储存寿命超过2000小时的高功率双面钙钛矿太阳能电池

有机-无机杂化钙钛矿太阳能电池自问世以来,因其光电转换效率迅速提升得到全球的广泛关注.目前,其光电转换效率已高达25.2%.为实现实际应用,提高其稳定性已成为该领域最为关键的问题.本文作者进行了室温磁控溅射ITO的技术研究,成功利用ITO代替钙钛矿太阳能电池的金属顶电极,其制备的半透明电池光电转换效率可达16.7%.最重要的是其在手套箱中储存2000小时以上,电池效率无任何衰减.此外,研究人员发现该半透明太阳能电池具有非常高的双面电池的应用前景,通过改变电池背电极后的反射介质可成功将其输出功率提高至20 m W/cm^2.最后文章指出目前室温下制备的ITO仍然存在透射率低的问题,随着该技术的进一步优化,不断提高其透过率,其双面光伏特性可得到大幅提高.届时,该类电池也将在光伏建筑一体化应用中崭露头角.

Relations between man and nature reflected by the evolution of the Neolithic production tools in the Three Gorges region of Yangtze River,China

The relations between man and nature reflected by evolution of Neolithic production tools in the Three Gorges region of Yangtze River is discussed in this paper.Our results show that there is a good correlation between the percentage vibration of cutting tool types and the environmental evolution indicated by the natural profile nearby.It is possible for ancestors from the Three Gorges region to learn the advantage of mortise and tenon in the early Neolithic Age because they used the stones as vital tools for processing woods.The hunting method in the early Neolithic is throwing,which was inherited in the mid-Neolithic Age when hunting with arrow and bow was developed.Fishing tools are found at the same period.Numbers of net sinkers and spinning wheels unearthed from the strata of the Western Zhou Dynasty from Zhongba Site reveal the fact of fishing with net,while a mass of fishbone pits indi- cate the powerful productivity brought by new production tools.Quantity of stone spades and stone hoes proves that cultivation agriculture by hoe is extremely attached importance by the ancestors in the Three Gorges region.Moreover,the developed agriculture in Daxi Culture at Zhongbao Island benefits from the landform,climate,traffic location,etc.Otherwise,the reason that the farming tools declined in the late Neolithic Age is related to the extreme flood during the early Xia Dynasty and the fishing hunting preference of some ancient settlements.This research shows that ancestors of the Three Gorges region during the Neolithic Age attached importance to fish hunting and cultivation, fought against the natural environment by production tools,constantly created and improved them, then comprehensively utilized them to evolve the relations between man and nature.

China's Import–exchange Rate Linkage:Evidence from the China-bound Exports of Japan and Korea

This paper examines how the China-bound exports of Japan and Korea are related to exchange rates, motivated by the fact that processing trade makes up a large proportion of China＇s trade, and that Japan and Korea are the leading source countries for processing imports. Because processing imports are inputs for exports, the link between such imports and China＇s exchange rates are ambiguous. We estimate export functions that include China＇s RMB real effective exchauge rates （REER） along with bilateral real exchange rates （B RER） using Johausen ＇s cointegration method aud find that the RMB REER significantly affects Japanese and Korean exports to China, even more so than BRER in most cases examined. These two exchange rates appear in the export equations with opposite signs. Subsequently, we use the estimated model to illustrate the importance of accounting for a concurrent change in B RER when analyzing the effects of a hypothetical RMB revaluation on China＇s trade balances despite the apparently weak imports-B RER linkage.