Materials Literature
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ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTFORMATION OF A THREE-STRANDED POLYNUCLEOTIDE MOLECULEG. Felsenfeld, David R. Davies, and Alexander RichCite this: J. Am. Chem. Soc. 1957, 79, 8, 2023–2024Publication Date (Print):April 1, 1957Publication History Published online1 May 2002Published inissue 1 April 1957https:/…
TOR momentum operators by applying projection operators and we form an orthogonal set.For the uniform solution, St=i+ (LkAtg kt+CC).k»0 Noting that the method has a variational aspect, L» need not be taken from the small-oscillation analysis but may be freely chosen to describe average largeamplitude effects.We obtain…
Abstract The fine structure of the tarso-metatarsus of avian embryos has been investigated by means of thin sections in the electron microscope. The morphological features of osteoblasts are similar to those of fibroblasts, and where the organic matrix is just being deposited, fibrogenesis is found to occur in intimat…
The infrared-absorption spectrum of BaTi${\mathrm{O}}_{3}$ has been measured for thin single crystals and for powder samples dispersed in pressed KBr disks. Absorption bands for single-crystal samples occur at 495 ${\mathrm{cm}}^{\ensuremath{-}1}$ and at ca 340 ${\mathrm{cm}}^{\ensuremath{-}1}$, arising from normal vi…
The structure of NiWO4 has been determined, using the Fourier difference method to locate the oxygen atoms. The structure is based on a distorted hexagonal close packing of oxygen atoms with Ni and W atoms each occupying one-fourth of the octahedral interstices. The Ni and W atoms lie off the centers of their respecti…
A new determination of the atomic structure of CaTiOa has been made. It is orthorhombic, with space group _Pcmn; atomic coordinates are given. Synthetic crystals are identical with the majority of natural perovskite specimens. Two of the modes of twinning reported by Bowman from optical analysis have been confirmed by…
SYNOPSIS Muds collected by immersing bakelite panels in four West African harbours were examined for diatoms. The flora was found to consist of 194 species, 13 being new to science.
The orientation of micelles in jute fiber of different varieties, both Tossa and White having different values of intrinsic strength and quality ratio, has been studied. The Hermans' orientation factor, average angle of orientation, and angle at 40% intensity of ten different samples of jute fibers have been determine…
Summary The cation‐exchange capacities of soil separates, isolated by the International soda method and decantation from five basaltic soil profiles were determined by the neutral normal ammonium‐acetate method of Schollenberger and Simon. The exchange capacities of the clays ranged from 41 to 60 m.e. per cent. The re…
Th e co rros ion of singl e crystals of high-puri ty aluminum i n strollg ac id and alkali media is di sclosed as an ordedy process, the rate of attack bein g de pendent on the ori ent ation of the corroding s L Ilface. For a 15-percen t N aOH solution , corrosion a pparent ly prog ressedby r evealin g facet surf3ces…
Oxides having the magnetoplumbite structure and a wide range of magnetic properties have been examined. The magnetic saturations of the compositions MIIFe12O19 can be lowered by replacing part of the iron with the ions Al3+, Ga3+, Mn3+, Cr3+, and Ge3+ amongst others. MII in the above formula can be Ba2+, Sr2+, or Pb2+…
Single-domain particles of 40:60 cobalt-iron alloy have been prepared with a median diameter of 200 angstrom units, a median elongation of 5.4:1, and an intrinsic coercive force of 1950 oersteds. By compacting these particles to various packing densities and degrees of alignment, shape anisotropy fine-particle magnets…
Abstract Polymerization of acrylonitrile in dilute aqueous solution initiated by the chloratesulfite redox was studied kinetically and with the aid of the electron microscope. Polymerization rate depended on the [ClO ] [H 2 SO 3 ] product, the monomer content and the sodium lauryl sulfate concentration. The rate was d…
Furnaces for the growth of naphthalene (m.p. 80 °C.) and anthracene (m.p. 217 °C.) crystals from the melt by the Bridgman method are described and discussed. The advantages of long furnaces are emphasized. A seeding technique may be used to produce long crystals, and has been successful in producing naphthalene crysta…
Th e glass transit ion te mpera t ures, T " of poly-(c hloro t riftuoJ'oethylen e), poly-( vinylid ene ftuorid e), and copolymers prepared from t hese two co monom ers were de termined usin g dilatometric and in terfero metric m et hods. The glass tempera t ure of poly-(chlorotriftuoroethylene) was found to be at 45 C…
Six case histories are given of the use of polyvinylidene chloride film in conjuction with microcrystalline wax to protect underground pipes. It was found that microcrystalline wax of high quality appears to be a superior wetting agent and when wrapped with a protective film of polyvinylidene chloride will thoroughly…
Abstract This paper examines the relationship between the stress-strain properties of highly swollen natural rubber vulcanizates and their equilibrium volume swelling. It is shown that the empirical relationship obtained can be described equally well by either the Flory-Huggins equation or the Flory Modification of th…
Infra-red absorptions now reported for 25 azoaryl derivatives bring the number of N=N- containing structures examined so far up to 83. Indications previously recognized, that the azo-stretching frequencies in azobenzenes lie between 1400 and 1450 cm-1, are confirmed by the present measurements.
Abstract Methods of synthesizing linear polyesters from fluorine‐containing diols have been investigated. The most suitable method consists of reacting the fluorine‐containing diols with dicarboxylic acid chlorides. Number‐average molecular weights in excess of 15,000 have been obtained. The polymers are rubberlike gu…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAn Electron Diffraction Investigation of the Structure of Cuprous Chloride TrimerChi-hsiang Wong and Verner SchomakerCite this: J. Phys. Chem. 1957, 61, 3, 358–360Publication Date (Print):March 1, 1957Publication History Published online1 May 2002Published inissue 1 March 19…