Search

In this paper, we report a passive mode-locking erbium-doped fiber laser (EDFL) that using Au triangles array (Au TA) as saturable absorber fabricated successfully on the fiber tips (OFTs) by nanosphere lithography technology. By using the nanosphere with diameter of 1300 nm, we obtain the localized surface plasmon resonance (LSPR) supported by the Au TA near the C-band (1614 nm). The stable passively mode-locked laser based on Au TA is obtained with a repetition rate of 2.08 MHz and a pulse period of 480 ns for a pump power of 704 mW at 1558 nm. These result may provide a reference in fields of nonlinear optics, micro nano sensing, medical imaging.

Power distribution system design of the green well-off villages and small towns in East China is studied in this paper. Electricity load forecasting, power distribution and energy-saving systems design, effect of distributed energy accessing to the villages and small towns grid are studied. Finally, the advices are given on the power distribution system design of the green well-off villages and small towns.

Considering the rapid increasing of building integrated photovoltaic, a design method based on Ecotect Analysis is proposed in this article. Modeling analysis of the building's sunshine condition is processed to get the annual total solar radiation and sunshine hours per unit area of the building facade and roof. According to the analysis result, the setting position of the photovoltaic system can be determined and the annual generation capacity of the photovoltaic system can be estimated, and all of these can provide references for the design of building integrated photovoltaic. In addition, several high voltage grid connected schemes are given analyzing the Hangzhou south railway station case.

The design feature and performance analysis based on circuit-field coupled finite element analysis of large scale direct-driven permanent magnet (PM) generators are introduced. Some experimental results are presented. The simulation and experimental results of a 1.5MW PM wind generator show that the pole-slot number combination has an important impact on the machine properties, and the optimization of PM's dimension is significant to the performance as well the cost of the direct-driven PM wind generator.

This paper presents the design and implementation of a ultrasound-based wireless ranging system that is suited for integration into the shaft of a conventional long cane to serve as a travel aid for the blind. The new cane provides distance and height information on overhanging obstacles in the travel path ahead of the user. The system consists of three ultrasonic sensors, a microcontroller-based RF telemetric data transmitter, and a data receiver. Systematic experiments using four representative objects have confirmed that the system is capable of detecting obstacles within four meters ahead, with the maximum relative error of detection less than 8%.

In this paper, a novel measurement system that can precisely measure the accuracy of recirculation ball bearing guide is described. This system can effectively realize precise measurement of the parallelism /spl delta/1 between the center of the upper face of sliding block and the bottom face of rail and the parallelism /spl delta/2 between the side face of sliding block and the same side face of rail. At the same time, it can also measure the friction force between sliding block and rail. DSP techniques are applied to improve testing accuracy and analyze error sources. Some suggestions for further analysis on this subject are provided.

This paper presents an optimal design approach based on the popular realistic field simulator Numerical Electromagnetic Code (NEC) and the effective real coded Emperor-Selective genetic algorithm (EMS-GA) for automatic antenna design optimisation. In this approach, the chromosomes used in EMS-GA are directly coded with real number geometrical dimensions. The geometrical input data for NEC is automatically generated and the electromagnetic response is also automatically simulated. The results are linked with the EMS-GA optimiser for optimisation of the desired parameters. As an example and a real engineering application, a special corner reflector antenna driven by a Yagi-Uda array is designed by the NEC/EMS-GA approach. Compared to the traditional Yagi-Uda, the designed antenna has much lower side lobe level (SLL) with better immunity to interference and may find applications in wireless communication and TV reception.

An in-situ, multi-level data fusion algorithm has been developed and implemented for an ultrasonic sensor-array that is embedded into a long cane as a travel aid for the blind. The algorithm is compact and efficient, appropriate for microcontroller-based portable applications. In this paper, several issues of the algorithm development are investigated, including echo signal quality verification and obstacle shape identification. A new technique based on dual-frequency ultrasound scanning is proposed. The algorithm development is based on an obstacle characterization scheme that describes obstacles using three representative groups. Analytical models for each group have been established.