春小麦应用固氮蓝藻促长物质的研究

<正> 固氮蓝藻是一类能进行光合和固氮作用的低等原核生物。在生长过程中,藻体尚可分泌出多种活性物质,可以促进农作物生长。但能否作为促长物质应用于大田作物

牵拉力对共培养的表皮干细胞及成纤维细胞迁移行为的影响

<正>背景:创面愈合是一个复杂的动态过程,是细胞之间、细胞与细胞外基质及细胞因子间相互影响和协同作用的结果。另外,大量相关研究表明机械应力可以诱导组织细胞增殖,促进创面愈合。因此创面愈合也是一个典型的力学-生物学耦合过程,但力学刺激促进创面愈合的细胞/分子的调控机制目前尚不清楚。皮肤由多种细胞组成,通过牵张皮肤等在体方法难以区分其中某类细胞对外界力学刺激的单独响应以及不

Molecular dynamics simulation of adsorption of Ag particles on a graphite substrate

We have performed for the first time a molecular dynamics simulation of the adsorption of gas-phase Ag particles on a graphite substrate to provide an insight into the results of a comprehensive STM-based experiment on this system. Both pair-wise and many-body interatomic potentials have been employed, and a Morse-type Ag–C potential was specifically constructed to describe the interactions at the interface. Our simulation has successfully reproduced a significant portion of the experimental findings. We have also observed the intercalation of silver in graphite.

Surface plasmon polariton propagation across a gentle silver step

Surface plasmon polaritons (SPPs) are excited with light of wavelength lambda (1) = 632.8 nm on or near a gentle Ag/Ag step structure using focused beam, prism coupling and detected using a bare, sharpened fibre tip. The tip-sample separation is controlled by means of an evanescent optical field at wavelength lambda (2) = 543.5 nm in a photon scanning tunnelling microscope (PSTM). The SPP propagation properties are first characterised on both the thin and thick sections of the Ag film structure either side of the step, both macroscopically, using attenuated total reflection, and microscopically from the PSTM images; the two techniques yield very good agreement. It is found that the SPP propagation length is similar to 10-11 mum across the step in each direction (thick to thin and vice versa) as observed in the PSTM images. Thus, with reference to the propagation lengths of 14.2 and 11.7 mum for the thick and thin planar parts of the Ag film respectively, it is concluded that the SPPs negotiate the step reasonably successfully. Importantly, also, it is shown that images may be produced, displaying SPPs with either an artificially enhanced (similar to 15-20 mum) or truncated (5-8 mum) propagation length across the step. Consideration of such images leads us to suggest the possibility that the photon tunnelling occurs in a local water environment. (C) 2001 Elsevier Science B.V. All rights reserved.

SK1 of graded division algebras

The reduced Whitehead group $\SK$ of a graded division algebra graded by a torsion-free abelian group is studied. It is observed that the computations here are much more straightforward than in the non-graded setting. Bridges to the ungraded case are then established by the following two theorems: It is proved that $\SK$ of a tame valued division algebra over a henselian field coincides with $\SK$ of its associated graded division algebra. Furthermore, it is shown that $\SK$ of a graded division algebra is isomorphic to $\SK$ of its quotient division algebra. The first theorem gives the established formulas for the reduced Whitehead group of certain valued division algebras in a unified manner, whereas the latter theorem covers the stability of reduced Whitehead groups, and also describes $\SK$ for generic abelian crossed products.

Non-uniform printed antenna array for wireless communications in sports arenas

Wireless communications had a great development in the last years and nowadays they are present everywhere, public and private, being increasingly used for different applications. Their application in the business of sports events as a means to improve the experience of the fans at the games is becoming essential, such as sharing messages and multimedia material on social networks. In the stadiums, given the high density of people, the wireless networks require very large data capacity. Hence radio coverage employing many small sized sectors is unavoidable. In this paper, an antenna is designed to operate in the Wi-Fi 5GHz frequency band, with a directive radiation pattern suitable to this kind of applications. Furthermore, despite the large bandwidth and low losses, this antenna has been developed using low cost, off-the-shelf materials without sacrificing quality or performance, essential to mass production. © 2015 EurAAP.

L'Écho de Paris

1900/11/30 (Numéro 6028).

