Inverted polymer solar cells with a solution-processed cesium halide interlayer

We demonstrate the utility of a low-cost cesium iodide interlayer spun from an aqueous or 2-ethoxyethanol solution on ITO in inverted polymer solar cells of the structure ITO/CsI/P3HT:PCBM/MoO₃/Al, where P3HT is poly(3-hexylthiophene) and PCBM is [6,6]-phenyl-C₆₀-butyric acid methyl ester. The power conversion efficiency (PCE) of optimized cells was ～3.4%, comparable to that we obtained for inverted cells with Cs carbonate. The thickness of the CsI film was adjusted by varying the solution concentration. The concentration affected the surface morphology of P3HT:PCBM and the density of fractal-like aggregates (possibly related to the presence of Cs and film fabrication conditions) formed near the anode, as revealed by scanning electron microscopy. Auger analysis indicated a P3HT-rich surface. Optimization of the cells was achieved also by varying the thickness of the MoO₃ and the drying/annealing conditions of the active layer, as was evident from the current–voltage characteristics, external quantum efficiency spectra, and PCE. The cells with the CsI interlayer were compared additionally to cells with CsCl or CsF interlayers (with a PCE of up to ～2.7%), which were inferior to the comparable cells with Cs₂CO₃ or CsI. The surface concentrations of Cs and the halide on ITO were monitored using X-ray photoelectron spectroscopy. The iodine level was low with the Cs:I ratio exceeding 8:1. In contrast, the Cs:Cl ratio was ～1.4:1 and the Cs:F ratio was ～1:1; the Cs₂CO₃ decomposed partially, as expected. Therefore, for CsI, as is the case for Cs₂CO₃ but not for CsF, Cs–O bonds are formed at the surface. Such bonds on ITO are important in modifying the ITO work function, improving the cell performance. The results indicate that spin coating solutions of the high polarity CsI is a promising and easy approach to introduce Cs–O on ITO in inverted structures for increased electron extraction from PCBM and possibly hole extraction from the P3HT-rich surface at the anode.     

川西地区二叠系火山岩异常高压演化与天然气成藏的关系

川西地区二叠系火山岩天然气藏发育较高的异常压力,异常压力的成因和天然气成藏的动力学过程较复杂,目前对研究区异常高压的演化过程及其对天然气成藏的影响规律仍认识不清。通过分析川西地区二叠系实测地层压力、测井响应资料和包裹体捕获压力,明确了异常高压的成因和演化过程。基于不同成藏期次形成的烃类包裹体中的含油流体包裹体颗粒（GOI）丰度,分析了地层压力演化与天然气成藏之间的关系。结果表明：寒武系筇竹寺组烃源岩的生-排烃作用和火山岩内部的原油裂解对异常高压的发育具有重要的贡献;储层内共发育3类包裹体,其形成对应3期大规模油气聚集,即二叠纪末期（距今256~251 Ma）形成碳质沥青包裹体、晚三叠世（距今230~208 Ma）形成油-水包裹体、侏罗纪中-晚期（距今175~152 Ma）形成气-水包裹体。在多期油气聚集过程中,古地层压力系数和烃类包裹体的GOI丰度逐渐升高,表明地层压力的变化为天然气大规模充注提供了充足的动力条件。     

川南地区嘉陵江组天然气气源研究

对川南地区下三叠统嘉陵江组烃源岩生烃条件、碳同位素特征、气源方向及运移通道作了分析研究，认为其自身生烃条件较差，气藏常规组分差异较大，高干燥系数与储量大小关系密切；烷烃类气体碳同位素特征分析证实该组气源与下伏上二叠统的烃源地层有关，混源特征明显；氩同位素特征表明该组气藏气源与二叠系具明显的亲缘关系；结合运移与聚集条件等分析确认该区嘉陵江组天然气主要来源于深层二叠系烃源层，储量大与混源密切相关；烃源岩内部断层是其主要运移通道。     

A High‐Rate V2O5 Hollow Microclew Cathode for an All‐Vanadium‐Based Lithium‐Ion Full Cell

V₂O₅ hollow microclews (V₂O₅‐HMs) have been fabricated through a facile solvothermal method with subsequent calcination. The synthesized V₂O₅‐HMs exhibit a 3D hierarchical structure constructed by intertangled nanowires, which could realize superior ion transport, good structural stability, and significantly improved tap density. When used as the cathodes for lithium‐ion batteries (LIBs), the V₂O₅‐HMs deliver a high capacity (145.3 mAh g^‐1) and a superior rate capability (94.8 mAh g^‐1 at 65 C). When coupled with a lithiated Li₃VO₄ anode, the all‐vanadium‐based lithium‐ion full cell exhibits remarkable cycling stability with a capacity retention of 71.7% over 1500 cycles at 6.7 C. The excellent electrochemical performance demonstrates that the V₂O₅‐HM is a promising candidate for LIBs. The insight obtained from this work also provides a novel strategy for assembling 1D materials into hierarchical microarchitectures with anti‐pulverization ability, excellent electrochemical kinetics, and enhanced tap density.     

