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Dynamic process analysis of the Niumiangou landslide triggered by the Wenchuan earthquake using the finite difference method and a modified discontinuous deformation analysis

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Journal of Mountain Science 2021年第4期18卷 1034-1048页

作者： HUANG Da MENG Qiu-jie SONG Yi-xiang CUI Sheng-hua CEN Duo-feng School of Civil and Transportation Engineering Hebei University of TechnologyTianjin 300401China State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of TechnologyChengdu 610059China

The Niumiangou landslide was the largest landslide triggered by the 2008 Wenchuan earthquake,which was significantly affected by the amplification effect of seismic acceleration.The ringshear experiments indicated that the materials in the source area of the Niumiangou landslide were subjected to friction degradation under a big shear displacement,which may result in rapid movement of the landslide.In order to better understand the landslide movement and study the effect of the friction degradation on movement mechanisms,the dynamic process of Niumiangou landslide was simulated with a new numerical method,which combines the finite difference method(FDM)and the discontinuous deformation analysis(DDA).First,the FDM was used to study the initiation time,amplification effect and velocity of the landslide.Afterwards,these initiation velocities were applied to the blocks in the DDA model by corresponding coordination in the FDM model.A displacementdependent friction model of the sliding surface was incorporated into DDA code to further understand the kinetic behavior of the landslide.The results show that the displacement-dependent friction strongly decreases the friction coefficient of sliding surface under a big displacement,which can obviously promote the run-out and velocity of landslide.The model output well matches the topographic map formed by the landslide.This implies that the proposed model can be applied to the simulation of earthquake-induced landslides with amplification effect,and the friction degradation model is important to clarify the movement mechanism of high-speed and long-distance landslides.

关键词： Wenchuan earthquake Discontinuous deformation analysis(DDA) Niumiangou landslide Amplification effects Displacement-dependent friction model

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Mg-Al-hydrotalcite with alkaline sites protects Ni/KIT-6 from formation of amorphous coke in glycerol steam reforming via tailoring reaction intermediates

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Frontiers of Chemical Science and Engineering 2024年第4期18卷 25-39页

作者： Yunyu Guo yiran Wang Yuewen Shao Shu Zhang yi Wang song Hu Jun xiang Xun Hu School of Material Science and Engineering University of JinanJinan 250022China Joint International Research Laboratory of Biomass Energy and Materials College of Materials Science and EngineeringNanjing Forestry UniversityNanjing 210037China State Key Laboratory of Coal Combustion Huazhong University of Science and TechnologyWuhan 430074China

During steam reforming,the performance of a catalyst and amount/property of coke are closely related to reaction intermediates reaching surface of a catalyst.Herein,modification of reaction intermediates by placing Mg-Al-hydrotalcite above Ni/KIT-6 catalyst in steam reforming of glycerol was conducted at 300 to 600°C.The results revealed that the catalytic activity of Ni/KIT-6 in the lower bed was enhanced with either Mg1-Al5-hydrotalcite(containing more acidic sites)or Mg5-Al1-hydrotalcite(containing more alkaline sites)as upper-layer catalyst.The in situ infrared characterization of steam reforming demonstrated that Mg-Al-hydrotalcite catalyzed the deoxygenation of glycerol,facilitating the reforming of the partially deoxygenated intermediates over Ni/KIT-6.Mg-Al-hydrotalcite as protective catalyst,however,did not protect the Ni/KIT-6 from formation of more coke.Nonetheless,this did not lead to further deactivation of Ni/KIT-6 while Mg5-Al1-hydrotalcite even substantially enhanced the catalytic stability,even though the coke was much more significant than that in the use of single Ni/KIT-6(52.7%vs.28.6%).The reason beneath this was change of the property of coke from more aliphatic to more aromatic.Mg5-Al1-hydrotalcite catalyzed dehydration of glycerol,producing dominantly reaction intermediates bearing C=C,which formed the catalytic coke of with carbon nanotube as the main form with smooth outer walls as well as higher aromaticity,C/H ratio,crystallinity,crystal carbon size,thermal stability,and resistivity toward oxidation on Ni/KIT-6 in the lower bed.In comparison,the abundance of acidic sites on Mg1-Al5-hydrotalcite catalyzed the formation of more oxygen-containing species,leading to the formation of carbon nanotubes of rough surface on Ni/KIT-6.

