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Influence of Rare Earth Elements on Microstructure and Mechanical Properties of Cast High-Speed Steel Rolls

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Journal of Rare Earths 2007年第4期25卷 490-494页

作者：王明家穆松梅孙菲菲王艳 State Key Laboratory of Metastable Materials Science and Technology Yanshan University Experiment Center Northeastern University in Qinhuangdao Yanming Alloy Roll Co. Ltd. Qinhuangdao 066004 China

The influence of rare earth （RE） elements on the solidification process and eutectic transformation and mechanical properties of the high-V type cast, high-speed steel roll was studied. Test materials with different RE additions were prepared on a horizontal centrifugal casting machine. The solidification process, eutectic structure transformation, carbide morphology, and the elements present, were all investigated by means of differential scanning calorimetry （DSC） and scanning electron microscopy energy dispersive spectrometry （SEM-EDS）. The energy produced by crack initiation and crack extension was analyzed using a digital impact test machine. It was found that rare earth elements increased the tensile strength of the steel by inducing crystallization of earlier eutectic γ-Fe during the solidification process, which in turn increased the solidification temperature and thinned the dendritic grains. Rare earth elements with large atomic radius changed the lattice parameters of the MC carbide by forming rare earth carbides. This had the effect of dispersing longpole M C carbides to provide carbide grains, thereby, reducing the formation of the gross carbide and making more V available, to increase the secondary hardening process and improve the hardness level. The presence of rare earth elements in the steel raised the impact toughness by changing the mechanism of MC carbide formation, thereby increasing the crack initiation energy.

关键词： eutectic carbide impact toughness differential scanning calorimetry high-speed steel roll rare earths

Nozzle test system for droplet deposition characteristics of orchard air-assisted sprayer and its application

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International Journal of Agricultural and Biological Engineering 2014年第2期7卷 122-129,I0003页

作者： Zhai Changyuan Zhao Chunjiang Wang Xiu Li Wei Li Wei Zhu Ruixiang College of Mechanical and Electronic Engineering Yangling 712100ShaanxiChina Northwest A&F University Yangling 712100ShaanxiChina national Engineering Research Centre for Information Technology in Agriculture Beijing 100097China

In order to obtain nozzle droplet deposition characteristics for sprayer mechanical design and variable spraying control algorithms,a nozzle droplet deposition characteristics test system for air-assisted spraying was *** test system can supply a stable wind site with precisely controlled air speed whose speed control ranges from 2 m/s to 16 m/s with maximum relative error of 4.5%.It can spray out a certain amount of liquid pesticide with adjustable spraying pressure which can be controlled with high precision while the maximum relative error is only 1.33%.The distribution of droplet deposition can be collected and measured by using the acquisition device and a pesticide deposition optical measurement *** experiment of two-dimensional nozzle flow measurement was carried *** results show that nozzle flow distribution is uniform and symmetric with“double-hump”shape in the spray ***-nozzle overlapped droplet deposition ranges from 85%to 116%relative to the *** nozzle droplet deposition experiment was *** experiment results show that in air-assisted spraying,the higher the wind speed,the less droplet deposition is affected by *** the wind speed is higher than 12 m/s and spraying distance is 0.80 m,droplet deposition is concentrated on the originally designated point and hardly affected by *** horizontal spray width becomes smaller with higher wind *** the wind speed is high,it can be considered that nozzle deposition only focuses on the nozzle center,if the position requirement is not very high in orchard spraying.

