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Simultaneous Bulk-and Surface-initiated Living Polymerization Studied with a Heterogeneous Stochastic Reaction Model

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Chinese Journal of Polymer Science 2024年第3期42卷 364-372,I0008页

作者： Jia-Shu Ma zhi-ning Huang Jia-Hao Li Bang-Ping Jiang Yan-Da Liao Shi-Chen Ji Xing-Can Shen State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources(Ministry of Education of China)School of Chemistry and Pharmaceutical SciencesGuangxi Normal UniversityGuilin 541004China School of Computer Science and Engineering&School of Software Guangxi Normal UniversityGuilin 541004China

To better characterize the properties of surface-initiated polymers, simultaneous bulk-and surface-initiated polymerizations are usually carried out by assuming that the properties of the surface-initiated polymers resemble those of the bulk-initiated polymers. Through a Monte Carlo simulation using a heterogeneous stochastic reaction model, it was discovered that the bulk-initiated polymers exhibit a higher molecular weight and a lower dispersity than the corresponding surface-initiated polymers, which indicates that the equivalent assumption is invalid. Furthermore, the molecular weight distributions of the two types of polymers are also different, suggesting different polymerization mechanisms. The results can be simply explained by the heterogeneous distributions of reactants in the system. This study is helpful to better understand surface-initiated polymerization.

关键词： Surface-initiated polymerization Polymer brush Stochastic reaction model Heterogeneous polymerization Simultaneous polymerization

Hydrodynamic Performance of An Integrated System of Breakwater and A Multi-Chamber OWC Wave Energy Converter

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China Ocean Engineering 2024年第4期38卷 543-556页

作者： ning De-zhi ZHANG Xiang-yu WANG Rong-quan ZHAO Ming State Key Laboratory of Coastal and Offshore Engineering Dalian University of TechnologyDalian 116024China Dalian Key Laboratory of Offshore Renewable Energy Dalian University of TechnologyDalian 116024China School of Computing Engineering and MathematicsUniversity of Western SydneyPenrith NSW 2751Australia

A multi-chamber oscillating water column wave energy converter(OWC-WEC)integrated to a breakwater is *** hydrodynamic characteristics of the device are analyzed using an analytical model based on the linear potential flow theory.A pneumatic model is employed to investigate the relationship between the air mass flux in the chamber and the turbine *** effects of chamber width,wall draft and wall thickness on the hydrodynamic performance of a dual-chamber OWC-WEC are *** results demonstrate that the device,with a smaller front wall draft and a wider rear chamber exhibits a broader effective frequency *** device with a chamber-width-ratio of 1:3 performs better in terms of power ***,results from the analysis of a triplechamber OWC-WEC demonstrate that reducing the front chamber width and increasing the rearward chamber width can improve the total performance of the *** the number of chambers from 1 to 2 or 3 can widen the effective frequency bandwidth.

关键词： oscillating water column power extraction efficiency potential flow theory wave energy converter multi-chamber

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同轴旋转可压缩气流中黏性液体射流形态研究

内燃机学报 2024年第1期42卷 53-60页

作者：吕明郭立梅宁智北京交通大学机械与电子控制工程学院北京100044

采用射流线性稳定性分析方法,考虑液体黏性、周围气流的同轴旋转运动以及可压缩性的条件下,建立了描述同轴旋转可压缩气流中黏性液体射流的数学模型,并进行了验证,研究了气流量纲为1旋转强度以及流体物性对液体射流不稳定形态的影响.研... 详细信息

采用射流线性稳定性分析方法,考虑液体黏性、周围气流的同轴旋转运动以及可压缩性的条件下,建立了描述同轴旋转可压缩气流中黏性液体射流的数学模型,并进行了验证,研究了气流量纲为1旋转强度以及流体物性对液体射流不稳定形态的影响.研究表明:周围气流的旋转速度较小时,对射流起促稳作用,继续增大气流量纲为1旋转强度,开始对射流起促分裂作用;且随着气流旋转强度的增大,射流扰动沿周向方向发展,射流柱变的高度不对称.在研究参数范围内,气体可压缩性和气/液密度比均能促进射流的失稳,并会影响射流空间形态,尤其是在周向方向上能够改变射流的占优模式,增强射流的不对称性;液体黏性以及表面张力对射流均具有增强稳定性的作用.

