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Incommensurate Magnetic Order in Sm_(3)BWO_(9)with Distorted Kagome Lattice

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Chinese Physics Letters 2022年第10期39卷 39-44页

作者： Kai-Yue Zeng Fang-Yuan Song lang-sheng ling Wei Tong Shi-Liang Li Zhao-Ming Tian Long Ma Li Pi Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions High Magnetic Field LaboratoryChinese Academy of SciencesHefei 230031China Hefei National Research Center for Physical Sciences at the Microscale University of Science and Technology of ChinaHefei 230026China School of Physics and Wuhan National High Magnetic Field Center Huazhong University of Science and TechnologyWuhan 430074China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100190China

We investigate the magnetic ground state of Sm_(3)BWO_(9)with a distorted kagome lattice.A magnetic phase transition is identified at T_(N)=0.75 K from the temperature dependence of specific *** 11B nuclear magnetic resonance measurements,an incommensurate magnetic order is shown by the double-horn type spectra under a c-axis magnetic field,and absence of line splitting is observed for field oriented within the ab-plane,indicating the incommensurate modulation of the internal field strictly along𝑐*** the spin dynamics,the critical slowing-down behavior is observed in the temperature dependence of 1/T_(1)with𝜇_(μ0)H⊥c-axis,which is completely absent in the case with𝜇_(μ0)H||*** on the local symmetry of 11B sites,we analyze the hyperfine coupling tensors and propose two constraints on the possible magnetic *** single ion anisotropy should play an important role in determination of contrasting ground states of Sm_(3)BWO_(9) and Pr_(3)BWO_(9).

关键词： structure incommensurate symmetry

Two New Sesquiterpenoid Glucosides from the Aerial Parts of Saussurea involucrate

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Journal of Integrative Plant Biology 2007年第5期49卷 609-614页

作者： Xlao-ling Wang Suo-lang Gesang Wei Jiao Xun Liao Li-sheng Ding Chengdu Institute of Biology the Chinese Academy of Sciences Chengdu 610041 China Institute of National Medicine Southwest University for Nationalities Chengdu 610041 China Tibet Autonomous Region Institute for Drug Control Lasa 850000 China

Two new sesqulterpenoid glucosides, namely α-hydroxycostic acid 6-β-D-glucopyranoside （compound 1） and 11 βH-11,13-dlhydrodehydrocostuslactone 8α-O-（6＇-acetyl）-β-D-glucopyranoside （compound 2）, along with 11 known sesqulterpenoids （compounds 3-13） were isolated from the aerial parts of Saussurea involucrate （Kar. et Kir.） Sch.- BIp. The structures of the new sesquiterpenoid glucosides were established by one- and two-dimensional nuclear magnetic resonance and mass spectrometry analysis.

关键词： 6α-hydroxycostic acid 6-β-D-glucoside 11 βH-11,13-dihydrodehydrocostuslactone 8α-O-(6'-acetyl)- α-D-glucoside Saussureainvolucrate sesquiterpenoid glucoside.

Unicyclic Graphs of Minimal Spectral Radius

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Acta Mathematica Sinica,English Series 2013年第2期29卷 281-286页

作者： ling sheng SHI Department of Mathematical Sciences Tsinghua University

It was conjectured by Li and Feng in 1979 that the unicyclic graph formed by a cycle of order g linking to an endvertex of a path of length k minimizes the spectral radius of all unicyclic graphs of order g ＋ k and girth g. In 1987, Cao proved that this conjecture is true for k ≥ g（g - 2）/8 and false for k = 2 and sufficiently large g. In this note, we show that g 〉12 suffices for the counterexample and give more counterexamples with large girth for any integer k 〉 1.

关键词： Extremal graph Li-Feng's conjecture spectral radius unicyclic

Eigenfunctions of Five-Qubit XX Chain and Ground State Concurrence

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Communications in Theoretical Physics 2008年第12期50卷 1295-1298页

作者： ling Yin-sheng School of Physical Science and Technology Suzhou University Suzhou 215006 China

Use Jordan-Wigner transformation the eigenstates and eigenenergies of live qubits XX chain including external magnetic field are obtained. The concurrences Co,1 and Co,2 of ground state are obtained. For the ferromagnetic, when [（√5 - 1）/2]｜J｜〈 B ≤ ｜J｜, the values of C0,1 and C0,2 are the same. The C0,2 is easily broken by temperature.

关键词： XX chain entanglement Jordan-Wigner transformation concurrence

A corrosion-reconstructed and stabilized economical Fe-based catalyst for oxygen evolution

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Nano Research 2023年第2期16卷 2224-2229页

作者： Zhiquan lang Guang-ling Song Pengpeng Wu Dajiang Zheng Center for Marine Materials Corrosion and Protection Xiamen UniversityXiamen 361005China Department of Ocean Science and Engineering Southern University of Science and TechnologyShenzhen 518055China State Key Laboratory of Physical Chemistry of Solid Surfaces Xiamen UniversityXiamen 361005China The University of Queensland St.LuciaQLD 4072Australia

The anode activity can to a great degree limit the cathodic hydrogen evolution efficiency in an electrolyte ***,cost-efficient electrocatalysts with good water oxidation performance and stability are highly desired in widespread implementation of the hydrogen production from water *** paper proposes a facile corrosion-reconstruction strategy to transform Fe surface into a Fe-Co hydroxide layer to improve the oxygen evolution *** as-prepared catalyst was measured to have an over-potentential as low as 320 mV at 100 mA·cm^(−2),and its stability even exceeded 600 *** and Raman spectroscopy analyses indicated that the catalyst experienced chemical changes from hydroxides to oxyhydroxides and Co^(2+)to Co^(3+)during oxygen evolution reaction(OER).The corrosion-reconstruction is not only an economical method to synthesize a highly efficient,stable and durable Fe-based catalysts,it also converses the detrimental corrosion into a beneficial catalyst fabrication process.

