Abstract: A mesomorphic compound represented by the following formula (I): ##STR1## wherein R.sub.1 and R.sub.2 respectively denote a linear or branched alkyl group having 1-16 carbon atoms capable of having a substituent; Y.sub.1 denotes --COO--, --OCO--, --CH.sub.2 --or --OCH.sub.2 --; Z.sub.1 denotes a single bond, --O--, --COO--, --OCO-- or --OCOO--; and X denotes a halogen, cyano group or methyl group.

Abstract: 1. A mesomorphic compound represented by the following formula 8 I]: ##STR1## wherein R.sub.1 and R.sub.2 respectively denote a straight chain or branch chain allyl group having 1-18 carbon atoms, wherein --CH.sub.2 -- in the alkyl group may be substituted by ##STR2## on condition that hetero atoms are not adjacent each other, R.sup.2 may be hydrogen atom, halogen atom, cyano group and trifluoromethyl group; n is 0 or 1, with the proviso that A.sup.1 denotes a single bond, ##STR3## when n is 0, A.sup.1 denotes a single bond when n is 1; A.sup.2 denotes any one of ##STR4## and X.sup.1, X.sup.2, Z.sup.1 and Z.sup.2 denote independently any one of hydrogen atom, halogen atom, cyano group and trifluoromethyl group, with proviso that X.sup.1, X.sup.2, Z.sup.1 and Z.sup.2 may not be all hydrogen atoms; Y denotes any one of ##STR5## a single bond.

Abstract: A mesomorphic compound represented by the following formula [I]: ##STR1## wherein R.sub.1 and R.sub.2 independently denote an alkyl group having 1-16 carbon atoms capable of having a substituent; X.sub.1, X.sub.2, X.sub.3 and X.sub.4 independently denote a single bond ##STR2## A.sub.1, A.sub.2 and A.sub.3 independently denote ##STR3## X.sub.5 and X.sub.6 independently denote hydrogen atom, fluorine, chlorine, bromine, CH.sub.3, CN or CF.sub.3 ; n.sub.1 and n.sub.2 are 0 or 1, with provisos that (1) X.sub.2 cannot be a single bond when n.sub.1 is 0, (2) X.sub.3 cannot be a single bond when N.sub.2 is 1 and (3) at least one of X.sub.2 and X.sub.3 denotes ##STR4## when both n.sub.1 and n.sub.2 is O and A.sub.

Abstract: A mesomorphic compound represented by the following formula (I):R.sub.1 --A.sub.1 --B.sub.1 --A.sub.2 --R.sub.2 (I),wherein R.sub.1 and R.sub.2 respectively denote a linear or branched alkyl group having 3-18 carbon atoms capable of including one or non-neighboring two or more methylene groups which can be replaced with at least one species of ##STR1## wherein Z denotes --O-- or --S-- and R.sub.3 denotes hydrogen or an alkyl group having 1-5 carbon atoms; B.sub.1 denotes ##STR2## A.sub.1 denotes a single bond, ##STR3## A.sub.2 denotes a single bond, --A.sub.3 -- or --A.sub.3 --A.sub.4 -- wherein A.sub.3 and A.sub.4 respectively denote any one of ##STR4## and Y.sub.1 and Y.sub.2 respectively denote any one of hydrogen, fluorine, chlorine, bromine, --CH.sub.3, --CN and --CF.sub.3.

Abstract: A mesomorphic compound represented by the following formula (I): ##STR1## wherein R.sub.1 denotes a linear or branched alkyl group having 2-16 carbon atoms capable of including one or non-neighboring two methylene groups which can be replaced with --O--, --S--, --CO--, --COO-- or --OCO-- and capable of including a hydrogen atom which can be replaced with a fluorine atom; A denotes --A.sub.1 -- or --A.sub.1 --A.sub.2 --; B.sub.2 denotes --B.sub.3 -- or --B.sub.3 --B.sub.4 --; A.sub.1, A.sub.2, B.sub.1, B.sub.3 and B.sub.4 independently denote ##STR2## wherein Y.sub.1 and Y.sub.2 independently denote a hydrogen atom, F, Cl, Br, --CH.sub.3, --CN or --CF.sub.3, with the proviso that B.sub.1 can be a single bond; Z.sub.1 and Z.sub.2 independently denote a single bond, --COO--, --OCO--, --CH.sub.2 O-- or --OCH.sub.2 --; Z.sub.3 denotes --O--, --CO--, --COO-- or --OCO--; R.sub.2, R.sub.3 and R.sub.

Abstract: A mesomorphic compound represented by the following formula (I): ##STR1## wherein R.sub.1 and R.sub.2 respectively denote an alkyl group having 1-16 carbon atoms optionally substituted; X.sub.1 and X.sub.3 respectively denote a single bond, --O--, ##STR2## X.sub.2 denotes a single bond, ##STR3## A.sub.1 denotes a single bond ##STR4## A.sub.3 denotes ##STR5## A.sub.2 denotes 9, 10-dihydro-2,7-phenanthrenediyl, 2,7-fluorenediyl or 2,7-fluorenonediyl; n is 0 or 1; and X.sub.4 and X.sub.5 respectively denote hydrogen, F, Cl, Br, --CH.sub.3, --CN or --CF.sub.3, with proviso that X.sub.1 is a single bond when A.sub.1 is a single bond.

