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Chinese Physics B 2020年第10期29卷 227-232页

作者： Yu-Qin yao ji li Department of Applied Mathematics China Agricultural UniversityBeijing 102206China Department of Physics Taiyuan Normal UniversityTaiyuan 030031China

The three-component Gross–Pitaevskii equation with an angular momentum rotational term can be served as a model to study spinor Bose–Einstein condensates (BECs) with time–space modulated interactions. Vortex solutions of the spinor BECs with spatiotemporally modulated interactions are worked out by similarity transformation. Theoretical analysis and numerical simulation of vortex states are demonstrated. Stable vortex states are obtained by adjusting the frequency of the external potential and the spatiotemporally modulated interaction.

关键词： spinor Bose-Einstein condensates spatiotemporal modulation vortex solution dynamical stability

Hydrothermal Synthesis of Exfoliative LDH in the Presence of Glycine

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Chinese Journal of Chemical Physics 2006年第3期19卷 253-258页

作者： Bao-guang li Yuan hu Zu-yao Chen State Key Lab of Fire Science Department of Chemistry University of Science and Technology of China Hefei 230026 China

Exfoliative Mg/Al layered double hydroxide （Mg/Al-LDHGly） was obtained via hydrothermal synthesis in the presence of glyeine. The product prepared by hydrothermal reaction for 10 h at 120℃possesses high thermal stability and maximal erystallite size in a, c directions. TEM and SEM analyses show that Mg/Al-LDHGly was of well-crystallized hexagonal product with stacks of slightly curved layers. Benefiting from mechanism investigation on its gradual delamination in formamide, rapid delamination of Mg/Al-LDHGly at room temperature was realized, which provided fundamental for preparation of （Mg/Al-LDHGly）/polymer nanoeomposites by using exfoliation-adsorption method.

关键词： Layered double hydroxide (LDH) Glyeine intercalation Delamination Hydrothermal synthesis

Effect of six years of nitrogen additions on soil chemistry in a subtropical Pleioblastus amarus forest, Southwest China

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Journal of Forestry Research 2018年第6期29卷 1657-1664页

作者： Guan-tao Chen li-hua Tu guang-sheng Chen jin-yao hu Zhou-lin Han Ecological Security and Protection Key Laboratory of Sichuan Province Mianyang Normal University College of Forestry Sichuan Agricultural University

Soil chemistry influences plant health and carbon storage in forest ecosystems. Increasing nitrogen(N) deposition has potential effect on soil chemistry. We studied N deposition effects on soil chemistry in subtropical Pleioblastus amarus bamboo forest ecosystems. An experiment with four N treatment levels(0, 50, 150,and300 kg N ha-1a-1,applied monthly, expressed as CK,LN,MN, HN,respectively) in three replicates. After6 years of N additions, soil base cations, acid-forming cations, exchangeable acidity(EA), organic carbon fractions and nitrogen components were measured in all four seasons. The mean soil pH values in CK,LN,MN and HN were 4.71, 4.62, 4.71, and 4.40, respectively, with a significant difference between CK and HN. Nitrogen additions significantly increased soil exchangeable Al3+,EA, and Al/Ca,and exchangeable Al3+ in HN increased by 70%compared to CK. Soil base cations(Ca2+, Mg2+, K+, and Na+) did not respond to N additions. Nitrogen treatments significantly increased soil NO3--N but had little effect on soil total nitrogen, particulate organic nitrogen, or NH4~+-N. Nitrogen additions did not affect soil total organic carbon, extractable dissolved organic carbon,incorporated organic carbon, or particulate organic *** study suggests that increasing N deposition could increase soil NO3--N, reduce soil pH, and increase mobilization of Al3+. These changes induced by N deposition can impede root grow and function, further may influence soil carbon storage and nutrient cycles in the future.

关键词： Base cations Carbon fractions Nitrogen deposition Soil chemistry Soil acidification

Recent progress in layered rare-earth hydroxide (LRH) and its application in luminescence

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Journal of Advanced Ceramics 2017年第3期6卷 177-186页

作者： Qi Zhu Xuejiao WANG ji-guang li Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education) Northeastern University Shenyang 110819 ChinaInstitute of Ceramics and Powder Metallurgy School of Materials Science and Engineering Northeastern University Shenyang 110819 China Research Center for Functional Materials National Institute for Materials Science Namiki 1-1 Tsukuba Ibaraki 305-0044 JapanCollege of New Energy Bohai University Jinzhou 121000 China Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education) Northeastern University Shenyang 110819 ChinaInstitute of Ceramics and Powder Metallurgy School of Materials Science and Engineering Northeastern University Shenyang 110819 ChinaResearch Center for Functional Materials National Institute for Materials Science Namiki 1-1 Tsukuba Ibaraki 305-0044 Japan

This review article compiles the recent achievements made in layered rare-earth (RE) hydroxide (LRH), including controlled crystallization, structural and morphological features, anion exchange, nanosheet exfoliation, and application in the field of luminescence for both the Ln2(OH)5(Ax-)1/x·nH2O (251-LRH) and Ln2(OH)4(Ax-)2/x·nH2O (241-LRH) phases. The luminescent properties of the LRHs themselves, the oxide, oxysulfate, and oxysulfide phosphors derived from the LRHs via controlled calcination, and the highly oriented transparent phosphor films of enhanced luminescence and/or novel emission features are summarized.

