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To evaluate the characteristics of commercial memory devices for space use, the Japan Aerospace Exploration Agency (JAXA) launched a Solid State Recorder (SSR) on the Mission Demonstration test Satellite-1 (MDS-1 or 'Tsubas') into geo-stationary transfer orbit (GTO) in February 2002. Passing through the radiation belt exposed the MDS-1 to severe radiation environment in every orbit. This flight experiment allowed the observation of Single-Event Upsets (SEU) and Total Ionizing Dose (TID) effect on a large number of stacked 64 Mbit Dynamic Random Access Memories (DRAM). As a result, the actual SEU rates could be calculated, and the capabilities of two types of on-the-fly Error Detection and Correction (EDAC) mechanisms were confirmed. This paper presents the results of the space experiment of SSR, focusing especially on SEU analysis

Isotopic compositions of the noble gases (He, Ne, Ar, Kr, Xe) were obtained by stepwise heating of separated mineral phases from carbonatites from Brazil (Jacupiranga, Tapira) and Canada (Borden, Oka, and Prairie Lake) as well as one syenite (Poohbah Lake, Canada). Mineral phases used were apatite, forsterite, diopside, calcite, monticellite, and perovskite. Large amount of in situ produced 238U-fissiogenic 131–136Xe, along with lesser amounts of 238U-fissio-genic 83–86Kr and in situ 4He were found in most samples. An apatite sample from the Prairie Lake carbonatite showed a 136Xe130Xe ratio of about 1400. Some samples, mostly apatites, showed excess 129Xe relative to air in the high temperature (1800°C) gas fractions. The highest 129Xe130Xe ratios, between 7.0 and 8.6, are similar to those found in other mantle-derived materials such as MORBs and diamonds. The excess `Xe is considered to be primordial and attributed to now extinct nuclide 129I once present in the early history of the Earth. Neon isotopic compositions were also anomalous showing very low 20Ne22Ne ratios (down to 0.01) and high 21Ne22Ne ratios (up to 1.25). They are attributed to Wetherill reactions, such as 18O(α,n)21Ne, 19F(α,n)22Na(β+)22Ne, and so on. The measured 40Ar/36Ar ratios are extremely variable and range from values that are close to atmospheric to values as high as 42400. Stepwise heating studies of an apatite from the Jacupiranga carbonatite indicate that the high temperature fractions retain the original noble gas signature of the carbonatite source. The 40Ar/36Ar ratios for the high temperature gas fractions are about 6400 or smaller. A plot of 40Ar/36Ar vs. 129Xe/130Xe shows that the source of carbonatites is different and less degassed than that of MORBs. The presence of excess 129Xe in carbonatites suggests that carbon in carbonatites is unlikely to be recycled C related to subduction processes.

The CD4 molecule acts as a receptor for class II MHC molecules to stabilize Ag recognition by the TCR and as a high affinity receptor for HIV-1. In this study, we investigated the effect of oxidative stress on the level of CD4 expression on cultured peripheral blood T lymphocytes (PBL blasts). As previously reported, we observed that the surface CD4 was down-regulated by PMA. Unexpectedly, treatment of PBL blasts with hydrogen peroxide (H2O2) or a sulfhydryl oxidative reagent, diamide, almost completely inhibited PMA-induced CD4 down-regulation, although these oxidants per se did not affect the level of CD4 expression. We next assessed the serine phosphorylation of CD4, which is reported to be an indispensable process for PMA-induced CD4 endocytosis. PMA could induce the serine phosphorylation even in the presence of oxidants. We also found that these oxidants had an additive effect on PMA-induced dissociation between CD4 and p56(lck), which is known to be another necessary step for CD4 endocytosis. These results indicate that in T cells, oxidants inhibit protein kinase C-mediated CD4 down-regulation due to perturbing a signaling process other than the above two steps, implying that oxidative stress may tune the functions of CD4+ T cells and their susceptibility to HIV-1 through the control of CD4 expression.

