检索结果-南通市图书馆

Effect of fore/aft-loaded rotor on compressor stability under inlet circumferential distortion

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese journal of Aeronautics 2024年第5期37卷 199-213页

作者： Dakun sun Benhao GU Fangfei NING Dengke XU Xiaofeng sun School of Energy and Power Engineering Beihang UniversityBeijing 102206China Research Institute of Aero-engine Beihang UniversityBeijing 102206China

A modified small perturbation stability prediction model for axial compressors with circumferential inlet distortions is established and applied to investigate the effect of fore/aft-loaded rotor on compressor stability under circumferentially distorted inlet *** inlet total pressure distribution downstream of the distortion screen is measured in experiments and employed for simulations which are implemented via time-space spectral *** stall inception prediction results via the stability model indicate that the compressor with aft-loaded rotor not only performs better in terms of stability under uniform inlet,but also maintains a larger stability margin under circumferentially distorted *** experiments for compressors with fore-loaded and aft-loaded rotor are respectively carried *** results validate the reliability of numerical simulations and the predicted conclusion that the aft-loaded rotor is beneficial for compressor ***,the ability of the developed theoretical model for compressor stability prediction under circumferential distortions is *** addition,dynamic pressure signals at rotor tip measured in experiments illustrate that the circumferential distortion has little effect on the compressor stall pattern.

关键词： Axial compressor stability Inlet distortion Blade loading Small perturbation Time-space spectral method

Multilayer polyethylene separator with enhanced thermal properties for safe lithium-ion batteries Author links open overlay panel

在线全文

学校读者我要写书评

暂无评论

Particuology 2024年第8期91卷 29-37页

作者： Ying jiang Chen sun Feilong Dong Haiming Xie liqun sun National&local United Engineering laboratory for Power Battery Department of ChemistryNortheast Normal UniversityChangchun130024China

The separator plays an important part in battery safety and *** separators are widely used in commercial lithium-ion batteries(lIBs),owing to their excellent properties,but they suffer from serious thermal shrinkage and poor electrolyte ***,a multilayer separator(ASPESA)is developed by coating two thin layers of low-density polyethylene(lDPE)and Al_(2)O_(3)on both sides of a polyethylene membrane using a facile and environmentally friendly casting *** ASPESA separator demonstrates a shutdown function at 120℃and shows enhanced thermal stability under 185℃,with a small thermal shrinkage of 1%.Meanwhile,the lDPE and Al_(2)O_(3)layers can improve the electrolyte wettability and electrolyte uptake(407.23%).The multilayer ASPESA separator delivers an excellent cycle performance in liFePO_(4)||li cells with a discharge capacity of 144.5 mAh g^(-1)after 900 cycles,with a high-capacity retention of 98.9%(compared to the 5th cycle).Therefore,the multilayer ASPESA separator has great utilization potential as a high-safety separator in lIBs.

关键词： low-density polyethylene microspheres Al_(2)O_(3)particles Thermal shutdown High safety lithium-ionbatteries

Compressive property and energy absorption characteristic of interconnected porous Mg-Zn-Y alloys with adjusting Y addition

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

journal of Magnesium and Alloys 2024年第1期12卷 171-185页

作者： j.A.liu S.j.liu B.Wang W.B.sun X.j.liu Z.W.Han College of Materials Science and Engineering Key Laboratory of Automobile Materials(Ministry of Education)Jilin UniversityChangchun 130022PR China Key laboratory of Bionic Engineering(Ministry of Education) College of Biological and Agricultural EngineeringJilin UniversityChangchun130022PR China Weihai Institute for Bionics-jilin University Weihai 264205PR China

In this study,interconnected porous Mg-2Zn-xY alloys with different phase compositions were prepared by various Y additions(x=0.4,3,and 6 wt.%)to adjust the compressive properties and energy absorption *** characterization methods were then applied to identify the microstructure of the porous Mg-Zn-Y and describe the details of the second *** tests were performed at room temperature(RT),200℃,and 300℃to study the impact of the Y addition and testing temperature on the compressive properties of the porous *** experimental results showed that a high Y content promotes a microstructure refinement and increases the volume fraction of the second *** the Y content increases,different Mg-Zn-Y ternary phases appear:I-phase(Mg_(3)Zn_(6)Y),W-phase(Mg_(3)Zn_(3)Y_(2)),and lPSO phase(Mg_(12)ZnY).When the Y content ranges between 0.4%and 6%,the compressive strength increases from 6.30MPa to 9.23 MPa,and the energy absorption capacity increases from 7.33 Mj/m^(3)to 10.97 Mj/m^(3)at RT,which is mainly attributed to the phase composition and volume fraction of the second ***,the average energy absorption efficiency is independent of the Y *** addition,the compressive deformation behaviors of the porous Mg-Zn-Y are altered by the testing *** compressive strength and energy absorption capacity of the porous Mg-Zn-Y decrease due to the softening effect of the high temperature on the *** deformation behaviors at different temperatures are finally observed to reflect the failure mechanisms of the struts.

