New synthesis of bicyclo[1.1.0]butane hydrocarbons

Conclusions A new general synthesis is proposed for bicyclo[1.1.0]butanes, by 1,3-cyclization of 1-bromo-chloromethylcyclopropanes, and a two-step synthesis of the latter from available allyl chlorides has been developed.Deceased.Translated from Izvestlya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2043–2047, September, 1985.     

Compact and portable terahertz source by mixing two frequencies generated simultaneously by a single solid-state laser

We have demonstrated a compact and portable terahertz (THz) source, based on difference-frequency generation in a GaSe crystal. The two input frequencies, required for achieving frequency mixing, are generated by a single Q-switched Nd:YLF laser incorporating two laser resonators. The average power of the THz output reaches 1 μW at 1.64 THz (182 μm) within a linewidth of 65 GHz. Such a THz source can be packaged into a compact and portable system.     

The contribution of bends and constrictions of a superconducting film to the photon detection by a single-photon superconducting detector

The contribution of bends and constrictions by a superconducting film to the detection by a singlephoton superconducting detector is investigated. It has been shown that, for currents smaller than the minimal detection current of a straight film, the detection efficiency of a film with a constriction attains saturation upon an increase in the current, which coincides qualitatively with the behavior of this dependence observed in the experiment. It has also been found that the effect of bends in the film and the external magnetic field on the detection efficiency for low-energy photons is essential, while for high-energy photons no such influence is observed.     

Singly resonant optical parametric oscillator based on adhesive-free-bonded periodically inverted KTiOPO4 plates: terahertz generation by mixing a pair of idler waves

We implemented a singly resonant optical parametric oscillator based on adhesive-free-bonded periodically inverted KTiOPO4 plates. It has major advantages such as walk-off compensation and oscillation at four wavelengths. The threshold of the oscillation was measured to be 8 MW/cm2, which is about a factor of 4 lower than that based in two separate KTiOPO4 crystals. By frequency-mixing the dual-wavelength output in GaP stacks, we generated the terahertz radiation at 2.54 THz. The tuning range of the terahertz output was demonstrated to be 2.19-2.77 THz.     

Nonlinear theory of channeling of radiation by a ribbon-shaped stream of cyclotron oscillators

The features of the nonlinear stage of radiation from transversely bounded, magnetically steered helical and rectilinear electron streams in a homogeneous medium and in vacuum are investigated theoretically under conditions of the normal and anomalous Doppler effects. The evolution of the transverse distribution of the radiated field is investigated, and the channeling effect of the electron stream is demonstrated. It is shown that in the radiation from a helical stream in a plasmalike medium a practically complete conversion of the energy of gyrational motion of the electrons into energy of electromagnetic oscillations can occur on account of the automatic fine tuning of the radiation angle. Zh. Tekh. Fiz. 69, 9–14 (January 1999)     

Development of the Concept of High-Power Microwave Oscillators with Phase Locking by an External Signal

Radiophysics and Quantum Electronics - By simulations and experiments we develop a method for generation phase locking of a Ka-band subgigawatt nonstationary relativistic backward-wave oscillator...     

Specific features of nucleophilic substitution in 1-chloro-3,4-dinitrobenzene

Effects of the solvent, temperature, and nucleophile nature on the selectivity of nucleophilic substitution in 1-chloro-3,4-dinitrobenzene were studied, and optimal conditions were found for the synthesis and isolation of particular products.Translated from Zhurnal Organicheskoi Khimii, Vol. 40, No. 10, 2004, pp. 1522–1525.Original Russian Text Copyright © 2004 by Zotova, Kushakova, Kuznetsov, Rodin, Garabadzhiu.     

Bis(triphenylphosphine)-5-nickela-3,3,7,7-tetramethyl-trans-tricyclo[4.1.0.02,4]heptane

The oxidative addition of 3,3-dimethylcyclopropene (DMCP) to the nickel complexes (Ph₃P)₃Ni and (π-C₂H₄)Ni(PPh₃)₂ resulting in the formation of bis(triphenylphosphine)-5-nickela-3,3,7,7-tetramethyl-trans-tricyclo[4.1.0.0^2,4]heptane has been carried out. The NMR (¹H and ³¹P-{¹H}) spectra, the reactivity and some of the catalytic properties of this complex in the cyclodimerization of DMCP have been studied.