The authors have developed a small digital camcorder deck mechanism with a tape loading and transport mechanism suitable for very thin, metal-evaporated, 1/4-in tape. The stability of the deck mechanism is excellent; track linearity is >

The authors propose an architecture for an error correction circuit suitable for high-rate data decoding of the Reed-Solomon code. It features a multiple-error correction capability of 4 errors or 8 erasures. The operational steps for multiple-error decoding are reduced by a 4-stage pipeline and a superscalar processor of a Galois field. The experimental circuit's 16 Mbyte/s rate of data decoding is sufficient for compressed video signals of high-definition as well as those of standard-definition TVs. >

An architecture for a high-speed Reed-Solomon decoder developed for digital VCRs is described. A maximum data rate of 16 MB/s and an error correction capability of 4-error- or 8-erasure-correction are realized using four-stage pipelines: a syndrome generator, a polynomial coefficient generator, a polynomial evaluator, and an error corrector. The polynomial coefficients are generated by a superscalar processor on a Galois field, which is controlled by instructions stored in ROM.

To determine the effect of the elemental composition of alloys on sliding wear, wear tests were carried out on several kinds of Cu-Zn, Cu-Sn, Cu-Ni, Ti-Ni and Ti-Al alloys under dry conditions using a pin-on-disk apparatus. The wear behaviours of these alloys were remarkably different from each other according to their metallurgical phase. In primary solid solutions the wear mode, especially the tendency of transition from severe to mild wear, was similar to that of the parent elemental metals. For example, in the α and η phases in the Cu-Zn alloy system the severe-to-mild wear transition was hardly observed. In the intermetallic compounds, on the other hand, the wear behaviour was very different from that of each of the constituent elements; that is, the severe-to-mild wear transition was observed at an early stage of sliding. In consequence, a higher wear resistance was revealed in intermetallic compounds as compared with primary solid solutions.

We have found that GeO2/Ge MOS structures fabricated by direct thermal oxidation yield significantly low interface trap density (Dit). Thus, Ge pMOSFETs using the GeO2/Ge MOS structures with the superior interface properties have been fabricated for achieving high hole mobility and investigated for examining the impact of the interface properties on the device performance. Al2O3 or SiO films were employed for protecting the GeO2/Ge MOS structures during the FET fabrication processes. The relationship between mobility and the fabrication conditions, such as the oxidation temperature, the annealing gas species, the substrate impurity concentration, the thickness of Al2O3 cap, and the surface orientation have been clarified.

The digital multichannel recorder, a PCM (pulse code modulated) audio recording unit, is described. An 8-PCM-channel with 20-bit/sample data slot is available at the sampling frequencies of 48, 44.1, and 32 kHz. High-quality recording and editing functions are provided for semiprofessional and superior amateur use. The newly developed thin-film magnetic heads and the high-density recording technology enable more than 20 minutes' recording on 8-mm tape loaded in a compact-size cassette. The features and signal processing technology of this digital audio recorder are described. >

The recording method, the composition, and the thin-film head of a compatible high-definition VCR mechanism for consumer use are described. This mechanism enables baseband recording or MUSE recording. A quasinonsegment recording method and a two-speed tape transport mechanism are used. This VCR has the following features: (1) two hours recording in the baseband mode and four hours recording in the MUSE mode with a cassette similar to VHS; (2) trick mode operation modes such as search and still; (3) simplicity of signal processing circuits at recording and reproducing; and (4) excellence of the reproduced picture and sound quality. >

During learning computer science theory, it is essential to learn sorting algorithms, but it is not easy to understand the concept of the different sorting algorithms. This paper describes a system called PSSLSA (PDA-based Participatory Simulation System for Learning Sorting Algorithms). This is an interactive simulation system to learn the sorting algorithms. Learners use it to deeply understand the sorting algorithms. Using this system, the teacher can assign tasks to his student and ask them to sort a list of numbers according to a certain algorithm. Learners receive these tasks, collaborate together and send the result to the server. The system will check it and feedback the student with the positions of the numbers if there is a mistake. The learners will correct the number positions and send it back to the server. Learners can understand the algorithm through the dissections and their errors.

