Abstract: A magnetic powder for magnetic recording media, which has an average particle diameter of at most 0.08 .mu.m and a ratio of the maximum diameter to the maximum thickness of at most 8 and is represented by the following general composition formula:(Fe).sub.a (Sn).sub.b (Si).sub.c (M.sup.1).sub.d (M.sup.2).sub.e (M.sup.3).sub.f (O).sub.gwherein M.sup.1 means at least one metal element selected from Ba, Sr, Ca and Pb, M.sup.2 denotes at least one metal element selected from Cr, Y, Ce, Nd, Sm, Al, La and Cd, M.sup.3 stands for at least one metal element selected from Mg, Ti, Mn, Ni, Cu, Zn, Sb, In, Mo and W, a, b, c, d, e, f and g respectively represent the numbers of Fe, Sn, Si, M.sup.1, M.sup.2, M.sup.3 and O atoms, a is a number of 8.0 to 12.0, b is a number of 0.01 to 6.0, c is a number of 0.05 to 6.0, d is a number of 0.3 to 6.0, e is a number of 0.01 to 6.0, and f is a number of 0.0 to 6.0, and g is the number of oxygen atoms satisfying the atomic valences of the other elements.

Abstract: A magnetic powder for magnetic recording media, which has an average particle diameter of at most 0.1 .mu.m and is represented by the following general composition formula:(Fe).sub.a (Zr).sub.b (Si).sub.c (M.sup.1).sub.d (M.sup.2).sub.e (M.sup.3).sub.f (O).sub.gwherein M.sup.1 means at least one metal element selected from Ba, Sr, Ca and Pb, M.sup.2 denotes at least one metal element selected from Mo and W, M.sup.3 stands for at least one metal element selected from Mg, Ti, Mn, Ni, Cu, Zn, Sb, La, Al, In, Ce, Nd and Sm, a, b, c, d, e, f and g respectively represent the numbers of Fe, Zr, Si, M.sup.1, M.sup.2, M.sup.3 and O atoms, a is a number of 8.0 to 12.0, b is a number of 0.01 to 6.0, c is a number of 0.05 to 6.0, d is a number of 0.3 to 6.0, e is a number of 0.01 to 6.0, and f is a number of 0.0 to 6.0, and g is the number of oxygen atoms satisfying the atomic valences of the other elements.

Abstract: Disclosed herein is a method of producing a magnetic recording medium, wherein a magnetic coating formulation containing a hexagonal ferrite magnetic powder is applied to the surface of a substrate. It is characterized in that the hexagonal ferrite magnetic powder is represented by the following general composition formula [I] and has an average particle diameter of at most 0.1 .mu.m , a ratio of the maximum diameter to the maximum thickness (a plate ratio) of at most 15, a particle size distribution (.sigma.gd) of at most 3.4 in terms of the geometric standard deviation based on the number and a coercive force of 200-3,000 oe, and a solvent containing at least 15 wt. % of at least one ketone compound having at most 10 carbon atoms is used in the magnetic coating formulation.(Fe).sub.a (Co).sub.b (M.sup.1).sub.c (M.sup.2).sub.d (M.sup.3).sub.e (O).sub.f [I]wherein M.sup.1 means at least one metal element selected from Ba, Sr, Ca and Pb, M.sup.

Abstract: An apparatus for firmly mounting solid-state image sensors to an image splitting prism in which a mounting glass block is bonded to an image splitting prism surface or to a glass plate bonded to a prism. A metal film is formed on the glass block, and a preliminary solder layer is formed on the metal film to improve wettability. A gap between the preliminary solder layer and a meltable metal member formed on a caging of a solid-state image sensor is filled with a meltable metal having a predetermined thickness, thus bonding the preliminary solder layer and the meltable metal member. When this construction can be obtained, the total thickness of the metal film can be reduced to 1 .mu.m or less.

Abstract: An imaging device having solid-state image sensors coupled to a prism for separating the light from an objective optical system, wherein a solder layer capable of adhering to a glass substance is formed on a part of said prism or on a glass plate adhered to said prism, and a gap between said solder layer and a solderable material formed on a casing of said solid-state image sensor is filled with a low-melting metal to unite the two. The metal layer thickness of the solder layer is disposed to cause the light receiving surface of the image sensor to correspond to a predetermined imaging plane of the imaging device.

