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24篇 您的检索式:作者名="He Siming"
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1Seismically Induced Slope Instabilities and the Corresponding Treatments:the Case of a Road in the Wenchuan Earthquake Hit Region显示文摘On May 12, 2008, a magnitude 8.0 earthquake hit Wenchuan County, Sichuan Province resulted in great loss of life and properties.Besides, abundant landslides and slope failures were triggered in the most seriously hit areas and caused disastrous damages to infrastructures and public facilities.Moreover, abundant unstable slopes caused by the quake have the potential to cause damages for a considerable long period of time.The variety of these slopes and the corresponding treatments are connected with the topographical and geological conditions of the sites.It is decided to document and identify some of these major slope instabilities caused by the earthquake and their treatments.The paper shows the condition of a road in Dujiangyan through in situ explorations.The case history showed significant implications to the reconstruction of the quake-hit regions and future disaster prevention and management works.LI Xinpo HE Siming 2009Journal of Mountain Science2009,6,1:22
2Discrete Element Modeling of Debris Avalanche Impact on Retaining Walls显示文摘In China,gravity retaining walls are widely used as protection structures against rockfalls,debris flows and debris avalanches along the roads in mountainous areas.In this paper,the Discrete Element Method(DEM) has been used to investigate the impact of granular avalanches and debris flows on retaining walls.The debris is modeled as two dimensional circular disks that interact through frictional sliding contacts.The basic equations that control the deformation and motion of the particles are introduced.A series of numerical experiments were conducted on an idealized debris slide impacting a retaining wall.The parametric study has been performed to examine the influences of slope geometry,travel distance of the sliding mass,wall position,and surface friction on the impact force exerted on the wall.Results show that:1) the force achieves its maximum value when slope angle is equal to 60°,as it varies from 30° to 75°;2) an approximate linear relationship between the impact force and the storage area length is determined.LI Xinpo HE Siming LUO Yu WU Yong 2010Journal of Mountain Science2010,7,3:12
3Study on the Rainfall and Aftershock Threshold for Debris Flow of Post-earthquake显示文摘Due to the special condition of provenance and disaster environment after '5·12' Earthquake, the probability and conditions of the occurrence of gully debris flow change greatly after the event, which make it difficult to prevent disaster effectively. In this study the hydrological model of ground water table in loose sediment is established. According to infinite slope theory, the safety factor of deposits is defined as the ratio of resistance force to driving force. The starting condition of post-earthquake gully debris flow is clearly studied by analyzing the effects of rainfall intensity, seismic strength, slope gradient and mechanical properties on the balance of accumulation body. Then the formulas of rainfall and aftershock threshold for starting of gully debris flow are proposed, and an example is given to illustrate the effect of rainfall, aftershocks and their coupling action on a debris flow. The result shows the critical rainfall intensity decreases as the lateral seismic acceleration and channel gradient increases, while the critical intensity linearly increases as the friction angle increases.HE Siming LI Dexin WU Yong LUO Yu 2011Journal of Mountain Science2011,8,5:7
4GIS-based Earthquake-Triggered Landslide Hazard Zoning Using Contributing Weight Model显示文摘Earthquake-triggered landslides have aroused widespread attention because of their tremendous ability to harm people's lives and properties.The best way to avoid and mitigate their damage is to develop landslide hazard maps and make them available to the public in advance of an earthquake.Future construction can then be built according to the level of hazard and existing structures can be retrofit as necessary.During recent years various approaches have been made to develop landslide hazard maps using statistical analysis or physical models.However,these methods have limitations.This study introduces a new GIS-based approach,using the contributing weight model,to evaluate the hazard of seismically-induced landslides.In this study,the city and surrounding area of Dujiangyan was selected as the research area because of its moderate-high seismic activity.The parameters incorporated into the model that related to the probability of landslide occurrence were:slope gradient,slope aspect,geomorphology,lithology,base level,surface roughness,earthquake