Recent advances in nickel-based catalysts in eCO_(2)RR for carbon neutrality

The excessive use of nonrenewable energy has brought about serious greenhouse effect.Converting CO_(2) into high-value-added chemicals is undoubtedly the best choice to solve energy problems.Due to the excellent cost-effectiveness and dramatic catalytic performance,nickel-based catalysts have been considered as the most promising candidates for the electrocatalytic CO_(2) reduction reaction(eCO_(2)RR).In this work,the electrocatalytic reduction mechanism of CO_(2) over Ni-based materials is reviewed.The strategies to improve the eCO_(2)RR performance are emphasized.Moreover,the research on Ni-based materials for syngas generation is briefly summarized.Finally,the prospects of nickel-based materials in the eCO_(2)RR are provided with the hope of improving transition-metal-based electrocatalysts for eCO_(2)RR in the future.

Theoretical understanding of electrocatalysis beyond thermodynamic analysis

As the green and sustainable development of human society highly relies on renewable energy,it has been recognized that electrocatalysis is a key technology to this end.High efficient ways of carbon-neutralization(eCO_(2)RR),reverse artificial nitrogen cycle(RANC),and oxygen chemistry(OER and ORR)all can be driven by electrocatalysis.Advanced theoretical study is an important means to fundamentally understanding electrocatalytic reactions.Herein,we review a few significant issues in theoretical electrocatalysis.First,electrochemical barriers and potential effects are essential for a more accurate description of reaction mechanism and activity.Meanwhile,consideration of competitive reaction path is also one of the important aspects,as novel insights and anomalous volcano trend can be obtained.Finally,a microenvironment exerted by confined space can tune the capacitance of electrochemical interface and(electro)chemical potential of proton,resulting in a possibility to improve reaction activity,which opens a new avenue for design of catalyst.

DITCHES AND PONDS CAN BE THE SOURCES OR SINKS OF NON-POINT SOURCE POLLUTION:OBSERVATIONS IN AN UPLAND AREA IN THE JINGLINXI CATCHMENT,CHINA

As the common features of agroecosystems,ditches and ponds benefit the irrigation and drainage,as well as intercepting non-point source pollutants.However,most ditch-pond studies have been conducted in lowland areas.To test this source-sink assumption in upland areas,this study made observations on the ecological function of the ditch and pond system in a typical catchment in China.First,the changes in ponds in the catchment were analyzed using high-resolution remote sensing data.Then,the migration of agricultural pollutants in ditches and ponds were analyzed by field sampling and laboratory detection.The results showed that over the past 15 years the length of ditches in the catchment and the number of small ponds(<500 m2)have increased by 32%and 75%,respectively.The rate of change in nutrient concentrations in the ditches and ponds were mostly from-20%to 20%,indicating ditches and ponds can be both sources and sinks for agricultural pollutants.Lastly,the contributing factors were explored and it was found that ditches and ponds are important sinks in dry season.However,during the rainy season,ditches and ponds become sources of pollutants,with the rapid drainage of ditches and the overflow of ponds in upland areas.The results of this study revealed that the ditches and ponds could be used for ecological engineering in upland catchments to balance drainage and intercept pollutants.

Global Dynamic Molecular Profiling of Stomatal Lineage Cell Development by Single-Cell RNA Sequencing

The regulation of stomatal lineage cell development has been extensively investigated.However,a comprehensive characterization of this biological process based on single-cell transcriptome analysis has not yet been reported.In this study,we performed RNA sequencing on 12844 individual cells from the cotyledons of 5-day-old Arabidopsis seedlings.We identified 11 cell clusters corresponding mostly to cells at specific stomatal developmental stages using a series of marker genes.Comparative analysis of genes with the highest variable expression among these cell clusters revealed transcriptional networks that regulate development from meristemoid mother cells to guard mother cells.Examination of the developmental dynamics of marker genes via pseudo-time analysis revealed potential interactions between these genes.Collectively,our study opens the door for understanding how the identified novel marker genes participate in the regulation of stomatal lineage cell development.

Coordination structure dominated performance of single-atomic Pt catalyst for anti-Markovnikov hydroboration of alkenes

The rational design of efficient single-atomic(SA)catalysts is essential and highly desirable but impeded by the lack of sufficient acknowledge between structure and property.To this end,it is critical to clarify the effect of the coordination structure of active metal centers on the catalytic activities for the design of such catalysts.Here,we report that different coordination structures of SA Pt catalysts can dramatically influence their activities for anti-Markovnikov hydroboration of alkenes.Compared with the other two coordination structures(Pt-N4 and Pt-O2),the SA Pt species coordinated with three O atoms(Pt-O3)display the highest turnover number value of 3288 for the hydroboration reaction to access the important alkylboronic esters.Density functional theory calculations reveal that a superior catalytic activity can be expected for alkene hydroboration over the three O coordinated Pt species due to the lowest reaction energy(ΔG)limiting step from the reaction phase diagram.

The computation of the pitch damping stability derivatives of supersonic blunt cones using unsteady sensitivity equations

The numerical methods for computing the stability derivatives of the aircraft by solving unsteady sensitivity equations which was proposed in our previous papers was extended to solve three-dimensional problems in this paper.Both the static and dynamic derivatives of the hypersonic blunt cone undergoing pitching oscillation around a fixed point were computed using the new methods.The predicted static derivative and dynamic derivative were found to be in reasonable agreement with the experimental data.For the present method,it is possible to distinguish the components of dynamic derivatives caused by different state parameters.It is found that C_(m_α) and C_(mq) are usually of opposite signs and tend to eliminate each other,which makes C_(m_α)+C_(mq) being much smaller than its individual components.Another feature of this method is that the moment of pressure derivatives proposed in the present paper can be used to predict the contribution of each part of the blunt cone to the overall stability quantitatively.It is found that the head region is crucial for the static stability and the body region contributes most to the dynamic stability.