期刊文献+
共找到138,163篇文章
< 1 2 250 >
每页显示 20 50 100
Hierarchical microstructures with high spatial frequency laser induced periodic surface structures possessing different orientations created by femtosecond laser ablation of silicon in liquids 预览
1
作者 Dongshi Zhang Koji Sugioka 《光电进展(英文)》 2019年第3期1-18,共18页
High spatial frequency laser induced periodic surface structures(HSFLs)on silicon substrates are often developed on flat surfaces at low fluences near ablation threshold of 0.1 J/cm2,seldom on microstructures or micro... High spatial frequency laser induced periodic surface structures(HSFLs)on silicon substrates are often developed on flat surfaces at low fluences near ablation threshold of 0.1 J/cm2,seldom on microstructures or microgrooves at relatively higher fluences above 1 J/cm^2.This work aims to enrich the variety of HSFLs-containing hierarchical microstructures,by femtosecond laser(pulse duration:457 fs,wavelength:1045 nm,and repetition rate:100 kHz)in liquids(water and acetone)at laser fluence of 1.7 J/cm^2.The period of Si-HSFLs in the range of 110–200 nm is independent of the scanning speeds(0.1,0.5,1 and 2 mm/s),line intervals(5,15 and 20μm)of scanning lines and scanning directions(perpendicular or parallel to light polarization direction).It is interestingly found that besides normal HSFLs whose orientations are perpendicular to the direction of light polarization,both clockwise or anticlockwise randomly tilted HSFLs with a maximal deviation angle of 50°as compared to those of normal HSFLSs are found on the microstructures with height gradients.Raman spectra and SEM characterization jointly clarify that surface melting and nanocapillary waves play important roles in the formation of Si-HSFLs.The fact that no HSFLs are produced by laser ablation in air indicates that moderate melting facilitated with ultrafast liquid cooling is beneficial for the formation of HSFLs by LALs.On the basis of our findings and previous reports,a synergistic formation mechanism for HSFLs at high fluence was proposed and discussed,including thermal melting with the concomitance of ultrafast cooling in liquids,transformation of the molten layers into ripples and nanotips by surface plasmon polaritons(SPP)and second-harmonic generation(SHG),and modulation of Si-HSFLs direction by both nanocapillary waves and the localized electric field coming from the excited large Si particles. 展开更多
关键词 HIGH spatial frequency LASER induced periodic SURFACE structures SILICON LASER ablation in liquids HIERARCHICAL MICROSTRUCTURES femtosecond LASER HIGH fluence formation mechanism SURFACE melting nanocapillary wave SURFACE plasmon polaritons second-harmonic generation
在线阅读 下载PDF
Satellite-observed trends in the Arctic sea ice concentration for the period 1979–2016 预览
2
作者 WANG Yunhe BI Haibo +5 位作者 HUANG Haijun LIU Yanxia LIU Yilin LIANG Xi FU Min ZHANG Zehua 《海洋湖沼学报(英文)》 SCIE CAS CSCD 2019年第1期18-37,共20页
Arctic sea ice cover has decreased dramatically over the last three decades.This study quantifi es the sea ice concentration(SIC)trends in the Arctic Ocean over the period of 1979–2016 and analyzes their spatial and ... Arctic sea ice cover has decreased dramatically over the last three decades.This study quantifi es the sea ice concentration(SIC)trends in the Arctic Ocean over the period of 1979–2016 and analyzes their spatial and temporal variations.During each month the SIC trends are negative over the Arctic Ocean,wherein the largest(smallest)rate of decline found in September(March)is-0.48%/a(-0.10%/a).The summer(-0.42%/a)and autumn(-0.31%/a)seasons show faster decrease rates than those of winter(-0.12%/a)and spring(-0.20%/a)seasons.Regional variability is large in the annual SIC trend.The largest SIC trends are observed for the Kara(-0.60%/a)and Barents Seas(-0.54%/a),followed by the Chukchi Sea(-0.48%/a),East Siberian Sea(-0.43%/a),Laptev Sea(-0.38%/a),and Beaufort Sea(-0.36%/a).The annual SIC trend for the whole Arctic Ocean is-0.26%/a over the same period.Furthermore,the infl uences and feedbacks between the SIC and three climate indexes and three climatic parameters,including the Arctic Oscillation(AO),North Atlantic Oscillation(NAO),Dipole anomaly(DA),sea surface temperature(SST),surface air temperature(SAT),and surface wind(SW),are investigated.Statistically,sea ice provides memory for the Arctic climate system so that changes in SIC driven by the climate indices(AO,NAO and DA)can be felt during the ensuing seasons.Positive SST trends can cause greater SIC reductions,which is observed in the Greenland and Barents Seas during the autumn and winter.In contrast,the removal of sea ice(i.e.,loss of the insulating layer)likely contributes to a colder sea surface(i.e.,decreased SST),as is observed in northern Barents Sea.Decreasing SIC trends can lead to an in-phase enhancement of SAT,while SAT variations seem to have a lagged infl uence on SIC trends.SW plays an important role in the modulating SIC trends in two ways:by transporting moist and warm air that melts sea ice in peripheral seas(typically evident inthe Barents Sea)and by exporting sea ice out of the Arctic Ocean via passages into the Greenland and Barents Seas, 展开更多
