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| 1 | Exploring the history of cultural exchange in prehistoric Eurasia from the perspectives of crop diffusion and consumption显示文摘The history of cultural exchange in prehistoric Eurasia(CEPE) has been widely investigated. Based on archaeological evidence, this process is thought to date back to at least the early Bronze Age, although details about timings and routes remain unclear. It is likely that CEPE promoted the spread and exchange of crops that originated in different parts of Eurasia; since these remains can be definitely identified and directly dated, they provide ideal research materials to explore the history of CEPE. In this paper, we review the available archaeobotanical evidence and direct radiocarbon dates for crop remains, alongside carbon isotopic data from human bones unearthed from prehistoric sites in Eurasia, in order to investigate the history of the spread of millet crops, and wheat and barley, that were first domesticated in the eastern and western parts of Eurasia during prehistoric times.In combination with other archaeological evidences, we discuss the history of CEPE. Our results suggest that wheat and barley were domesticated in western Asia around 10500 a BP, spread into Europe and western Central Asia before 8000 a BP, and reaching eastern Central Asia and northwestern China between 4500 and 4000 a BP. Data show that both broomcorn and foxtail millet were domesticated in eastern Asia before 7700 a BP, spread into eastern Central Asia between 4500 and 4000 a BP, and into western Asia and Europe prior to 3500 a BP. Wheat, barley, and millet crops were first utilized together in eastern Kazakhstan within Central Asia around 4400 a BP, the region where earliest CEPE is likely to have taken place. These crops were mixedly used mainly in eastern central Asia and northwest China between 4500 and 3500 a BP, and then across the Eurasia before 2200 a BP. The results of this study suggest that transcontinental CEPE might have been initiated during the fifth millennium, before intensifying during the Bronze Age to lay the foundations for the creation of the ancient Silk Road during the Han Dynasty(between 202 BC and 220AD). | DONG GuangHui YANG YiShi HAN JianYe WANG Hui CHEN FaHu | 2017 | Science China Earth Sciences2017，60，6： | 30 |
| 2 | Low C/N_0 Carrier Tracking Loop Based on Optimal Estimation Algorithm in GPS Software Receivers显示文摘Suppressing jitter noises in a phase locked loop(PLL) is of great importance in order to keep precise and continuous track of global positioning system(GPS) signals characterized by low carrier-to-noise ratio(C/N0).This article proposes and analyzes an improved Kalman-filter-based PLL to process weak carrier signals in GPS software receivers.After reviewing the optimal-bandwidth-based traditional second-order PLL,a Kalman-filter-based estimation algorithm is implemented for the new PLL by decorrelating the model error noises and the measurement noises.Finally,the efficiency of this new Kalman-filter-based PLL is verified by experimental data.Compared to the traditional second-order PLL,this new PLL is in position to make correct estimation of the carrier phase differences and Doppler shifts with less overshoots and noise disturbances and keeps an effective check on the disturbances out of jitter noises in PLL.The results show that during processing normal signals,this improved PLL reduces the standard deviation from 0.010 69 cycle to 0.007 63 cycle,and for weak signal processing,the phase jitter range and the Doppler shifts can be controlled within ±17° and ±5Hz as against ±25° and ±15 Hz by the traditional PLL. | Miao Jianfeng Chen Wu Sun Yongrong Liu Jianye | 2010 | Chinese Journal of Aeronautics2010，23，1： | 18 |
