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61.
In-Tae Bae Manabu Ishimaru Yoshihiko Hirotsu 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2006,250(1-2):315-319
Electron-beam-irradiation effects on silicon carbide (SiC) was investigated as a function of the irradiated temperatures. Single crystalline 6H-SiC was irradiated with 300 kV electrons at temperatures ranging from −170 to 250 °C. It was found that amorphous SiC is induced at −170 °C and room temperature, while crystalline Si is formed at 250 °C with a high electron fluence. It is considered that preferential knock-on displacement of C atoms and damage recovery play an important role in the formation of the amorphous SiC and crystalline Si. 相似文献
62.
Hirofumi Hirayama Toshihiro Itoh Yoshihiko Nakaki Takahiko Yoshida 《Artificial Life and Robotics》2005,9(3):144-160
A mathematical method is introduced to characterize the electrokinetic behavior (electrophoresis) of a biomolecular particle which passes through a specific channel pore on an excitable biological membrane. The basic approach was first proposed by Booth (1950). The system was described by an equation of continuity and an equation of motion in which the driving force involves the diffusion effect, the hydrostatic pressure, and the electrostatic potential. By assuming linear relations between the velocity and the applied electrical field, solutions for the potential, pressure, and velocity were given by a series expansion of the charges on the particle. To examine the influence of ions surrounding the particle and forming an ionic cloud, the Debye–Huckel parameter was introduced. As the thickness of the double layer around the particle increased, the potential, velocity, pressure, and viscosity were changed significantly. The maximum influence was obtained when the radius of the particle became equal to the thickness of the double layer. Although this theory is valid for a charged, spherical, nonconducting particle only, the method is available for evaluating the kinetic behavior of a biomolecule that passes through a channel pore on a cellular membrane.This work was presented, in part, at the 8th International Symposium on Artificial Life and Robotics, Oita, Japan, January 24–26, 2003 相似文献
63.
Generalized Partial Computation (GPC) is a program transformation method utilizing partial information about input data, abstract
data types of auxiliary functions and the logical structure of a source program. GPC uses both an inference engine such as
a theorem prover and a classical partial evaluator to optimize programs. Therefore, GPC is more powerful than classical partial
evaluators but harder to implement and control. We have implemented an experimental GPC system called WSDFU (Waseda Simplify-Distribute-Fold-Unfold).
This paper demonstrates the power of the program transformation system as well as its theorem prover and discusses some future
works.
Yoshihiko Futamura, Ph.D.: He is Professor of Department of Information and Computer Science and the director of the Institute for Software Production
Technology (ISPT) of Waseda University. He received his BS in mathematics from Hokkaido University in 1965, MS in applied
mathematics from Harvard University in 1972 and Ph.D. degree from Hokkaido University in 1985. He joined Hitachi Central Research
Laboratory in 1965 and moved to Waseda University in 1991. He was a visiting professor of Uppsala University from 1985 to
1986 and a visiting scholar of Harvard University from 1988 to 1989. Automatic generation of computer programs and programming
methodology are his main research fields. He is the inventor of the Futamura Projections in partial evaluation and ISO8631
PAD (Problem Analysis Diagram).
Zenjiro Konishi: He is a visiting lecturer of Institute for Software Production Technology, Waseda University. He received his M. Sc. degree
in mathematics from Waseda University in 1995. His research interests include automated theorem proving. He received JSSST
Takahashi Award in 2001. He is a member of JSSST and IPSJ.
Robert Glück, Ph.D., Habil.: He is an Associate Professor of Computer Science at the University of Copenhagen. He received his Ph.D. and Habilitation
(venia docendi) from the Vienna University of Technology in 1991 and 1997. He was research assistant at the City University of New York
and received twice the Erwin-Schrodinger-Fellowship of the Austrian Science Foundation (FWF). After being an Invited Fellow
of the Japan Society for the Promotion of Science (JSPS), he is now funded by the PRESTO21 program for basic research of the
Japan Science and Technology Corporation (JST) and located at Waseda University in Tokyo. His main research interests are
advanced programming languages, theory and practice of program transformation, and metaprogramming. 相似文献
64.
Structural changes of the hamster sperm head surface associated with maturation, capacitation and acrosome reaction were examined by atomic force microscopy. Spermatozoa were taken from the initial segment and distal cauda of the epididymis, washed in a modified Tyrode solution and fixed by glutaraldehyde. Some sperms taken from distal cauda epididymides were incubated with the capacitation medium before fixation. All samples were attached on the glass slide, dried in a critical point drier and observed by atomic force microscopy. The sperm head surface was characterized by the presence of numerous round particles, approximately 40 and 60 nm in diameter. The distribution and density of these particles on the sperm surface were significantly different between the equatorial segment and post-acrosomal region in each sperm, and also between sperms under different conditions. The surface of the equatorial segment was rather smooth in sperms from the initial segment of the epididymis, but had many large (60 nm) particles in sperms from the distal cauda epididymides, suggesting that the large particles were glycoproteins which were secreted from the epididymis and attached to the sperm surface during maturation. The number of these particles dramatically decreased in both capacitated acrosome-unreacted and acrosome-reacted sperms. This finding supports the idea that glycoproteins are removed from the sperm surface during capacitation. Atomic force microscopic studies of the sperm head surface are expected to be used for future molecular studies on the cell surface components involved in the mechanism of maturation, capacitation and acrosome reaction. 相似文献
65.
