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Effect of Cerium on Mechanical Properties and Morphology of ZZn4-1 Alloy

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Journal of Rare Earths 2000年第2期18卷 120-123页

作者：李亚国朱奕庆薛涛刘海林李平 Guizhou research centre of Physical testing and Chemical Analysis Guiyang 550002 China Guiyang Steel Mill Guiyang 550002 China

Effect of the addition of cerium in appropriate amount on the mechanical properties and morphology of ZZn4-1 alloy was investigated. In the case of samples collected from metal mould, the results show that the addition of cerium in appropriate amount can increase tensile strength and HE hardness, and can refine the microstructure of ZZn4-1 alloy considerably. In the case of samples collected from pressure die-casting, the addition of cerium in appropriate amount can refine the primary eta-phase and the eutectic structure of pressure die-casting and improve mechanical and processing properties of the alloy.

关键词： rare earths cerium zinc alloy

Critical Role of Silicon in Directing the Bio-inspired Mineralization of Gelatin in the Presence of Hydroxyapatite

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Journal of Bionic Engineering 2021年第6期18卷 1413-1429页

作者： Ruijuan Yao Yao Wang Bo Zhang Juan Liu Nihui Zhang Jing He Guolong Meng Bo Jiang Shanling Wang Fang Wu National Engineering research centre for Biomaterials Sichuan UniversityChengdu 610064China Analytical and testing Center Sichuan UniversityChengdu 601165China

Significant progress has been made on understanding the critical role of organic components in directing the collagen *** hypothesize that the inorganic trace elements might also play important role in the mineralization of collagenous *** this aim,we systematically compared the in-vitro biomineralization behaviors of gelatin,gelatin-HA and gelatin-SiHA electrospun *** results indicated that the presence of Si ions played a striking influence on the nucleation behaviors and mineralized *** gelatin-SiHA samples demonstrated more homogeneous nucleation within the gelatin fiber and growth along the fiber direction,in comparison with the heterogeneous nucleation and growth of spherulitic clusters on top of the nanofiber surface,*** *** likely shift of the nucleation mode to the intrafibrillar mineralization in the presence of Si ions led to good alignment of apatite c-axis with the long axis of the nanofiber,resulting in a mineralization process and microstructure that were closer to those in natural *** response analysis indicated that Si incorporation improved the MSC attachment and cytoskeleton *** findings might have important implication in both understanding the complex mechanisms involved in collagen mineralization and optimal designing of advanced bio-inspired materials with potential superior mechanical and biological properties.

关键词： Silicon Hydroxyapatite Biomineralization Electrospinning Nanofiber Gelatin

Angular-based spatially resolved laser-induced breakdown spectroscopy: a new technique for the effective enhancement of signals without an external time delay system

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Chinese Science Bulletin 2014年第27期59卷 3377-3384页

作者： Qingyu Lin Xu Wang Guanghui Niu Hongjun Lai Xiaoqin Zhu Kunping Liu Tao Xu Yixiang Duan research Center of Analytical Instrumentation Analytical & Testing Centre Sichuan University College of Chemistry and Bioengineering Hezhou University

In this study, we developed a novel angularbased spatially resolved laser-induced breakdown spectroscopy(ABSR-LIBS) technique. This new method allows the spatially resolved spectroscopic properties of laserinduced plasma to be investigated using different angles and polar distances with a spatially adjustable fiber optics probe. The experimental evaluations suggested that the intensity of the Al signal distributions in the ‘‘side-view''depended greatly on the angle of the collection probe. The location of a collection probe at 50° would facilitate efficient spectral collection and minimize the disturbance of the plasma plume. The spectral signals in the plasma emissions had different distribution at various polar distances using the same collection angle, and the highest signal intensity was observed between 15 and 35 mm polar distances. This ABSR-LIBS technique improved both the LIBS signal and the maximum emission intensity of Al atoms by several times at the best spatial position in our experimental conditions. Furthermore, we successfully obtained well-resolved line emission spectroscopy signals without any external time delay using a nongated spectrometer based on the ABSR-LIBS system. We consider that the ABSR-LIBS technique has great potential for obtaining new insights with laser-induced plasma instruments and it could facilitate the development of a low-cost instrument.

