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Dynamic electron transport theory for multiprobe mesoscopic structures
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作者 全军 田英 +1 位作者 张军 邵乐喜 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第7期373-379,共7页
Using the linear response theory and random phase approximation, we develop a general dynamic electron transport theory for multiprobe mesoscopic structures in an arbitrarily time-dependent external field. In this cas... Using the linear response theory and random phase approximation, we develop a general dynamic electron transport theory for multiprobe mesoscopic structures in an arbitrarily time-dependent external field. In this case, the responses of the dynamic current, charge and internal potential to the external fields can be determined self-consistently. Without loss of generality, charge (current) conservation and gauge invariance under a potential shift are satisfied. As an example, we employ a quantum wire with a single barrier to discuss the response of the internal potential. 展开更多
关键词 mesoscopic structure linear response theory electron transport quantum wire
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Biomechanical analysis of bone mesoscopic structure and mechanical properties of vertebral endplates of degenerated intervertebral discs in rabbits
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作者 Bingying Zhao Yuan Guo +3 位作者 Xushu Zhang Yibo Zhao Bin Zhao Ming Zhang 《Medicine in Novel Technology and Devices》 2024年第2期59-72,共14页
In previous studies of disc degeneration,the structural and mechanical properties of the endplate were often neglected.In this paper,the station legislation was used to construct an animal model of minor trauma disc d... In previous studies of disc degeneration,the structural and mechanical properties of the endplate were often neglected.In this paper,the station legislation was used to construct an animal model of minor trauma disc degeneration,and the mechanism of disc degeneration was further investigated by observing the changes of mesoscopic structure and developing the mechanical properties of endplate bone.Twenty-eight 6-month-old Japanese white rabbits were divided into two groups:control group and experimental group.An animal model of intervertebral disc degeneration was established by upright experiment in the experimental group.The bone mesoscopic structures in different areas of each endplate were observed by histological and imaging methods,and the mechanical properties of the endplates were measured by indentation method.The two groups of data were compared by one-way ANOVA.After the experimental animals stood for 17 weeks,The experimental group showed the characteristics of early disc degeneration.The microstructure of the degenerative group showed that the end plate mineralization degree was higher,the bone mass was larger,and the number and thickness of bone trabeculae were larger.The results of indentation test showed that the mechanical properties of the degeneration group were enhanced,and the lower endplate was obviously enhanced.We successfully established a model of human disc degeneration with non invasive trauma and more consistent with the process of human disc degeneration through the standing experiment.In the experimental group,the internal structure of the endplate was dense and pore distance was reduced.The change of bone mesoscopic structure further affects the endplate,resulting in the enhancement of the mechanical properties of the endplate after intervertebral disc degeneration.The reduction of the pore distance and the narrowing of the internal channel structure of the endplate also hinder the nutrition supply of the intervertebral disc,which may be the key reason affecting the degeneration of the intervertebral disc.A biomechanical method for investigating the mechanism of intervertebral disc degeneration can be provided in this paper. 展开更多
关键词 Vertebral endplate BIOMECHANICS Intervertebral disc degeneration model Mechanical properties mesoscopic structure
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Quantum pump effect in a four-terminal mesoscopic structure
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作者 王凯凯 《Journal of Semiconductors》 EI CAS CSCD 2015年第2期6-9,共4页
Quantum pump effect in a four-terminal mesoscopic structure constructed from a homogeneous two- dimensional electron gas is investigated. Oscillating electric potentials are applied to the two opposite terminals of th... Quantum pump effect in a four-terminal mesoscopic structure constructed from a homogeneous two- dimensional electron gas is investigated. Oscillating electric potentials are applied to the two opposite terminals of the four-terminal mesoscopic structure. In both the remaining two opposite terminals and in the central region there are constant potentials that do not change with time. The oscillating potentials change slowly in comparison with all of the internal time scales of the structure and the amplitude of the oscillating potentials is small in comparison with the Fermi energy. The current of each lead and the transmission coefficients from one lead to another are calculated by using the non-equilibrium Green's function approach under the adiabatic approximation. In the remaining two opposite terminals of the four-terminal structure, the quantum pump effect can produce an electric current whose magnitude and direction depends on the Fermi energy. The pumped currents are ascribed to the asymmetry of transmission coefficients with respect to the Fermi energy. 展开更多
关键词 quantum pump effect mesoscopic structure
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Mesoscopic Simulation of Aggregate Behaviour of Polymers in β-HMX-based PBXs
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作者 崔红玲 姬广富 +1 位作者 陈向荣 魏冬青 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2013年第4期462-466,J0002,共6页
The mesoscopic structures of β-HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine)- based PBXs (polymer bonded explosives) at room temperature were investigated using dissipative particle dynamics method. The ... The mesoscopic structures of β-HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine)- based PBXs (polymer bonded explosives) at room temperature were investigated using dissipative particle dynamics method. The parameters and repulsive parameters of dif- ferent polymers and β-HMX, the mesoscopic structures of β-HMX-based polymer-bonded explosives at different temperatures have been studied. The results showed that the compat-ibility between β-HMX and vinylidenedifluoride (VDF),β-HMX and chlorotrifluoroethylene (CTFE), VDF and CTFE increased with increasing temperature. The temperature and mo-lar ratio of the polymers played an important role in wrapped process. And there exists the optimum temperature and molar ratio. 展开更多
