An aluminum nitride sintered body is provided, wherein an average crystal grain diameter is 2.0 .mu.m or less, a crystalline phase detected by an X-ray diffractometer is an AlN phase only or an AlN phase and an AlON phase only, and SiO.sub.2 or MgO is present in an amount of more than 0.05 wt % to less than 1 wt %.

The brush holder device includes a holder base, metal brush holders and metal terminal plate elements. Each brush holder slidably receives a corresponding brush. Each brush holder includes securing claws, which are secured to the holder base by staking. Each securing claw includes a retorted portion, which is retorted toward a rear surface of the holder base beyond a top of a corresponding staking projection that projects from the rear surface of the holder base. Each metal terminal plate elemen...

An aluminum nitride ceramic including aluminum nitride grains and grain boundary phases comprises a grain boundary phase-rich layer including more amount of the grain boundary phases in a surface layer of the aluminum nitride ceramic than in an inside of the aluminum nitride ceramic. The grain boundary phases in the grain boundary phase-rich layer include at least one of rare earth element and alkali earth element.

A method for manufacturing an aluminum nitride single crystal is provided, including the steps of preparing a raw material composition containing aluminum oxide and/or an aluminum oxide precursor which is converted into aluminum oxide by heating, and aluminum nitride and/or an aluminum nitride precursor which is converted into aluminum nitride by heating, heating the raw material composition at 1600 to 2400.degree. C. to synthesize aluminum nitride, and causing crystal growth of the aluminum nit...

A nonwoven fabric suitable to be used as a kitchen paper including thermoplastic synthetic fibers being 7.about.30 mm long and as fine as of 0.1.about.0.8 d, in 90.about.10% by weight and pulp fibers being 2.about.7 mm long, in 10.about.90% by weight, these component fibers being mixed together as homogeneously as possible and mechanically entangled so as to have a basis weight of 10.about.80 g/m.sup.2 as a whole.

An aluminum nitride sintered body is provided, including a polycrystalline structure in which grain boundary fracture toughness K.sub.IC.sup.gb is 1.6 MPam.sup.1/2 or more. The grain boundary fracture toughness K.sub.IC.sup.gb is determined by the equation K.sub.IC.sup.gb=K.sub.ICcos.sup.2(.pi.PIF/200), wherein K.sub.IC is fracture toughness (MPam.sup.1/2), and PIF is a percentage of the intergranular fracture (%).

An aluminum nitride ceramic including aluminum nitride grains and grain boundary phases comprises a grain boundary phase-rich layer including more amount of the grain boundary phases in a surface layer of the aluminum nitride ceramic than in an inside of the aluminum nitride ceramic. The grain boundary phases in the grain boundary phase-rich layer include at least one of rare earth element and alkali earth element.

An aluminum nitride sintered body has characteristics such that an amount of total metal elements other than aluminum is smaller than 100 ppm, and a volume resistivity at room temperature is greater than 1.0.times.10.sup.9 .OMEGA..multidot.cm and is smaller than 1.0.times.10.sup.13 .OMEGA..multidot.cm. A metal including member has such a construction that a metal member is embedded in the aluminum nitride sintered body mentioned above. An electrostatic chuck is made by the metal including member...

The present invention relates to a method of testing the sensitivity of cancer drugs with cancer cells cultured in vitro. Cancer cells are cultured in a collagen gel substrate. A wide variety of human cancer cell types readily proliferate in the collagen gel substrate, however, fibroblast cells proliferate as well. The measurement of the growth of the cancer cells is hindered by the presence of the fibroblast cells. The present invention solves this problem by counting the number of colonies wit...

A novel aluminum nitride material having a low room temperature volume resistivity is provided. The aluminum nitride material has an aluminum nitride main component and includes at least 0.03 mol % of europium oxide. The aluminum nitride material has an aluminum nitride phase and an europium-aluminum composite oxide phase. An aluminum nitride material also provided having an aluminum nitride main component, wherein a total content of europium oxide and samarium oxide is at least 0.09 mol %. The ...