Transposition of large tabular data structures with applications to physical database organization

Acta Informatica - Tabular data structures of a relational database, placed in a paged virtual space or in some two-level storage, are discussed. To rearrange, or transpose, those data stored...     

三洋开发出了效率为22．8％的超薄太阳能电池

三洋电子有限公司（Sanyo Electric,东京）成功制作出．具有实用尺寸（100cm^2甚至更大）的超薄太阳能电池板,而且转换效率接近三洋在今年5月份报道的23％的最高纪录。该公司最新一代的HIT太阳能电池厚度只有98μm,不到该公司最高效率电池厚度的一半,而且其转换效率也高达22．8％。     

A molecular dynamics study of bubble nucleation in liquid oxygen with impurities

The present study investigates bubble nucleation in liquid oxygen with dissolved impurities (nitrogen or helium molecules) using molecular dynamics simulations. When the mole fraction of impurities is 0.05, there is a fundamental difference in the bubble nucleation mechanism between the two dissolved impurities cases; vaporization in the homogeneous bulk makes a bubble in the case of a nitrogen‐dissolved liquid while phase separation of impurities and liquid molecules makes a nucleus in the case of a helium‐dissolved liquid. Fluctuations can cause local voids, which in turn can grow to be bubbles, and this effect is stronger in the case of a helium‐dissolved liquid with a lower mole fraction (0.01) than in the case of a nitrogen‐dissolved liquid with a higher mole fraction (0.05). From these results, we conclude that helium molecules have a much stronger action to raise the bubble formation pressure compared with nitrogen. In this paper, the kinetically‐defined critical nucleus, which is a very important factor in quantitatively evaluating the nucleation mechanism, is also estimated through the calculation of the size change rate of each nucleus. © 2005 Wiley Periodicals, Inc. Heat Trans Asian Res, 34(7): 514–526, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20082     

Advanced fabrication technologies of integrated-type structure for a-Si solar cells

This paper proposes a new advanced fabrication technology for a low-cost integrated-type a-Si solar cell. Integrated-type cells provide many advantages and have been industrialized with a laser patterning method. However, a higher throughput and more efficient patterning method was required for applying a-Si solar cells to a power generating system. Plasma CVM (Chemical Vaporization Machining) was first applied to advanced patterning because of its advantages of high speed and selectivity. In this method, a plasma generated under high pressure localizes near the wire electrode and concentrates reactive radicals. As a result, we achieved an etching rate of more than 1 μm/s and selective patterning of a 200 μm-wide a-Si layer in 1 s multiline patterning was also developed for large-area modules.     

Optical triode switch module with a nonlinear etalon

An all-optical device in which a nonlinear etalon is operated stably as a triode switch at a high on-off ratio is discussed. A nonlinear etalon is sandwiched between two quarter-pitch GRIN (graded index) lenses. Detuning is adjusted by using the position-to-angle conversion feature of the lens. Two orthogonally polarized beams are used to obtain a high on-off ratio (~10:1) even for a weak signal beam by completely separating a control beam from an output beam     

Data Driven Cyber-Physical System for Landslide Detection

Mobile Networks and Applications - Natural disaster is one of the most important research topics worldwide. In this paper, a data driven cyber-physical system is introduced to detect landslides....     

Radical polymerization of (phenylethynyl)styrenes and characterization of poly(phenylethynyl)styrenes as a thermally curable material

Summary The radical polymerizations of 2-, 3-, and 4-(phenylethynyl)styrenes (1a–c) and the copolymerizations of 1a–c (M₁) with styrene (M₂) were carried out using AIBN as the initiator in toluene at 60°C. The number-average molecular weights (M _ns) were extremely low for poly(2-phenylethynylstyrene) (2a) and poly[(phenylethynyl)styrene-co-styrene] (3a), and increased in the order of 2a, 3a << 2b, 3b < 2c, 3c. Monomer reactivity ratios were determined as r ₁= 1.80 and r ₂= 0.51 for 1a, r ₁= 1.72 and r ₂= 0.53 for 1b, and r ₁= 3.17 and r ₂= 0.24 for 1c. Polymers 2a–c and 3a–c underwent an exothermic reaction at elevated temperature to form organic solvent-insoluble polymers. Although the decomposition of 2a was observed from 200°C, 2b and 2c exhibited a high heat-resistance property in both nitrogen and air atmospheres, in particular, 2b showed no significant weight loss below 450°C. Received: 28 January 1998/Accepted: 5 March 1998