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Fracture mechanism of inclusions in thick plate center under tensile loading

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Journal of Iron and Steel Research International 2024年第5期31卷 1196-1209页

作者： Lei Hu Li-qin Zhang Feng Hu Guo-hong Zhang kuan zheng Collaborative Innovation Center for Advanced Steels Wuhan University of Science and TechnologyWuhan430081HubeiChina Department of Applied Physics Wuhan University of Science and TechnologyWuhan430081HubeiChina Analysis and Testing Center Wuhan University of Science and TechnologyWuhan430081HubeiChina

Segregation of solute atoms in the center of thick plates of the tempered steel can cause an inhomogeneous structural transformation and generate micron-sized inclusions,which leads to lamellar tearing of thick plate and decreases the plasticity and *** formation and fragmentation mechanisms of micron-sized inclusions,like MnS and(Nb,Ti)C,in the center of thick plates were investigated by using thermodynamic calculations,finite element simulations,and electron backscatter diffraction characterization *** results show that micron-sized inclusions nucleate and grow in the liquid phase,and under tensile loading,they exhibit three fragmentation *** local stress during the fragmentation of inclusions is lower than the critical fracture stress of adjacent grains,and phase boundaries can effectively impede crack propagation into the *** existence of a low proportion of high-angle grain boundaries(58.1%)and high Kernel average misorientation value(0.534°)in the segregation band promotes inclusions fragmentation and crack *** difference in crack initiation and propagation direction caused by the morphology of inclusions and physical properties,as well as different matrix arrest abilities,is the main reasons for the diversity of inclusion fragmentation.

关键词： Thick plate Inclusion Finite element simulation Critical fracture stress Fracture mechanism

内陆清洁能源基地±800kV/10000MW直流外送拓扑设计

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高电压技术 2024年第5期50卷 2052-2066页

作者：向往梅晓波赵峥郑宽孟沛彧文劲宇强电磁技术全国重点实验室(华中科技大学) 武汉430074 华中科技大学电气与电子工程学院武汉430074 国网经济技术研究院有限公司北京102209

大力开发大规模清洁能源基地是国家“十四五”现代能源体系规划明确的重点任务。针对藏东南地区大规模水电、光伏送出场景,计及新能源基地海拔高、输电走廊受限问题,设计了±800 kV/10000 MW多直流电压等级混合直流、多直流电压等级柔... 详细信息

大力开发大规模清洁能源基地是国家“十四五”现代能源体系规划明确的重点任务。针对藏东南地区大规模水电、光伏送出场景,计及新能源基地海拔高、输电走廊受限问题,设计了±800 kV/10000 MW多直流电压等级混合直流、多直流电压等级柔直和四端混合直流系统送出拓扑。针对沙戈荒地区风电、光伏送出场景,设计了±800 kV/10000 MW三端柔直、四端柔直和多直流电压等级混合直流系统送出拓扑。最后,在PSCAD/EMTDC仿真平台搭建了各拓扑方案的仿真模型,对比分析了各拓扑的技术特点。通过研究,以期为未来相关工程实践拓扑设计提供参考。

关键词：可再生能源并网柔性直流输电常规直流输电换流器拓扑架空线传输

Evaluation of commutation failure risk in single-or multi-infeed LCC-HVDC systems based on equivalent-fault method

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Science China(Technological Sciences) 2018年第8期61卷 1207-1216页

作者： zheng kuan SHEN Chen LIU Feng State Key Laboratory of Power Systems Department of Electrical Engineering Tsinghua University

In single-or multi-infeed line-commutated converter-based high-voltage direct current(LCC-HVDC) systems, commutation failure(CF) induced by alternating current(AC) faults may lead to serious consequences. Considering the randomness of fault occurrences, an accurate evaluation of the CF risk(CFR) from the system point of view becomes necessary in power system planning and operation. This paper first provides a definition of the CF severity(CFS) index corresponding to an AC fault. Then,on the basis of electromagnetic transient(EMT) simulation, an approach to calculate the CFS index considering the randomness of fault-occurrence time is presented. A novel equivalent-fault method is further put forward to make the EMT simulation scalable to calculate the CFS index in terms of a fault occurring in a large-scale receiving-end grid. Thereafter, the CFR index is introduced, which is defined as the sum of the products of the CFS index of each AC fault and the corresponding fault ***, the proposed method is verified on the modified IEEE 9-bus and modified IEEE 39-bus systems using PSCAD/EMTDC.

