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Effect of ordered helium bubbles on deformation and fracture behavior of α-Zr

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Journal of Materials Science & Technology 2019年第7期35卷 1466-1472页

作者： Si-mian liu Shi-Hao Li Wei-Zhong Han Center for Advancing Materials Performance from the Nanoscale (CAMP-Nano) & Hysitron Applied Research Center in China(HARCC) State Key Laboratory for Mechanical Behavior of Materials Xi’an Jiaotong University

Radiation-induced helium bubbles are detrimental to the mechanical properties of metals, usually causing severe hardening and embrittlement. Hexagonal close-packed(HCP) α-Zr alloys are one of the primary structural materials for nuclear applications, however, the effect of helium bubbles on their deformation and fracture behaviors still remains unexplored. Here, we found that ordered helium bubbles prefer to align along the basal plane in HCP α-Zr. Micro-scale in situ tensile tests revealed that helium bubbles less than 8 nm in size can increase the critical resolved shear stress of the prismatic slip. However, once the helium bubbles are larger than 8 nm, a bubble-softening effect happens due to a decrease in number density of helium bubbles and an increase in porosity. Once the Schmid factor of basal slip is considerably higher than prismatic slip, bubble coalescence along the basal plane becomes the major failure mode in helium-irradiated α-Zr.

关键词： α-Zr Helium bubbles Prismatic slip Coalescence Fracture

An integrated analysis of mRNA-miRNA transcriptome data revealed hub regulatory networks in three genitourinary cancers

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BIOCELL 2017年第1期41卷 19-26页

作者： mian liu Xumeng ZHANG Center for Reproductive Medicine Department of Obstetrics and GynecologyNanfang HospitalSouthern Medical UniversityGuangzhou 510515P.R.C State Key Laboratory of Biocontrol School of Life SciencesSun Yat-sen UniversityGuangzhou 510006P.R.C

Bladder,kidney,prostate and testicular carcinoma are the top four genitourinary cancers in *** we analyzed mRNA and miRNA expression profiles of carcinomas of the bladder(TCC),kidney(ccRCC)and testis(TGCT)to uncover their specific regulatory *** gene expression profiles of GSE31617 were downloaded from GEO database,which contained 27 samples,including 10 TCC,7 TGCT and 10 *** up-and downregulated differentially expressed genes(DEGs)and differentially expressed microRNAs(DEmiRNAs)of each cancer were selected and target genes of DEmiRNAs were *** interaction network of the shared genes and target genes of DEmiRNAs of each cancer was predicted by STRING and constructed by *** each cancer,we build regulatory networks of hub genes selected and conducted GO analysis of enriched ***,we chose four hub genes(SALL4,RHEB,CDC42 and TNN)for survival analysis in OncoLnc database,and they all had effects on the survival rate of another genitourinary cancer-kidney renal clear cell carcinoma(KIRC).In conclusion,the present study indicated that the identified hub genes promote our understanding of molecular mechanisms underlying the development of three genitourinary cancers,and might be used as molecular targets and diagnostic biomarkers for the treatment of them.

关键词： Genitourinary cancers Differentially expressed genes Differentially expressed miRNAs Hub genes

Transmission electron microscopy characterization of dislocation loops in irradiated zirconium

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Tungsten 2021年第4期3卷 470-481页

作者： Si-mian liu Wei-Zhong Han Center for Advancing Materials Performance from the Nanoscale State Key Laboratory for Mechanical Behavior of MaterialsXi’an Jiaotong UniversityXi’an 710049China

Characterization of irradiation defects is of great importanceto mitigate irradiation damage,reduce irradiation growth and tune mechanical properties in Zr ***,we describe a practical method to characterize the dislocation loops in irradiated Zr using conventional transmission electron microscopy(TEM).Vacancy or interstitial nature of dislocation loops is determined using the inside and outside contrast *** habit plane of dislocation loops is determined by tilting the sample to multiple zone axes and judged based on the projected loop *** size ofloops is measured by tilting the sample to an edge-on position and the loop number is counted under a weak-beam dark-field TEM condition.loops have a line contrast under viewing direction of a-axis and a circular shape under viewing direction of *** addition,a large number of triangle-shaped vacancy platelets(TVPs)were formed on the basal *** increasing the irradiation damage from 0.5 to 1.5 dpa,the number density ofloops keeps constant,while the number density of TVPs increased significantly,owing to the anisotropic diffusion and accumulation of point defects within basal *** methods introduced here are easy to follow and extend into other related investigations.

