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Metasurface array for single-shot spectroscopic ellipsometry

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Light(Science & Applications) 2024年第5期13卷 835-842页

作者： Shun wen Xinyuan Xue Shuai Wang Yibo ni Liqun Sun Yuanmu Yang Department of Precision Instrument State Key Laboratory of Precision Measurement Technology and InstrumentsTsinghua UniversityBeijing 100084China

Spectroscopic ellipsometry is a potent method that is widely adopted for the measurement of thin film thickness and refractive *** conventional ellipsometers utilize mechanically rotating polarizers and grating-based spectrometers for spectropolarimetric ***,we demonstrated a compact metasurface array-based spectroscopic ellipsometry system that allows single-shot spectropolarimetric detection and accurate determination of thin film properties without any mechanical *** silicon-based metasurface array with a highly anisotropic and diverse spectral response is combined with iterative optimization to reconstruct the full Stokes polarization spectrum of the light reflected by the thin film with high ***,the film thickness and refractive index can be determined by fitting the measurement results to a proper material model with high *** approach opens up a new pathway towards a compact and robust spectroscopic ellipsometry system for the high throughput measurement of thin film properties.

关键词： properties. spectroscopic film

Reconstruct recent multi-population migration history by using identical-by-descent sharing

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Journal of Genetics and Genomics 2024年第6期51卷 642-651页

作者： wenxiao Zhang Kai Yuan Ru wen Haifang Li Xumin ni School of Mathematics and Statistics Beijing Jiaotong UniversityBeijing 100044China The Stanley Center for Psychiatric Research Broad Institute of MIT and HarvardCambridgeMA 02142USA Baidu Incorporated Beijing 100085China

Identical-by-descent(IBD)is a fundamental genomic characteristic in population genetics and has been widely used for population history ***,limited by the nature of IBD,which could only capture the relationship between two individuals/haplotypes,existing IBD-based history inference is constrained to two *** this study,we propose a framework by leveraging IBD sharing in multipopulation and develop a method,MatrixiBD,to reconstruct recent multi-population migration ***,we employ the structured coalescent theory to precisely model the genealogical process and then estimate the IBD sharing across multiple *** our model,we establish a theoretical connection between migration history and IBD *** method is rigorously evaluated through simulations,revealing its remarkable accuracy and ***,we apply MatrixiBD to Central and South Asia in the Human Genome Diversity Project and successfully reconstruct the recent migration history of three closely related populations in South *** taking into account the IBD sharing across multiple populations simultaneously,MatrixlBD enables us to attain clearer and more comprehensive insights into the history of regions characterized by complex migration dynamics,providing a holistic perspective on intricate patterns embedded within the recent population migration history.

关键词： Population genetics IBD sharing Migration history Structured coalescent theory Gene flow

Beam dynamics,RF measurement,and commissioning of a CW heavy ion IH-DTL

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Nuclear Science and Techniques 2018年第3期29卷 143-155页

作者： Heng Du You-Jin Yuan Zhong-Shan Li Zhi-Jun Wang Peng Jin Xiao-ni Li Guo-Zhu Cai wen-wen Ge Guo-Feng Qu Yuan He jia-wen Xia jian-Cheng Yang Xue-Jun Yin Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China

A 53.667 MHz CW(continuous-wave) heavy ion IH-DTL has been designed for the SSC-LINAC injector of HIRFL-CSR(Heavy Ions Research Facility at Lanzhou-Cooling Storage Ring). It accelerates ions with maximum mass-to-charge ratio of 7.0 from 143 to 295 ke V/u. Low-power RF measurement of the IH-DTL1 has been taken to investigate the RF performance and the quality of the electric field distribution on the beam *** measured Q_0 value and the shunt impedance are 10,400 and 198 MX/m, respectively. The electric field distributions on and around the beam axis were evaluated and compared with the design value. By a new approach,the dipole field component is also estimated. The beam dynamics simulation using measured field distribution was presented in this paper. Based on the dynamics analysis in both transverse and longitudinal phase space, the field distribution can meet the design requirement. Finally, the RF conditioning and very first beam commissioning on the IH-DTL1 were finished. The beam test results agree well with the simulation results; what's more, the property of the variable output beam energy about the separated functions DTL was verified.

