bluuebunny/crossref_metadata_2025_split huggingface dataset:
Detection of Taste Substances Using Impedance Change of Phospholipid Langmuir-Blodgett Membrane
Authors: Hideyuki Akiyama Hideyuki Akiyama , Kiyoshi Toko Kiyoshi Toko , Kaoru Yamafuji Kaoru Yamafuji 
Published: October 2002

Impedance changes in a phospholipid Langmuir-Blodgett (LB) membrane by several taste substances were measured. A recently developed multichannel taste sensor that uses lipid/polymer membranes responds to taste substances by the membrane potential change. The potential change is based on the change of a diffuse electric double layer near the membrane surface; the sensitivity to nonelectrolytes and weak electrolytes is lower than that to strong electrolytes. Although bitter substances include both electrolytes and nonelectrolytes, outputs of the taste sensor were quite different from each other. Therefore the “bitter" response of human gustatory sensation cannot be represented by the change of the diffuse electric double layer. In this work, most bitter substances were found to increase the resistance of the phospholipid LB membrane. This implies that the increase of membrane resistance is related to the generation of bitter taste in humans and that the sensing system based on impedance measurement is quite effective for the detection of bitterness.
Photovoltaic Effect in Titanium Dioxide/Zinc Phthalocyanine Cell
Authors: Koichi Kajihara Koichi Kajihara , Katsuhisa Tanaka Katsuhisa Tanaka , Kazuyuki Hirao Kazuyuki Hirao , Naohiro Soga Naohiro Soga 
Published: October 2002

The photovoltaic effect has been observed for a titanium dioxide (TiO2) and zinc phthalocyanine (ZnPc) composite cell which is denoted as ITO/TiO2/ZnPc/Au. The photocurrent flows from the ZnPc layer to the TiO2 layer in the external circuit when the cell is illuminated, and the photocurrent and photovoltage of the cell are directly and logarithmically proportional to the light intensity, respectively. A clear rectifying effect is observed in their current-voltage relationships. Not only the photovoltaic effect in the cell but also photoconduction in the TiO2 layer is observed under ultraviolet light illumination. The wavelength dependence of the photocurrent reveals that the collection efficiency of the cell at any wavelength is determined mainly by optical absorption in the ZnPc layer. This result also shows that the major part of incident light in the visible region effectively contributes to photocarrier generation because of the wide band gap of TiO2, and the excited ZnPc molecules play an important role in the photovoltaic effect.
Mode Change of 1 MHz Discharge in O 2 Gas at Low Pressure
Authors: Kenji Aoyagi Kenji Aoyagi , Itsuo Ishikawa Itsuo Ishikawa , Yukinori Saito Yukinori Saito , Shinji Suganomata Shinji Suganomata 
Published: October 2002

Radial distributions of plasma density change significantly at pressures above and below 0.2 Torr. At 0.5 Torr, the discharge is almost hollow with high density around the edge, and its color is almost white. At 0.1 Torr, the density distribution becomes high in the central region both axially and radially, and the discharge color becomes yellowish white. Two prominent lines of optical emission show different spatiotemporal profiles. The O2
+ 559.8 nm line is bright in the central region, while the O I 777.2 nm line is bright just in front of the instantaneous cathode.
Virtual Point Source Pumped cw Nd:YAG Laser with 81 W Output from Linear Cavity and 22 W Output from Ring Cavity
Authors: Jie Song Jie Song , An Ping Liu An Ping Liu , Kazunori Okino Kazunori Okino , Kenichi Ueda Kenichi Ueda 
Published: October 2002

Using a 32-diode-pumped virtual point source, we investigated the output characteristics of a cw Nd:YAG laser of both a linear cavity and a ring cavity. CW output power of 81 W was obtained from the linear-cavity laser under 291 W pumping power and 22 W cw output power was obtained from the ring-cavity laser under 149 W pumping power.
Relationship between Effective Work Functions and Noise Powers of Emission Currents in Nickel-Deposited Field Emitters
Authors: Yasuhito Gotoh Yasuhito Gotoh , Masayoshi Nagao Masayoshi Nagao , Motoki Matsubara Motoki Matsubara , Kazunori Inoue Kazunori Inoue , Hiroshi Tsuji Hiroshi Tsuji , Junzo Ishikawa Junzo Ishikawa 
Published: October 2002

