Preparation of Zr-rich PZT and La-doped PbTiO3 thin films by RF magnetron sputtering and their properties for pyroelectric applications

Abstract

Zr-rich PZT and La-doped PT films were fabricated on a PLT/Pt/Ti/SiO₂/Si or Pt/Ti/SiO₂/Si substrate by an RF planar magnetron sputtering equipment using powder targets with compositions of PbZr_{0 94}Ti_0.06O₃, PbZr_0.92Ti_0.08O₃ and Pb_0.85La_0.15 Ti_0.96O₃ with excess PbO of 20 mol%. The dielectric constants of PZT and PLT films showed anomalies at the transition temperatures of around 246 and 300°C, and their dielectric constants at room temperature were 350 and 1070, respectively. Significant pytroelectric currents were observed in both as-grown PZT and PLT films even without a poling treatment. The pyroelectric coefficients of those films were 10 and 30 nC/cm²K, respectively. Therefore, Zr-rich PZT and [111]-oriented PLT films sputtered on Pt/Ti/SiO₂/Si substrates possess desirable properties for potential applications to pyroelectric devices.     

The association between colors and emotions for emotional words and facial expressions

Color sensations are tied not only to other sensations, but also emotions. There have been many studies on this. One study regarding architectural color showed that colors were associated with mental status; for example, red relates to arousal, excitation, and stimulus. The purpose of the present study is to investigate how colors are evoked by emotions. The emotions were described both by emotional words and by schematic faces. Since facial expressions are accompanied by facial color, facial expressions should relate more closely to facial color than emotional words. Therefore, we used numerous color samples for our experiments to show discrimination sensitivity to stimuli in subtle differences of color. Some associations between colors and emotions were found, and the tendencies of associations were different among emotions. Anger, joy, surprise, sadness, and no emotion were connected to particular colors. The distribution of color responses in sadness was spread among bluish colors. The emotional tendencies, among anger, joy, surprise, and sadness, were similar in the two conditions of our experiment. However, in the schematic face condition, the color responses for all emotions were increased in the skin‐colored samples. Thus, the context of the face elicited the color responses.     

Sequence‐Specific DNA Photosplitting of Crosslinked DNAs Containing the 3‐Cyanovinylcarbazole Nucleoside by Using DNA Strand Displacement

An oligodeoxynucleotide (ODN) containing the ultrafast reversible 3‐cyanovinylcarbazole (^CNVK) photo‐crosslinker was photo‐crosslinked to a complementary strand upon exposure to 366 nm irradiation and photosplit by use of 312 nm irradiation. In this paper we report that the photoreaction of ^CNVK on irradiation at 366 nm involves a photostationary state and that its reaction can be controlled by temperature. Guided by this new insight, we proposed and have now demonstrated previously unknown photosplitting of ^CNVK aided by DNA strand displacement as an alternative to heating. The photo‐crosslinked double‐stranded DNA (dsDNA) underwent >80 % photosplitting aided by DNA strand displacement on irradiation at 366 nm without heating. In this photosplitting based on DNA strand displacement, the relative thermal stability of the invader strand with respect to the template strands plays an important role, and an invader strand/template strand system that is more stable than the passenger strand/template strand system induces photosplitting without heating. This new strand‐displacement‐aided photosplitting occurred in a sequence‐specific manner through irradiation at 366 nm in the presence of an invader strand.     

Respondents with low motivation tend to choose middle category: survey questions on happiness in Japan

Behaviormetrika - Some studies have shown low proportions of Japanese people rating their lives as happy. However, most surveys in Japan revealed that response distributions for subjective...     

Design of a small‐size interlocking system with high availability

An interlocking system consists of an interlocking logical unit and a power controlling unit. After this logical unit calculates the relationship among the train position, the rail shifting position, and the signal, it decides the aspect of the signal. The power controlling unit supplies electrical power to the switch motor and the signal light according to the decision of the logical unit. This paper proposes a small‐sized interlocking system which uses a triplex redundant off‐the‐shelf controller with fail‐safe checker as an interlocking logical unit. A majority voting circuit ensures the safety of parallel output from the interlocking logical unit. This circuit satisfies the condition of total self‐checking (of D.A. Anderson) and also the condition of high availability. In other words, no single fault ever leads to a hazardous state and this circuit ensures safety after single fault occurrence. © 1999 Scripta Technica, Electr Eng Jpn, 128(2): 63–73, 1999     