| 3 | Euphorbia factor L2 induces apoptosis in A549 cells through the mitochondrial pathway显示文摘Euphorbia factor L2, a lathyrane diterpenoid isolated from caper euphorbia seed(the seeds of Euphorbia lathyris L.), has been traditionally applied to treat cancer. This article focuses on the cytotoxic activity of Euphorbia factor L2 against lung carcinoma A549 cells and the mechanism by which apoptosis is induced. We analyzed the cytotoxicity and related mechanism of Euphorbia factor L2 with an MTT assay, an annexin V-FITC/PI test, a colorimetric assay, and immunoblotting. Euphorbia factor L2 showed potent cytotoxicity to A549 cells. Euphorbia factor L2 led to an increase in reactive oxygen species(ROS) generation,a loss of mitochondrial electrochemical potential, release of cytochrome c, activation of caspase-9 and caspase-3, and cleavage of poly(ADP-ribose) polymerase, suggesting that Euphorbia factor L2 induced apoptosis through a mitochondrial pathway. The cytotoxic activity of Euphorbia factor L2 in A549 cells and the related mechanisms of apoptotic induction provide support for the further investigation of caper euphorbia seeds. | Minting Lin Sili Tang Chao Zhang Hubiao Chen Wenjing Huang Yun Liu Jianye Zhang | 2017 | Acta Pharmaceutica Sinica B2017，7，1： | 14 |
| 4 | Key vacuum technology issues to be solved in evacuated tube transportation显示文摘Evacuated tube transportation(ETT) will be one of the ultra-large-scale vacuum application areas.This paper lists some key vacuum technology issues in ETT:(1) how to construct ultra-large-scale vacuum chamber with lower cost and high reliability,(2) how to evacuate gas out of the ETT tube in short time,(3) how to release heat or reduce temperature in the vacuum tube,(4) how to avoid vacuum discharge,(5) how to make vehicles with airproof shells and life support system,and(6) how to detect leaks and find leak positions efficiently.At the same time,some solutions are proposed. | Yaoping ZHANG Daryl OSTER Masayuki KUMADA Jianye YU Shengshan LI | 2011 | Journal of Modern Transportation2011，19，2： | 13 |
| 5 | Simultaneous removal of COD and nitrogen using a novel carbon-membrane aerated biofilm reactor显示文摘膜给简历电影反应堆充气了是为废水处理的一种有希望的技术。在这研究,碳膜给简历电影反应堆(CMABR ) 充气了被开发了,到同时把碳 organics 和氮从一个反应堆移开。当它与 20 h 的一水力的保留时间(HRT ) 被操作,结果证明 CMABR 有一个高化学的氧要求(货到付款) 和氮移动效率,并且它也显示出完美的表演,就算 HRT 被弄短到 12 h。在这个时期,货到付款,氨氮(NH4+-N ) ,和总氮(TN ) 的移动效率分别地到达了 86% , 94% ,和 84% 。然而,当 HRT 被弄短到 8 h, NH4+-N 和 TN 的移动效率很快衰退了。这因为非编织的纤维和很高器官的装载率上的生物资源的过多的生长。荧光原位杂交(鱼) 分析显示氧化的氨细菌(AOB ) 主要在简历电影的内部层被散布。在一部简历电影的 AOB 和 eubacteria 的共存能提高货到付款和氮的同时的移动。 | HU Shaowei YANG Fenglin SUN Cui ZHANG Jianye WANG Tonghua | 2008 | Journal of Environmental Sciences2008，20，2： | 12 |
| 6 | Novel method of improving the alignment accuracy of SINS on revolving mounting base显示文摘In the process of initial alignment for a strapdown inertial navigation system(SINS) on a stationary base,the east gyro drift rate is an important factor affecting the alignment accuracy of the azimuth misalignment angle.When the Kalman filtering algorithm is adopted in initial alignment,it yields a constant error in the estimation of the azimuth misalignment angle because the east gyro drift rate cannot be estimated.To improve the alignment accuracy,a novel alignment method on revolving mounting base is proposed.The Kalman filtering algorithm of extending the measured values is studied.The theory of spectral condition number is utilized to analyze the degrees of observability of states.Simulation results show that the estimation accuracy of the azimuth misalignment angle is greatly improved through revolving mounting base,and the proposed method is efficient in initial alignment for a medium accurate SINS. | Qian Weixing Liu Jianye Zhao Wei Zhu Yanhua | 2009 | Journal of Systems Engineering and Electronics2009，20，5： | 11 |
| 7 | Impact of one satellite outage on ARAIM depleted constellation configurations显示文摘Advanced Receiver Autonomous Integrity Monitoring(ARAIM) is a new technology that will provide worldwide coverage of vertical guidance in aviation navigation. The ARAIM performance and improvement under depleted constellations is a practical problem that needs to be faced and researched further. It is a shortcut that improves the availability in position domain whose key idea is to replace the conventional least squares process with a non-least-squares estimator to lower the integrity risk in exchange for a slight increase in nominal position error. The contributions given in this paper include two parts: First, the impacts of one satellite outage on different constellations are analyzed and compared. The conclusion is that GPS is more sensitive and vulnerable to one satellite outage. Second, a constellation