| 1. |
- Cheng, Ming, et al.
(författare)
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Efficient dye-sensitized solar cells based on an iodine-free electrolyte using L-cysteine/L-cystine as a redox couple
- 2012
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Ingår i: Energy & Environmental Science. - : Royal Society of Chemistry (RSC). - 1754-5692 .- 1754-5706. ; 5:4, s. 6290-6293
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Tidskriftsartikel (refereegranskat)abstract
- A new iodine-free electrolyte based on amino acids L-cysteine/L-cystine as a redox couple has been designed and synthesized. DSSCs fabricated with the conventional I-/I-3(-) redox couple gave efficiencies of 8.1% and 6.3% under optimized experimental conditions based on ruthenium dye, N719, and metal-free organic dye, TH202, respectively. Based on the same dyes, the DSSCs employing the new L-cysteine/L-cystine redox couple showed comparable efficiencies of 7.7% and 5.6%, respectively. However, higher incident-photon-to-electron (IPCE) conversion efficiencies and larger J(sc) values were found for devices with the L-cysteine/L-cystine redox couple than with I-/I-3(-). From an electrochemical impedance spectroscopic study, we found that the charge recombination between the conduction band electrons in the TiO2 film and the electrolyte containing the L-cysteine/L-cystine redox couple is restrained.
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| 2. |
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| 3. |
- Leebens-Mack, James H., et al.
(författare)
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One thousand plant transcriptomes and the phylogenomics of green plants
- 2019
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Ingår i: Nature. - : Nature Publishing Group. - 0028-0836 .- 1476-4687. ; 574:7780, s. 679-
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Tidskriftsartikel (refereegranskat)abstract
- Green plants (Viridiplantae) include around 450,000-500,000 species(1,2) of great diversity and have important roles in terrestrial and aquatic ecosystems. Here, as part of the One Thousand Plant Transcriptomes Initiative, we sequenced the vegetative transcriptomes of 1,124 species that span the diversity of plants in a broad sense (Archaeplastida), including green plants (Viridiplantae), glaucophytes (Glaucophyta) and red algae (Rhodophyta). Our analysis provides a robust phylogenomic framework for examining the evolution of green plants. Most inferred species relationships are well supported across multiple species tree and supermatrix analyses, but discordance among plastid and nuclear gene trees at a few important nodes highlights the complexity of plant genome evolution, including polyploidy, periods of rapid speciation, and extinction. Incomplete sorting of ancestral variation, polyploidization and massive expansions of gene families punctuate the evolutionary history of green plants. Notably, we find that large expansions of gene families preceded the origins of green plants, land plants and vascular plants, whereas whole-genome duplications are inferred to have occurred repeatedly throughout the evolution of flowering plants and ferns. The increasing availability of high-quality plant genome sequences and advances in functional genomics are enabling research on genome evolution across the green tree of life.
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| 4. |
- Radhakrishnan, Guru V., et al.
(författare)
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An ancestral signalling pathway is conserved in intracellular symbioses-forming plant lineages
- 2020
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Ingår i: NATURE PLANTS. - : NATURE PUBLISHING GROUP. - 2055-026X .- 2055-0278. ; 6:3, s. 280-289
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Tidskriftsartikel (refereegranskat)abstract
- Plants are the foundation of terrestrial ecosystems, and their colonization of land was probably facilitated by mutualistic associations with arbuscular mycorrhizal fungi. Following this founding event, plant diversification has led to the emergence of a tremendous diversity of mutualistic symbioses with microorganisms, ranging from extracellular associations to the most intimate intracellular associations, where fungal or bacterial symbionts are hosted inside plant cells. Here, through analysis of 271 transcriptomes and 116 plant genomes spanning the entire land-plant diversity, we demonstrate that a common symbiosis signalling pathway co-evolved with intracellular endosymbioses, from the ancestral arbuscular mycorrhiza to the more recent ericoid and orchid mycorrhizae in angiosperms and ericoid-like associations of bryophytes. By contrast, species forming exclusively extracellular symbioses, such as ectomycorrhizae, and those forming associations with cyanobacteria, have lost this signalling pathway. This work unifies intracellular symbioses, revealing conservation in their evolution across 450 million yr of plant diversification. An extensive phylogenomics study based on hundreds of genomes and transcriptomes provides a new interpretation of the evolution of different types of symbiotic associations in land plants, and reveals a conserved ancestral symbiosis pathway.
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| 5. |
- Teng, Chao, et al.
