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Active tuning of anisotropic phonon polaritons in natural van der Waals crystals with negative permittivity substrates and its application in energy transport

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Opto-Electronic Science 2024年第6期3卷 1-19页

作者： Shuo Chen Xiaohu wu Ceji Fu LTCS and department of Mechanics and Engineering Science College of EngineeringPeking UniversityBeijing 100871China Shandong Institute of Advanced Technology Jinan 250100China

Phonon polaritons(PhPs)exhibit directional in-plane propagation and ultralow losses in van der Waals(vdW)crystals,offering new possibilities for controlling the flow of light at the ***,these PhPs,including their directional propagation,are inherently determined by the anisotropic crystal structure of the host *** in-plane anisotropic PhPs can be manipulated by twisting engineering,such as twisting individual vdW slabs,dynamically adjusting their propagation presents a significant *** limited application of the twisted bilayer structure in bare films further restricts its *** this study,we present a technique in which anisotropic PhPs supported by bare biaxial vdW slabs can be actively tuned by modifying their local dielectric ***,we predict that the iso-frequency contour of PhPs can be reoriented to enable propagation along forbidden directions when the crystal is placed on a substrate with a moderate negative ***,we systematically investigate the impact of polaritonic coupling on near-field radiative heat transfer(NFRHT)between heterostructures integrated with different substrates that have negative *** main findings reveal that through the analysis of dispersion contour and photon transmission coefficient,the excitation and reorientation of the fundamental mode facilitate increased photon tunneling,thereby enhancing heat transfer between ***,the annihilation of the fundamental mode hinders heat ***,we find the enhancement or suppression of radiative energy transport depends on the relative magnitude of the slab thickness and the vacuum gap ***,the effect of negative permittivity substrates on NFRHT along the[001]crystalline direction ofα-MoO3 is *** spectral band where the excited fundamental mode resulting from the negative permittivity substrates is shifted to the first Reststrahlen Band(RB 1)ofα-MoO_(3) and

关键词： anisotropic phonon polaritons forbidden direction substrate with a negative permittivity near-field energy transport

NUMERICAL INVESTIGATION OF THE MECHANISM OF ASYMMETRIC VORTEX FLOWS

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Acta Mechanica Sinica 1990年第4期6卷 311-315页

作者： Zhang wu (department of Mechanics,peking university)Luo Shijun (Dept.of Mechanical Engng.,Northwestern Polytech,Univ.,Xian) department of Mechanics Peking University Beijing China Dept. of Mechanical Engng. Northwestern Polytech. Univ. Xian China

A robust iterative method suitable for the numerical simulation of high angle-of-attack vortex flows is established based upon the multiple line-vortex model(MLVM).With symmetric or asymmetric positions of sep- aration lines given,the first converged solution at an angle of attack as high as 60 degree is obtained by means of the present *** experiments for a tangent-ogive forebody indicate the viscous onset mechanism of asymmetric vortex flows over a body of revolution at high angles of attack and zero sideslip.

关键词： asymmetric vortex flow viscous mechanism multiple line-vortex model numerical investigation

In situ hybridization analysis of the expression of human telomerase reverse transcriptase (hTERT) in skin tumors

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In situ hybridization analysis of the expression of human te...

International Forum 2003 Academic Conference of Dermatology of the Integration of TCM with Western Medicine

作者： Ding Yingguo, wu Lingshen, Tu Ping department of Dermatology, peking university First Hospital,beijing 100034, china

Objective:To study the role of telomerase in the pathogenesis of malig-nant skin tumors. Methods:Digoxiginin-labled hTERT cRNA probe was applied to in situhybridize to mRNA of hTERT in paraffin-embedded sections of 30... 详细信息

关键词： Skin, Skin tumor Telomerase, Human telomerase reverse transcriptase (hTERT) In situ hybridization

An elastic-plastic constitutive framework for micropolar continua

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An elastic-plastic constitutive framework for micropolar con...

