On Energy Assessment of Titanium Alloys Belt Grinding Involving Abrasive Wear Effects

Improved energy utilisation,precision,and quality are critical in the current trend of low-carbon green manufactur-ing.In this study,three abrasive belts were prepared at various wear stages and characterised quantitatively.The effects of abrasive belt wear on the specific grinding energy partition were investigated by evaluating robotic belt grinding of titanium plates.A specific grinding energy model based on subdivided tangential forces of cutting and sliding was developed for investigating specific energy and energy utilisation coefficient EUC.The surface mor-phology and Abbott–Firestone curves of the belts were introduced to analyse the experimental findings from the per-spective of the micro cutting behaviour.The specific grinding energy increased with abrasive belt wear,especially when the belt was near the end of its life.Moreover,the belt wear could lead to a predominance change of sliding and chip formation energy.The highest EUC was observed in the middle of the belt life because of its retained sharp cutting edge and uniform distribution of the grit protrusion height.This study provides guidance for balancing the energy consumption and energy utilization efficiency of belt grinding.

Discussion on the Main Reasons for a Large Number of Père David s Deer ( Elaphurus davidianus ) with Abnormal Antler Shedding

[Objectives]This study was conducted to find out the causes of abnormal antler shedding in Père David s deer(Elaphurus davidianus).[Methods]Abnormally-shed antlers were compared with normally-shed antlers in terms of light condition,antler development and bone nutritional status during the abnormal shedding season in the growth area of Père David s deer.[Results]Abnormally-shed antlers had no significant differences in the development of shed antlers,or even in the overall composition of antlers,from those of normal Père David s deer.[Conclusions]Insufficient light was the main cause of abnormal antler shedding in Père David s deer.

关于畜牧兽医专业群人才需求与专业改革的调研报告

2019年新年伊始,国务院就颁布了“国家职业教育改革实施方案(国发〔2019〕4号)”,自此中国职业教育将驶入内涵建设的快车道。紧接着国家启动实施中国特色高水平高等职业学校和骨干专业(群)建设计划,这表明专业群建设将是形成高职院校核心竞争力的关键。

Residual Condition and Risk Assessment of Heavy Metals in Potato of Inner Mongolia

[Objective] This study was conducted to investigate the pollution degrees of heavy metals in potato and estimate the risk to human health. [Method] The pollution distribution of 7 heavy metals total As, Hg, Cd, Pb, Cr, Ni and Cu in potato was analyzed by monitoring heavy metals in potato samples in Inner Mongolia. [Result] Residual heavy metals in potato in producing areas in Inner Mongolia satisfied national limit standards, and comprehensive heavy metal pollution index was smaller than 0.7, belonging to the safe grade. Among the 7 heavy metals, Pb and Cr pollution was relatively heavier, and contributed more to the comprehensive pollution index. The THQ values and the TTHQ value of the 7 heavy metals were all lower than 1, indicating that pollution of heavy metals in potato in Inner Mongolia caused no remarkably risk to human health. Among the 7 heavy metals, Cr content contributed the most to risk to human health, and the risk caused by Cr intake through potato was higher than that caused by other heavy metals. In different sampling regions, there were differences in risk of heavy metals in potato to human health. [Conclusion] This study provides an objective scientific basis for management of quality safety risk of potato.

A k-mer-based pangenome approach for cataloging seed-storage-protein genes in wheat to facilitate genotype-to-phenotype prediction and improvement of end-use quality

