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Experimental Study on Diesel Spray and Flame Asymmetry Characteristics of Dual-Orifice Nozzles for a Medium-Speed Engine

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Journal of Thermal Science 2025年第1期34卷 303-322页

作者： JU Dehao LIU Rui zheng liang DENG Jiahui ZHANG Wenzheng HUO Jinlu HUANG Li Shanghai Marine Diesel Engine Research Institute National Key Laboratory of Marine Engine Science and Technology Key Laboratory for Power Machinery and Engineering Ministry of EducationShanghai Jiao Tong University

The asymmetry of the multi-orifice spray will cause uneven heat load of the marine diesel engine,thereby affecting its working performance and service ***,an in-depth understanding of the spray and flame characteristics of multi-orifice nozzles will guide the optimization of the nozzle structure,needle design and diesel atomization and combustion *** this reason,four groups of dual-orifice nozzles with different hole diameters(0.1-0.55 mm) and mass flow rates covering the typical marine medium-speed diesel injections are designed and customized,and the constant volume chamber(CVC) with high temperature and pressure is used to simulate the actual in-cylinder working conditions of the diesel engine for the spray visualization *** study the asymmetry of the fuel sprays discharged from a diesel injector,the multi-orifice nozzle is simplified as a dual-orifice nozzle in this *** with X-ray Computed Tomography(CT) imaging technology,the influences of the nozzle internal structure on the spray and flame asymmetry are studied in the constructed supercritical *** is found that the asymmetry of the inlet angle and the equivalent length-diameter ratio is positively correlated with the inconsistency of the dual *** an increase in the injection pressure and nozzle diameter,the asymmetry of the dual spray becomes more pronounced,resulting in greater disparities in the ignition delay times and ignition positions of the two ***,the increase in nozzle diameter also leads to combustion instability,resulting in a flame with a serrated *** the increase of ambient temperature,the proportion of liquid phase in the jet decreases and the relative density of spray front decreases.

关键词： atomization dual-orifice nozzle nozzle structure spray flame asymmetry

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Synthesis and Electrochemical Properties of SnCo_(1-x)Fe_x/C Composite

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Journal of Materials Science & Technology 2010年第7期26卷 653-659页

作者： zheng liang Shaobin Yang College of Materials Science and Engineering Liaoning Technical University Fuxin 123000 China University of Michigan-Shanghai Jiao Tong University Joint Institute Shanghai 200240 China

The SnCo1-xFex/C （x=0.1, 0.2, 0.3, 0.4） composites as novel anode materials for lithium-ion batteries with large capacity were prepared by ball milling first and then solid-state sintering. The influences of the partial substitution of inert metal Fe for Co on material structures and the electrochemical properties were investigated. Structure analyses show that the uniform solid dissolution of Fe into CoSn phase promotes the formation of CoSn2 impurity phase. With the growth of x, the cell volumes of CoSn phase is enlarged, the grain size decreases and the content of CoSn2 increases. Carbon black is mainly physically mixed with other phases on the surface of particles. Electrochemical analyses reveal that the reversible capacity and cycle performance are both improved through the introduction of Fe. When x is 0.2, the cycle performance is up to the maximum, 85.1% of the reversible capacity after 50 cycles. During cycling, among SnCo/C, SnCo0.8Fe0.2/C and SnCo0.6Fe0.4/C samples, the grain size of CoSn phase for SnCo0.8Fe0.2/C sample increases leastly. It is usually believed that the comprehensive effects of grain size, structure stability and impurity-phase content lead to the maximum of the cycle performance at appropriate content of Fe （x=0.2）.

关键词： Lithium-ion batteries SnCo/C Fe Cycle performance Grain refinement

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Further developments of a multi-phase transport model for relativistic nuclear collisions

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Nuclear Science and Techniques 2021年第10期32卷 110-142页

作者： Zi-Wei Lin liang zheng Department of Physics East Carolina UniversityGreenvilleNC 27858USA School of Mathematics and Physics China University of Geosciences(Wuhan)Wuhan 430074China

A multi-phase transport(AMPT)model was constructed as a self-contained kinetic theory-based description of relativistic nuclear collisions as it contains four main components:the fluctuating initial condition,a parton cascade,hadronization,and a hadron ***,we review the main developments after the first public release of the AMPT source code in 2004 and the corre-sponding publication that described the physics details of the model at that *** also discuss possible directions for future developments of the AMPT model to better study the properties of the dense matter created in relativistic collisions of small or large systems.

