| 21. |
- Meng, Pingping, et al.
(författare)
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Role of the air-water interface in removing perfluoroalkyl acids from drinking water by activated carbon treatment
- 2020
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Ingår i: Journal of Hazardous Materials. - : Elsevier BV. - 0304-3894 .- 1873-3336. ; 386
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Tidskriftsartikel (refereegranskat)abstract
- Contamination of drinking water by per- and polyfluoroalkyl substances (PFASs) is a worldwide problem. In this study, we for the first time revealed the role of the air-water interface in enhancing the removal of long-chain perfluoroalkyl carboxylic (PFCAs; CnF2n+1COOH, n >= 7) and perfluoroalkane sulfonic (PFSAs; CnF2n+1SO3H, n >= 6) acids, collectively termed as perfluoroalkyl acids (PFAAs), through combined aeration and adsorption on two kinds of activated carbon (AC). Aeration was shown to enhance the removal of long-chain PFAAs through adsorption at the air-water interface and subsequent adsorption of PFAA-enriched air bubbles to the AC. The removal of selected long-chain PFAAs was increased by 50-115 % with the assistance of aeration, depending on the perfluoroalkyl chain length. Aeration is more effective in enhancing long-chain PFAA removal as air-water interface adsorption increases with PFAA chain length due to higher surface activity. After removing adsorbed air bubbles by centrifugation, up to 80 % of the long-chain PFAAs were able to desorb from the sorbent, confirming the contribution of the air-water interface to the adsorption of PFAAs on AC. Aeration during AC treatment of water could enhance the removal of long-chain PFAAs, and improve the performance of AC during water treatment.
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| 22. |
- Qu, Gang, et al.
(författare)
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Enhancing the Performance of the p-n Heterostructure Electrolyte for Solid Oxide Fuel Cells via A-Site-Deficiency Engineering
- 2023
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 15:42, s. 49154-49169
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Tidskriftsartikel (refereegranskat)abstract
- Semiconductor ionic electrolytes are attracting growing interest for developing low-temperature solid oxide fuel cells (LT-SOFCs). Our recent study has proposed a p-n heterostructure electrolyte based on perovskite oxide BaCo0.4Fe0.4Zr0.1Y0.1O3-δ (BCFZY) and ZnO, achieving promising fuel cell performance. Herein, to further improve the performance of the heterostructure electrolyte, an A-site-deficiency strategy is used to solely modify BCFZY for regulating the ionic conduction and catalytic activity of the heterostructure. Two new electrolytes, B0.9CFZY-ZnO and B0.8CFZY-ZnO, were developed and systematically studied. The results show that the two samples gain improved ionic conductivity and auxiliary catalytic activity after A-site deficiency as a result of the increment of the surface and interface oxygen vacancies. The single cells with B0.9CFZY-ZnO and B0.8CFZY-ZnO exhibit enhanced peak power outputs at 450-550 °C compared to the cell based on B1.0CFZY-ZnO (typically, 745 and 795 vs 542 mW cm-2 at 550 °C). Particular attention is paid to the impact of A-site deficiency on the interface energy band alignment between BxCFZY and ZnO, which suggests that the p-n heterojunction effect of BxCFZY-ZnO for charge carrier regulation can be tuned by A-site deficiency to enable high proton transport while avoiding fuel cell current leakage. This study thus confirms the feasibility of A-site-deficiency engineering to optimize the performance of the heterostructure electrolyte for developing LT-SOFCs.
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| 23. |
- Riera-Galindo, Sergi, et al.
(författare)
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Impact of Singly Occupied Molecular Orbital Energy on the n-Doping Efficiency of Benzimidazole Derivatives
- 2019
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Ingår i: ACS Applied Materials and Interfaces. - : AMER CHEMICAL SOC. - 1944-8244 .- 1944-8252. ; 11:41, s. 37981-37990
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Tidskriftsartikel (refereegranskat)abstract
- We investigated the impact of singly occupied molecular orbital (SOMO) energy on the n-doping efficiency of benzimidazole derivatives. By designing and synthesizing a series of new air-stable benzimidazole-based dopants with different SOMO energy levels, we demonstrated that an increase of the dopant SOMO energy by only similar to 0.3 eV enhances the electrical conductivity of a benchmark electron-transporting naphthalenediimide-bithiophene polymer by more than 1 order of magnitude. By combining electrical, X-ray diffraction, and electron paramagnetic resonance measurements with density functional theory calculations and analytical transport simulations, we quantitatively characterized the conductivity, Seebeck coefficient, spin density, and crystallinity of the doped polymer as a function of the dopant SOMO energy. Our findings strongly indicate that charge and energy transport are dominated by the (relative) position of the SOMO level, whereas morphological differences appear to play a lesser role. These results set molecular-design guidelines for next-generation n-type dopants.
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| 24. |
- Shao, Mingjiao, et al.
