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Science China Mathematics 2022年第4期65卷 707-730页

作者： hairong liu Xiaoping Yang College of Science Nanjing Forestry UniversityNanjing210037China Department of Mathematics Nanjing UniversityNanjing210093China

In this paper we prove the strong unique continuation property for a class of fourth order elliptic equations involving strongly singular *** argument is to establish some Hardy-Rellich type inequalities with boundary terms and introduce an Almgren’s type frequency function to show some doubling conditions for the solutions to the above-mentioned equations.

关键词： strong unique continuation property fourth order elliptic equation singular potential Hardy-Rellich type inequality

Strong Unique Continuation of Sub-elliptic Operator on the Heisenberg Group

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Chinese Annals of Mathematics,Series B 2013年第3期34卷 461-478页

作者： hairong liu Xiaoping YANG School of Science Nanjing University of Science and Technology School of Science Nanjing Forestry University

In this paper, the Almgren＇s frequency function of the following sub-elliptic equation with singular potential on the Heisenberg group：-Cu＋V（z,t）u=Xi（aij（z,t）Xju）＋V（z,t）u=0 is introduced. The monotonicity property of the frequency is established and a doubling condition is obtained. Consequently, a quantitative proof of the strong unique continuation property for such equation is given.

关键词： Heisenberg group Frequency function Doubling condition Strongunique continuation principle

The growth of H-harmonic functions on the Heisenberg group

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Science China Mathematics 2014年第4期57卷 795-806页

作者： liu hairong TIAN Long YANG XiaoPing School of Science Nanjing University of Science and Technology School of Science Nanjing Forestry University

We discuss the relationship between the frequency and the growth of H-harmonic functions on the Heisenberg ***,we prove that an H-harmonic function must be a polynomial if its frequency is globally ***,we show that a class of H-harmonic functions are homogeneous polynomials provided that the frequency of such a function is equal to some constant.

关键词： Heisenberg group H-harmonic function frequency

Temperature performance of Raman scattering in data fiber and its application in distributed temperature fiber-optic sensor

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Frontiers of Optoelectronics 2009年第2期2卷 159-162页

作者： Deming liu Shuang liu hairong liu Wuhan National Laboratory for Optoelectronics College of Optoelectronic Science and Engineering Huazhong University of Science and Technology

A wavelength division multiplexer(WDM)was used to extract the Raman scattering signal from a data fiber. The temperature performance of Raman scattering spectrum was studied theoretically and experimentally. On the base of this study, a distributed fiber-optic temperature sensor(DFTS) system was developed. The sensing distance was 4 km. The temperature accuracy and the distance resolution reached to ±1°C and ±1 m, respectively. The system is stable and adequate for commercial usage, such as the power industry, the underground tunnel,the subway, and the pipe laying, and also for the mission applications, such as the warship and the airplane.

关键词： fiber-optic sensor distributed temperature sensor data fiber Raman scattering

Curvature optical fiber sensor by using bend enhanced method

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Frontiers of Optoelectronics 2009年第2期2卷 204-209页

作者： Jianrong ZHANG hairong liu Xinkun WU College of Optoelectronic Science and Engineering Huazhong University of Science and Technology State Key Laboratory of Modern Optical Instruments Zhejiang University

Deflection curvature measurement can offer a number of advantages compared with the well-established strain measurement alternative. It is able to measure thin structure; fiber has no resistance with force, which leads to a high precision. There are many kinds of curvature gauges with different operation principles. A low-cost curvature optical fiber sensor using bend enhanced method to improve its curvature measurement sensitivity was developed in recent years. This sensor can distinguish between convex bending and concave bending and has a good linearity in measuring large curvature *** gallery ray theory and Monte Carlo simulation are new achievements by computer experiment. The operation mechanism of this curvature optical fiber sensor is presented based on light scattering theory. The attenuation is ascribed to the transmission mode changing by the curvature of the fiber, which affects the attenuation of the surface scattering. The mathematical model of relationship among light loss, bending curvature, surface roughness, and parameters of the fiber's configuration is also presented. We design different kinds of shapes of sensitive zones; each zone has different *** detecting their output optical attenuations in different curvatures and fitting the results by exponential decaying functions, the proposed model is demonstrated by experimental results. Also, we compare the experimental results with the theoretical analysis and discuss the sensitivity dependence on bending direction.

