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Hybrid propulsion technologies, including hybrid electric and hydraulic hybrid, equip vehicles with nonconventional power sources (in addition to the internal combustion engine) to provide higher fuel efficiency. However, these technologies tend to lead to higher levels of noise, vibration, and harshness in the vehicles, mainly due to the switching between the multiple power sources involved. In addition, the shocks and vibrations associated with the power sources switching may occur over a wide range of frequencies. It has been proven that passive vibration isolators (e.g., elastomeric and hydraulic mounts) are unable to mitigate or totally isolate such shocks and vibrations. Active mounts, while effective, are more complex, require significant power to operate, and can lead to system instabilities. Semiactive vibration isolators have been shown to be as effective as active mounts while being less complex and requiring less power to operate. This paper presents a review of novel semiactive shock and vibration isolators developed using magnetorheological and electrorheological fluids. These fluids change their yield stress in response to an externally applied magnetic and electric field, respectively. As a result, these fluids allow one to transform a passive hydraulic vibration isolator into a semiactive device.

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An open-source electrochemistry simulation package has been developed that simulates the electrode processes of four reaction mechanisms and two typical electroanalysis techniques: cyclic voltammetry and chronoamperometry. Unlike other open-source simulation software, this package balances the features with ease of learning and implementation and can run on mainstream operating systems. In an elctroanalysis lecture for graduate students, we have simulated the cyclic voltammetry of an electron transfer reaction with varied scan rates. The dynamical concentration profiles were demonstrated in an animation to help students understand the relation between currents and evolving concentration profiles, and the relations between peak currents and scan rates were also discussed.

In order to avoid serious safety accidents caused by closed fire zone, based on the continuous monitoring of atmospheric pressure at different monitoring points in multiple mines, the atmospheric pressure fluctuation model and the air leakage model were established and analyzed. The change law with time of oxygen concentration and gas concentration in the fire zone were obtained due to atmospheric disturbances under the influence of different pressure difference, volume and size of fire area, wind resistance, gas emission, sealing moments, etc. so as to evaluate the explosion risk of a closed fire zone. Research showed that the mine atmosphere fluctuates with the atmosphere of ground, and the pressure difference between the inner and outer sides of the enclosed fire zone is affected by the periodic fluctuation of atmosphere, which has about 16-h cosine fluctuation and approximate 8-h fixed value. Compared with the fire zone with poor sealing quality, good sealing fire zone has better resistance to atmospheric disturbance. The reduction of oxygen concentration in the inner side of a well-sealed fire zone mainly depends on the dilution of methane, which is more likely to accumulate and rise rapidly. And the fire zone with poor sealing quality is easy to be interfered. The inner oxygen concentration and gas concentration are easily affected by the absolute gas emission and the air leakage in the fire zone. Fire zone with small wind resistance and small volume is especially obvious. At the initial stage of the closed fire zone it's very possible to happen explosion. The time duration of explosion danger varies under different conditions, and the atmospheric disturbance may lead to repeated explosions in some cases. It's suggested to take some methods to avoid explosions according to the real-time situation, closure time, oxygen concentration and gas concentration of fire zone.

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