关键词： commutation failure severity equivalent-fault method commutation failure risk fault randomness electromagnetictransient simulations

基于“煤电矛盾”问题的煤炭中长期合同辩证研究

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中国煤炭 2024年第3期50卷 39-45页

作者：桂俊卿刘平阔郑宽孙千慧上海电力大学经济与管理学院上海市浦东新区201306 中金公司研究院北京市朝阳区100022

煤炭中长期合同是“煤电矛盾”中的功能性问题,虽然目前政府力推签订煤炭中长期合同,但针对煤炭契约仍存在诸多认知不足的问题。分析了煤炭中长期合同的优、缺点,梳理煤电定价模式与煤电交易契约的关系,讨论煤炭契约定价方法与价格波动... 详细信息

煤炭中长期合同是“煤电矛盾”中的功能性问题,虽然目前政府力推签订煤炭中长期合同,但针对煤炭契约仍存在诸多认知不足的问题。分析了煤炭中长期合同的优、缺点,梳理煤电定价模式与煤电交易契约的关系,讨论煤炭契约定价方法与价格波动风险对煤电交易有效性的影响。研究发现,“市场煤、计划电”的定价模式会在一定程度上激化“煤电矛盾”,且该模式在短期内无法改变;煤炭中长期合同是现阶段有效的治理工具,但仍存在机会主义行为与成本疏导问题;目前的煤炭中长期合同应辅以合理的弹性定价法,并利用煤炭差价合约降低价格风险。在此基础上,提出了针对性的政策建议。

关键词：煤电矛盾煤炭中长期合同定价方法价格波动风险

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风电齿轮箱滑动轴承脱黏缺陷超声检测

轴承 2024年第9期 92-99页

作者：郑宽朱琦吴晨晨李青松王文上海大学机电工程与自动化学院上海200444

为了解决铜-钢双金属浇铸成型工件在界面处出现的脱黏缺陷问题,以风电齿轮箱滑动轴承为研究对象,利用Comsol Multiphysics有限元软件建立了双金属浇铸成型工件超声检测仿真模型并进行数值模拟,分析超声波在不同缺陷尺寸下的传播特性;通... 详细信息

为了解决铜-钢双金属浇铸成型工件在界面处出现的脱黏缺陷问题,以风电齿轮箱滑动轴承为研究对象,利用Comsol Multiphysics有限元软件建立了双金属浇铸成型工件超声检测仿真模型并进行数值模拟,分析超声波在不同缺陷尺寸下的传播特性;通过接触式超声检测试验和水浸超声检测试验分析了缺陷波振幅与缺陷尺寸的关系,并对缺陷进行定量表征。结果表明:缺陷波及底波的振幅变化均与缺陷尺寸存在线性关系,C扫描成像能够检测缺陷的相对位置及大小,仿真与试验结果具有良好的一致性。

关键词：滑动轴承风电轴承脱黏数值模拟超声检测

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Radiative Decay Bc → Ds*γ in the Technicolor with a Massless Scalar Doublet Model

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Communications in Theoretical Physics 2002年第7期38卷 47-52页

作者： CAO Yi-Gang JIAO zheng-kuan Department of Physics Zhejiang University Hangzhou 310027 China Department of Physics Zhejiang University Hangzhou 310027 China

Applying perturbative QCD, we study the process Bc → Dsγ in the technicolor with a massless scalar doublet model (TCMLSM). There are mainly two mechanisms contributing to the Bc → D*sγ process. One proceeds through the short distance b → sγ transition and the other through weak annihilation accompanied by a photon *** find that, compared with the standard model, the modification of Bc → D*sγ from πρ (the physical pions in the TCMLSM) is so small that can be neglected for the allowed mass ofπρ. The weak-annihilation contribution is found to be about one order larger than that of the electromagnetic penguin diagrams.