Low-frequency current fluctuations in nickel-deposited field emitters were evaluated quantitatively with normalized noise power which was obtained by integrating the spectral density of the current fluctuation between the frequencies of 0.2 and 2 Hz. The distance between the emitter and the collector was adjusted to 1.5 µm, in order to realize an electrode spacing similar to those of vacuum microelectronics devices. Measurements were performed under an ultrahigh-vacuum environment. The obtained noise powers were analyzed with the Seppen-Katamuki chart which indicates the effective work function and apex radius of the emitter. It was found that the emitters with higher effective work functions showed higher noise powers. The results were explained qualitatively from the differential of the Fowler-Nordheim equation.
Highly Sensitive and Stress-Free Chemically Amplified Negative Working Resist, TDUR-N9, for 0.1 µm Synchrotron Radiation (SR) Lithography
Authors: Shinji Tsuboi Shinji Tsuboi , Yoshio Yamashita Yoshio Yamashita , Soichiro Mitsui Soichiro Mitsui 
Published: October 2002

A chemically amplified negative working resist, TDUR-N9 (Tokyo Ohka) for KrF excimer laser (248 nm) lithography, has been investigated for use in synchrotron radiation (SR) lithography. The resist shows high sensitivity and high resolution in SR lithography. Lines and spaces down to 0.1 µm are delineated at an exposure dose of 50 mJ/cm2. This high sensitivity will enable high-throughput SR lithography. In addition, the resist stress is less than 1 MPa, which is much smaller than those of other commercially available resists. It is found that this characteristic is essential for prevention of pattern deformation in pattern replication of around 0.1 µm.
Study of Initial Stage of Molecular Adsorption on Si(100) by Scanning Tunneling Microscopy
Authors: Ken Nakajima Ken Nakajima , Tomihiro Hashizume Tomihiro Hashizume , Seiji Heike Seiji Heike , Satoshi Watanabe Satoshi Watanabe , Munehisa Mitsuya Munehisa Mitsuya , Takayuki Ikehara Takayuki Ikehara , Yasuo Wada Yasuo Wada , Toshio Nishi Toshio Nishi 
Published: October 2002

We have investigated the initial stage of adsorption of a conjugated aromatic compound, 1,4-bis[β-pyridyl-(2)-vinyl]benzene (P2VB), on the clean Si(100)–2×1 surface. Using scanning tunneling microscopy (STM), we observed four different adsorption directions. An individual molecule appears as two or three bright spots, the brightness and distance between bright spots varying for different adsorption directions. We conclude that STM revealed the electronic states of the Si(100) dimers modulated by the adsorbed molecules, rather than the molecules themselves. Initial stage of adsorption of this molecule is explained by considering the molecular size and shape and strong interaction between the molecule and the Si dimers.
100-K Operation of Al-Based Single-Electron Transistors
Authors: Yasunobu Nakamura Yasunobu Nakamura , ChiiDong Chen ChiiDong Chen , Jaw-Shen Tsai Jaw-Shen Tsai 
Published: October 2002

We have made Al-based single-electron transistors with an artificially fabricated 20-nm island electrode by utilizing standard electron-beam lithography and three-angle shadow evaporation. A periodic gate-voltage dependence of current at above 100 K is demonstrated with this device. In addition, we increased the charging energy about 20% by using anodization.
Adsorption Site Determination by Reflection High-Energy Electron Diffraction Combined with Interface Energy Calculation
Authors: Kamei Masayuki , Yasuaki Tanaka Yasuaki Tanaka , Yoshihiko Gotoh Yoshihiko Gotoh 
Published: October 2002

A new method of reflection high-energy electron diffraction combined with interface energy calculation (RHEED-IEC) was proposed for the purpose of determining adsorption sites on substrate surfaces. This RHEED-IEC was adopted to determine the adsorption sites in a model of the \sscriptsize( 4 \atop-13 \atop3) superstructure of Ce film grown on a Mo(110) surface. The adsorption sites in this Ce \sscriptsize( 4 \atop-13 \atop3) superstructure were determined not to be the hollow sites where a single Ce atom is expected to adsorb, but the highly symmetric bridge sites of the Mo(110) surface.
Detection of Synchrotron Radiation by Nb-Based Superconducting Tunnel Junctions
Authors: Shimizu Keisuke Maehata , Masami Yoshizawa Masami Yoshizawa , Masaki Katagiri Masaki Katagiri 
Published: October 2002

X-rays extracted from synchrotron radiation were detected by Nb-based superconducting tunnel junctions. Measurements were carried out under severe noisy circumstances. Spectra of X-rays were obtained for energies in a range of 4 to 15 keV. The energy for single electron collection increased by 20% at X-ray energies from 4 to 15 keV.
Ion and Neutral Temperatures in a Novel Ultrahigh-Frequency Discharge Plasma
Authors: Toshiki Nakano Toshiki Nakano , Hiroto Ohtake Hiroto Ohtake , Seiji Samukawa Seiji Samukawa 
Published: October 2002