intensity,fault proximity,drainage proximity,and road proximity.The parameters were converted into raster data format with a resolution of 25×25m2 pixels.Analysis of the GIS correlations shows that the highest earthquake-induced landslide hazard areas are mainly in the hills and in some of the moderately steep mountainous areas of central Dujiangyan.The highest hazard zone covers an area of 11.1% of the study area,and the density distribution of seismically-induced landslides was 3.025/km2 from the 2008 Wenchuan earthquake.The moderately hazardous areas are mainly distributed within the moderately steep mountainous regions of the northern and southeastern parts of the study area and the hills of the northeastern part;covering 32.0% of the study area and with a density distribution of 2.123/km2 resulting from the Wenchuan earthquake.The lowest hazard areas are mainly distributed in the topographically flat plain in the northeastern part and some of the relatively gently slopes in the moderately steep mountainous areas of the northern part of Dujiangyan and the surrounding area.The lowest hazard areas cover 56.9% of the study area and exhibited landslide densities of 0.941/km2 and less from the Wenchuan earthquake.The quality of the hazard map was validated using a comparison with the distribution of landslides that were cataloged as occurring from the Wenchuan earthquake.43.1% of the study area consists of high and moderate hazardous zones,and these regions include 83.5% of landslides caused by the Wenchuan earthquake.The successful analysis shows that the contributing weight model can be effective for earthquake-triggered landslide hazard appraisal.The model's results can provide the basis for risk management and regional planning is.WANG Meng 2010Journal of Mountain Science2010,7,4:6
5Cellulose fibers-reinforced self-expanding porous composite with multiple hemostatic efficacy and shape adaptability for uncontrollable massive hemorrhage treatment显示文摘Uncontrollable hemorrhage leads to high mortality and thus effective bleeding control becomes increasingly important in the military field and civilian trauma arena.However,current hemostats not only present limitation when treating major bleeding,but also have various side effects.Here we report a self-expanding porous composites(CMCP)based on novel carboxymethyl cellulose(CMC)fibers and acetalized polyvinyl alcohol(PVA)for lethal hemorrhage control.The CMC fibers with uniform fibrous structure,high liquid absorption and procoagulant ability,are evenly interspersed inside the composite matrix.The obtained composites possess unique fiber-porous network,excellent absorption capacity,fast liquid-triggered self-expanding ability and robust fatigue resistance,and their physicochemical performance can be fine-tuned through varying the CMC content.In vitro tests show that the porous composite exhibits strong blood clotting ability,high adhesion to blood cells and protein,and the ability to activate platelet and the coagulation system.In vivo hemostatic evaluation further confirms that the CMCP presents high hemostatic efficacy and multiple hemostatic effects in swine femoral artery major hemorrhage model.Additionally,the CMCP will not fall off from the injury site,and is also easy to surgically remove from the wound cavity after the hemostasis.Importantly,results of CT tomography and 3D reconstruction indicate that CMCP can achieve shape adaptation to the surrounding tissues and the wound cavities with different depths and shapes,to accelerate hemostasis while protecting wound tissue and preventing infection.Yansen Wang Yifan Zhao Longxue Qiao Faxing Zou Yajie Xie Yudong Zheng Yong Chao Ying Yang Wei He Siming Yang 2021Bioactive Materials2021,6,7:6
6Xeno-repopulation of Fah^(-/-)Nod/Scid mice livers by human hepatocytes显示文摘Functional human hepatocytes xenografted into the liver of mice can be used as a model system to study pharmacokinetics,infection of hepatitis viruses,and the efficacy of hepatitis vaccines.Significant levels of liver xeno-repopulation have been reported in Fah-/-Rag2-/-Il2rg-/-mice.However,the high mortality and low breeding rate of this model may hinder its application.A new model,termed Fah-/-Nod/Scid mice,which combines the advantages of liver repopulation in Fah-/-mice with the ease of xenotransplantation in Nod/Scid mice was obtained by gradual cross-breeding.Fah-/-Nod/Scid mice were easily maintained in breeding colonies and in adult animal care facilities.FK506 treatment combined with gradual withdrawal of NTBC before cell transplantation ensured that Fah-/-Nod/Scid mice were susceptible to liver xeno-repopulation by human hepatocytes;the proportion of engrafted human hepatocytes reached 33.6%.The function of the expanded human hepatocytes within the chimeric liver was confirmed by weight curve analysis,the expression of characteristic proteins,and the biochemical analysis of liver function.These results show that Fah-/-Nod/Scid mice are an ideal humanized liver mouse model with many useful applications.SU BaoLiang LIU ChangCheng XIANG Dao ZHANG HaiBin YUAN SiMing WANG MinJun CHEN Fei ZHU HaiYing HE ZhiYing WANG Xin HU YiPing 2011Science China(Life Sciences)2011,54,3:5
