Abstract: A secondary battery is provided that is capable of improving the cycle characteristics. The secondary battery includes a cathode, an anode, and an electrolytic solution. The electrolytic solution is impregnated into a separator provided between the cathode and the anode. In the anode, an anode active material layer and a compound layer are provided on both faces of an anode current collector. The anode active material layer contains a plurality of anode active material particles. The anode active material particles have a multilayer structure of an anode active material containing silicon as an element. The thickness of each layer in the multilayer structure ranges from 50 nm to 1050 nm. Thus, contact characteristics between each layer, contact characteristics between the anode active material layer and the anode current collector, and current collectivity are improved.

Abstract: A secondary battery having high cycle characteristics is provided. The secondary battery includes a cathode, an anode, and an electrolyte. In the anode, an anode active material layer containing silicon, carbon, and oxygen as an anode active material is provided on an anode current collector. In the anode active material, a content of carbon is from 0.2 atomic % to 10 atomic % both inclusive, and a content of oxygen is from 0.5 atomic % to 40 atomic % both inclusive. A ratio from 0.1% to 17.29% both inclusive of the silicon contained in the anode active material exists as Si—C bond.

Abstract: An optical subscriber unit comprises a portion for detecting whether or not an installation distance of the optical subscriber unit is a short distance or a long distance when the optical subscriber unit receives a subscriber command from a center unit by referring to a received optical power, and a portion for transmitting response burst signal to an entrance use slot of the current frame when the installation distance is the short distance and to an entrance use slot of the next frame when the installation distance is the long distance.