Novel porphyrinoids
E. VOGEL1990-01-01Pure and Applied Chemistry
Abstract
Porphyrin and Phthalocyanine ChemistryPorphyrin Metabolism and DisordersSynthesis and Characterization of Heterocyclic Compounds
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Novel porphyrinoids
Abstract
Observation of Three Subphases in Smectic C* of MHPOBC by Dielectric Measurements
In the phase transition from the paraelectric smectic A to the antiferroelectric SmC A * phase via the ferroelectric SmC * phase in MHPOBC, the existence of a subphase, SmC α * , between SmA and the normal SmC * (SmC β * ) was confirmed in addition to that of another subphase, SmC γ * , between SmC * and SmC A * by me…
Calibration of the anchizone: a critical comparison of illite ‘crystallinity’scales used for definition
Instrumental settings for determination of illite/muscovite ‘crystallinity’(half‐height width of the 10‐Å X‐ray diffraction peak) and the limits of the anchimetamorphic zone adopted by various authors fall into several groups. The variation in the limiting peak widths between the authors that have adopted Kubler's Neu…
Mechanisms of reactions of iron(III) porphyrins with hydrogen peroxide and hydroperoxides: solvent and solvent isotope effects
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMechanisms of reactions of iron(III) porphyrins with hydrogen peroxide and hydroperoxides: solvent and solvent isotope effectsTeddy G. Traylor and Feng XuCite this: J. Am. Chem. Soc. 1990, 112, 1, 178–186Publication Date (Print):January 1, 1990Publication History Published o…
The properties of a-C:H films deposited by plasma decomposition of C2H2
Diamondlike a-C:H films have been deposited by plasma decomposition of C2 H2. 50 samples were prepared with a systematic variation of the deposition parameters: the substrate bias voltage was between −100 and −1400 V and the C2 H2 gas pressure was between 4×10−4 and 2.6×10−1 mbar. The following properties of the films…
.beta.-Agostic interactions in (C5H4Me)2Zr(CH2CH2R)(PMe3)+ complexes
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXT.beta.-Agostic interactions in (C5H4Me)2Zr(CH2CH2R)(PMe3)+ complexesRichard F. Jordan, Prudence K. Bradley, Norman C. Baenziger, and Robert E. LaPointeCite this: J. Am. Chem. Soc. 1990, 112, 3, 1289–1291Publication Date (Print):January 1, 1990Publication History Published on…
New scanning tunneling microscopy tip for measuring surface topography
Electron-beam deposition inside scanning electron microscope (SEM) is used to prepare a new scanning tunneling microscope (STM) tip [electron-beam deposited (EBD) tip] which has a submicron diameter and a long straight sidewall. An EBD tip as small as less than 0.1 μm in diameter can be formed with careful beam focusi…
Icosahedral AlCuFe alloys : towards ideal quasicrystals
The topological and chemical long range orders in the icosahedral Al 65Cu20Fe15 alloy have been studied by X-ray powder diffraction. The spectacular enhancement of the quasicrystal-line state by annealing of rapidly quenched samples have been quantitatively measured showing that the final annealed product fits the the…
Mechanical Characterization of Unnotched SCS6/Ti-15-3 Metal Matrix Composites at Room Temperature
The Ti-15-3 metal matrix composites containing silicon carbide (SCS6) fibers, in five different lay-ups, have been tested at room temperature to determine static strengths and mechanical properties. Experimental data and predicted values of the laminate properties and strengths showed good correlation. The off-axis la…
Stable Icosahedral Al–Pd–Mn and Al–Pd–Re Alloys
A thermodynamically stable quasicrystalline phase with an icosahedral structure was found to be formed at atomic compositions of Al70Pd20Mn10 and Al70Pd20Re10 in conventionally solidified and fully annealed states as well as in a rapidly solidified state. The substitution of Mn by Re leads to an increase in the intens…
Ferroelectric materials for 64 Mb and 256 Mb DRAMs
The authors have studied the feasibility of using ferroelectric materials as the capacitor dielectric in the one-transistor memory cells for 64-Mb and 256-Mb DRAMs. They have performed an intensive literature search and analysis. They discuss the crystal structure of the materials reviewed, their hysteresis curve, tem…
Effect of Si Addition on the Cellular Precipitation in a Cu-10Ni-8Sn Alloy
The effect of Si addition on the nucleation and growth of the grain boundary cell in a Cu-10%Ni-8%Sn alloy on aging at 723 K after quenching from 1123 K were investigated by means of hardness measurements, optical and electron microscopic observations, and X-ray analysis. The addition of Si retarded the precipitation…
Influence of Grain Size and Temperature on Fracture Toughness of MgO Sintered Body
The purpose of this paper is to investigate the influence of grain size and temperature on fracture toughness of MgO sintered bodies, Specimens were made by hot pressing, and a wide range of grain size (12-230μm) was obtained by annealing at high temperatures. Porosities of specimens were less than 1%. Fracture toughn…
Engineering behavior of uplifted Smectite‐rich Cochin and Mangalore marine clays
The present study aims to assess whether the smectite‐rich Cochin and Mangalore clays, which were deposited in a marine medium and subsequently uplifted, exhibit consistency limits response typical of expanding lattice or nonexpanding (fixed) lattice‐type clays on artificially changing the chemical environment. The ch…
Experimental study on thermophysical and kinetic properties of the LaNi5-H2 system.
Thermophysical and kinetic properties of the LaNi5-H2 system are investigated for the practical utilization of hydriding alloys. The measurements of the thermophysical properties are carried out by a transient hot-wire method along the P-C isotherms. The effective thermal conductivities of the system increase not only…
Octahedral monomeric molybdenum(III)
The first magneto-optical study of the 4 A 2g → 2 T 2g absorption, 2 E g → 4 A 2g and 2 T 2g → 2 T 1g, 2 E g luminescences of MoCl3- 6 in Cs2NaYCl6, as well as the absorption spectrum of the spin-allowed 4 T 2g and 4 T 1g ligand field states, are reported. Magneto-optical methods have allowed difficulties in a previou…
Zinc and Zinc Alloys
Abstract This article describes the zinc and zinc alloys for decorative and functional applications. It focuses on the types of zinc coatings, namely, hot dip galvanizing, electrogalvanizing, metallizing, and mechanical galvanizing. The article covers the uses of zinc alloy castings, including pressure die castings, a…
Grain-boundary diffusion: an historical perspective
About 60 years ago it was first realised that grain boundaries in crystalline solids were preferential pathways for diffusion, especially at relatively low temperatures. This paper traces the main developments in the field from its inception to the present day. Particular emphasis is placed on experimental methods and…
Elastic properties of the nitrates of lithium, sodium, potassium, cesium, silver and thallium
Single crystals of optical quality of LiNO 3 , NaNO 3 , KNO 3 , CsNO 3 , AgNO 3 and TlNO 3 have been grown from aqueous solutions. Their elastic and thermoelastic constants were determined from ultrasonic resonance frequencies of thick plates and from temperature-induced shifts of resonance frequencies. For NaNO 3 and…
Examination on conversion factors to estimate effective dose equivalent from absorbed dose in air for natural gamma radiations.
A practical conversion factor to estimate the value of effective dose equivalent rate in Sv unit from absorbed dose rate in air in Gy unit was examined for natural gamma radiations. The experimental examination was carried out by two methods; one measures the effective dose equivalent rate directly by using a measurin…