Accelerating Oxygen Electrocatalysis Kinetics on Metal-Organic Frameworks via Bond Length Optimization

Metal-organic frameworks(MOFs)have been developed as an ideal platform for exploration of the relationship between intrinsic structure and catalytic activity,but the limited catalytic activity and stability has hampered their practical use in water splitting.Herein,we develop a bond length adjustment strategy for optimizing naphthalene-based MOFs that synthesized by acid etching Co-naphthalenedicarboxylic acid-based MOFs(donated as AE-CoNDA)to serve as efficient catalyst for water splitting.AE-CoNDA exhibits a low overpotential of 260 mV to reach 10 mA cm^(−2)and a small Tafel slope of 62 mV dec^(−1)with excellent stability over 100 h.After integrated AE-CoNDA onto BiVO_(4),photocurrent density of 4.3 mA cm^(−2)is achieved at 1.23 V.Experimental investigations demonstrate that the stretched Co-O bond length was found to optimize the orbitals hybridization of Co 3d and O 2p,which accounts for the fast kinetics and high activity.Theoretical calculations reveal that the stretched Co-O bond length strengthens the adsorption of oxygen-contained intermediates at the Co active sites for highly efficient water splitting.

Highly efficient electrosynthesis of H_(2)O_(2)in acidic electrolyte on metal-free heteroatoms co-doped carbon nanosheets and simultaneously promoting Fenton process

Recently electrochemical synthesis of H_(2)O_(2)through oxygen reduction reaction(ORR)via 2e^(-)pathway is considered as a green and on-site route.However,it still remains a big challenge for fabricating novel metal-free catalysts under acidic solutions,since it suffers from high overpotential due to the intrinsically week*OOH adsorption.Herein,a co-doped carbon nanosheet(O/N–C)catalyst toward regulating O and N content was synthesized for improving the selectivity and activity of H_(2)O_(2)electrosynthesis process.The O/N–C exhibits outstanding 2e-ORR performance with low onset potential of 0.4 V(vs.RHE)and a selectivity of 92.4%in 0.1 mol/L HClO_(4)solutions.The in situ electrochemical impedance spectroscopy(EIS)tests reveals that the N incorporation contributes to the fast ORR kinetics.The density functional theory(DFT)calculations demonstrate that the binding strength of*OOH was optimized by the co-doping of oxygen and nitrogen at certain content,and the O/N–C–COOH site exhibits a lower theoretical overpotential for H_(2)O_(2)formation than O–C–COOH site.Furthermore,the promoted kinetics for typical organic dye degradation in simultaneous electron-Fenton process on O/N–C catalyst was demonstrated particularly for broadening its environmental application.

Function investigation of p11.5 in ASFV infection

Virus replication relies on complex interactions between viral proteins.In the case of African swine fever virus(ASFV),only a few such interactions have been identified so far.In this study,we demonstrate that ASFV protein p72 interacts with p11.5 using co-immunoprecipitation and liquid chromatography-mass spectrometry(LC-MS).It was found that protein p72 interacts specifically with p11.5 at sites amino acids(aa)1–216 of p72 and aa 1–68 of p11.5.To assess the importance of p11.5 in ASFV infection,we developed a recombinant virus(ASFVGZΔA137R)by deleting the A137R gene from the ASFVGZ genome.Compared with ASFVGZ,the infectious progeny virus titers of ASFVGZΔA137R were reduced by approximately 1.0 logs.In addition,we demonstrated that the growth defect was partially attributable to a higher genome copies-to-infectious virus titer ratios produced in ASFVGZΔA137R-infected MA104 cells than in those infected with ASFVGZ.This finding suggests that MA104 cells infected with ASFVGZΔA137R may generate larger quantities of noninfectious particles.Importantly,we found that p11.5 did not affect virus-cell binding or endocytosis.Collectively,we show for the first time the interaction between ASFV p72 and p11.5.Our results effectively provide the relevant information of the p11.5 protein.These results extend our understanding of complex interactions between viral proteins,paving the way for further studies of the potential mechanisms and pathogenesis of ASFV infection.

Model test and discrete element method simulation of shield tunneling face stability in transparent clay

The stability of the shield tunneling face is an extremely important factor affecting the safety of tunnel construction.In this study,a transparent clay with properties similar to those of Tianjin clay is prepared and a new transparent clay model test apparatus is developed to overcome the“black box”problem in the traditional model test.The stability of the shield tunneling face(failure mode,influence range,support force,and surface settlement)is investigated in transparent clay under active failure.A series of transparent clay model tests is performed to investigate the active failure mode,influence range,and support force of the shield tunneling face under different burial depth conditions,whereas particle flow code three-dimensional numerical simulations are conducted to verify the failure mode of the shield tunneling face and surface settlement along the transverse section under different burial depth conditions.The results show that the engineering characteristics of transparent clay are similar to those of soft clay in Binhai,Tianjin and satisfy visibility requirements.Two types of failure modes are obtained:the overall failure mode(cover/diameter:C/D£1.0)and local failure mode(C/D≥2.0).The influence range of the transverse section is wider than that of the longitudinal section when C/D≥2.0.Additionally,the normalized thresholds of the relative displacement and support force ratio are 3%-6%and 0.2-0.4,respectively.Owing to the cushioning effect of the clay layer,the surface settlement is significantly reduced as the tunnel burial depth increases.

20世纪三十年代宁波海洋渔业生产成本分析

生产成本是核算一个产业发展状况的重要指标。在整理和分析1935-1936年宁波渔业相关调查报告的基础上,本文基于民国时期宁波海洋渔业产业的生产、流通与交易方式,从捕捞成本、交易成本和运输成本三个方面着重讨论宁波海洋渔业生产成本构成,并指出在鱼行金融资本的介入下,宁波海洋渔业产品已经完全商品化。

Progress in Electrospun Fibers for Manipulating Cell Behaviors

The manipulation of cell behaviors is essential to maintaining cell functions,which plays a critical role in repairing and regenerating damaged tissue.To this end,a rich variety of tissue-engineered scaffolds have been designed and fabricated to serve as matrix for supporting cell growth and functionalization.Among others,scaffolds made of electrospun fibers showed great potential in regulating cell behaviors,mainly owing to their capability of replicating the dimension,composition,and function of the natural extracellular matrix.In particular,electrospun fibers provided both topological cues and biofunctions simply by adjusting the electrospinning parameters and/or post-treatment.In this review,we summarized the most recent applications and advances in electrospun nanofibers for manipulating cell behaviors.First,the engineering of the secondary structures of individual fibers and the construction of two-dimensional nanofiber mats and nanofiber-based,three-dimensional scaffolds were introduced.Then,the functionalization strategies,such as endowing the fibers with bioactive,physical,and chemical cues,were explored.Finally,the typical applications of electrospun fibers in controlling cell behaviors(i.e.,cell adhesion and proliferation,infiltration,migration,neurite outgrowth,stem cell differentiation,and cancer cell capture and killing)were demonstrated.Taken together,this review will provide valuable information to the specific design of nanofiber-based scaffolds and extend their use in controlling cell behaviors for the purpose of tissue repair and regeneration.