Ion and neutral temperatures are measured in an ultrahigh-frequency discharge plasma through Ar and Ne by Doppler-shifted laser-induced fluorescence. The ion and neutral temperatures are estimated to be ≈0.066 eV (770 K) for Ar+ and 0.033±0.004 eV ( 380 ±50 K) for Ne, respectively. These temperatures are lower than those reported for electron cyclotron resonance and helicon wave plasmas. The low temperatures are attributed to the low electron temperature ( ≈2 eV) and excellent uniformity of the UHF plasma.
Experimental Study of Beam Steering in 980-nm InGaP Cladding Lasers
Authors: Ohkubo Michio , Ikegami Yoshikazu , Tetsurou Ijichi Tetsurou Ijichi , Takao Ninomiya Takao Ninomiya 
Published: October 2002

The beam steering phenomenon was directly observed by means of backplane electroluminescence in 980 nm InGaP cladding power lasers. The electroluminescence of the lasers which showed lateral beam steering had a periodic pattern along the active region, which was assumed to be due to spatial hole burning. The period of this pattern was roughly estimated using the effective refractive index method. A laser satisfying the cut-off condition for higher lateral modes did not exhibit a periodic pattern of electroluminescence.
Vapor Phase Epitaxial Growth of ZnTe Films Using Metallic Sources
Authors: Tetsuo Muranoi Tetsuo Muranoi , Masami Sekine Masami Sekine 
Published: October 2002

Undoped ZnTe films with very low resisitivity were grown by vapor phase epitaxy (VPE) with elemental Zn and Te as source materials. The source vapors were transported separately to the vicinity of the substrates, kept at 450–560\degrC, by flow through a thin quartz tube. The growth rate showed two activation energies (45 kcal/mol and 15 kcal/mol) according to the growth temperature. The epitaxial growth was confirmed by using high energy electorn diffraction (RHEED) measurements. Hall effect measurements showed p-type conductivity. Conductive films were obtained when the flow rates of Zn and Te were almost equal and the substrate temperature was above 500°C.
Redox Potential Imaging Sensor
Authors: Noriko Oba Noriko Oba , Tatsuo Yoshinobu Tatsuo Yoshinobu , Hiroshi Iwasaki Hiroshi Iwasaki 
Published: October 2002

We developed a chemical imaging sensor which can be used to visualize the spatial distribution and temporal evolution of redox potential in chemical reaction systems. It is based on the light-addressable potentiometric sensor (LAPS), in which the insulating surface is found to be sensitive not only to the pH value but also to the redox potential of the adjacent electrolyte: a voltage shift of 50.3 mV/decade was observed for the [K3Fe(CN)6]/[K4Fe(CN)6] system. We show that it is possible to measure the distribution of redox potential with high speed (22 s for 64×64 pixels) using this sensor.
Hole Transport in Hydrazone Doped Polymers
Authors: Sinicropi J. A. , Lin L.-B. , P. M. Borsenberger P. M. Borsenberger , E. H. Magin E. H. Magin 
Published: October 2002

Hole mobilities have been measured in poly(styrene) doped with a series of hydrazone (HDZ) molecules with different dipole moments. The results are described by a formalism based on disorder. The formalism is premised on the argument that charge transport occurs by hopping through a manifold of localized states that are distributed in energy. The parameters of the formalism are σ, the energy width of the hopping site manifold or DOS (density-of-states), µ0a prefactor mobility, and Σ the degree of positional disorder. The results show that the widths are between 0.098 and 0.113 eV, increasing with increasing dipole moment. The widths are described by an argument based on dipolar disorder. The argument is that the total width of the DOS is comprised of a dipolar component and a van der Waals component. Describing the dipolar component by the model of Young leads to the conclusion that the van der Waals components are approximately 0.091 eV. The prefactor mobilities are between 6 and 9×10-3cm2/ Vs. Values of Σ are approximately 1.5. Compared to other classes of doped polymers with similar dipole moments, the relatively low mobilities of these materials are attributed to the high values of the van der Waals components and the low prefactor mobilities. The degree of positional disorder is similar to literature values reported for a wide range of doped polymers.
Bias-enhanced Nucleation of Oriented Diamond on Singlecrystalline 6H-SiC Substrates
Authors: Xi Li Xi Li , Yasuaki Hayashi Yasuaki Hayashi , Stanislav Lilov Stanislav Lilov , Shigehiro Nishino Shigehiro Nishino 
Published: October 2002

