Shanghai UniversityShanghai

Shanghai, China

Shanghai UniversityShanghai

Shanghai, China
SEARCH FILTERS
Time filter
Source Type

Zou F.,Shanghai UniversityShanghai | Wu B.,Shanghai UniversityShanghai | Wang X.,Shanghai UniversityShanghai | Wang X.,Shanghai University | And 4 more authors.
Sensors and Actuators, B: Chemical | Year: 2017

A signal-amplification and dual-recognition strategy was designed to construct a signal-enhanced surface plasmon resonance (SPR) platform for the highly sensitive detection of dopamine. This strategy was based on the specific recognition of boronic acid to diol and that of calix[4]arene crown ether-modified gold nanoparticles (CAL[4]-AuNPs) to amine groups. A 3-aminophenyl boronic acid monohydrate probe was immobilized onto a gold chip surface as capture probes via covalent bonds with 11-mercaptoundecanoic acid. CAL[4]-AuNPs were designed as signal probes and characterized by transmission electron microscopy and spectroscopic techniques. Upon the binding of dopamine with boronic acid followed by CAL[4]-AuNPs, the AuNPs were captured on the chip surface to enhance the SPR signal, thereby producing an ultra-low background signal. Signal amplification and dual recognition were used to quantify dopamine concentration from 0.1 nM to 1 μM, with a detection limit of 1.17 pM. This strategy is a new concept for the design of highly selective analytical methods to detect small biomolecules. © 2016


Yu X.,Shanghai UniversityShanghai | Wang M.,Shanghai UniversityShanghai | Gagnoud A.,SIMAP EPM Madylam G INP CNRS | Fautrelle Y.,SIMAP EPM Madylam G INP CNRS | And 2 more authors.
Electrochimica Acta | Year: 2017

A novel, facile and scalable process of simultaneous activation and templating is developed for in situ synthesis of graphene-enhanced 3D hierarchical porous carbon nanobelt networks uniformly anchored with polycrystalline Fe3O4 nanoparticles (5–45 nm) (Fe3O4–rGO/poly(vinyl alcohol) (PVA)-derived carbon) as a high-performance supercapacitor electrode. During the synthesis, 3D self-assembled NaCl particles are adopted as a structural template to direct the growth of 3D carbon nanobelt networks with interconnected macropores, KOH is used as an activating reagent to generate porous nanobelts with masses of micro-, meso- and macropores, and graphene sheets behave as a chemical activator to promote the growth of hierarchical porous thin nanobelts. The resulting Fe3O4–rGO/PVA-derived carbon electrode leads to a combination of the redox pseudo-capacitance of Fe3O4 and the electric double-layer capacitance of the carbon species with a remarkably high capacitivity (538.8 F g−1 at 5 A g−1) and outstanding cycle performance (∼590 F g−1 after 5000 cycles at 5 A g−1). This work offers a new strategy for preparation of 3D hierarchical porous carbon networks for future applications. © 2017


Wang C.,South China University of Technology | Zhou Z.,Tongji University | Jin X.-L.,Shanghai UniversityShanghai | Fang Y.,City University of Hong Kong | Lee M.K.O.,City University of Hong Kong
Information Processing and Management | Year: 2017

Instant information sharing on microblogs is important for promoting social awareness, influencing customer attitudes, and providing political and economic benefits. However, research on the antecedents and mechanisms of such instant information sharing is limited. To address that issue, this study develops a research model to investigate the factors (affective cues in particular) that drive users to instantly share information on microblogs and explores the moderating role of gender. An online survey was conducted on a microblogging platform to collect data for testing the proposed research model and hypotheses. The results confirm the positive effects of informational (i.e., information uniqueness), ambient (i.e., information crowding), and social (i.e., social interactivity) cues on individuals’ positive emotion, which subsequently promotes their urge to share information on microblogs. Moreover, the moderating effects of gender are identified. This study contributes to the understanding of instant information sharing from an impulsive behavior perspective. The results also provide important insights for service providers and practitioners who wish to promote instant information sharing on microblogs. © 2017 Elsevier Ltd


Jian H.,Shanghai UniversityShanghai | Jian H.,Shanghai Creative Superconductor Technologies Co. | Zhong H.,Shanghai Creative Superconductor Technologies Co. | Liu X.,Shanghai Creative Superconductor Technologies Co. | And 13 more authors.
Physica C: Superconductivity and its Applications | Year: 2017