关键词： QGP Transport model Heavy-ion collisions

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Detailed string stability analysis for bi-directional optimal velocity model

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Journal of Central South University 2015年第4期22卷 1563-1573页

作者：郑亮 School of Traffic & Transportation Engineering Central South University

The class of bi-directional optimal velocity models can describe the bi-directional looking effect that usually exists in the reality and is even enhanced with the development of the connected vehicle technologies. Its combined string stability condition can be obtained through the method of the ring-road based string stability analysis. However, the partial string stability about traffic fluctuation propagated backward or forward was neglected, which will be analyzed in detail in this work by the method of transfer function and its H∞ norm from the viewpoint of control theory. Then, through comparing the conditions of combined and partial string stabilities, their relationships can make traffic flow be divided into three distinguishable regions, displaying various combined and partial string stability performance. Finally, the numerical experiments verify the theoretical results and find that the final displaying string stability or instability performance results from the accumulated and offset effects of traffic fluctuations propagated from different directions.

关键词： traffic flow string stability optimal velocity model linearized stability theory transfer function

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Discovering the relationship of disasters from big scholar and social media news datasets

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International Journal of Digital Earth 2019年第11期12卷 1341-1363页

作者： liang zheng Fei Wang Xiaocui zheng Binbin Liu Institute of Safety Science and Technology Department of Engineering PhysicsShenzhen Graduate SchoolTsinghua UniversityShenzhenPeople’s Republic of China

The construction method for chains of disasters or events is still one of the core scientific questions in studying the common rules of disaster’s *** when dealing with the complexity and diversity of disasters,it is critical to make a further investigation on reducing the dependency of prior knowledge and supporting the comprehensive chains of *** paper tries to propose a novel approach,through collecting the big scholar and social news data with disasterrelated keywords,analysing the strength of their relationships with the co-word analysis method,and constructing a complex network of all defined disaster types,in order to finally intelligently extract the unique disaster chain of a specific disaster *** Scholar,Baidu Scholar and Sina News search engines are employed to acquire the needed data,and the respectively obtained disaster chains are compared with each other to show the robustness of our proposed *** achieved disaster chains are also compared with the ones concluded from existing research methods,and the very reasonable result is *** is a great potential to apply this novel method in disaster management domain to find more secrets about disasters.

关键词： Disaster chain co-occurrence analysis co-word analysis community division complex network data mining disaster management

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Non-isothermal kinetics of synthesizing vanadium nitride by one-step method

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Rare Metals 2015年第10期34卷 738-743页

作者： Jiang Dong Yue Yu zheng-liang Xue School of Materials and Metallurgy Wuhan University of Science and Technology

Vanadium nitride was synthesized by one-step method using V2O5 and carbon black as raw materials in nitrogen atmosphere. The phases of different reaction products prepared in different reaction temperatures were analyzed by X-ray diffraction(XRD), and the dynamic behavior of the process of synthesizing vanadium nitride(VN) by one-step method was studied with non-isothermal thermogravimetry. The mechanism function and kinetic parameters of reaction process were calculated by thermal gravimetric analyses(TGA), and the reaction rate equation was established. The XRD results show that for the samples tested with minimal VN after holding for 4 h at 1273 K, the main phase of products is VN at 1476 K, while some vanadium nitrides transform into vanadium carbides again over 1573 K. It is found that N2 is beneficial to stimulate reduction and proceed carbonization reaction,and the reduction and nitridation reaction can occur simultaneously. The activation energy of preparing VN by one-step method is 104.005 kJ·mol-1, and the frequency factor is 470.52 at 1280–1358 K, and 150.052 kJ·mol-1 and 2.35 9 104 at 1358–1426 K, respectively.

关键词： Vanadium nitride Reduction and nitridation Thermog

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Traffic flow cellular automaton model with bi-directional information in an open boundary condition

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Transportation Safety and Environment 2021年第1期3卷 1-9页

作者： liang zheng zhengpeng He School of Traffic&Transportation Engineering Central South UniversityChangshaChina

With Connected Vehicle Technologies being popular,drivers not only perceive downstream traffic information but also get upstream information by routinely checking backward traffic conditions,and the backward-looking frequency or probability is usually affected by prevailing traffic ***,the bi-directional perception range of drivers is expected to significantly increase,which results in more informed and coordinated driving ***,we propose a traffic flow bi-directional CA model with two perception ranges,and perform the numerical simulations with the field data collected from a one-lane highway in Richmond,California,USA as the benchmark *** results show that the CA model can effectively reproduce the oscillation of relatively congested traffic and the traffic hysteresis *** adjusting the backward-looking probability and the perception range,the CA model can well simulate the travel times of all vehicles,and the generation and dissolution of traffic jams under various scenarios.

