor PN junction shell structures
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作者 Tiqing WANG Feng ZHU +4 位作者 Peng LI Zelin XU Tingfeng MA I.KUZNETSOVA Zhenghua QIAN 《Applied Mathematics and Mechanics(English Edition)》 2025年第6期1167-1186,共20页
Based on the nonlinear drift-diffusion(NLDD)model,the coupled behavior between the mechanical and electrical fields in piezoelectric semiconductor(PS)PN junctions under two typical loading conditions is investigated.T... Based on the nonlinear drift-diffusion(NLDD)model,the coupled behavior between the mechanical and electrical fields in piezoelectric semiconductor(PS)PN junctions under two typical loading conditions is investigated.The governing equations for the general shell structure of the PS PN junction are derived within the framework of virtual work principles and charge continuity conditions.The distributions of the electromechanical coupling field are obtained by the Fourier series expansion and the differential quadrature method(DQM),and the nonlinearity is addressed with the iterative method.Several numerical examples are presented to investigate the effects of mechanical loading on the charge carrier transport characteristics.It is found that the barrier height of the heterojunction can be effectively modulated by mechanical loading.Furthermore,a nonlinearity index is introduced to quantify the influence of nonlinearity in the model.It is noted that,when the concentration difference between the two sides is considerable,the nonlinear results differ significantly from the linear results,thereby necessitating the adoption of the NLDD model. 展开更多
关键词 piezoelectric semiconductor(PS) PN junction shell structures nonlinear drift-diffusion(NLDD)model potential barrier(well)
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Characteristics,genetic mechanism and hydrocarbon accumulation of inverted structures in the Doseo Basin,Chad
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作者 SONG Yifan DOU Lirong +5 位作者 XIAO Kunye CHENG Dingsheng DU Yebo WANG Li YUAN Shengqiang ZHANG Xinshun 《Petroleum Exploration and Development》 2025年第4期1001-1016,共16页
Based on two-dimensional/three-dimensional seismic and logging data,combined with the analysis of low-temperature thermochronology data,the unconformity surface characteristics and the patterns and dynamic mechanisms ... Based on two-dimensional/three-dimensional seismic and logging data,combined with the analysis of low-temperature thermochronology data,the unconformity surface characteristics and the patterns and dynamic mechanisms of inverted structures in the Doseo Basin in the Central and West African rift systems are systematically analyzed.Seismic profiles reveal two key inversion unconformable surfaces in the basin,i.e.the T_(5)interface within the Upper Cretaceous and the T_(4)interface at the top of the Cretaceous,which control the development of inverted structures in the basin.Four types of inverted structures,i.e.fault-associated,thrust,fold,and back-shaped negative flower,are identified.Spatially,they form six inverted structural belts trending in NE-NEE direction.The thermal history simulation of apatite fission track reveals two rapid cooling events in the late Late Cretaceous(85-80 Ma,cooling by 15℃)and the Eocene-Oligocene(30-40 Ma,cooling by 35℃),corresponding respectively to the formation periods of the T_(5)and T_(4)interface.The dynamics analysis of structural inversion indicates that the structural inversion in the Late Cretaceous was controlled by the subduction and long-range compression within the Tethys Ocean in the north of African Plate,while the structural inversion in the Eocene-Oligocene was drived by the stress transmission from the African-Eurasian collision.The two events were all controlled by the continuous tectonic regulation of the intracratonic basin by the evolution of the Tethys tectonic domain.The two periods of structural inversion enhanced the efficiency of oil and gas migration by controlling the types of traps(anticline and fault-related traps)and fault activation,precisely matching the hydrocarbon generation peaks of the Lower Cretaceous source rocks in the Late Cretaceous and Eocene,thereby controlling the formation of large-scale oil and gas reservoirs in the Doseo Basin.This geological insight provides a critical basis for the theoretical research on the evolution and hydrocarbon accumulation of inverted structures in discrete strike-slip rift systems. 展开更多
