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Synthesis and formation mechanism of titanium lead carbide

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journal of Advanced Ceramics 2018年第2期7卷 178-183页

作者： C. LING w. B. TIAN P. ZHANG w. ZHENG Y. M. ZHANG Z. M. SUN jiangsu Key Laboratory of Advanced Metallic Materials School of Materials Science and Engineering Southeast University Nanjing 211189 China jiangsu Key Laboratory of Construction Materials School of Materials Science and Engineering Southeast University Nanjing 211189 China

Ti_2PbC was synthesized for the first time by pressureless reaction synthesis using Ti/Pb/TiC as starting materials at a heating rate of 2 ℃/min and holding at 1370 ℃for 2 h in a tube furnace protected by Ar atmosphere. The effects of starting powders, heating rates, and holding temperatures on the formation of Ti_2PbC were investigated. It was found that elementary mixture of Ti/Pb/C or higher heating rates fail to form Ti_2PbC. The decreased lattice parameters in the synthesized Ti_2PbC indicated the existence of Pb vacancies in the compound. A reaction mechanism was proposed to explain the formation of Ti_2PbC.

关键词： Ti2PbC 最大阶段微分扫描热量测定(DSC ) 热稳定性

Estimation of Tropical Forest Structural Characteristics Using ALOS-2 SAR Data

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Advances in Remote Sensing 2016年第2期5卷 131-144页

作者： Luong Viet Nguyen Ryutaro Tateishi Hoan Thanh Nguyen Ram C. Sharma Tu Trong To son Mai Le Center for Environmental Remote Sensing Chiba University Chiba Japan Space Technology Institute Vietnam Academy of Science and Technology Hanoi Vietnam Institute of Geography Vietnam Academy of Science and Technology Hanoi Vietnam

The potential of ALOS-2 SAR data for the estimation of tropical forest structural characteristics was assessed in Vietnam by collecting forest inventory data. The effect of polarization and seasonality of the SAR data on the estimation of forest biomass was analyzed. The combination of HH, HV, and HH/HV polarizations using multiple linear regression did not improve the estimation of biomass compared to using the HV channel independently, as the HH and HH/HV variables were not statistically significant. The dry season HV backscattering intensity was highly sensitive to the biomass compared to the rainy season backscattering intensity. The SAR data acquired in the rainy season with humid and wet canopies was not very sensitive to the biomass. The strong dependence of the biomass estimates with the season of SAR data acquisition confirmed that the choice of right season SAR data is very important for improving the satellite based estimates of the biomass. The validation results showed that the dry season HV polarization could explain 54% variation of the biomass.

关键词： Forest Structure Forest Biomass SAR ALOS-2 Backscattering Intensity Sensitivity Analysis

On the role of the constitutive model and basal texture on the mechanical behaviour of magnesium alloy AZ31B sheet

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journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第10期11卷 744-755页

作者： H. wANG P. D. wU K. w. NEALE Department of Mechanical Engineering McMaster University Hamilton Ontario L8S 4L7 Canada Faculty of Engineering University of Sherbrooke Sherbrooke Quebec J1K 2R1 Canada

The recently developed elastic-viscoplastic self-consistent model with various self-consistent schemes was applied to study the effect of basal texture on the mechanical behavior of magnesium alloy AZ31B sheet. The influence of the basal texture was investigated using various initial textures generated by artificially tilting the measured texture of the reference AZ31B sheet around in a transverse direction. The material parameters for the various models were fitted to experimental uniaxial tension and compression along the rolling direction and were then used to study the effects of the basal texture on the yield stress, R value, ultimate stress and uniform strain under uniaxial tension. The effect of the basal texture on sheet metal forming was further assessed by calculating the limit strain under in-plane plane strain tension. An assessment of the predictive capability of polycrystal plasticity models was made based on comparisons of predictions and experimental observations. Among the available self-consistent approaches, the Affine self-consistent scheme resulted in the best overall performance.

关键词： AZ31B 板材成形力学性能镁合金织构基面本构模型极限应变

Review:Measurement-Based Monitoring and Fault Identification in Centrifugal Pumps

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journal of Harbin Institute of Technology(New Series) 2023年第2期30卷 25-47页

作者： janani Shruti Rapur Rajiv Tiwari Aakash Dewangan D.j.Bordoloi Department of Mechanical Engineering Indian Institute of Technology GuwahatiGuwahati 781039India

Condition based maintenance(CBM) is one of the solutions to machinery maintenance requirements. Latest approaches to CBM aim at reducing human engagement in the real-time fault detection and decision making. Machine learning techniques like fuzzy-logic-based systems, neural networks, and support vector machines help to reduce human involvement. Most of these techniques provide fault information with 100% confidence. It is undeniably apparent that this area has a vast application scope. To facilitate future exploration, this review is presented describing the centrifugal pump faults, the signals they generate, their CBM based diagnostic schemes, and case studies for blockage and cavitation fault detection in centrifugal pump(CP) by performing the experiment on test rig. The classification accuracy is above 98% for fault detection. This review gives a head-start to new researchers in this field and identifies the un-touched areas pertaining to CP fault diagnosis.

