Search

Based on the basic knowledge of reconfigurable manufacturing system and axiomatic design, this paper designed the reconfigurable manufacturing system through two axioms (independence axiom and information axiom) of axiomatic design. In the application of independence axiom, the general goal was decomposed into four levels and each decomposition was accomplished by four steps with their respective design equations. And then the corresponding functional structure table in summary is listed. While in the application of information axiom, the information content of system was calculated under the circumstances of uncoupled design and quasi-coupled design. Finally, the problems and their corresponding solutions of the two axioms of axiomatic design were put forward.

The loose coupling structure of Contactless Electrical Power Transfer System (CEPTS) is the main cause of transmission inefficiency. Compensation capacitors were calculated and mounted on both sides of primary and secondary coils which forming the following four compensation topologies: primary secondary series (SS compensation), primary series-secondary parallel (SP compensation), primary parallel-secondary series (PS compensation) and primary secondary parallel (PP compensation). Experiment results show that the transmission efficiency differs according to different compensation topologies. SP structure is the most efficient among these four topologies and the transmission efficiency of SP structure is about 40% higher than that of basic structure without compensation.

In recent years, piezoelectric energy harvester which can replace the traditional battery supply has become a hot topic in global research field of microelectronic devices. Characteristics of a trapezoidal-loop piezoelectric energy harvester (TLPEH) were analyzed through finite-element analysis. The output voltage density is 4.251V/cm2 when 0.1N force is applied to the free end of ten-arm energy harvester. Comparisons of the resonant frequencies and output voltages were made. The first order resonant frequency could reach 15Hz by increasing the number of arms. Meanwhile, the output voltage is improved greatly when excited at first-order resonant frequencies. The trapezoidal-loop structure of TLPEH could enhance frequency response, which means scavenging energy more efficiently in vibration environment. The TLPEH mentioned here might be useful for the future structure design of piezoelectric energy harvester with low resonance frequency.

The ambient energy harvesting based on piezoelectric has become an important subject in recent research publications. A new rectangular-loop piezoelectric energy harvester(RLPEH) is proposed. The characteristic is analyzed by the finite element analysis (FEA) which includes the static analysis, modal analysis and harmonic response analysis. The analysis results show that the RLPEH could reduce the resonant frequency and improve the output voltage. The three order resonant frequency is 18.6Hz, 40.8Hz and 85.4Hz. The output voltage is 42V under 3m/s2 of acceleration and the effective bandwidth is 18.7Hz with output voltage above 10V.

Landslide generated waves in the reservoir were investigated in a three-dimension physical model based on the generalized Froude similarity. The tests included the following several influence factors: still water depth, still water width, landslide volume, landslide fall, slide angle. The waves generated process, as a complex solid-air-water phenomena, is composed of landslide entering water, the first wave generation, air-spray group forming, the second wave generation, wave run-up, wave propagation. Empirical equations base on most of experiments of the first maximum wave amplitude, the second maximum wave amplitude, the maximum wave run-up are described by multiple regressions of following dimensionless quantities: the relative slide Froude number, the relative landslide volume, the relative still water wide.

Based on Entropy and dissipative structure theory, the structural model of social information field space is explored in this paper. Studies have shown that a relatively independent complex social system is posed by all kinds of "information men". And because of interconnected relationship and mutual transformation among "information men", it develops into a social group or social organization with the characteristics of mathematics.A complex system of society is finally regard as a "superior" constituted by different social groups according to certain rules.

The traditional method of the offshore caisson positioning and installing is using the barge or floating crane, but for the large caisson with 26,000 tons, the method is unable to achieve apparently. In this paper, the offshore location and installation of the large caisson with mooring line system and anchor cable system are studied. The research gets the wave and flow conditions results as well as the related and advertent items, which provide the reference for large caisson positioning and installation as well as the similar engineering construction technology.

At present, many oil tank wharfs of 300,000DWT which taken the maximum of 450,000DWT supertanker into account had been built in our country. In this paper, through the physical model test on 450,000DWT supertanker, the mooring line tension with different mooring arrangements, cable diameters and cable materials were studied and the wave condition for the supertanker safety operation was given. The results showed that: on the same wave condition, to increase the steel cable’s diameter could reduce the ship’s movements, which could enhance the ability to operation. In addition, using the combination cable on the same diameter instead of the steel cable could reduce the tension of mooring line and increase the working ability effectively. The research results can provide reference and guidance for the future of supertankers mooring operation.

The streamline is of great importance for the visualization of 3D vector field. In order to solve those problems of streamline occlusion and visual confusion caused by of excessive streamlines. Meanwhile the streamlines have to present the variation law and important features of vector field exactly. In this paper, a view-dependent and physical feature-preservation streamline simplification method for 3D vector field visualization is proposed. Firstly, streamline set of 3D vector field is generated by particle tracking. Secondly, view-dependent mapping of the streamline set is implemented. Finally, the streamline set is simplified effectively following an iterative feature-preservation computation and view-dependent computation. The experiment results show that the streamlines are visually enhanced meanwhile the physical features of vector field are effectively maintained.

