Engineering of geometrical configurations in dual-atom catalysts for electrocatalytic applications

Geometrical configurations play a crucial role in dual-atom catalysts(DACs)for electrocatalytic applications.Significant progress has been made to design DACs electrocatalysts with various geometri-cal configurations,but in-depth understanding the relationship between geometrical configurations and metal-metal interaction mechanisms for designing targeted DACs is still required.In this review,the recent progress in engineering of geometrical configurations of DACs is systematically summarized.Based on the polarity of geometrical configuration,DACs can be classified into two different types that are homonuclear and heteronuclear DACs.Furthermore,with regard to the geometrical configurations of the active sites,homonuclear DACs are identified into adjacent and bridged configurations,and heteronuclear DACs can be classified into adjacent,bridged,and separated configurations.Subsequently,metal-metal interactions in DACs with different geometrical configurations are introduced.Additionally,the applications of DACs in different electrocatalytic reactions are discussed,including the oxygen reduction reaction(ORR),oxygen evolution reaction(OER),hydrogen evolution reaction(HER),and other catalysis.Finally,the future challenges and perspectives for advancements in DACs are high-lighted.This review aims to provide inspiration for the design of highly effcient DACs towards energy relatedapplications.

Sliding and damming properties of granular debris with different geometric configurations and grain size distributions

Granular debris plays a significant role in determining damming deposit characteristics. An indepth understanding of how variations in grain size distribution(GSD) and geometric configurations impact the behavior of granular debris during the occurrence of granular debris is essential for precise assessment and effective mitigation of landslide hazards in mountainous terrains. This research aims to investigate the impact of GSD and geometric configurations on sliding and damming properties through laboratory experiments. The geometric configurations were categorized into three categories based on the spatial distribution of maximum volume: located at the front(Type Ⅰ), middle(Type Ⅱ), and rear(Type Ⅲ) of the granular debris. Our experimental findings highlight that the sliding and damming processes primarily depend on the interaction among the geometric configuration, grain size, and GSD in granular debris. Different sliding and damming mechanisms across various geometric configurations induce variability in motion parameters and deposition patterns. For Type Ⅰ configurations, the front debris functions as the critical and primary driving component, with energy dissipation primarily occurring through inter-grain interactions. In contrast, Type Ⅱ configurations feature the middle debris as the dominant driving component, experiencing hindrance from the front debris and propulsion from the rear, leading to complex alterations in sliding motion. Here, energy dissipation arises from a combination of inter-grain and grain-substrate interactions. Lastly, in Type Ⅲ configurations, both the middle and rear debris serve as the main driving components, with the rear sliding debris impeded by the front. In this case, energy dissipation predominantly results from grainsubstrate interaction. Moreover, we have quantitatively demonstrated that the inverse grading in damming deposits, where coarse grain moves upward and fine grain moves downward, is primarily caused by grain sorting due to collisions among the grains and between the grain and the base. The impact of grain on the horizontal channel further aids grain sorting and contributes to inverse grading. The proposed classification of three geometric configurations in our study enhances the understanding of damming properties from the view of mechanism, which provides valuable insights for related study about damming granular debris.

Seismic fragility analysis of three-tower cable-stayed bridges with different connection configurations

Seismic fragility analysis of three-tower cable-stayed bridges with three different structural systems,including rigid system(RS),floating system(FS),and passive energy dissipation system(PEDS),is conducted to study the effects of connection configurations on seismic responses and fragilities.Finite element models of bridges are established using OpenSees.A new ground motion screening method based on the statistical characteristic of the predominant period is proposed to avoid irregular behavior in the selection process of ground motions,and incremental dynamic analysis(IDA)is performed to develop components and systems fragility curves.The effects of damper failure on calculated results for PEDS are examined in terms of seismic response and fragility analysis.The results show that the bridge tower is the most affected component by different structural systems.For RS,the fragility of the middle tower is significantly higher than other components,and the bridge failure starts from the middle tower,exhibiting a characteristic of local failure.For FS and PEDS,the fragility of the edge tower is higher than the middle tower.The system fragility of RS is higher than FS and PEDS.Taking the failure of dampers into account is necessary to obtain reliable seismic capacity of cable-stayed bridges.

