Applied Mechanics and Materials Vols. 475-476

Abstract: Ionic current characterization is critical for the application of nanopores with sub 5 nm as bio medical sensors and devices. Here, we demonstrate an eccentric ionic current behavior in graphene nanopore fabricated by high resolution transmission electron microscopy (HR-TEM). A spike-like current enhancement is shown in the absence of any bio molecule or nanoparticle in the LaCl₃ and KCl solution. By tuning the hydrophobicity of the graphene surface, the spikes diminish in the current recordings acquired in graphene nanopore after 20 seconds plasma etching. We consider that the hydrophocity-induced nanobubble is present in the nanopore area, leading to the currents change as the bubbles deformation due to the voltage driven electrostatic forces on the transported ions surrounding the bubble surface.

Abstract: In this paper we present exact numerical procedure to calculate the binding energy and wave function of impurity states in a quantum dot with parabolic confinement. The developed method allows control the accuracy of obtained results, as well as calculates the characteristics of not only ground state, but also of the excited states. Comparison of our results with data obtained by other methods is in quantitative and qualitative agreement. We studied the effects of impurity position on the binding energy.

Abstract: To improve the propagation quality in photonic crystal fibers,a novel dual elliptical assistant holes hollow fiber is proposed. Numerical model of confinement loss has been modeled by vector finite element method, then the core loss characteristics and the power ratio of the hollow fiber has been simulated and analyzed. The results show that the x-polarization confinement loss and the core power ratio are 0.06dB/m and 98.2% at 1550nm, respectively. By contrast, the y-polarization confinement loss is up to 243.34dB/m while the core power ratio is 47.86%. The novel optical fiber exhibits good single polarization characteristics and transmission characteristics, and the bandwidth range of single mode single polarization is 55nm. The novel optical fiber is very good to satisfy the requirement of single mode single polarization at the 1550nm.

Abstract: Using a two-dimensional ensemble Monte Carlo (EMC) method, the steady and transient properties of side-gated nanotransistors with single gate and double gate are studied in detail. Simulation results show that the double-gated nanotransistor has more powerful controlling ability on the channel than the single-gated one. The transient processes of the drain current for the two devices are both about 3 ps, which imply that the working speed of the two devices may reach about 0.3 THz. The detail of transient processes for the double-gated nanotransistor is trivial. But for the single-gated nanotransistor, the drain current response shows obviously oscillating during approaching the next steady state. The phenomenon of drain current oscillations is also discussed.

Abstract: In order to improve the join fastness of silent chain, a new silent chain assembly method is proposed. It increases the capability that the silent chain stands against transverse vibration, reduces the meshing noise of silent chain without changing the space size of silent chain, by replacing the installing of outer link plate and pin as a press-fit configuration, and taking wire lock on the joint. The result of extrusion force comparative experiment showed that the extrusion force of outer link plate press-fit configuration was 2.5 times than gasket press-fit configuration. Through the platform contrast test, a noise test of two types of silent chain were made at the same speed, the result showed that the new silent chain drive more smoothly than the traditional one, the average noise level was decreased by 1.5dB. The two test results verified that the new silent chain assembly method is validity.

Abstract: In order to calculate the friction work of lock-up clutch, which come from the lock-up process of hydraulic torque converter, this article established a simplified dynamic model of the engine and hydraulic torque converter , according to the route of power transmission and the rule of moment balance. And then the mathematical model of the lock-up process was deduced. This article reached a calculation method of lock-up clutch friction work by the mathematical model , and did some further simplified. Meanwhile, the lock-up process was simulated by Matlab/Simulink. By analyzing the simulatin resultthe computed result of machinery bookthe computed result of the improved method, the correctness of the improved method was verified.

Abstract: Horizontal preloading domestic waste transfer station is the core equipment for domestic waste disposal. Compression equipment is the elementary equipment of horizontal preloading domestic waste transfer station, which should be ensured its mechanical properties and structural lightweight. According to the compression box structure in this paper, structural topology optimization model is established. By using HyperWorks software, the result of structural topology optimization result of compression box is obtained. Based on the result of topology optimization, the structural improvement design model of compression box is established, and the number, location, size of strengthening rib for bottom plate, top plate, side plate are optimal designed so as to realize structural lightweight.

Abstract: This paper proposes a way of design a transplanting mechanism with plane five-bar linkage for the transplanter. The dimensions of five-bar linkage, which fit the agronomic needs, are designed. Multiple-population genetic algorithm is used to generate the mechanisms in optimum synthesis. And a five-bar linkage is generated in typical example. Also it can fit the needs of given seedling.

Abstract: The submersible buoy system is an important tool in the profile observation of marine environment. According to the lumped mass based method, the dynamic modeling of the submersible buoy system is established, then the dynamic analysis is carried out. The dynamic model is solved and analyzed by using the software MATLAB. The result provides theoretical reference for its structural design and numerical computation of the submersible buoy system.

Abstract: Due to the poor conditions of wet brake cooling and the high temperature of the working characteristics, this paper intended to introduce the oil film vadose between the brake linings, considered the variation of volume of grooves on the friction plate, and then proposes the three-dimensional transient dynamic response of fluid-solid coupling mathematical model. By numerical analysis of the disc transient thermal stress field distribution on the friction plate, the friction surface temperature field variation is obtained. Finally, the results shows that the mathematical model is effective and feasible.