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Chinese Physics B 2019年第4期28卷 381-391页

作者： Zuoxian Xiang Chuanxiang Tang lixin yan Department of Engineering Physics Tsinghua University

Microtubules(MTs) are part of the cellular cytoskeleton and they play a role in many activities, such as cell division and maintenance of cell shape. In recent years, MTs have been thought to be involved in storing and processing *** models have been developed to describe the information-processing ability of MTs. In these models, MTs are considered as a device that can transmit quantum information. However, MTs are affected by the "wet and warm" cellular environment, thus it is essential to calculate the decoherence time. Many researchers have attempted to calculate this parameter but the values that have been obtained vary markedly. Previous studies considered the cellular environment as a distant ion; however, this treatment is somewhat simplified. In this study, we develop a model to determine the decoherence time in neuronal MTs while considering the interaction effects of the neuronal fluid environment. The neuronal environment is considered as a plasmon reservoir. The coupling between MTs and neuronal environment occurs due to the interaction between dipoles and plasmon. The interaction Hamiltonian is derived by using the second quantization method, and the coupling coefficient is calculated. Finally, the decoherence time scale is estimated according to the interaction *** this paper, the time scale of decoherence in MTs is approximately 1 fs-100 fs. This model may be used as a reference in other decoherence processes in biological tissues.

关键词： consciousness microtubules quantum decoherence

q-Deformations of 3-Lie Algebras

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Algebra Colloquium 2017年第3期24卷 519-540页

作者： Ruipu Bai lixin Lin yan Zhang Chuangchuang Kang College of Mathematics and Information Science Hebei University Baoding Hebei 071002 China

q-Deformations of 3-Lie algebras and representations of q-3-Lie algebras are discussed. A q-3-Lie algebra （A, [, ,]q, [, ,]＇q, Ja）, where q ∈ F and q ≠ 0, is a vector space A over a field F with 3-cry linear multiplications [,, ]q and [,, ]＇q from A 3 to A, and a map Jq ： A 5→ F satisfying the q-Jacobi identity Jq（x1, x2, x3, x4, x5）[x1, x2, [x3, x4, x5]q]＇q = Jq（x4, x5, x1, x2, x3）[x4, x5, [x1, x2, x3]q]＇q for all x1 ∈ A. If the multiplications satisfy that [,,]q = [,,]＇q and [,,]q is skew-symmetry, then （A, [,,]q, Jq） is called a type （I）-q-3- Lie algebra. From q-Lie algebras, group algebras and commutative associative algebras, q-3-Lie algebras and type （I）-q-3-Lie algebras are constructed. Also, the non-trivial one- dimensional central extension of q-3-Lie algebras is investigated, and new q-3-Lie algebras （DerqC[x,x-1], [, ,]q, [, ,]＇q, Jq）, and （Derδq C[x,x-1], [, ,]q, [,,]＇q, Jq） are obtained.

关键词： q-3-Lie algebra q-deformation q-Jacobi identity

A local version of Hardy spaces associated with operators on metric spaces

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Science China Mathematics 2013年第2期56卷 315-330页

作者： GONG RuMing LI Ji yan lixin School of Mathematics and Information Science Guangzhou University Key Laboratory of Mathematics and Interdisciplinary Sciences of Guangdong Higher Education Institutes Guangzhou University Department of Mathematics Sun Yat-sen University

Let （X, d, μ） be a metric measure space endowed with a distance d and a nonnegative Borel doubling measure μ. Let L be a second order self-adjoint positive operator on L^2（X）. Assume that the semigroup e-^tL generated by -L satisfies the Gaussian upper bounds on L2（X）. In this article we study a local version of Hardy space hi （X） associated with L in terms of the area function characterization, and prove their atomic characters. Furthermore, we introduce a Moser type local boundedness condition for L, and then we apply this condition to show that the space hzL（X） can be characterized in terms of the Littlewood-Paley function. Finally, a broad class of applications of these results is described.

关键词： local Hardy space non-negative self-adjoint operator semigroups local (1 p)-atoms Moser typelocal boundedness condition space of homogeneous type

Carleson measures, BMO spaces and balayages associated to Schrdinger operators

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Science China Mathematics 2017年第11期60卷 2077-2092页

作者： CHEN Peng DUONG XuanThinh LI Ji SONG Liang yan lixin Department of Mathematics Sun Yat-sen University Department of Mathematics Macquarie University

Let L be a Schrdinger operator of the form L =-? + V acting on L^2(R^n), n≥3, where the nonnegative potential V belongs to the reverse Hlder class B_q for some q≥n. Let BMO_L(R^n) denote the BMO space associated to the Schrdinger operator L on R^n. In this article, we show that for every f ∈ BMO_L(R^n) with compact support, then there exist g ∈ L~∞(R^n) and a finite Carleson measure μ such that f(x) = g(x) + S_(μ,P)(x) with ∥g∥∞ + |||μ|||c≤ C∥f∥BMO_L(R^n), where S_(μ,P)=∫(R_+^(n+1))Pt(x,y)dμ(y, t),and Pt(x, y) is the kernel of the Poisson semigroup {e-^(t(L)^(1/2))}t>0 on L^2(R^n). Conversely, if μ is a Carleson measure, then S_(μ,P) belongs to the space BMO_L(R^n). This extends the result for the classical John-Nirenberg BMO space by Carleson(1976)(see also Garnett and Jones(1982), Uchiyama(1980) and Wilson(1988)) to the BMO setting associated to Schrdinger operators.