关键词： layered rare-earth hydroxide (LRH) anion exchange exfoliation assembly luminescence

Clustering and scheduling methods based on SLNR in downlink CoMP system

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The Journal of China Universities of Posts and Telecommunications 2014年第1期21卷 74-78,103页

作者： WU Xu-guang li Yi ji Hong School of Telecommunication Engineering Beijing University of Posts and Telecommunications

In downlink coordinated multi-point（CoMP） system, full cooperation is always not applicable in real world because of its high request in the backhaul. To deal with this problem, clustering decision is made to process transmission. In this paper clustering methods based on the metric signal-to-leakage-plus-noise（SLNR） is proposed. In addition, user scheduling schemes based on SLNR is also put up to make the scheduling set as large as possible. Simulation results show that the proposed clustering methods not only reduce the data sharing among the cooperating base stations（BSs）, but also improve the system throughput compared with the traditional clustering methods based on channel strength.

关键词： CoMP clustering formation SLNR user scheduling

Highly Thermoconductive,Strong Graphene‑Based Composite Films by Eliminating Nanosheets Wrinkles

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Nano-Micro Letters 2024年第1期16卷 328-340页

作者： guang Xiao Hao li Zhizhou Yu Haoting Niu Yagang yao College of Engineering and Applied Sciences Jiangsu Key Laboratory of Artificial Functional Materialsand Collaborative Innovation Center of Advanced MicrostructuresNational Laboratory of Solid State MicrostructuresNanjing UniversityNanjing 210093People’s Republic of China Institute of Laser Manufacturing Henan Academy of SciencesZhengzhou 450052People’s Republic of China Center for Quantum Transport and Thermal Energy Science School of Physics and TechnologyNanjing Normal UniversityNanjing 210023People’s Republic of China

Graphene-based thermally conductive composites have been proposed as effective thermal management materials for cooling high-power electronic ***,when flexible graphene nanosheets are assembled into macroscopic thermally conductive composites,capillary forces induce shrinkage of graphene nanosheets to form wrinkles during solution-based spontaneous drying,which greatly reduces the thermal conductivity of the ***,graphene nanosheets/aramid nanofiber(GNS/ANF)composite films with high thermal conductivity were prepared by in-plane stretching of GNS/ANF composite hydrogel networks with hydrogen bonds andπ-π*** in-plane mechanical stretching eliminates graphene nanosheets wrinkles by suppressing inward shrinkage due to capillary forces during drying and achieves a high in-plane orientation of graphene nanosheets,thereby creating a fast in-plane heat transfer *** composite films(GNS/ANF-60 wt%)with eliminated graphene nanosheets wrinkles showed a significant increase in thermal conductivity(146 W m^(−1)K^(−1))and tensile strength(207 MPa).The combination of these excellent properties enables the GNS/ANF composite films to be effectively used for cooling flexible LED chips and smartphones,showing promising applications in the thermal management of high-power electronic devices.

关键词： Graphene Aramid nanofiber Wrinkles elimination In-plane stretching Thermal conductivity

X-Ray Properties of the Point Source Population in the Spiral Galaxy NGC 5055 (M63) with Chandra

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Chinese Journal of Astronomy and Astrophysics 2007年第3期7卷 335-344页

作者： Bing Luo ji-yao Chen Zhong-li Zhang Yu Wang jing-Ying Wang Hai-guang Xu Department of Physics Fudan University Shanghai 200433 Department of Physics Shanghai Jiao Tong University Shanghai 200240

Using Chandra ACIS S3 data we studied the X-ray properties of low-and highmass X-ray binary populations in the nearby spiral galaxy NGC 5055. A total of 43 X-ray point sources were detected within two effective radii, with 31 sources located on the disk and the rest 12 sources in the bulge. The resolved point sources dominate the X-ray emission of the galaxy, accounting for about 80% of the total counts in 0.3-10keV. From spectral fittings we calculated the 0.3-10.0keV luminosities of all the detected X-ray point sources and found that they span a wide range from a few times 10^37 erg s^-1 to over 10^39 erg s^-1. After compensating for incompleteness at the low luminosity end, we found that the corrected XLF of the bulge population is well fitted with a broken power-law with a break at 1.57-0.20^＋0.21 1038 erg s^-1, while the profile of the disk population＇s XLF agrees with a single powerlaw distribution of slope 0 9-0.06^＋0.07 The disk population is significantly richer at ≥ 2 × 10^38 erg s^- 1 than the bulge population, indicating that the disk may have undergone relatively recent, strong starbursts that significantly increased the HMXB population, although ongoing starbursts are also observed in the nuclear region. Similar XLF profiles of the bulge and disk populations were found in M81. However, in most other spiral galaxies different patterns of spatial variation of the XLF profiles from the bulge to the disk have been observed, indicating that the star formation and evolution history may be more complex than we have expected.