This paper introduces the server design of a personal cloud sync storage system based on Android mobile terminal, including system architecture, workflow and module design. According to the application characteristics of personal cloud, this thesis selects Servlet as the core development technology of server-side system, describes the development process of the personal cloud server based on Tomcat container and establishes a secure connection between the mobile terminal and the personal cloud server center. Under the LAN environment, the server system has successfully completed the function module of the test and assembly verification test. Test results show that the whole system runs in good condition and has certain applicative value.

In order to improve the energy harvesting efficiency of piezoelectric cantilever beam (PCB) in the environment. This paper presents a new type of piezoelectric cantilever beam which is the single-sided trapezoidal loop shaped PCB. By theory analysis, the equivalent circuit model was established, resonant angular frequency is inversely proportional to the length of cantilever beam. Based on finite element analysis method, the piezoelectric performance of single-sided trapezoidal loop shaped PCB and that of single-sided rectangular loop shaped PCB are compared with the same areas. The analysis results show that the coupling voltage of the former is larger, the output power of single-sided trapezoidal loop shaped PCB is improved, and the theoretical derivation of the inverse relationship between the frequency and length is verified.

This paper introduces the client design based on Android mobile sync of cloud storage system, including system architecture and its module design. Through the Android mobile sync client software, user can access the cloud server to implement some functions, such as upload and download, data backup and restore, file management and sharing in the distance. Under the LAN environment, the client system has successfully completed the tests of both function module and assembly verification. The results show that the whole system runs in good condition.

FePO4·2H2O with orthorhombic flower-like microstructure was synthesized by a facile hydrothermal process which was of low-cost and easy processing in large area. The formation mechanism of the flower-like FePO4·2H2O was discussed in details by investigating the different concentration of reactants and reaction time. The results show that the morphology of FePO4·2H2O changed from microsphere to flower-like structure, which possess an unique morphology with six petals and the angle of each petal being 60o. The formation mechanism of FePO4·2H2O flowers can be explained by the dissolution-recrystallization and crystal splitting.

Through the physical model test research on the dynamic response of jacket structure during floating transportation, the state of motion and the cable towing force under different wave conditions are given. The study results not only the scientific basis for the jacket structure construction, but also can be regarded as the relevant technical reserves of the jacket structure for deep-water offshore wharf construction in our country.

Bend channel is common seen in inland waterways. Due to the complex flow conditions, it’s often of great difficulty for ship maneuvering. To improve navigation conditions, usually the regulation is needed. In this paper, a 3D flow simulation model and ship maneuvering model are coupled. Based on the simulation results, the navigation conditions in Yiyang-Lulintan waterway project are evaluated. The simulation based evaluation provides a scientific basis and guidance for regulation projects in bend channel.

The construction of reservoir is beneficial to improving channel conditions, but at the same time, it also increases the possibility of ship-bridge collision, especially for arch bridge, the navigable clearance of which reduces. Once the collision happens, it will lead to a serious accident, therefore, the construction of anti-collision device is particularly important. “Arc Water Lifting Anti-collision Device” is designed to protect reservoir arch bridge from being hit by ships, which is mainly composed of three parts, that’s collision belt, buoy and oriented well, and it can lift freely with the water level changing. In this paper, this device is applied in Wanzhou Yangtze River Highway Bridge, and it is proved that this new device can meet the security requirements of ship, bridge, and itself when the collision occurs.

A new type of squeeze film damper (SFD) is designed to reduce spool’s impact and vibration which happen in the two-stage larger flow rate high-speed on/off valve with the 450 L/min flow rate and 8ms turn-off time, the valve’s sealing performance、reliability and service life improve largely, and the valve’s response speed doesn’t drop. The simulated and experimental results show: The damper has optimum buffering performance when oil film thickness is 0.1mm, and the spool closing process approach ideal state. The valve will has a great potential application in the powerful occasions because of it's perfect performance: larger flow rate、fast response and novel damper.

Conical valve’s spool-seat contact pairs is consisted of two surfaces of different curvature radius, and form closed circular contact line. It can be considered as the model of elastic hemi-space contact by the Hertz Theory. The numerical simulation and experiment show: The model is suitable for the analysis of conical valve’s spool-seat contact pairs. The conical valve’ sealing performance is very credible and its performance is very good. Maximum stress is smaller than allowable stress of the seat’s material. The consistency of experiment and simulation proves the validity and practicability of the hemi-space contact model of the valve’s spool-seat contact pairs.