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Reduced blister quantity in damaged tungsten exposed to deuterium plasma

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Science China(Physics,Mechanics & Astronomy) 2019年第5期62卷 125-128页

作者： Xiu-Li Zhu Long Cheng ShiWei Wang Yue Yuan Guang-Hong Lu Ying Zhang Er-Yang Lu Xing-Zhong Cao Jian-Jun Huang Advanced Energy Research Center Shenzhen University Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province College of Optoelectronic Engineering Shenzhen University School of Physics Beihang University Institute of High Energy Physics Chinese Academy of Sciences

Tungsten (W) is a promising candidate for plasma-facing materials (PFMs) in fusion reactors owing to its excellent thermal conductivity, sputtering resistance, and low hydrogen isotope solubility [1]. W PFMs encounter the challenges of triple irradiations generated by high-heat loads;high-flux particles, including helium/deuterium (D)/tritium (T);and high-energy neutrons.

关键词： damaged tungsten deuterium plasma

Assessing fracturing mechanisms and evolution of excavation damaged zone of tunnels in interlocked rock masses at high stresses using a finitediscrete element approach

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Journal of Rock Mechanics and Geotechnical Engineering 2019年第4期11卷 701-722页

作者： I.Vazaios N.Vlachopoulos M.S.Diederichs Arup LondonW1T 4BQUnited Kingdom Department of Geological Sciences and Geological Engineering Queen’s UniversityKingstonOntarioK7L 3N6Canada Department of Civil Engineering Royal Military College of CanadaKingstonOntarioK7L 4V3Canada

Deep underground excavations within hard rocks can result in damage to the surrounding rock mass mostly due to redistribution of *** within rock masses with non-persistent joints,the role of the pre-existing joints in the damage evolution around the underground opening is of critical importance as they govern the fracturing mechanisms and influence the brittle responses of these hard rock masses under highly anisotropic in situ *** this study,the main focus is the impact of joint network geometry,joint strength and applied field stresses on the rock mass behaviours and the evolution of excavation induced damage due to the loss of confinement as a tunnel face *** of such a phenomenon was conducted using the finite-discrete element method (FDEM).The numerical model is initially calibrated in order to match the behaviour of the fracture-free,massive Lac du Bonnet granite during the excavation of the Underground Research Laboratory (URL) Test Tunnel,*** influence of the pre-existing joints on the rock mass response during excavation is investigated by integrating discrete fracture networks (DFNs) of various characteristics into the numerical models under varying in situ *** numerical results obtained highlight the significance of the pre-existing joints on the reduction of in situ rock mass strength and its capacity for extension with both factors controlling the brittle response of the ***,the impact of spatial distribution of natural joints on the stability of an underground excavation is discussed,as well as the potentially minor influence of joint strength on the stress induced damage within joint systems of a non-persistent nature under specific ***,the in situ stress-joint network interaction is examined,revealing the complex fracturing mechanisms that may lead to uncontrolled fracture propagation that compromises the overall stability of an underground excavation.

关键词： Excavation damaged zone (EDZ) Brittle failure Finite-discrete element method (FDEM) Tunnelling Discrete fracture network (DFN)

In situ experiments on width and evolution characteristics of excavation damaged zone in deeply buried tunnels

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Science China(Technological Sciences) 2011年第S1期54卷 167-174页

作者： LI ShaoJun 1,FENG XiaTing 1,LI ZhanHai 3,CHEN BingRui 1,JIANG Quan 1,WU ShiYong 2,HU Bin 2 &XU JinSong 2 1 State Key Laboratory of Geomechanics and Geotechinical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430071,China 2 Ertan Hydropower Development Company,Ltd.,Chengdu 610051,China 3 School of Resources and Civil Engineering,Northeastern University,Shenyang 110004,China State Key Laboratory of Geomechanics and Geotechinical Engineering Institute of Rock and Soil Mechanics Chinese Academy of Sciences Wuhan China School of Resources and Civil Engineering Northeastern University Shenyang China Ertan Hydropower Development Company Ltd. Chengdu China

The seven long tunnels of Jinping II hydropower station are deeply *** width and evolution characteristics of excavation damaged zone(EDZ) are the key problem to the design of tunnels excavation and *** order to study this problem,several specific experimental tunnels with different overburden and geometric sizes were excavated at this *** borehole camera,sliding micrometer,cross-hole acoustic wave equipment and acoustic emission apparatus were *** paper introduced the comprehensive in situ experimental methods through pre-installed facilities and pre-drilled *** properties of the surrounding rock mass,including cracks,deformation,elastic wave and micro fractures,were measured during the whole process of the tunnel *** width and characteristics of formation and evolution of tunnels EDZ were analyzed under different construction methods involving of TBM and drilling and blasting,the test tunnels were excavated by full-face or two *** relationships between EDZ and tunnel geometry sizes,overburden and excavation method were described as *** results will not only contribute a great deal to the analysis of rock mass behavior in deeply buried rock mass,but also provide direct data for support design and rockburst prediction.

