Foliations of some 3-manifolds which fiber over the circle

We show that a hyperbolic punctured torus bundle admits a foliation by lines which is covered by a product foliation. Thus its fundamental group acts freely on the plane.

     

矩阵连分式序列的收敛性

本文研究了矩阵连分式的性质，获得了关于矩阵连分式序列收敛性的一些结果．     

Separated AlxIn1−xN quantum dots grown by plasma-reactive co-sputtering

Separated Al_xIn_1−xN quantum dots (QDs) embedded in amorphous AlN films have been produced by radio-frequency co-sputtering technique on silicon (1 1 1) and quartz glass substrates. The mean size and density of Al_xIn_1−xN QDs can be conveniently monitored by deposition parameters. Transparent electron microscope, and X-ray diffraction were used to detect the structure of the Al_xIn_1−xN QDs system; field-emission scanning-electron microscope was adopted to measure the surface morphology and anticipate the size of the QDs; X-ray photoelectronic spectroscopy was used to measure the stoichiometric ratios of the QDs.     

Alcohols＇ Classification by Infrared Spectra Segment Based on Support Vector Machines

This paper studies various classifiers to identify primary, secondary or tertiary alcohols by using segmental spectra and their combinations to support vector machines （SVMs）. The results showed that the O-H in-plane bending absorption contributed most to identification their substitute. This conclusion disagrees with related known research results.     

MORPHOLOGY EVOLUTION IN PTFE AS A FUNCTION OF MELT TIME AND TEMPERATURE——Ⅱ. LOW MOLECULAR WEIGHT FOLDED CHAIN SINGLE CRYSTALS AND BAND STRUCTURES

The effect of sintering dispersed and bulk, low molecular weight (Mn = 50,000 Da), nano-emulsion polytetrafluoroethylene (PTFE) particles near their melting point is described. With the nascent particles consisting of ca.75 nm diameter, hexagonal, single crystals, sintering at, e.g., 350℃, results, initially, in merger of neighboring particles,followed by individual molecular motion on the substrate and the formation of folded chain, lamellar single crystals and spherulites, and on-edge ribbons. It is suggested these structures develop, with time, in the mesomorphic “melt”. Sintering of the bulk resin yields extended chain, band structures, as well as folded chain lamellae; end-surface to end-surface merger,possibly by end-to-end polymerization, occurs with increasing time.     

Copolymers of 2,5‐bis[(4‐methoxyphenyl) oxycarbonyl]styrene with n‐butyl acrylate: Design,synthesis, and characterization

A series of rod–coil diblock copolymers, consisting of poly{2,5‐bis[(4‐methoxyphenyl)oxycarbonyl]styrene} as a rigid segment and poly(n‐butyl acrylate) as a flexible part, were successfully prepared through two inverse procedures by atom transfer radical polymerization. The copolymers were characterized by ¹H NMR and gel permeation chromatography and had high molecular weights and relatively narrow polydispersities (polydispersity index < 1.20). All the block copolymers synthesized had two distinct glass‐transition temperatures according to differential scanning calorimetry. A polarizing optical microscopy investigation demonstrated the liquid crystallinity of the diblock copolymers. The self‐assembly behaviors in dilute solutions was studied by transmission electron microscopy. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5935–5943, 2005     

Synthesis and characterization of poly(2‐ethylhexyl methacrylate) copolymers containing pendant,self‐complementary multiple‐hydrogen‐bonding sites

The synthesis and characterization of copolymers containing 2‐ethylhexyl methacrylate and a quadruple‐hydrogen‐bonding site, 2‐ureido‐4[1H]‐pyrimidone methacrylate (UPyMA), are described. An analogous dimeric hydrogen‐bond‐containing copolymer based on 2‐ethylhexyl methacrylate and methacrylic acid (PEHMA‐co‐MAA) was also synthesized for comparative purposes. The glass‐transition temperatures of the poly(2‐ethylhexyl methacrylate‐co‐2‐ureido‐4[1H]‐pyrimidone methacrylate) (PEHMA‐co‐UPyMA) series increased linearly with increasing UPyMA content. Creep compliance measurements as a function of temperature indicated a decrease in the creep compliance with increasing UPyMA content over the range of 1–10 mol % UPyMA. Melt rheological analysis also showed an increase and lengthening of the plateau modulus as a function of frequency with increasing UPyMA content, as well as increasing complex viscosity as a function of temperature. The analogous PEHMA‐co‐MAA copolymer, which contained 11 mol % methacrylic acid, showed, in the melt rheological analysis, behavior similar to that of the PEHMA‐co‐UPyMA copolymer containing only 1 mol % UPyMA units. The multiple‐hydrogen‐bond‐containing copolymers were successfully analyzed with time–temperature superposition for the construction of master curves. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4618–4631, 2005