关键词：激光诱导等离子体空间分辨光谱性质时滞系统信号分布技术击穿等离子发射

Accumulation of heavy metals in stemwood of forest tree plantations fertilized with different sewage sludge doses

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Journal of Forestry research 2018年第2期29卷 345-359页

作者： Marius Praspaliauskas Nerijus Pedisius Audrius Gradeckas Laboratory of Heat-Equipment research and testing Lithuanian Energy Institute Laboratory of Forest Plant and Biotechnology Institute of Forestry Branch of Lithuanian Research Centre for Agriculture and Forestry

The levels of heavy metals that accumulated in stemwood of mature trees grown for 20 years in a plantation in an abandoned peat quarry in areas that were fertilized with different amounts of domestic sewage sludge(180,360,and720 Mg ha-1on a dry basis) were compared with trees grown in a reference nonfertilized *** in the study was a hybrid poplar(Populus tremula x Populus tremuloides) developed for use as an energy crop,three local tree species and one introduced tree *** concentrations of Cd,Cr,Cu,Ni,Pb and Zn in the stemwood of the trees grown in the fertilized and nonfertilized fields were determined,and found to be significantly lower than their respective concentrations in the *** and Cr were found only in several wood samples at concentrations close to the limits of detection or qualification; therefore,they were not analyzed further.A correlation analysis suggested that 75%of the correlations between the concentrations of heavy metals in the stemwood and the concentrations in the soil were *** ability of trees to accumulate the metals from soil in most cases decreased for Cu and Ni; however,the correlations were not as clear for Pb and *** followingsequence for the levels of heavy metals found in the stemwood of the analysed trees was Zn [ Pb [ Ni [ Cu [(Cr,Cd).The results of this study showed that the levels of heavy metals in the studied wood would not exceed the permitted limits of heavy metal pollution in the air and ash when used for energy production.

关键词： Forest tree plantation Accumulation factor Saturation limit Biosolids Heavy metals Long-term field experiments Biofuels

testing TECHNOLOGY OF OXYGEN IN MINERALS WITH EPMA

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Journal of Wuhan University of Technology(Materials Science) 1998年第3期13卷 30-33页

作者：叶先贤 Wuhan University of Technology China Mat. research and testing centre Wuhan Univ. of Tech. Wuhan 430070 China

EPMA has used to measure oxygen con- tent directly in recentyears. This paper discusses the fac- tors affecting the quantitativeanalysis of oxygen content and the optimal experimental conditions,and gives some measure... 详细信息

关键词： oxygen testing technology EPMA experimental conditions

Microbial electricity-driven anaerobic phenol degradation in bioelectrochemical systems

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Environmental Science and Ecotechnology 2024年第1期17卷 40-47页

作者： Shixiang Dai Falk Harnisch Micjel Chávez Morejòn Nina Sophie Keller Benjamin Korth Carsten Vogt Department of Environmental Microbiology Helmholtz Centre for Environmental Research GmbH-UFZLeipzigGermany Department of Isotope Biogeochemistry Helmholtz Centre for Environmental Research GmbH-UFZLeipzigGermany

Microbial electrochemical technologies have been extensively employed for phenol ***,previous research has yielded inconsistent results,leaving uncertainties regarding the feasibility of phenol degradation under strictly anaerobic conditions using anodes as sole terminal electron *** this study,we employed high-performance liquid chromatography and gas chromatography-mass spectrometry to investigate the anaerobic phenol degradation *** findings provide robust evidence for the purely anaerobic degradation of phenol,as we identified benzoic acid,4-hydroxybenzoic acid,glutaric acid,and other metabolites of this ***,no typical intermediates of the aerobic phenol degradation pathway were ***-chamber reactors(t0.4 V ***)exhibited a phenol removal rate of 3.5±0.2 mg L^(-1) d^(-1),while two-chamber reactors showed 3.6±0.1 and 2.6±0.9 mg L^(-1) d^(-1) at anode potentials of t0.4 and t 0.2 V,*** results also suggest that the reactor configuration certainly influenced the microbial community,presumably leading to different ratios of phenol consumers and microorganisms feeding on degradation products.

关键词： Microbial electroremediation Geobacter Extracellular electron transfer Anaerobic phenol degradation Microbial syntrophy

Effect of deep cryogenic treatment on the microstructural,mechanical and ballistic properties of AA7075-T6 aluminum alloy

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Defence Technology（防务技术） 2023年第12期30卷 101-110页

作者： S.Dharani kumar U.Magarajan Saurabh S Kumar Rodríguez-Millan M centre for Machining and Material testing KPR Institute of Engineering and TechnologyCoimbatoreIndia Department of Mechanical Engineering Sri Venkateswara College of EngineeringChennaiIndia Scientific Officer Ballistic Research Centre&Testing RangeNational Forensic Sciences UniversityGandhi NagarIndia Department of Mechanical Engineering University Carlos Ⅲ of MadridLeganesMadridSpain

