Fabrication and electrical properties of SrTiO3/diamond junctions

Strontium titanate (STO) films were directly deposited on Ib (100) single crystal diamond by r.f. magnetron sputtering. The as-deposited STO film was in amorphous state. On the other hand, the crystalline STO film was obtained under the optimized condition of a deposition temperature of 250 °C and a post-annealing temperature of 650 °C. STO/diamond junctions were fabricated on boron-doped homoepitaxial layers grown on p⁺-type single crystal diamond substrates. Electrical properties of the STO/diamond junction were investigated by changing the surface terminations of diamond with hydrogen or oxygen and the crystallinity of the STO film. It was found that the amorphous STO acted like a semi-insulator on H-diamond surface and that the amorphous STO/O-diamond junction behaved like a Schottky diode. The crystalline STO/O-diamond showed a complex rectifying behavior. The crystalline STO film possessed a higher dielectric constant as compared to that of the amorphous one.     

Rates for intramolecular excimer formation of poly(α-methylstyrene) measured by using picosecond pulse radiolysis

Summary The rate constants for intramolecular excimer formation, k_DM, of poly(α-methylstyrene) with different molecular weight were determined by using picosecond pulse radiolysis. Values of k_DM for poly(α-methylstyrene) are a little smaller than those for polystyrene with nearly same molecular weight. It appears to be mainly due to steric hindrance by methyl substituent of main chain.     

MolSpace: a computer desktop tool for visualization of massive molecular data

The authors have developed a software tool, MolSpace, to visualize massive molecular datasets. MolSpace can project a set of massive multivariate data onto a visual space (two- or three-dimensional space) by means of principal component analysis. MolSpace allows users not only to draw a scatter diagram of the data but also to display their two- or three-dimensional molecular structures as the objects in that space. With a probe (a molecular object) the user can navigate vast data spaces, thus facilitating understanding of the data structure. In addition, partial space searching is also available that is based on similarity searching techniques. It is possible to interrogate a three-dimensional structure of a chemical compound that corresponds to each object on the space in real time. The detail of the system is discussed with an illustrative example.     

Preparation of diamondlike carbon films using nanopulse generator employing SI thyristor

Diamondlike carbon (DLC) films show high hardness, high electric resistivity, and the self‐lubricant characteristic, and many applications and synthesis methods have been reported. Pulse plasma chemical vapor deposition (CVD) is one of the synthesis methods suitable for DLC films on complicated form work, such as molding and extruding die. Ordinary, microsecond‐order pulse is used in this method. This paper describes the development of the synthesis method using nanosecond‐order pulse plasma CVD for DLC films. To realize this process, a static induction (SI) thyristor with an inductive energy storage (IES) circuit was used. Compared with microsecond, nanosecond‐order pulse plasma CVD method shows the characteristics of high electron temperature and exponential relationship between pulse frequency and growth rate. The characteristics of the thus‐obtained DLC films show two broad peaks of the disordered band at 1360 cm^?1 and the graphitic band at 1580 cm^?1 by Raman spectroscopy and hardness of 16.0 GPa and elastic modulus of 170 GPa. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 159(4): 1–7, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20341     

Sex differences in audiovisual discrimination learning by Bengalese Finches (Lonchura striata var. domestica).

Both visual and auditory information are important for songbirds, especially in developmental and sexual contexts. To investigate bimodal cognition in songbirds, the authors conducted audiovisual discrimination training in Bengalese finches. The authors used two types of stimulus: an "artificial stimulus," which is a combination of simple figures and sound, and a "biological stimulus," consisting of video images of singing males along with their songs. The authors found that while both sexes predominantly used visual cues in the discrimination tasks, males tended to be more dependent on auditory information for the biological stimulus. Female responses were always dependent on the visual stimulus for both stimulus types. Only males changed their discrimination strategy according to stimulus type. Although males used both visual and auditory cues for the biological stimulus, they responded to the artificial stimulus depending only on visual information, as the females did. These findings suggest a sex difference in innate auditory sensitivity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Improving the photovoltaic performance of co‐evaporated Cu2ZnSnS4 thin‐film solar cells by incorporation of sodium from NaF layers

We have investigated the influence of sodium (Na) on the properties of co‐evaporated Cu₂ZnSnS₄ (CZTS) layer microstructures and solar cells. The photovoltaic performance and diode properties were improved by incorporating Na from NaF layers into the CZTS layers, while Na had a negligible effect on the microstructural properties of the layer. The best cell fabricated by using an optimal CZTS layer (Cu/(Zn + Sn) = 0.70, Zn/Sn = 1.8) yielded an active area efficiency of 5.23%. The analysis of device properties suggests that charge‐carrier recombination at CZTS/CdS interface is suppressed by intentional Na incorporation from NaF layers. Copyright © 2016 John Wiley & Sons, Ltd.     

