In plants with infrequent pollinator services, the benefits of reproductive assurance could be eroded by severe ovule discounting and inbreeding depression (ID). However, it remains unclear how selfing evolves under complete pollinator failure and strong ID. We examined the mating system and ID under netting and robbing conditions in Comastoma pulmonarium (Turcz.) Toyok. (Gentianaceae), an alpine annual experiencing a high ratio of nectar robbery on the Qinghai-Tibet Plateau. Comastoma pulmonarium produced seeds via selfing at the study site. No pollinator was observed and thus the nectar was consumed exclusively by robbers. Inbreeding depression occurred in the life stages of seed mass and germination, and the cumulative ID was much higher than 0.5 under netting and robbing conditions. Overall, in comparison with netting, the magnitude of ID under robbing conditions tended to decrease. Our results suggested that selfing could assure reproduction for plants under complete pollinator failure and strong ID, supporting the better than nothing role of selfing and providing one of the few cases of the evolution of selfing under strong ID.
In this note, we consider positive entire large solutions for semilinear elliptic equations Au = p（x）f（u） in R^N with N ≥ 3. More precisely, we are interested in the link between the existence of entire large solution with the behavior of solution for --△u = p（x） in R^N. Especially for the radial case, we try to give a survey of all possible situations under Keller-Osserman type conditions.
Based on free carrier plasma dispersion effect, a 2 × 2 optical switch is fabricated in a silicon-on-insulator substrate by inductively coupled-plasma technology and ion implantation. The device has a Mach-Zehnder interferometer structure, in which two directional couplers serve as the power splitter and combiner. The switch presents an insertion loss of 3.04 dB and a response time of 496ns.
Zincblende CrSb （zb-CrSb） layers with room-temperature ferromagnetism have been grown on relaxed and strained （In,Ga）As buffer layers epitaxially prepared on （001） GaAs substrates by molecular-beam epitaxy. The structural characterizations of CrSb layers fabricated under the two cases are studied by using synchrotron grazing incidence x-ray diffraction （GID）. The results of GID experiments indicate that no sign of second phase exists in all the zb-CrSb layers. Superconducting quantum interference device measurements demonstrate that the thickness of zb-CrSb layers grown on both relaxed and strained （In,Ga）As buffer layers can be increased to ～12 monolayers （～3.6nm）, compared to ,～3 monolayers （～1 nm） on GaAs directly.
Antireflection surfaces and coatings have attracted considerable interests because they can maximize light transmittance of the substrates. In this work, zeolite antireflective （ZAR） coatings are prepared via layer-by-layer （LBL） assembly of MFI-type zeolite silicalite-1 and polyelectrolyte. A micro- and macroporous hierarchical structure was obtained which contributes to the antireflective property of the zeolite coatings. The light transmittance of the coating on quartz can achieve as high as 99.3% at 650 nm. Furthermore, a superh~/drophobic ZAR coating can be obtained by chemical modification with 1H,1H,2H,2H-perfluorooctyl-triethoxysilane. This work demonstrates that zeolites are excellent candidates as high transparent superhydrophobic coatings.
In this paper,we investigate the effects of kinematic transports on the nematic liquid crystal system numerically and theoretically.The model we used is a"1+2"elastic continuum model simplified from the Ericksen-Leslie system.The numerical experiments are carried out by using a Legendre-Galerkin spectral method which can preserve the energy law in the discrete form.Based on this highly accurate numerical approach we find some interesting and important relationships between the kinematic transports and the characteristics of the flow.We make some analysis to explain these results.Several significant scaling properties are also verified by our simulations.
A new aluminophosphate [Cu(en)2]0.5[Al3P3O12(OH)] (denoted as AlPO-CJ53; en = ethylenediamine) with zeotype AWO topology has been synthesized under hydrothermal conditions in which the self-assembled Cu(en)22+ cations in the reaction system act as the template. AlPO-CJ53 crystallizes in the monoclinic space group P21/n (No. 14) with a = 0.85547(11) nm, b = 1.7671(2) nm, c = 0.90500(12) nm, β= 107.725(2)°, V = 1.3031(3) nm3. Its framework consists of AlO4(OH)/AlO4 and PO4 units forming 8-ring channels along the c direction, where the copper complex cations Cu(en)22+ are located to neutralize the negative charges of the framework. AlPO-CJ53 transforms to AlPO4-25 with zeotype ATV upon calcination at 400 °C.
DUAN FangZheng, LI JiYang, SUN Wei, CHEN Peng, YU JiHong & XU RuRen State Key Laboratory of Inorganic Synthesis and Preparative Chemistry
Thirty-pair Alo.3 Gao.T N/A1N distributed Bragg reflectors centred at 32Ohm are designed and grown on sapphire substrates by metalorganic chemical vapour deposition. No cracks are observed in the main area of the 2-inch wafer except for about 4 mm margin under an optical microscope. Regular stack of alternating layers is shown by scanning electron microscopy. Clear two-dimensional growth steps and very low surface roughness are shown by atomic force microscopy （AFM）. Well-defined periodicity is shown by high resolution x-ray diffraction. High refiectivity of 93% at 313nm with a bandwidth of 13nm is obtained.
CeO2 nanowires are successful synthesized by hydrothermal method and their field emission （FE） properties are investigated. The turn-on electric field is 5.8 V/μm at an emitter-anode spacing of 700μm. The FE current is stable and the current fluctuations are less than 3% over 5 h. All the plotted Fowler-Nordheim curves yield straight lines, which are in agreement with the Fowler-Nordheim theory. The relationship between the field enhancement factor β and the emitter-anode spacing d follows a universal equation. Our results imply that the CeO2 nanowires are promising materials for fabricating FE cathodes.