(författare)
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Molecular Design of Anthracene-Bridged Metal-Free Organic Dyes for Efficient Dye-Sensitized Solar Cells
- 2010
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Ingår i: The Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 114:19, s. 9101-9110
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Tidskriftsartikel (refereegranskat)abstract
- A series of metal-free organic dyes bridged by anthracene-containing pi-conjugations were designed and synthesized as new chromophores for the application of dye-sensitized solar cells (DSCs). Detailed investigations on the relationship between the dye structures, photophysical properties, electrochemical properties, and performances of DSCs are described. With the introduction of the anthracene moiety, together with a triple bond for the fine-tuning of molecular planar configurations and to broaden absorption spectra, the short-circuit photocurrent densities (J(sc)) and open-circuit photovoltages (V-oc) of DSCs were improved to a large extent. The improvement of J(sc) is attributed to much broader absorption spectra of the dyes with the anthracene moiety. Electrochemical impedance spectroscopy (EIS) analysis reveals that the introduction of the anthracene moiety suppresses the charge recombination arising from electrons in TiO2 films with I-3(-) ions in the electrolyte, thus improving V-oc considerably. On the basis of optimized molecular structures and DSC test conditions, the dye TC501 shows a prominent solar energy conversion efficiency (eta) up to 7.03% (J(sc) = 12.96 mA . cm(-2), V-OC = 720 mV, ff = 0.753) under simulated AM 1.5 irradiation (100 mW . cm(-2)).
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| 6. |
- Teng, Chao, et al.
(författare)
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Tuning the HOMO Energy Levels of Organic Dyes for Dye-Sensitized Solar Cells Based on Br(-)/Br(3)(-) Electrolytes
- 2010
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Ingår i: Chemistry - A European Journal. - : Wiley. - 0947-6539 .- 1521-3765. ; 16:44, s. 13127-13138
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Tidskriftsartikel (refereegranskat)abstract
- A series of novel metal free organic dyes TC301-TC310 with relatively high HOMO levels were synthesized and applied in dye sensitized solar cells (DSCs) based on electrolytes that contain Br(-)/Br(3)- and I(-)/I(3)(-) The effects of additive Li(+) ions and the HOMO levels of the dyes have an important influence on properties of the dyes and performance of DSCs The addition of Li(+) ions in electrolytes can broaden the absorption spectra of the dyes on TiO(2) films and shift both the LUMO levels of the dyes and the conduction band of TiO(2) thus leading to the increase of J(sc) and the decrease of V(oc) Upon using Br(-)/Br(3)(-) instead of I(-)/I(3)(-), a large increase of V(oc) is attributed to the enlarged energy difference between the redox potentials of electrolyte and the Fermi level of TiO(2), as well as the suppressed electron recombination Incident photon to current efficiency (IPCE) action spectra, electrochemical impedance spectra, and nanosecond laser transient absorption reveal that both the electron collection yields and the dye regeneration yields ((sic)(r)) depend on the potential difference (the driving forces) between the oxidized dyes and the Br(-)/Br(3)(-) redox couple For the dyes for which the HOMO levels are more positive than the redox potential of Br(-)/Br(3)(-) sufficient driving forces lead to the longer effective electron diffusion lengths and almost the same efficient dye regenerations, whereas for the dyes for which the HOMO levels are similar to the redox potential of Br(-)/Br(3)(-), insufficient driving forces lead to shorter effective electron-diffusion lengths and inefficient dye regenerations
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| 7. |
- Yang, Xichuan, et al.
(författare)
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A new type of organic sensitizers with pyridine-N-oxide as the anchoring group for dye-sensitized solar cells
- 2013
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Ingår i: RSC Advances. - : Royal Society of Chemistry (RSC). - 2046-2069. ; 3:33, s. 13677-13680
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Tidskriftsartikel (refereegranskat)abstract
- A series of organic dyes with alkaline pyridine-N-oxide as the electron acceptor and anchoring group have been synthesized and applied in dye-sensitized solar cells. Photoelectrical data show a good coordination between pyridine-N-oxide and TiO2 films, which effectively guarantee the injection and adsorption of the dye molecules. With the simple WL102 dye, the best photon-to-electron conversion efficiency of 3.72% and an excellent IPCE value about 95% have been achieved under optimized conditions.
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| 8. |
- Zhang, Yu, et al.