关键词 Dissipative particle dynamics mesoscopic structure β-HMX-based PBXs
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Bound in continuum states and induced transparency in mesoscopic demultiplexer with two outputs
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作者 Z Labdouti T Mrabti +3 位作者 A Mouadili E H El Boudouti F Fethi B Djafari-Rouhani 《Chinese Physics B》 SCIE EI CAS CSCD 2020年第12期429-437,共9页
We investigate the electronic transport in a simple mesoscopic cross structure made of two wires(stubs)grafted at the same point along a quantum waveguide.We show that the structure may exhibit important phenomena suc... We investigate the electronic transport in a simple mesoscopic cross structure made of two wires(stubs)grafted at the same point along a quantum waveguide.We show that the structure may exhibit important phenomena such as bound in continuum(BIC)states.These states are transformed into electromagnetically induced transparency(EIT)resonance by detuning slightly the lengths of the stubs.The last phenomenon is used to propose and study a mesoscopic demultiplexer device with an input waveguide and two output waveguides.We give closed-form expressions of the geometrical parameters that allow a selective transfer of a given state in the first waveguide without perturbing the second waveguide.The effect of temperature on the transmission resonances is also examined by using Landauer-Büttiker formula.The analytical results of the dispersion relation and transmission and reflection coefficient are obtained using the Green's function method. 展开更多
关键词 mesoscopic structure demultiplexer device bound states in continuum(BIC) EIT resonance
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Persistent Currents in the Double Aharonov-Bohm Ring Connected to Electron Reservoirs 被引量:4
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作者 ZHANG Ying XIAO Jing-Lin 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第3期573-576,共4页
We study persistent currents in the double Aharonov-Bohm ring connected to two electron reservoirs by quantum waveguide theory. It is found that the persistent currents in the double Aharonov-Bohm ring depend .on the ... We study persistent currents in the double Aharonov-Bohm ring connected to two electron reservoirs by quantum waveguide theory. It is found that the persistent currents in the double Aharonov-Bohm ring depend .on the direction of the current flow from one reservoir to another. When the direction of the current flow reverses, tl2e persistent current in each ring of the double Aharonov-Bohm ring changes. If the two rings are of the same size, the persistent currents in the left and the right rings exchange at the reversal of the current flow direction. 展开更多
关键词 quantum waveguide theory mesoscopic structure persistent currents
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Numerical simulation of mesoscopic cracking of cement-treated base material based on random polygon aggregate model 被引量:4
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作者 Qiao Dong Xiaokang Zhao +3 位作者 Xueqin Chen Jiawei Yuan Wei Hu Ahmad Jahanzaib 《Journal of Traffic and Transportation Engineering(English Edition)》 EI CSCD 2023年第3期454-468,共15页
Cracking failure of cement-treated base(CTB)has always been the concern of highway constructors.Mesoscale cracking analysis is an important means to study the damage degradation mechanism,which is difficult to be char... Cracking failure of cement-treated base(CTB)has always been the concern of highway constructors.Mesoscale cracking analysis is an important means to study the damage degradation mechanism,which is difficult to be characterized by experimental techniques alone.The objective of this paper is to develop a random aggregate modelling method to simulate the mesoscopic cracking of CTB material.A minimum rectangle area method was proposed to calculate the polygon aggregate size,which is closer to the sieving analysis than the average radius method.A buffer zone method was proposed to determine the distance between randomly generated polygon aggregates.Based on the proposed random algorithm,finite element method(FEM)was adopted to build the mesoscopic model of CTB including aggregate,mortar,interfacial transition zone(ITZ)and air voids.Laboratory tests were conducted to validate the numerical model.Then the sensitivity analyses were conducted to study the influencing factors on cracking behavior.The simulation results indicate that the higher aggregate content and the finer gradation lead to the increase of ITZ,thus reducing the cracking resistance of the CTB material.Low porosity content is able to significantly reduce the stress concentration and thus improves the cracking resistance.The research results of this paper could be used to guide the crack resistant design of CTB material. 展开更多
关键词 Cement-treated base Random aggregate mesoscopic structure Sensitivity analysis Finite element method
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Recent Progress of Applying Mesoscopic Functionalization Engineering Principles to Spin Advanced Regenerated Silk Fibroin Fibers 被引量:3
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作者 Wu Qiu Xiang Yang Liu 《Advanced Fiber Materials》 SCIE CAS 2022年第3期390-403,共14页
The Bombyx mori silk fbers are regarded as one of the most fascinating fexible materials in the twenty-frst century and have shown great potential in areas including fber sensors,fber actuators,optical fbers,energy ha... The Bombyx mori silk fbers are regarded as one of the most fascinating fexible materials in the twenty-frst century and have shown great potential in areas including fber sensors,fber actuators,optical fbers,energy harvester,etc.The regenerated silk fbroin(SF)molecules taken from B.mori cocoon fbers have been verifed to be capable of mesoscopically reconstructing during the SF molecules refolding process.The key concern of this review is to summarize recent engineering applying principles of meso reconstruction,meso hybridization and meso doping to synthesize artifcial regenerated SF fbers with enhanced or even novel functions,especially based on rerouting the refolding process of SF molecules via controlling nucleation pathway.In general,the knowledge of the meso reconstruction of silk fbre shed light on the design and fabrication of other ultra-performance SF materials from the crystallization and meso structural point of view. 展开更多
关键词 Silk fbroin mesoscopic structure WET-SPINNING mesoscopic reconstruction
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