Seafloor observation network provides limited opportunity for repair due to the atrocious weather on the sea. As a result, reasonable reliability allocation methods are required to assure the network is sufficiently reliable during expected years. In this thesis, betweenness is used for evaluating the importance of component based on binary search algorithm, and residual connectedness reliability is calculated according to Monte Carlo method to avoid combinatorial explosion. This method is applied on meshed seafloor observation network to obtain satisfying reliability allocation for backbone nodes. Further, the relationship between nodes reliability allocation and residual connectedness reliability is discussed, on the basis of which certain suggestions for network improvement are proposed.

Study on the deterioration of the constant current remote feeding system throughout the life of the structure is always one of the most important issues in seafloor observatory network reliability engineering. Relationship between current-to-current convertor subsystem and amount of loads in branch line is described by introducing failure rate factor. Multistate reliability model of remote power feeding system has been set up and solved by genetic algorithms. Simulation results show that as the load configuration in trunk line and branch line changing, there exists best combination maximizes the system reliability, besides, appropriate increasing amount of loads in branch line can optimize the preventive strategy.

The paper presents digital closed loop fiber-optic current sensor (FOCT)’s optical path which combines integrated optical modulator and polarization beam splitter as optimum combination, as well as numerical analysis on insertion loss of traditional optical path scheme which consists of straight waveguide and optical path proposed by ABB. It shows that loss causes equivalent noise current which will affect the sensitivity of photo detector. The calculation and experiment confirm that loss of optical path is an important factor for FOCT’s sensitivity, and optical path composed of integrated optical phase modulator with Y-Branch profile and polarization beam splitter can effectively reduce the insertion loss and improve sensitivity of the system.

This paper presents a scheme of information transmission system for undersea observation platform based on all-optical network. Through flexible using of WDM, OADM, EDFA, RFA, DCF and other technology, it effectively compensates chromatic dispersion, restrains nonlinear effects and noise problems. Fibers in primary nodes are directly assigned to ensure mutual independence between different transmission links. Dual-fiber bidirectional transmission mode that wavelength of one fiber drops to the node by OADM, then return to the same transmission station in the other fiber, increases the reliability of the transmission system. The simulation results show that this scheme can ensure information transmission quality and effectively achieve wavelength adding and dropping, further verify the feasibility of the scheme.

Rare earth is one of the most important strategic resources related to the national security and development. Nowadays, all countries over the world have a fierce competition on the rare earth. Although China has rich rare earth resource, the advantage decreases gradually due to various factors such as the technology level, waste of resource and so on. It goes against China's long-term development strategy of mineral resource seriously. So it is urgent to carry out rare earth mineral lands reserve system. In such background, according to the existing research results at home and abroad, this paper mainly summarizes the current supply and demand situation of rare earth in China, the conception and characteristic of mineral reserve, factors that affect the rare earth reserve scale, and then establishes a basic calculating model of rare earth mineral lands reserve scale.