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Role of Bloch oscillation in high-order harmonic generation from periodic structure

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Chinese Physics B 2019年第11期28卷 60-66页

作者： Lu Liu Jing zhao Jian-Min Yuan zeng-xiu zhao Graduate School of China Academy of Engineering Physics Beijing 100193China Department of Physics College of Liberal Arts and ScienceNational University of Defense TechnologyChangsha 410073China

The high-order harmonic generation from a model solid structure driven by an intense laser pulse is investigated using the semiconductor Bloch equations(SBEs). The main features of harmonic spectrum from SBEs agree well with the result of the time-dependent Schro¨dinger equation(TDSE), and the cut-off energy can be precisely estimated by the recollision model. With increasing the field strength, the harmonic spectrum shows an extra plateau. Based on the temporal population of electron and the time–frequency analysis, the harmonics in the extra plateau are generated by the Bloch oscillation. Due to the ultrafast time response of the Bloch electron, the generated harmonics provide a potential source of shorter isolated attosecond pulse.

关键词： high-order harmonic generation attosecond pulse semiconductor Bloch equations time-dependent Schrodinger equation

Polarity Reversal of Terahertz Electric Field from Heavily p-Doped Silicon Surfaces

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Chinese Physics Letters 2021年第7期38卷 34-39页

作者： Hai-Zhong Wu Quan Guo Yan-Yun Tu Zhi-Hui Lyu Xiao-Wei Wang Yong-Qiang Li zhao-Yan Zhou Dong-Wen Zhang zeng-xiu zhao Jian-Min Yuan College of Liberal Arts and Sciences National University of Defense TechnologyChangsha 410073China Northwest Institute of Nuclear Technology Xi'an 710024China Graduate School of China Academic of Engineering Physics Beijing 100193China

Above-band-gap optical excitation of electron-hole pairs screens the doping-induced surface electric field and generates terahertz(THz)pulses via free-carrier *** emission from a heavily doped silicon surface is much weaker than that of lightly doped samples.A polarity reversal of the THz electric field is observed in heavily doped p-type silicon,indicating that the doping related and carrier induced surface electric fields oppose each *** comparing the penetration depth of the excitation laser with the thickness of the depletion layer for the doped silicon,it is shown that competition between diffusion and drift current causes the polarity reversal.

关键词： excitation doping polarity

Numerical Study on the Aerodynamic and Fluid−Structure Interaction of An NREL-5MW Wind Turbine

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China Ocean Engineering 2024年第3期38卷 363-378页

作者： zhao Mi YU Wan-li WANG Pi-guang QU Yang DU xiu-li Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education Beijing University of TechnologyBeijing 100124China State Key Laboratory of Bridge Engineering Safety and Resilience Beijing University of TechnologyBeijing 100124China

A 5-MW wind turbine has been modeled and analyzed for fluid-structure interaction and aerodynamic *** this study, a full-scale model of a 5-MW wind turbine is first developed based on a computational fluid dynamics(CFD) approach, in which the unsteady, noncompressible Reynolds Averaged Navier-Stokes(RANS) method is used. The main focus of the study is to analyze the tower shadow effect on the aerodynamic performance of the wind turbine under different inlet flow conditions. Subsequently, the finite element model is established by considering fluid/structure interactions to study the structural stress, displacement, strain distributions and flow field information of the structure under the uniform wind speed. Finally, the fluid-structure interaction model is established by considering turbulent wind and the tower shadow effect. The variation rules of the dynamic response of the one-way and two-way fluid-structure interaction(FSI) models under different wind speeds are analyzed, and the numerical calculation results are compared with those of the centralized mass model. The results show that the tower shadow effect and structural deformation are the main factors affecting the aerodynamic load fluctuation of the wind turbine, which in turn affects the aerodynamic performance and structural stability of the blades. The structural dynamic response of the coupled model shows significant similarity, while the structural displacement response of the former exhibits less fluctuation compared with the conventional centralized mass model. The one-way fluid-structure interaction(FSI)model shows a higher frequency of stress-strain and displacement oscillations on the blade compared with the two-way FSI model.

关键词： computational fluid dynamics methods(CFD) tower shadow effect aerodynamic performance fluidstructure interaction space flow field

Analytical Solution and Simplified Formula for Added Mass of Horizontal and Vertical Motions of Truncated Cylinders Under Earthquake Action

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China Ocean Engineering 2024年第1期38卷 54-67页

作者： WANG Pi-guang LYU Si-yu QU Yang zhao Mi DU xiu-li State Key Laboratory of Bridge Engineering Safety and Resilience Beijing University of TechnologyBeijing 100124China Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education Beijing University of Tech-nologyBeijing 100124China

This paper investigates the hydrodynamic characteristics of floating truncated cylinders undergoing horizontal and vertical motions due to earthquake excitations in the finite water *** governing equation of the hydrodynamic pressure acting on the cylinder is derived based on the radiation theory with the inviscid and incompressible *** governing equation is solved by using the method of separating variables and analytical solutions are obtained by assigning reasonable boundary *** analytical result is validated by a numerical model using the exact artificial boundary simulation of the infinite *** main variation and distribution characteristics of the hydrodynamic pressure acting on the side and bottom of the cylinder are analyzed for different combinations of wide-height and immersion *** added mass coefficient of the cylinder is calculated by integrating the hydrodynamic pressure and simplified formulas are proposed for engineering *** calculation results show that the simplified formulas are in good agreement with the analytical solutions.

