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Chinese Physics B 2024年第1期33卷 666-670页

作者：李锐岗刘军丰汪军 Department of Physics Guangzhou UniversityGuangzhou 510006China Department of Physics Southeast UniversityNanjing 210096China

We investigated the electric controllable spin-filtering effect in a zigzag phosphorene nanoribbon(ZPNR) based normal–antiferromagnet–normal junction. Two ferromagnets are closely coupled to the edges of the nanoribbon and form the edge-to-edge antiferromagnetism. Under an in-plane electric field, the two degenerate edge bands of the edge-to-edge antiferromagnet split into four spin-polarized sub-bands and a 100% spin-polarized current can be easily induced with the maximal conductance 2e~2/h. The spin polarization changes with the strength of the electric field and the exchange field,and changes sign at opposite electric fields. The spin-polarized current switches from one edge to the other by reversing the direction of the electric field. The edge current can also be controlled spatially by changing the electric potential of the scattering region. The manipulation of edge current is useful in spin-transfer-torque magnetic random-access memory and provides a practical way to develop controllable spintronic devices.

关键词： zigzag phosphorene electrically controllable spin filter quantum transport

Moderate Deviations for Stochastic Heat Equation with Rough Dependence in Space

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Acta Mathematica Sinica,English Series 2019年第9期35卷 1491-1510页

作者： jun feng liu School of Statistics and Mathematics Nanjing Audit University

In this paper, we establish a moderate deviation principle for the stochastic heat equation driven by a Gaussian noise which is white in time and which has the covariance of a fractional Brownian motion with Hurst par... 详细信息

关键词： Stochastic heat equation fractional Brownian motion moderate deviations weak convergence approach

Uniform Asymptotics for Finite-time Ruin Probability in a Dependent Risk Model with General Stochastic Investment Return Process

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Acta Mathematicae Applicatae Sinica 2021年第4期37卷 847-857页

作者： Yang YANG Kam Chuen YUEN jun-feng liu School of Statistics and Data Science Nanjing Audit UniversityNanjing211815China Department of Statistics and Actuarial Science The University of Hong KongPokfulam RoadHong KongChina

In this paper,we consider a non-standard renewal risk model with dependent claim sizes,where an insurance company is allowed to invest his/her wealth in financial assets,leading to some stochastic investment log-returns described as a general adapted càdlàg *** the assumptions that the claim sizes are heavy-tailed and the stochastic log-return process on investments is bounded from below almost surely,we derive some asymptotic formulas for the finite-time ruin probability holding uniformly in any finite time horizon.

关键词： finite-time ruin probability stochastic log-return process on investments upper tail asymptotic independence dominated variation uniformity

Investigation of cholecystokinin receptors in the human lower esophageal sphincter

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World Journal of Gastroenterology 2014年第21期20卷 6554-6559页

作者： jun-feng liu Jian Zhang Xin-Bo liu Paul A Drew Department of Thoracic Surgery Fourth HospitalHebei Medical University School of Nursing and Midwifery Flinders UniversityAdelaide 5001Australia

AIM: To compare the binding of cholecystokinin (CCK)-8 to CCK receptors in sling and clasp fibers of the human lower esophageal sphincter.

关键词： Cholecystokinins Cholecystokinins-A receptor Cholecystokinins-B receptor Radioligand binding Lower esophageal sphincter Sling fibers Clasp fibers

Effect of magnesia on properties and microstructure of alkali-activated slag cement

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Water Science and Engineering 2011年第4期4卷 463-469页

作者： Yong-hao FANG jun-feng liu Yi-qun CHEN College of Mechanics and Materials Hohai University Nanjing 210098 P. R. China

The effect of magnesia bumt at 800-950℃ on the properties, especially the shrinkage, of alkali-activated slag cement （AASC.） was experimentally studied. Experimental results show that, although adding 4%-8% lightly-burnt magnesia may shorten the setting time and slightly reduce the compressive strength of AASC, it c, an remarkably reduce the shrinkage of AASC. The results also show that the setting time of AASC with a certain amount of magnesia increases with the buming temperature, and that the flexural and compressive strengths of AASC decrease with the increase of the additive amount of magnesia. Generally, the adverse effect of magnesia decreases with the increase of the burning temperature：, and the shrinkage-reducing effect of magnesia increases with the additive amount of magnesia. X-ray diffraction （XRD） and scanning electron microscopy （SEM） analyses show that some magnesia particles in the hardened AASC paste at a 28-d age remained unhydrated, and that the compactness decreased a little as magnesia was added. We can also conclude that magnesia bumt at 850-950℃ can be used to reduce the shrinkage of AASC only when its additive amount does not exceed 8%; otherwise, the setting time may be too short, and the flexural and compressive strengths may severely decrease.