关键词：液体射流气流旋转数学模型射流形态

Improving Radiation Pattern Roundness of Henge-Like Metaring-Loaded Monopoles Above a Finite Ground for MIMO Systems

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Electromagnetic Science 2024年第2期2卷 104-115页

作者： Bo Zhang zhi ning Chen Yucong Zhou Qun Lou Jiahao Wang Koen Mouthaan Department of Electrical and Computer Engineering National University of SingaporeSingapore 117583Singapore Huawei Technologies Co. Ltd.Shenzhen 518129China

A henge-like metaring(HMR)is proposed for improving the radiation pattern roundness of monopole antennas offcenter mounted on a finite ground by localizing the radiation from the monopole and suppressing the scattering by the *** improved patterns enhance uniform coverage of multiple-input and multiple-output(MIMO)*** study reveals that the radiation pattern of an off-center monopole is distorted by the asymmetric ground currents excited by both the feed and the radiation of the *** distorted radiation patterns severely degrade wireless communication link *** HMR,composed of an annular array of mushroom unit cells,simultaneously functions as an electromagnetic bandgap(EBG)and a radiator,and encircles the monopole to form a henge monopole antenna(HMA).The HMR as an EBG is used to suppress the ground currents outside the HMR analyzed by an equivalent circuit *** HMR as a radiator is designed to decouple the monopole from the ground with its elevated radiation pattern using characteristic mode *** examples,two prototypes of single and four off-center MIMO HMAs are designed and investigated in the 2.45-GHz *** and measured results show that the single HMA and each of the four HMAs achieve the un-roundness of the radiation pattern atθ=65°plane lower than 2 dB and 3 dB in the 2.45-GHz *** a result,near the radiation nulls,the SNR is improved by 6 *** compact construction and efficient current suppression facilitate the application of HMAs in multi-antenna systems above a finite ground with uniform coverage and reliable connections.

关键词： Antenna radiation pattern Characteristic mode analysis Metamaterials MIMO communication Omnidirectional antennas Wireless access points

Review on Service Curves of Typical Scheduling Algorithms

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ZTE Communications 2024年第2期22卷 55-70页

作者： GAO Yuehong ning zhi HE Jia ZHOU Jinfei GAO Chenqiang TANG Qingkun YU Jinghai Beijing University of Posts and Telecommunications Beijing 100876China ZTE Corporation Shenzhen 518057China State Key Laboratory of Mobile Network and Mobile Multimedia Tech-nology Shenzhen 518055China

In recent years,various internet architectures,such as Integrated Services(IntServ),Differentiated Services(DiffServ),Time Sensitive Networking(TSN)and Deterministic Networking(DetNet),have been proposed to meet the quality-of-service(QoS)requirements of different network ***,network calculus has found widespread application in network modeling and QoS *** calculus abstracts the details of how nodes or networks process data packets using the concept of service *** paper summarizes the service curves for typical scheduling algorithms,including Strict Priority(SP),Round Robin(RR),Cycling Queuing and Forwarding(CQF),Time Aware Shaper(TAS),Credit Based Shaper(CBS),and Asynchronous Traffic Shaper(ATS).It introduces the theory of network calculus and then provides an overview of various scheduling algorithms and their associated service *** delay bound analysis for different scheduling algorithms in specific scenarios is also conducted for more insights.

关键词： network calculus service curve scheduling algorithm QoS

公平竞争审查制度与备案审查制度的衔接机制研究

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西北大学学报（哲学社会科学版） 2024年第4期54卷 140-153页

作者：宁立志龚涛武汉大学法学院湖北武汉430072

公平竞争审查制度与备案审查制度是我国约束规范性文件制发的两种审查制度,但部门法之间的隔阂导致它们在理论上长期割裂。这两种审查制度在监督机制、审查能力、审查动力等方面具有互补性,使得建立它们之间的衔接机制具有现实可能性和... 详细信息

公平竞争审查制度与备案审查制度是我国约束规范性文件制发的两种审查制度,但部门法之间的隔阂导致它们在理论上长期割裂。这两种审查制度在监督机制、审查能力、审查动力等方面具有互补性,使得建立它们之间的衔接机制具有现实可能性和必要性。在坚持公平竞争审查的事前自我审查这一基本定位的前提下,可以将事后审查部分纳入备案审查制度中,将公平竞争审查结论作为备案审查中合法性与适当性审查的参考文件。还可以适时扩张公平竞争审查对象,将部分涉及市场主体经济活动的党组织规范性文件以及人大及其常委会立法、决议和决定纳入公平竞争审查制度,并建立党委、人大、政府之间的公平竞争审查衔接联动机制。

关键词：公平竞争审查备案审查反垄断法合法性审查适当性审查自我审查

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二硝酰胺铵液滴微爆特性的试验研究

汽车安全与节能学报 2024年第2期15卷 226-234页

作者：何帆赵锦胜宁智吕明北京交通大学机械与电子控制工程学院北京100044

该研究旨在揭示绿色无毒航天推进剂二硝酰胺铵(ADN)液滴在燃烧室内的微爆特性,以期提高发动机燃烧效率并减少污染物排放。通过建立挂滴式试验系统,研究了ADN液滴微爆过程中的形态变化,并分析了环境温度和液滴初始直径对微爆特性的影响... 详细信息

