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Friction 2024年第11期12卷 2563-2575页

作者： Zhengchao XI Jianbo SUN Lei CHEN haixia cui Yanjun MA Huidi ZHOU Jianmin CHEN State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Aerospace Research Institute of Materials&Processing Technology Beijing 100076China

Magnesium silicate hydroxides(MSHs)with granular,schistose,and tubular morphologies were separately incorporated to enhance the tribological properties of phosphate/MoS2 composite *** nano-schistose MSH demonstrated superior tribological performance due to its effective interactions with the worn surface and frictional synergies with solid *** of nano-schistose MSH decreased the friction coefficient of composite coatings by about 34.7%and increased the anti-wear performance of composite coatings by about thirteen ***-schistose MSH facilitated the formation of a friction-induced multi-layer heterogenous slipping structure with layered solid lubricants at the friction ***,tribo-chemical reactions between nano-schistose MSH and worn surface promoted the in-situ formation of a cermet supporting film,and this also induced the gradual in-situ formation of a lubrication film on the top of worn ***,the contact state between tribo-pairs was timely regulated and the invalidation of the nanocomposite slipping structure was effectively restrained during the friction *** a result,the service life of the phosphate composite coatings was significantly extended and further abrasion on the worn surface was notably reduced.

关键词： nano-sized magnesium silicate hydroxide(MSH) morphology regulation nanocomposite slipping structure tribo-film

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欧盟食物系统研发创新支持政策的经验

科技导报 2024年第16期42卷 98-107页

作者：崔海霞高一丹宗义湘河北农业大学经济管理学院保定071000 河北农业大学乡村振兴战略研究中心保定071000

欧盟高度重视食物系统研发创新。分析了欧盟食物系统研发创新支持政策历史沿革和政策架构、食物系统研发资金构成、重点支持领域和支持特征。欧盟食物系统研发资金来自欧盟和成员国2个层面,其中,《框架协议》为研发创新提供资金支持,《... 详细信息

欧盟高度重视食物系统研发创新。分析了欧盟食物系统研发创新支持政策历史沿革和政策架构、食物系统研发资金构成、重点支持领域和支持特征。欧盟食物系统研发资金来自欧盟和成员国2个层面,其中,《框架协议》为研发创新提供资金支持,《食物2030》为食物系统研发创新提供政策指引;食物系统研发支出不断提高,且呈现与《食物2030》优先事项和路径一致趋势;重点关注初级生产部门;注重基础项目研发以及中小企业参与。结合中国食物系统研发创新支持政策分析,提出加大研发创新资金支持、构建多主体参与机制形成政策合力、提高基础研发支持和关注市场端成果转化等政策建议。

关键词：欧盟研发创新支持政策食物系统

Joint User Association and Fair Scheduling for Dual Connectivity Heterogeneous Networks

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China Communications 2023年第1期20卷 171-183页

作者： haixia cui Yongliang Du School of Electronics and Information Engineering South China Normal UniversityFoshan 528225China School of Physics and Telecommunication Engineering South China Normal UniversityGuangzhou 510006China

Heterogeneous small cell network is one of the most effective solutions to overcome spectrum scarcity for the next generation of mobile *** connectivity(DC)can improve the throughput for each individual user by allowing concurrent access to two heterogeneous radio *** this paper,we propose a joint user association and fair scheduling algorithm(JUAFS)to deal with the resource allocation and load balancing issues for DC heterogeneous small cell *** different coverage sizes,numbers of users,and quality of experience characteristics of heterogeneous cells,we present a proportional fair scheduling for user association among cells and utilize interference graph to minimize the transmission conflict *** results show the performance improvement of the proposed algorithm in spectrum efficiency and fairness comparing to the existing schemes.

关键词： fair scheduling heterogeneous networks dual connectivity interference management

Unlicensed Band Sharing Based on Bargaining Game for Heterogeneous Networks

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China Communications 2022年第12期19卷 129-141页

作者： haixia cui Shujie Zou School of Electronics and Information Engineering South China Normal UniversityFoshan 528225China School of Physics and Telecommunication Engineering South China Normal UniversityGuangzhou 510006China

Currently,limited licensed frequency bands cannot meet the increasing demands for various wireless communication applications any *** is necessary to extend wireless communication networks to unlicensed *** this paper,we propose a new bargaining framework for unlicensed band access to achieve high spectrum efficiency,where one radio access technology(RAT)(such as macro cellular network)“competes”the unlicensed bands with multiple other RATs(such as small cellular networks or Wi-Fi)*** that macro cell can share unlicensed frequencies with multiple small cells which are in the same coverage area for more freedom,we use bargaining game theory to fairly and effectively share the unlicensed spectrum between macro and multiple heterogeneous small cell networks,where bargaining loss and time dissipation loss for virtual“price”of unlicensed bands are mainly *** the oneto-many bargaining process,we also develop a multiple RAT alliance game strategy to reduce transmission loss in a joint *** results show that the proposed unlicensed band sharing algorithm significantly improves the spectrum efficiency performance compared with the other practical schemes for heterogeneous networks.