Resoluciones Cámara de Comercio de Bogotá

Doctrina

Scottish Rite (Masonic Order) French Language Collection, 1787-1825, 1907, n.d.

The origins of the Scottish Rite of Freemasonry can be traced to France around 1754, when a Chapter of Claremont was founded in Paris. Initially this chapter had seven degrees, but by 1758 there were twenty-five degrees, known as the Rite of Perfection. In 1761, Stephen Morin was appointed to introduce the Rite into the New World. He began with Kingston, Jamaica and San Domingo. Further establishments were made in New Orleans, LA(1763); Albany, NY (1767); Philadelphia, PA (1782); and Charleston, SC (1783). In order to improve the disorganized state of the degrees in Europe, “Grand Constitutions” were enacted in 1786. These Constitutions formally brought into existence the “Ancient and Accepted Scottish Rite”. None of the degrees of the Scottish Rite would seem to have origins in Scotland. “Scottish” is translated from the French word “Ecossais”, which is found in some of the French titles of some of the degrees of the Rite of Perfection. It is possible that the Scottish connection is a result of the involvement of a Scotsman, Andrew Michael Ramsey, who may have devised some of the degrees.

La transgresión a la ley como posibilidad de existencia. Un caso de perversión.

Tesis (Maestría en Psicología con orientación en Clínica Psicoanalítica) UANL, 2014.

L'Action universitaire – vol. 18, no 2, janv. 1952

Pour toute demande de reproduction de contenu se trouvant dans cette publication, communiquer avec l’Association des diplômés de l’UdeM.

El paradigma del Razonamiento Basado en Casos en el ámbito de los Sistemas de Enseñanza-Aprendizaje Inteligentes.

Resumen tomado del autor

Adsorption, orientation and thermal decomposition of copper(II) hexafluoroacetylacetonate on rutile TiO2(110)

We have investigated the adsorption and thermal decomposition of copper hexafluoroacetylacetonate (Cu-11(hfaC)(2)) on single crystal rutile TiO2(110). Low energy electron diffraction shows that room temperature saturation coverage of the Cu-II(hfac)(2) adsorbate forms an ordered (2 x 1) over-layer. X-ray and ultra-violet photoemission spectroscopy of the saturated surface were recorded as the sample was annealed in a sequential manner to reveal decomposition pathways. The results show that the molecule dissociatively adsorbs by detachment of one of the two ligands to form hfac and Cu-1(hfac) which chemisorb to the substrate at 298 K. These ligands only begin to decompose once the surface temperature exceeds 473 K where Cu core level shifts indicate metallisation. This reduction from Cu(I) to Cu(0) takes place in the absence of an external reducing agent and without disproportionation and is accompanied by the onset of decomposition of the hfac ligands. Finally, C K-edge near edge X-ray absorption fine structure experiments indicate that both the ligands adsorb aligned in the < 001 > direction and we propose a model in which the hfac ligands adsorb on the 5-fold coordinated Ti atoms and the Cu-1(hfac) moiety attaches to the bridging O atoms in a square planar geometry. The calculated tilt angle for these combined geometries is approximately 10 degrees to the surface normal.

Evaluation of forest snow processes models (SnowMIP2)

Thirty‐three snowpack models of varying complexity and purpose were evaluated across a wide range of hydrometeorological and forest canopy conditions at five Northern Hemisphere locations, for up to two winter snow seasons. Modeled estimates of snow water equivalent (SWE) or depth were compared to observations at forest and open sites at each location. Precipitation phase and duration of above‐freezing air temperatures are shown to be major influences on divergence and convergence of modeled estimates of the subcanopy snowpack. When models are considered collectively at all locations, comparisons with observations show that it is harder to model SWE at forested sites than open sites. There is no universal “best” model for all sites or locations, but comparison of the consistency of individual model performances relative to one another at different sites shows that there is less consistency at forest sites than open sites, and even less consistency between forest and open sites in the same year. A good performance by a model at a forest site is therefore unlikely to mean a good model performance by the same model at an open site (and vice versa). Calibration of models at forest sites provides lower errors than uncalibrated models at three out of four locations. However, benefits of calibration do not translate to subsequent years, and benefits gained by models calibrated for forest snow processes are not translated to open conditions.