Bound and Resonating Multiquark Configurations

We review the predictions of quark models for multiquark configurations that are bound or resonant states,and compare different methods for estimating the properties of resonances.

Integrated Experimental and Simulation Investigation of Breakdown Voltage Characteristics Across Electrode Configurations in SF_(6) Circuit Breakers

This study investigates the breakdown voltage characteristics in sulfur hexafluoride(SF6)circuit breakers,employing a novel approach that integrates both experimental investigations and finite element simulations.Utilizing a sphere-sphere electrode configuration,we meticulously measured the relationship between breakdown voltage and electrode gap distances ranging from 1 cm to 4.5 cm.Subsequent simulations,conducted using COMSOL Multiphysics,mirrored the experimental setup to validate the model’s accuracy through a comparison of the breakdown voltage-electrode gap distance curves.The simulation results not only aligned closely with the experimental data but also allowed the extraction of detailed electric field strength,electric potential contours,and electric current flow curves at the breakdown voltage for gap distances extending from 1 to 4.5 cm.Extending the analysis,the study explored the electric field and potential distribution at a constant voltage of 72.5 kV for gap distances between 1 to 10 cm,identifying the maximum electric field strength.A comprehensive comparison of five different electrode configurations(sphere-sphere,sphere-rod,sphere-plane,rod-plane,rod-rod)at 72.5 kV and a gap distance of 1.84 cm underscored the significant influence of electrode geometry on the breakdown process.Moreover,the research contrasts the breakdown voltage in SF6 with that in air,emphasizing SF6’s superior insulating properties.This investigation not only elucidates the intricate dynamics of electrical breakdown in SF6 circuit breakers but also contributes valuable insights into the optimal electrode configurations and the potential for alternative insulating gases,steering future advancements in high-voltage circuit breaker technology.

Environmental Analysis Using Integrated GIS and Spatial Configurations in Israel

The scope for environmental analysis constitutes a critical factor in recent times, yet demanding importance due to the concerns of environmental sustainability. The study aims at analysing the prospects of implementing an integrated GIS and spatial configuration for environment analysis in Israel. The study adopts an empirical study design to consider the multi-dimensional utilisation of an integrated GIS and spatial configuration for environment analysis. The study considers the materials and methods of the GIS system modelling as well, consisting of satellite imagery, GPS-based location identification, Esri ArcGIS, CyberGIS, and BIM integration to present a comprehensive system for the environmental analysis of Israel. The results of the study indicate that the threats of natural disasters and climate change can be identified based on the synergy of spatial data within an integrated GIS modelling. In many cases, it is also used in collaboration with a BIM to ensure that planning and decision-making processes are sustainable, economically beneficial and environmentally considered. Thus, it is concluded that environmental analysis through the projection of visually represented satellite imagery within an integrated GIS with spatial configurations in Israel can minimise the conflicts between the infrastructural designs, human activities, and environmental sustainability.

A rescaling algorithm for multi-relaxation-time lattice Boltzmann method towards turbulent flows with complex configurations

Understanding and modeling flows over porous layers are of great industrial significance.To accurately solve the turbulent multi-scale flows on complex configurations,a rescaling algorithm designed for turbulent flows with the Chapman-Enskog analysis is proposed.The mesh layout and the detailed rescaling procedure are also introduced.Direct numerical simulations(DNSs)for a turbulent channel flow and a porous walled turbulent channel flow are performed with the three-dimensional nineteen-velocity(D3Q19)multiple-relaxation-time(MRT)lattice Boltzmann method(LBM)to validate the accuracy,adaptability,and computational performance of the present rescaling algorithm.The results,which are consistent with the previous DNS studies based on the finite difference method and the LBM,demonstrate that the present method can maintain the continuity of the macro values across the grid interface and is able to adapt to complex geometries.The reasonable time consumption of the rescaling procedure shows that the present method can accurately calculate various turbulent flows with multi-scale and complex configurations while maintaining high computational efficiency.

