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971.
Since immobilized metal ion affinity chromatography (IMAC) was first introduced, several variants of this method and many other metal affinity-based techniques have been devised. IMAC quickly established itself as a highly reliable purification procedure, showing rapid expansion in the number of preparative and analytical applications while not remaining confined to protein separation. It was soon applied to protein refolding (matrix-assisted refolding), evaluation of protein folding status, protein surface topography studies and biosensor development. In this review, applications in protein processing are described of IMAC as well as other metal affinity-based technologies. 相似文献
972.
Kageyama H Nishi M Aso N Onizuka K Yosihama T Nukui K Kodama K Kakurai K Ueda Y 《Physical review letters》2000,84(25):5876-5879
We performed inelastic neutron scattering on the 2D Shastry-Sutherland system SrCu2(11BO3)2 with an exact dimer ground state. Three energy levels at around 3, 5, and 9 meV were observed at 1.7 K. The lowest excitation at 3.0 meV is almost dispersionless with a bandwidth of 0.2 meV at most, showing a significant constraint on a single-triplet hopping owing to the orthogonality of the neighboring dimers. In contrast, the correlated two-triplet excitations at 5 meV exhibit a more dispersive behavior. 相似文献
973.
The ground-state properties of the spin-1 antiferromagnetic Heisenberg model on the corner-sharing tetrahedra, the pyrochlore lattice, are investigated. By breaking up each spin into a pair of 1/2-spins, the problem is reduced to the equivalent one of the spin-1/2 tetrahedral network in analogy with the valence bond solid state in one dimension. The twofold degeneracy of the spin singlets of a tetrahedron is lifted by a Jahn-Teller mechanism, leading to a cubic to tetragonal structural transition. It is proposed that the present mechanism is responsible for the phase transition observed in the spin-1 spinel compounds ZnV2O4 and MgV2O4. 相似文献
974.
The exact eigenspectra and eigenstates of spin-1 and spin-2 Bose-Einstein condensates (BECs) are found, and their response to a weak magnetic field is studied and compared with their mean-field counterparts. Whereas mean-field theory predicts the vanishing population of the zero magnetic-quantum-number component of a spin-1 antiferromagnetic BEC, the component is found to become populated as the magnetic field decreases. The spin-2 BEC exhibits an even richer magnetic response due to quantum correlations among three bosons. 相似文献
975.
The velocity, temperature and velocity fluctuation distributions within falling spindle oil films in an inclined rectangular channel were measured using hot-wire techniques and thin thermocouples. The interfacial shear was caused by cocurrent air flow.The results indicate that the liquid films are as a whole much more laminar-like than turbulent in a range of Reynolds numbers (4γ/μ) up to the experimental limit of 6000. Mixing motion occurs in the vicinity of the interface; however, the flow near the wall surface exhibits no sign of such eddy motions, as predicted by the wall law for single phase turbulent flow. Although velocity fluctuation is observed within films with interfacial shear, mean velocity profiles are approximately the same as those obtained by the laminar film prediction. 相似文献
976.
Velocity-temperature correlation in strongly heated channel flow 总被引:2,自引:0,他引:2
Velocity-temperature correlations in a strongly heated channel flow were investigated experimentally by a LDV and a resistance
thermometer. The wall heat flux is varied up to 50,000 W/m2 with reference mean-velocity of 15 m/s, and then, the wall temperature reaches up to 1,000 K. The results show that the ejection
fluid motion is intensified by the strong heating near the wall increasing the turbulent heat flux from the wall. The intensification
of ejection motion balances the destruction of turbulent heat flux. Then, the overall turbulent heat transfer does not change
clearly.
Part of this work was supported by Tanikawa Fund, Promotion of Thermal Technology 相似文献
977.
Stress intensity factors are determined for glass-fiber reinforced plastics with an infinite row of parallel cracks at low temperatures under tension. A state of generalized plane strain is assumed. The thermal and mechanical properties as functions of temperature are obtained from the experimental data. Fourier transforms are used to reduce the problem to the solution of a pair of dual integral equations. The solution of the dual integral equations is then expressed in terms of a Fredholm integral equation of the second kind. Numerical calculations are carried out, and the stress intensity factors at different temperatures are shown graphically. 相似文献
978.