关键词： perturbative QCD, technicolor, massless scalar doublet model

长链非编码RNA ZFAS1通过miR-193b-3p影响胶质瘤顺铂敏感性研究

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中国临床药理学杂志 2024年第12期40卷 1774-1778页

作者：张慧郑款云齐丽娜薛子娇唐山市工人医院检验科河北唐山063000 华北理工大学护理与康复学院河北唐山063000 华北理工大学附属医院康复医学科河北唐山063000

目的研究长链非编码RNA锌指结构反义转录本1(ZFAS1)在胶质瘤细胞中对顺铂敏感性的作用及其潜在机制。方法通过实时荧光定量聚合酶链反应(qRT-PCR)实验分析敲低ZFAS1对胶质瘤细胞顺铂敏感性,分为sh-NC组(转染sh-NC慢病毒质粒)、sh#1组... 详细信息

目的研究长链非编码RNA锌指结构反义转录本1(ZFAS1)在胶质瘤细胞中对顺铂敏感性的作用及其潜在机制。方法通过实时荧光定量聚合酶链反应(qRT-PCR)实验分析敲低ZFAS1对胶质瘤细胞顺铂敏感性,分为sh-NC组(转染sh-NC慢病毒质粒)、sh#1组(转染sh-ZFAS1-1慢病毒质粒)、sh#2组(转染sh-ZFAS1-2慢病毒质粒)。双荧光素酶实验验证ZFAS1与miR-193b-3p之间的相互作用,分为ZFAS1-WT+NC inhibitor组(转染ZFAS1野生型质粒和NC inhibitor)、ZFAS1-WT+miR-193b-3p inhibitor组(转染ZFAS1野生型质粒和miR-193b-3p inhibitor)、ZFAS1-Mut+NC inhibitor组(转染ZFAS1突变型质粒和NC inhibitor)、ZFAS1-Mut+miR-193b-3p inhibitor组(转染ZFAS1突变型质粒和miR-193b-3p inhibitor)。用细胞计数试剂盒-8(CCK-8)和原位末端标记(TUNEL)实验分析ZFAS1/miR-193b-3p影响胶质瘤细胞对顺铂敏感性,分为空白对照组(0μg·mL^(-1)顺铂处理U251细胞)、0.5μg·mL^(-1)顺铂+sh-NC+NC inhibitor组(0.5μg·mL^(-1)顺铂处理共转染sh-NC慢病毒质粒和NC inhibitor的U251细胞)、0.5μg·mL^(-1)顺铂+sh#1+NC inhibitor组(0.5μg·mL^(-1)顺铂处理共转染sh-NC慢病毒质粒和NC inhibitor的U251细胞)和0.5μg·mL^(-1)顺铂+sh#1+miR-193b-3p inhibitor组(0.5μg·mL^(-1)顺铂处理共转染sh-ZFAS1-1慢病毒质粒和miR-193b-3p inhibitor的U251细胞)。结果 sh-NC组、sh#1组和sh#2组的ZFAS1的表达水平分别为1.00±0.17、0.48±0.06和0.68±0.08。ZFAS1-WT+NC inhibitor组、ZFAS1-WT+miR-193b-3p inhibitor组、ZFAS1-Mut+NC inhibitor组、ZFAS1-Mut+miR-193b-3p inhibitor组的荧光活性分别为1.00±0.10、1.45±0.11、1.02±0.09和0.97±0.13。空白对照组、0.5μg·mL^(-1)顺铂+sh-NC+NC inhibitor组、0.5μg·mL^(-1)顺铂+sh#1+NC inhibitor组、0.5μg·mL^(-1)顺铂+sh#1+miR-193b-3p inhibitor组的72 h增殖率分别为(100.00±14.13)%、(96.62±9.82)%、(60.56±6.08)%和(78.64±7.22)%;72 h凋亡率分别为(9.52±1.11)%、(10.12±1.34)%、(16.08±1.52)%和(12.22±1.19)%。空白对照组与0.5μg·mL^(-1)顺铂+sh-NC+NC inhibitor组比较,0.5μg·mL^(-1)顺铂+sh#1+NC inhibitor组与0.5μg·mL^(-1)顺铂+sh#1+miR-193b-3p inhibitor组比较,在统计学上差异均有统计学意义(均P<0.05)。结论本研究揭示了ZFAS1在胶质瘤中对顺铂敏感性的重要作用,并阐明了其通过调控miR-193b-3p影响药物敏感性的机制。