关键词 SEA ice concentration(SIC) Arctic Ocean SURFACE air temperature(SAT) SEA SURFACE temperature(SST) SURFACE wind(SW) INTERANNUAL and DECADAL oscillation
在线阅读 下载PDF
Surface charge accumulation behavior and its influence on surface flashover performance of Al2O3-filled epoxy resin insulators under DC voltages
3
作者 刘彦琴 吴广宁 +3 位作者 高国强 薛建议 康永强 石超群 《等离子体科学与技术:英文版》 SCIE EI CAS CSCD 2019年第5期132-141,共10页
Surface charge accumulation on insulator surface can have great influence on surface flashover performance.An experimental system is established to investigate surface charge accumulation and decay characteristics of ... Surface charge accumulation on insulator surface can have great influence on surface flashover performance.An experimental system is established to investigate surface charge accumulation and decay characteristics of Al2O3-filled epoxy resin insulators in 0.1 MPa SF6 under DC voltages.Surface potential is recorded by a Kelvin vibrating probe connected to an electrostatic voltmeter.By pre-depositing charges on insulator surface,the influence of surface charges on surface flashover performance is studied.The results reveal that surface charge distribution appearance is the combined effect of electrode injection,back discharge and gas ionization.Surface charge distribution has obvious polarity effect.It is concentrated near the HV electrode under positive voltages and dispersed under negative voltages.The difference in positive and negative surface flashover voltage is attributed to the difference in surface charge distribution under DC voltages of different polarities.Surface charge decay contains two stages,which satisfies the law of double exponential function.At first stage,surface charge decays fast,which corresponds to charges escaping from shallower traps.While it decays slowly at the second stage,which corresponds to charge escaping from deeper traps.Surface charge decay process is dominated by surface conductivity mechanism.The pre-deposited charges on insulation surface have great influence on surface flashover performance.The deposited positive charges can increase positive flashover voltage but decrease negative flashover voltage. 展开更多
关键词 SURFACE charge electrode injection SURFACE FLASHOVER SURFACE CONDUCTIVITY pre-deposited CHARGES
Subwavelength negative-index waveguiding enabled by coupled spoof magnetic localized surface plasmons
4
作者 Zhen Liao Guo Qing Luo +2 位作者 Ben Geng Cai Bai Cao Pan Wen Hui Cao 《光子学研究:英文版》 CSCD 2019年第3期274-282,共9页
Magnetic localized surface plasmon modes are supported on metallic spiral structures. Coupling mechanisms for these metamaterial resonators, which are the joint action of magnetic and electric coupling, are studied. B... Magnetic localized surface plasmon modes are supported on metallic spiral structures. Coupling mechanisms for these metamaterial resonators, which are the joint action of magnetic and electric coupling, are studied. Based on the strong coupling, spoof magnetic plasmon modes propagating in the backward direction are proposed along a chain of subwavelength resonators. The theoretical analysis, numerical simulations, and experiments are in good agreement. The proposed novel route for achieving negative-index waveguiding has potential applications in integrated devices and circuits. 展开更多
关键词 SUBWAVELENGTH NEGATIVE-INDEX waveguiding COUPLED spoof MAGNETIC LOCALIZED SURFACE plasmons MAGNETIC LOCALIZED SURFACE plasmon modes
Investigation of the factors affecting the limit of detection of laser-induced breakdown spectroscopy for surface inspection
5
作者 Tadatake SATO Kenichi TASHIRO +2 位作者 Yoshizo KAWAGUCHI Hideki OHMURA Haruhisa AKIYAMA 《等离子体科学与技术:英文版》 SCIE EI CAS CSCD 2019年第3期174-181,共8页
