检索结果-南通市图书馆

Adaptive monopulse beamforming with partial parallel structure

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2012年第6期23卷 802-814页

作者： Liang Chen Weixing sheng Xiaofeng ma fei Huang and Yubing Han School of Electronic and Optical Engineering Nanjing University of Science and Technology Nanjing 210094 P. R. China

A new recursive algorithm with the partial parallel structure based on the linearly constrained minimum variance （LCMV） criterion for adaptive monopulse systems is proposed. The weight vector associated with the original whole antenna array is decomposed into several adaptive weight sub-vectors firstly. An adaptive algorithm based on the conventional LCMV principle is then deduced to update the weight sub-vectors for sum and difference beam, respectively. The optimal weight vector can be obtained after convergence. The required computational complexity is evaluated for the proposed technique, which is on the order of O（N） and less than that of the conventional LCMV method. The flow chart scheme with the partial parallel structure of the proposed algorithm is introduced. This scheme is easy to be implemented on a distributed computer/digital signal processor （DSP） system to solve the problems of the heavy computational burden and vast data transmission of the large-scale adaptive monopulse array. Then, the monopulse ratio and convergence rate of the proposed algorithm are evaluated by numerical simulations. Compared with some recent adaptive monopulse estimation methods, a better performance on computational complexity and monopulse ratio can be achieved with the proposed adaptive method.

关键词： digital beamforming monopulse estimation linearlyconstrainted minimum variance (LCMV) parallel distributed com-putation.

Shuttle-run synchronization in mobile ad hoc networks

在线全文

学校读者我要写书评

暂无评论

Frontiers of physics 2015年第3期10卷 105-112页

作者： sheng-fei ma Hong-Jie Bi Yong Zou Zong-Hua Liu Shu-Guang Guan Department of Physics East China Normal University Shanghai 200241 China State Key Laboratory of Theoretical Physics Institute of Theoretical Physics Chinese Academy of Sciences Beijing 100190 China

In this work, we study the collective dynamics of phase oscillators in a mobile ad hoc network whose topology changes dynamically. As the network size or the communication radius of individual oscillators increases, the topology of the ad hoc network first undergoes percolation, forming a giant cluster, and then gradually achieves global connectivity. It is shown that oscillator mobility generally enhances the coherence in such networks. Interestingly, we find a new type of phase synchronization/clustering, in which the phases of the oscillators are distributed in a certain narrow range, while the instantaneous frequencies change signs frequently, leading to shuttle-run-like motion of the oscillators in phase space. We conduct a theoretical analysis to explain the mechanism of this synchronization and obtain the critical transition point.

关键词： synchronization phase transition ad hoc network

Interaction of major facilitator superfamily domain containing 2A with the blood-brain barrier

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第8期20卷 2133-2152页

作者： Yilun ma Taiwei Dong fei Luan Juanjuan Yang Feng Miao Peifeng Wei College of Pharmacy and First Clinical Medical College Shaanxi University of Chinese MedicineXianyangShaanxi ProvinceChina National Drug Clinical Trial Agency The Second Affiliated Hospital of Shaanxi University of Chinese Medicine/Xixian New District Central HospitalXi′anShaanxi ProvinceChina

The functional and structural integrity of the blood-brain barrier is crucial in maintaining homeostasis in the brain microenvironment;however,the molecular mechanisms underlying the formation and function of the blood-brain barrier remain poorly *** major facilitator superfamily domain containing 2A has been identified as a key regulator of blood-brain barrier *** plays a critical role in promoting and maintaining the formation and functional stability of the blood-brain barrier,in addition to the transport of lipids,such as docosahexaenoic acid,across the blood-brain ***,an increasing number of studies have suggested that major facilitator superfamily domain containing 2A is involved in the molecular mechanisms of blood-brain barrier dysfunction in a variety of neurological diseases;however,little is known regarding the mechanisms by which major facilitator superfamily domain containing 2A affects the blood-brain *** paper provides a comprehensive and systematic review of the close relationship between major facilitator superfamily domain containing 2A proteins and the blood-brain barrier,including their basic structures and functions,cross-linking between major facilitator superfamily domain containing 2A and the blood-brain barrier,and the in-depth studies on lipid transport and the regulation of blood-brain barrier *** comprehensive systematic review contributes to an in-depth understanding of the important role of major facilitator superfamily domain containing 2A proteins in maintaining the structure and function of the blood-brain barrier and the research progress to *** will not only help to elucidate the pathogenesis of neurological diseases,improve the accuracy of laboratory diagnosis,and optimize clinical treatment strategies,but it may also play an important role in prognostic *** addition,the effects of major facilitator superfamily domain containing 2A on blood-brain barrier lea

关键词： blood-brain barrier(BBB) caveolin-1 central nervous system docosahexaenoic acid endothelial cells lysophosphatidylcholine major facilitator superfamily domain containing 2A(MFSD2A) transcytosis

