Advanced Materials Research Vol. 773

Abstract: In transformer-Z-source inverters (TZSI), the impedance networks consist of a transformer and one capacitor. While maintaining the main features of traditional Z-source network, the new networks exhibit some unique advantages, such as the increased voltage gain and reduced voltage stress in the voltage-fed TZSI, when the turns ratio of the transformer windings is over 1. This paper contributes to the ac small signal modeling and analysis of TZSI in continuous conduction mode. The ac small signal model considers the dynamics introduced by network uniquely contained in TZSI. And a double loop control method which is impedance source network output dc voltage and current loop has been proposed to realize the control of TZSI. Results of simulations and experiments are used to validate the control method and show that this method is correct and feasible.

Abstract: DC bias widely exists in power system. In order to analyze its influence on metering current transformer (MCT), a new digital simulation model based on Preisach theory is constructed firstly. Using this digital model, the ratio error and angle error of a running MCT are calculated under different levels of DC bias. Simulation results show that the current DC bias in power system has only little influence on the error of MCT.

Abstract: Heave plates can increase the added mass and viscous damping of marine structures. It's a more economical way to improve the stability of the marine structures' heave movement by adding heave plates compared to other methods. Many scholars have studied on the influencing factors of theirs properties. This paper describes the findings of each factor, and the results are compared. Some experimental results have still not been explained, so it is needed to continue to study heave plates.

Abstract: The hybrid polymer-GaN nanocrystal heterojunction solar cell has been fabricated by blending of GaN and regioregular poly (3-hexylthiophene)(P3HT) through solution process and spin-coating on the glass substrate, in which the Gallium Nitride (GaN) nanocrystal was successfully synthesized by means of sol-gel process The cell shows the Voc and Isc of 0.71V and 3.5mA/cm²

Abstract: Sediment microbial fuel cells (SMFCs) can generate electricity without maintenance in the field. SMFC is considered as an alternative renewable and sustainable power source. Though the SMFC is very appealing energy source, it presents certain challenges for real applications. Its output voltage and current are very low and its output voltage cant be increased by stacking several SMFCs in series in an open water body such as the lake. In this research, we construct and simulate a field SMFC with sediment from Xuanwu Lake in Nanjing, China. Open-circuit voltage of the SMFC is 750 mV and the maximal power density is 7.8 mW/m². A custom-designed power management system (PMS) is developed to harvest energy from SMFC and boost the output power that can drive a wireless sensor. With the PMS, wireless sensor can utilize the harvested energy from SMFC and transmit data to computer without additional power source.

Abstract: In this paper we report on optical absorption measurements performed on several metal oxide nanoparticles (ZnO, CeO₂, Fe₂O₃) as a function of temperature in the range 25500 °C, in order to study the optical properties, and to investigate how several heating cycles could affect nanoparticle structural stability and absorption characteristics. These are quite important issues to be investigated in order to assess the possibility to use such metal-oxide nanoparticles as gas-based high temperature nanofluid in concentrated solar power (CSP).

Abstract: Based on the background of wind power, considering the wind blade sweep area on the uneven distribution, this paper is using the PID control algorithm to control the pitch system. At the same time, this paper is using Siemens SCL to programming, simulating on the experimental platform. Simulation results show the validity of the theory and the feasibility of the system, realizing variable pitch control of fan blade.

Abstract: This test was operated on a s195 diesel engine. The test results showed that the corn-diesel fuels were quite good at the specific property of dissolution and low temperatures flow.They could be used as fuel on diesel engine.The fuel consumption rates of corn-diesel fuels were higher than pure diesel fuels. But with the increase of load,the gap dicreased.The corn-diesel fuels couldn't improve CO and HC emissions,but they were good at emissions of NOx and soot. Furthermore, in most of the conditions, NOx emissions of the corn-diesel fuels were lower than the pure diesel fuels, and Small proportion of the corn-diesel fuels were good. Soot emissions of the corn-diesel fuels were lower than the pure diesel,as proportion of the corn oils increased, Soot emissions were lower.

Abstract: In this paper, a novel photosynthetic bacteria solar cell with Rhodopseudomonas as the electricity generation bacteria was designed and prepared, and photo current changing with the time of the cell was investigated by testing current-time（i-t） curve under alternating light and dark. The results showed that the maximum photo current of the cell could be 13 μA. The influence of glucose, sucrose, chitosan, anthraquinone and hydroquinone on the photo current was investigated. The results indicated that glucose and chitosan made the photo current of solar cell increased about 21 μA and 27 μA, respectively; but sucrose, anthraquinone or hydroquinone had not such effect. It illustrated that photo electrons could be emitted by Rhodopseudomonas and were transmitted to the anode of the cell in the presence of electronic media under light, and the photo current could be improved further by the adding of some additives.

Abstract: In Hubei Province in China, About 15%-40% yield of Burley tobacco losses caused by mildew during air-curing period for High humidity and low temperature. In this paper, active solar utility system was first applied to condition temperature and humidity in the air-curing process. Forced convection solar collectors, natural convection solar collectors and air circulates system were applied in the solar Burley barns. The results showed that: The cost of the system was about 1226 ¥ per drying barn, but it could quickly increase the temperature and reduce the relative humidity of the barn, and the quality and yield were raised. The collector efficiency was about 18.8-24.9%. The average temperature of barn could be improved to 3-4 °Ceven in rainy days. The quality of upper and middle tobacco was enhanced by 11% to 13%; Yields increased by 18% to 23%; The income per acre added 371-392¥; the average income of tobacco increased from 10.49 to 10.87 ¥ per kilograms .