Abstract: A magnetic powder for magnetic recording which has an average particle diameter of 0.01 to 0.3 micrometers and is represented by the following general composition formulaFe.sub.a Co.sub.b Ti.sub.c M.sup.I.sub.d M.sup.II.sub.e M.sup.III.sub.f O.sub.gwherein M.sup.I represents at least one metal element selected from Ba, Sr, Ca and Pb, M.sup.II represents at least one element selected from Si, Sn, Mo and W, M.sup.III represents at least one element selected from Ni, Cu, V, Zr, La, Ce, Nd, Sm, Mn, Zn, Mg, P, Cr, In, Tl and Ge, a, b, c, d, e, f and g respectively represent the numbers of Fe, Co, Ti, M.sup.I, M.sup.II, M.sup.III and O atoms, a is a number of 8 to 11.8, b is a number of 0.05 to 2.0, c is a number of 0.05 to 2.0, d is a number of 0.5 to 3.0, e is a number of 0.001 to 3.0, and f is a number of 0.001 to 3.0, and g is the number of oxygen atoms satisfying the atomic valences of the other elements.

Abstract: A process for producing butadiene which comprises (1) a reaction step of forming butadiene by gas-phase catalytic oxidative dehydrogenation of n-butene, (2) a cooling step of cooling the resulting gas discharged from the reaction step (1) to remove trace amounts of high boiling by-products contained in the resulting gas, (3) an aldehyde removal step of removing small amounts of aldehydes contained in the cooled gas discharged from the cooling step (2), (4) a compression step of compressing the gas discharged from the aldehyde removal step (3), and (5) a C.sub.4 component recovery step of recovering a C.sub.4 component containing butadiene and other C.sub.4 hydrocarbons from the compressed gas discharged from the compression step (4).

Abstract: In a process for preparing methacrylic acid by the vapor-phase catalytic oxidation of methacrolein or a methacrolein-containing mixture with molecular oxygen in the presence of an oxidation catalyst; the improvement wherein said process comprisesa first-stage oxidation step of oxidizing methacrolein or a methacrolein-containing mixture as a starting material,a first-stage separating step of separating the resulting methacrylic acid from the reaction product obtained in the first-stage oxidation step,a second-stage oxidation step of oxidizing the mixture containing the unreacted methacrolein and obtained in the first-stage separating step, anda second-stage separating step of separating the resulting methacrylic acid from the reaction product obtained in the second-stage oxidation step, andwith or without at least one additional oxidation step and separating step subsequent to the second-stage separating step,and wherein the conversion of methacrolein in the first-stage oxidation step is adjusted to 30-85 mole

Abstract: A process for producing a conjugated diolefin, which comprises oxidatively dehydrogenating a monoolefin having at least 4 carbon atoms in the vapor phase with molecular oxygen to form the corresponding conjugated diolefin, said reaction being carried out in the presence of a catalyst having the general composition formulaMo.sub.a Bi.sub.b Cr.sub.c Ni.sub.d X.sub.e Fe.sub.f Y.sub.g Z.sub.h O.sub.iwherein X represents Zr or Al, Y represents at least one element selected from the group consisting of metal elements of Group Ia of the periodic table, metal elements of Group II of the periodic table, Tl and P, Z represents at least one element selected from the group consisting of In, Ag, Ti, Nb, Ta, Co, La, Ce, Nd and Mn, a, b, c, d, e, f, g, h and i are respectively the atomic numbers of Mo, Bi, Cr, Ni, X, Fe, Y, Z and O, and when a=12, b=0.05-20, c=0.05-20, d=0.1-30, e=0.01-20, f=0.01-20, g=0.001-20, h=0-20, and i is the atomic number of oxygen satisfying the atomic valences of the other elements.

Abstract: In a process for producing a conjugated diolefin which comprises oxidatively dehydrogenating a monolefin having at least 4 carbon atoms in the vapor phase with molecular oxygen to form the corresponding conjugated diolefin; the improvement wherein the oxidative dehydrogenation is carried out in the presence of a catalyst having the general composition formulaMo.sub.a Bi.sub.b Cr.sub.c Ni.sub.d X.sub.e Y.sub.f O.sub.gwherein X represents at least one element selected from Li, Na, K, Rb, Cs, Tl and P, Y represents at least one element selected from Al, Ga, Zr, Pb, Nb, Ta, Hf and Mn, and a, b, c, d, e, f and g respectively represent the number of Mo, Bi, Cr, Ni, X, Y and O atoms, and when a=12, b=0.05-20, c=0.05-20, d=0.1-30, e=0.01-10, f=0.01-20, and g is the number of oxygen atoms which satisfies the atomic valences of the other elements.