关键词： unlicensed spectrum bargaining game alliance game one-to-many bargaining game

Green Distributed Antenna Systems for Smart Communities: A Comprehensive Survey

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China Communications 2019年第11期16卷 70-80页

作者： haixia cui Yi Liu School of Physics and Telecommunication Engineering South China Normal University

Smart communities are an emerging communication means in which humans and smart devices will interact with each other and deliver ubiquitous services by exploiting social *** antenna system(DAS),one of the key technologies to realize smart decisions in smart communities,can settle network smart coverage problem and improve system energy/spectrum efficiency *** that energy consumption is an important element for community communications,in this paper,we survey the existing green DAS research for smart *** particular,our investigation covers antenna distribution,system capacity,spectrum efficiency,energy efficiency,and green access ***,we analyze the existing application opportunities and *** survey contributes to better understanding of the challenges and approaches for green DAS in existing smart community networks and further shed novel light on some future research directions.

关键词： smart communities distributed antenna systems spectrum efficiency energy efficiency green communications

Superimposed training for channel estimation of OFDM modulated amplify-and-forward relay networks

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Science China(Information Sciences) 2013年第10期56卷 55-66页

作者： ZHANG Han PAN DaRu cui haixia GAO FeiFei School of Physics and Telecommunication Engineering South China Normal University Tsinghua National Laboratory for Information Science and Technology National Mobile Communications Research Laboratory Southeast University

This paper is concerned with the problem of channel estimation for amplify-and-forward(AF)cooperative relay networks with orthogonal frequency division multiplexing(OFDM)*** algorithm is based on both the least square(LS)and minimum mean square error(MMSE)technique with a superimposed training ***,both the source and relay superimpose their own training signal onto data stream prior to transmission so as to estimate the separate channel state information of the source to relay link and the relay to destination *** also present the performance analysis and derive the approximated closed-form expressions for the MSE of separate channel estimation of source to relay link and the relay to destination link,respectively,from which we compute the optimal training signal as well as the relay power-amplifcation *** further improve the performance of channel estimation,we adopt a weighted average process to enhance the estimation performance over multiple OFDM blocks,from which we compute the optimal tracking *** results are provided to corroborate the proposed scheme.

关键词： channel estimation amplify-and-forward relay network OFDM superimposed training

Preparation of Cu-Ni bimetallic nanoparticles surface-capped with dodecanethiol and their tribological properties as lubricant additive

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Particuology 2017年第5期15卷 89-96页

作者： Lei Chen Haiyan Xu haixia cui Huidi Zhou Hongqi Wan Jianmin Chen State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical Physics Chinese Academy of Sciences Lanzhou 730000 China

Cu-Ni bimetallic nanoparticles surface-capped with dodecanethiol were prepared via the controlled reduction of nickel nitrate and copper nitrate in the presence of dodecanethiol as ligand and hydrazine hydrate as reductant. The morphology and structure of the Cu-Ni nanoparticles were analyzed by trans- mission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectrometry, and thermal gravimetric analysis. Furthermore, the tribological properties of the Cu-Ni nanoparticles as a lubricant additive in liquid paraffin were evaluated with a four-ball machine, and the morphology and elemental composition of the worn surfaces were analyzed by three-dimensional non-contact surface profilometry and X-ray photoelectron spectroscopy, respectively, The results indi- cated that Cu-Ni nanoparticles prepared at a sufficient dodecanethiol concentration showed almost no signs of aggregation, and exhibited good dispersibility in various apolar solvents. The addition of the Cu-Ni nanoparticles improved the load-carrying capacity as well as friction-reducing and anti-wear abilities of liquid paraffin, attributed to the roiling effect of agglomerated Cu-Ni nanocores released by the Cu-Ni nanoparticles during sliding, and the formation of a boundary lubricating film containing tribochemical reaction products such as iron oxides and iron sulfate.

关键词： Cu-Ni bimetallic nanoparticles Dodecanethiol Surface capping Tribological properties

Phase field modeling of multiple dendrite growth of Al-Si binary alloy under isothermal solidification

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China Foundry 2008年第4期5卷 265-267页

作者： Sun Qiang Zhang Yutuo cui haixia Wang Chengzhi Shenyang Ligong University Shenyang 110168 China

Phase field method offers the prospect of being able to perform realistic numerical experiments on dendrite growth in metallic systems. In this study, the growth process of multiple dendrites in AI-2-mole-%-Si binary alloy under isothermal solidification was simulated using phase field model. The simulation results showed the impingement of arbitrarily oriented crystals and the competitive growth among the grains during solidification. With the increase of growing time, the grains begin to coalesce and impinge the adjacent grains. When the dendrites start to impinge, the dendrite growth is obviously inhibited.

