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文章速递Quantization of electromagnetic modes and angular momentum on plasmonic nanowires 认领
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作者 朱国栋 郭杨喆 +1 位作者 董斌 方蔚瑞 《中国物理B:英文版》 SCIE EI CAS CSCD 2020年第8期428-436,共9页
Quantum theory of surface plasmons is very important for studying the interactions between light and different metal nanostructures in nanoplasmonics.In this work,using the canonical quantization method,the SPPs on na... Quantum theory of surface plasmons is very important for studying the interactions between light and different metal nanostructures in nanoplasmonics.In this work,using the canonical quantization method,the SPPs on nanowires and their orbital and spin angular momentums are investigated.The results show that the SPPs on nanowire carry both orbital and spin momentums during propagation.Later,the result is applied to the plasmonic nanowire waveguide to show the agreement of the theory.The study is helpful for the nano wire based plasmonic interactions and the quantum information based optical circuit in the future. 展开更多
关键词 surface plasmons surface waves optical angular momentum
文章速递Study of machining induced surface defects and its effect on fatigue performance of AZ91/15%SiCp metal matrix composite 认领
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作者 Nishita Anandan M.Ramulu 《镁合金学报(英文)》 SCIE 2020年第2期387-395,共9页
The quality of surface generated in a peripheral milling of AZ91/SiCp/15%for varying machining conditions and its effect on the fatigue performance are investigated in this study.The machined surface quality was evalu... The quality of surface generated in a peripheral milling of AZ91/SiCp/15%for varying machining conditions and its effect on the fatigue performance are investigated in this study.The machined surface quality was evaluated through roughness measurements and SEM micrographs of ine machined surface.Tensile iesis were pcifumicu io iiieasure the mechanical properties of the composite.Subsequently,fatigue life of milled specimens was measured through axial fatigue tests at four loading conditions.Optical and SEM/EDS micrographs of the fractured surface were studied to identify the crack initiation site and propagation mechanism.Specimens machined at a lower feed rate of 0.1 mm/rev was found to have excellent surface finish and consequently higher fatigue life.At 0.3 mm/rev,the presence of feed marks and other surface defects resulted in a drastic decrease in fatigue life.Five distinct regions were identified on the fractured surface,particle fracture along and perpendicular to the surface,voids in the matrix due to particle debonding and pull out and typical ductile failure of matrix with embedded SiC particles. 展开更多
关键词 Magnesium composite Machined surface Surface integrity Fatigue
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Integration of satellite remote sensing data in underground coal fire detection:A case study of the Fukang region,Xinjiang,China 认领
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作者 Shiyong YAN Ke SHI +2 位作者 Yi LI Jinglong LIU Hongfeng ZHAO 《地球科学前沿:英文版》 SCIE CAS CSCD 2020年第1期1-12,共12页
Xinjiang in China is one of the areas worst affected by coal fires.Coal fires cannot only waste a large amount of natural resources and cause serious economic losses,but they also cause huge damage to the atmosphere,t... Xinjiang in China is one of the areas worst affected by coal fires.Coal fires cannot only waste a large amount of natural resources and cause serious economic losses,but they also cause huge damage to the atmosphere,the soil,the surrounding geology,and the environment.Therefore,there is an urgent need to effectively explore remote sensing based detection of coal fires for timely understanding of their latest development trend.In this study,in order to investigate the distribution of coal fires in an accurate and reliable manner,we exploited both Landsat-8 optical data and Sentinel-1A synthetic aperture radar(SAR)images,using the generalized single-channel algorithm and the InSAR time-series analysis approach,respectively,for coal fire detection in the southern part of the Fukang region of Xinjiang,China.The generalized single-channel algorithm was used for land surface temperature information extraction.Meanwhile,the timeseries InSAR analysis technology was employed for estimating the surface micro deformation information,which was then used for building a band-pass filter.The suspected coal fire locations could then be established by a band-pass filtering operation on the obtained surface temperature map.Finally,the locations of the suspected coal fires were validated by the use of field survey data.The results indicate that the integration of thermal infrared remote sensing and radar interferometry technologies is an efficient investigation approach for coal fire detection in a large-scale region,which would provide the necessary spatial information support for the survey and control of coal fires. 展开更多