数字中国背景下城市韧性提升路径研究——基于模糊集定性比较分析(fsQCA)

增强城市韧性既是城市提升恢复能力和适应能力的重要保障,也是城市高质量发展的重要支撑。目前“数字中国”建设步伐不断加快,城市数字化对城市新形态的塑造具有重要影响作用,进而深度赋能提升城市韧性。该文运用组态思维和fsQCA方法对我国45个城市研究影响因素的协同联动机制,最后得出城市韧性的驱动路径。研究发现:(1)单一条件变量并不是城市韧性的必要条件;(2)实现高韧性城市的路径有3条,即数字经济与数字基础设施主导型、数字经济与数字政府主导型、“四轮”驱动型;(3)数字经济和数字政府两个条件变量对城市韧性具有更为重要的作用。因此,韧性较低的城市可以依据自身资源禀赋,因城施策,选择适宜的韧性提升路径,从而有效地提升城市韧性。

纳米碳/铝复合材料强韧化研究现状及展望

以碳纳米管、石墨烯为代表的超高性能纳米碳,具有优越的力、热、电等综合性能,是复合材料的理想增强体,以纳米碳为强化相少量加入到铝中,有望开发出高强、高模、低热膨胀的复合材料,并使复合材料保持轻质、易加工等特性,在航空、航天、国防等领域具有重大的应用前景,因而以纳米碳/铝为代表的新一代铝基复合材料备受关注。然而,碳纳米管等纳米碳易团聚,与铝等大多数金属并不浸润,且容易分布在晶界上诱导显著的晶粒细化,使得复合材料的强韧性等关键性能指标提升困难,或者使强度提高的同时使塑韧性下降显著,限制了其工程应用潜力。综述近年来国内外研究者在纳米碳/铝复合材料强韧化方面的策略和方法,包括纳米碳分散、界面和构型调控等,以期推动新一代轻质高强纳米碳/铝复合材料的发展,支撑国家未来重大工程应用。

软件运行时配置研究综述

运行时配置为用户使用软件提供了灵活性和可定制性,但其巨大的规模和复杂的机制也带来了巨大的挑战.大量学者和研究机构针对软件运行时配置展开了研究,以提升软件系统在复杂外部环境中的可用性和适应性.建立运行时配置研究分析框架,从配置分析与理解、配置缺陷检测与故障诊断、配置应用3个阶段对现有研究工作进行归类和分析,总结归纳现有研究的不足和面临的挑战,并对未来的研究趋势进行展望,对下一步研究具有一定的指导意义.

制造企业衍生工业互联网平台创新生态驱动价值创造路径研究——基于fsQCA的组态分析

工业互联网作为数字经济与实体经济深度融合的关键路径,能够推动我国制造业实现高质量发展。区别于单一视角实证检验工业互联网平台成长影响因素的研究,本文基于整体观视角从创新主体、创新环境、创新资源三个层面构建制造企业衍生平台创新生态价值创造的分析框架,以35家制造企业衍生平台为案例样本,采用模糊集定性比较分析方法探究六个前因条件对衍生平台创新生态价值创造的影响。研究发现:(1)单个前因条件不构成引致高价值创造的必要条件;(2)存在四条产生高价值创造的组态,可归为企业主导型(H1)、政府-企业推动型(H2)和政府-市场-企业联合驱动型(H3a、H3b);(3)在一定条件下,实现高价值创造的平台创新生态系统要素组合之间具有替代关系。

