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Science China(Information Sciences) 2015年第4期58卷 103-114页

作者： TONG En ding fei PAN ZhiWen YOU xiao Hu National Mobile Communications Research Laboratory Southeast University Research and Development Center China Mobile Group Jiangsu Co. Ltd.

Energy saving has become an important issue in wireless communications from both environment and economic considerations. In this paper, an energy minimization algorithm based on distributed dynamic clustering(DDCEM) with lower complexity, higher performance, and better adaptability for heterogeneous network(Het Net) is proposed. A Het Net could be divided into several clusters, which is defined as one group of a network node and users served by the node. A energy efficient user association, which dynamically changes according to real-time energy efficiency(EE) evaluation with traffic load and location distribution of each cluster, can be employed to save consumed energy. Then, the optimal sleeping relay is found as follows. First,the sleeping probability cost of each relay station(RS) is computed and ranked based on the user traffic and the position distribution of each cluster, and the relay with minimum sleeping probability is selected to be switched off. Hence, the sleep node is selected taking into account the traffic load and location of the Evolved Node B(e NB) and all the RSs. The complexity of the algorithm is greatly reduced because the user association operation and network load evaluation are fulfilled cluster by cluster. Simulation results show that the proposed DDCEM strategy offers EE gain with low system complexity.

关键词： energy efficiency heterogeneous network traffic cluster sleeping probability cost

Revolutionizing solid-state single-photon sources with multifunctional metalenses

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Light(Science & Applications) 2024年第1期13卷 8-9页

作者： fei ding Centre for Nano Optics University of Southern DenmarkCampusvej 55Odense MDK-5230Denmark

Ultrathin multifunctional metalenses are demonstrated to control the multiple degrees of freedom of a single-photon source in hexagonal boron nitride.

关键词： hexagonal boron state

Turning machining induced microstructural stability of a high Nb-containing TiAl alloy during high temperature exposure

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Rare Metals 2016年第1期35卷 77-84页

作者： Lu Fang Jun-Pin Lin xiao-Chan Qiu Jin-xiao Ou Xian-fei ding State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing School of Architecture and Engineering Heilongjiang University National Center for Materials Service Safety University of Science and Technology Beijing

Turning machining induced microstructural instability was investigated in a fully lamellar Ti-45Al-8.5Nb-（W,B,Y） alloy during high temperature *** turning machining followed by thermal exposure at900 or 1000℃ for 100,300 and 500 h,a depth-dependent gradient microstructure with random orientations was produced in the region close to the machining *** typical layers,a fine-grained（FG） layer with equiaxed grains and a coarse-grained（CG） layer with elongated grains,are formed in this region in transversal *** thickness of the two layers is up to 120 urn after thermal exposure at 1000℃ for 500 h,which is less than the depth of the hardened region（200 μm） after turning *** of the new grains in FG and CG layers are constituted of γ single phase,while short α_2 segments and few B2 particles are precipitated at the γ/γ interface or inside the γ *** and phase boundary bulging are found to be the major mechanisms responsible for lamellar degradation in FG layer and CG layer,*** residual deformation energy stored is considered to be the main driving force of this process.

关键词： High Nb-containing TiAl alloy Residualdeformation energy Microstructural instability Recrystallization Phase transformation

Study on neutron-gamma discrimination methods based on GMM-KNN and LabVIEW implementation

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Nuclear Science and Techniques 2024年第11期35卷 82-97页

作者： Ting-Meng ding Yu-Hang Jiang Xuan-Xi Wang xiao-fei Jiang Big Data and Information Engineering GuiZhou UniversityGuiyang 550025China

Machine learning algorithms are considered as effective methods for improving the effectiveness of neutron-gamma(n-γ)*** study proposed an intelligent discrimination method that combined a Gaussian mixture model(GMM)with the K-nearest neighbor(KNN)algorithm,referred to as ***,the unlabeled training and test data were categorized into three energy ranges:0–25 keV,25–100 keV,and 100–2100 ***,GMM-KNN achieved small-batch clustering in three energy intervals with only the tail integral Q_(tail) and total integral Q_(total) as the pulse ***,we selected the pulses with a probability greater than 99%from the GMM clustering results to construct the training ***,we improved the KNN algorithm such that GMM-KNN realized the classification and regression algorithms through the LabVIEW *** outputs of GMM-KNN were the category or regression *** proposed GMM-KNN constructed the training set using unlabeled real pulse data and realized n-γdiscrimination of ^(241)Am-Be pulses using the LabVIEW *** experimental results demonstrated the high robustness and flexibility of *** when using only 1/4 of the training set,the execution time of GMM-KNN was only 2021 ms,with a difference of only 0.13%compared with the results obtained on the full training ***,GMM-KNN outperformed the charge comparison method in terms of accuracy,and correctly classified 5.52%of the ambiguous *** addition,the GMM-KNN regressor achieved a higher figure of merit(FOM),with FOM values of 0.877,1.262,and 1.020,corresponding to the three energy ranges,with a 32.08%improvement in 0–25 *** conclusion,the GMM-KNN algorithm demonstrates accurate and readily deployable real-time n-γdiscrimination performance,rendering it suitable for on-site analysis.