An actuator structure and servo technology for a Holographic Versatile Disc (HVD™) drive system, based on Collinear™ Technology is proposed. Servo technology is introduced to control the objective lens position precisely to the disc surface, eliminating the requirement for a vibration isolator. Holographic Versatile Disc (HVD™) system using Collinear™ Technology, a new technology for HISS, is proposed and demonstrated by OPTWARE Corporation (1). This technology can produce a small, practical HISS more easily than conventional 2-axis holography. In this paper, we propose the servo technology that is widely used in the optical disc (like CD and DVD) and is applied to HVD™ using Collinear™ Technology. The construction of the actuator being employed in this technology, and the structure of the HVD are presented.

Holographic versatile disc (HVDtrade) evaluation system based on Collineartrade Technology, which is used to evaluate a rotating HVDtrade, is proposed. This system can easily be used to evaluate the specification of media or HVDtrade drive system

A separation optical setup for holographic versatile disc (HVDtrade) drive system, using Collineartrade Technology, is proposed. With this unique designed system configuration the pick-up can read or write holograms from any position on the rotating HVDtrade media

To evaluate the characteristics of commercial memory devices for space use, the Japan Aerospace Exploration Agency (JAXA) launched a Solid State Recorder (SSR) on the Mission Demonstration test Satellite-1 (MDS-1 or "Tsubasa") into geo-stationary transfer orbit (GTO) in February 2002. Passing through the radiation belt exposed the MDS-1 to severe radioactive rays in every orbit. This flight experiment measured the rate of single-event upsets (SEUs) on a large number of stacked 64 Mbit dynamic random access memories (DRAMs), and total ionizing dose (TID) effects. As a result, we could calculate the actual SEU rate, and we confirmed the capabilities of two types of on-the-fly error detection and correction (EDAC) mechanisms. This paper presents the results of the space experiment of SSR, focusing especially on SEU analysis.

To evaluate the characteristics of commercial memory devices, Japan Aerospace Exploration Agency (JAXA) launched a solid state recorder (SSR) on the mission demonstration test satellite-1 (MDS-1 or "Tsubasa") into geo-stationary transfer orbit (GTO) in February 2002. Passing through the Van Allen Belt exposed MDS-1 to severe radioactive rays in every orbit. This flight experiment measured the rate of single-event-upsets (SEUs) on a large number of stacked 64 Mbit dynamic random access memory (DRAM), and the distribution of total ionizing dose (TID) effects. As a result, we can calculate the actual SEU rate, and we confirmed the capabilities of two types of on-the-fly error detection and correction (EDAC) mechanisms. This paper presents the results of the space experiment of SSR, especially focusing on SEU analysis.

In 1999, Japan Aerospace Exploration Agency (JAXA) began developing a high-speed, large-volume and low-power-consumption solid state recorder (SSR) for space-use. This aim was to develop a SSR for installation in Earth observation satellites that could store and process large amounts of data. A prototype of the SSR was completed in spring 2004, and an engineering model is currently being constructed. The main features of the SSR are 200GBytes capacity, 2.5Gbps data transmission speed, low weight (25kg) and low power consumption (120W). Stacked 512Mbits synchronous dynamic random access memory (SDRAM) with on-board multi-bit error detection and correction (EDAC) mechanism, as well as a CompactPCI bus for fast data exchange, are used to improve the efficiency of data collection and storage capabilities. In this paper, we describe the main feature of the SSR system, and the technologies used in its development and manufacture. Preliminary results of several system tests are also reported

In their migration to SONET (synchronous optical network), network providers will be faced with the need to operate both their present asynchronous and their growing synchronous networks simultaneously. Operating these combined networks will require innovative approaches to the unique characteristics of both networks. One means to provide a transition strategy for today's network toward SONET is a mediation device. An architecture for a mediation device supporting both asynchronous and synchronous network equipment is presented. The common view of the network will follow the Bellcore TA-200 recommendation for X.25 and TL/1. The architecture is based on the INM system developed by the NEC. >