weighted ARAIM(CW-ARAIM)position estimator is proposed. The position solution is replaced by a constellation weighted average solution to eliminate the constellation difference. The new solution will move close to the constellation solutions with respect to the accuracy requirement. The simulation results under baseline GPS and Galileo dual-constellation show that the one GPS satellite outage will knock the availability from 91% to only 50%. The performance remains stable with one Galileo satellite outage. With the assistance of the CW-ARAIM method, the availability can increase from 50% to more than80% under depleted GPS configurations. Even without any satellite outage, the proposed method can effectively improve the availability from 91.29% to 98.75%. The test results under optimistic constellations further verify that a balanced constellation is more important than more satellites on orbit and the superiority of CW-ARAIM method is still effective. | Qian MENG Jianye LIU Qinghua ZENG Shaojun FENG Rui XU | 2019 | Chinese Journal of Aeronautics2019，32，4： | 11 |
| 8 | Molecular Characterization of a Leaf Senescence-Related Transcription Factor BrWRKY75 of Chinese Flowering Cabbage显示文摘WRKY is a plant-specific transcription factor(TF) involved in the regulation of many biological processes; however, its role in leaf senescence of leafy vegetables remains unknown. In the present work, a WRKY TF, termed Br WRKY75 was isolated from Chinese flowering cabbage [Brassica rapa L. ssp. chinensis(L.) Mokino var. utilis Tsen et Lee]. Analysis of deduced amino acid sequence and the phylogenetic tree showed that Br WRKY75 has high homology with WRKY75 from Brassica oleracea and Arabidopsis thaliana, and belongs to the II c sub-group. Sub-cellular localization and transcriptional activity analysis revealed that Br WRKY75 is a nuclear protein with transcriptional repression activity, and was up-regulated during leaf senescence. Electrophoretic mobility shift assay confirmed that Br WRKY75 directly bound to the W-box(TTGAC) cis-element. Collectively,these results provide a basis for further investigation of the transcriptional regulation of Chinese flowering cabbage leaf senescence. | TAN Xiaoli FAN Zhongqi LI Lulu WU Ya KUANG Jianfei LU Wangjin CHEN Jianye | 2016 | Horticultural Plant Journal2016，2，5： | 11 |
| 9 | A NAC transcription factor, NOR-like1, is a new positive regulator of tomato fruit ripening显示文摘Ripening of the model fruit tomato(Solanum lycopersicum)is controlled by a transcription factor network including NAC(NAM,ATAF1/2,and CUC2)domain proteins such as No-ripening(NOR),SlNAC1,and SlNAC4,but very little is known about the NAC targets or how they regulate ripening.Here,we conducted a systematic search of fruit-expressed NAC genes and showed that silencing NOR-like1(Solyc07g063420)using virus-induced gene silencing(VIGS)inhibited specific aspects of ripening.Ripening initiation was delayed by 14 days when NOR-like1 function was inactivated by CRISPR/Cas9 and fruits showed obviously reduced ethylene production,retarded softening and chlorophyll loss,and reduced lycopene accumulation.RNA-sequencing profiling and gene promoter analysis suggested that genes involved in ethylene biosynthesis(SlACS2,SlACS4),color formation(SlGgpps2,SlSGR1),and cell wall metabolism(SlPG2a,SlPL,SlCEL2,and SlEXP1)are direct targets of NOR-like1.Electrophoretic mobility shift assays(EMSA),chromatin immunoprecipitation-quantitative PCR(ChIP-qPCR),and dual-luciferase reporter assay(DLR)confirmed that NOR-like1 bound to the promoters of these genes both in vitro and in vivo,and activated their expression.Our findings demonstrate that NOR-like1 is a new positive regulator of tomato fruit ripening,with an important role in the transcriptional regulatory network. | Ying Gao Wei Wei Xiaodan Zhao Xiaoli Tan Zhongqi Fan Yiping Zhang Yuan Jing Lanhuan Meng Benzhong Zhu Hongliang Zhu Jianye Chen Cai-Zhong Jiang Donald Grierson Yunbo Luo Da-Qi Fu | 2018 | Horticulture Research2018，5，1： | 9 |
