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Characteristics of Controlled Bridge Circuit and Its Application in Magnetic Field Induction Measurement

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Tsinghua Science and Technology 2024年第4期29卷 1105-1117页

作者： Yanchu Li qingqing ding Mingchen Yan Jiyao Wang Jun Xu Xinzhou Dong Department of Electrical Engineering Tsinghua UniversityBeijing 100084China State Key Laboratory of Control and Simulation of Power System and Generation Equipments Tsinghua UniversityBeijing 100084China School of Electrical and Electronic Engineering North China Electric Power UniversityBeijing 100096China

The article designs a new type of bridge circuit with a controlled source—when the resistance on the bridge arm of the controlled source bridge circuit meets the bridge balance condition, and the bridge branch contains only one Current-Controlled Current Source (CCCS), a Voltage-Controlled Current Source (VCCS), a Current-Controlled Voltage Source (CCVS), or a Voltage-Controlled Voltage Source (VCVS), the circuit is called a controlled bridge circuit, which has the characteristics of bridge balance. Due to the relationship between the controlled source and the bridge arm, the sensitivity of the components on the bridge is higher mathematically and logically. When applied to measurement, engineering, automatic control, and other fields, the controlled bridge circuit has higher control ac-curacy. Mathematical derivation and simulation results prove the correctness of the bridge balance conclusion and the special properties of this bridge when applied to the measurement field.

关键词： bridge bircuit bridge circuit applications bridge balanced condition controlled bridge circuit magnetic field induction measurement

Atomic-scale mechanism of the θ’’→θ’ phase transformation in Al-Cu alloys

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Journal of Materials Science & Technology 2017年第10期33卷 1159-1164页

作者： Zhenju Shen qingqing ding Chunhui Liu Jiangwei Wang He Tian Jixue Li Ze Zhang Center of Electron Microscopy Zhejiang University Hangzhou 310027 China Center for High-Resolution Electron Microscopy College of Materials Science and Engineering Hunan University Changsha 410082 China State Key Laboratory of Silicon Materials Department of Materials Science and Engineering Zhejiang University Hangzhou 310027 China

The phase transformation of θ’’→θ’ in an Al-5.7 Cu alloy was investigated by aberration-corrected scanning transmission electron microscopy, and the tranformation mode of θ’’→θ’ during aging treatment was clarified. In the presence of the θ’ phases, θ’ was found to be formed by in-situ transformation fromθ’’ with the same plate shape, size and broad faces. The transformation starts from multiple sites within the θ’ precipitate and the whole θ’ phase finally forms as the preferential θ’ sections grow and connect with each other. Antiphase domain boundaries are also found in some θ’ precipitates when the disregistry exists between different θ’ sections.

关键词： Al-Cu alloy θ’ phase Phase transformation Antiphase domains High-angle annular dark field(HAADF)

Inconsistent creep between dendrite core and interdendritic region under different degrees of elemental inhomogeneity in nickel-based single crystal superalloys

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Journal of Materials Science & Technology 2021年第33期92卷 88-97页

作者： Wanshun Xia Xinbao Zhao Liang Yue Quanzhao Yue Jiangwei Wang qingqing ding Hongbin Bei Ze Zhang Institute of Superalloys Science and Technology School of Materials Science and EngineeringZhejiang UniversityHangzhou 310027China Zhejiang Univ Ctr Electron MicroscopyHangzhou 310027China

The creep inconsistency between dendrite core and interdendritic region is investigated in a nickel-based single crystal superalloy under 1373 K and 137 *** specimens with higher and lower degree of elemental inhomogeneity on dendritic structures are *** specimen with higher inhomogeneity,stronger segregation of refractory elements reinforces the local strength in dendrite core,but damages the strength in interdendritic *** strain is accumulated faster in interdendritic region giving rise to promoted dislocation shearing inγphase,faster degradation of dislocation networks and facilitated topological inversion of rated *** the segregation of refractory elements produces a high density of topologically close-packed(TCP)phase in dendrite core,faster accumulation of creep strain forms microcracks prior in interdendritic region that gives rise to final rupture of the *** another specimen,increased solid solution time gives rise to overall reduced *** inconsistency is relieved to show more uniform evolution of dislocation substructures and rafting between dendrite core and interdendritic *** second specimen is ruptured by formation and extension of microcracks along TCP phase although the precipitation of TCP phase is relatively restricted under reduced ***,the balance of local strength between dendrite core and interdendritic region results in over 40%increase of creep rupture life of the second specimen.

关键词： Nickel-based single crystal superalloys Dendritic structure Inhomogeneity Creep Rafting Dislocation networks

Electrical properties of fly ash and its decarbonization by electrostatic separation

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International Journal of Mining Science and Technology 2015年第4期25卷 629-633页

作者： Tao Youjun ding qingqing Deng Mingrui Tao Dongping Wang Xu Zhang Jie School of Chemical Engineering and Technology China University of Mining & Technology Tangshan Branch Tiandi Science & Technology Co. Ltd.