关键词： air-assisted spraying orchard sprayer flow distribution droplet deposition nozzle test system characteristics test system

Stable ^(85)Rb micro vapour cells:fabrication based on anodic bonding and application in chip-scale atomic clocks

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Chinese Physics B 2010年第11期19卷 243-250页

作者：苏娟邓科郭等柱汪中陈兢张耿民陈徐宗 Key Laboratory for the Physics & Chemistry of Nanodevices School of Electronics Engineering & Computer SciencePeking University Institute of Quantum Electronics School of Electronics Engineering & Computer SciencePeking University Department of Microelectronics School of Electronics Engineering & Computer SciencePeking University

We describe the microfabrication of ^85Rb vapour cells using a glass-silicon anodic bonding technique and in situ chemical reaction between rubidium chloride and barium azide to produce Rb. Under controlled conditions, the pure metallic Rb drops and buffer gases were obtained in the cells with a few mm^3 internal volumes during the cell sealing process. At an ambient temperature of 90 ℃ the optical absorption resonance of ^85Rb D1 transition with proper broadening and the corresponding coherent population trapping （CPT） resonance, with a signal contrast of 1.5% and linewidth of about 1.7 kHz, have been detected. The sealing quality and the stability of the cells have also been demonstrated experimentally by using the helium leaking detection and the after-9-month optoelectronics measurement which shows a similar CPT signal as its original status. In addition, the physics package of chip-scale atomic clock （CSAC） based on the cell was realized. The measured frequency stability of the physics package can reach to 2.1 × 10^-10 at one second when the cell was heated to 100 ℃ which proved that the cell has the quality to be used in portable and battery-operated devices.

关键词： ^85Rb Micro vapour cell anodic bonding coherent population trapping chip-scale atomic clock frequency stability

LINEAR AND GEOMETRICALLY NONLINEAR ANALYSIS WITH 4-NODE PLANE QUASI-CONFORMING ELEMENT WITH INTERNAL PARAMETERS

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Acta Mechanica Solida Sinica 2015年第6期28卷 668-681页

作者： Changsheng Wang Xiangkui Zhang Ping Hu Zhaohui Qi School of Automotive Engineering Dalian University of Technology State Key Laboratory of Structural Analysis for Industrial Equipment Dalian University of Technology Department of Engineering Mechanics Dalian University of Technology

A linear 4-node quadrilateral quasi-conforming plane element with internal parameters is proposed. The element preserves advantages of the quasi-conforming technique, including an explicit stiffness matrix, which can be applied to nonlinear problems. The weak patch test guarantees the convergence of the element. Then the linear element is extended to the geometri- cally nonlinear analysis in the framework of Total Lagrangian （TL） formulation. The numerical tests indicate that the present element is accurate and insensitive to mesh distortion.

关键词： quasi-conforming internal parameters plane element geometrically nonlinear

Gas Sensor Based on Interdigitated Gate Electrode Field Effect Transistor

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稀有金属材料与工程 2006年第A3期35卷 140-142页

作者： Tong Zhang Sheng Qiang Frank Lewis Edward S.Kolesar Yalin Wu Xiaozhu Chi Hongquan Zhang Harbin Institute of Technology Harbin 150001 China Automobile Electronic Engineering Technology Research and Development Center Harbin 150001 China The University of Texas at Arlington Arlington T X 76019 USA Texas Christian University Fort Worth T X 76129 USA

The paper presents a new method for fabricating a gas-sensitive micro-sensor based on *** primary target agents are nitrogen dioxides (NO_2),and ***-per-billion concentration levels of these two chemicals can be *** interdigitated gate electrode field-effect transistor (IGEFET) has been coupled with a chemically-active and electron-beam evaporated copper phthaiocyanine (CuPc) thin film to implement a gas-sensitive *** sensor is excited with voltage *** and frequency-domain response were *** magnitude of the normalized difference Fourier transform is distinct distinguished.

关键词： IGEFET sensor (NO2) DIMP Fourier transform

4×4 nonblocking optical switch fabric based on cascaded multimode interferometers

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Photonics Research 2016年第1期4卷 21-26页

作者： Zuxiang Li Linjie Zhou Liangjun Lu Shuoyi Zhao Dong Li Jianping Chen State Key Laboratory of Advanced Optical Communication Systems and Networks Department of ElectronicEngineering Shanghai Jiao Tong University

We experimentally demonstrate a 4 × 4 nonblocking silicon thermo-optic(TO) switch fabric consisting of three stages of tunable generalized Mach–Zehnder interferometers. All 24 routing states for nonblocking switching are characterized. The device's footprint is 4.6 mm × 1.0 mm. Measurements show that the worst cross talk of all switching states is-7.2 dB. The on-chip insertion loss is in the range of 3.7–13.1 dB. The average TO switching power consumption is 104.8 mW.