Co-production of hydrogen, oxygen, and electricity via an integrated solar-driven system with decoupled water electrolyzer and Na-Zn ion battery

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2025年第1期100卷 621-627页

作者： fei Lv Longjie Liu Jiazhe Wu Pengfei Wang Lixia Pan Dengwei Jing Yubin Chen International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University

Combining water electrolysis and rechargeable battery technologies into a single system holds great promise for the co-production of hydrogen （H2） and ***,the design and development of such systems is still in its ***,an integrated hydrogen-oxygen （O2）-electricity co-production system featuring a bipolar membrane-assisted decoupled electrolyzer and a Na-Zn ion battery was established with sodium nickelhexacyanoferrate （NaNiHCF） and Zn2+/Zn as dual redox *** decoupled electrolyzer enables to produce H2and O2in different time and space with almost 100%Faradaic efficiency at 100 ma ***,the charged NaNiHCF and Zn electrodes after the electrolysis processes formed a Na-Zn ion battery,which can generate electricity with an average cell voltage of 1.75 V at 10 m A *** connecting Si photovoltaics with the modular electrochemical device,a well-matched solar driven system was built to convert the intermittent solar energy into hydrogen and electric energy with a solar to hydrogen-electricity efficiency of 16.7%,demonstrating the flexible storage and conversion of renewables.

关键词： Hydrogen Electricity Decoupled water electrolyzer Na-Zn ion battery Solar energy

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

用于水下图像增强的多层级联融合增强网络

电光与控制 2025年第1期32卷 68-73页

作者：王炫钧邵菲马彦卿西安建筑科技大学理学院西安710000

为了提高水下无人潜航器决策的准确性,构建了一种用于增强水下图像的多层级联融合增强网络。首先,设计注意力引导的色彩增强模块并结合多层级联增强架构,在提取图像多尺度特征的同时,加强特征重用;其次,设计全局调整模块,将Swin Transfo... 详细信息

为了提高水下无人潜航器决策的准确性,构建了一种用于增强水下图像的多层级联融合增强网络。首先,设计注意力引导的色彩增强模块并结合多层级联增强架构,在提取图像多尺度特征的同时,加强特征重用;其次,设计全局调整模块,将Swin Transformer与扩张卷积相结合,提升网络对于退化图像整体增强效果;最后,将各模块提取到的特征信息经由三重特征聚合模块进行融合增强,得到增强水下图像。为了可以更好地训练模型,构造了联合损失函数。与其他水下图像增强方法的对比实验结果表明,所提方法对于水下图像存在的色偏、模糊等问题均有着良好的增强效果,并对后续特征提取任务的完成有着较大的促进作用。

关键词：水下无人潜航器水下图像增强多层级联增强架构全局调整三重特征聚合

同方期刊数据库博看期刊

Effect of Olefin-based Compatibilizers on the Formation of Cocontinuous Structure in Immiscible HDPE/iPP Blends

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2020年第11期38卷 1248-1257,I0008页

作者： fei Yang Li Pan Hui-Zhen Du Zhe ma Yue-sheng Li Tianjin Key Laboratory of Composite and Functional materials and School of Materials Science and EngineeringTianjin UniversityTianjin 300072China Collaborative Innovation Center of Chemical Science and Engineering(Tianjin) Tianjin 300072China

In this work,the formation of cocontinuous structure in immiscible high density polyethylene/isotactic polypropylene(HDPE/iPP)blends was investigated for various olefin-based compatibilizers of distinct molecular architectures,including ternary random copolymer EPDM,olefin block copolymer(OBC),polypropylene-based OBC(PP-OBC),ethylene/a-olefin copolymer(POE),bottlebrush polymer poly(1-dodecene),and comb-like poly(propylene-co-high a-olefin)(PPO).The scanning electron microscopy results show that after adding OBC,PP-OBC,and POE copolymers,the finer droplet-in-matrix morphologies were obtained in 70/30 HDPE/iPP ***,for 70/30 HDPE/iPP blend with just 5 wt%of PPO copolymers,the phase inversion from droplet-in-matrix to cocontinuous morphology can be *** was proposed that the development of cocontinuous morphology contained the following steps:(1)in terfacial saturati on of compatibilizers and droplet deformation,(2)droplet-droplet coalesce nee,(3)continuity development,and(4)the formation of dual-phase con *** the diverse copolymers studied in this work,PPO copolymer can be easily removed out of the interface during droplet coalescence and stabilize the curvature of minor fiber phase,facilitating the formation of cocontinuous *** contrast,other olefin-based compatibilizers(EPDM,OBC,PP-OBC,and POE)exhibit the distinct steric repulsion effect to prohibit droplet ***,the cocontinous interval varies with the compatibilizer ***,after adding 10 wt%of PPO copolymers,the cocontinuous interval was greatly broadened from HDPE/iPP range of 45/55-60/40 to that of 40/60-70/30.