关键词 land SURFACE temperature generalized singlechannel algorithm SURFACE deformation time-series INSAR analysis FILTERING operation coal fire DETECTION
Comparison Study of Constitutive Models for Overconsolidated Clays 认领
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作者 Z.Wan Y.P.Yao Z.W.Gao 《固体力学学报:英文版》 SCIE EI CSCD 2020年第1期98-120,共23页
Widely distributed in natural deposits,the overconsolidated(OC)clays have attracted extensive experimental investigations on their mechanical behaviors,especially in the 1960s and 1970s.Based on these results,numerous... Widely distributed in natural deposits,the overconsolidated(OC)clays have attracted extensive experimental investigations on their mechanical behaviors,especially in the 1960s and 1970s.Based on these results,numerous constitutive models have also been established.These models generally fall into two categories:one based on the classical plasticity theory and the other the bounding surface(BS)plasticity theory,with the latter being more popular and successful.The BS concept and the subloading surface(SS)concept are the two major BS plasticity theories.The features of these two concepts and the representative models based on them are introduced,respectively.The unified hardening(UH)model for OC clays is also based on the BS plasticity theory but distinguishes itself from other models by the integration of the reference yield surface,unified hardening parameter,potential failure stress ratio,arid transformed stress tensor.Modification is made to the Hvorslev envelop employed in the UH model to improve its capability of describing the behaviors of clays with extremely high overconsolidation ratio in this paper.The comparison among the BS model,SS model,and UH model is performed.Evidence shows that all these three models can characterize the fundamental behaviors of OC clays,such as the stress dilatancy,strain softening and attainment of the critical state.The UH model with the revised Hvorslev envelop has the fewest parameters which are identical to those of the modified Cam-Clay model. 展开更多
关键词 CLAY Overconsolidation Critical state Bounding surface Subloading surface Unified hardening model
Measurement of the sea surface using a GPS towing-body in Wanshan area 认领
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作者 Wanlin Zhai Jianhua Zhu +4 位作者 Chaofei Ma Xiaohui Fan Longhao Yan He Wang Chuntao Chen 《海洋学报:英文版》 SCIE CAS CSCD 2020年第5期123-132,共10页
Wanshan area has been chosen to be the specified field to calibrate and validate(Cal/Val)the HY-2 altimeter and its follow-on satellites.In March 2018,an experiment has been conducted to determine the sea surface heig... Wanshan area has been chosen to be the specified field to calibrate and validate(Cal/Val)the HY-2 altimeter and its follow-on satellites.In March 2018,an experiment has been conducted to determine the sea surface height(SSH)under the HY-2 A ground track(Pass No.203).A GPS towing-body(GPS-TB)was designed to measure the SSH covering an area of about 6 km×28 km wide centered on the HY-2 A altimeter satellite ground track.Three GPS reference stations,one tide gauge and a GPS buoy were placed in the research area,in order to process and resolve the kinematic solution and check the precision of the GPS-TB respectively.All the GPS data were calculated by the GAMIT/GLOBK software and TRACK module.The sea surface was determined by the GPS-TB solution and the tide gauge placed on Zhiwan Island.Then the sea surface of this area was interpolated by Arc GIS10.2 with ordinary Kriging method.The results showed that the precision of the GPS-TB is about 1.10 cm compared with the tide gauge placed nearby,which has an equivalent precision with the GPS buoy.The interpolated sea surface has a bias of–1.5–4.0 cm with standard deviation of 0.2–2.4 cm compared with the checking line.The gradient of the measured sea surface is about 1.62 cm/km along the HY-2 orbit which shows a good agreement compared with the CLS11 mean sea surface(MSS).In the Cal/Val of satellites,the sea surface between the tide gauge/GPS buoy and the footprint of altimeter can be improved by this work. 展开更多
关键词 GPS towing-body sea surface height GPS buoy GPS reference station tide gauge sea surface
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Interfacial phenomena of water striders on water surfaces: a review from biology to biomechanics 认领
