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Based on the energy method, considering the stress wave effect, the buckling problem of cylindrical shell subjected to impact is studied. Substituting the Lagrange function and the trial function satisfied the boundary condition into the second Lagrange equation. After the second-order linear partial differential equation is obtained, the analytical expression of the critical buckling speed of a rigid mass impacting cylindrical shell is obtained by analyzing the properties of the equations. The influence of critical length, impact mass, axial mode number, circumferential mode number and diameter-thickness ratio on buckling is discussed by analyzing the examples. The results show that the stress wave effect, initial kinetic energy and diameter-thickness ratio have a significant effect on the dynamic buckling of cylindrical shells; the higher-order modes of buckling and the buckling of cylindrical shell are easily motivated by high-speed impact.

Considering the effect of stress wave, the dynamic buckling problem of elastic bar with clamped-free boundary condition subjected to impact of rigid mass is studied using the energy method. The Lagrange function is built. Both of the trial function that satisfy the boundary conditions and the Lagrange function are substituted into the second Lagrange equation. After that an analytical expression of critical impact velocity can be deduced. By the analytical expression, it is obtained that the critical impact velocity is related to the impact mass of rigid block, the critical length and the inertia radius of the bar. The result show that the critical velocity decreases by increasing the impact mass and critical length, while increases by the increasing of inertia radius.

This paper mainly analyzes the reason of seawater leaking into lubricating oil system of one 1000 MW unit in some coastal power plant in Shandong province and presents the corresponding treatment measure. Dissolving elution method is proposed to determine the chlorine ion content in the oil, to judge whether oil entrained water is cleaned. By the oil filter processing, the moisture content of turbine oil fall from 24414 mg/L to 10.1 mg/L, the chloride ion content is from 155 mg/L down to not detected. The serious pollution of the seawater leakage returns to normal in a short time, which ensured the safe operation of the unit, avoided the malignant accidents after treatment in time.

In this paper, the method for detecting the acid value in transformer oil was studied, and the temperature titration method was used to determine the acid value of transformer oil. Meanwhile, several major factors that may affect the outcome were discussed.

Important test methods for acid number of oil products were introduced, and their characters, difference and selection Principle were described. And the temperature titration method was used to determine the acid number of transformer oil. Meanwhile, several major factors that may affect the outcome were discussed.

Considering the stress wave effect, the dynamic buckling problem of a composite rod with one side fixed on one side being axially impacted by a rigid mass is studied. Based on the Hamilton principle and the axial inertia and rotational inertia, the dynamic buckling control equation is derived. For the dimensionless, the central differential method is used to solve the governing equation. The buckling mode of the composite bar with different initial deflections under different impact mass, impact velocity, critical length and layup mode is obtained by B-R criterion. The results show that the impact velocity, impact mass, critical length and layup mode have an effect on the dynamic buckling of composite rods, and the initial deflection changes have a significant effect on the buckling mode.