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141.
Per Helvig Christensen Steen Mørup Henrik Topsøe Bjerne Steffen Clausen 《Hyperfine Interactions》1986,28(1-4):945-948
Bimetallic Fe-Co alloy catalysts supported on silica have been studied by use of combined Mössbauer absorption and emisson spectroscopy. Effects of carburization on samples with different particle size are discussed. 相似文献
142.
FT-IR spectroscopy and SFM were used to investigate the growth of thin films of the organic semiconductor 3,4,9,10-perylenetetracarboxylicdianhydride (PTCDA) deposited by vacuum sublimation onto various substrates, i.e. Ag(111) layers on mica, KBr(100), mica, oxidized Si, and TiO2 nanoparticles on Si. Layer thicknesses of PTCDA varied from 10 to 1500 nm.The anhydride vibrations of PTCDA differ for the used substrates, which can be connected to the orientation of the molecules relative to the substrate surface and the film morphology as detected in the SFM pictures. 相似文献
143.
Laser nitriding and laser cementation are investigated by Mössbauer spectroscopy and complementary methods. It is demonstrated how the backscattering versions of Conversion Electron and Conversion X-ray Mössbauer spectroscopy can contribute to the investigation of surface processes, like the laser-induced formation of nitrides and carbides. Additionally, the formation of semiconducting iron disilicide can be achieved by ion-beam mixing and pulsed laser irradiation of Fe/Si bilayers. The results of both processes are compared.
相似文献144.
145.
Stable equivalences are studied between any finite dimensional algebra A with a simple projective module and a simple injective module and an algebra B obtained from A by ‘gluing’ the corresponding idempotents of A; this extends results by Martinez-Villa. Stable equivalences modulo projectives are compared to stable equivalences modulo semisimples, and in either situation a characterization is given for a radical embedding to induce such a stable equivalence. 相似文献
146.
Steffen Eller Stefano Mezzato Dr. Bas R. Leeflang Prof. Dr. Carlo Unverzagt Prof. Dr. F. Javier Cañada Prof. Dr. Jesús Jiménez‐Barbero 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(35):10715-10726
Protein‐carbohydrate interactions are at the heart of a variety of essential molecular recognition events. Hevein, a model lectin related to the superantigen family, recognizes the trisaccharide core of N‐glycoproteins ( 1 ). A combined approach of NMR spectroscopy and molecular modeling has permitted us to demonstrate that an Asn‐linked Man(GlcNAc)2 ( 2 ) is bound with even higher affinity than (GlcNAc)3. The molecular recognition process entails conformational selection of only one of the possibilities existing for chitooligosaccharides. The deduced 3D structure of the hevein/ 2 complex permits the extension of polypeptide chains from the Asn moiety of 2 , as well as glycosylation at Man O‐3 and Man O‐6 of the terminal sugar. Given the ubiquity of the Man(GlcNAc)2 core in all mammalian N‐glycoproteins, the basic recognition mode presented herein might be extended to a variety of systems with biomedical importance. 相似文献
147.
Trusch M Ehlert S Bertsch A Kohlbacher O Hildebrand D Schlüter H Tallarek U 《Journal of separation science》2010,33(21):3283-3291
The influence of packing process parameters (packing pressure, application of ultrasound) and the stationary phase particle size (3.5 and 5 μm) on the chromatographic performance of HPLC/MS chips was systematically investigated for proteomic samples. First, reproducibility and detection limits of the separation were evaluated with a low‐complexity sample of tryptic BSA peptides. The influence of adsorbent packing quality on protein identification was then tested with a typical proteomics sample of high complexity, a human plasma protein fraction (Cohn fraction IV‐4). All HPLC/MS chips provided highly reproducible separations of these proteomic samples, but improved packing conditions and smaller particle sizes resulted in chromatograms with narrower peaks and correspondingly higher signal intensities. Improved separation performance increased the peak capacity, the number of identified peptides, and thus the sequence coverage in the proteomic samples, particularly for low sample amounts. 相似文献
148.