This paper proposes a practical control method using neural networks and fuzzy control techniques. Neural networks effectively simulate a well-experienced operator's procedure to control the tank level with estimation of a rough control target. Fuzzy control techniques compensate the estimated rough control target using operator's knowledge. The control system was applied to a reflux tank level control of a hydro-desulfurizing plant in the feed oil switching and it controlled the level effectively.

Bleomycin (BLM) is an anticancer drug, administration of which leads to severe lung injury, in which the generation of intracellular reactive oxygen species (ROS) is thought to participate in that. Thioredoxin (TRX) has been found to function as a powerful antioxidant by reducing ROS, and thus protecting against ROS-mediated cytotoxicity. However, a protective role of TRX in BLM-induced lung injury has not been determined. In the present study, we therefore attempted to clarify this issue. Human TRX-transfected L929 murine fibrosarcoma cells were more resistant to BLM-induced cytotoxicity than the parental and the control transfected cells, indicating that TRX plays the protective role in BLM-induced cytotoxicity. Next, we examined TRX expression in the lung of in vivo model of BLM-induced lung injury and BLM-stimulated bronchial epithelial cells in vitro to clarify the role of TRX in BLM-induced lung injury. In the lungs of BLM-treated mice, the expression of TRX was strongly induced in bronchial epithelial cells. TRX expression was also up-regulated at both the mRNA and protein levels in cultured BEC with the treatment with BLM. However, the expression of other major antioxidants, such as Cu/Zn-SOD, Mn-SOD, catalase and glutathione peroxidase, was not affected by BLM. These observations suggest that the cellular reduction and oxidation (redox) state modified by TRX is involved in the BLM resistancy and the induction of TRX in bronchial epithelial cells might play a protective role in BLM-induced lung injury.

Human thioredoxin (hTRX)/adult T-cell leukemia (ATL)-derived factor (ADF) was originally reported as an interleukin-2 (IL-2) receptor-alpha-inducing factor produced by human T-cell lymphotropic virus-1-positive (HTLV-1+) cell lines. Growing evidence indicates that hTRX/ADF plays important roles in cellular responses against oxidative stress and is involved in a variety of cellular functions. A high level of hTRX/ADF expression is also observed in other human virus-infected cell lines including those of Epstein-Barr virus (EBV) and human papillomavirus. In this report, we analyzed the effect of hTRX/ADF on lytic amplification and persistent replication of EBV as a model for lytic versus latent phase of viral replication in host cells. Addition of hTRX/ADF clearly suppressed lytic replication of EBV in Raji cells and B95-8 cells induced to the lytic phase of 12-O-tetradecanoylphorbol-13-acetate (TPA), and it prevented the death of these cells evoked by the lytic induction. In contrast, hTRX/ADF did not have any effect on persistent replication in the latent phase. These data indicated that hTRX/ADF prevents EBV-transformed cells from proceeding into the lytic phase and regulates cohabitation of EBV and its host cells.

The T lineage repertoire is shaped by opposing processes of positive and negative selection. To probe the specificity of selection, N15 TCR-transgenic (tg) recombinase-activating gene (RAG)-2(- / -) H-2(b) mice recognizing the VSV8 octapeptide RGYVYQGL bound to K(b) were utilized in conjunction with VSV8 variants differing only at the central p4 position. The V4I mutant octamer, like VSV8, induces negative selection of immature double-positive thymocytes on the beta(2)-microglobulin (beta(2)M)(+ / +) background and is a strong agonist for mature N15 T cells. In contrast, V4L or V4norvaline octamers promote positive selection in N15tg RAG-2(-/-) beta(2)M(-/-) H-2(b) fetal thymic organ culture and are weak agonists for N15 T cells. Hence, the absence of a p4 side chain Cbeta-methyl group results in positive selection of the N15 TCR. Hydrophobicity of the p4 residues also modulates thymocyte fate: the positively selecting norvaline and leucine variants have one and two Cgamma-methyl groups, respectively, while the weakly selecting gamma-methylleucine p4 contains three Cgamma-methyl groups. Moreover, the most hydrophobic octamer containing p4 cyclohexylglycine substitution fails to select. Thus, for N15 and presumably other MHC class I-restricted TCR, there is a high degree of structural specificity to peptide-dependent thymic selection processes.