关键词： phase field model multiple dendrite growth binary alloy isothermal solidification

A Compact Ultra-Wideband Circularly Polarized Antenna Array for Vehicular Communications

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China Communications 2023年第6期20卷 310-320页

作者： Wei He Yejun He Long Zhang Jun Hong haixia cui Amir Boag School of Electrical and Information Engineering Hunan Institute of TechnologyHengyang 421002China College of Electronics and Information Engineering Shenzhen UniversityShenzhen 518060China School of Physics and Telecommunication Engineering South China Normal UniversityGuangzhou 510630China School of Electrical Engineering Tel Aviv UniversityTel Aviv 69978Israel

In this paper,a new compact ultrawideband(UWB)circularly polarized(CP)antenna array for vehicular communications is *** antenna array consists of a 2×2 sequentially rotated T-shaped cross dipole,four parasitic elements,and a feeding *** loading the T-shaped cross dipoles with parasitic rectangular elements with cut corners,the bandwidth can be *** this basis,the radiation pattern can be improved by the topology with sequential rotation of four T-shaped cross-dipole antennas,and the axial ratio(AR)bandwidth of the antenna also can be further *** addition,due to the special topology that the vertical arms of all Tshaped cross dipoles are all oriented toward the center of the antenna array,the gain of proposed antenna is improved while the size of the antenna is almost the same as the traditional cross *** and measured results show that the proposed antenna has good CP characteristics,an impedance bandwidth for S11<-10 d B of about 106.1%(3.26:1,1.57-5.12 GHz)and the 3-d B AR bandwidth of about 104.1%(3.17:1,1.57-4.98 GHz),a wide 3-d B gain bandwidth of 73.3%as well as the peak gain of 8.6 d Bic at 3.5 *** overall size of antenna is 0.56λ×0.56λ×0.12λ(λrefers to the wavelength of the lowest operating frequency in free space).The good performance of this compact UWB CP antenna array is promising for applications in vehicular communications.

关键词： circularly polarized antenna vehicle satellite communications cross-dipole antenna ultrawideband(UWB)antenna

IL-6、CRP、NLR和NT-proBNP对老年心力衰竭合并肺炎的诊断价值

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检验医学与临床 2024年第9期21卷 1250-1253,1258页

作者：吴政燮韩才均崔海霞朴美花延边大学附属医院医学检验科吉林延吉133000

目的探讨白细胞介素-6(IL-6)、C-反应蛋白(CRP)、中性粒细胞与淋巴细胞比值(NLR)和N末端前脑钠肽前体(NT-proBNP)对老年心力衰竭(以下简称心衰)合并肺炎的诊断价值。方法选取2022年4月至2023年4月该院收治的165例老年心衰患者作为研究对... 详细信息

目的探讨白细胞介素-6(IL-6)、C-反应蛋白(CRP)、中性粒细胞与淋巴细胞比值(NLR)和N末端前脑钠肽前体(NT-proBNP)对老年心力衰竭(以下简称心衰)合并肺炎的诊断价值。方法选取2022年4月至2023年4月该院收治的165例老年心衰患者作为研究对象,根据是否合并肺炎分为心衰合并肺炎组(78例)和单纯心衰组(87例),根据美国纽约心脏病协会(NYHA)心功能分级标准分为Ⅱ级组(59例)和Ⅲ级+Ⅳ级组(106例)。比较各组IL-6、CRP、NT-proBNP水平和NLR;采用Spearman相关分析IL-6、CRP、NLR与NT-proBNP水平的相关性;采用受试者工作特征(ROC)曲线评估IL-6、CRP、NLR、NT-proBNP单独及联合检测对心衰患者合并肺炎的诊断效能。结果心衰合并肺炎组IL-6、CRP、NT-proBNP水平及NLR明显高于单纯心衰组(P<0.05),Ⅲ级+Ⅳ级组IL-6、CRP、NT-proBNP水平及NLR明显高于Ⅱ级组(P<0.05)。Spearman相关性分析结果显示,NT-proBNP水平与IL-6、CRP、NLR水平呈正相关(r=0.263、0.419、0.468,P<0.001)。IL-6、CRP、NLR和NTproBNP联合诊断心衰合并肺炎的曲线下面积(AUC)为0.726(95%CI:0.650~0.803),灵敏度为67.9%,特异度为71.3%。结论心衰合并肺炎患者IL-6、CRP、NT-proBNP水平和NLR明显高于单纯心衰患者,上述4项指标联合检测对心衰合并肺炎患者有一定的诊断效能。

关键词：白细胞介素-6 C-反应蛋白中性粒细胞淋巴细胞比 N末端前脑钠肽前体心力衰竭肺炎