Abstract: In a process for producing a conjugated diolefin which comprises oxidatively dehydrogenating a monolefin having at least 4 carbon atoms in the vapor phase with molecular oxygen to form the corresponding conjugated diolefin; the improvement wherein the oxidative dehydrogenation is carried out in the presence of a catalyst having the general composition formulaMo.sub.a Bi.sub.b Cr.sub.c Ni.sub.d X.sub.e Y.sub.f O.sub.gwherein X represents at least one element selected from Li, Na, K, Rb, Cs, Tl and P, Y represents at least one element selected from metal elements of Group II of the periodic table, and a, b, c, d, e, f and g respectively represent the number of Mo, Bi, Cr, Ni, X, Y and O atoms, and when a=12, b=0.05-20, c=0.05-20, d=0.1-30, e=0.01-10, f=0.01-20, and g is the number of oxygen atoms which satisfies the atomic valences of the other elements.

Abstract: A catalyst for oxidation of isobutylene which has a composition of the general formulaMo.sub.a Bi.sub.b Fe.sub.c Co.sub.d Ni.sub.e P.sub.f Pb.sub.g X.sub.h O.sub.iwherein X is at least one alkali metal element selected from K, Rb and Cs; a, b, c, d, e, f, g and h respectively represent the number of Mo, Bi, Fe, Co, Ni, P, Pb and X atoms, and when a is 12, b is 0.1-10, c is 9-20, d is 0-12, e is 0-12 with the proviso that the sum of d and e is 0.5-15, f is 0.1-5, g is 0.05-8 and h is 0.01-5; and i is the number of oxygen atoms which satisfies the atomic valences of the other elements.

Abstract: Catalysts for the oxidation of unsaturated aldehydes, said catalysts being expressed by the formulaA.sub.a B.sub.b C.sub.c Mo.sub.d P.sub.e O.sub.fwherein A represents at least one element selected from K, Rb, Cs and Tl; B represents at least one element selected from Be, Ag, Y, La, Nd, Sm and Hf; C represents at least one element selected from V, Cr, Ba, Sr, Al, Sn, Pb, Mn, Zr, W and Bi; a, b, c, d, e and f are the number of the atoms of A, B, C, Mo, P and O, respectively; and when d is 12, a, b and e are independently 0.05 to 12, c is 0 to 12, and f is the number of oxygen atoms which satisfies the valences of the other elements.

Abstract: A catalyst composition for use in preparing unsaturated carboxylic acids by the vapor-phase oxidation of unsaturated aldehydes, said catalyst composition comprising an oxide composition containing as essential ingredients (1) phosphorus, (2) molybdenum and (3) X in which X is at least one element selected from the group consisting of thallium and metals of Groups IA and II of the periodic table, characterized in that said oxide composition has a surface area of 4 to 20 m.sup.2 /g and a pore volume of 0.08 to 0.5 ml/g, whereby said catalyst composition has an excellent reproducibility of catalytic activity and a process for preparing aforesaid catalyst composition.

Abstract: A process for the preparation of acrylic acid which comprises reacting acrolein with molecular oxygen in the vapor phase in the presence of an oxidation catalyst composition having the following empirical formulaMo.sub.a P.sub.b V.sub.c L.sub.d M.sub.e O.sub.fwherein L is at least one element selected from the group consisting of Rb, Cs and K; M is at least one element selected from the group consisting of Sr, Nb, Cd, B, Zn and Pb; and a, b, c, d, e and f each represent the number of atoms of each element; the atomic ratio of a:b:c:d:e being 12:0.1-8:0.1-8:0.1-8:0-6; and f being the number of oxygen atoms determined by the valence requirement of the other elements present; and an oxidation catalyst used therefor.