| 10 | Study of the Surface Morphology of Gas Hydrate显示文摘Study of the surface morphology of gas hydrate is of great importance in understanding its physical properties and occurrence.In order to investigate the surface morphology of different types(sI and sII)and occurrences(pore-filling and fracture-filling)of gas hydrate,both lab-synthesized and drilled-gas hydrate samples were measured using cryo-scanning electron microscopy(cryo-SEM).Results showed that the surface of s I hydrate was relatively smooth,and spongy nano-pores(200–400 nm)gradually occurred at the surface during continuous observation.The surface of sII hydrate was more compact,showing a tier-like structure.Hydrate occurred in quartz sand and usually filled the pores of the sediments and both hydrate and sediments were cemented with each other.SEM observation of the gas hydrates collected from the South China Sea showed that the surface morphology and contact relation with sediments varied with hydrate occurrence.For instance,hydrates dispersed in sediments mainly filled the pores of the sediments.The existence of microorganism shells,such as foraminifera,was beneficial to the formation of gas hydrate.When hydrate occurred as a massive or vein structure,it was easily distinguished from the surrounding sediments.The surface of hydrate with massive or vein structure showed two distinct characters:one was dense and smooth,the other is porous(several to tens of micrometers in diameter).The occurrence of different hydrate morphologies was probably caused by the supplement rates of methane gas. | SUN Jianye LI Chengfeng HAO Xiluo LIU Changling CHEN Qiang WANG Daigang | 2020 | Journal of Ocean University of China2020，19，2： | 9 |
| 11 | Big data and machine learning in geoscience and geoengineering:Introduction显示文摘In recent years,we have entered the so-called Fourth Paradigm with the regular production of huge amount of observational data.Big data is often characterized by the three‘V's:Volume of data,Variety and Velocity.The concept of big data can potentially address some existing issues in areas of geoscience and geoengineering.Large-scale,comprehensive,multidirectional and multifield geotechnical monitoring is becoming a reality in the very near future. | Wengang Zhang Jianye Ching Anthony T.C.Goh Andy Y.F.Leung | 2021 | Geoscience Frontiers2021，12，1： | 8 |
| 12 | BubR1 phosphorylates CENP-E as a switch enabling the transition from lateral association to end-on capture of spindle microtubules显示文摘Error-free mitosis depends on accurate chromosome attachment to spindle microtubules, powered congression of those chromosomes, their segregation in anaphase, and assembly of a spindle midzone at mitotic exit. The centromere-associated kinesin motor CENP-E, whose binding partner is BubR1, has been implicated in congression of misaligned chromosomes and the transition from lateral kinetochore-microtubule association to end-on capture. Although previously proposed to be a pseudokinase, here we report the structure of the kinase domain of Drosophila melanogaster BubR1, revealing its folding into a conformation predicted to be catalytically active. BubR1 is shown to be a bona fide kinase whose phosphorylation of CENP-E switches it from a laterally attached microtubule motor to a plus-end microtubule tip tracker. Computational modeling is used to identify bubristatin as a selective BubR1 kinase antagonist that targets the αN1 helix of N-terminal extension and αC helix of the BubR1 kinase domain. Inhibition of CENP-E phosphorylation is shown to prevent proper microtubule capture at kinetochores and, surprisingly, proper assembly of the central spindle at mitotic exit. Thus, BubR1-mediated CENP-E phosphorylation produces a temporal switch that enables transition from lateral to end-on microtubule capture and organization of microtubules into stable midzone arrays. | Yuejia Huang Lin Lin Xing Liu Sheng Ye Phil Y. Yao Wenwen Wang Fengrui Yang Xinjiao Gao Junying Li Yin Zhang Jiancun Zhang Zhihong Yang Xu Liu Zhenye Yang Jianye Zang Maikun Teng Zhiyong Wang Ke Ruan Xia Ding Lin Li Don W. Cleveland Rongguang Zhang Xuebiao Yao | 2019 | Cell Research2019，29，7： | 8 |
