Fly compound-eye inspired inorganic nanostructures with extraordinary visible-light responses

Inorganic bio-inspired nanomaterials, which integrate the unique properties of metal oxide nanomaterials and the features of well-evolved biological structures and functions, are a novel direction towards mining the potential of existing materials to further enhance the performance of various microelectronic and energy harvesting, conversion, and storage devices, although the facile fabrication of bio-inspired materials still remains a major challenge. We noticed that some compound eyes presented extremely strong responses to light and displayed beautiful colours and patterns, which inspired us to design novel photonic materials. In this study, we fabricated fly compound-eye inspired ZnO nanomaterials in the forms of either isolated microspheres or highly-ordered coatings grown in-situ, in which the three-zone structures were similar to the anatomical structure of the biological compound eyes, including an outermost faceted microlens array, a middle rhabdom-like channel layer, and a central hollow zone. The bio-inspired nanomaterials, as we expected, presented extraordinary visible-light response behaviour and would make it possible to capture energy across a wide solar spectrum with a single semiconductor material. This study thus paves the way to further improving the performance of the current photoelectronic and energy harvesting, conversion, and storage devices.     

Thermally stable coherent domain boundaries in complex-structured Cr2Nb intermetallics

The strength and hardness of nanostructured materials are significantly enhanced owing to the large amount of grain boundaries (GB) produced by a reduced grain size. The thermal stability of the GB is a key to maintaining the grain size and thus the strength/hardness in nanostructured materials at high temperatures. In this work, coherent domain boundaries (DB) were introduced by compressive processing to sub-divide a complex-structured intermetallic Cr₂Nb into nanograins of size down to 2 nm. These DB persisted after an annealing of 10 h at 1273 K. The coherent DB have been investigated by aberration-corrected high-resolution transmission electron microscopy and first-principles calculations. The high thermal stability is evidently a result of low formation energies of the DB.     

Comparative studies of flexible aliphatic ternary/binary benzoxazines and their copolymers: Thermal and dynamic mechanical properties

Aliphatic ternary benzoxazine (Bz) based from triamine with long chain, as well as flexible binary Bz, was successfully synthesized, which was named as BzT and BzD respectively. The corresponding polybenzoxazines (PBz) rooting from BzT and BzD (PBzT and PBzD) respectively and their copolybenzoxazines (co-PBzs) were obtained to improve the mechanical and thermal properties via chemical cross-linking. The onset polymerization temperatures of the copolymers decreased from 189.1°C to 143.9°C, and the exothermic peak temperature reduced significantly from 232.5°C to 217°C as the content of BzT increased from 0 wt% to 100 wt% in the copolymers. The value of char yield at 800°C increased gradually from 21.5 wt% for PBzD to 28.7 wt% for PBzT. The increasing crosslink density resulted higher glass transition temperatures and improved storage moduli in glassy region because of the introduction of BzT.     

Identification of 19 phthalic acid esters in dairy products by gas chromatography with mass spectrometry

A detection method for 19 kinds of phthalic acid ester compounds analyzed by n‐hexane/ether/acetonitrile 1:7:8 v/v/v mixed solvent extraction, quick, easy, cheap, effective, rugged, and safe purification and internal standard method of quantitative gas chromatography with mass spectrometry was established. This method can effectively remove interfering materials, such as lipids, fatty acids, and pigments, from dairy products. The 19 kinds of phthalic acid ester compounds were within a 0.025–0.2 mg/kg range, the recovery rate was 65.2–125.7%, relative standard deviation was 7.9–15.4% (n = 6), and the limit of detection was 0.005–0.02 mg/kg. Concentrations of the 19 kinds of phthalic acid ester compounds ranged between 0.01 and 0.12 mg/kg in ten dairy materials and 20 dairy products. The established method is simple, rapid, accurate, and highly sensitive.     

基于动态随机点立体图的立体视觉深度运动特性分析

利用动态随机点立体图,排除心理暗示线索对深度运动的影响,对立体视觉深度运动特性进行了研究.利用主观实验,分析了深度运动物体的运动位置、运动方向和运动速度等运动特性对于立体视觉舒适度(Stereo visual comfort,SVC)的影响, 并提出深度运动情况下的SVC与运动速度的预测模型.实验结果表明,动态随机点立体图中,运动物体的深度运动诱发了透视效果;在交叉视差(屏幕前)和非交叉视差(屏幕后)情况下,立体视觉深度运动导致的SVC不同.对计算得到的SVC的预测值和实测值进行相关性检测,三种深度运动的皮尔森相关系数(Pearson correlation coefficient,PCC)分别为0.956、0.972、0.977,充分表明该预测模型能够准确地预测SVC.     

