1. |
- Hawkes, Jeffrey A., et al.
(author)
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An international laboratory comparison of dissolved organic matter composition by high resolution mass spectrometry : Are we getting the same answer?
- 2020
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In: Limnology and Oceanography. - : Wiley. - 1541-5856. ; 18:6, s. 235-258
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Journal article (peer-reviewed)abstract
- High-resolution mass spectrometry (HRMS) has become a vital tool for dissolved organic matter (DOM) characterization. The upward trend in HRMS analysis of DOM presents challenges in data comparison and interpretation among laboratories operating instruments with differing performance and user operating conditions. It is therefore essential that the community establishes metric ranges and compositional trends for data comparison with reference samples so that data can be robustly compared among research groups. To this end, four identically prepared DOM samples were each measured by 16 laboratories, using 17 commercially purchased instruments, using positive-ion and negative-ion mode electrospray ionization (ESI) HRMS analyses. The instruments identified similar to 1000 common ions in both negative- and positive-ion modes over a wide range of m/z values and chemical space, as determined by van Krevelen diagrams. Calculated metrics of abundance-weighted average indices (H/C, O/C, aromaticity and m/z) of the commonly detected ions showed that hydrogen saturation and aromaticity were consistent for each reference sample across the instruments, while average mass and oxygenation were more affected by differences in instrument type and settings. In this paper we present 32 metric values for future benchmarking. The metric values were obtained for the four different parameters from four samples in two ionization modes and can be used in future work to evaluate the performance of HRMS instruments.
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2. |
- Artiglia, Luca, et al.
(author)
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A surface-stabilized ozonide triggers bromide oxidation at the aqueous solution-vapour interface
- 2017
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In: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 8
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Journal article (peer-reviewed)abstract
- Oxidation of bromide in aqueous environments initiates the formation of molecular halogen compounds, which is important for the global tropospheric ozone budget. In the aqueous bulk, oxidation of bromide by ozone involves a [Br center dot OOO-] complex as intermediate. Here we report liquid jet X-ray photoelectron spectroscopy measurements that provide direct experimental evidence for the ozonide and establish its propensity for the solution-vapour interface. Theoretical calculations support these findings, showing that water stabilizes the ozonide and lowers the energy of the transition state at neutral pH. Kinetic experiments confirm the dominance of the heterogeneous oxidation route established by this precursor at low, atmospherically relevant ozone concentrations. Taken together, our results provide a strong case of different reaction kinetics and mechanisms of reactions occurring at the aqueous phase-vapour interface compared with the bulk aqueous phase.
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3. |
- Chen, Shuzhen, et al.
(author)
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A revealed damage cost method to evaluate environmental performance of production : Evaluating treatment efficiency of emissions and scaling treatment cost bounds
- 2018
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In: Journal of Cleaner Production. - : Elsevier BV. - 0959-6526 .- 1879-1786. ; 194, s. 101-111
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Journal article (peer-reviewed)abstract
- Environmental performance indices are in great demand for environmental policy support. This paper addresses the particular problem of evaluating environmental performance of industries and identifying the worst performed industries that should be strictly regulated. Specifically, an input-output analysis method is developed to disentangle the environmental pressures of production processes; treatment costs are introduced to reveal the damage costs of relevant pressures which is integrated in the DEA based index to restrict the weight assignment. The proposed method is advantageous in data requirements as well as definition of process boundaries and can alleviate the underestimation of damages from predominant pressures. The results of evaluation provide a more reliable reference to industrial regulation.
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4. |
- Chen, Shuzhen, et al.
(author)
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Adapting ecological risk valuation for natural resource damage assessment in water pollution
- 2018
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In: Environmental Research. - : Elsevier BV. - 0013-9351 .- 1096-0953. ; 164, s. 85-92
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Journal article (peer-reviewed)abstract
- Ecological risk assessment can address requirements of natural resource damage assessment by quantifying the magnitude of possible damages to the ecosystem. This paper investigates an approach to assess water damages from pollution incident on the basis of concentrations of contaminants. The baseline of water pollution is determined with not-to-exceed concentration of contaminants required by water quality standards. The values of damage cost to water quality are estimated through sewage treatment cost. To get a reliable estimate of treatment cost, DEA is employed to classify samples of sewage plants based on their efficiency of sewage treatment. And exponential fitting is adopted to determine the relation between treatment cost and the decrease of COCs. The range of damage costs is determined through the fitting curves respectively based on efficient and inefficient samples.
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5. |
- Chen, Shuzhen, et al.
