检索结果-南通市图书馆

High-Temperature Oxidation Behavior of a Ni-Cr-W-Al Alloy

在线全文

学校读者我要写书评

暂无评论

journal of Materials Science & Technology 2011年第9期27卷 841-845页

作者： Y.C. Ma X.j. Zhao M. Gao K. Liu Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China

A study was conducted to examine the isothermal oxidation behavior of a new Ni-Cr-W-AI alloy in air at 1250℃ with different time. Oxidation kinetics was determined from weight-change measurements. The microstructure and composition of the oxide scale were investigated by means of scanning electron microcopy and X-ray diffraction. The results showed that the oxide scales of the alloy were a compact and continuous outer Cr2O3 and NiCr2O4 layer and an inner Al2O3 layer that was in dendrite shape. Oxides scales with good adherence were formed on the surface of the alloy, which made the alloy perform excellent high-temperature oxidation resistance.

关键词： Oxidation kinetics Oxide scale High-temperature oxidation resistance

Magnetic filtration of an iron oxide aerosol by means of magnetizable grates

在线全文

学校读者我要写书评

暂无评论

China Particuology 2007年第1期5卷 140-144页

作者： A. Alvaro j.M. Rodríguez Paulo A. Augusto A.M. Estvez Department of Chemical Engineering University of Salamanca Plaza de los Caídos 1-5 37008 Salamanca Spain Department of Chemical Engineering University of Salamanca Plaza de los Caídos 1-5 37008 Salamanca Spain Department of Chemical Engineering Faculty of Engineering University of Porto Rua Dr. Roberto Frias 4200-465 Porto Portugal

The cleaning of gases with low concentrations of small ferromagnetic or paramagnetic particles is a difficult task for conventional filtration. A new alternative procedure, magnetic filtration, is used in this work. Iron oxide aerosol was generated by elutriation of iron oxide particles from a fluidized bed consisting of a mixture of Geldart-C iron oxide powder and large spherical Geldart-B sand particles. The aerosol was filtered by means of a magnetic filter which consisted of one, two or three iron grates staggered to each other. The experimental installation contained also an isokinetic sampling system and a Microtrac SRA 150 Particle Analyser. A theoretical expression for filtration efficiency was deduced from a previous model taking into account the different forces acting on the iron oxide particles. Experimental filtration efficiency matches quite well calculated theoretical efficiency. It was found that an increase in particle size, in thee number of grates or in the applied magnetic field produced higher filtration efficiencies up to 100% in some cases. In all filtration experiments pressure drop through the magnetic filter was very small.

关键词： Iron oxide aerosol Magnetic filtration Iron grates

Nitrogen transformations during pig manure composting

在线全文

学校读者我要写书评

暂无评论

journal of Environmental Sciences 2001年第4期13卷 401-405页

作者： HUANG Guo-feng WU Qi-tang LI Fang-bai WONG j.W.C College of Natural Resources and Environment South China Agricultural UniversityWushanGuangzhou 510642 Department of Biology Hong Kong Baptist UniversityKowloonHKSAR

Composting is now suggested as one of the environmentally and friendly alternative method for disposal of solid organic wastes, as it leads to minimization, stabilization, and utilization of organic waste. Transformations of nitrogen were investigated in co-composting of pig manure with different amendments, such as sawdust and leaves. Samples were analyzed for pH, total-N, soluble NH4-N, soluble NO3-N and soluble organic-N. The total-N increased after 63 days of composting, as well as the soluble NO3-N and soluble organic-N. Soluble NH4,-N increased significantly and showed peak values at day 7, thereafter decreased sharply and gradually to lower levels. Seed germination index (GI) showed that co-composting of pig manure with sawdust reached maturity after 49 days of composting, while co-composting of pig manure with sawdust and leases required shorter time for 35 days. Soluble NH4-N was significantly negatively ( P < 0.05) , while soluble NO3-N and soluble organic-N were significantly positively ( P < 0.05), correlated with seed germination index (GI). Addition of leaves in co-composting of pig manure with sawdust had no significant impacts on nitrogen transformations, but it was beneficial for maturity of pig manure compost.

