Short circuit current improvement in planar heterojunction organic solar cells by multijunction charge transfer

A multijunction structure was applied on an organic photovoltaic (OPV) device for broadening the absorption spectrum and enhancing the power conversion efficiency through charge transfer process. By inserting the tris[4-(2-thienyl)]amine (TTPA) into a boron subphthalocyanine chloride (SubPc)/C 60 OPV device, the short circuit current density (J sc) showed a 47.5% increases from 3.05 to 4.50 mA/cm 2 in the bilayer planar heterojunction device, while the open circuit voltage (V oc) remained constant. Based on the single junction (TTPA/SubPc) device and photoluminescence absorption results, we confirmed both TTPA/SubPc and SubPc/C 60 junctions are contributing to the exciton dissociation process hence the efficiency enhancement. © 2012 American Institute of Physics.published_or_final_versio

Dynamic depth-dependent osmotic swelling and solute diffusion in articular cartilage monitored using real-time ultrasound

Author name used in this publication: Y. P. ZhengAuthor name used in this publication: J. ShiAuthor name used in this publication: S. G. Patil2003-2004 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe

Improving Mechanical Strength of YBCO Bulk Superconductors by Addition of Ag

The widespread use of ceramic (RE)Ba2Cu3O7 bulk superconductors (RE-123), where RE=Y, Gd or Sm, is generally hindered by their poor mechanical properties. While a large number of techniques can be used to improve the mechanical properties of conventional ceramic materials, many of these are incompatible with the growth of single grain, bulk RE-123 super- conductors using the top seeded melt growth (TSMG) process. Complications arise due to the need to minimize the degradation of the superconducting properties and produce a single-grained sample. Nonetheless, the addition of Ag to RE-Ba-Cu-O [(RE)BCO] precursor powder has been demonstrated to be effec- tive in improving the mechanical properties of single grain bulk superconductors fabricated by TSMG without deleterious effects on performance. Although large single grains of GdBa2Cu3O7-Ag and SmBa2Cu3O7-Ag have been successfully and reliably grown, it has proven more difficult to grow large single grains of YBa2Cu3O7-Ag. We recently demonstrated the growth of single grain YBa2Cu3O7-Ag bulk superconductors that exhibit relative- ly good superconducting properties. In this work, we report the flexural stress at a number of locations within YBa2Cu3O7 single grains grown by TSMG with and without additional liquid phase and with silver addition. In addition, we have compared the dis- tribution of the failure stress with the pore and silver distribu- tion

A dynamic and continuous allowances allocation methodology for the prevention of carbon leakage: Emission control coefficients

© 2018 Elsevier Ltd Carbon leakage has become the core issue of emission trading systems. Using data from Hubei Province, this paper identifies the drawbacks of the prevailing methods for preventing carbon leakage and proposes a new methodology to overcome them, namely, Emission Control Coefficients. In contrast to the common tiered structure method, the Emission Control Coefficients generate a dynamic and continuous emission control coefficient for each industry which will improve the effectiveness and fairness of allowance allocation, set aside sufficient time for the low carbon transformation of industries, and balance the needs to protect competitiveness and decarbonize and are particularly suitable for the emission trading systems of developing counties. This paper makes three main academic contributions: Firstly, it proposes a new indicator, the abatement potential for more effective determining allowance allocation than the prevailing method. Secondly, it better distinguishes industrial differences. Thirdly, it can better respond to the problem of excess allowances that is due to technological advances and trade pattern changes

Improved prediction of RNA secondary structure by integrating the free energy model with restraints derived from experimental probing data.

