Luminescence properties of nanoparticles synthesized in electric discharge in liquid under ultrasonic cavitation

The differences in the luminescence intensity of metal oxide nanoparticles synthesized in electric discharges in liquidmedia under intense ultrasonic vibrations in the absence and presence of cavitation are studied.     

[18F]CuCF3: A [18F]Trifluoromethylating Agent for Arylboronic Acids and Aryl Iodides

Positron emission tomography has emerged as the leading method for medical imaging with fluorine‐18 as the most widely used radioactive isotope. Here we report a semi‐automated method for the preparation of valuable [¹⁸F]trifluoromethylcopper, as well as its use for the radiosynthesis of [¹⁸F]trifluoromethylarenes and heteroarenes. Mild conditions of [¹⁸F]trifluoromethylation make this method particularly useful for the radiosynthesis of pharmacologically relevant [¹⁸F]trifluoromethylarenes and heteroarenes.     

Effect of the rise time of the remagnetizing pulse on the nanosecond remagnetization of permalloy films

A study was made of the effect of the rise time of the remagnetizing pulse on the nanosecond-remagnetization signals of permalloy films, on the average-magnetization trajectory, and on the effective damping parameter. These effects intensify with increasing coercive force of the films.Translated from Izvestiya Vysshikh Uchenbykh Zavedenii Fizika, No. 2, pp. 7–10, February, 1971.     

Test of exotic scalar and tensor interactions in K e3 decay using stopped positive kaons

The form factors of the decay K ⁺ → π ⁰ e ⁺ ν _e (K _e3) have been determined from the comparison of the experimental and Monte Carlo Dalitz distributions containing about 10⁵ K _e3 events. The following values of the parameters were obtained: λ ₊=0.0278±0.0017 (stat.)±0.0015 (syst.), |f _S/f ₊(0)|=0.0040±0.0160 (stat.)±0.0067 (syst.), and |f _T/f ₊(0)|=0.019±0.080 (stat.)±0.038 (syst.). Both scalar f _S and tensor f _T form factors are consistent with the Standard Model predictions of zero values.     

Electrochemical processing of WC-Ni pseudoalloys in sulfuric acid solutions to ammonium paratungstate and nickel(II) sulfate

Electrolysis of a WC-Ni pseudoalloy in aqueous sulfuric acid solutions was studied. A flowsheet for production of ammonium paratungstate and nickel(II) sulfate is suggested, in which the process solutions are recycled. The principal electrolysis parameters are presented.     

On the structure of the set of probable Earth-impact trajectories for the asteroid Apophis in 2036

The probable set of Earth-collision trajectories for the asteroid Apophis in 2036 has been determined. The characteristics of these trajectories and the corresponding probable asteroid impact zone on the Earth have been analyzed.     

Syntheses and Applications of Monofluorinated Cyclopropanes

The combination of a fluorine atom and a cyclopropane ring, which both possess unique structural and chemical features, can generate new relevant building blocks for the discovery of efficient fluorinated biologically active agents. In this review, we report the different strategies to access monofluorocyclopropanes and highlight some of their attractive biological applications.     

Optimal trajectories for spacecraft with low electric-jet thrust in mission to asteroid Apophis

There is considered the problem of space flights to the asteroid Apophis. We analyze the flight scheme, which includes the geocentric stage, when a spacecraft with a high-thrust engine is accelerated; the heliocentric stage, in which the spacecraft moves using a low-thrust engine; and, finally, the deceleration stage, when the spacecraft becomes an artificial satellite orbiting the asteroid. We solve the problem of optimal control for the ideal and piecewise-constant low thrust, as well as determine the optimal value and direction of the hyperbolic velocity at ??infinity?? achieved by the spacecraft when it leaves the Earth sphere of influence. There is defined the set of space trajectories for a wide range of start dates and various flight durations using a complex method of optimization. We estimate the final mass of the spacecraft and the mass of the payload that can be delivered to the asteroid using the Soyuz-Fregat launcher.     

New search for T violation in the decays of the charged kaon

We report the results of the measurement of T-violating transverse muon polarization in the decays K ⁺→μ ⁺ ν _μ π ⁰ (K _μ3) and K ⁺→μ ⁺ ν _μ γ(K _μ2γ) performed in experiment E246 at KEK. The preliminary results obtained for the entire data set taken in the period 1996–2000 are consistent with no T violation in both decays.