关键词： Irradiation damage Dislocation loop Habit plane Zirconium alloys

Crustal extension in North China since the Mesozoic: A numerical study

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Geodesy and Geodynamics 2019年第5期10卷 363-371页

作者： Feng Lin mian liu Dept.of Geological Sciences University of MissouriColumbiaMO65211USA

The ~1.8 billion years old North China Craton(NCC)has been thermally rejuvenated during the Mesozoic,experiencing two major phases of crustal extension and volcanism since *** earlier phase of extension,lasted from middle Mesozoic to early Cenozoic,was widespread in eastern NCC and accompanied with extensive *** later phase of extension,started in late Cenozoic and is active today,has been localized around the Ordos block,a residual core of the NCC,with limited *** we investigate the causes of the NCC extension using finite element *** results indicate that the diffuse and closely-spaced extension during Mesozoic and early Cenozoic requires a thin and weak lithosphere,which supports the notion of significant lithospheric thinning under the eastern NCC,perhaps by delamination or thermal erosion of the lithospheric *** western NCC,including the Ordos block,was largely spared by this phase of *** late Cenozoic extension around the Ordos block is commonly attributed to the Indo-Asian collision and mantle flow under eastern *** numerical results show that,regardless of the causing mechanism,a relatively thick and strong lithosphere is needed for the localized extension in western NCC,and preexisting weak zones in the lithosphere is a necessary condition for localized rifting around the *** preexisting lithospheric weakness is most likely inherited from the amalgamation of the NCC basement ~1.8 billion years *** late Cenozoic circum-Ordos rifting thus illustrates the control of ancient continental structures on recent tectonics.

关键词： North China Extension Rifting Ordos Numerical model

Factors influencing the formation of chlorination brominated trihalomethanes in drinking water

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第2期11卷 143-150页

作者： Huan WANG Dong-mei liu Zhi-wei ZHAO Fu-yi CUI Qi ZHU Tong-mian liu State Key Laboratory of Urban Water Resources and Environments School of Municipal and Environmental Engineering Harbin Institute of Technology Harbin 150090 China School of Chemistry and Material Sciences Heilongjiang University Harbin 150080 China

The formation of brominated trihalomethanes (THMs-Br) which is proved more carcinogenic than their chlorinated analogues reported was very different at various water *** study was performed to assess the effects of water quality parameters (bromide concentration,pH value and ammonia concentration),chlorination conditions (chlorine dose,reaction time) and ratios of Br-/DOC and Br-/Cl2 consumption on the formation and distribution of THMs-Br in *** results showed good correlation between the bromine incorporation factor (BIF) n(Br) and Br-/Cl2 consumption *** formation of total THM (TTHM) was found to decrease with increasing ammonia concentration but to increase with bromide concentration and pH *** n(Br) trends were significantly affected by the presence of bromide *** effects on the molar yields of THMs were more strongly influenced by bromide concentration and dissolved organic carbon (DOC) concentration than pH value and natural organic matter (NOM) *** Br-/DOC and Br-/Cl2 favor the formation of THMs-Br over chlorinated THMs (THMs-Cl).The experimental data including the main parameters such as bromide,DOC,ammonia,pH and reaction time were used for developing the predictive model for THMs-Br.

关键词： Brominated trihalomethanes (THMs-Br) Bromine incorporation factor (BIF) Total THM (TTHM) Chlorination,Predictive model

Influence of fault geometry and fault interaction on strain partitioning within western Sichuan and its adjacent region

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Science China Earth Sciences 2010年第7期53卷 1056-1070页

作者： WANG Hui liu Jie SHEN XuHui liu mian LI QingSong SHI YaoLin ZHANG GuoMin Institute of Earthquake Science China Earthquake AdministrationBeijing 100036China Department of Geological Sciences University of MissouriColumbiaMO 65211USA China Earthquake Network Center China Earthquake AdministrationBeijing 100045China Lunar and Planetary Institute HoustonTX 77058USA Laboratory of Computational Geodynamics Graduate University of Chinese Academy of SciencesBeijing 100049China

There are several major active fault zones in the western Sichuan and its vicinity. Slip rates and seismicity vary on different fault zones. For example, slip rates on the Xianshuihe fault zone are higher than 10 mm/a. Its seismicity is also intense. Slip rates on the Longmenshan fault zone are low. However, Wenchuan Ms8.0 earthquake occurred on this fault zone in 2008. Here we study the impact of fault geometry on strain partitioning in the western Sichuan region using a three-dimensional viscoe- lastoplastic model. We conclude that the slip partitioning on the Xianshuihe-Xiaojiang fault presents as segmented, and it is related to fault geometry and fault structure. Slip rate is high on fault segment with simple geometry and structure, and vice versa. Strain rate outside the fault is localized around the fault segment with complex geometry and fault structure. Strain partitioning on the central section of the Xianshuihe-Xiaojiang fault zone is influenced by the interaction between the Anninghe-Zemuhe fault and the Daliangshan fault zone. Striking of the Longmenshan fault zone is nearly orthogonal to the direction of eastward extrusion in the Tibetan Plateau. It leads to low slip rate on the fault zone.