Physical state of radiation-polymerized polyethylene blends

The physical state of the blends of radiation-polymerized polyethylene with high-density polyethylene was studied. Only one peak was observed in DSC heating curves of the blends quenched from the melt regardless of the each polymer content. In addition, transparency of the high-density polyethylene was improved by melt blending with radiation-polymerized polyethylene. This is a characteristic of high-density polyethylene and radiation-polymerized polyethylene blends different from high-density and low-density polyethylene blends. A new peak and/or a new shoulder, however, appeared in DSC heating curves of the blends with heat treatment at 110°, 120°, and 125°C. These results suggest that the physical state of the blends quenched from the melt is one where the crystallization of the radiation-polymerized polyethylene is high hindered by the presence of high-density polyethylene. The radiation-polymerized polyethylene may remain mainly in a physical state similar to the melt. The haze value of the blends increased with heat treatment. The increase in the haze is caused by change in physical states, such as growth of spherulites and formation of microcrystals and microvoids, by the heat treatment.     

Removal of virus from water by filtration using microporous membranes made of poly(N-benzyl-4-vinylpyridinium chloride)

Two types of microporous filter materials were developed for removing virus from water by using poly(N-benzyl-4-vinylpyridinium chloride) that captures virus in water. Conventional ultrafiltration using one to three sheets of 145-μm-thick cellulose nitrate membrane with a pore size of 0.45 μm and coated with 1.7 mg/g of poly(N-benzyl-4-vinylpyridinium chloride-co-styrene) showed 99.4–99.998% removal (2.2–4.7 log₁₀-unit reduction in concentration) of bacteriophage T4, whereas the control experiments using noncoated membrane showed 91–96% removal (1.0–1.4 log₁₀-unit reduction in concentration) of the virus. A composite 360-μm-thick microporous membrane with a pore size of 20 ¨︁m was prepared that consisted of connected minute beads of 1.7 ¨︁m in diameter made of crosslinked poly(N-benzyl-4-vinylpyridinium chloride) and reinforced by a nonwoven cloth. Simple filtration using one sheet of the composite membrane at 34.2cm/h showed 99.96–99.9995% removal (3.4–5.3 log₁₀-unit reduction in concentration). The virus was not detected in the filtrate when two sheets of the composite membrane were used. © 1996 John Wiley & Sons, Inc.     

A control method for the active power filter in unsymmetrical voltage systems

In this paper, the authors propose a calculation method for the compensating current reference of the active power filter, where a nonlinear load exists in a three-phase, three-wire unsymmetrical voltage system. This new method has been named the extension pq method. The authors have experimented with the extension pq method and the pq method, using the same current-controlled intelligent power module inverter for both methods. The results of the experiments proved that in the unsymmetrical voltage system the source current was distorted in the case of the pq method, but undistorted in the case of the extension pq method.     

Quantitative analyses of topography and elasticity of living and fixed astrocytes

The topography and elasticity of living and fixed astrocytes cultured from the rat cerebra were studied quantitatively by atomic force microscopy (AFM). Ridge-like structures reflecting F-actin beneath the cell membrane were prominent in the contact-mode images of living astrocytes. Many of these ridges became unclear after fixation (2% glutaraldehyde). In addition, the ridge-like structures were invisible in the topography of living cells observed at zero-loading force in the force mapping mode, which is considered to show the real cell surface not pressed down by an AFM tip. The topography of fixed cells observed both in the contact mode and at zero-loading force in the force mapping mode was similar to that of living cells observed at zero-loading force in the force mapping mode, although some deformed areas were detected in the fixed cells. The elasticity map images of living astrocytes showed that the cell membrane above the nucleus was softer (2-3 kPa) than the surroundings, and that the cell membrane above F-actin was stiffer (10-20 kPa) than the surroundings. In the elasticity map images of fixed astrocytes, on the other hand, the elasticity of the cells was found to be relatively uniform (200-700 kPa) irrespective of the inner structures of cells. These results show that images observed by AFM should be carefully examined in consideration of the force introduced to specimens and the elasticity of specimens to find out the real surface topography.