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Experimental study on compaction-induced anisotropic mechanical property of rockfill material

Frontiers of Structural and Civil Engineering 2021年第1期15卷 109-123页

作者： Xiangtao ZHANG Yizhao GAO yuan WANG yu-zhen yu Xun SUN State Key Laboratory of Hydroscience and Engineering Department of Hydraulic EngineeringTsinghua UniversityBeijing 100084China

The anisotropy of rockfill materials has a significant influence on the performance of engineering ***,relevant research data are very limited,because of the difficulty with preparing specimens with different inclination angles using traditional ***,the anisotropy test of rockfill materials is complex and complicated,especially for triaxial tests,in which the major principal stress plane intersects with the compaction plane at different *** this study,the geometric characteristics of a typical particle fraction consisting of a specific rockfill material were statistically investigated,and the distribution characteristics of particle orientation in specimens prepared via different compaction methods were *** high-density rockfill materials,a set of specimen preparation devices for inclined compaction planes was developed,and a series of conventional triaxial compression tests with different principal stress direction angles were *** results reveal that the principal stress direction angle has a significant effect on the modulus,shear strength,and dilatancy of the compacted rockfill *** of the relationship between the principal stress direction angles,change in the stress state,and change in the corresponding dominant shear plane shows that the angle between the compacted surface and dominant shear plane is closely related to interlocking resistance associated with the particle *** addition,different principal stress direction angles can change the extent of the particle interlocking effect,causing the specimen to exhibit different degrees of anisotropy.

关键词： rockfill inclination of specimen preparation anisotropy mechanical property mechanism

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Generation of 3D random meso-structure of soil-rock mixture and its meso-structural mechanics based on numerical tests

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Journal of Central South University 2015年第2期22卷 619-630页

作者：徐文杰张海洋介玉新于玉贞 State Key Laboratory of Hydroscience and Hydraulic Engineering(Department of Hydraulic Engineering Tsinghua University)

The mesoscopic failure mechanism and the macro-mechanical characteristics of soil-rock mixture(S-RM) under external load are largely controlled by S-RM's meso-structural features. The objective of this work is to improve the three-dimensional technology for the generation of the random meso-structural models of S-RM, for randomly generating irregular rock blocks in S-RM with different shapes, sizes, and distributions according to the characteristics of the rock blocks' size distribution. Based on the new improved technology, a software system named as R-SRM3 D for generation and visualization of S-RM is developed. Using R-SRM3 D, a three-dimensional meso-structural model of S-RM is generated and used to study the meso-mechanical behavior through a series of true-triaxial numerical tests. From the numerical tests, the following conclusions are obtained. The meso-stress field of S-RM is influenced by the distribution of the internal rock blocks, and the macro-mechanical characteristics of S-RM are anisotropic in 3D; the intermediate principal stress and the soil-rock interface properties have significant influence on the macro strength of S-RM.

关键词： soil-rock mixture(S-RM) three dimensional meso-structure meso-structural mechanics(M-SM) true-triaxial numerical test random simulation

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Severe bile duct complication after yttrium-90 radioembolization therapy in a patient with recurrent hepatocellular carcinoma after liver transplantation: A case report

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Liver Research 2021年第1期5卷 33-35页

作者： Jian-Wen Zhang zhen-yu yu Hai-Bo Li Shu-Hong Yi Wei Liu Yang Yang Guo-Ying Wang Department of Hepatic Surgery and Liver Transplantation Center The Third Affiliated Hospital of Sun Yat-sen UniversityGuangzhouChina Organ Transplantation Institute of Sun Yat-sen University GuangzhouChina Organ Transplantation Research Center of Guangdong Province GuangzhouChina Guangdong Key Laboratory of Liver Disease Research The Third Affiliated Hospital of Sun Yat-sen UniversityGuangzhouChina

Patients with recurrent hepatocellular carcinoma(HCC)following liver transplantation(LT)have a poor prognosis owing to rapid tumor ***-90 radioembolization(^(90)Y-RE)has been shown to be a safe and efficacious transarterial radioembolization treatment for patients with advanced ***,to our knowledge,no data are available for patients with recurrent HCC following *** we report a case of severe bile duct complication after transarterial radioembolization with yttrium-90 in a patient who experienced HCC recurrence following *** present case suggests that ^(90)Y-RE should be cautiously performed in patients with recurrent HCC following LT.