数字化转型背景下中小制造企业如何编排资源利用数字机会——基于资源编排理论的fsQCA研究

利用数字机会是中小制造企业实现数字化转型的关键。资源编排理论指出,利用数字机会离不开企业资源和能力的支持,尤其要将各种资源和能力有效组合起来。但大量中小制造企业难以有效编排自身资源和能力来利用数字机会。为此,本文关注中小制造企业的五种传统资源和能力(实物资源、关系资源、制造能力、营销能力和创新能力)及两种数字资源和能力(大数据资源和数字平台能力),运用模糊集定性比较分析(fsQCA)方法对392份问卷数据进行分析,研究发现:五种传统资源和能力及两种数字资源和能力都不能单独作为中小制造企业数字机会利用的必要条件,但数字平台能力作为核心条件能发挥较为普适的作用。同时,中小制造企业的数字机会利用存在三种路径,可归纳为“内向型”“外向型”和“内外兼顾型”,通过进一步聚焦高技术制造业,发现其数字机会利用存在两种路径:“渐进型”和“突破型”。本文有助于发现如何在数字化背景下编排企业资源和能力,拓展了资源编排理论的研究情境(数字化背景)和研究范围(数字资源和能力),回应了识别“数据时代的资源编排规律”的呼吁。

两种乔木落叶浸提液对高羊茅幼苗生长和根际土壤酶活性的影响

为探讨林木落叶浸提液对高羊茅(Festucaarundinacea)幼苗生长和根际土壤性质的影响,通过室内模拟试验,设置不同浓度银杏(Ginkgo biloba)、鸡爪槭(Acer palmatum)落叶浸提液[10(T_(1))、40(T2)、80 g·L^(-1)(T_(3)),以清水为对照]分别浇灌盆栽高羊茅幼苗,研究两种乔木落叶浸提液对高羊茅幼苗生长和根际土壤酶活性的影响。结果表明,在两种乔木落叶浸提液处理下,高羊茅过氧化氢酶(CAT)活性较对照变化不大。超氧化物歧化酶(SOD)、过氧化物酶(POD)活性随银杏落叶浸提液浓度的增加呈先升高后降低的变化趋势,而丙二醛(MDA)含量则呈先升高后降低再升高的趋势,T_(3)处理时,MDA含量较对照上升了60.33%;在鸡爪槭落叶浸提液处理下,高羊茅SOD活性逐渐降低,MDA含量呈先升高后降低趋势,POD活性随浸提液浓度增加呈先升高后降低再升高的趋势,T_(3)处理时,POD活性较对照上升了151.03%(P<0.05)。两种乔木落叶浸提液处理下高羊茅根际土壤木糖苷酶(XYL)、β-葡萄糖苷酶(BG)、α-葡萄糖苷酶(AG)和纤维二糖酶(CBH)、总酶活性较对照显著上升,而亮氨酸氨基肽酶(LAP)活性则先降低后升高,但各处理下LAP活性均低于对照,尤其在银杏、鸡爪槭落叶浸提液T_(1)处理时,LAP活性较对照分别降低了31.69%和70.40%,导致基质土壤氮素利用率低,显著降低高羊茅生长指标和生理指标。研究结果表明,两种乔木落叶浸提液对高羊茅幼苗株高、根长和叶绿素含量均有明显抑制作用,银杏落叶浸提液的化感抑制作用强于鸡爪槭。

美丽乡村建设背景下乡村旅游发展的组态路径研究——以湖南武陵山片区为例

美丽乡村建设是巩固拓展脱贫攻坚成果与全面推进乡村振兴战略的重要衔接点,乡村旅游是美丽乡村建设的重要支撑。本文以湖南武陵山片区为实证靶向,深入剖析乡村旅游的核心作用与溢出效用,基于复杂性理论,综合运用熵权法、NCA和fsQCA等方法,探究美丽乡村建设背景下乡村旅游发展的组态路径。结果表明:一是在美丽乡村建设的背景下,单一变量不构成发展乡村旅游的关键性因素,这给予了“美丽乡村建设背景下各乡村地区发展乡村旅游是否存在不可或缺的发展条件”问题的否定回答;二是通过NCA瓶颈水平分析进一步证实了上述结论,强调向更高水平的乡村旅游发展阶段迈进则需要前因变量相对齐全且配合得当;三是探究出“田园综合体型”“生态氛围突出型”“‘产业+环境’双轮驱动型”三条乡村旅游发展的组态路径,为“何为决定乡村旅游发展的主要条件”提供了科学回答。据此提出促进乡村旅游发展的建议,以助力乡村旅游高质量发展。

