Reactions of massive nuclei for the synthesis of heavy and superheavy nuclei

We study the effect of the entrance channel and the shell structure of reacting massive nuclei on the fusion mechanism and the formation of evaporation residues of heavy and superheavy nuclei. In the framework of the combined dinuclear system concept and advanced statistical model, we analyze the reactions ³²S+¹⁸²W, ⁴⁸Ti+¹⁶⁶Er and ⁶⁰Ni+¹⁵⁴Sm leading to ²¹⁴Th^*, and the reactions ⁴⁸Ca+²⁴⁸Cm and the ⁴⁸Ca+²⁴⁹Cf leading to the ²⁹⁶116 and ²⁹⁷118 compound nuclei, respectively.     

Eligibility of spherical-well approximation for calculations of nucleon-transfer matrix elements

Single-particle matrix elements of nucleon transfer were calculated by the Woods-Saxon potential wave functions. The results are compared with the ones calculated by the spherical-well approximation. The eligibility of the approximation of the mean field of nuclei by the spherical well to study the initial stage of nuclear reactions at heavy-ion collisions is demonstrated. The text was submitted by the authors in English.     

Dynamics of capture and fusion in heavy ion collisions

The effect of entrance channel on decrease of the complete fusion cross sections and on the yield of reaction products are associated with the quasifission which depends on the mass asymmetry and shell structure of colliding nuclei. In reactions of massive projectile and target nuclei, the competition between complete fusion and quasifission appears at the stage of compound nucleus formation, in addition to the increase of the fission probability. It is shown that the yield of quasifission products may be symmetric or asymmetric in dependence on peculiarities of shell structure of reaction fragments. Marima of mass or charge distributions are connected with the peculiarities of shell structure of reaction fragments.     

Effect of metal and solvent on kinetics of metalation of fluorene by anthracene anion-radicals

Conclusions The contact ion pairs of the anthracene anion-radicals containing the cations of the alkali metals (Li⁺, Na⁺, K⁺) are more reactive in the reaction with fluorene than are the ion pairs that are separated by a solvent.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 215–216, January, 1973.     

核对称轴不同相对取向对熔合动力学的影响

计算了核对称轴不同相对取向时的熔合位垒.基于双核模型观念，考虑了熔合与准裂变的竞争，通过数值法求解主方程，计算了⁷⁶Ge+²⁰⁸Pb，⁴⁸Ca+²⁴⁴Pu核对称轴不同相对取向对熔合概率的影响，探索了最有利于超重元素合成的弹靶相对取向.取向不同时，对熔合反应的影响较大，计算结果表明弹靶碰撞为腰对腰时，更有利于发生熔合反应. 关键词： 超重元素 熔合概率 变形核 方向角度     

X-ray structural investigation of alkaloids. III. Molecular structure and absolute configuration of (+)-excelsine

By a complete x-ray structural investigation, the structural formula of (−)-pseudokopsinine has been refined and its absolute configuration has been determined.     

X-ray structural investigation of alkaloids. III. Molecular structure and absolute configuration of (+)-excelsine

Summary On the basis of a complete x-ray structural investigation, the structural formula of (+)-excelsine has been refined and its absolute configuration has been determined.Institute of Heteroorganic Compounds, Academy of Sciences of the USSR, Moscow. Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 206–217, March–April, 1976.