Recent Developments of Polymer Solar Cells with Photovoltaic Performance over 17%

With the emergence of ADA'DA-type (Y-series) non-fullerene acceptors (NFAs), the power conversion efficiencies (PCEs) of organic photovoltaic devices have been constantly refreshed and gradually reached 20% in recent years (19% for single junction and 20% for tandem device). The acceptors possess specific design concept, which greatly enrich the NFA types and have excellent compatibility with many donor materials. It is gratifying to note that the previously underperforming donor materials combine with these regulated acceptors to shine again. Nowadays, the concept of modular design is widely used in the research of acceptors and donors, injecting new vitality into the field of organic photovoltaics. Furthermore, these acceptors also promote the research of multicomponent devices, tandem devices, bilayer devices, processing solvent engineering, and additive engineering. Herein, the latest progresses of polymer solar cells with efficiency over 17% are briefly reviewed from the aspects of active material design, interface material development, and device technology. At last, the opportunities and challenges of organic photovoltaic commercialization in the future are discussed.     

Comparison of the polyphenol profiles of apple fruit cultivars by correspondence analysis

Concentrations of the major flavonoids and phenolic acids in the peel and cortex of fruit of eight commercial apple cultivars were determined by HPLC. The multivariate statistical technique of correspondence analysis was applied to the polyphenol profiles to describe distinctive groups of cultivars and of polyphenols, and their joint correspondences. Cultural and growing conditions had a limited effect on the polyphenol profiles of the cortex and peel. Chlorogenic acid was the principal polyphenol in the cortex with the lowest levels being in Red Delicious and the highest in Jerseymac, which were compensated by changes in phlorizin. Cortland had low levels of chlorogenic acid and Gravenstein had high levels, but these were offset by the levels of catechins. The quercetin, rhamnoside, was the principal phenolic compound for the peel data with low levels in Red Delicious, Cortland, Spartan and Jerseymac and high levels in Golden Delicious, Gravenstein and Northern Spy. Levels of chlorogenic acid, offset by levels of phlorizin and catechins, distinguished between Red Delicious and Cortland. Rutin was important in distinguishing between Jerseymac and Spartan.     

Cognitive dissonance.

This article reviews critically the experimental evidence in support of cognitive dissonance theory as applied to complex social events. The criticisms which can be made of this literature fall into 2 main classes. 1st, the experimental manipulations are usually so complex and the crucial variables so confounded that no valid conclusions can be drawn from the data. 2nd, a number of fundamental methodological inadequacies in the analysis of results—as, e.g., rejection of cases and faulty statistical analysis of the data—vitiate the findings. As a result, one can only say that the evidence adduced for cognitive dissonance theory is inconclusive. Suggestions are offered for the methodological improvement of studies in this area. The review concludes with the thesis that the most attractive feature of cognitive dissonance theory, its simplicity, is in actual fact a self-defeating limitation. (44 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

60 channel WDM transmitter using multiwavelength modelocked

The simultaneous generation of 60 discrete wavelengths, with a 75 GHz interwavelength spacing, from a modelocked semiconductor diode laser is reported. The individual wavelengths are emitted as mutually synchronised 898 MHz return-to-zero pulse trains. Optical spectra and temporal diagnostics are provided     

Variability in starch physicochemical and functional properties of yam (Dioscorea sp) cultivated in Ivory Coast

