Weyl transformation in Fermi systems

In the path integral representation, the Hamiltonian in a quantum system is associated with the Hamiltonian in a classical system through the Weyl transformation. From this, it is possible to describe the time evolution in a quantum system by the Hamiltonian in a classical system. In a Bose system, the Weyl transformation is defined by the eigenstates of the canonical operators, since the Hamiltonian is given by a function of the canonical operators. On the other hand, in a Fermi system, the Hamiltonian is usually described by a function of the creation and annihilation operators, and hence the Weyl transformation is defined by the coherent states which are the eigenstate of an annihilation operator. Here, we formulate the Weyl transformation in Fermi systems in terms of the eigenstates of the canonical operators so as to clarify the correspondence between both systems. Using this, we can derive the path integral representation in Fermi systems.     

Radiation effects in ionic solids

Current development of the research of radiation damage in ionic solids is reviewed. Emphasis is placed on the correlation between elementary radiation damage processes and the atomic and electronic structures of the materials. Both the radiation damage induced by electronic excitation and by elastic collision are treated. For the former two crucial processes, the self-trapping of excitons and the formation of stable Frenkel pairs from the self-trapped excitons in several materials, is discussed in terms of the structures of materials. Deficiency in the available data on the knock-on threshold energies are pointed out. Available information of Frenkel pairs produced by electronic and elastic encounters is surveyed. Possible models of defect clustering are summarized and existing information on clustering is discussed on their basis.     

Restricted hydration structures of Rb and Br ions confined in slit-shaped carbon nanospace

Hydration structures of "nanosolutions" around both cation and anion for rubidium bromide confined in nanospaces (pore width = 1.1 nm) of activated carbon fiber were determined with EXAFS measurements and related analysis. The analytical results indicate that the ionic solutions confined in hydrophobic nanospaces tend to form an incomplete dehydration structure, because of the spatial restriction by the nanospace and capturing water molecules in the ordered structure.     

Generation of 10- microJ coherent extreme-ultraviolet light by use of high-order harmonics

We demonstrate the generation of 10-microJ coherent extreme-ultraviolet (XUV) light at wavelengths from 73.6 to 42.6 nm, using high-order harmonics. The peak power of this coherent XUV light is estimated to be 0.13 GW at 62.3 nm, and the peak brightness achieved was 3x10(28) photons/(mm(2)mrad(2)s) . To our knowledge, this XUV energy is the highest value achieved with high-order harmonics.     

Prevention of carcinogenesis and cancer metastasis by bovine lactoferrin

Increasing attention is being paid to chemopreventive agents for individuals at high risk of cancer. We have concentrated on bovine lactoferrin (bLF), an 80 kDa iron-binding glycoprotein known to have anti-microbial and immunoprotective effects. Lactoferrin is particularly abundant in colostrum, and is also present in tears, saliva and seminal and uterine secretions. However, only little is known regarding its influence on carcinogenesis. We have shown preventive effects of bLF and its fragment peptide, lactoferricin (bLFcin), consisting of a 25 amino acid sequence without iron binding capacity, on chemically-induced colon carcinogenesis in the rat and transplanted carcinoma cell metastasis in the mouse. The mechanisms are wide-spectrum, including elevation of caspase-1 and IL-18 in the small intestine, enhancement of the cell killing activity of cytotoxic T and natural killer (NK) cells, and anti-inflammatory and anti-angiogenic effects. It also inhibits the induction of liver CYP1A2, a carcinogen activating enzyme, and induces apoptosis in the colon epithelium of carcinogen treated rats. Thus, bLF possesses multi-functional potential to suppress carcinogenesis and is a good candidate for practical application in humans.     

Enabling technologies for SCM basedoptically fed wireless communication systems

Basic configurations and system requirements for subcarrier multiplexing (SCM)-based optically fed wireless communication systems are summarized. The key issues for their fast deployment are improving performance and reducing the initial introduction cost. Major enabling technologies are introduced such as development of highly linear LDs, the multiple-LD method to improve carrier-to-noise ratio (CNR), super wideband frequency modulation to obtain a large power margin, and low-cost feeder design with a Fabry–Perot LD and multimode fiber. The introduction of optical feeders, which will increase the flexibility of the wireless system, is inevitable for providing multimedia services.     

High-throughput, high-damage-threshold broadband beam splitter for high-order harmonics in the extreme-ultraviolet region

We demonstrate a high-throughput and high-damage-threshold beam splitter for high-order harmonics in the soft-x-ray region that uses Si and (or) SiC plates set at Brewster's angle with respect to the pump wavelength. The beam splitters are guaranteed to have a damage threshold of at least 0.8 TW/cm2 (average power density, 0.25 W/cm2) and an attenuation rate of 10(-4)-10(-5) for a 30-fs pump pulse. The measured reflection efficiency at the 27th harmonic (29.6 nm) was 0.56 for Si and 0.45 for SiC. These beam splitters are useful not only for high harmonics but also for longitudinally pumped x-ray lasers.     

Behavior of Ultrafine Particles generated from organic vapors by corona ionizers

This paper reports an experimental study on the stability, coagulation and diffusion of molecular clusters and ultrafine particles generated from organic vapors by corona ionizers. Upon leaving the ionizer, particles are made to flow within several types of vessels: depending on the specific geometry of the flow system, clusters either coagulate into large particles or are deposited on the walls. Particles larger than 4nm and molecular clusters penetrate through a wire-screen type diffusion battery, but particles in the size range between 2 and 4nm are collected. Among the organic compounds tested (aromatics, alcohols, ketones and others), only aromatic compounds appear to yield unstable clusters which grow into detectable particles (>2nm) through Brownian coagulation. The other compounds either do not undergo the gas-to-particle conversion process or are too small to be detected. Furthermore, the presence of moisture seems to be of fundamental importance in the particle generation phenomenon. The addition of alcohols to the vapor mixture inhibits particle formation.     

Studies on furan derivatives. XIV. Nucleophilic substitution of methyl 5-nitro-2-furancarboxylate and 5-Nitrofuran-2-nitrile

Methyl 5-alkoxy-2-furancarboxylates, methyl 5-alkylthio-2-furancarboxylates and methyl 5-phenylthio-2-furancarboxylate were prepared by nucleophilic substitution of methyl 5-nitro-2-furancarboxylates. Also, 5-phenoxyfuran-2-nitriles and 5-phenylthiofuran-2-nitriles were prepared.     

Analyses of particle production in hadron-nucleus reactions at several GeV with a two-moving-source model

Spectra of protons and pions emitted in the target-rapidity region in hadron-nucleus reactions at 3 and 4 $\text{GeV}\text{c}$ were observed in wide momentum- and angular-acceptance measurements. Fitting to the data with the two-moving-source model well reproduced experimental proton spectra with the slope parameters of 50–60 MeV for one component and 110–125 MeV for another. The slope parameters for pions were 120–165 MeV, larger than those for protons. Energy depositions of GeV particles were estimated by integrating energies carried away through the particle production