This study investigates the statistical characteristics of raindrop size distributions (DSDs) in monsoon season with observations collected by the second-generation Particle Size and Velocity (Parsivel2) disdrometer located in Zhuhai, southern China. The characteristics are quantified based on convective and stratiform precipitation classified using the rainfall intensity and total number of drops. On average of the whole dataset, the DSD characteristic in southern China consists of a higher number concentration of relatively small-sized drops when compare with eastern China and northern China, respectively. In the meanwhile, the Dm and log10Nw scatter plots prove that the convective rain in monsoon season can be identified as maritime-like cluster. The DSD is in good agreement with a three-parameter gamma distribution, especially for the medium to large raindrop size. Using filtered data observed by Parsivel2 disdrometer, a new Z–R relationship, Z = 498R1.3, is derived for convective rain in monsoon season in southern China. These results offer insights of the microphysical nature of precipitation in Zhuhai during monsoon season, and provide essential information that may be useful for precipitation retrievals based on weather radar observations.

We reported a facile solution-processed method to fabricate a MoSx anode buffer layer through thermal decomposition of (NH4)2MoS4. Organic solar cells (OSCs) based on in situ growth MoSx as the anode buffer layer showed impressive improvements, and the power conversion efficiency was higher than that of conventional PEDOT:PSS-based device. The MoSx films obtained at different temperatures and the corresponding device performance were systematically studied. The results indicated that both MoS3 and MoS2 were beneficial to the device performance. MoS3 could result in higher Voc, while MoS2 could lead to higher Jsc. Our results proved that, apart from MoO3, molybdenum sulfides and Mo(4+) were also promising candidates for the anode buffer materials in OSCs.

This study assesses the performance of the latest version 05B (V5B) Integrated Multi-Satellite Retrievals for Global Precipitation Measurement (GPM) (IMERG) Early and Final Runs over southern China during six extremely heavy precipitation events brought by six powerful typhoons from 2016 to 2017. Observations from a dense network composed of 2449 rain gauges are used as reference to quantify the performance in terms of spatiotemporal variability, probability distribution of precipitation rates, contingency scores, and bias analysis. The results show that: (1) both IMERG with gauge calibration (IMERG_Cal) and without gauge correction (IMERG_Uncal) generally capture the spatial patterns of storm-accumulated precipitation with moderate to high correlation coefficients (CCs) of 0.57–0.87, and relative bias (RB) varying from −17.21% to 30.58%; (2) IMERG_Uncal and IMERG_Cal capture well the area-average hourly series of precipitation over rainfall centers with high CCs ranging from 0.78 to 0.94; (3) IMERG_Cal tends to underestimate precipitation especially the rainfall over the rainfall centers when compared to IMERG_Uncal. The IMERG Final Run shows promising potentials in typhoon-related extreme precipitation storm applications. This study is expected to give useful feedbacks about the latest V5B Final Run IMERG product to both algorithm developers and the scientific end users, providing a better understanding of how well the V5B IMERG products capture the typhoon extreme precipitation events over southern China.

A novel hybrid material CdS/2,9-Dimethyl-4,7-diphenyl-1,10-phenanthroline (CdS·BCP) was prepared from the decomposition of its organic soluble precursor complex Cd(S2COEt)2·(BCP) by low-temperature treatment. CdS·BCP, which integrated the favorable properties of solvent durability, and high electron mobility of CdS as well as the good hole blocking property of BCP, was designed and developed as the interface modification material to improve electron collection in bulk heterojunction organic solar cells (OSCs). The inverted OSCs with CdS·BCP as buffer layer on ITO showed improved efficiency compared with the pure CdS or BCP. Devices with CdS·BCP as interlayer exhibited excellent stability, only 14.19% decay of power conversion efficiencies (PCEs) was observed (from 7.47% to 6.41%) after stored in glovebox for 3264 h (136 days). Our results demonstrate promising potentials of hybrid materials as the interface modification layers in OSCs, and provide new insights for the development of new interface modification materials in the future.

