Raies ultimes principle

The coordination theory and the principles governing coordinated structures provide the foundation for an interpretation of the structure of the complex silicates and other complex ionic crystals which may ultimately lead to the understanding of the nature and the explanation of the properties of these interesting substances. This will be achieved completely only after the investigation of the structures of many crystals with x-rays. To illustrate the clarification introduced by the new conception the following by no means exhaustive examples are discussed. 

In addition, any rational approach to peptide hormone and neurotransmitter design must ultimately depend on the application of physical-chemical principles of conformation and structure, the use of various spectroscopic methods (especially nuclear magnetic resonance, circular dlchrolsm, and Raman spectroscopies. X-ray analysis where possible, etc.), and an understanding of the nature of a hormone-receptor Interaction In physical-chemical terms. Here again the use of conformatlonally restricted peptide structures Is critical (, 2. Recently we have... 

Typically, synthetic capsules have a contained volume in the range 200-350 A3. In 1997, we discovered a spherical assembly consisting of [(C-methylresorcin[4]arene)6 (H20)8], 1. This assembly, Figure 1, with an enclosed volume of 1375 A3, was characterized by a single-crystal X-ray diffraction study and was found to be stable in nonpolar solvents [25]. Supramolecular assembly 1 ultimately led to the discovery of the link between 1 and the solid geometry principles of Plato and Archimedes [26], Before this discussion progresses, it is useful to examine briefly Platonic and Archimedean solids. 

In 1970 the first report of the molecular hydrogen laser opened up a decade of activity in VUV laser development, which included the appearance of rare gas excimer and exciplex lasers and the achievement of tunable coherent radiation in the Lyman-a region via harmonic generation. The surge of activity in the development of VUV lasers arose in part from the uniqueness of the VUV region, in part from the ultimate interest in X-ray lasers and, from our perspective, from the exciting prospects in spectroscopy and molecular dynamics promised by narrow linewidth, tunable, high-power VUV laser pulses for state-selective studies. Here we review the principles on which VUV lasers are based. 

The resolution of X-ray microscopy is between the visible light microscope on the one hand and the electron microscope on the other. Instruments available today deliver about five times better resolution than visible light microscopes on a routine basis and the best achievable resolution today is 20-30 nm. The ultimate resolution of X-ray microscopy is limited, in principle, only by the wavelength ... 

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