The basic principle of fly ash triboelectrification is analysed. The mineral electrical index and test method are introduced. The electric difference of different mineral composition of fly ash is discussed by analysis of chemical and mineral composition of fly ash in Xinwen power plant. The dielectric constant and charge-mass ratio of carbon and ash of fly ash are tested. Combined with the experimental study on rotary triboelectrostatic separation, the charged characteristic of fly ash particles with different size is gained. The results show that the dielectric constant of fly ash with different grain size decreased with the decrease of particle size, which lead to the poor electrical conductivity, Thus it can be seen that par- ticle size plays a leading role in conductivity, The charge of carbon and ash with each size increased with the decreased of particle size; and the charge-mass ratio between carbon and ash with the same size lar- ger with the decrease of size, which indicated that the finer particle size, the more favorable for triboelec- trification separation. In the same conditions, the best decarburization effect is realized when the particle size ranges from 0.038 to 0.074 ram, whose decarbonization rate and efficiency index reached 38.93% and 120.83% respectively.

关键词： Fly ash Rotary triboelectrostatic separation Electrical property Decarbonization emciency

The dependence of stress and strain rate on the deformation behavior of a Ni‐based single crystal superalloy at 1050°C

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International Journal of Mechanical System Dynamics 2021年第1期1卷 121-131页

作者： qingqing ding Hongbin Bei Lulu Li Jie Ouyang Xinbao Zhao Xiao Wei Ze Zhang School of Materials Science and Engineering Zhejiang UniversityHangzhouChina Polytechnic Institute Zhejiang UniversityHangzhouChina

Ni‐based single crystal(SX)superalloys are important high‐temperature materials used for manufacturing turbine blades in aero‐*** service under combinational impacts of temperature and stress,the SX superalloy may reach its life due to plastic deformation,which normally accompanies time‐dependent microstructural *** reveal this dynamically mechanical response,tensile tests at 1050°C are carried out to record stress‐strain curves at five stain rates as well as creep curves at four applied *** microstructures and defects have been analyzed to understand mechanical behaviors and the underlying mechanism by using advanced scanning electron and scanning transmission electron *** show that the de-formation mode of the alloy strongly depends on the strain rates/applied stresses under mechanical *** dislocation density inside theγphase is extremely low at all tests,indicating that theγphase is relatively weak and ready to flow at this temperature even at a very fast strain *** deformation behavior of theγ′phase is much *** fast strain rates or high applied stresses,the dislocation density in theγ′phase is very high,contributing to high‐stress requirements to deform the *** slow strain rates or low applied stresses,rafting microstructures develop and the de-formation mode becomes directional coarsening/diffusion‐*** results de-monstrate a comprehensive understanding of the deformation mechanism of Ni‐based SX superalloys,which may provide lifetime prediction of the mechanical fail-ure,as well as the database for superalloy applications in mechanical systems.

关键词： creep defects deformation behavior microstructure Ni‐based single crystal superalloy strain rate sensitivity

Comparative analysis of constitutes and metabolites for traditional Chinese medicine using IDA and SWATH data acquisition modes on LC-Q-TOF MS

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Journal of Pharmaceutical Analysis 2020年第6期10卷 588-596页

作者： Dian Kang qingqing ding Yangfan Xu Xiaoxi Yin Huimin Guo Tengjie Yu He Wang Wenshuo Xu Guangji Wang Yan Liang Key Lab of Drug Metabolism&Pharmacokinetics State Key Laboratory of Natural MedicinesChina Pharmaceutical UniversityTongjiaxiang 24Nanjing210009PR China Department of Geriatric Oncology First Affiliated Hospital of Nanjing Medical University(Jiangsu People’s Hospital)No.300 Guangzhou RoadNanjing210029PR China

Identification of components and metabolites of traditional Chinese medicines(TCMs)employing liquid chromatography-quadrupole time-of-flight mass spectrometry(LC-Q-TOF MS)techniques with information-dependent acquisition(IDA)approaches is increasingly frequent.A current drawback of IDA-MS is that the complexity of a sample might prevent important compounds from being triggered in IDA *** window acquisition of all theoretical fragment-ion spectra(SWATH)is a dataindependent acquisition(DIA)method where the instrument deterministically fragments all precursor ions within the predefined m/z range in a systematic and unbiased ***,the superiority of SWATH on the detection of TCMs’components was firstly investigated by comparing the detection efficiency of SWATH-MS and IDA-MS data acquisition modes,and sanguisorbin extract was used as a mode *** optimizing the setting parameters of SWATH,rolling collision energy(CE)and variable Q1 isolation windows were found to be more efficient for sanguisorbin identification than the fixed CE and fixed Q1 isolation *** importantly,the qualitative efficiency of SWATH-MS on sanguisorbins was found significantly higher than that of IDA-MS data *** IDA mode,18 kinds of sanguisorbins were detected in sanguisorbin extract.A total of 47 sanguisorbins were detected when SWATH-MS was used under rolling CE and flexible Q1 isolation window ***,26 metabolites of sanguisorbins were identified in rat plasma,and their metabolic pathways could be deduced as decarbonylation,oxidization,reduction,methylation,and glucuronidation according to their fragmental ions acquired in SWATH-MS ***,SWATH-MS data acquisition could provide more comprehensive information for the component and metabolite identification for TCMs than IDA-MS.