关键词： Porous magnesium Rare earth elements Microstructure Compressive behavior Energy absorption characteristic

Adaptive Event-Triggered Time-Varying Output Group Formation Containment Control of Heterogeneous Multiagent Systems

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA journal of Automatica Sinica 2024年第6期11卷 1398-1409页

作者： lihong Feng Bonan Huang jiayue sun Qiuye sun Xiangpeng Xie College of Information Science and Engineering Northeastern UniversityShenyang 110819China College of Automation and College of Artificial Intelligence Nanjing University of Posts and TelecommunicationsNanjing 210023China IEEE

In this paper,a class of time-varying output group formation containment control problem of general linear hetero-geneous multiagent systems(MASs)is investigated under directed *** MAS is composed of a number of tracking leaders,formation leaders and followers,where two different types of leaders are used to provide reference trajectories for movement and to achieve certain formations,***,compen-sators are designed whose states are estimations of tracking lead-ers,based on which,a controller is developed for each formation leader to accomplish the expected ***,two event-triggered compensators are proposed for each follower to evalu-ate the state and formation information of the formation leaders in the same group,***,a control protocol is designed for each follower,utilizing the output information,to guide the output towards the convex hull generated by the forma-tion leaders within the ***,the triggering sequence in this paper is decomposed into two sequences,and the inter-event intervals of these two triggering conditions are provided to rule out the Zeno ***,a numerical simulation is intro-duced to confirm the validity of the proposed results.

关键词： Adaptive control event-triggered mechanisms for-mation containment(FC) heterogeneous multiagent systems time-varying group formation.

Heat Recuperation for the Self-Condensing CO_(2)Transcritical Power Cycle

在线全文

学校读者我要写书评

暂无评论

journal of Thermal Science 2024年第5期33卷 1630-1641页

作者： PAN lisheng SHI Weixiu sun Yin sun Yiwei WEI Xiaolin State Key laboratory of High-temperature Gas Dynamics Institute of MechanicsChinese Academy of SciencesBeijing 100190China School of Environment and Energy Engineering Beijing University of Civil Engineering and ArchitectureBeijing 100044China

The supercritical CO_(2)Brayton cycle has potential to be used in electricity generation occasions with its advantages of high efficiency and compact *** on a so-called self-condensing CO_(2)transcritical power cycle,a model was established and four different layouts of heat recuperation process were analyzed,a without-recuperation cycle,a post-recuperation cycle,a pre-recuperation cycle and a re-recuperation *** results showed that the internal normal cycle's share of the whole cycle increases with increasing the cooling pressure and decreasing the final cooled *** load in the supercritical heater decreases with increasing the cooling *** perspective of performance,the re-recuperation cycle and the pre-recuperation cycle have similar thermal efficiency which is much higher than other two *** thermal efficiency and net power output have a maximum value with the cooling pressure,except in the condition with the final cooled temperature of 31℃.Considering both the complexity and the economy,the pre-recuperation cycle is more applicable than the other *** 35℃of the final cooled temperature,the thermal efficiency of the pre-recuperation cycle reaches the peak 0.34 with the cooling pressure of 8.4 MPa and the maximum net power output is 2355.24 kW at 8.2 MPa of the cooling pressure.

关键词： CO_(2)transcritical power cycle heat recuperation process self-condensing

Cardiovascular computed tomography in cardiovascular disease:An overview of its applications from diagnosis to prediction

在线全文

学校读者我要写书评

暂无评论

journal of Geriatric Cardiology 2024年第5期21卷 550-576页

作者： Zhong-Hua sun Discipline of Medical Radiation Science Curtin Medical SchoolCurtin UniversityPerthAustralia Curtin Health Innovation Research Institute(CHIRI) Curtin UniversityPerth 6012Australia

Cardiovascular computed tomography angiography(CTA)is a widely used imaging modality in the diagnosis of cardiovascular *** in CT imaging technology have further advanced its applications from high diagnostic value to minimising radiation exposure to *** addition to the standard application of assessing vascular lumen changes,CTA-derived applications including 3D printed personalised models,3D visualisations such as virtual endoscopy,virtual reality,augmented reality and mixed reality,as well as CT-derived hemodynamic flow analysis and fractional flow reserve(FFRCT)greatly enhance the diagnostic performance of CTA in cardiovascular *** widespread application of artificial intelligence in medicine also significantly contributes to the clinical value of CTA in cardiovascular *** value of CTA has extended from the initial diagnosis to identification of vulnerable lesions,and prediction of disease extent,hence improving patient care and *** this review article,as an active researcher in cardiovascular imaging for more than 20 years,I will provide an overview of cardiovascular CTA in cardiovascular *** is expected that this review will provide readers with an update of CTA applications,from the initial lumen assessment to recent developments utilising latest novel imaging and visualisation *** will serve as a useful resource for researchers and clinicians to judiciously use the cardiovascular CT in clinical practice.