关键词： traffic flow cellular automaton backward-looking perception range hysteresis phenomenon

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Protective effects of two food hydrocolloids on dental erosion:Nanomechanical properties and microtribological behavior study

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Friction 2021年第2期9卷 356-366页

作者： Heng XIAO liang zheng Wei HAN Rui WU Jing zheng Zhongrong ZHOU Tribology Research Institute Key Laboratory of Advanced Technologies of MaterialsMinistry of EducationSouthwest Jiaotong UniversityChengdu 610031China Institute of Oceanographic Instrumentation Shandong Provincial Key Laboratory of Marine Monitoring Instrument and Equipment TechnologyQilu University of Technology(Shandong Academy of Sciences)Qingdao 266061China

In this study,the protective effects of two food hydrocolloids,Xanthan gum and Arabic gum,on dental erosion are investigated from the perspective of the nanomechanical properties and microtribological behavior of acid-eroded *** specimens prepared from extracted human teeth were immersed in citric acid solution(CAS),CAS with 0.03%w/v Xanthan gum and CAS with 0.03%w/v Arabic gum,respectively,for 10 min to obtain three groups of eroded *** nanomechanical properties and microtribological behavior of enamel were examined using nano-indentation/scratch *** results show that compared with Arabic gum,Xanthan gum inhibits enamel surface demineralization and acid permeation more effectively because of a more uniform and denser adsorption on the surface of the *** impairment of the nanomechanical and microtribological properties of the enamel surface by acid erosion is mitigated more significantly by adding trace amounts of Xanthan gum than Arabic *** summary,adding trace food hydrocolloids reduces enamel surface demineralization and inhibits acid permeation to mitigate the influence of erosion on the mechanical and tribological properties of *** adsorption state of food hydrocolloids is the determining factor in the permeability of acid agents into the enamel and plays a significant role in preventing dental erosion.

关键词： dental erosion Xanthan gum Arabic gum nanomechanical properties microtribological behavior

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Mantle dynamics of the reactivating North China Craton:Constraints from the topographies of the 410-km and 660-km discontinuities

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Science China Earth Sciences 2011年第6期54卷 881-887页

作者： XU WeiWei zheng TianYu ZHAO liang Seismological Laboratory State Key Laboratory of Lithospheric Evolution Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China

The topographies of the 410-km and 660-km discontinuities have important implications for mantle *** we present high-resolution seismic imaging of the 410-km and 660-km discontinuities beneath the North China Craton (NCC) employing the receiver function *** anomalies (deeper or shallower than the global average depths) at both discontinuities were detected by introducing a three-dimensional regional velocity *** depressions of the 410-km discontinuity are mostly located in the eastern NCC.A local elevation of the 660-km discontinuity appeared in the northwest of the NCC and a significant depression of the 660-km discontinuity is located in the southeast of the *** dynamic mantle regimes are speculated to explain the formation of the anomalous depth zones in the *** possibility is a complex mantle upwelling linked to edge-derived convection between the stagnant slab and the thick cratonic *** other potential dynamic regime is slab stagnating,sinking,and induced upwelling at the neighboring slab *** regimes hint that the mantle flow was possibly dominated by dynamic interactions among the subducting slab,cratonic root,and ambient mantle beneath the NCC.

关键词： 410-km discontinuity 660-km discontinuity receiver function imaging dynamic mantle regime North China Craton

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Thermoequilibrium statistics for a finite system with energy nonextensivity

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Chinese Science Bulletin 2011年第34期56卷 3666-3670页

作者： zheng liang LI Wei Institute of Particle Physics and Complexity Science Center Central China Normal University Wuhan 430079 China Max-Planck-lnstitutefor Mathematics in the Sciences Leipzig 04103 Germany

A first-principles derivation is presented of canonical distributions for a finite thermostat taking into account nonextensive energy. Parameterizing this energy by λ , we derive an explicit form for the distribution functions by regulating λ , and then explore the nontrivial relationship between these functions and energy nonextensivity, as well other system parameters such as system size. A variational entropy function is also derived from these distribution functions.

关键词：有限系统统计数据能源分布函数第一原理熵函数

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