Wheat is a staple foodfor more than 35%of the world's population,with wheatflourused to make hundreds of baked goods.Superior end-use quality is a major breeding target;however,improving it is especially time-consuming and expensive.Furthermore,genes encoding seed-storage proteins(ssPs)form multigene families and are repetitive,with gaps commonplace in several genome assemblies.To overcome these barriers and efficiently identify superior wheat SSP alleles,we developed"PanSK"(Pan-SSP k-mer)for genotype-to-phenotype prediction based on an SsP-based pangenome resource.PanSK uses 29-mer sequences that represent each ssP gene at the pangenomic level to reveal untapped diversity across landraces and modern cultivars.Genome-wide association studies with k-mers identified 23 Ssp genes associated with end-use quality that represent novel targets for improvement.We evaluated the effect of rye secalin genes on end-use quality and found that removal of w-secalins from 1BL/1RS wheat translocation lines is associated with enhanced end-use quality.Finally,using machine-learning-based prediction inspired by PanSK,we predicted the quality phenotypes with high accuracy from genotypes alone.This study provides an effective approach for genome design based on ssP genes,enabling the breeding of wheat varieties with superior processing capabilities and improved end-use quality.

Innovative computational tools provide new insights into the polyploid wheat genome

Bread wheat(Triticum aestivum)is an important crop and serves as a significant source of protein and calories for humans,worldwide.Nevertheless,its large and allopolyploid genome poses constraints on genetic improvement.The complex reticulate evolutionary history and the intricacy of genomic resources make the deciphering of the functional genome considerably more challenging.Recently,we have developed a comprehensive list of versatile computational tools with the integration of statistical models for dissecting the polyploid wheat genome.Here,we summarize the methodological innovations and applications of these tools and databases.A series of step-by-step examples illustrates how these tools can be utilized for dissecting wheat germplasm resources and unveiling functional genes associated with important agronomic traits.Furthermore,we outline future perspectives on new advanced tools and databases,taking into consideration the unique features of bread wheat,to accelerate genomic-assisted wheat breeding.

lcQTH:Rapid quantitative trait mapping by tracing parental haplotypes with ultra-low-coverage sequencing

Dear Editor,Gene cloning has a fundamental role in crop research but has long been hindered by high costs and labor requirements,which have limited the numbers of genes that have been functionally characterized,especially in wheat(Liang et al.,2021).Quantitative trait locus(QTL)mapping is the first step in gene cloning,enabling the localization of genomic loci that show significant associations with quantitative traits.One commonly used strategy is based on single-nucleotide polymorphism(SNP)arrays(Sun et al.,2020).

Facile electrodeposition of 3D concentration-gradient Ni-Co hydroxide nanostructures on nickel foam as high performance electrodes for asymmetric supercapacitors

Novel three-dimensional （3D） concentration-gradient Ni-Co hydroxide nanostructures （3DCGNC） have been directly grown on nickel foam by a facile stepwise electrochemical deposition method and intensively investigated as binder- and conductor-free electrode for supercapacitors. Based on a three- electrode electrochemical characterization technique, the obtained 3DCGNC electrodes demonstrated a high specific capacitance of 1,760 F·g^-1 and a remarkable rate capability whereby more than 62.5% capacitance was retained when the current density was raised from 1 to 100 A·g^-1. More importantly, asymmetric supercapacitors were assembled by using the obtained 3DCGNC as the cathode and Ketjenblack as a conventional activated carbon anode. The fabricated asymmetric supercapacitors exhibited very promising electrochemical performances with an excellent combination of high energy density of 103.0 Wh·kg^-1 at a power density of 3.0 kW·kg^-1, and excellent rate capability-energy densities of about 70.4 and 26.0 Wh·kg^-1 were achieved when the average power densities were increased to 26.2 and 133.4 kW·kg^-1, respectively. Moreover, an extremely stable cycling life with only 2.7% capacitance loss after 20,000 cycles at a current density of 5 A·g^-1 was achieved, which compares very well with the traditional doublelayer supercapacitors.

