Abstract: A process for producing a synthetic silica glass optical component which contains at least 1×1017 molecules/cm3 and has an OH concentration of at most 200 ppm and substantially no reduction type defects, by treating a synthetic silica glass having a hydrogen molecule content of less than 1×1017 molecules/cm3 at a temperature of from 300 to 600° C. in a hydrogen gas-containing atmosphere at a pressure of from 2 to 30 atms.

Abstract: A synthetic quartz glass for optical use, to be used by irradiation with light within a range of from the ultraviolet region to the vacuum ultraviolet region, which contains fluorine, which has a ratio of the scattering peak intensity of 2250 cm?1 (I2250) to the scattering peak intensity of 800 cm?1 (I800), i.e. I2250/I800, of at most 1×10?4 in the laser Raman spectrum, and which has an absorption coefficient of light of 245 nm of at most 2×10?3 cm?1.

Abstract: A synthetic quartz glass for optical use, to be used by irradiation with light within a range of from the ultraviolet region to the vacuum ultraviolet region, which contains fluorine, which has a ratio of the scattering peak intensity of 2250 cm−1 (I2250) to the scattering peak intensity of 800 cm−1 (I800), i.e. I2250/I800, of at most 1×10−4 in the laser Raman spectrum, and which has an absorption coefficient of light of 245 nm of at most 2×10−3 cm−1.

Abstract: An exposure apparatus, wherein at least one of optical members constituting an exposure light source system, an illuminating optical system, a photomask and a projection optical system, is made of a synthetic quartz glass for an optical member, which has an absorption coefficient of 0.70 cm−1 or less at a wavelength of 157 nm and an infrared absorption peak attributable to SiOH stretching vibration at about 3640 cm−1.

Abstract: A synthetic quartz glass to be used for light with a wavelength of from 150 to 200 nm, wherein the OH group concentration is at most 100 ppm, the hydrogen molecule concentration is at most 1×1017 molecules/cm3, reduction type defects are at most 1×1015 defects/cm3, and the relation between &Dgr;k163 and &Dgr;k190, as between before and after irradiation of ultraviolet rays, satisfies 0<&Dgr;k163<&Dgr;k190, and a process for its production.

Abstract: A process for producing a synthetic quartz glass for an optical member, which comprises a step of irradiating a synthetic quartz glass having an OH group content of 50 ppm or lower with vacuum ultraviolet light having a wavelength of 180 nm or shorter to improve the transmittance in a region of wavelengths of not longer than 165 nm.

Abstract: A process for producing a synthetic silica glass optical component which contains at least 1×1017 molecules/cm3 and has an OH concentration of at most 200 ppm and substantially no reduction type defects, by treating a synthetic silica glass having a hydrogen molecule content of less than 1×1017 molecules/cm3 at a temperature of from 300 to 600° C. in a hydrogen gas-containing atmosphere at a pressure of from 2 to 30 atms.

Abstract: A synthetic quartz glass for optical use, to be used by irradiation with light within a range of from the ultraviolet region to the vacuum ultraviolet region, which contains fluorine, which has a ratio of the scattering peak intensity of 2250 cm−1 (I2250) to the scattering peak intensity of 800 cm−1 (I800), i.e. I2250/I800, of at most 1×10−4 in the laser Raman spectrum, and which has an absorption coefficient of light of 245 nm of at most 2×10−3 cm−1.

Abstract: A novel hydrazine derivative and a pesticidal composition containing the hydrazine derivative as the effecting ingredient. The hydrazine derivative show high pesticidal activity against harmful pests which are resistant to known pesticides such as organophosphorus pesticides, pyrethroids, etc., especially against Lepidoptera harmful pests such as Plutella xylostella, Spodoptera litura, Cnaphalocrocis medinalis, Adoxophyes orana, etc., and is effective for controlling harmful pests in paddy field, upland field, orchard, forest or places to be kept environmentally hygienic.

