聚光型光伏电池冷却热管蒸发端的数值模拟

针对碟式聚光型太阳能光伏电池效率受温度制约的问题,采用两相闭式热虹吸管(重力热管)散热的方式,工质采用水.热管的蒸发端与聚光太阳能电池接触,其温度场对电池性能和热管效率影响显著.通过FLuENT建立了蒸发端底部的数学模型,计算过程中考虑热流密度、蒸汽饱和温度以及充液量对蒸发端性能的影响.计算结果表明,在聚光倍数为140...     

有机太阳能电池研究进展

为了减轻当前能源危机所带来的压力,各国在太阳能电池等清洁能源领域投入了大量的人力、物力和财力.由于有机太阳能电池具有独特的优点(有机材料易于修饰,器件制备方法简便且可制备出柔韧器件),并且随着相关研究的深入,有机太阳能电池的能量转换效率逐步得到提高,这昭示了有机太阳能电池商业化的美好前景,目前已经有大批科研工作者投身于有机太阳能电池领域的研发工作.文章从太阳能电池小分子材料、聚合物材料和提高有机太阳能电池能量转换效率的方法这三方面入手,对有机太阳能电池领域进行综述.     

溶液法制备全无机钙钛矿太阳能电池的研究进展

太阳能光伏技术,能实现太阳能与电能的高效转换,是实现人类文明可持续发展的关键绿色能源技术.其中,有机无机杂化钙钛矿太阳能电池具有优异的光电特性、低廉的制备成本、高效的转换效率,已成为该领域的研究前沿.虽然有机无机杂化钙钛矿太阳能电池的光电转换效率已约高达24%,但其体系中的有机物组分易受环境中的光、热、潮等因素影响而分解,致使器件稳定性存在严重的缺陷,极大地限制了钙钛矿太阳能电池的产业化进程.因此,如何制备高效稳定的钙钛矿太阳能电池,是目前该领域的研究热点与难点,而发展具有更高环境稳定性的全无机钙钛矿太阳能电池具有重要意义.本文回顾了近年来全无机钙钛矿太阳能电池领域的研究成果,重点审视了钙钛矿薄膜的湿法制备工艺,并探讨了器件在光热稳定性方面的改善,为进一步推动钙钛矿太阳能电池的实用化进程提供可行性参考.     

溶胶-凝胶法制备GaInP/GaAs/Ge三结太阳能电池梯度折射率减反膜

为了减少太阳能电池表面反射,提高多结太阳能电池效率,针对GaInP/GaAs/Ge三结太阳能电池和AM0光谱,设计了折射率梯度排列的四层减反膜系结构.利用溶胶-凝胶技术,通过对材料折射率的定向调节,制备了折射率梯度排列的TiO_2/ZrO_2/酸性SiO_2/碱性SiO_2四层减反膜.实验结果表明,镀膜后的三结太阳能电池在300~1 700 nm波长范围内的加权平均反射率由原先的28.58%降低至4.86%,最高反射率由46.35%降低至15.45%.     

一维和双层二维光子晶体太阳能电池背反射器

利用a-Si∶H和SiO2等介质,设计了一种由一维光子晶体和双层二维光子晶体组成的非晶硅薄膜太阳能电池背反射器.利用时域有限差分法对该背反射器在入射光波长范围为300~1 100nm波段的反射率和透射率进行仿真,计算不同结构参量下非晶硅太阳能电池短路电流密度并进行比较分析,最终得到了最佳背反射器结构.结果表明:设计的太阳能电池背反射器能够有效地延长入射光在太阳能电池吸收层的传播路径,有助于缓解太阳能电池吸收层厚度对电池吸收效率的影响,提高了电池吸收层对入射光的吸收效率.一维光子晶体和双层二维光子晶体结构的背反射器可以大幅度提高电池的光捕获能力,将非晶硅薄膜太阳能电池的短路电流密度提高到31.96mA/cm2,较常用的Ag/ZnO背反射器结构非晶硅薄膜太阳能电池提高了51.0%.     

高效太阳能转换的材料创新

多尺度材料的装配和集成对新一代太阳能电池器件的运行至关重要,需要基础科学的设计和阐述。关键是要了解和利用定制材料的内在特性,以及材料组件之间的相互作用,从而实现所需要的功能。主要介绍了通过溶液过程连接和组装各种纳米结构方面的最新成果。这些材料已经被用作高效太阳能转换装置的高效光吸收层、载流子传输层、界面层和表面反应促进剂,特别是在钙钛矿太阳能电池和光电化学电池中。并讨论了这些结果对新型太阳能装置的未来发展的影响。     

异质结及其技术在新型硅基太阳能电池中的应用

文章综述了异质结及其技术在新型硅基太阳能电池中的应用.从太阳能电池特性角度,点评了其在晶体硅、非晶硅薄膜太阳能电池及新结构太阳能电池应用中的研究热点和研究现状.在此基础上,讨论了其在不断与晶体硅、薄膜硅太阳能电池融合中的发展动态.     

