Fundamental Understanding of Hydrogen Evolution Reaction on Zinc Anode Surface:A First‑Principles Study

Hydrogen evolution reaction(HER)has become a key factor affecting the cycling stability of aqueous Zn-ion batteries,while the corresponding fundamental issues involving HER are still unclear.Herein,the reaction mechanisms of HER on various crystalline surfaces have been investigated by first-principle calculations based on density functional theory.It is found that the Volmer step is the ratelimiting step of HER on the Zn(002)and(100)surfaces,while,the reaction rates of HER on the Zn(101),(102)and(103)surfaces are determined by the Tafel step.Moreover,the correlation between HER activity and the generalized coordination number(CN)of Zn at the surfaces has been revealed.The relatively weaker HER activity on Zn(002)surface can be attributed to the higher CN of surface Zn atom.The atomically uneven Zn(002)surface shows significantly higher HER activity than the flat Zn(002)surface as the CN of the surface Zn atom is lowered.The CN of surface Zn atom is proposed as a key descriptor of HER activity.Tuning the CN of surface Zn atom would be a vital strategy to inhibit HER on the Zn anode surface based on the presented theoretical studies.Furthermore,this work provides a theoretical basis for the in-depth understanding of HER on the Zn surface.

A gap-free reference genome reveals structural variations associated with flowering time in rapeseed(Brassica napus)

Allopolyploid oilseed rape(Brassica napus)is an important oil crop and vegetable.However,the latest version of its reference genome,with collapsed duplications,gaps,and other issues,prevents comprehensive genomic analysis.Herein,we report a gap-free assembly of the rapeseed cv.Xiang5A genome using a combination of ONT(Oxford Nanopore Technologies)ultra-long reads,PacBio high-fidelity reads,and Hi-C datasets.It includes gap-free assemblies of all 19 chromosomes and telomere-to-telomere assemblies of eight chromosomes.Compared with previously published genomes of B.napus,our gap-free genome,with a contig N50 length of 50.70 Mb,has complete assemblies of 9 of 19 chromosomes without manual intervention,and greatly improves contiguity and completeness,thereby representing the highest quality genome assembly to date.Our results revealed that B.napus Xiang5A underwent nearly complete triplication and allotetraploidy relative to Arabidopsis thaliana.Using the gap-free assembly,we found that 917 flowering-related genes were affected by structural variation,including BnaA03.VERNALIZATION INSENSITIVE 3 and BnaC04.HIGH EXPRESSION OF OSMOTICALLY RESPONSIVE GENES 1.These genes may play crucial roles in regulating flowering time and facilitating the adaptation of Xiang5A in the Yangtze River Basin of China.This reference genome provides a valuable genetic resource for rapeseed functional genomic studies and breeding.

城市轨道交通系统安全评估体系及重点方法

以地铁为主要形式的城市轨道交通系统是现代城市公共交通体系的重要组成部分,其安全高效运行对保障当地人民生命财产安全、保持城市社会经济发展具有十分重要的意义。文章对我国城市轨道交通安全评估发展现状进行综述和分析,针对城市轨道交通系统安全保障的特殊要求,提出建立关键节点安全评估与系统生命周期全过程安全评估相结合的城市轨道交通系统安全评估体系的设想,并提出可供选择的重点安全评估方法。

A novel minority sample fault diagnosis method based on multisource data enhancement

Effective fault diagnosis has a crucial impact on the safety and cost of complex manufacturing systems.However,the complex structure of the collected multisource data and scarcity of fault samples make it difficult to accurately identify multiple fault conditions.To address this challenge,this paper proposes a novel deep-learning model for multisource data augmentation and small sample fault diagnosis.The raw multisource data are first converted into two-dimensional images using the Gramian Angular Field,and a generator is built to transform random noise into images through transposed convolution operations.Then,two discriminators are constructed to evaluate the authenticity of input images and the fault diagnosis ability.The Vision Transformer network is built to diagnose faults and obtain the classification error for the discriminator.Furthermore,a global optimization strategy is designed to upgrade parameters in the model.The discriminators and generator compete with each other until Nash equilibrium is achieved.A real-world multistep forging machine is adopted to compare and validate the performance of different methods.The experimental results indicate that the proposed method has multisource data augmentation and minority sample fault diagnosis capabilities.Compared with other state-of-the-art models,the proposed approach has better fault diagnosis accuracy in various scenarios.

