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Al-CeO_(2)-Mg refiner on grain refinement,cast fluidity and mechanical properties of AZ91 alloy

china Foundry 2024年第6期21卷 667-675页

作者： Wen-xue Fan Yu Bai Hai Hao Bo Zhang Xing-guo Zhang Kai-xi Jiang Ningbo Research Institute of Dalian University of Technology Ningbo 315016China Key Laboratory of Solidification Control and Digital Preparation Technology(Liaoning Province) School of Materials Science and EngineeringDalian University of TechnologyDalian 116024LiaoningChina School of Energy and Power Engineering Dalian University of TechnologyDalian 116024LiaoningChina

Grain refinement is a satisfying method to enhance the comprehensive performance of Mg alloys,and using grain refiners to improve the quality of Mg castings has become a common practice in the current casting *** this study,the effects of Al-CeO_(2)-Mg grain refiner addition on microstructure,cast fluidity,and mechanical properties of AZ91 alloy were systemically investigated by OM,SEM,DSC,TEM,sand Archimedean spiral mold fluidity test,and tensile *** results show that the Al-CeO_(2)-Mg grain refiner has a remarkable effect on as-cast AZ91 alloy including notable grain refinement,enhancement of cast fluidity,and improvement of tensile *** average grain size of AZ91 alloy is refined by 63%with 1.0wt.%Al-CeO_(2)-Mg grain ***,the casting flow length of the as-cast AZ91 alloy is increased from 332 mm to 440 *** improvement of cast fluidity is attributed to the decreased liquidus temperature,shortening of solid-liquid two-phase temperature range,and refinement of microstructure.

关键词： AZ91 magnesium alloy grain refiner cast fluidity mechanical properties

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Grid-forming Control Based on Adaptive Reactive Power Allocation for Offshore Wind Farms Connected to Diode-rectifier-based HVDC System

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Journal of Modern Power Systems and Clean Energy 2025年第1期13卷 154-166页

作者： Ganghua Zhang Wang Xiang Xia Chen Rui Tu Xuebo Qiao Jinyu Wen School of Electrical and Electronic Engineering Huazhong University of Science and TechnologyWuhan 430074China

Diode-rectifier-based high-voltage direct current(DR-HVDC)systems are considered an attractive solution for integrating offshore wind farms(OWFs).Grid-forming(GFM)control with a rational reactive power allocation capability is crucial for the safe operation of numerous wind turbines(WTs).Most typical GFM controls aim to share surplus reactive power of the system equally among WTs,easily rendering capacity overloads for WTs that are outputting high levels of active *** this paper,a novel GFM control for OWFs is proposed,allowing for adaptively allocating the reactive power according to the actual active power output of ***,the reactive power characteristics of the AC collection networks and WTs are analyzed across a wide wind power ***,combining the positive correlation of WT active power with the output AC voltage,a Q-θtype GFM control for WTs is *** adaptive reactive power allocation mechanism and the parameter design of the Q-θbased reactive power controller are elucidated,ensuring that WTs with lower active power output contribute more reactive power to the system than WTs with higher active power *** AC impedance models of WTs under various GFM controls are established to evaluate the impact of different reactive power ***,the feasibility of the proposed control is validated in PSCAD/EMTDC,accompanied by stability analysis.

关键词： Offshore wind farm diode-rectifier high-voltage direct current(HVDC) grid-forming control reactive power allocation stability analysis

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Relationship Between Climate Change and Marmot Plague of Marmota himalayana Plague Focus—the Altun Mountains of the Qinghai-Xizang Plateau,china,2000–2022

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china CDC weekly 2024年第4期6卷 69-74,I0006页

作者： Qun Duan Xiaojin Zheng Zhiqiang Gan Dongyue Lyu Hanyu Sha Xinmin Lu Xiaoling Zhao Asaiti Bukai Ran Duan Shuai Qin Li Wang Jinxiao Xi Di Wu Peng Zhang Deming Tang Zhaokai He Huaiqi Jing Biao Kan Xin Wang National Institute for Communicable Disease Control and Prevention Chinese Center for Disease Control and PreventionBeijingChina Akesai Kazak Autonomous County Center for Disease Control and Prevention Jiuquan CityGansu ProvinceChina Jiuquan Center for Disease Control and Prevention Jiuquan CityGansu ProvinceChina Gansu Provincial Center for Disease Control and Prevention Lanzhou CityGansu ProvinceChina

