The reaction kinetics of the synthesis of quaternary ammonium salt under two sets of different reaction conditions, including microwave irradiation condition and conventional heating condition, were studied. In order to make sure that the microwave would not be interrupted, the reaction temperature was maintained at the boiling point of reaction solvents. The results showed that the reaction was a first-order reaction under both set of conditions and microwave irradiation changed the value of the activation energy of the reaction, indicating a change in the reaction mechanism. The activation energy was 41.44 kJ/mol under microwave irradiation condition, and 61.21 kJ/mol under conventional condition.

A hydraulic excavator is taken as the object to study. Considering the characteristics of slewing transmission mechanism of hydraulic excavator, the torsional vibration equation is established by the finite element method. According to the torsional vibration equation, the effects of the equivalent moment of inertia of working device on the torsional dynamic properties of slewing transmission mechanism are analyzed. Using the optimization theory, the mathematical model is built, which is by means of the equivalent moment of inertia of working device as objective function and by means of the position parameters of the working device as design variables. Based on the mathematical model, the optimization of torsional dynamic properties of slewing transmission mechanism is studied. Finally, a numerical example is presented.

By the kinematic and dynamic characteristics analysis of hydraulic excavator’s working mechanism system, the system was divided into three linear varying cross-section beam elements by using Finite-Element Method, then the dynamic differential equation of hydraulic excavator’s working mechanism system was established. The built equation better reflected the intrinsic relationships among the mechanism parameters, load parameters and its nonlinear dynamic properties, and it reflected the dynamic performances which the previous equations didn’t, so it laid the foundation of the further studies of the intrinsic relationships among the dynamics characteristics and mechanism parameters, load parameters of hydraulic excavator’s working mechanism system.