Hitachi, Ltd.

Kousei Nagayama

Hisao Yamashita

Satoru Ogihara

Osamu Kuroda

Nobuyuki Ushifusa

Yuichi Kitahara

Hidehiro Iizuka

Masato Kaneeda

Hiroichi Shinohara

Kojiro Okude

Toshio Ogawa

Toshifumi Hiratsuka

Morio Fujitani

Tasao Soga

Masahisa Inagaki

Takao Funamoto

Gyozo Toda

Satoshi Kokura

Takashi Haramaki

Toshimi Sasaki

Ryutaro Jimbou

In a method and apparatus for removing nitrogen oxides from the exhaust gas of a lean-burn automobile, a CO adsorbent component, which may, for example be made of Pd, Ru or Ir, is contained in an exhaust gas cleaning catalyst which captures NOx when the air-fuel ratio of exhaust gas is higher than theoretical air-fuel ratio, and reduces the captured NOx when the air-fuel ratio of exhaust gad is less than or equal to the theoretical air-fuel ratio. The catalyst, which includes Rh, Pt, and element selected from among the alkaline and alkaline earth metals (Na, Mg, K, Li, Cs, Sr and Ca), and a CO adsorbent material comprising Pd, Ir or Ru, has a CO desorption capacity that reaches at maximum level at a temperature within the range from 200 to 220&#xb0; C. when its temperature is increased in a He gas flow at the rate of 5 to 10&#xb0; C./min, after said catalyst is saturated at 100&#xb0; C. Exhaust gas having an air-fuel ratio higher than theoretical air-fuel and exhaust gas having an air-fuel ratio less than or equal to the theoretical air-fuel ratio are alternately made to flow to the catalyst.

Method for cleaning exhaust gas from an internal combustion engine

Nitrogen oxides contained in an exhaust gas emitted from a lean-burn engine-mounted internal combustion engines are eliminated with a high efficiency. In an exhaust gas purification apparatus and process for eliminating nitrogen oxides contained in a combustion exhaust gas emitted from an internal combustion engine with a reducing gas such as carbon monoxide, hydrocarbons, etc. contained in the exhaust gas in the presence of a catalyst, a catalyst comprising all of Rh, Pt and Pd, at least one member selected from alkali metals and alkaline earth metals, and Mn or its compound, supported on a porous carrier is used.

Internal combustion engine exhaust gas purification apparatus, exhaust gas purification process and exhaust gas purification catalyst

In an exhaust gas purification process for eliminating nitrogen oxides contained in a combustion exhaust gas emitted from an internal combustion engine with a reducing gas such as carbon monoxide, hydrocarbons, etc. contained in the exhaust gas in the presence of a catalyst, a catalyst comprising all of Rh, Pt and Pd, at least one member selected from alkali metals and alkaline earth metals, and Mn or its compound, supported on a porous carrier is used.

Exhaust emission control process for internal combustion engines

A ceramic multilayer circuit board comprising ceramic layers and wiring conductor layers laminated alternately, in which the ceramic layer has a thermal expansion coefficient lower than that of the wiring conductor and not lower than one half of that of the conductor layer and is formed from a glass which softens at a temperature not higher than the melting point of the wiring conductor layer; a semiconductor module having a high reliability in its solder joint part comprising said ceramic multilayer circuit board mounted with a ceramic carrier substrate being mounted with a semiconductor device, said board being able to use a silver or copper conductor having a good electro-conductivity; and an amorphous glass powder for said ceramic multilayer circuit board.

Ceramic multilayer circuit board and semiconductor module

Ceramic insulating substrate layers (1) for a multilayered ceramic wiring circuit board (3) consist essentially of crystals of mullite and sillimanite, non-crystalline silicon dioxide occupying the interstices between the crystals and magnesium oxide dissolved substantially in the crystals in solid solution and have a thermal expansion coefficient of 40-60.times.10.sup.-7 /.degree. C. and a dielectric constant below 6.7.

Multilayered ceramic wiring circuit board and the method of producing

Disclosed is a diffusion bonding method which can be applied to superalloys and comprises forming in advance an alloy layer containing an additional element or elements having a higher diffusion speed than that of the principal constituent element of a base metal and a lower melting point than that of the base metal on the joint surface of the base metal consisting of a heat-resistant superalloy based on Co, Ni, Fe, Ti or the like, and bringing the joint surfaces into contact so as to diffuse B.

Diffusion bonding method using a high energy beam

A ceramic insulating layer (2) for the multilayer ceramic circuit board (11) consists of 60 wt % of crystallized glass and 40 wt % of a filler such as silicon dioxide bonded by the crystallized glass, which consists of 6-15 wt % of lithium oxide, 70-90 wt % of silicon dioxide, 1-8 wt % of aluminum oxide, 1-5 wt % of alkaline metal oxide other than lithium oxide and 2-5 wt % of alkaline earth metal oxide. The sintered ceramic insulating layer (2) has a dielectric constant below 6.1 and a flexural strength above 150 MPa and is co-firable with a wiring conductor layer of such as gold, silver and copper.

Multilayer ceramic circuit board

Growing community of inventors

Tokai-mura, Japan

Kousei Nagayama