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An experimental method to obtain the hard alpha anomaly distribution for titanium alloy aeroengine disks

Chinese Journal of Aeronautics 2021年第4期34卷 67-82页

作者： Shuiting DING Huimin ZHOU Bochao PAN Haibin JI xiaojun guo guo LI Aircraft/Engine Integrated System Safety Beijing Key Laboratory School of Energy and Power EngineeringBeihang UniversityBeijing 100083China Institute of Metal Research Chinese Academy of SciencesShenyang 110004China Aero Engine Corporation of China(AECC) Hunan Aviation Powerplant Research InstituteZhuzhou 412000China

A probability-based damage tolerance methodology has been proposed to improve the recognition of material anomalies, especially hard alpha(TiN) anomalies for aeroengine rotor disks. A key input to this method is hard alpha anomaly distribution, which reflects the occurrence rate and size of anomalies present in the finished part material of titanium rotors. Since anomalies rarely occur naturally, an experimental method is proposed to obtain the anomaly distribution for titanium alloy aeroengine disks to reflect and equivalently replace the manufacturing development in titanium industry. In general, the anomaly distribution information can be divided into two parts: the Probability of Detection(POD) curve and the detected anomaly distribution, which contains the size and frequency data of the detected anomalies. The distribution can be established based on several appropriate assumptions and derivation steps with different confidence levels of POD curves and detected anomaly distributions. In this case, the distribution can be obtained in a relatively short time as a key input to the probability-based damage tolerance methodology. Then the Probability of Failure(POF) can be calculated, and the value is found to vary with different confidence levels. On this basis, the conservative estimated POF can be obtained in conjunction with confidence levels.

关键词： Aeroengine disk Artificial preparation Hard alpha anomaly distribution Probability of detection(POD) Probability risk assessment

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Paraffin wax as a diluent for extraction and separation of trivalent gallium, indium, and thallium with 2,6-bis-(l'-phenyl-3'-methyl-5'-oxopyrazole-4') pyridineacyl

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Rare Metals 2003年第2期22卷 86-90页

作者： Gao Jinzhang Deng Qiliang Peng Bo guo xiaojun Chemistry & Chemical Engineering College Northwest Normal University Lanzhou 730070

A method is proposed for the extraction and separation of trivalent gallium,indium and thallium from their corresponding aqueous solutions at 65 deg C with 2,6-bis-(1'-phenyl-3'-methyl-5'-oxopyrazole-4') pyridineacyl (H_2PMBPP or H_2A) using molten paraffinwax as a diluent. The values of pH_(1/2) for extraction of gallium, indium and thallium are2.62,4.32 and 4.93, respectively. Gallium can he extracted by H_2PMBPP at a lower acid medium. Theeffect of solvent and the composition of the extracted species are reported. And the thermodynamicdata of the extraction are also obtained.

关键词： separation in inorganic chemistry solvent extraction gallium indium thallium H_2PMBPP

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Trace Projection Transformation： a new method for measurement of debris flow surface velocity fields

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Frontiers of Earth Science 2016年第4期10卷 761-771页

作者： Yan YAN Peng CUI xiaojun guo Yonggang GE Key Laboratory of Mountain Surface Process and Hazards/Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 China University of Chinese Academy of Sciences Beijing 100049 China Center for Excellence in Tibetan Plateau Earth Sciences Chinese Academy of Sciences Beijing 100101 China

Spatiotemporal variation of velocity is impor- tant for debris flow dynamics. This paper presents a new method, the trace projection transformation, for accurate, non-contact measurement of a debris-flow surface velocity field based on a combination of dense optical flow and perspective projection transformation. The algorithm for interpreting and processing is implemented in C ＋＋ and realized in Visual Studio 2012. The method allows quantitative analysis of flow motion through videos from various angles （camera positioned at the opposite direction of fluid motion）. It yields the spatiotemporal distribution of surface velocity field at pixel level and thus provides a quantitative description of the surface processes. The trace projection transformation is superior to conventional measurement methods in that it obtains the full surface velocity field by computing the optical flow of all pixels. The result achieves a 90% accuracy of when comparing with the observed values. As a case study, the method is applied to the quantitative analysis of surface velocity field of a specific debris flow.

关键词： debris flow surface velocity field spatiotem-poral variation dense optical flow perspective projectiontransformation

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Advances in flexible organic field-effect transistors and their applications for flexible electronics

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npj Flexible Electronics 2022年第1期6卷 1-19页

作者： Kai Liu Bang Ouyang xiaojun guo Yunlong guo Yunqi Liu Beijing National Laboratory for Molecular Sciences Key Laboratory of Organic SolidsInstitute of ChemistryChinese Academy of Sciences100190 BeijingPeople’s Republic of China School of Chemical Sciences University of Chinese Academy of Sciences100049 BeijingPeople’s Republic of China Department of Electronic Engineering School of Electronic Information and Electrical EngineeringShanghai Jiao Tong University200240 ShanghaiPeople’s Republic of China

Flexible electronics have suggested tremendous potential to shape human lives for more convenience and *** efforts have been devoted to developing flexible organic field-effect transistor(FOFET)technologies for rollable displays,bendable smart cards,flexible sensors and artificial ***,these applications are still in a nascent stage for lack of standard highperformance material stacks as well as mature manufacturing *** this review,the material choice and device design for FOFET devices and circuits,as well as the demonstrated applications are summarized in ***,the technical challenges and potential applications of FOFETs in the future are discussed.

