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Evaluation of service-induced microstructural damage for directionally solidified turbine blade of aircraft engine

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Rare Metals 2019年第2期38卷 157-164页

作者： Wei-Qing huang Xiao-guang Yang Shao-Lin Li School of Energy and Power Engineering Beihang University Beijing Key Laboratory of Aero-Engine Structure and Strength

Turbine blades of gas turbine engines usually suffer from severe operational conditions characterized by high temperature and stress. Severe operational conditions during service cause microstructural changes in turbine blades and degrade their mechanical properties. In this study, service-induced microstructural damages in serviced turbine blades manufactured from a directionally solidified superalloy were evaluated. The observed microstructural damage of the turbine blade mainly involves the coarsening and rafting of γ' precipitates. The leading edge of 60% height of the turbine blades undergone most severe microstructural damage with significant microstructural evolution at this area. Microstructural damage affects the mechanical properties such as Vickers hardness, that is,Vickers hardness decreases as the equivalent diameter decreases. Microstructural damage shows great positiondependent feature as service temperature and radial stress on blade changes. With the aid of energy-dispersive spectrometer(EDS) analysis on carbide, the transformation of carbide does not exist. In addition, no topological closed-packed phase exists in the turbine blade.

关键词： Service-induced Microstructural damage Directionally solidified Turbine blade: Aircraft engine

Study on reliability technology of contactor relay

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第3期8卷 481-484页

作者： LIU Guoojin ZHAO Jing-ying WANG Hai-tao YANG Chen-guang SUN shun-li Postdoctor＇s Work Station Delixi Group Co. Ltd. Wenzhou 325604 China Electrical Department Hebei University of Technology Tianjin 300130 China

In this paper, the reliability of contactor relay is studied. There are three main parts about reliability test and analysis. First, in order to analyze reliability level of contact relay, the failure ratio ranks are established as index base on the product level. Second, the reliability test method is put forward. The sample plan of reliability compliance test is gained from reliability sample theory. The failure criterion is ensured according to the failure modes of contactor relay. Third, after reliability test experiment, the analysis of failure physics is made and the failure reason is found.

关键词： Contactor relay Reliability Failure mode

Identification of key genes involved in flavonoid and terpenoid biosynthesis and the pathway of triterpenoid biosynthesis in Passiflora edulis

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Journal of Integrative Agriculture 2023年第5期22卷 1412-1423页

作者： XU Yi huang Dong-mei MA Fu-ning YANG Liu WU Bin XING Wen-ting SUN Pei-guang CHEN Di XU Bing-qiang SONG shun National Key Laboratory for Tropical Crop Breeding/Haikou Experimental Station Chinese Academy of Tropical Agricultural Sciences/Key Laboratory of Genetic Improvement of BananasSanya Research Institute of Chinese Academy of Tropical Agricultural SciencesSanya 572000P.R.China Hainan Yazhou Bay Seed Laboratory Sanya 572000P.R.China guangxi Crop Genetic Improvement and Biotechnology Laboratory Guangxi Academy of Agricultural SciencesNanning 530007P.R.China

Passion fruit(Passiflora edulis Sims) is a vine of the Passiflora genus in the Passifloraceae family. The extracted components include flavonoids and terpenoids, which have good anti-anxiety and anti-inflammatory effects in *** this study, we analyzed the transcriptomes of four tissues of the ‘Zixiang’ cultivar using RNA-Seq, which provided a dataset for functional gene mining. The de novo assembly of these reads generated 96 883 unigenes, among which 61 022 unigenes were annotated(62.99% yield). In addition to its edible value, another important application of passion fruit is its medicinal value. The flavonoids and terpenoids are mainly derivatives of luteolin, apigenin, cycloartane triterpenoid saponins and other active substances in leaf extracts. A series of candidate unigenes in the transcriptome data that are potentially involved in the flavonoid and terpenoid synthesis pathways were screened using homologybased BLAST and phylogenetic analysis. The results showed that the biosynthesis of triterpenoids in passion fruit comes from the branches of the mevalonate(MVA) and 2-C-methyl-D-erythritol 4-phosphate/1-deoxy-D-xylulose 5-phosphate(MEP/DOXP) pathways, which is different from the MVA pathway that is used in other fruit trees. Most of the candidate genes were found to be highly expressed in the leaves and/or flowers. Quantitative real-time PCR(qRT-PCR) verification was carried out and confirmed the reliability of the RNA-Seq data. Further amplification and functional analysis of these putative unigenes will provide additional insight into the biosynthesis of flavonoids and terpenoids in passion fruit.