Laser-induced breakdown spectroscopy(LIBS)was examined to detect a trace substance adhered onto Al alloys for the surface inspection of materials to be adhesively bonded.As an example of Si contamination,silicone oil ... Laser-induced breakdown spectroscopy(LIBS)was examined to detect a trace substance adhered onto Al alloys for the surface inspection of materials to be adhesively bonded.As an example of Si contamination,silicone oil was employed and sprayed onto substrates with a controlled surface concentration.LIBS measurements employing nanosecond UV pulses(λ=266 nm)and an off-axis emission collection system with different detecting heights were performed.Because surface contaminants are involved in the plasma formed by laser ablation of the substrates,the relative contribution of the surface contaminants and the substrates to the plasma emission could be changed depending on the conditions for plasma formation.The limit of detection(LOD)was evaluated under several detecting conditions for investigating the factors that affected the LOD.A significant factor was the standard deviation values of signal intensities obtained for the clean substrates.This value varied depending on the measurement conditions.For the Al alloy(A6061),the smallest LOD obtained was 0.529μg·cm^-2.Furthermore,an improved LOD(0.299μg·cm^-2)was obtained for the Al alloy with a lower Si content. 展开更多
关键词 LASER-INDUCED BREAKDOWN spectroscopy adhesive BONDING SURFACE CONTAMINATION detection pre-bond SURFACE inspection
Invitro Biodegradability of Silk Fibroin/Xanthan Biopolymeric Composite Scaffolds
6
作者 Shailendra Singh Shera Shraddha Sahu Rathindra Mohan Banik 《仿生工程学报:英文版》 SCIE EI CSCD 2019年第2期299-310,共12页
Silk fibroin/xanthan scaffolds were prepared by blending silk fibroin and xanthan in the ratios 80SF:20Xa(SFX82),60SF:40Xa(SFX64),and 50SF:50Xa(SFX55)using freeze drying method.In-vitro degradation behavior of the pre... Silk fibroin/xanthan scaffolds were prepared by blending silk fibroin and xanthan in the ratios 80SF:20Xa(SFX82),60SF:40Xa(SFX64),and 50SF:50Xa(SFX55)using freeze drying method.In-vitro degradation behavior of the prepared scaffolds was studied for 37 days in phosphate buffer saline.The degradation rate was the function of silk fibroin,xanthan and^-crystallite contents in the silk fibroin/xanthan composites.SFX82 degraded extremely slowly whereas SFX55 showed faster degradation rate.Hydrophilic xanthan was the main contributor of weight loss.SFX82 and SFX64 exhibited surface degradation whereas SFX55 showed bulk degradation which indicated that higher silk fibroin ratios favor surface degradation.Due to bulk degradation,SFX55 showed maximum surface roughness among the composite scaffolds.The FTIR spectrum revealed total loss of xanthan from the composites after degradation.The broad and low-intensity peaks in the FTIR spectrum of composite scaffolds con finned reduction in 0-sheet crystallite content during degradation.XRD analysis also confirmed reduction in 0-sheet crystals and revealed that degraded composite scaffold had predominantly amorphous structure.The degraded scaffold showed higher porous structure than the non-degraded scaffold.The in vitro degradability testing gives a good approximation of degradation of scaffold in vivo and helps in designing a robust biopolymeric composite scaffold for tissue engineering. 展开更多
关键词 BIOPOLYMER composites SURFACE ROUGHNESS BIOPOLYMER DEGRADATION SURFACE DEGRADATION tissue engineering
Trends of sea surface temperature and sea surface temperature fronts in the South China Sea during 2003–2017 预览
7
作者 Yi Yu Hao-Ran Zhang +1 位作者 Jiangbo Jin Yuntao Wang 《海洋学报:英文版》 SCIE CAS CSCD 2019年第4期106-115,共10页
The trends of the sea surface temperature(SST)and SST fronts in the South China Sea(SCS)are analyzed during 2003–2017 using high-resolution satellite data.The linear trend of the basin averaged SST is 0.31℃per decad... The trends of the sea surface temperature(SST)and SST fronts in the South China Sea(SCS)are analyzed during 2003–2017 using high-resolution satellite data.The linear trend of the basin averaged SST is 0.31℃per decade,with the strongest warming identified in southeastern Vietnam.Although the rate of warming is comparable in summer and winter for the entire basin,the corresponding spatial patterns of the linear trend are substantially different between them.The SST trend to the west of the Luzon Strait is characterized by rapid warming in summer,exceeding approximately 0.6℃per decade,but the trend is insignificant in winter.The strongest warming trend occurs in the southeast of Vietnam in winter,with much less pronounced