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Stress-controlled LCF experiments and ratcheting behaviour simulation of a nickel-based single crystal superalloy with [001] orientation

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Chinese Journal of Aeronautics 2021年第8期34卷 112-121页

作者： Bin ZHANG Rongqiao WANG Dianyin HU Kanghe JIANG Jianxing MAO Fulei JING Xinyi hao School of Energy Power EngineeringBeihang UniversityBeijing 100083China Beijing Key Laboratory of Aero-Engine Structure and Strength Beijing 100083China Research Institute of Aero-Engine Beihang UniversityBeijing 100083China Hunan Aviation Powerplant Research Institute Aero Engine(Group)Corporation of ChinaZhuzhou 412002China Aero Engine Academy of China Aero Engine(Group)Corporation of ChinaBeijing 101304China

Uniaxial ratcheting behaviour and low cycle fatigue(LCF)failure mechanism of nickel-based single crystal superalloy DD6 with[001]orientation are investigated through the stresscontrolled LCF tests with stress ratio *** the deformation behaviour during the wholelifetime from the beginning of the experiment to the fracture of the specimen,as well as the fractographic/metallographic morphology,are compared with the strain-controlled LCF experimental *** the scanning electron microscope(SEM)observations,it is shown that the failure characteristics under stress-controlled LCF loading are similar with those under strain-controlled ***,unlike strain-controlled LCF loading,even under fully reversed cycle loading for stress-controlled LCF,DD6 shows significant ratcheting behaviour due to the tensioncompression *** addition,the LCF lifetimes under stress control are significantly shorter than the LCF lifetimes under strain control,and the culprit might be the detrimental effect of ratcheting strain on LCF *** on these phenomena,an improved crystal plasticity constitutive model on the basis of slip-based Walker constitutive model is developed through modifying the kinematic hardening rule in order to overcome the inaccurate prediction of decelerating stageand stable stage of ratcheting ***,combining the continuum damage mechanics,a damage-coupled crystal plasticity constitutive model is proposed to reflect the damage behaviour of DD6 and the accelerating stage of ratcheting *** simulation results for the stress-controlled LCF deformation behaviour including the whole-lifetime ratcheting behaviour show good agreement with the experimental data.

关键词： Crystal plasticity constitutive model Low cycle fatigue Nickel-based single crystal superalloy Ratcheting behaviour Stress-controlled experiment

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Polyarylene Ether Nitrile and Titanium Dioxide Hybrids as Thermal Resistant Dielectrics

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Chinese Journal of Polymer Science 2021年第2期39卷 211-218,I0007页

作者： Ren-Bo Wei Chen-hao Zhan Yang Yang Peng-Lin He Xiao-Bo Liu Research Branch of Advanced Functional Materials School of Materials and EnergyUniversity of Electronic Science and Technology of ChinaChengdu 610054China School of Chemical Engineering Northwest UniversityXi’an 710069China

With the expanding application of capacitors,thermal resistant dielectric materials are in high demand due to the increasing harsh environments where the capacitors are needed and the heat generated by the ***,we present polyarylene ether nitrile and titanium dioxide hybrids which can be used as thermal resistant dielectrics for these *** modified titanium dioxide(TiO_(2)-CN)and phthalonitrile end-capped polyarylene ether nitrile(PEN-Ph)are firstly *** being cast into TiO_(2)-CN/PEN nanocomposite films,these composites self-crosslink upon heating at 320℃for 4 h,forming the polyarylene ether nitrile and titanium dioxide hybrids(TiO_(2)-PEN).Improved dielectric constants which are stable from room temperature to 200℃of these hybrids are observed,indicating the potential application of the hybrids as thermal resistant dielectrics.

关键词： Hybrid TiO2 Polyarylene ether nitrile Thermal resistance Dielectric properties

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Evidence of ancient rock-ice avalanches along the China-Bhutan Chomolhari Range,and their implications for demise of the summit

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Journal of Mountain Science 2024年第9期21卷 2876-2890页

作者： HU Kaiheng ZHANG Qiyuan LI Pu ZHANG Xiaopeng LIU Shuang LI hao Institute of Mountain Hazards and Environment Chinese Academy of SciencesChengdu 610299China University of Chinese Academy of Sciences Beijing 100149China