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作者 Jing-Ze Ma Hong-Yu Lu +1 位作者 Xiao-Song Li Yu Tian 《动物学研究》 SCIE CAS CSCD 2020年第3期231-246,共16页
Water striders have intrigued researchers for centuries from the viewpoints of biology to biomechanics. In this review, we introduce the basic theories and techniques of physics and force measurement for biomechanical... Water striders have intrigued researchers for centuries from the viewpoints of biology to biomechanics. In this review, we introduce the basic theories and techniques of physics and force measurement for biomechanical research into water striders. Morphological and behavioral traits of water striders are summarized and discussed from biomechanical perspectives, along with comparative study. This integrated review also highlights potential directions for studies on water-walking arthropods,which might inspire future biological and biomechanical research. 展开更多
关键词 Water strider Water repellency Surface tension Surface propulsion
Nature-inspired surface topography: design and function 认领
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作者 XianTong Yan YuanKai Jin +3 位作者 XueMei Chen Chao Zhang ChongLei Hao ZuanKai Wang 《中国科学:物理学、力学、天文学英文版》 SCIE EI CAS CSCD 2020年第2期32-46,共15页
Learning from nature has traditionally and continuously provided important insights to drive a paradigm shift in technology.In particular,recent studies show that many biological organisms exhibit spectacular surface ... Learning from nature has traditionally and continuously provided important insights to drive a paradigm shift in technology.In particular,recent studies show that many biological organisms exhibit spectacular surface topography such as shape,size,spatial organization,periodicity,interconnectivity,and hierarchy to endow them with the capability to adapt dynamically and responsively to a wide range of environments.More excitingly,in a broader perspective,these normally neglected topological features have the potential to fundamentally change the way of how engineering surface works,such as how fluid flows,how heat is transported,and how energy is generated,saved,and converted,to name a few.Thus,the design of nature-inspired surface topography for unique functions will spur new thinking and provide paradigm shift in the development of the new engineering surfaces.In this review,we first present a brief introduction to some insights extracted from nature.Then,we highlight recent progress in designing new surface topographies and demonstrate their applications in emerging areas including thermal-fluid transport,anti-icing,water harvesting,power generation,adhesive control,and soft robotics.Finally,we offer our perspectives on this emerging field,with the aim to stimulate new thinking on the development of next-generation of new materials and devices,and dramatically extend the boundaries of traditional engineering. 展开更多
关键词 natural INSPIRATION BIOMIMETIC SURFACE TOPOGRAPHY SURFACE engineering UNIQUE functions INTERFACIAL interaction mechanisms
Convective heat transfer on flat and concave surfaces subjected to an impinging jet form lobed nozzle 认领
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作者 LYU Yuan Wei ZHANG JingZhou +1 位作者 WANG BoYan TAN XiaoMing 《中国科学:技术科学英文版》 SCIE EI CAS CSCD 2020年第1期116-127,共12页
A tri-dimensional lobed nozzle is concerned in the jet impingement on a flat target and a concave target in the current study. The jet impingement heat transfer experiments are conducted under two jet Reynolds numbers... A tri-dimensional lobed nozzle is concerned in the jet impingement on a flat target and a concave target in the current study. The jet impingement heat transfer experiments are conducted under two jet Reynolds numbers(Re=10000 and 20000) and four nozzle-to-surface distances(H/d=2, 4, 6 and 8). Simultaneously, to characterize the flow dynamics of lobed jet impingement onto different target surfaces, some computations are conducted under a specific jet Reynolds number. The results show that the lobed jet is capable of achieving an increase of stagnation Nusselt number about 25% in relative to the round jet at small nozzle-tosurface distances. However, at large nozzle-to-surface distances, the lobed jet otherwise weakens the convective heat transfer in the vicinity of jet stagnation, especially under high jet Reynolds number. When compared to the flat target, approximately a20%–30% reduction of stagnation Nusselt number is produced on a concave target, which is attributed to the combined effect of destabilization and confinement due to the concave curvature. 展开更多
关键词 jet IMPINGEMENT enhanced heat transfer lobed nozzle FLAT SURFACE CONCAVE SURFACE
Effects of Surface Modifications on the Mechanical Properties of Reinforced Pineapple Leaf Fibre Polypropylene Composites 认领
