Photochemical behavior of some p-styryistilbenes and related compounds: Spectral properties and photoisomerization in solution and in solid state

Author Posting. © The Authors (2006) This is the author's version of the work. It is posted here for personal use, not for redistribution. The definitive version was published in PHOTOCHEMISTRY AND PHOTOBIOLOGY, 82(6): 1645-1650. https://doi.org/10.1562/2006-01-17-RA-780ArticlePhotochemistry and Photobiology. 82(6): 1645-1650 (2006)journal articl

Different photochemical behavior of bis(biphenyl)ethylenes and ethenes in solution and in the solid-state: Structurally controlled Z/E-photoisomerization in the solid-state

ArticleJOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY. 184(1-2): 44-49 (2006)journal articl

Halfvortices in flat nanomagnets

We discuss a new type of topological defect in XY systems where the O(2) symmetry is broken in the presence of a boundary. Of particular interest is the appearance of such defects in nanomagnets with a planar geometry. They are manifested as kinks of magnetization along the edge and can be viewed as halfvortices with winding numbers \pm 1/2. We argue that halfvortices play a role equally important to that of ordinary vortices in the statics and dynamics of flat nanomagnets. Domain walls found in experiments and numerical simulations are composite objects containing two or more of these elementary defects. We also discuss a closely related system: the two-dimensional smectic liquid crystal films with planar boundary condition.Comment: 7 pages, 8 figures, To appear as a chapter in Les Houches summer school on Quantum Magnetis

Photoluminescence study on coarsening of self-assembled InAlAs quantum dots on GaAs (001)

Red-emission at similar to 640 nm from self-assembled In0.55Al0.45As/Al0.5Ga0.5As quantum dots grown on GaAs substrate by molecular beam epitaxy (MBE) has been demonstrated. We obtained a double-peak structure of photoluminescence (PL) spectra from quantum dots. An atomic force micrograph (AFM) image for uncapped sample also shows a bimodal distribution of dot sizes. From the temperature and excitation intensity dependence of PL spectra, we found that the double-peak structure of PL spectra from quantum dots was strongly correlated to the two predominant quantum dot families. Taking into account quantum-size effect on the peak energy, we propose that the high (low) energy peak results from a smaller (larger) dot family, and this result is identical with the statistical distribution of dot lateral size from the AFM image

Seed Regeneration Potential of Canopy Gaps at Early Formation Stage in Temperate Secondary Forests, Northeast China

Promoting the seed regeneration potential of secondary forests undergoing gap disturbances is an important approach for achieving forest restoration and sustainable management. Seedling recruitment from seed banks strongly determines the seed regeneration potential, but the process is poorly understood in the gaps of secondary forests. The objectives of the present study were to evaluate the effects of gap size, seed availability, and environmental conditions on the seed regeneration potential in temperate secondary forests. It was found that gap formation could favor the invasion of more varieties of species in seed banks, but it also could speed up the turnover rate of seed banks leading to lower seed densities. Seeds of the dominant species, Fraxinus rhynchophylla, were transient in soil and there was a minor and discontinuous contribution of the seed bank to its seedling emergence. For Quercus mongolica, emerging seedling number was positively correlated with seed density in gaps (R = 0.32, P<0.01), especially in medium and small gaps (<500 m2). Furthermore, under canopies, there was a positive correlation between seedling number and seed density of Acer mono (R = 0.43, P<0.01). Gap formation could promote seedling emergence of two gap-dependent species (i.e., Q. mongolica and A. mono), but the contribution of seed banks to seedlings was below 10% after gap creation. Soil moisture and temperature were the restrictive factors controlling the seedling emergence from seeds in gaps and under canopies, respectively. Thus, the regeneration potential from seed banks is limited after gap formation

Slip-Flow and Heat Transfer of a Non-Newtonian Nanofluid in a Microtube

The slip-flow and heat transfer of a non-Newtonian nanofluid in a microtube is theoretically studied. The power-law rheology is adopted to describe the non-Newtonian characteristics of the flow, in which the fluid consistency coefficient and the flow behavior index depend on the nanoparticle volume fraction. The velocity profile, volumetric flow rate and local Nusselt number are calculated for different values of nanoparticle volume fraction and slip length. The results show that the influence of nanoparticle volume fraction on the flow of the nanofluid depends on the pressure gradient, which is quite different from that of the Newtonian nanofluid. Increase of the nanoparticle volume fraction has the effect to impede the flow at a small pressure gradient, but it changes to facilitate the flow when the pressure gradient is large enough. This remarkable phenomenon is observed when the tube radius shrinks to micrometer scale. On the other hand, we find that increase of the slip length always results in larger flow rate of the nanofluid. Furthermore, the heat transfer rate of the nanofluid in the microtube can be enhanced due to the non-Newtonian rheology and slip boundary effects. The thermally fully developed heat transfer rate under constant wall temperature and constant heat flux boundary conditions is also compared

Prognostic significance of the expression of GFRα1, GFRα3 and Syndecan-3, Proteins binding ARTEMIN, In mammary carcinoma

10.1186/1471-2407-13-34BMC Cancer13-BCMA

Biocleavable Polycationic Micelles as Highly Efficient Gene Delivery Vectors

An amphiphilic disulfide-containing polyamidoamine was synthesized by Michael-type polyaddition reaction of piperazine to equimolar N, N′-bis(acryloyl)cystamine with 90% yield. The polycationic micelles (198 nm, 32.5 mV), prepared from the amphiphilic polyamidoamine by dialysis method, can condense foreign plasmid DNA to form nanosized polycationic micelles/DNA polyelectrolyte complexes with positive charges, which transfected 293T cells with high efficiency. Under optimized conditions, the transfection efficiencies of polycationic micelles/DNA complexes are comparable to, or even higher than that of commercially available branched PEI (Mw 25 kDa)