Study of baryon number transport dynamics and strangeness conservation effects using Ω-hadron correlations

In nuclear collisions at RHIC energies, an excess of Ω hyperons over ■ is observed, indicating that Ω has a net baryon number despite s and s quarks being produced in pairs. The baryon number in Ω may have been transported from the incident nuclei and/or produced in the baryon-pair production of Ω with other types of anti-hyperons such as Ξ. To investigate these two scenarios, we propose to measure the correlations between Ω and K and between Ω and anti-hyperons. We use two versions, the default and string-melting, of a multiphase transport(AMPT) model to illustrate the method for measuring the correlation and to demonstrate the general shape of the correlation. We present the Ω-hadron correlations from simulated Au+Au collisions at ■ =7.7 and 14.6 Ge V and discuss the dependence on the collision energy and on the hadronization scheme in these two AMPT versions. These correlations can be used to explore the mechanism of baryon number transport and the effects of baryon number and strangeness conservation on nuclear collisions.

A new review of single-ion conducting polymer electrolytes in the light of ion transport mechanisms

With the depletion of fossil fuels and the demand for high-performance energy storage devices,solidstate lithium metal batteries have received widespread attention due to their high energy density and safety advantages.Among them,the earliest developed organic solid-state polymer electrolyte has a promising future due to its advantages such as good mechanical flexibility,but its poor ion transport performance dramatically limits its performance improvement.Therefore,single-ion conducting polymer electrolytes(SICPEs)with high lithium-ion transport number,capable of improving the concentration polarization and inhibiting the growth of lithium dendrites,have been proposed,which provide a new direction for the further development of high-performance organic polymer electrolytes.In view of this,lithium ions transport mechanisms and design principles in SICPEs are summarized and discussed in this paper.The modification principles currently used can be categorized into the following three types:enhancement of lithium salt anion-polymer interactions,weakening of lithium salt anion-cation interactions,and modulation of lithium ion-polymer interactions.In addition,the advances in single-ion conductors of conventional and novel polymer electrolytes are summarized,and several typical highperformance single-ion conductors are enumerated and analyzed in what way they improve ionic conductivity,lithium ions mobility,and the ability to inhibit lithium dendrites.Finally,the advantages and design methodology of SICPEs are summarized again and the future directions are outlined.

Synergetic Control of Li^(+)Transport Ability and Solid Electrolyte Interphase by Boron-Rich Hexagonal Skeleton Structured All-Solid-State Polymer Electrolyte

High Li^(+)transference number electrolytes have long been understood to provide attractive candidates for realizing uniform deposition of Li^(+).However,such electrolytes with immobilized anions would result in incomplete solid electrolyte interphase(SEI)formation on the Li anode because it suffers from the absence of appropriate inorganic components entirely derived from anions decomposition.Herein,a boron-rich hexagonal polymer structured all-solid-state polymer electrolyte(BSPE+10%LiBOB)with regulated intermolecular interaction is proposed to trade off a high Li^(+)transference number against stable SEI properties.The Li^(+)transference number of the as-prepared electrolyte is increased from 0.23 to 0.83 owing to the boron-rich cross-linker(BC)addition.More intriguingly,for the first time,the experiments combined with theoretical calculation results reveal that BOB^(-)anions have stronger interaction with B atoms in polymer chain than TFSI^(-),which significantly induce the TFSI^(-)decomposition and consequently increase the amount of LiF and Li3N in the SEI layer.Eventually,a LiFePO_(4)|BSPE+10%LiBOBlLi cell retains 96.7%after 400 cycles while the cell without BC-resisted electrolyte only retains 40.8%.BSPE+10%LiBOB also facilitates stable electrochemical cycling of solid-state Li-S cells.This study blazes a new trail in controlling the Li^(+)transport ability and SEI properties,synergistically.

Lithium-ion transport in inorganic solid state electrolyte

An overview of ion transport in lithium-ion inorganic solid state electrolytes is presented, aimed at exploring and de signing better electrolyte materials. Ionic conductivity is one of the most important indices of the performance of inorganic solid state electrolytes. The general definition of solid state electrolytes is presented in terms of their role in a working cell （to convey ions while isolate electrons）, and the history of solid electrolyte development is briefly summarized. Ways of using the available theoretical models and experimental methods to characterize lithium-ion transport in solid state elec- trolytes are systematically introduced. Then the various factors that affect ionic conductivity are itemized, including mainly structural disorder, composite materials and interface effects between a solid electrolyte and an electrode. Finally, strategies for future material systems, for synthesis and characterization methods, and for theory and calculation are proposed, aiming to help accelerate the design and development of new solid electrolytes.

