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A Wind Tunnel Experimental Study on the Wake Characteristics of a Horizontal Axis Wind Turbine

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Journal of Thermal Science 2025年第1期 145-158页

作者： GUO Xingduo LI Yinran LI Rennian MA Yulong WEI Kui College of Energy and Power Engineering Lanzhou University of Technology Key Laboratory of Fluid Machinery and Systems Gansu Provincial Technology centre for Wind Turbines

The characteristics of wind turbine wakes are influenced by multiple factors,including the atmospheric boundary layer(ABL) wind and wind turbine operating conditions(e.g.,tip speed ratio and yaw angle).In this study,two types of ABL winds with different velocity gradients and turbulence intensities are generated in a wind tunnel through configurations of spires,baffles,and various numbers of roughness elements.A wind turbine with a rotor diameter of 0.8 m and a hub height of 0.6 m is tested under varying tip speed ratios,yaw angles,and ABL wind *** results indicate that the streamwise velocity deficit in the near-wake region becomes more pronounced with an increase in the tip speed ratio,while the far-wake velocity deficit remains largely unaffected by changes in the tip speed *** the yaw angle increases,the wake deflection becomes more prominent and the wake narrows;the offset of the wake center at various downstream positions grows linearly,reaching a maximum value of approximately half the rotor ***,the turbulence level and influence range in the wake region are reduced when the turbine is *** ABL wind conditions,high turbulence intensity in the incoming flow accelerates wake recovery,and the Reynolds stress at different lateral positions tends to become consistent with increasing longitudinal ***,turbulence has a significant impact on the meandering characteristics of the wind turbine wake,with greater fluctuations in the wake center observed under higher turbulence ***,this study provides insights that could inform the optimal operation of wind farms.

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Role of boron in TiAl alloy development: a review

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Rare Metals 2016年第1期35卷 1-14页

作者： Dawei Hu Interdisciplinary Research centre in Materials University of Birmingham

Boron was found to be a unique grain refiner in cast TiAl alloys in the beginning of 1990 s and has become an element in most of the TiAl alloys developed to *** the past 25 or so years,efforts to understand the role of boron in solidification,solid-phase transformation,thermal and thermomechanical processing and mechanical properties of TiAl alloys and the relevant mechanisms never *** a result,abundant knowledge on boron in TiAl alloys has been accumulated but scattered in various research papers and conference *** review summarises the progress in understanding boron and its impacts on the TiAl alloy systems.

关键词： Titanium aluminide TiAl Ti3Al Boron Grain refinement

Optimal rejection of bounded perturbations in linear leader-following consensus protocol: invariant ellipsoid method

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Science China(Information Sciences) 2024年第8期67卷 24-34页

作者： Siyuan WANG Andrey POLYAKOV Min LI Gang ZHENG Driss BOUTAT INSA centre Val de Loire INRIA

The objective of the invariant ellipsoid method is to minimize the smallest invariant and attractive set of a linear control system operating under the influence of bounded external disturbances. This study extends the application of this method to address the leader-following consensus problem. Initially, a linear control protocol is designed for the multi-agent system in the absence of disturbances. Subsequently, in the presence of bounded disturbances, by employing a similar linear control protocol, a necessary and sufficient condition is introduced to derive the optimal control parameters for the multi-agent system such that the state of followers converges to and remains in a minimal invariant ellipsoid around the state of the leader.

关键词： multi-agent system leader-following consensus invariant ellipsoid disturbance

A Comparative Study on the Corrosion Behaviour of Hard Anodic Coatings on AA 6061 Obtained Using DC and Pulsed DC Power Sources

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Acta Metallurgica Sinica(English Letters) 2013年第6期26卷 647-656页

作者： Franco M. Hari Krishna T. Anju M.Pillai A.Rajendra A.K.Sharma Thermal Systems Group ISRO Satellite Centre

The corrosion behaviour of the hard anodic coatings prepared by three different methods viz., conventional hard anodizing （C-HA）, pulse hard anodizing （P-HA） and low voltage room temperature pulse hard anodizing （LVP- HA） on AA 6061 was compared using electrochemical impedance spectroscopy （EIS） and linear polarisation. Scanning electron microscope （SEM） was used to study the surface morphology before and after corrosion. EIS data revealed that no significant difference in corrosion resistance was observed among three types. Rp, Icorr and Ecorr were found to be highly stable over the exposure period up to 72 h which confirms the excellent corrosion resistance. The studies indicate that the corrosion resistance of LVP-HA and P-HA, which are processed at lower voltage and at relatively higher temperatures, are comparable to that of C-HA which is processed at sub-zero temperatures and high operating voltages. The corrosion resistance of all coatings was found to be improved after hydrothermal sealing.

