LITERATURE CITED i. M. S. Green, M. I. Cooper, and J. M. Levelt Sengers, Phys. Rev. Lett., 26, 492 (1971). 2. B. Wallace and J. M. Mayer, Phys. Rev., 9A, 1610 (1970). 3. Yu. P. Blagoi and V. L. Zozulya, in: Physics of the Condensed State [in Russian], No. 33, FTINT Akad. Nauk UkrSSR (1974), p. 67. 4. H. B. Palmer, J. Chem. Phys., 22, 625 (1954). 5. L. M. Artyukhovskaya, E. T. Shimanskaya, and Yu. I. Shimanskii, Ukr. Fiz. Zh., 14, No. 12 (1970). 6. L. M. Artyukhovskaya, E. T. Shimanskaya, and Yu. I. Shimanskii, Zh. Eksp. Teor. Fiz., 64, No. 5, 1679 (1973). 7. A. Z. Golik, Yuo I. Shimanskii, A. D. Alekhin, et al., in: Equation of State of Gases and Liquids [in Russian], Nauka, Moscow (1975), pp. 189-216. 8. L. D. Landau and E. M. Lifshitz, Statistical Physics, Pergamon (1969). 9. A. Z. Patashinskii and V. L. Pokrovskii, Fluctuational Theory of Phase Transitions [in Russian], Nauka, Moscow (1975). i0. A. D. Alekhin, Ukr. Fiz. Zh., 26, No. 11, 1817 (1981). II. A. D. Alekhin, Ukr. Fiz. Zh., 28, No. 9 (1983). 12. A. D. Alekhin, Izv. Vyssh. Uchebn. Zaved., Fiz., No. 4, i0 (1983). 13. A. Z. Golik, Yu. I. Shimanskii, A. D. Alekhin, et al., Ukr. Fiz. Zh., 13, 472 (1969). 14. A. D. Alekhin, I. I. Kondilenko, P. A. Korotkov, et al., Opt. Spektrosk., 42, No. 4, 704 (1977). PARTIAL CONTRIBUTIONS OF 3He TO THE AMPLITUDE OF THE EQUATION OF THE LIQUID-VAPOR BOUNDARY CURVE OF DILUTE 3He-C02 MIXTURES L. A. Bulavin and Yu. B. Mel'nichenko UDC 532.77 Using the method of omitting slow neutrons, we have studied the shape of the liquid-vapor boundary curve of dilute 3He-C02 solutions as well as the tempera- ture dependence of the numerical density of 3He in the coexisting phases of the indicated mixtures. The experimental data obtained support the conclusions of the theory of isomorphous critical phenomena. INTRODUCTION The hypothesis of the isomorphism [i, 2] of critical phenomena predicts that the be- havior of binary solutions in the critical region of vaporization can be described on the basis of the theory of scaling transformations [3, 4] that has been developed for individual liquids. According to this hypothesis, the equation of state of mixtures in isomorphous variables should take on the same functional form as for systems with an isolated critical point. If the thermodynamic variables prescribed by the conditions of the experiment are not consistent with the isomorphous variables of the mixture, the nature of the anomalies of the physical quantities of the solution near the liquid-vapor critical point should differ from the nature of the anomalies of the corresponding quantities of a one-component system. Verification of the conclusions of the isomorphism hypothesis requires combined data on the heat capacity, susceptibility, the dependence of the density of the mixture on the temperature and pressure, and data on the temperature dependence of the numerical density of the components on the liquid-vapor boundary curve in the vicinity of the critical point. Only a very few studies, however, have been made on the density of binary solutions on the liquid-~apor boundary curve and almost no data are available about the behavior of the num- erical density of the components of binary mixtures on this curve, this being due to the difficulties in obtaining the indicated information by traditional methods of studying crit- ical phenomena. T. G. Shevchenko State University, Kiev Institute of the Chemistry of High-Molecular Compounds, Academy of Sciences of the Ukrainian SSR. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. I, pp. 83-88, January, 1986. Original article submitted October 15, 1984. 0038-5697/86/2901-0073512.50 9 1986 Plenum Publishing Corporation 73