Platinum/carbon multilayer reflectors for soft-x-ray optics

We have fabricated platinum/carbon (Pt/C) multilayer reflectors with 2d spacaings between 50 and 200 ?, using an electron-beam evaporator. We investigated the effects of 2d values, the number of layer pairs, substrate temperature, coatings, and the long-term stability on the reflectivity performance by using characteristic x rays and monochromatized synchrotron radiation in the 0.8-8-keV region. In this study we show that Pt/C multilayers with 10-20 layer pairs exhibit high and stable soft-x-ray reflectivity. The interfacial roughness was measured in the range of 5 ? and becomes lower for structures deposited at liquid-nitrogen temperatures. Coating these reflectors with a 100-?-thick platinum layer increased the grazing angle reflectivity without significantly lowering the Bragg peak reflectivity.     

Carbide Formation and Dissolution in Biomedical Co-Cr-Mo Alloys with Different Carbon Contents during Solution Treatment

The microstructures of as-cast and heat-treated biomedical Co-Cr-Mo (ASTM F75) alloys with four different carbon contents were investigated. The as-cast alloys were solution treated at 1473 to 1548 K for 0 to 43.2 ks. The precipitates in the matrix were electrolytically extracted from the as-cast and heat-treated alloys. An M₂₃C₆ type carbide and an intermetallic σ phase (Co(Cr,Mo)) were detected as precipitates in the as-cast Co-28Cr-6Mo-0.12C alloy; an M₂₃C₆ type carbide, a σ phase, an η phase (M₆C-M₁₂C type carbide), and a π phase (M₂T₃X type carbide with a β-manganese structure) were detected in the as-cast Co-28Cr-6Mo-0.15C alloy; and an M₂₃C₆ type carbide and an η phase were detected in the as-cast Co-28Cr-6Mo-0.25C and Co-28Cr-6Mo-0.35C alloys. After solution treatment, complete precipitate dissolution occurred in all four alloys. Under incomplete precipitate dissolution conditions, the phase and shape of precipitates depended on the heat-treatment conditions and the carbon content in the alloys. The π phase was detected in the alloys with carbon contents of 0.15, 0.25, and 0.35 mass pct after heat treatment at high temperature such as 1548 K for a short holding time of less than 1.8 ks. The presence of the π phase in the Co-Cr-Mo alloys has been revealed in this study for the first time.     

Test Compression for IP Core Testing with Reconfigurable Network and Fixing-Flipping Coding

This paper proposes a class of test compression for IP (intellectual property) core testing. The proposed compression requires only test cubes for the IP cores and it dose not require the structural information about the IP cores. It uses both a reconfigurable network and classes of coding, namely fixing-flipping coding and fixing-shifting-flipping coding. The proposed compression is evaluated from the viewpoint of compression rates and hardware overhead. For three out of four large ISCAS89 benchmark circuits, the compression rates of the proposed compression are better than those of the four existing test compressions.

Morphological and physiological bases of crayfish local circuit neurones

As the subject of neuroethological studies, arthropods offer several advantages to elucidate the neural processes that generate and control behavioural acts. The relative simplicity of their neural organization and their identifiable neurones are particularly advantageous. The crayfish, Procambarus clarkii, uropods are paired appendages of the last abdominal segment that show bilateral closing movement in response to mechanical stimulation. This movement, the avoidance "dart" response, is mediated by a cascade and parallel organization of local circuit neurones in the terminal abdominal ganglion. Thirty intersegmental ascending interneurones and 20 spiking local interneurones have been identified both morphologically and physiologically. They receive exteroceptive inputs directly from the sensory afferents. Two complementary groups of unilateral nonspiking local interneurones have also been functionally identified. They exert fine control over the wide range of activity of motor neurones in a graded and sustained manner. These nonspiking interneurones form opposing and parallel pathways that are essential in modulating the pattern of movement of the uropods.     

晶圆干燥缺陷的机理与控制

长期以来,人们对于硅片在经过HF湿法处理之后出现的水印早已有所认识,尤其是图形包含亲水和疏水层时最为明显。我们系统地研究了经过HF后道处理之缺陷形成的机理,并确认了与先前报道的水印截然不同的缺陷类型。根据X射线和其它分析表明,认为这些缺陷与周围环境残余的汽相HF和随后的晶圆表面反应有关。根据反应腔室HF浓度的不同可以产生不同类型的缺陷。由于水印是由硅在水中的氧化和随后产生的氧化物的分解形成的,少量的HF具有加速这个过程的效果。形成不同缺陷的条件,还有避免这些缺陷的策略均得以认定。正确的排空管理是一个关键的因素。最后发现,重参杂的硅更易产生缺陷。     

Imperfections in friction stir welded zones and their precision non-destructive testing. Studies on characteristics of friction stir welded joints in structural thin aluminium alloys

The purpose of this study is to investigate various characteristics of thin aluminium alloy structural plate joints welded by the friction stir welding (FSW) process. A number of reports have been published concerning these characteristics. Most of these reports concern joints made by the relevant company's unique procedures using selected parent materials; consequently, the joints were made under restricted specified conditions. Accordingly, for this study, welded joints were produced by combinations of identical alloy base metals manufactured by several companies using the friction stir welding process with procedures which are unique to each individual company; an investigation was carried out into a variety of characteristics whilst attention was paid to the differences due to variations in the base metal and welding procedures.     

Effect of mechanical stress induced by etch-stop nitride: impact on deep-submicron transistor performance

This paper reports that process-induced mechanical stress affects the performance of short-channel MOSFETs, and focuses on the effect of a plasma-enhanced CVD nitride contact-etch-stop layer. The stress in the channel region induced by the nitride layer changes transconductance (G_m), thereby changing the device performance. When the nitride stress varies from +300 MPa (tensile) to −1.4 GPa (compressive), NMOSFET performance degrades by up to 8% and PMOSFET performance improves up to 7%. These changes are caused by the modulation of the electron/hole mobilities, so controlling process-induced stress and considering this mobility change in a precise transistor model are necessary for deep-submicron transistor design.