A widespread response of Gram-negative bacterial acyl-homoserine lactone receptors to Gram-positive Streptomyces γ-butyrolactone signaling molecules

Cell-cell communication is critical for bacterial survival in natural habitats,in which miscellaneous regulatory networks are encompassed.However,elucidating the interaction networks of a microbial community has been hindered by the population complexity.This study reveals thatγ-butyrolactone(GBL)molecules from Streptomyces species,the major antibiotic producers,can directly bind to the acyl-homoserine lactone(AHL)receptor of Chromobacterium violaceum and influence violacein production controlled by the quorum sensing(QS)system.Subsequently,the widespread responses of more Gram-negative bacterial AHL receptors to Gram-positive Streptomyces signaling molecules are unveiled.Based on the cross-talk between GBL and AHL signaling systems,combinatorial regulatory circuits(CRC)are designed and proved to be workable in Escherichia coli(E.coli).It is significant that the QS systems of Gram-positive and Gram-negative bacteria can be bridged via native Streptomyces signaling molecules.These findings pave a new path for unlocking the comprehensive cell-cell communications in microbial communities and facilitate the exploitation of innovative regulatory elements for synthetic biology.

Remarkable anodic performance of lead titanate 1D nanostructures via in-situ irreversible formation of abundant Ti^3＋ as conduction pathways

PX-phase PbTiO3 （PT） nanowires with open channels running along the length direction have been investigated as an anode material for lithium ion batteries. This material shows a stabilized reversible specific capacity of about 410 mAh·g^-1 up to 200 cycles with a charge/discharge voltage plateau of around 0.3-0.65 V. In addition, it exhibits superior high-rate performance, with 90% and 77% capacity retention observed at 1 and 2 A·g^-1, respectively. At a very high current rate of 10 A·g^-1, a specific capacity of over 170 mAh·g^-1 is retained up to 100 cycles, significantly outperforming the rate capability reported for Pb and Pb oxides. The results of X-ray photoelectron spectroscopy （XPS） and transmission electron microscopy （TEM） analyses along with the cyclic voltammogram results reveal that the PX-phase PT nanowires undergo irreversible structural amorphization and reduction reactions during the initial cycle, which allow them to transform into a composite structure composed of 2-5 nm Pb nanoparticles uniformly dispersed in the 1D amorphous Li2O·TiO2·LiTiO2 matrix. In this composite structure, the presence of abundant amounts of Ti^3＋ in both the charged and discharged states enhances the electrical conductance of the system, whereas the presence of ultrafine Pb nanoparticles imparts high reversible capacity. The structurally stable TiO2-based amorphous matrix can also considerably buffer the volume variation during the charge/discharge process, thereby facilitating extremely stable cycling performance. This compound combines the high specific capacity of Pb-based materials and the good rate capability of Ti^3＋-based wiring. Our results might furnish a possible route for achieving superior cycling and rate performance and contribute towards the search for next-generation anode materials.

On the evolution and genetic diversity of the bread wheat D genome

Bread wheat(Triticum aestivum)became a globally dominant crop after incorporating the D genome from the donor species Aegilops tauschii,but the evolutionary history that shaped the D genome during this process remains to be clarified.Here,we propose a renewed evolutionary model linking Ae.tauschii and the hexaploid wheat D genome by constructing an ancestral haplotype map covering 762 Ae.tauschii and hexaploid wheat accessions.We dissected the evolutionary trajectories of Ae.tauschii lineages and reported a few independent intermediate accessions,demonstrating that low-frequency intersublineage gene flow had enriched the diversity of Ae.tauschii.We discovered that the D genome of hexaploid wheat was inherited from a unified ancestral template,but with a mosaic composition that was highly mixed and derived mainly from three Ae.tauschii L2 sublineages located in the Caspian coastal region.This result suggests that early agricultural activities facilitated innovations in D-genome composition and finalized the success of hexaploidization.We found that the majority(51.4%)of genetic diversity was attributed to novel mutations absent in Ae.tauschii,and we identified large Ae.tauschii introgressions from various lineages,which expanded the diversity of the wheat D genome and introduced beneficial alleles.This work sheds light on the process of wheat hexaploidization and highlights the evolutionary significance of the multi-layered genetic diversity of the bread wheat D genome.