Introduction:Plague is a zoonotic disease that occurs naturally in specific geographic *** change can influence the populations of the plague host or vector,leading to variations in the occurrence and epidemiology of plague in ***:In this study,we collected meteorological and plague epidemiological data from the Marmota himalayana plague focus in the Altun Mountains of the Qinghai-Xizang *** data spanned from 2000 to *** describe the climatic factors and plague epidemic conditions and we describe their analysis by Pearson’s ***:During the period from 2000 to 2022,the isolation rates of Yersinia pestis(***)from marmots and fleas were 9.27%(451/4,864)and 7.17%(118/1,646),***,we observed a positive rate of F1 antibody of 11.25%(443/3,937)in marmots and 18.16%(142/782)in *** regards to climate,there was little variation,and a decreasing trend in blowing-sand days was *** temperature in the previous year showed a negative correlation with the *** isolation rate in marmots(r=−0.555,P=0.011)and the positive rate of F1 antibody in marmots(r=−0.552,P=0.012)in the current *** average annual precipitation in the previous two years showed a positive correlation with marmot density(r=0.514,P=0.024),while blowingsand days showed a negative correlation with marmot density(r=−0.701,P=0.001).Furthermore,the average annual precipitation in the previous three years showed a positive correlation with the isolation rate of *** from marmots(r=0.666,P=0.003),and blowing-sand days showed a negative correlation with marmot density(r=−0.597,P=0.009).Conclusions:The findings of this study indicate that there is a hysteresis effect of climate change on the prevalence of ***,monitoring climate conditions can offer significant insights for implementing timely preventive and control measures to combat plague epidemics.

关键词： Plague epidemiology Plateau

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High-performance and robust high-temperature polymer electrolyte membranes with moderate microphase separation by implementation of terphenyl-based polymers

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Journal of Energy Chemistry 2024年第5期92卷 572-578页

作者： Jinyuan Li Congrong Yang Haojiang Lin Jicai Huang Suli Wang Gongquan Sun Division of Fuel Cells and Battery Dalian National Laboratory for Clean EnergyDalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023LiaoningChina Key Laboratory of Fuel Cells&Hybrid Power Sources Chinese Academy of SciencesDalian 116023LiaoningChina University of Chinese Academy of Sciences Beijing 100039China

Acid loss and plasticization of phosphoric acid(PA)-doped high-temperature polymer electrolyte membranes(HT-PEMs)are critical limitations to their practical application in fuel *** overcome these barriers,poly(terphenyl piperidinium)s constructed from the m-and p-isomers of terphenyl were synthesized to regulate the microstructure of the *** rigid p-terphenyl units prompt the formation of moderate PA aggregates,where the ion-pair interaction between piperidinium and biphosphate is reinforced,leading to a reduction in the plasticizing *** a result,there are trade-offs between the proton conductivity,mechanical strength,and PA retention of the membranes with varied m/p-isomer *** designed PA-doped PTP-20m membrane exhibits superior ionic conductivity,good mechanical strength,and excellent PA retention over a wide range of temperature(80–160°C)as well as satisfactory resistance to harsh accelerated aging *** a result,the membrane presents a desirable combination of performance(1.462 W cm^(-2) under the H_(2)/O_(2)condition,which is 1.5 times higher than that of PBI-based membrane)and durability(300 h at 160°C and 0.2 A cm^(-2))in the fuel *** results of this study provide new insights that will guide molecular design from the perspective of microstructure to improve the performance and robustness of HT-PEMs.