该研究旨在揭示绿色无毒航天推进剂二硝酰胺铵(ADN)液滴在燃烧室内的微爆特性,以期提高发动机燃烧效率并减少污染物排放。通过建立挂滴式试验系统,研究了ADN液滴微爆过程中的形态变化,并分析了环境温度和液滴初始直径对微爆特性的影响。结果表明:环境温度升高并未缩短微爆延迟时间,但导致微爆强度和持续时间减小;液滴微爆持续时间与环境温度无显著负相关性,而当量蒸发速率随温度升高而增加,增加速率逐渐减缓;着火时刻随环境温度升高而提前;液滴初始直径的增大导致微爆延迟时间增加,微爆强度、持续时间和当量蒸发速率与初始直径无明显正相关关系,着火时刻则随之延迟,但趋势逐渐减弱。研究表明,环境温度和液滴初始直径是影响ADN液滴微爆特性的关键因素,对优化ADN作为航天推进剂的使用具有重要理论和工程意义。

关键词：含氧燃料航天推进剂二硝酰胺铵(ADN) 液滴形态微爆特性

混合所有制改革与民营企业精准扶贫——基于资源互补和监督制衡的视角

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经济管理 2024年第2期46卷 91-109页

作者：姜富伟丁慧张芷宁何冬昕中央财经大学金融学院北京102206

精准扶贫是打赢脱贫攻坚战的制胜法宝,为实现共同富裕积累了宝贵的经验。通过混合所有制改革,企业经济效益显著提升,促进实现“做大蛋糕”,但进一步能否推动企业参与精准扶贫来“分好蛋糕”仍有待检验。鉴于此,本文以2016—2021年我国A... 详细信息

精准扶贫是打赢脱贫攻坚战的制胜法宝,为实现共同富裕积累了宝贵的经验。通过混合所有制改革,企业经济效益显著提升,促进实现“做大蛋糕”,但进一步能否推动企业参与精准扶贫来“分好蛋糕”仍有待检验。鉴于此,本文以2016—2021年我国A股民营企业为研究样本,探究混合所有制改革对精准扶贫投入水平、机制和方式的影响。研究发现,国有资本参股比例越高,民营企业的精准扶贫投入水平越高,表明混合所有制改革有助于推动民营企业承担促进共同富裕的社会责任。机制检验发现,国有资本参股主要通过资源互补效应缓解企业融资约束,从而促进民营企业参与精准扶贫。相比之下,通过缓解代理问题来促进企业扶贫的监督制衡效应尚未发挥显著作用。从扶贫模式来看,国有资本参股促进民营企业采用输血和造血相结合的方式,通过产业发展、教育资源投入、生态保护投入等方式推动精准扶贫落户;从扶贫地区来看,国有资本参股对于经济发展落后、失业率高以及中西部地区实现脱贫具有更显著的作用。本文为深化混合所有制改革和扎实推动共同富裕提供新的经验证据。

关键词：混合所有制精准扶贫国有资本资源互补监督制衡

Experimental study on fusion and break-up motion after droplet collision

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Chinese Journal of Chemical Engineering 2020年第3期28卷 712-720页

作者： Yi Li zhi ning Ming Lü Beijing Jiaotong University School of MechanicalElectronic and Control EngineeringBeijing 100044China Beijing Jiaotong University Beijing Key Lab Powertrain New Energy VehicleBeijing 100044China

The interactions between droplets have an important influence on the atomization of liquid fuel,the combustion efficiency,and the reduction of particulate matter emissions for an *** this reason,this paper presents results from an experimental study on the coalescence and break-up of droplets after *** to the shape and parameters of the droplets at different times after the collision of the droplets was captured by a high speed camera,analysis was done for the following effects of droplet collisions:the collision-coalescence motion for the collision between the droplets,the change history of the dimensionless length-to-width ratio of the oscillation motion,the critical size ratio of the breakup motion,and the liquid physical properties of the *** results show that the droplets collide and exhibit two forms of coalescence oscillation and break-up:for oscillating motion,at higher droplet collision velocities and dimensionless size ratios,there will be a larger dimensionless length-to-width ratio for the droplet oscillation;for the break-up motion,at higher collision velocities,there will be lower dimensionless size ratios,and lower liquid surface tension,shorter times over which the droplet breaks,and facilitated droplet *** research results presented here can be used for atomization in engine cylinder,increasing the gas/liquid contact area and enhancing the combustion efficiency of gas/liquid heat transfer to improve the combustion efficiency of the engine.

关键词： Collision between droplets Size ratio Collision velocity Broken moment