新形态太阳能电池

保护环境、发展可再生资源是关系到国计民生的重大问题,特别是怎样利用取之不尽、用之不竭的太阳能这一问题,逐渐受到世界各国的重视.太阳能电池作为能有效地将太阳能转化为电能的器件,近年来受到了学术界及产业界的广泛关注.目前国际上广泛应用的平板硅太阳能电池存在造价昂贵、质量重、无形变能力等缺点,因此,怎样从降低成本、提高柔性等方面改进太阳能电池的设计与制备就成为了研究的热点.文章结合近年来国内外期刊杂志上发表的相关研究工作,从电池形态上,分类综述了硬性平板、柔性平板、丝网状、纤维态太阳能电池的结构特点、研究历史及发展现状,提出了目前柔性太阳能电池存在的技术难题和部分解决方案.特别是近年来最新研究报道的纤维态柔性太阳能电池,由于完全突破了平面基底的限制,具有质量轻、可弯折、用途广泛等特点,作为新形态太阳能电池的代表在文中进行了较全面的介绍.     

减小边缘复合助力28%效率的四端钙钛矿/硅叠层太阳能电池

钙钛矿/硅叠层太阳能电池由于能突破单结太阳能电池的效率极限而吸引了广泛的研究兴趣.然而,在将商业化的大面积硅电池切割为实验室所需的平方厘米级的小面积电池时,会造成显著的效率下降,限制了叠层电池的性能.为了消除传统的激光切割法造成的热损伤和热传导,减少切割后的异质结硅电池的非辐射复合,本工作采用砂轮划片这一冷加工方法,对异质结硅电池进行切割.与采用激光切割法得到的器件相比,冷加工法得到的异质结硅电池的截面损伤小,非辐射复合得到显著抑制,器件的开路电压和填充因子均得到提高,平均光电转换效率提高了1%.将得到的硅电池与正式半透明钙钛矿太阳能电池进行机械堆叠,获得了效率超过28%的四端钙钛矿/硅叠层太阳能电池.     

新型空穴传输材料在钙钛矿太阳能电池中的研究进展

钙钛矿太阳能电池是一种全新的全固态薄膜电池. 报道的能量转换效率已提高到19.3%, 成为可再生能源领域的热点研究方向. 空穴传输材料是构成高效钙钛矿太阳能电池的重要组分之一. 本文介绍了钙钛矿太阳能电池的基本结构, 对空穴传输材料的分子结构、能级水平和迁移率等对电池性能的影响进行了详细的总结和评述.     

Solar cells

Solar cells are based on the photovoltaic effect of converting solar energy into electric energy. The mechanism for solar cells is divided into steps, that is, electron-hole pair generation by absorption of light in semiconductors, separation of electron-hole pairs by built-in potential, electron-hole recombination, collection of charge carriers by metal electrodes, etc. In this article, the principle and the theories of these basic steps are presented. On the basis of these steps, methods to improve the efficiency for solar cells are discussed. The fabrication process and the situation of currently produced solar cells are also presented. Solar cells having no p-n junction, that is, photoelectrochemical solar cells and MIS solar cells, are discussed from the perspective of low-cost solar cells.     

Examination of the transition of cultured neuronal cells from submerged to exposed using an environmental scanning electron microscope (ESEM)

Relatively few studies of fully hydrated live or fixed cultured animal cells viewed by environmental scanning electron microscopy (ESEM) have been published. In some cases there may have been some drying out of the cells. In this study the interface between water and cells is imaged as water is carefully evaporated to expose cells. Technical difficulties associated with the process, including inadvertent rewetting of cells are described. Suggestions are made for optimising operating parameters for viewing fully hydrated cultured cells by ESEM. The prospects for viewing live cultured cells are discussed.     

太阳电池新进展

介绍了各种太阳电池技术和发展概况 ,其中晶硅太阳电池技术发展比较成熟 ,商业化程度最高 ,许多技术和理论问题带有普遍性 ,对其他电池的研究开发有借鉴作用 ,文章对此作了较详细的介绍 .薄膜电池是未来发展方向 ,文章对目前国际上研究得最多的几种薄膜电池 ,如非晶硅 (a Si)、碲化镉 (CdTe)、铜铟硒 (CuInSe2 ,CIS)、多晶硅、染料敏化TiO2 等电池的技术发展概况作了介绍 ,并简要说明了不同电池的商业化生产情况 .     

大型预焙铝电解槽电、热场的有限元计算

采用加权余量的伽辽金法推导了铝电解槽电、热场计算的有限元方程.利用ANSYS有限元软件具有的多重单元、多重属性及其能耦合求解电、热场的特点,建立了铝电解槽阳极和熔体大面切片的有限元模型.在合适的边界条件的假定下,对160kA预焙槽的电、热场进行了仿真计算,分析了槽内的温度分布和电压、电流分布.结果表明:所建有限元模型的仿真结果与设计值吻合较好,证实了采用ANSYS软件优化铝电解槽设计和开发新型铝电解槽的可行性与准确性.     

