Substrate rotation effects on β-FeSi2 epitaxial film growth using MBE

This study showed that substrate rotation plays an important role in the growth of high-quality β-FeSi₂ epitaxial film on hydrogen terminated Si (1 1 1) substrate using molecular beam epitaxy (MBE). The present work elucidated the substrate rotation effects on morphology, thickness, and purity. Results verified that substrate rotation is essential to grow thicker epilayers with better morphology and compositional uniformity. In addition, purity analyses indicated that substrate rotation increases the concentration of non-metallic impurities (H, C, and O), but does not further introduce metallic impurities into β-FeSi₂ films.     

偏压对MCECR溅射碳氮膜特性的影响

用封闭式电子回旋共振(MCECR)等离子体溅射的方法在硅(100)基片上沉积了碳氮膜(CNx),膜层厚度约80 nm.采用Ar/N2等离子体溅射纯石墨靶,研究了基片偏压对CNx膜机械特性和微观结构的影响,详细分析了基片偏压对CNx膜性能影响的机理.实验结果表明,当基片偏压为 30 V时,CNx膜层性能良好,硬度约为31.48 Gpa,摩擦系数约为0.14,磨损率为6.75×10-15m3/m,系数x接近于4/3.     

The Influence of Nitrogen and Boron Implant into Silicon Substrate on the Phase and Internal Stress of c-BN Films

Cubic boron nitride(c-BN) film was deposited on a Si (100) substrate by the RF-magnetron sputtering.The mainly problems for fabrication of c-BN films are the low purity and high intrinsic compressive stress. In order to solve the two problems, the c-BN film with the buffer interlayer was deposited on the substrate which had been implanted with nitrogen and/or boron ions. The results show: the implantation of nitrogen ions can obviously increase c-BN content and reduce the internal stress slightly; while the implantation of boron shows no obvious improvement to the content of c-BN, which can reduce the internal stress in the film obviously. In addition, it is suggested that the implantation of nitrogen and boron shows the best result, which not only can increase the content of c-BN, but also reduce the internal stress in the c-BN film obviously.     

基片对间接耦合式超磁致伸缩薄膜静态磁化性能的影响

间接耦合式超磁致伸缩薄膜是一种新兴的具有优异机械物理性能的功能材料，已成为微型器件材料研究的热点之一。由于是在弹性基片上通过物理沉积方法得到该种薄膜材料，因此基片的物理性能对薄膜材料的磁化性能会产生重要影响。通过对物理性能差异较大的铜、聚酰亚胺两种基片的间接耦合式超磁致伸缩薄膜的磁化曲线、饱和磁化强度等进行实验研究与分析比较，得到不同物理性能基片对超磁致伸缩薄膜特性的影响规律，为进一步制备性能各异的薄膜材料奠定基础。     

Effect of different substrate concentrations and salinity on hydrogen production from mariculture organic waste (MOW)

In this paper, the influence of substrate concentrations and salinity on hydrogen production from mariculture organic waste (MOW) at mesophilic condition in batch reactors was determined. It was found that the hydrogen yield and hydrogen content were influenced by the initial substrate concentrations and salinity. The optimum concentration for hydrogen production was 20 g/L. The salinity could produce inhibit effect for hydrogen production. The low hydrogen content was detected at high salinity condition. The nutrients changing and metabolites composition could also be significantly influenced by the salinity. The releasing of carbohydrate from MOW could be easily used for hydrogen production, and protein could be accumulated and assimilated during the hydrogen fermentation. The enhancing of salinity was disadvantage for total metabolites accumulation.     

Influence of the Substrate/Inoculum Ratio on Process Stability and Performance during Batch Digestion of Grass Silage

The impact of the substrate/inoculum ratio on the performance and process stability during batch digestion of grass silage, an important substrate in biogas plants, was investigated. The methane yield, degradability, and evolution of intermediary products were monitored in mesophilic reactors fed with increasing amounts of grass silage. A first‐order kinetics model was also applied. Signs of inhibition were observed for the highest loadings, but the system recovered and process failure was not observed. The methane yield decreased with increasing loading but the system was resilient to high loadings under batch conditions.     

In situ vapor-deposited parylene substrates for ultra-thin,lightweight organic solar cells

We fabricate the thinnest (1.3 μm) and lightest (3.6 g/m²) solar cells yet demonstrated, with weight-specific power exceeding 6 W/g, in order to illustrate the lower limits of substrate thickness and materials use achievable with a new processing paradigm. Our fabrication process uniquely starts with growth of an ultra-thin flexible polymer substrate in vacuum, followed by deposition of electrodes and photoactive layers in situ. With this process sequence, the entire cell—from transparent substrate to active layers to encapsulation—can be fabricated at room temperature without solvents and without breaking vacuum, avoiding exposure to dust and other contaminants, and minimizing damage risk associated with handling of thin substrates. We use in situ vapor-phase growth of smooth, transparent, and flexible parylene-C films to produce ultra-thin, lightweight molecular organic solar cells as thin as 2.3 μm including encapsulation with a second parylene-C film. These parylene-based devices exhibit power conversion efficiencies and fabrication yields comparable to glass-based cells. Flexible solar cells on parylene membranes can be seamlessly adhered to a variety of solid surfaces to provide additive solar power.     

The mutual influence of surface energy and substrate temperature on the saturation mobility in organic semiconductors

We report on a mutual correlation between the substrate temperature during semiconductor deposition and the surface energy of the gate dielectric on the charge carrier mobility in bottom gate top contact organic field effect transistors (OFETs) with N,N′-diphenyl-3,4,9,10-perylene tetracarboxylic diimide (DP-PDI) as organic semiconductor.     

The distribution,density, and biomass of the zebra mussel (Dreissena polymorpha) on natural substrates in Lake Winnipeg 2017–2019

The distribution, density, biomass and size-structure of the zebra mussel (Dreissena polymorpha) population in Lake Winnipeg were examined between 2017 and 2019. Zebra mussels have colonized most of the available hard substrate in the south basin and Narrows region, but colonization of the north basin remains low at present, even on suitable substrate. Numerical densities and shell free biomass peaked at 5530 ± 953 m^?2 and 64.7 ± 57.9 g shell free dry mass m^?2 respectively. The distribution appeared to be strongly limited by substrate type and availability, with further limitations on the distribution imposed by physical disturbance in shallow waters and unsuitable substrate in deeper areas of the lake. Zebra mussels <1 year old dominated the populations, and individuals >18 mm were exceedingly rare. Poor recruitment was observed at sites along the eastern side of the south basin compared to elsewhere in the lake. The proximate causes of these differences in colonization success and recruitment are not clear, but may be in part due to heterogeneous patterns of key physico-chemical environmental conditions such as calcium concentrations required for successful development of juvenile mussels and colder water temperatures in the north basin. This study provides a baseline of information on which to track further expansion of zebra mussels in Lake Winnipeg and assist efforts to develop an understanding of how zebra mussels may affect the ecology of Lake Winnipeg.