7Coupled Model of Two-phase Debris Flow,Sediment Transport and Morphological Evolution显示文摘The volume fraction of the solid and liquid phase of debris flows,which evolves simultaneously across terrains,largely determines the dynamic property of debris flows. The entrainment process significantly influences the amplitude of the volume fraction. In this paper,we present a depth-averaged two-phase debris-flow model describing the simultaneous evolution of the phase velocity and depth,the solid and fluid volume fractions and the bed morphological evolution. The model employs the Mohr–Coulomb plasticity for the solid stress,and the fluid stress is modeled as a Newtonian viscous stress. The interfacial momentum transfer includes viscous drag and buoyancy. A new extended entrainment rate formula that satisfies the boundary momentum jump condition(Iverson and Ouyang,2015) is presented. In this formula,the basal traction stress is a function of the solid volume fraction and can take advantage of both the Coulomb and velocity-dependent friction models. A finite volume method using Roe's Riemann approximation is suggested to solve the equations. Three computational cases are conducted and compared with experiments or previous results. The results show that the current computational model and framework are robust and suitable for capturing the characteristics of debris flows.HE Siming OUYANG Chaojun LIU Wei WANG Dongpo 2016Acta Geologica Sinica(English Edition)2016,90,6:5
8Two-dimensional Dynamics Simulation of Two-phase Debris Flow显示文摘To investigate the movement mechanism of debris flow, a two-dimensional, two-phase, depthintegrated model is introduced. The model uses Mohr-Coulomb plasticity for the solid rheology, and the fluid stress is modeled as a Newtonian fluid. The interaction between solid and liquid phases, which plays a major role in debris flow movement, is assumed to consist of drag and buoyancy forces. The applicability of drag force formulas is discussed. Considering the complex interaction between debris flow and the bed surface, a combined friction boundary condition is imposed on the bottom, and this is also discussed. To solve the complex model equations, a numerical method with second-order accuracy based on the finite volume method is proposed. Several numerical experiments are performed to verify the feasibilities of model and numerical schemes. Numerical results demonstrate that different solid volume fractions substantially affect debris flow movement.LIU Wei HE Siming OUYANG Chaojun 2017Acta Geologica Sinica(English Edition)2017,91,5:2
9Failure Mechanisms of Post-Earthquake Bedrock Landslides in Response to Rainfall Infiltration显示文摘Among the triggering factors of post-earthquake bedrock landslides,rainfall plays an important role.However,with slope variation,the mechanism of its effects on the failure of rock landslides is not clear.Here,from the viewpoint of fracture mechanics,and based on post-earthquake conditions,the mechanisms of crack propagation,water infiltration and development of the sliding surface were investigated.Then,according to the upper boundary theorem,the effects of water infiltrated into fractures on the stability of rock slopes were analyzed quantitatively.Finally,an example is presented to verify the theory.The results show that the propagation and coalescence of cracks and the lubrication of incipient sliding surfaces are the main causes of the failure of post-earthquake rock landslides in response to rainfall.WU Yong HE Siming LUO Yu LI Xinpo 2011Journal of Mountain Science2011,8,1:2
10Effects of cyclic dynamic loading onthe mechanical properties of intact rock samples under confiningpressure conditions显示文摘LIU Enlong HE Siming 2012Engineering Geology2012,125,:1
11Effects of cyclic dynamic loading on the mechanical properties of intact rock samples under confining pressure conditions 显示文摘Liu Enlong He Siming 2012Engineering Geology2012,125,:1
12Seismic stability analysis of gravity retaining walls 显示文摘Li Xinpo Wu Yong He Siming 2010Soil Dynamics and Earthquake Engineering2010,30,10:1
13Development of 240 novel EST-SSRs in Eucalyptus L’Hérit显示文摘Changpin Zhou Xudong He Fagen Li Qijie Weng Xiaoli Yu Yu Wang Mei Li Jisen Shi Siming Gan 2014Molecular Breeding2014,,:1