N. Hasebe T. Nakamura K. Yoshikawa M. Ueda 《Archive of Applied Mechanics (Ingenieur Archiv)》1994,64(5):295-306
Summary A solution is obtained for the second mixed boundary value problem with two boundaries loaded with external forces, and the other two boundaries simply supported. A rational mapping function formed as a sum of fractional expressions and complex stress functions is used for the analysis. A closed form solution can be obtained under uniform tensile and shearing loadings. These solutions are applicable to crack problems in linear elastic fracture mechanics. In order to illustrate the general solution, a double connected region is considered, in which interaction between a square hole with a crack extension and another crack is investigated. Stress distributions and stress intensity factors are obtained.
Ebene elastinche Lösung des zweiten gemischten Randwertproblems und ihre Anwendung
Übersicht Die Lösung des zweiten gemischten Randwertproblems der ebenen Elastizität mit zwei kraftbeanspruchten und zwei gestützten Rändern wird dargestellt. Für die Analyse wird eine rationale Abbildung verwendet, die als Summe partieller Lösungen aus komplexen Spannungsfunktionen aufgebaut ist. Für gleichmäßige Zug- und Schubbeanspruchungen kann die Lösung in geschlossener Form dargestellt werden und ist verwendbar in Rißaufgaben der linear elastischen Bruchmechanik. Als Illustration der allgemeinen Lösung dient ein verzweigter Bereich der gegenseitigen Einwirkung einer quadratischen Öffnung mit Seitenkerbe und eines Risses. Die Spannungsverteilungen und Spannungsintensitäten werden dabei berechnet.相似文献
979.
Hitomi Miyamoto Dmitry M. Rein Kazuyoshi Ueda Chihiro Yamane Yachin Cohen 《Cellulose (London, England)》2017,24(7):2699-2711
The behaviors of cellulose chains and cellulose mini-crystal in oil-in-water emulsions were studied by molecular dynamics simulations to investigate the coating states and the structural features of cellulose in these emulsions. In oil-in-water emulsion, dispersed cellulose chains gradually assemble during the progress of the simulation, eventually surrounding the octane droplet. In case of a cellulose mini-crystal, the cellulose chain at the corner of the crystal first contacts with the octane droplet through its hydrophobic surface. The other cellulose chains along the crystal plane then gradually move toward the octane molecules. In both emulsions, the cellulose was found to interact with both water and octane surfaces with specific conformations that allow the CH groups of the glucose rings to contact with octane molecules, while the OH groups of these rings contact with water molecules to form hydrogen bonds. The cellulose chains on the octane droplet also contact with each other through lateral hydrogen bonding between chains. These interactions stabilize the emulsion formed by cellulose molecules as surfactants. 相似文献
980.
Dr. Ayuko Meguro Yudai Motoyoshi Kazuya Teramoto Shota Ueda Yusuke Totsuka Yumi Ando Dr. Takeo Tomita Dr. Seung‐Young Kim Dr. Tomoyuki Kimura Dr. Masayuki Igarashi Dr. Ryuichi Sawa Prof. Dr. Tetsuro Shinada Prof. Dr. Makoto Nishiyama Prof. Dr. Tomohisa Kuzuyama 《Angewandte Chemie (International ed. in English)》2015,54(14):4353-4356
Terpene cyclization reactions are fascinating owing to the precise control of connectivity and stereochemistry during the catalytic process. Cyclooctat‐9‐en‐7‐ol synthase (CotB2) synthesizes an unusual 5‐8‐5 fused‐ring structure with six chiral centers from the universal diterpene precursor, the achiral C20 geranylgeranyl diphosphate substrate. An unusual new mechanism for the exquisite CotB2‐catalyzed cyclization that involves a carbon–carbon backbone rearrangement and three long‐range hydride shifts is proposed, based on a powerful combination of in vivo studies using uniformly 13C‐labeled glucose and in vitro reactions of regiospecifically deuterium‐substituted geranylgeranyl diphosphate substrates. This study shows that CotB2 elegantly demonstrates the synthetic virtuosity and stereochemical control that evolution has conferred on terpene synthases. 相似文献