| 1. |
- Wu, Keming, et al.
(author)
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Surface Reconstruction on Uniform Cu Nanodisks Boosted Electrochemical Nitrate Reduction to Ammonia
- 2022
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In: ACS Materials Letters. - : American Chemical Society (ACS). - 2639-4979. ; 4, s. 650-656
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Journal article (peer-reviewed)abstract
- The Haber-Bosch (HB) process has provided most of commercial ammonia at the expense of high energy consumption and high CO2 emission. Nitrate electroreduction is showing great potential as an alternative route for the green and scale-up synthesis of ammonia at ambient conditions. However, the performance has lagged due to lack of efficient electrocatalysts. In this work, we present the facile synthesis of uniform Cu nanodisks with exposed (111) facets as highly active electrocatalyst for electrochemical ammonia synthesis, delivering a high ammonia yield of 2.16 mg mg-1cat h-1 and a maximum Faradaic efficiency of 81.1% at -0.5 V versus a reversible hydrogen electrode (RHE). The remarkable activity is originated from the surface reconstructed triatomic Cu clusters due to the cathodic deoxygenation process. As a result, the reconstructed surface shows enhanced affinity to the adsorption of nitrate ions which undergo successive break of three N-O bonds, followed by subsequent formation of three N-H bonds to finally form NH3. The present study provides the feasible preparation of Cu based advanced catalysts and a unique insight into the mechanism of nitrate electroreduction.
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| 2. |
- Andreoni, Igor, et al.
(author)
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GROWTH on S190510g : DECam Observation Planning and Follow-up of a Distant Binary Neutron Star Merger Candidate
- 2019
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In: Astrophysical Journal Letters. - : American Astronomical Society. - 2041-8205 .- 2041-8213. ; 881:1
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Journal article (peer-reviewed)abstract
- The first two months of the third Advanced LIGO and Virgo observing run (2019 April-May) showed that distant gravitational-wave (GW) events can now be readily detected. Three candidate mergers containing neutron stars (NS) were reported in a span of 15 days, all likely located more than 100 Mpc away. However, distant events such as the three new NS mergers are likely to be coarsely localized, which highlights the importance of facilities and scheduling systems that enable deep observations over hundreds to thousands of square degrees to detect the electromagnetic counterparts. On 2019 May 10 02: 59:39.292 UT the GW candidate S190510g was discovered and initially classified as a binary neutron star (BNS) merger with 98% probability. The GW event was localized within an area of 3462 deg(2), later refined to 1166 deg(2) (90%) at a distance of 227 +/- 92 Mpc. We triggered Target-of-Opportunity observations with the Dark Energy Camera (DECam), a wide-field optical imager mounted at the prime focus of the 4 m Blanco Telescope at Cerro Tololo Inter-American Observatory in Chile. This Letter describes our DECam observations and our real-time analysis results, focusing in particular on the design and implementation of the observing strategy. Within 24 hr of the merger time, we observed 65% of the total enclosed probability of the final skymap with an observing efficiency of 94%. We identified and publicly announced 13 candidate counterparts. S190510g was reclassified 1.7 days after the merger, after our observations were completed, with a BNS merger probability reduced from 98% to 42% in favor of a terrestrial classification.
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| 3. |
- Andreoni, Igor, et al.
(author)
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GROWTH on S190814bv : Deep Synoptic Limits on the Optical/Near-infrared Counterpart to a Neutron Star-Black Hole Merger
- 2020
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In: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 890:2
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Journal article (peer-reviewed)abstract
- On 2019 August 14, the Advanced LIGO and Virgo interferometers detected the high-significance gravitational wave (GW) signal S190814bv. The GW data indicated that the event resulted from a neutron star-black hole (NSBH) merger, or potentially a low-mass binary BH merger. Due to the low false-alarm rate and the precise localization (23 deg(2) at 90%), S190814bv presented the community with the best opportunity yet to directly observe an optical/near-infrared counterpart to an NSBH merger. To search for potential counterparts, the GROWTH Collaboration performed real-time image subtraction on six nights of public Dark Energy Camera images acquired in the 3 weeks following the merger, covering >98% of the localization probability. Using a worldwide network of follow-up facilities, we systematically undertook spectroscopy and imaging of optical counterpart candidates. Combining these data with a photometric redshift catalog, we ruled out each candidate as the counterpart to S190814bv and placed deep, uniform limits on the optical emission associated with S190814bv. For the nearest consistent GW distance, radiative transfer simulations of NSBH mergers constrain the ejecta mass of S190814bv to be M-ej < 0.04 M-circle dot at polar viewing angles, or M-ej < 0.03 M-circle dot if the opacity is kappa < 2 cm(2)g(-1). Assuming a tidal deformability for the NS at the high end of the range compatible with GW170817 results, our limits would constrain the BH spin component aligned with the orbital momentum to be chi < 0.7 for mass ratios Q < 6, with weaker constraints for more compact NSs.
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| 4. |
- Wang, Yong, et al.
(author)
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Research on Pharmaceutical Supply Chain Decision-Making Model Considering Output and Demand Fluctuations
- 2024
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In: IEEE Access. - : Institute of Electrical and Electronics Engineers (IEEE). - 2169-3536. ; 12, s. 61629-61641
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Journal article (peer-reviewed)abstract
- In response to the evolving pharmaceutical supply chain market, which is shifting from a seller's to a buyer's market, this study introduces an innovative decision-making model that addresses the volatility in output and demand. Our primary innovation lies in the development of a "revenue-sharing plus margin" collaborative decision-making optimization model, designed to enhance supply chain coordination amidst uncertainty. By establishing a revenue function, we propose a coordinated approach that leverages both revenue-sharing coefficients and profit margins to achieve Pareto improvements for supply chain partners. Through numerical analysis, we identify an optimal value range for the model's parameters, demonstrating the model's efficacy in balancing the expected returns for both suppliers and retailers. The study's contributions are threefold: (1) the introduction of a novel decision-making model tailored to the pharmaceutical supply chain, (2) the provision of a clear framework for comparing collaborative versus decentralized decision-making outcomes, and (3) the empirical validation of the model through case studies, showcasing its superiority in overall supply chain efficiency. This research significantly extends the current literature by providing a nuanced understanding of how supply chain coordination can be optimized under conditions of uncertainty. The findings underscore the importance of collaborative decision-making in achieving supply chain stability and offer practical insights for supply chain management in the pharmaceutical industry.
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