Abstract: A synthetic adsorbent, where a maximum value of a differential pore volume under a pressure condition of 0.5 to 30.0 psia is greater than 0.05 mL/g. A method of measuring the differential pore volume includes reducing a pressure in a sample container where the synthetic adsorbent that has been dried is placed to 10 Pa or less, mercury is degassed by reducing the pressure to 10 Pa or less, and the sample container is filled with the mercury at a pressure of 0.5 psia, measuring a mercury intrusion amount when the pressure in the sample container filled with the mercury is increased from 0.5 to 30.0 psia, and calculating the differential pore volume by dividing an amount of an increase in the mercury intrusion amount when a first-stage pressure calculated based on the mercury intrusion amount measured in the measuring is increased, by a measured amount of the synthetic adsorbent.

Abstract: A card information-storing portion is provided in a semiconductor memory card, and information relating to access performance such as access condition and access rate is held in the storing portion. Further, an access device acquires the held information from the semiconductor memory card to make it possible that the information can be used for control of a file system. This optimizes processing of the access device and the semiconductor memory card independent of differences in characteristics of semiconductor memory cards and management methods used, realizing high-rate access from the access device to a semiconductor memory card.

Abstract: A host information memory is provided in a semiconductor memory card and a data write start address and a data size supplied by an access unit are stored. A free physical area generation section determines whether or not to perform erasing of an invalid block of a nonvolatile memory when writing of data based on the data write start address and data size, and determines the number of blocks to be erased. When erasing, writing of data and erasing of invalid blocks are simultaneously performed with respect to different memory chips. Erase process of data, herewith, can be optimized and high speed access from the access unit to a semiconductor memory card can be realized.

Abstract: A card information storage part (119) is provided in a semiconductor memory device (110) to store information of the characteristics of the semiconductor memory device (110). There is also provided a file system interface control part (120) for performing, based on the stored characteristic information, a file access suitable for the characteristics of the semiconductor memory device (110). This allows an access device (100) to perform an optimum file access via the file system interface control part (120) without awareness of the characteristics of the semiconductor memory device (110).

Abstract: A card information-storing portion is provided in a semiconductor memory card, and information relating to access performance such as access condition and access rate is held in the storing portion. Further, an access device acquires the held information from the semiconductor memory card to make it possible that the information can be used for control of a file system. This optimizes processing of the access device and the semiconductor memory card independent of differences in characteristics of semiconductor memory cards and management methods used, realizing high-rate access from the access device to a semiconductor memory card.

Abstract: A host information memory is provided in a semiconductor memory card and a data write start address and a data size supplied by an access unit are stored. A free physical area generation section determines whether or not to perform erasing of an invalid block of a nonvolatile memory when writing of data based on the data write start address and data size, and determines the number of blocks to be erased. When erasing, writing of data and erasing of invalid blocks are simultaneously performed with respect to different memory chips. Erase process of data, herewith, can be optimized and high speed access from the access unit to a semiconductor memory card can be realized.

Abstract: A polypropylene composition for a laminated and oriented film comprising (A) 73 to 97% by weight of a crystalline propylene random copolymer having a propylene content of 60 to 97% by weight, an ethylene content of 0 to 6% by weight and an .alpha.-olefin content of 3 to 40% by weight, (B) 2.5 to 17% by weight of a propylene- .alpha.-olefin random copolymer having a propylene content of 35 to 75% by weight and an .alpha.-olefin content of 25 to 65% by weight, and (c) 0.5 to 10% by weight of a crystalline propylene polymer. A polypropylene composition for a laminated and oriented film being film-formed for a long time without hurting a transparency and a low temperature heat-sealing property and having an excellent solvent resistance and an excellent hot-tack property, and a laminated and oriented film having this composition on a surface layer are provided.

Abstract: A propylene-.alpha.-olefin random copolymer composition for use in a laminated and oriented film. The composition includes:(A) from 75 to 95% by weight of a crystalline propylene random copolymer obtained by gas-phase polymerization of propylene and an .alpha.-olefin wherein the amount of components of the copolymer which are soluble in xylene at 20.degree. C. is less than 15% by weight, the propylene content is from 73 to 97% by weight, the .alpha.-olefin content is from 3 to 27% by weight, and(B) from 5 to 25% by weight of a propylene random copolymer of propylene and .alpha.-olefin, wherein the propylene content is from 50 to 60% by weight, and the .alpha.-olefin content is from 35 to 65 % by weight,wherein the amounts of components in the propylene-.alpha.-olefin random copolymer composition which are soluble in xylene at 20.degree. C. is less than 30% by weight.