Institution
Dalian University of Technology
Education•Dalian, China•
About: Dalian University of Technology is a education organization based out in Dalian, China. It is known for research contribution in the topics: Catalysis & Finite element method. The organization has 60890 authors who have published 71921 publications receiving 1188356 citations. The organization is also known as: Dàlián Lǐgōng Dàxué.
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TL;DR: The methods for switching (or modulation) of the triplet excited state of Bodipy were discussed, such as those based on the photo-induced electron transfer (PET), by controlling the competing Förster-resonance-energy-transfer (FRET), or the intermolecular charge transfer (ICT).
Abstract: Boron dipyrromethene (Bodipy) is one of the most extensively investigated organic chromophores. Most of the investigations are focused on the singlet excited state of Bodipy, such as fluorescence. In stark contrast, the study of the triplet excited state of Bodipy is limited, but it is an emerging area, since the triplet state of Bodipy is tremendously important for several areas, such as the fundamental photochemistry study, photodynamic therapy (PDT), photocatalysis and triplet–triplet annihilation (TTA) upconversion. The recent developments in the study of the production, modulation and application of the triplet excited state of Bodipy are discussed in this review article. The formation of the triplet state of Bodipy upon photoexcitation, via the well known approach such as the heavy atom effect (including I, Br, Ru, Ir, etc.), and the new methods, such as using a spin converter (e.g. C60), charge recombination, exciton coupling and the doubly substituted excited state, are summarized. All the Bodipy-based triplet photosensitizers show strong absorption of visible or near IR light and the long-lived triplet excited state, which are important for the application of the triplet excited state in PDT or photocatalysis. Moreover, the methods for switching (or modulation) of the triplet excited state of Bodipy were discussed, such as those based on the photo-induced electron transfer (PET), by controlling the competing Forster-resonance-energy-transfer (FRET), or the intermolecular charge transfer (ICT). Controlling the triplet excited state will give functional molecules such as activatable PDT reagents or molecular devices. It is worth noting that switching of the singlet excited state and the triplet state of Bodipy may follow different principles. Application of the triplet excited state of Bodipy in PDT, hydrogen (H2) production, photoredox catalytic organic reactions and TTA upconversion were discussed. The challenges and the opportunities in these areas were briefly discussed.
583 citations
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TL;DR: Results indicate that after 5 days of training, the IBMT group shows better regulation of the ANS by a ventral midfrontal brain system than does the relaxation group.
Abstract: Five days of integrative body–mind training (IBMT) improves attention and self-regulation in comparison with the same amount of relaxation training. This paper explores the underlying mechanisms of this finding. We measured the physiological and brain changes at rest before, during, and after 5 days of IBMT and relaxation training. During and after training, the IBMT group showed significantly better physiological reactions in heart rate, respiratory amplitude and rate, and skin conductance response (SCR) than the relaxation control. Differences in heart rate variability (HRV) and EEG power suggested greater involvement of the autonomic nervous system (ANS) in the IBMT group during and after training. Imaging data demonstrated stronger subgenual and adjacent ventral anterior cingulate cortex (ACC) activity in the IBMT group. Frontal midline ACC theta was correlated with high-frequency HRV, suggesting control by the ACC over parasympathetic activity. These results indicate that after 5 days of training, the IBMT group shows better regulation of the ANS by a ventral midfrontal brain system than does the relaxation group. This changed state probably reflects training in the coordination of body and mind given in the IBMT but not in the control group. These results could be useful in the design of further specific interventions.