关键词： LC-Q-TOF MS SWATH-MS IDA-MS Sanguisorbin extract Sanguisorbins

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核动力对无人航空飞行器续航能力提升研究

清华大学学报（自然科学版） 2021年第11期61卷 1295-1300页

作者：朱炳聿丁青青清华大学电机工程与应用电子技术系北京100084

续航能力是飞行器性能的重要指标。核能以其能量密度极高的显著优势,有望对无人航空飞行器续航能力带来巨大的提升。该文以国际上某型号无人航空飞行器为原型,通过分析比较核热推进堆芯方案,设计出适用于该无人航空飞行器的核能动力系... 详细信息

续航能力是飞行器性能的重要指标。核能以其能量密度极高的显著优势,有望对无人航空飞行器续航能力带来巨大的提升。该文以国际上某型号无人航空飞行器为原型,通过分析比较核热推进堆芯方案,设计出适用于该无人航空飞行器的核能动力系统核心模块的堆芯方案,用以替代原动力系统发动机中的核心模块燃烧室,并对发动机核心模块装备核动力的可行性、核动力驱动的无人航空飞行器续航能力的提升进行分析研究。结果表明,核动力堆芯重1504.75 kg,需要3%富集度UC 119 kg,燃料工作温度低于2500 K,符合反应堆物理、热工的可行性要求,最终续航时间达近170 d,能够显著提升无人航空飞行器的续航能力。

关键词：核动力无人航空飞行器续航能力

A modified lumped parameter model of distribution transformer winding

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Global Energy Interconnection 2020年第2期3卷 158-165页

作者： qingqing ding Yao Yao Bingqian Wang Jingwei Fu Wei Zhang Chao Zeng Xiaoping Li Stanimir Valtchev State Key Laboratory of Power System Department of Electrical EngineeringTsinghua UniversityHaidian DistrictBeijing100084P.R.China State Grid Hubei Electric Power Co. Research Institute(HBEPRI)Hongshan DistrictWuhan 430077P.R.China Flexible Transmission Engineering Department Nari-Relays Electric Company210003 NanjingP.R.China State Grid Hubei Electric Power Co. LtdHongshan District430077 WuhanP.R.China Department of Electrical and Computer Engineering Faculty of Science and TechnologyUNLPortugal

The modelling of the distribution transformer winding is the starting point and serves as important basis for the transformer characteristics analysis and the lightning pulse response prediction.A distributed parameters model can depict the winding characteristics accurately,but it requires complex *** parameter model requires less calculations,but its applicable frequency range is not *** paper studies the amplitude-frequency characteristics of the lightning wave,compares the transformer modelling methods and finally proposes a modified lumped parameter model,based on the above *** proposed model minimizes the errors provoked by the lumped parameter approximation,and the hyperbolic functions of the distributed parameter *** this modification it becomes possible to accurately describe the winding characteristics and rapidly obtain the node voltage *** proposed model can provide theoretical and experimental support to lightning protection of the distribution transformer.

关键词： Wide band frequency response Distributed parameter model Lumped parameter model Distribution transformer Lightning protection

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电子垃圾拆解区土壤中多氯联苯的垂直分布

环境化学 2015年第8期34卷 1514-1519页

作者：李科丁晴晴北京工商大学环境科学与工程系北京100048

以典型电子垃圾拆解区作为研究区域,采集土芯样品,研究不同深度土壤中多氯联苯(PCBs)的污染状况.研究表明,从事电子垃圾拆解时间较短的采样点A土芯以及从事拆解时间较长的采样点B土芯不同深度土壤中PCBs总含量分别为0.54—45.43 ng·g-... 详细信息

以典型电子垃圾拆解区作为研究区域,采集土芯样品,研究不同深度土壤中多氯联苯(PCBs)的污染状况.研究表明,从事电子垃圾拆解时间较短的采样点A土芯以及从事拆解时间较长的采样点B土芯不同深度土壤中PCBs总含量分别为0.54—45.43 ng·g-1干重和2.16—543.96 ng·g-1干重,两个采样点均受到了不同程度的PCBs污染,B土芯较A土芯污染严重.A和B土芯中PCBs含量由上到下呈下降趋势,表层(0—5cm)最高,5—10 cm层分别减少96.4%和92.6%.A土芯不同深度土壤中PCBs组成有所差异;B土芯各层土壤中PCBs组成较接近,含量较高的PCBs同系物均为5-CBs和6-CBs.相关性分析表明,土芯中1-CBs至9-CBs有相同的污染来源,即电子垃圾拆解,1-CBs至9-CBs随土壤深度向下迁移的能力接近.

关键词：电子垃圾拆解区土芯多氯联苯