Abstract
The traditional teaching mode of music course is still based on the theory teaching mode of teachers. It is difficult to give full play to the main position of students, which leads to the ...low learning enthusiasm of students and the difficulty to fully stimulate their interest in learning. Based on this, this paper first analyses the music knowledge and the application of music software, and then studies the commonly used computer music software in university traditional music teaching, and finally gives the advantages and specific utilization strategies of brain Music software in traditional university music course.
The recent rise of low‐dimensional Ruddlesden–Popper (RP) perovskites is notable for superior humidity stability, however they suffer from low power conversion efficiency (PCE). Suitable organic ...spacer cations with special properties display a critical effect on the performance and stability of perovskite solar cells (PSCs). Herein, a new strategy of designing self‐additive low‐dimensional RP perovskites is first proposed by employing a glycine salt (Gly+) with outstanding additive effect to improve the photovoltaic performance. Due to the strong interaction between CO and Pb2+, the Gly+ can become a nucleation center and be beneficial to uniform and fast growth of the Gly‐based RP perovskites with larger grain sizes, leading to reduced grain boundary and increased carrier transport. As a result, the Gly‐based self‐additive low‐dimensional RP perovskites exhibit remarkable photoelectric properties, yielding the highest PCE of 18.06% for Gly (n = 8) devices and 15.61% for Gly (n = 4) devices with negligible hysteresis. Furthermore, the Gly‐based devices without encapsulation show excellent long‐term stability against humidity, heat, and UV light in comparison to BA‐based low‐dimensional PSCs. This approach provides a feasible design strategy of new‐type low‐dimensional RP perovskites to obtain highly efficient and stable devices for next‐generation photovoltaic applications.
By employing HOOCCH2NH3+ (Gly+) with its outstanding additive effect, self‐additive low‐dimensional Ruddlesden–Popper perovskites are first designed. As a result, the Gly‐based self‐additive low‐dimensional RP perovskites with large grain sizes exhibit remarkable photoelectric properties, yielding the highest power conversion efficiency of 18.06% with negligible hysteresis. More importantly, Gly‐based devices exhibit markedly improved stability against humidity, heat, and UV light.
One of the key challenges of aqueous supercapacitors is the relatively low voltage (0.8–2.0 V), which significantly limits the energy density and feasibility of practical applications of the device. ...Herein, this study reports a novel Ni–Mn–O solid‐solution cathode to widen the supercapacitor device voltage, which can potentially suppress the oxygen evolution reaction and thus be operated stably within a quite wide potential window of 0–1.4 V (vs saturated calomel electrode) after a simple but unique phase‐transformation electrochemical activation. The solid‐solution structure is designed with an ordered array architecture and in situ nanocarbon modification to promote the charge/mass transfer kinetics. By paring with commercial activated carbon anode, an ultrahigh voltage asymmetric supercapacitor in neutral aqueous LiCl electrolyte is assembled (2.4 V; among the highest for single‐cell supercapacitors). Moreover, by using a polyvinyl alcohol (PVA)–LiCl electrolyte, a 2.4 V hydrogel supercapacitor is further developed with an excellent Coulombic efficiency, good rate capability, and remarkable cycle life (>5000 cycles; 95.5% capacity retention). Only one cell can power the light‐emitting diode indicator brightly. The resulting maximum volumetric energy density is 4.72 mWh cm−3, which is much superior to previous thin‐film manganese‐oxide‐based supercapacitors and even battery–supercapacitor hybrid devices.
A very simple but unique phase‐transformation electrochemical activation strategy is developed to enable a solid‐solution Ni–Mn–O nanoprism array to suppress the oxygen evolution and exhibit ultrawide stable electrochemical window (0–1.4 V vs saturated calomel electrode). With such as an array as the cathode, a 2.4 V ultrahigh voltage aqueous supercapacitor is constructed, demonstrating high volumetric energy/power densities.
Identification of grain shape determining genes can facilitate breeding of rice cultivars with optimal grain shape and appearance quality. Here, we identify GS9 (Grain Shape Gene on Chromosome 9) ...gene by map-based cloning. The gs9 null mutant has slender grains, while overexpression GS9 results in round grains. GS9 encodes a protein without known conserved functional domain. It regulates grain shape by altering cell division. The interaction of GS9 and ovate family proteins OsOFP14 and OsOFP8 is modulated by OsGSK2 kinase, a key regulator of the brassinosteroids signaling pathway. Genetic interaction analysis reveals that GS9 functions independently from other previously identified grain size genes. Introducing the gs9 allele into elite rice cultivars significantly improves grain shape and appearance quality. It suggests potential application of gs9, alone or in combination with other grain size determining genes, in breeding of rice varieties with optimized grain shape.
