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1.
Hung-Yi Tsi Wen-Chin Tsen Yao-Chi Shu Fu-Sheng Chuang Chien-Chung Chen 《Polymer Testing》2009,28(8):875-885
Propylene-co-ethylene elastomer resin (PER) has been blended into biodegradable poly(butylene succinate) copolymer (PBS) by a melt-blending process to develop a novel semi-biodegradable thermoplastic elastomer. The PBS/PER blends displayed good compatibility in the range 70/30 > PBS/PER > 30/70 according to analyses by DSC, DMA and the Couchman method. Although the PBS/PER blends displayed compatibility, SEM analyses of most of the PBS/PER blends revealed two-phase structures including sea-island and irregular fiber-shaped morphologies, except for PBS/PER (70/30). PBS/PER (60/40) and PBS/PER (50/50) display low tensile strength due to large sea-phase and irregular fiber-shaped morphologies, even though they have good compatibility. PBS/PER (70/30) apparently exhibited a single phase by SEM and showed the best compatibility by DSC and DMA. Furthermore, the tan δ, elongation and initial moduli of the PBS/PER blends were seen to increase with increasing PER content, indicating that the toughness and shock resistance of PBS are improved by incorporating PER into the composition. 相似文献
2.
We present an interpretation of the recent neutron data on the commensurate and incommensurate spin fluctuations found in YBa2Cu3O6+y based on a special configuration of the electronic dispersion and intervention from the dx2−y2-wave superconducting phase. The observed switch-over between the commensurate and incommensurate fluctuation spectra at the change of frequency or temperature is naturally accounted within this scenario. 相似文献
3.
In this note, we shall give a partition-theoretic interpretation which explains the non-negativity of the coefficients of some q-series arising from Ramanujan's Lost Notebook and prove the almost-increasingness of the coefficients via a vector partition generating function. 相似文献
4.
Bruce C. Berndt Heng Huat Chan Song Heng Chan Wen-Chin Liaw 《The Ramanujan Journal》2010,23(1-3):3-15
A survey of Ramanujan’s work on cranks in his lost notebook is given. We give evidence that Ramanujan was concentrating on cranks when he died, that is to say, the final problem on which Ramanujan worked was cranks—not mock theta functions. 相似文献
5.
In an interferometric pump-probe experiment, we demonstrate the phase tuning of the spin polarization of photoelectrons emitted in a three-photon process from Cu(001). A phase shift of pi between delayed ultrafast circularly polarized light pulses can switch the spin polarization from +/-20% to -/+40%. In the delay regime of overlapping pulses, we show the dominating role of optical interference effects in determining the spin polarization. For longer delays, we detect the influence of the coherent material response, manifested in both the final state electron population as well as the final state spin polarization. 相似文献
6.
Fu-Sheng Chuang Hung-Yi Tsi Wen-Chin Tsen Shin-Cheng Jang 《Polymer Degradation and Stability》2008,93(10):1753-1761
The aim of this study was to investigate the characteristics and mechanism of the degradation of poly(siloxane-urethane) (PSiU) copolymers by thermogravimetric analysis (TGA) and TGA coupled with Fourier-transform infra-red spectroscopy (TG-FTIR). The PSiU copolymers consisted of 4,4′-diphenylmethane diisocyanate (MDI), 1,4-butanediol (1,4-BD), and OH-terminated polydimethylsiloxane (PDMS). In TGA they exhibited a two-stage degradation at 250-650 °C. The two stages of degradation have been found to comprise eight degradation steps and two interchange reactions, as revealed by TG-FTIR analysis. The main decomposition products have been identified as CO2, tetrahydrofuran, cyclosiloxane, and macrocyclic species. In addition, the effects of hard segment content (HSC) on the degradation and thermal stability of PSiU copolymers have been investigated by means of TG and DTG curves; notably, a stability region at 410-470 °C is caused by the cyclosiloxane, as verified by TG-FTIR. 相似文献
7.
Heng Huat Chan Shaun Cooper Wen-Chin Liaw 《Proceedings of the American Mathematical Society》2007,135(11):3417-3424
Properties of the Rogers-Ramanujan continued fraction are used to obtain a formula for calculating with quintic convergence.
8.
Neutral benzene-ammonia clusters, prepared in a supersonic expansion, were ionized using multiphoton ionization. The cluster ions were investigated with a time-of-flight mass spectrometer. The observed major cluster ions, under 355-nm laser irradiation, resulting from prompt intracluster ion-molecule reaction and fragmentation following ionization are (C6H6)m(NH3)nH+, m = 1–6, n = 1–4 and (C6H6)m+, m = 1–3. The results of isotopic labeling experiments clearly indicate that C6H6 does not participate in intracluster ion-molecule reactions to form (C6H6)m(NH3)nH+. A local maximum appears at n = 2 in the intensity distribution of (C6H6)m(NH3) nH+ for each value of m under all experimental conditions. This finding indicates that (C6H6)m(NH3)2H+ is more stable than any other (C6H5)m(NH3)mH+ (n = 1,3,4) for m = 1–6. 相似文献
9.
Keng-Liang Ou Chin-Sung Chen Li-Hsiang Lin Jen-Chieh Lu Yao-Chi Shu Wen-Chin Tseng Jen-Chang Yang Sheng-Yang Lee Chien-Chung Chen 《European Polymer Journal》2011,47(5):882-892
Novel epitaxial-like packed, super aligned, mono-layered hollow fibrous membranes were prepared by co-axial electrospinning technology. PLLA pellets were dissolved in solvent mixture of dichloromethane and dimethyl formamide (DCM/DMF = 9:1) to prepare sheath solution dope with various concentrations (from 8 to 19 wt.%). Aqueous solution of poly-ethylene glycol (PEG) was used as core solution dope. During the electrospinning process, dope concentrations and feed rate ratios were adjusted, separately, to evaluate the formation of resulting membranes. With lower shell solution concentration (from 8 to 15 wt.%), the collected, flattened film showed arrangement of lower order. A stood-up film was clearly seen when concentration increased to 17 wt.% and higher. As the collecting time went longer, these fibers piled up and eventually, stood up as a thin film from the surface of collector. Increasing flow rate ratio (FRR) also resulted similar outcomes and verify the cause of this phenomenon. After washing with water, scanning electron microscopy (SEM) revealed sheets of mono-layered, micron-sized hollow fiber arrays which were well aligned and tightly packed, just like the epitaxial growth of some semiconducting materials. These perfectly aligned and tightly packed hollow fiber arrays can be considered as highly anisotropic scaffolds that mimic tissue structures, such as nerve tissue, vascular structure as well as other application. 相似文献
10.
Huang YC Chiang LW Chang KS Su WC Lin YH Jeng KC Lin KI Liao KY Huang HL Yu CS 《Molecules (Basel, Switzerland)》2012,17(3):3058-3081
1-Aminophytosphingosine and 6-aminogalactosyl phytosphingosine were prepared in 61% and 40% yield libraries with 44 carboxylic acids showed that a 4-butylbenzoic acid-derived product exe, respectively. Glycosylation using benzoyl-protected lipid resulted in better a-selectivity for ceramide analogs, but the yield was less than that obtained with benzyl moieties. Screening the amide rted less cytotoxicity. These analogs were purified for validation of immunological potencies and the a-GalCer analog but not the sphingosine analog stimulated human iNKT cell population. 相似文献