Large-scale rock-ice avalanches resulting from the interaction of tectonics and climate are characterized with high mobility,huge volumes of sediment,and rapid denudation,being a major agent of landscape evolution in high altitude mountainous ***,the extreme glaciated slope failures often transform into extraordinarily large and mobile debris flows,resulting in disastrous consequences such as sedimentation and *** to a dearth of on-site observation data and experimental data collection,our comprehension of the geomorphic and kinematic characteristics of rock-ice avalanches remains *** we report a cluster of ancient rock-ice avalanches spreading along the Chomolhari range of the China-Bhutan *** integrating remote sensing image interpretation with detailed field investigations,we demonstrate the geomorphic and sedimentary characteristics of four events among the *** estimated volumes of the four are 23.73 Mm³,39.69 Mm³,38.43 Mm³,and 38.25 Mm³,*** presence of pre-existing moraines or alluvial fans constrained their movement,resulting in deposition features such as marginal digitated lobes at higher elevations and large depressed areas in the *** the Savage-Hutter theory,we calculate the basal friction angle and travel angle of these ancient rock-ice avalanches that are both less than 10°,affirming the similarity of these avalanches in the study area to those occurring in other *** study significantly contributes to understanding the geomorphic and kinematic characteristics of rock-ice avalanches in high-altitude mountainous regions,providing valuable insights into their response to the disproportionate growth of Himalayan peaks.

关键词： Rock-ice avalanche Himalayas Southern Yadong-Gulu rift Vertical slip-rate Landscape evolution

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High-voltage frequency domain spectroscopy analysis of a thermally aged XLPE submarine cable under continuous and cyclic voltage based on carrier transport and polarisation characteristics

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High Voltage 2022年第3期7卷 473-482页

作者： Xize Dai Jian hao Zheng Jian Ruijin Liao Xinlong Zheng Yiyi Zhang State Key Laboratory of Power Transmission Equipment&System Security and New Technology Chongqing UniversityChongqingChina State Grid Zhejiang Electric Power Supply Company ZhoushanChina School of Electrical Engineering Guangxi UniversityNanningChina

In order to ensure the safe operation of submarine cables,it is of great significance to analyse the insulation state of submarine cables from the perspectives of microstructure,carrier transport characteristics and macroscopic dielectric *** this study,based on the high-voltage frequency domain spectroscopy(HV-FDS)measurement system,HV-FDS experiments of fresh and thermally aged submarine cables were carried out under continuous(0.5,2,4 and 10 kV)and cyclic(2-10-2 kV)applied alternating ***,combining the changes of the microstructure structure of cross-linked poly-ethylene(XLPE)insulation,the aggregate structure deterioration model of XLPE was proposed to discuss the physical mechanism of HV-FDS characteristics of submarine cables under different voltages and insulation *** show that the HV-FDS characteristics of submarine cables have significant voltage dependence under contin-uous voltage *** HV-FDS of submarine cables show memory characteristics under cyclic voltage *** with the fresh submarine cable,the thermally aged submarine cable shows more significant voltage dependence and memory charac-teristics of *** memory characteristics of HV-FDS are mainly determined by the carriers transport and the interfacial polarisation caused by the accumulation of polar particles at the electrode/dielectric *** study covers the correlation mecha-nism among the microstructure,carrier transport and macroscopic HV-FDS properties of submarine cable insulation,which lays a foundation for further research and condition evaluation of submarine cables.

关键词： submarine characteristics transport

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Design and synthesis of unique thiazoloisoquinolinium thiolates and derivatives

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Chinese Chemical Letters 2021年第10期32卷 3211-3214页

作者： Wasim Ahmed Zi-hao Huang Zi-Ning Cui Ri-Yuan Tang Department of Applied Chemistry College of Materials and EnergySouth China Agricultural UniversityGuangzhou 510642China State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources Integrative Microbiology Research CentreGuangdong Province Key Laboratory of Microbial Signals and Disease ControlSouth China Agricultural UniversityGuangzhou 510642China Guangdong Laboratory for Lingnan Modern Agriculture Guangzhou 510642China

Natural isoquinolinium alkaloids possess a wide range of biological *** design and synthesis of mesoionic isoquinoliniums is of great *** paper reports the synthesis of unique mesoionic thiazoloisoquinolinium thiolates stabilized by aromatization and 1,*** compounds can be synthesized via the three component [2 + 2 + 1] cycloaddition reaction of isoquinolines with ethyl propionate and elemental sulfur in the absence of any metal catalyst and ***,thiazoloisoquinolinium thiolates can be transformed to thioether-containing thiazoloisoquinolinium halides.A selective [4 + 2] cycloaddition can also be used to form S-bridged fused tetracyclic compounds with a thiothiamide ring unit and two quarternary carbon *** I-1 shows good bioactivity against the chlorophyll of duckweed(Lemna minor) with inhibition rate of 51.5 mg/mL.