第五届国际非线性力学会议

作者： Zhu-ping Huang~1,Geng-kai Hu~2,Hong-wu Zhang~3 (1.LTCS and department of Mechanics,peking university,beijing 100871,china 2.department of Applied Mechanics,beijing Institute of Technology,beijing 100081,china 3.SAIL,department of Engineering Mechanics,Dalian university of Technology,Dalian 116024,china)

＜正＞In this paper,a rate-type constitutive framework in micropolar plasticity is presented. In order to describe the plastic dissipation in the deformation process,a set of internal variables is introduced,thus the Helmholtz free energy can be expressed as a function of the non-symmetric strain,rotation and internal *** the introduction of the loading（yield） surfaces both in the non-symmetric strain and rotation space,and in the work conjugate non-symmetric stress and couple stress space,a loading-unloading criterion for a micropolar plastic material is suggested,and three types of material response,namely hardening,softening and perfectly plastic behaviors are *** on a mechanical postulate of non-negative work proposed by the present authors,the normality condition and the corresponding incremental constitutive relations are *** present results can be applied for the description of path-dependent mechanical behaviors of micropolar elastic-plastic materials.

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Acoustically evoked potentials in the lateral nucleus of the amygdala is enhanced by tetanic stimulation of the auditory thalamus:the role of metabotropic glutamate subtype 5 receptors

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Acoustically evoked potentials in the lateral nucleus of the...

中国神经科学学会第四次会员代表大会暨第七届全国学术会议

作者： Jia-Wei ZHENG,Xi-Hong wu,Liang LI department of Psychology,Speech and Hearing Research Center,National Key Laboratory on Machine Perception, peking university,beijing 100871,china

＜正＞The lateral nucleus of the amygdala（LA） receives axonal projections from the auditory thalamus and mediates auditory fear *** electrical stimulation of the auditory thalamus induces long-term potentiation（LTP） of acoustically evoked potentials（AEPs） in the LA in anesthetized *** present study investigated whether the metabotropic glutamate receptors subtype 5（mGluR5） mediates this AEP *** results show that AEPs in the LA to a broadband-noise burst was enhanced immediately after tetanic stimulation of the auditory thalamus,and further increased 45 min after the ***-dose（1.5μg/4μl） microinjection of the selective antagonist of mGluR5,2- methyl-6-（phenylethynyl）-pyridine（MPEP）,into the ipsilateral ventricle 30 min before the tetanization completely blocked the AEP potentiation without affecting the baseline ***-dose（0.5μg/4μl） injection only partially suppressed the potentiation that occurred 60 min after the *** the high-dose MPEP was injected 40 min after the tetanization, the AEP potentiation was not *** results indicate that there are both an early phase,which occurs shortly after tetanic stimulation of the auditory thalamus,and a late phase,which occurs 40-60 min after the tetanization,in the development of LTP in the LA,and mGluR5 mainly mediates the early-phase development.

关键词： lateral nucleus of the amygdala long-term potentiation acoustically evoked potentials tetanic stimulation auditory thalamus metabotropic glutamate receptors

Prediction of solar activities:Sunspot numbers and solar magnetic synoptic maps

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Science china Earth Sciences 2024年第8期67卷 2460-2477页

作者： Rui ZHUO Jiansen HE Die DUAN Rong LIN Ziqi wu Limei YAN Yong WEI School of Earth and Space Sciences Peking UniversityBeijing 100091China College of Advanced Interdisciplinary Studies National University of Defense TechnologyChangsha 410073China Centre for Mathematical Plasma Astrophysics Department of MathematicsKU LeuvenLeuven 3001Belgium Key Laboratory of Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China

The evolution of solar magnetic fields is significant for understanding and predicting solar *** our knowledge of solar magnetic fields largely depends on the photospheric magnetic *** this paper,based on the spherical harmonic expansion of the photospheric magnetic field observed by Wilcox Solar Observatory,we analyze the time series of spherical harmonic coefficients and predict Sunspot Number as well as synoptic maps for Solar Cycle *** find that solar maximum years have complex short-period disturbances,and the time series of coefficient g_(7)~0 is nearly in-phase with Sunspot Number,which may be related to solar meridional *** Long Short-Term Memory networks(LSTM),our prediction suggests that the maximum of Solar Cycle 25 is likely to occur in June 2024 with an error of 8 months,the peak sunspot number may be 166.9±22.6,and the next solar minimum may occur around January *** incorporating Empirical Mode Decomposition,we enhance our forecast of synoptic maps truncated to Order 5,validating their relative *** prediction not only addresses a gap in forecasting the global distribution of the solar magnetic field but also holds potential reference value for forthcoming solar observation plans.

