Abstract: Provided are a cellulose fiber containing cellulose II, the cellulose fiber having improved heat resistance, as well as a fiber reinforced resin composition, a method for producing the cellulose fiber, and a method for producing the fiber reinforced resin composition. The cellulose fiber contains the cellulose II having a content of an imidazolium salt of 1% by mass or less.

Abstract: Provided is a cellulose solution (a composition) in which decomposition of cellulose does not easily proceed even if heated. Further, provided is a method for producing a cellulose fiber excellent in mechanical strength. The composition includes cellulose and a compound represented by the following formula (1), a concentration of 1-methylimidazolium chloride being 300 ppm or less on a mass basis with respect to the compound represented by the formula (1). In the formula (1), R is an alkyl group having 2 to 6 carbon atoms, and Me is a methyl group.

Abstract: A semiconductor crystal containing a clathrate compound represented by the following formula (I), the semiconductor crystal having one end portion and the other end portion, wherein the one and the other end portions differ in concentration of at least one element in the formula (I): AxDyE46-y??(I) wherein A represents at least one element selected from the group consisting of Ba, Na, Sr, and K, D represents at least one element selected from the group consisting of B, Ga, and In, E represents at least one element selected from the group consisting of Si, Ge, and Sn, x is 7 or more and 8 or less, and y is 14 or more and 20 or less.

Abstract: A semiconductor crystal containing a clathrate compound represented by the following formula (I), the semiconductor crystal having one end portion and the other end portion, wherein the one and the other end portions differ in concentration of at least one element in the formula (I): AxDyE46-y??(I) wherein A represents at least one element selected from the group consisting of Ba, Na, Sr, and K, D represents at least one element selected from the group consisting of B, Ga, and In, E represents at least one element selected from the group consisting of Si, Ge, and Sn, x is 7 or more and 8 or less, and y is 14 or more and 20 or less.