Slurry-like hybrid electrolyte with high lithium-ion transference number for dendrite-free lithium metal anode

Lithium metal anode is regarded as the ultimate choice for next-generation energy storage systems,due to the lowest negative electrochemical potential and super high theoretical specific capacity.However,the growth of lithium dendrite during the cycling process is still one of the most critical bottlenecks for its application.In this work,a slurry-like hybrid electrolyte is proposed towards the application for lithium metal anode,which is composed of a liquid electrolyte part and a nanometric silane-Al2O3 particle part.The hybrid electrolyte shows high ionic conductivity(3.89×10-3 S cm-1 at 25℃)and lithium-ion transference number(0.88).Especially,the resistance of hybrid electrolyte decreases compared to that of liquid electrolyte,while the viscosity of hybrid electrolyte increases.It is demonstrated that the hybrid electrolyte can effectively suppress the growth of lithium dendrite.Stable cycling of Li/Li cells at a current density up to 1 mA cm-2 is possible.The hybrid electrolyte helps to uniform the lithium ion flux inside the battery and partly comes from the formation of a rigid and highly conductive hybrid interfacial layer on the surface of lithium metal.This work not only provides a fresh way to stabilize lithium metal anode but also sheds light on further research for electrolyte optimization and design of lithium metal battery system.

Power and Cross-Spectra for the Turbulent Atmospheric Motion and Transports in the Domain of Wave Number Frequency Space: Theoretical Aspects

The study of large-scale atmospheric turbulence and transport processes is of vital importance in the general circulation of the atmosphere. The governing equations of the power and cross-spectra for the atmospheric motion and transports in the domain of wave number frequency space have been derived. The contributions of the nonlinear interactions of the atmospheric waves in velocity and temperature fields to the conversion of kinetic and potential energies and to the meridional transports of angular momentum and sensible heat in the atmosphere have been discussed.

Optimal Solution of Fuzzy Transportation Problem Using Octagonal Fuzzy Numbers

In this paper a fuzzy transportation problem under a fuzzy environment is solved using octagonal fuzzy numbers.The transportation problem is significant and has been widely studied in the field of applied mathematics to solve a system of linear equations in many applications in science.Systems of concurrent linear equations play a vital major role in operational research.The main perspective of this research paper is to find out the minimum amount of transportation cost of some supplies through a capacitated network formerly the availability and the demand notes are octagonal fuzzy numbers.Octagonal fuzzy numbers are used and showed a membership function.To illustrate this method,a fuzzy transportation problem is solved by using octagonal fuzzy numbers using the ranking technique.It is shown that it is the best optimal solution and it is demonstrated with a numerical example.

考虑Pareto最优的列车运行图与维修天窗协调优化

列车运行图与维修天窗之间的冲突始终无法避免,且维修天窗开设时间的长短显著影响列车总运行时间。针对此问题,综合考虑维修天窗对列车运行造成的限速约束、车站到发线数量约束等,建立列车总运行时间最小,以及维修天窗实际开设时长与理想时长总偏差最小的双目标混合整数规划模型;对困难约束设置中间辅助变量将模型线性化以提高求解效率,并设计约束转换算法求解双目标模型的Pareto最优;微观化处理铁路线,将站内资源和站间资源细化为一系列行车资源单元,得到更加符合实际旅客运输需求的运行图。以某地区铁路线夜间开行列车及维修天窗开设计划为研究背景,调用商业软件求解双目标函数模型的Pareto最优,并对双目标模型的最小支配解和最优支配解进行对比分析;针对最优支配解下的列车进入、离开行车资源单元的时间、停站作业时间及维修天窗的开始时间及开设时长,绘制列车运行图。求解结果表明:模型在满足维修天窗最小开设时长的同时,能够兼顾列车运行总时间最小和维修天窗开设时长更充裕。基于最优支配解绘制的列车运行图表明:微观路网下的列车运行时刻表优化结果更符合实际旅客运输生产作业需要。研究结果可为铁路运营管理部门进一步优化列车运行图编制与维修天窗开设提供参考。