Genomic,transcriptomic,and epigenomic analysis of a medicinal snake,Bungarus multicinctus,to provides insights into the origin of Elapidae neurotoxins

The many-banded krait,Bungarus multicinctus,has been recorded as the animal resource of JinQianBaiHuaShe in the Chinese Pharmacopoeia.Characterization of its venoms classified chief phyla of modern animal neurotoxins.However,the evolutionary origin and diversification of its neurotoxins as well as biosynthesis of its active compounds remain largely unknown due to the lack of its high-quality genome.Here,we present the 1.58 Gbp genome of B.multicinctus assembled into 18 chromosomes with contig/scaffold N50 of 7.53 Mbp/149.8 Mbp.Major bungarotoxin-coding genes were clustered within genome by family and found to be associated with ancient local duplications.The truncation of glycosylphosphatidylinositol anchor in the 3'-terminal of a LY6E paralog released modern three-finger toxins(3FTxs)from membrane tethering before the Colubroidea divergence.Subsequent expansion and mutations diversified and recruited these 3FTxs.After the cobra/krait divergence,the modern unit-B ofβ-bungarotoxin emerged with an extra cysteine residue.A subsequent point substitution in unit-A enabled theβ-bungarotoxin covalent linkage.The B.multicinctus gene expression,chromatin topological organization,and histone modification characteristics were featured by transcriptome,proteome,chromatin conformation capture sequencing,and ChIP-seq.The results highlighted that venom production was under a sophisticated regulation.Our findings provide new insights into snake neurotoxin research,meanwhile will facilitate antivenom development,toxin-driven drug discovery and the quality control of JinQianBaiHuaShe.

Adaptive vector field based accurate homing control of aerial delivery systems

This paper investigates the homing control problem of a flexible aerial delivery system with external wind,at-mospheric turbulence,and aerodynamic uncertainties.An accurate homing control strategy is presented,consisting of a trajectory generation algorithm and a lateral tracking controller.A high-altitude trajectory generation is de-veloped with system characteristics explicitly considered to generate the desired trajectory for the aerial delivery control system design.It significantly compensates for the altitude deviation of the existing multiphase theory based trajectory generation methodologies.A novel adaptive vector field control law is then designed to accomplish the lateral tracking maneuvers.The key feature of the proposed method is that the complete lateral closed-loop control,including position and heading angle loops,is achieved in the presence of disturbances and dynamic uncertainties.The homing control with high landing accuracy is therefore achieved.Simulation and hardware-in-loop testing results are finally presented to validate the proposed method’s effectiveness compared to a conventional homing control scheme.

A restoration-promoting integrated floating bed and its experimental performance in eutrophication remediation

Numerous studies on eutrophication remediation have mainly focused on purifying water first, then restoring submerged macrophytes. A restoration-promoting integrated floating bed （RPIFB） was designed to combine the processes of water purification and macrophyte restoration simultaneously. Two outdoor experiments were conducted to evaluate the ecological functions of the RP1FB. Trial 1 was conducted to compare the eutrophication purification among floating bed, gradual-submerging bed （GSB） and RPIFB technologies. The results illustrated that RPIFB has the best purification capacity. Removal efficiencies of RPIFB for TN, TP,NH4＋-N, NO3-N, CODcr, Chlorophyll-a and turbidity were 74.45%, 98.31%, 74.71%, 88.81%, 71.42%, 90.17% and 85%, respectively. In trial 2, influences of depth of GSB and photic area in RPIFB on biota were investigated. When the depth of GSB decreased and the photic area of RPIFB grew, the height of Potamogeton crispus Linn. increased, but the biomass of Canna indica Linn. was reduced. The mortalities of Misgurnus anguillicaudatus and Bellamya aeruginosa in each group were all less than 7%. All results indicated that when the RPIFB was embedded into the eutrophic water, the regime shift from phytoplankton-dominated to macrophyte-dominated state could be promoted. Thus, the RPIFB is a promising remediation technology for eutrophication and submerged macrophyte restoration.

Factor graph based navigation and positioning for control system design:A review

Navigation and positioning is an important and challenging problem in many control engineering applications.It provides feedback information to design controllers for systems.In this paper,a bibliographical review on factor graph based navigation and positioning is presented.More specifically,the sensor modeling,the factor graph optimization methods,and the topology factor based cooperative localization are reviewed.The navigation and positioning methods via factor graph are considered and classified.Focuses in the current research of factor graph based navigation and positioning are also discussed with emphasis on its practical application.The limitations of the existing methods,some solutions for future techniques,and recommendations are finally given.

Centroidal Voronoi Tessellation and Model Predictive Control–Based Macro-Micro Trajectory Optimization of Microsatellite Swarm

Probabilistic swarm guidance enables autonomous microsatellites to generate their individual trajectories independently so that the entire swarm converges to the desired distribution shape.However,it is essential to avoid crowding for reducing the possibility of collisions between microsatellites.To determine the collision-free guidance trajectory of each microsatellite from the current position to the target space,a collision avoidance algorithm is necessary.A synthesis method is proposed that generate the collision avoidance trajectories.The idea is that the trajectory planning is divided into macro-planning and microplanning;macro-planning guides where the microsatellites move step by step from the initial cube to the target cube by probabilistic swarm guidance with Centroidal Voronoi tessellation,while the micro-planning is to generate the optimal path for each step and finally reach the specified position in the target cube by model predictive control.Simulation results are presented for the collision-free guidance trajectory of microsatellites to verify the benefits of this planning scheme.

