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31.
Conductive composite films of poly(styrene‐co‐n‐butylacrylate) copolymers filled with low‐density, Ni‐plated core‐shell polymeric particles were prepared and their behaviors of positive temperature coefficient of resistance (PTCR) were investigated. When the conductive fillers in the composite film were loaded beyond the critical volume, 10 up to 25 vol %, composite films exhibited a unique electrical resistant transition behavior, which the electrical resistance rapidly increased by several orders of magnitude at the critical temperature. The PTCR transition temperature, in general, occurred before the glass transition temperature of polymer matrix. Further increased the conductive filler loading to 30 vol %, the overpacked conduction paths were formed in the entire composite and the PTCR effects became blurred. While the composite film treated with thermal cycle several times from room temperature up to 120 °C, the electrical resistivity increased accompanied with the shift of the PTCR transition to lower temperature. The reason might have been caused by the formed interfacial cracks within the composite film. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 322–329, 2007 相似文献
32.
Amanda J. Ziegler Craig C. McLauchlan Cyndi R. Sosnowski Albert W. Herlinger 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(2):o132-o134
The title compound (H2DTMSP[EBP]), C14H36O6P2Si2, was crystallized by the slow evaporation of a solution in a 20:1 mixture of pentane and acetone. The H2DTMSP[EBP] molecule lies about an inversion center. In the solid state, the molecule exists in an anti configuration, with the molecular backbone C—C bond located on an inversion center. The compound exists in the solid state as hydrogen‐bonded infinite sheets in the ab plane, unlike the methylene analogue, which exists as hydrogen‐bonded infinite chains, demonstrating an `even–odd' effect of the length of the backbone alkyl chain. 相似文献
33.
E. Maria Claesson Nilesh C. Mehendale Robertus J.M. Klein Gebbink Gerard van Koten Albert P. Philipse 《Journal of magnetism and magnetic materials》2007
Monodisperse magnetizable colloidal silica particles in a stable dispersion have been functionalized with a homogeneous catalyst: a PCP–pincer Pd-complex. In a proof-of-principle experiment we demonstrate the catalytic activity of the colloids in a C–C bond formation reaction. Advantages of the magnetic silica carriers are the large surface-to-volume ratio and the easy recovery by magnetic separation. After magnetic separation, the catalyst-loaded particles are readily redispersed for further use. 相似文献
34.
Albert Raugi 《Probability Theory and Related Fields》1988,77(4):481-496
Résumé SoitG un groupe moyennable connexe, locallement compact, à base dénombrable. Soit une mesure positive sur les boréliens deG. Nous étudions les fonctions boréliennes positivesh vérifiant: g G,
. Sous de bonnes hypothèses sur , nous obtenons, pour ces fonctions, une représentation intégrale à l'aide d'exponentielles.
Summary LetG be a connected locally compact separable amenable group. Let be a positive measure on the Borel -field ofG. We study the positive Borel functionsh onG which satisfy: g G, . Under smooth assumptions on , we establish an integral representation of these functions in term of exponentials.相似文献
35.
36.
Mishra SR Bachmann KT Bernstein RH Blair RE Foudas C Lefmann WC Leung WC Oltman E Quintas PZ Sciulli FJ Shaevitz MH Smith WH Merritt FS Oreglia MJ Schellman H Schumm BA Borcherding F Fisk HE Lamm MJ Marsh W Merritt KW Yovanovitch DD Bodek A Budd HS Sakumoto WK 《Physical review letters》1989,63(2):132-135
37.
E. W. Chung E. N. M. Ho D. K. K. Leung F. P. W. Tang K. C. H. Yiu T. S. M. Wan 《Chromatographia》2004,59(1):S29-S38
This paper describes a convenient method for the extraction and detection of eight anti-ulcer drugs simultaneously in horse urine, a relatively complex and viscous matrix, using a single-step liquid-liquid extraction followed by high-performance liquid chromatography – mass spectrometry (LC-MS). Anti-ulcer drugs were isolated from horse urine by salting out and liquid-liquid extraction. Detection of these drugs at concentrations below 1 ng mL?1 could be achieved using LC-MS-MS in the positive atmospheric pressure chemical ionisation (APCI) mode. The above analysis was also extended to elimination studies of horses administered with ranitidine and omeprazole. The urinary elimination data of these two drugs suggest that ranitidine was eliminated from horse urine at a much slower rate than omeprazole. In addition, three ranitidine metabolites and six omeprazole metabolites were identified for the first time in equine urine samples. 相似文献
38.
Bao Liu Ling Huang Juntao Liu Yao Zhong Xingshu Li Albert S.C. Chan 《Tetrahedron: Asymmetry》2007,18(24):2901-2904
Chiral tridentate N-tosylated aminoimine ligands were used in the Cu(II)-catalyzed enantioselective addition of phenylacetylene to N-aryl arylimines, affording products up to 92% ee. 相似文献
39.
40.
Two fluorophore-nitrilotriacetic acid conjugates, Pro-Q Sapphire 365 and Pro-Q Sapphire 488 oligohistidine gel stains, have been developed for the fluorescence detection of fusion proteins containing oligohistidine tags directly in sodium dodecyl sulfate polyacrylamide gels, without the requirement for electroblotting, reporter enzymes or secondary detection reagents. Pro-Q Sapphire 365 oligohistidine gel stain exhibits bright-blue fluorescence (emission maximum = 450 nm) when illuminated with UV-A or UV-B light from a standard ultraviolet transilluminator. Pro-Q Sapphire 488 oligohistidine gel stain exhibits bright-green fluorescence (emission maximum = 515 nm) when illuminated with visible light from a laser-based gel scanner equipped with a 470 nm second-harmonic generation (SHG) or 488 nm argon-ion laser source. Typically, 25-65 ng of oligohistidine-tagged fusion protein in whole cell lysates is detectable using either stain. After documenting the fluorescence signal from the Pro-Q Sapphire dyes, gels may be post-stained with the red-fluorescent SYPRO Ruby protein gel stain in order to reveal the total protein pattern. 相似文献