国Ⅵ直喷汽油机颗粒数量及微观形貌排气输运演变特性

开展了某一国Ⅵ直喷汽油机三元催化转化器(TWC)前、TWC后、汽油机颗粒捕集器(GPF)后3个位置的颗粒物采样及微观形貌研究,分析了发动机工况、TWC、GPF对国Ⅵ直喷汽油机尾气颗粒数量、粒径分布、微观形貌的影响。结果表明,该直喷汽油机尾气颗粒数量排放整体上呈单峰分布,低转速小负荷工况下,粒径<23nm的颗粒数量较高。随着发动机转速和负荷的增大,峰值粒径向大粒径方向移动。直喷汽油机尾气颗粒物由“核‒壳”结构基本碳粒子堆积形成,呈链状、枝状、簇状等结构;负荷增大,颗粒物尺寸略有增大,基本碳粒子重叠度增强,分形维数增大;转速增大,颗粒物尺寸减小,基本碳粒子重叠度减弱,分形维数减小。随着排气输运的进行,颗粒数量逐渐降低;TWC不影响颗粒的粒径分布形态,颗粒数量净化效率41.6%~94.2%,对<23 nm的小粒径颗粒净化效果较好,低转速小负荷工况的颗粒数量净化效率较高;GPF的颗粒数量净化效率约80%,23~100 nm颗粒数量净化效率较高,对粒径<10nm的颗粒净化作用不大。TWC和GPF不影响颗粒物结构形式,TWC和GPF后颗粒物基本碳粒子重叠度减弱,分形维数减小。

航空弹药装载运输最优路径选取仿真研究

航空弹药运输最优路径的选择要从运行阐述以及最佳路径选择等角度着手,并对运输相关信息进行整合与分析,对提高航空弹药运输的综合效率有促进作用。在这一视角下,通过对航空弹药装载的最优路径进行求解中,以安全管理、时间价值为核心,在路段划分与选择下,可对不同路段进行聚类,通过差异化选择,实现航空弹药装载运输最优路径的精度提升,满足航空弹药装载运输的综合发展需求。

机坪管制移交区域划设影响因素研究

论文针对机坪管制移交工作中责任边界划设问题,构建机坪管制移交区域划设影响因素体系,将灰数系统理论融入DEMATEL-AISM模型中,利用中心度与熵权法改进模型主观赋权问题,构建Grey-DEMATEL-AISM模型,探寻因素间耦合关系,划分因素层级结构,并根据成都双流国际机场机坪管制移交情况进行实例验证。结果表明:机坪管制移交区域划设影响因素共15个,其结构体系可划分为5个层次,机坪管制员负荷与空管塔台管制员负荷为原因度最小的结果因素,位于上层直观层;塔台位置、跑滑构型等12项因素位于中间过渡层;场面流量是原因度最大的原因因素,位于底层根源层。

电动公交车队规模与充电桩配置协同优化

为了保障电动公交系统的车辆能源供给和线路顺畅运营,本文在多线路与多充电站场景下考虑线路行程时间的随机性,建立面向线路层面的电动公交系统车辆与充电桩配置双层优化模型。模型以车辆和充电桩投资成本与乘客候车成本之和的最小化为目标,对各线路车队规模、各充电站充电桩数量及线路与充电站间的充电匹配关系进行优化决策。在下层模型中,为反映随机行程时间下车辆充电过程对线路运营的影响,引入顾客源有限下的多服务台排队模型来刻画固定线路与充电站匹配下的排队充电过程;在上层模型中,考虑充电站与场站容量约束,对电动公交系统的线路与充电站匹配关系进行优化。在求解方面,首先基于排队模型设计算法求解特定线路与充电站匹配下的车队规模及充电桩数量,进而利用CPLEX求解器对线路与充电站匹配关系进行优化。在实验环节,设计不同规模的算例验证本文所提双层模型与算法框架的有效性,计算结果表明,本文所提的双层模型和算法框架可在满足充电站和场站容量限制的前提下尽可能缩减车队成本、充电桩成本与乘客候车成本;相比较两种人工经验方法,本文算法可将总成本分别降低5.65%和4.54%。

“烟渚”——奇妙的流水输运作用

从“移舟泊烟渚”这一诗意画面说起,探讨奇妙的流水输运作用。分析了流水在塑造地貌过程中的关键作用,包括侵蚀、输运和沉积,以及这些作用如何影响地表形态的形成。通过讨论斯托克斯数与悬浮颗粒在流体中运动行为的关系以及河流中泥沙的输运和沉积模式,并以典型江心洲为例,介绍了河流地貌演变、水力学特性等,揭示了自然力作用下地貌形态与水流特性的科学规律。