Oxygenation is one of the most essential processes for practical applications of REBa2Cu3O7−δ (RE123, RE = Y, Gd etc. rare earths) superconductors. Second generation high-Tc superconducting coated conductors are based on biaxial textured RE123 thin films, on which, a cover layer of silver for protecting is normally applied. It results in a little more complicated oxygenation process compared to naked film without silver protective layer. In the present work, a series of absorbing oxygen post-annealing processes were carried out for YBa2Cu3O7−δ coated conductors. The oxygen diffusion procedure and the kinetics in the annealing process were investigated. Analysis and calculations show that the activation energy was 1.01 eV, consistent with previous reports. Moreover, experiments show that the “over-doping” phenomena frequently occurs in coated conductors, and thus dropping the Tc to as low as 86–88 K. To improve the temperature margin for practical applications (temperature difference between the superconducting transition temperature Tc and application temperature), we investigated the potential of increase in Tc by preventing from the “over-doped” happening, while keeping oxygen in order. Finally, by employing the new annealing process, we can produce long (several hundred meters) coated conductor with high Tc,onset (92 K), narrow transition width and stable performance. © 2017


Hu Q.,Shanghai University | Hu Q.,Shanghai UniversityShanghai | Li W.,Shanghai University | Zhang H.,Shanghai University | And 4 more authors.
Acta Astronautica | Year: 2017

The problem that the space membranes are easily torn open is the main focus in this paper, and a bionic strengthening-ribs structure is proposed for a space membrane based on interdisciplinary strengths, such as topology optimization, composite materials, and rapid prototyping. The optimization method and modeling method of membranes with bionic strengthening-ribs was studied. The PEEK and SCF/PEEK composite material which are applied to the space environment are chosen, and FDM technology is used. Through topology optimization, bionic strengthening-ribs with good tensile and tear capacities were obtained. Cracked membranes, cracked membranes with PEEK strengthening-ribs and SCF/PEEK strengthening-ribs were tested and test data were obtained. An extension situation and tension fracture were compared for three cases. The experimental results showed that membranes with the bionic strengthening-ribs structure have better mechanical properties, and the strength of the membranes with PEEK and SCF/PEEK strengthening-ribs were raised, respectively, up to 266.9% and 185.9%. The strengthening-ribs structure greatly improves the capacity to halt membrane crack-growth, which has an important significance to avoid membrane tear, and to ensure the spacecraft orbital lifetime. © 2017 IAA


Ma Y.,Shanghai University | Sheng L.,Shanghai University | Zhao H.,Shanghai UniversityShanghai | An K.,Shanghai University | And 3 more authors.
Solid State Sciences | Year: 2015

Abstract In this study, NiO/carbon shell/single-walled carbon nanotube composites are prepared by heat treating the single-walled carbon nanotube samples synthesized by direct current arc discharge method. The morphology and nanostructure of the composites are affected by the heat treatment temperature according to the X-ray diffraction, Raman spectra and high-resolution transmission electron microscopy results. The electrochemical measurements are evaluated in coin-type cells versus metallic lithium. After heat treatment in H2 at 600 °C for 1 h and in air at 300 °C for 10 h, the NiO nanoparticles encapsulated by carbon shells are evenly distributed on the surface of web-like single-walled carbon nanotubes and a perfect NiO/carbon shell/single-walled carbon nanotube nanostructure is formed. This NiO/carbon shell/single-walled carbon nanotube composite shows a high reversible specific capacity of 758 mA h g-1 after 60 cycles at a current density of 100 mA g-1 and an excellent rate capacity of about 594 mA h g-1 even at a high current density of 1600 mA g-1. Therefore, the NiO/carbon shell/single-walled carbon nanotube composites have significant potential for applications in energy storage devices. © 2015 Elsevier Masson SAS.


