bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nano-Molecular Electronics: Ideas and Experiments
Authors: Wilson Edward Guy 
Published: October 2002

Two designs for information processing devices, comprised of organised assemblies of organic molecules, are described. Information is represented by charges in molecular layers. In the inchworm memory bits are shifted between the layers by electric fields; in the optical shift register, bits are shifted by light pulses. The devices are designed to be interfaceable to existing silicon technology.
Photoconduction experiments are described on molecules assembled by the Langmuir Blodgett technique, which are able to measure electron transport properties, at a molecular level, and on a 35 ps time scale. Interlayer and intralayer intermolecular tunnelling rates are determined, and related to molecular parameters. Control of electron position, at a molecular scale, has been achieved by means of using blocking molecular bilayers.
Novel InGaAs/GaAs Quantum Dot Structures Formed in Tetrahedral-Shaped Recesses on (111)B GaAs Substrate Using Metalorganic Vapor Phase Epitaxy
Authors: Yoshihiro Sugiyama Yoshihiro Sugiyama , Yoshiki Sakuma Yoshiki Sakuma , Shunichi Muto Shunichi Muto , Naoki Yokoyama Naoki Yokoyama 
Published: October 2002

We report a novel GaAs/InGaAs/GaAs quantum dot structure formed in a tetrahedral-shaped recess (TSR) pattered on a (111)B GaAs substrate with anisotropic chemical etching. The pseudomorphic heterostructure shows two clear photoluminescence (PL) peaks, which are attributed to an In anisotropic incorporation on (111)B compared to (111)A. Cathodoluminescence at a lower energy peak with InGaAs of 2.5 nm shows bright image at the bottom of TSRs, which indicates the local minimum of potential energy is at the bottom of the TSR.
Quantitative Analysis for CH 3 Radicals in Low-Temperature Growth of 3C-SiC on Si(001) Clean Surface
Authors: Tomoaki Hatayama Tomoaki Hatayama , Takashi Fuyuki Takashi Fuyuki , Hiroyuki Matsunami Hiroyuki Matsunami 
Published: October 2002

Using cracked propane (C3H8), carbonization of a Si(001) clean surface with a (2×1) structure can be realized reproducibly at as low as 750°C in gas source molecular beam epitaxy. The carbonized layer indicates single-crystalline 3C-SiC, and surface morphology is very smooth. Methyl (CH3) radicals in a cracked-C3H8 molecular beam can be detected with a mass spectrometer utilizing a threshold ionization technique. The number of CH3 radicals is estimated, and it can reach up to 3.0×1011 cm-3 with a C3H8 flow rate of 0.8 sccm and a cracker temperature of 1200°C. Based on quantitative analysis, the condensation coefficient of CH3 radicals in carbonization is discussed.
Characterization of Stress in Porous Silicon Films Prepared by Reactive Hydrogen Plasma Sputtering Technique
Authors: Yong Sun Yong Sun , Tatsuro Miyasato Tatsuro Miyasato 
Published: October 2002

Hydrogenated porous silicon (P-Si:H) films with columnar structure are prepared by reactive hydrogen plasma sputtering of silicon. Stress in the films is characterized by X-ray diffraction and Raman scattering measurement. Experimental results show that the stress mainly results due to a lattice expansion (Δa/a
0) of Si grains in the films. Δa/a
0 increases with decrease in Si grain size, and tends towards the limiting value of about 1.2%, both when Si grain size is below 100 Å and when a large amount of amorphous silicon hydrides are present in the films.
Characteristics of a Discretely Weighted Conical Transducer for Generation of Limited Diffraction Beams
Authors: Takashi Koike Takashi Koike , Ken Yamada Ken Yamada , Kiyoshi Nakamura Kiyoshi Nakamura 
Published: October 2002

We proposed discretely weighted conical transducers as a simple and practical method of generating Bessel-type limited diffraction beams. In this paper we present the design and fabrication of a discretely weighted conical transducer and examine its capability of generating narrow-beam ultrasound. The transducer has eight annular electrodes, to which position-dependent discrete voltages are applied to create approximately the desired velocity distribution of vibration. It is shown experimentally that an almost uniform -6 dB beamwidth of 6–9 wavelengths is obtained in the axial range of z=10 mm to 200 mm using a transducer 25 mm in diameter operating at 3.6 MHz.
Mesogenic Polymer Stabilized Ferroelectric Liquid Crystal Display Exhibiting Monostability with High Contrast Ratio and Grayscale Capability.
Authors: Hirokazu Furue Hirokazu Furue , Tomohiro Miyama Tomohiro Miyama , Yasufumi Iimura Yasufumi Iimura , Hiroshi Hasebe Hiroshi Hasebe , Haruyoshi Takatsu Haruyoshi Takatsu , Shunsuke Kobayashi Shunsuke Kobayashi 
Published: October 2002