关键词： passion fruit RNA-Seq gene mining flavonoids terpenoids

Distribution- and Metabolism-Based Drug Discovery: A Potassium-Competitive Acid Blocker as a Proof of Concept

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Research 2022年第4期2022卷 609-620页

作者： Ming-Shu Wang Yi Gong Lin-Sheng Zhuo Xing-Xing Shi Yan-guang Tian Chang-Kang huang Wei huang guang-Fu Yang Key Laboratory of Pesticide e Chemical Biology of Ministry of Education International Joint Research Center for Intelligent Biosensor Technology and HealthCollege of ChemistryCentral China Normal UniversityWuhan 430079China Nanjing Shuohui Pharmatechnology Co. Ltd.Nanjing 210046China

Conventional methods of drug design require compromise in the form of side effects to achieve sufficient efficacy because targeting drugs to specific organs remains ***,new strategies to design organ-specific drugs that induce little toxicity are *** on characteristic tissue niche-mediated drug distribution(TNMDD)and patterns of drug metabolism into specific intermediates,we propose a strategy of distribution-and metabolism-based drug design(DMBDD);through a physicochemical property-driven distribution optimization cooperated with a well-designed metabolism pathway,SH-337,a candidate potassium-competitive acid blocker(P-CAB),was ***-337 showed specific distribution in the stomach in the long term and was rapidly cleared from the systemic ***,SH-337 exerted a comparable pharmacological effect but a 3.3-fold higher no observed adverse effect level(NOAEL)compared with FDA-approved *** study contributes a proof-of-concept demonstration of DMBDD and provides a new perspective for the development of highly efficient,organ-specific drugs with low toxicity.

关键词： drugs organs Potassium

The prediction of external flow field and hydrodynamic force with limited data using deep neural network

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Journal of Hydrodynamics 2023年第3期35卷 549-570页

作者： Tong-sheng Wang guang Xi Zhong-guo Sun Zhu huang School of Energy and Power Engineering Xi'an Jiaotong UniversityXi'an 710049China

Predicting the external flow field with limited data or limited measurements has attracted long-time interests of researchers in many industrial *** informed neural network(PINN)provides a seamless framework for combining the measured data with the deep neural network,making the neural network capable of executing certain physical *** the data-driven model to learn the end-to-end mapping between the sensor data and high-dimensional flow field,PINN need no prior high-dimensional field as the training dataset and can construct the mapping from sensor data to high dimensional flow field ***,the extrapolation of the flow field in the temporal direction is limited due to the lack of training ***,we apply the long short-term memory(LSTM)network and physics-informed neural network(PINN)to predict the flow field and hydrodynamic force in the future temporal domain with limited data measured in the spatial *** physical constraints(conservation laws of fluid flow,e.g.,Navier-Stokes equations)are embedded into the loss function to enforce the trained neural network to capture some latent physical relation between the output fluid parameters and input tempo-spatial *** sparsely measured points in this work are obtained from computational fluid dynamics(CFD)solver based on the local radial basis function(RBF)*** numbers of spatial measured points(4–35)downstream the cylinder are trained with/without the prior knowledge of Reynolds number to validate the availability and accuracy of the proposed *** practical applications of flow field prediction can compute the drag and lift force along with the cylinder,while different geometry shapes are taken into *** comparing the flow field reconstruction and force prediction with CFD results,the proposed approach produces a comparable level of accuracy while significantly fewer data in the spatial domain is *** numerical results d

关键词： Flow field prediction hydrodynamic force prediction long short-term memory physics informed neural network limited data local radial basis function method

Experimental investigation of unsteady attached cavitating flow induced pressure fluctuation

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Journal of Hydrodynamics 2022年第1期34卷 31-42页

作者： Hou-sheng Zhang guang-hao Chen Qin Wu Biao huang School of Mechanical Engineering Beijing Institute of TechnologyBeijing100081China AVIC Jincheng Nanjing Engineering Institute of Aircraft System Nanjing211106China

This paper experimentally investigates the pressure fluctuation induced by the unsteady attached cavitating flow, with special focus on the quasi-periodic cloud cavitation. A simultaneous sampling method is adopted for the synchronous measurement of the wall pressure signals and the cavitating flow images in a convergent-divergent channel. The results show that the pressure fluctuation is composed of three parts, the flow noise, the low-frequency fluctuation, and the cavity collapse induced impulse, and the pressure evolution of the quasi-periodic cloud cavitation is well consistent with the cavitation evolution. The statistical analysis of the pressure fluctuation shows that, when σ > 1.01, the probability density function (PDF) is nearly in the normal distribution, implying the randomness of the pressure fluctuation, when 0.84 1.01, when σ < 0.84, the PDF becomes narrow and asymmetric. In addition, the variance and the average value of the pressure indicate that the fluctuation intensity increases downstream along the cavity and reaches the maximum at the cavity closure and it also increases with the decrease of the cavitation number. The spectral analysis shows that the low-frequency pressure fluctuations mainly consist of two dominant components, the cavity shedding induced fluctuation and the lock-in fluctuation. The cavity shedding induced frequency decreases with the decrease of the cavitation number but the lock-in frequency is kept nearly constant. According to the spectral analysis of the cavity area fluctuation and the modal analysis of the flow system, the lock-in is possibly caused when the fluctuation frequency of the cavity volume approaches the natural frequency of the flow system.

