A photochemical C-N coupling of aryl halides with nitroarenes is demonstrated for the first time. Catalyzed by a Ni II complex in the absence of any external photosensitizer, readily available nitroarenes undergo coupling with a variety of aryl halides, providing a step-economic extension to the widely used Buchwald-Hartwig C-N coupling reaction. The method tolerates coupling partners with steric-congestion and functional groups sensitive to bases and nucleophiles. Mechanistic studies suggest that the reaction proceeds via the addition of an aryl radical, generated from a Ni I /Ni III cycle, to a nitrosoarene intermediate. Scheme 1. Methods for the formation of aryl CÀN bonds.

Abstract-Three notched bands are generated, at selected frequencies, in an extremely wideband base antenna to support multiple communication systems while avoiding inference from other existing narrowband systems. The design of a fully printed extremely wideband antenna and creating triple band-notched functions are addressed in this paper. Measurements demonstrate that the proposed printed base antenna has an extremely wide 2 : 1 VSWR bandwidth from 0.72 GHz, to 25 GHz with a ratio bandwidth of 34 : 1. The antenna has a simple structure and can be fabricated at low cost for multi-band and wideband wireless communication devices. Besides, this paper presents a technique to form three notched bands within the operating frequency range of the base antenna. By introducing a half-wavelength U-shaped defected ground structure (DGS) and a pair of quarter-wavelength open arc-shaped slots to the radiating patch, three notched bands are created to prevent interference from WLAN (2.4-2.484 GHz and 5.15-5.85 GHz) systems and downlinks of X-band satellite communication (7.25-7.75 GHz) systems.

[1] Comprehensive surface-based retrievals of cloud optical and microphysical properties were made at Taihu, a highly polluted site in the central Yangtze Delta region, during a research campaign from May 2008 to December 2009. Cloud optical depth (COD), effective radius (R e ), and liquid water path (LWP) were retrieved from measurements made with a suite of ground-based and spaceborne instruments, including an Analytical Spectral Devices spectroradiometer, a multifilter rotating shadowband radiometer, a multichannel microwave radiometer profiler, and the Moderate Resolution Imaging Spectroradiometer (MODIS) on Terra and Aqua satellites. Retrievals from zenith radiance measurements capture better the temporal variation of cloud properties than do retrievals from hemispherical fluxes. Annual mean LWP, COD, and R e are 115.8 ± 90.8 g/m 2 , 28.5 ± 19.2, and 6.9 ± 4.2 μm. Over 90% of LWP values are less than 250 g/m 2 . Most of the COD values (>90%) fall between 5 and 60, and~80% of R e values are less than 10 μm. Maximum (minimum) values of LWP and R e occur in summer (winter); COD is highest in winter and spring. Raining and nonraining clouds have significant differences in LWP, COD, and R e . Rainfall frequency is best correlated with LWP, followed by COD and R e . Cloud properties retrieved from multiple ground-based instruments are also compared with those from satellite retrievals. On average, relative to surface retrievals, mean differences of satellite retrievals in cloud LWP, COD, and R e were À33.6 g/m 2 (À26.4%), À5.8 (À31.4%), and 2.9 μm (29.3%) for 11 MODIS-Terra overpasses and À43.3 g/m 2 (À22.3%), À3.0 (À10.0%), and À1.3 μm (À12.0%) for 8 MODIS-Aqua overpasses, respectively. These discrepancies indicate that MODIS cloud products still suffer from large uncertainties in this region.Citation: Liu, J., Z. Li, Y. Zheng, J. C. Chiu, F. Zhao, M. Cadeddu, F. Weng, and M. Cribb (2013), Cloud optical and microphysical properties derived from ground-based and satellite sensors over a site in the Yangtze Delta region,