The study focused on investigating the effect of Deep Cryogenic Treatment(DCT)on the mechanical and ballistic properties of AA7075-T6 aluminum *** microstructure,microhardness,tensile strength,and impact strength of the Base Material(BM)and DCT-treated 7075 samples were analyzed through metallographic analysis and mechanical *** microstructure of the DCT-treated 7075 samples revealed fine grains and a distribution of secondary phase *** tensile strength,impact strength,and microhardness of DCT-treated samples increased by 7.41%,4%,and 9.68%,respectively,compared to the BM *** fractography analysis of the tensile samples showed cleavage facets,microvoids,and dimples in both the *** ballistic behavior of the BM and DCT target plates were studied by impacting hard steel core projectiles at a velocity of 750±10 m/*** target plates failed due to petaling and ductile hole enlargement,and the depth of penetration(DOP)of the DCT target was less than that of the BM target,indicating a higher ballistic *** post-ballistic microstructure examination of the target plates showed the formation of an Adiabatic Shear Band(ASB)without any *** was concluded that the DCT treatment improved the mechanical and ballistic properties of the aluminum alloy due to grain refinement and high dislocation density.

关键词： Deep cryogenic treatment AA7075-T6 Mechanical properties Ballistic Adiabatic shear band

Optical tracking of picosecond coherent phonon pulse focusing inside a sub-micron object

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Light(Science & Applications) 2016年第1期5卷 653-659页

作者： Thomas Dehoux Kenichi Ishikawa Paul H Otsuka Motonobu Tomoda Osamu Matsuda Masazumi Fujiwara Shigeki Takeuchi Istvan A Veres Vitalyi E Gusev Oliver B Wright Institut Lumière Matière UMR5306UniversitéLyon 1-CNRSUniversitéde Lyon69622 VilleurbanneFrance Division of Applied Physics Faculty of EngineeringHokkaido UniversitySapporo 060-8628Japan research Institute for Electronic Science Hokkaido UniversitySapporo 001-0020Japan School of Science and Technology Kwansei Gakuin UniversitySandaHyogo 669-1337Japan Department of Electronic Science and Engineering Kyoto UniversityKyoto 615-8510Japan research centre for non-destructive testing gmbh Altenberger Strasse 69A-4040 LinzAustria Laboratoire d'Acoustique de l'Université du MaineLe Mans 72085France

By means of an ultrafast optical technique,we track focused gigahertz coherent phonon pulses in objects down to sub-micron in *** light pulses illuminating the surface of a single metal-coated silica fibre generate longitudinal-phonon wave *** of visible probe light pulses from the fibre surface allows the vibrational modes of the fibre to be detected,and Brillouin optical scattering of partially transmitted light pulses allows the acoustic wavefronts inside the transparent fibre to be continuously *** thereby probe acoustic focusing in the time domain resulting from generation at the curved fibre *** analytical model,supported by three-dimensional simulations,suggests that we have followed the focusing of the acoustic beam down to a~150-nm diameter waist inside the *** work significantly narrows the lateral resolution for focusing of picosecond acoustic pulses,normally limited by the diffraction limit of focused optical pulses to~1μm,and thereby opens up a new range of possibilities including nanoscale acoustic microscopy and nanoscale computed tomography.

关键词： acoustic–optic fibre optical scattering picosecond ultrasonics

Flow and heat transfer behaviour of nanofluids in microchannels

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Progress in Natural Science:Materials International 2018年第2期28卷 225-234页

作者： James Bowers Hui Cao Geng Qiao Qi Li Gan Zhang Ernesto Mura Yulong Ding SSE Engineering centre Birmingham centre for Energy Storage & School of Chemical Engineering University of Birmingham Global Energy Interconnection research Institute Europe gmbh

Flow and heat transfer of aqueous based silica and alumina nanofluids in microchannels were experimentally investigated. The measured friction factors were higher than conventional model predictions at low Reynolds numbers particularly with high nanoparticle concentrations. A decrease in the friction factor was observed with increasing Reynolds number, possibly due to the augmentation of nanoparticle aggregate shape arising from fluid shear and alteration of local nanoparticle concentration and nanofluid viscosity. Augmentation of the silica nanoparticle morphology by fluid shear may also have affected the friction factor due to possible formation of a core/shell structure of the particles. Measured thermal conductivities of the silica nanofluids were in approximate agreement with the Maxwell-Crosser model, whereas the alumina nanofluids only showed slight enhancements. Enhanced convective heat transfer was observed for both nanofluids, relative to their base fluids(water), at low particle concentrations. Heat transfer enhancement increased with increasing Reynolds number and microchannel hydraulic diameter. However, the majority of experiments showed a larger increase in pumping power requirements relative to heat transfer enhancements, which may hinder the industrial uptake of the nanofluids, particularly in confined environments, such as Micro Electro-Mechanical Systems(MEMS).

关键词： Nanofluid Microchannel Heat transfer Pressure drop Friction factor Thermal conductivity Viscosity