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作者 Samuel Wadzani Gadzama O. K. Sunmonu +1 位作者 U. S. Isiaku Abdullahi Danladi 《化学工程与科学期刊(英文)》 2020年第1期24-39,共16页
Pineapple Leaf Fibre (PALF) is one of the natural fibres that have high potential in the industry. Natural fibres have become the main alternative source for reinforced polymer composites. The objective of this study ... Pineapple Leaf Fibre (PALF) is one of the natural fibres that have high potential in the industry. Natural fibres have become the main alternative source for reinforced polymer composites. The objective of this study is to observe the effect of chemical treatments using Sodium Hydroxide (NaOH) solution, Zinc chloride, Acetic Anhydride and Nitric acid on the mechanical properties of pineapple leaf fibre reinforced polypropylene composites. The tensile test was conducted by using the ASTM D638-10 to obtain the tensile strength (TS) and Young’s modulus (YM), Flexural properties were conducted to determine the flexural strength (FS) and flexural modulus (FM) of the reinforced composites using the ASTM D256-10 method, and impact test was conducted to determine the impact strength (IS) of the reinforced composites using the Izod ASTM D790-17 method. From the results obtained, the composites with surface modified PALF fillers show enhanced mechanical properties over the untreated PALF fillers in this order;for TS untreated composite C3H6O3 3. For YM untreated composite 3 C3H6O3 3 3H6O3. For FM, untreated reinforced PALF/PP composites C3H6O3 3. For IS, the untreated reinforced PALF/PP composites 3 C3H6O3. SEM analysis was carried out on the PALF before the compounding to analyze the effect of the surface modification agents. 展开更多
关键词 SURFACE Modifications PROPERTIES
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Assessing Drought Conditions in Cloudy Regions Using Reconstructed Land Surface Temperature 认领
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作者 Shiqi YANG Dejun ZHANG +2 位作者 Liang SUN Yongqian WANG Yanghua GAO 《气象学报:英文版》 SCIE CSCD 2020年第2期264-279,共16页
Temperature vegetation dryness index(TVDI)in a triangular or trapezoidal feature space can be calculated from the land surface temperature(LST)and normalized difference vegetation index(NDVI),and has been widely appli... Temperature vegetation dryness index(TVDI)in a triangular or trapezoidal feature space can be calculated from the land surface temperature(LST)and normalized difference vegetation index(NDVI),and has been widely applied to regional drought monitoring.However,thermal infrared sensors cannot penetrate clouds to detect surface information of sub-cloud pixels.In cloudy areas,LST data include a large number of cloudy pixels,seriously degrading the spatial and temporal continuity of drought monitoring.In this paper,the Remotely Sensed Daily Land Surface Temperature Reconstruction model(RSDAST)is combined with the LST reconstructed(RLST)by the RSDAST and applied to drought monitoring in a cloudy area.The drought monitoring capability of the reconstructed temperature vegetation drought index(RTVDI)under cloudy conditions is evaluated by comparing the correlation between land surface observations for soil moisture and the TVDI before and after surface temperature reconstruction.Results show that the effective duration and area of the RTVDI in the study area were larger than those of the original TVDI(OTVDI)in 2011.In addition,RLST/NDVI scatter plots cover a wide range of values,with the fitted dry–wet boundaries more representative of real soil moisture conditions.Under continuously cloudy conditions,the OTVDI inverted from the original LST(OLST)loses its drought monitoring capability,whereas RTVDI can completely and accurately reconstruct surface moisture conditions across the entire study area.The correlation between TVDI and soil moisture is stronger for RTVDI(R=-0.45)than that for OTVDI(R=-0.33).In terms of the spatial and temporal distributions,the R value for correlation between RTVDI and soil moisture was higher than that for OTVDI.Hence,in continuously cloudy areas,RTVDI not only expands drought monitoring capability in time and space,but also improves the accuracy of surface soil moisture monitoring and enhances the applicability and reliability of thermal infrared data under extreme conditions. 展开更多
关键词 LAND SURFACE TEMPERATURE RECONSTRUCTION Remotely Sensed Daily LAND SURFACE TEMPERATURE RECONSTRUCTION model(RSDAST) TEMPERATURE vegetation DRYNESS index(TVDI) soil moisture drought
曲面参数方程面积公式的推导 认领
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作者 李舜 谢祥俊 《四川文理学院学报》 2020年第2期50-53,共4页
给出了曲面参数方程的二重积分计算其面积公式的新的两种推导方法,这两种推导方法,更加展示这一公式推导的细节,所做这些对《数学分析》、《高等数学》这部分教学都将有一定的指导意义.