Abstract: A novel hydrazine derivative and a pesticidal composition containing the hydrazine derivative as the effecting ingredient. The hydrazine derivative show high pesticidal activity against harmful pests which are resistant to known pesticides such as organophosphorus pesticides, pyrethroids, etc., especially against Lepidopters harmful pests such as Plutella xylostella, Spodoptera litura, Cnaphalocrocis medinalis, Adoxophyes orana, etc., and is effective for controlling harmful pests in paddy field, upland field, orchard, forest or places to be kept environmentally hygienic.

Abstract: Disclosed herein is a compound of the formula: ##STR1## wherein Ar is pyridine ring, pyridazine ring, pyrimidine ring, pyrazine ring, isoquinoline ring or thiazole ring, and those rings may be substituted by 1.about.3 of substituents selected from the group consisting of halogen, C.sub. 1 .about.C.sub.4 -alkyl, C.sub.1 .about.C.sub.4 -alkoxy, CF.sub.3 and nitro,R.sup.1 is C.sub.1 .about.C.sub.8 -alkyl; C.sub.1 .about.C.sub.7 -alkyl which is substituted by 1.about.3 of F, Cl or Br, C.sub.1 .about.C.sub.4 -alkoxy or C.sub.1 .about.C.sub.4 -alkylthio; C.sub.3 .about.C.sub.7 -cycloalkyl which may be substituted by 1.about.4 of F, Cl or methyl; C.sub.3 .about.C.sub.6 -cycloalkylmethyl which may be substituted by 1.about.4 of F, Cl, Br or methyl; allyl, propargyl, phenyl or benzyl; R.sup.2 is C.sub.1 .about.C.sub.4 -alkyl which may be substituted by 1.about.3 of F or Cl,x is integer of 0, 1 or 2, excepting wherein Ar is pyridine ring which is substituted by R.sup.1 --S(O)x and --O--SO.sub.2 R.sup.

Abstract: Disclosed herein is a compound of the formula:R.sup.1 --S(O)x--Ar--O--SO.sub.2 --R.sup.2 (I)whereinAr is pyridine ring, pyridazine ring, pyrimidine ring, pyrazine ring, isoquinoline ring or thiazole ring, and those rings may be substituted by 1.about.3 of substituents selected from the group consisting of halogen, C.sub.1 .about.C.sub.4 -alkyl, C.sub.1 .about.C.sub.4 -alkoxy, CF.sub.3 and nitro,R.sup.1 is C.sub.1 .about.C.sub.8 -alkyl; C.sub.1 .about.C.sub.7 -alkyl which is substituted by 1.about.3 of F, Cl or Br, C.sub.1 .about.C.sub.4 -alkoxy or C.sub.1 .about.C.sub.4 -alkylthio; C.sub.3 .about.C.sub.7 -cycloalkyl which may be substituted by 1.about.4 of F, Cl or methyl; C.sub.3 .about.C.sub.6 -cycloalkylmethyl which may be substituted by 1.about.4 of F, Cl, Br or methyl; allyl, propargyl, phenyl or benzyl; R.sup.2 is C.sub.1 .about.C.sub.4 -alkyl which may be substituted by 1.about.3 of F or Cl,x is integer of 0, 1 or 2, excepting wherein Ar is pyridine ring which is substituted by R.sup.

Abstract: Disclosed is a compound of the formula: ##STR1## wherein X.sub.1 and X.sub.3 represent chloro or fluoro, X.sub.2 represents hydrogen, chloro or fluoro, X.sub.4 represents hydrogen or halogen, X.sub.5 represents --CF.sub.3 or --OCF.sub.3, Y represents oxygen or sulfur and an insecticidal composition containing said compound, a method for killing insect pests and a process for producing said compound and its use as pesticide.

Abstract: A compound of the formula: ##STR1## wherein R.sup.1 is C.sub.1 -C.sub.12 alkyl, R.sup.2 is C.sub.1 -C.sub.12 alkyl or C.sub.1 -C.sub.4 alkyl which is substituted with halogen, X is halogen, m is 0, 1 or 2 and n is 0, 1 or 2,a process for producing said compound and use thereof as an insecticide acaricide and nematicide.