钢骨混凝土梁式托柱转换层结构的研究

通过对钢骨混凝土（ＳＲＣ） 和钢筋混凝土（ＲＣ）梁式托柱转换层结构模型在低周反复水平荷载下的对比试验研究及非线性有限元分析,探讨了ＳＲＣ 和ＲＣ梁式托柱转换层结构的破坏机制,提出了ＳＲＣ梁式托柱转换层的有关设计建议。结果表明,ＳＲＣ梁式托柱转换层结构的破坏机制优于ＲＣ梁式托柱转换层结构。     

Effects of Flood Flow on Flood Plain Soil and Riparian Vegetation in a Gravel River

Field observations were performed to determine the effects of flood flow on the geometrical and chemical characteristics of flood plain soil and the distribution of riparian vegetation in a gravel river. The results of the observations show a decrease in the amounts of the particulate nutrients in the flood plain soil during fairly large flood, because the fine sands that serve as a nutrient source were removed by the flood flow. Numerical simulations for the transport of suspended sediments were performed by varying the peak discharge of the flood, and the change of the particulate nutrients in flood plain soil was estimated by using the results of the simulations. The numerical analysis predicts the reduction of the particulate nutrients in the flood plain soils well. The particulate nutrients on the flood plains decrease if the discharge exceeds the flood of approximately 2 year return period in the observation area.     

Synthesis of well‐defined dendritic hyperbranched polymers by iterative methodologies using living/controlled polymerizations

This review presents firstly the synthesis of various dendritic hyperbranched polymers with well‐defined structures by generation‐based growth methodologies using living/controlled polymerization. Secondly, the synthesis of dendritic hyperbranched poly(methyl methacrylate)s (PMMAs) and their functionalized block copolymers using a novel iterative methodology is described. The methodology involves a two‐reaction sequence in each iterative process: (a) a linking reaction of α‐functionalized living anionic PMMA with tert‐butyldimethylsilyloxymethylphenyl (SMP) groups with benzyl bromide (BnBr)‐chain‐end‐functionalized polymer and (b) a transformation reaction of the SMP groups into BnBr functions. This reaction sequence is repeated several times to construct high‐generation (maximum seventh generation) dendritic hyperbranched polymers. Similar branched architectural block copolymers have also been synthesized by the same iterative methodology using other α‐functionalized living anionic polymers. Surface structures of the resulting dendritic hyperbranched block copolymers composed of PMMA and poly(2‐(perfluorobutyl)ethyl methacrylate) segments have been characterized using X‐ray photoelectron spectroscopy and contact angle measurements. Solution behaviors of dendritic hyperbranched PMMAs with different generations and branch densities are discussed based on their intrinsic viscosities, g′ values and R_h values. Copyright © 2007 Society of Chemical Industry     

Eating habits in childhood relate to preference for traditional diets among young Japanese

The present study investigated whether eating habits during childhood, specifically the type of food eaten for breakfast, is related to later attitudes toward traditional foods among young Japanese. In the experiment, participants were classified into two groups: one consisting of freshmen that habitually ate a Japanese-style breakfast during childhood (n = 28) and the other of freshmen that habitually ate a Western-style breakfast (n = 20). They were asked to complete a personalized implicit association test (IAT) and a self-report questionnaire, both of which measure attitudes toward Japanese and Western foods. Results demonstrated that implicit and explicit associations between Japanese food and attitude in the Japanese-style breakfast group were stronger than those between type of food and attitude in the Western-style breakfast group. Thus, positive attitudes toward traditional diets in young Japanese are likely related to the type of breakfast eaten in childhood.     

Effect of suction force and starting powders on microstructure of Bi4Ti3O12 ceramics prepared by magnetic alignment via slip casting

The microstructures of Bi₄Ti₃O₁₂ (BIT) ceramics made in a vertical magnetic field via a slip casting route are investigated. Two kinds of BIT powders, with equiaxial and plate-like particles, are used. Magnetic force aligns the BIT particles successfully, but the samples are not homogenous. In the top zone, BIT grains in both samples have a–b-plane orientation due to the strong magnetic force. In the bottom zone, the sample using equiaxial particles shows a random microstructure, and the sample using plate-like particles shows c-plane orientation. This is because of the suction force of slip casting.     

Ultrasonic detection of moving interfaces in gas–liquid two-phase flow

Ultrasound reflects strongly off the gas–liquid interface when there is a large change in acoustic impedance. We exploit this phenomenon to detect the instantaneous position of the interface from the time of flight of pulsed ultrasound. Because the characteristics of the reflected wave depend on the shape and size of the interface relative to the ultrasound wavelength, the single-sensing principle is insufficient to capture the interface for generalized gas–liquid two-phase flows. In the present study, we design and examine three types of ultrasound interface detection techniques: the echo intensity technique, the local Doppler technique, and the velocity-variance technique, and investigate and compare the merits and limitations of each. The results indicate that the echo intensity technique is appropriate for turbulent interfaces that cause ultrasound scattering over wide angles. In contrast, the local Doppler technique is required to capture information from waves reflected from smooth interfaces and bubbles. Finally, we find that the velocity-variance technique works for quasi-steady and periodical two-phase flow, and we apply this technique to horizontal slug flow in a tube.     

Plug-in type 1.3-/spl mu/m fiber amplifier module for rack-mounted shelves

We have successfully developed a plug-in type PDFA module for rack mounted shelves which is assembled on a printed-board. In this module, we use a newly developed Pr/sup 3+/-doped high-NA PbF/sub 2//InF/sub 3/-based fluoride fiber and wavelength stabilized 1.017-/spl mu/m laser diodes (LDs). We have obtained a small-signal gain of 24 dB and a noise figure of 6.6 dB at 1.30 /spl mu/m with an LD drive current of 240 mA/spl times/2. We achieved an output power of 10 dBm with a signal input power of 0 dBm. The total power consumption of this module, including that of a Peltier cooler, was 3.5 W when the LD drive current was 240 mA/spl times/2.     

Microstructures of semiconducting silicide layers grown by novel growth techniques

Semiconducting silicides, such as Mg₂Si, β-FeSi₂, Ca₂Si, MnSi_1.7 and Mn(Fe)Si_1.7, were grown and their structural and morphological properties have been characterized. The layers were grown by interdiffusion process between deposited atoms and substrates. When the appropriate substrates and deposition species are used, the silicides can be easily grown using the interdiffusion process. The layers consist of smaller domains for all layers examined, and the shape and size of the domains were much affected by the silicide materials and their growth processes. The structural and morphological features of the silicides are compared, and the growth mechanism and the growth evolution of the silicides are discussed.