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This article is from Scientific Reports , volume 4 . Abstract We report a method to obtain the stress of crystalline materials directly from lattice deformation by Hooke's law. The lattice deformation was calculated using the crystallographic orientations obtained from electron backscatter diffraction (EBSD) technology. The stress distribution over a large area was obtained efficiently and accurately using this method. Wurtzite structure gallium nitride (GaN) crystal was used as the example of a hexagonal crystal system. With this method, the stress distribution of a GaN crystal was obtained. Raman spectroscopy was used to verify the stress distribution. The cause of the stress distribution found in the GaN crystal was discussed from theoretical analysis and EBSD data. Other properties related to lattice deformation, such as piezoelectricity, can also be analyzed by this novel approach based on EBSD data.

Two novel switchable, mesoscopically periodic materials were created by combining crystalline colloidal array (CCA) self-assembly with the temperature-induced volume phase transition of poly(N-isopropylacrylamide) (PNIPAM). Body-centered cubic (BCC) CCA of hydrated, swollen PNIPAM particles Bragg diffract infrared (IR), visible, and ultraviolet (UV) light weakly, while arrays of compact shrunken particles diffract efficiently. A tunable diffracting array was also created by embedding a CCA of polystyrene spheres within a PNIPAM hydrogel, that swells and contracts with temperature; thus, the array lattice constant varies with temperature and the diffracted wavelength is thermally tunable across the entire visible spectrum. These materials may find applications in many areas of optics and materials science.

(short version) Accurate determination of the coherent static structure factor of disordered materials containing proton nuclei is prohibitively difficult by neutron diffraction, due to the large incoherent cross section of $^1$H. This notorious problem has set severe obstacles to the structure determination of hydrogenous materials up to now, via introducing large uncertainties into neutron diffraction data processing. Here we present the first accurate separate measurements, using polarized neutron diffraction, of the coherent and incoherent contributions to the total static structure factor of 5 mixtures of light and heavy water, over an unprecedentedly wide momentum transfer range. The structure factors of H$_2$O and D$_2$O mixtures derived in this work may signify the beginning of a new era in the structure determination of hydrogenous materials, using neutron diffraction.

We show that the information gained in spectroscopic experiments regarding the number and distribution of atomic environments can be used as a valuable constraint in the refinement of the atomic-scale structures of nanostructured or amorphous materials from pair distribution function (PDF) data. We illustrate the effectiveness of this approach for three paradigmatic disordered systems: molecular C60, a-Si, and a-SiO2 . Much improved atomistic models are attained in each case without any a-priori assumptions regarding coordination number or local geometry. We propose that this approach may form the basis for a generalised methodology for structure "solution" from PDF data applicable to network, nanostructured and molecular systems alike.

We show that the information gained in spectroscopic experiments regarding the number and distribution of atomic environments can be used as a valuable constraint in the refinement of the atomic-scale structures of nanostructured or amorphous materials from pair distribution function (PDF) data. We illustrate the effectiveness of this approach for three paradigmatic disordered systems: molecular C60, a-Si, and a-SiO2 . Much improved atomistic models are attained in each case without any a-priori assumptions regarding coordination number or local geometry. We propose that this approach may form the basis for a generalised methodology for structure "solution" from PDF data applicable to network, nanostructured and molecular systems alike.

Published in 1899, Vassar Studies is a collection of twelve realistic glimpses into the character of attending students at Vassar College. It delves more with the inner workings of people rather than with dramatic incidents or what was studied in college. The glimpses themselves are both wordy and enlightening. The dialogue within each tends to have a background of various people, some with names and some who remain nameless as part of the scenery. The manner in which they speak may be surprisingly academic for those used to college girl stories of the adventurous or mysterious nature.<br /><br />Julia Augusta Schwartz graduated from Vassar in 1896 and earned an MA in English literature the following year. (Summary by Daryl Wor)

2Wilderness Babies

By Julia Augusta Schwartz

This book tells the stories of some of the baby mammals of the wilderness,—how they grow and learn day by day to take care of themselves. In hollow trees or down under water among the lily leaves, in the cool sea or on the rugged mountains, on the grassy plains or among the waving tree-tops, in the dark caves and burrows or hidden in the tangles underfoot,—all the world is alive with young creatures. - Summary by introduction