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Fabrication of an r-Al_2Ti intermetallic matrix composite reinforced with α-Al_2O_3 ceramic by discontinuous mechanical milling for thermite reaction

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International Journal of minerals,metallurgy and materials 2014年第10期21卷 1037-1043页

作者： A.mosleh m.Ehteshamzadeh R.Taherzadeh mousavian Department of materials Science and Engineering Shahid Bahonar University of Kerman Department of metallurgy Zanjan Branch Islamic Azad University

In this study, a powder mixture with an Al/TiO2 molar ratio of 10/3 was used to form an r-Al2Ti intermetallic matrix composite （ImC） reinforced with α-Al2O3 ceramic by a novel milling technique, called discontinuous mechanical milling （Dmm） instead of milling and ignition of the produced thermite. The results of energy dispersive X-ray spectroscopy （EDX） and X-ray diffraction （XRD） of samples with varying milling time indicate that this fabrication process requires considerable mechanical energy. It is shown that Al2Ti-α-Al2O3 ImC with small grain size was produced by Dmm after 15 h of ball milling. Peaks for γ-TLA1 as well as Al2Ti and Al2O3 are observed in XRD patterns after Dmm followed by heat treatment. The microhardness of the Dmm-treated composite produced after heat treatment was higher than Hv 700.

关键词： composite materials intermetallics alumina titanium aluminide ball milling thermite reaction process

Tungsten carbide coatings with different binders prepared by low power plasma spray system

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中国有色金属学会会刊：英文版 2004年第z1期14卷 77-82页

作者： GAO Yang m.F.morks FU Ying-qing materials and Technology Institute Dalian Maritime University Dalian 116026 China Materials and Technology Institute Dalian Maritime University Dalian 116026 China Central metallurgical Research and Development Institute P.O. Box 87 Helwan El-Tibben Cairo Egypt Materials and Technology Institute Dalian Maritime University Dalian 116026 China

Thermal spraying of cermet coatings is widely used for protection of machining parts against wear and corrosion. These coatings consist of WC particles in metal binders such as Co, Cr and Ni. Three kinds of WC powders with different metal binders (Co, NiCr and CoCr) were sprayed by low power plasma spray system on Al-Si-Cu alloy substrate. Fundamental aspects of sprayed cermet coatings, including (i) the effects of binder type on the coating structure, (ii) the hardness and (iii) the microstructure, were investigated. All cermet coatings have the same phase structure such as WC and W2 C. However, the intensities of these phases are different in each coating, mainly due to the difference in solidification rate in each case. moreover, the hardness measurements are found to be different in each coating. The results show that, binder type has a significant effect on the physical and mechanical properties of the sprayed coatings.

关键词： tungsten carbide binders aluminum alloy substrate hardness microstructure

Decomposition of trifluoromethane in a dielectric barrier discharge non-thermal plasma reactor

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Journal of Environmental Sciences 2012年第7期24卷 1234-1239页

作者： m. Sanjeeva Gandhi Y. S. mok Department of Chemical and Biological Engineering Jeju National University

The decomposition of trifluoromethane （CHF3） was carried out using non-thermal plasma generated in a dielectric barrier discharge （DBD） reactor. The effects of reactor temperature, electric power, initial concentration and oxygen content were examined. The DBD reactor was able to completely destroy CHF3 with alumina beads as a packing material. The decomposition efficiency increased with increasing electric power and reactor temperature. The destruction of CHF3 gradually increased with the addition of O2 up to 2%, but further increase in the oxygen content led to a decrease in the decomposition efficiency. The degradation pathways were explained with the identified by-products. The main by-products from CHF3 were found to be COF2, CF4, CO2 and CO although the COF2 and CF4 disappeared when the plasma were combined with alumina catalyst.

关键词： trifluoromethane plasma alumina dielectric barrier discharge decomposition

Influence of alkaline treatment and fiber loading on the physical and mechanical properties of kenaf/polypropylene composites for variety of applications

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Progress in Natural Science:materials International 2016年第6期26卷 657-664页

作者： majid Niaz Akhtar Abu Bakar Sulong m.K.Fadzly Radzi N.F.Ismail m.R.Raza Norhamidi muhamad muhammad Azhar Khan Department of Physics COMSATS Institute of Information Technology Department of mechanical and materials Engineering Faculty of Engineering and Built EnvironmentUniversiti Kebangsaan Malaysia Department of Basic Sciences and Humanities Muhammad Nawaz Sharief University of Engineering and Technology(MNSUET) Department of mechanical Engineering COMSATS Institute of Information Technology Department of Physics The Islamia University of Bahawalpur

