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Vegetation/Soil Synthesis Water Index Using MODIS Data

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Journal of China University of Mining and Technology 2005年第3期15卷 222-226页

作者： SONG xiao-ning zhao Ying-shi LIU zhen-hua College of Resources and Environment Graduate School of Chinese Academy of Sciences Beijing 100049 China College of Information South China Agricultural University Guangzhou Guangdong 510642 China

In consideration of the spectral character of MODIS (Moderate Resolution Imaging Spectroradiometer) dataand the reflective spectrum of vegetation and soil, NDVI (Normalized Difference Vegetation Index) and NDWI (Nor-malized Difference Water Index) are deduced using one visible band (0.66μm) and two near-infrared bands (0.86μm,1.24 μm). Vegetation canopy temperature is derived using two thermal infrared bands (8.6 μm and 11μm). Then thevegetation/soil synthesis water index (VSWI) is acquired through analyzing the coupling character of three indexeswhich can reflect the water condition of vegetation. Finally, the synthesis index is verified by equivalent water contentof a single leaf. The matching results show that the synthesis index is directly proportional to the modeled data,which means that the vegetation water content can be reflected using the synthesis index effectively.

关键词： MODIS NDVI NDWI vegetation/soil synthesis water index

Effects of Offline Relaxation Quenching on Microstructure and Mechanical Properties of a Newly Designed High Performance Steel

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Journal of Iron and Steel Research International 2014年第4期21卷 459-463页

作者： Wen-zhen XIA Xian-ming zhao xiao-ming ZHANG Di WU State Key Laboratory of Rolling and Automation Northeastern University

The newly designed high performance tested steel was prepared by the process of vacuum induction furnace smelting and forging. According to the ideas of online relaxation and quenching intercritieal quenching-tempering （Q- L-T） process, effects of offline relaxation process on microstructure and mechanical properties of the tested steel were investigated. Offline results process was simulated using the MMS-300 thermal simulation testing apparatus and heat treating furnace. The results show that the microstructures are composed of bainite and martensite when the specimens are quenched in the austenite region. Once the specimens are ai〉cooled into the dual phase region, ferrite and granular bainite start to form. In the relaxation process, fine Nb（C, N） carbonitrides are precipitated first and then grow and coarsen. The microstructure is affected by process and determines mechanical properties. The Vickers hardness and yield strength （YS） first rise then fall when the relaxation temperature drops in austenite region, and then decline dramatically in dual phase region. When the relaxation time is 20 s, the tensile strength reaches the peak （1034 MPa）, and at that time YS is 872 MPa, elongation is 17.7% and Charpy V-notch impact energy is 171 J at -20℃. When the relaxation time increases to 100 s, the yield and tensile strengths are 750 and 934 MPa respectively, elon- gation is 18.6% and Charpy V-notch impact energy is 165 J at -20℃.

关键词： high performance steel offline relaxation process microstrueture mechanical property

Magneto-optic Crystal Polarization Controller Assisted Mode-Locked Fiber Laser

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Chinese Physics Letters 2011年第3期28卷 81-84页

作者： zhao Guang-zhen GUI Li-Li xiao xiao-Sheng YANG Chang-Xi State Key Laboratory of Precision Measurement Technology and Instruments Department of Precision InstrumentsTsinghua UniversityBeijing 100084

We report a passively mode-locked erbium-doped fiber laser based on a compact magneto-optic crystal polarization *** length of the polarization controller consisting of four magneto-optic crystal rotators and two quarter wave-plates is only *** the polarization controller,central wavelength around 1559nm and repetition rate 21.10 MHz mode-locked pulse are *** duration and 3 dB spectrum width are 598.4fs and 6.24nm *** pulse energy is about *** of its small size,low insertion loss,good controllability and negligible dispersion,the magneto-optic crystal polarization controller could be an ideal polarization controller in fiber lasers.

关键词： polarization fiber passive

Cloud based 3D printing service platform for personalized manufacturing

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Science China(Information Sciences) 2020年第2期63卷 215-217页

作者： Lin ZHANG xiao LUO Lei REN Jingeng MAI Fan PAN zhen zhao Bing LI School of Automation Science and Electrical Engineering Beihang University College of Engineering Peking University China Aerospace Science Industry Corp.

Recently, the rapid development of 3D printing technology and continuous breakthroughs in new material technology has increased the application of 3D printing in a wide range of fields, such as automobile industry, me... 详细信息

关键词： service Cloud based 3D printing service platform for personalized manufacturing

The Harmonic Bergman Kernels for Punctured Domains

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Acta Mathematica Sinica,English Series 2014年第11期30卷 1977-1988页

作者： zhen Gang zhao Department of Mathematics Capital Normal University

We obtain the explicit formulae for the harmonic Bergman kernels of Bn／{0} and Rn／Bn and study the connection between harmonic Bergman kernel and weighted harmonic Bergman *** also get the explicit formula for the w... 详细信息

关键词： Harmonic Bergman kernel harmonic Bergman weighted harmonic Bergman kernel

基于O'NET半结构化访谈建构大学生职业适应力故事

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高校辅导员学刊 2025年第1期17卷 34-42,97页

作者：林振余权肖龙福建商学院传媒与会展学院福建福州350012

职业适应力是大学生转型为职场人士的关键能力,其中职业兴趣是核心要素。然而,当前对大学生职业兴趣的分析主要局限于定量评估,导致学生对自身职业兴趣的理解较为表面,甚至开始怀疑其价值。研究采用O'NET半结构化访谈,结合主题演绎驱动... 详细信息

