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Diverse terahertz wavefront manipulations empowered by the spatially interleaved metasurfaces

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Science China(Information Sciences) 2023年第3期66卷 230-238页

作者： Jitao li Zhen YUE Jie li Chenglong ZHENG Silei WANG Mengyao li Yating ZHANG yan ZHANG Jianquan YAO School of Precision Instruments and Opto-Electronics Engineering Tianjin University College of Optoelectronic Engineering Chengdu University of Information Technology Department of Physics Capital Normal University

Optical metasurfaces have advanced approaches for manipulating light information in the spatial domain, in which the spatially interleaved metasurfaces demonstrate the ability to manipulate a more complex wavefront of light than metasurfaces without the spatial interleaving. The potential of the spatially interleaved metasurfaces has not been fully exploited. In this paper, we design the spatially interleaved terahertz(THz) metasurfaces based on the ingenious spatial interleaving principles to develop the diverse THz wavefront manipulations. Four functions are performed, including the orbital angular momentum(OAM)superposition of single-frequency vortex beams, the separate vortex focusing of single-frequency dual beams,the different OAM manipulations of bifrequency beams in different planes, and achromatic focusing. The demonstrated functions prove that the spatially interleaved metasurface can manipulate THz wavefront at both single frequency and bifrequency, which traditional metasurfaces cannot. This work paves the way for diverse THz wavefront manipulations.

关键词： terahertz wavefront manipulations metasurfaces spatial interleaving onformation optics

Expression of BMP Receptors in Porcine Granulosa Cells (GCs) and Their Regulation by Luteinizing Hormone (LH)

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Agricultural Sciences in China 2011年第2期10卷 289-295页

作者： WANG Wei ZHANG Hai-yan HE Yu ZHAO Yong-yan WANG li li Xin-xiu CHEN Xia XU Yin-xue College of Animal Science ＆ Technology Nanjing Agricultural UniversityNanjing 210095P.R.China

bone morphogenetic proteins（BMPs） play critical roles in follicle growth and *** initiate signaling by assembling BMP receptors and activating Smads,which in turn alter expression of target *** mechanism underlying the regulation of the expression of BMP receptors and Smads during follicle development in pigs is still *** quantitative real-time PCR,the mRNA expression of BMP receptors and Smads in granulosa cells（GC） was *** were obtained from small porcine follicles（SF;3 mm diameter） and dominant follicles（DF;6 mm diameter）;ActR1A and BMPR2 mRNA levels in DF were significantly higher（P0.05） than that in SF,whereas BMPR1B,Smad4 and Smad7 expression tended to decrease（P0.05）.The levels of BMPR1A,ActR2,Smad1,Smad5,and Smad8 mRNA did not differ between DFs and *** investigate the effect of LH on BMP receptors in GC,cells obtained from porcine DFs were cultured in medium supplemented with different doses of luteinizing hormone（LH）.High doses of LH（4 IU mL-1） significantly decreased the concentration of estradiol（E2） and progesterone（P4） in medium and the expression of Cyp19a1（P450 aromatase,P450arom） and Cyp11a1（cholesterol side-chain cleavage enzyme P450,P450scc）,while significantly increased viable cell numbers and up-regulated expression of cyclin dependent kinase-4（CDK4） and cyclin ***,LH had no effect on the expression of BMP receptor ***,the present study indicates that the expression of members of the BMP signaling pathway in porcine GC is regulated during follicle development and the expression of BMP receptors are not regulated by LH in porcine GCs.

关键词： porcine GCs mRNA expression BMP receptors Smads LH E2 P4

Candidate members of star clusters from LAMOST DR2

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Research in Astronomy and Astrophysics 2015年第8期15卷 1197-1208页

作者： bo Zhang Xiao-yan Chen Chao liu li Chen li-Cai Deng Jin-liang Hou Zheng-Yi Shao Fan yang Yue Wu Ming yang Yong Zhang Yong-Hui Hou Yue-Fei Wang Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of Sciences University of Chinese Academy of Sciences Shanghai Astronomical Observatory Chinese Academy of Sciences Nanjing Institute of Astronomical Optics & Technology National Astronomical ObservatoriesChinese Academy of Sciences

In this work, we provide 2189 photometrically- and kinematically-selected candidate members of 24 star clusters from the LAMOST DR2 catalog. We perform two-step membership identification： selection along the stellar track in the colormagnitude diagram, i.e., photometric identification, and selection from the distribution of radial velocities, i.e. the kinematic identification. We find that the radial velocities from the LAMOST data are very helpful in the membership identification. The mean probability of membership is 40% for the sample selected with radial velocity. With these 24 star clusters, we investigate the performance of the radial velocity and metallicity estimated with the LAMOST pipeline. We find that the systematic offsets in radial velocity and metallicity are 0.85 ± 1.26 km s-1and-0.08 ± 0.04 dex, with dispersions of 5.47＋1.16-0.71 km s-1and 0.13＋0.04-0.02 dex, respectively. Finally, we propose that the photometrically-selected candidate members of the clusters covered by the LAMOST footprint should be assigned higher priority so that more candidate stars can be observed.

