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10Ni5CrMoV厚板连续差温轧制工艺

钢铁 2024年第7期59卷 94-101页

作者：王宝山王卫卫张宏亮张翔博冯光宏钢铁研究总院有限公司冶金工艺研究所北京100081

厚板是船舶、化工、高压管道、压力容器等行业必需的钢材品种,但在轧制成形时由于心部变形不充分,导致内部孔洞难以压合,存在心部力学性能偏低、厚度方向上性能不均匀的问题。以10Ni5CrMoV厚板为例,研究了其在差温轧制工艺下的变形规律... 详细信息

厚板是船舶、化工、高压管道、压力容器等行业必需的钢材品种,但在轧制成形时由于心部变形不充分,导致内部孔洞难以压合,存在心部力学性能偏低、厚度方向上性能不均匀的问题。以10Ni5CrMoV厚板为例,研究了其在差温轧制工艺下的变形规律,目的是解决厚板心部变形不足的问题,为差温轧制在厚板成形中的应用提供理论依据。首先通过Gleeble热压缩试验测定了10Ni5CrMoV钢的高温真实应力-真实应变曲线,建立了10Ni5CrMoV钢的本构方程,基于此本构模型,应用有限元方法进行了10Ni5CrMoV厚板5道次轧制过程的数值模拟,分析了心-表温度分布规律和应变分布规律,并进行了轧制验证试验,对比了不同轧制工艺下厚度方向上的变形及组织均匀性。结果表明,当5道次轧制的总变形量为58.3%时,与均温轧制相比,连续差温轧制和首道次差温轧制10Ni5CrMoV厚板心部的等效塑性应变分别提高了5.40%和1.04%,连续差温轧制工艺最有利于心部变形,但是,需要进行道次间冷却才能维持厚板差温轧制所需的心表大温差的温度分布状态。10Ni5CrMoV厚板变形均匀程度依次为连续差温轧制>首道次差温轧制>均温轧制,连续差温轧制后内部晶粒明显细化、组织更均匀。连续差温轧制能有效促进变形向厚板心部渗透,这对均匀化组织、提高力学性能、改善质量具有重要意义。

关键词：厚板本构模型 10Ni5CrMoV钢差温轧制工艺有限元模拟

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基于GNSS载波相位的守时系统远程性能评估方法研究

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大地测量与地球动力学 2024年第3期44卷 251-256页

作者：施敏琳张向波赵当丽孙保琪武建锋中国科学院国家授时中心西安市710600 中国科学院大学北京市100049 中国科学院时间频率基准重点实验室西安市710600

为测试在建守时系统性能,提出基于GNSS载波相位的远程评估方法,并开展实验验证。以国家标准时间UTC(NTSC)为参考,基于西安和北京地区4个测站连续15 d的GNSS观测数据,分别采用PPP和载波相位共视(PCV)法解算得到待测守时系统相对UTC(NTSC... 详细信息

为测试在建守时系统性能,提出基于GNSS载波相位的远程评估方法,并开展实验验证。以国家标准时间UTC(NTSC)为参考,基于西安和北京地区4个测站连续15 d的GNSS观测数据,分别采用PPP和载波相位共视(PCV)法解算得到待测守时系统相对UTC(NTSC)的时间偏差,然后对待测守时系统的相对频率偏差、频率稳定度等关键指标进行分析。结果表明,PCV和PPP时间传递链路的系统误差小,时间传递准确度高,采用PCV和PPP时间传递可准确测量相距较远的守时系统的频率稳定度、相对频率偏差等特性,可为下一步国产守时系统性能远程测试打下坚实基础。

关键词： GNSS 精密单点定位载波相位共视频率稳定度相对频率偏差

知识与数据融合驱动的油气藏智能表征及研究进展

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地球物理学进展 2024年第1期39卷 119-140页

作者：张国印林承焰王志章任丽华张宪国曲康张向博中国石油大学(华东)地球科学与技术学院青岛266580 深层油气全国重点实验室青岛266580 山东省油藏地质重点实验室青岛266580 中国石油大学(北京)地球科学学院北京102249

油气藏是一个极其复杂的地下系统,油气藏表征是一个充满不确定性的科学与技术难题,主要基于知识驱动的传统油气藏表征理论与方法具有局限性,遇到众多难题和发展瓶颈.近年来,以深度学习为代表的人工智能技术广泛应用于油气藏表征问题研究... 详细信息