关键词： deeply buried tunnel excavation damaged zone evolution characteristics in situ experiments

Physical energies to the rescue of damaged tissues

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World Journal of Stem Cells 2019年第6期11卷 297-321页

作者： Federica Facchin Silvia Canaider Riccardo Tassinari Chiara Zannini Eva Bianconi Valentina Taglioli Elena Olivi Claudia Cavallini Marco Tausel Carlo Ventura Department of Experimental Diagnostic and Specialty Medicine (DIMES)School of MedicineUniversity of BolognaBologna 40100Italy National Laboratory of Molecular Biology and Stem Cell Engineering National Institute of Biostructures and BiosystemsCNRBologna 40100Italy iB3 SA Lugano 6900Switzerland

Rhythmic oscillatory patterns sustain cellular dynamics, driving the concerted action of regulatory molecules, microtubules, and molecular motors. We describe cellular microtubules as oscillators capable of synchronization and swarming, generating mechanical and electric patterns that impact biomolecular recognition. We consider the biological relevance of seeing the inside of cells populated by a network of molecules that behave as bioelectronic circuits and chromophores. We discuss the novel perspectives disclosed by mechanobiology, bioelectromagnetism, and photobiomodulation, both in term of fundamental basic science and in light of the biomedical implication of using physical energies to govern (stem) cell fate. We focus on the feasibility of exploiting atomic force microscopy and hyperspectral imaging to detect signatures of nanomotions and electromagnetic radiation (light), respectively, generated by the stem cells across the specification of their multilineage repertoire. The chance is reported of using these signatures and the diffusive features of physical waves to direct specifically the differentiation program of stem cells in situ, where they already are resident in all the tissues of the human body. We discuss how this strategy may pave the way to a regenerative and precision medicine without the needs for (stem) cell or tissue transplantation. We describe a novel paradigm based upon boosting our inherent ability for self-healing.

关键词： Stem cells Physical energies Mechanical forces Electric fields Electromagnetic fields Electromagnetic radiation Photobiomodulation damaged tissues

AN ENDOCHRONIC CONSTITUTIVE EQUATION FOR damaged MATERIALS

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Science China Mathematics 1989年第2期32卷 246-256页

作者：范镜泓张俊乾 Institute of Constitutive Theory Department of Engineering Mechanics Chongqing University

The irreversible thermodynamic process of damaged material is described in theεsup>TqD space and the thermodynamic state variables including entropy are defined in its εTsubspace. Based on the proposed physical mechanism and model for the coupling effectsof damage on the inelastic internal variable qα, the evolution equations of qα anddDβ/dφ have been studied in the εTq and εTD subspace respectively. By this approach thesecond order coupling effects are neglected and the Clausius-Duhem inequality could beeasily satisfied. A new type of constitutive equation of damaged material bas then beendeveloped. Among its many salient features the constitutive equations are also to followthe form invariance law of dissipative material. Lemaitre’s model, Valanis’s formulasand main results of classical plasticity theory could be obtained by these constitutiveequations under specified conditions. Developed finite element algorithm and method fordetermination of material parameters are given briefly. The analysis of elastoplasticstrain and damage distribution of a plat with two cracks made of 2024 CuAl are con-ducted. Some significant results are observed.

关键词： damaged material thermodynamic process.

Instability Analysis of damaged Pile Due to Static or Dynamic Overload

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Geomaterials 2012年第4期2卷 114-120页

作者： P. N. Jiki J. U. Agber Civil Engineering Department University of Agriculture Makurdi Nigeria Electrical Engineering University of Agriculture Makurdi Nigeria