Due to current trend and increasing interest towards natural based fiber products, Kenaf(Hibiscus cannabinus)fibers have been used for the developments of many products. Therefore, Kenaf fiber-reinforced composites have been widely used in engineering and industrial applications. The present work deals with the fabricating and characterization of untreated and treated kenaf/polypropylene(PP)-reinforced composites. Composites of PP reinforced with treated and untreated kenaf fibers were fabricated using the injection molding *** fiber loadings of 10, 20, 30, 40, 50 wt% treated and untreated kenaf composites were also prepared. Xray diffraction(XRD), scanning electron microscopy(SEm), Fourier transform infrared(FTIR) spectroscopy and thermo gravimetric analysis(TGA) were performed on the treated, untreated kenaf fibers and kenaf/PP composites. moreover, the alkaline-treated kenaf composites exhibit better physical, morphological, and mechanical properties because of the compatibility of kenaf with PP. However, variations in tensile and flexural properties depend on treatment and kenaf fiber contents. The percentage increase in the mechanical properties of the treated kenaf/PP composites relative to that of PP was also measured. In addition, 40 wt%kenaf fiber loading resulted in higher mechanical properties. By contrast, kenaf/PP composite with 50% fiber loading was not successfully prepared because of improper mixing and the burning of kenaf fibers in the PP matrix. To conclude, 40% kenaf/PP composites with superior physical and mechanical properties may be used in variety of applications such as automotive, sports, construction, animal bedding, and mass production industries.

关键词： Kenaf composites microstructures Physical properties mechanical Testing Injection-molding

The foraging behavior of japanese macaques macaca fuscata in a forested enclosure: Effects of nutrient composition,energy and its seasonal variation on the consumption of natural plant foods

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Current Zoology 2010年第2期56卷 198-208页

作者： m.Firoj jamAN michael A.HUFFmAN Hiroyuki TAKEmOTO Primate Research Institute Kyoto University Department of Zoology University of Dhaka

In the wild, primate foraging behaviors are related to the diversity and nutritional properties of food, which are affected by seasonal variation. The goal of environmental enrichment is to stimulate captive animals to exhibit similar foraging behavior of their wild counterparts, e.g. to extend foraging time. We conducted a 12-month study on the foraging behavior of japanese macaques in a semi-naturally forested enclosure to understand how they use both provisioned foods and naturally available plant foods and what are the nutritional criteria of their consumption of natural plants. We recorded time spent feeding on provisioned and natural plant foods and collected the plant parts ingested of their major plant food species monthly, when available. We conducted nutritional analysis （crude protein, crude lipid, neutral detergent fiber-‘NDF＇, ash） and calculated total non-structural carbohydrate - ‘TNC＇ and total energy of those food items. monkeys spent 47% of their feeding time foraging on natural plant species. The consumption of plant parts varied significantly across seasons. We found that leaf items were consumed in months when crude protein, crude protein-to-NDF ratio, TNC and total energy were significantly higher and NDF was significantly lower, fruit/nut items in months when crude protein and TNC were significantly higher and crude lipid content was significantly lower, and bark items in months when TNC and total energy were higher and crude lipid content was lower. This preliminary investigation showed that the forested enclosure allowed troop members to more fully express their species typical flexible behavior by challenging them to adjust their foraging behavior to seasonal changes of plant item diversity and nutritional content, also providing the possibility for individuals to nutritionally enhance their diet .

关键词： Nutrition Food consumption Semi-natural vegetation Provisioned foods Captive primates Enrichment

Impacts of weaning weights and mycotoxin challenges on jejunal mucosa-associated microbiota,intestinal and systemic health,and growth performance of nursery pigs

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Journal of Animal Science and Biotechnology 2022年第5期13卷 1440-1457页

作者： D.m.Holanda S.W.Kim Department of Animal Science North Carolina State UniversityRaleigh 27695USA