Abstract: A novel catalyst expressed by the formulaA.sub.a B.sub.b Ce.sub.c Mo.sub.d P.sub.e O.sub.fwherein A represents at least one element selected from K, R.sub.b, C.sub.s and Tl; B represents at least one element selected from Be, Sr, Zn, Pb, Sb, Bi, Cr, Ag, Ga, Y, Ge, Te, La, Nd and Sm; a, b, c, d, e and f are the number of the atoms of A, B, Ce, Mo, P and O, respectively; and when d is 12, a, b, c and e are independently 0.05 to 12, and f is the number of oxygen atoms which satisfies the valences of the other elementsis provided. This catalyst, when used in a reaction for preparing unsaturated carboxylic acids by oxidizing unsaturated aldehydes in the vapor phase, exhibits superior catalytic activity and does not cause reduction in activity by impurities such as olefins.

Abstract: A catalyst for oxidation of olefins which has a composition of the general formulaMo.sub.a Bi.sub.b Fe.sub.c Co.sub.d Ni.sub.e Be.sub.f Q.sub.g R.sub.h X.sub.i O.sub.jwherein Q is at least one element selected from K, Rb, Cs and Tl; R is at least one element selected from P, As and B; X is at least one element selected from Ce, Ti, Te, Zn, Ge, Sn, Cr, Ga, La, In, Al, Cd, Pd, Mn, V, Pb, Nb, Ag, Zr, Cu, Nd and U; a, b, c, d, e, f, g, h and i respectively represent the numbers of Mo, Bi, Fe, Co, Ni, Be, Q, R and X atoms, and when a is 12, b is 0.1-10, c is 0.5-40, d is 0-12, e is 0-12 with the proviso that the sum of d and e is 0.5-15, f is 0.1-35, g is 0.01-5, h is 0-5, i is 0-12; and j is the number of oxygen atoms which satisfies the atomic valences of the other elements.Unsaturated aldehydes can be prepared in a high selectivity and a high one-pass yield by oxidizing olefins containing 3 carbon atoms in the straight chain in the vapor phase in the presence of the aforesaid catalyst at a temperature of 250.

Abstract: A catalyst for oxidation of olefins which has a composition of the general formulaMo.sub.a Bi.sub.b Fe.sub.c Co.sub.d Ni.sub.e Q.sub.f R.sub.g X.sub.h Z.sub.i O.sub.jwherein Q is at least one element selected from Au and Nd; R is at least one elemet selected from K, Rb, Cs and Tl; X is at least one lement selected from P, As and B; Z is at least one element selected from Ce, Ti, Te, Zn, Ge, Sn, Cr, Ga, La, In, Al, Cd, Pd, Mn, V, W, Pb, Nb, Ag, Zr, Cu and U; a, b, c, d, e, f, g, h and i respectively represent the numbers of Mo, Bi, Fe, Co, Ni, Q, R, X and Z atoms, and when a is 12, b is 0.1-10, c is 0.5-40, d is 0-12, e is 0-12 with the proviso that the sum of d and e is 0.5-15, f is 0.1-8, g is 0.01-5, h is 0-5, i is 0-12; and j is the number of oxygen atoms which satisfies the atomic valences of the other elements.

Abstract: A process for the preparation of an unsaturated carboxylic acid which comprises reacting an unsaturated aldehyde with molecular oxygen in the vapor phase in the presence of an oxidation catalyst composition having the following empirical formulaMo.sub.a P.sub.b Cr.sub.c Q.sub.d L.sub.e O.sub.fwherein Q is at least one element selected from the group consisting of Tl, Rb, Cs and K; L is at least one element selected from the group consisting of Sr, Zn, Cd, V, Nb, B, Pb, Bi and W; and a, b, c, d, e and f each represent the number of atoms of each element; the atomic ratio of a:b:c:d:e is 12:0.1-8:0.1-8:0.1-8:0.01-6; and f is the number of oxygen atoms determined by the valence requirement of the other elements present.

Abstract: A process for the preparation of methacrylic acid which comprises reacting methacrolein with molecular oxygen in the vapor phase in the presence of an oxidation catalyst composition having the following empirical formulaMo.sub.a P.sub.b V.sub.c L.sub.d M.sub.e O.sub.fwherein L is at least one element selected from the group consisting of Rb, Cs and K; M is at least one element selected from the group consisting of Sr, Zn, Cd, Nb, B, Pb, and W; and a, b, c, d, e and f each represent the number of atoms of each element; the atomic ratio of a:b:c:d:e is 12:0.1-8:0.1-8:0.1-8:0-6; and f is the number of oxygen atoms determined by the valence requirement of the other elements present.