Shape‐Controlled Synthesis of High‐Quality Cu7S4 Nanocrystals for Efficient Light‐Induced Water Evaporation

Copper sulfides (Cu_2–xS), are a novel kind of photothermal material exhibiting significant photothermal conversion efficiency, making them very attractive in various energy conversion related devices. Preparing high quality uniform Cu_2‐xS nanocrystals (NCs) is a top priority for further energy‐and sustainability relevant nanodevices. Here, a shape‐controlled high quality Cu₇S₄ NCs synthesis strategy is reported using sulfur in 1‐octadecene as precursor by varying the heating temperature, as well as its forming mechanism. The performance of the Cu₇S₄ NCs is further explored for light‐driven water evaporation without the need of heating the bulk liquid to the boiling point, and the results suggest that as‐synthesized highly monodisperse NCs perform higher evaporation rate than polydisperse NCs under the identical morphology. Furthermore, disk‐like NCs exhibit higher water evaporation rate than spherical NCs. The water evaporation rate can be further enhanced by assembling the organic phase Cu₇S₄ NCs into a dense film on the aqueous solution surface. The maximum photothermal conversion efficiency is as high as 77.1%.     

Ti-13Al-29Nb-2.5MoISM过程中Al元素的挥发损失速率

借助于Kohler三元溶液模型和Miedema二元溶液生长热模型 ,计算了Ti -1 3Al -2 9Nb -2 .5Mo合金中Ti、Al及Nb组元的活度系数 ,并在此基础上计算了合金中组元的平衡分压及Al元素的挥发损失速率 .结果表明 ,组元的活度系数、平衡分压及Al元素的挥发损失速率均随温度的升高而增大 .存在一个临界外压 (约为 1 3 3Pa) ,当外压大于此值 ,挥发损失速率急剧减小并趋于一稳定值 .这给合金熔炼过程中合金成分控制提供了理论指导 .     

制冷空调系统水平管降膜蒸发研究

在制冷剂面临严峻的环境保护控制要求的背景下,研究表明,降膜蒸发由于其较低的制冷剂充注量在制冷空调行业具有重大的应用潜力。本文主要从降膜蒸发管外液膜的流动模式和强化传热2个方面,对水平管降膜蒸发的国内外研究现状进行研究分析。分析表明,管外液膜存在滴状流、射（柱状）流和片状流等模式,而且强化传热须区分高低热流密度情况。为了进一步探究降膜蒸发的机制,从换热和可视化的角度开展强化管外降膜蒸发的特性实验研究。     

电子束蒸镀纳米TiO_2薄膜结构、相组成及亲水性研究

利用电子束蒸镀技术在石英玻璃和单晶Si〈100〉上制备了纳米TiO2薄膜,研究了衬底温度和退火温度对其结构、相组成和亲水性能的影响。结果表明,衬底温度为40~240℃时,石英玻璃上制备的薄膜为无定型TiO2,单晶Si〈100〉上制备的薄膜为弱结晶性的金红石TiO2,两类薄膜的亲水性均很差。退火温度显著影响薄膜的相组成及亲水性能。石英玻璃上不同衬底温度制备的TiO2薄膜经550,650℃退火后均转变为锐钛矿TiO2,具有很好的亲水性能。单晶Si〈100〉上不同衬底温度制备的TiO2薄膜经550~950℃退火后,均由金红石和锐钛矿TiO2混晶组成,且随退火温度升高,薄膜中锐钛矿TiO2含量逐渐增加;随退火温度升高,衬底温度为40℃时制备的TiO2薄膜的亲水性能逐渐降低,而衬底温度为240℃时制备的TiO2薄膜的亲水性能逐渐增强。     

电子式真空阴极弧离子镀引弧器的研制

研制了电子式真空阴极弧离子镀引弧器 ,分析了其工作原理及工作时序 ,给出了它的关键部分的电路 ,介绍了它的离子镀引弧器的性能及特点。     

Surface acoustic wave properties of aluminum oxide films on lithium niobate

Aluminum oxide (Al₂O₃) films have been deposited on lithium niobate (LiNbO₃) substrates by electron beam evaporation without any interlayer between them to ensure a good adhesion of the Al₂O₃ films to LiNbO₃ substrates. As Al₂O₃ thin films can sufficiently increase the surface acoustic wave (SAW) velocity, they can be used to improve the performance of the SAW device. The SAW phase velocity in the Al₂O₃/LiNbO₃ structure was found to increase with the insertion of an Al₂O₃ film, which can be attributed to the stiffening effect of the Al₂O₃ layer. The velocity change ratio of SAW was about 4.39% (at 304 MHz) for the Al₂O₃ (9.7 μm)/LiNbO₃ sample. A comparison with other findings in literature reveals that this result is better than what is available from diamond-like carbon/SiC buffer layer/LiNbO₃ structure, whose the velocity change ratio is 2%.     

Local Enrichment of Active Element Y in Y-modified PVD Films on Mild Steel Substrate

By means of EPMA,SIMS and XTEM tech-niques,the element distribution at the transitionzone of Y-modified ion plated titanium andtitanium nitride film on A3 steel substrate and thevariation of the element content on the surface ofthe evaporation source before and after service werestudied in detail.A mode was proposed in terms ofpreferential evaporation and micro-tunnel trans-portation of Y at the interface of film/substrate.     

Metal-doped diamond-like carbon films synthesized by filter-arc deposition

Diamond-like carbon (DLC) thin films are extensively utilized in the semiconductor, electric and cutting machine industries owing to their high hardness, high elastic modulus, low friction coefficients and high chemical stability. DLC films are prepared by ion beam-assisted deposition (BAD), sputter deposition, plasma-enhanced chemical vapor deposition (PECVD), cathodic arc evaporation (CAE), and filter arc deposition (FAD). The major drawbacks of these methods are the degraded hardness associated with the low sp³/sp² bonding ratio, the rough surface and poor adhesion caused by the presence of particles. In this study, a self-developed filter arc deposition (FAD) system was employed to prepare metal-containing DLC films with a low particle density. The relationships between the DLC film properties, such as film structure, surface morphology and mechanical behavior, with variation of substrate bias and target current, are examined. Experimental results demonstrate that FAD-DLC films have a lower ratio, suggesting that FAD-DLC films have a greater sp³ bonding than the CAE-DLC films. FAD-DLC films also exhibit a low friction coefficient of 0.14 and half of the number of surface particles as in the CAE-DLC films. Introducing a CrN interfacial layer between the substrate and the DLC films enables the magnetic field strength of the filter to be controlled to improve the adhesion and effectively eliminate the contaminating particles. Accordingly, the FAD system improves the tribological properties of the DLC films.     

镀厚膜工艺技术研究

通过分析现有镀膜工艺设备的电子束加热原理、结构和热量损耗,并针对实际应用过程中镀膜存在的问题,提出了对现有设备的改进措施,开发出一种新的镀厚膜工艺,较好解决了芯片镀厚膜的工艺技术难题和存在的镀厚膜工艺质量问题,大大提高了镀厚膜工艺的工作效率,极大地改善了特高压超大功率电力电子器件的电性能参数,收到了良好的效果.