Pancreatic cancer (pancreatic ductal carcinoma) is one of the most malignant solid tumors with poor prognosis. There is accumulating evidence that cellular reduction/oxidation (redox) status is deeply involved in the growth promotion and drug resistance of cancer cells. We therefore investigated the expression of redox-regulating proteins, such as thioredoxin (TRX) and glutaredoxin (GRX) in surgically resected pancreatic tissues and cis-diamminedichloroplatinum (CDDP)-resistant cells. Plasma levels of TRX were also measured in subjects with pancreatic diseases. Pancreatic ductal carcinoma tissues were immunohistochemically more positive for TRX (24/32 cases) and GRX (29/32 cases) than pancreatic cystadenocarcinoma or normal pancreas tissues. Plasma levels of TRX (mean +/- SD) measured by ELISA were significantly higher in patients with pancreatic ductal carcinoma (54.8 +/- 37.6 ng/ml, n = 60) than in healthy controls (24.4 +/- 12.9 ng/ml, n = 81). CDDP-resistant subclones of HeLa cells, HeLa-CP5 cells, had higher expression of TRX (1.5 fold) and GRX (1.6 fold) compared with parental HeLa cells by immunoblotting. These results indicate the possible association of TRX and GRX with malignant potential of pancreatic ductal carcinoma.

Oxidative stress induces a variety of cellular responses, including apoptosis, and caspase family proteases are known to be involved in apoptosis. Caspase-3(-like) protease activity was examined in Jurkat T cells to investigate the mechanism of apoptosis induced by a thioloxidant, diamide. Caspase-3 was activated when cells were cultured with 200 microM diamide that induced apoptosis, whereas no caspase-3 activation was detected with 500 microM diamide that induced necrosis. When apoptosis was induced in cells with exposure to 200 microM diamide, the intracellular thioredoxin (TRX) levels were maintained and the intracellular generation of reactive oxygen intermediates was marginal. The cytosolic fractions of cytochrome c were increased earlier than the activation of caspase-3. In contrast, when cells were exposed to 500 microM diamide, intracellular reactive oxygen intermediate generation was increased and processing of caspase-3 was not detected despite cytochrome c release, resulting in necrosis. Caspase-3 activity in cell lysate precultured with anti-Fas Ab was suppressed dose dependently by diamide and restored by thiol-reducing agents, DTT or TRX. When cells were precultured with 5 mM of buthionine sulfoximine, an inhibitor of glutathione synthesis, intracellular TRX levels were maintained, and as low as 20 microM diamide could induce apoptosis associated with the increase of cytosolic cytochrome c and the activation of caspase-3. These results indicate that the activation of caspase-3 in diamide-induced apoptosis is mediated, at least partly, by cytochrome c release from mitochondria, and the cellular reducing environment maintained by TRX, as well as glutathione, is required for caspase-3 activity to induce apoptosis.