关键词： nonblocking optical switch fabric based on cascaded multimode interferometers OOK Figure

Practical implementation of Hilbert-Huang Transform algorithm

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Acta Oceanologica Sinica 2003年第1期22卷 1-14页

作者：黄大吉赵进平苏纪兰 Laboratory of the Ocean Dynamic Processes and Satellite Oceanography Second Institute of OceanographyState Oceanic AdministrationHangzhou 310012China

Hilbert-Huang Transform (HHT) is a newly developed powerful method for nonlinear and non-stationary time series analysis. The empirical mode decomposition is the key part of HHT, while its algorithm was protected by NASA as a US patent, which limits the wide application among the scientific community. Two approaches, mirror periodic and extrema extending methods, have been developed for handling the end effects of empirical mode decomposition. The implementation of the HHT is realized in detail to widen the application. The detailed comparison of the results from two methods with that from Huang et al. (1998, 1999), and the comparison between two methods are presented. Generally, both methods reproduce faithful results as those of Huang et al. For mirror periodic method (MPM), the data are extended once forever. Ideally, it is a way for handling the end effects of the HHT, especially for the signal that has symmetric waveform. The extrema extending method (EEM) behaves as good as MPM, and it is better than MPM for the signal that has strong asymmetric waveform. However, it has to perform extrema envelope extending in every shifting process.

关键词： Hilbert-Huang Transform (HHT) signal processing Empirical Mode Decomposition (EMD)

Feature Recognition of Low-resolution Fiber Image

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Journal of Donghua University(English Edition) 2006年第4期23卷 63-68页

作者：禹素萍曾培峰吴雄英陈建平 State Key Laboratory on Fiber-Optic Local Area Network and Advanced Optical Communication Systems Shanghai Jiaotong University Shanghai 200030College of Information Science and Technology Donghua University Shanghai 201620 College of Computer Science and Technology Donghua University Shanghai 201620 Shanghai Entry-Exit Inspection and Quarantine Bureau of P. R. C. Shanghai 200135 State Key Laboratory on Fiber-Optic Local Area Network and Advanced Optical Communication Systems Shanghai Jiaotong University Shanghai 200030

The interpolatory edge operator is applied to the recognition of cotton and ramie fibers. Its performance is studied in comparison with the Canny edge operator in the fiber’s edge detection for cross-sectional image. The input image is interpolated other than Gaussian function smoothing. The quality of edge output is improved by the interpolatory edge operator. It produces edge output with good continuity for low-resolution input. The fine edge output, such as cross-markings, can be distinguished clearly, so the interpolatory edge operator is suitable for the study of cotton and ramie fibers. Furthermore, the application of the interpolatory edge operator can cut the hardware cost, reduce the storage and speed up the data transmission.

关键词： B-spline interpolation edge detection multiresolution fiber image processing.

Optimization of regularization parameter of inversion in particle sizing using light extinction method

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China Particuology 2007年第4期5卷 295-299页

作者： Mingxu Su Feng Xu Xiaoshu Cai Kuanfang Ren Jianqi Shen Institute of Particle and Two Phase Flow Measurement Technology University of Shanghai .for Science and Technology Shanghai 200093 China LESP UMR6614/CORIA CNRS-Universite France INSA de Rouen 76801 France

In particle sizing by light extinction method, the regularization parameter plays an important role in applying regularization to find the solution to ill-posed inverse problems. We combine the generalized cross-validation （GCV） and L-curve criteria with the Twomey-NNLS algorithm in parameter optimization. Numerical simulation and experimental validation show that the resistance of the newly developed algorithms to measurement errors can be improved leading to stable inversion results for unimodal particle size distribution.

关键词： Particle size analysis Light extinction Inversion algorithm Regularization parameter