(författare)
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High-Performance Biodegradable Energy Storage Devices Enabled by Heterostructured MoO3-MoS2 Composites
- 2023
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Ingår i: Small. - : Wiley-VCH Verlagsgesellschaft. - 1613-6810 .- 1613-6829. ; 19:10
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Tidskriftsartikel (refereegranskat)abstract
- Biodegradable implantable devices are of growing interest in biosensors and bioelectronics. One of the key unresolved challenges is the availability of power supply. To enable biodegradable energy-storage devices, herein, 2D heterostructured MoO3–MoS2 nanosheet arrays are synthesized on water-soluble Mo foil, showing a high areal capacitance of 164.38 mF cm−2 (at 0.5 mA cm−2). Employing the MoO3–MoS2 composite as electrodes of a symmetric supercapacitor, an asymmetric Zn-ion hybrid supercapacitor, and an Mg primary battery are demonstrated. Benefiting from the advantages of MoO3–MoS2 heterostructure, the Zn-ion hybrid supercapacitors deliver a high areal capacitance (181.86 mF cm−2 at 0.5 mA cm−2) and energy density (30.56 µWh cm−2), and the Mg primary batteries provide a stable high output voltage (≈1.6 V) and a long working life in air/liquid environment. All of the used materials exhibit desirable biocompatibility, and these fabricated devices are also fully biodegradable. Demonstration experiments display their potential applications as biodegradable power sources for various electronic devices.
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| 25. |
- Shen, Qian, et al.
(författare)
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The Genome of Artemisia annua Provides Insight into the Evolution of Asteraceae Family and Artemisinin Biosynthesis
- 2018
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Ingår i: Molecular Plant. - : Cell Press. - 1674-2052 .- 1752-9867. ; 11:6, s. 776-788
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Tidskriftsartikel (refereegranskat)abstract
- Artemisia annua, commonly known as sweet wormwood or Qinghao, is a shrub native to China and has long been used for medicinal purposes. A. annua is now cultivated globally as the only natural source of a potent anti-malarial compound, artemisinin. Here, we report a high-quality draft assembly of the 1.74-gigabase genome of A. annua, which is highly heterozygous, rich in repetitive sequences, and contains 63 226 protein-coding genes, one of the largest numbers among the sequenced plant species. We found that, as one of a few sequenced genomes in the Asteraceae, the A. annua genome contains a large number of genes specific to this large angiosperm clade. Notably, the expansion and functional diversification of genes encoding enzymes involved in terpene biosynthesis are consistent with the evolution of the artemisinin biosynthetic pathway. We further revealed by transcriptome profiling that A. annua has evolved the sophisticated transcriptional regulatory networks underlying artemisinin biosynthesis. Based on comprehensive genomic and transcriptomic analyses we generated transgenic A. annua lines producing high levels of artemisinin, which are now ready for large-scale production and thereby will help meet the challenge of increasing global demand of artemisinin.
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| 26. |
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| 27. |
- Sidén, Johan, 1975-, et al.
(författare)
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Design of High-Directivity Wideband Microstrip Directional Coupler With Fragment-Type Structure
- 2015
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Ingår i: IEEE transactions on microwave theory and techniques. - 0018-9480 .- 1557-9670. ; 63:12, s. 3962-3970
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Tidskriftsartikel (refereegranskat)abstract
- A novel design for a microstrip wideband directional coupler is proposedby using fragment-type structures. The use of a fragment-type structuremay provide satisfactory flexibility and excellent performance. For agiven design space, a fragment-type wideband coupler can be designed byfirst gridding the space into fragment cells and then metallizing thefragment cells selected by a multi-objective optimization searchingalgorithm, such as a multi-objective evolutionary algorithm based ondecomposition combined with enhanced genetic operators. Fordemonstration, a 20-dB wideband microstrip directional coupler isdesigned and verified by test. A 45% bandwidth centered at 2 GHz hasbeen measured in terms of maximum variation of 0.5 dB in the 20-dBcoupling level. In the operation band, the designed coupler hasdirectivity above 37 dB, and a maximum directivity of 48 dB at 2 GHz. Inaddition, some technique aspects related to multi-objective optimizationsearching, such as effects of design space, control of coupling level,and efficiency consideration for optimization searching, are furtherdiscussed. Fragment-type structures may also be used to designhigh-performance wideband directional couplers of tight coupling level.
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| 28. |
- Wang, Bin, et al.