关键词： alkali-activated slag cement magnesia shrinkage microstructure

Synthesis and Crystal Structure of Dehydroandrographolide Dipolycyclophosphate

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Chinese Journal of Structural Chemistry 2005年第10期24卷 1198-1202页

作者： XU Hai-Wei WANG jun-feng liu Hong-Min ZHANG Jian-Ye New Drug Research ＆ Development Center Zhengzhou University Zhengzhou 450052 China

The title compound was synthesized and characterized by IR, NMR, HRSI-MS and MS, and its crystal structure was determined by single-crystal X-ray diffraction. The crystal is of orthorhombic system （C40H52O11P2, Mr= 770.76）, space group P21212, with a = 22.562（5）, b = 29.224（6）, c = 7.1953（14） A, V = 4744.2（16） A^3, Z = 4, Dc = 1.079 g/cm^3, F（000） = 1640 and μ = 0.141 mm^-1. The final R = 0.0758 and wR = 0.1778 for 2794 observed reflections with I 〉 20（I）. Intermolecular hydrogen bonds are found between the O atom of carbonyl group and H atoms of olefinic carbon. The absolute configuration of this molecule was confirmed by comparison with that of the original material.

关键词： crystal structure andrographolide cyciophosphate synthesis

Topological phase in one-dimensional Rashba wire

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Chinese Physics B 2016年第7期25卷 393-400页

作者：汪萨克汪军刘军丰 Department of Physics Southeast University Department of Physics South University of Science and Technology of China

We study the possible topological phase in a one-dimensional（1D） quantum wire with an oscillating Rashba spin–orbital coupling in real space. It is shown that there are a pair of particle–hole symmetric gaps forming in the bulk energy band and fractional boundary states residing in the gap when the system has an inversion symmetry. These states are topologically nontrivial and can be characterized by a quantized Berry phase ±π or nonzero Chern number through dimensional extension. When the Rashba spin–orbital coupling varies slowly with time, the system can pump out 2 charges in a pumping cycle because of the spin flip effect. This quantized pumping is protected by topology and is robust against moderate disorders as long as the disorder strength does not exceed the opened energy gap.

关键词： one-dimensional topological phase Rashba spin–orbit interaction spatial modulation quantized pump

Unstructured Road Extraction in UAV Images based on Lightweight Model

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Chinese Journal of Mechanical Engineering 2024年第2期37卷 372-384页

作者： Di Zhang Qichao An Xiaoxue feng Ronghua liu jun Han feng Pan School of Automation Beijing Institute of TechnologyBeijing 100081China Tianjin Institute of Maritime Navigation Instruments Tianjin 300130China The 716th Research Institute of China Shipbuilding Group Co. LtdJiangsu 222061China

There is no unified planning standard for unstructured roads,and the morphological structures of these roads are complex and *** is important to maintain a balance between accuracy and speed for unstructured road extraction *** road extraction algorithms based on deep learning have problems such as high model complexity,high computational cost,and the inability to adapt to current edge computing ***,it is best to use lightweight network *** the need for lightweight models and the characteristics of unstructured roads with different pattern shapes,such as blocks and strips,a TMB(Triple Multi-Block)feature extraction module is proposed,and the overall structure of the TMBNet network is *** TMB module was compared with SS-nbt,Non-bottleneck-1D,and other modules via *** feasibility and effectiveness of the TMB module design were proven through experiments and *** comparison experiment,using multiple convolution kernel categories,proved that the TMB module can improve the segmentation accuracy of the *** comparison with different semantic segmentation networks demonstrates that the TMBNet network has advantages in terms of unstructured road extraction.

关键词： Unstructured road Lightweight model Triple Multi-Block(TMB) Semantic segmentation net

The synthesis of porphyrin-anthraquinone dyad via an azo-rearrangement

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Chinese Chemical Letters 2011年第5期22卷 539-542页

作者： Cheng Jie Li Ya Qing feng Xiu jun liu Tian Yi Zhang School of Chemical Engineering and Technology Tianjin University Tianjin 300072 China

One novel porphyrin P-Q2 is planned to be synthesized by condensation between ATPP and ***,after separation by chromatography and characterization with IR,~1H NMR,HR-MS and X-ray,P-Q1 is obtained *** the structure of P-Q1 with that of P-Q2,it is realized that an intramolecular cyclization rearrangement takes place when the azo group is situated in the O-position to the amido *** rearrangement offers a new way to prepare indazole *** addition,the spectral properties of P-Q1 have been studied by UV-vis and steady state fluorescence *** fluorescence quenching is observed in the preliminary emission spectrum due to the proposed electron transfer from the excited porphyrin to the anthraquinone moieties.

关键词： Porphyrin Anthraquinone Azo-rearrangement Fluorescence quenching

A Linear Mixed Integer Programming Model for N-Vehicle Exploration Problem

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Journal of the Operations Research Society of China 2015年第4期3卷 489-498页

作者： Li-Li Wang Bing-Ling She jun-feng liu Jin-Chaun Cui Institute of Applied Mathematics Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China Institute of Zoology Chinese Academy of SciencesBeijing 100190China

Finding the accurate solution for N-vehicle exploration problem is NP-hard in strong *** this paper,authors build a linear mixed integer programming model for N-vehicle exploration problem based on its *** model is then proved equivalent to the original *** the model,one can apply the already existed methods and algorithms for mixed integer linear programming on N-vehicle exploration problem,which helps to enrich methods for solving N-vehicle exploration problem.

关键词： Linear mixed integer programming N-Vehicle exploration problem NP-hard