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Structural Stability of Natural Magnesiochromite at High-Temperature-Pressure Conditions

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Journal of Earth Science 2024年第4期35卷 1196-1203页

作者： Shuyu Jin Xiang Wu Yungui Liu yanfei Zhang Chao Wang State Key Laboratory of Geological Processes and Mineral Resources China University of GeosciencesWuhan430074China College of Gems and Materials Hebei GEO UniversityShijiazhuang050031China

The podiform chromitites in the Luobusha ophiolite have been thought to experience a very deep formation,but the maximum depth is still an open ***,we have investigated the structural stability of natural magnesiochromite using the synchrotron-based powder X-ray diffraction and diamond anvil cells up to 48.6 GPa and 2450 *** results have shown that spinel-type magnesiochromite first decomposes into corundum-type‘Cr_(2)O_(3)’+B1-type‘MgO’at 11–14 GPa and 1250–1450 K,then modified ludwigite(mLd)-type‘Mg_(2)Cr_(2)O_(5)’+corundum-type‘Cr_(2)O_(3)’at 14.3–20.5 GPa and 1300–2000 K,and finally CaTi_(2)O_(4)-type phase at 24.5 *** the quenching procession from high-temperature-pressure conditions,the mLd-type phase appeared again and was kept at ambient *** also obtained the isothermal equation states of spinel-type and CaTi_(2)O_(4)-type phases,revealing the composition effect on their *** on the updated results,we propose chromitites could not experience pressure exceeding∼14.3 GPa(approximate maximum depth∼400 km)in the subduction-recycling genesis model.

关键词： chromite high-temperature and high-pressure phase transitions equation of state chromitites genesis

Exploring the ultrahigh rolling contact fatigue life of M50 bearing steel by adjusting the cryogenic sequence

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Journal of Materials Science & Technology 2024年第2期169卷 243-250页

作者： Xin Cai Xiaoqiang Hu Xingyu Lu Hongwei Liu yanfei Cao Dianzhong Li Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China

The influence of different cryogenic sequences on the rolling contact fatigue(RCF)life of M50-bearing steel has been *** results show that direct cryogenic treatment after quenching can effectively improve RCF *** L_(10)life is strikingly 5 times longer than that with cryogenic treatment after *** is caused by the distinct lattice construction of martensite and the transformation of retained *** secondary nanocarbides and fine twins are formed via cryogenic treatment before tem-pering compared with cryogenic treatment after *** improvement in the RCF life of the steel is attributed to the joint effects of the secondary nanocarbides and twin boundaries with a width of 5-13 nm,which delays significantly crack initiation and *** study highlights a common method to improve the service life of high-carbon and high-alloy steels by adjusting the cryogenic se-quence.

关键词： M50 steel Cryogenic treatment Rolling contact fatigue life Carbide Twin

Analysis of phase preservation and interferometric offset test in sparse SAR imaging

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Science China(Information Sciences) 2024年第2期67卷 219-231页

作者： Zhongqiu XU Bingchen ZHANG Guangzuo LI Xueli ZHAN yanfei BAO Yirong WU Key Laboratory of Spatial Information Processing and Application System Technology Chinese Academy of Sciences Aerospace Information Research Institute Chinese Academy of Sciences School of Electronic Electrical and Communication EngineeringUniversity of Chinese Academy of Sciences PLA Academy of Military Sciences

Sparse synthetic aperture radar(SAR) imaging has emerged as a reliable microwave imaging scheme in the recent decade and excels in down-sampling reconstruction and full-sampling performance improvements such as noise, sidelobe, speckle, and ambiguity suppression. To utilize complex image products of sparse reconstruction for improvement in polarimetric, interferometric, and tomographic SAR imaging, it is necessary to evaluate the phase preservation of sparse SAR imaging. In this study, we first introduce the general alternating direction method of multipliers(ADMM) as the universal framework for sparse reconstruction algorithms and adopt chirp scaling algorithm(CSA)-based azimuth-range decouple operators to avoid expensive data storage and processing. Further, we theoretically analyze the phase preservation of the sparse reconstruction algorithm through a comparison with the reconstruction results of CSA. Finally,we conduct the interferometric offset test on the sparse reconstruction results of simulated and real Gaofen-3(GF-3) SAR data, demonstrating the phase-preserving ability of sparse methods.

关键词： sparse SAR imaging phase preservation interferometric offset test general ADMM azimuth-range decouple

Unraveling Interactions Between Gut Epithelium and Microbiota UsingModels of Intestinal Organoids

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Infectious Microbes & Diseases 2024年第3期6卷 117-126页

作者： Yi Huang Kangxin He yanfei Chen State Key Laboratory for Diagnosis and Treatment of Infectious Diseases National Clinical Research Center for Infectious DiseasesNational Medical Center for Infectious DiseasesCollaborative Innovation Center for Diagnosis and Treatment of Infectious DiseasesThe First Affiliated HospitalZhejiang University School of MedicineHangzhouChina

Intestinal microbiota is an indispensable part of intestinal homeostasis and is closely related to human *** microbiota participates in the development of a variety of intestinal diseases in a complex and diverse *** results have confirmed microbiota dysbiosis in a variety of diseases,while the mechanism is not *** is valuable to unravel these complex mechanisms,which would guide future therapies.A limiting factor of studies exploring interaction mechanisms between gut epithelium and microbiota was a lack of an in vitro organ *** development of organoids has provided an indispensable tool for gastrointestinal ***,we review the applications of organoids in exploring the roles of gut microbiota and its metabolites in diseases,summarize the advantages and limitations of organoid models,and discuss future prospective and challenges in this area.