关键词： Aluminium Anodic films EIS Polarisation SEM

Effects of Sr^(2+) substitution on the structural, dielectric, and piezoelectric properties of PZT-PMN ceramics

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International Journal of Minerals,Metallurgy and Materials 2014年第2期21卷 175-180页

作者： Arvind Kumar S.K. Mishra Research and Technology Development centre Sharda University

This study described the structural, dielectric, and piezoelectric behavior of Pb1-xSrx[（Zr0.52Ti0.48）0.95（Mn1/3Nb2/3）0.05]O3 ceramics （PSZT-PMN, x=0, 0.025, 0.050, and 0.075）, prepared by a semi-wet route. X-ray diffraction, dielectric, and piezoelectric investigations were carried out to analyze the crystal structure. The relative dielectric constant and dielectric loss were both calculated as the functions of temperature. The room-temperature dielectric constant reaches a maximum for a Sr2＋-modified PZT-PMN ceramic with an x value of 0.050, which corresponds to the morphotropic phase boundary （MPB）. Raman spectroscopy studies also confirm the existence of this MPB for x=0.050. The piezoelectric strain coefficients （d33） value shows a maximum response for this composition. In addition, the phase transition temperature decreases significantly when the Sr2＋concentration increases in the PZT-PMN ceramics.

关键词： ceramic materials strontium substitution structural properties dielectric properties piezoelectricity

Review of solvent based carbon-dioxide capture technologies

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Frontiers of Chemical Science and Engineering 2015年第2期9卷 125-141页

作者： Kathryn A. MUMFORD Yue WU Kathryn H. SMITH Geoffrey W. STEVENS Peter Cook centre for CCS Research Particulate Fluids Processing Centre Cooperative Centre for Greenhouse Gas Technologies Department of Chemical and Biomolecular Engineering The University of Melbourne Victoria Australia

Currently, a large proportion of global fossil fuel emissions originate from large point sources such as power generation or industrial processes. This trend is expected to continue until the year 2030 and beyond. Carbon capture and storage （CCS）, a straightforward and effective carbon reduction approach, will play a significant role in reducing emissions from these sources into the future if atmospheric carbon dioxide （CO2） emissions are to be stabilized and global warming limited below a threshold of 2 ℃. This review provides an update on the status of large scale integrated CCS technologies using solvent absorption for CO2 capture and provides an insight into the development of new solvents, including advanced amine solvents, amino acid salts, carbonate systems, aqueous ammonia, immiscible liquids and ionic liquids. These proposed new solvents aim to reduce the overall cost CO2 capture by improving the CO2 absorption rate, CO2 capture capacity, thereby reducing equipment size and decreasing the energy required for solvent regeneration.

关键词： carbon dioxide carbon capture solventabsorption large scale

A CLIMATOLOGY OF DEEP CONVECTION OVER SOUTH CHINA AND THE ADJACENT WATERS DURING SUMMER

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Journal of Tropical Meteorology 2013年第1期19卷 1-15页

作者：郑永光陈炯 National Meteorological centre

Due to the higher temporal and spatial resolution and the better integrality of long-term satellite infrared(IR) Brightness Temperature(TBB) data,a climatology of deep convection during summer over South China and the adjacent waters is presented in this paper based on the 1-hourly infrared IR TBB data during June-August of 1996-2007(except 2004).The results show that the geographic distribution of deep convection denoted by TBB ≤-52℃ over South China and the adjacent waters are basically consistent with previous statistical results based on surface thunderstorm observations and low-orbit satellite lightning *** monthly,ten-day,five-day and diurnal variations of deep convection in this region are focused on in this *** are 5 active deep-convection areas in *** monthly variations of the deep convection are closely associated with the large-scale atmospheric *** deep convection over the land areas of South China is more active in June while that over the South China Sea is more active in July and *** development of deep convection is prominently intermittent and its period is about 3 to 5 five-day ***,the deep convection over the coastal areas in South China remains more active during summer and has no apparent *** ten-day and five-day variations of deep convection show that there are different variations of deep convection over different areas in South China and the adjacent *** tendency of deep convection over the land areas of South China is negatively correlated with that over the South China *** diurnal variations of deep convection show that the sea-land breeze,caused by the thermal differences between land and sea,and the mountain-valley breeze,caused by the thermal differences between mountains and plains or basins,cause deep convection to propagate from sea to land in the afternoon and from land to sea after midnight,and the convection over mountains propagates from moun