油气藏是一个极其复杂的地下系统,油气藏表征是一个充满不确定性的科学与技术难题,主要基于知识驱动的传统油气藏表征理论与方法具有局限性,遇到众多难题和发展瓶颈.近年来,以深度学习为代表的人工智能技术广泛应用于油气藏表征问题研究中,并在特定问题上取得突破性进展,但是各方向研究相对分散,缺乏系统性理论认识,人工智能技术与专业领域知识的融合不足.本文提出知识与数据融合驱动的油气藏智能表征的理念与方法,基于油气藏数据特征,利用先进的人工智能技术,融合专业领域知识,充分挖掘油气藏大数据中隐含的有效信息,以实现更可靠、更高精度、更高效率的油气藏表征.同时对油气藏智能表征关键研究内容的最新进展综述,主要包括基于深度学习的测井智能储层评价、地震智能储层预测、储层智能随机建模等方面的研究进展,最后提出油气藏智能表征的发展展望.

关键词：油气藏表征油气藏大数据知识驱动数据驱动人工智能深度学习

Investigation into gas lubrication performance of porous gas bearing considering velocity slip boundary condition

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Friction 2022年第6期10卷 891-910页

作者： xiangbo zhang Shuiting DING Farong DU Fenzhu JI Zheng XU Jiang LIU Qi zhang Yu ZHOU School of Energy and Power Engineering Beihang UniversityBeijing 100191China Aircraft/Engine Integrated System Safety Beijing Key Laboratory Beihang UniversityBeijing 100191China Research Institute of Aero-Engine Beihang UniversityBeijing 100191China School of Transportation Science and Engineering Beihang UniversityBeijing 100191China

Porous gas bearings(PGBs)have a proactive application in aerospace and *** study investigates the gas lubrication performance of a PGB with the condition of velocity slip boundary(VSB)owing to the high Knudsen number in the gas *** Darcy-Forchheimer laws and modified Navier-Stokes equations were adopted to describe the gas flow in the porous layer and gas film region,*** improved bearing experimental platform was established to verify the accuracy of the derived theory and the reliability of the numerical *** effects of various parameters on the pressure distribution,flow cycle,load capacity,mass flow rate,and velocity profile are demonstrated and *** results show that the gas can flow in both directions,from the porous layer to the gas film region,or in *** load capacity of the PGB increases with an increase in speed and inlet pressure and decreases with an increase in *** mass flow rate increases as the inlet pressure and permeability ***,the simulation results using VSB are in agreement with the experimental results,with an average error of 3.4%,which indicates that the model using VSB achieves a high *** simulation results ignoring the VSB overrate the load capacity by 16.42%and undervalue the mass flow rate by 11.29%.This study may aid in understanding the gas lubrication mechanism in PGBs and the development of novel gas lubricants.

关键词： porous gas bearing(PGB) velocity slip boundary(VSB) numerical simulation gas lubrication flow characteristics

Single-cell RNA sequencing reveals the landscape of maize root tips and assists in identification of cell type-specific nitrate-response genes

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The Crop Journal 2022年第6期10卷 1589-1600页

作者： Xuhui Li xiangbo zhang Shuai Gao Fangqing Cui Weiwei Chen Lina Fan Yongwen Qi Institute of Nanfan&Seed Industry Guangdong Academy of ScienceGuangzhou 510316GuangdongChina College of Agriculture and Biology Zhongkai University of Agriculture and EngineeringGuangzhou 510325GuangdongChina

The root system is fundamental for maize growth and *** its heterogeneity and cell type-specific response to nitrate at the single-cell level will shed light on root development and nutrient *** profiled the transcriptomes of>7000 cells derived from root tips of maize seedlings grown on media with or without nitrate,and identified 11 major cell types or tissues and 85 cell type-specific nitrate-response genes,including several known nitrate metabolic genes.A pseudotime analysis showed a continuous pseudotime series with the beginning at meristematic zone cells and showed that the root hair cell was derived by differentiation of a subset of epidermal *** comparison of root cells between maize and rice revealed the conservation and divergence of the root cell types and identified 57,216,and 80 conserved orthologous genes in root hair,endodermis,and phloem cells *** study provides a global view of maize root tip developmental processes and responses to nitrate at the single-cell *** genes described in the present work could serve as targets for further genetic analyses and accurate regulation of gene expression and phenotypic variation in specific cell types or tissues.

