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Observability Analysis of Integrated Electricity and Heating Systems with Thermal Quasi-dynamics in Pipelines

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CSEE Journal of Power and Energy Systems 2024年第3期10卷 1145-1158页

作者： Zhigang Li Wenjian zheng Junbo Zhao J.H.zheng Q.H.Wu School of Electric Power Engineering South China University of TechnologyGuangzhou 510641China Fuzhou Changle District Power Supply Company of State Grid Fujian Electric Power Co. Ltd.Fuzhou 350000China Department of Electrical and Computer Engineering University of ConnecticutStorrsCT 06269USA CSEE IEEE

Observability analysis(OA)is vital to obtaining the available input measurements of state estimation(SE)in an integrated electricity and heating system(IEHS).Considering the thermal quasi-dynamics in pipelines,the measurement equations in heating systems are dependent on the estimated results,leading to an interdependency between OA and *** OA methods require measurement equations be known exactly before SE is performed,and they are not applicable to *** bridge this gap,a scenario-based OA scheme for IEHSs is devised that yields reliable analysis results for a predefined set of time-delay scenarios to cope with this *** its core procedure,the observable state identification and observability restoration are formulated in terms of integer linear *** tests are conducted to demonstrate the validity and superiority of the proposed formulation.

关键词： Integrated electricity and heating system measurement observability analysis state estimation thermal quasi-dynamics

Locating Sources of Oscillations Induced by Control of Voltage Source Converters Based on Energy Structure and Nonlinearity Detection

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Journal of Modern Power Systems and Clean Energy 2024年第4期12卷 1285-1294页

作者： Zetian zheng Shaowei Huang Jun Yan Qiangsheng Bu Chen Shen Mingzhong zheng Ye Liu State Key Laboratory of Power Systems Department of Electrical EngineeringTsinghua UniversityBeijing 100084China State Grid Jiangsu Electric Power Co. Ltd.Research InstituteNanjing 211103China

The oscillation phenomena associated with the con-trol of voltage source converters(VSCs)are concerning,mak-ing it crucial to locate the sources of such oscillations and sup-press the ***,this paper presents a location scheme based on the energy structure and nonlinearity *** energy structure,which conforms to the principle of the energy-based method and dissipativity theory,is developed to describe the transient energy flow for VSCs,based on which a defined characteristic quantity is implemented to narrow the scope for locating the sources of ***,based on the self-sustained oscillation characteristics of VsCs,an in-dex for nonlinearity detection is applied to locate the VSCs that produce the oscillation *** combination of the energy structure and nonlinearity detection distinguishes the contribu-tions of different VSCs to the *** results of a case study implemented by the PSCAD/EMTDC simulation validate theproposed scheme.

关键词： Double-loop proportional-integral(PI)control energy structure Hamiltonian model nonlinearity detection oscillation source location(OSL) voltage source converter(VSC)

A Novel Scheduling Framework for Multi-Programming Quantum Computing in Cloud Environment

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Computers, Materials & Continua 2024年第5期79卷 1957-1974页

作者： Danyang zheng Jinchen Xv Feng Yue Qiming Du ZhihengWang zheng Shan Information Engineering University Zhengzhou450001China

As cloud quantum computing gains broader acceptance,a growing quantity of researchers are directing their focus towards this ***,the rapid surge in demand for cloud-based quantum computing resources has led to a scarcity,which in turn hampers users from achieving optimal ***,cloud quantum computing service providers require a unified analysis and scheduling framework for their quantumresources and user jobs to meet the ever-growing usage *** paper introduces a new multi-programming scheduling framework for quantum computing in a cloud *** framework addresses the issue of limited quantum computing resources in cloud environments and ensures a satisfactory user *** introduces three innovative designs:1)Our framework automatically allocates tasks to different quantum backends while ensuring fairness among users by considering both the cloud-based quantum resources and the user-submitted tasks.2)Multi-programming mechanism is employed across different quantum backends to enhance the overall throughput of the quantum *** comparison to conventional task schedulers,our proposed framework achieves a throughput improvement of more than two-fold in the quantum cloud.3)The framework can balance fidelity and user waiting time by adaptively adjusting scheduling parameters.