关键词： Compatibilizer Polyolefin Cocontinuous structure Droplet-coalescence Phase inversion

Synthesis,Characterization of Polyethylene Ionomers and Their Antibacterial Properties

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第8期42卷 1077-1084页

作者： Jia-Jia Wu fei Wang Peng-Qi Wan Li Pan Chun-sheng Xiao Zhe ma Yue-sheng Li Tianjin Key Lab Composite&Functional materials School of Materials Science and EngineeringTianjin UniversityTianjin 300350China Key Lab Polymer Ecomaterials Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China

Owing to its high production volume and wide range of application s,polyethylene has gained a great deal of attention,but its low surface energy and non-polar nature have limited its application in some important *** this study,ethylene/11-iodo-1-undecene copolymers were prepared and used as the intermediates to afford a series of imidazolium-based ionomers bearing methanesulfonate(CH_(3)SO_(3)^(-)),trifluoromethanesulfonate(CF_(3)SO_(3)^(-)),or bis(trifluoromethane)sulfonimide(Tf_(2)N^(-))*** tensile test results showed that the stress-at-break(7.8-25.6 MPa)and the elongation-at-break(445%-847%)of the ionomers could be adjusted by changing the counterion species and the ionic group *** importantly,the ionomers exhibited marvelous antibacterial activities against Staphylococcus aureus(***)and Escherichia coli(***).The ionomers bearing Tf_(2)N^(-)exhibited antibacterial activities>99%against both *** and *** when ionic content reached 9.1%.The imidazolium-based ionomers prepared in this work demonstrated excellent comprehensive properties,especially highefficient and broad-spectrum antibacterial ability,exhibiting the potential fo r the application as the antibacterial materials in packaging,medical,and other fields.

关键词： Polyethylene Ionomer Polymerization catalysis Imidazolium Antibacterial material

Effects of Sb Addition on Microstructural Evolution and Mechanical Properties of Mg–9Al–5Sn Alloy

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2021年第2期34卷 278-288页

作者： Chun-Hua ma Fu-sheng Pan Ding-fei Zhang Ai-Tao Tang Zhi-Wen Lu College of materials Science and Engineering Chongqing UniversityChongqing 400045China College of Mechanical and Electronic Engineering Nanyang Normal UniversityNanyang 473061China

The Mg–9Al–5Sn-xSb(x=0.0,0.3,0.6,1.0,1.5 wt%)alloys were prepared by a simple alloying process followed by hot extrusion with an extrusion ratio of *** effects of Sb additions on the microstructure and mechanical properties of the Mg–9 Al–5 Sn alloys were investigated by optical microscopy,X-ray diffraction,transmission electron microscopy,scanning electron microscopy equipped with an energy-dispersive X-ray *** results indicated that the phasesα-Mg matrix,Mg2Sn,Mg_(3)Sb_(2) and Mg17 Al12 exist in the as-cast Sb-containing *** addition results in the precipitation of Mg_(3)Sb_(2).The dendritic size of these alloys decreases with the addition of *** their ultimate tensile strength and yield strength of extruded alloys increase,and their elongation decreases gradually with increasing the content of *** better mechanical properties of the as-extruded alloys were achieved due to the refined grains and the formation of dispersive second phases Mg_(3)Sb_(2).

关键词： Mg–Al–Sn–Sb alloy Microstructure Extrusion Second phase Mechanical properties

Derivation of the Spiral Motion of an Eruptive Prominence and Its Explanation

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Astronomy and Astrophysics 2006年第5期6卷 617-624页

作者： Xiao-ma Gu Shu-Hua Zhong Hong-fei Liang La-sheng Zhan National Astronomical Observatories / Yunnan Observatory Chinese Academy of Sciences Kunming650011 Jingdezhen Ceramic Institute Jingdezhen 333000

A 2D velocity field of the eruptive prominence （EP） of 1991 march 5 is obtained from its spectral data observed at the Yunnan Observatory and the velocity distributions along the entrance slit are derived for different observing frames. Under the assumption that matter in the EP undergoes axial, radial and possible rotational motions, we construct a theoretical velocity distribution of the EP along the entrance slit, to derive, by fitting, the angular velocity of rotation ω and the other three parameters （axial velocity v0, radial velocity vr and the angle between the EP plane and the line of sight Ф）. We found： an averaged angular velocity ω of 3.0 × 10^-3 arc s^-1 and the variation of ω with the height above the solar limb. As the EP rises, the matter within it in fact moves along a spiral path around its axis. The spiral motion may be explained by the theory of plasma ‘double pole diffusion＇（DPD） caused by a sharp density gradient between the eruptive prominence and the surrounding corona. A theoretical angular velocity ω′ is estimated based on the DPD and basically coincides with ω obtained from the optimal velocity fitting.

关键词： Sun eruptive prominence -- Sun Spiral motion