关键词： bending direction curvature measurement operation mechanism sensitive zone sensitized optical fiber surface scattering

Polymorph selection of magnesium under different pressures: A simulation study

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Chinese Physics B 2022年第1期31卷 445-452页

作者： Wei liu Boqiang Wu Ze'an Tian Yunfei Mo Tingfei Xi Zhiyi Wan Rangsu liu hairong liu College of Materials Science and Engineering Hunan UniversityChangsha 410082China School of Physics and Microelectronics Hunan UniversityChangsha 410082China School of Electronics and Communication Engineering Changsha UniversityChangsha 410003China School of Materials Science and Engineering Zhejiang Sci-Tech UniversityHangzhou 310018China

Molecular dynamics simulations were used to investigate the influence of pressure on the structural properties and dynamics of magnesium(Mg)during rapid *** dynamics analysis revealed that,with an increase in pressure,the dynamics of Mg melt slowed down sharply and the dynamical heterogeneities increased,leading to a denser ***-level structural analysis using the cluster-type index method suggested that the predominant structure transformed from hexagonal closed-packed to face-centered cubic with increasing pressure from 0 GPa to 5 GPa,and then transformed to the A15 complex crystal structure as the pressure increased above 10 *** addition,the nature of polymorph selection was investigated by analyzing the phonon dispersion of Mg under different *** findings provide a novel insight into polymorphic transitions of Mg under pressure and guide the selection of Mg polymorphs for practical applications.

关键词： magnesium polymorph selection molecular dynamics pressure

Identification of potential indicators for testis quality in swamp eels(Monopterus albus)through metabolomics analysis

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Water Biology and Security 2023年第4期2卷 78-90页

作者： Fei liu Xing Lin Kaifeng Meng Yuanyuan Chen hairong liu Yuanli Zhao Daji Luo Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture Institute of HydrobiologyThe Innovative Academy of Seed DesignHubei Hongshan LaboratoryChinese Academy of SciencesWuhan430072China College of Advanced Agricultural Sciences University of Chinese Academy of SciencesBeijing100049China Guangdong Laboratory for Lingnan Modern Agriculture Guangzhou510642China

The swamp eel(Monopterus albus)is a commonly cultured freshwater *** and cultivation of fecund broodstock is crucial for efficient artificial reproduction in this ***,there are currently no guidelines for selecting high-quality males in *** study quantitatively investigated the sperm motility of male swamp eels during the breeding season by using computer-assisted sperm analysis *** in the proportion and number of motile sperm was observed between individual *** testes were grouped into high-quality and low-quality according to sperm *** parameters of the two groups were *** found that high-quality testes were longer(150±27 mm verses 127±19 mm)than low-quality ***,the proportion of testes with a dark appearance was slightly higher(58.3%verses 48.1%)in the high-quality group than in the low-quality *** analysis was conducted to compare the metabolite profiles of high-quality and low-quality ***,organic acids,glycerolipids,amino acids,sphingolipids,and nucleotides were the most abundant metabolites in the testes of swamp ***,135 differential metabolites were *** nucleotide derivatives,including 50-deoxyadenosine,20-deoxyadenosine,and ribosyl adenosine,were the most significantly enriched metabolites in highquality *** metabolites are potential indicators for the testis quality in ***,our work provides systematic and quantitative data about the physiological and biochemical characteristics of *** testis,which provides an evidential basis for the selection of high-fecundity parents to improve artificial reproduction efficiency of ***.

关键词： Monopterus albus Sperm motility Testis quality Metabolomics Nucleotide metabolites

Design of distributed Raman temperature sensing system based on single-mode optical fiber

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Frontiers of Optoelectronics 2009年第2期2卷 215-218页

作者： Ziheng XU Deming liu hairong liu Qizhen SUN Zhifeng SUN Xu ZHANG Wengang WANG College of Optoelectronic Science and Engineering Huazhong University of Science and Technology

The distributed optical fiber temperature sensor system based on Raman scattering has developed rapidly since it was invented in 1970s. The optical wavelengths used in most of the distributed temperature optical fiber sensor system based on the Raman scattering are around from 840 to 1330 nm, and the system operates with multimode optical fibers. However, this wavelength range is not suitable for long-distance transmission due to the high attenuation and dispersion of the transmission optical fiber. A novel distributed optical fiber Raman temperature sensor system based on standard single-mode optical fiber is proposed. The system employs the wavelength of 1550 nm as the probe light and the standard communication optical fiber as the sensing medium to increase the sensing distance. This system mainly includes three modules: the probe light transmitting module, the light magnifying and transmission module, and the signal acquisition module.