关键词： Isoquinoline Heterocycle Zewitterionic Elemental sulfur Cycloaddition

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What can we learn from neonates with COVID-19?

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World Journal of Pediatrics 2020年第3期16卷 280-283页

作者： Tian-Tian Xiao Kai Yan Lai-Shuan Wang Wen-hao Zhou National Clinical Research Center for Children's Hospital of Fudan University ShanghaiChina Department of Neonatology Children's Hospital of Fudan University399 Wanyuan RoadShanghai 201102China

The coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a global *** on epidemiological and clinical characteristics of patients with COVID-19 have indicated that children are susceptible to SARS-CoV-2 [1-3].To date,the largest study in China reported that over 90% of 2143 children with COVID-19 were asymptomatic,or had mild or moderate illness,and that 5.8% presented critical illness [3].Although the data of neonates are limited and only six neonates with COVID-19 have been reported thus far,several important points should be addressed from these neonatal cases.

关键词： acute respiratory nates

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A method of estimating the Martian neutral atmospheric density at 130 km, and comparison of its results with Mars Global Surveyor and Mars Odyssey aerobraking observations based on the Mars Climate Database outputs

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Earth and Planetary Physics 2020年第4期4卷 408-419页

作者： JunFeng Qin Hong Zou YuGuang Ye YongQiang hao JinSong Wang Erling Nielsen Institute of Space Physics and Applied Technology School of Earth and Space SciencePeking UniversityBeijing 100871China National Center for Space Weather China Meteorological AdministrationBeijing 100081China Max Planck Institute for Solar System Research Katlenburg-Lindau 37191Germany

Profiles of the Martian dayside ionosphere can be used to derive the neutral atmospheric densities at 130 km,which can also be obtained from the Mars Climate Database(MCD)and spacecraft aerobraking *** this research,we explain the method used to calculate neutral densities at 130 km via ionosphere observations and three long-period 130-km neutral density data sets at northern high latitudes(latitudes>60°)acquired through ionospheric data measured by the Mars Global Surveyor(MGS)Radio Occultation *** calculated 130-km neutral density data,along with 130-km density data from the aerobraking observations of the MGS and Mars Odyssey(ODY)in the northern high latitudes,were compared with MCD outputs at the same latitude,longitude,altitude,solar latitude,and local *** 130-km density data derived from both the ionospheric profiles and aerobraking observations were found to show seasonal variations similar to those in the MCD *** a negative shift of about 2×10^10 cm^−3,the corrected 130-km neutral densities derived from MCD v4.3 were consistent with those obtained from the two different *** result means that(1)the method used to derive the 130-km neutral densities with ionospheric profiles was effective,(2)the MCD v4.3 data sets generally overestimated the 130-km neutral densities at high latitudes,and(3)the neutral density observations from the MGS Radio Science Experiment could be used to calibrate a new atmospheric model of Mars.

关键词： Martian upper atmosphere Mars Climate Database v4.3 aerobraking observations Mars global circulation

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Hierarchical microstructure enables high strength and good ductility in as-cast Fe_(27)Ni_(35)Cr_(18.25)Al_(13.75)Co_(2)Ti_(2)Mo_(2) high-entropy alloy

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Journal of Materials Science & Technology 2024年第12期179卷 9-21页

作者： Jiacheng Niu Zhiqiang Fu Weiping Chen Tiwen Lu Liangyan hao Wei Xiong Haiming Wen Guangdong Key Laboratory for Advanced Metallic Materials Processing South China University of TechnologyGuangzhou 510640China National Engineering Research Center of Near-net-shape Forming for Metallic Materials South China University of TechnologyGuangzhou 510640China Key Laboratory of Pressure Systems and Safety Ministry of EducationEast China University of Science and TechnologyShanghai 200237China Physical Metallurgy and Materials Design Laboratory Department of Mechanical Engineering and Materials ScienceUniversity of PittsburghPittsburghPA15261United States of America Department of Materials Science and Engineering Missouri University of Science and TechnologyRollaMissouri 65409United States of America

As-cast alloys often require complex thermomechanical processing to obtain a hierarchical structure to achieve a good combination of strength and *** in this work,a novel hierarchical Fe_(27)Ni_(35)Cr_(18.25)Al_(13.75)Co_(2)Ti_(2)Mo_(2) high-entropy alloy(HEA)with ultra-high tensile strength and excellent ductility was fabricated by direct *** as-cast alloy exhibits hierarchical structure with an ul-trafine lamellar microstructure(ULM),ultrafine rhombus microstructure(URM),ultrafine vermicular mi-crostructure(UVM),nanosized precipitates and spinodal decomposition(SP)that develops during casting and *** incompatibility of face-centered cubic(FCC)and body-centered cubic(BCC)phases in the deformation process leads to heterogeneous deformation-induced(HDI)hardening,which brings the alloy a tensile yield strength(YS)of~1056 MPa,an ultimate tensile strength(UTS)of~1526 MPa and a total elongation(El)of~15.6%.Additionally,the numerous interfaces generated by the hierarchical structure absorb the energy during deformation,effectively retarding the dislocation motion and causing strong work-hardening.