关键词： Fuel cell High-temperature polymer electrolyte membranes Microphase separation Poly(terphenyl piperidinium)s Phosphoric acid

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GOES-16 ABI Brightness Temperature Observations Capturing Vortex Rossby Wave Signals during Rapid Intensification of Hurricane Irma(2017)

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Journal of Meteorological research 2024年第4期38卷 768-783页

作者： Yanyang HU Xiaolei ZOU Joint Center of Data Assimilation for Research and Application Nanjing University of Information Science&TechnologyNanjing 210044

Geostationary Operational Environmental Satellite-16(GOES-16) Advanced Baseline Imager(ABI) observations of brightness temperature(TB) are used to examine the temporal evolutions of convection-affected structures of Hurricane Irma(2017) during its rapid intensification(RI) period from 0600 to 1800 UTC 4 September *** ABI observations reveal that both an elliptical eye and a spiral rainband that originated from Irma's eyewall obviously exhibit wavenumber-2 TB *** elliptical eye underwent a counterclockwise rotation at a mean speed of a wavenumber-2 vortex Rossby edge wave from 0815 to 1005 UTC 4 *** the following about 2 hours(1025–1255 UTC 4 September),an inner spiral rainband originated from the eyewall and propagated at a phase speed that approximates the vortex Rossby wave(VRW) phase speed calculated from the aircraft reconnaissance *** the RI period of Irma,ABI TB observations show an on–off occurrence of low TB intrusions into the eye,accompanying a phase lock of eyewall TB asymmetries of wavenumbers 1 and 2 and an outward propagation of VRW-like inner spiral rainbands from the *** phase lock leads to an energy growth of Irma's eyewall *** the eye remained clear from 1415 to 1725 UTC 4 September,an inner spiral rainband that originated from a large convective area also had a VRW-like outward propagation,which is probably due to a vertical tilt of *** study suggests a potential link between convection sensitive GOES imager observations and hurricane dynamics.

关键词： Geostationary Operational Environmental Satellite(GOES)imager brightness temperature(TB) hurricane vortex Rossby wave(VRW)

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The origin of microstructural inhomogeneity in vacuum-sintered ZrO2-doped Lu2O3 transparent ceramics

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JOURNAL OF THE AMERICAN CERAMIC SOCIETY 2024年第2期107卷 1105-1116页

作者： Ren, Yi Li, Xiaodong Mu, Haojie Zhu, Qi Zhang, Mu Sun, Xudong Northeastern Univ Key Lab Anisotropy & Texture Mat Minist Educ Shenyang Peoples R China Northeastern Univ Res Ctr Adv Ceram Mat Sch Mat Sci & Engn Shenyang Peoples R China Northeastern Univ Foshan Grad Sch Foshan Peoples R China Northeastern Univ Key Lab Anisotropy & Texture Mat Minist Educ Shenyang 110819 Liaoning Peoples R China

Highly transparent Lu2O3 ceramics were prepared by using co-precipitation combined with vacuum sintering method with ZrO2 as sintering aid. The effect of ZrO2 on densification, transmittance, and microstructure evolution of the Lu2O3 ceramics was carefully studied. It was found that the addition of ZrO2 was very effective in improving densification of Lu2O3. The highest transmittance (at 600 nm) of the 3 at.% ZrO2 doped Lu2O3 ceramic (1.6-mm thickness) sintered at 1800 degrees C reached 80.1%. Microstructural inhomogeneity was found after vacuum sintering with larger grain sizes at the central. The microstructural inhomogeneity mainly occurred in the final stage of sintering. Doping ZrO2 mitigated microstructural inhomogeneity and decreased markedly the grain size of Lu2O3 ceramics. Raman measurements indicated that the disordered structure was formed due to oxygen vacancy, and the oxygen vacancy concentration at the central was higher than at the peripheral. The oxygen vacancy concentration gradient is the dominant factor governing nonuniform microstructure evolution during vacuum sintering. Furthermore, a uniform microstructure was obtained by the inhibition of oxygen vacancy formation by the Lu2O3/ZrO2 double powder bed.