关键词： Quantum computing scheduling multi-programming qubit mapping

Greedy Lattice Paths with General Weights

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Acta Mathematica Sinica,English Series 2024年第9期40卷 2213-2222页

作者： Yin Shan CHANG An Qi zheng College of Mathematics Sichuan UniversityChengdu 610065P.R.China

Let{X_(v):v∈Z^(d)}be *** *** S(π)=Σ_(v∈π)X_(v)be the weight of a self-avoiding lattice pathπ.Let M_(n)=max{S(π):πhas length n and starts from the origin}.We are interested in the asymptotics of Mn as n→∞.This model is closely related to the first passage percolation when the weights{X_(v):v∈Z^(d)}are non-positive and it is closely related to the last passage percolation when the weights{X_(v):v∈Z^(d)}are *** general weights,this model could be viewed as an interpolation between first passage models and last passage ***,this model is also closely related to a variant of the position of right-most particles of branching random *** the two assumptions that∃α>0,E(X_(0)^(+))^(d)(log^(+)X_(0)^(+))^(d+α)0,E(X_(0)^(+))^(d)(log^(+)X_(0)^(+))^(d+α)<+∞and that E[(X_(0)^(−))^(4)]<+∞,we prove that M_(n)/n converges to the same constant M almost surely as n tends to infinity.

关键词： Last passage percolation first passage percolation greedy lattice path

Fatigue-resistant sliding ferroelectricity

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Science China Materials 2024年第10期67卷 3417-3418页

作者： zheng Liu School of Materials Science and Engineering Nanyang Technological University

The direction of spontaneous polarization in ferroelectricity can be reoriented by an external electric *** special feature of ferroelectricity is important candidates for fabricating advanced nonvolatile random-access memory[1].However,repeatedly switching polarization induces the ferroelectric device performance degenerates due to a reduction of polarization.

关键词： THIN-FILMS

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基于提高冷却温度的机车柴油机部件可靠性研究

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铁道机车车辆 2020年第4期40卷 80-84页

作者：郑永强薛良君张强中车戚墅堰机车有限公司产品设计部江苏常州213011

基于提高柴油机高温冷却水、机油出口温度,可降低内燃机车冷却单节的体积及质量,利于机车的总体设计,对燃油经济性及热效率有一定改善。通过热平衡试验研究确定了冷却温度提高的范围,采用有限元法分析了气缸盖温度场分布及热应力水平;... 详细信息

基于提高柴油机高温冷却水、机油出口温度,可降低内燃机车冷却单节的体积及质量,利于机车的总体设计,对燃油经济性及热效率有一定改善。通过热平衡试验研究确定了冷却温度提高的范围,采用有限元法分析了气缸盖温度场分布及热应力水平;进行了滑动轴承NHD分析,明确了该型柴油机滑动轴承的使用温度范围;测试并对比了活塞温度场在温升前、后的变化,确保了承受热负荷部件的使用可靠性,为干线机车用柴油机的设计提供数据支撑。

关键词：内燃机车柴油机温度场热应力 NHD分析

Black hole evaporation and its remnants with the generalized uncertainty principle including a linear term

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Communications in Theoretical Physics 2024年第2期76卷 125-136页

作者： Bo Yu zheng-wen Long College of Physics Guizhou UniversityGuiyang550025China

In recent years,researchers have investigated the evaporation of Schwarzschild black holes using various forms of the generalized uncertainty principle(GUP),metric quantum correction,and noncommutative geometry,***,there are differences between the GUP correction and the other two methods in terms of describing the later stages of black hole ***,some studies argue that the GUP with a negative parameter cannot effectively correct black hole evaporation,while others contend that the positivity or negativity of the GUP parameters should not affect the correction *** the above into consideration,we reconsider black hole evaporation with the generalized uncertainty principle including a linear term(LGUP),and examine the case of negative *** results indicate that the evaporation behavior of both Schwarzschild black holes and Reissner–Nordstr?m black holes,under LGUP correction,is consistent with the results of metric quantum correction and non-commutative ***,the negative parameter LGUP can also effectively correct for black hole evaporation.

