Metallic state in a lime-alumina compound with nanoporous structure

We report a metallic state in a nanostructured porous crystal 12CaO x 7Al2O3 by incorporating electrons in the inherent subnanometer-sized cages, in which a three-dimensionally closely packed cage structure acts as an electronic conduction path. High-density electron doping ( approximately 2 x 10(21) cm(-3)), which was achieved by a thermal treatment in Ti metal vapor at approximately 1100 degrees C, induces homogenization of the cage geometry to a symmetric state, resulting in an insulator-metal transition with a sharp enhancement of the electron drift mobility from approximately 0.1 to 4 cm(2) V(-1) s(-1). The results provide an approach for the realization of electroactive functions in materials composed only of environmentally benign elements by utilizing the appropriate nanostructures.     

通过功率MOSFET的顶面温度估算结点温度

通常,MOSFET数据手册中提供的结点温度数据只限于结到引脚和结到环境之间的热阻。虽然可根据定制条件使用一些工具来实现更精确的热仿真,但有时只需要时间来运行仿真就可以了。     

A neural decoding approach to auditory temporal assimilation

By constructing Gaussian Naïve Bayes Classifiers, we have re-analyzed data from an earlier event-related potential (ERP) study of an illusion in time perception known as auditory temporal assimilation. In auditory temporal assimilation, two neighboring physically unequal time intervals marked by three successive tone bursts are illusorily perceived as equal if the two time intervals satisfy a certain relationship. The classifiers could discriminate whether or not the subject was engaged in the task, which was judgment of the subjective equality between the two intervals, at an accuracy of >79%, and from principal component scores of individual average ERP waveforms, we were able to predict their subjective judgments to each stimulus at an accuracy of >70%. Chernoff information, unlike accuracy or Kullback–Leibler (KL) distance, suggested brain activation associated with auditory temporal assimilation at an early pre-decision stage. This may provide us with a simple and useful neural decoding scheme in analyzing information processing of temporal patterns in the brain.     

Fabrication and characterizations of new glassy Co<Subscript>71</Subscript>Ti<Subscript>24</Subscript>B<Subscript>5</Subscript> alloy powders and subsequent hot pressing into a fully dense bulk glass

A single glassy phase of Co₇₁Ti₂₄B₅ alloy has been synthesized by high-energy ball milling the elemental powders at room temperature, using the mechanical alloying method. The synthetic glassy powder obtained after 130 ks of ball milling exhibits good soft magnetic properties with a polarization magnetization and coercivity values of 1.01 T and 2.86 kA/m, respectively. This ternary glassy alloy in which its glass transition temperature (T _g ) lies at a rather high temperature (805 K) crystallizes at 868 K through a single sharp exothermic peak with an enthalpy change of crystallization (ΔH _x ) of −3.28 kJ/mol. The supercooled liquid region before crystallization, ΔT _x of the synthesized glassy powders shows a large value (63 K) for a ternary system. The reduced glass transition temperature (ratio between T _g and liquidus temperatures, T _l (T _g /T _l )) was found to be 0.55. The end product of the glassy powder (130 ks) was compacted in an argon gas atmosphere at 835 K with a pressure of 780 MPa, using the hot-pressing technique. The consolidated sample is fully dense (∼99.5 pct) and maintains its chemically homogeneous glassy structure. The measured polarization magnetization and coercivity values of as-consolidated powders are measured and found to be 0.96 T and 2.92 kA/m, respectively. The Vickers microhardness of the bulk glassy Co₇₁Ti₂₄B₅ sample is measured and found to be in the range between 7.32 and 7.46 GPa.     

Dynamic characteristics of flying head slider with ultra thin spacing (CIP method and linearized method)

The cubic interpolated propagation (CIP) method, which is an effective numerical scheme for differential equations that include advection and nonadvection terms, is employed for the dynamic analyses of ultra thin gas film lubrication using the molecular gas-film lubrication equation. First, pressure generation caused by the running wavy disk under the fixed slider was analyzed by the CIP method and is found to agree well with the analytical solution for the running wavy disk with a small amplitude. 2-DOF slider dynamics with the spacing of several tens of nanometers caused by a running disk with projections were investigated by the CIP method and the linearized solutions, which show that both results agree well with each other and the CIP method is promising scheme for slider dynamics even in the near-contact region.     

