1971-02-12 | S. W. Mayer, M. A. Kwock, R. W. F. Gross and D. J. Spencer
The article discusses the successful separation of hydrogen isotopes using selective laser-induced chemical reactions. The process involves irradiating mixtures of ordinary and deuteromethanol with 0.44 eV photons at a total power of about 100 watts. The selectivity is achieved by matching the laser frequency to the vibration of the —OH bond, without involving kinetic isotope effects or photolysis. The method shows promise for heavier isotopes but may require chemical ingenuity and recycling arrangements. This technique opens new possibilities for observing specific vibrational modes in reactive molecules, potentially leading to significant advancements in chemical kinetics.
The study examines the effect of various 3d transition metals and copper on the indentation hardness of β-boron. All solute metals were arc-melted with boron at a concentration of 5 atm per cent, producing saturated solid solutions. The unit cell volumes of these solutions were closely correlated with microhardness, with Cu, Sc, and Mn solutes showing the highest increase in hardness (up to 20% relative to pure β-boron). Given boron's importance as a fiber-reinforcing metal, the authors suggest investigating alloyed boron for enhanced strength in fibers or whiskers. Previous research has shown that carbon fiber can be strengthened by alloying it with boron, suggesting that boron-alloyed carbon fibers might also be particularly strong.
The Niagara River is noted for its stability, with no significant uncontrolled rivers joining it above the Horseshoe Falls. The article also discusses the removal of orbital degeneracy in molecules or ions of high symmetry, which has been used to explain stereochemical distortions in transition metal complexes. Recent work by Pearson, based on earlier studies by Bader and Longuet-Higgins, explores the second-order Jahn–Teller effect, which can predict the consequences of mixing electronically excited states with the ground state geometries of molecules. This theory, grounded in symmetry considerations, may prove useful for understanding organometallic molecules, similar to Walsh’s rules for simpler systems.The article discusses the successful separation of hydrogen isotopes using selective laser-induced chemical reactions. The process involves irradiating mixtures of ordinary and deuteromethanol with 0.44 eV photons at a total power of about 100 watts. The selectivity is achieved by matching the laser frequency to the vibration of the —OH bond, without involving kinetic isotope effects or photolysis. The method shows promise for heavier isotopes but may require chemical ingenuity and recycling arrangements. This technique opens new possibilities for observing specific vibrational modes in reactive molecules, potentially leading to significant advancements in chemical kinetics.
The study examines the effect of various 3d transition metals and copper on the indentation hardness of β-boron. All solute metals were arc-melted with boron at a concentration of 5 atm per cent, producing saturated solid solutions. The unit cell volumes of these solutions were closely correlated with microhardness, with Cu, Sc, and Mn solutes showing the highest increase in hardness (up to 20% relative to pure β-boron). Given boron's importance as a fiber-reinforcing metal, the authors suggest investigating alloyed boron for enhanced strength in fibers or whiskers. Previous research has shown that carbon fiber can be strengthened by alloying it with boron, suggesting that boron-alloyed carbon fibers might also be particularly strong.
The Niagara River is noted for its stability, with no significant uncontrolled rivers joining it above the Horseshoe Falls. The article also discusses the removal of orbital degeneracy in molecules or ions of high symmetry, which has been used to explain stereochemical distortions in transition metal complexes. Recent work by Pearson, based on earlier studies by Bader and Longuet-Higgins, explores the second-order Jahn–Teller effect, which can predict the consequences of mixing electronically excited states with the ground state geometries of molecules. This theory, grounded in symmetry considerations, may prove useful for understanding organometallic molecules, similar to Walsh’s rules for simpler systems.