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| 2. |
- Miao, Ruijiao, et al.
(författare)
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Influence of Quantum Interference on the Thermoelectric Properties of Molecular Junctions
- 2018
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Ingår i: Nano Letters. - : American Chemical Society (ACS). - 1530-6984 .- 1530-6992. ; 18:9, s. 5666-5672
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Tidskriftsartikel (refereegranskat)abstract
- Molecular junctions offer unique opportunities for controlling charge transport on the atomic scale and for studying energy conversion. For example, quantum interference effects in molecular junctions have been proposed as an avenue for highly efficient thermoelectric power conversion at room temperature. Toward this goal, we investigated the effect of quantum interference on the thermoelectric properties of molecular junctions. Specifically, we employed oligo(phenylene ethynylene) (OPE) derivatives with a para-connected central phenyl ring (para-OPE3) and meta-connected central ring (meta-OPE3), which both covalently bind to gold via sulfur anchoring atoms located at their ends. In agreement with predictions from ab initio modeling, our experiments on both single molecules and monolayers show that meta-OPE3 junctions, which are expected to exhibit destructive interference effects, yield a higher thermopower (with ∼20 μV/K) compared with para-OPE3 (with ∼10 μV/K). Our results show that quantum interference effects can indeed be employed to enhance the thermoelectric properties of molecular junctions.
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| 3. |
- Mustafa, M., et al.
(författare)
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Diverse collective excitations in Er-159 up to high spin
- 2011
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Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 84:5
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Tidskriftsartikel (refereegranskat)abstract
- A spectroscopic investigation of the gamma decays from excited states in Er-159 has been performed to study the changing structural properties exhibited as ultrahigh spins (I > 60 (h) over bar) are approached. The nucleus of Er-159 was populated by the reaction Cd-116(Ca-48, 5n gamma) at a beam energy of 215 MeV, and the resulting gamma decays were studied using the Gammasphere spectrometer. New rotational bands and extensions to existing sequences were observed, which are discussed in terms of the cranked shell model, revealing a diverse range of quasiparticle configurations. At spins around 50 (h) over bar, there is evidence for a change from dominant prolate collective motion at the yrast line to oblate non-collective structures via the mechanism of band termination. A possible strongly deformed triaxial band occurs at these high spins, which indicates collectivity beyond 50 (h) over bar. The high-spin data are interpreted within the framework of cranked Nilsson-Strutinsky calculations.
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| 4. |
- Wang, Kui, et al.
(författare)
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Efficient electro-demulsification of O/W emulsions and simultaneous oil removal enabled by a multiscale porous biocarbon electrode
- 2024
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Ingår i: Chemical Engineering Journal. - : Elsevier BV. - 1385-8947 .- 1873-3212. ; 481
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Tidskriftsartikel (refereegranskat)abstract
- Emulsion wastewater contain substantial amounts of oil and various additives, which pose threats to the environment and human health. Demulsification is a crucial pretreatment stage for wastewater. This study aims to identify a novel electro-demulsification method with high oil removal efficiency and low energy consumption. Modified carbonized birch wood with a unique isotropic multiscale pore structure is used as a self-standing electrode to treat a toluene oil-in-water (O/W) emulsion. The electrode must have a highly porous structure to facilitate efficient water diffusion and oil adsorption. It must also have high electronic conductivity to expedite polarized molecular electrophoresis to realize penetration into the pores and, subsequently, demulsification. Guided by an applied electric field force, polarized O/W droplets are drawn toward the electrode, revealing electrical characteristics distinct from those of polarized organic molecules. This electric field force augments the capture and adhesion of droplets by the electric double layer at the electrode interface. Consequently, adsorbed droplets in close proximity to the electrode rupture due to the combined influence of the electric field force and the electrostatic effects stemming from the electrode's multiscale porous structure. This synergistic action enables demulsification to occur efficiently at low energy consumption levels. This study has revealed that electro-demulsification can effectively treat toluene emulsions stabilized by various surfactants and microemulsion containing toluene. Therefore, this electro-demulsification technology can be further developed for various types of water pollution.
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| 5. |
- Wang, Ruoxu, et al.
(författare)
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Demonstration of Programmable In-Band OSNR Monitoring Using LCFBG With Commercial Thermal Printer Head
- 2015
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Ingår i: IEEE PHOTONICS JOURNAL. - : Institute of Electrical and Electronics Engineers (IEEE). - 1943-0655. ; 7:4
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Tidskriftsartikel (refereegranskat)abstract
- We proposed and experimentally demonstrated a programmable optical signal-to-noise ratio (OSNR) monitoring scheme by using linearly chirped fiber Bragg grating (LCFBG) and a commercial thermal printer head. For the coherent optical orthogonal frequency-division multiplexing (CO-OFDM) transmission system, the monitor's working wavelength can be flexibly software-controlled from 1530 to 1538 nm to support standard ITU-T grid or flex-grid operation. The linear OSNR monitoring range has been achieved from 9 to 26 dB for a 16-quadrature amplitude modulation (QAM) OFDM transmission system with negligible errors, respectively. Neither chromatic dispersion nor polarization mode dispersion affect the monitoring accuracy of our system.
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| 6. |
- Wang, Yazhou, et al.