关键词： Cavitation pressure fluctuation statistical features lock-in phenomenon

Wind-tunnel experimental studies of the spatial snow distribution over grass and bush surfaces

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Journal of Hydrodynamics 2022年第1期34卷 85-93页

作者： guang Li Jun-ming Qin Hong-xiang Yu Ning huang Key Laboratory of Mechanics on Disaster and Environment in Western China The Ministry of Education of ChinaLanzhou UniversityLanzhou730000China School of Civil Engineering and Mechanics Lanzhou UniversityLanzhou730000China College of Atmospheric Science Lanzhou UniversityLanzhou730000China School of Architecture Civil and Environmental EngineeringSwiss Federal Institute of Technology LausanneLausanneSwitzerland

The snow is one of the most important water resources in grassland in northern and western China, while the wind blowing snow due to the strong wind there is a common phenomenon, which can lead to heavy disasters to harm the local animal husbandry and transportation. A reasonable arrangement of the snow protection forests is one of the most economical and effective methods to prevent the wind blowing snow, and a great number of investigations were carried out for its wind block effects. However, the deposition patterns of the snowfall and the blowing snow in the forests are still largely unknown. In this study, the wind tunnel experiments are performed to investigate the influences of the vegetation (grass and bush) on the wind speed profiles and the spatial distribution of the accumulated snow, by using the bran as the snow substitute. The snow blocking abilities of two bush models are analyzed to show the effects of different coverages. The results show that the grass and the bush have different effects on the wind speed profiles, and the snow-blocking abilities of the vegetation and the resulting spatial distribution are determined by the amount of the snowfall, the wind speed, and the height and the coverage of the vegetation. For the engineering design, if the snow is required on the windward side of the vegetation or in the vegetation, the densely arranged forest belts are needed, if the snow is required to accumulate on the leeward side of the vegetation, the sparse forest belts can be used. This work would be helpful as a reference to the reasonable arrangement of the snow-protection forests in pastoral areas.

关键词： Wind tunnel experiment wind speed profile vegetation snow-protection forest snow blocking ability

High safety separators for rechargeable lithium batteries

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Science China Chemistry 2021年第7期64卷 1131-1156页

作者： Miaomiao Su guang huang Suqing Wang Yanjie Wang Haihui Wang School of Chemistry and Chemical Engineering South China University of TechnologyGuangzhou 510640China Beijing Key Laboratory of Membrane Materials and Engineering Department of Chemical EngineeringTsinghua UniversityBeijing 100084China Shenzhen Senior Technology Material Co. Ltd.Shenzhen 518106China

Lithium-ion batteries(LIBs)are presently dominant mobile power sources due to their high energy density,long lifespan,and low self-discharging *** safety of LIBs has been concerned all the time and become the main problem restricting the development of high energy density *** a significant part of LIBs,the properties of separators have a significant effect on the capacity and performances of batteries and play an important role in the safety of *** recent years,researchers devoted themselves to the development of various multi-functional safe separators from different views of methods,materials,and practical *** this review,we mainly focus on the recent progress in the development of high-safety separators with high thermal stability,good lithium dendritic resistance,high mechanical strength and novel multifunction for high-safety LIBs and have in-depth discussions regarding the separator's significant contribution to enhance the safety and performances of the ***,the future directions and challenges of separators for the next-generation high-safety and high energy density rechargeable lithium batteries are also provided.

关键词： separator high safety lithium-ion batteries

Experimental study on the detonation process of a pulse detonation engine with ionized seeds

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Defence Technology（防务技术） 2020年第1期16卷 178-187页

作者： Ling Lin shun-an Hu Yan-bin Hu guang-ju Xu Hong-yu Jiao Chun-sheng Weng School of Automotive Engineering Changshu Institute of TechnologySuzhou215500China National Key Laboratory of Transient Physics Nanjing University of Science and TechnologyNanjing210094China

An experimental platform of a pulse detonation engine(PDE) was established to study the effect of different K_2 CO_3 ionized seed mass contents on the detonation *** pressure and ion concentration were detected in the detonation process of the PDE with different contents of ionized *** initiation process of the PDE at different ignition frequencies was *** results show that the gas conductivity in the detonation process increased by adding ionized seeds to the PDE tube,and the conductivity increased with the increase in ionized seed mass *** the increase in ionized seed mass content,the range of the conductivity *** PDE was successfully ignited and formed a stable detonation wave at ignition frequencies of 5 Hz and 10 Hz,and the peak pressure of the stable detonation with the ignition frequency of 5 Hz was 17% higher than that with an ignition frequency of 10 *** detonation wave intensity was weake ned and dege nerated to a shock wave that propagated in the tube without the fuel filled at the ignition frequency of 20 Hz.

关键词： Pulse detonation engine Ionized seeds Detonation process Ignition frequency