关键词： Solar activity prediction Solar magnetic field Spherical harmonic expansion Long-Short Term Memory(LSTM) Empirical Mode Decomposition(EMD)

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国内购物网站信息服务实证研究及改进策略

图书情报工作 2005年第2期49卷 22-26页

作者：刘鼎盛吴龙婷北京大学信息管理系北京100871

通过时国内著名购物网站信息服务情况的调查研究,结合对网上消费者购物行为和消费心理的分析,总结出购物网站在向消费者提供信息服务方面存在的问题,并试图从信号发送机制、信息服务策略和价格模式等方面探讨以上问题的改进策略,以促进... 详细信息

通过时国内著名购物网站信息服务情况的调查研究,结合对网上消费者购物行为和消费心理的分析,总结出购物网站在向消费者提供信息服务方面存在的问题,并试图从信号发送机制、信息服务策略和价格模式等方面探讨以上问题的改进策略,以促进国内购物网站的发展。

关键词：信息服务购物网站网上购物

PALEOTETHYAN OCEANIC ISLAND AND ISLAND-ARC BORDERING YUNNAN AND GUANGXI: PETROCHEMISTRY OF VOLCANIC ROCKS

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Scientia Geologica Sinica 2000年第2期 123-132页

作者： wu Genyao wu Haoruo and Zhong Dalai (Institute of Geology and Geophysics, Chinese Academy of Sciences, beijing 100029) Kuang Guodun (Guangxi Institute of Geology, Nanning 530023) Ji Jianning (department of Geology peking university, beijing 100871)

Based on systematic petrochendstry are explored the tectonic settings of volcanic rocks bordering Yunnan and Guangxi in age of Permian-Middle Triassic. The oceanic island basalt is represented by the Longhuai pillow lava, which is, originally Hawaii-type one in the Paleotethyan ocean, an allochthon in the Indosinian foreland fold-and-thrust belt. The andesitic-basalhc rocks from Yutang-Natang, Yanaiia Mts. and Fuhng River indicate the oceanic basin subducted, overall, from Perman right up to Middle Triassic, which reflects dishnct geodynamc background of the Paleotethyan evolution from that in southwest Yunnan. The knowledge provides new teshmonies for the area bordering china and Vieinarn being, tectonica1ly, Paleotethysides and key data for reconstructing Paleotethyan evolution there

关键词： Wang ARC TiO PETROCHEMISTRY OF VOLCANIC ROCKS PALEOTETHYAN OCEANIC ISLAND AND ISLAND-ARC BORDERING YUNNAN AND GUANGXI

Expression,purification and serological analysis of hepatocellular carcinoma associated antigen HCA587 in insect cells

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World Journal of Gastroenterology 2003年第4期9卷 678-682页

作者： Bing Li Hong-Yan wu Xiao-Ping Qian Yan Li Wei-Feng Chen Immunology department of peking university Health Science Center,beijing,100083,china Immunology department of peking university Health Science Center 38 Xueyuan Road Beijing 100083 China. wfchen@***

AIM: In order to assess hepatocellular carcinoma associated antigen HCA587 as a potential target for immunotherapy,the Bac-to-Bac expression system was used to express recombinant protein HCA587 in insect ***: The cDNA encoding HCA587 gene was cloned into donor vector pFasBacHtb and recombinant pFasBac Htb587 was transformed into competent cells *** Bacmid-587 was transfected into Sf9 insect cells using CELLFECTIN, Recombinant HCA587 protein was produced in Sf9 insect cells after infection with recombinant baculovirus, and was purified using Ni-NTA resin. Sera from HCC patients were also screened using recombinant protein ***: The molecular weight of the recombinant protein HCA587 expressed in insect cells was approximately *** blot results proved the recombinant protein HCA587had the similar antigenicity with its native *** analysis told that the rate of seroreactivity to HCA587 was not high in HCC ***: The recombinant protein HCA587 was successfully expressed and purified using Bac-to-Bac expression system. It paved the way for generation of specific antibody and investigation of immunohistochemical analysis and immune responses of HCC in the future.

关键词： HCA587抗原肝细胞癌血清学检查免疫疗法免疫组织化学