关键词 Central and West African rifting systems CHAD Doseo Basin structural inversion TRAP thermal history simulation hydrocarbon accumulation basin-forming dynamic mechanism
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李四光对地质力学(Geomechanics)的开创性贡献——纪念李四光诞辰135周年 被引量:1
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作者 童亨茂 《地质力学学报》 北大核心 2025年第1期1-7,共7页
中国学术界熟知李四光创立了地质力学,但学术界对该“地质力学”的理解还存差异,部分学者对李四光创立Geomechanics(地质力学)还存在疑问,导致对李四光学术贡献的理解存在偏颇,对李四光创立的“地质力学”和国际上使用的“geomechanics... 中国学术界熟知李四光创立了地质力学,但学术界对该“地质力学”的理解还存差异,部分学者对李四光创立Geomechanics(地质力学)还存在疑问,导致对李四光学术贡献的理解存在偏颇,对李四光创立的“地质力学”和国际上使用的“geomechanics”属于同一术语还明显存在争议,这或多或少地影响地质力学(Geomechanics)术语的使用和该学科的发展。笔者在长期从事地质力学研究实践的基础上,通过对李四光地质力学著作(尤其是李四光1945年版的《地质力学之基础与方法》一书)的系统研读和分析,结合深入的调研分析,确认李四光不仅创立了地质力学(Geomechanics),而且对地质力学及构造变形力学分析有一系列开创性贡献,如提出主应力平面和主应力的概念;把摩尔圆引入构造变形力学分析;建立了广义胡克定律的解析表达式等。在此基础上,简要评述了李四光创立的地质力学,并简要回顾了地质力学的发展历史并展望其发展前景。该文在李四光诞辰135周年之际完成,以此纪念其对地质力学的开创性贡献。 展开更多
关键词 李四光 地质力学 构造变形力学分析 构造体系
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油桐VfICS2基因的克隆和功能分析
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作者 李俊倩 杨程博 +1 位作者 张琳 刘美兰 《植物生理学报》 北大核心 2025年第9期1271-1283,共13页
油桐(Vernicia fordii)是我国特有的经济林木,具有重要的经济价值。水杨酸(SA)在调节植物生长发育中发挥着重要作用,而异分支酸合酶(isochorismate synthase,ICS)在植物SA合成途径中能够催化分支酸生成异分支酸,正向调控SA的合成。本研... 油桐(Vernicia fordii)是我国特有的经济林木,具有重要的经济价值。水杨酸(SA)在调节植物生长发育中发挥着重要作用,而异分支酸合酶(isochorismate synthase,ICS)在植物SA合成途径中能够催化分支酸生成异分支酸,正向调控SA的合成。本研究利用基因克隆、生物信息学分析、表达模式分析和生物学功能分析等方法,全面探究了油桐中VfICS2基因的功能。结果表明,油桐中仅有1个ICS2成员,编码序列长为1656 bp,编码551个氨基酸,是一种无跨膜结构域的亲水性蛋白,含12个α螺旋和16个β折叠,β折叠上包含Ile292、Ala357、Pro448等3个保守位点;表达模式分析发现,VfICS2主要表达于根、茎、叶中,且在茎中的表达量分别是根和叶的21.44倍、18.62倍;功能研究发现外源SA可抑制油桐花序轴伸长和减少花序轴数量及其花数量,拟南芥中过表达VfICS2可以抑制根毛生长发育和增强植株的抗旱抗盐能力,烟草中过表达VfICS2可减少烟草花数量和降低结实率。以上研究为进一步探索VfICS2功能奠定了基础,同时也为油桐遗传改良提供了基因资源。 展开更多
关键词 油桐 ics2基因 水杨酸 基因克隆 功能分析
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Phase structures and critical behavior of rational non-linear electrodynamics Anti de Sitter black holes in Rastall gravity
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作者 Yassine Sekhmani Dhruba Jyoti Gogoi +1 位作者 Ratbay Myrzakulov Javlon Rayimbaev 《Communications in Theoretical Physics》 SCIE CAS CSCD 2024年第4期134-152,共19页
This research paper presents a black hole solution with a rational nonlinear electrodynamics source within the Rastall gravity framework.The paper analyzes the thermodynamic properties of the solution in normal phase ... This research paper presents a black hole solution with a rational nonlinear electrodynamics source within the Rastall gravity framework.The paper analyzes the thermodynamic properties of the solution in normal phase space and explores its critical behavior.The phase structure is examined using the extended first law of thermodynamics,with the cosmological constantΛserving as pressure P.The isotherms exhibit van der Waals behavior at small values of horizon r_(+).The paper also investigates the Gibbs free energy behavior and finds two critical points with two pressures where the re-entrant phase transition occurs and disappears.We also explore the prevalent microstructure of black holes in Ruppeiner geometry,uncovering significant deviations in the nature of particle interactions from conventional practice.Moreover,the thermodynamic geometry is analyzed using the Ruppeiner formalism,with the normalized Ricci scalar indicating possible point-phase transitions of the heat capacity,and the normalized extrinsic curvature having the same sign as the normalized Ricci scalar.The three-phase transitions of the heat capacity are those that we find for the normalized Ruppeiner curvatures.Thus,there is an absolute correspondence. 展开更多
关键词 Rastall gravity biack hole Phase structures
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Evaluating the characteristics of geological structures in karst groundwater inflow, Nowsud Tunnel
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作者 BAYAT Narges SADEGHI Erfan NASSERY Hamid Reza 《Journal of Mountain Science》 SCIE CSCD 2024年第10期3434-3452,共19页