关键词： steam reforming of glycerol Mg-Alhydrotalcite sacrificial catalyst reaction intermediates property of coke

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Nb-and Ta-doped(Hf,Zr,Ti)C multicomponent carbides with enhanced oxidation resistance at 2500℃

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Journal of Advanced Ceramics 2024年第3期13卷 332-344页

作者： Shiyan Chen Jinming Wang Zhaoke Chen Weilong song yi Zeng Xingchao Li Tongqi Li xiang Xiong State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China Aerospace Research Institute of Materials&Processing Technology China Academy of Launch Vehicle TechnologyBeijing 100076China

Enhancing oxidation resistance of multicomponent carbides above 2000℃is critical for their thermal protection applications.For this purpose,novel Nb-and Ta-doped(Hf,Zr,Ti)C multicomponent carbides were designed to improve their oxidation resistance at 2500℃.The results demonstrated that Nb and Ta doping reduced the oxidation rate constant by 16.67%and 25.17%,respectively,thereby significantly improving the oxidation resistance of(Hf,Zr,Ti)C.This enhancement was attributed to the changes in oxycarbide composition and distribution within the oxide layer by adding Nb and Ta.Owing to the different oxidation tendencies of the constituent elements,a distinctive structure was formed in which(Hf,Zr)O_(2)served as a skeleton,and various oxycarbides were dispersed throughout the oxide layer.The doped Nb and Ta were retained within oxycarbides,retarding the diffusion of oxygen into the lattice.More importantly,the addition of Nb and Ta reduced the size of oxycarbides,decreasing both size and quantity of the pores in the oxide layer and facilitating the formation of a more effective oxygen barrier.

关键词： (Hf,Zr,Ti)C oxidation behaviour ultra-high-temperature oxidation Nb and Ta doping oxycarbides

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Thrust force model for ultrasonic-assisted micro drilling of DD6 superalloy

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Advances in Manufacturing 2022年第2期10卷 313-325页

作者： Xiao-xiang Zhu Wen-Hu Wang Rui-song Jiang yi-Feng Xiong Xiao-Fen Liu Key Laboratory of High Performance Manufacturing for Aero Engine Ministry of Industry and Information TechnologySchool of Mechanical EngineeringNorthwestern Polytechnical UniversityXi'an 710072People's Republic of China Engineering Research Center of Advanced Manufacturing Technology for Aero Engine Ministry of EducationSchool of Mechanical EngineeringNorthwestern Polytechnical UniversityXi'an 710072People's Republic of China School of Aeronautics and Astronautics Sichuan UniversityChengdu 610065People's Republic of China

As a typical refractory material,the DD6 nickelbased single-crystal superalloy has important applications in the aviation industry.Ultrasonic-assisted drilling is an advanced machining method that significantly improves machining of refractory materials.The drilling thrust force influences the hole surface quality,burr height,and bit wear.Therefore,it is necessary to predict the thrust force during ultrasonic-assisted drilling.However,there are few reports on the modeling of the thrust force in the ultrasonicassisted drilling of micro-holes.A thrust force prediction model for ultrasonic-assisted micro-drilling is proposed in this study.Based on the basic cutting principle,the dynamic cutting speed,dynamic cutting thickness,and acoustic softening effect caused by ultrasonic vibrations are factored into this model.Through model calibration,the specific friction force and specific normal force coefficients were determined.The model was verified through ultrasonic-assisted drilling experiments conducted at different feed rates,spindle speeds,frequencies,and amplitudes.The maximum and minimum errors of the average thrust force were 10.5%and 2.3%,respectively.This model accurately predicts the thrust force based on the parameters used for ultrasonic-assisted micro-hole drilling and can assist in the analysis and modeling of DD6 superalloy processing.