| 13 | Characterising the nature, evolution and origin of detachment fault in central depression belt, Qiongdongnan Basin of South China Sea: evidence from seismic reflection data显示文摘Using regional geological, newly acquired 2D and 3D seismic, drilling and well log data, especially 2D long cable seismic profiles, the structure and stratigraphy in the deep-water area of Qiongdongnan Basin are interpreted. The geometry of No.2 fault system is also re-defined, which is an important fault in the central depression belt of the deep-water area in the Qiongdongnan Basin by employing the quantitative analysis techniques of fault activity and backstripping. Furthermore, the dynamical evolution of the No.2 fault system and its controls on the central depression belt are analyzed. This study indicates that the Qiongdongnan Basin was strongly influenced by the NW-trending tensile stress field during the Late Eocene. At this time, No.2 fault system initiated and was characterized by several discontinuous fault segments, which controlled a series small NE-trending fault basins. During the Oligocene, the regional extensional stress field changed from NW-SE to SN with the oceanic spreading of South China Sea, the early small faults started to grow along their strikes, eventually connected and merged as the listric shape of the No.2 fault system as observed today. No.2 fault detaches along the crustal Moho surface in the deep domain of the seismic profiles as a large-scale detachment fault. A large-scale rollover anticline formed in hanging wall of the detachment fault. There are a series of small fault basins in both limbs of the rollover anticline, showing that the early small basins were involved into fold deformation of the rollover anticline. Structurally, from west to east, the central depression belt is characterized by alternatively arranged graben and half-graben. The central depression belt of the Qiongdongnan Basin lies at the extension zone of the tip of the V-shaped northwestern ocean sub-basin of the South China Sea, its activity period is the same as the development period of the northwestern ocean sub-basin, furthermore the emplacement and eruption of magma that originated from the mantle below the Moho surface occurred at the region between Songnan-Baodao and Changchang sags, from east to west with the early-stage spreading of the South China Sea. Therefore, this study not only helps in depicting the structural features and evolution of the deep-water basin in the Qiongdongnan Basin, but also provides the geological and structural evidence for establishing a unified model of continental margin extension and oceanic spreading. | REN Jianye ZHANG Daojun TONG Dianjun HUANG Anmin WANG Yahui LEI Chao ZUO Qianmei ZHAO Yanghui HE Weijun YANG Linlong | 2014 | Acta Oceanologica Sinica2014，33，12： | 8 |
| 14 | Tectonic-Hydrocarbon Accumulation of Laoyemiao Region in the Nanpu Sag,Bohai Bay Basin显示文摘This paper aims to gain insight into Laoyemiao(LYM) tectonic features and utilizes the tectonic-hydrocarbon accumulation model by integrated analysis tectonic controls on suitable reservoirs,trap styles,and hydrocarbon migration.On the basis of 3-D seismic data interpretation and the Xi'nanzhuang(XNZ) Fault geometry analysis,it has been assessed that the LYM tectonics is essentially a transverse anticline produced by flexure of the XNZ Fault surface and superimposed by Neocene north-east-trending strike-slip faults.Transverse anticline is found to exert controls both on major sediment transportation pathways and sedimentary facies distribution.Fan-delta plains that accumulated on the anticline crest near the XNZ Fault scrap and fan-delta front on the anticline front and the upper part of both limbs slumps on synclines and the Linque subsag.In combination with the reservoir properties,suitable reservoirs are predicted in the subfacies of subaqueous distributary channel and mouth bar deposited on the anticline crest.The LYM-faulted anticline accounts for the following trap groups:faulted-block and anticline-dominated trap,fault-dominated traps,and combined and stratigraphic traps.Evidence from biomarkers of crude oil and hydrocarbon-filling period simultaneous,or a little later to the strike-slip fault activity,reveal that the strike-slip faults penetrating into the deep source rock,by connecting with shallow reservoirs,provide the major hydrocarbon migration pathways. | ZHANG Cuimei LIU Xiaofeng REN Jianye | 2009 | Acta Geologica Sinica(English Edition)2009，83，5： | 8 |
