The study of the vibrations of polyatomic molecules has recently turned into one of the most widespread and powerful methods of studying molecular structure. These vibrations ap- pear directly in the infrared absorption spectra and Raman spectra of gases, liquids, and solids. A measurement of the number of bands in addition to their positions (frequencies or wavelengths) offers the possibility of obtaining a great deal of important information regarding the geometric and mechanical properties of the molecules, the types of chemical bonds, and so forth. It is now quite difficult to list the...

This collection of articles contains a systematic outline of original experimental and theoretical research on photoproduction of neutral pions at protons and at a strongly bound system of a few nucleons, i.e., the helium nucleus. Spark chambers and their use as spectrometers for photons and electrons are described in detail. The articles of the collection include information on a novel method of determining the efficiency of recording apparatus by generating monochromatic photons. The articles de- scribe original theoretical research on the optical anisotropy of nuclei. Problems encountered...

In this volume are collected scientific research reports written in recent years at the Radio-Astronomy Laboratory in the field of radio-astronomical apparatus and methods of ob- servation. Modern radiometers of high sensitivity, using masers and parametric amplifiers, have been installed at the R T-22 radio telescope of the Laboratory's Radio-Astronomy station. Some of the papers are devoted to a description of these original radiometers and to their operating conditions. Considerable space is given to a description of the meter-wave equipment and to the ad- justment of the DKR-1000 diapason...