关键词： BMO space Carleson measure balayage Poisson semigroup the reverse Holder class Schrodinger operators

High power THz source based on coherent radiation of picosecond relativistic electron bunch train

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Science China(Physics,Mechanics & Astronomy) 2011年第S2期54卷 197-200页

作者： YOU yan yan lixin DU YingChao HUA JianFei HUANG WenHui TANG ChuanXiang Accelerator Laboratory Department of Engineering PhysicsTsinghua UniversityBeijing 100084China Key Laboratory of Particle&Radiation Imaging(Tsinghua University) Ministry of Education Key Laboratory of High Energy Radiation Imaging Fundamental Science for National DefenseBeijing 100084China

Tunable and compact high power terahertz (THz) radiation based on coherent radiation (CR) of the picosecond relativistic electron bunch train is under development at the Tsinghua accelerator lab. Coherent synchronization radiation (CSR) and coherent transition radiation (CTR) are researched based on an S-band compact electron linac, a bending magnet or a thin foil. The bunch train's form factors, which are the key factor of THz radiation, are analyzed by the PARMELA simulation. The effects of electron bunch trains under different conditions, such as the bunch number, bunch charges, micro-pulses inter-distance, and accelerating gradient of the gun are investigated separately in this paper. The optimal radiated THz power and spectra should take these factors as a whole into account.

关键词： THz radiation high power relativistic electrons CR PARMELA

Slice emittance measurement for photocathode RF gun with solenoid scanning and RF deflecting cavity

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Science China(Physics,Mechanics & Astronomy) 2011年第S2期54卷 283-286页

作者： LI Chen HUANG WenHui DU YingChao yan lixin TANG ChuanXiang Accelerator Laboratory Department of Engineering PhysicsTsinghua UniversityBeijing 100084China Key Laboratory of Particle and Radiation Imaging(Tsinghua University) Ministry of EducationBeijing 100084China Key Laboratory of High Energy Radiation Imaging Fundamental Science for National Defense Beijing 100084China

The radiation of high-gain short-wavelength free-electron laser depends on the slice transverse emittance of the electron bunch. This essay introduces the method of slice emittance measurement, and shows the brief setup of this experiment using the solenoid scanning and RF deflecting cavity at Tsinghua University. The preliminary experimental results show that the slice rms emittance of the electron bunch generated by photocathode RF gun has considerable variations along the bunch and is typically less than 0.55 mm mrad for the laser rms radius of 0.4 mm.

关键词： slice emittance measurement solenoid scanning RF deflecting cavity

COMMUTATORS OF BMO FUNCTIONS AND SINGULAR INTEGRAL OPERATORS WITH NON-SMOOTH KERNELS ON SPACES OF HOMOGENEOUS TYPE OF FINITE MEASURE

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Analysis in Theory and Applications 2006年第1期22卷 41-55页

作者： Donggao Deng yanbo Xu lixin yan Zhongshan University China Huaihai Institute of Technology China

Let X be a space of homogeneous type with finite measure. Let T be a singular integral operator which is bounded on L^p （X）, 1 〈 p 〈 ∞. We give a sufficient condition on the kernel k（x,y） of Tso thatwhen a function b ∈ BMO （X）,the commutator [b,T] （f）=T （b f）- bT （f） is bounded on spaces L^p for all p, 1 〈 p 〈 ∞.

关键词： commutator homogeneous space BMO function singular integral operator

A new viewpoint and model of neural signal generation and transmission: Signal transmission on myelinated neuron

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Chinese Physics B 2020年第10期29卷 578-587页

作者： Zuoxian Xiang Chuanxiang Tang lixin yan Chao Chang Guozhi Liu Department of Engineering Physics Tsinghua UniversityBeijing 100084China Innovation Laboratory of Terahertz Biophysics National Innovation Institute of Defense TechnologyBeijing 100071China

Based on our previous work, we study the problem of neural signal transmission of myelinated neurons. We found that the transmembrane ion current at Ranvier's node acts as an energy supplement. In addition, the length of the myelin sheath has an upper limit of lT. Above this upper limit, the neural signal will not be effectively transmitted. In the range of normal physiological parameters, lT is on the order of mm. Finally, the effect of temperature on the transmission of nerve signals is investigated. temperatures that are too high and too low are not conducive to the conduction of nerve signals.

关键词： THz myelinated neuron signal transmission

High power THz source based on coherent radiation of picosecond relativistic electron bunch train

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High power THz source based on coherent radiation of picosec...

Slice emittance measurement for photocathode RF gun with solenoid scanning and RF deflecting cavity

第一届中国粒子加速器会议

作者： YOU yan yan lixin DU YingChao HUA JianFei HUANG WenHui TANG ChuanXiang Accelerator Laboratory Department of Engineering PhysicsTsinghua University Key Laboratory of Particle & Radiation Imaging(Tsinghua University) Ministry of Education Key Laboratory of High Energy Radiation Imaging Fundamental Science for National Defense

Tunable and compact high power terahertz(THz) radiation based on coherent radiation(CR) of the picosecond relativistic electron bunch train is under development at the Tsinghua accelerator *** synchronization radiation(CSR) and coherent transition radiation(CTR) are researched based on an S-band compact electron linac,a bending magnet or a thin foil. The bunch train’s form factors,which are the key factor of THz radiation,are analyzed by the PARMELA *** effects of electron bunch trains under different conditions,such as the bunch number,bunch charges,micro-pulses inter-distance, and accelerating gradient of the gun are investigated separately in this *** optimal radiated THz power and spectra should take these factors as a whole into account.

关键词： THz radiation high power relativistic electrons CR PARMELA

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Slice emittance measurement for photocathode RF gun with sol...