2,835 research outputs found
Reactivity of organism in prolonged space flights
An analysis of published data are presented as well as the results of experiments which show that the state of weightlessness and hypodynamia result in a reduced orthostatic and vestibular resistance, increased sensitivity to infections, decreased endurance of accelerations and physical exercises, and altered reactivity of the organism to drugs. Various consequences of weightlessness on the human body, especially weightlessness combined with other factors linked to long space flights are also considered
Molecular Structures of the Metastable Charge-Transfer Complexes of Benzene (and Toluene) With Bromine as the Pre-Reactive Intermediates in Electrophilic Aromatic Bromination
Successful crystallization and X-ray crystallographic analyses of the highly metastable (1∶1) complexes of bromine with benzene and toluene establish the unique (localized) structure B that differs in notable ways from the long-accepted (delocalized) structure A. Furthermore, we demonstrate the (highly structured) charge-transfer complexes [C6H6,Br2] and [CH3C6H5,Br2] to be the pre-reactive intermediates that are converted (via an overall Br+ transfer) to the Wheland intermediates in electrophilic aromatic bromination. The role of the dative ion pairs [C6H6˙+ Br2˙−] and [CH3C6H5˙+ Br2˙−] in the rate-limiting activation processes is underscored
Noncovalent Binding of the Halogens to Aromatic Donors. Discrete Structures of Labile Br\u3csub\u3e2\u3c/sub\u3e Complexes with Benzene and Toluene
Precise molecular structures resulting from the noncovalent interaction of Br2 with benzene (and toluene) reveal the unusual localized bonding to specific (one or two) carbon centers in prereactive complexes leading directly to the transition states for electrophilic aromatic brominations
Time-Continuous Bell Measurements
We combine the concept of Bell measurements, in which two systems are
projected into a maximally entangled state, with the concept of continuous
measurements, which concerns the evolution of a continuously monitored quantum
system. For such time-continuous Bell measurements we derive the corresponding
stochastic Schr\"odinger equations, as well as the unconditional feedback
master equations. Our results apply to a wide range of physical systems, and
are easily adapted to describe an arbitrary number of systems and measurements.
Time-continuous Bell measurements therefore provide a versatile tool for the
control of complex quantum systems and networks. As examples we show show that
(i) two two-level systems can be deterministically entangled via homodyne
detection, tolerating photon loss up to 50%, and (ii) a quantum state of light
can be continuously teleported to a mechanical oscillator, which works under
the same conditions as are required for optomechanical ground state cooling.Comment: 4+4 pages, 4 figure
- …