关键词： Direct casting High-entropy alloy Hierarchical microstructure Mechanical properties

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Quantification of pesticide residues on plastic mulching films in typical farmlands of the North China

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Frontiers of Environmental Science & Engineering 2020年第1期14卷 55-64页

作者： Baoyuan Guo Jiao Meng Xinyu Wang Chengnan Yin Weiyu hao Baiwen Ma Zhang Tao Research Center for Eco-Environmental Sciences Chinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China Beijing Union University Beijing 100101China Academy of National Food and Strategic Reserves Administration Beijing 100037China

Plastic debris as new pollutants attracts much attention in the recent *** plastic mulching films is one of the most important plastic debirs source in the *** aim of this work was to investigate the current status of pesticide residues on the plastic mulching *** on the QuEChERS method,multi-residue methods for detection of pesticide residues with gas chromatography tandem mass spectrum(GC-MS)and high performance liquid chromatography tandem mass spectrum(HPLC-MS)were developed for the analysis of the pesticides residues in plastic film and soil samples from Tianjin,Hebei and *** total concentrations of pesticide residues were in the range of 86.4-22213.2 ng/g in plastic film debris,which was about 20 times higher than that in soil(9.3—535.3 ng/g).Residual level of pesticides varied greatly in different *** historical usage and recent application of pesticides were the main sources for pesticide residues on plastic films and *** short,plastic mulching films could act as a sink for pesticides in farmland and the ubiquitous pesticide residues on plastic films should draw more attention.

关键词： Pesticides Plastic mulching film Soil QuEChERS Farmland

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A study on singlet oxygen generation for tetracycline degradation via modulating the size ofα-Fe_(2)O_(3)nanoparticle anchored on g-C_(3)N_(4) nanotube photocatalyst

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Nano Research 2023年第2期16卷 2236-2244页

作者： Hongjie Zhu Minghui Li Luning Zou Youyou Hu Hongguo hao Jianmin Dou Junjie Mao Shandong Provincial Key Laboratory of Chemical Energy Storage and Novel Cell Technology School of Chemistry and Chemical EngineeringLiaocheng UniversityLiaocheng 252059China Key Laboratory of Functional Molecular Solids Ministry of EducationCollege of Chemistry and Materials ScienceAnhui Normal UniversityWuhu 241002China State Key Laboratory of Pollution Control and Resource Reuse School of the EnvironmentNanjing UniversityNanjing 210023China Gaotang liguo chemical plant Liaocheng 252059China

Photocatalysis is considered as an effective technique for mitigating ecological risks posed by residual tetracycline(TC).To improve the efficiency of this technique,it is necessary to enable photocatalysts to produce highly reactive species,such as singlet oxygen(1O2).However,due to the high activation energy of 1O2,photocatalysts can hardly produce 1O2 without assistance from external ***,we find that the size-reducedα-Fe_(2)O_(3)nanoparticles(~4 nm)that anchored on g-C_(3)N_(4)nanotube(α-Fe_(2)O_(3)@CNNT)can spontaneously generate ^(1)O_(2) for degradation of *** comparison,only hydroxyl radical(·OH)can be produced by g-C_(3)N_(4)nanotube loaded with~14 nmα-Fe_(2)O_(3)nanoparticles(α-Fe_(2)O_(3)/CNNT).Owing to the high reactivity of the ^(1)O_(2) species,the photocatalytic degradation rate(Kapp)of TC withα-Fe_(2)O_(3)@CNNT(0.056 min^(−1))was 1.8 times higher than that ofα-Fe_(2)O_(3)/*** experimental results and theoretical calculations suggested that reducing the size ofα-Fe_(2)O_(3)nanoparticles anchored on g-C_(3)N_(4)nanotube decreased the surface electron density ofα-Fe_(2)O_(3),which induces the generation of high-valent Fe(IV)active sites overα-Fe_(2)O_(3)@CNNT and turns the degradation pathway into a unique ^(1)O_(2) dominated *** study provides a new insight on the generation of ^(1)O_(2) for effective degradation of environmental pollutant.

关键词： singlet oxygen degradation pathway high-valent Fe(IV) tetracycline degradation

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