Background:This study aimed at investigating the effects of mycotoxin challenge on the growth and physiology of nursery pigs with different weaning ***:At weaning,10 pigs were euthanized to collect jejunal mucosa and 90 pigs were assigned following a randomized complete block design in a 2×2 factorial arrangement of treatments with 3 pigs per *** were:weaning weight(light:body weight,BW9.0 kg);and dietary mycotoxins(supplementation of 0.2 mg/kg aflatoxins,2.0 mg/kg deoxynivalenol).All diets had titanium dioxide as an external marker at 0.5%.Growth performance and fecal score were recorded until pigs achieved 20 kg BW(light pigs average BW=21.1 kg and heavy pigs average BW=20.5 kg).Pigs were sampled for blood,ileal digesta,jejunal tissue and mucosa at 20 kg *** were analyzed using the mixed procedure of *** weaning,light pigs had decreased(Pmor necrosis factor-α,and increased(Pmucosa-associated *** 20 kg of BW,light pigs had decreased(Pmycotoxins decreased(Pmalondialdehydes and interleukin *** tended to increase(P=0.060)intestinal tumor necrosis factor-α.Conclusions:Nursery pigs with light weaning weight were more susceptible to jejunal inflammation and had impaired intestinal health due to weaning stress,whereas mycotoxins diminished the health and growth of nursery pigs regardless of weaning weight.

关键词： Growth Health mycotoxins Nursery pig Weaning weight

Emerging analytical methods to characterize zeolite-based materials

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National Science Review 2022年第9期9卷 47-66页

作者： Sophie H.van Vreeswijk Bert m.Weckhuysen Inorganic Chemistry and Catalysis Debye Institute for NanomaterialsUtrecht University

Zeolites and zeolitic materials are,through their use in numerous conventional and sustainable applications,very important to our daily lives,including to foster the necessary transition to a more circular *** characterization of zeolite-based materials has a tremendous history and a great number of applications and properties of these materials have been discovered in the past *** review focuses on recently developed novel as well as more conventional techniques applied with the aim of better understanding zeolite-based *** explored analytical methods,*** probe tomography,scanning transmission X-ray microscopy,confocal fluorescence microscopy and photo-induced force microscopy,are discussed on their important contributions to the better understanding of zeolites as they mainly focus on the micro-to nanoscale chemical imaging and the revelation of structure-composition-performance *** other techniques have a long and established history,*** magnetic resonance,infrared,neutron scattering,electron microscopy and X-ray diffraction techniques,and have gone through increasing developments allowing the techniques to discover new and important features in zeolite-based *** to the increasing application of these methods,multiple techniques are nowadays used to study zeolites under working conditions(*** in situ/operando mode of analysis) providing new insights in reaction and deactivation mechanisms.

关键词： catalysis zeolites spectroscopy microscopy structure–composition–performance relationships

Palaeoskapha sichuanensis gen. et sp. nov. (menispermaceae) from the Eocene Relu Formation in western Sichuan, West China

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植物分类学报 2007年第4期45卷 576-582页

作者： Frederic m. B. jaCQUES GUO Shuang-Xing museum National d＇Histoire Naturelle D~partement Histoire de la Terre CP 38 UMR 5143 - USM 0203 8 rue Buffon 75231 Pads Cedex 05 France Nanjmg Institute of Geology and Palaeontology the Chinese Academy of Sciences Nanjing 210008 China Kunming lnstitute of Botany the Chinese Academy of Sciences Ktmming 650204 China

Palaeoskapha sichuanensis gen. et sp. nov. of menispermaceae is described here for the first time based on a well preserved fossil fruit. The specimen was found in the Relu Formation of western Sichuan, West China. The specimen, straight, boat-shaped endocarp with large ventral condyle, clearly belongs to the tribe Tinosporeae. The wide aperture of the double condyle, combined with a whole shape not deeply invaginated, indicates a genus different from what was already known to science for this tribe. This fossil widens the distribution of the tribe during Eocene from North America and Europe to Asia, where it was formerly unknown.

关键词：防已科始新世四川群系新种植物化石果实

Kinetic Study on CO_2 Reforming of methane

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Chinese Journal of Chemical Engineering 2001年第2期9卷 190-195页

作者： C.E.Quincoces m.G.González Centro de Investigacion y Desarrollo en Procesos Cataliticos (CINDECA) 阿根廷

The kinetics of CO2 reforming of methane has been studied at 976－1033K on a commercial NiO/CaO/Al2O3 catalyst in a packed-bed continuous reactor. The reaction was carried out at atmospheric pressure and CO2/CH4 ratio ＞ 2. The Hougen-Watson rate models were fitted to experimental data assuming the disso ciative adsorption of methane as the rate-determining step. The reaction rate showed an effective reaction order of about unity for CH4. The apparent activity energy was found to be 104 kJ·mol-1. Therefore the kinetic reaction parameters were determined and a possible reaction mechanism was proposed.

关键词： CH4 reforming Ni catalysts syngas