Transition in fouling mechanism in microfiltration of a surface water

The main disadvantage of membrane filtration is membrane fouling, which remains as the major obstacle for more efficient use of this technology. Information about the constituents that cause fouling is indispensable for more efficient operation. We examined the changes in both foulant characteristics and membrane morphology by performing the pilot-scale filtration test using one microfiltration membrane. During the operation, we cut the membrane fibers three times, and the components that caused irreversible fouling were extracted by acid or alkaline solution. We found that the characteristic of inorganic matter extracted by acid solution completely differed depending on the filtration period. A large amount of iron was extracted in the second chemical cleaning, while manganese was the dominant component of the extracted inorganic matter in the third chemical cleaning. The analysis of Fourier transform infrared (FTIR) and cross polarization magic angle spinning carbon-13 (CPMAS (13)C) nuclear magnetic resonance (NMR) demonstrated that the contribution of humic substances and carbohydrate in the organic foulant had increased as fouling developed. The changes in the major foulant have no relation with the fluctuation in feed water. The analysis of membrane morphology illustrated that the cake layer started to build up after the blockage of membrane pores. Based on the above results, we hypothesized the following fouling mechanism: the pores were covered or narrowed with relatively large particles such as iron, carbohydrate or protein; small particles such as manganese or humic substances blocked the narrowed pores; and finally an irreversible cake layer started to build up on the membrane surface.     

Shear viscosity of the B phase of superfluid3He

The shear viscosity (T) in the Balian-Werthamer (BW) state of superfluid ³ He is calculated variationally throughout the region 0t 1(t=T/T _c) from the transport equation for Bogoliubov quasiparticles. Coherence factors are treated exactly in the calculation of the collision integral. The numerical result for =_s= _s(T)/_n(T_c) agree very well with experiment in the range 0.8t1.0. Analytic expressions = 0.577 (1–1.0008t) and =1–(23/64) [=(T)/k _B T] are obtained in the low-temperature region and in the vicinity ofT _c, respectively. From the numerical analysis it is shown that the latter equation is valid only in the temperature range 0.9997t1.0.Supported by the Research Institute for Fundamental Physics, Kyoto University.     

Real-time system for measuring gaze direction and facial features: towards automatic discrimination of lies using diverse nonverbal information

Interactive and autonomous agents might be common in everyday life in the future; we expect that such agents will have the ability to communicate with people naturally. For natural communication, the agents should speculate about the intentions of the people they interact with. To enable agents to speculate about intentions like deception, we focused on unconscious expressions when people tell a lie. However, there is no system that can meet the necessary conditions for measuring nonverbal information in natural communication. Therefore, we made a real-time system for measuring gaze direction and facial features. We conducted experiments for discriminating lies by using the system in a situation similar to actual communication. As a result, we found that we could discriminate lies by using diverse nonverbal information in the same way people did.     

Molecular screening of both the promoter and the protein coding regions in the human ob gene in Japanese obese subjects with non-insulin-dependent diabetes mellitus

OBJECTIVE: Although the molecular mechanism of obesity has been poorly understood, recent studies indicate that leptin plays a critical role in regulating both food intake and body weight. Because obesity decreases the sensitivity to insulin, the human ob gene is presumed to be one of the candidate genes for non-insulin-dependent diabetes mellitus (NIDDM) associated with obesity. Although the protein coding region in the ob gene has been screened for mutations, the promoter region and the non-coding first exon have not yet been studied. We investigated the involvement of the human ob gene, especially mutations at the promoter region and the non-coding first exon, in the development of NIDDM associated with obesity. SUBJECTS: The study group comprised 60 Japanese obese subjects with NIDDM (body mass index (BMI) 43.6 > or = BMI > or = 26.4, 29.0+/-0.41 (mean+/-S.E.M.)) and 24 obese individuals with impaired glucose tolerance (IGT) (30 > or = BMI > or = 26.4, 27.1+/-0.22). METHODS: Mutations at both the promoter region and all three exons in the human ob gene were screened by the single-stranded conformational polymorphism analysis. When aberrantly migrated bands were recognized, the PCR-amplified DNA fragment was directly sequenced. RESULTS: In the protein coding region a silent mutation in the second exon was detected. The non-coding first exon and the about 100 bp 5'-flanking region of the gene which contains a proximal CCAAT/enhancer-binding protein site were screened, but no mutations were found. CONCLUSION: These results suggest that no mutations in either the promoter region at the about 100 bp 5'-flanking region of the gene, or in any of the three exons, are involved in the development of NIDDM or IGT associated with obesity.