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Enhancing the CO_(2) methanation activity of Ni/CeO_(2) via activation treatment-determined metal-support interaction

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Journal of Energy Chemistry 2021年第8期30卷 334-342,I0008页

作者： Shuangxi Lin Ziwen Hao Jindong Shen Xiao Chang Shouying Huang Maoshuai Li Xinbin Ma Key Laboratory for Green Chemical Technology of Ministry of Education Collaborative Innovation Center of Chemical Science and EngineeringSchool of Chemical Engineering and TechnologyTianjin University300350 TianjinChina

The metal-support interaction is of critical importance to enhance the catalytic activity and ***,it is still challenging to construct an appropriate interaction starting from the catalyst fabrication and/or *** herein established low-temperature treatment of Ni^(2+)ions impregnated on ceria in reductive atmosphere and reduction-oxidation cycles as effective approachs to regulate the metal-support interaction and raise the catalytic performance in the CO_(2)*** proposed construction approach yielded Ni/Ce O_(2)that displayed highly dispersed Ni nanoparticles in contact with Ce O_(2)(111)and(100)facet,higher density of surface oxygen vacancies and larger amounts of weak basic sites relative to the reference samples,which increased the capacity for H2 and CO_(2)adsorption/*** interaction resulted in appreciably(2-3 fold)higher activity in the CO_(2)methanation with maintaining almost full selectivity to CH4 and high *** of Ni surface by Ce O_(2)-x thin layer as a typical structure of strong metal-support interaction resulting from high-temperature reduction,can be alleviated via reduction-oxidation *** also demonstrate the activation treatment-determined metalsupport interaction effect can generally extend to(Ti O_(2)and Zr O_(2))supported Ni catalysts.

关键词： CO_(2)methanation Nickel Ceria Metal-support interaction thermal treatment Reduction-oxidation cycles

IMPACT PROPERTIES OF METALLOCENE - CATALYZED ETHYLENE-α-OLEFIN COPOLYMERS

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Chinese Journal of Polymer Science 2002年第5期20卷 473-480页

作者： Xu-rong Xu Jun-ting Xu Lin-xian Feng Department of Polymer Science and Engineering Zhejiang University Hangzhou 310027,China Department of Polymer Science and Engineering College of Chemistry & Molecular Engineering Peking University Beijing 100871, China Department of Polymer Science and Engineering Zhejiang University Hangzhou 310027

The impact properties of two selected metallocene-catalyzed ethylene-butene copolymers and one conventionalcopolymer were evaluated using Izod impact test. It is found that the metallocene-catalyzed copolymer shows superior impactproperties. This result was explained on the basis of the more homogeneous inter-molecular composition distribution andnarrower molecular weight distribution, which leads to more homogeneous morphology with fewer defects. Stepwisecrystallization improves the impact properties, especially in the crack propagation process, to a large extent. This is due to thedecrease of entanglements by stepwise crystallization, which is advantageous for the chain slip and shear. The polymer withheterogeneous intra-molecular composition distribution exhibits a more evident improvement of impact properties understepwise crystallization.

关键词： Metallocene-catalyzed ethylene-butene copolymer Impact properties Molecular heterogeneities thermal treatment

Effects of thermal treatments on Helium Retention and thermal Desorption Behaviors in a V-4Ti Aalloy

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Southwestern Institute of Physics Annual Report

Southwestern Institute of Physics Annual Report 2004年第1期 102-105页

作者： LIU Xiang T. Yamada T. Hino Hokkaido University Japan 不详

Vanadium alloys are considered as the promising first wall and structure materials of the future fusion reactors owing to their perfect low neutron-induced radioactivity and good high temperature performance. Helium retention and thermal desorption behaviors are key issues for the applications of vanadium alloys in fusion reactors since helium can be produced by helium discharge cleaning and neutron transmutation. A. van Veen groupt investigated helium trapping and thermal desorption mechanisms in vanadium alloys by using 1 keV helium ion irradiation to the fluence of 10^13～10^14He/cm^2, and the influenee of pre-annealing treatments on helium trapping. Two group of peaks were found at the thermal helium desorption spectrum. They thought one was due to helium-vacancyimpurity clusters and the other was corresponding to helium trapping into pre-existing traps, such as fine-size precipitates.