关键词：长链非编码RNA 锌指结构反义转录本1 微小RNA-193b-3p 胶质瘤顺铂敏感性

A Modular Synthesis of Antitumor Macrolide (-)-Lasonolide A

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Chinese Journal of Chemistry 2020年第7期38卷 725-736页

作者： Lin Yang Zuming Lin kuan zheng Luyao Kong Ran Hong CAS Key Laboratory of Synthetic Chemistry of Natural Substances Center for Excellence in Molecular SynthesisShanghai Institute of Organic ChemistryChinese Academy of Sciences345 Lingling RoadShanghai 200032China University of Chinese Academy of Sciences 19A Yuquan RoadBeijing 100049China

Lasonolide A was identified as a potent antitumor macrolide towards various cancer cell *** two tetrahydropyrans bearing multiple stereogenic centers as well as the polyvene linkage attracted a dozen synthetic research groups to launch the total *** on the synthetic methods developed in our group,namely,the hydroboration of allene and its subsequent allylation as well as the iterative hydroboration of allene and oxidation,the polyol subunits were efficiently constructed and then integrated into the final target.A new Julia olefination reagent,double-headed sulfone,was designed to promote the rapid coupling of two aldehydes bearing multiple functional groups to secure the whole carbon *** highlight of our approach is the application of a traceless protecting group,9-BBN(9-borabicyclo[3.3.1]nonane),to hide the secondary alcohol for debenzylation,and for the first time,to mask the carboxylic acid for Julia olefination under strong basic conditions.

关键词： aldehydes linkage reagent

MapReduce Based Parallel Bayesian Network for Manufacturing Quality Control

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Chinese Journal of Mechanical Engineering 2017年第5期30卷 1216-1226页

作者： Mao-kuan zheng Xin-Guo Ming Xian-Yu Zhang Guo-Ming Li School of Mechanical Engineering Shanghai Jiao Tong University

Increasing complexity of industrial products and manufacturing processes have challenged conventional statistics based quality management approaches in the cir- cumstances of dynamic production. A Bayesian network and big data analytics integrated approach for manufacturing process quality analysis and control is proposed. Based on Hadoop distributed architecture and MapReduce parallel computing model, big volume and variety quality related data generated during the manufacturing process could be dealt with. Artificial intelligent algorithms, including Bayesian network learning, classification and reasoning, are embedded into the Reduce process. Relying on the ability of the Bayesian network in dealing with dynamic and uncertain problem and the parallel computing power of MapReduce, Bayesian net- work of impact factors on quality are built based on prior probability distribution and modified with posterior probability distribution. A case study on hull segment manufacturing precision management for ship and offshore platform building shows that computing speed accelerates almost directly pro- portionally to the increase of computing nodes. It is also proved that the proposed model is feasible for locating and reasoning of root causes, forecasting of manufacturing outcome, and intelligent decision for precision problem solving. The inte- gration ofbigdata analytics and BN method offers a whole new perspective in manufacturing quality control.

关键词： Bayesian network Big data analytics MapReduce Quality control