warming in summer.A positive trend of SST fronts is identified for the coast of China and is associated with increasing wind stress.The increasing trend of SST fronts is also found in the east of Vietnam.Large-scale circulation,such as El Nino,can influence the trends of the SST and SST fronts.A significant correlation is found between the SST anomaly and Nino3.4 index,and the ENSO signal leads by eight months.The basin averaged SST linear trends increase after the El Nino event(2009–2010),which is,at least,due to the rapid warming rate causing by the enhanced northeasterly wind.Peaks of positive anomalous SST and negatively anomalous SST fronts are found to co-occur with the strong El Nino events. 展开更多
关键词 South China SEA SEA SURFACE TEMPERATURE SEA SURFACE TEMPERATURE FRONTS WARMING trend wind stress
在线阅读 下载PDF
Plasmon-tunable Au@Ag core-shell spiky nanoparticles for surfaceenhanced Raman scattering
8
作者 Zhulin Huang Guowen Meng +5 位作者 Xiaoye Hu Qijun Pan Dexian Huo Hongjian Zhou Yan Ke Nianqiang Wu 《纳米研究:英文版》 SCIE EI CAS CSCD 2019年第2期449-455,共7页
A facile synthetic approach has been developed to prepare uniform and size-tunable spiky Au@Ag core-shell nan oparticles (NPs) to tailor the localized surface plasm on res onance (LSPR) properties. The gradual assembl... A facile synthetic approach has been developed to prepare uniform and size-tunable spiky Au@Ag core-shell nan oparticles (NPs) to tailor the localized surface plasm on res onance (LSPR) properties. The gradual assembly of small Au nano crystals allows the size of spiky Au NPs to be modulated from tens to several hundreds of nano meters by tuning the concentration of initial Au seeds and Au source;and the thick ness of the Ag shell can be adjusted with stepwise reduction of Ag(l)ions. The LSPR bands of such spiky Au@Ag core-shell NPs resemble those of pure spiky Au NP cores of similar sizes in near-infrared region, and increasing the Ag shell thickness results in a blue shift and broadening of the LSPR band in the n ear-i nfrared regi on. Additi on ally, the spiky Au@Ag core-shell NPs exhibit improved surface-e nhan ced Rama n scattering (SERS) activity as compared to the bare spiky Au NPs and spherical Ag@Au NPs. This work has offered a facile route to synthesize plasmonic metal NPs with LSPR band in 650 to 800 nm that show strong enhancement of localized electromagnetic field, which provides an effective SERS substrate for SERS imaging and detection in biological fluids and tissues. 展开更多
关键词 LOCALIZED surface PLASMON resonanee gold silver surface-enhanced RAMAN spectroscopy
Design and Simulation of a Highly Sensitive SPR Optical Fiber Sensor
9
作者 Motahare Sadat HOSEINIAN Mohammad Agha BOLORIZADEH 《光子传感器:英文版》 EI CAS CSCD 2019年第1期33-42,共10页
An idea of the surface plasmon resonance(SPR)has been utilized for the design of highly sensitive sensors based on the wagon-wheel fiber technology.Such sensors are sensitive to changes in the refractive index of samp... An idea of the surface plasmon resonance(SPR)has been utilized for the design of highly sensitive sensors based on the wagon-wheel fiber technology.Such sensors are sensitive to changes in the refractive index of sample analyte.In this study,a three-strut wagon-wheel structure,coated with the gold layer of nano-sized thickness,has been proposed as the SPR sensor.Finite element method is employed to simulate and tune the proposed SPR's design,which leads to a highly sensitive and multichannel plasmonic sensor with the ability for a dual reading on a single analyte or simultaneous identification of two analytes.In this design,suitable thickness values for the gold layer and core struts are determined.Sensitivities of the detector due to the first resonance peak, second resonance peak,and the difference in resonance peaks are calculated to be 1120nm/RIU, 1540nm/RIU,and 420nm/RIU,respectively,when analytes are placed in all three channels of the fiber.Sensitivity of the detector with respect to the second resonant peak for analyte in Channels 2 and 3 is also found to be 1252nm/RIU when Channel 1 is filled with the reference.The sensitivity and resolution of the sensor increase as the refractive index of the analyte increases by almost a linear proportion.If the sensor is utilized to detect the difference in two peaks,it would substantially reduce the noise,and the best result is expected.The thicknesses of the struts and the gold layer are proper parameters to be tuned in designing the detector. 展开更多
关键词 PLASMONICS surface plasmon-polaritons sensor wagon-wheel fiber