关键词 曲面 参数方程 曲面面积
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Correlation between surface charge and hydration on mineral surfaces in aqueous solutions: A critical review 认领
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作者 Hong-liang Li Wen-nan Xu +3 位作者 Fei-fei Jia Jian-bo Li Shao-xian Song Yuri Nahmad 《矿物冶金与材料学报:英文版》 SCIE EI CAS CSCD 2020年第7期857-871,共15页
Surface charges and hydration are predominant properties of colloidal particles that govern colloidal stability in aqueous suspensions.These properties usually coexist and interact with each other.The correlation betw... Surface charges and hydration are predominant properties of colloidal particles that govern colloidal stability in aqueous suspensions.These properties usually coexist and interact with each other.The correlation between the surface charge and hydration of minerals is summarized on the basis of innovative experimental,theoretical,and molecular dynamics simulation studies.The factors affecting the adsorption behavior of ions and water molecules,such as ion concentration,ion hydration radius and valence,and surface properties,are discussed.For example,the hydration and adsorption states completely differ between monovalent and divalent ions.For ions of the same valence,the effect of surface charge on the hydration force follows the Hofmeister adsorption series.Electrolyte concentration exerts a significant effect on the hydration force at high ion concentrations.Meanwhile,the ion correlations in high-concentration electrolyte systems become long range.The interfacial water structure largely depends on surface chemistry.The hydration layer between different surfaces shows large qualitative differences. 展开更多
关键词 surface hydration surface charged ion MINERAL water molecule
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Tropical Cyclone Size Change under Ocean Warming and Associated Responses of Tropical Cyclone Destructiveness: Idealized Experiments 认领
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作者 Zanmin XU Yuan SUN +3 位作者 Tim LI Zhong ZHONG Jia LIU Chen MA 《气象学报:英文版》 SCIE CSCD 2020年第1期163-175,共13页
The power dissipation index(PDI),which is defined as the sum of the cube of tropical cyclone(TC)maximum wind speed during TC lifetime,is widely used to estimate the TC destructive potential.However,due to the lack of ... The power dissipation index(PDI),which is defined as the sum of the cube of tropical cyclone(TC)maximum wind speed during TC lifetime,is widely used to estimate the TC destructive potential.However,due to the lack of high-resolution observations,little attention has been paid to the contribution of TC size change to TC destructive potential in response to ocean warming.In this study,sensitivity experiments are performed by using the high-resolution Weather Research and Forecasting(WRF)model to investigate the responses of TC size and TC destructive potential to prescribed sea surface temperature(SST)increase under the present climate condition.The results show that TC size increases with the ocean warming.Possible reasons for TC size change are investigated with a focus on the outer air–sea moisture difference(ASMD).As SST increases,ASMD in the outer zone of the TC is larger than that in the inner zone,which increases the surface entropy flux(SEF)of the outer zone.This change in the radial distribution of SEF causes the increase of tangential wind in the outer zone,which further increases SEF,resulting in a positive feedback between outer-zone SEF and outer-zone tangential wind.This feedback leads to the increase of the radius of gale-force wind,leading to the expansion of TC size.Moreover,to estimate the contribution of TC size change to TC destructiveness,we calculate TC size-dependent destructive potential(PDS)as the storm size information is available in the model outputs,as well as PDI that does not consider the effect of TC size change.We find that PDS increases exponentially as SST increases from 1 to 4°C,while PDI increases linearly;hence the former is soon much greater than the latter.This suggests that the growth effect of TC size cannot be ignored in estimating destructiveness under ocean warming. 展开更多
关键词 TROPICAL CYCLONE destructive potential TROPICAL CYCLONE size SURFACE entropy flux air–sea moisture difference SEA SURFACE temperature
Laser ablation and structuring of CdZnTe with femtosecond laser pulses 认领
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作者 J.J.J.Nivas E.Allahyari +3 位作者 A.Vecchione Q.Hao S.Amoruso X.Wang 《材料科学技术:英文版》 SCIE EI CAS CSCD 2020年第13期180-185,共6页
