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Parts molded from reground BPA polycarbonate (PC) resin recovered from used objects do not always give the desired physical properties as parts molded from virgin resin. This loss of properties appears due to a surface hydrolysis of the PC which results in a reduction in molecular weight and formation of bis-phenol-A (BPA). The hydrolysis appears to be aided by exposure to uv-light and humidity. If the surface of the PC is washed with caustic solution, BPA and low MW oligomers are removed and many of the physical properties of the PC are restored. 相似文献
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Irwin M. Chaiken Yechiel Shai Giorgio Fassina Paolo Caliceti 《Macromolecular Symposia》1988,17(1):269-279
Analytical high performance liquid affinity chromatography (analytical HPLAC) has been investigated as an experimental guide to both synthetic design and affinity technological use of peptide and protein recognition surfaces. This work has progressed from the ongoing use of analytical affinity chromatography to study interaction mechanisms of naturally-occurring peptides and proteins, including enzyme fragment complexes and neuroendocrine biosynthetic precursors. We recently initiated a study to use analytical HPLAC for de novo design of recognition peptides called “anti-sense peptides”. Present data suggest the potential to use anti-sense peptides as “synthetic antibodies”, in immobilized forms, for biomolecular separation and analysis. Analogous studies have been started with immobilized natural antibodies in analytical immuno HPLAC. Our present data typify the growing usefulness of analytical HPLAC when designing recognition molecules, analyzing their interaction characteristics, and devising ways to use them in affinity technology. 相似文献
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The feasibility of an orthogonal deprotection-conjugation protocol, holding the promise of libraries of functionally diverse chemical probes attached to cysteine-anchored peptide scaffolds, has been explored with a model system. The necessary tools for assembly of the hybrid libraries have been prepared and the tandem procedure optimized. S-alkylation and S-sulfenylation are featured as the chemoselective ligation reactions. [reaction: see text] 相似文献
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In this note we present a new proof of the quintuple product identity which is based on our study of order theta functions with characteristics and the identities they satisfy. In this context the quintuple product identity is another example of an identity which when phrased in terms of theta functions, rather than infinite products and sums, has a simpler form and is much less mysterious.
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Irwin I. Shapiro 《General Relativity and Gravitation》1972,3(1-2):135-148
Recent results from radar and radio gravity experiments are:
- Retardation of radar signals: 1.02 +?0.05 (planetary radar), 1.00 +? 0.04 (spacecraft);
- Deflection of radio waves: 0.99 +? 0.12 (short baseline interferometry), +0.15 1.04 (short baseline interferometry), ?0.10. 0.90 +? 0.05 (short baseline interferometry);
- Relativistic perihelion advance of Mercury: 0.99 +? 0.03 (planetary radar), 1.00 +? 0.01 (radar plus optical);
- Time variation of the gravitational constant: (G/G) < 4 ×10?10/yr (planetary radar). The first three results are expressed as fractions of the corresponding effects predicted by general relativity. In terms of the Eddington-Robertson parameters, the first two are approximately equal to (1+γ)/2 and the third to (2 + 2γ-β)/3. The third result depends on the assumption that the solar gravitational quadrupole moment vanishes; its effects cannot be separated usefully from those of general relativity with the present data set. The uncertainties are as given by the individual experimenters; in some cases they represent formal standard errors, in others an allowance for possible systematic errors is included.
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Four one-phonon Raman lines have been found in CdIn2S4 (ZnIn2S4) spinels at 92 (72) cm-1, 186 (184) cm-1, 246 (253) cm-1, and 367 (372) cm-1 for incident photon energies well below the energy gap EG ~ 2.4 (2.2) eV at 300 K. For photon energies close to EG, the 367 cm-1 mode underwent a resonant enhancement in CdIn2S4 and four infrared active but Raman forbidden F1u modes appeared in the CdIn2S4 and ZnIn2S4 Raman spectra: TO modes at 226 (221) cm-1 and 309 (312) cm-1, and LO modes at 274 (272) cm-1 and 340 (342) cm-1. 相似文献