关键词： Lu2O3 microstructural inhomogeneity oxygen vacancy raman spectra transparent ceramics

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Formation processes and source contributions of ground-level ozone in urban and suburban Beijing using the WRF-CMAQ modelling system

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Journal of Environmental Sciences 2023年第5期127卷 753-766页

作者： Shuxian Zhang Zhongzhi Zhang Yang Li Xiaohui Du Linglu Qu Wei Tang Jun Xu Fan Meng Research Institute of Atmospheric Environment Chinese Research Academy of Environmental SciencesBeijing 100012China College of Water Sciences Beijing Normal UniversityBeijing 100875China Asia Center for Air Pollution Research Niigata 950-2144Japan

Beijing faces the challenge of high levels of ozone(O_(3))*** this study,the Weather research and Forecasting model and Community Multiscale Air Qualitymodel(CMAQ)were used to simulate atmospheric O_(3) concentrations in *** investigate the formation mechanisms and source contributions of O_(3) pollution in different regions of Beijing,process analysis and the integrated source apportionmentmethodwithin the CMAQwere applied to O_(3) concentrations in the summer of *** process analysis results showed that vertical diffusion was the major contributor to O_(3) concentrations at all receptor sites in Beijing,at>65.94μg/(m^(3)·hr).Gas-phase chemical reactions consumed a significant amount of O_(3) in urban and inner suburban areas(>−5.57μg/(m^(3)·hr)),while near-surface chemical reactions made positive contributions in outer suburban areas(>4.72μg/(m^(3)·hr)).The O_(3) formation chemical reactions indicated that NO titration,which removes O_(3) at night-time,mainly occurred in urban *** weaker chemical reactions occurring near the surface in outer suburbs suggested that suburban-area O_(3) was produced in the upper atmospheric layers and was transported vertically to the lower *** O_(3) source apportionment results showed that boundary contributions were the dominant contributor to O_(3) pollution in Beijing(>40%).The contribution of non-local emissions to O_(3) levels was significantly greater in the outer suburbs than in urban and inner suburban areas due to *** study increases the understanding of the complex processes of O_(3) formation in different areas of Beijing and informs the implementation of O_(3) control plans.

关键词： Ozone Source apportionment Process analysis Air quality model

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Congenital hydrocephalus:a review of recent advances in genetic etiology and molecular mechanisms

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Military Medical research 2024年第6期11卷 942-958页

作者： Xiu-Yun Liu Xin Song Marek Czosnyka Chiara Robba Zofia Czosnyka Jennifer Lee Summers Hui-Jie Yu Guo-Yi Gao Peter Smielewski Fang Guo Mei-Jun Pang Dong Ming Medical School Tianjin UniversityTianjin 300072China State Key Laboratory of Advanced Medical Materials and Devices Tianjin UniversityTianjin 300072China Haihe Laboratory of Brain-Computer Interaction and Human-Machine Integration Tianjin 300380China School of Pharmaceutical Science and Technology Tianjin University300072 TianjinChina Department of Clinical Neurosciences Addenbrooke’s HospitalUniversity of CambridgeCambridge CB20QQUK San Martino Policlinico Hospital IRCCS for Oncology and Neuroscience16132 GenoaItaly Department of Anesthesiology and Critical Care Medicine Johns Hopkins UniversityBaltimoreMD 21287USA Department of Neurosurgery Tianjin Medical University General HospitalTianjin 300052China Department of Neurosurgery Beijing Tiantan HospitalCapital Medical UniversityBeijing 100070China Department of Neurosurgery Tianjin Huanhu HospitalTianjin 300350China

The global prevalence rate for congenital hydrocephalus(CH)is approximately one out of every five hundred births with multifaceted predisposing factors at *** influences stand as a major contributor to CH pathogenesis,and epidemiological evidence suggests their involvement in up to 40%of all cases observed *** about an individual’s genetic susceptibility can significantly improve prognostic precision while aiding clinical decision-making ***,the precise genetic etiology has only been pinpointed in fewer than 5%of human *** occurrences of CH cases are required for comprehensive gene sequencing aimed at uncovering additional potential genetic loci.A deeper comprehension of its underlying genetics may offer invaluable insights into the molecular and cellular basis of this brain *** review provides a summary of pertinent genes identified through gene sequencing technologies in humans,in addition to the 4 genes currently associated with CH(2 X-linked genes L1CAM and AP1S2,2 autosomal recessive MPDZ and CCDC88C).Others predominantly participate in aqueduct abnormalities,ciliary movement,and nervous system *** prospective CH-related genes revealed through animal model gene-editing techniques are further outlined,focusing mainly on 4 pathways,namely cilia synthesis and movement,ion channels and transportation,Reissner’s fiber(RF)synthesis,cell apoptosis,and ***,the proper functioning of motile cilia provides significant impulsion for cerebrospinal fluid(CSF)circulation within the brain ventricles while mutations in cilia-related genes constitute a primary cause underlying this *** far,only a limited number of CH-associated genes have been identified in *** integration of genotype and phenotype for disease diagnosis represents a new trend in the medical *** models provide insights into the pathogenesis of CH and contribute to our understanding of its association w