14Hydraulic mechanism and time-dependent characteristics of loose gully deposits failure induced by rainfall显示文摘Failure of loose gully deposits under the effect of rainfall contributes to the potential risk of debris flow.In the past decades,researches on hydraulic mechanism and time-dependent characteristics of loose deposits failure are frequently reported,however adequate measures for reducing debris flow are not available practically.In this context,a time-dependent model was established to determine the changes of water table of loose deposits using hydraulic and topographic theories.In addition,the variation in water table with elapsed time was analyzed.The formulas for calculating hydrodynamic and hydrostatic pressures on each strip and block unit of deposit were proposed,and the slope stability and failure risk of the loose deposits were assessed based on the time-dependent hydraulic characteristics of established model.Finally,the failure mechanism of deposits based on infinite slope theory was illustrated,with an example,to calculate sliding force,anti-sliding force and residual sliding force applied to each slice.The results indicate that failure of gully deposits under the effect of rainfall is the result of continuously increasing hydraulic pressure and water table.The time-dependent characteristics of loose deposit failure are determined by the factors of hydraulic properties,drainage area of interest,rainfall pattern,rainfall duration and intensity.Yong Wu Siming He 2015Journal of Rock Mechanics and Geotechnical Engineering2015,7,6:1
15The cost effectiveness ofbevacizumab when added to capecitabine, with or without mitomycin-C, in first line treatment of metastatic colorectal cancer: results from the Australasian phase III MAX study显示文摘Carter HE Zannino D John Simes R 2014Eur J Cancer2014,50,3:1
16Study on mechanism of fiber grouted material in pre-stressed anchor rope显示文摘The fiber grouted material can reinforce the tension strength, shear strength as well as the index of fracture ductile, and remarkably improve the endurance of pre-stressed anchor rope under long-time loading. As a result, it has the better application foreground. Based on the shear log model and Hashin-Shtrikman upper and lower limited theorem, we have studied the mechanism of fiber grouted material applied in pre-stressed anchor rope and material property, and analyzed the effect of resistance strength of bond, resistance distribution of anchor section and the loading-deformation relationship of anchor body.HE Siming, QIAO Jianping & WANG Chenghua Institute of Mountain Hazards and Environment, Chinese Academy of Sciences and Ministry of Water Resources, Chengdu 610041, China 2003Science China(Technological Sciences)2003,46,z1:1
17A loss-of-function mutant allele of a glycosyl hydrolase gene has been co-opted for seed weight control during soybean domestication显示文摘The resultant DNA from loss-of-function mutation can be recruited in biological evolution and development.Here,we present such a rare and potential case of“to gain by loss”as a neomorphic mutation during soybean domestication for increasing seed weight.Using a population derived from a chromosome segment substitution line of Glycine max(SN14)and Glycine soja(ZYD06),a quantitative trait locus(QTL)of 100-seed weight(q HSW)was mapped on chromosome 11,corresponding to a truncatedβ-1,3-glucosidase(βGlu)gene.The novel gene hsw results from a 14-bp deletion,causing a frameshift mutation and a premature stop codon in theβGlu.In contrast to HSW,the hsw completely lostβGlu activity and function but acquired a novel function to promote cell expansion,thus increasing seed weight.Overexpressing hsw instead of HSW produced large soybean seeds,and surprisingly,truncating hsw via gene editing further increased the seed size.We further found that the core 21-aa peptide of hsw and its variants acted as a promoter of seed size.Transcriptomic variation in these transgenic soybean lines substantiated the integration hsw into cell and seed size control.Moreover,the hsw allele underwent selection and expansion during soybean domestication and improvement.Our work cloned a likely domesticated QTL controlling soybean seed weight,revealed a novel genetic variation and mechanism in soybean domestication,and provided new insight into crop domestication and breeding,and plant evolution.Siming Wei Bin Yong Hongwei Jiang Zhenghong An Yan Wang Bingbing Li Ce Yang Weiwei Zhu Qingshan Chen Chaoying He 2023Journal of Integrative Plant Biology2023,65,11:1
18Effects of cyclic dynamic loading on the mechanical properties of intact rock samples under confining pressure conditions显示文摘Enlong Liu Siming He 2011Engineering Geology2011,,:1
19Dynamic-simulation of landslide based on thermo-poro-elastic approach显示文摘Siming He Wei Iiu Juan Wang 2015Com- puters & Geosciences2015,75,:1
20Effects of cyclic dynamic loading on the mechanical properties of intact rock samples under confining pressure conditions显示文摘Enlong Liu Siming He 2011Engineering Geology2011,,:1
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