Abstract: The electromagnetic wave absorber of the present invention is made of a sintered body that contains Fe and at least one element selected from Si, Mg, Zr, Ni, Al and Co, and an attenuation of electromagnetic wave is 2 dB or more at frequencies of 10 GHz and higher so as to provide good electromagnetic wave absorbing characteristic with no corrosive gas generated at all, and is easy to manufacture. The electromagnetic wave absorber is used mainly as a component of a high-frequency circuit package.

Abstract: The present inventions provides a dielectric ceramic comprising an oxide containing, as a metal element, at least a rare earth element (Ln), Al, M (M is Ca and/or Sr) and Ti, and at least part of the oxide of Al being present as a crystal phase of &bgr;-Al2O3 and/or &thgr;-Al2O3, thereby having a high &egr; r, high Q value and a small temperature coefficient of resonance frequency in a high frequency region.

Abstract: A gas-insulated switchgear is miniaturized and bus-bars connected to bushings are simplified in configuration. A distance L between outer peripheries of a first vacuum interrupter 12 and a second vacuum interrupter 13 is established to be smaller than an external diameter D of the vacuum interrupters 12 to 14, and insulating barriers 28 to 30 are installed between the first vacuum interrupter 12 and the second vacuum interrupter 13, between the first vacuum interrupter 12 and a hermetically sealed container 11, between the second vacuum interrupter 13 and the hermetically sealed container 11, and between the first and second vacuum interrupters 12 and 13 and the third vacuum interrupter 14.

Abstract: There is provided a dielectric ceramic composition wherein a main crystal phase is a perovskite-type crystal phase, comprising a complex oxide which contains, as a metal element, at least a rare earth element, Al, M (M is Sr, alternatively, Sr and Ca) and Ti, and is represented by the following composition formula: aLn2OxbAl2O3cMOdBaOeTiO2 wherein Ln is a rare earth element; and a, b, c, d and e is a mole ratio in a predetermined range, and more specifically comprising a solid solution of LnAlO(x+3)/2 (3≦x≦4) and RTiO3 (R is an alkaline earth metal containing at least Sr). This composition provides a large dielectric constant ∈r and a high Q value in a high frequency region, and also lessens the variation in dielectric constant ∈r, Q value, and resonance frequency temperature coefficient &tgr;f.

Abstract: The dielectric porcelain of the present invention comprises a polycrystalline material of which a main component comprises oxides containing at least a rare earth element (Ln), Al, M (M represents Ca and/or Sr) and Ti as metal elements, wherein the thickness of a grain boundary layer is 20 nm or less, thereby achieving a high value of &egr;r, high Q factor and small absolute value of the temperature coefficient &tgr;f of resonant frequency in a high frequency region. Thus this dielectric porcelain is preferably used in dielectric resonators.

Abstract: A gas-insulated switchgear is miniaturized and bus-bars connected to bushings are simplified in configuration. A distance L between outer peripheries of a first vacuum interrupter 12 and a second vacuum interrupter 13 is established to be smaller than an external diameter D of the vacuum interrupters 12 to 14, and insulating barriers 28 to 30 are installed between the first vacuum interrupter 12 and the second vacuum interrupter 13, between the first vacuum interrupter 12 and a hermetically sealed container 11, between the second vacuum interrupter 13 and the hermetically sealed container 11, and between the first and second vacuum interrupters 12 and 13 and the third vacuum interrupter 14.

Abstract: The present inventions provides a dielectric ceramic comprising an oxide containing, as a metal element, at least a rare earth element (Ln), Al, M (M is Ca and/or Sr) and Ti, and at least part of the oxide of Al being present as a crystal phase of &bgr;-Al2O3 and/or &thgr;-Al2O3. thereby having a high &egr; r, high Q value and a small temperature coefficient of resonance frequency in a high frequency region.