关键词： n-discrimination GMM KNN LabVIEW Classification Regression

Quantum dots get a bright upgrade

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Light(Science & Applications) 2024年第11期13卷 2438-2440页

作者： fei ding Institut für Festkörperphysik Leibniz Universität HannoverAppelstraße 230167 HannoverGermany

Developing a bright,deterministic source of entangled photon pairs has been an outstanding scientific and technological *** quantum dots are a promising candidate for this task.A new device combining a circular Bragg resonator and a piezoelectric actuator achieves high brightness and entanglement fidelity simultaneously,overcoming previous *** breakthrough enhances quantum dot applications in entanglement-based quantum communication protocols.

关键词： quantum breakthrough piezoelectric

Antiosteoporotic Tetrahydroxanthone Dimers from Aspergillus brunneoviolaceus FB-2 Residing in Human Gut

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Chinese Journal of Chemistry 2021年第6期39卷 1580-1586页

作者： xiao-Jing Lv fei ding Ying-Jie Wei Ren-Xiang Tan State Key Laboratory Cultivation Base for TCM Quality and Efficacy Nanjing University of Chinese MedicineNanjingJiangsu 210023China State Key Laboratory of Pharmaceutical Biotechnology School of Life SciencesNanjing UniversityNanjingJiangsu 210023China

A complex community of human-associated microorganisms plays diversely important roles in maintaining health,and the metabolites help to define whether a particular human-associated microbe is a friend or a *** work shows that Aspergillus brunneoviolaceus FB-2,derived from the stool of a healthy individual,produces a family of antiosteoporotic xanthone dinners including penibishexahydroxanthone A(1)and brunneoxanthones A-E(2-6,undescribed previously).The structures of 1-6 were elucidated by MS and NMR spectroscopic analysis,and the absolute configuration of 2 was established by X-ray *** 4-6 are relatively rare examples of highly oxidized heterodimeric xanthones with an 8-ketone ***,the prednisolone-induced osteoporotic zebrafish enabled our demonstration that the antiosteoporotic effects of 1-6 are dose-dependent.

关键词： Aspergillus brunneoviolaceus Gut-associated fungus Natural products Structure elucidation Biological activity

Dynamic manipulation of multimodal emission in Er^(3+)-activated non-core-shell structure for optical thermometry and information security

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Rare Metals 2024年第4期43卷 1702-1712页

作者： Xuan Liu Zi-Xia Lin Yin-Biao Shi xiao-Yan Wang Ming-Ye ding xiao-fei Yang College of Science Nanjing Forestry UniversityNanjing210037China Testing Center Yangzhou UniversityYangzhou225009China

Regulating luminescent dynamics of lanthanide-based luminescent materials via external stimuli is of great significance in the fields of optical thermometry and high-level ***,it is still a huge challenge to realize multimodal emissions with tunable color outputs from a single activator in simple structures via smart dynamic control of photon transition ***,we present a mechanistic strategy to achieve multimodal luminescence of Er^(3+)activators with color-switchable outputs in a non-core-shell *** the control of excitation dynamics(λ_(ex)=980,808,1532,377 nm),the population among the intermediate en ergy levels of Er^(3+)and the interaction between Er^(3+)and Yb^(3+)could be precisely modulated through energy transfer and migration processes,leading to the generation of colortunable multimodal luminescence upon diverse excitation modes(non-steady-state,single-/dual-wavelength steady,thermal activation).Inspired by its special luminescent performance,the as-obtained material exhibits great potential in noncontact thermometry,multimodal anticounterfeiting,and high-capacity information encryption by performing a series of proof-of-concept *** findings might provide a conceptual model to modulate the luminescent dynamics in a simple-structured system for the generation of color-adjustable multimodal emissions,which is convenient for the development of advanced luminescent materials toward versatile cuttingedge applications.