Designing an in situ remediation strategy for polluted surface water bodies through the specific regulation of microbial community
10
作者 Boran Wu Xiaoli Chai +1 位作者 Youcai Zhao Xiaohu Dai 《中国环境科学与工程前沿:英文版》 SCIE EI CAS CSCD 2019年第1期21-26,共6页
This paper proposes an in situ restoration strategy, ecosystem activation system (EAS), for selfpurification abilities of polluted water ecosystems through the specific regulation of microbial community. EAS utilizes ... This paper proposes an in situ restoration strategy, ecosystem activation system (EAS), for selfpurification abilities of polluted water ecosystems through the specific regulation of microbial community. EAS utilizes polyhydroxyalkanoates (PHA) to modify indigenous microbial communities of polluted water bodies. Microorganisms preferentially utilizing PHA as the carbon source for their enhanced growth are defined as specific, and those with no special selectivity to PHA and raw-water dissolved organic matter are defined as non-specific and can be phased out during EAS operation. As a result, the microbial community can be regulated to the specific structure, which is beneficial for the water quality improvement. The developed model described the above principle with accounting for the growth kinetics of specific microorganisms, competitive inhabitation of specific microorganisms on non-specific microorganisms, and coupled EAS-induced self-purification of polluted water bodies. The conceptual model is believed to be a primary step toward quantitative design, operation, and optimization of EAS. 展开更多
关键词 REMEDIATION Surface water POLYHYDROXYALKANOATES MICROBIAL PROLIFERATION
Revealing the plasmon coupling in gold nanochains directly from the near field 预览
11
作者 Quan Sun Han Yu +3 位作者 Kosei Ueno Shuai Zu Yasutaka Matsuo Hiroaki Misawa 《光电进展(英文)》 2019年第4期1-7,共7页
We studied the near-field properties of localized surface plasmon resonances in finite linear gold nanochains using photoemission electron microscopy(PEEM).The localization of the electromagnetic field in the near-fie... We studied the near-field properties of localized surface plasmon resonances in finite linear gold nanochains using photoemission electron microscopy(PEEM).The localization of the electromagnetic field in the near-field region was mapped at high spatial resolution.By tuning the excitation laser wavelength,we can obtain the near-field spectra,from which the energy splitting between longitudinal(L)and transverse(T)plasmon modes can be revealed.In particular,the L-mode red shifts and the T-mode blue shifts with increasing chain length.The red shift of the L-mode is highly dependent on the gap distance.In contrast,the T-mode almost remains constant within the range of gap distance we investigated.This energy splitting between the L-mode and the T-mode of metallic chains is in agreement with previous far-field measurements,where it was explained by dipole-dipole near-field coupling.Here,we provide direct proof of this near-field plasmon coupling in nanochains via the above-described near-field measurements using PEEM.In addition,we explore the energy transport along the gold nanochains under excitation at oblique illumination via PEEM measurements together with numerical simulations. 展开更多
关键词 surface PLASMON RESONANCE metallic nanochains NEAR-FIELD imaging PHOTOEMISSION electron MICROSCOPY
在线阅读 下载PDF
A review of crosstalk research for plasmonic waveguides 预览
12
作者 Junxian Ma Dezheng Zeng +3 位作者 Yatao Yang Can Pan Li Zhang Haidong Xu 《光电进展(英文)》 2019年第4期8-15,共8页
Plasmonic waveguides,as a competitive candidate,have been widely studied in rapid developing photonic integrated circuits(PICs)and optical interconnection fields.However,crosstalk between plasmonic waveguides is a cri... Plasmonic waveguides,as a competitive candidate,have been widely studied in rapid developing photonic integrated circuits(PICs)and optical interconnection fields.However,crosstalk between plasmonic waveguides is a critical issue that has to be considered in practice.Actually,crosstalk dominates the ultimate integration density of the planar photonic circuits.This paper reviews the recent research work on evaluation methods and crosstalk suppression approaches of plasmonic waveguides.Three crosstalk evaluation methods based on comparison of specific parameters of waveguides have been summarized.Furthermore,four specific approaches to reduce crosstalk have been illustrated as two categories according to their impacts on waveguide performances and the whole circuit.One means of crosstalk suppression is changing the placement of waveguides,which could maintain the transmission characteristics of the original waveguide.The other means is inserting medium,which has the advantage of occupying smaller space compared to the first method.Consequently,to suppress crosstalk between plasmonic waveguides,one should choose suitable approach. 展开更多