580 citations
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TL;DR: In this paper, solid state hybrid solar cells with hybrid organolead halide perovskites (CH3NH3PbBr3 and CH3NH 3PbI3) as light harvesters and p-type polymer poly[N-9-hepta-decanyl-2,7-carbazole-alt-3,6-bis(thiophen-5-yl)-2,5-dioctyl-2.5-di-hydropyrrolo[3,4]-pyrrole-1
Abstract: Solid state hybrid solar cells with hybrid organolead halide perovskites (CH3NH3PbBr3 and CH3NH3PbI3) as light harvesters and p-type polymer poly[N-9-hepta-decanyl-2,7-carbazole-alt-3,6-bis(thiophen-5-yl)-2,5-dioctyl-2,5-di-hydropyrrolo[3,4-]pyrrole-1,4-dione] (PCBTDPP) as a hole transporting material were studied. The CH3NH3PbBr3-sensitized hybrid devices display an outstanding open circuit voltage (Voc) of ∼1.15 V, and the CH3NH3PbI3-based cells exhibit a power conversion efficiency (PCE) of ∼5.55% along with high stability. The present results show that PCBTDPP is superior to the model p-type polymer P3HT as a HTM in these hybrid solar cells to achieve remarkably high Voc and high PCE. The possible mechanisms have been suggested.
578 citations
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TL;DR: By switching from an acidic medium to a basic one, hydroxide (OH ) exchange membrane fuel cells (HEMFCs) have the potential to solve the problems of catalyst cost and durability while achieving high power and energy density.
Abstract: Hydrogen proton exchange membrane fuel cells (PEMFCs) have been demonstrated to have high power density and reasonable energy density. Their commercialization, however, has been hampered by the high cost and low durability of their electrocatalysts. By switching from an acidic medium to a basic one, hydroxide (OH ) exchange membrane fuel cells (HEMFCs) have the potential to solve the problems of catalyst cost and durability while achieving high power and energy density. In a basic environment, the cathode oxygen reduction over-potential can be significantly reduced, leading to high fuel cell efficiency, and catalysts in basic medium are also more durable. In addition, the facile cathode kinetics allows nonprecious metals to be used as catalysts, thus drastically reducing the cost of the fuel cell. Further, HEMFCs can offer fuel flexibility (e.g., methanol, ethanol, ethylene glycol, etc.) because of their low overpotential for hydrocarbon fuel oxidation and reduced fuel crossover. One of the most significant problems for HEMFCs is the lack of a soluble ionomer that can be used in the catalyst layer to build an efficient three-phase boundary and thus drastically improve the utilization of the catalyst particles and reduce the internal resistance. One of the most desirable properties of an ionomer for use in the catalyst layer is high solubility in low-boiling-point water-soluble solvents such as ethanol and (nor 2-)propanol, because these solvents are easy and safe to handle and remove during the electrode preparation. The ionomer should also have high hydroxide conductivity and alkaline stability. For PEMFCs, Nafion has been the ionomer of choice because it meets these requirements. But for HEMFCs, the most commonly used material for the hydroxide exchange membrane (HEM) is a quaternary ammonium hydroxide containing polymer that has poor solubility in the aforementioned simple solvents, low hydroxide conductivity, and poor alkaline stability. For example, Tokuyama Co. very recently reported two types of soluble quaternary ammonium hydroxide containing polymers (product code: A3Ver2, soluble in tetrahydrofuran or n-propanol, and AS-4, soluble in n-propanol); however, as a result of their low hydroxide conductivity, their incorporation into the catalyst layers of HEMFCs only led to a moderate improvement in performance. In another case, Park et al. prepared an ionomer solution of the trimethylamine (TMA) and N,N,N’,N’-tetramethyl-1,6-hexanediamine (TMHDA) based polysulfone– methylene quaternary ammonium hydroxide (T/TPQAOH) in dimethylacetamide (DMAc, b.p. 166 8C). Similar to the Tokuyama results, the low hydroxide conductivity of the ionomer significantly limited the improvement in fuel cell performance, and in addition, removal of the high-boilingpoint solvent is considered difficult and unsafe in the presence of finely dispersed