Concentrated portfolio selection models based on historical data

A new risk measure fully based on historical data is proposed, from which we can naturally derive concentrated optimal portfolios rather than imposing cardinality constraints. The new risk measure can be expressed as a quadratics of the introduced greedy matrix, which takes investors' joint behavior into account. We construct distribution‐free portfolio selection models in simple case and realistic case, respectively. The latest techniques for describing transaction cost constraints and solving nonconvex quadratic programs are utilized to obtain the optimal portfolio efficiently. In order to show the practicality, efficiency, and robustness of our new risk measure and corresponding portfolio selection models, a series of empirical studies are carried out with trading data from advanced stock markets and emerging stock markets. Different performance indicators are adopted to comprehensively compare results obtained under our new models with those obtained under the mean‐variance, mean‐semivariance, and mean‐conditional value‐at‐risk models. Out‐of‐sample results sufficiently show that our models outperform the others and provide a simple and practical approach for choosing concentrated, efficient, and robust portfolios. Copyright © 2014 John Wiley & Sons, Ltd.     

Novel ruthenium sensitizer with multiple butadiene equivalent thienyls as conjugation on ancillary ligand for dye-sensitized solar cells

A heteroleptic polypyridyl ruthenium complex ‘cis-Ru(4,4′-bis(3,5-bis(5-hexylthiophen-2-yl)phenyl)-2,2′-bipyridine)(4,4′-dicarboxyl-2,2′-bipyridine) (NCS)₂, MC102′, with a high molar extinction coefficient was synthesized and characterized with IR, ¹H NMR, Mass, UV–Vis spectroscopy. The test cell DSSC devices constructed with 0.23 cm² active area photo-electrode in combination with an electrolyte composed of 0.6 M dimethylpropyl-imidazolium iodide (DMPII), 0.05 M I₂, and 0.1 M LiI in acetonitrile yielded solar to electric energy conversion efficiency (η) of 4.42% under Air Mass (AM) 1.5 sunlight, while the reference N719 sensitized solar cell fabricated and evaluated under similar conditions exhibited η-value of 5.84%.     

Large-eddy structures of turbulent swirling flows and methane-air swirling diffusion combustion

Turbulent swirling flows and methane-air swirling diffusion combustion are studied by large-eddy simulation (LES) using a Smagorinsky-Lilly subgrid scale turbulence model and a second-order moment (SOM) SGS combustion model, and also by RANS modeling using the Reynolds Stress equation model with the IPCM+wall and IPCM pressure-strain models and SOM combustion model. The LES statistical results for swirling flows give good agreement with the experimental results, indicating that the adopted subgrid-scale turbulence model is suitable for swirling flows. The LES instantaneous results show the complex vortex shedding pattern in swirling flows. The initially formed large vortex structures soon break up in swirling flows. The LES statistical results of combustion modeling are near the experimental results and are as good as the RANS-SOM modeling results. The LES results show that the size and range of large vortex structures in swirling combustion are different from those of isothermal swirling flows, and the chemical reaction is intensified by the large-eddy vortex structures. The project supported by the Special Funds for Major State Basic Research (G-1999-0222-07). The English text was polished by Keren Wang.     

一族沿曲面的解析极大函数的弱型估计

设Ｄｘ是一族给定的分布且满足＜Ｄ－１,Ｆ＞＝Ｆ（１）,定义一族极大函数Ｍｘ其中ｆ上许瓦兹函数     

A Pilot Study of Rare Renal Amyloidosis Based on FFPE Proteomics

Renal amyloidosis typically manifests albuminuria, nephrotic-range proteinuria, and ultimately progresses to end-stage renal failure if diagnosed late. Different types of renal amyloidosis have completely different treatments and outcomes. Therefore, amyloidosis typing is essential for disease prognosis, genetic counseling and treatment. Thirty-six distinct proteins currently known to cause amyloidosis that have been described as amyloidogenic precursors, immunohistochemistry (IHC) or immunofluorescence (IF), can be challenging for amyloidosis typing especially in rare or hereditary amyloidosis in clinical practice. We made a pilot study that optimized the proteomics pre-processing procedures for trace renal amyloidosis formalin-fixed paraffin-embedded (FFPE) tissue samples, combined with statistical and bioinformatics analysis to screen out the amyloidosis-related proteins to accurately type or subtype renal amyloidosis in order to achieve individual treatment. A sensitive, specific and reliable FFPE-based proteomics analysis for trace sample manipulation was developed for amyloidosis typing. Our results not only underlined the great promise of traditional proteomics and bioinformatics analysis using FFPE tissues for amyloidosis typing, but also proved that retrospective diagnosis and analysis of previous cases laid a solid foundation for personalized treatment.