We have fabricated a new ferroelectric liquid crystal (FLC) display that exhibits monostable electrooptical characteristics with high contrast ratio (160:1) owing to freedom from defects, grayscale capability without threshold, and fast response (70 µs). A FLC(ZLI-4654-100, Merck) is subjected to polymer stabilization by UV photocure of a mixture of doped monoacrylates with a mesogenic side chain particularly at a temperature where the LC medium is in the SmC* phase under the simultaneous application of a monopolar electric field.
Epitaxial Si on Al2O3 Films Grown with O2 Gas by the Ultrahigh-Vacuum Chemical Vapor Deposition Method
Authors: Takayuki Kimura Takayuki Kimura , Hideki Yaginuma Hideki Yaginuma , Atsuhiro Sengoku Atsuhiro Sengoku , Yoshitaka Moriyasu Yoshitaka Moriyasu , Makoto Ishida Makoto Ishida 
Published: October 2002

By an improved Al2O3(100) growth on Si(100) using O2 gas instead of N2O gas, high-crystalline quality silicon on insulator (SOI) and multistacked SOI structures were successfully fabricated on a 2-inch Si(100) wafer by the ultrahigh-vacuum chemical vapor deposition (UHV-CVD) method. The surface morphology of the Si top layer of the fabricated SOI structure is better than that of the silicon on sapphire (SOS) structure grown by the UHV-CVD method. The transistor action was confirmed from the electrical properties of the MOSFET, and the field effect mobility of 748 cm2/V s was obtained. These results were similar to those obtained from bulk Si. This improved Si top layer of SOI and multistacked SOI structures is due to the improved surface morphology and crystalline quality of the Al2O3 layer grown on Si with O2 gas.
Organic Light Emitting Diodes with Reduced Spectral and Spacial Halfwidths
Authors: Siegfried Dirr Siegfried Dirr , Achim Böhler Achim Böhler , Stefan Wiese Stefan Wiese , Hans-Hermann Johannes Hans-Hermann Johannes , Wolfgang Kowalsky Wolfgang Kowalsky 
Published: October 2002

Organic light emitting diodes (OLEDs) with reduced spectral and spacial halfwidths for full-color imaging applications are investigated. The electroluminescence behaviour of the lanthanide complexes Eu(TTFA)3Phen and Tb(ACAC)3Phen having sharp emission lines in the red and green spectrum, respectively, is examined for different OLED structures. Device optimization criteria with respect to multilayer design and material choice for this type of device are given. A Fabry-Pérot microcavity OLED is investigated to narrow the spectral width of commonly used organic materials (e.g. Alq3) from 100 nm to only 13 nm, demonstrating blue and green emission. In addition, the forward emission at the resonance wavelength is 8 times higher in intensity accompanied by a reduced spacial halfwidth. The directivity is further improved using materials with inherent narrow spectral widths. A spacial full-width at half maximum (FWHM) of 12° is demonstrated if the europium complex Eu(TTFA)3Phen is embedded into a microcavity structure. Compared to a non-cavity device as a reference, the emission intensity in this direction is significantly enhanced by a factor of about 8.
Effect of Grain Size on Bi4Ti3O12 Thin Film Properties
Authors: Masaki Yamaguchi Masaki Yamaguchi , Takao Nagatomo Takao Nagatomo 
Published: October 2002

Bismuth titanate (Bi4Ti3O12) thin films with a c-axis orientation were prepared on (100) silicon wafers by rf magnetron sputtering.
The average grain size and the c-axis lattice constant depend on the substrate temperature.
The c-axis lattice constant was decreased with increasing grain size.
The leakage current characteristics of the Bi4Ti3O12 thin film consisting of small grains with a closely packed structure, are superior to those of others.
The apparent remanent polarization and the apparent coercive field of the film with small grain sizes were estimated to be 2.4 µC·cm-2 and 2.3 kV·cm-1, respectively.
The refractive index dispersion characteristics for the film show that the large grains increase the distortion of the oxygen-octahedra.
Consequently, this result indicates that the small grain size of Bi4Ti3O12 thin films can improve the ferroelectric properties.
Application of Sr2Nb2O7 Family Ferroelectric Films for Ferroelectric Memory Field Effect Transistor
Authors: Yoshikazu Fujimori Yoshikazu Fujimori , Naoki Izumi Naoki Izumi , Takashi Nakamura Takashi Nakamura , Akira Kamisawa Akira Kamisawa 
Published: October 2002