关键词： earthquake hydrodynamic pressure truncated cylinder added mass simplified formula

Observation and Analysis of VLF Nocturnal Multimode Interference Phenomenon based on Waveguide Mode Theory

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Research in Astronomy and Astrophysics 2024年第1期24卷 78-86页

作者： Sai Yang You-Tian Niu Zhe Wang xiu-Kun zhao Bei Li Yu-Ling Ding Ge-Ge zhao An-Qi Zhang College of Electronic and Electrical Engineering Henan Normal UniversityXinxiang 453007China Academician Workstation of Electromagnetic Wave Engineering of Henan Province Xinxiang 453007China Key Laboratory of Optoelectronic Sensing Integrated Application of Henan Province Xinxiang 453007China Engineering Laboratory of Intelligent Additive Manufacturing of Henan Province Xinxiang 453007China

Very low frequency(VLF)signals are propagated between the *** interference will cause the phase to show oscillatory changes with distance while propagating at night,leading to abnormalities in the received VLF *** study uses the VLF signal received in Qingdao City,Shandong Province,from the Russian Alpha navigation system to explore the multimode interference problem of VLF signal *** characteristics of the effect of multimode interference phenomena on the phase are analyzed according to the variation of the phase of the VLF ***,the phase of VLF signals will also be affected by the X-ray and energetic particles that are released during the eruption of solar flares,therefore the two phenomena are studied in this *** is concluded that the X-ray will not affect the phase of VLF signals at night,but the energetic particles will affect the phase change,and the influence of energetic particles should be excluded in the study of multimode interference *** VLF signals for navigation positioning in degraded or unavailable GPS conditions is of great practical significance for VLF navigation systems as it can avoid the influence of multimode interference and improve positioning accuracy.

关键词： waves methods:data analysis Sun:flares Sun:X-rays gamma-rays

Tunable VO_(2) cavity enables multispectral manipulation from visible to microwave frequencies

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Light(Science & Applications) 2024年第3期13卷 510-518页

作者： Hang Wei Jinxin Gu Tao zhao Zhiyuan Yan He-xiu Xu Shuliang Dou Cheng-Wei Qiu Yao Li Center for Composite Materials and Structure Harbin Institute of TechnologyHarbin 150001China National University of Singapore Department of Electrical&Computer EngineeringSingapore 117583Singapore School of Chemical Engineering and Technology Harbin Institute of TechnologyHarbin 150001China Suzhou Laboratory Suzhou 215123China

Optical materials capable of dynamically manipulating electromagnetic waves are an emerging field in memories,optical modulators,and thermal ***,their multispectral design preliminarily attracts much attention,aiming to enhance their efficiency and integration of ***,the multispectral manipulation based on these materials is challenging due to their ubiquitous wavelength dependence restricting their capacity to narrow *** this article,we cascade multiple tunable optical cavities with selective-transparent layers,enabling a universal approach to overcoming wavelength dependence and establishing a multispectral platform with highly integrated *** on it,we demonstrate the multispectral(ranging from 400 nm to 3 cm),fast response speed(0.9 s),and reversible manipulation based on a typical phase change material,vanadium *** platform involves tandem VO_(2)-based Fabry–Pérot(F-P)cavities enabling the customization of optical responses at target bands *** can achieve broadband color-changing capacity in the visible region(a shift of~60 nm in resonant wavelength)and is capable of freely switching between three typical optical models(transmittance,reflectance,and absorptance)in the infrared to microwave regions with drastic amplitude tunability exceeding *** work represents a state-of-art advance in multispectral optics and material science,providing a critical approach for expanding the multispectral manipulation ability of optical systems.

关键词： spectral microwave visible

Liu-Jun-Zi decoction alleviates chemotherapy-induced anorexia by regulating gut microbiota and TLR4/MyD88/NF-κB p65 signaling pathway

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Traditional Medicine Research 2024年第8期9卷 47-58页

作者： Yu-Jie Gao Xi-Pei Wu Bin-Bin Ye Yong-zhao Dai Yao-Zhong zhao xiu-xiu Liao Ke Nie School of Chinese Materia Medica Guangdong Pharmaceutical UniversityGuangzhou 510006China