关键词： optical fiber distributed temperature sensor Raman scattering field-programmable gate array (FPGA)

Distributed optical fiber perturbation sensing system based on Mach-Zehnder interferometer

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Frontiers of Optoelectronics 2009年第2期2卷 229-232页

作者： Wengang WANG Deming liu hairong liu Qizhen SUN Zhifeng SUN Xu ZHANG Ziheng XU College of Optoelectronic Science and Engineering Huazhong University of Science and Technology

A novel distributed optical fiber vibrationsensing system based on Mach-Zehnder interferometer has been designed and experimentally demonstrated. Firstly,the principle of Mach-Zehnder optical path interferometer technique is clarified. The output of the Mach-Zehnder interferometer is proportional to the phase shift induced by the perturbation. Secondly, the system consists of the laser diode（LD） as the light source, fiber, Mach-Zehnder optical interferometers as the sensing units, a 1×N star fiber-optic coupler, an N×1 fiber-optic coupler, a photodiode（PD）detector, and a computer used in signal processing. The entire monitoring region of this system is divided into several small zones, and each small monitoring zone is independent from each other. All of the small monitoring zones have their own sensing unit, which is defined by Mach-Zehnder optical interferometer. A series of sensing units are connected by the star fiber-optic couplers to form a whole sensing net. Thirdly, signal-processing techniques are subsequently used to calculate the phase shift to estimate whether intruders appear. The sensing system is able to locate the vibration signal simultaneously, including multiple vibrations at different positions, by employing the time-division multiplexed（TDM） technique. Finally,the operation performance of the proposed system is tested in the experiment lab with the conditions as follows:the number of the sensing units is 3, the length of the sensing fiber is 50 m, and the wavelength of the light diode is 1550 nm. Based on these investigations, the fiber surrounding alert system is achieved. We have experimentally demonstrated that the sensing system can measure both the frequency and position of the vibration in real time, with a spatial positional resolution better than 50 m in an area of 1 km2.

关键词： distributed Mach-Zehnder interferometer time-division multiplexed (TDM) vibration

High-power EDFA applied in distributed optical fiber Raman temperature sensor system

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Frontiers of Optoelectronics 2009年第2期2卷 210-214页

作者： Xu ZHANG Deming liu hairong liu Qizhen SUN Zhifeng SUN Ziheng XU Wengang WANG College of Optoelectronic Science and Engineering Huazhong University of Science and Technology

In this paper, a high-power erbium-doped fiber amplifier(EDFA) for the temperature sensor system is theoretically designed and experimentally demonstrated. It consists of an erbium-doped fiber that is pumped bidirectionally with two 980-nm high-power laser diodes(LDs). At the EDFA input, an optical isolator(ISO) is used to ensure that the signal pulse transmits forward only. After that, a wavelength division multiplexer(WDM) is employed to combine the forward pump laser(980 nm)and incident optical pulse(1550 nm) into the erbiumdoped fiber for direct amplification in the optical *** the EDFA output, another WDM couples the backward pump laser(980 nm) into the erbium-doped fiber and outputs the amplified optical pulse(1550 nm) with an ISO followed to isolate the backscattering light. According to this structure, we carried out the experiment in the condition as follows. For 980 nm pump LD, the operating current is 590 mA, and the setting temperature is 25°C. For EDFA, the length of erbium-doped fiber is 12.5 m, and the power of 1550 nm input signal is 1.5 mW. As a result, the power of pump LD is 330 mW, and the power uncertainty is 0.5%. The power of EDFA output at 1550 nm is 300 m W,and the power uncertainty is ± 3 mW.

关键词： erbium-doped fiber amplifier (EDFA) fiber sensor bidirectional pump laser diodes (LDs) driver thermoelectric cooler (TEC)