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1.
Jin-Bo Pan Sheng Shen Lang Chen Chak-Tong Au Shuang-Feng Yin 《Advanced functional materials》2021,31(36):2104269
Photoelectrochemical (PEC) water splitting into hydrogen and oxygen is a promising solution for the conversion and storage of solar energy. Because sluggish water oxidation is the bottleneck of water splitting, the design and preparation of an efficient photoanode is intensively investigated. Currently, all known photoanode materials suffer from at least one of the following drawbacks: ① low carriers separation efficiency; ② sluggish surface water oxidation reaction; ③ poor long-term stability; ④ insufficient water adsorption and gas desorption. Core–shell configurations can endow a photoanode with improved activity and stability by coating an overlayer that plays energetic, catalytic, and/or protective roles. The construction strategy has an important effect on the activity of a core–shell photoanode. Nonetheless, the mechanism for the improvement of performance is still ambiguous and is worthy of a closer examination. In this review, the successes and challenges of core–shell photoanodes for water oxidation, focusing on synthesis strategies as well as functionalities (facilitating carrier separation, surface reaction promotion, corrosion prevention, and bubble detachment) are explored. Finally, the perspectives of this class of materials in terms of new opportunities and efforts are discussed. 相似文献
2.
Shuo Wan Yunlong Ma Dongdong Cai Wenyuan Lin Pengsong Wang Jinyun Wang Qingdong Zheng 《Advanced functional materials》2021,31(15):2010436
Ending group halogenation is an effective strategy for modulating the energy levels, bandgaps, and intermolecular interactions of nonfullerene acceptors. Understanding the influence of different halogen atoms on the acceptor properties is of great importance for designing high-performance nonfullerene acceptors. Here, three acceptor–donor–acceptor (A-D-A) type nonfullerene acceptors (M5, M6, and M7), which are constructed by using a ladder-type heteroheptacene core without the traditional sp3 carbon-bonded side chains as the electron-rich core, and 2-(3-oxo-2,3-dihydro-1H-inden-1-ylidene)malononitrile without or with halogen atoms as the ending groups. The nonfullerene acceptors with chlorinated (M6) and brominated (M7) ending groups exhibit broadened absorption spectra, down-shifted energy levels, and enhanced molecular ordering compared to the counterpart without any halogenated ending groups (M5). Among the nonfullerene acceptors, M6 has the strongest intermolecular π π interaction with its shortest π π interaction distance and the longest coherent length which are beneficial for enhancing the charge transport and therefore boosting the photovoltaic performance. An excellent power conversion efficiency of 15.45% is achieved for the best-performing polymer solar cell based on M6. These results suggest that the halogenated ending groups are essential for high-performance heteroheptacene-based nonfullerene acceptors considering their simultaneous enhancements in both the light-harvesting and the charge transport. 相似文献
3.
Luo Xin Yufeng Zhang Wenshan Duan Mingyan Ai Hongbo Song Qun Huang Jiankang Lu 《International Journal of Food Science & Technology》2022,57(5):2646-2655
Oil, accounting for 45% of almonds, is easily oxidised and can further induce the protein oxidation to reduce their quality. Structure and physicochemical properties of amandin, the main water-soluble protein in almonds, inducing oxidation by malondialdehyde (MDA) were investigated. The results showed that the content of carbonyl group increased from 5.23 to 33.25 nmol mg−1 of protein with the increase in MDA concentration (P < 0.05). However, the sulphydryl content, surface hydrophobicity, particle size and the absolute value of ζ-potential first increased and then decreased. Fourier-transformed infrared spectroscopy (FT-IR) confirmed that the structure of amandin changed from order to disorder. Fluorescence spectroscopic analysis revealed that mild oxidation (0–0.1 mmol L−1 MDA) exposed hydrophobic groups of the protein. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) suggested that protein oxidation promoted crosslinking between protein molecules. Furthermore, protein oxidation markedly declined the total amino acid content of amandin (P < 0.05). In conclusion, MDA oxidation changed the structure and amino acid content of amandin, and caused the protein aggregate and crosslink through hydrophobic interaction and electrostatic interaction. 相似文献
4.
Nutrient Cycling in Agroecosystems - Most studies on soil CO2 fluxes focus on the upper soil layers (i.e., 0–200 mm); however, there is a lack of investigation into soil layers below... 相似文献
5.
Hong Zhong Guodong Wu Zhihua Fu Haowei Lv Gang Xu Ruihu Wang 《Advanced materials (Deerfield Beach, Fla.)》2020,32(21):2000730
Artificial transistors represent an ideal means for meeting the requirements in interfacing with biological systems. It is pivotal to develop new proton-conductive materials for the transduction between biochemical events and electronic signals. Herein, the first demonstration of a porous organic polymer membrane (POPM) as a proton-conductive material for protonic field-effect transistors is presented. The POPM is readily prepared through a thiourea-formation condensation reaction. Under hydrated conditions and at room temperature, the POPM delivers a proton mobility of 5.7 × 10−3 cm2 V−1 s−1; the charge carrier densities are successfully modulated from 4.3 × 1017 to 14.1 × 1017 cm−3 by the gate voltage. This study provides a type of promising modular proton-conductive materials for bioelectronics application. 相似文献
6.