(författare)
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A primary estimate of global PCDD/F release based on the quantity and quality of national economic and social activities
- 2016
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Ingår i: Chemosphere. - Oxford, United Kingdom : Elsevier. - 0045-6535 .- 1879-1298. ; 151, s. 303-309
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Tidskriftsartikel (refereegranskat)abstract
- The correlations between polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) releases and factors relevant to human social-economic activities (HSEAs) were analyzed. The multiple linear regression model was successfully developed to estimate the total global PCDD/F release. The PCDD/F releases significantly correlated with population, area, GDP and GNI, suggesting that "quantity" of HSEAs have significantly contributed to the PCDD/F releases. On another aspect, advanced technologies are usually adopted in developed countries/regions, and hence reduce the PCDD/F release. The significant correlation between PCDD/F release and CO2 emission implies the potential of simultaneous reduction of CO2 emission and PCDD/F release. The total global PCDD/F release from 196 countries/regions was estimated to be 100.4 kg-TEQ yr(-1). The estimated annual PCDD/F release per unit area ranged from 0.007 to 28 mg-TEQ km(-2). Asia is estimated to have the highest PCDD/F release of 47.1 kg-TEQ yr(-1), almost half of the total world release. Oceania is estimated to have the smallest total release but the largest per-capita release. For the developed areas, such as Europe and North America, the PCDD/F release per unit GDP is lower, while for Africa, it is much higher.
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| 29. |
- Wang, Gang, et al.
(författare)
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Aggregation control in natural brush-printed conjugated polymer films and implications for enhancing charge transport
- 2017
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : NATL ACAD SCIENCES. - 0027-8424 .- 1091-6490. ; 114:47, s. E10066-E10073
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Tidskriftsartikel (refereegranskat)abstract
- Shear-printing is a promising processing technique in organic electronics for microstructure/charge transport modification and large-area film fabrication. Nevertheless, the mechanism by which shear-printing can enhance charge transport is not well-understood. In this study, a printing method using natural brushes is adopted as an informative tool to realize direct aggregation control of conjugated polymers and to investigate the interplay between printing parameters, macromolecule backbone alignment and aggregation, and charge transport anisotropy in a conjugated polymer series differing in architecture and electronic structure. This series includes (i) semicrystalline hole-transporting P3HT, (ii) semicrystalline electron transporting N2200, (iii) low-crystallinity hole-transporting PBDTT-FTTE, and (iv) low-crystallinity conducting PEDOT:PSS. The (semi-)conducting films are characterized by a battery of morphology and microstructure analysis techniques and by charge transport measurements. We report that remarkably enhanced mobilities/conductivities, as high as 5.7x/3.9x, are achieved by controlled growth of nanofibril aggregates and by backbone alignment, with the adjusted R-2 (R-adj(2)) correlation between aggregation and charge transport as high as 95%. However, while shear-induced aggregation is important for enhancing charge transport, backbone alignment alone does not guarantee charge transport anisotropy. The correlations between efficient charge transport and aggregation are clearly shown, while mobility and degree of orientation are not always well-correlated. These observations provide insights into macroscopic charge transport mechanisms in conjugated polymers and suggest guidelines for optimization.
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| 30. |
- Wang, Gang, et al.
(författare)
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Mixed-flow design for microfluidic printing of two-component polymer semiconductor systems
- 2020
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : NATL ACAD SCIENCES. - 0027-8424 .- 1091-6490. ; 117:30, s. 17551-17557
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Tidskriftsartikel (refereegranskat)abstract
- The rational creation of two-component conjugated polymer sys-tems with high levels of phase purity in each component is challenging but crucial for realizing printed soft-matter electronics. Here, we report a mixed-flow microfluidic printing (MFMP) approach for two-component pi-polymer systems that significantly elevates phase purity in bulk-heterojunction solar cells and thin-film transistors. MFMP integrates laminar and extensional flows using a specially microstructured shear blade, designed with fluid flow simulation tools to tune the flow patterns and induce shear, stretch, and pushout effects. This optimizes polymer conformation and semi-conducting blend order as assessed by atomic force microscopy (AFM), transmission electron microscopy (TEM), grazing incidence wide-angle X-ray scattering (GIWAXS), resonant soft X-ray scattering (R-SoXS), photovoltaic response, and field effect mobility. For printed all-polymer (poly[(5,6-difluoro-2-octyl-2H-benzotriazole-4,7-diyl)-2,5-thiophenediyl[4,8-bis[5-(2-hexyldecyl)-2-thienyl]benzo[1,2-b:4,5-b ]dithiophene-2,6-diyl]-2,5-thiophenediyl]) [J51]:(poly{[N,N -bis(2-octyldodecyl) naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5 -(2,2 -bithio-phene)}) [N2200]) solar cells, this approach enhances short-circuit currents and fill factors, with power conversion efficiency increasing from 5.20% for conventional blade coating to 7.80% for MFMP. Moreover, the performance of mixed polymer ambipolar [poly(3-hexylthiophene-2,5-diyl) (P3HT):N2200] and semiconducting:insulat-ing polymer unipolar (N2200:polystyrene) transistors is similarly enhanced, underscoring versatility for two-component pi-polymer systems. Mixed-flow designs offer modalities for achieving high-performance organic optoelectronics via innovative printing methodologies.
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