Highly permeable geological structures such as dissolution channels, open fractures, and faults create environmental challenges regard to hydrological and hydrogeological aspects of underground construction, often cau... Highly permeable geological structures such as dissolution channels, open fractures, and faults create environmental challenges regard to hydrological and hydrogeological aspects of underground construction, often causing significant groundwater inflow during drilling due to the limitations of empirical and analytical methods. This study aims to identify the geological factors influencing water flow into the tunnel. High-flow zones' geological features have been identified and examined for this purpose. According to the geological complexity of the Nowsud tunnel, presence of different formations with different permeability and karstification have led to a high volume of underground inflow water (up to 4700 L/s) to the tunnel. The Nowsud tunnel faces significant geological and hydrogeological challenges due to its passage through the Ilam formation's LI2 unit, characterized by dissolution channels, faults, and fractures. The highest inflow rate (4700 L/s) occurred in the Hz-9 zone within the Zimkan anticline. The relationship between geological features and groundwater inflow indicates that anticlines are more susceptible to inflow than synclines. Additionally, different types of faults exhibit varying hydraulic effects, with strike-slip faults having the most significant impact on groundwater inflow, thrust faults conducting less water into the tunnel, and inflow through normal faults being negligible compared to the other two types of faults. The novelty of this paper lies in its detailed analysis of geological features influencing groundwater inflow into the Nowsud tunnel, providing empirical data on high-flow zones and differentiating the hydraulic effects of various fault types, which enhances the understanding and prediction of groundwater inflow in underground constructions. 展开更多
关键词 Geological structures Groundwater inflow HYDROGEOLOGY Nowsud tunnel KARST
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VUV imaging of type-ⅠELM filamentary structures and their temporal characteristics on EAST
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作者 Rongjing DENG Tingfeng MING +9 位作者 Bang LI Qiqi SHI Shanwei HOU Shuqi YANG Xiaoju LIU Shaocheng LIU Guoqiang LI Xiang GAO Yasuhiro SUZUKI Yunfeng LIANG 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第11期22-31,共10页
In the H-mode experiments conducted on the Experimental Advanced Superconducting Tokamak(EAST),fluctuations induced by the so-called edge localized modes(ELMs)are captured by a high-speed vacuum ultraviolet(VUV)imagin... In the H-mode experiments conducted on the Experimental Advanced Superconducting Tokamak(EAST),fluctuations induced by the so-called edge localized modes(ELMs)are captured by a high-speed vacuum ultraviolet(VUV)imaging system.Clear field line-aligned filamentary structures are analyzed in this work.Ion transport induced by ELM filaments in the scrape-off layer(SOL)under different discharge conditions is analyzed by comparing the VUV signals with the divertor probe signals.It is found that convective transport along open field lines towards the divertor target dominates the parallel ion particle transport mechanism during ELMs.The toroidal mode number of the filamentary structure derived from the VUV images increases with the electron density pedestal height.The analysis of the toroidal distribution characteristics during ELM bursts reveals toroidal asymmetry.The influence of resonance magnetic perturbation(RMP)on the ELM size is also analyzed using VUV imaging data.When the phase difference of the coil changes periodically,the widths of the filaments change as well.Additionally,the temporal evolution of the ELMs on the VUV signals provides rise time and decay time for each single ELM event,and the results indicate a negative correlation trend between these two times. 展开更多
关键词 EAST tokamak VUV imaging filamentary structure temporal characteristics RMP
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Design Guidelines for Composition of Brazing Filler Metals and Evolution Mechanisms of Typical Microstructures 被引量:4
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作者 Long Weimin 《稀有金属材料与工程》 北大核心 2025年第4期837-853,共17页
Brazing filler metals are widely applied,which serve as an industrial adhesive in the joining of dissimilar structures.With the continuous emergence of new structures and materials,the demand for novel brazing filler ... Brazing filler metals are widely applied,which serve as an industrial adhesive in the joining of dissimilar structures.With the continuous emergence of new structures and materials,the demand for novel brazing filler metals is ever-increasing.It is of great significance to investigate the optimized composition design methods and to establish systematic design guidelines for brazing filler metals.This study elucidated the fundamental rules for the composition design of brazing filler metals