Molecular genetics of Krabbe disease (globoid cell leukodystrophy): diagnostic and clinical implications

Galactocerebrosidase (GALC) is a lysosomal beta-galactosidase responsible for the hydrolysis of the galactosyl moiety from several galactolipids, including galactosylceramide and psychosine. The deficiency of this enzyme results in the autosomal recessive disorder called Krabbe disease. It is also called globoid cell leukodystrophy (GLD), because of the characteristic storage cells found around cerebral blood vessels in the white matter of affected human patients and animal models. Although most patients present with clinical symptoms before 6 months of age, older patients, including adults, have been diagnosed by their severe deficiency of GALC activity. More than 40 mutations have been identified in patients with all clinical types of GLD. While some mutations clearly result in the infantile type if found homozygous or with another severe mutation, it is difficult to predict the phenotype of novel mutations or when mutations are found in the heterozygous state. A high incidence of polymorphic changes on apparent disease-causing alleles also complicates the interpretation of the effects of mutations. The detection of mutations has greatly improved carrier identification among family members and will permit preimplantation diagnosis for some families. The molecular characterization of the naturally occurring mouse, dog, and monkey models will permit their use in trials to evaluate different modes of therapy.     

Hydrogen-induced cracking in a very-high-purity high-strength steel

It is shown that intergranular fracture along prior-austenite grain boundaries in a ultrahigh-strength quenched and tempered 4340-type steel is not suppressed by eliminating all segregated embrittling elements. This leaves open the question of how brittle intergranular cracks are nucleated in hydrogen in the absence of such impurities.     

Imputation through finite Gaussian mixture models

Imputation is a widely used method for handling missing data. It consists in the replacement of missing values with plausible ones. Parametric and nonparametric techniques are generally adopted for modelling incomplete data. Both of them have advantages and drawbacks. Parametric techniques are parsimonious but depend on the model assumed, while nonparametric techniques are more flexible but require a high amount of observations. The use of finite mixture of multivariate Gaussian distributions for handling missing data is proposed. The main reason is that it allows to control the trade-off between parsimony and flexibility. An experimental comparison with the widely used imputation nearest neighbour donor is illustrated.     

Functional Properties of Plasticized Bio-Based Poly(Lactic Acid)_Poly(Hydroxybutyrate) (PLA_PHB) Films for Active Food Packaging

Fully bio-based and biodegradable active films based on poly(lactic acid) (PLA) blended with poly(3-hydroxybutyrate) (PHB) and incorporating lactic acid oligomers (OLA) as plasticizers and carvacrol as active agent were extruded and fully characterized in their functional properties for antimicrobial active packaging. PLA_PHB films showed good barrier to water vapor, while the resistance to oxygen diffusion decreased with the addition of OLA and carvacrol. Their overall migration in aqueous food simulant was determined and no significant changes were observed by the addition of carvacrol and OLA to the PLA_PHB formulations. However, the effect of both additives in fatty food simulant can be considered a positive feature for the potential protection of foodstuff with high fat content. Moreover, the antioxidant and antimicrobial activities of the proposed formulations increased by the presence of carvacrol, with enhanced activity against Staphylococcus aureus if compared to Escherichia coli at short and long incubation times. These results underlined the specific antimicrobial properties of these bio-films suggesting their applicability in active food packaging.     

Determination of dimethindene in human tears by high-performance liquid chromatography

A high-performance liquid chromatographic method is described for the determination of dimethindene in human tears. The tear samples were diluted in a 0.01 M hydrochloric acid-n-propanol mixture to prevent the irreversible adsorption of dimethindene. The diluted samples were directly injected into the chromatographic system to avoid sample pretreatment. The validation data demonstrate that the method is specific, precise and accurate within the calibration range of 12 to 1000 ng/ml dimethindene free base.