关键词： Linac RF measurement Beam dynamic simulation Commissioning

Four New Phloroglucinol-Terpene Adducts from the Leaves of Myrciaria cauliflora

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Natural Products and Bioprospecting 2021年第1期11卷 111-118页

作者： Ming Chen jia-Qing Cao wen-Jing Wang ni-Ping Li Yan Wu Lei Wang wen-Cai Ye Institute of Traditional Chinese Medicine&Natural Products College of PharmacyJinan UniversityGuangzhou 510632People’s Republic of China Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research Jinan UniversityGuangzhou 510632People’s Republic of China

Myrcauones A-D(1-4),four new phloroglucinol-terpene adducts were isolated from the leaves of Myrciaria *** structures with absolute configurations were elucidated by combination of spectroscopic analysis,single crystal X-ray diffraction,and electronic circular dichroism(ECD)*** 1 was a rearranged isobutylphloroglucinol-pinene adduct featuring an unusual 2,3,4,4a,10,11-hexahydro-1H-3,11a-methanodibenzo[b,f]oxepin *** 4 showed moderate antibacterial activity against Gram-positive bacteria including multiresistant strains.

关键词： Myrciaria cauliflora Phloroglucinol-terpene adducts Antibacterial activity

Phosphate Diester Hydrolysis by Dinuclear Tb(III) Complexes with BDBPH in Second-order Dependence

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Chinese Chemical Letters 2006年第1期17卷 89-92页

作者： Guo Qiang SHANGGUAN Jun ZHU ning WANG jia Zuan ni Department of Chemistry Jining Medical College Jining 272013 Key Laboratory of Rare Earth Chemistry and Physics Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun 130022 Graduate School of Chinese Academy of Sciences. Beijing 100039

The kinetic study on the hydrolysis reaction of bis（4-nitrophenyl） phosphate （BNPP） catalyzed by Tb-BDBPH system（2：1） was carried out in 50% ethanol solution （pH 7.0-10.0） at 35℃ with I=0.10NaNO3. The second-order rate constant kBNPP, 2.3×10.3 （mol^-1L S^-1）, was determined. The dinuclear monohydroxo species, L-2Tb-OH, is kinetically mainly active species. The hydrolysis rate of BNPP by the complex is increased almost 2.6 million-fold compared with the background hydroxide rate at the same condition.

关键词： Tb(Ⅲ)-BDBPH phosphate diester hydrolysis rate constant.

Reinforcing effect of graphene on the mechanical properties of Al2O3/TiC ceramics

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International Journal of Minerals,Metallurgy and Materials 2017年第12期24卷 1403-1411页

作者： Zuo-li Li Jun Zhao jia-lin Sun Feng Gong Xiu-ying ni Key Laboratory of High Efficiency and Clean Mechanical Manufacture of Ministry of Education School of Mechanical EngineeringShandong UniversityJinan 250061China

Multilayer graphene(MLG)-reinforced Al_2O_3/TiC ceramics were fabricated through hot pressing sintering, and the reinforcing effect of MLG on the microstructure and mechanical properties of the composites was investigated by experiment and simulation. The simulation of dynamic crack initiation and propagation was investigated based on the cohesive zone method. The results show that the composite added with 0.2 wt% MLG has excellent flexural strength and high fracture toughness. The major reinforcing mechanisms are the synergistic effect by strong and weak bonding interfaces, MLG pull-out, and grain refinement resulting from the addition of MLG. In addition, the aggravating of crack deflection, branching, blunting, and bridging have indispensable contribution to the improvement of the as-designed materials.

关键词： mechanical properties ceramics graphene simulation interface

Synthesis and Crystal Structure of [MoOS_3Cu_3I(dmpzm)_2]·2(MeCN)_(0.5) (dmpzm=Bis(3,5-dimethylpyrazolyl)methane)

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Chinese Journal of Structural Chemistry 2006年第5期25卷 557-561页

作者： DING ni-ni ZHANG wen-Hua CHEN Jin-Xiang REN Zhi-Gang ZHANG Yong LANG jian-Ping Key Laboratory of Organic Synthesis of jiangsu Province School of Chemistry and Chemical Engineering Suzhou Universiry Suzhou 215006 China State Key Laboratory. of Structural Chemistry Fujian Institute of Research on the Structure of MatterThe Chinese Academy of Sciences Fuzhou Fujian 350002 China