关键词： Ultrasonic-assisted drilling DD6 superalloy:Thrust force model-Dynamic cutting thickness Acoustic softening effect

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Highly enhanced microwave absorption for carbon nanotube/barium ferrite composite with ultra-low carbon nanotube loading

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Journal of Materials Science & Technology 2022年第7期102卷 115-122页

作者： Yue-yi Wang song-Yang Wen-Jin Sun Kun Dai Ding-xiang Yan Zhong-Ming Li College of Polymer Science and Engineering State Key Laboratory of Polymer Materials EngineeringSichuan UniversityChengdu 610065China School of Materials Science and Engineering Zhengzhou UniversityZhengzhou 450001China School of Aeronautics and Astronautics Sichuan UniversityChengdu 610065China

Barium ferrite(BaFe_(12)O_(19))is considered as potential microwave absorption(MA)material thanks to the large saturation magnetization,high Curie temperature,and excellent chemical stability.The integration of carbon nanotube(CNT)can improve the dielectric loss of BaFe_(12)O_(19)for further enhanced MA perfor-mance,nevertheless,the MA performance is still not desirable because of the poor CNT dispersion in the CNT/BaFe_(12)O_(19)composites,which usually prepared via the ball-milling method,unless high CNT loading was used.Herein,according to the thermal stability of CNT in different atmosphere and the formation mechanism of BaFe_(12)O_(19)from precursor,CNT was introduced in the precursor of BaFe_(12)O_(19)uniformly during auto-ignition process and calcined under different atmosphere.When CNT loading is only 2.0 wt%,the CNT/BaFe_(12)O_(19)composites obtained exhibits a minimum reflection loss(RL_(min))of-43.9 dB and effective bandwidth(with RL<-10 dB)of 3.9 GHz with the thickness of 1.5 mm,which are much supe-rior to-10.2 dB and 2.2 GHz for pure BaFe_(12)O_(19),and-13.6 dB and 2.5 GHz for CNT/BaFe_(12)O_(19)composite prepared by ball-milling method.These results may pave the way to design high-performance BaFe_(12)O_(19)based microwave absorbers.

关键词： Carbon nanotube Barium ferrite Microwave absorption

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Dihydromyricetin Alleviates H9C2 Cell Apoptosis and Autophagy by Regulating CircHIPK3 Expression and PI3K/AKT/mTOR Pathway

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Chinese Journal of Integrative Medicine 2023年第5期29卷 434-440页

作者： ZHANG Zhi-ying LIU Chao WANG Peng-xiang HAN yi-wei ZHANG yi-wen HAO Mei-li song Zi-xu ZHANG Xiao-ying Key Laboratory for Molecular Genetic Mechanisms and Intervention Research on High Altitude Disease of Tibet Autonomous Region School of MedicineXizang Minzu UniversityXianyangShaanxi Province(712082)China Key Laboratory of High Altitude Environment and Gene Related to Disease of Tibet Ministry of Education School of MedicineXizang Minzu UniversityXianyangShaanxi Province(712082)China School of Finance Economics Xizang Minzu UniversityXianyangShaanxi Province(712082)China School of Information Engineering Xizang Minzu UniversityXianyangShaanxi Province(712082)China

Objective: To investigate the effect and potential mechanism of dihydromyricetin(Dmy) on H9C2 cell proliferation, apoptosis, and autophagy. Methods: H9C2 cells were randomly divided into 7 groups, namely control, model, EV(empty p CDH-CMV-MCS-EF1-Cop GFP-T2A-Puro vector), IV(circHIPK3 interference), Dmy(50 μmol/L), Dmy+IV, and Dmy+EV groups. Cell proliferation and apoptosis were detected by cell counting kit-8 assay and flow cytometry, respectivley. Western blot was used to evaluate the levels of light chain 3 Ⅱ/Ⅰ(LC3Ⅱ/Ⅰ), phospho-phosphoinositide 3-kinase(p-PI3K), protein kinase B(p-AKT), and phospho-mammalian target of rapamycin(p-mTOR). The level of circHIPK3 was determined using reverse transcriptase polymerase chain reaction. Electron microscopy was used to observe autophagosomes in H9C2 cells. Results: Compared to H9C2 cells, the expression of circHIPK in H9C2 hypoxia model cells increased significantly(P<0.05). Compared to the control group, the cell apoptosis and autophagosomes increased, cell proliferation rate decreased significantly, and the expression of LC3Ⅱ/Ⅰ significantly increased(all P<0.05). Compared to the model group, the rate of apoptosis and autophagosomes in IV, Dmy, and Dmy+IV group decreased, the cell proliferation rate increased, and the expression of LC3Ⅱ/Ⅰ decreased significantly(all P<0.05). Compared to the control group, the expressions of p-PI3K, p-AKT, and p-mTOR in the model group significantly reduced(P<0.05), whereas after treatment with Dmy and sh-circHIPK3, the above situation was reversed(P<0.05). Conclusion: Dmy plays a protective role in H9C2 cells by inhibiting circHIPK expression and cell apoptosis and autophagy, and the mechanism may be related to PI3K/AKT/mTOR pathway.