Is TrpM5 a reliable marker for chemosensory cells? Multiple types of microvillous cells in the main olfactory epithelium of mice

Background  

In the past, ciliated receptor neurons, basal cells, and supporting cells were considered the principal components of the main olfactory epithelium. Several studies reported the presence of microvillous cells but their function is unknown. A recent report showed cells in the main olfactory epithelium that express the transient receptor potential channel TrpM5 claiming that these cells are chemosensory and that TrpM5 is an intrinsic signaling component of mammalian chemosensory organs. We asked whether the TrpM5-positive cells in the olfactory epithelium are microvillous and whether they belong to a chemosensory system, i.e. are olfactory neurons or trigeminally-innervated solitary chemosensory cells.     

A comprehensive study of classification methods for medical diagnosis

In this model study, we developed a method to distinguish between breast cancer cells and normal epithelial cells, which is in principal suitable for online diagnosis by Raman spectroscopy. Two cell lines were chosen as model systems for cancer and normal tissue. Both cell lines consist of epithelial cells, but the cells of the MCF‐7 series are carcinogenic, where the MCF‐10A cells are normal growing. An algorithm is presented for distinguishing cells of the MCF‐7 and MCF‐10A cell lines, which has an accuracy rate of above 99%. For this purpose, two classification steps are utilized. The first step, the so‐called top‐level classifier searches for Raman spectra, which are measured in the nuclei region. In the second step, a wide range of discriminant models are possible and these models are compared. The classification rates are always estimated using a cross‐validation and a holdout‐validation procedure to ensure the ability of the routine diagnosis to work in clinical environments. Copyright © 2009 John Wiley & Sons, Ltd.     

Stability issues of the next generation solar cells

Polymer, perovskite, and dye‐sensitized solar cells (DSSCs) are promising technologies for next generation low cost photovoltaic cells. Among these, perovskite solar cells are the newest technology and have the highest efficiency, while DSSCs are closest to commercialization with several companies producing the DSSC materials and modules and existing DSSC installations. However, all three types of solar cells share a concern about lifetime and stability. For each type of devices, there are specific concerns and degradation mechanisms, and all of the devices require encapsulation and exhibit varying degrees of sensitivity to moisture, oxygen, elevated temperature and UV illumination depending on the device structure and materials used. We are discussing the stability and lifetime for each type of cells and future outlook of these technologies. (© 2016 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim)     

一种使用高灵敏度荧光显微镜系统进行活细胞研究的方法

利用显微镜进行细胞观察和实验，一般的做法都是将细胞做成切片，细胞难免会受到损伤，从而影响实验及观察结果。为了使细胞研究更为准确，便于临床应用，开发、研制活细胞的观察工具是必由之路。以高灵敏度荧光显微镜为基础，合理设计了一种新型暗场照明器。这种新型暗场照明器的工作距离可达３００ｍｍ，完全可以满足为活细胞滴加试剂的需要，已采得经过荧光染色的活细胞图像。这一设计解决了一个非常实际的问题，为活细胞的医学研究奠定了坚实的基础。     

Ultrastructural changes and programmed cell death of trophocytes in the gonad of Isohypsibius granulifer granulifer Thulin, 1928 (Tardigrada,Eutardigrada, Isohypsibiidae)

The studies on the fates of the trophocytes, the apoptosis and autophagy in the gonad of Isohypsibius granulifer granulifer have been described using transmission electron microscope, light and fluorescent microscopes. The results presented here are the first that are connected with the cell death of nurse cells in the gonad of tardigrades. However, here we complete the results presented by Węglarska (1987).The reproductive system of I. g. granulifer contains a single sack-like hermaphroditic gonad and a single gonoduct. The gonad is composed of three parts: a germarium filled with proliferating germ cells (oogonia); a vitellarium that has clusters of female germ cells (the region of oocytes development); and a male part filled with male germ cells in which the sperm cells develop. The trophocytes (nurse cells) show distinct alterations during all of the stages of oogenesis: previtello-, vitello- and choriogenesis. During previtellogenesis the female germ cells situated in the vitellarium are connected by cytoplasmic bridges, and form clusters of cells. No ultrastructural differences appear among the germ cells in a cluster during this stage of oogenesis. In early vitellogenesis, the cells in each cluster start to grow and numerous organelles gradually accumulate in their cytoplasm. However, at the beginning of the middle of vitellogenesis, one cell in each cluster starts to grow in order to differentiate into oocyte, while the remaining cells are trophocytes. Eventually, the cytoplasmic bridges between the oocyte and trophocytes disappear. Autophagosomes also appear in the cytoplasm of nurse cells together with many degenerating organelles. The cytoplasm starts to shrink, which causes the degeneration of the cytoplasmic bridges between trophocytes. Apoptosis begins when the cytoplasm of these cells is full of autophagosomes/autolysosomes and causes their death.     

Primary cells

The systems of the Leclanché, magnesium and R.M. (mercury) cells are described in detail, together with the lesser-known air depolarized and reserve type cells. Nuclear cells are still in the development stage and will be used for specialized applications only. Fuel cells are of great interest to the electrical engineer and a great deal of work has been done on this type of cell resulting in the recent production of a practical operating unit.