We report an experimental investigation on laser ablation and associated surface structuring of CdZnTe by femtosecond Ti:Sa laser pulses(laser wavelengthλ≈800 nm,≈35 fs,10 Hz),in air.By exploiting different static ... We report an experimental investigation on laser ablation and associated surface structuring of CdZnTe by femtosecond Ti:Sa laser pulses(laser wavelengthλ≈800 nm,≈35 fs,10 Hz),in air.By exploiting different static irradiation conditions,the fluence threshold and the incubation effect in CdZnTe are estimated.Interestingly,surface treatment with a low laser fluence(laser pulse energy E≈5-10_μJ)and number of shots(5<N<50)show the formation of well-defined cracks in the central part of the shallow crater,which is likely associated to a different thermal expansion coefficients of Te inclusions and matrix during the sample heating and cooling processes ensuing femtosecond laser irradiation.Irradiation with a larger number of pulses(N≈500,1000)with higher pulse energies(E≈30-50μJ)results in the formation of welldefined laser-induced periodic surface structures(LIPSS)in the outskirts of the main crater,where the local fluence is well below the material ablation threshold.Both low spatial frequency and high spatial frequency LIPSS perpendicular to the laser polarization are found together and separately depending on the irradiation condition.These are ascribed to a process of progressive aggregation of randomly distributed nanoparticles produced during laser ablation of the deep crater in the region of the target irradiated by a fluence below the ablation threshold with many laser pulses. 展开更多
关键词 Laser ablation Femtosecond laser surface processing CDZNTE Laser induced periodic surface structures Laser processing
Unveiling the molecule–plasmon interactions in surface-enhanced infrared absorption spectroscopy 认领
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作者 Jun Yi En-Ming You +1 位作者 Song-Yuan Ding Zhong-Qun Tian 《国家科学评论:英文版》 SCIE EI CSCD 2020年第7期1228-1238,共11页
Nanostructure-based surface-enhanced infrared absorption(SEIRA)spectroscopy has attracted tremendous interest as an ultrasensitive detection tool that supplies chemical-fingerprint information.The interactions between... Nanostructure-based surface-enhanced infrared absorption(SEIRA)spectroscopy has attracted tremendous interest as an ultrasensitive detection tool that supplies chemical-fingerprint information.The interactions between molecular vibrations and plasmons lead to not only the enhancement of spectral intensity,but also the distortion of spectral Lorentzian lineshapes into asymmetric Fano-type or more complicated lineshapes in the SEIRA spectra;this effect hampers the correct readout of vibrational frequencies and intensities for an accurate interpretation of the measured spectra and quantitative analysis.In this work,we investigate the Fano interference between molecular vibrations and plasmons based on exact electrodynamic simulations and theoretical models.We report that,even if the molecular vibrational energy is equal to the plasmon resonant energy,the molecule–nanostructure distance-dependent dipole–dipole interactions,the plasmon-mediated coherent intermolecular interactions and the decay rates of plasmons have a significant impact on the SEIRA lineshapes.This study paves the way for controllable Fano interference at the nanoscale and more studies on plasmon-dressed molecular electronic or vibrational excited states. 展开更多
关键词 surface plasmons surface-enhanced infrared absorption Fano resonance coupling strength spectral lineshape
Surface Quality Improvement in Machining an Aluminum Honeycomb by Ice Fixation 认领
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作者 Yongqing Wang Yongquan Gan +3 位作者 Haibo Liu Lingsheng Han Jinyu Wang Kuo Liu 《中国机械工程学报:英文版》 SCIE EI CAS CSCD 2020年第1期162-169,共8页