职业适应力是大学生转型为职场人士的关键能力,其中职业兴趣是核心要素。然而,当前对大学生职业兴趣的分析主要局限于定量评估,导致学生对自身职业兴趣的理解较为表面,甚至开始怀疑其价值。研究采用O'NET半结构化访谈,结合主题演绎驱动理论,深入分析了大学生在职业适应力故事中的关注、控制、好奇、自信、合作五个维度,旨在探讨半结构化访谈如何定性地将职业兴趣代码与这五个维度的故事关联起来,并揭示其在提升大学生职业适应力方面的作用。研究结果显示,通过半结构化访谈建构的职业适应力故事,成功整合了定量与定性职业兴趣评估,这种方法不仅能帮助大学生更深入地理解自身的霍兰德职业兴趣代码,还能促使他们系统地叙述职业适应力故事,从而有效提升其职业适应力。

关键词：故事建构半结构化访谈职业适应力定性 O'NET

Performance of Forearm FMG and sEMG for Estimating Elbow, Forearm and Wrist Positions

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Journal of Bionic Engineering 2017年第2期14卷 284-295页

作者： zhen Gang xiao Carlo Menon Menrva Research Group Schools of Mechatronic Systems Engineering and Engineering Science Simon Fraser University British Columbia V3T0A3 Canada

The ability to track upper extremity movement during activity of daily living has the potential to facilitate the recovery of individuals with neurological or physical injuries. Hence, the use of Surface Electromyography （sEMG） signals to predict upper extremity movement is an area of interest in the research community. A less established technique, Force Myography （FMG）, which uses force sensors to detect forearm muscle contraction patterns, is also able to detect some movements of the arm. This paper investigates the comparative performance of sEMG and FMG when predicting wrist, forearm and elbow positions using signals extracted from the forearm only. Support Vector Machine （SVM） and Linear Discriminant Analysis （LDA） classifiers were used to evaluate the prediction performance of both FMG and sEMG data. Ten healthy volunteers participated in this study. Under a cross validation across a repetition evaluation scheme, the SVM classifier obtained averaged accuracies of 84.3%, 82.4% and 71.0%, respectively, for predicting elbow, forearm and wrist positions using FMG; while sEMG yielded 75.4%, 83.4% and 92.4% accuracies for predicting the same respective positions. The accuracies obtained using SVM are slightly, but statistical significantly, higher than the ones obtained using LDA. However, the trends on the classification performances between FMG and sEMG are consistent. These results also indicate that the forearm FMG pattern is highly influenced by the change of elbow position, while the forearm sEMG is less subjected to the change. Overall, both forearm FMG and sEMG techniques provide abundant information that can be utilized for tracking the upper extremity movements.

关键词： Surface Electromyography (sEMG) Force Myography (FMG) classification limb movement activity monitoring,upper extremity

Multiple Dissipative Solitons in a Long-Cavity Normal-Dispersion Mode-Locked Yb-Doped Fiber Laser

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Chinese Physics Letters 2012年第3期29卷 107-110页

作者： zhao Guang-zhen xiao xiao-Sheng MEI Jia-Wei YANG Chang-Xi State Key Laboratory of Precision Measurement Technology and Instruments Department of Precision InstrumentsTsinghua UniversityBeijing 100084

Transitional operations of multiple dissipative solitons in a long-cavity normal-dispersion Yb-doped fiber laser are experimentally *** dissipative solitons,including a stable soliton pair and a soliton triplet are observed by increasing the pump power or adjusting the polarization *** main boundaries of the stable asymmetric soliton and oscillating soliton are found between steady ***,multiple dissipative solitons with greater quantities of solitons are observed with pump power *** experimental results agree well with a previous numerical study of multiple dissipative solitons.

关键词： soliton solitons dissipative

The effects of calcium combined with chitosan amendment on the bioavailability of exogenous Pb in calcareous soil

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Journal of Integrative Agriculture 2020年第5期19卷 1375-1386页

作者： CHANG Hui-qing WANG Qi-zhen LI zhao-jun WU Jie XU xiao-feng SHI zhao-yong Henan University of Science and Technology Luoyang 471000P.R.China Key Laboratory of Plant Nutrition and Fertilizer Ministry of Agriculture and Rural Affairs/China-New Zealand Joint Laboratory for Soil Molecular EcologyInstitute of Agricultural Resources and Regional PlanningChinese Academy of Agricultural SciencesBeijing 100081P.R.China

Lead(Pb) in soil may accumulate in crops and enter the human body. This study aimed to understand the speciation transformation and accumulation characteristics of exogenous Pb in calcareous soil with or without the application of soil amendments. Field experiments with continuous maize cultivation have been carried out for two years. The results showed that the contents of total Pb were slightly lower in 2016 than in 2015 for the same treatments;however, no significant difference between the years was observed. Soil Pb existed mainly in the residual fraction without exogenous Pb addition, and its proportion was more than 33% of the total soil Pb in the control and Ca treatments. When Pb was added to calcareous soil, Pb existed largely in the oxidizable and reducible fractions during the two-year experimental period, and those fractions made up over 83% of the total Pb. The proportion of the water-soluble Pb, regardless of the addition of Pb, was the lowest and was less than 0.0019% in all treatments, but the addition of Ca and chitosan amendments reduced the water-soluble and exchangeable Pb contents. The Pb content in different parts of maize followed the order root>leaf>stem>grain during the experimental period. Although maize had low transfer and enrichment factors in calcareous soil, which make the Pb content in the grain show no significant difference among the five treatments in the same year, adding Ca and chitosan to calcareous soil can reduce the Pb contents of maize, especially reduce the Pb contents of root, stem and leaf. Therefore, the addition of calcium and chitosan is an effective strategy for reducing Pb availability in calcareous soils.

关键词： exogenous Pb maize calcareous soil speciation transformation amendments