from a three-dimensional perspective encompassing the basic properties of applied brazing filler metals,formability and processability,and overall cost.The basic properties of brazing filler metals refer to their mechanical properties,physicochemical properties,electromagnetic properties,corrosion resistance,and the wettability and fluidity during brazing.The formability and processability of brazing filler metals include the processes of smelting and casting,extrusion,rolling,drawing and ring-making,as well as the processes of granulation,powder production,and the molding of amorphous and microcrystalline structures.The cost of brazing filler metals corresponds to the sum of materials value and manufacturing cost.Improving the comprehensive properties of brazing filler metals requires a comprehensive and systematic consideration of design indicators.Highlighting the unique characteristics of brazing filler metals should focus on relevant technical indicators.Binary or ternary eutectic structures can effectively enhance the flow spreading ability of brazing filler metals,and solid solution structures contribute to the formability.By employing the proposed design guidelines,typical Ag based,Cu based,Zn based brazing filler metals,and Sn based solders were designed and successfully applied in major scientific and engineering projects. 展开更多
关键词 design of brazing filler metals design guidelines for composition Ag based brazing filler metals eutectic structures evolution
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Characterization and Analysis of Abnormal Grain Structures in WSTi6421 Titanium Alloy AfterβAnnealing Treatment 被引量:1
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作者 Wang Wensheng Liu Xianghong +5 位作者 Wang Haipeng Wang Kaixuan Tian Yanwen Yan Jianchuan Li Yulu Chen Haisheng 《稀有金属材料与工程》 北大核心 2025年第2期354-362,共9页
As-forged WSTi6421 titanium alloy billet afterβannealing was investigated.Abnormally coarse grains larger than adjacent grains could be observed in the microstructures,forming abnormal grain structures with uneven si... As-forged WSTi6421 titanium alloy billet afterβannealing was investigated.Abnormally coarse grains larger than adjacent grains could be observed in the microstructures,forming abnormal grain structures with uneven size distribution.Through electron backscattered diffraction(EBSD),the forged microstructure at various locations of as-forged WSTi6421 titanium alloy billet was analyzed,revealing that the strength of theβphase cubic texture generated by forging significantly influences the grain size afterβannealing.Heat treatment experiments were conducted within the temperature range from T_(β)−50°C to T_(β)+10°C to observe the macro-and micro-morphologies.Results show that the cubic texture ofβphase caused by forging impacts the texture of the secondaryαphase,which subsequently influences theβphase formed during the post-βannealing process.Moreover,the pinning effect of the residual primaryαphase plays a crucial role in the growth ofβgrains during theβannealing process.EBSD analysis results suggest that the strength ofβphase with cubic texture formed during forging process impacts the orientation distribution differences ofβgrains afterβannealing.Additionally,the development of grains with large orientations within the cubic texture shows a certain degree of selectivity duringβannealing,which is affected by various factors,including the pinning effect of the primaryαphase,the strength of the matrix cubic texture,and the orientation relationship betweenβgrain and matrix.Comprehensively,the stronger the texture in a certain region,the less likely the large misoriented grains suffering secondary growth,thereby aggregating the difference in microstructure and grain orientation distribution across different regions afterβannealing. 展开更多
关键词 WSTi6421 titanium alloy βannealing abnormal grain structure
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Structural Color Dynamic Graphics Display Based on Microlens Array 被引量:1
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作者 LI Xue-han LIU Ling-zhi +1 位作者 HUANG Min LI Xiu 《印刷与数字媒体技术研究》 北大核心 2025年第2期162-168,共7页