A honeycomb structure is widely used in sandwich structure components in aeronautics and astronautics;however,machining is required to reveal some of its features.In honeycomb structures,deficiencies,such as burrs,edg... A honeycomb structure is widely used in sandwich structure components in aeronautics and astronautics;however,machining is required to reveal some of its features.In honeycomb structures,deficiencies,such as burrs,edge subsiding,and cracking,can easily appear,owing to poor specific sti ness in the radial direction.Some e ective fixation methods based on a filling principle have been applied by researchers,including approaches based on wax,polyethylene glycol,iron powder,and(especially)ice.However,few studies have addressed the optimization of the cutting parameters.This study focused on optimizing the cutting parameters to obtain a better surface roughness(calculated as a roughness average or Ra)and surface morphology in the machining of an aluminum alloy honeycomb by an ice fixation method.A Taguchi method and an analysis of variance were used to analyze the e ects and contributions of spindle speed,cutting depth,and feed rate.The optimal cutting parameters were determined using the signal-to-noise ratio combined with the surface morphology.An F-value and P-value were calculated for the value of the Ra,according to a"smaller is better"model.Additionally,the optimum cutting parameters for machining the aluminum honeycomb by ice fixation were found at different levels.The results of this study showed that the optimal parameters were a feed rate of 50 mm/min,cutting depth of 1.2 mm,and spindle speed of 4000 r/min.Feed rate was the most significant factor for minimizing Ra and improving the surface morphology,followed by spindle speed.The cutting depth had little e ect on Ra and surface morphology.After optimization,the value of Ra could reach 0.218μm,and no surface morphology deterioration was observed in the verified experiment.Thus,this research proposes optimal parameters based on ice fixation for improving the surface quality. 展开更多
关键词 HONEYCOMB ICE FIXATION CRYOGENIC MILLING SURFACE roughness SURFACE morphology Optimal parameters
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Thermodynamic and kinetic roles of H2 in structure evolution of urchin-like Co:A density functional theory study 认领
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作者 Xiaolei Wang Ning Liu +3 位作者 Qinwei Zhang Xin Liang Biaohua Chen Donghai Mei 《颗粒学报:英文版》 SCIE EI CAS CSCD 2020年第1期2-12,共11页
Small gas molecules acting as good capping agents play important roles in controlling the morphologies and surface structures of metal nanocrystals.In the present work,the thermodynamic and kinetic roles of H2 molecul... Small gas molecules acting as good capping agents play important roles in controlling the morphologies and surface structures of metal nanocrystals.In the present work,the thermodynamic and kinetic roles of H2 molecules in the morphology of Co nanocrystals were systematically studied by density functional theory(DFT).The Gibbs surface free energies of Co(100),Co(110),and Co(111)at different hydrogen surface coverages were determined by ab initio thermodynamics.The phase diagram of stable H coverage on each plane was obtained and morphology evolution of the Co nanocrystals with various surface hydrogen coverages was predicted by the Wulff construction.Addition of H2 changes the facet stability,generating diverse morphological Co nuclei.The kinetic role of H2 in adatom Co surface diffusion at different H coverages was investigated by DFT.The results suggest that surface H hinders Co surface diffusions,except for Co(100)at 0.56 monolayer coverage.The projected density of states gives deeper insight into the electronic structures of Co adatoms with addition of the surface H atoms,which affect its surface diffusion ability. 展开更多
关键词 Nanocrystal Co Surface free energy Surface diffusion Density functional theory
Add-on pegylated interferon augments hepatitis B surface antigen clearance vs continuous nucleos(t)ide analog monotherapy in Chinese patients with chronic hepatitis B and hepatitis B surface antigen≤1500 IU/mL:An observational study 认领
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作者 Feng-Ping Wu Ying Yang +7 位作者 Mei Li Yi-Xin Liu Ya-Ping Li Wen-Jun Wang Juan-Juan Shi Xin Zhang Xiao-Li Jia Shuang-Suo Dang 《世界胃肠病学杂志:英文版》 SCIE CAS 2020年第13期1525-1539,共15页
BACKGROUND Nucleos(t)ide analog(NA)has shown limited effectiveness against hepatitis B surface antigen(HBsAg)clearance in chronic hepatitis B(CHB)patients.AIM To evaluate the efficacy and safety of add-on peginterfero... BACKGROUND Nucleos(t)ide analog(NA)has shown limited effectiveness against hepatitis B surface antigen(HBsAg)clearance in chronic hepatitis B(CHB)patients.AIM To evaluate the efficacy and safety of add-on peginterferonα-2a(peg-IFNα-2a)to an ongoing NA regimen in CHB patients.METHODS In this observational study,195 CHB patients with HBsAg≤1500 IU/m L,hepatitis B e antigen(HBeAg)-negative(including HBeAg-negative patients or HBeAg-positive patients who achieved HBeAg-negative after antiviral treatment with NA)and