(författare)
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Comparative phylogenomics and phylotranscriptomics provide insights into the genetic complexity of nitrogen-fixing root-nodule symbiosis
- 2024
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Ingår i: Plant communications. - 2590-3462. ; 5:1
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Tidskriftsartikel (refereegranskat)abstract
- Plant root-nodule symbiosis (RNS) with mutualistic nitrogen-fixing bacteria is restricted to a single clade of angiosperms, the Nitrogen-Fixing Nodulation Clade (NFNC), and is best understood in the legume family. Nodulating species share many commonalities, explained either by divergence from a common ancestor over 100 million years ago or by convergence following independent origins over that same time period. Regardless, comparative analyses of diverse nodulation syndromes can provide insights into constraints on nodulation-what must be acquired or cannot be lost for a functional symbiosis-and the latitude for variation in the symbiosis. However, much remains to be learned about nodulation, especially outside of legumes. Here, we employed a large-scale phylogenomic analysis across 88 species, complemented by 151 RNA-seq libraries, to elucidate the evolution of RNS. Our phylogenomic analyses further emphasize the uniqueness of the transcription factor NIN as a master regulator of nodulation and identify key mutations that affect its function across the NFNC. Comparative transcriptomic assessment revealed nodulespecific upregulated genes across diverse nodulating plants, while also identifying nodule-specific and nitrogen-response genes. Approximately 70% of symbiosis-related genes are highly conserved in the four representative species, whereas defense-related and host-range restriction genes tend to be lineage specific. Our study also identified over 900 000 conserved non-coding elements (CNEs), over 300 000 of which are unique to sampled NFNC species. NFNC-specific CNEs are enriched with the active H3K9ac mark and are correlated with accessible chromatin regions, thus representing a pool of candidate regulatory elements for genes involved in RNS. Collectively, our results provide novel insights into the evolution of nodulation and lay a foundation for engineering of RNS traits in agriculturally important crops.
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| 9. |
- Zhao, Jianghua, et al.
(författare)
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Highly efficient iso-quinoline cationic organic dyes without vinyl groups for dye-sensitized solar cells
- 2013
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Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry (RSC). - 2050-7488 .- 2050-7496. ; 1:7, s. 2441-2446
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Tidskriftsartikel (refereegranskat)abstract
- Four organic dyes without a vinyl group are synthesized and applied in dye-sensitized solar cells (DSSCs). The iso-quinoline cation is employed firstly as an electron acceptor in the dye molecular structure. The effect of different dye structures on the photo-electrochemical properties and the performance of the DSSCs are systematically studied. The photovoltaic performances of the DSSCs sensitized by the JH304 dye exhibit the best conversion efficiency of 7.3% (under standard AM 1.5G illumination (100 mW cm(-2))) with a short-circuit current density (J(sc)) of 14.4 mA cm(-2), an open-circuit voltage (V-oc) of 684 mV and a fill factor (ff) of 74.4%. In comparison, the device sensitized by the N719 dye shows an efficiency of 7.9%. The DSSC device sensitized by JH304 also exhibits excellent soaking stability under sunlight for 1000 h.
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| 10. |
- Zhao, Jianghua, et al.
(författare)
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Molecular Design and Performance of Hydroxylpyridium Sensitizers for Dye-Sensitized Solar Cells
- 2013
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 5:11, s. 5227-5231
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Tidskriftsartikel (refereegranskat)abstract
- Four hydroxylpyridium organic dyes were synthesized and applied in dye-sensitized solar cells (DSSCs). Hydroxylpyridium was introduced as an electron acceptor in donor-pi-conjugated bridge-acceptor (D-pi-A) system. The traditional anchoring groups, such as the carboxyl group, were replaced by hydroxyl group. It was found that the existence of the hydroxylpyridium exhibits a large effect on the absorption spectra of dyes JH401-JH404. For JH series of dyes, hexylthiophene was employed as the pi-conjugated bridge, and triphenylamine, phenothiazine, and their derivatives were used as the electron donor. The performances of the dyes with different structure were investigated by photophysical, photovoltaic, and electrochemical methods. When applied in the DSSCs, the sensitizer JH401 yields the best efficiency, 2.6% (J(sc) = 6.35 mA/cm(2), V-oc = 605 mV, FF = 67.696) under 100 mW/cm(2) light illumination. Its maximum incident photon-to-current conversion efficiency (IPCE) is 80% at 440 nm light wavelength, which is the highest IPCE value achieved with hydroxyl group adsorbent organic dyes so far.
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| 11. |
- Zhao, Jianghua, et al.
(författare)
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New Organic Dyes with a Phenanthrenequinone Derivative as the pi-Conjugated Bridge for Dye-Sensitized Solar Cells
- 2013
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Ingår i: The Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 117:25, s. 12936-12941
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Tidskriftsartikel (refereegranskat)abstract
- A series of organic dyes based on a phenanthrenequinone derivative have been employed for the first time as a it-conjugated bridge in the molecular design of D-pi-A structured organic dyes. Photophysical and electrochemical properties of dyes JH201-JH203 have been systematically investigated. The result shows that dye JH202 exhibits a higher molar extinction coefficient and widened absorption spectrum than dye JH201. Upon replacing the butoxyltriphenylamiine electron donor with phenothiazine, a bathochromic shift absorption spectrum for dye JH203 was observed. When applied in dye-sensitized solar cells (DSSCs), the device sensitized by JH203 yields the best photo-to-current conversion efficiency of 6.0% under standard AM 1.5G illumination (100 rnW/cm(2)) with a short-circuit photocurrent density (J(sc)) of 11.1 mA/cm(2), an open circuit photovoltage (V-oc) of 720 mV, and a fill factor (ff) of 74.9%. The maximum incident photo-to-current conversion efficiency reaches 87% at 460 nm.
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