关键词： Maize Single-cell RNA sequencing Root Nitrate

Preparation of freestanding palladium nanosheets modified with gold nanoparticles at edges

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Nano Research 2018年第8期11卷 4142-4148页

作者： xiangbo zhang Chao Lian Zheng Chen Chen Chen Yadong Li Department of Chemistry Tsinghua University Beijing 100084 China Department of Chemistry School of Science Belling Jiaotong University Belling 100044 China xiangbo zhang and Chao Lian contributed equally to this work.

Electronic adjustment is one of the most commonly used strategies to improve the catalytic performance of heterogeneous catalysts. We prepared hexagonal ultrathin Pd nanosheets with edges modified by gold nanoparticles （Au@Pd nanosheets） using galvanic replacement method. By virtue of the electronic interactions between the Pd nanosheets and Au nanoparticles, the Au@Pd nanosheets exhibited excellent catalytic performances in the carbonylation of iodobenzene by carbon monoxide. The novel nanocomposites could be applied as model catalysts to explore electronic effects in catalysis.

关键词： palladium gold nanocomposite model catalyst electronic effect

MP3RNA-seq:Massively parallel 3’end RNA sequencing for high-throughput gene expression profiling and genotyping

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Journal of Integrative Plant Biology 2021年第7期63卷 1227-1239页

作者： Jian Chen xiangbo zhang Fei Yi Xiang Gao Weibin Song Haiming Zhao Jinsheng Lai State Key Laboratory of Plant Physiology and Biochemistry National Maize Improvement CenterDepartment of Plant Genetics and BreedingChina Agricultural UniversityBeijing 100193China Center for Crop Functional Genomics and Molecular Breeding China Agricultural UniversityBeijing 100193China

Transcriptome deep sequencing(RNA‐seq)hasbecome a routine method for global geneexpression ***,its application tolarge‐scale experiments remains limited by costand labor *** we describe amassively parallel 3′end RNA‐seq(MP3RNA‐seq)method that introduces unique samplebarcodes during reverse transcription to permitsample pooling immediately following this ***3RNA‐seq allows for handling of hun-dreds of samples in a single experiment,at acost of about$6 per sample for libraryconstruction and ***3RNA‐seq iseffective for not only high‐throughput geneexpression profiling,but also *** its utility,we applied MP3RNA‐seqto 477 double haploid lines of *** iden-tified 19,429 genes expressed in at least 50%ofthe lines and 35,836 high‐quality singlenucleotide polymorphisms for *** with these data,we performedexpression and agronomic trait quantitativetrait locus(QTL)mapping and identified 25,797expression QTLs for 15,335 genes and 21 QTLsfor plant height,ear height,and relative *** conclude that MP3RNA‐seq is highlyreproducible,accurate,and sensitive forhigh‐throughput gene expression profiling andgenotyping,and should be generally applicableto most eukaryotic species.

关键词： gene expression profiling genotyping maize MP3RNA‐seq quantitative trait loci

Overexpression of the Wounding-Responsive Gene AtMYB15 Activates the Shikimate Pathway in Arabidopsis

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Journal of Integrative Plant Biology 2006年第9期48卷 1084-1095页

作者： Yanhui Chen xiangbo zhang Wei Wu zhangliang Chen Hongya Gu Li-Jia Qu National Laboratory for Protein Engineering and Plant Genetic Engineering Peking-Yale Joint Research Center for Plant Molecular Genetics and AgroBiotechnology College of Life Sciences Peking University Beijing 100871 China The National Plant Gene Research Center （Beijing） Beijing 100101 China

The MYB transcription factor genes play important roles in many developmental processes and various defense responses of plants. The shikimate pathway is a major biosynthetic pathway for the production of three aromatic amino acids and other aromatic compounds that are involved in multiple responses of plants, including protection against UV and defense. Herein, we describe the characterization of the R2R3-MYB gene AtMYB15as an activator of the shikimate pathway in Arabidopsis. The AtMYB15 protein is nuclear localized and a transcriptional activation domain is found in its C-terminal portion. Northern blots showed that AtMYB15 is an early wounding-inducible gene. Resutls of microarray analysis, confirmed using quantitative real-time polymerase chain reaction, showed that overexpression of AtMYB15 in transgenic plants resulted in elevated expression of almost all the genes involved in the shikimate pathway. Bioinformatics analysis showed that one or more AtMYB15-binding AC elements were detected in the promoters of these upregulated genes. Furthermore, these genes in the shikimate pathway were also found to be induced by wounding. These data suggest an important role of AtMYB15as a possible direct regulator of the Arabidopsis shikimate pathway in response to wounding.

关键词： MYB transcription factor shikimate pathway transcriptional activation domain wounding inducible