A highly efficient polymer solar cell was fabricated using a polar fullerene derivative C60 pyrrolidine tris-acid (CPTA) as the cathode buffer layer. By introducing CPTA, the V oc , J sc and FF were all much enhanced simultaneously. The power conversion efficiency (PCE) was significantly improved to 7.92%, which outperformed the device using Ca/Al as the cathode in our experiment.

Conjugated organic optoelectronic materials have attracted significant attention owing to their application in lightemitting diodes (LEDs), solar cells, thin-film transistors, optically amplified biosensor assays, and other areas. [1] For organic optoelectronic devices, interfacial modification between the organic material and the electrode is a crucial issue and becomes one of the most important research focal points, since charge injection/extraction affect device performance greatly. [2] Excellent charge injection leads to a lower turn-on voltage and higher efficiency in organic LEDs. [3] In the case of organic solar cells, good interface properties result in a higher short-circuit current and a higher open-circuit voltage, which are the most important factors for solar-cell performance. [4] Among the many kinds of solution-processable interfacial-modification materials, [4a,b, 5] conjugated polyelectrolytes (CPEs) and oligoelectrolytes (OEs) containing a p-delocalized backbone with pendant groups that can be ionized have attracted great interest. Their solubility in polar solvents enables the fabrication of multilayer polymer-based devices by the solution-processing approach. [6a-g] The reported performance of devices based on CPEs/OEs is comparable to that of devices based on the conventional Ca/Ba electrode. However, mobile counterions, such as Na + , Br À , and tetrasubstituted borates, [6a,b, 7] which can migrate during device operation, make the device mechanism more complicated and seriously affect the device turn-on time. [1h, 8] In recent years, conjugated zwitterionic materials have attracted great interest as a new kind of charge-injection materials owing to their unique chemical structure, in which both the positive and the negative ions are combined. As the ions are not mobile, the device response time is improved significantly. Furthermore, the solubility of the materials in polar solvents is good enough for multilayer-device fabrication as a result of the presence of the charged groups. [2a] In 2009, Bazan and co-workers reported small-molecule zwitterionic materials synthesized by the addition of iodoalkanes to sodium tetrakis(1-imidazolyl)borate (NaBIm 4 ); the device response time and performance were comparable to those of the Ba/Al electrode. [6d] In a previous study, [9] one of our research groups reported a conjugated polyelectrolyte with a fluorene-based zwitterionic sulfoammonium structure and no free counterions. When this zwitterionic polymer known as "F(NSO 3 ) 2 " (CPE1) was used as the electron-injection layer, devices based on poly(9,9'-dioctylfluorene-co-benzothiadiazole) (F8BT) as the emitter showed very fast response times; moreover, both efficiency and brightness were considerably improved (by a factor of more than 2) in comparison with standard calcium-based devices. Huang and co-workers independently reported a fluorene-based zwitterionic polymer, "PF 6 NSO", [3a] the luminance efficiency of which was as high as 23.8 cdA with poly[2-(4-(3',7'-dimethyloctyloxy)phe...

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Abstract. Sea ice volume export through the Fram Strait plays an important role in the Arctic freshwater and energy redistribution. The combined model and satellite sea ice thickness (CMST) data set assimilates CryoSat-2 and soil moisture and ocean salinity (SMOS) thickness products together with satellite sea ice concentration. The CMST data set closes the gap of stand-alone satellite-derived sea ice thickness in summer and therefore allows us to estimate sea ice volume export during the melt season. In this study, we first validate the CMST data set using field observations, and then we estimate the continuous seasonal and interannual variations in Arctic sea ice volume flux through the Fram Strait from September 2010 to December 2016. The results show that seasonal and interannual sea ice volume export vary from about -240(±40) to -970(±60) km3 and -1970(±290) to -2490(±280) km3, respectively. The sea ice volume export reaches its maximum in spring and about one-third of the yearly total volume export occurs in the melt season. The minimum monthly sea ice export is −11 km3 in August 2015, and the maximum (−442 km3) appears in March 2011. The seasonal relative frequencies of sea ice thickness and drift suggest that the Fram Strait outlet in summer is dominated by sea ice that is thicker than 2 m with relatively slow seasonal mean drift of about 3 km d−1.