关键词： organoids gut microbiota interaction gut epithelium

Pupillometry Analysis of Rapid Serial Visual Presentation at Five Presentation Rates

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Tsinghua Science and Technology 2024年第2期29卷 543-552页

作者： Xi Luo yanfei Lin Rongxiao Guo Xirui Zhao Shangen Zhang Xiaorong Gao School of Integrated Circuits and Electronics Beijing Institute of TechnologyBeijing 100081China School of Computer and Communication Engineering University of Science and Technology BeijingBeijing 100083China School of Medicine Tsinghua UniversityBeijing 100084China

In this study,the effect of presentation rates on pupil dilation is investigated for target recognition in the Rapid Serial Visual Presentation(RSVP)*** this experiment,the RSVP paradigm with five different presentation rates,including 50,80,100,150,and 200 ms,is *** pupillometry data of 15 subjects are collected and *** pupillometry results reveal that the peak and average amplitudes for pupil size and velocity at the 80-ms presentation rate are considerably higher than those at other presentation *** average amplitude of pupil acceleration at the 80-ms presentation rate is significantly higher than those at the other presentation *** latencies under 50-and 80-ms presentation rates are considerably lower than those of 100-,150-,and 200-ms presentation ***,no considerable differences are observed in the peak,average amplitude,and latency of pupil size,pupil velocity,and acceleration under 100-,150-,and 200-ms presentation *** results reveal that with the increase in the presentation rate,pupil dilation first increases,then decreases,and later reaches *** 80-ms presentation rate results in the largest point of pupil *** correlation is observed between pupil dilation and recognition accuracy under the five presentation rates.

关键词： pupil dilation presentation rate Rapid Serial Visual Presentation(RSVP)

A novel optical emission spectroscopy method for diagnostics of contribution of different ionization mechanisms and flux of ions in different valences in discharge channel of a Hall thruster

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Chinese Journal of Aeronautics 2024年第4期37卷 294-307页

作者： yanfei WANG Ximing ZHU Renqiu ZOU Shilin YAN Junwei JIA Zhongxi NING Daren YU School of Energy Science and Engineering Harbin Institute of TechnologyHarbin 150001China Key Laboratory of Aerospace Plasma Propulsion Ministry of Industry and Information TechnologyHarbin 150001China Beijing Orient Institute of Measurement and Test Beijing 100094China Beijing Aerospace Long March Aircraft Research Institute Beijing 100076China

The mass application of Hall thrusters poses the need for a diagnostic method of ionization mechanism in the discharge channel to boost the iteration and optimization of thruster *** work presents an Optical Emission Spectroscopy (OES) method for diagnostics of the contribution of different ionization mechanisms and the flux of ions in different valences in the discharge channel of a Hall *** emission spectra in the discharge channel are analyzed by jointly utilizing a collisional-radiative model,an ionization-excitation model,and a flux-conservation *** is found that the intensities of some spectral lines can be converted into the reaction rates of collision processes,e.g.,electron-induced excitation and ionization *** latter can further be used to determine the evolutions of particle fluxes by utilizing the conservation law of *** novel method is demonstrated on a kilo-watt Hall *** evolutions of several parameters are determined using this method along the discharge channel,including the ionization rates of different mechanisms,particle fluxes,particle densities,and particle *** novel method can be further developed by being jointly utilized with spectral imaging and tomography techniques,enabling diagnostics of multi-dimensional distributions of the above-mentioned parameters in the discharge channel and near-field plume.

关键词： Hall thruster Optical emission spectroscopy Ionization mechanism Particle flux Divalent ion

A mite parasitoid,Pyemotes zhonghuajia,negatively impacts the fitness traits and immune response of the fall armyworm,Spodoptera frugiperda

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Journal of Integrative Agriculture 2024年第1期23卷 205-216页

作者： yanfei Song Tai’an Tian Yichai Chen Keshi Zhang maofa Yang Jianfeng Liu Institute of Entomology Guizhou Provincial Key Laboratory for Agricultural Pest Management of the Mountainous RegionGuizhou University/Scientific Observing and Experiment Station of Crop Pests in GuiyangMinistry of Agriculture and Rural AffairsGuiyang 550025China Administration of Guizhou Fanjingshan National Nature Reserve Jiangkou 554400China Centre for Biodiversity and Biosecurity School of Biological SciencesThe University of AucklandAuckland 1072New Zealand College of Tobacco Science Guizhou UniversityGuiyang 550025China

