Influence of an additional carbon layer at the back contact-absorber interface in Cu(In,Ga)Se2 thin film solar cells

For paste-coated Cu(In,Ga)Se₂ (CIGS) absorber layers used for thin film solar cells one often gets a residual carbon layer between back contact and absorber layer. We investigate the influence of this layer on the solar cells’ performance with co-evaporated CIGS absorbers and find a beneficial effect. The power conversion efficiencies of thin chalcopyrite absorber layers are often limited by the influence of back contact recombination. It is assumed that the carbon layer between the back contact and the absorber layer helps lower this recombination and allows higher open circuit voltages and thus higher conversion efficiencies.     

The influence of socioeconomic and nutritional status on menarche in Nigerian school girls

Two once-daily electroconvulsive shocks (ECS) produced retrograde amnesia in rats trained on a Hebb-Williams maze; Verapamil (12.5 mg/kg, i.p.) or felodipine (10 mg/kg, p.o.) administered half an hour before each ECS attenuated this ECS-induced amnesia. Hence, these drugs may hold promise for the containment of amnesia induced by electroconvulsive therapy (ECT). Speculatively, one or more of several mechanisms may be involved: cerebral vasodilatation, enhancement of cholinergic tone, and inhibition of calcium-mediated impairment of neuronal function. These drugs may also act by attenuating the systolic surge in blood pressure during ECT, thereby decreasing edema due to cerebral hyperperfusion, as well as decreasing the possible transfer of potentially neurotoxic macromolecules through a putative breach in the blood-brain barrier.     

不同料型、存放时间及制粒过程对嗜热毛壳菌木聚糖酶活性影响的研究

采用体外酶活检测的方法,针对不同料型、存放时间和饲料制粒的加工过程导致的酶活损失进行了研究。结果表明:不同料型极显著影响木聚糖酶的活性(P<0.01),在预混合饲料、浓缩饲料、全价饲料中24h木聚糖酶的剩余活性分别为:15.41%、23.22%和26.97%,随着存放时间的延长,木聚糖酶的活性逐渐降低(P<0.01),存放45d后木聚糖酶在预混合饲料、浓缩饲料、全价饲料中的活性又可降低42.83%、31.93%和19.85%。加工过程极显著影响嗜热毛壳菌纤维酶中木聚糖酶的活性(P<0.01),经过混合、调质、制粒和冷却工艺后,木聚糖酶的活性分别降至56.68%、32.48%、24.00%和27.42%。     

γ心功能仪FT-1908软件改进的临床意义

自Wagner倡导“核听诊器”以来已十年。1979年北京阜外医院引进了“核听诊器”,在推广这一简单有效的仪器方面做了大量工作。与此同时,上海中山医院对“核听诊器”的方法学进行探讨,1980年提出固定本底概念与公式,以及HF-HR座标图与斜率指标等。其后,固定本底法的可行性与实用性得到了进一步证实,并被核听诊器所采用。1982年,清华大学、阜外医院和北京核仪器厂等单位研制成功γ心功能仪。1983年北京核仪器厂正式投产。1984年上海中山医院在原“核听诊器”方法学探讨的基础上,结合临床应用的发展,提高改进原γ心功能仪软件,与上海交通大学密切合作,完成此项工作。本文介绍新软件的特点及其在临床中的应用价值。     

Temperature effect on PI/Cu interface

The interfacial reaction and peel strength of polyimide with copper foil at various cure schedules have been investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and peel test to determine the temperature effect on polyimide/copper interface diffusion and adhesion. SEM studies indicate that the polyimide/copper interfaces are fairly smooth for all samples studied in this experiment. The TEM microstructure reveals the existence of a copper-polyimide interaction zone at the interface when it is cured at a temperature higher than 250°C, which also results in a high peel strength. XPS spectra revealed higher copper and carbonyl carbon contents at the polyimide interface when it is cured at a high-temperature schedule (350°C). From the results of these interface studies, it is concluded that chemical bonding resulting from the interaction of copper oxide and polyimide carbonyl group provides the binding force for polyimide and copper foil. © 1993 John Wiley & Sons, Inc.     

Enhanced laser weldability of an aerospace superalloy by thermal treatment

ABSTRACT

Weldability improvement of the Inconel 738 alloy, subjected to different pre-weld heat treatments and, thermomechanical fatigue of the unwelded and welded alloy is investigated. A new pre-weld heat treatment is found to significantly reduce the susceptibility of the extremely difficult-to-weld alloy to weld cracking. The heat treatment also produces welded material with enhanced resistance to thermomechanical fatigue failure at high mechanical strain ranges, in comparison to the unwelded alloy. Furthermore, by comparing polycrystalline and single crystal materials, without altering the chemistry/microstructure of the superalloy, the presence of grain boundaries in the alloy is found to aid damage mechanisms during in-phase thermomechanical fatigue.     

~(99m)Tc-HM-PAO脑灌注显像剂的研制和动物实验

用自己合成的(DL)-HM-PAO进行了~(99m)Tc的标记和动物实验研究,并初步应用于临床,得到满意的结果。     

Plating of small blind vias [multilayer PCBs]

Metallization of laminates with blind vias on the dielectric side was performed by electroless copper plating with subsequent copper electroplating. The vertical cross section of blind vias with diameters between 125 and 75 μm were analyzed by reflective microscopy. Results indicate that ultrasonic vibration during the pretreatment processes of metallization enables complete electroless copper deposition of the inside wall of the small blind vias without any voids. Furthermore, the introduction of periodic pulse reversal current for the subsequent copper electroplating process resulted in high throwing power deposition. By employing these two protocols, it has been demonstrated that high throwing power deposition can be readily achieved for blind vias as small as 75 μm in diameter with an aspect ratio of 3:1     

Engineered organic/inorganic hybrids for superhydrophobic coatings by wet and vapour procedures

Siloxane/oxide hybrids have attracted growing attention thanks to their ability to modulate the surface energy, wettability, or self-lubricity of a material. Here, we compare two functionalisation procedures (chemical vapour deposition and wet impregnation) on substrate films composed by preformed oxide particles. Three kinds of particles, characterised by different natures (SiO₂ and TiO₂) and average particle size, were studied to highlight possible effects related to the chemical and morphological state of the substrate surface. Morphological characterisations were carried out using dynamic light scattering and scanning electron microscopy, while the structure of the hydrophobing layer was studied by combining Fourier transform infrared spectroscopy and solid-state nuclear magnetic resonance. The degree of functionalisation and the features of the siloxane layer vary significantly among the adopted oxides and functionalisation methods. The wettability features of the different hybrids closely mirror the results of the spectroscopic characterisations, giving rise to either Lotus leaf or patch-wise hydrophobic systems depending on the adopted conditions.