关键词： South China climatology of deep convection IR TBB diurnal variations

A functional tacrolimus-releasing nerve wrap for enhancing nerve regeneration following surgical nerve repair

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Neural Regeneration Research 2025年第1期20卷 291-304页

作者： Simeon C.Daeschler Katelyn J.W.So Konstantin Feinberg Marina Manoraj Jenny Cheung Jennifer Zhang Kaveh Mirmoeini JPaul Santerre Tessa Gordon Gregory HBorschel SickKids Research Institute Neuroscience and Mental Health ProgramTorontoONCanada Institute of Biomaterials and Biomedical Engineering University of TorontoTorontoONCanada Indiana University School of Medicine IndianapolisINUSA Division of Plastic and Reconstructive Surgery the Hospital for Sick ChildrenTorontoONCanada Translational Biology and Engineering Program Ted Rogers Centre for Heart ResearchInstitute of Biomedical EngineeringFaculty of DentistryUniversity of TorontoTorontoONCanada

Axonal regeneration following surgical nerve repair is slow and often incomplete,resulting in poor functional recovery which sometimes contributes to lifelong ***,there are no FDA-approved therapies available to promote nerve *** accelerates axonal regeneration,but systemic side effects presently outweigh its potential benefits for peripheral nerve *** authors describe herein a biodegradable polyurethane-based drug delivery system for the sustained local release of tacrolimus at the nerve repair site,with suitable properties for scalable production and clinical application,aiming to promote nerve regeneration and functional recovery with minimal systemic drug *** is encapsulated into co-axially electrospun polycarbonate-urethane nanofibers to generate an implantable nerve wrap that releases therapeutic doses of bioactive tacrolimus over 31 *** and drug loading are adjustable for applications in small and large caliber nerves,and the wrap degrades within 120 days into biocompatible *** released from the nerve wrap promotes axon elongation in vitro and accelerates nerve regeneration and functional recovery in preclinical nerve repair models while off-target systemic drug exposure is reduced by 80%compared with systemic *** its surgical suitability and preclinical efficacy and safety,this system may provide a readily translatable approach to support axonal regeneration and recovery in patients undergoing nerve surgery.

关键词： biodegradable local drug delivery nerve injury nerve regeneration nerve wrap tacrolimus

Geologic framework as a factor controlling coastal morphometry and *** Spit, Lithuania

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International Journal of Sediment Research 2017年第4期32卷 597-603页

作者： Darius Jarmalavicius Gintautas Zilinskas Donatas Pupienis Nature Research centre

The geologic framework is an important factor worth consideration when analyzing the development of seacoasts. The different coastal responses to hydrometeorological and anthropogenic factors depend on the composition and amount of original coast-forming sediments. The impact of sediment composition on morphometric parameters is best observed in areas where sand unrepresentative of the adjacent coastal sectors appears on beaches with a relatively uniform lithological composition. These areas are referred to as lithological anomalies. Large amounts of coarse-grained sand, uncharacteristic of the adjacent coastal sectors of the Curonian spit, accumulated in the area of the strait that existed in the Post-Littorina Late Subboreal(3.7-2.5 ka BP) time south of the Juodkrante settlement. Due to accumulation of coarse sand, the beach in this sector is narrow and has a higher slope, and the ridge is lower and with a smaller volume of sand than in the adjacent coastal sectors. The specific sand composition and morphology of this coastal sector are responsible for different coastal dynamics during storms. During extreme storms, beach erosion in this coastal sector is minimal(sometimes even accretion takes place)compared with other sectors where beach erosion is rather substantial. Meanwhile, during periods of relatively calm weather, i.e. times of expected regeneration of the cross profile, this sector stands out for active erosion processes.

关键词： Beach morphometry Coastal erosion Sand composition Baltic Sea