| 15 | Validation of dynamic cavitation model for unsteady cavitating flow on NACA66显示文摘Unsteady cavitating flow is extremely complicated and brings more serious damages and unignorable problems compared with steady cavitating flow.CFD has become a practical way to model cavitation;however,the popularly used full cavitation model cannot reflect the pressure-change that the bubble experiences during its life path in the highly unsteady flow like cloud cavitating.Thus a dynamic cavitation model(DCM)is proposed and it has been considered to have not only the first-order pressure effects but also zero-order effect and can provide greater insight into the physical process of bubble producing,developing and collapsing compared to the traditional cavitation model.DCM has already been validated for steady cavitating flow,and the results were reported.Furthermore,DCM is designed and supposed to be more accurate and efficient in modeling unsteady cavitating flow,which is also the purpose of this paper.The basic characteristic of the unsteady cavitating flow,such as the vapor volume fraction distribution and the evolution of pressure amplitude and frequency at different locations of the hydrofoil,are carefully studied to validate DCM.It is found that not only these characteristics mentioned above accord well with the experimental results,but also some detailed transient flow information is depicted,including the re-entrant jet flow that caused the shedding of the cavity,and the phenomenon of two-peak pressure fluctuation in the vicinity of the cavity closure in a cycle.The numerical results validate the capability of DCM for the application of modeling the complicated unsteady cavitating flow. | ZHANG XiaoBin ZHANG Wei CHEN JianYe QIU LiMin SUN DaMing | 2014 | Science China(Technological Sciences)2014，57，4： | 8 |
| 16 | The periodic law of trace elements in coal——A case study of the 5~# coal from the Weibei Coalfield显示文摘To better understand the 5# coal (late Paleozoic) from the Weibei Coalfield, nine samples were collected in different locations of the 5# coal seam. The correlation coefficients between 51 trace elements including organic carbon, as well as ash, were calculated by statistical method. The variations of the squares of correlation coefficients with the first ionization energy, as well as ion radii of the corresponding elements, were comparetively investigated. The results show that the distribution law of the trace elements is in accordance with the chemical element periodic law and can be theoretically explained in detail. The distribution law is also suitable to the stable coal layer formed under the function of the coal accumulation, such as that in the Ordos Basin. | YANG JianYe | 2011 | Science China Earth Sciences2011，54，10： | 7 |
| 17 | Overactive bladder symptom score to evaluate efficacy of solifenacin for the treatment of overactive bladder symptoms显示文摘 | Liu Ming Wang Jianye Yang Yong An Ruihua Wen Jianguo Guan Zhichen Zheng Shaobin Wang Dongwen Song Bo Liao Limin Guo Hongqian Xiao Jiaquan Sun Yinghao Shen Zhoujun Kong Chuize He Dalin Huang Yiran Wang Xiaofeng Zhang Xu Li Hanzhong Huang Jian Zhao Xiaokun Zeng Puqing Song Xishuang Ye Zhangqun | 2014 | Chinese Medical Journal2014，，2： | 7 |
| 18 | Influence of foraminifera on formation and occurrence characteristics of natural gas hydrates in fine-grained sediments from Shenhu area, South China Sea显示文摘Marine gas hydrates accumulate primarily in coarse-grained, high-permeability layers; however, highly saturated natural gas hydrates have been discovered in the fine-grained sediments of Shenhu area, South China Sea(SCS). This may be explained by key factors, such as the great abundance of foraminifera shells. In this paper, by analyzing the SCS foraminifera structure and performing hydrate formation experiments in the foraminifera shells, the contribution of foraminifera to hydrate accumulation in the SCS was investigated from a microscopic point of view. Simulations of hydrate formation were carried out in both pure SCS foraminifera shells and the host sediments. Pore structures in typical foraminifera were studied by use of micro-focus X-ray computed tomography(CT) and scanning electron microscopy(SEM). Hydrate growth and occurrence characteristics in the foraminifera shells