关键词： pig manure composting nitrogen transformation maturity

Immunological battlefield in gastric cancer and role of immunotherapies

在线全文

学校读者我要写书评

暂无评论

World journal of Gastroenterology 2016年第28期22卷 6373-6384页

作者： Minyu Wang Rita A Busuttil Sharon Pattison Paul j Neeson Alex Boussioutas Cancer Genetics and Genomics Laboratory Peter MacCallum Cancer Centre East Melbourne 3002 Victoria Australia Sir Peter MacCallum Department of Oncology The University of Melbourne Parkville 3050 Victoria Australia Department of Medicine The University of Melbourne Royal Melbourne Hospital Parkville 3050 Victoria Australia Department of Medicine Dunedin School of Medicine University of Otago Dunedin 9016 New Zealand Southern Blood and Cancer Service Southern District Health Board Dunedin 9054 New Zealand Cancer Immunology Research Peter MacCallum Cancer Centre East Melbourne 3002 Victoria Australia Pathology Department University of Melbourne Parkville 3050 Victoria Australia

Like the wars predating the First World War where human foot soldiers were deemed tools in the battlefield against an enemy, so too are the host immune cells of a patient battling a malignant gastric cancer. Indeed, the tumour microenvironment resembles a battlefield, where the patient's immune cells are the defence against invading tumour cells. However, the relationship between different immune components of the host response to cancer is more complex than an "us against them" model. Components of the immune system inadvertently work against the interests of the host and become pro-tumourigenic while other components soldier on against the common enemy – the tumour cell.

关键词： Immune Gastric cancer Immune therapy Immunology Tumour microenvironment

Biological approaches to the repair and regeneration of the rotator cuff tendon-bone enthesis:a literature review

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Biomaterials Translational 2023年第2期4卷 85-103页

作者： Ahlam A.Abdalla Catherine j.Pendegrass Institute of Sport Exercise and Health(ISEH)Division of Surgery&Interventional SciencesUniversity College LondonLondonUK Department of Orthopaedics&Musculoskeletal Science Division of Surgery&Interventional SciencesUniversity College LondonBrockley HillStanmoreUK

Entheses are highly specialised organs connecting ligaments and tendons to bones,facilitating force transmission,and providing mechanical strengths to absorb forces *** types of entheses,fibrocartilaginous and fibrous,exist in *** gradual fibrocartilaginous type is in rotator cuff tendons and is more frequently injured due to the poor healing capacity that leads to loss of the original structural and biomechanical properties and is attributed to the high prevalence of *** methodologies and outcomes of biological approaches are challenges to overcome for them to be routinely used in ***,stratifying the existing literature according to different categories(chronicity,extent of tear,and studied population)would effectively guide repair *** literature review supports tissue engineering approaches to promote rotator cuff enthesis healing employing cells,growth factors,and scaffolds *** suggest its promising role in animal studies as well as some clinical trials and that combination therapies are more beneficial than individualized *** then highlights the importance of tailoring interventions according to the tear extent,chronicity,and the population being *** factors such as loading,deficiencies,and lifestyle habits should also be taken into *** results can be achieved if biological,mechanical,and environmental factors are *** is challenging to determine whether variations are due to the interventions themselves,the animal models,loading regimen,materials,or tear *** research should focus on tailoring interventions for different categories to formulate protocols,which would best guide regenerative medicine decision making.