关键词： open clusters and associations: general—stars: statistics—catalogs—surveys—methods: data analysis

Non-isothermal Crystallization Kinetics and Isothermal Crystallization Kinetics in Supercooled liquid Region of Cu–Zr–Al–Y Bulk Metallic Glass

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Acta Metallurgica Sinica(English Letters) 2018年第3期31卷 290-298页

作者： Ke yang Xin-Hui Fan Bing li yan-Hong li Xin Wang Xuan-Xuan Xu School of Material and Chemical Engineering Xi'an Technological University

The crystallization kinetics of Cu43Zr48Al9 and（Cu43Zr48Al9）98Y2 bulk metallic glasses in non-isothermal and isothermal conditions was studied by differential scanning *** the non-isothermal and isothermal modes,the average activation energy of（Cu43Zra8Al9）98Y2 is larger than that of Cu43Zr48Al9,meaning the higher stability against crystallization of（Cu43Zr48Al9）*** addition,the average activation energies for Cu43Zr48Al9 and（Cu43Zr48Al9）98Y2 calculated using Arrhenius equation in isothermal mode are larger than the values calculated by Kissinger-Akahira-Sunose method in non-isothermal mode,indicating that the energy barrier is higher in isothermal *** Johnson-Mehl-Avrami model was used to analyze the crystallization kinetics in the non-isothermal and isothermal *** Avrami exponent n for Cu43Zr48Al9 is above 2.5,indicating that the crystallization is mainly determined by a diffusion-controlled three-dimensional growth with an increasing nucleation rate,while the Avrami exponent n for（Cu43Zr48Al9）98Y2 is in the range of 1.5-2.5 in the non-isothermal mode,implying that the crystallization is mainly governed by diffusion-controlled three-dimensional growth with decreasing nucleation ***,the Avrami exponents n for Cu43Zr48Al9 and（Cu43Zr48Al9）98Y2 are different in the non-isothermal and isothermal conditions,which imply different nucleation and growth behaviors during the crystallization processes.

关键词： Bulk metallic glass Yttrium addition Crystallization behavior Activation energy

Synergistic optimal operation for a combined cooling,heating and power system with hybrid energy storage

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Science China(Information Sciences) 2018年第11期61卷 8-10页

作者： Yi yan Chenghui ZHANG Ke li Xiaopeng HAI School of Control Science and Engineering Shandong University

Dear editor,Improved penetration of renewable energy sources(RES) and strong coupling of multi-energy flows are crucial factors hindering the efficient utilization of energy in combined cooling, heating, and power (CCHP) systems [1]. To tackle this problem, energy storage, especially the adiabatic compressed air energy storage (A-CAES)-based hybrid energy storage system (HESS)[2, 3], is considered an important solution [4,5]. This system combines

关键词： Synergistic optimal operation for a combined cooling,heating and power system with hybrid energy storage RES

Reaction behavior of trace oxygen during combustion of falling FeSi75 powder in a nitrogen flow

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International Journal of Minerals,Metallurgy and Materials 2016年第8期23卷 959-965页

作者： Bin li Jun-hong Chen Peng Jiang Ming-wei yan Jia-lin Sun Yong li School of Materials Science and Engineering University of Science and Technology Beijing

To explore the reaction behavior of trace oxygen during the flash combustion process of falling FeSi75 powder in a nitrogen flow, a flash-combustion-synthesized Fe-Si;N;sample was heat-treated to remove SiO;. The samples before and after the treatment were investigated by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy, and the formation mechanism of SiO;was investigated. The results show that SiO;in the Fe-Si;N;is mainly located on the surface or around the Si;N;particles in dense areas, existing in both crystalline and amorphous states; when the FeSi75 particles, which are less than 0.074 mm in size, fell in up-flowing hot N;stream, trace oxygen in the N;stream did not significantly hinder the nitridation of FeSi75 particles as it was consumed by the surface oxidation of the generated Si;N;particles to form SiO;. At the reaction zone, the oxidation of Si;N;particles decreased the oxygen partial pressure in the N;stream and greatly reduced the opportunity for FeSi75 particles to be oxidized into SiO;; by virtue of the SiO;film developed on the surface, the Si;N;particles adhered to each other and formed dense areas in the material.