Background:Liu-Jun-Zi decoction(LJZD),a classical nourishing formula in China,has been proven to be effective in treating chemotherapy-induced *** this study,the mechanism of LJZD in alleviating chemotherapy-induced anorexia was discussed from the aspects of regulating gut microbiota,repairing intestinal barrier injury and inhibiting inflammatory ***:A rat model of chemotherapy-induced anorexia was established using *** study evaluated the therapeutic effects of LJZD by observing the weight,food intake,and intestinal pathology of *** impact of LJZD on gut microbiota and metabolites,specifically short-chain fatty acids,was investigated through gut microbiota analysis and targeted *** anti-inflammatory and intestinal protective effects of LJZD were assessed by examining the expression of intestinal tight junction proteins associated with the inflammatory ***:LJZD alleviated cisplatin-induced inflammation and intestinal barrier disruption,as evidenced by upregulated expression of tight junction protein 1(TJ-1)and occludin,along with reduced serum levels of interleukin 6(IL-6),interleukin-1β(IL-1β),tumor necrosis factor-α(TNF-α),and ***,LJZD alleviated microbiota imbalance and regulated the levels of short-chain fatty acids,especially increased the relative abundance of Coriobacteriales Incertae Sedis,Lactabacillus johnsonii F19785,Parasutterella,and reduced the *** the hypothalamus,LJZD exerts suppressive effects on the toll-like receptor 4(TLR4)/myeloid differentiation factor 88(MyD88)/nuclear factor-κB(NF-κB)p65 signaling pathway,leading to a downregulation in the transcriptional activity of IL-6 and IL-1β,as well as Interleukin 6 receptors(IL-6R)and Interleukin-1βreceptors(IL-1R1)mRNA expression ***:In summary,LJZD alleviate chemotherapy-induced anorexia by modulating the gut microbiota,repairing the intestinal mechanical barriers,and suppressing the TLR4

关键词： Liu-Jun-Zi decoction chemotherapy-induced anorexia cisplatin TLR4/MyD818/NF-κB p65 gut microbiota rat

Journal of Genetics and Genomics in 2023:progresses and beyond

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Journal of Genetics and Genomics 2024年第1期51卷 1-2页

作者： xiu-Fen Song Xiaoxuan Guo Jing zhao Yutian Zhang Yuan Qin Jianru Zuo Journal of Genetics and Genomics Institute of Genetics and Developmental BiologyChinese Academy of Sciences&the Genetics Society of ChinaBeijing 100101China

Journal of Genetics and Genomics(JGG),launched in 1974,celebrates its 50th birthday in *** continuous support from our authors,reviewers,readers,and the editorial board,JGG has made remarkable progress in the past year by publishing 122 papers covering major disciplines in life sciences and medical genetics with exciting *** is worthwhile to note that we have recruited 66 young talents to join JGG as junior editors,resulting in significant improvement in manuscript evaluation and journal ***,we summarize major progresses reported in JGG in 2023 fromaneditorial view.

关键词： journal beyond promotion

Ginsenoside Rg3 Promotes the Survival and Migration of Trophoblast Cells in a Rat Model of Gestational Hypertension by Regulating miR-100a/Insulin Growth Factor-2 Axis

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World Journal of Traditional Chinese Medicine 2024年第1期10卷 65-74页

作者： xiu-Mei Fan Li Yang Gang zhao Sen-Ye Huo Yan Gao Department of Obstetrics Xingtai Third HospitalXingtaiChina Department of Obstetrics Xingtai Maternal and Child Health Care HospitalXingtaiChina

Objective:Preeclampsia(PE)is a common complication during ***-100a is expressed in the placenta and regulates the survival and development of placental *** growth factor-2(IGF-2)may serve as its downstream *** study investigated the protective mechanisms of ginsenoside Rg3 against PE in rat *** and Methods:LPS-induced rat PE models were suitable for intravenous administration of the highly expressed miR-100a ginsenoside Rg3 lentiviral *** trophoblasts were cultured in vitro for JEG-3,and PE cell models were *** vivo effects on tumor growth and apoptosis were *** Rg3 was treated with different concentrations of shRNA,miR-100a analogs,inhibitors,or *** and the expression of autophagy-related proteins were *** activity and migration were determined using Cell Counting Kit-8 and Transwell *** drugs strongly inhibited trophoblasts under normal conditions with some synergy between ***-luciferase return assay confirmed the binding affinity of miR-100a for ***:In response to Rg3,autophagy and the expression of autophagy-related proteins LC3-I/II,Beclin1,and SQSTM1 were reduced in PE rat placental ***3 inhibited autophagy in JEG-3 cells and promoted JEG-3 survival and migration in a concentration-dependent ***-100a upregulated PE *** results suggested that autophagy was a vital signaling ***3 intervention inhibited miR-100a expression and miR-100a downregulated IGF-2 expression in placental tissues and promoted autophagy,thereby inhibiting JEG-3cell survival and *** rats,Rg3 inhibited PE development by regulating the activity of the miR-100a-IGF-2 signaling ***:Ginsenoside Rg3 positively regulates the miR-100a-IGF-2 axis and protects PE rats by inhibiting trophoblastic autophagy and promoting trophoblastic cell survival and migration.

关键词： Ginsenoside Rg3 inflammatory response miR-100a/insulin growth factor-2 axis preeclampsia pregnancy-induced hypertension