Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTQuantun chain process in the sensitized cis-trans photoisomerization of 1,3-dienesJack. Saltiel, David E. Townsend, and Alan. SkyesCite this: J. Am. Chem. Soc. 1973, 95, 18, 5968–5973Publication Date (Print):September 1, 1973Publication History Published online1 May 2002Publ…
The preparation of nortropane N-oxyl (8-azabicyclo[3.2. 1]octane N-oxyl) and some homologs and derivatives is described. This radical oxidizes hydrogen peroxide and 2-propanol; labeling studies show that the bridgehead protons are not involved in these reactions. Nortropane N-oxyl dimerizes irreversibly in several sol…
Abstract The purpose of the work was to test existing theories of chain folded polymer crystallization over a supercooling range which is much is excess to what could be hitherto realized. This was made possible by the recognition that crystallization of isotactic polystyrene in solution could be conducted over an exc…
Abstract The magnetic transition from the ferro- to the para-magnetic state of manganese(II) phthalocyanine (C32H16N8Mn) has been observed by measurements of the magnetic susceptibility, the magnetization and the proton magnetic resonance in the low-temperature range. The positive Weiss constants were obtained from th…
The precipitates responsible for magnetic age hardening of a Co3.8Cu0.9Fe0.5Ce alloy have been directly observed by transmission electron microscopy. The precipitates are coherent, plate shaped disks which possess the rhombohedral Co17Ce2structure. They form in a [001] plate normal orientation and cluster in staggered…
The flashover performance of post-type support spacers for concentric compressed gas-insulated transmission lines was investigated. The experiments were made with SF6 gas at 4.4 atm. abs. and low frequency AC voltage in the EHV range. Nine cast epoxy spacers with metal inserts at each end shaped to produce different e…
Abstract The morphological character of uniaxially oriented poly(ethylene terephthalate) (PET) films was investigated as a function of draw ratio. Dynamic mechanical, infrared, and crystallite‐size measurements were made on the samples. In addition, selective degradation experiments and molecular weight determinations…
The modulation of guided optical waves has been accomplished using an integrated ferroelectric thin-film structure. LiTaO3 was rf sputtered onto 7059 glass in an argon-oxygen environment. Electrodes for applying the modulation signal were formed by chemically etching an interdigital pattern in gold which was rf sputte…
We have studied the ordering of Fe atoms and the magnetic properties of Th(Co1-xFex)5alloys with the CaCu5- type structure. From the neutron diffraction analysis it is concluded that the larger Fe atoms prefer to occupy the site3gwhereas the smaller Co prefer to occupy the site 2c. The ordering between Fe and Co in th…
Aggregates of polyethylene lamellae, whose average thickness can be increased progressively from about 200 to 2000 A and beyond have been produced by annealing drawn polymer hydrostatically. All lamellae share a common c axis orientation and have a surface free energy of 95 erg cm−2. The physical texture of the result…
SUMMARY A cluster analysis and a principal components analysis were performed to examine the degree to which the diatom flora of Yaquina estuary can be partitioned into discrete associations and to relate the composition of the flora to selected physical properties of the estuary. The species composition of the diatom…
Ultraviolet photosensitivity of the single-stranded forms of poly(A) and poly(dA) is compared. In contrast to poly(A), poly(dA) is rather sensitive to ultraviolet irradiation. Relatively low doses of ultraviolet light lead to characteristic changes of the ultraviolet and circular dichroism spectra of poly(dA), suggest…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMagnetic properties of low-symmetry d2 octahedral complexes. Synthesis and magnetic susceptibilities of some six-corrdinate tungsten(IV) halide complexesMargaret A. Schaefer King and R E. McCarleyCite this: Inorg. Chem. 1973, 12, 9, 1972–1979Publication Date (Print):Septembe…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTLiquid crystals. IV. Effects of terminal substituents on the nematic mesomorphism of p-phenylene dibenzoatesJ. P. Schroeder and D. W. BristolCite this: J. Org. Chem. 1973, 38, 18, 3160–3164Publication Date (Print):September 1, 1973Publication History Published online1 May 20…
Simple domain structures were observed in iron-silicon and cobalt-iron single crystals by three techniques using polarized neutrons. The first method involves scanning the specimen with a fine beam and measuring the depolarization suffered by the beam after transmission: it can only detect regions where the magnetizat…
Observation of the nucleation of surface disclination lines in nematics shows their correspondence to emergences of walls at the boundary of the sample; these lines have no core discontinuity and their width gives an estimate of the anchoring energy of the molecules to the surface.
Exposure trials in different water supplies have been carried out using copper tubes having various degrees of carbon contamination in the bore. On exposure to a water that supports pitting, the electrode potential of highly-contaminated tubes increases to a value greater than the critical potential for pitting. On th…
Abstract The infrared spectra of amorphous films of GaP, GaAs, GaSb, InAs, and Ge prepared by sputtering have been measured from 10 to 4000 cm −1 . The absorption spectra in the region of the “optical” phonon frequencies show similarities to the phonon density of states as deduced from Raman scattering but the absorpt…
An improved atmosphere sintering process was developed for fabricating large transparent PLZT plates for electrooptic applications. Cold‐pressed 9/85/35 PLZT slugs were sintered in O 2 in Pt crucibles for ∼45 min at 1180°C and were then heat‐treated in air for 60 h at 1200°C in Al 2 O 3 crucibles containing PbZrO 3 at…
Spectral transmission losses of unclad optical fibers drawn from various types of commercial vitreous silica and of soda-lime-silicate glasses were measured in the wavelength range between 0.5 and 1.12 µm. The automated technique employed was both convenient to use and sensitive enough to measure losses of 6 dB/km, i.…