Distinct effects of copper on the degradation of β-lactam antibiotics in fulvic acid solutions during light and dark cycle

This study revealed the dual roles of Cu(Ⅱ)on the β-lactam antibiotics degradation in Suwannee River fulvic acid(SRFA)solution during day and night cycle.Amoxicillin(AMX)and ampicillin(AMP)were selected as the representative β-lactam antibiotics.Cu(Ⅱ)played a key role in the dark degradation of AMX and AMP via catalytic hydrolysis and oxidation.However,Cu(Ⅱ)mainly exhibited an inhibitory effect on SRFA-involved photochemical degradation of AMX and AMP.In the presence of 500 nM of Cu(Ⅱ),the degradation rate of AMX and AMP in the light condition were around 5 times higher than that in the dark condition,suggesting the photodegradation of β-lactam antibiotics was much more pronounced than catalyzed hydrolysis and oxidation.The triplet excited state of SRFA(^(3)SRFA*)primarily contributed to AMX and AMP photodegradation.Hydroxyl radicals(·OH)and singlet oxygen(^(1)O_(2))exhibited limit impacts.The redox cycle of Cu(Ⅱ)/Cu(Ⅰ)restricted the electron transfer pathway of ^(3)SRFA* with AMX and AMP.During the day and night cycles for 48 h,Cu(Ⅱ)served as a stronger inhibitor rather than a promotor.These findings highlight the interactions between Cu(Ⅱ)and SRFA are distinct under day and night conditions,which could further affect the fate of β-lactam antibiotics in natural environments.

Nondestructive Phenomic Tools for the Prediction of Heat and Drought Tolerance at Anthesis in Brassica Species

Oilseed Brassica species are vulnerable to heat and drought stress,especially in the early reproductive stage.We evaluated plant imaging of whole plant and flower tissue,leaf stomatal conductance,leaf and bud temperature,photochemical reflectance index,quantumyield of photosynthesis,and leaf gas exchange for their suitability to detect tolerance to heat(H)and/or drought(D)stress treatments in 12 Brassica genotypes(G).A replicated factorial experiment was set up with 7 d of stress treatment fromthe beginning of anthesis with various levels of three factors H,D,and𝐺.Most phenomics tools detected plant stress as indicated by significant main effects of H,D,and H×D.Whole plant volume was highly correlated with fresh weight changes,suggesting that whole plant imaging may be a useful surrogate for fresh weight in future studies.Vcmax,the maximum carboxylation rate of photosynthesis,increased rapidly on day 1 in H and H+D treatments,and there were significant interactions of G×H and G×D.Vcmax of genotypes on day 1 inHandH+Dtreatments was positively correlated with their harvested seed yield.Vcmax onday 1 andday3were clustered with seed yield in H and H+D treatments as shown in the heatmaps of genotypic correlations.TPU,the rate of triose phosphate use,also showed significant positive genotypic correlations with seed yield in H+D treatments.Flower volume showed significant interactions of G×H and G×D on day 7,and flower volume of genotypes on day 7 inHwas positively correlated with their harvested seed yield.There were few interactions of G×H or G×D for leaf stomatal conductance,leaf and bud temperature,photochemical reflectance index,and quantum yield of photosynthesis.Vcmax,TPU,and volume of flowers are potential nondestructive phenomic traits for heat or combined heat and drought stress tolerance screening in Brassica germplasm.

董事高管责任保险是否增大了“理财诱惑”?

伴随金融供给侧改革的深入,多层次金融产品供给日益增加,然而投资者能否从金融机构身上薅到“真羊毛”却未得其解。鉴于此,本文从高管行为倾向性视角,检验了董事高管责任保险购买对企业委托理财行为的影响。研究发现,董事高管责任保险购买使高管的收益感知提升,损失感知降低,风险感知降低,进而会增大“理财诱惑”,使企业倾向于采取委托理财行为,配置高风险理财产品,并且该“诱惑”在金融关联度高的样本中更为显著。进一步的研究表明:第一,董事高管责任保险带来的“理财诱惑”源于覆盖率条款发挥的兜底效应;第二,购买董事高管责任保险的企业中,稳健型的委托理财行为对企业业绩有正向影响,激进型的委托理财行为对企业业绩有负向影响。本文建议上市公司适度购买董事高管责任保险,促进公司治理机制与董事高管责任保险的良性互动,使投资者远离理财“陷阱”。