我国民航客运碳排放因子及影响因素研究

针对民航碳排放问题,对民航客运碳排放影响因素进行研究,构建飞机碳排放因子模型,选取保有量较高的典型机型进行实证研究,分析机型大小、航程、客座率、经停次数对碳排放因子的影响.研究结果表明:飞行器技术提升、客座率、平均运距、大型飞机的比例上升,我国民航客运碳排放因子呈下降趋势;仅改变航程时,碳排放因子随航程增加而下降,2 000 km航程下典型机型A330、B787、A321、B737满载且以额定巡航速度飞行的碳排放因子较800 km下降13%~22%;仅改变经停次数时,碳排放因子随经停次数增加而增大,且大型飞机经停的碳排放因子增幅更大,1 000 km航程下,A330、A321满载时经停1次碳排放因子较直达时分别增加约31%、19%;经停导致的碳排放因子上升可由经停带来的客座率提升抵消,为保持碳排放因子保持不变,大型飞机所需客座率上升的比例更高,1 500 km航程下,直达航班客座率为50%时,A330、A321机型经停1次的客座率需要分别达到62.1%、57.7%,才能使经停航班的碳排放因子与直达航班保持一致;从碳排放角度考虑,中型客机比大型客机更适合开行经停航班.

Constructing high-toughness polyimide binder with robust polarity and ion-conductive mechanisms ensuring long-term operational stability of silicon-based anodes

Silicon-based materials have demonstrated remarkable potential in high-energy-density batteries owing to their high theoretical capacity.However,the significant volume expansion of silicon seriously hinders its utilization as a lithium-ion anode.Herein,a functionalized high-toughness polyimide(PDMI) is synthesized by copolymerizing the 4,4'-Oxydiphthalic anhydride(ODPA) with 4,4'-oxydianiline(ODA),2,3-diaminobenzoic acid(DABA),and 1,3-bis(3-aminopropyl)-tetramethyl disiloxane(DMS).The combination of rigid benzene rings and flexible oxygen groups(-O-) in the PDMI molecular chain via a rigidness/softness coupling mechanism contributes to high toughness.The plentiful polar carboxyl(-COOH) groups establish robust bonding strength.Rapid ionic transport is achieved by incorporating the flexible siloxane segment(Si-O-Si),which imparts high molecular chain motility and augments free volume holes to facilitate lithium-ion transport(9.8 × 10^(-10) cm^(2) s^(-1) vs.16 × 10^(-10) cm^(2) s~(-1)).As expected,the SiO_x@PDMI-1.5 electrode delivers brilliant long-term cycle performance with a remarkable capacity retention of 85% over 500 cycles at 1.3 A g^(-1).The well-designed functionalized polyimide also significantly enhances the electrochemical properties of Si nanoparticles electrode.Meanwhile,the assembled SiO_x@PDMI-1.5/NCM811 full cell delivers a high retention of 80% after 100 cycles.The perspective of the binder design strategy based on polyimide modification delivers a novel path toward high-capacity electrodes for high-energy-density batteries.

Suppressing dendritic metallic Li formation on graphite anode under battery fast charging

Lithium-ion batteries(LIBs)with fast-charging capability are essential for enhancing consumer experience and accelerating the global market adoption of electric vehicles.However,achieving fast-charging capability without compromising energy density,cycling lifespan,and safety of LIBs remains a significant challenge due to the formation of dendritic Li metal on graphite anode under fast charging condition.In view of this,the fundamentals for the dendritic metallic Li formation and the strategies for suppressing metallic Li plating based on analyzing the entire Li^(+)transport pathway at the anode including electrolyte,pore structure of electrode,and surface and bulk of materials are summarized and discussed in this review.Besides,we highlight the importance of designing thick electrodes with fast Li^(+)transport kinetics and comprehensively understanding the interaction between solid electrolyte interphase(SEI)and Li^(+)migration in order to avoid the formation of dendritic Li metal in practical fast-charging batteries.Finally,the regulation of Li metal plating with plane morphology,instead of dendritic structure,on the surface of graphite electrode under fast-charging condition is analyzed as a future direction to achieve higher energy density of batteries without safety concerns.

武汉市城市低碳交通发展水平评价

为解决低碳交通发展水平评价中主客观权重差异和群决策定性指标量化的不确定性问题,建立基于博弈论和TOPSIS(逼近理想解排序方法)的城市低碳交通发展水平评价模型。首先,采用可拓层次分析法(EAHP)和熵权法确定指标主客观权重。其次,使用博弈论确定指标综合权重,以解决主客观权重带来的差异问题。最后,采用三角模糊数对定性指标进行量化,并结合TOPSIS进行综合评价,客观全面反映不同专家对定性指标的意见。通过上述模型对武汉市2015-2021年低碳交通发展各方面和综合发展水平进行评价。结果表明,2015-2021年武汉市低碳交通发展水平呈稳步增长趋势,评价值从0.4048上升到0.6067,与实际情况相符。该评价方法可以应用于其他城市的低碳交通发展水平评价,进而更好地推进城市低碳交通系统建设。