A nanometric precision three-degrees-of-freedom positioner is designed and fabricated. Actuation is based on piezoelectric stacks. Capacitive gap sensors with less than 1.0-nm resolution are used for position feedback. In order to design a proper closed-loop controller, the open-loop characteristics of the nanopositioner (static stiffness, hysteresis, drift, frequency response, and the coupling effects) are experimentally investigated. A cerebellar model articulation controller neural network control algorithm was applied in order to provide real-time learning and better tracking capability compared to a standard proportional-integral-derivative control algorithm.

The magnetic properties of iron phthalocyanine doped with potassium (K-FePc) were examined. K-FePc obtainedat 550 °C for 5hr is regarded as ferromagnetic based on the SQUID measurements. The saturation magnetization of this sample is 15.3emuG/g at 298K. The existence of isolated iron was not able to be confirmed in the sample by means of X-ray diffraction analysis and TEM observation. In the ESR spectra, the g-value of K-FePc was in contrast to that of isolated iron. These results suggest that the origin of the ferromagnetism of K-FePc is not due to isolated iron but other ferromagnetic interactions. The thermal history (cooling rate, post heat treatment) after the doping reaction significantly influences the magnetic property.

Summary form only given as follows. A nano-metric precision three degrees of freedom (DOF) positioner is designed and fabricated. Actuation is based on piezo-electric stack actuators. Capacitive gap sensors with less than 1.0 nanometer resolution are used for position feedback. In order to design a proper closed loop controller, the open loop characteristics of the nano-positioner (hysteresis, static stiffness, drift, frequency response, and the coupling effects) are experimentally investigated. A CMAC neural network control algorithm was applied in order to provide online learning and better tracking capability compared to a standard PID control algorithm. The closed loop controller was implemented using C language on a DSP based PC bus board. The learning CMAC control provides significantly better tracking accuracy and robustness against hysteresis and drift effects.

The magnetic properties of the titled resin prepared photochemically have been studied with SQUID and ESR measurements. The changes observed in susceptibility(χ) and temperature(T) do not follow Curie's law, although the sample exhibits paramagnetism. The gap observed is remarkable in the 50–150K temperature region, and depends on heat-rates of the measurements. Moreover, this phenomenon is correlated to the presence of oxygen.

Summary form only given. The magnetic properties of the COPNA resin pre pared by photoirradiation have been studied by ESR and SQUID measurements. ESR spectra were obtained as a singlet with g=2.0035. The temperature dependence of the susceptibility (X) is shown in the figure. In the 50-150K temperature region, the value of X doesn't follow Curie law. The X value gradually increased with time. The intensity of the ESR signal decreased in the same temperature region. Furthermore, this intensity decreased extraordinarily with increase of oxygen pressure in the sample. It was also found that this anomalous magnetic properties characteristic to the COPNA resin was related to the changes of molecular weight distribution by photoirradiation. It is considered that this behavior is due to the structural changes related to oxygen.

This paper gives a design method for the single-polarization optical fiber which satisfies simultaneously the wide single-polarization bandwidth, the large modal birefringence, and the zero total dispersion at the wavelength of 1.55 /spl mu/m. As a type of single-polarization fiber, the optical fiber with two hollow circular pits across the core-clad interface is proposed and designed. The normalized power (=/spl Delta/ the power in the core/the total power) in the core is also evaluated for the designed fibers. It was found from the numerical analysis that when the zero total dispersion is satisfied at the wavelength of 1.55 /spl mu/m, the maximum modal birefringence of 1.133/spl times/10/sup -3/ and the maximum single-polarization bandwidth of 100.6 nm are attained for the relative index difference of 1.6%. Then the normalized power in the core is 0.859.

Complexes of polyaniline (PANI) with various organic r-electron acceptors such as TCNQ and others were prepared by the automatic doping method. The relationship between current and applied voltage was linear and ohmic in argon atmosphere at voltages below 5 V, but in air it was non-linear. A field-effect current was observed at PANI-chloranil complex on silicon substrate.

