相变蓄能材料在建筑节能方面的应用研究进展

相变蓄能材料由于相变时吸收或释放潜热的独特性能,在建筑节能方面得到了广泛的应用和研究。分析了相变材料的分类和性能,综述了国内外对相变蓄能材料基本性能的研究进展,并系统地阐述了相变蓄能材料在蓄冷空调系统以及被动式太阳房中的应用研究。     

Influence of surfactant addition for the texture etching process on multi-crystalline silicon wafer

This study investigates the effects of different recipes and concentrations of surfactant on the texture and reflectance of a multi-crystalline silicon wafer surface. The morphology of the surface was examined and photographed using a field emission scanning electronic microscope. The reflectance of the surface was measured and analyzed using a self-designed optical system. The results of this study show that a higher hydrocarbon-surfactant (CH-surfactant) concentration in the etchant resulted in a slower reaction time. The optimum concentration of CH-surfactant was 1%. However, there were many white bubbles in the etching process. The optimum recipe for surfactant included fluoride 2% to diminish these bubbles. The reflectance was less than 22% in visible light. This cost effective acid chemical etching method is suitable for texturing silicon surfaces on 50?nm nanostructures. This is a critical criterion for determining the optimum recipe for surface texturing of acidic etching in solar cells.     

Experimental investigation on a parabolic trough solar collector for thermal power generation

Developing solar thermal power technology in an effective manner is a great challenge in China.In this paper an experiment platform of a parabolic trough solar collector system(PTCS) was developed for thermal power generation,and the performance of the PTCS was experimentally investigated with synthetic oil as the circulate heat transfer fluid(HTF).The solar collector's efficiency with the variation of the solar flux and the flow rate of the HTF was identified.The collector efficiency of the PTCS can be in ...     

TiO2多孔膜上水热合成ZnO结构及其光电性能

The synthesis of ZnO architecture on a fluorine-doped SnO_2(FTO) conducting glass pre-coated with nanoporous TiO_2 film has been achieved by a one-step hydrothermal method at a temperature of 70℃.The effect of the reaction time on the morphology of the ZnO architecture has been investigated,and a possible growth mechanism for the formation of the ZnO architecture is discussed in detail.The morphology and phase structures of the as-obtained composite films have been investigated by field-emission scanning...     

A novel and simple model for estimating the hourly global solar radiation

This letter proposes a novel and simple method for estimating solar radiation, named the ‘three‐point method’. The three points used to form the model are sunrise, sunset, and the maximum radiation point. The issue of obtaining maximum radiation is performed with the weighting evaluation of the HOTTEL and ASHRAE models. The feasibility and effectiveness of the proposed model is shown by simulation results. This model is equally applicable in any part of the world with a reassessment of the weighting factors for the maximum radiation. © 2012 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

基于太阳能输出电压的跟踪方法研究

研究一种车载太阳能的自动跟踪方法。该方法以太阳能输出电压为细跟踪参数,以光敏管组成的比较电路输出电平为粗跟踪参数,并针对太阳能最大输出电压随车载电器负荷变化及天气状态变化的问题,对给定目标值采取了实时调节策略。由于跟踪参数直接取自于太阳能输出电压,因而较好地反映出了太阳能的实际跟踪状态。实验表明,即使车载电器负荷变化及天气状态变化,上述方法均能较好地满足太阳能的动态跟踪要求。     

Throwing New Light on the Reduction of CO2

While the chemical energy in fossil fuels has enabled the rapid rise of modern civilization, their utilization and accompanying anthropogenic CO₂ emissions is occurring at a rate that is outpacing nature's carbon cycle. Its effect is now considered to be irreversible and this could lead to the demise of human society. This is a complex issue without a single solution, yet from the burgeoning global research activity and development in the field of CO₂ capture and utilization, there is light at the end of the tunnel. In this article a couple of recent advances are illuminated. Attention is focused on the discovery of gas‐phase, light‐assisted heterogeneous catalytic materials and processes for CO₂ photoreduction that operate at sufficiently high rates and conversion efficiencies, and under mild conditions, to open a new pathway for an energy transition from today's “fossil fuel economy” to a new and sustainable “CO₂ economy”. Whichever of the competing CO₂ capture and utilization approaches proves to be the best way forward for the development of a future CO₂‐based solar fuels economy, hopefully this can occur in a period short enough to circumvent the predicted adverse consequences of greenhouse gas climate change.