A bias-enhanced nucleation (BEN) technique in hot-filament chemical vapor deposition (HF-CVD) has been applied to single-crystalline 6H-SiC substrates for the deposition of oriented diamond films. The results of scanning electron microscopy (SEM) showed that on the (000\overline1) face not only oriented diamond films with the relationship (111) Dia.//(000\overline1) 6H-SiC and <110> Dia. // <11\overline20> 6H-SiC, but also that high nucleation density (\symbol"3E109 cm-2) has been achieved. In the case of deposition on the (0001) face of the 6H-SiC under the same experimental conditions, although the nucleation density of diamond was enhanced (above 109 cm-2), however, oriented diamond was not observed. The diamond nucleation density is greater on the (0001) face than on the (000\overline1) face. The differences in oriented nucleation and nucleation density on these two faces are attributed to the difference of their specific free surface energy and chemical bonds.
Optical Properties of Manganese-Doped ZnSe/ZnS Quantum Dots Grown by Molecular Beam Epitaxy
Authors: Shen Yihong Wu , Takenari Goto Takenari Goto 
Published: October 2002

Optical properties of Mn-doped ZnSe/ZnS quantum dots (QD's) have been investigated by both steady-state and time-resolved photoluminescence (PL) measurements. Strong photoluminescence associated with Mn intra-d shell transitions has been observed for QD's with a longitudinal thickness of just few monolayers (ML's). The PL decay involves two processes with different lifetimes of which the faster one has a lifetime of about 5 µs which is almost independent of the well thickness, while the other process has a lifetime varying from 40 to 80 µs when the well width decreases from 6 to 0.25 ML. The experimental results are interpreted by the use of rate equations which suggests that the enhanced Mn emission might be due to the relatively enhanced energy transfer from the QD's to the Mn atoms.
Electron Energy-Loss Spectroscopy Study of the Metal-Insulator Transition in V2O3
Authors: Hiroyuki Abe Hiroyuki Abe , Masami Terauchi Masami Terauchi , Michiyoshi Tanaka Michiyoshi Tanaka , Shik Shin Shik Shin 
Published: October 2002

Electron energy-loss spectra of V2O3 of the paramagnetic metallic (PM) and antiferromagnetic insulating (AFI) phases have been measured by a high-resolution transmission electron energy-loss spectroscopy (EELS) technique. An excitation at about 1 eV was previously observed in both the PM and AFI phases by an optical measurement and assigned to the excitation of a free-carrier plasmon. A sharp peak has, however, been observed at 1.1 eV in our EELS spectra of the PM phase but not in those of the AFI phase. We assigned the peak to an interband plasmon due to d-d transitions by inspecting the dielectric function derived from the EELS spectra. The peak of the O 1s EELS spectra due to the O 1s → V 3d(t
2g
) transition increased in energy by 0.4 eV but decreased in intensity at the transition from the PM phase to the AFI phase. The increase of the energy is due to a splitting of the V 3d(t
2g
) band, which is partly filled at the PM phase, into the fully occupied and unoccupied bands and a shift of the unoccupied band to an energy higher than the Fermi level in the PM phase. The decrease of intensity is considered to be due to the decrease of the transition probability of the O 1s → V 3d(t
2g
) transition, which is attributed to the decrease of the hybridization of the V 3d with O 2p orbitals at the transition from the PM phase to the AFI phase.
Competing Surface Oxidation Reactions During Diamond Synthesis in Low Pressure Flames
Authors: Kim J. S. , Cappelli M. A. 
Published: October 2002

Carbon oxidation reactions affecting diamond growth in
low pressure premixed flames are addressed. Modifications
are made to the relatively simple yet robust Harris growth
mechanism [S. J. Harris: Appl. Phys. Lett. 56 (1990) 2298],
to better capture anomalous behavior seen in past
experimental studies of films deposited from low pressure
acetylene-oxygen (C2H2–O2), ethylene-oxygen (C2H4–O2), and
methane-oxygen (CH4–O2) flames. With surface reactions
involving oxygen, detailed simulations are shown to better
predict the observed growth rates, generally to within a
factor of two for C2H2–O2 and C2H4–O2 flames. More
importantly, the simulations with oxidation reactions
capture the sharp onset of growth as reactant mixture
compositions are varied towards rich flame conditions. The
model is less successful at capturing the growth rates seen
in CH4–O2 flames. The diamond synthesized in CH4–O2 is seen
to be more defective, with a seemingly greater fraction of
sp
2 bonds, the presence of which are not accounted for in
the simple growth mechanism employed in this study.
Low Energy Electron Beam Stimulated Surface Reaction: Selective Etching of SiO 2/Si Using Scanning Tunneling Microscope
Authors: Nan Li Nan Li , Tatsuo Yoshinobu Tatsuo Yoshinobu , Hiroshi Iwasaki Hiroshi Iwasaki 
Published: October 2002

