Finding the range: Linguistic analysis and its role in computer-assisted literary study

This article describes how linguistic analysis can be used to change the computer from being a generator of data that can be used to develop a critical analysis to being a tool that provides a means to explore the processes and inputs that generate different interpretations of literary works. Using Michael Gregory's Communication Linguistics model to analyze Shakespeare's Sonnet CXXX, we see how the linguistic structure of the poem allows for multiple readings of the text. The article goes on to describe how this kind of analysis can be extended by employing artificial intelligence as a means to explore the interaction between language and meaning.Stephen N. Matsuba is currently completing his doctorate in English at York University, Canada.     

Stereospecific synthesis of ditactic polymers

Summary Polymerizations of t-butyl crotonate (E-TBC) and t-butyl isocrotonate (Z-TBC) were carried out in toluene at-78°C using t-BuMgBr as initiator. E-TBC gave polymers, whereas Z-TBC did not. The dimer of E-TBC isolated from the polymerization mixture by means of GPC contained predominatly one of the four possible diastereomers. X-ray crystallographic determination showed that the predominant dimer was the erythro-diisotactic isomer. t-BuLi/Et₃Al polymerized effectively both E-TBC and Z-TBC in toluene. The poly(E-TBC)s prepared with t-BuMgBr and t-BuLi/Et₃Al were insoluble in toluene, THF, and chloroform, but soluble in 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP). Stereostructure of the poly(TBC)s was analyzed by the one- and two-dimensional NMR spectra measured in HFIP. The poly(E-TBC) prepared with t-BuMgBr was a 1:1 mixture of the erythro- and threo-diisotactic polymers with high stereoregularity. The poly(E-TBC) and poly(Z-TBC) obtained from the polymerizations with t-BuLi/Et₃Al were rich in disyndiotactic structure. Polymerization of TBCs with t-BuLi in toluene and THF was also studied.

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α-sulfonated fatty acid esters: II. Solution behavior of α-sulfonated fatty acid polyethylene glycol esters

Sodium α-sulfonated, fatty acid polyethylene glycol monoesters [C _m H_2m+1CH(SO₃Na)COO(C₂H₄O) _n H] and diesters [C _m H_2m+1CH(SO₃Na)COO(C₂H₄O) _n COCH(SO₃Na)C _m H_2m+1], wherem=10–16 andn=1–35, were prepared by esterification of α-sulfonated, fatty acids with polyethylene glycols, followed by neutralization with NaOH. Crude products were purified by reversed-phase column chromatography on an octadecyl-modified silica gel. Characteristic solution behavior of these α-sulfonated fatty acid esters was, examined, and the following features were observed. All monoesters prepared in this work had Krafft points below 0°C and also possessed good calcium stabilities. Critical micelle concentrations of the monoesters increased monotonously, as a rule, with an increase in the number of oxyethylene units. These results suggest that the polyethylene glycol residue of the monoester behaves as a hydrophile. On the other hand, diesters possessed high water solubility, low foamability, and critical micelle concentrations that were lower by a factor of ten compared to those of the monoesters.     

Polymers of α-substituted benzyl methacrylates as a new type of electron-beam resist

Summary Polymer of α-substituted benzyl methacrylate was found to be used as a new type of positive electron-beam resist, which forms methacrylic acid units in the polymer chain on the exposure to electron-beam and can be developed using alkaline solution as a developer. The sensitivity was dependent on the bulkiness of the ester group and the number of ?-hydrogen atoms in the ester group. The sensitivity and γ-value of atactic poly(α, α-dimethylbenzyl methacrylate) were improved by a factor of more than three over poly (methyl methacrylate).     

Asymmetric polymerization of N-phenylmaleimide

Summary Asymmetric polymerization of N-phenylmaleimide was carried out with the complexes of butyllithium and chiral ligands and optically active polymers were obtained. The optical activity of the polymers should be based on the chiral trans structure of the main chain.A part of this work was reported at The 28th Meeting of Polymer Science (Kobe), July 1982     

Stereospecific anionic polymerization and copolymerization of 1,1-diphenylethyl methacrylate

1,1-Diphenylethyl methacrylate (DPEMA), which is a new methacrylic ester, was synthesized and polymerized by n-butyllithium (n-BuLi) in toluene and THF. The triad tacticity of the polymers was determined from the n.m.r. spectrum of poly(methyl methacrylate) (PMMA) which was derived from them. A highly stereoregular polymer was not formed either in toluene or in THF by n-BuLi between ?78° and 30°C. In toluene, the tacticity depended very much on the polymerization temperature, and unexpectedly, the polymer obtained at ?78°C was rich in syndiotacticity. The polymers obtained in THF were atactic regardless of the temperature. A highly isotactic polymer was formed with Grignard reagents. DPEMA (M₁) was also copolymerized with methyl methacrylate (MMA), diphenylmethyl methacrylate (DPMMA), and trityl methacrylate (TrMA) (M₂) in toluene and THF with n-BuLi; the tacticity of the copolymers was determined. Generally, the stereoregularity of the copolymers was lower than those of the M₂ homopolymers. In the copolymerization with MMA monomer reactivity ratios were also determined.