关键词： diagnosis cardiovascular prediction

Exploring luminescence quenching on lanthanide-doped nanoparticles through changing the spatial distribution of sensitizer and activator

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第5期17卷 4517-4524页

作者： jiwei li Yao Xie Renrui sun junxun Zhou lining sun Department of Chemistry College of SciencesShanghai UniversityShanghai 200444China Department of Physics College of SciencesShanghai UniversityShanghai 200444China School of Medicine Shanghai UniversityShanghai 200444China

luminescence quench is common in overdoped upconversion *** methods have been proposed to counteract the adverse effects of concentration quenching on luminescence,but in upconversion nanoparticles that are highly doped with both sensitizers and activators,the factors that contribute to the diminishing of the emission cannot be summarized by a single ***,a core-shell design is used to spatially separate the sensitizer(Yb^(3+))and activator(Er^(3+))and to modulate the emission by changes in the distribution position as well as the concentration of the dopant ions in order to probe the factors affecting the *** the sensitizer ions are located in the core,the luminescence intensity of the nanoparticles is significantly weaker than that of the other distribution,which implies that the effect of sensitizer and activator on luminescence in the highly doped state has a different and more complex *** intensity of the emission is more affected by Yb^(3+)than Er^(3+),which includes not only the self-quenching of Yb^(3+),but also the dominance in the Yb^(3+)-Er^(3+)*** this finding may provide new ideas for revealing the reasons for the diminished luminescence of highly doped upconversion nanoparticles and thus for enhancing luminescence.

关键词： upconversion luminescence lanthanide ion core-shell nanoparticles concentration quenching cross-relaxation

NiO-Doped Fe_(2)O_(3)/MgO Properties for the Chemical looping Oxidative Dehydrogenation of Ethane

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China Petroleum Processing & Petrochemical Technology 2024年第1期26卷 27-33页

作者： liang Hao Chen junjie sun jie sun Hui Shenyang ligong University Shenyang 110159China Fushun Ecology Environment Bureau Qingyuan County Branch Fushun 113399China

Ethane chemical looping oxidative dehydrogenation(Cl-ODH)to ethylene is a new technology for ethylene ***_(2)O_(3)/MgO oxygen carrier was prepared using the co-precipitation *** influence of added NiO and its different loadings on Fe_(2)O_(3)/MgO were ***,a series of oxygen carriers were applied in the Cl-ODH of the ethane cycle ***-Emmett-Teller(BET),X-ray diffractometry(XRD),X-ray photoelection spectroscopy(XPS),and H2-temperature programmed reduction(TPR)were used to characterize the physicochemical properties of these oxygen *** was confirmed that an interaction between NiO and Fe_(2)O_(3) occurred based on the XPS and H2-TPR *** on the Cl-ODH activity performance tests conducted in a fixed-bed reactor,it was revealed that ethylene selectivity was significantly improved after NiO ***_(2)O_(3)-10%NiO/MgO showed the best activity performance with 93%ethane conversion and 50%ethylene selectivity at a reaction temperature of 650℃,atmospheric pressure,and space velocity of 7500 ml/(g·h).

关键词： chemical looping oxidative dehydrogenation oxygen carrier Fe_(2)O_(3)/MgO NiO

Substrate screening for superclean graphene growth using firstprinciples calculations

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第4期17卷 2216-2222页

作者： Zhihao li Xiucai sun Xiaoli sun Wan-jian Yin Zhongfan liu College of Energy Soochow Institute for Energy and Materials InnovationS(SIEMIS)and Jiangsu Provincial Key Laboratory for Advanced Carbon Materials and Wearable Energy TechnologiesSoochow UniversitySuzhou 215006China Graphene Basic Science Research Center Beijing Graphene Institute(BGI)Beijing 100095China Center for Nanochemistry Beijing Science and Engineering Center for NanocarbonsBeijing National Laboratory for Molecular ScienceCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China

Suppressing the formation of amorphous surface carbon and contaminants during the preparation of graphene by chemical vapor deposition remains an ongoing ***,we analyzed how substrate characteristics affect graphene quality by simulating margin extension,the nucleation process,and defect pegging configurations on mono-crystalline oriented metal substrates with the aim of enhancing graphene *** formation energy and nucleation potential,which are indirect substrate–graphene interaction features,were found to appropriately evaluate graphene *** crystallographic orientation of the metal substrate was discovered to be critical for producing superclean graphene.A low graphene defect density and high nucleation rate on the Cu(100)facet guarantee growth of high-quality graphene,especially in terms of suppressing the formation of amorphous *** addition,rapid kink growth and self-healing on the Cu(100)facet facilitate rapid graphene synthesis,which is also promoted by rapid kink splicing and margin self-repair on this *** study provides theoretical insight useful for the synthesis of superclean graphene.

关键词： superclean graphene defects nucleation metal substrates density functional theory calculations