Abstract: An information recording and reproducing device uses a disk-shaped recording medium which is rotated at a constant angular velocity. The recording medium is divided into a plurality ring-shaped zones of concentric circles. In a recording area of the recording medium, the number of sectors per track is uniform in each zone and the number of sectors increases from an innermost zone towards an outermost zone. Each sector has a header area wherein header information including address information is recorded and a data area wherein data is recorded. In this device, data is recorded and reproduced in the data area in accordance with clock signals whose frequencies increase from the innermost zone towards the outermost zone. This device has a first clock generating circuit for generating a first clock signal of a fixed frequency, and the header information is recorded and reproduced in the header area in accordance with the first clock signal.

Abstract: A mesomorphic compound represented by the following formula (I): ##STR1## wherein R.sub.1 and R.sub.2 respectively denote a linear or branched alkyl group having 1-18 carbon atoms capable of including one or non-neighboring two or more methylene groups which can be replaced with at least one species of --O--, --S--, --CO--, --COO--, --OCO-- and --OCOO--; ##STR2## and n is 0 or 1.

Abstract: An optically active compound represented by the following formula (I): ##STR1## wherein R.sub.1 denotes a linear or branched alkyl group having 1-18 carbon atoms optionally including one or non-neighboring two or more methylene groups which can be replaced with --X-- or ##STR2## with the proviso that X denotes O or S and Y denotes halogen; R.sub.2 denotes a linear alkyl group having 4-8 carbon atoms: and C* denotes an optically active asymmetric carbon atom. The mesomorphic compound is effective for providing a ferroelectric liquid crystal composition showing improved response characteristics and also effective for suppressing occurrence of reverse domain.

Abstract: A mesomorphic compound represented by the following formula (I): ##STR1## wherein R.sub.1 and R.sub.2 respectively denote an alkyl group having 1-16 carbon atoms capable of having a substituent; X.sub.1 and X.sub.2 respectively denote a single bond, ##STR2## and A.sub.1 and A.sub.2 respectively denote ##STR3## wherein X.sub.3 and X.sub.4 respectively denote hydrogen, fluorine, chlorine, bromine, --CH.sub.3, --CN or --CF.sub.3 ; and Z denotes --O-- or --S--.

Abstract: A mesomorphic compound represented by the following formula (I): ##STR1## wherein R.sub.1 denotes a linear or branched alkyl group having 2-16 carbon atoms capable of including one or two non-neighboring methylene groups which can be replaced with ##STR2## and capable of including fluorine substituted for hydrogen; A denotes --A.sub.1 -- or --A.sub.1 --A.sub.2 -- and B denotes --B.sub.1 -- or --B.sub.1 --B.sub.2 -- wherein A.sub.1, A.sub.2, B.sub.1 and B.sub.2 respectively denote ##STR3## wherein Y.sub.1 and Y.sub.2 respectively denote H, F, Cl, Br, --CH.sub.3, --CN or --CF.sub.3 ; Z.sub.1 and Z.sub.2 respectively denote ##STR4## Z.sub.3 denotes ##STR5## R.sub.2, R.sub.3 and R.sub.4 respectively denote a linear or branched alkyl group having 1-16 carbon atoms including a methylene group which can be replaced with ##STR6## with proviso that it is not adjacent to the silicon atom; p and q are respectively 0 or 1 with proviso that p+q is 0 or 1; and n is an integer of 1-12.

Abstract: A ferroelectric chiral smectic liquid crystal composition, comprising at least one compound represented by the following formula (I): ##STR1## wherein R.sub.1 denotes a linear or branched alkyl group having 1-18 carbon atoms capable of having a substituent, R.sub.2 denotes a linear or branched alkyl group having 1-14 carbon atoms capable of having a substituent; X.sub.1 and X.sub.2 respectively denote a single bond, --O--, ##STR2## m is 0-7; and n is 0 or 1; and at least one compound represented by the following formula (II): ##STR3## wherein R.sub.3 and R.sub.4 respectively denote a linear or branched alkyl group having 1-18 carbon atoms capable of having a substituent; X.sub.3 and X.sub.4 respectively denote a single bond, --O--, ##STR4## Y.sub.1 denotes --CH.sub.2 O-- or --OCH.sub.2 --; and p and q are respectively 1 or 2.

Abstract: A mesomorphic compound represented by the following formula (I): ##STR1## wherein R.sup.1 and R.sup.2 respectively denote a linear or branched alkyl group having 3-18 carbon atoms capable of including one or more methylene groups which can be replaced with at least one species of ##STR2## with the proviso that --O-- cannot directly be connected to --O--, and R.sup.2 can also be halogen, --CN or --CF.sub.3 ; X denotes ##STR3## --CH.sub.2 O-- or --OCH.sub.2 ; A denotes ##STR4## and m and n are respecitvely 0 or 1 with the proviso that m+n=0 or 1. The mesomorphic compound is effective for providing a ferroelectric liquid crystal composition showing an improved low-temperature operation characteristic and a decreased temperature-dependence of response speed.