考虑动态能耗的无人机采收菠萝田间收集点优化配置研究

为了深化无人机在田间菠萝采收和运输过程中的应用,探索无人机悬停放置菠萝到收集箱中的技术方案。无人机的续航能力限制菠萝采收工作的完成,而对续航能力影响最大的因素是无人机的载重,提出在田间设立菠萝收集点,并确定收集点的最优设立数量及位置,以确保菠萝采收工作的有效完成。在研究方法上,基于K-means算法寻找最佳收集点位置及分组方式,建立无人机采收菠萝的能耗及成本模型,通过编写程序对模型进行求解,并以无人机续航能力为约束条件,确定了无人机采收菠萝的最大覆盖范围和菠萝采摘数量。通过比较不同设立数量和位置的收集点方案,得出综合最优的结果。在不更换无人机电池的情况下,1台农业无人机采收菠萝约480个,采收面积约44m^(2)。随着收集点设立数量增加,无人机总路程和总能耗呈稳步下降状态,总成本呈稳步上升状态,分析发现667 m^(2)菠萝地设立15个固定位置的收集点时总能耗、总路程和总成本达到均衡最优。无人机采收菠萝的收集点配置优化方案,可为应用无人机进行田间作物采收及运输时收集点的数量和选址提供建设性意见。

我国高等教育数字化转型建设路径的定性比较分析

高等教育数字化转型是推动高等教育高质量发展的关键举措,也是加快实现高等教育现代化的必由之路｡研究基于TOE框架,从技术､组织､环境三个维度构建高等教育数字化转型分析框架,提炼出数字技术嵌入､战略规划､数字素养与能力､开放教育资源､协作共享五个条件变量｡运用清晰集定性比较分析(csQCA)方法,以组态视角对我国28个高等教育数字化转型典型实践案例进行分析,探索条件变量之间的“多向互动”以及不同条件组合对高等教育数字化转型产生的“联合效应”｡研究发现,单一条件无法单独构成高等教育数字化转型高水平建设的必要条件;高水平建设路径包括“合作驱动型”､“潜力发挥型”和“禀赋优越型”;在特定的客观禀赋条件下,数字技术嵌入和战略规划可以通过等效替代以“殊途同归”的方式推动高等教育数字化转型.

准噶尔盆地玛湖凹陷三叠系百口泉组储层特征及油气成藏规律

通过岩心分析测试、地震厚度预测、包裹体成藏期次分析以及源储配置关系研究,对准噶尔盆地玛湖凹陷三叠系百口泉组储层特征及油气成藏规律进行了刻画。研究结果表明:①玛湖凹陷斜坡区三叠系百口泉组主要发育扇三角洲沉积,岩性普遍较粗,相对优质的储集层主要分布于扇三角洲前缘水下分流河道微相及少量河口砂坝微相中,其成分以长石岩屑砂砾岩为主,其次为岩屑砂砾岩。岩石普遍较致密。岩心孔隙度为3.17%~23.40%,平均为9.04%,渗透率为0.01~934.00mD,平均为0.73mD,属低孔特低渗型储集层。储集空间类型以次生溶孔为主,可见粒间缝和其他微裂缝。②研究区油气主要来源于下二叠统风城组碱湖沉积的泥页岩,最厚处超过400m,为残留海—潟湖相沉积,水体盐度较高,岩性以云质泥岩和泥质岩为主。有机质类型以Ⅰ和Ⅱ1型为主,总有机碳含量(TOC)多大于1.0%,生烃潜量(S1+S2)多大于6.0mg/g,氯仿沥青“A”平均为0.2%,HI平均为322mg/g,有机质演化处于成熟阶段,为中等—好烃源岩。③研究区具有3期成藏特征,晚三叠世之前为第1期油气充注,未能聚集成藏,早侏罗世为第2期油气充注期,对应黄色荧光烃类包裹体;早—中白垩世为第3期油气充注期,对应蓝白色荧光烃类包裹体,后2期油气充注对百口泉组油气成藏起主要贡献作用。④研究区源储配置紧密性是导致玛湖西斜坡和玛湖东斜坡油气差异性聚集的核心要素。