Abstract: There is provided a dielectric ceramic composition containing metal elements Ca, Ti, La, Zn and M which is at least one metal element selected from the group consisting of W, Ni, Co, Zr, Sn, Mn and Cu, and represented on a molar fraction basis by the following composition formula:aCaO.multidot.bTiO.sub.2 .multidot.cLa.sub.2 O.sub.3 .multidot.dZnO.multidot.eMO.sub.xwherein 1.ltoreq.x.ltoreq.3, and a to e are molar fractions which are each set within a predetermined range. The composition has a high dielectric constant, a high Q value and a stably low resonant frequency temperature coefficient .tau.f.

Abstract: A method of producing a steel sheet useful for making cans. The method steps include hot-rolling a slab consisting of about 0.0005 to 0.01 wt % C, about 0.001 to 0.04 wt % N (the total of C and N is at least about 0.008 wt %), about 0.05 to 2.0 wt % Mn, about 0.005 wt % or less Al, about 0.01 wt % or less O at a finish rolling temperature within a temperature range of about the Ar.sub.3 point to about 950.degree. C., coiling the rolled material at a temperature range of about 400 to 600.degree. C., cold rolling the material, continuously annealing the material at a temperature higher than the recrystallization temperature, and then temper-rolling the material. The steel sheet exhibits good workability during can making and which can be formed into a can having high strength.

Abstract: A dielectric ceramic composition being characterized in that the composition contains at least Ba and Ti as metal elements, and when the formula of the composition in accordance with the mole ratios of these elements is represented by BaO.xTiO.sub.2, the composition contains the main ingredient determined by x satisfying the relationship of 3.9.ltoreq.x.ltoreq.4.1, and 0.01 to 7 weight parts of Cu in terms of CuO, and, if necessary, 20 or less weight parts of Zn in terms of ZnO with respect to 100 weight parts of the main ingredient, whereby the dielectric coefficient can have a value in the range of 30 to 42, and Qf can have a value of 40000 GHz or more, the temperature coefficient .pi..sub.f of the resonance frequency can have a value in the range of -15 to +15 ppm/.degree.C., and the temperature drift .DELTA..pi..sub.f of the temperature coefficient .pi..sub.f of the resonance frequency can have a value in the range of -2 to +2 ppm/.degree.C.

Abstract: A dielectric ceramic composition for high-frequency applications comprising a composite oxide containing at least Ba, Zn and W as metal elements. When the composition formula of the composite oxide is expressed in the form of molar ratios of the metal oxides, the molar ratios of the metal oxides lie within particular ranges. The ceramic composition exhibits a high dielectric constant and a large Q-value in high-frequency regions.

Abstract: A molded article is prepared from an AlN powder of a high purity without adding sintering assistant, baked in a nitrogen atmosphere without containing carbon, and is further heat-treated in a nitrogen atmosphere containing carbon in order to remove impurities in the sintered product. There is obtained a highly pure and dense sintered product which comprises mainly a phase of aluminum nitride, which has an average grain size of greater than 9 .mu.m, cationic metal impurities other aluminum, and Si, Fe and Ca in amounts smaller than predetermined values. The sintered product exhibits a very small creep rate when stress is applied thereto at high temperatures and is used as a material for high temperature uses such as a baking jig. Owing to its excellent anti-creeping property at high temperatures, tile product is suitably used as a structural material subject to stress at high temperatures for extended periods of time.

Abstract: Disclosed is an aluminum nitride sintered body comprising aluminum nitride and a sintering aid, wherein the sintering aid is composed mainly of at least one component selected, as the oxide, from the group consisting of Yb.sub.2 O.sub.3 and Er.sub.2 O.sub.3, and the sintered body contains up to 0.5% by weight of Yb and/or Er as the metal and has a density of 3.2 to 3.3 g/cm.sup.3 and a heat conductivity of at least 170 W/m.multidot.k.If a CaO component is incorporated as the second sintering aid in an amount of up to 0.1% by weight, the heat conductivity is further increased.