were observed in-situ. The results showed that the presence of foraminifera significantly enhanced the effective porosity of the SCS sediments. Moreover, while the hydrates grew preferentially in the chambers of the coarse-grained foraminifera by adhering to the inner walls of the foraminifera shells, no apparent hydrate accumulation was observed in the fine-grained or argillaceous matrix. These findings provide a basis for further studies on the accumulation mechanism of hydrates and physical properties of hydrate reservoir in the South China Sea. | LI ChengFeng HU GaoWei ZHANG Wei YE YuGuang LIU ChangLing LI Qing SUN JianYe | 2016 | Science China Earth Sciences2016，59，11： | 7 |
| 19 | Comparison of Modified Mohr-Coulomb Model and Bai-Wierzbicki Model for Constructing 3D Ductile Fracture Envelope of AA6063显示文摘Ductile fracture of metal often occurs in the plastic forming process of parts.The establishment of ductile fracture criterion can effectively guide the selection of process parameters and avoid ductile fracture of parts during machining.The 3D ductile fracture envelope of AA6063-T6 was developed to predict and prevent its fracture.Smooth round bar tension tests were performed to characterize the flow stress,and a series of experiments were conducted to characterize the ductile fracture firstly,such as notched round bar tension tests,compression tests and torsion tests.These tests cover a wide range of stress triaxiality(ST)and Lode parameter(LP)to calibrate the ductile fracture criterion.Plasticity modeling was performed,and the predicted results were compared with corresponding experimental data to verify the plasticity model after these experiments.Then the relationship between ductile fracture strain and ST with LP was constructed using the modified Mohr-Coulomb(MMC)model and Bai-Wierzbicki(BW)model to develop the 3D ductile fracture envelope.Finally,two ductile damage models were proposed based on the 3D fracture envelope of AA6063.Through the comparison of the two models,it was found that BW model had better fitting effect,and the sum of squares of residual error of BW model was 0.9901.The two models had relatively large errors in predicting the fracture strain of SRB tensile test and torsion test,but both of the predicting error of both two models were within the acceptable range of 15%.In the process of finite element simulation,the evolution process of ductile fracture can be well simulated by the two models.However,BW model can predict the location of fracture more accurately than MMC model. | Jianye Gao Tao He Yuanming Huo Miao Song Tingting Yao Wanbo Yang | 2021 | Chinese Journal of Mechanical Engineering2021，34，2： | 6 |
| 20 | Ambient noise surface wave tomography of marginal seas in east Asia显示文摘We conducted ambient noise tomography in east Asia, including the Chinese coastal provinces, Korea Peninsular, Japan,Taiwan Island, and marginal seas in between. We retrieved Rayleigh Green's functions from inter-station correlations of 12 months of continuous waveform data at 573 broadband stations in the region. We obtained group and phase velocity dispersion curves and dispersion maps for periods from 10 to 70 s and inverted for 3D Vs model of the crust and uppermost mantle. Moho and lithosphere thickness were derived from the 3D model. We observed three prominent low velocity zones in the upper mantle, two in the accretionary wedges above the Pacific and Philippine subduction slabs and one beneath the Changbai Mountain region. The crust and lithosphere are generally thin in the region. The velocity anomalies, crustal thickness, and lithosphere thickness all show a similar trend in NNE-SSW direction. The lithosphere shows a striking ' sausage'-type structure with alternating thickness. The crust thickness and lithosphere thickness both decrease progressively from NW to SE direction, which coincides with the distribution of episodic magmatism in SE China.We propose that the subduction of paleo-Pacific slab and its rollback were mainly responsible for the crustal and lithosphere extension and the mantle lithosphere removal in east Asia. | Qing Wang XiaoDong Song JianYe Ren | 2017 | Earth and Planetary Physics2017，1，1： | 6 |
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