Collinear second harmonic generations in a nonlinear photonic quasicrystal

LiNbO₃ nonlinear photonic quasicrystal with octagonal symmetry was fabricated. The collinear quasiphase matched second harmonic generations at 22 wavelengths were observed. It is shown that not only the standard type quasiphase matching but also the recently proposed projection-based quasiphase matching plays an important role in these harmonic generations.The financial support of Chinese Academy of Science, Max Plank Society, and Deutscher Akademischer Austauschdienst DAAD is gratefully acknowledged

Assessment of Three Satellite-Derived Surface Downward Longwave Radiation Products in Polar Regions

The radiation budget in polar regions plays an important role in global climate change study. This study investigates the performance of downward longwave radiation (DLR) of three satellite radiation products in polar regions, including GEWEX-SRB, ISCCP-FD, and CERES-SYN. The RMSEs are 35.8, 40.5, and 26.9 W/m2 at all polar sites for GEWEX-SRB, ISCCP-FD, and CERES-SYN. The results in the Arctic are much better than those in the Antarctic, RMSEs of the three products are 34.7 W/m2, 36.0 W/m2, and 26.2 W/m2 in the Arctic and are 38.8 W/m2 and 54.8 W/m2, and 28.6 W/m2 in the Antarctic. Both GEWEX-SRB and CERES-SYN underestimate DLRs at most sites, while ISCCP-FD overestimates DLRs at most sites. CERES-SYN and GEWEX-SRB DLR products can capture most of the DLR seasonal variation in both the Antarctic and Arctic. Though CERES-SYN has the best results that RMSE within 30 W/m2 in most polar sites, the accuracy of satellite products in polar regions still cannot meet the requirement of climate research. The improvement of satellite DLR products in polar regions mainly depends on the quality of improving input atmospheric parameters, the accuracy of improving cloud detection over the snow and ice surface and cloud parameters, and better consideration of spatial resolution and heterogeneity

Experimental Investigation of Relationship between the object- and Image Distance

Abstract-We experimentally investigate the focusing properties of a triangular two-dimensional photonic crystals of which all the cylinders are coated. The relationship between the location of object and image point is analyzed. It's demonstrated that at a certain frequency with relative refractive index of −1, the position of image point obey the geometric-optics analysis and non-near-field imaging can be achieved

Anomalous reflection from hybrid metamaterial slab

We report for the first time that an ultra-thin hybrid metamaterial slab can reflect an incident plane wave in -1st diffraction order, giving rise to anomalous reflection in a "negative" way. The functionality is derived from the hybridized surface resonant states of the slab. The retro-directive reflection is demonstrated numerically for a Gaussian beam at oblique incidence and verified experimentally at microwave frequencies. (C)2010 Optical Society of Americ

Spatially coherent surface resonance states derived from magnetic resonances

A thin metamaterial slab comprising a dielectric spacer sandwiched between a metallic grating and a ground plane is shown to possess spatially coherent surface resonance states that span a large frequency range and can be tuned by structural and material parameters. They give rise to nearly perfect angle-selective absorption and thus exhibit directional thermal emissivity. Direct numerical simulations show that the metamaterial slab supports spatially coherent thermal emission in a wide frequency range that is robust against structural disorder

Brincidofovir is a robust replication inhibitor against African Swine Fever virus in vivo and in vitro

African swine fever virus (ASFV) infection is a major public and socioeconomic concern that has a serious impact on the global swine industry. Unfortunately, there are currently no commercially available vaccines or antiviral agents that are both safe and effective against ASFV. In the study, we use primary porcine alveolar macrophages to screen a kinase inhibitor library for anti-ASFV compounds. Six candidate compounds that inhibited ASFV infection with inhibition of > 90% were identified, among which brincidofovir exhibited optimal inhibitory effects on ASFV. Brincidofovir reduces ASFV replication in a dose-dependent manner (IC50 = 2.76 nM) without cytotoxicity (CC50 = 58 μM). It possesses the ability to reduce viral titres and inhibit viral structural protein expression. Time-of-addition assays suggest that the compound interferes with the post-invasion stage of the viral infection cycle. In pig challenge experiments, brincidofovir was indicated to protect pigs against ASFV-induced lethality by decreasing the viral load in organs and peripheral blood, while it alleviated the histopathological changes associated with ASFV infection. Furthermore, brincidofovir also decreased viral shedding in pigs with ASFV infection. Our data together demonstrate that brincidofovir may serve as a potentially effective agent for the prevention and control of ASFV infection, whereas further investigations are still required

The effects of fertilization on average weed densities.

<p>Analyses of variance were performed on log_e-transformed data, but means of untransformed data are shown. Error bars are the SE of the mean.</p

The influence of fertilization on wheat yield and light transmittance at the ground surface.

<p>The influence of fertilization on wheat yield and light transmittance at the ground surface.</p