关键词： dihydromyricetin circHIPK autophagy cell apoptosis PI3K/AKT/mTOR

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MP3RNA-seq:Massively parallel 3’end RNA sequencing for high-throughput gene expression profiling and genotyping

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Journal of Integrative Plant Biology 2021年第7期63卷 1227-1239页

作者： Jian Chen xiangbo Zhang Fei yi xiang Gao Weibin song Haiming Zhao Jinsheng Lai State Key Laboratory of Plant Physiology and Biochemistry National Maize Improvement CenterDepartment of Plant Genetics and BreedingChina Agricultural UniversityBeijing 100193China Center for Crop Functional Genomics and Molecular Breeding China Agricultural UniversityBeijing 100193China

Transcriptome deep sequencing(RNA‐seq)hasbecome a routine method for global geneexpression profiling.However,its application tolarge‐scale experiments remains limited by costand labor constraints.Here we describe amassively parallel 3′end RNA‐seq(MP3RNA‐seq)method that introduces unique samplebarcodes during reverse transcription to permitsample pooling immediately following this initialstep.MP3RNA‐seq allows for handling of hun-dreds of samples in a single experiment,at acost of about$6 per sample for libraryconstruction and sequencing.MP3RNA‐seq iseffective for not only high‐throughput geneexpression profiling,but also genotyping.Todemonstrate its utility,we applied MP3RNA‐seqto 477 double haploid lines of maize.We iden-tified 19,429 genes expressed in at least 50%ofthe lines and 35,836 high‐quality singlenucleotide polymorphisms for genotypinganalysis.Armed with these data,we performedexpression and agronomic trait quantitativetrait locus(QTL)mapping and identified 25,797expression QTLs for 15,335 genes and 21 QTLsfor plant height,ear height,and relative earheight.We conclude that MP3RNA‐seq is highlyreproducible,accurate,and sensitive forhigh‐throughput gene expression profiling andgenotyping,and should be generally applicableto most eukaryotic species.

关键词： gene expression profiling genotyping maize MP3RNA‐seq quantitative trait loci

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Advanced Role of Hippo Signaling in Endometrial Fibrosis： Implications for Intrauterine Adhesion

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Chinese Medical Journal 2017年第22期130卷 2732-2737页

作者： Hai-Yan Zhu Tian-xiang Ge yi-Bin Pan song-ying Zhang Assisted Reproduction Unit Department of Obstetrics and Gynecology Sir Run Run Shaw Hospital School of Medicine Zhejiang University Hangzhou Zhejiang 310016 China

Objective： Intrauterine adhesion （IUA） is a major health problem that causes infertility, menstrual irregularities, and recurrent pregnancy losses in women. Unfortunately, treatments for IUA are limited, and there are currently no effective strategies for preventing IUA recurrence. In this review, we introduced the role of Hippo signaling in the normal endometrium and IUA and described the mechanisms by which the Hippo pathway integrates with the Wnt and transforming growth factor-β （TGF-β） signaling pathways to form an intricate network governing the development of fibrosis. Data Sources： Original research articles in English that were published until July 2017 were collected from the PubMed database. Study Selection： Literature search was conducted using the search terms ＂endometrial fibrosis OR fibrosis AND or OR intrauterine adhesion OR Asherman syndrome OR IUA,＂＂Hippo AND or OR Hippo/TAZ,＂＂TGF-β,＂ and ＂Wnt.＂ Related original research articles were included in the comprehensive analysis. Results： Endometrial fibrosis is recognized as a key pathological event in the development of IUA, which is characterized by epithelial/fibroblast-myofibroblast transition. Myofibroblasts play crucial roles in the pathogenesis of fibrous scarring, and myofibroblast differentiation can be triggered by multiple signaling pathways. H ippo signaling is a critical regulator of the epithelial/fibroblast-myofibroblast transition and α-smooth muscle actin, which exhibits a specific spatiotemporal expression in the endometrium. Conclusions： Hippo signaling plays a critical role in fibrous diseases and participates in cross talks with Wnt and TGF-β signaling. Our findings not only contributed to knowledge on the pathogenesis of endometrial fibrosis, but can also serve as a useful resource for developing specific molecular inhibitors for IUA treatment and prevention.

