A new correlation method for transit-time estimation

A new correlation method for transit-time estimation is proposed. The transit-time of a propagating quantity between two points along the propagation path could be measured by noise analysis technique when this quantity conveys some measurable stochastic signal with it. This is usually performed by observing directly the peak in the cross-correlation function of the stochastic signal measured at two points in the propagation path, or indirectly by reading the slope of the phase-angular frequency curve. The proposed method presents the transit-time information directly in the same way as in the ordinary cross-correlation technique, but with a better resolution when the conveyed noise signal is band-limited. It also rejects extraneous noise contamination when such noise appears in a narrow frequency band. The usefulness of this method was tested in an air-water two-phase flow channel to estimate the transit-time of the bubbles.     

High resolution for single-strand conformation polymorphism analysis by capillary electrophoresis

Since the successful completion of the Human Genome Project, increasing concern is being directed toward the polymorphic aspect of the genome and its clinical relevance. A form of single-strand DNA-conformation polymorphism analysis (SSCP) employing nondenaturing slab-gel electrophoresis (SGE) is applicable to the genetic diagnosis of bladder cancer from urine samples. To bring this technique into routine clinical practice, the use of capillary electrophoresis (CE) is naturally favorable in terms of speed and automation. However, the resolving power of SSCP, a prerequisite basis for reliability required in diagnostics, remains as a challenge for CE systems. We thus focused on this topic and conducted studies on CE instruments equipped with a single capillary or an array of multiple capillaries, using the resolution (Rs) as a quantitative scale for the resolving power. Polymer concentration and buffer are shown to be the decisive parameters. High Rs values of >2.5 are achieved for representative SNPs markers under the optimized conditions, without sacrificing such intrinsic advantages of CE over SGE as the 10-fold quicker migration time and operation that is reproducible, continuous, and automatic. The strategies presented broaden the limits of CE in both the current and related applications.     

Analysis of residual solvents in natural flavorings by headspace GC using the standard addition method

Headspace GC using the standard addition method has been developed for the simultaneous determination of organic solvents in natural flavorings. The procedure can be outlined as follows: an aliquot of the sample is transferred to a 10 mL vial. To each vial, a DMSO solution containing solvents at different concentrations is added as the standard solution. The vials are kept at 50 degrees C (for automatic injection) or 40 degrees C (for hand-operated injection) for 40 minutes. One mL of the vapor phase in each vial is injected into a gas chromatograph equipped with an Aquatic-2 column (0.25 mm i.d. x 60 m). To evaluate this method, we conducted a performance study in collaboration with 10 laboratories, using ginger oleoresin. We analyzed 6 solvents (methanol, 2-propanol, acetone, dichloromethane, hexane, and 1,1,2-trichloroethene) for which the maximum residue limits are established in Japan's Specifications and Standards for Food Additives. Methanol and acetone existed in the ginger oleoresin, so only the other that four kinds of solvents were added to it. Eight of the laboratories used automatic injection, while the remaining two used hand-operated injection. Statistical analyses were conducted on the data obtained from the 8 laboratories. Repeatability standard deviations (RSDr) ranged from 4.3 to 11.4%, and reproducibility standard deviations (RSDR) ranged from 8.4 to 19.0%.     

A new FIB fabrication method for micropillar specimens for three-dimensional observation using scanning transmission electron microscopy

A new method to prepare micropillar specimens with a high aspect ratio that is suitable for three-dimensional scanning transmission electron microscopy (3D-STEM) was developed. The key features of the micropillar fabrication are: first, microsampling to extract a small piece including the structure of interest in an IC chip, and second, an ion-beam with an incident direction of 60 degrees to the pillar's axis that enables the parallel sidewalls of the pillar to be produced with a high aspect ratio. A memory-cell structure (length: 6 microm; width: 300 x 500 nm) was fabricated in the micropillar and observed from various directions with a 3D-STEM. A planiform capacitor covered with granular surfaces and a solid crossing gate and metal lines was successfully observed threedimensionally at a resolution of approximately 5 nm.     

JAXA-GCF project - high-quality protein crystals grown under microgravity environment for better understanding of protein structure

Since 2003, Japan Aerospace Exploration Agency (JAXA, former NASDA) has been conducting a project on a semi-annual basis (JAXA-GCF) to obtain high-quality protein crystals in the microgravity environment using the Russian transportation system. For this project, protein samples were mostly provided by Japanese users for whom JAXA provided technical and clerical support for crystallization experiments in microgravity. For the project, JAXA has constructed a user-friendly support service for microgravity experiments and provided regular and frequent flight opportunities. To simplify and improve technological matters, JAXA devised a gel-tube method crystallization device, which is effective both in space and on ground, based on the counter-diffusion technique. JAXA also provided ground-based techniques for efficient preliminary optimization of crystallization conditions using a 1-dimensional simulation and for harvesting and cryoprotecting crystals before X-ray diffraction experiments. These improvements have significantly increased the success rate of obtaining useful results. In conclusion, JAXA has developed technologies for growing, in microgravity, high-quality protein crystals, which may diffract up to atomic resolution, for a better understanding of 3-dimensional protein structures through X-ray diffraction experiments.     

手写中文地址识别后处理方法的研究

OCR(光学字符识别技术)作为方便有效的字体识别技术,在办公自动化、信息恢复、数字图书馆等方面发挥着日益重要的作用。语言模型在OCR后处理,特别是在中文的文字识别后处理方面有着广泛的应用。本文针对手写中文地址的后处理,讨论了语言模型的粒度对识别正确率的影响,分析了基于字和基于词的语言模型各自的优点和缺点,并采用了基于词的语言模型,在此基础上提出了加权词图搜索算法。实验证明,在58269条中文手写地址的测试集上,手写地址的整体识别率由原来的28.56%上升到了75.66% ,错误率下降了65.93% ,大大提高了系统的性能。     

Identification of deformation behavior in high‐thermal‐resistant poly(acrylonitrile‐butadiene‐styrene) (ABS)

Deformation mechanisms in postfractured high‐thermal‐resistant poly(acrylonitrile‐butadiene‐styrene) (ABS) were investigated using transmission electron microscopy (TEM) and small‐angle X‐ray scattering (SAXS). Although crazes were clearly identified by TEM, they were not detectable by SAXS. This was possibly due to a short distance between sample and imaging plate in the SAXS set‐up and invisibility of craze fibril scattering from the postfractured samples. A rhomboid‐shaped SAXS pattern was obtained from ABS samples with high ductility but with no crazes shown in the TEM micrographs. It is believed that the rhomboid‐shaped SAXS pattern was generated from matrix shear yielding. The results show that a combination of TEM and SAXS enable us to distinguish crazing and shear yielding in the postfractured ABS. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1316–1321, 2001     

Use of Double Wash-Coatings of Platinum and Zeolite Catalysts to Improve Selective Reduction of NOx by Hydrocarbons

The selective catalytic reduction by hydrocarbons (HC-SCR) of NO _x under lean conditions has been improved by the use of double-layered catalysts with a lower layer of Pt/SiO₂ and an upper layer of a zeolite such as H-, Ce-, and Cu-ferrierite (-FER). H-FER wash-coated over Pt/SiO₂ (H-FER//Pt/SiO₂) performed best among the samples examined. The promotional effect was attributed to the synergy of the oxidation catalyst (Pt/SiO₂) in converting NO into NO₂, which is more reactive to C₃H₆, and the HC-SCR catalyst (H-FER). Cu-FER//Pt/SiO₂ was also effective at widening the temperature window, but with this combination the performance was attributed to a simple summation of the activity of two HC-SCR catalysts that were active at different temperatures.