关键词： effect field devoted

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Lamb wave sensors array for nonviscous liquid sensing

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Science China(Physics,Mechanics & Astronomy) 2006年第4期49卷 461-472页

作者： CHEN Zhijun HAN Tao JI xiaojun guo Huawei SHI Wenkang Department of Instrumentation Engineering Shanghai Jiao Tong University Shanghai 200240 China Department of Instrumentation Engineering Shanghai Jiao Tong University Shanghai 200240 China Department of Instrumentation Engineering Shanghai Jiao Tong University Shanghai 200240 China Department of Instrumentation Engineering Shanghai Jiao Tong University Shanghai 200240 China Department of Instrumentation Engineering Shanghai Jiao Tong University Shanghai 200240 China

The interdigital transducer (IDT) can excite Lamb wave in a piezoelectric plate loading with a liquid layer, and the phase velocity of Lamb wave is associated with the properties of the liquid layer. In this paper, the concept of effective permittivity is introduced to study the Lamb wave's potential application in liquid sensing. Considering the measuring of ideal nonviscous liquid, the sensors array is designed to sense the density and the dielectric constant of the liquid layer simultaneously. Using LiNbO3 as piezoelectric material, in order to improve the sensors array sensitivity and the electro-mechanical coupling coefficient, the optimized results including plate thicknesses and cut orientations are presented by numerical simulation. These studies show that the Lamb wave sensors array can be potential in liquid sensing.

关键词： Lamb wave sensors array, density, dielectric constant, plate thickness, cut orientation.

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THEORETICAL ANALYSIS OF THE BACKDRAFT PHENOMENA INDUCED BY LIQUID FUEL

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Chinese Science Bulletin 2006年第3期51卷 364-368页

作者： GONG Jian YANG Lizhong CHEN xiaojun guo Zaifu State Key Laboratory of Fire Science University of Science and Technology of China Hefei 230026 China

A dynamical model of temperature of hot smoke layer is quantitatively established based on the whole backdraft procedure induced by liquid fuel. The whole procedure consists of the preburn fire (the first period), the secondary fuel injection (the second period) and backdraft development (the third period). The model considers enthalpy loss of liquid fuel vola- tilization and hot smoke layer mass gain. In this paper, simulative results of the model are well compared with experimental results, and simulative results of the model are analyzed. Furthermore, combustion efficiency under limited ventilation and practical combustion reaction rate are worth investigating.

关键词：倒转现象液体燃料动力学模型温度挥发作用

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Characteristics and mechanisms of turboshaft engine axial compressor casing containment

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Chinese Journal of Aeronautics 2021年第1期34卷 171-180页

作者： Zekan HE xiaojun guo Haijun XUAN Xiaoming SHAN Xiaojing FAN Chuanyong CHEN Weirong HONG College of Energy Engineering Zhejiang UniversityHangzhou 310027China Collaborative Innovation Center for Advanced Aero-engine Beijing 100083China AECC Hunan Aviation Power plant Research Institute Zhuzhou 410002China

To investigate the containment characteristics and mechanisms of axial compressor blade and casing in turboshaft engine,experimental and simulation research is conducted on Titanium alloy axial compressor blades and stainless steel simulator casings in this *** for four thicknesses(from 0.8 mm to 1.4 mm)of casings are presented on high-speed spin ***,ricochet with and without failure of the casings are obtained in test *** obvious bulges or dishing region are observed,petaling failure occurs in the first bulge or the third deformation *** and elongated dimples are observed at the fracture *** Element(FE)models with calibrated Johnson-Cook material behavior law are built and analyzed by using explicit dynamic software for a better understanding on the containment *** agreement is obtained between the experimental observations and numerical *** evolution of the impact force,energy absorption,temperature increase and the cracks’propagation are *** force peaks occur in the impact *** analysis reveals that penetration condition of ricochet with failure leads to most internal energy of the casing.

