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Institution

University of Macau

EducationMacao, Macau, China
About: University of Macau is a education organization based out in Macao, Macau, China. It is known for research contribution in the topics: Population & Control theory. The organization has 6636 authors who have published 18324 publications receiving 327384 citations. The organization is also known as: UM & UMAC.


Papers
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Journal ArticleDOI
TL;DR: This study presents well‐aligned molybdenum dioxide@nitrogen‐doped carbon (MoO2@NC) and copper cobalt sulfide (CuCo2S4) tubular nanostructures grown on flexible carbon fiber for use as electrode materials in supercapacitors and provides an effective strategy to develop electrode materials with superior electrochemical performance for flexiblesupercapacitor.
Abstract: Flexible quasi-/all-solid-state supercapacitors have elicited scientific attention to fulfill the explosive demand for portable and wearable electronic devices. However, the use of electrode materials faces several challenges, such as intrinsically slow kinetics and volume change upon cycling, which impede the energy output and electrochemical stability. This study presents well-aligned molybdenum dioxide@nitrogen-doped carbon (MoO2@NC) and copper cobalt sulfide (CuCo2S4) tubular nanostructures grown on flexible carbon fiber for use as electrode materials in supercapacitors. Benefiting from the chemically stable interfaces, affluent active sites, and efficient 1D electron transport, the MoO2@NC and CuCo2S4 nanostructures integrated on conductive substrates deliver excellent electrochemical performance. A flexible quasi-solid-state asymmetric supercapacitor composed of MoO2@NC as the negative electrode and CuCo2S4 as the positive electrode achieves an ultrahigh energy density of 65.1 W h kg-1 at a power density of 800 W kg-1 and retains a favorable energy density of 27.6 W h kg-1 at an ultrahigh power density of 12.8 kW kg-1. Moreover, it demonstrates good cycling performance with 90.6% capacitance retention after 5000 cycles and excellent mechanical flexibility by enabling 92.2% capacitance retention after 2000 bending cycles. This study provides an effective strategy to develop electrode materials with superior electrochemical performance for flexible supercapacitors.

139 citations

Journal ArticleDOI
TL;DR: A novel Ir(III) complex was found to be highly selective for G- quadruplex DNA, and was employed in a label-free G-quadruplex-based detection assay for nicking endonuclease activity in aqueous solution.
Abstract: A series of luminescent Ir(III) complexes were synthesised and evaluated for their ability to act as G-quadruplex-selective probes. A novel Ir(III) complex was found to be highly selective for G-quadruplex DNA, and was employed in a label-free G-quadruplex-based detection assay for nicking endonuclease activity in aqueous solution. A proof-of-concept of this probe has been demonstrated by using Nb·BbvCI as a model enzyme. In this assay, a DNA substrate comprised of oligonucleotides ON1 (5′-GTG3TAG3CG3T2G2CTGAG2TGA-3′) and ON2 (5′-TCAC2TCAGC2A2C2-3′) initially exists in a duplex conformation, resulting in a low luminescence signal due to the weak interaction between the Ir(III) complex and duplex DNA. Upon cleavage by Nb·BbvCI, the guanine-rich sequence is released and folds into a G-quadruplex, which greatly enhances the luminescence of the Ir(III) probe. This method was highly sensitive for Nb·BbvCI over other DNA-modifying enzymes.

139 citations

Journal ArticleDOI
TL;DR: A novel luminescent G- quadruplex-selective iridium(iii) complex was employed in a label-free G-quadruplex -based detection assay for hepatitis C virus NS3 helicase activity.
Abstract: A series of luminescent Ir(III) complexes were synthesised and evaluated for their ability to act as luminescent G-quadruplex-selective probes. The Ir(III) complex 9, [Ir(phq)2(phen)]PF6 (where phq = 2-phenylquinoline; phen = 1,10-phenanthroline), exhibited high luminescence in the presence of G-quadruplex DNA compared to dsDNA and ssDNA, and was employed to construct a label-free G-quadruplex-based assay for hepatitis C virus NS3 helicase activity in aqueous solution. Moreover, the application of the assay for screening potential helicase inhibitors was demonstrated. To our knowledge, this is the first G-quadruplex-based assay for helicase activity.

139 citations

Journal ArticleDOI
TL;DR: The light absorption coefficient of methanol-soluble BrC at 365 nm was found to correlate strongly with both parent polycyclic aromatic hydrocarbons and their carbonyl oxygenated derivatives in all seasons, and fractional solar absorption by BrC relative to element carbon in the ultraviolet range is significant during winter.
Abstract: Light-absorbing organic carbon (i.e., brown carbon or BrC) in the atmospheric aerosol has significant contribution to light absorption and radiative forcing. However, the link between BrC optical properties and chemical composition remains poorly constrained. In this study, we combine spectrophotometric measurements and chemical analyses of BrC samples collected from July 2008 to June 2009 in urban Xi’an, Northwest China. Elevated BrC was observed in winter (5 times higher than in summer), largely due to increased emissions from wintertime domestic biomass burning. The light absorption coefficient of methanol-soluble BrC at 365 nm (on average approximately twice that of water-soluble BrC) was found to correlate strongly with both parent polycyclic aromatic hydrocarbons (parent-PAHs, 27 species) and their carbonyl oxygenated derivatives (carbonyl-OPAHs, 15 species) in all seasons (r2 > 0.61). These measured parent-PAHs and carbonyl-OPAHs account for on average ∼1.7% of the overall absorption of methanol-so...

139 citations

Journal ArticleDOI
Qingsong Xu1
TL;DR: The design and validation of a new robust impedance control for high-speed position and force regulation of a compliant gripper which is driven by a piezoelectric stack actuator is presented.
Abstract: High-speed simultaneous position and contact force control is vital for microgrippers dedicated to automated high-throughput microassembly tasks. This paper presents the design and validation of a new robust impedance control for high-speed position and force regulation of a compliant gripper which is driven by a piezoelectric stack actuator. Unlike traditional position/force switching control, the proposed scheme enables a smooth transition between the free and constrained motions of the gripper. A single controller is devised to regulate both the gripper tip position and the contact force, rendering a simplification in control design. The stability of the closed-loop system in the presence of piezoelectric nonlinearities is guaranteed by a digital sliding mode impedance control algorithm. Moreover, the proposed control scheme is applicable to high-order systems, and the control algorithm simplification enables a high-speed loop rate. The high-speed control is realized by deploying the algorithm to a field-programmable gate array controller. The effectiveness of the proposed scheme is verified through experimental studies on grasp–hold–release operation of a graphite microrod. The control scheme can be extended to other microassembly systems as well.

139 citations


Authors

Showing all 6766 results

NameH-indexPapersCitations
Henry T. Lynch13392586270
Chu-Xia Deng12544457000
H. Vincent Poor109211667723
Peng Chen10391843415
George F. Gao10279382219
MengChu Zhou96112436969
Gang Li9348668181
Rob Law8171431002
Zongjin Li8063022103
Han-Ming Shen8023727410
Heng Li7974523385
Lionel M. Ni7546628770
C. L. Philip Chen7448220223
Chun-Su Yuan7239721089
Joao P. Hespanha7241839004
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
202345
2022307
20212,579
20202,357
20192,075
20181,714