摘要:
Disclosed is a method for quantitatively determining the width of a soft zone area of a partially hardened metallic workpiece, which has at least one hardened and one unhardened area, by means of at least one multifrequency eddy current sensor. A single workpiece being individually is moved relative to the multifrequency eddy current sensor in such a manner that a spatially delimited eddy current field generated by the multifrequency eddy current interacts with the workpiece contactlessly, generates eddy currents therein which, in turn, generate a measuring signal in the multifrequency eddy current sensor, in which the spatially delimited eddy current field has a greatest extension oriented in longitudinal direction to the surface of the workpiece which extension is greater than the maximum extension of the soft zone area in longitudinal direction of the surface of the workpiece.
摘要:
The invention relates to a device for preventing shifting of a vibration-loaded seal retained between two components braced against one another with the aid of clamping means, in particular to prevent shifting of a seal retained between a plug strip and a housing half shell of a motor vehicle clutch control element. This device includes stop faces for the seal, which act in a plane essentially perpendicular to the prestressing direction and which are embodied at least in part on the clamping means.
摘要:
A process for preparing polytetrahydrofuran, polytetrahydrofuran copolymers or diesters or monoesters of these polymers comprises polymerizing tetrahydrofuran in the presence of at least one telogen and/or comonomer over a heterogeneous catalyst comprising hectorite.
摘要:
A process for preparing 1,4-butanediol by continuous catalytic hydrogenation of 1,4-butynediol comprises reacting 1,4-butynediol with hydrogen in the liquid continuous phase in the presence of a heterogeneous hydrogenation catalyst at from 20 to 300° C., a pressure of from 1 to 200 bar and values of the liquid-side volumetric mass transfer coefficient kLa of from 0.1 s−1 to 1 s−1 a) using a catalyst suspended in the reaction medium, where if a packed bubble column is employed this is operated in the upflow mode and at a ratio of gas leaving the reaction vessel to gas fed to the reaction vessel of from 0.99:1 to 0.4:1, or b) passing the liquid and gas in cocurrent in an upward direction through a fixed-bed reactor operated in the gas-circulation mode while maintaining a ratio of the gas fed to the reaction vessel to gas leaving the reaction vessel of from 0.99:1 to 0.4:1.
摘要:
The disclosure is a process for preparing a phthalide of the general formula I ##STR1## where R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are each independently of the others hydrogen, C.sub.1 -C.sub.4 -alkyl or C.sub.1 -C.sub.4 -alkoxy, by hydrogenation of a phthalic anhydride of the general formula II ##STR2## where R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are each as defined above, with the aid of a hydrogenation catalyst, which comprises performing the hydrogenation with the aid of a nickel catalyst doped with metals of subgroup 1, subgroup 6 and/or subgroup 7 of the Periodic Table.
摘要:
Tetrahydrofuran/but-2-yne-1,4-diol copolymers containing C--C triple bonds and having an average molecular weight M.sub.n of from 500 to 3500 Dalton and a content of from 0.5 to 3 mol of triple bonds/mol of copolymer and blends of these copolymers with polytetrahydrofuran having an average molecular weight M.sub.n of from 500 to 3500 Dalton, processes for their preparation and their use.
摘要:
A process for the preparation of polytetrahydrofuran or polytetrahydrofuran monoesters of C.sub.1 -C.sub.10 monocarboxylic acids by the polymerization of tetrahydrofuran over a heterogeneous catalyst in the presence of one of the telogens water, 1,4-butanediol or polytetrahydrofuran having a molecular weight of from 200 to 700 dalton or a C.sub.1 -C.sub.10 monocarboxylic acid or mixtures of these telogens, wherein a supported catalyst is used as catalyst, which contains a catalytically active amount of an oxygen-containing tungsten or molybdenum compound or mixtures of these compounds on an oxidic support material and which was calcined at temperatures ranging from 500.degree. to 1000.degree. C. following the application of the precursor compounds of said oxygen-containing molybdenum and/or tungsten compounds to the support material precursor.
摘要:
Catalyst and process for the preparation of butene-2-diol-1,4 by the hydrogenation of butyne-2-diol-1,4 in aqueous solution over a palladium-containing fixed-bed catalyst, which is doped with lead or cadmium, in which a catalyst is used which has been made by applying Pd and Pb or Pd and Cd successively, by vapor deposition or sputtering, to a metal gauze or a metal foil acting as support material followed by forming the catalyst at an elevated temperature in air.
摘要:
Fuels for gasoline engines contain small amounts of polyetheramines IR.sup.1 --(OBu).sub.n --NR.sup.2 R.sup.3 (I)whereR.sup.1 is C.sub.2 -C.sub.30 -alkyl,R.sup.2 and R.sup.3, independently of one another, are each hydrogen, C.sub.1 -C.sub.8 -alkyl, aminoalkylene of the general formula II--R.sup.4 --NR.sup.5 R.sup.6 (II)or polyaminoalkylene of the general formula III--(R.sup.4 --NR.sup.5).sub.m --R.sup.6 (III)whereR.sup.4 is C.sub.2 -C.sub.10 -alkylene, R.sup.5 and R.sup.6, independently of one another, are each hydrogen or C.sub.1 -C.sub.8 -alkyl and m is from 2 to 8,Bu is a butylene radical derived from butylene oxide andn is from 12 to 28.
摘要:
A process for preparing glutaraldehyde by reaction of alkoxydihydropyrans of the general formula I ##STR1## where R is C.sub.1 -C.sub.20 -alkoxy, with water at from 0.degree. to 150.degree. C. and from 0.01 to 50 bar in the presence of a catalyst consisting essentially of a bleaching earth.