S. Ohsugi Y. Kitaoka M. Azuma Y. Fujishiro M. Takano 《Journal of Low Temperature Physics》1999,117(5-6):1671-1675
We carried out the extensive Cu-nuclear magnetic and quadrupole resonance (NMR/NQR) experiments on the Zn(Ni)-doped ladder compound SrCu
2
O
3
(Sr123), Sr(Cu
1–x
M
x
)
2
O
3
(M=Zn and Ni) with x 0.02 and the Ladoped Sr123, Sr
1–x
La
x
Cu
2
O
3
with x 0.03. A spin-correlation length
s
/a (a: the lattice spacing between the Cu sites along the leg) of nonmagnetic impurity-induced staggered polarization (IISP) estimated from a quasi-one-dimensional (Q1D) IISP along the two legs in the 0.1–2 % Zn-doped Sr123 was found to be independent of temperature (T) and scaled to an mean impurity distance D
AV
with the relation of
s
/a = 2.5 + 0.1D
AV
The
s
/a's are much longer in x = 0.001 (
s
/a 50) and 0.005 (
s
/a 12) than an instantaneous spin-correlation length
0
/a 3 – 8 in Sr123. The formula of Néel T, T
N
(WC-Q1D)=J exp(–D
AV
/(s/a)) (J = 2000 K) based on the weakly interladder-coupled (WC) Q1D model explains the experimental T
N
values quantitatively. 相似文献
66.
67.
68.
Yamaguchi A Uejo F Yoda T Uchida T Tanamura Y Yamashita T Teramae N 《Nature materials》2004,3(5):337-341
A mesoporous membrane composed of nanochannels with a uniform diameter has a potential use for precise size-exclusive separation of molecules. Here, we report a novel method to form a hybrid membrane composed of silica-surfactant nanocomposite and a porous alumina membrane, by which size-selective transport of molecules across the membrane becomes possible. The nanocomposite formed inside each columnar alumina pore was an assembly of surfactant-templated silica-nanochannels with a channel diameter of 3.4 nm; the channel direction being predominantly oriented along the wall of the columnar alumina pore. Molecules could be transported across the membrane including the silica-surfactant nanocomposite with a capability of nanometre-order size-exclusive separation. Our proposed membrane system has a potential use not only for separation science, but also catalysis and chip technologies. 相似文献
69.
Akahane K Hashimoto M Hada M Takano Y Ono K Kai M Kusama T 《Radiation protection dosimetry》2003,103(1):41-45
As the survival rate of newborns has increased, the number of X ray computed tomography (CT) examinations performed on neonates has been increasing. The exposure doses from CT examinations are known to be higher than those from conventional radiography. Although radiation sensitivity of neonates is higher than that of adults, there are few reports on dose estimates of neonates in CT examinations. Four cylindrical phantoms and one neonatal phantom have been developed to estimate doses to neonates during CT examinations. Using these phantoms and glass dosemeters, absorbed doses were measured. Estimated exposure doses to neonates were higher than those to adults, and our results suggest a need to optimise carefully CT examinations in newborns. 相似文献
70.
Nagayama T Takano I Kobayashi M Tamura Y Tomizawa S Tateishi Y Kimura N Kitayama K Saito K 《Shokuhin eiseigaku zasshi. Journal of the Food Hygienic Society of Japan》2003,44(2):126-131
A simple and rapid method is described for the determination of the non-registered pesticides, captafol, quintozene (PCNB), cyhexatin and 1-naphthylacetic acid (NAA), in fruits. These pesticides were extracted with acidified acetone, then captafol and PCNB were purified with a Florisil mini column and analyzed by GC-ECD. Cyhexatin was ethylated with ethylmagnesium bromide, and the ethyl derivative was analyzed by GC-FPD (Sn filter). NAA was purified with liquid-liquid extraction and determined by HPLC equipped with a fluorescence detector. These analytes were identified with GC/MS or LC/MS. The minimum identified concentration of the pesticides was below 0.2 ng per injection, which corresponds to a detection limit of below 0.02 microgram/g in the original samples. Recoveries of the pesticides spiked at 0.1 microgram/g into apple, Japanese pear and melon were greater than 61%. 相似文献