An Erratum has been published for this article in Journal Of the Science of Food and Agriculture 85(5), 889 (2005). Native starches were extracted from 21 cultivars of four yam species representative of the yam population of Ivory Coast. They were first characterized for their proximate composition, starch physico‐chemical properties (amylose content, particle size distribution, crystallinity, thermal properties and intrinsic viscosity). Some functional properties (swelling, solubility and pasting behaviour and paste clarity) were then determined. Analysis of variance and principal component analysis showed that three homogenous groups could be distinguished, mainly based on starch physico‐chemical properties. The first group contained all yam starches of the D alata and the D cayenensis‐rotundata complex species. It was characterized by a large diameter grain (approximately 25 µm), a high amylose content (around 25% db), a high intrinsic viscosity (mean of 190 cm³ g^?1), and a high apparent viscosity and clarity of the paste. The second group contained the D esculenta varieties, characterized by a small granule size (diameter 6 µm), a low intrinsic viscosity (121 cm³ g^?1), a high gelatinization enthalpy change (19 J g^?1) and a low paste viscosity. The D dumetorum sample differed from the D esculenta group by having a pure A‐type crystalline form and an opaque paste. A multiple regression showed that the volume fraction of the dispersed phase and native granule size (or amylose content) could account for close to 80% of the variability of paste apparent viscosity. Gel clarity appeared mainly linked to granule size, small granules from D dumetorum and D esculenta giving the most opaque gels. Copyright © 2004 Society of Chemical Industry     

通过改造底物结合区氨基酸疏水性提高氨肽酶热稳定性

通过提高枯草芽孢杆菌来源的氨肽酶底物结合区域氨基酸的疏水性,提高氨肽酶YwaD的热稳定性。基于氨肽酶底物结合区域氨基酸特性分析,选定亲水性氨基酸残基N385为目标,通过定点突变使其突变为疏水氨基酸残基L385,获得突变体N385L。结果表明,与野生型ywaD相比,突变体N385L酶热稳定性明显提高,在80℃放置30 min,野生型YwaD完全失活,而突变体N385L仍保留20%的酶活力。另外,突变型N385L对底物氨基酰基-硝基苯胺的亲和力提高了47.4%,催化效率提高了28.5%。该研究有利于提高氨基肽酶工业应用前景。     

Phase-field simulations with inhomogeneous elasticity: Comparison with an atomic-scale method and application to superalloys

We present a 2D and 3D phase-field analysis of microstructure evolution in the presence of a lattice misfit and with inhomogeneous elastic constants. The method is first critically compared with a Monte Carlo modeling at the atomic scale. We then apply the phase-field model to the Ni–Al system under external load along a cubic axis. We find that the microstructure becomes anisotropic and that the situation qualitatively differs depending on the sign of the applied stress. The microstructure evolution operates mainly by shape changes and alignments of precipitates, but also by splitting of precipitates initially elongated along directions perpendicular to the stress-induced, elastically favorable directions. The final microstructure is finally qualitatively analyzed in terms of a mean field theory in which the elastic inhomogeneity is embedded into an effective eigenstrain. This analysis leads to a simple formulation which can be used to easily predict the coherent microstructural anisotropy induced by any external loading condition.     

One role or two?: The function of psychological separation in role conflict.

Student athletes vary in how much they view their academic and athletic role identities as separate from and interfering with each other. The authors investigated the relation of these perceptions to psychological well-being in 200 intercollegiate athletes. Measures included role separation, interference, identity, and well-being. Correlations indicated that interference related negatively to well-being, whereas viewing the roles as distinct related positively to well-being. Regression analyses of demographic and role identity variables also showed a positive association between role separation and well-being, and a significant Separation×Interference interaction. Specifically, role interference was negatively related to well-being for those who viewed the two roles as distinct but unrelated for those who did not. The buffering effects of role separation are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Men, machines, and models.

"Models are analogies." Among the values of models are: they describe and help us to understand complex systems or events, they help us learn complex skills, they provide the framework within which experiments are done, they help us see new relationships, they help us predict when experiments are impossible, and they assist in engineering design. Some dangers in the use of models include: they invite overgeneralization, they entice us into committing a logical fallacy, the relationships between the variables may be incorrect, the constants used in the model may be incorrect, models are too often not validated, and model building diverts useful energy into nonproductive activity. From Psyc Abstracts 36:02:2LJ13C. (PsycINFO Database Record (c) 2010 APA, all rights reserved)