关键词 CROSSTALK surface PLASMONS GUIDED WAVES PHOTONIC integrated circuits optical INTERCONNECTION
在线阅读 下载PDF
Probabilistic assessment of rock slopes stability using the response surface approach-A case study 预览
13
作者 Hassan Basahel Hani Mitri 《矿业科学技术学报:英文版》 CSCD 2019年第3期357-370,共14页
This paper examines the stability condition of a jointed rock slope in the south western region of Saudi Arabia using deterministic and probabilistic approaches,under both dry and wet conditions.The study area is char... This paper examines the stability condition of a jointed rock slope in the south western region of Saudi Arabia using deterministic and probabilistic approaches,under both dry and wet conditions.The study area is characterized by complex geology in rugged terrains.The stability analysis is carried out using the code FLAC3D to generate a 3-dimensional,ubiquitous joint model,to determine the influence of the dominant,unfavourable discontinuity orientation with respect to the slope face.The deterministic analysis is first implemented using the mean values of the selected random variables,namely the dip,dip direction and friction angle of the dominant discontinuity set,and the stability condition is assessed with a factor of safety based on the classical frictional joint constitutive model.A Box-Behnken design(BBD)approach is then adopted to create the surface response function as a second order polynomial for the factor of safety.To do so,fifteen FLAC3D models are generated in accordance with the BBD.Based on this,10,000 simulations of different slope realizations are carried out using Monte-Carlo simulation technique,and the probability of unsatisfactory of performance of the rock slope is assessed.It is shown that the probabilistic approach provides more insight and confidence in the stability condition of the rock slope,both under dry and steady state heavy rainfall conditions.A discussion is presented on the significance of accepting lower safety factors when heavy rainfall conditions are encountered. 展开更多
关键词 ROCK SLOPE STABILITY Box-Behnken design PROBABILISTIC analysis of SLOPES RESPONSE surface
在线阅读 下载PDF
An innovative study on low surface energy micronano coatings with multilevel structures for laminar flow design
14
作者 Jun TAO Gang SUN +4 位作者 Gang WU Liqiang GUO Yongjian ZHONG Meng WANG Bo YOU 《中国航空学报:英文版》 SCIE EI CAS CSCD 2019年第3期577-584,共8页
Laminar flow design is one of the most effective ways to reduce the drag of a commercial aircraft by expanding the laminar flow region on the surface of the aircraft. As material science develops, the emergence of new... Laminar flow design is one of the most effective ways to reduce the drag of a commercial aircraft by expanding the laminar flow region on the surface of the aircraft. As material science develops, the emergence of new materials such as low surface energy materials has offered new choices for laminar flow design of commercial aircraft. Different types of low surface energy micro-nano coatings are prepared to verify the effects on the boundary layer transition position and the drag of the airfoil through wind tunnel tests. The infrared thermal imaging technology is adopted for measuring the boundary layer transition, while the momentum integral approach is employed to measure the drag coefficient through a wake rake. Infrared thermal imaging results indicate that the coatings are capable of moving backward the boundary layer transition position at both a low velocity of Mach number 0.15 and a high velocity of Mach number 0.785. Results of the momentum integral approach demonstrate that the drag coefficients are reduced obviously within the cruising angle of attack range from 1°and 5° by introducing the low surface energy micro-nano coating technology. 展开更多
关键词 Coating TECHNIQUES Drag REDUCTION LAMINAR flow Surface energy WIND TUNNEL test
Control of wall thickness and surface morphology of tungsten thin wall parts by adjusting selective laser melting parameters
15
作者 Yan-jun Xie Huai-chao Yang +3 位作者 Xue-bing Wang Lin Zhao Chun-jiang Kuang Wei Han 《钢铁研究学报:英文版》 SCIE EI CAS CSCD 2019年第2期182-190,共9页
