Papers by Keyword: Tunneling

Abstract: In this paper we developed a recombination model for the steady state photoconductivity (SSP) with the assumption that the correlated dangling bond states (DB) act as the essential recombination centres and the electron recombination proceeds by tunneling from the conduction band tail states (TS) for n-type a-Si:H. The modeled temperature dependence of the SSP presents the main measured features, particularly the small activation energy and the thermal quenching.

Abstract: As a single advanced geological prediction method has its adaptability and deficiency, it is hard to find unfavorable geological body comprehensively and accurately, so an integrated advance geological prediction system is proposed. The system divided the prediction process into three stages, which are long term prediction, medium term prediction and short term prediction. The three stages are complement and verification for each other to achieve a reliable geological prediction result. The system has been applied to a practical geological prediction of Doupengshan Tunnel on the high speed railway from Guiyang to Guangzhou of China. From the application, a finalized geological prediction result has been obtained, which suggests that the system can obtain a reliable geological prediction result.

Abstract: RTD (resonant tunneling diode) is a nonlinear device in nm scale level and operates at ps time level which is promising to be used into integrated circuits in the coming years. J.N.Schulmans physical model has beenproven to be suitable to emulate the device accurately. In this paper, a novelRTD based on new material structure is proposed which could reach a relative high PVCR (peak-valley-current-ratio). Then NFP (Nonlinear Fitting based on Physical model) method which is suitable to calculate the parameters for Schulmans physical model more quickly is proposed. At the end of paper the SPICE model of the proposed RTD is proven that it could emulate the RTD device, and shows its application ability in high frequency oscillation circuit.

Abstract: In spite of progress in silicon technology, the end of Mosfet scaling can be anticipated for the year 2015 so the introduction of high permittivity gate dielectric is the envisaged solution to reduce the current leakage that drives up power consumption. In this paper we investigate the impact of different gate length on SOI double gate MOSFET when SiO2 is replaced by ZrO2 as the gate dielectric using Nextnano Simulator. The impact of the quantum effects also observed on performance parameters of the DG-MOSFET such as on current, off current, drain induced barrier lowering, and sub-threshold. It is observed that less EOT with high permittivity reduces the tunnel current and serves to maintain high drive current.

Abstract: In order to understand the security situation in the process of coal lane tunneling project effectively, this paper determines the safety evaluation indicators according to the actual situation in the coal lane tunneling, and then combining the indicators using grey relation analysis to evaluate the security situation of the sample coal lane tunneling projects. The evaluation method is simple, and compares the security situation of the various coal lane tunneling projects, so it can provide a reliable basis for the safety evaluation of the coal lane tunneling projects.

Abstract: This paper analyzes the wireless local area network existing safety and efficiency problem. It put forward the VPN tunnel technology to solve these problems. Theory explains that it is very the advantages of layer second tunneling protocol in a wireless local area network. This technology is proved to be reliable by Network Simulate 2 tool. It is proved that the technique is the advantage of high efficiency and safety.

Abstract: The tunneling of a plane monochromatic acoustic wave through a gap between two ferromagnets under conditions of their relative longitudinal displacement has been considered. It has been shown that, the inclusion of the longitudinal displacement of one of the crystals, in all cases, leads to the violation of resonance conditions and, consequently, to a noticeable decrease in the coefficient of transmission of the acoustic wave through the gap between two ferromagnets; this effect is more pronounced, the higher is the velocity of motion of the crystal. It has been demonstrated that there is a possibility of the wave front reversal occurring with the amplification of the reflected magnetoacoustic wave.

Abstract: Combine with the practice of Kunming city first-phase subway project construction, detailedly introduce the success construction experiences of shield crossing the dense buildings in the unfavorable conditions of shallow soil covering, big gradient, curve in small radius, complex geological condition and upgrade excavation etc. in the paper. Reasonable choosing the grout of synchronization grouting and the main technical parameters of shield tunneling on supporting pressure of working chamber, tunneling speed, total thrust, cutter head torque and excavation quantity etc., and strengthen the link of secondary grouting and technology management, the amount of settlement and uplift of the ground and the buildings can be effectively controlled.

Abstract: Because of the Limited urban space and the development of transport, underground space development, especially the metro construction, is vigorously developed in many cities. Subway passing through the existing building inevitably may cause the settlement and deformation of the buildings and their foundations. Therefore, research on the influence of tunneling on existing buildings has important significance. In order to study the influence of tunneling on settlement of existing pile foundations, soil elastic modulus, cohesion, friction angle, tunneling sizes, distance between tunnel opening boundaries and existing pile foundation etc. are discussed as analysis factors in this paper. The calculation schemes are designed based on orthogonal design, and then the influence of tunneling on existing buildings is researched according to the numerical calculation model which is established by the finite element software. Finally, the sensitivity of pile foundation settlement to various factors is analyzed according to the results of simulation analysis. we can draw the conclusions: the influence of tunneling on settlement of existing pile foundation is positively correlated with tunneling sizes, and is negatively correlated with soil parameters and distance between tunnel opening boundaries and existing pile foundations; The settlement of pile foundations can be effectively controlled by application of composite anchor isolation piles around the existing buildings piles, but with the increase of soil parameters and distance between tunnel opening boundaries and existing pile foundations, the strengthening effects are decreased; soil elastic modulus and excavation sizes are the key impact-factors of pile settlement within the distance of 5m between tunneling boundaries and existing pile foundations, which have extremely remarkable effect on the subsidence of pile foundations.

Abstract: The electrical properties of the SiO₂/SiC interface fabricated by sodium-enhanced oxidation (SEO) of n-type 4H-SiC were studied by temperature-dependent C-V and constant-capacitance deep level transient spectroscopy (CCDLTS). With the exception of near-interface traps in the SiC epi-layer, which are not present in the SEO samples, the trap species observed in SEO capacitors are the same as those observed in both standard-oxidized and NO-annealed MOS capacitors. Total electron trapping in accumulation is comparable in SEO and NO-annealed capacitors; however, the traps in SEO capacitors are located at the interface whereas tunneling into oxide traps is observed in NO-annealed samples. A series of bias-temperature stress tests show that electron trapping is essentially unchanged when mobile sodium ions are moved toward the interface. The improved mobility attained by this process compared to NO annealing may be due to the absence of near-interface SiC traps in SEO samples.