(author)
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Connectivity, Netting, and Systemic Risk of Payment Systems
- 2019
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In: IEEE Systems Journal. - 1932-8184 .- 1937-9234. ; 13:2, s. 1658-1668
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Journal article (peer-reviewed)abstract
- The stability of payment system is of vital importance to the credit market as well as the economic development. Most researches focus on the effect of system connectivity on systemic risk and demonstrate that connectivity provides both risk-spread channel and risk-sharing mechanism. But the management of systemic risk is quite different in real-time gross settlement system and net settlement system. We provide an integrated analysis of the effect of connectivity and netting on systemic risk in payment systems by considering more detailed network structures of pure creditors and pure debtors. We show that the effect of netting is partly due to the change of network connectivity, which severs the contagion channel of shocks. Moreover, netting can lower the actual magnitude of the shock from the beginning by reducing source bank's debt.
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6. |
- Chen, Shuzhen, et al.
(author)
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In-house versus outsourcing collection in a closed-loop supply chain with remanufacturing technology development
- 2023
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In: International Journal of Production Research. - : Informa UK Limited. - 0020-7543 .- 1366-588X. ; 61:6, s. 1720-1735
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Journal article (peer-reviewed)abstract
- This paper develops a game model of a closed-loop supply chain consisting of one manufacturer, one remanufacturer and one retailer and investigates the long-term collection strategies of the manufacturer who needs to cooperate with the remanufacturer to develop the remanufacturing technology. The game model is developed from a fully dynamic perspective on the remanufacturing technology development and analyzed using the system dynamics method. We identify the trade-off in the choice of collection strategies: the early entry in the remanufacturing industry versus the complete control in the later stage. The simulation results show that when the entry barrier to the remanufacturing industry is low, the manufacturer can develop the remanufacturing technology in a short time and the direct reverse channel outperforms the indirect reverse channel; when the entry barrier is high, the manufacturer can achieve more profits under the indirect reverse channel by acquiring the remanufacturing technology directly from the remanufacturer. Moreover, the indirect reverse channel is more likely to be superior for low-barrier remanufacturing industry when the cost advantage is high as the early entry in the remanufacturing industry becomes more important than the complete control in the later stage.
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7. |
- Huang, Shoushuang, et al.
(author)
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Enhancing electroreduction activity and selectivity of N2-to-NH3 through proton-feeding adjustments in Ag@AgP2@Ni-CoP@C core-shell nanowires
- 2023
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In: Applied Catalysis B. - : ELSEVIER. - 0926-3373 .- 1873-3883. ; 337
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Journal article (peer-reviewed)abstract
- The synthesis of NH3 via electrochemical N2 fixation at ambient conditions has been proposed as a promising alternative to the traditional Haber-Bosch process. However, the development of highly efficient and selective electrocatalysts remains a challenge. In this study, uniform Ag@AgP2 @Ni-CoP@C core-shell nanowires were synthesized using a template-engaged strategy. The merging of conductive Ag core with active AgP2 and porous carbon-coated Ni-doped CoP shells favors the mass and electron transfers, effectively lowering the activation energy toward the reduction of N2 to NH3. Density functional theory (DFT) calculations further indicates that the sandwiched AgP2 layer plays crucial roles in promoting electrocatalytic kinetics and suppressing the competitive hydrogen evolution reactions. Benefiting from these advantages, the titled catalyst achieved a high NH3 yield of 16.84 & mu;g h-1 mg-1 cat. at-0.4 V (vs. reversible hydrogen electrode, RHE) and a high Faradaic efficiency of 21.7 % at-0.3 V vs. RHE, as well as high electrochemical and structure stability.
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8. |
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9. |
- Liang, Liang, et al.
(author)
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A Decision Support Approach to Liquidate a Distressed Debt Network
- 2020
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In: IEEE Transactions on Systems, Man & Cybernetics. Systems. - 2168-2216 .- 2168-2232. ; 50:4, s. 1242-1251
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Journal article (peer-reviewed)abstract
- This paper investigates the debt clearing problem in a debt network with complicated debt relations among various debtors. Each pair of debt relations is modeled with both forward debt chain and backward debt chain to simplify the whole debt network with a developed algorithm. A debt clearing strategy is derived and its benefits and managerial implications are shown in risk management. This paper further demonstrates the validation of the approach for sovereign debt analysis and risk analytics using real debt data from ten developed countries.
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10. |
- Wu, Desheng, et al.
(author)
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Benchmarking Discount Rate in Natural Resource Damage Assessment with Risk Aversion
- 2017
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In: Risk Analysis. - : Wiley. - 0272-4332 .- 1539-6924. ; 37:8, s. 1522-1531
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Journal article (peer-reviewed)abstract
- Benchmarking a credible discount rate is of crucial importance in natural resource damage assessment (NRDA) and restoration evaluation. This article integrates a holistic framework of NRDA with prevailing low discount rate theory, and proposes a discount rate benchmarking decision support system based on service-specific risk aversion. The proposed approach has the flexibility of choosing appropriate discount rates for gauging long-term services, as opposed to decisions based simply on duration. It improves injury identification in NRDA since potential damages and side-effects to ecosystem services are revealed within the service-specific framework. A real embankment case study demonstrates valid implementation of the method.
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