The compounds of the Sr2Nb2O7 (SNO) family are suitable for use
as ferroelectric materials for ferroelectric memory field effect transistors
(FETs),
because these substances have a low dielectric constant,
low coercive field
and high heat-resistance.
In this study, we succeeded in preparing
Sr2(Ta,Nb)2O7 (STN) capacitors
on polycrystalline silicon (poly-Si).
From SIMS profiles,
no interdiffusion
in the STN metal ferroelectric metal insulator semiconductor (MFMIS)
structure was confirmed.
C–V and I
D–V
G hysteresis curves
which were dependent on ferroelectric polarization were obtained.
These capacitors were applied to
floating gate type ferroelectric random access memory (FFRAM) cells.
The degradation in ferroelectricity of STN capacitors
was not observed
during FFRAM cell fabrication process.
We succeeded in operating FFRAM cells with a lower voltage
than that required for PZT
and confirmed
the drain current difference of 1 or 2 orders
at the 30 s after applying write pulses of ±5 V or ±10 V.
Enhanced Growth of β-C 3N 4 Crystallites at a High Substrate Temperature
Authors: Chau-Nan Hong Chia-Yuan Hsu 
Published: October 2002

The growth of β-C3N4 crystallites is studied at various
substrate temperatures by an inductively-coupled plasma sputtering
method
using 500 W of radio frequency power to enhance the gas dissociation.
The
crystallites deposited are demonstrated to be β-C3N4 phase
rather than other phases from the transmission electron diffraction and
the X-ray photoelectron spectroscopy results. Upon increasing the substrate
temperature from 400°C to 800°C,
β-C3N4
crystallite size increases from 0.02 µm to 0.2 µm, but the
[N]/[C] atomic ratio in the film decreases slightly from 1.0 to 0.85,
suggesting that the film contains larger β-C3N4 crystallites
in a less nitrogenated amorphous carbon matrix at a higher temperature.
The film deposited at 800°C exhibits a highly spotty
transmission
electron diffraction pattern and contains a high percentage (90%) of
sp
3 C-N bonding as estimated from X-ray photoelectron
spectroscopy.
The results suggest that a high substrate temperature enhances the
formation
of β-C3N4 crystallites at a high degree of gas
dissociation.
Fabrication and Characteristics of a Field Effect Transistor Using CdF 2/CaF 2 Heterostructures on a Si Substrate
Authors: Wataru Saitoh Wataru Saitoh , Katsuyuki Yamazaki Katsuyuki Yamazaki , Masafumi Tsutsui Masafumi Tsutsui , Atsushi Itoh Atsushi Itoh , Masahiro Asada Masahiro Asada 
Published: October 2002

One-hundred-nanometre-long channel field effect transistors
using CdF2/CaF2 heterostructures on a Si substrate
were fabricated by molecular beam epitaxy growth
and electron beam lithography.
In these transistors, the gate was a highly doped Si substrate,
the gate insulator was a 5-nm-thick layer of CaF2,
the channel was a 5-nm-thick layer of CdF2,
and the source and drain were Au/Cr.
We observed effective modulation of the drain current with the
gate-source voltage at 16 K.
The drain current and the transconductance were
16 nA and 28 nS, respectively.
The operating voltage was high and the drain current was very
small due to the high potential barrier of the Schottky contact
at the source and drain electrodes.
Gain Spectrum Measurement of GaInAsP/InP Compressively-Strained Quantum-Wire Lasers
Authors: Takashi Kojima Takashi Kojima , Suguru Tanaka Suguru Tanaka , Hideo Yasumoto Hideo Yasumoto , Hiroyuki Nakaya Hiroyuki Nakaya , Shigeo Tamura Shigeo Tamura , Shigehisa Arai Shigehisa Arai 
Published: October 2002