We report here an experimental study of the low energy electron stimulated reaction (LEESR) carried out on a SiO2/Si surface using a scanning tunneling microscope (STM). By applying 100–150 V bias voltage and about 5 nA to below 1 µA current to the SiO2/Si surface, while the surface was kept at 700°C and 100-200 nm away from the STM tip, a surface reaction was induced by the low energy e-beam exposure. A surface of the Si substrate with clear atomic steps was observed within the exposed area, which indicates selective etching of SiO2 by which windows as small as 70 nm in diameter were cut through the SiO2 layer. This result demonstrates the possibility of fabricating a SiO2/Si surface by the LEESR etching and of performing a new type of well-controlled nanofabrication using STM.
Effect of Leakage Current on Pulse-Width Characteristic in Q-Switched Two-Section AlGaAs Multiple-Quantum-Well Semiconductor Lasers
Authors: Shimizu Mitsuaki , Suzuki Yoshihiro , Watanabe SeijiMukai , ToshifumiHasama ToshifumiHasama 
Published: October 2002

We investigated the effect of leakage current on optical pulse width in Q-switched two-section AlGaAs multiple-quantum-well (MQW) lasers, employing numerical analysis using traveling-wave rate equations which include the effect of the carrier leakage. The analysis shows that the pulse width of Q-switched semiconductor lasers is broadened when carrier leakage current is present. This effect becomes significant and is one of the main reasons for the pulse-width broadening for short cavity. These numerical results agree with previously obtained experimental results. [1]
Control of Surface Current on a Si(111) Surface by Using Nanofabrication
Authors: Seiji Heike Seiji Heike , Satoshi Watanabe Satoshi Watanabe , Yasuo Wada Yasuo Wada , Tomihiro Hashizume Tomihiro Hashizume 
Published: October 2002

A scanning tunneling microscope (STM) is used to fabricate insulating trenches on a Si(111)-7×7 surface, and these trenches are used to control the current through the surface states.
When the STM tip is moved along the surface with a high current of approximately 100 nA, surface silicon atoms are extracted and a trench pattern is formed.
Tunneling-spectroscopy data indicate that the surface states are eliminated in the trench region.
Because the trench hinders conduction of electrons through the surface states, properly designed trench patterns can regulate the current path near the surface.
By surrounding the surface with the trench, the effects of the Schottky barrier between the surface states and the bulk are observed in the STM images.
The conduction path through the surface states is investigated by fabricating various trench patterns.
Li-Doped Nickel Oxide as a Thermoelectric Material
Authors: Woosuck Shin Woosuck Shin , Norimitsu Murayama Norimitsu Murayama 
Published: October 2002

Thermoelectric properties of ceramic samples of NiO doped with Li are studied in the
temperature range of 450–1280 K, with different Li contents. The substitution of Li for Ni
atoms in a cubic NiO lattice results in a high thermoelectric power factor over a wide
temperature range. Furthermore, Li substitution decreased the thermal conductivity
resulting in an increase in the thermoelectric figure of merit,
Z = 0.75 ×10-4 K-1 over 1000 K, suggesting that NiO is a promising oxide-base material for high-temperature thermoelectric devices.
Alternative Buffer Architectures for High Critical Current Density YBCO Superconducting Deposits on Rolling Assisted Biaxially-Textured Substrates
Authors: Dominic F. Lee Dominic F. Lee , Mariappan Paranthaman Mariappan Paranthaman , John E. Mathis John E. Mathis , Amit Goyal Amit Goyal , Donald M. Kroeger Donald M. Kroeger , Eliot D. Specht Eliot D. Specht , Robert K. Williams Robert K. Williams , Frederick A. List Frederick A. List , Patrick M. Martin Patrick M. Martin , Chan Park Chan Park , David P. Norton David P. Norton , David K. Christen David K. Christen 
Published: October 2002

Although high critical current density (J

c
) YBCO can be deposited on rolling
assisted
biaxially-textured substrates (RABiTS) with the YSZ/CeO2/Ni architecture, improvement
in uniformity is needed due to the presence of two-component YBCO epitaxy and cracking in
the CeO2 buffer. We have determined that Yb2O3 is an excellent buffer
material that provides a single-component YBCO epitaxy. In addition, crack-free epitaxial
Y2O3 can be consistently deposited onto textured Ni substrates. High quality YBCO
films have been deposited, and J

c
as high as 1.8 ×106 A/cm2 at 77 K
has been
obtained on this Yb2O3/Y2O3/Ni alternative RABiTS architecture.