Instability of a damaged pile due to a statically or dynamically applied overload is studied in this work using the finite element method. A damage parameter from such a pile is calculated using fracture mechanics concepts. The parameter is used to modify the beam element at the cracked or damaged location. Soil samples were obtained from the site of the pile and were subjected to laboratory tri-axial tests to obtain shear strength parameters c and . Other soil parameters such as Young’s modulus E and Poisson’s ratio were also obtained from the tri-axial tests. These were used to calculate shear strength and sub-grade modulus k for the soil. The parameters , E, and k were later used together with the damage parameter in the finite element simulation of the strength of the damaged pile using Eigen value analyses. The layered soil modulus is approximated by taking the mean value and is denoted by . The discrete element matrices are assembled into a system Eigen-value equation, the solution of which provides the stability or instability loads for the damaged pile. The results obtained for a pile without damage, that is, when =0 , are in good agreement with those published in the literature. It has also been found that higher soil resistance is needed to support the damaged pile. It is concluded that the proposed model is a good candidate for use in the analysis and repair of damaged piles due to earthquake overload by soil stabilization methods.

关键词： damaged Piles Earthquake Overload Instability Analysis Layered Soil Support

Protection of Environment from damaged Nuclear Station and Transparent Inflatable Blanket for Cities—Protection from Radioactive Dust and Chemical, Biological Weapons

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Journal of Environmental Protection 2011年第4期2卷 327-341页

作者： Alexander Bolonkin New Jersey Institute of Technology New Jersey USA

The author, in a series of previous articles, designed the “AB Dome” made of transparent thin film supported by a small additional air overpressure for the purpose of covering a city or other important large installations or sub-regions. In present article the author offers a variation in which a damaged nuclear station can be quickly covered by such a cheap inflatable dome. By containing the radioactive dust from the damaged nuclear station, the danger zone is reduced to about 2 km2 rather than large regions which requires the resettlement of huge masses of people and which stops indus-try in large areas. If there is a big city (as Tokyo) near the nuclear disaster or there is already a dangerous amount of radioactive dust near a city, the city may also be covered by a large inflatable transparent Dome. The building of a gi-gantic inflatable AB Dome over an empty flat surface is not difficult. The cover is spread on a flat surface and a venti-lator (fan system) pumps air under the film cover and lifts the new dome into place but inflation takes many hours. However, to cover a city, garden, forest or other obstacle course in contrast to an empty, mowed field, the thin film cannot be easily deployed over building or trees without risking damage to it by snagging and other complications. This article proposes a new method which solves this problem. The design is a double film blanket filled by light gas such as, methane, hydrogen, or helium - although of these, methane will be the most practical and least likely to leak. Sections of this AB Blanket are lighter than air and will rise in the atmosphere. They can be made on a flat area serving as an as-sembly area and delivered by dirigible or helicopter to station at altitude over the city. Here they connect to the already assembled AB Blanket subassemblies, cover the city in an AB Dome and protect it from bad weather, chemical, bio-logical and radioactive fallout or particulates. After assembly of the dome is completed,

关键词： Radiation Shield Protection Of Environment From damaged Nuclear Station Dome For City Blanket For City Protection Of Cities From Chemical Biological And Radioactive Weapons Encapsulating Nuclear Sites

Dynamic Characteristic of damaged Ship Structures Considering the Warping Deformations

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Journal of Marine Science and Application 2002年第1期1卷 1-8页

作者： NIE Wu, WEN Bao- hua, CHEN Guo- longCollege of Shipbuilding Engineering, Harbin Engineering University, Harbin 150001 , China College of Shipbuilding Engineering Harbin Engineering University Harbin 150001 China

For some largely damaged ships, the conventional methods are unadaptable to estimate their dynamic characteristics asto ships with symmetrical hull section. Based on dry hull modal analysis of flexure-torsion coupling vibration of unsymmetricalship structures about longitudinal center line, a transfer matrix method to calculate the dynamic characteristics is *** both shear effect and warping deformations into account, the point and field transfer matrices are derived, and the influ-

关键词： damaged ship coupling vibration warping dynamic characteristics.

Study on Harnessing of Roadway with Badly damaged Surrounding Rock

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International Journal of Mining Science and Technology 1998年第1期19卷 38-44页

作者：吕家立颜志平

This paper, based on the strain softening character of rock, and the de formation feature of roadway with badly damaged surrounding rock and adopting the ideal elastoplastic softening model, derives the formula for calculating the supporting resistance for the roadway. It is pointed out that controlling the rheid speed of the rock in the plastic softening area is critical and that the combined supporting, i. e. combining surrounding rock internal rein forcement with external supporting f is the reasonahle supporting to this kiud of roadways. The theory and practice introduced in this paper are of universal significance for harnessing the roadway with badly damaged surrounding rock.

关键词： roadway with badly damaged surrounding rock ideal elastoplastic softening model internal reinforcement external supporting boundary structure effect