The gain spectral characteristics of 1.5 µm wavelength GaInAsP/InP compressively-strained quantum-wire lasers with a wire width of 20 nm and 25 nm, fabricated by electron beam lithography and 2-step
organometallic vapor phase epitaxial growth, were measured at a temperature of 100 K and were compared
with those of quantum-film lasers fabricated on the same wafer.
It was found for the first time that the material gain spectrum of quantum-wire lasers was narrower
than that of the quantum-film laser.
Anisotropic Polarization Properties of Photoluminescence from GaInAsP/InP Quantum-Wire Structures Fabricated by Two-Step Organometallic Vapor Phase Epitaxy Growth
Authors: Kojima Takashi , Shigehisa Arai and Gerd U. Bacher Shigehisa Arai and Gerd U. Bacher 
Published: October 2002

The polarization dependence of 1.5µm wavelength GaInAsP/InP quantum-wire structures fabricated by electron beam lithography and two-step organometallic vapor phase epitaxy growth were measured and compared with quantum-film structures fabricated on the same wafer. As a result, clear anisotropic photoluminescence (PL) properties of the quantum-wire structure corresponding to the wire width (25 nm and 35 nm) were confirmed. This anisotropy was observed to be slightly stronger in the 1% compressively-strained quantum-wire structure than that in the lattice-matched one with the same wire width (35 nm).
Development of a Hybrid Scanning Near-field Optical/Tunneling Microscope (SNOM/STM) System
Authors: Ken Nakajima Ken Nakajima , Ruggero Micheletto Ruggero Micheletto , Keita Mitsui Keita Mitsui , Takashi Isoshima Takashi Isoshima , Masahiko Hara Masahiko Hara , Tatsuo Wada Tatsuo Wada , Hiroyuki Sasabe Hiroyuki Sasabe , Wolfgang Knoll Wolfgang Knoll 
Published: October 2002

Scanning near-field optical microscope (SNOM) is hybridized with a scanning tunneling
microscope (STM) to investigate nanoscopic optical phenomena in both the near-field region
and its proximity. The system is realized by introducing a doubly metal-coated optical fiber
tip with an extremely small aperture (<100 nm), where the metal is coated on the aperture
to obtain a half-transparent conducting tip after the fabrication of an
“aperture probe.” A simultaneous SNOM/STM observation is performed for an Au (111)
surface, where the evanescent field at the tip vicinity through the aperture is scattered
by the local structures of the sample and the far-field component of the scattered light is
collected as an optical signal. The distance control is carried out under the constant-current
condition in order to separate the optical properties from surface topography.
An optical resolution of λ/ 100 and identical channel transport for both electrons and photons
are achieved. The intensity changes, as a function of the gap distance, are also measured in the
far-field and the near-field regions and the proximity.
The Study of Interface States in ZnO Varistors by Injection Pulse Width Dependence of Transient Response
Authors: Yasuhiro Ohbuchi Yasuhiro Ohbuchi , Toshio Kawahara Toshio Kawahara , Yoichi Okamoto Yoichi Okamoto , Jun Morimoto Jun Morimoto 
Published: October 2002

The injection pulse width dependence of transient response was studied to investigate the interface states in the Bi- and Pr-type ZnO varistors in more detail using isothermal capacitance transient spectroscopy (ICTS). Although the interface states have been considered to be distributed monoenergetically or discretely, two or three different interface states of the emission process were confirmed by varying the injection pulse width at each measurement temperature. For both types of ZnO varistors, the ICTS spectrum overlapping of the interface states consists of two transient responses: the previously reported trap (Trap 1) and Trap 0 which has a faster emission process than Trap 1. For only Bi-type ZnO, Trap 2 which has a slower emission process, was successfully detected at the longer region of the injection pulse widths t
W from 1 s to 100 s. This result suggests that the formation of Trap 2 can be attributed to the existence of Bi2O3. In the case of the application of ICTS for the interface states in ZnO varistors, it is necessary to select the optimal injection pulse width which takes into account the emission processes at each measurement temperature.
The Samson Story as Border Fiction
Authors: Weitzman Steve 
Published: October 2002

AbstractThis essay explores the role of story-telling in constructing Judah's border with the Philistines in the shephelah. Judah's struggle to control this frontier involved overcoming social pressures and incentives that naturally pulled Israelites and Philistines living in it toward integration and hybridization. The Samson story, the most famous biblical narrative associated with the shephelah, offers us an opportunity to reconstruct a possible role for story-telling in counteracting this pressure. Drawing on parallels with Greek myth, I argue that the Samson narrative does not merely reflect the ethnic and cultural ambiguities of the shephelah but seeks to assert control over them, doing so in ways that delegitimize Philistine claims to this region and stigmatize border-crossing. What we have in the Samson story, in other words, is an attempt to impose a fictional border between Judah and the Philistines in the shephelah, a border no less inhibitive for being imaginary.
"TO MIX OR NOT TO MIX": SYNCRETISM/ANTI-SYNCRETISM IN THE HISTORY OF THEOSOPHY
Authors: Kraft Siv Ellen 
Published: October 2002