关键词： Congenital hydrocephalus Genetic disease Central system Cilia Ventricle

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Pre-mating nitenpyram exposure in male mice leads to depression-like behavior in offspring by affecting tryptophan metabolism in gut microbiota

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Journal of Environmental Sciences 2024年第3期137卷 120-130页

作者： Sen Yan Wei Sun Sinuo Tian Zhiyuan Meng Jinling Diao Zhiqiang Zhou Li Li Wentao Zhu Innovation Center of Pesticide Research Department of Applied ChemistryCollege of ScienceChina Agricultural UniversityBeijing 100193China College of Plant Protection/Joint International Research Laboratory of Agriculture&Agri-Product Safety Yangzhou UniversityYangzhou 225009China College of Plant Protection Shanxi Agricultural UniversityTaiyuan 030031China

Several studies have confirmed that the health status of the paternal affects the health of the offspring,however,it remains unknown whether paternal exposure to pesticides affect the offspring ***,we used untargeted metabolomics and 16S rRNA sequencing technology,combined with tail suspension test and RT-qPCR to explore the effects of paternal exposure to nitenpyram on the neurotoxicity of *** results found that the paternal exposure to nitenpyram led to the offspring’s depressive-like behaviors,accompanied by the reduction of tryptophan content and the disorder of microbial abundance in the gut of the ***,we determined the expression of tryptophan metabolism-related genes tryptophanase(tnaA)and tryptophan hydroxylase 1(TpH1)in gut bacteria and colonic *** found that tryptophan is metabolized to indoles rather than being absorbed into colonocytes,which coursed the reduce of tryptophan availability after nitenpyram *** conclusion,our study deepens our understanding of the intergenerational toxic effects of pesticides.

关键词： Nitenpyram Depressive-like behaviors Gut microbiota Tryptophan metabolism

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Three-dimensional quantitative characterization of defects in inconel 625 superalloy based on deep learning image identification

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Progress in Natural Science:Materials International 2024年第5期34卷 1000-1008页

作者： Wenyu Zhang Qun Ren Weihao Wan Mengru Shi Xiaofen Zhang Lei Zhao Lixia Yang Cheng Zhong Suran Liu Song Chai Yaxin Ma Haizhou Wang National Center for Materials Service Safety University of Science and Technology Beijing Beijing Key Laboratory of Metal Materials Characterization The NCS Testing Technology Co. Ltd. Central Iron and Steel Research Institute Co. Ltd. School of Metallurgical Engineering Xi'an University of Architecture and Technology

Three-dimensional(3D) quantitative characterization of defects in superalloys is an important way to promote the ability of material design and service life prediction. In this work, 3D spatial distribution of defects for Inconel 625 superalloy manufactured by laser additive manufacturing(LAM) is carried out deep learning(DL) image identification technology and 3D image reconstruction. Firstly, computer tomography(CT) technology was used to obtain continuous slice images of sample. The U-net DL algorithm was applied to intelligently identify material defects in the continuous slices. On this basis, quantitative identification and analysis of spatial defect positions and typical sizes is achieved by using 3D reconstruction software. Compared with traditional threshold segmentation(TS) techniques, the defect recognition rate has significantly improved from 61.90 % to 95.00 %. This work provides a promising characterization method for efficient characterizing alloy defects and damage especially during material performance evaluation.

关键词： Inconel 625 superalloy Defects and damage Three-dimensional characterization Deep learning Image identification

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