Electron Configuration Modulation of Nickel Single Atoms for Elevated Photocatalytic Hydrogen Evolution

The emerging metal single‐atom catalyst has aroused extensive attention in multiple fields, such as clean energy, environmental protection, and biomedicine. Unfortunately, though it has been shown to be highly active, the origins of the activity of the single‐atom sites remain unrevealed to date owing to the lack of deep insight on electronic level. Now, partially oxidized Ni single‐atom sites were constructed in polymeric carbon nitride (CN), which elevates the photocatalytic performance by over 30‐fold. The 3d orbital of the partially oxidized Ni single‐atom sites is filled with unpaired d‐electrons, which are ready to be excited under irradiation. Such an electron configuration results in elevated light response, conductivity, charge separation, and mobility of the photocatalyst concurrently, thus largely augmenting the photocatalytic performance.     

The antidepressant effect of 4-hydroxybenzyl alcohol 2-naphthoate through monoaminergic,GABAergic system and BDNF signaling pathway

Abstract

Gastrodigenin, also known as 4-hydroxybenzyl alcohol (HBA), is one of the main components of Gastrodia elata, which is a perfect lead compound of natural products. In order to get new active compounds, we modified the structure of HBA through esterification with carboxylic acid, and got a series of derivatives in which 4-hydroxybenzyl alcohol 2-naphthoate (NHBA) showed stronger antidepressant activity than HBA. In this paper, we firstly evaluated the antidepressant activity of NHBA by tail suspension test (TST) and forced swimming test (FST). Then, we carried out the biochemical assay and western blot to determine its mechanism. The results displayed that NHBA could increase the content of serotonin, dopamine, norepinephrine, γ-aminobutyric acid, brain-derived neurotrophic factor (BDNF) and tropomyosin receptor kinase B (TrkB) in mice brain. It suggested that NHBA exhibited an antidepressant-like effect through monoaminergic system, GABAergic system and BDNF/TrkB signaling pathways.     

氮低温制冷循环系统在大科学装置中的应用与发展

大科学装置中低温设备的氮低温冷量需要日益快速增长,为减少能耗和保障装置的长期稳定运行,基于大科学装置氮低温系统运行需求,介绍了氮低温制冷循环系统在国内外大科学装置中的应用情况,总结了目前大科学装置中应用氮低温制冷循环系统的研究现状,并探讨以氮制冷机为核心的氮低温制冷循环系统在未来大科学装置中发展方向。     

A novel asymmetric activated carbon electrode doped with metal-organic frameworks for high desalination performance

Journal of Solid State Electrochemistry - In this work, we synthesized metal-organic framework Cu3(BTC)2 which was applied as the doping materials of anode electrodes in capacitive deionization...     

Can (H2O) n (n = 1–2) as effective catalysts in the CH2OO + H2S reaction under tropospheric conditions?

The addition reaction of CH₂OO?+?H₂S → HSCH₂OOH without and with catalyst X (X?=?H₂O and (H₂O)₂) has been investigated by CCSD(T)-F12a/VTZ-F12//B3LYP/aug-cc-pVTZ method and canonical variational transition state theory with small curvature tunneling correction. When H₂O was introduced in the CH₂OO?+?H₂S reaction, it not only acts as a catalyst for producing HSCH₂OOH, but also plays as a reactant to forming HOCH₂OOH. The formation channel of HSCH₂OOH is more important than the formation channel of HOCH₂OOH with its calculated rate constant larger by 11.0–43.2 times within the temperature 280–320?K. Then, (H₂O)₂ catalysed CH₂OO?+?H₂S → HSCH₂OOH reaction has been taken into account with its rate lower 1.9–4.2 times than the reaction of CH₂OO?+?H₂S → HSCH₂OOH with water. Also, CH₂OO?+?H₂S with H₂O cannot compete with the CH₂OO?+?H₂S reaction without water. This is different from CH₂OO?+?(H₂O)₂ reaction, which is about 4 orders of magnitude larger than the rate constant for CH₂OO?+?H₂O reaction. Such discrepancy is possible because C(CH₂OO)···O(H₂O) interaction has been enhanced more obviously by H₂O as compared to that of C(CH₂OO)···O(H₂S) interaction.     

Terahertz wave emission from water lin es

To make further understanding of terahertz(THz)wave generation from liquid water,we study THz wave emission from water lines of different diameters.The water line with a smaller diameter generates a stronger THz electric field for the diameters from 0.2 mm to 0.5 mm.The THz electric field strength and polarity change with the relative position between the incident laser and water line.Moreover,the THz energy has an optimal radiation angle of about 60°.A two-dimensional dipole array model is introduced to illustrate the phenomenon.Our observations contribute to optimizing the scheme of the liquid THz source.     

Rational design of perfluorinated sulfonic acid ionic sieve modified separator for high-performance Li-S battery

Journal of Solid State Electrochemistry - Practical application of Li-S battery is limited by the fast capacity decay and low coulombic efficiency caused by the shuttling phenomenon. Modification...     

Exceptional Cycles in the Bounded Derived Categories of Quivers

An exceptional n-cycle in a Hom-finite triangulated category with Serre functor has been recently introduced by Broomhead,Pauksztello and Ploog.When n=1,it is a spherical object.We explicitly determine all the exceptional cycles in the bounded derived category D^b(kQ)of a finite quiver Q without oriented cycles.In particular,if Q is an Euclidean quiver,then the length type of exceptional cycles in D^b(kQ)is exactly the tubular type of Q;if Q is a Dynkin quiver of type E_m(m=6,7,8),or Q is a wild quiver,then there are no exceptional cycles in D^b(kQ);and if Q is a Dynkin quiver of type An or D_n,then the length of an exceptional cycle in D^b(kQ)is either h or h/2,where h is the Coxeter number of Q.     

A Statistical Study of the Correlation between Geomagnetic Storms and M ≥ 7.0 Global Earthquakes during 1957–2020

In order to find out whether the geomagnetic storms and large-mega earthquakes are correlated or not, statistical studies based on Superposed Epoch Analysis (SEA), significance analysis, and Z test have been applied to the Dst index data and M ≥ 7.0 global earthquakes during 1957–2020. The results indicate that before M ≥ 7.0 global earthquakes, there are clearly higher probabilities of geomagnetic storms than after them. Geomagnetic storms are more likely to be related with shallow earthquakes rather than deep ones. Further statistical investigations of the results based on cumulative storm hours show consistency with those based on storm days, suggesting that the high probability of geomagnetic storms prior to large-mega earthquakes is significant and robust. Some possible mechanisms such as a reverse piezoelectric effect and/or electroosmotic flow are discussed to explain the statistical correlation. The result might open new perspectives in the complex process of earthquakes and the Lithosphere-Atmosphere-Ionosphere (LAI) coupling.