catalysts. Owing to the lack of a soluble highly conductive solid ionomer, aqueous solutions of KOH or NaOH have been previously used in the electrodes, where the introduction of metal cations (M) offsets the key advantages of a HEMFC over traditional liquid-electrolytebased alkaline fuel cells (AFCs). Furthermore, owing to the lack of a good ionomer as the binder, non-ionic conductive PTFE and proton-conductive Nafion ionomers were used as substitutes in the electrodes, even though these materials were known to have no hydroxide conductivity. Recently, Varcoe et al. reported a TMHDA-based polyvinylbenzylcrosslinked quaternary ammonium hydroxide (TPCQAOH) electrochemical interface to enhance HEMFC performance. Because the polymer used was not soluble in ionomer form, one could question its ability to form an efficient three-phase-boundary structure in the catalyst layer, thereby limiting performance. Moreover, the hydroxide conductivity and stability of the electrochemical interface are still of concern because it is based on quaternary ammonium hydroxide groups. Quaternary phosphonium containing polymers showed excellent solubility in methanol. The strong basicity of the tertiary phosphine suggests that quaternary phosphonium hydroxides are very strong bases. Therefore in this work, we synthesized a new quaternary phosphonium based ionomer that is soluble in low-boiling-point water-soluble solvents and is highly hydroxide conductive: tris(2,4,6-trimethoxyphenyl) polysulfone-methylene quaternary phosphonium hydroxide (TPQPOH; Scheme 1). The TPQPOH ionomer exhibits excellent solubility in pure methanol, ethanol, and n-propanol and in their aqueous solutions (50 wt% in water, see Table S1 in the Supporting Information). On the other hand, the TPQPOH is insoluble in pure water, even at 80 8C, suggesting that it can be used in the [*] Dr. S. Gu, Dr. R. Cai, T. Luo, Dr. Z. Chen, M. Sun, Y. Liu, Prof. Dr. Y. S. Yan Department of Chemical and Environmental Engineering University of California—Riverside Riverside, CA 92521 (USA) Fax: (+1)951-827-5696 E-mail: yushan.yan@ucr.edu Homepage: http://www.engr.ucr.edu/faculty/chemenv/ yushanyan.html
578 citations
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TL;DR: In this paper, the authors present the current situation of circular economy practice in China and describe current measures being implemented in China for the long-term promotion of a circular economy, including the formulation of objectives, legislation, policies and measures, so that the country can 'leapfrog' its way from environmentally damaging development to a more sustainable path.
Abstract: China is pioneering a new sustainable development model which has the ability to overcome current environmental and resource management problems, while achieving improvements in resource productivity and eco-efficiency. This model, formally accepted in 2002 and termed the 'circular economy', is understood to mean the realisation of a closed loop of material flows in the Chinese economic system. Successful implementation of this model is seen as one way in which China can 'leapfrog' past environmental damage that is typically seen as economies industrialise. This paper introduces the development of the model in China, and presents the current situation of circular economy practice in China. The paper describes current measures being implemented in China for the long-term promotion of a circular economy, including the formulation of objectives, legislation, policies and measures, so that the country can 'leapfrog' its way from environmentally-damaging development to a more sustainable path. The paper then i...
576 citations
Authors
Showing all 61205 results
Name | H-index | Papers | Citations |
---|---|---|---|
Yang Yang | 171 | 2644 | 153049 |
Yury Gogotsi | 171 | 956 | 144520 |
Hui Li | 135 | 2982 | 105903 |
Michael I. Posner | 134 | 414 | 104201 |
Anders Hagfeldt | 129 | 600 | 79912 |
Jian Zhou | 128 | 3007 | 91402 |
Chao Zhang | 127 | 3119 | 84711 |
Bin Wang | 126 | 2226 | 74364 |
Chi Lin | 125 | 1313 | 102710 |
Tao Zhang | 123 | 2772 | 83866 |
Bo Wang | 119 | 2905 | 84863 |
Zhenyu Zhang | 118 | 1167 | 64887 |
Liang Cheng | 116 | 1779 | 65520 |
Anthony G. Fane | 112 | 565 | 40904 |
Xuelong Li | 110 | 1044 | 46648 |