OBJECTIVE: To determine how much and why static load influences friction in synovial joints. DESIGN: Start-up coefficient of friction in canine stifles was measured after different duration of static load. BACKGROUND: Previous investigators have shown that friction of cartilage on cartilage contact configurations sharply increases with stationary load duration. This phenomenon has not been confirmed in the entire synovial joint. METHODS:: A system to measure joint friction was designed using a robotic arm. Ten canine stifles from six animals were used. Start-up friction of the femoral condyle on the tibial plateau and femoral condyle on glass plate contact configurations was measured. The glass plate was chosen as a rigid surface where ploughing effect cannot occur. RESULTS: The mean value of the start-up frictional coefficient from femoral condyle on tibial plateau was 0.112 (SD 0.005) at 0 s stationary loading, and sharply increased with the stationary loading duration to 0.313 (SD 0.095) at 1800 s. Those from femoral condyles on glass plate were 0.005 (SD 0.003) at 0 s and 0.457 (SD 0.128) at 1800 s. CONCLUSIONS: Friction in synovial joints sharply increases with duration under static load. The ploughing effect on this increase is slight in friction in canine stifles. RELEVANCE: The lubrication mechanism is worth investigating to understand the pathology of joint diseases. Determining friction behaviour is necessary for the investigation of the lubrication mechanism.

We have shown that cell cycle progression of human T-cell leukemia virus type I (HTLV-I)-transformed T-cell lines was inhibited by 13-cis-retinoic acid (13cRA). In the present study, we report that 13cRA inhibited proliferation and induced cell death of peripheral blood mononuclear cells obtained from four patients with acute adult T-cell leukemia but not of mitogen- or interleukin 2-activated peripheral blood mononuclear cells from HTLV-I-negative healthy donors. Because HTLV-I-infected lymphocytes are susceptible to oxidative stress, we examined the role of the intracellular redox state in 13cRA-induced cell death using a HTLV-I-positive T-cell line, ATL2, as a model. 13cRA induced apoptosis in ATL2 cells within 48 h in a dose-dependent manner. The ability of 13cRA to induce apoptosis was more potent than that of all-trans-retinoic acid. Apoptosis induction by 13cRA was significantly enhanced by buthionine sulfoximine (BSO), which decreased the levels of intracellular reduced glutathione, although 13cRA by itself did not alter them, suggesting that intracellular reduced glutathione may modulate 13cRA-induced apoptosis. In addition, flow cytometric analysis revealed that 13cRA increased intracellular peroxides in 24 h and that the addition of BSO further enhanced them. Although N-acetylcysteine had only a marginal effect, pretreatment with catalase markedly inhibited 13cRA-induced apoptosis. These results suggest that peroxide generation, ie., oxidative stress, may play a crucial role in the induction of apoptosis by 13cRA and further demonstrate that combined treatment with 13cRA and BSO induces apoptosis of HTLV-I-positive lymphocytes even more potently.

Objective . To relate conformity of sliding surfaces with the lubricating ability of synovial joints. Design . Measurement of start-up friction in the stifles of various animals. Assessment of conformity by Hertzian contact area. Background . Past studies showed that the start-up friction in synovial joints sharply increased with the loading duration. The reasons why the friction increased and why the increasing rate is different in different joints were, however, not found. Methods . Nine stifle joints from various animals were used. A robotic arm was used to give the compressive force and the sliding motion to the joint. Start-up friction was measured by a universal force sensor. The principal curvatures of the sliding surfaces were directly measured by a radius-gauge. Hertzian contact area was calculated from the principal curvatures of the sliding surfaces. Results . The duration until the frictional coefficient reached 0.1 was related to the Hertzian contact area. Conclusion . The conformity of sliding surfaces is related to the lubrication ability in synovial joints. The squeeze-film mechanism plays an important role in joint lubrication.

The development progress and operation results with the gas turbine developed for the first coal gasification pilot plant (200T/D) in Japan are reported hereafter. The gas turbine based on the scale down of the commercial machine (H25), is called H14. To deal with coal gasification, the development of the combustor is main subject because of the low caloric value of fuel. We developed the combustor through many combustion tests with simulation gas, and the selected combustor was supplied to the actual gas test at the pilot plant. We could grasp the limit of stable combustion of the combustor because the fuel characteristics of actual fluctuated sharply. In addition, we could experience phenomena peculiar to the gasification such as the back fire problem and finally succeeded in air extraction linkage operation by no means inferior to the used coal fired thermal power generation. Thus we established the gas turbine technology for coal gasification and opened a way to future large gasification plants.

