Beitrag zur Ermittlung der Verdampfungsw?rmen der Gemische

Ohne Zusammenfassung     

Light pulse narrowing and power density increase in a laser-produced spark

The gaussian shape of a light pulse is distorted in a laser spark. A narrowing pulse appears with an amplitude enlarged by an order of magnitude due to self-focusing.     

Thermische Eigenschaften des Poly?thylens und der Copolymerisate von ?thylen und Propylen

Ohne Zusammenfassung     

Electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry to reveal the substrate specificity of the peptidyl-cysteine decarboxylase EpiD

The microbial flavoenzyme EpiD catalyzes the oxidative decarboxylation of peptidyl-cysteines to peptidyl-aminoenethiols. These unusual C-terminally modified peptides are intermediates in the biosynthesis of the tetracyclic peptide antibiotic epidermin, which belongs to the lantibiotics family. The peptide SFNSYCC represents the C-terminal partial sequence of the natural precursor peptide EpiA. EpiA is posttranslationally modified to form finally the lantibiotic epidermin. The substrate specificity of EpiD was investigated using high-resolution mass spectrometry and the heptapeptide library SFNSXCC. The enzymatic conversion of particular peptides can be observed by a mass loss of m/z 46. In contrast to the previously used triple quadrupole instrument, electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR-MS) was able to resolve and detect all precursor and converted peptides with identical nominal masses in a single measurement, avoiding the necessity to investigate single peptides. Furthermore, a new substrate SFNSCCC of the enzyme EpiD was detected within the reaction mixture.     

The Preparation and Properties of Some α-Acyloxy- and α-Carbamoyloxy-Phosphonothionates

New f -acyloxy and f -carbamoyloxy derivatives of dimethyl 2,2,2-trichloroethyl-phosphonothionate have been prepared, characterized, and screened for activity against free-living soil nematodes. Several of the more easily hydrolysable esters, and also the N -methylcarbamoyl derivative, were as active as the parent pesticide, dimethyl f -hydroxy-2,2,2-trichloroethylphosphonothionate, after an induction period during which the active species is assumed to be released in vivo . It is concluded that the 2,2,2-trichloroethyl group is essential for activity in compounds of these types and that the presence of the N -methylcarbamoyl group does not in itself confer activity.     

Asymmetric synthesis of (−)-bissetone via a highly enantioselective hetero-Diels–Alder reaction

We demonstrate a new approach for the asymmetric synthesis of bissetone. The key reaction is the highly enantioselective hetero-Diels–Alder cycloaddition of triene 3 with ethyl glyoxylate catalyzed by readily available BINOL–Ti complexes. The HDA cycloadduct 4 was then transformed in five steps into O-protected bissetone (8) and its C5-epimer in good yield.     

Cavity QED with magnetically coupled collective spin states

We report strong coupling between an ensemble of nitrogen-vacancy center electron spins in diamond and a superconducting microwave coplanar waveguide resonator. The characteristic scaling of the collective coupling strength with the square root of the number of emitters is observed directly. Additionally, we measure hyperfine coupling to (13)C nuclear spins, which is a first step towards a nuclear ensemble quantum memory. Using the dispersive shift of the cavity resonance frequency, we measure the relaxation time of the NV center at millikelvin temperatures in a nondestructive way.     

On the existence of infinitely many periodic solutions to some problems of n-body type

We prove the existence of infinitely many periodic solutions with prescribed period to a class of problems of n-body type.