AbstractOnce defined as a "mishmash of religions," syncretism has been referred to as a meaningless, derogatory and essentialistic term which should be banned from the fields of religio-historical research. Written in defence of the category, this article provides a review of problematic aspects and recent attempts to deal with them. Particularly useful in this concern, anthropologists Rosalind Shaw and Charles Stewart have suggested a demarcation between "syncretism" (as the politics of religious synthesis) and "anti-syncretism" (as attempts to protect religious boundaries). Taking their tools as a starting point, this article discusses shifting tendencies in the history of Theosophy. The Theosophical Society started out, it is argued, as a hyper-syncretistic religion, while at the same time promoting anti-syncretism on behalf of other religions. More recently, these strategies have been replaced by efforts to protect boundaries and demarcate its Blavatskian roots.
On Modeling Cognition and Culture: Why cultural evolution does not require replication of representations
Authors: Henrich Joseph , Boyd Robert 
Published: October 2002

Abstract
Formal models of cultural evolution analyze how cognitive processes combine with social interaction to generate the distributions and dynamics of 'representations.' Recently, cognitive anthropologists have criticized such models. They make three points: mental representations are non-discrete, cultural transmission is highly inaccurate, and mental representations are not replicated, but rather are 'reconstructed' through an inferential process that is strongly affected by cognitive 'attractors.' They argue that it follows from these three claims that: 1) models that assume replication or replicators are inappropriate, 2) selective cultural learning cannot account for stable traditions, and 3) selective cultural learning cannot generate cumulative adaptation. Here we use three formal models to show that even if the premises of this critique are correct, the deductions that have been drawn from them are false. In the first model, we assume continuously varying representations under the influence of weak selective transmission and strong attractors. We show that if the attractors are sufficiently strong relative to selective forces, the continuous representation model reduces to the standard discrete-trait replicator model, and the weak selective component determines the final equilibrium of the system. In the second model, we assume inaccurate replication and discrete traits. We show that very low fidelity replication of representations at the individual level does not preclude accurate replication at the population level, and therefore, accurate individual-level replication of representations is not necessary for either cultural inertia or cumulative cultural adaptation. In the third model, we derive plausible conditions for cumulative adaptive evolution, assuming continuous cultural representations, incomplete transmission and substantial inferential transformations.
Testosterone versus psychological castration in the expression of dominance, territoriality and breeding behavior by male village weavers (Ploceus cucullatus)
Authors: Collias Nicholas , Barfield Ronald , Tarvyd Edward 
Published: October 2002

Abstract
The village weaver (Ploceus cucullatus), a tropical passerine bird widely distributed in subSaharan Africa, was the subject of experiments in aviaries at our university. Castrated males fall in the dominance hierarchy, fewer such males establish territorial ownership, they sing less often and weave fewer nests. Injection with testosterone propionate in castrates, or in normal males outside the breeding season, tends to stimulate aggressiveness and breeding behavior. However, the most dominant individuals may strongly suppress breeding behavior by subordinate males (psychological castration). Thus, outside the breeding season, subordinate males that were injected with testosterone propionate to which they at first showed little response, promptly began to sing or sang significantly much more often, and established territories, after dominant males were removed from their aviary.
Do kentish plovers regulate the amount of their nest material? an experimental test
Authors: Szentirmai István , Székely Tamás 
Published: October 2002

Abstract
Parent birds are often assumed to regulate the amount of their nest material during incubation in response to various costs and benefits. This assumption, however, is rarely tested. We investigated this assumption in a ground-nesting shorebird, the Kentish plover (Charadrius alexandrinus) by experimentally manipulating the amount of nest material. Materials were removed from some nests (reduced nests) and added to other nests (increased nests), whereas in control nests the amount of nest material was not manipulated. In both reduced and increased nests the parents restored the original amount of nest material within 24 hours. The parents tended to spend more time on arranging nest material in both reduced and increased nests than in control nests. However, neither incubation behaviour nor internal egg temperatures were different between reduced, increased and control nests. We conclude that Kentish plovers can quickly adjust the amount of materials around their eggs. This suggests that the parents carefully balance the various costs and benefits of nest material use during incubation.