关键词： centrifugal pumps condition-based maintenance fault diagnosis machine learning techniques review

Hilbert Space of Probability Density Functions Based on Aitchison Geometry

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Acta Mathematica Sinica,English Series 2006年第4期22卷 1175-1182页

作者： j.j.EGOZCUE j.L.DIAZ-BARRERO V.PAwLOwSKY-GLAHN Applied Mathematics Ⅲ Universitat Politàcnica de CatalunyaJordi Girona 1-3C208034BarcelonaSpain Applied Mathematics Ⅲ Universitat Politàcnica de CatalunyaJordi Girona 13C208034BarcelonaSpain Informatics and Applied Mathematics Universitat de GironaCampus MontiliviP417071GironaSpain

The set of probability functions is a convex subset of L1 and it does not have a linear space structure when using ordinary sum and multiplication by real constants. Moreover, difficulties arise when dealing with distances between densities. The crucial point is that usual distances are not invariant under relevant transformations of densities. To overcome these limitations, Aitchison＇s ideas on compositional data analysis are used, generalizing perturbation and power transformation, as well as the Aitchison inner product, to operations on probability density functions with support on a finite interval. with these operations at hand, it is shown that the set of bounded probability density functions on finite intervals is a pre-Hilbert space. A Hilbert space of densities, whose logarithm is square-integrable, is obtained as the natural completion of the pre-Hilbert space.

关键词： Bayes' theorem Fourier coefficients Haar basis Aitchison distance Simplex Least squares approximation

Structural Characterization of Thin Epitaxial GaN Films on Polymer Polyimides Substrates by Ion Beam Assisted Deposition

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Advances in Materials Physics and Chemistry 2020年第9期10卷 199-206页

作者： Sri Vidawati jürgen w. Gerlach Benjamin Herold Bernd Rauschenbach Faculty of Post Graduate National Institute of Science and Technology Jakarta 12640 Indonesia Leibniz Institute of Surface Engineering (IOM) Permoserstrasse 15 D-04318 Leipzig Germany

The Epitaxial GaN thin films have been fabricated by Ion Beam Assisted Deposition (IBAD) process using nitrogen ions with hyperthermal energies on the polyimides polymer substrates. By applying with the Reflection of High-Energy Electron Diffraction (RHEED), Scanning Electron Microscopy (SEM) and Quantum Design Physical Properties Measurement System, the behaviour of hexagonal GaN thin films is investigated. The result showed that the high quality of the deposited GaN layers kept appearing for many parameters depending on the temperature greatly. The behaviour of high quality of epitaxial GaN coating on the polyimide polymer substrates is a promising material for optoelectronic devices and semiconductor devices application.

关键词： Ion Beam Assisted Deposition Hexagonal GaN Thin Film SEM Quantum Design Physical Properties Measurement System RHEED

Biomarkers of Aging: An Overview

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Biomedical and Environmental Sciences 1991年第1期4卷 130-133页

作者： ANGELO TURTURRO RONALD w.HART National Center for Toxicological Research JeffersonNational Center for Toxicological Research Jefferson Akansas 72079Akansas 72079

INTRODUCTION Although aging has often been thought of as some intrinsic, immutable process, an alternative is to approach aging as a toxic endpoint resulting from a combination of endogenous and exogenous damage. Aging is then defined as consisting of a combination of functional declines observed in every organism system, occurring at different ages for different systems (Shock, 1985). One measure of this decline is death, and mortality is often used as a surrogate for aging. The sources of endogenous

关键词： Biomarkers of Aging An Overview

DISTRIBUTION OF THE MAGNETIC FIELD AND ITS CONTROLEFFECT ON THE MOLTEN METAL FLOw IN FLOw CONTROLMOLD

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Acta Metallurgica Sinica(English Letters) 2000年第5期13卷 1093-1100页

作者： G.j.Xu j.C.He The Key Laboratory of National Education Ministry for Electromagnetic Processing of Materials Northeastern UniversityShenyang 110006China

A thermo-simulation experimental continuous caster was established to study the effect of two static magnetic fields imposed the whole width of the mold on the molten metal flow. Low melting point Bi-Pb-Sn alloy and silicon oil were adopted to simulate the molten metal and mold powder respectively. The results show that the control effect of electromagnetic fields on the molten metal flow in the different zones of mold is different. Therefore it is important to study and design new types of magnetic fields to satisfy the request of controlling the molten metal flow in the mold.

关键词： continuous casting mold magnetic field flow control

Divergence in the ovipositional behavior of the Papilio glaucus group

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Insect Science 2008年第4期15卷 361-367页

作者： Rodrigo j. Mercader j. Mark Scriber Department of Entomology Michigan State University East Lansing MI48824 USA

This study contrasts the ovipositional profiles of four members of the Papilio glaucus group, P. glaucus, P. multicaudatus, P. canadensis, and P. rutulus. we used seven choice oviposition bioassays containing leaves from hosts in seven plant families utilized by members of the P. glaucus group. Specifically, we contrast the overall ovipositional profiles of these species and their acceptance of a host in a novel plant family （Populus tremuloides： Salicaceae） and a host in a putatively ancestral host plant family （Liriodendron tulipifera： Magnoliaceae）. Significant differences were observed between the ovipositional profiles of P. glaucus and P. multicaudatus relative to each other and to P. canadensis and P. rutulus. In contrast, no significant differences were observed between the ovipositional profiles of P. canadensis and P. rutulus, which were also the only species that accepted P. tremuloides. Unlike the acceptance of P. tremuloides, the acceptance of L. tulipifera was present throughout the group despite the inability of the larvae of most species in the group to utilize this host. These results support the prediction of the ＂hierarchical threshold model＂ that ancestral host plants are likely to be retained in the ovipositional hierarchy while novel hosts should only be accepted by derived populations.

关键词： host preference insect-plant interactions Lepidoptera Papilionidae