关于可分2－D系统的几个注记

可分２－Ｄ系统是一类具有良好特性的重要的特殊２－Ｄ系统，它在多方面均有重要的应用．本文在已有结果的基础上对具有可分性的２－Ｄ多输入多输出系统在再实现问题、渐近稳定性代数判据、状态观测器设计等方面进行了较为广泛的研究，得到了许多较好的结果．     

ESTIMATION OF DAILY INTAKE OF FOUR KINDS OF TRIHALOMETHANE BY JAPANESE HOUSEWIVES

Duplicate portions of the daily meals consumed by 30 housewives were collected for 3 consecutive days in the cities of Nagoya and Yokohama in Japan.
Meals were analyzed for chloroform, bromodichloromethane (BDCM), chlorodibromomethane (CDBM) and bromoform by using a purge-trap procedure. The average concentration (and the range) of these four kinds of trihalomethane in each of the 24 h duplicate meals were, chloroform 19.6±18.1 ppb(n.d.-106.8 ppb), BDCM 0.3±0.3 ppb(n.d.-1.7 ppb), CDBM 0.1±0.2 ppb(n.d.-0.6 ppb) and bromoform 0.5±1.3 ppb(n.d.-8.1 ppb).
The mean daily dietary intake of the four kinds of trihalomethane by housewives were, chloroform 40.0±25.4 μg, BDCM 0.6±0.5 μg, CDBM 0.3±0.3 μg and bromoform 0.9±1.3 μg.     

Oxygen gas sorption of Mn(II) complex salts of ethylene ionomer with various organic amines

Manganese(II) (Mn(II)) complex salts of poly(ethylene-co-methacrylic acid) (EMAA) were produced from a precursor Mn(II) salt of EMAA and eight different kinds of organic amines, and their oxygen-gas (O2) sorption behavior was investigated using visible absorption and infrared spectroscopies. It was found that the Mn(II) complex salts exhibit a selective O2 sorption during ageing at room temperature in air and release sorbed O2 molecules from ionic aggregates of the Mn(II) complex ions above 343 K in vacuo. From these results, the relationship between the O2 sorption behaviour and the chemical structure of amines is discussed.     

某轻混凝土γ屏蔽积累因子的计算

使用蒙特卡罗程序EGS4计算了光子能量范围0.015~15MeV、屏蔽厚度达40个平均自由程的某核电厂中使用的轻混凝土的γ照射量积累因子,程序计算中考虑了轫致辐射、荧光效应和相干（瑞利）散射对积累因子的影响。使用G-P近似拟合公式对γ屏蔽积累因子计算结果进行拟合计算,给出了相应的积累因子G-P拟合公式的拟合参数。利用此方法可得到此种轻混凝土的任意光子能量和屏蔽厚度的γ屏蔽积累因子。     

Mechanism of inactivation of heat-tolerant spores of Bacillus stearothermophilus IFO 12550 by Rapid Decompression

The effect of three rapid decompression methods to clear the mechanism of inactivation of heat tolerant spores of Bacillus stearothermophilus IFO 12550 was investigated. Pressurization of the spores at 200 MPa and 75°C for 60 min caused a kill of 10⁴ CFU/mL by the link-motion system but the nonrotational rod valve and E.G. seal methods gave a kill of about 10³ CFU/mL. Sterilization was due to the physical breakdown of spore coat, and was induced by its physical permeability of water at high pressure and temperature. Rapid decompression by the link-motion system at 200 MPa decreased the D-value of the spores from 3000 min (100°C, one atmosphere) to 6 min, 11 min, and 17 min at 95, 85, and 75°C, respectively.     

Fractal Structure of Deformed Potato Starch and Its Sorption Characteristics

A deformation of microstructure was attempted on native potato starch and the change in the microstructure was analyzed from the fractal view point. The surface area calculated from the monolayer molecular number was different depending on the molecules used (Ar, N₂, Kr, 1-propanol, and benzene), which showed the surface microstructure was a fractal with the dimension 2.1-2.4. The specific surface area measured using N₂ and benzene was a function of the mean diameter of the material particles, which also showed that the porous structure of the particle was a fractal with the dimension 2.2-3.0. On the other hand, the sorption isotherm of water vapor was independent of particle diameter.     

Formation Reaction of ZrO2 Scatterers in ZrF4-Based Fluoride Fibers

This paper clarifies the formation reaction of ZrO₂ crystals which appear as extrinsic scatterers in fluoride fibers. EPMA analysis indicates that BaO exists at grain boundaries of BaF₂ purified by sublimation. BaO reacts with ZrF₄ to form ZrO₂ at 600°C during a glass-melting process. The ZrO₂ formation reaction is influenced by H₂O. Ba(OH)₂, which is formed by the reaction between BaO and water vapor, melts at 370° to 420°C and reacts with ZrF₄ to form ZrO₂ at 450° to 520°C. When low-oxide-content BaF₂ is used for fiber preparation, scatterers significantly decrease.     

The product cycling problem under increasing yield rates

We investigate the product cycling problem (also known as the common cycle scheduling problem) when there are economies of scale due to increasing yield rates. Increasing yield rates are characteristic of production processes in which the percentage of acceptable parts increases with the duration of the production run, usually owing to adjustments made during the initial portion of the production run. We develop a solution procedure that is optimal for a wide range of production cost functions under very mild conditions. We then compare optimal solutions with those obtained from the commonly used 'fixed-plus-linear' approximation of costs. Computational results suggest that the 'fixed-plus-linear' approximation generally performs well, but may result in substantial errors under certain extreme conditions.     

A comparison of solution approaches for the fixed-sequence economic lot scheduling problem

The economic lot scheduling problem (ELSP) has received much attention recently. The general version of the problem has a non-convex objective function, so it is difficult to find truly optimal solutions. We examine the three most popular heuristic approaches to the fixed-sequence ELSP. Each approach imposes one or both of these simplifying constraints: the zero-switch constraint (production of a part is started only when its inventory is depleted) and the equal-lot constraint (the lot size of a given part is constant through time). We provide a formulation that clarifies the relationships between the general problem and the three constrained versions, and compare their performances in a computational study.     

Improvement of the Half-embryo Test for Detection of Gamma-irradiated Grapefruit and Its Application to Irradiated Oranges and Lemons

The duration of the half-embryo test used for identification of gamma-irradiated grapefruit was shortened by increasing germination temperature to 35°C. Maximum shooting percentages were reached within 3 days. Gibberellin application reduced the required incubation time to 2 days. Half-embryos extracted from irradiated orange and lemon gave similar results to those of grapefruit. This half-embryo test is proposed as an identification method for irradiated citrus. Assessment can be made after 3 to 4 days when shooting percentage is greater than 50%.