Conventional thermally activated delayed fluorescence (TADF) molecules achieve small energy differences between the lowest singlet and triplet excited states (ΔEST) by enhancing the intramolecular charge transfer, which inevitably leads to a wide emission spectrum and low fluorescence rate. Here, we prepared a deep blue TADF molecule via a small ΔEST pyridine-phenol fluoroboron complex as the acceptor. The small ΔEST is maintained when carbazole donors are attached to the 4-position of the phenyl rings in the fluoroboron complex. Benefiting from the strong electron coupling between the donor (D) and acceptor (A) moieties, the compound Cz-4-BF exhibits a high fluorescence rate of 4.8 × 108 s−1 and a small D-A dihedral angle change in the excited state. Consequently, a photoluminescence (PL) quantum yield of nearly 100% and a PL spectrum with full-width at half-maximum (FWHM) < 60 nm were obtained in solution and low-concentration doped films. A TADF-sensitized fluorescence (TSF) device containing Cz-4-BF achieves an external quantum efficiency of 21%, which is higher than the devices employing classical fluorescent emitters and multiple resonance-type TADF emitters. The Cz-4-BF-based TSF device shows significantly improved color coordinates of (0.14, 0.10) versus a control device without Cz-4-BF. 相似文献
7.
8.
《中国稀土学报(英文版)》2019,37(7):760-766
A novel process of calcification-leaching for bastnaesite concentrate(REFCO_3) was proposed. The prior calcification was carried out in the system of NaOH-CaO-H_2O and the lgC-pH pattern for Ce-F-Ca-C-H_2O system was drawn. The thermodynamics result indicates that decomposition for bastnaesite requires certain alkaline condition, but excessive alkalinity also causes decomposition of CaF_2. XRD and SEM-EDS analyses on the calcification-leaching process reveal that bastnaesite first decomposes into RE(OH)_3 and CaF_2. Then, by HCl leaching rare earths were extracted,while CaF_2 was left in the leaching residue. In addition, effects of temperature, time, NaOH and CaO on the calcification were investigated. The results show that the leaching rate of rare earths(REs)reaches 72.5 wt%, at the same time 99.2 wt% of F is left in leaching residue with 20 wt% NaOH and 38 wt% CaO at 493 K for 180 min. 相似文献
9.
Public-private partnership (PPP) projects have been widely applied in infrastructure construction. A suitable risk distribution strategy is crucial for promoting negotiations between the government and investors. The government usually provides guarantees to investors to distribute risk. However, an excessive guarantee increases the government's financial burden, whereas an insufficient guarantee reduces the confidence of the investors participating in the project. In a minimum revenue guarantee (MRG), the government subsidizes the investors the difference between the actual revenue and the government guarantee line if there is a loss. In PPP power plant and highway projects, investors' revenues come from two sources: government guarantees and the project company's self-sale. To support project companies and to optimize the projects' benefits, the government should set a reasonable benchmark for purchase amounts. Based on the traditional principal-agent model, this paper introduces the reciprocal preference theory to analyze the risk-sharing ratio most suitable for the government. Then, an optimal incentive mechanism is established to guarantee the project's income. The results indicate that by setting a different guarantee strategy for different participants, the government can utilize reciprocal preference to incentivize investors to exert more effort during a partnership and avoid moral hazard. 相似文献
10.
《中国稀土学报(英文版)》2020,38(5):523-530
A multidisciplinary approach for the production and characterization of a series of high concentration Er~(3+)activated SrLaGa_3 O_7(abbreviated as Er:SLGO) crystal fibers is shown to have a great promise for implementation in mid-infrared laser applications.The current approach includes the design and formation of unique layered tetrahedral network structures with several kinds of rare earth(RE) ions including Er ions distributing statistically between layers,such as Er:SLGO,Er,Nd:SLGO,Er,Yb,Ho:SLGO,Er,Eu:SLGO and Er,Ho:SLGO.Five kinds of Er:SLGO crystal fibers were designed to grow via a micropulling down method.Spectroscopic analyses show that Er,Yb,Ho:SLGO and Nd,Er:SLGO crystal fibers were superiorly endowed with inhomogeneous broadening absorption and strong emission.The unique structural components design enables the generation of improved absorption and emission recombination,and the inhibition of self-termination as well.Generally,the use of structural components design may warrant high-efficiency emissions in RE-doped crystal fibers. 相似文献