Progression of osteoporosis is caused by a decline in bone formation activity relative to the resorption activity. In this paper, the authors carried out a theoretical analysis of the progression of osteoporosis to estimate the osteoporotic change in the upper end of the femur. According to this analysis, the progression rate of osteoporosis in cancellous bone depends on the product of remodeling activity, Ract, and the trabecular structure parameter, Ktr. To confirm that the theoretical results were reasonably comparable to actual osteoporotic change, these two factors were measured in rabbits. From the results, it was concluded that the highest progression rate was shown in bar/bar-like trabecular structure (type 3); the next highest rate, was shown in plate/bar-like structure (type 2); and the plate/plate-like structure (type 1) was the most insensible. Furthermore, the bone volume fractions of cancellous bone were measured at the upper end of human femurs with and without osteoporosis. Then the measured value was compared with the theoretical value for each type of trabecular structure. Results showed that the decrease in bone volume fraction predicted by Eq. 7 was well in accord with the actual decrease.

Zn pin is rubbed against Zn disk in SEM chamber and in various oxygen pressures. It is observed that the transfer particle grows larger in higher oxygen pressure. By the observation in SEM, it is clarified that the wear particle is the conversion of transfer particle. In another experimental rig, Cu pin is rubbed against Cu disk in Pt-Pd atmosphere. The size of wear particle is increased by the existence of this atmosphere. The inclusion of impurity atoms at the interface or in the transfer particle enhances the shear strength of them, which is the possible mechanism of the growth of transfer particle.

Gold atoms are sputter deposited by argon gas onto the friction surfaces of a disk specimen during friction between a pin and disk of Sn and of Zn. For the range of deposition rates 0.05 to 0.20 angstrom/sec, the growth of transfer particles is enhanced by the deposition, resulting in the generation of larger wear particles and more wear than those without deposition. The shear strength of Sn and Zn with an Au impurity is assumed to be higher than that of pure Sn or Zn, and this is attributed to be the cause for the enhancement of growth of transfer particles by the deposition.

Radiation and Its Effects on Components and Systems, 2005（19-23 Sept. 2005）, 資料番号: ARDS05026000

The path-integral formalism is developed to obtain the quantum spectrum of a kink in the classical continuous one-dimensional Heisenberg ferromagnet with easy plane, noting the analogy between its quantum spin 1/2 lattice version and the Heisenberg antiferromagnet of spin 1/2. From the equivalence of the spectra, the quantum kink (antikink) is identified with the antiferromagnetic magnon of spin 1/2, consistent with the recent argument by Faddeev and Takhtajan (1981). A picture of the doublet of this magnon in their claim is now given by the excitation of a pair of the kink and antikink which are stable against their mutual collision.

The concept of gauge equivalence is introduced for the classical one-dimensional Heisenberg ferromagnets with single-site anisotropy. The classical continuum version of the one-dimensional anisotropic Heisenberg antiferromagnet (ferromagnet) of spin 1/2 is shown to be gauge-equivalent to the nonlinear Schrodinger equation with the repulsive (attractive) interaction, which is consistent with the Yang and Yang statement on thermodynamical equivalence between the corresponding quantum systems.

The authors develop a path-integral formalism to obtain the semiclassical quantum spectrum of the pulse soliton with an internal degree of freedom in the one-dimensional continuous Heisenberg ferromagnet with an easy axis. No restriction is imposed on the spin magnitude S. For S=1/2, the pulse soliton yields the same quantum spectrum as that of the S=1/2 lattice Heisenberg-Ising ferromagnet obtained by the Bethe ansatz method. This agreement supports a plausible particle picture of the multimagnon bound state. For S>1/2, the present semiclassical spectrum can also be interpreted, aside from its prefactor, in terms of an underlying spin S(>1/2) quantum lattice model if the cut-off condition for the wave-number of the soliton is taken into account.