Ma H.,Shaoxing University | Ma H.,Shanghai University | Su S.,Shanghai UniversityShanghai | Simon D.,Cleveland State University | Fei M.,Shanghai University
Engineering Applications of Artificial Intelligence | Year: 2015

This paper proposes an ensemble multi-objective biogeography-based optimization (EMBBO) algorithm, which is inspired by ensemble learning, to solve the automated warehouse scheduling problem. First, a real-world automated warehouse scheduling problem is formulated as a constrained multi-objective optimization problem. Then EMBBO is formulated as a combination of several multi-objective biogeography-based optimization (MBBO) algorithms, including vector evaluated biogeography-based optimization (VEBBO), non-dominated sorting biogeography-based optimization (NSBBO), and niched Pareto biogeography-based optimization (NPBBO). Performance is tested on a set of 10 unconstrained multi-objective benchmark functions and 10 constrained multi-objective benchmark functions from the 2009 Congress on Evolutionary Computation (CEC), and compared with single constituent MBBO and CEC competition algorithms. Results show that EMBBO is better than its constituent algorithms, and among the best CEC competition algorithms, for the benchmark functions studied in this paper. Finally, EMBBO is successfully applied to the automated warehouse scheduling problem, and the results show that EMBBO is a competitive algorithm for automated warehouse scheduling. © 2015 Elsevier Ltd.


Wu P.,Shanghai UniversityShanghai | Xie S.,Shanghai UniversityShanghai | Luo J.,Shanghai UniversityShanghai | Qu D.,Shanghai UniversityShanghai | Li Q.,Shanghai Second Polytechnic University
Revista Tecnica de la Facultad de Ingenieria Universidad del Zulia | Year: 2015

The robot path planning is the important element of .the robot navigation. There were several algorithms for obstacle planning, but the most efficient obstacle avoidance algorithm has not been found. So we should continue to research the problem. Artificial Potential Field (APF) and Ant Colony Optimization (ACO) are often used in local and global path planning. However there are some inherent problems, for examples, the problem of GNRON in APF, slow convergence and prematurity in ACO. In order to solve this issue, the global path planning should be compensated by the local path planning. In this paper, we combine the ACO algorithm with Artificial Potential Field (APF)algorithm in goal path planning, and then the modified ACO algorithm can drive the USV to the target. Otherwise, when the environment is changeable, the algorithm switches to the Angle Potential Field method and the robot can escape from the dilemma smoothly. Then the initial global planning algorithm continues to drive the robot to the target. Finally, the simulation results demonstrate that the modified method is with high quality in optimal path planning.


Lu X.-J.,Shanghai UniversityShanghai | Lu X.-J.,Polytechnic University of Valencia | Palmero M.,Polytechnic University of Valencia | Ruschhaupt A.,University College CorkCork | And 3 more authors.
Physica Scripta | Year: 2015

We investigate the effect of slow spring-constant drifts of the trap used to shuttle two ions of different mass. We design transport protocols to suppress or mitigate the final excitation energy by applying invariant-based inverse engineering, perturbation theory, and a harmonic dynamical normal-mode approximation. A simple, explicit trigonometric protocol for the trap trajectory is found to be robust with respect to the spring-constant drifts. © 2015 The Royal Swedish Academy of Sciences.


Xing X.,Shanghai UniversityShanghai | Min J.,Shanghai UniversityShanghai | Liang X.,Shanghai UniversityShanghai | Zhang J.,Shanghai UniversityShanghai | And 5 more authors.
Journal of Crystal Growth | Year: 2015

Abstract The In-doped Cd0.9Zn0.1Te (CZT) crystals were grown by the modified Vertical Bridgeman method and treated by in-situ annealing with six different cooling rates. Photo-Induced Transient Spectroscopy (PICTS) and IR microscopy were employed to investigate the evolution mechanism of point defects and bulk defects (mainly Te inclusions) in the CZT crystals with different cooling rates. Related optical and electrical properties were investigated by Fourier Transform Infrared Spectrometer (FTIR) and I-V measurements. The results indicated that cooling at slow rate (10-20 K/h) could decrease the concentration of point defects, such as A center, Cd vacancy (formula presented), Te antisite (formula presented) and so on, while the Te inclusions are of larger dimension and lower concentration. Otherwise, the faster cooling rate (50-60 K/h), the higher concentration of these point defects, and Te inclusion present small size but much larger concentration. Moreover, cooling too fast or too slow significantly degrades the optical and electrical properties. When cooled at 30-40 K/h, the concentration of internal point defects is the lowest, suggesting that VCd2- compensated with TeCd2+ to reach a new equilibrium corresponding to the theory of quasichemical defect reactions (QCDR). In addition, a certain concentration of TeCd2+ was beneficial to pin the Fermi-level, and the Te inclusions presented lowest total volume fraction, which made the crystals perform great with higher resistivity and infrared transmittance. © 2015 Elsevier B.V.

Loading Shanghai UniversityShanghai collaborators
Loading Shanghai UniversityShanghai collaborators