关键词： Xianshuihe-Xiaojiang fault zone Longmenshan fault zone fault geometry strain partitioning 3D viscoelastoplastic model

Long aftershock sequences in North China and Central US: implications for hazard assessment in mid-continents

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Earthquake Science 2014年第1期27卷 27-35页

作者： mian liu Gang Luo Hui Wang Seth Stein Department of Geological Sciences University of Missouri The Key Laboratory of Computational Geodynamics Chinese Academy of Sciences Bureau of Economic Geology Jackson School of Geosciences University of Texas at Austin Institute of Earthquake Science China Earthquake Administration Department of Earth and Planetary Sciences Northwestern University

Because seismic activity within mid-continents is usually much lower than that along plate boundary zones, even small earthquakes can cause widespread con- cerns, especially when these events occur in the source regions of previous large earthquakes. However, these small earthquakes may be just aftershocks that continue for decades or even longer. The recent seismicity in the Tangshan region in North China is likely aftershocks of the 1976 Great Tangshan earthquake. The current earthquake sequence in the New Madrid seismic zone in central United States, which includes a cluster of M- 7.0 events in 1811-1812 and a number of similar events in the past millennium, is believed to result from recent fault reactivation that releases pre-stored strain energy in the crust. If so, this earthquake sequence is similar to aftershocks in that the rates of energy release should decay with time and the sequence of earthquakes will eventually end. We use simple physical analysis and numerical simulations to show that the current sequence of large earthquakes in the New Madrid fault zone is likely ending or has ended. Recognizing that mid-continental earthquakes have long aftershock sequences and complex spatiotemporal occur- rences are critical to improve hazard assessments.

关键词： Aftershock Earthquake Intraplateseismicity Earthquake hazard

Active tectonics in Taiwan:insights from a 3-D viscous finite element model

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Earthquake Science 2015年第5期28卷 353-363页

作者： Yujun Sun mian liu Shuwen Dong Huai Zhang Yaolin Shi Institute of Geomechanics Chinese Academy of Geological Sciences Key Laboratory of Computational Geodynamics Chinese Academy of Sciences Department of Geological Sciences University of Missouri Chinese Academy of Geological Sciences

Taiwan is a young orogenic belt with complex spatial distributions of deformation and earthquakes. We have constructed a three-dimensional finite element model to explore how the interplays between lithospheric struc- ture and plate boundary processes control the distribution of stress and strain rates in the Taiwan region. The model assumes a liberalized power-law rheology and incorporates main lithospheric structures; the model domain is loaded by the present-day crustal velocity applied at its bound- aries. The model successfully reproduces the main features of the GPS-measured strain rate patterns and the earth- quake-indicated stress states in the Taiwan region. The best fitting model requires the viscosity of the lower crust to be two orders of magnitude lower than that of the upper crust and lithospheric mantle. The calculated deviatoric stress is high in regions of thrust faulting and low in regions of extensional and strike-slip faulting, consistent with the spatial pattern of seismic intensity in Taiwan.

关键词： Taiwan Stress Strain rate FEM model Earthquake

Receiver function analysis for seismic structure of the crust and uppermost mantle in the liupanshan area,China

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Science China Earth Sciences 2007年第z2期50卷 227-233页

作者： TONG WeiWei WANG LiangShu MI Ning XU MingJie LI Hua YU DaYong LI Cheng liu ShaoWen liu mian Eric SanDvol Department of Earth Sciences Nanjing UniversityNanjing 200093China Department of Earth SciencesNanjing UniversityNanjing 200093China Department of Geological Science University of MissouriColumbiaMO 65211USA

A portable broadband seismic array was deployed from the northeast Tibetan Plateau to the southwest Ordos block,*** seismic structure of the crust and uppermost mantle of the liupanshan area is obtained using receiver function analysis of teleseismic body *** crustal thickness and Poisson's ratios are estimated by stacking the weighted amplitudes of receiver *** results reveal complex seismic phases in the liupanshan area,implying intense deformation at the boundary between the Tibetan Plateau and the Ordos *** average crustal thickness is 51.5 km in the northeast Tibetan Plateau,53.5 km in the liupan Mountain and 50 km in the southwest Ordos block,resulting in a concave Moho beneath the liupan *** Poisson's ratio of the liupanshan area varies between 0.27-0.29,higher than the value of 0.25-0.26 to the east and west of the liupan Mountain,suggesting partial melting in the lower *** variance in Poisson's ratio across the liupan Mountain indicates notable changes in the crustal composition and mechanical properties,which may be formed by the northeastward flow of the Tibetan lower crust during the India-Eurasia collision.

关键词： receiver function liupan Mountain crustal structure Poisson's ratio India-Eurasia collision