关键词： Endometrial Fibrosis： Hippo Signaling Intrauterine Adhesion Transforming Growth Factor-β Wnt Signaling

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Noble-metal-free cobalt hydroxide nanosheets for efficient electrocatalytic oxidation

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Frontiers of Chemical Science and Engineering 2020年第6期14卷 948-955页

作者： Jie Lan Daizong Qi Jie song Peng Liu yi Liu Yun-xiang Pan Institute of Nano Biomedicine and Engineering Shanghai Engineering Research Centre for Intelligent Diagnosis and Treatment InstrumentDepartment of Instrument Science and EngineeringSchool of Electronic Information and Electrical EngineeringShanghai Jiao Tong UniversityShanghai 200240China

Cobalt hydroxide has been emerging as a promising catalyst for the electrocatalytic oxidation reactions,including the oxygen evolution reaction(OER)and glucose oxidation reaction(GOR).Herein,we prepared cobalt hydroxide nanoparticles(CoHP)and cobalt hydroxide nanosheets(CoHS)on nickel foam.In the electrocatalytic OER,CoHS shows an overpotential of 306 mV at a current density of 10 mA·cm^-2.This is enhanced as compared with that of CoHP(367 mV at 10 mA·cm^-2).In addition,CoHS also exhibits an improved performance in the electrocatalytic GOR.The improved electrocatalytic performance of CoHS could be due to the higher ability of the two-dimensional nanosheets on CoHS in electron transfer.These results are useful for fabricating efficient catalysts for electrocatalytic oxidation reactions.

关键词： electrocatalytic oxidation cobalt hydroxide nanosheet water glucose

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Numerical study on gas production via a horizontal well from hydrate reservoirs with different slope angles in the South China Sea

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Deep Underground Science and Engineering 2024年第2期3卷 171-181页

作者： Tingting Luo Jianlin song xiang Sun Fanbao Cheng Madhusudhan Bangalore Narasimha Murthy Yulu Chen yi Zhao Yongchen song School of Mechanics and Civil Engineering China University of Mining and TechnologyXuzhouChina Institute of Rock and Soil Mechanics Chinese Academy of SciencesWuhanChina Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education Dalian University of TechnologyDalianChina Faculty of Engineering and the Environment University of SouthamptonSouthamptonUK

It is important to study the effect of hydrate production on the physical and mechanical properties of low-permeability clayey–silty reservoirs for the largescale exploitation of hydrate reservoirs in the South China Sea.In this study,a multiphysical-field coupling model,combined with actual exploration drilling data and the mechanical experimental data of hydrate cores in the laboratory,was established to investigate the physical and mechanical properties of low-permeability reservoirs with different slope angles during 5-year hydrate production by the depressurization method via a horizontal well.The result shows that the permeability of reservoirs severely affects gas production rate,and the maximum gas production amount of a 20-m-long horizontal well can reach186.8 m3/day during the 5-year hydrate production.Reservoirs with smaller slope angles show higher gas production rates.The depressurization propagation and hydrate dissociation mainly develop along the direction parallel to the slope.Besides,the mean effective stress of reservoirs is concentrated in the near-wellbore area with the on-going hydrate production,and gradually decreases with the increase of the slope angle.Different from the effective stress distribution law,the total reservoir settlement amount first decreases and then increases with the increase of the slope angle.The maximum settlement of reservoirs with a 0°slope angle is up to 3.4 m,and the displacement in the near-wellbore area is as high as2.2 m after 5 years of hydrate production.It is concluded that the pore pressure drop region of low-permeability reservoirs in the South China Sea is limited,and various slope angles further lead to differences in effective stress and strain of reservoirs during hydrate production,resulting in severe uneven settlement of reservoirs.

关键词： effective stress low‐permeability reservoirs natural gas hydrate production numerical simulation settlement slope angle the South China

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