关键词： Hepatocellular carcinoma(HCC) Post-liver transplant Yttrium-90 radioembolization(^(90)Y-RE) Complication

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Effects of Soil Aeration on Sweet Potato Yield and Its Physiological Mechanism

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Agricultural Sciences in China 2002年第2期1卷 189-194页

作者： SHI Chun-yu,WANG zhen-lin and yu Song-lie(College of Agronomy, Shandong Agricultural University, Taian 271018) College of Agronomy Shandong Agricultural University Taian 271018

The effects of soil aeration on physiological characters and root tuber yield of Ipomoea batatas (L.) Lam. CV Lushu7 and Xushu18 were studied. The results showed that soil aeration improvement could increase ATP content and ATPase activity in functional leaves and root tubers and ABA content in root tubers. It also accelerated the transportation of 14C-photosynthate from leaves to root tubers and enhanced dry matter distribution in root tubers and thus root tuber yield was significantly raised. The role of ATP, ATPase and ABA in accelerating the transportation of 14C-photosynthate was discussed based on the changes of soluble carbonhydrate content in sweet potato plant.

关键词： Sweet potato Soil aeration Root tuber yield Physiological peculiarity

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Simulation of three-dimensional tension-induced cracks based on cracking potential function-incorporated extended finite element method

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Journal of Central South University 2021年第1期28卷 235-246页

作者： WANG Xiang-nan yu Peng ZHANG Xiang-tao yu Jia-lin HAO Qing-shuo LI Quan-ming yu yu-zhen State Key Laboratory of Hydroscience and Engineering Tsinghua UniversityBeijing 100084China China Renewable Energy Engineering Institute Beijing 100120China China Academy of Safety Science and Technology Beijing 100012China

In the finite element method,the numerical simulation of three-dimensional crack propagation is relatively rare,and it is often realized by commercial *** addition to the geometric complexity,the determination of the cracking direction constitutes a great *** most cases,the local stress state provides the fundamental criterion to judge the presence of cracks and the direction of crack ***,in the case of three-dimensional analysis,the coordination relationship between grid elements due to occurrence of cracks becomes a difficult problem for this *** this paper,based on the extended finite element method,the stress-related function field is introduced into the calculation domain,and then the boundary value problem of the function is ***,the envelope surface of all propagation directions can be obtained at one *** last,the possible surface can be selected as the direction of crack *** on the aforementioned procedure,such method greatly reduces the programming complexity of tracking the crack *** a suitable method for simulating tension-induced failure,it can simulate multiple cracks simultaneously.

关键词： extended finite element method crack three-dimensional calculation cracking potential function tensile failure

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Dynamic Regulation of Hydrogen Bonding Networks and Solvation Structures for Synergistic Solar‑Thermal Desalination of Seawater and Catalytic Degradation of Organic Pollutants

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Nano-Micro Letters 2025年第2期17卷 548-565页

作者： Ming‑yuan yu Jing Wu Guang Yin Fan‑zhen Jiao Zhong‑zhen yu Jin Qu Beijing Key Laboratory of Advanced Functional Polymer Composites Beijing University of Chemical TechnologyBeijing 100029People’s Republic of China State Key Laboratory of Organic‑Inorganic Composites College of Materials Science and EngineeringBeijing University of Chemical TechnologyBeijing 100029People’s Republic of China

Although solar steam generation strategy is efficient in desalinating seawater,it is still challenging to achieve continuous solar-thermal desalination of seawater and catalytic degradation of organic ***,dynamic regulations of hydrogen bonding networks and solvation structures are realized by designing an asymmetric bilayer membrane consisting of a bacterial cellulose/carbon nanotube/Co_(2)(OH)_(2)CO_(3)nanorod top layer and a bacterial cellulose/Co_(2)(OH)_(2)CO_(3)nanorod(BCH)bottom ***,the hydrogen bonding networks inside the membrane can be tuned by the rich surface–OH groups of the bacterial cellulose and Co_(2)(OH)_(2)CO_(3)as well as the ions and radicals in situ generated during the catalysis ***,both SO_(4)^(2−)and HSO_(5)−can regulate the solvation structure of Na^(+)and be adsorbed more preferentially on the evaporation surface than Cl^(−),thus hindering the de-solvation of the solvated Na^(+)and subsequent nucleation/growth of ***,the heat generated by the solar-thermal energy conversion can accelerate the reaction kinetics and enhance the catalytic degradation *** work provides a flow-bed water purification system with an asymmetric solar-thermal and catalytic membrane for synergistic solar thermal desalination of seawater/brine and catalytic degradation of organic pollutants.