Combining the advantages of homogeneous and heterogeneous catalysts, single‐atom catalysts (SACs) are bringing new opportunities to revolutionize ORR catalysis in terms of cost, activity and ...durability. However, the lack of high‐performance SACs as well as the fundamental understanding of their unique catalytic mechanisms call for serious advances in this field. Herein, for the first time, we develop an Ir‐N‐C single‐atom catalyst (Ir‐SAC) which mimics homogeneous iridium porphyrins for high‐efficiency ORR catalysis. In accordance with theoretical predictions, the as‐developed Ir‐SAC exhibits orders of magnitude higher ORR activity than iridium nanoparticles with a record‐high turnover frequency (TOF) of 24.3 e− site−1 s−1 at 0.85 V vs. RHE) and an impressive mass activity of 12.2 A mg−1Ir, which far outperforms the previously reported SACs and commercial Pt/C. Atomic structural characterizations and density functional theory calculations reveal that the high activity of Ir‐SAC is attributed to the moderate adsorption energy of reaction intermediates on the mononuclear iridium ion coordinated with four nitrogen atom sites.
Ir‐N‐C: Single‐atom catalysts (SACs) combine the advantages of homogeneous and heterogeneous catalysts. A single‐atom iridium catalyst coordinated with four nitrogen atoms has been designed and synthesized to mimic homogeneous iridium porphyrins for high‐efficiency oxygen reduction reaction catalysis.
Mixed lead–tin perovskite solar cells (LTPSCs) with an ideal bandgap are demonstrated as a promising candidate to reach higher power conversion efficiency (PCE) than their Pb‐counterparts. Herein, a ...Br‐free mixed lead–tin perovskite material, FA0.8MA0.2Pb0.8Sn0.2I3, with a bandgap of 1.33 eV, as a perovskite absorber, is selected. Through density functional theory calculations and optoelectronic techniques, it is demonstrated that both Pb‐ and Sn‐related A‐site vacancies are pushed into deeper energetic depth, causing severe nonradiative recombination. Hence, a selective targeting anchor strategy that employs phenethylammonium iodide and ethylenediamine diiodide as co‐modifiers to selectively anchor with Pb‐ and Sn‐related active sites and passivate bimetallic traps, respectively, is established. Furthermore, the selectivity of the molecular oriented anchor passivation is demonstrated through energetic depth specificity of Pb‐ and Sn‐related traps. As a result, a substantially enhanced open‐circuit voltage (VOC) from 0.79 to 0.90 V for the LTPSCs is achieved, yielding a champion PCE of 22.51%, which is the highest PCE among the reported ideal‐bandgap PSCs. The VOC loss is reduced to 0.43 V.
Aiming for hybrid perovskite solar cells, a novel strategy is developed that using ethylenediamine diiodide and phenethylammonium iodide as co‐modifiers to selectively targeting anchor with lead–tin binary perovskite materials, resulting in comprehensively healing the dual‐sourced defects. As a result, a champion efficiency of 22.51% is achieved, which is the record efficiency among the ideal‐bandgap perovskite solar cells.
The redox reactions occurring in the Li-S battery positive electrode conceal various and critical electrocatalytic processes, which strongly influence the performances of this electrochemical energy ...storage system. Here, we report the development of a single-dispersed molecular cluster catalyst composite comprising of a polyoxometalate framework (Co
(PW
O
)
) and multilayer reduced graphene oxide. Due to the interfacial charge transfer and exposure of unsaturated cobalt sites, the composite demonstrates efficient polysulfides adsorption and reduced activation energy for polysulfides conversion, thus serving as a bifunctional electrocatalyst. When tested in full Li-S coin cell configuration, the composite allows for a long-term Li-S battery cycling with a capacity fading of 0.015% per cycle after 1000 cycles at 2 C (i.e., 3.36 A g
). An areal capacity of 4.55 mAh cm
is also achieved with a sulfur loading of 5.6 mg cm
and E/S ratio of 4.5 μL mg
. Moreover, Li-S single-electrode pouch cells tested with the bifunctional electrocatalyst demonstrate a specific capacity of about 800 mAh g
at a sulfur loading of 3.6 mg cm
for 100 cycles at 0.2 C (i.e., 336 mA g
) with E/S ratio of 5 μL mg
.
In recent years, visible-light-mediated C–H bond functionalization has become an emerging field at the forefront of organic synthesis. It is of considerable interest to academic and industrial ...chemists owing to the atom/step economical features as well as the overall sustainability. In this Letter, we mainly discussed the recent typical examples in sp2 and sp3 C–H bond functionalization by means of visible-light photoredox catalysis.
Abstract
Magnetic reconnection has been proposed to play an important role in energy dissipation in space plasma. The diffusion region is an essential place for generation of energetic electrons. ...However, the mechanism responsible for the generation of these energetic electrons in such a confined region remains elusive. Here a diffusion region of asymmetric reconnection is observed at the turbulent magnetopause. The diffusion region is a rather structured region where two dynamical filamentary currents at subion scale were observed. Intense electron flow and nonideal electric field inside the filamentary currents induced significant energy dissipation. Concurrently, the electron parallel temperature between the current layers increases from 58 to 80 eV. Direct evidence indicates that the electrons inside the three-dimensional diffusion region are accelerated by the parallel electric fields inside the current layers and are effectively heated by the turbulence between them.