关键词： oxygen evolution reaction electrocatalyst corrosion stability

Conditional Connectivity of Bubble Sort Graphs

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Acta Mathematicae Applicatae Sinica 2017年第4期33卷 933-944页

作者： ling-sheng SHI Peng WU Department of Mathematical Sciences Tsinghua University Beijing 100084 China

A subset F V（G） is called an Rk-vertex-cut of a graph G if G - F is disconnected and each vertex of G - F has at least k neighbors in G - F. The Rk-vertex-connectivity of G, denoted by κk（G）, is the cardinality of a minimum Rk-vertex-cut of G. Let Bn be the bubble sort graph of dimension n. It is known that κk（Bn） = 2k（n - k - 1） for n _〉 2k and k = 1,2. In this paper, we prove it for k =3 and conjecture that it is true for all k ∈ N. We also prove that the connectivity cannot be more than conjectured.

关键词： bubble sort graph connectivity cut

Strengthening granulation behavior of specularite concentrates based on matching of characteristics of iron ores in sintering process

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Journal of Iron and Steel Research International 2018年第10期25卷 1017-1025页

作者： sheng-li Wu Zhi-gang Que Kai-lang Li School of Metallurgical and Ecological EngineeringUniversity of Science and Technology Beijing Beijing 100083 China

Specularite concentrates have advantages of high ferrous grade, less harmful impurities and low price. However, the small size and poor granulation behavior of specularite concentrates consequently deteriorate the permeability of sinter bed and reduce the productivity of sinter, resulting in un-effective utilization in sintering process. The granulation experiments were carried out when specularite concentrates matched with five kinds of fine or coarse ores, and the effects of surface property and wettability of fine or coarse ores on granulation behavior of specularite concentrates were investigated. Then, the optimized ore blending recipes were proposed to strengthen the granulation behavior of specularite concentrates. The results indicated that the growth index increased with increasing the specific surface area of fine ores and had a positive linear correlation with the circularity degree of coarse ores, whereas negative correlations exist between the growth index and the contact angle of fine or coarse ores. Compared with the concentrates, the growth index increased by approximately 22% scheme of blended ores containing 15 mass% specularite in the case of using Ore-A and Ore-E with greater surface property and higher wettability to replace all of Ore-B and half of Ore-D, respectively. Furthermore, the vertical sintering speed and the productivity of sinter improved by approximately 23% and 20%, respectively.

关键词： Iron ore sinter Granulation behavior Specularite concentrate Surface property Wettability

Weighted Least Squares Method for the Accelerated Failure Time Model with Auxiliary Covariates

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Acta Mathematica Sinica,English Series 2019年第7期35卷 1163-1178页

作者： ling Hui JIN Yan Yan LIU lang WU School of Mathematics and Statistics Wuhan University Wuhan 430072 P. R. China City College Wuhan University of Science and Technology Wuhan 430083 P. R. China Department of Statistics University of British Columbia Vancouver Canada

This paper deals with the analysis of accelerated failure time model when the primary covariate is subject to missing. We assume that the true covariate is measured precisely on a randomly chosen validation set, whereas auxiliary information for primary covariate is available to all study subjects. The asymptotic properties for the proposed estimator are developed and the simulation studies show that the efficiency gain is remarkable compared to the method using only the validation sample. A real example is also provided as an illustration.

关键词： Survival analysis accelerated failure time model auxiliary covariates validation sample weighted least squares estimation

Numerical Prediction and Performance Experiment in a Deep-well Centrifugal Pump with Different Impeller Outlet Width

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Chinese Journal of Mechanical Engineering 2013年第1期26卷 46-52页

作者： SHI Weidong ZHOU ling LU Weigang PEI Bing lang Tao National Research Center of Pumps and Pumping System Engineering and Technology Jiangsu UniversityZhenjiang 212013China

The existing research of the deep-well centrifugal pump mainly focuses on reduce the manufacturing cost and improve the pump performance, and how to combine above two aspects together is the most difficult and important topic. In this study, the performances of the deep-well centrifugal pump with four different impeller outlet widths are studied by the numerical, theoretical and experimental methods in this paper. Two stages deep-well centrifugal pump equipped with different impellers are simulated employing the commercial CFD software to solve the Navier-Stokes equations for three-dimensional incompressible steady flow. The sensitivity analyses of the grid size and turbulence model have been performed to improve numerical accuracy. The flow field distributions are acquired and compared under the design operating conditions, including the static pressure, turbulence kinetic energy and velocity. The prototype is manufactured and tested to certify the numerical predicted performance. The numerical results of pump performance are higher than the test results, but their change trends have an acceptable agreement with each other. The performance results indicted that the oversize impeller outlet width leads to poor pump performances and increasing shaft power. Changing the performance of deep-well centrifugal pump by alter impeller outlet width is practicable and convenient, which is worth popularizing in the engineering application. The proposed research enhances the theoretical basis of pump design to improve the performance and reduce the manufacturing cost of deep-well centrifugal pump.

关键词： deep-well centrifugal pump impeller outlet width performance numerical simulation