关键词： Vanadium alloy TDS thermal treatment

Relation between silico-aluminous fly ash and its coal of origin

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Particuology 2008年第2期6卷 85-92页

作者： Jean-Charles Benezet Pierre Adamiec Ali Benhassaine Ecole des Mines d'Alès 6 Avenue de Clavieres30319 ALES CedexFrance

Fly ashes are typical complex solids which incorporate at the same time intrinsic properties derived from the layers （various mineralogical and dimensional spectra） and major transformations generated during prior processing. To use fly ashes in various applications, it is necessary to characterise them completely. The first research to date carried out on silico-aluminous fly ashes in order to characterise them physically, morphologically, chemically and mineralogically, resulted in the recognition that they are relatively simple materials. In the present study, a silico-aluminous fly ash coming from the power station of Albi （France） was selected. Heat treatment at 450 and 1200℃ together with coal simulated the treatment undergone by coal in the power station in order to mimic real coal residue. In conclusion, the diversity of the particles contained in fly ash could only be exolained by the relation existing between the fly ash and its coal of origin.

关键词： Fly ash Selection thermal treatment

thermal stabilization of chromium slag by sewage sludge: Effects of sludge quantity and temperature

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Journal of Environmental Sciences 2010年第7期22卷 1110-1115页

作者： Changlin Wu,Hua Zhang,Pinjing He,Liming Shao State Key Laboratory of Pollution Control and Resources Reuse,Key Laboratory of Yangtze River Water Environment,College of Environmental Science & Engineering,Tongji University,Shanghai 200092,China. State Key Laboratory of Pollution Control and Resources Reuse Key Laboratory of Yangtze River Water Environment College of Environmental Science & Engineering Tongji University Shanghai 200092 China. E-mail: solidwaste@***

To investigate the feasibility of detoxifying chromium slag by sewage sludge, synthetic chromium slag containing 3% of Cr（Ⅵ） was mixed with sewage sludge followed by thermal treatment in nitrogen gas for stabilizing chromium. The effects of slag to sludge ratio （0.5, 1 and 2） and temperature （200, 300, 500, 700 and 900℃） on treatment efficiency were investigated. During the mixing process before thermal treatment, 59.8%-99.7% of Cr（Ⅵ） was reduced, but Cr could be easily leached from the reduction product. Increasing heating temperature and decreasing slag to sludge ratio strengthened the reduction and stabilization of Cr（Ⅵ）. When the slag to sludge ratio was 0.5 and thermal treatment temperature was 300℃, the total leached Cr and Cr（Ⅵ） declined to 0.55 mg/L and 0.17 mg/L respectively, and 45.5% of Cr in the thermally treated residue existed as residual fraction. A two-stage mechanism was proposed for the reduction and stabilization of Cr.

关键词： chromium slag sewage sludge reduction detoxification thermal treatment leached concentration

Metagenomic insights into microorganisms and antibiotic resistance genes of waste antibiotic fermentation residues along production,storage and treatment processes

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Journal of Environmental Sciences 2024年第2期136卷 45-55页

作者： Ziming Han Xiao Luan Haodi Feng Yanqin Deng Min Yang Yu Zhang State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China National Engineering Research Center of Industrial Wastewater Detoxication and Resource Recovery Beijing 100085China Wuhan Agricultural Inspection Center Wuhan 430016China University of Chinese Academy of Sciences Beijing 100049China

Antibiotic fermentation residue(AFR)is nutrient-rich solid waste generated from fermentative antibiotic production *** is demonstrated that AFR contains high-concentration of remaining antibiotics,and thus may promote antibiotic resistance development in receiving environment or feeding farmed ***,the dominate microorganisms and antibiotic resistance genes(ARGs)in AFRs have not been adequately explored,hampering understanding on the potential antibiotic resistance risk development caused by ***,seven kinds of representative AFRs along their production,storage,and treatment processes were collected,and multiple methods including amplicon sequencing,metagenomic sequencing,and bioinformatic approaches were adopted to explore the biological characteristics of *** expected,antibiotic fermentation producer was found as the predominant species in raw AFRs,which were collected at the outlet of fermentation ***,except for producer species,more environment-derived species persisted in stored AFRs,which were temporarily stored at a semi-open *** genus,classified as Firmicutes phylum and Bacilli class,became predominant bacterial taxa in stored AFRs,which might attribute to its tolerance to high concentration of *** from metagenomic sequencing together with assembly and binning approaches showed that these newly-colonizing species(e.g.,Lactobacillus genus)tended to carry ARGs conferring resistance to the remaining ***,after thermal treatment,remaining antibiotic could be efficiently removed from AFRs,and microorganisms together with DNA could be strongly *** sum,the main risk from the AFRs was the remaining antibiotic,while environment-derived bacteria which tolerate extreme environment,survived in ARFs with high content antibiotics,and may carry ***,hydrothermal or other harmless treatment technologies are recommended to remove antibiotic content and inactivate bacteria befor

关键词： Pharmaceutical manufacturing Antibiotic mycelia residue Antibiotic resistance bacteria thermal treatment Solid waste

