The deep sea is one of the most extensive ecosystems on earth. Organisms living there survive in an extremely harsh environment, and their mitochondrial energy metabolism might be a result of evolution. As one of the most important organelles, mitochondria generate energy through energy metabolism and play an important role in almost all biological activities. In this study, the mitogenome of a deep‐sea sea anemone (Bolocera sp.) was sequenced and characterized. Like other metazoans, it contained 13 energy pathway protein‐coding genes and two ribosomal RNAs. However, it also exhibited some unique features: just two transfer RNA genes, two group I introns, two transposon‐like noncanonical open reading frames (ORFs), and a control region‐like (CR‐like) element. All of the mitochondrial genes were coded by the same strand (the H‐strand). The genetic order and orientation were identical to those of most sequenced actiniarians. Phylogenetic analyses showed that this species was closely related to Bolocera tuediae. Positive selection analysis showed that three residues (31 L and 42 N in ATP6, 570 S in ND5) of Bolocera sp. were positively selected sites. By comparing these features with those of shallow sea anemone species, we deduced that these novel gene features may influence the activity of mitochondrial genes. This study may provide some clues regarding the adaptation of Bolocera sp. to the deep‐sea environment.

In order to study dynamic characteristics of fluid filled pipe under hydraulic excitation force generated actively by a new developed vibration exciter, at first mathematical model of pulsating fluid was established and a computer code based on the method of characteristics (MOC) was developed. Then the excitation force calculated by MOC was forced upon the corresponding nodes of finite element of pipe, meanwhile, the nodes of fluid by MOC were assured to coincide with that of the pipe by the method of finite element (FEM). Finally, using Newmark’s method, the dynamic response at every cross section of pipe was solved. The numerical simulations show that a simple harmonic motion arises at every cross section of the pipe. The lateral vibration amplitude of every node along the pipe increases as the rising system pressure. So, this work is expected to provide some theoretical and exploratory basis for studying two dimensional vibration characteristics of fluid filled pipe.

To study artificially produced and actively controlled water hammer wave caused by hydraulic vibration exciter, a mathematical model was established and an experimental system was designed to verify it. Through the given partial differential equations, a computer code based on the method of characteristics was developed to calculate transient pressure distributed along the pipe under different rotational frequency of vibration exciter. The numerical simulation indicates that there is a simple harmonic vibration rising at the cross sections along the pipe, corresponding to different excitation pressure at every cross section. In addition, the excitation pressure can also be adjusted by system pressure via overflow valve. So, this work is expected to serve for the optimum design of the hydraulic excitation system and play a theoretical guiding role to experimental research in future.