Abstract: A double-passage balance structure of a carburetor includes a carburetor body and a float chamber composed of the carburetor body and a housing; the carburetor body is provided with balance passages and a through cavity for the air to enter and mix with a fuel and for a mixture to be output, the balance passages include A and second balance passages, openings of the A and second balance passages in the float chamber are staggered in an axial direction and a radial direction of the cavity, and the opening of the first balance passage in the float chamber is higher than the opening of the second balance passage in the float chamber; and other ends of the A and second balance passages are both communicated with a converging passage provided in the carburetor body, and the converging passage is communicated with the atmosphere.

Abstract: The present invention provides a luminous storage material that emits a blue or bluish green light, that has high persistence, that is thermally and structurally stable, and that exhibits a high weather resistance in chemically severe conditions. The present invention also provides manufacturing method for this material. A blue aluminum silicate luminous storage material according to this invention is composed of a powdered product that has been activated by Eu.sup.2+ wherein its composition formula is expressed as follows:(M.sub.l-n-m M*.sub.n -Eu.sub.m)(Al.sub.1-x Si.sub.3/4 x.quadrature..sub.1/4.times.).sub.2 O.sub.4(wherein .quadrature. is vacancy; M is one or more types of alkali earth metal elements selected from a group of magnesium, calcium, strontium, and barium; M* is one or more types of bivalent metal elements selected from a group of manganese, zinc, and cadmium; and (n), (m), and (x) consist of numerical values meeting the ranges 0.ltoreq.n.ltoreq.0.2, 0<x<0.6, 0.0001.ltoreq.m.ltoreq.0.1).