关键词： Axial compressor Blade and casing containment Damage characteristic Deformation and failure mechanism

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Effect of high stirring speed on the agglomerate behaviors for cohesive SiO_(2) powders in gas fluidization

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Particuology 2023年第9期80卷 192-201页

作者： Fan Liu Zhan Du Qingshan Zhu xiaojun guo Hebang Shi Pengpeng Lv Hongzhong Li School of Chemical Engineering University of Chinese Academy of SciencesBeijing100049China State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChina Academy of SciencesBeijing100190China

The effects of superficial gas velocity and mechanical stirring speed on the precise regulation of flow regimes for cohesive SiO2 powders(mean diameter is 16μm)were experimentally investigated in a stirring-assisted fluidized *** results showed that compared with the agglomerates formed in the non-assisted fluidization of cohesive SiO2 powders,the introduction of mechanical stirring could effectively reduce the size of agglomerates and well disperse the agglomerates during *** best regulation range of agglomerate particulate fluidization can be achieved at 600 rpm when agglomerate sizes were reduced to below 200μ*** investigation based on the operational phase diagram revealed that transformations of flow regimes were dominated by both stirring speed and gas *** stirring applied enlarges the operational range of agglomerate particulate fluidization(APF)with a delayed onset of bubbling for cohesive ***,the exorbitant speed increases the collision velocity and contact area between small agglomerates,which results in the formation of unstable agglomerates and the whirlpool of powder.

关键词： Cohesive powders Stirring-assisted fluidized bed Agglomerate size Agglomerate particulate fluidization

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Chiral CdSe/CdS quantum dot (in rod)-light-emitting diodes with circularly polarized electroluminescence

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Nano Research 2022年第10期15卷 9573-9577页

作者： Tianwei Duan Jing Ai Sujie Chen Gufeng He xiaojun guo Lu Han Shunai Che Yingying Duan School of Chemistry and Chemical Engineering Frontiers Science Center for Transformative MoleculesState Key Laboratory of Metal Matrix CompositesShanghai Key Laboratory for Molecular Engineering of Chiral DrugsShanghai Jiao Tong UniversityShanghai 200240China School of Chemical Science and Engineering Tongji UniversityShanghai 200092China Department of Electronic Engineering School of Electronic Information and Electrical EngineeringShanghai Jiao Tong UniversityShanghai 200240China

Chiral quantum dot(in rod)-light-emitting diodes(CQLEDs)with circularly polarized electroluminescence(CPEL)have driven interest in the future display,communication,and storage ***,the preparation of CQLEDs is still a challenging ***,we fabricated CQLEDs through spin-coating evaporation of chiral CdSe/CdS quantum rods(CCCQs)colloidal solution on indium tin oxide *** CCCQs were synthesized via an isotropically epitaxial growth with cholic acid as the symmetry breaking agent,which induced one-direction chiral dislocation around the c axis of their hexagonal crystal *** CCCQs were ranked side-by-side in right-handed chiral arrangement with helical axis perpendicular to substrate due to chiral driving force of the cholic acid *** CQLEDs exhibited a negative CPEL signal at 600 nm with a|gEL|of 2×10^(−4),which is ascribable to the selective filtration on emission arising from the circular Bragg resonance by quasi-photonic crystal structures.

关键词： electroluminescence circularly polarized light emission helical assembly chiral nanoparticle CdSe/CdS nanorods

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Spatiotemporal characteristics of rainfall process in a small mountainous catchment

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Journal of Mountain Science 2024年第12期21卷 4033-4049页

作者： CHENG Jianyi guo xiaojun LI Yong LIU Daochuan LIU Jihong Key Laboratory of Mountain Hazards and Surface Process/Institute of Mountain Hazards and Environment Chinese Academy of SciencesChengdu 610041China University of Chinese Academy of Sciences Beijing 100081China Sichuan Highway Planning SurveyDesign and Research Institute Ltd.Chengdu 610041China State Key Laboratory of Subtropical Silviculture Zhejiang A&F UniversityHangzhou 311300China

The spatial distribution and temporal process of rainfall are major problems in small mountainous *** study investigated the spatiotemporal characteristics of rainfalls using data obtained from a dense monitoring network(10 gauges)in a small catchment of 48.6 *** rainfall process is determined by empirical relations(rainfall-elevation and rainfall-duration relations)with a random *** rainfall-elevation relation of event-scale is R=21.7h+4.6,the rainfall-area relations are suggested as a Gaussian distribution,and the rainfall-duration relation is a power law *** process was investigated at 1-min resolution and characterized by index including the onset time,duration,and center time of the rainfall peak *** revealed that the errors were random and followed a normal ***,a method that incorporates the relations of rainfall amount and the stochastic errors is proposed to simulate the rainfall *** with the monitored data,both the errors of simulated rainfall amount and peak intensity were in the range of[−30%,30%].Additionally,the relations of the simulated and monitored rainfall amount/intensity with the area are both very *** study marks an attempt to establish a framework for simulation of rainfall at a high temporal resolution(1-min)which is significant to the hydrological hazards forecasting,and realizing the spatial distribution of rainfall within a small catchment.

关键词： Rainfall Spatial distribution Temporal process Stochastic simulation

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