(författare)
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Hybrid Alkyl-Ethylene Glycol Side Chains Enhance Substrate Adhesion and Operational Stability in Accumulation Mode Organic Electrochemical Transistors
- 2019
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Ingår i: Chemistry of Materials. - : AMER CHEMICAL SOC. - 0897-4756 .- 1520-5002. ; 31:23, s. 9797-9806
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Tidskriftsartikel (refereegranskat)abstract
- Donor-acceptor copolymers featuring electron-deficient isoindigo units and electron-rich 3,4-ethyl-E enedioxy (EDOT) groups are presented as new materials for accumulation mode organic electrochemical transistors (OECTs). Grafting hybrid alkyl-ethylene glycol side chains on the isoindigo units of the copolymer leads to OECTs with outstanding substrate adhesion and operational stability in contact with an aqueous electrolyte, as demonstrated by their preserved performance after extensive ultrasonication (1.5 h) or after continuous on-off switching for over 6 h. Hybrid side chains outperform copolymers with alkyl only or ethylene glycol only side chains, which retain only 27% and 10% of the on currents after 40 min of on-off switching, respectively, under the same biasing conditions. These devices are promising candidates for in vitro and in vivo bioelectronics, applications where stability as well as robust adhesion of the conjugated polymer to the substrate are essential.
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| 7. |
- Zhou, Wei, et al.
(författare)
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Global Biobank Meta-analysis Initiative : Powering genetic discovery across human disease
- 2022
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Ingår i: Cell Genomics. - : Elsevier. - 2666-979X. ; 2:10
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Tidskriftsartikel (refereegranskat)abstract
- Biobanks facilitate genome-wide association studies (GWASs), which have mapped genomic loci across a range of human diseases and traits. However, most biobanks are primarily composed of individuals of European ancestry. We introduce the Global Biobank Meta-analysis Initiative (GBMI)-a collaborative network of 23 biobanks from 4 continents representing more than 2.2 million consented individuals with genetic data linked to electronic health records. GBMI meta-analyzes summary statistics from GWASs generated using harmonized genotypes and phenotypes from member biobanks for 14 exemplar diseases and endpoints. This strategy validates that GWASs conducted in diverse biobanks can be integrated despite heterogeneity in case definitions, recruitment strategies, and baseline characteristics. This collaborative effort improves GWAS power for diseases, benefits understudied diseases, and improves risk prediction while also enabling the nomination of disease genes and drug candidates by incorporating gene and protein expression data and providing insight into the underlying biology of human diseases and traits.
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| 8. |
- Zhou, Yu, et al.
(författare)
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Revealing the Contribution of Individual Factors to Hydrogen Evolution Reaction Catalytic Activity
- 2018
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Ingår i: Advanced Materials. - : Wiley-VCH Verlagsgesellschaft. - 0935-9648 .- 1521-4095. ; 30:18
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Tidskriftsartikel (refereegranskat)abstract
- For the electrochemical hydrogen evolution reaction (HER), the electrical properties of catalysts can play an important role in influencing the overall catalytic activity. This is particularly important for semiconducting HER catalysts such as MoS2, which has been extensively studied over the last decade. Herein, on-chip microreactors on two model catalysts, semiconducting MoS2 and semimetallic WTe2, are employed to extract the effects of individual factors and study their relations with the HER catalytic activity. It is shown that electron injection at the catalyst/current collector interface and intralayer and interlayer charge transport within the catalyst can be more important than thermodynamic energy considerations. For WTe2, the site-dependent activities and the relations of the pure thermodynamics to the overall activity are measured and established, as the microreactors allow precise measurements of the type and area of the catalytic sites. The approach presents opportunities to study electrochemical reactions systematically to help establish rational design principles for future electrocatalysts.
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| 9. |
- Zhou, Yu, et al.
(författare)
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Unveiling the Interfacial Effects for Enhanced Hydrogen Evolution Reaction on MoS2/WTe2 Hybrid Structures
- 2019
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Ingår i: Small. - : Wiley-VCH Verlagsgesellschaft. - 1613-6810 .- 1613-6829. ; 15:19
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Tidskriftsartikel (refereegranskat)abstract
- Using the MoS2-WTe2 heterostructure as a model system combined with electrochemical microreactors and density function theory calculations, it is shown that heterostructured contacts enhance the hydrogen evolution reaction (HER) activity of monolayer MoS2. Two possible mechanisms are suggested to explain this enhancement: efficient charge injection through large-area heterojunctions between MoS2 and WTe2 and effective screening of mirror charges due to the semimetallic nature of WTe2. The dielectric screening effect is proven minor, probed by measuring the HER activity of monolayer MoS2 on various support substrates with dielectric constants ranging from 4 to 300. Thus, the enhanced HER is attributed to the increased charge injection into MoS2 through large-area heterojunctions. Based on this understanding, a MoS2/WTe2 hybrid catalyst is fabricated with an HER overpotential of -140 mV at 10 mA cm(-2), a Tafel slope of 40 mV dec(-1), and long stability. These results demonstrate the importance of interfacial design in transition metal dichalcogenide HER catalysts. The microreactor platform presents an unambiguous approach to probe interfacial effects in various electrocatalytic reactions.
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