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IBM Journal of Research and Development

Issue 1 • Jan. 1971

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Displaying Results 1 - 14 of 14
  • Preface

    Publication Year: 1971, Page(s): 2
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (119 KB)

    In current computer technology, the most obvious role of chemistry is that involving the study of solid-state inorganics. Diode and transistor fabrication techniques involve silicon, germanium and III–V species like gallium arsenide. Selective and nonselective etching, passivation and doping are representative of the chemical processes involved. View full abstract»

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  • Digital Simulation of the Global Transport of Carbon Monoxide

    Publication Year: 1971, Page(s):3 - 9
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (744 KB)

    A numerical model of the general atmospheric circulation is used to simulate the global transport of carbon monoxide. The sources are estimated from gasoline consumption data. Since the strongest sources lie in the northern hemisphere belt of strong prevailing westerly winds, “chaining” effects are quite pronounced. Emissions generated in one populous area are soon superimposed upon ... View full abstract»

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  • A New Technique for Gas-phase Kinetic Spectroscopy of Molecules in the Triplet State

    Publication Year: 1971, Page(s):10 - 26
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1423 KB)

    A recently developed experimental method is described to populate by Hg photosensitization and observe by absorption spectroscopy the triplet states of polyatomic molecules in the gas phase; detailed discussion and analysis of the experiment are given. The technique can be used to investigate triplet states that cannot be populated efficiently by the intersystem crossing process and to detect trip... View full abstract»

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  • Photoconduction in Aromatic Hydrocarbons

    Publication Year: 1971, Page(s):27 - 33
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (640 KB)

    Photoconduction has been observed in single crystals of benzene, naphthalene, biphenyl and pyrene using the pulse technique. Experimental procedures have been found for the purification and crystal growth of the materials that produce specimens whose charge carrier lifetimes are sufficiently long to allow the measurement of drift mobilities, and thus to determine the number of charge carriers prod... View full abstract»

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  • Photochemical Addition of Benzene to Cyclobutene

    Publication Year: 1971, Page(s):34 - 40
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (554 KB)

    The major products of the photochemical addition at 253.7 nm of benzene to cyclobutene in solution were found to be tetracyclo[5.3.0.02,1003,6]-decene-8 and tricyclo[4.2.2.02,5]deca-7,9-diene, which arise from 1,3- and 1,4-additions. The quantum yields for both reactions were independent of benzene concentration below 2M but decreased at higher concentrations. The ... View full abstract»

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  • Preparation and Thermodynamics of Some Homologous Nitrones, a New Group of Liquid Crystals

    Publication Year: 1971, Page(s):41 - 51
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (863 KB)

    To investigate the mesomorphic behavior of aldonitrones, a series of 13 homologs of N-(p-alkoxyphenyl)-α-anisylnitrones was prepared and characterized. Although most of these substances exhibit normal nematic or smectic mesophases, the trend in nematic-isotropic transition temperatures to increase as a function of alkoxy chain length is an exceptional occurrence. Comparison of our data with... View full abstract»

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  • Polymorphism in Cholesteryl Esters: Cholesteryl Palmitate

    Publication Year: 1971, Page(s):52 - 58
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (729 KB)

    The thermal transitions in cholesteryl palmitate, an ester having liquid-crystalline states, have been evaluated and compared to previously reported data. A sample synthesized from carefully purified cholesterol and palmitic acid using p-toluene sulfonic acid compared directly with previously reported data. A sample of recrystallized ester from a commercial source showed a slightly depressed solid... View full abstract»

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  • On Measuring Nuclear Magnetic Shielding Anisotropies in Liquid Crystal Solvents

    Publication Year: 1971, Page(s):59 - 63
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (566 KB)

    Up to the present time nuclear magnetic shielding anisotropies (Δσ) have been determined in nematic liquid crystal solutions by comparing the chemical shifts in the isotropic and nematic phases. Unknown changes in solvent-induced shifts arising from the isotropic → nematic phase transition constitute a serious problem in the interpretation of the results. To avoid the ambiguit... View full abstract»

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  • Application of Probabilistic Decoding to Digital Magnetic Recording Systems

    Publication Year: 1971, Page(s):64 - 74
    Cited by:  Papers (103)  |  Patents (26)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (858 KB)

    A digital magnetic recording system is viewed in this paper as a linear system that inherently includes a correlative level encoder. This encoder can be regarded as a linear finite-state machine like a convolutional encoder. The maximum likelihood decoding method recently devised by Viterbi to decode convolutional codes is then applied to digital magnetic recording systems. The decoding algorithm ... View full abstract»

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  • A New High-sensitivity Organic Photoconductor for Electrophotography

    Publication Year: 1971, Page(s):75 - 89
    Cited by:  Papers (9)  |  Patents (5)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1132 KB)

    A new organic photoconductor has been developed, consisting essentially of a 1:1 molar ratio of one molecule of 2, 4, 7-trinitro-9-fluorenone (TNF) to one monomer unit of poly-N-vinylcarbazole (PVCz). This photoconductor (1:1 TPC) is nearly panchromatic in the visible range of the spectrum and has a white-light sensitivity approximately equal to that of amorphous selenium when used for electrostat... View full abstract»

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  • Recent Papers by IBM Authors

    Publication Year: 1971, Page(s):90 - 95
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (689 KB)

    Reprints of the papers listed here may usually be obtained most efficiently by writing directly to the authors. The authors' IBM divisions and locations are identified as follows: ASDD is the Advanced Systems Development Division; CD, Components Division; DPD, Data Processing Division; FED, Field Engineering Division; FSD, Federal Systems Division; GSD, General Systems Division; RES, Research Divi... View full abstract»

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  • Patents Recently Issued to IBM Inventors

    Publication Year: 1971, Page(s):96 - 97
    IEEE is not the copyright holder of this material | PDF file iconPDF (300 KB)
    Freely Available from IEEE
  • Authors

    Publication Year: 1971, Page(s):98 - 99
    IEEE is not the copyright holder of this material | PDF file iconPDF (412 KB)
    Freely Available from IEEE
  • Contents of previous two issues

    Publication Year: 1971, Page(s): 100
    IEEE is not the copyright holder of this material | PDF file iconPDF (168 KB)
    Freely Available from IEEE

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Clifford A. Pickover
IBM T. J. Watson Research Center