关键词： silicon nitride combustion synthesis oxygen atmosphere

Preparation of titanium dioxide from titania-rich slag by molten NaOH method

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International Journal of Minerals,Metallurgy and Materials 2012年第3期19卷 205-211页

作者： yan-fang Han Ti-changSun Jie li Tao Qi li-na Wang Jing-kui Qu School of Civil and Environmental Engineering University of Science and Technology Beijing Beijing 100083 China National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology Institute of Process Engineering Chinese Academy of Sciences Beijing 100190 China Key Laboratory of Green Process and Engineering Institute of Process Engineering Chinese Academy of Sciences Beijing 100190 China

Preparing titanium dioxide from titania-rich slag （TiO2 73wt%） by molten NaOH method has been developed. The effects of temperature and reaction time on the titanium conversion were investigated. The results showed that temperature had significant influence on the titanium conversion as well as the structure of the product. About 92% of titanium in the titania-rich slag could be converted after reacting with NaOH at 500℃ for 1 h. Metatitanic acid was formed through the steps of washing treatment, acid dissolution, and hydrolysis. Well-dispersed spherical titanium dioxide particles with an average size of 0.1-0.4μm can be obtained by calcination of metatitanic acid. In addition, the content of titanium dioxide in the product is up to 98.6wt%, which can be used as pigments after further treatment of coating and crushing.

关键词： slags titanium dioxide molten salt method pigments

Effect of thermal aging on the fatigue crack growth behavior of cast duplex stainless steels

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International Journal of Minerals,Metallurgy and Materials 2015年第11期22卷 1163-1170页

作者： Xu-ming Lü Shi-lei li Hai-long Zhang yan-li Wang Xi-tao Wang State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing Collaborative Innovation Center of Steel Technology University of Science and Technology Beijing

The effect of thermal aging on the fatigue crack growth（FCG） behavior of Z3CN20？09M cast duplex stainless steel with low ferrite content was investigated in this study. The crack surfaces and crack growth paths were analyzed to clarify the FCG mechanisms. The microstructure and micromechanical properties before and after thermal aging were also studied. Spinodal decomposition in the aged ferrite phase led to an increase in the hardness and a decrease in the plastic deformation capacity, whereas the hardness and plastic deformation capacity of the austenite phase were almost unchanged after thermal aging. The aged material exhibited a better FCG resistance than the unaged material in the near-threshold regime because of the increased roughness-induced crack closure associated with the tortuous crack path and rougher fracture surface; however, the tendency was reversed in the Paris regime because of the cleavage fracture in the aged ferrite phases.

关键词： stainless steels fatigue crack growth thermal aging embrittlement fracture morphology

Numerical study on influence of protrusion heights on Reynolds stress and viscous stress variations in turbulent vortical structures

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Chinese Journal of Aeronautics 2024年第9期37卷 59-71页

作者： Zhiping li Long HE Jingsai ZHOU Yueren ZUO Yao YIN Peng ZHANG bo MENG Research Institute of Aero-Engine Beihang UniversityBeijing 100191China School of Energy and Power Engineering Beihang UniversityBejing 100191China Institute of Acoustics Chinese Academy of SciencesBeijing 100190China College of Aeronautical Engineering Civil Aviation University of ChinaTianjin 300300China AECC Hunan Aviation Powerplant Research Institute Zhuzhou 412002China

Analysing the influence mechanism of the riblet protrusion height on turbulent drag components is more beneficial in organising the vortical structure over the riblet ***, the Large Eddy Simulation(LES) is used to investigate the vortex structure over the riblet surface with different protrusion heights. Then, the variations of Reynolds stress and viscous shear stress in a turbulent channel are analysed. As a result, the drag reduction rate increases from3.4% when the riblets are completely submerged in the turbulent boundary layer to 7.9% when the protrusion height is 11.2. Further analysis shows that the protrusion height affects the streamwise vortices and the normal diffusivity of spanwise and normal vortices, thus driving the variation of Reynolds stress. Compared with the smooth surface, the vorticity strength and the number of streamwise vortices are weakened near the wall but increase in the logarithmic layer with increased protrusion height. Meanwhile, the normal diffusivity of spanwise vorticity decreases with the increase of protrusion height, and the normal diffusivity of normal vorticity is the smallest when the protrusion height is 11.2. Moreover, the protrusion height affects the velocity gradient of the riblet tip and riblet valley, thus driving the variation of viscous shear stress. With the increase of protrusion height, the velocity gradient of the riblet tip increases dramatically but decreases in the riblet valley.

关键词： Riblet Dragreduction Protrusion height Vortical structure Vortexdiffusivity Reynolds stress Viscous stress