Diabetes mellitus-associated glycogen storage hepatomegaly: report of a case and review of the Japanese literature

A huge hepatomegaly was seen in a 30-yr-old female diabetic who was treated with high dose of insulin for her uncontrollable food ingestion. The liver function at the peak of the hepatic enlargement showed a moderate increase of transaminases, alkaline phosphatase, and gamma-glutamyl transpeptidase. The histology of the enlarged liver revealed PAS-positive granules in enlarged hepatocytes, indicating the presence of massive glycogen storage. On admission, she was maintained under a calorie-restricted diet and received approximately 15 to 20 units per day of insulin supplement. At one month after admission, a marked shrinkage of her enlarged liver and restoration of normal liver function were observed concomitantly with the return of fair control of her blood sugar levels. One year later, she had an episode of diabetic ketoacidosis which subsequently was treated with a continuous low-dose infusion of insulin; however, she showed neither hepatomegaly nor liver dysfunction during this episode. There have been 20 cases reported of Japanese diabetics with marked hepatomegaly, in whom the vigorous treatment of diabetic ketoacidosis with insulin seemed to be a trigger of the enlarged liver. This has occurred mostly in patients with insulin-dependent diabetes mellitus. We present a case of non-insulin-dependent diabetes mellitus with glycogen storage hepatomegaly, presumably due to excessive insulin supplements. This suggests that glycogen storage hepatomegaly in diabetics may not be only due to an acute restoration from diabetic ketoacidosis, but may also be due to an overinsulinization in an attempt to maintain a euglycemic condition in spite of excess food intake.     

Two-way deterministic multi-weak-counter machines

In this paper, we consider two-way deterministic machines which have counters, each capable of storing any nonnegative integer, but not having the ability to detect empty counter, and which accept by final state. We call these machines two-way deterministic multi-weak-counter machines. Let 2NWC^(k) and 2DWC^(k) denote the classes of languages recognized by two-way nondeterministic and deterministic k-weak-counter machines, respectively. In particular, for k = 1, we denote the corresponding classes by 2NWC and 2DWC. The following results are shown: (1) 2DWC^(k) = 2DWCfork ?1. (2) A bounded language in 2DWC is a bounded semilinear language. (3) 2NWC ≠ 2DWC.     

A logical basis for programming methodology

In this paper, the relation between WHILE-programs and formal proofs of their quantified specification is studied. This gives us a logical basis for programming methodology since the programming concepts such as assignment statements, IF-statements and WHILE-statements are fully explained logically, here ‘logically’ means ‘how to think’. As an example, Hoare's program FIND is studied methodologically.     

On the reaction between UO2 and Zr

The reaction between UO₂ and Zr has been studied from both equilibrium and kinetic points of view. In the equilibrium study, the reaction of UO₂ with Zr with several Zr/UO₂ mole ratios has been made at 1000°C and the products have been identified using X-ray diffraction method. The interfacial reaction zones after the heat-treatment of the reaction couples of UO₂ pellet and Zr sheet have been studied using a SEM.     

Decentralized exciter stabilizing control for multimachine power systems

In this paper, a systematic approach to design controllers based on H‐infinity theory for a multimachine power system is presented. Generally, a centralized control scheme is difficult for a large‐scale interconnected power system because of the necessity of obtaining information on the whole system, computation times, and so on. In order to handle these problems, two decentralized control schemes are proposed. One is based on the decomposition of information. The feedback gains for the whole system are obtained, and after decomposing the gains into subblocks for each area, the diagonal block is used to design the controller for each generator. The other is based on area decompositions. The procedure is carried out by decomposing the original system into blocks for each area and the local feedback gain is obtained by using information for each decomposed system. Furthermore, to improve the robustness of the system, an effective weighting matrix design, which involves the allocation of eigenvalues, is also proposed. Several simulation tests show the effectiveness of the proposed methods. © 2002 Scripta Technica, Electr Eng Jpn, 139(1): 35–43, 2002; DOI 10.1002/eej.1144