It is of great scientific significance to construct a 3D dynamic structural color with a special color effect based on the microlens array.However,the problems of imperfect mechanisms and poor color quality need to be... It is of great scientific significance to construct a 3D dynamic structural color with a special color effect based on the microlens array.However,the problems of imperfect mechanisms and poor color quality need to be solved.A method of 3D structural color turning on periodic metasurfaces fabricated by the microlens array and self-assembly technology was proposed in this study.In the experiment,Polydimethylsiloxane(PDMS)flexible film was used as a substrate,and SiO2 microspheres were scraped into grooves of the PDMS film to form 3D photonic crystal structures.By adjusting the number of blade-coated times and microsphere concentrations,high-saturation structural color micropatterns were obtained.These films were then matched with microlens arrays to produce dynamic graphics with iridescent effects.The results showed that by blade-coated two times and SiO2 microsphere concentrations of 50%are the best conditions.This method demonstrates the potential for being widely applied in the anticounterfeiting printing and ultra-high-resolution display. 展开更多
关键词 Structural color Microlens array Dynamic graphics display Moirémagnification Optical anti-counterfeiting
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Towards Net Zero Resilience: A Futuristic Architectural Strategy for Cyber-Attack Defence in Industrial Control Systems (ICS) and Operational Technology (OT) 被引量:1
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作者 Hariharan Ramachandran Richard Smith +2 位作者 Kenny Awuson David Tawfik Al-Hadhrami Parag Acharya 《Computers, Materials & Continua》 2025年第2期3619-3641,共23页
This paper introduces the Integrated Security Embedded Resilience Architecture (ISERA) as an advanced resilience mechanism for Industrial Control Systems (ICS) and Operational Technology (OT) environments. The ISERA f... This paper introduces the Integrated Security Embedded Resilience Architecture (ISERA) as an advanced resilience mechanism for Industrial Control Systems (ICS) and Operational Technology (OT) environments. The ISERA framework integrates security by design principles, micro-segmentation, and Island Mode Operation (IMO) to enhance cyber resilience and ensure continuous, secure operations. The methodology deploys a Forward-Thinking Architecture Strategy (FTAS) algorithm, which utilises an industrial Intrusion Detection System (IDS) implemented with Python’s Network Intrusion Detection System (NIDS) library. The FTAS algorithm successfully identified and responded to cyber-attacks, ensuring minimal system disruption. ISERA has been validated through comprehensive testing scenarios simulating Denial of Service (DoS) attacks and malware intrusions, at both the IT and OT layers where it successfully mitigates the impact of malicious activity. Results demonstrate ISERA’s efficacy in real-time threat detection, containment, and incident response, thus ensuring the integrity and reliability of critical infrastructure systems. ISERA’s decentralised approach contributes to global net zero goals by optimising resource use and minimising environmental impact. By adopting a decentralised control architecture and leveraging virtualisation, ISERA significantly enhances the cyber resilience and sustainability of critical infrastructure systems. This approach not only strengthens defences against evolving cyber threats but also optimises resource allocation, reducing the system’s carbon footprint. As a result, ISERA ensures the uninterrupted operation of essential services while contributing to broader net zero goals. 展开更多
关键词 ics/OT cyber Programmable Logic Controllers(PLC)security detection safety reliability proof testing gas compressor station ics resilience security architecture ics
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Clinical characteristics of peripapillary hyperreflective ovoid mass-like structures in myopic children
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作者 Lu Zhang Zuo-Hui-Zi Yi +5 位作者 Xuan Jiang Gong-Peng Sun Fang Zhao Li Zhang Yi Xiang Chang-Zheng Chen 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2024年第7期1292-1299,共8页