A metal-insulator-semiconductor field-effect transistor (MISFET) using the InAs-GaAs superlattice as a channel layer has been successfully demonstrated for the first time. Device structure was grown by molecular beam epitaxy. The MISFET with 1.0 μm gate length exhibits a maximum external dc transconductance of 212 mS/mm at Vds =3.0 V and Vg =−1.5 V. This value is high among 1.0 μm gate length devices.

We found shallow serpiginous, longitudinal ulcerations in the descending colon at the first examination of a 17-year-old female patient with Crohn's disease. Four months later at the second examination, we observed that a polypoid lesion had formed longitudinally in the region of the healed ulcers. The third examination, one year later, showed the presence of pedunculated and semi-pedunculated giant polyps in the descending colon. The lesion of the descending colon was removed surgically to cure the crampy abdominal pain caused by colonic obstruction. The segmental colectomy specimen showed longitudinally aligned pedunculated polyps of various sizes. The pathological diagnosis was inflammatory polyposis. To the best of our knowledge, there have been very few reports on the appearance of a number of pedunculated polyps such as in this case. This reports shows, through endoscopic pictures, the evolution of the polyp and discusses its formation.

The gate oxide region affected by injected hot electrons and/or holes along the channel is experimentally determined. The oxide region varies with bias conditions, and the device degradation rate is correlated with the change in the hot-carrier injected region. Based on these results, the following degradation mechanism is proposed: 1) The degradations in transconductance, threshold voltage, and s...

This paper describes circuit techniques necessary for dynamic RAMs with high-packing density to implement submicron device technology. An on-chip error checking and correcting technique using bidirectional parity checking is proposed to reduce the soft error rate. In a sense-refresh amplifier, capacitor-coupled presenting is introduced to compensate for threshold imbalance. An on-chip supply volta...

The possible degree of miniaturization is compared for Dynamically Switched Buried Channel (DSC) cells, Taper Isolated Dynamic Gain (TIDG) RAM cells, and DMOS cells. In this comparison, the permitted number of leakage electrons (or holes) Nein storage charges is of prime importance. These cells have a readout signal-gain effect, and the signal amount is mostly unaffected by cell miniaturization. H...

Production of multiply-charged ions of Ne, Ar, Kr and Xe has been studied by use of an electron-bombarded hot cathode type ion source of the IPCR 160cm cyclotron, which is similar to Morozov's source. These multiply-charged ions were accelerated by a 3rd harmonics acceleration mode in the cyclotron and detected with a beam probe fixed at the radius of 55cm. Observed multiply-charged ions are Ne2+,...

The design and performance of the ion source which is now used in the IPCR variable energy cyclotron are described. The source is of the electron-bombarded hot cathode type having two cylindrical cathodes of tungsten and a water-cooled copper anode containing a replaceable molybdenum slit plate. The arc discharge is established continuously but not pulsed. The source is usually operated very stably under an arc power of 1.5 to 3kW with a gas flow rate of 1 to 2 cc/min. The lifetime of the source is mainly limited by the erosion of the upper tungsten cathode at about 24 hours. At present, C4+, N4+, O4+, N5+ and O5+ ions are accelerated up to 48~100, 56~1100, 70~95, 56~125 and 70~125 MeV respectively, and a few micro-amperes of these ions are extracted from the cyclotron. The vacuum obtainable in the accelerating chamber is usually 2 ~ 4 × 10-6 mHg, and the loss of ion beam by the charge exchange effect is comparatively small. Extracted ion beams are used in several experiments for about 1900 hours in a year.

An electron bombarded hot cathode type ion source was constructed for the IPCR 160 cm variable energy cyclotron. The behavior of this source was investigated to determine the charge- state yield of ions for carbon, nitrogen and oxygen gases and to determine the parameters that effected these yields and source stability. The relative yields of multiple-charged ions were found to be critically dependent on the rate of gas flow, the arc voltage and the arc power. For the source stability, the alignment of the arc axis with the magnetic field was found to be important and it was effective to decrease undesired sparks and glow discharges in the source system. At present, ions of N4+, N5+ and C4+ are accelerated to energies between 4 and 10 MeV per nucleon in the cyclotron and they are extracted to the beam transport system with intensities of a few μA.