The tungsten thin wall parts which were used as high-performance collimator devices were fabricated by optimizing selective laser melting laser parameters.The effect of laser power and scan rate on wall thickness and ... The tungsten thin wall parts which were used as high-performance collimator devices were fabricated by optimizing selective laser melting laser parameters.The effect of laser power and scan rate on wall thickness and surface morphology of tungsten山in wall parts was investigated,respectively.The results indicated that the wall thickness increased with the enhancemem in laser power as a linear relationship.On the contrary,the wall thickness decayed exponentially with the acceleration in laser sean rate.Meanwhile,the wall thickness of the parts fabricated by laser double-pass melting was ihinner than that fabricated by laser single-pass melting.In addition,mathematic models for selecting suitable laser power and laser sean rate to fabricate specified tungsten thin wall parts were proposed.Furthermore,the effects of laser parameters on the top surface roughness,adhesive parts and hot cracks were also discussed. 展开更多
关键词 Selective LASER MELTING TUNGSTEN LASER power SCAN rate THIN wall part Surface morphology
The Conversion Relationship between the Local Earthquake Magnitude and Surface Wave Magnitude in the Inner Mongolia Digital Seismic Network
16
作者 LIU Fang SU Riya +2 位作者 XU Xiquan LI Hui NA Re 《中国地震研究:英文版》 CSCD 2019年第1期86-96,共11页
Using 116 earthquakes over ML3. 8 in the Inner Mongolia region from 2008 to 2015, the local earthquake magnitude ML and surface wave magnitude MS are remeasured. Based on norm linear regression (SR1 and SR2) and norm ... Using 116 earthquakes over ML3. 8 in the Inner Mongolia region from 2008 to 2015, the local earthquake magnitude ML and surface wave magnitude MS are remeasured. Based on norm linear regression (SR1 and SR2) and norm (OR) orthogonal regression method, we established the conversion relationship between ML and MS . The results were tested with Gaussian disturbance. The result shows that the orthogonal regression method (OR) result has the best fitting curve, and the conversion relation is MS = 0. 96 ML - 0. 10. The difference between our result and Guo Lücan's (MS = 1. 13 ML -1. 08) may be caused by regional tectonic characteristics. MS Inner Mongolia value is significantly higher than the MS empirical value, with an average difference of 0. 23, the difference distribution of empirical relation and the rectified relation is in the range of 0. 2-0. 3. 展开更多
关键词 Local EARTHQUAKE MAGNITUDE ML Surface wave MAGNITUDE MS GAUSS PERTURBATION MAGNITUDE CONVERSION
在线阅读 免费下载
Optimization of Chelation Process for Complex Microelement Iron Supplement Derived from Pig Blood by Response Surface Methodology 预览
17
作者 Jingjing HUANG Yan YAN +3 位作者 Fusheng ZHANG Junfeng YIN Yingqin ZHOU Ningning XIE 《农业生物技术:英文版》 CAS 2019年第1期235-240,共6页
[Objectives]This study aimed to optimize the chelation process for complex microelement iron supplement derived from pig blood by response surface methodology.[Methods]On the basis of single-factor test,pH value,conce... [Objectives]This study aimed to optimize the chelation process for complex microelement iron supplement derived from pig blood by response surface methodology.[Methods]On the basis of single-factor test,pH value,concentration of polypeptide solution and volume ratio of polypeptide solution to FeCl 2 solution were selected as influencing factors with Fe(II)chelation rate as the indicator for Box-Behnken central composite experimental design with three factors and three levels.The effects of three factors on the response value were analyzed by response surface methodology.[Results]The optimized chelation process for complex microelement iron supplement derived from pig blood by response surface methodology was as follows:pH 5.40,polypeptide solution concentration 2.27%,volume ratio of polypeptide solution to FeCl 2 solution 2.16∶1.Under this condition,the predictive Fe(II)chelation rate of iron supplement was 79.37%,while the actual value was 79.41%.[Conclusions]The optimized process may provide new thoughts for the development and utilization of complex microelement iron supplement derived from pig blood. 展开更多
关键词 Response surface METHODOLOGY PIG BLOOD protein Iron SUPPLEMENT Fe(II)chelation rate
在线阅读 下载PDF
从两道例题看高等数学知识的前后贯通 预览
18
作者 李宜阳 《高等数学研究》 2019年第1期124-125,共2页
本文通过探究偏导数几何意义方面的两道例题,将涉及到偏导数,空间曲面,空间曲线,直线,平面,二元函数的标准线性近似等内容融会贯通.