hepatitis B virus-deoxyribonucleic acid<1.0×10^2 IU/mL after over 1 year of NA therapy were enrolled between November 2015 and December2018 at the Second Affiliated Hospital of Xi'an Jiaotong University,China.Patients were given the choice between receiving either peg-IFNα-2a add-on therapy to an ongoing NA regimen(add-on group,n=91)or continuous NA monotherapy(monotherapy group,n=104)after being informed of the benefits and risks of the peg-IFNα-2a therapy.Total therapy duration of peg-IFNα-2a was 48 wk.All patients were followed-up to week 72(24 wk after discontinuation of peg-IFNα-2a).The primary endpoint was the proportion of patients with HBsAg clearance at week 72.RESULTS Demographic and baseline characteristics were comparable between the two groups.Intention-to-treatment analysis showed that the HBsAg clearance rate in the add-on group and monotherapy group was 37.4%(34/91)and 1.9%(2/104)at week 72,respectively.The HBsAg seroconversion rate in the add-on group was 29.7%(27/91)at week 72,and no patient in the monotherapy group achieved HBsAg seroconversion at week 72.The HBsAg clearance and seroconversion rates in the add-on group were significantly higher than in the monotherapy group at week 72(P<0.001).Younger patients,lower baseline HBsAg concentration,lower HBsAg concentrations at weeks 12 and 24,greater HBsAg decline from baseline to weeks 12 and 24 and the alanine aminotransferase≥2×upper limit of normal during the first 12 wk of therapy were strong predictors of HBsAg clearance i 展开更多
关键词 Chronic HEPATITIS B Peginterferonα-2a Nucleos(t)ide ANALOG HEPATITIS B surface ANTIGEN CLEARANCE HEPATITIS B surface ANTIGEN seroconversion ADD-ON therapy
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基于表面电荷的新兴应用 认领
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作者 张文峦 孙强强 +2 位作者 Hans-Jürgen Butt 王钻开 邓旭 《科学通报:英文版》 SCIE EI CAS CSCD 2020年第13期1052-1054,M0003,共4页
Surface charges are ubiquitous in nature and their existence is in many forms.For example,at macro-length scale,by contacting and separating two objects,i.e.,contact electrification,one is able to obtain static surfac... Surface charges are ubiquitous in nature and their existence is in many forms.For example,at macro-length scale,by contacting and separating two objects,i.e.,contact electrification,one is able to obtain static surface charges.At micro-length scale,electric charges can be found at the air–water interface of a microdroplet because of the triboelectric effect or ionization from high-voltage spray fission.Although static surface charge is a familiar subject,much still remains unknown about how and why such charges form.Contact charge exchange between two metals is known to result from the transfer of electrons.But when at least one of the materials is an insulator or liquid,there is no general understanding of what carries charges from one surface to the other. 展开更多
关键词 表面电荷 SURFACE SEPARATING
Effects of surface vortex on the drawdown and dispersion of floating particles in stirred tanks 认领
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作者 Wentao Xu Yangbo Tan +3 位作者 Meng Li Jianglong Sun De Xie Zeng Liu 《颗粒学报:英文版》 SCIE EI CAS CSCD 2020年第2期159-168,共10页
The effects of surface vortex on the drawdown and dispersion of floating particles in stirred tanks were investigated.Particle distribution and power consumption were analyzed by experiments and numerical simulations ... The effects of surface vortex on the drawdown and dispersion of floating particles in stirred tanks were investigated.Particle distribution and power consumption were analyzed by experiments and numerical simulations in both baffled and unbaffled tanks agitated by a Rushton impeller.In unbaffled tanks,a non-aggregation rule was applied and the average dispersion index was found to serve as a reasonable prediction of the full drawdown of floating particles.The critical impeller speeds in an unbaffled tank were higher than those in a tank with vertical baffles.At each immersion depth in a baffled tank,particles distributed more uniformly and more power was consumed.Comparison of snapshots of the baffled and unbaffled tanks shows that the surface vortex increases the drawdown speed while it decreases the particle distribution uniformity and power consumption.Therefore,the use of baffles to suppress the surface vortex provides for a more uniform particle distribution in stirred tanks. 展开更多
关键词 Stirred tank Surface vortex Solids drawdown Complete dispersion
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