Abstract: The present invention relates to a process for the cleavage of dialkoxyalkanes to give corresponding aldehydes or ketones, where the cleavage is carried out in the presence of at least one ionic liquid of the general formula K+A?.

Abstract: The present invention relates to a process for the dehydration of alcohols, polyalcohols or alcoholates having at least one CH group in the ?-position to the alcoholate or alcohol function to give alcenes or ethers, where the dehydration is carried out in ionic liquids of the general formula K+A?.

Abstract: The present invention relates to a process for the cleavage of dialkoxyalkanes to give corresponding aldehydes or ketones, where the cleavage is carried out in the presence of at least one ionic liquid of the general formula K+A?.

Abstract: A micromanipulator for the movement of an object relative to a treatment or analyzing position so that at least a part of the surface of the object can be treated or analyzed. The micromanipulator possesses a plurality of kinematic elements which support the object or an object holder and which, for this purpose, are equipped with a support for the object or the object holder. For the implementation of micromovements, the kinematic elements are piezo-electrically displaceable. The object is supported on at least one of the kinematic elements in such a manner that there can also be concurrently implemented micromovement and macromovements normal to the treatment or analysis plane of the object.

Abstract: A scanning tunnel microscope having an emission tip, specimen holder and xyz movement mechanism as well as devices for applying a voltage between the emission tip and the specimen and for detecting the electrons emanating from the specimen can be used for verifying secondary electrons generated in the same surface region and/or an energy analysis of electrons emitted by the emission tip and scattered by the surface if a cylindrical mirror analyzer with assigned detector is arranged coaxially to the emission tip. With relatively high applied voltages, a cylindrically symmetrical correction electrode between the emission tip and the cylindrical mirror, arranged coaxially to the emission tip, is expedient, with which electrode the imaging properties of the analyzer open toward the specimen are made to approximate those of a conventional cylindrical mirror. A masking device allows a solid angle-oriented detection of scattered and secondary electrons.

Abstract: Apparatus for use in maxillary orthopaedics comprises a time-measuring device 18 fitted in a cavity in a moulding means 13 which is made of plastics material and is carried in the mouth. The time-measuring device 18 consists of an electronic counter which is connected to an impulse generator. The impulse generator is actuated by a switch 17 which is arranged to be in a different state according to whether the device is worn or not. The time-measuring device is connected, via leads 20' and switch 17, to a battery 16 also fitted in a cavity in the moulding means 13.