AIM:To describe the characteristics of peripapillary hyperreflective ovoid mass-like structure(PHOMS)in myopic children and to investigate factors associated with PHOMS.METHODS:This retrospective observational study i... AIM:To describe the characteristics of peripapillary hyperreflective ovoid mass-like structure(PHOMS)in myopic children and to investigate factors associated with PHOMS.METHODS:This retrospective observational study included 101 eyes of 101 children(age≤17y)with myopia.All included patients underwent comprehensive clinical examination.Optic nerve canal parameters,including disc diameter,optic nerve head(ONH)tilt angle,and border tissue angle were measured using serial enhanced-depth imaging spectral-domain optical coherence tomography(EDI-OCT).Based on the optic disc drusen consortium’s definition of PHOMS,eyes were classified as PHOMS group and non-PHOMS group.PHOMS was categorized according to height.RESULTS:Sixty-seven(66.3%)eyes were found with PHOMS.Small PHOMS could only be detected by optical coherence tomography(OCT).Medium PHOMS could be seen with blurred optic disc borders corresponding to OCT.The most frequent location of PHOMS was at the nasosuperior(91%,61 of 67 eyes)to ONH disc.The axial length and spherical equivalent were more myopic in the PHOMS group than in the non-PHOMS group(both P<0.001).ONH tilt angle was also significantly greater in PHOMS group than in non-PHOMS group[8.90(7.16-10.54)vs 3.93(3.09-5.25),P<0.001].Border tissue angle was significantly smaller in PHOMS group than in non-PHOMS group[29.70(20.90-43.81)vs 45.62(35.18-60.45),P<0.001].In the multivariable analysis,spherical equivalent(OR=3.246,95%CI=1.209-8.718,P=0.019)and ONH tilt angle(OR=3.275,95%CI=1.422-7.542,P=0.005)were significantly correlated with PHOMS.There was no disc diameter associated with PHOMS.In the linear regression analysis,border tissue angle was negatively associated with PHOMS height(β=-2.227,P<0.001).CONCLUSION:PHOMS is associated with optic disc tilt and optic disc nasal shift in myopia.Disc diameter is not a risk factor for PHOMS.The changes in ONH caused by axial elongation facilitated an understanding of the mechanism of PHOMS. 展开更多
关键词 peripapillary hyperreflective ovoid masslike structure MYOPIA optic disc edema enhanced-depth imaging spectral-domain optical coherence tomography
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Characteristics of geological structures in Shiling and Zhuanshanhu areas of Yehe Uplift,NE China
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作者 GUAN Yue YU Yinghua +1 位作者 ZHANG Yaxiong YUAN Hongqi 《Global Geology》 2024年第2期105-120,共16页
The basin marginal fault system is the key to understand the formation and evolution of Songliao Basin.In order to investigate the influence of marginal fault system on the structural evolution of Songliao Basin,a com... The basin marginal fault system is the key to understand the formation and evolution of Songliao Basin.In order to investigate the influence of marginal fault system on the structural evolution of Songliao Basin,a comprehensive study was conducted on Shiling Town and Zhuanshanhu area of Yehe Town in Siping City of Jilin Province,where is the southeastern margin of the Songliao Basin and there are a series of well-exposed fault,fold and intrusive bodies belonging to the main marginal fault system of the Songliao Basin known as the Jiamusi-Yitong(Jia-Yi)fault zone.Through profile measurement and field investigation,samples with various lithologies and distinctive features were collected.Detailed field and laboratory works include component and microstructure analysis of these samples,rock-rock contact analysis,main strike measurement and statistics analysis.These data reveal the structural characteristics of the fold,fault and intrusive bodies in the study area.The research results show that the folds are distributed in the Mesozoic strata near the main fault of the eastern branch of the Jia-Yi fault zone,and the folded strata involve the Cretaceous Denglouku and Quantou formations.In addition,the section is dominated by high-angle strikeslip thrust faults.Light-colored veins and dark-colored veins are extensively distributed in the exposed granites.Statistical analysis of joint and fault attitudes in the study area reveals a right-lateral strike-sliping along the main fault.The large-scale right-lateral strike-slip and thrust fault system in Shiling Town occurred in right-lateral transpressive stage in Late Cretaceous.Based on the results above,tectonic evolution sequence in Shiling section of the Jia-Yi fault zone during the Mesozoic can be divided into five stages:Middle Jurassic left-lateral ductile strike-slip stage,Late Jurassic compression stage,Early Cretaceous tension stage,Early Cretaceous extension stage and Late Cretaceous right-lateral transpressive stage.These may have important constraint on understanding the Mesozoic evolution of the Songliao Basin. 展开更多
关键词 Jia-Yi fault structural characteristics evolution sequence Shiling Zhuanshanhu northern segment Tanlu fault
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