Mine tailings as a raw material in alkali activation: A review

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International Journal of Minerals,Metallurgy and Materials 2020年第8期27卷 1009-1020页

作者： Jenni Kiventerä Priyadharshini Perumal Juho Yliniemi Mirja Illikainen Fibre and Particle Engineering Research Unit University of OuluPentti Kaiteran Katu 190014 OuluFinland

The mining industry produces billions of tons of mine tailings ***,because of their lack of economic value,most of the tailings are discarded near the mining sites,typically under *** primary environmental concerns of mine tailings are related to their heavy metal and sulfidic mineral *** of sulfidic minerals can produce acid mine drainage that leaches heavy metals into the surrounding *** management of tailing dams requires expensive construction and careful control,and there is the need for stable,sustainable,and economically viable management *** activation as a solidification/stabilization technology offers an attractive way to deal with mine *** activated materials are hardened,concrete-like structures that can be formed from raw materials that are rich in aluminum and silicon,which fortunately,are the main elements in mining ***,alkali activation can immobilize harmful heavy metals within the *** review describes the research on alkali activated mine *** reactivity and chemistry of different minerals are *** many mine tailings are poorly reactive under alkaline conditions,different pretreatment methods and their effects on the mineralogy are *** applications for these materials are also discussed.

关键词： Mine tailings alkali activation thermal treatment mechanical activation alkaline fusion heavy metal immobilization

Preparation of Self-limiting Heating Cables with Excellent Processability, Mechanical Properties and PTC Effect via thermal and Electrical treatments

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Chinese Journal of Polymer Science 2024年第4期42卷 511-520页

作者： Tian-Hao Yang Tong Wu Qiang Fu State Key Laboratory of Polymer Materials Engineering College of Polymer Science and EngineeringSichuan UniversityChengdu610065China State Key Laboratory of Polymer Materials Engineering Polymer Research Institute of Sichuan UniversityChengdu610065China

Polymer/conductive filler composites have been widely used for the preparation of self-limiting heating cables with the positive temperature coefficient (PTC) effect. The control of conductive filler distribution and network in polymer matrix is the most critical for performance of PTC materials. In order to compensate for the destruction of the filler network structure caused by strong shearing during processing, an excessive conductive filler content is usually added into the polymer matrix, which in turn sacrifices its processability and mechanical properties. In this work, a facile post-treatment of the as-extruded cable, including thermal and electrical treatment to produce high-density polyethylene (HDPE)/carbon black (CB) cable with excellent PTC effect, is developed. It is found for the as-extruded sample, the strong shearing makes the CB particles disperse uniformly in HDPE matrix, and 25 wt% CB is needed for the formation of conductive paths. For the thermal-treated sample, a gradually aggregated CB filler structure is observed, which leads to the improvement of PTC effect and the notable reduction of CB content to 20 wt%. It is very interesting to see that for the sample with combined thermal and electrical treatment, CB particles are agglomerated and oriented along the electric field direction to create substantial conductive paths, which leads to a further decrease of CB content down to 15 wt%. In this way, self-limiting heating cables with excellent processability, mechanical properties and PTC effect have simultaneously been achieved.

关键词： Self-limiting heating cables Positive temperature coefficient thermal treatment Electrical treatment

Semisolid joining of aluminum A356 alloy by partial remelting and mechanical stirring

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Transactions of Nonferrous Metals Society of China 2010年第9期20卷 1792-1798页

作者： S.M.J.ALVANI H.AASHURI A.KOKABI R.BEYGI Materials Science and Engineering Department Sharif University of Technology

A method to reach the globular weld structure of A356 aluminum alloy using stirring the localized semisolid zone during butt-joining is *** the heat conductivity of this alloy is very high, the accurate controlling of temperature during joining must be considered.A gas heating system was used to heat up the nitrogen gas up to the required temperature.A dried and free oxygen gas was prepared when a stream of nitrogen gas could pass closely around a hot *** and pure nitrogen gas flow through a precise ceramic nozzle was used to create a localized semisolid *** this stage a fine stirrer was introduced into the weld seam in order to mix the two sides into a single uniform *** were moved in direction of joint line by a small trolley to avoid the deviation of nozzle from the joint line and its distance and angle from the substrate.A fixture system was used to hold two substrates together on the trolley.A narrow hot plate was located on the trolley to heat up the joint line due to high heat conductivity of *** of gas temperature was investigated on the microstructure and mechanical properties of weld *** showed that increase in temperature promoted the final welding properties, and also at liquid fractions less than 50% joining was not fully *** best mechanical properties were achieved with liquid fraction of about 70%.

关键词： semisolid joining A356 localized stirring shear punch semi-solid holding thermal treatment