关键词 偏导数 空间曲线 空间曲面 切线 切平面
在线阅读 下载PDF
Selective modification of two-dimensional MoS2 nanosheets by polymer grafting
19
作者 Hang Bian Xuejian Zhang +1 位作者 Dexin Huang Ning Zhang 《中国化学快报:英文版》 SCIE CAS CSCD 2019年第2期311-313,共3页
As an emerging two-dimensional (2D) nanomaterial, single layer ora few layers of molybdenum disulfide (MoS2) has drawn significant attention in the past decade. In the present work, we report a strategy in direct crea... As an emerging two-dimensional (2D) nanomaterial, single layer ora few layers of molybdenum disulfide (MoS2) has drawn significant attention in the past decade. In the present work, we report a strategy in direct creating polymer brushes on MoS2 surfaces via S—C bond in the presence of UV light. The modification of MoS2 nanosheets can be achieved bilaterally or homolaterally by performing the UVgrafting polymerization on exfoliated MoS2 nanosheets or a single layer of MoS2 deposited on a silicon substrate. A series of vinyl monomers including methyl methacrylate (MMA), styrene (St) and 2-isopropenyl-2-oxazoline (IPOx) could be applied to this approach, leading to the formation of poly (methyl methacrylate) (PMMA), polystyrene (PS) and poly (2-isopropenyl-2-oxazoline) (PIPOx) brushes.AFM, IR, and XPS characterizations indicate the successful formation of homogeneous brush layers on MoS2 surfaces. The polymer brushes modified MoS2 may found potential applications in photo dynamic therapy and sensing technologies. 展开更多
关键词 MOLYBDENUM DISULFIDE Polymer BRUSHES SIPGP Surface MODIFICATION S-C BOND
Estimation of wind speeds inside Super Typhoon Nepartak from AMSR2 low-frequency brightness temperatures
20
作者 Lei ZHANG Xiaobin YIN +2 位作者 Hanqing SH Zhenzhan WANG Qing XU 《地球科学前沿:英文版》 SCIE CAS CSCD 2019年第1期124-131,共8页
Accurate estimations of typhoon-level winds are highly desired over the westem Pacific Ocean.A wind speed retrieval algorithm is used to retrieve the wind speeds within Super Typhoon Nepartak (2016)using 6.9- and 10.7... Accurate estimations of typhoon-level winds are highly desired over the westem Pacific Ocean.A wind speed retrieval algorithm is used to retrieve the wind speeds within Super Typhoon Nepartak (2016)using 6.9- and 10.7-GHz brightness temperatures from the Japanese Advanced Microwave Scanning Radiometer 2 (AMSR2) sensor on board the Global Change Observation Mission-Water 1 (GCOM-Wl)satellite.The results show that the retrieved wind speeds clearly represent the intensification process of Super Typhoon Nepartak.A good agreement is found between the retrieved wind speeds and the Soil Moisture Active Passive wind speed product.The mean bias is 0.51 m/s,and the root-mean-square difference is 1.93 m/s between them.The retrieved maximum wind speeds are 59.6 m/s at 04:45 UTC on July 6 and 71.3 m/s at 16:58 UTC on July 6.The two results demonstrate good agreement with the results reported by the China Meteorological Administration and the Joint Typhoon Warning Center.In addition,Feng-Yun 2G (FY-2G) satellite infrared images,Feng-Yun 3C (FY-3C)microwave atmospheric sounder data,and AMSR2 brightness temperature images are also used to describe the development and structure of Super Typhoon Nepartak. 展开更多
关键词 MICROWAVE RADIOMETER sea surface WIND RETRIEVAL AMSR2 Nepartak SMAP
上一页 1 2 250 下一页 到第
使用帮助 返回顶部 意见反馈