关键词： galaxies individual (NGC 5055)-X-ray binaries-stars luminosity function-stars formation

Influence of yaw damper layouts on locomotive lateral dynamics performance:Pareto optimization and parameter analysis

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2023年第5期24卷 450-464页

作者： guang li Yuan yao Longjiang SHEN Xiaoxing DENG Wensheng ZHONG State Key Laboratory of Traction Power Southwest Jiaotong UniversityChengdu 610031China Bogie R&D Department of CRRC Zhuzhou Electric Locomotive Co. Ltd.Zhuzhou 412001China

High-speed locomotives are prone to carbody or bogie hunting when the wheel-rail contact conicity is excessively low or *** can cause negative impacts on vehicle dynamics *** study presents four types of typical yaw damper layouts for a high-speed locomotive(Bo-Bo)and compares,by using the multi-objective optimization method,the influences of those layouts on the lateral dynamics performance of the locomotive;the linear stability indexes under lowconicity and high-conicity conditions are selected as optimization ***,the radial basis function-based highdimensional model representation(RBF-HDMR)method is used to conduct a global sensitivity analysis(GSA)between key suspension parameters and the lateral dynamics performance of the locomotive,including the lateral ride comfort on straight tracks under the low-conicity condition,and also the operational safety on curved *** is concluded that the layout of yaw dampers has a considerable impact on low-conicity stability and lateral ride comfort but has little influence on curving *** is also an important finding that only when the locomotive adopts the layout with opening outward,the difference in lateral ride comfort between the front and rear ends of the carbody can be eliminated by adjusting the lateral installation angle of the yaw ***,force analysis and modal analysis methods are adopted to explain the influence mechanism of yaw damper layouts on the lateral stability and differences in lateral ride comfort between the front and rear ends of the carbody.

关键词： High-speed locomotive Yaw damper layout Lateral stability Lateral ride comfort Multi objective optimization Global sensitivity analysis(GSA)

Quantum speed limit for mixed states in a unitary system

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Chinese Physics B 2022年第11期31卷 236-243页

作者： jie-hui huang li-Guo Qin guang-Long Chen li-Yun hu Fu-yao liu School of Mathematics Physics and StatisticsShanghai University of Engineering ScienceShanghai 201620China College of Physics and Communication Electronics Jiangxi Normal UniversityNanchang 330022China

Since the evolution of a mixed state in a unitary system is equivalent to the joint evolution of the eigenvectors contained in it,we could use the tool of instantaneous angular velocity for pure states to study the quantum speed limit(QSL)of a mixed *** derive a lower bound for the evolution time of a mixed state to a target state in a unitary system,which automatically reduces to the quantum speed limit induced by the Fubini–Study metric for pure *** computation of the QSL of a degenerate mixed state is more complicated than that of a non-degenerate mixed state,where we have to make a singular value decomposition(SVD)on the inner product between the two eigenvector matrices of the initial and target *** combing these results,a lower bound for the evolution time of a general mixed state is *** order to compare the tightness among the lower bound proposed here and lower bounds reported in the references,two examples in a single-qubit system and in a single-qutrit system are studied analytically and numerically,*** conclusions derived in this work are independent of the eigenvalues of the mixed state,which is in accord with the evolution properties of a quantum unitary system.

关键词： quantum speed limit instantaneous angular velocity singular value decomposition

Synthesis of Ultraviolet Absorption Polylactide via Immortal Polymerization of rac-Lactide Initiated by a Salan-yttrium Catalyst

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Chinese Journal of Polymer Science 2018年第2期36卷 202-206页

作者： Wei Zhao Chuan-Yang li Chun-ji Wu Xin-li liu Ze-huai Mou Chang-guang yao Dong-Mei Cui State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China University of Chinese Academy of Sciences Changchun BranchChangchun 130022China College of Bioresources Chemical and Materials Engineering Shaanxi University of Science and TechnologyXi'an 710021China

A highly efficient strategy for the synthesis of polylactide with the UV absorption ability was established by employing a Salan-yttrium complex（acting as a fast runing catalyst） combined with large excess hydroxyl functionalized benzophenone, BP′-OH. During polymerization, BP′-OH, acting as the chain transfer agent, attached to the active rare-earth metal catalyst via a rapid-reversible exchange reaction to initiate the polymerization. Thus, more polyester chains appeared to grow from one active metal species, and the UV absorption fragments were incorporated into the polymer chains at specific sites, in situ. A high productivity up to 1000 mol LA/mol（Salan-Y） was successfully achieved and 100 BP′-labeled PLA chains grew from each active metal center.

关键词： Yttrium catalyst Ring-opening polymerization Polylactide Ultraviolet absorption