关键词： Solar steam generation Seawater desalination Catalytic degradation Bacterial cellulose Cobalt hydroxycarbonate nanorods

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城轨列车制动模型及参数辨识

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铁道学报 2011年第10期33卷 37-40页

作者：于振宇陈德旺北京交通大学轨道交通控制与安全国家重点实验室北京100044

列车制动模型是设计ATO精确停车控制策略的依据。本文通过分析城轨列车制动系统的构成、特性及其和驾驶员的接口,从面向控制的角度提出适合控制器设计的制动模型以及模型参数的辨识方法。现场实验表明:该模型能够较好描述城轨列车制动... 详细信息

列车制动模型是设计ATO精确停车控制策略的依据。本文通过分析城轨列车制动系统的构成、特性及其和驾驶员的接口,从面向控制的角度提出适合控制器设计的制动模型以及模型参数的辨识方法。现场实验表明:该模型能够较好描述城轨列车制动系统的动态特性,并且基于该模型的自动停车控制系统在实验中也取得了满意的性能。

关键词：制动模型参数辨识城轨列车 ATO

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Application of Improved PSO Algorithm in Hydraulic Pressing System Identification

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Journal of Iron and Steel Research International 2012年第9期19卷 29-35页

作者： yu yu-zhen 1 , 2 , REN Xin-yi 2 , DU Feng-shan 2 , SHI Jun-jie 2 ( 1.Institute of Mechanical Engineering , Hebei United University , Tangshan 063009 , Hebei , China 2.Institute of Mechanical Engineering , Yanshan University , Qinhuangdao 066004 , Hebei , China ) Institute of Mechanical Engineering Hebei United University Tangshan Hebei China Institute of Mechanical Engineering Yanshan University Qinhuangdao Hebei China

In view of characteristics of particle swarm optimization ( PSO ) algorithm of fast convergence but easily falling into local optimum value , a novel improved particle swarm optimization algorithm is put forward , and it is applicable to identify parameters of hydraulic pressure system model in strip rolling *** order to maintain population diversity and enhance global optimization capability , the algorithm is firstly improved by means of decreasing its inertia weight linearly from the maximum to the minimum and then combined with chaotic characteristics of ergodicity , randomness and sensitivity to initial *** the improved algorithm is used to identify parameters of hydraulic pressure system , the comparison of simulation curves and measured curves indicates that the identification results are reliable and close to actual situation.A new method was provided for hydraulic AGC system model identification.

关键词： hydraulic pressing system PSO algorithm chaos self-adaptive parameter identification

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Generalized plasticity model considering grain crushing and anisotropy for rockfill materials

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Journal of Central South University 2022年第4期29卷 1274-1288页

作者： ZHANG Xiang-tao GAO Yi-zhao yu yu-zhen WANG Xiang-nan ZHAN zheng-gang State Key Laboratory of Hydroscience and Engineering Tsinghua UniversityBeijing 100084China Power China Guiyang Engineering Co. Ltd.Guiyang 550081China

Rockfill materials have been widely used in the construction of rockfill dam,railway and highway subgrade due to its high filling density,good compaction performance,strong water permeability,small settlement deformation and high bearing capacity.A reasonable constitutive model for rockfill materials is very important for engineering computation and analysis,and has a great development *** on the crushing stress and spatial mobilized plane(SMP),a state parameter that can comprehensively reflect the anisotropy and grain crushing is *** state parameter is used to improve the MPZ model(a modifed ZienkiewiczⅢmodel),so that a generalized plastic model is constructed to describe the stress and deformation characteristics of rockfill materials in *** validity of the developed model is verified by a series of conventional triaxial tests with different inclination angles of the compaction *** variation trend of the constructed anisotropy indexωcan reflect the non monotonic variation of the deformation and strength of rockfill with the direction angle of large principal stress,so the model can reflect the obvious difference caused by the initial anisotropy of rockfill on the mechanical properties.

关键词： constitutive model anisotropy grain crushing rockfill materials

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抗滑桩加固边坡地震响应离心模型试验

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岩土工程学报 2007年第9期29卷 1320-1323页

作者：于玉贞邓丽军清华大学水沙科学与水利水电工程国家重点实验室北京100084

为研究抗滑桩加固边坡的地震响应和桩土相互作用规律,利用土工离心机及专用振动台进行了砂土边坡的动力离心模型试验。在50g离心加速度条件下,输入El Centro地震波,记录了边坡不同位置的加速度时程并作频谱分析,采集了桩前动土压力和抗... 详细信息

为研究抗滑桩加固边坡的地震响应和桩土相互作用规律,利用土工离心机及专用振动台进行了砂土边坡的动力离心模型试验。在50g离心加速度条件下,输入El Centro地震波,记录了边坡不同位置的加速度时程并作频谱分析,采集了桩前动土压力和抗滑桩应变等。结果表明:边坡的地震动力响应自下而上逐渐放大;抗滑桩对周围土体响应有一定阻滞作用;桩前动土压力随着地震输入而迅速增大至峰值,此后保持稳定直至地震结束;抗滑桩各截面弯矩的变化规律与动土压力类似,弯矩最大值出现在抗滑桩下部。

关键词：边坡抗滑桩地震响应桩土相互作用振动台离心模型试验

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