基于fsQCA组态视角的我国医疗资源配置效率提升路径分析

背景当前我国医疗资源配置区域失衡、公平性缺失问题仍然突出。党的“二十大”报告明确提出要“促进优质医疗资源扩容和区域均衡布局”。目的探究提升我国医疗资源配置效率的具体路径,为实现我国医疗资源合理且高效配置、促进基本公共服务均等化提供科学参考。方法于2022年9月—2023年2月开展研究,数据源于《2021中国统计年鉴》《2021中国卫生健康统计年鉴》。将医疗卫生机构数、卫生技术人员数、床位数作为投入指标,以诊疗人次和入院人数为产出指标,通过数据包络分析(DEA)方法对我国2020年31个省份医疗资源配置效率进行测度;以医疗资源配置效率为结果变量,以卫生技术人员占比、每千人口床位数、出院者平均住院日、人均国内生产总值(GDP)、居民可支配收入、财政收入分权和医疗卫生财政预算支出占比为条件变量,运用模糊集定性比较分析(fsQCA)方法从组态视角探究内外部要素对医疗资源配置效率的协同影响机制,剖析高或非高水平医疗资源配置效率的条件组态,明确医疗资源高效率和低效率配置的多重路径。结果2020年我国31个省份医疗资源配置效率整体水平较高,均值为0.852,但省际存在较大差异。组态分析结果可知,医疗资源配置效率的提升是多因素共同作用的结果,共存在3种医疗资源高效率配置的路径。路径1:政府主导型驱动路径,以广西壮族自治区为典型案例。路径2:内外协调型驱动路径,以云南省和甘肃省为代表案例。路径3:均衡型驱动路径,代表案例主要有广东省、福建省和湖北省。非高医疗资源配置效率的路径也存在3条。路径1:政府制约型路径。路径2:经济-政府双重制约型路径,代表案例有黑龙江省和吉林省。路径3:内外制约型路径,典型案例有山西省和西藏自治区。结论内外部各要素及要素间的协同在良性互动过程中共同影响着医疗资源配置效率水平,需优化内外部环境,并对关键资源要素进行有效整合,以形成合力,促进区域医疗资源合理配置。

数字经济助推中国产业转型升级——基于创新要素配置的中介效应

数字经济作为构建现代化产业体系的重要引擎,为赋能产业转型升级提供核心驱动力。区别于以往研究多从宏观视角考察数字经济对产业转型升级的直接影响,在对产业转型升级和数字经济发展水平测度框架进一步拓展完善的基础上,从创新要素配置这一微观视角,对数字经济影响产业转型升级的直接、间接作用机制及空间溢出效应进行了实证检验。研究发现:数字经济发展对产业转型升级具有显著的直接效应;数字经济通过人力和资本创新要素配置的中介效应正向促进产业结构高级化和绿色化,反向抑制产业结构合理化,且更多依赖资本创新要素的配置来影响产业转型升级;数字经济发展对产业转型升级的影响均具有空间溢出效应,并存在区域异质性。

何种组态有助于提升省域企业孵化网络资源配置效率——基于fsQCA的结构与环境因素匹配分析

我国各省科技企业孵化网络在实践进程中暴露出一系列资源配置不均衡和效率低下的问题,严重影响了创新经济的高质量发展。本文构建省域企业孵化网络资源配置的二阶段效率评价模型并完成效率测算;基于组态理论探索网络结构与区域环境的高资源配置效率匹配路径。研究发现:(1)省域企业孵化网络资源配置效率整体不高且呈波动下降趋势。(2) 7种组态有助于孵化网络实现资源的高效配置,现阶段扩大网络规模是效率提升的普适性手段。(3)在创新力强的经济发达省份,网络密度和网络中心势呈替代关系;在不具备经济和地理区位优势的省份,网络密度的提升能帮助节点组织拓展资源共享渠道从而提高资源配置效率。研究基于中观和宏观视角,为我国省域企业孵化网络资源配置工作的优化提供了政策建议。