关键词： enthesis rotator cuff stem cells tissue engineering tendon-bone enthesis

Low Coercivity of Amorphous La-Co Films

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics Letters 1997年第12期14卷 943-945页

作者： ZHAO Tong-yun ZHAO jian-gao SHEN Bao-gen SHAN Zheng-sheng D.j.Sellmyer State Key Laboratory for Magnetism Institute of PhysicsChinese Academy of SciencesBeijing 100080 Behlen Laboratory of Physics and Center for Materials Research and Anajysis University of NebraskaLincolnNE 68588-0113

The structure and magnetic properties of sputtered La-Co alloy films have been *** than 10A/m(100mOe)coercivity can be obtained in amorphous La_(100-x)Co_(x) films around x=80 and the coercivity of amorphous La^(20)Co_(80) film depends on the thickness of the *** magnetization behaviour has been examined for the films with different compositions through magnetic hysteresis *** excellent rectangular magnetic hysteresis loop was obtained for films with thickness less than 60nm.

关键词： alloy hysteresis amorphous

ATOMIC　FORCE　MICROSCOPY　OBSERVATION　OF　MAGNETRON　SPUTTERED　ALUMINUM－SILICON　ALLOY　FILMS

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 1996年第4期9卷 263-266页

作者： j.W.Wu,j.H. Fang and Z.H.Lu (National Laboratory of Molecule and Biomolecule Electronics,Southeast University,Nanjing 210096, China

wo different surface morphology characteristics of magnetron sputtered aluminumsilicon(Al-Si)alloy films deposited at 0 and 200℃ were observed by atomic force microscopy(AFM).One is irregularly shaped grains put togther on a *** other is irregularly shaped grains Piled up in space. Nanometer-sized particles with heights from 1.6 to 2.9 nm were first observed. On the basis of these observations the growth mechanism of magnetron sputtered films is discussed.

关键词： magnetron sputtering Al-Si alloy surface morphology,atomic force microscopy,film growth mechanism

On Evolution Algebras

在线全文

学校读者我要写书评

暂无评论

Algebra Colloquium 2014年第2期21卷 331-342页

作者： j.M. Casas M. Ladra B.A. Omirov U.A. Rozikov Department of Applied Mathematics E. U.I.T. Forestal Pontevedra University of Vigo 36005 Spain Department of Algebra University of Santiago de Compostela 15782 Spain Institute of Mathematics Tashkent 100125 Uzbekistan

The structural constants of an evolution algebra are given by a quadratic matrix. In this work we establish an equivalence between nil, right nilpotent evolution algebras and evolution algebras defined by upper triangular matrices. The classification of 2-dimensional complex evolution algebras is obtained. For an evolution algebra with a special form of the matrix, we describe all its isomorphisms and their compositions. We construct an algorithm running under Mathematica which decides if two finite dimensional evolution algebras are isomorphic.

关键词： evolution algebra nil algebra right nilpotent algebra group of endomor-phisms classification

Effect of Cerium Doping on Microstructure and Dielectric Properties of BaTiO_3 Ceramics

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

journal of Materials Science & Technology 2011年第8期27卷 759-763页

作者： Sabina Yasmin Shamima Choudhury M.A. Hakim A.H. Bhuiyan M.j. Rahman Department of Physics University of Dhaka Materials Science Division Atomic Energy Centre Department of Physics Bangladesh University of Engineering and Technology

A solid state reaction method was used to synthesize barium titanate （BT） and barium cerium titanate （BCT） ceramics at sintering temperature of 1473 K for 4 h. The effect of cerium （Ce） on the structure, microstructure and dielectric properties of BCT was investigated. The scanning electron microscopy （SEM） investigations revealed that the grain size increases with increasing Ce content. The X-ray diffraction （XI^D） patterns showed mostly the BT phase, where the lattice parameter decreased with the addition of Ce. The temperature dependence of dielectric constant showed decrease in the phase transition temperature with higher Ce content. The dielectric constant decreased slightly with increasing frequency. The direct current （dc） density-voltage characteristics of the ceramics showed ohmic behavior for both the BT and BCT. As the temperature increased, the dc resistivity of the ceramics decreased. The activation energy increased with increasing Ce content.

关键词： Cerium doped Ba1-xCexTiO3 Dielectric constant Current density