关键词： black hole evaporation generalized uncertainty principle negative parameter

Nanoscale materials transformations revealed by liquid phase TEM

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Nano Research 2024年第10期17卷 9152-9165页

作者： Qiubo Zhang Daewon Lee Haimei zheng Materials Sciences Division Lawrence Berkeley National LaboratoryBerkeleyCalifornia 94720USA Department of Materials Science and Engineering University of CaliforniaBerkeleyCalifornia 94720USA

Nanoscale materials often undergo structural,morphological,or chemical changes,especially in solution processes,where heterogeneity and defects may significantly impact the transformation *** phase transmission electron microscopy(TEM),allowing us to track dynamic transformations of individual nanoparticles,has become a powerful platform to reveal nanoscale materials transformation pathways and address challenging issues that are hard to approach by other *** the development of modern liquid cells,implementing advanced imaging and image analysis methods,and strategically exploring diverse systems,significant advances have been made in liquid phase TEM,including improved high-resolution imaging through liquids at the atomic level and remarkable capabilities in handling complex systems and *** the past more than a decade,we spent much effort in developing and applying liquid phase TEM to elucidate how atomic level heterogeneity and defects impact various physicochemical processes in liquids,such as growth,self-assembly of nanoparticles,etching/corrosion,electrodeposition of alkali metals,catalyst restructuring during reactions,and so *** article provides a brief review of the liquid phase TEM study of nanoscale materials transformations,focusing on the growth of nanomaterials with distinct shape/hierarchical structures,such as one-dimensional(1D)growth by nanoparticle attachment,two-dimensional(2D)growth with nanoparticles as intermediates,core-shell structure ripening,solid-liquid interfaces including those in batteries and electrocatalysis,highlighting the impacts of heterogeneity and defects on broad nanoscale transformation pathways.

关键词： liquid phase transmission electron microscopy(TEM) liquid cells nanomaterials growth transformations pathways solid-liquid interface heterogeneity and fluctuations

Effect of Pre-strain on Microstructure and Stamping Performance of High-strength Low-alloy Steel

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Journal of Wuhan University of Technology(Materials Science) 2024年第3期39卷 774-780页

作者：刘坡 WEN Zhicheng LIU zheng 许峰 School of Mechanical Engineering Guilin University of Aerospace TechnologyGuilin 541004China School of Automotive Engineer-ing Changshu Institute of TechnologyChangshu 215500China

In this study,pre-strain ranging from 0 to 0.12 was applied through uniaxial tension on high-strength low-alloy(HSLA)specimens with four kinds of grain *** of pre-strain and grain size on me-chanical property was investigated through tensile *** of the pre-strained and tensile tested samples were analyzed,*** 30.8°v-bending and following flattening,as well as Erichson cupping tests,were performed on the pre-strained *** show the elongation ratio of grain and dislocation density increases with *** platform is removed when pre-strain is larger than 0.06 while yielding plateau period decreases with pre-strain less than 0.06 due to reduction of pinning *** 30.8°v-bending and the following flattening tests are successfully accomplished on all the pre-strained samples with different grain *** in grain size,along with increase in pre-strain,causes increase in strength and decrease in elongation rate as well as cupping ***-strain causes very slight effect on bending ability,much less than that on mechanical property and cupping test *** impact of the pre-strain and grain size on HSLA steel deformability is inconspicuous.

关键词： strain hardening dislocation texture bending erichson cupping test