Reaction of a preformed cluster [Et4N]4[Mo2O2S6Cu6I6] with bis（3,5-dimethylpyrazolyl）methane （dmpzm） in acetonitrile afforded the title compound [MoOS3Cu3I（dmpzm）2]·2（MeCN）0.5 1. The single-crystal X-ray diffraction study shows that 1 （C24H35Cu3IMoN9OS3, Mr = 975.25） crystallizes in triclinic, space group P1^- with a = 11.442（2）, b = 11.644（2）, c = 16.211（3） A, α = 99.26（3）, β= 102.22（3）, γ = 118.51（3）°, V = 1766.5（10） A^3, Z = 2, Dc = 1.834 g/cm^3, T = 193（2） K, F（000） = 960, μ = 32.12 cm^-1, λ = 0.71073A^3, R = 0.0355 and wR = 0.0915 for 5686 observed reflections with Ⅰ 〉 2σ（Ⅰ）. In the molecular structure of 1, the [MoOS3]^2- anion acts as a tridentate ligand to bind one CuI group and two [Cu（dmpzm）]^＋ units to form a nido-like [MoOS3Cu3] core with an approximate C2v symmetry. The Mo…Cu contacts are in the range of 2.6460（12）～2.6798（11）A.

关键词： molybdenum copper sulfur crystal structure cluster

SO2 Emission Characteristics and BP Neural Networks Prediction in MSW/Coal Co-Fired Fluidized Beds

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Journal of Thermal Science 2006年第3期15卷 281-288页

作者： Junming wen jianhua YAN Dongping ZHANG Yong CHI Mingjiang ni Kefa CEN State Key Laboratory of Clean Energy Utilization Institute for Thermal Power Engineering of ZhejiangUniversity Hangzhou 310027 China Shanghai Electric Environment Protection Group Shanghai 200041 China Suyuan Environment Protection Engineering Ltd. Co. /~anjing 210024 China

The SO2 emission characteristics of typical Msw components and their mixtures have been investigated in a φ150mm fluidized bed. Some influencing factors of SO2 emission in MSW fluidized bed incinerator were found out in this study. The SO2 emission is increasing with the growth of the bed temperature, and it is rising with the increasing oxygen concentration at furnace exit. When the weight percentage of auxiliary coal is being raised, the conversion rate of S to SO2 is largely going up. The SO2 emission decreases if the desulfurizing agent （CaCO3） is added during the incineration process, but the desulfurizing efficiency is weakened with the enhancement of the bed temperature. The fuel moisture content has a slight effect on the SO2 emission. Based on these experimental results, a 12 × 6 × 1 three-layer BP neural networks prediction model of SO2 emission in MSW/coal co-fired fluidized bed incinerator was built. The prediction results of this model give good agreement with the experimental results, which indicates that the model has relatively high accuracy and good generalization ability. It was found that BP neural network is an effectual method used to predict the SO2 emission of MSW/coal co-fired fluidized bed incinerator.

关键词： municipal solid waste (MSW) S02 emission fluidized bed BP neural networks prediction model.

Study on an automatic multi-pin insertion system for preparing Z-pin composite laminates

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Chinese Journal of Aeronautics 2014年第2期27卷 413-419页

作者： Song Qinghua Li Yong Qi Junwei wen Liwei Xiao Jun ni Jinhui College of Material Science and Technology Nanjing University of Aeronautics and Astronautics

As a three-dimensional layer enhancement technology, the Z-pin technology is suitable for manufacturing composite prepreg laminates and can also effectively improve their interlaminar properties. In order to manufacture Z-pin composite parts efficiently, this paper proposes a transi- tional insertion system, and according to the technical requirements of the transitional insertion process and the functional requirements of the transitional insertion platform, proposes a transition insertion plan which can insert multiple Z-pins into a carrier. A prototype machine has been designed and made, and a series of function debugging and verification experiments have been car- ried out on the machine. Some problems show up during the experiments, but based on the analysis of the reasons, this paper provides lots of solutions, and finally demonstrates the feasibility and practical value of the system. The results show that the system meets all technical requirements of the Z-pin insertion process. It is capable to insert multiple Z-pins into a foam carrier; as a result, the system is as much as 5 times more efficient than existing equipment, and the deviation for the insertion distance can be controlled within 0.3 mm. This Z-pin transitional insertion platform pro- motes the use of Z-pins in national defense and lays the foundation for commercializing the Z-pin technology.

关键词： Composite materialsInsertion Multi-pin Three-dimensional Z-pin