Smart Design and Manufacturing the Welded Q350 Steel Frames via Lifecycle Management Strategy of Digital Twin

Artificial intelligent aided design and manufacturing have been recognized as one kind of robust data-driven and data-intensive technologies in the integrated computational material engi-neering(ICME)era.Motivated by the dramatical developments of the services of China Railway High-speed series for more than a decade,it is essential to reveal the foundations of lifecycle man-agement of those trains under environmental conditions.Here,the smart design and manufacturing of welded Q350 steel frames of CR200J series are introduced,presenting the capability and opportu-nity of ICME in weight reduction and lifecycle management at a cost-effective approach.In order to address the required fatigue life time enduring more than 9×10^(6)km,the response of optimized frames to the static and the dynamic loads are comprehensively investigated.It is highlighted that the maximum residual stress of the optimized welded frame is reduced to 69 MPa from 477 MPa of previous existing one.Based on the measured stress and acceleration from the railways,the fatigue life of modified frame under various loading modes could fulfil the requirements of the lifecycle man-agement.Moreover,our recent developed intelligent quality control strategy of welding process mediated by machine learning is also introduced,envisioning its application in the intelligent weld-ing.

Transcriptional analysis and histochemistry reveal that hypersensitive cell death and H2O2 have crucial roles in the resistance of tea plant (Camellia sinensis (L.) O. Kuntze) to anthracnose

Anthracnose causes severe losses of tea production in China.Although genes and biological processes involved in anthracnose resistance have been reported in other plants,the molecular response to anthracnose in tea plant is unknown.We used the susceptible tea cultivar Longjing 43 and the resistant cultivar Zhongcha 108 as materials and compared transcriptome changes in the leaves of both cultivars following Colletotrichum fructicola inoculation.In all,9015 and 8624 genes were differentially expressed between the resistant and susceptible cultivars and their controls(0 h),respectively.In both cultivars,the differentially expressed genes(DEGs)were enriched in 215 pathways,including responses to sugar metabolism,phytohormones,reactive oxygen species(ROS),biotic stimuli and signalling,transmembrane transporter activity,protease activity and signalling receptor activity,but DEG expression levels were higher in Zhongcha 108 than in Longjing 43.Moreover,functional enrichment analysis of the DEGs showed that hydrogen peroxide(H2O2)metabolism,cell death,secondary metabolism,and carbohydrate metabolism are involved in the defence of Zhongcha 108,and 88 key genes were identified.Protein–protein interaction(PPI)network demonstrated that putative mitogen-activated protein kinase(MAPK)cascades are activated by resistance(R)genes and mediate downstream defence responses.Histochemical analysis subsequently validated the strong hypersensitive response(HR)and H2O2 accumulation that occurred around the hyphal infection sites in Zhongcha 108.Overall,our results indicate that the HR and H2O2 are critical mechanisms in tea plant defence against anthracnose and may be activated by R genes via MAPK cascades.

Genome-wide identification and expression profiling reveal the diverse role of Methyl-CpG-binding domain proteins in tea plant Camellia sinensis

Methyl-CpG-binding domain(MBD)proteins are important DNA methylation readers that recognise methylated CpG sites and recruit histone deacetylase(HDAC)complexes and chromatin remodelling factors,leading to chromatin compaction,gene transcription,and genome integrity.Currently,MBD genes have only been identified in a few plant species and their structure and function in tea plants(Camellia sinensis)are unknown.In this study,16 C.sinensis MBD genes(CsMBD)were identified on a genome-wide level and classified into eight classes.The CsMBD genes were mapped on nine chromosomes in tea plants,and nine pairs of CsMBD genes existed.Based on conserved domain analysis,all of the identified CsMBD proteins contained at least one MBD domain.Expression analyses showed that CsMBD genes were expressed in tissue-and organ-specific patterns.We investigated the expression patterns of CsMBD genes in response to abiotic and biotic stresses and during different plant growth and development stages.Multiple pthytohormone and stress-related cis-acting was evaluated in their promoter region,such as GGTCA,TGACG,ABRE and LTR.Specific CsMBD genes were associated with environmental stresses and developmental stages,with little overlap.Overall,our findings reveal the diverse roles of CsMBD genes under different stress and developmental conditions,highlighting candidate genes for further functional studies on tea plants.

简单易得的自氧化纳米泡沫镍用于高性能析氢和析氧催化

开发组成简单、无贵金属、制备简洁的自支撑析氢、析氧催化反应(HER和OER)催化剂是电解水的关键需求之一.本文以Mg_(80)Ni_(20)非晶合金薄带为前驱体,采用一步脱合金法制备了具有自支撑结构的自氧化纳米泡沫镍,在电流密度为10 mA cm^(-2)时HER和OER的过电位仅分别为33.1和330 mV,且均具有长达100 h的长期稳定性.基于纳米泡沫镍的水电解槽达到10 mA cm^(-2)的外加电压仅为1.58 V.纳米泡沫镍独特的三维超细多孔结构显著促进了其表观活性,同时其Ni/NiO复合结构显著提高了本征HER活性.本工作验证了纳米泡沫金属是一种有潜力的高性能催化材料.

Catalytic reductive amination of furfural to furfurylamine on robust ultra-small Ni nanoparticles

The synthesis of primary amines via reductive amination in the presence of NH_(3)and H_(2),as a green and sustainable process,has attracted much attention.In this paper,we prepared series of Ni/SiO_(2)catalysts with deposition-precipitation and impregnation methods,and their catalytic performances on the reductive amination of a biomass derived compound of furfural to produce furfurylamine were studied.The catalytic activity and the yield were correlated to the structure and the surface properties of catalysts largely.The Ni/SiO_(2)is of high Lewis acidity and small Ni particle with numerous large Ni flat step surface showed high activity and selectivity,it afforded a reaction rate of 12.8 h^(−1)and a high yield to furfurylamine around 98%.These results are superior to the most non-noble metal catalysts reported so far.Moreover,the reaction route was examined with the unit control reactions of the intermediate.To produce furfurylamine selectively,the most suitable catalyst should have the moderate but not the highest activity in activation of hydrogen and hydrogenation in the reductive amination of furfural.This work provides some useful information for the catalytic reductive amination of aldehydes both in the design of catalyst and the reaction route.

Arene C-H Iodination Using Aryl Iodides

Metathesis reactions represent powerful synthetic tools that have been used in a number of fields from the synthesis of natural product to functional material preparation.However,the C-H metathesis reaction is extremely rare.Herein,we report the first Pd(Ⅱ)-catalyzed C-H iodination of arenes using 2-nitrophenyl iodides as the mild iodinating reagents via a formal metathesis reaction.Unusual C-I bond formation occurred with aryl iodides in preference to competing C-C coupling in this reaction.Assisted by aliphatic carboxyl directing groups,a range of hydrocinnamic acids and related arenes could be selectively iodinated at either meta-or orthopositions of the phenyl ring.Remote diastereoselective C-H activation was also promising.This method might unfold a novel approach to iodinate challenging substrates.