Abstract: An optically active mesomorphic compound represented by the formula (III) is obtained through an optically active compound represented by the formula (I) and then through a compound represented by the formula (II), respectively, shown below. ##STR1## In the above formulas, R represents a linear, branched or cyclic saturated or unsaturated hydrocarbon group having 1-18 carbon atoms each capable of having a substituent, C* represents an asymmetric carbon atom, k is an integer of from 2 to 5, A is a releasable active group such as hydroxyl, l is 0 or 1, and when l is 1, m is 0, 1 or 2 and n is 0 or 1; R.sup.1 represents an alkyl or alkoxy group having 1-18 carbon atoms; ##STR2## respectively denote ##STR3## p, q and r are respectively 0 or 1 satisfying the relation of p+q+r.gtoreq.1.

Abstract: A liquid crystal composition comprises at least one compound represented by the formula [I] below and at least one compound represented by the formula [II] below: ##STR1## wherein R.sub.1 denotes an alkyl group having 1-16 carbon atoms capable of having a substituent; R.sub.2 denotes any one of alkyl group, alkoxy group, alkoxycarbonyl group, acyloxy group and alkoxycarbonyloxy group, each having 1-16 carbon atoms and being capable of having a substituent; and A denotes any one of ##STR2## each capable of having a substituent; and ##STR3## wherein R.sub.3 denotes a linear alkyl group having 1-16 carbon atoms; R.sub.4 denotes a linear alkyl group having 1-12 carbon atoms; X.sub.1 is a single bond, --O--, ##STR4## X.sub.2 is --OCH.sub.2 --, ##STR5## or --CH.sub.

Abstract: A mesomorphic compound represented by the following formula (I): ##STR1## wherein R.sub.1 and R.sub.2 respectively denote a linear or branched alkyl group having 1-18 carbon atoms capable of having a substituent; X denotes any one of a single bond, --O--, ##STR2## Y denotes ##STR3## or --CH.sub.2 O--; and Z denotes any one of --O--, ##STR4## .

Abstract: A track jumping apparatus for an optical disk pickup which can detect a tracking error signal in performing a track jump, and determine a time of acceleration or deceleration of a jump signal by comparing the tracking error signal with a reference level, the track jumping apparatus comprising storing device for storing of standard values corresponding to the kinds of track jumps, standard value selecting device for selecting a standard value corresponding to a kind of track jump in performing the track jump, reference level setting device for setting a reference level so that the ratio of the reference level to a peak value of the tracking error signal agrees with a value based on the standard value selected by the standard value selecting device in performing the track jump, and standard value amending device for amending the standard value in the storing device selected at that moment according to a state of the tracking error signal at the end of the track jump.

Abstract: There is provided a liquid crystal compound represented by the following general formula (I), a liquid crystal composite including at least one kind of above liquid crystal compound and a liquid crystal device in which the liquid crystal composite is disposed between a pair of electrode substrates. ##STR1## In the above formula (I), R.sub.1 is a straight chain alkyl having 1-12 carbon atoms. R.sub.2 is a straight chain or branched chain alkyl, which may have a substituted radical, having 1-18 carbon atoms and in which one or more than two methylene, which do not adjoin, may be substituted by --Y--, ##STR2## --CH.dbd.CH--, or --C.vertline.C--. Y is O or S. A is --A.sub.1 -- or --A.sub.1 --A.sub.2 --, and B is --B.sub.1 -- or --B.sub.1 --B.sub.2 --. A.sub.1, A.sub.2, B.sub.1, and B.sub.2 each is selected from ##STR3## and a single bond. Z is hydrogen, halogen, cyano or methyl. X.sub.1 is a single bond when A is a single bond and is --CH.sub.2 O--, ##STR4## in other cases. n is 0 or 1, ##STR5## --OCH.sub.

Abstract: A hydrogen engine system comprises an engine, a metal hydride container connected with the engine and providing the engine with hydrogen, a heat intermedium providing mechanism connected with the hydrogen occluding alloy container and providing the metal hydride container with heat intermedium, a first control mechanism connected with the heat intermedium providing mechanism and controlling the heat intermedium providing mechanism so that the temperature of the heat intermedium supplied to the metal hydride container be kept at a constant value, and a second control mechanism connected with the heat intermedium providing mechanism between the first control mechanism and the metal hydride container and controlling the amount of the heat intermedium supplied from the heat intermedium providing mechanism to the metal hydride container.

Abstract: A mesomorphic compound represented by the following formula (I): ##STR1## wherein R.sub.1 and R.sub.2 respectively denote an alkyl group having 1-16 carbon atoms capable of having a substituent; X.sub.1, X.sub.2 and X.sub.3 respectively denote a single bond, --O--, ##STR2## A.sub.1 and A.sub.2 respectively ##STR3## wherein X.sub.4 and X.sub.5 respectively denote hydrogen, fluorine, chlorine, bromine, --CH.sub.3, --CN or --CF.sub.3 with proviso that X.sub.1 always denotes a single bond when A.sub.1 denotes a single bond; and n is 0 or 1.