关键词： Lanthanide ions Multimodal emission Upconversion Downshifting Anti-counterfeiting Luminescent thermometry

Surface Polarization Effects on Collapse Transition of Polyelectrolyte Brushes

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Chinese Journal of Polymer Science 2024年第9期42卷 1313-1320,I0006页

作者： xiao-fei Xu State Key Laboratory of Chemical Engineering and School of Chemical Engineering East China University of Science and TechnologyShanghai200237China

Polyelectrolyte brushes(PEBs)are commonly used to modify surface that have attracted great research *** dielectric permittivity of the grafted surface is typically significantly different from that of solution,which results in surface polarization(SP)effect with a jump of electric *** is thus important to study how SP alters the PEB’s structure and *** this work,the SP effects on PEB structure was studied using a statistical thermodynamic *** free energy functional to describe SP effect was constructed by using the image-charge ***,the electrostatic potential was solved from a modified Poisson-Boltzmann equation taking the ion solvation effect into *** the absence of SP,the thickness of PEB exhibited a continuous collapse transition when decreasing the solvent *** the presence of SP,the collapse became a jump-like *** energy analysis showed that the long-range Coulombic interaction dominated the transition because of the enhanced counterion condensation in the presence of *** theory provides an effective tool to study SP effect on PEBs,and the results explain the underlying physics in PEB collapse transition.

关键词： Surface polarization Polyelectrolyte brush Image charge Ion solvation Polyelectrolyte collapse transition

Cu掺杂SnS_(2)纳米花高效电化学还原CO_(2)合成甲酸盐的研究

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现代化工 2025年第1期45卷 220-224页

作者：丁笑含赵林飞袁章福田越徐秉声北京科技大学钢铁共性技术协同创新中心北京100083 中国标准化研究院资源环境研究分院北京100191

为了提高Sn基材料表面CO_(2)电化学还原为甲酸盐的法拉第效率,利用一步溶剂热法合成了具有丰富硫空位的Cu掺杂SnS_(2)纳米花(Cu-SnS_(2-x))催化剂,在较宽的电位窗口实现了CO_(2)电化学还原制备甲酸盐。结果表明,通过调控催化剂制备过程... 详细信息

为了提高Sn基材料表面CO_(2)电化学还原为甲酸盐的法拉第效率,利用一步溶剂热法合成了具有丰富硫空位的Cu掺杂SnS_(2)纳米花(Cu-SnS_(2-x))催化剂,在较宽的电位窗口实现了CO_(2)电化学还原制备甲酸盐。结果表明,通过调控催化剂制备过程中Cu和Sn的摩尔比,在-1.1 V ***电位条件下得到了72.64%的FE_(formate),电流密度J_(formate)达到-14.38 mA/cm^(2)。二维纳米片阵列增加了催化活性位点,Cu掺杂所产生的硫空位能够协同提高催化活性、促进电子转移,从而提高甲酸盐的选择性。

关键词： CO_(2)还原电化学掺杂溶剂热甲酸

Microstructure evolution in grey cast iron during directional solidification

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International Journal of Minerals,Metallurgy and Materials 2017年第8期24卷 884-890页

作者： Xian-fei ding xiao-zheng Li Qiang Feng Warkentin Matthias Shi-yao Huang National Center for Materials Service Safety University of Science and Technology Beijing Beijing Key Laboratory of Special Melting and Preparation of High-end Metal University of Science and Technology Beijing State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing Ford Research & Advanced Engineering Europe Materials and Process Research Ford Motor Research and Engineering Center

The solidification characteristics and microstructure evolution in grey cast iron were investigated through Jmat-Pro simulations and quenching performed during directional solidification. The phase transition sequence of grey cast iron was determined as L → L + γ→ L + γ + G →γ + G → P(α + Fe_3C) + α + G. The graphite can be formed in three ways: directly nucleated from liquid through the eutectic reaction(L →γ + G), independently precipitated from the oversaturated γ phase(γ→γ + G), and produced via the eutectoid transformation(γ→ G + α). The area fraction and length of graphite as well as the primary dendrite spacing decrease with increasing cooling rate. Type-A graphite is formed at a low cooling rate, whereas a high cooling rate results in the precipitation of type-D graphite. After analyzing the graphite precipitation in the as-cast and transition regions separately solidified with and without inoculation, we concluded that, induced by the inoculant addition, the location of graphite precipitation changes from mainly the γ interdendritic region to the entire γ matrix. It suggests that inoculation mainly acts on graphite precipitation in the γ matrix, not in the liquid or at the solid–liquid front.

关键词： directional solidification grey cast iron phase transition graphite