PublishedEvaluation StudiesJournal ArticleResearch Support, Non-U.S. Gov'tRecently, several experimental techniques have emerged for probing RNA structures based on high-throughput sequencing. However, most secondary structure prediction tools that incorporate probing data are designed and optimized for particular types of experiments. For example, RNAstructure-Fold is optimized for SHAPE data, while SeqFold is optimized for PARS data. Here, we report a new RNA secondary structure prediction method, restrained MaxExpect (RME), which can incorporate multiple types of experimental probing data and is based on a free energy model and an MEA (maximizing expected accuracy) algorithm. We first demonstrated that RME substantially improved secondary structure prediction with perfect restraints (base pair information of known structures). Next, we collected structure-probing data from diverse experiments (e.g. SHAPE, PARS and DMS-seq) and transformed them into a unified set of pairing probabilities with a posterior probabilistic model. By using the probability scores as restraints in RME, we compared its secondary structure prediction performance with two other well-known tools, RNAstructure-Fold (based on a free energy minimization algorithm) and SeqFold (based on a sampling algorithm). For SHAPE data, RME and RNAstructure-Fold performed better than SeqFold, because they markedly altered the energy model with the experimental restraints. For high-throughput data (e.g. PARS and DMS-seq) with lower probing efficiency, the secondary structure prediction performances of the tested tools were comparable, with performance improvements for only a portion of the tested RNAs. However, when the effects of tertiary structure and protein interactions were removed, RME showed the highest prediction accuracy in the DMS-accessible regions by incorporating in vivo DMS-seq data.National Key Basic Research Program of China [2012CB316503]; National High-Tech Research and Development Program of China [2014AA021103]; National Natural Science Foundation of China [31271402]; Tsinghua University Initiative Scientific Research Program [2014z21045]; Hong Kong Research Grants Council Early Career Scheme [419612 to K.Y.]; National Science Foundation [1339282 to D.H.M.]; Computing Platform of the National Protein Facilities (Tsinghua University). Funding for open access charge: National Natural Science Foundation of China [31271402]

Preliminary research of sonomyography(SMG) based on correlation tracking

2006-2007 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Study of the transient and depth-dependent swelling behavior of articular cartilage by ultrasound

2004-2005 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Development and applications of ultrasound elastomicroscopy

2006-2007 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Flux vortex dynamics in type-II superconductors

Abstract The flux-pinning landscape in type-II superconductors determines the response of the flux line lattice to changing magnetic fields. Typically, the flux vortex behaviour is hysteretic and well described within the framework of the Bean critical-state model and its extensions. However, if the changing magnetic field does not move the flux vortices from their pinning sites, their response remains linear and reversible. The vortex displacement, then, is characterised by the Campbell penetration depth, which itself is related directly to the effective size of the pinning potential. Here, we present measurements of the Campbell penetration depth (and the effective size of the pinning potential) as a function of magnetic field in a single-grain bulk GdBa2Cu3O 7 − δ superconductor using a pick-up coil method. Hence, the hysteretic losses, which take into account the reversible vortex movement, are established.This work was supported by Siemens AG. Dr Mark Ainslie would like to acknowledge financial support from an Engineering and Physical Sciences Research Council (EPSRC) Early Career Fellowship EP/P020313/1

Demagnetization study of pulse-field magnetized bulk superconductors

GdBa2Cu3O7-δ bulk superconductors are a route to higher magnetic fields in rotating machines. Here we examine the resistance of pulse-field magnetized bulks to the demagnetization fields they may experience in such a system. The bulks were magnetized at 77 K, after which several thousand cycles of AC field were applied. Subsequently, the decay of the trapped field was characterized. We found the decay per cycle decreases with frequency and is, normalized to the initial trapped field, largest at the edge of the bulk. At 77 K the reduction in trapped field proved significant (25% in the center for 150 mT (peak) AC field at 6 Hz), however reducing below 1% when lowering the temperature to 60 K. We explain this observation as being due to increased flux pinning strength at low temperatures. When applying an AC field we found a temperature rise that increased with applied field amplitude and frequency. However, when applying an AC field of amplitude 45 mT with a frequency of 48 Hz we found an increase of the bulk temperature of only 100 mK. Therefore, we conclude the temperature rise within the analyzed AC field frequency and amplitude range does not contribute significantly to the decay of trapped field