A Novel Deep Blue LE-Dominated HLCT Excited State Design Strategy and Material for OLED

Deep blue luminescent materials play a crucial role in the organic light-emitting diodes (OLEDs). In this work, a novel deep blue molecule based on hybridized local and charge-transfer (HLCT) excited state was reported with the emission wavelength of 423 nm. The OLED based on this material achieved high maximum external quantum efficiency (EQE) of 4% with good color purity. The results revealed that the locally-excited (LE)-dominated HLCT excited state had obvious advantages in short wavelength and narrow spectrum emission. What is more, the experimental and theoretical combination was used to describe the excited state characteristic and to understand photophysical property.     

柴里煤人工氧化过程中性质和化学结构的变化

对鲁南柴里矿山西组三号煤层煤样进行了氧化模拟实验，对氧化系列煤样进行了元素分析、腐植酸含量和傅里叶变换红外光谱分析，讨论了氧化过程中元素成分和腐植酸含量的变化规律。以高岭石谱带为内标，利用差谱技术测定了氧化过程中柴里煤结构中含氧官能团、脂肪烃和芳烃的变化。结果表明，在煤氧化过程中，含氧官能团明显增加，主要是碳基；脂肪烃含量明显降低，但甲基、亚甲基之间没有发现优先攻击现象；而芳烃在氧化过程中基本上没有发生变化。     

消自旋ESR法测量铝酞菁光敏反应中阴离子自由基的生成

用氮氧自由基消自旋ESR法探测铝酞菁原初反应过程中的阴离子自由基.结果显示在无氧条件下,当体系中存在连苯三酚或半胱胺酸这些电子施主时,可有铝酞菁阴离子自由基生成,这可能是除了单线态氧外的另一种光敏作用机制.     

Estimating the Number of Clusters via the GUD Statistic

Estimating the number of clusters is one of the most difficult problems in cluster analysis. Most previous approaches require knowing the data matrix and may not work when only a Euclidean distance matrix is available. Other approaches also suffer from the curse of dimensionality and work poorly in high dimension. In this article, we develop a new statistic, called the GUD statistic, based on the idea of the Gap method, but use the determinant of the pooled within-group scatter matrix instead of the within-cluster sum of squared distances. Some theory is developed to show this statistic can work well when only the Euclidean distance matrix is known. More generally, this statistic can even work for any dissimilarity matrix that satisfies some properties. We also propose a modification for high-dimensional datasets, called the R-GUD statistic, which can give a robust estimation in high-dimensional settings. The simulation shows our method needs less information but is generally found to be more accurate and robust than other methods considered in the study, especially in many difficult settings.     

Imaging brain tumor by dendrimer-based optical/paramagnetic nanoprobe across the blood-brain barrier

A multimodal optical/paramagnetic nanoprobe, Den-Angio, was developed and demonstrated a capability to circumvent the blood brain barrier (BBB) and visualize brain tumors with high sensitivity in vivo. Den-Angio holds promise to pre-operatively localize brain tumors and make image-guided tumor resection possible during surgery.     

Proton sponge-functionalized silica as high performance adsorbents for solid-phase extraction of trace perfluoroalkyl sulfonates in the environmental water samples and their direct analysis by MALDI-TOF-MS

1,8-Bis(dimethylamino)naphthalene (DMAN), a classical 'proton sponge', was functionalized on silica particles as a novel solid-phase extraction (SPE) adsorbent (DMAN@silica) for extracting perfluoroalkyl sulfonates (PFSs). High reproducibility and excellent extraction capability for PFSs were obtained in a wide pH range (3.0~8.5). The adsorbed PFSs on DMAN@silica sorbents could be efficiently eluted by 1,8-bis(tetramethylguanidino)naphthalene (TMGN) solution which is a proton sponge with higher proton affinity than DMAN. The elution could be directly analyzed by MALDI-TOF-MS using TMGN as matrix. Clear mass spectra for the PFSs were obtained due to no matrix ions interference observed. Furthermore, a novel strategy based on the DMAN@silica-SPE enrichment, followed by MALDI-TOF-MS analysis, was proposed and applied for PFSs quantification in environmental water samples. The calibration curves of each of the target analytes showed a wide linear dynamic range of response (0.1-10 ng L(-1) for perfluorooctane sulfonate (PFOS), perfluorohexyl sulfonate (PFHxS) and perfluorobutylsulfonate (PFBS)), which were over 2 orders of magnitude. The detection limits for PFOS, PFHxS, and PFBS were 0.021, 0.016, and 0.013 ng L(-1), respectively (S/N = 3). Recoveries of PFOS, PFHxS, and PFBS are in the ranges of 92-104%, 95-102%, and 98-109% for spiked river water samples. These results indicated that the prepared DMAN@silica adsorbents could efficiently enrich PFSs and that the proposed method is reliable.     

牙菌斑有机酸的气相色谱-质谱分析

采用ＧＣ／ＭＳ联用技术分析了正常人牙菌斑内有机酸成分。发现了１４种有机酸,其中有８种直链饱和脂肪酸、４种直链非饱和脂肪酸、２种芳香酸。含量最多的是Ｃ１６∶０,Ｃ１８∶０,Ｃ１８∶１３种脂肪酸。其中苯乙酸、苯丙酸及十五碳酸等３种成分是第１次在牙菌斑中检测出。