We present the hamiltonian structures for a wide class of coupled Korteweg-de Vries systems, including the Gear and Grimshaw system that models the strong interaction of internal waves in a stratified liquid and the system of Lou, Tong, Hu and Tang that describes a two layer fluid model. Among the hamiltonian structures of these systems we found new Poisson brackets which define consistent alge...

With the continuous development of national economy, big gear was widely applied in metallurgy and mine domains. So, big gear plays an important role in above domains. In practical production, big gear abrasion and breach take place often. It affects normal production and causes unnecessary economic loss. A kind of intelligent test method was put forward on worn big gear mainly aimed at the big...

In-line skating injuries and protective gear use were explored in a sample of college students (n = 217). A minority of respondents wore protective gear. One third of skaters had experienced at least one minor injury, and a smaller percentage had experienced fractures or head injuries. Most minor injuries occurred during the first 1-2 times skating, while more serious injuries tended to occur a...

While operating a gear with local fault impulse is created, the high-frequency shock vibration is then generated and the vibration amplitude is modulated by the pulse force. Both the envelope and cepstrum analyses are useful tools to identify the fault frequencies and distinguish them from other frequency contents. Since the envelope analysis method provides an important and effective approach ...

Based on RNG k-ε turbulence model and dynamic grid technology, the internal fluid dynamics of splash lubrication three stage planetary gear reducer system is established. The distribution lubricating oil convective heat transfer characteristic in at different input rotational speeds are analyzed. results show that high speed condition, gas mixing volume degree atomization higher, coefficient to...

Landing gear is one of the critical subsystems of an aircraft. The need to design landing gear with minimum weight, minimum volume, high performance, improved life, and reduced life cycle cost have posed many challenges to landing gear designers and practitioners. Further, it is essential to reduce the landing gear design and development cycle time while meeting all the regulatory and safety re...