Heqing Jiang Dr. Fangyi Liang Oliver Czuprat Konstantin Efimov Armin Feldhoff Dr. Steffen Schirrmeister Dr. Thomas Schiestel Dr. Haihui Wang Prof. Jürgen Caro Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(26):7898-7903
A porous perovskite BaCoxFeyZr0.9?x?yPd0.1O3?δ (BCFZ‐Pd) coating was deposited onto the outer surface of a BaCoxFeyZr1?x?yO3?δ (BCFZ) perovskite hollow‐fiber membrane. The surface morphology of the modified BCFZ fiber was characterized by scanning electron microscopy (SEM), indicating the formation of a BCFZ‐Pd porous layer on the outer surface of a dense BCFZ hollow‐fiber membrane. The oxygen permeation flux of the BCFZ membrane with a BCFZ‐Pd porous layer increased 3.5 times more than that of the blank BCFZ membrane when feeding reactive CH4 onto the permeation side of the membrane. The blank BCFZ membrane and surface‐modified BCFZ membrane were used as reactors to shift the equilibrium of thermal water dissociation for hydrogen production because they allow the selective removal of the produced oxygen from the water dissociation system. It was found that the hydrogen production rate increased from 0.7 to 2.1 mL H2 min?1 cm?2 at 950 °C after depositing a BCFZ‐Pd porous layer onto the BCFZ membrane. 相似文献
149.
Parracino A Gajula GP di Gennaro AK Neves-Petersen MT Rafaelsen J Petersen SB 《Journal of fluorescence》2011,21(2):663-672
Medical interest in nanotechnology originates from a belief that nanoscale therapeutic devices can be constructed and directed
towards its target inside the human body. Such nanodevices can be engineered by coupling superparamagnetic nanoparticle to
biomedically active proteins. We hereby report the immobilization of a PhEst, a S-formylglutathione hydrolase from the psychrophilic
P. haloplanktis TAC125 onto the gold coated surface of modified superparamagnetic core-shell nanoparticles (Fe3O4@Au). The synthesis of the nanoparticles is also reported. S-formylglutathione hydrolases constitute a family of ubiquitous
enzymes which play a key role in formaldehyde detoxification both in prokaryotes and eukaryotes. PhEst was originally annotated
as a putative feruloyl esterase, an enzyme that releases ferulic acid (an antioxidant reactive towards free radicals such
as reactive oxygen species) from polysaccharides esters. Dynamic light scattering, scanning electron microscopy with energy
dispersive X-ray spectroscopy, UV–visible absorption spectroscopy, fluorescence spectroscopy, magnetic separation technique
and enzyme catalytic assay confirmed the chemical composition of the gold covered superparamagnetic nanoparticles, the binding
and activity of the enzyme onto the nanoparticles. Activity data in U/ml confirmed that the immobilized enzyme is approximately
2 times more active than the free enzyme in solution. Such particles can be directed with external magnetic fields for bio-separation
and focused towards a medical target for therapeutical as well as bio-sensor applications. 相似文献
150.
Chen QF Troshyn A Ernsting I Kayser S Vasilyev S Nevsky A Schiller S 《Physical review letters》2011,107(22):223202
Using an ultrastable continuous-wave laser at 580 nm we performed spectral hole burning of Eu(3+):Y(2)SiO(5) at a very high spectral resolution. The essential parameters determining the usefulness as a macroscopic frequency reference, linewidth, temperature sensitivity, and long-term stability, were characterized using a H-maser stabilized frequency comb. Spectral holes with a linewidth as low as 6 kHz were observed and the upper limit of the drift of the hole frequency was determined to be 5±3 mHz/s. We discuss the necessary requirements for achieving ultrahigh stability in laser frequency stabilization to these spectral holes. 相似文献