The author analyses the action principle of V_1-model igniting method and gives some effective measures in engineering application.

Action principle of high gravity technology was reviewed,and its research progress was introduced.

The paper points out the construction method,the vibro-replacement crushed stone column,for the large area of soft ground in high-fill sections,introduces the features and the acceptable conditions of the construction method,indicates its action principle as well as the construction keys of the method;furthermore it also undertakes the effectiveness check and profits analysis.

The functional principle,main features of tension device on warping wachine are introduced,the product adaptability and existed problems are discussed.

This paper introduces the principle and making of the improved FR-and the experience of using it to treat malocclusion of Angle .

Described are the function principles of the spring parking devices in tread braking units produced in our country and in Germany.

This paper introduces precisely the construction technology of ahead pipe roof support used in highway tunnel construction from design parameters, function principle, construction process, progress, quality control.