Parasitoids are key regulators in ecological communities and widely used as agents in biocontrol *** fall armyworm,Spodoptera frugiperda,recently invaded multiple continents and caused substantial economic losses in *** zhonghuajia,a newly identified mite parasitoid,has shown potential for controlling various agricultural insect ***,this study tested the performance of *** in parasitising *** also investigated the sublethal effects of parasitism by *** on host fitness traits,transgenerational impacts,and cellular and humoral *** result showed that the fifth-instar larvae of *** parasitised by 40 *** were all dead(i.e.,a lethal effect),while parasitism by 5 or 10 *** was considered sublethal since many *** survived to adulthood and produced offspring after *** sublethal influences from parasitism by *** resulted in reduced pupal weight,adult emergence rate and fecundity,but increased developmental time and *** at both lethal(40 mites)and sublethal(10 mites)levels impaired the cellular and humoral immunity of *** study presents the first empirical evidence that mite parasitoids can negatively influence host ***,it provides insights into the biocontrol potential of mite parasitoids and their interactions with hosts.

关键词： Pyemotes zhonghuajia Spodoptera frugiperda immunity parasitically-induced influence biocontrol parasitoid

Ultra-conservative noncoding RNA uc.243 confers chemo-resistance by facilitating the efflux of the chemotherapeutic drug in ovarian cancer

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BIOCELL 2024年第8期48卷 1265-1273页

作者： SHAN JIANG XIUFENG LIN yanfei CHEN XINNING LI JIALI KANG Department of Gynecology and Obstetrics The First Affiliated Hospital of Jinan UniversityGuangzhou510180China Reproductive Medical Center Boai Hospital of Zhongshan Affiliated to Southern Medical UniversityZhongshan528400China Department of Gynecology and Obstetrics Boai Hospital of Zhongshan Affiliated to Southern Medical UniversityZhongshan528400China Department of Gynecology and Obstetrics Guangzhou First People’s HospitalGuangzhou Medical UniversityGuangzhou510180China

Background:Despite improvements in objective response rates to cisplatin-based combination chemotherapy,the majority of advanced ovarian cancer remains suboptimal,resulting in poor *** has been found that non-coding RNAs(ncRNAs)not only participate in the transmission of signals between various cells but also participate in tumor immunity and anti-tumor immune responses,thereby regulating tumor occurrence and ***,the function and detailed mechanism of ultraconserved RNA(ucRNA)in ovarian cancer chemoresistance is still ***:Western blotting assay,Quantitative real-time PCR analysis(qPCR),and Kaplan-Meier Plotter analysis were performed to analyze the expression and prognosis of uc.243 in ovarian *** assay and Annexin V assay were performed to analyze the function of uc.243 in cisplatin resistance in ovarian cancer *** pull-down and qPCR experiments were performed to explore the molecular mechanism of uc.243 enhancing cisplatin resistance in ovarian cancer ***:Herein,we found that uc.243 was remarkably upregulated and correlated with patient survival in chemoresistance ovarian cancer patients compared with chemo-sensitive ovarian *** experiment displayed that uc.243 induced cisplatin resistance on ovarian cancer cells by facilitating the efflux of cisplatin(CDDP);but inhibiting the expression of uc.243 significantly reverses this ***,uc.243 can inhibit the binding of RNA binding protein DGCR8 microprocessor complex subunit to pri-miR-155,thereby inhibiting the cleavage of pri-miR-155 and decrease in mature miR-155,subsequently upregulates the expression of ATP binding cassette subfamily B member(ABCB1,ABCC2).Conclusion:Our research findings indicate that uc.243 can induce chemotherapy resistance in ovarian cancer,suggesting that it may become a new prognostic biomarker for malignant ovarian cancer.

关键词： Ultra-conserved non-coding RNA uc.243 Drug efflux Drug transporters Chemoresistance Ovarian cancer

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起重机金属结构裂纹的复合修复方法

中国机械工程 2018年第13期29卷 1610-1614页

作者：孔璞萍刘志平周凯毛艳飞武汉理工大学物流工程学院武汉430063

针对起重机金属结构在长期疲劳交变载荷作用下易产生疲劳裂纹的问题,采用碳纤维复合材料(CFRP)加固止裂孔的方法对裂纹进行复合修复。建立不同载荷下止裂孔、CFRP以及复合修复的有限元模型,分析计算应力应变状态和应力集中系数;建立止... 详细信息

针对起重机金属结构在长期疲劳交变载荷作用下易产生疲劳裂纹的问题,采用碳纤维复合材料(CFRP)加固止裂孔的方法对裂纹进行复合修复。建立不同载荷下止裂孔、CFRP以及复合修复的有限元模型,分析计算应力应变状态和应力集中系数;建立止裂孔打偏情况下复合修复的有限元模型,研究CFRP加固对止裂孔修复的影响;通过静拉伸强度试验,研究复合修复方法对损伤构件的修复效果,并与仿真结果进行对比,验证了CFRP与止裂孔复合修复这一技术的可行性。结果表明,复合修复方法相比于止裂孔及CFRP修复效果,不仅可以消除裂纹尖端的奇异性,减小名义应力,提高试件的承载能力,还可以弥补钻止裂孔修复焊缝裂纹的不足,为工程维修提供了参考。

关键词：碳纤维复合材料止裂孔复合修复奇异性名义应力承载能力