检索结果-南通市图书馆

Identification of Heat Transfer coefficients by Use conditions of Quenching Oil

在线全文

学校读者我要写书评

暂无评论

材料热处理学报 2004年第5期25卷 453-456页

作者： katsumi Ichitani Lubricants Research Laboratory Idemitsu Kosan Co. Ltd. Chiba Japan

Heat transfer coefficients of the quench medium are necessary for heat-treatment simulation. cooling characteristics of quenching oil vary with kinds and usage greatly. Users are selecting oil solutions that come up to their desired hardness and quenching distortion requirements. In particular cooling performance rises by agitation and decompression. Therefore we identified a heat transfer coefficient by usage and kinds of quenching oil. cooling characteristics are different greatly by a kind of quenching oil. A difference of a cooling characteristic by a kind of oil depends on a temperature range of a boiling stage and the maximum heat transfer coefficient mainly. On the other hand, in a convection stage, there are few changes in a boiling stage. Even if quenching oil temperature is changed, heat transfer coefficients do not change greatly. When quenching oil stirred, heat transfer coefficients of vapor blanket stage and a convection stage rise, but there are a few changes in a boiling stage. When quenching oil is decompressed a temperature range of a high heat transfer coefficient moves to the low temperature side. In addition, a heat transfer coefficient in a vapor blanket stage comes down. For precision improvement of heat-treatment simulation, it is important that the heat transfer coefficient is calculated in conformity to the on-site use reality.

关键词：传热系数淬火油热处理冷却曲线

Gaussian Support Vector Machine Algorithm Based Air Pollution Prediction

在线全文

学校读者我要写书评

暂无评论

computers, Materials & continua 2022年第4期71卷 683-695页

作者： k.S.Bhuvaneshwari j.Uma k.Venkatachalam Mehedi Masud Mohamed Abouhawwash T.Logeswaran Department of computer Sceince and Engineering Karpagam College of EngineeringCoimbatore641032India Department of Electrical and Electronics Engineering M.Kumarasamy College of EngineeringKarur639113India Department of Applied Cybernetics Faculty of ScienceUniversity of Hradec KrálovéHradec Králové50003Czech Republic Department of computer Science College of Computers and Information TechnologyTaif UniversityTaif21944Saudi Arabia Department of Mathematics Faculty of ScienceMansoura UniversityMansoura35516Egypt Department of computational Mathematics Scienceand Engineering(CMSE)Michigan State UniversityEast LansingMI48824USA Department of Electrical and Electronics Engineering Kongu Engineering CollegeErode638060India

Air pollution is one of the major concerns considering detriments to human *** type of pollution leads to several health problems for humans,such as asthma,heart issues,skin diseases,bronchitis,lung cancer,and throat and eye *** pollution also poses serious issues to the *** from the vehicle industry is the cause of greenhouse effect and co2 ***,real-time monitoring of air pollution in these areas will help local authorities to analyze the current situation of the city and take necessary *** monitoring process has become efficient and dynamic with the advancement of the Internet of things and wireless sensor *** is the main issue in WSNs;if the sensor node location is unknown,then coverage and power and routing are not *** study concentrates on localization-based air pollution prediction systems for real-time monitoring of smart *** systems comprise two phases considering the prediction as heavy or light traffic area using the Gaussian support vector machine algorithm based on the air pollutants,such as PM2.5 particulate matter,PM10,nitrogen dioxide(NO2),carbon monoxide(co),ozone(O3),and sulfur dioxide(SO2).The sensor nodes are localized on the basis of the predicted area using the meta-heuristic algorithms called fast correlation-based elephant herding *** dataset is divided into training and testing parts based on 10 *** evaluation on predicting the air pollutant for localization is performed with the training *** error prediction in localizing nodes is 9.83 which is lesser than existing solutions and accuracy is 95%.

关键词： Air pollution monitoring air pollutant SVM Gaussian EHO fast correlation WSN localization

comparative study of 2mol% Li- and Mn-substituted lead-free potassium sodium niobate ceramics

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International journal of Minerals,Metallurgy and Materials 2014年第12期21卷 1241-1246页

作者： Asha Dahiya O.P.Thakur j.k.juneja Sangeeta Singh Dipti School of Applied Sciences Netaji Subhas Institute of Technology Dwarka University of Delhi Department of Physics Hindu College Department of Physics Geeta Vidya Mandir Girls College School of Physics & Material Sciences Thapar University

The effect of Li and Mn substitution on the dielectric, ferroelectric and piezoelectric properties of lead free k0.5Na0.5NbO3 （kNN） was investigated. Samples were prepared using a conventional solid state reaction method. The sintefing temperature for all the samples was 1050℃. The optimum doping concentration for the enhancement of different properties without the introduction of any other co-dopants such as Ti, Sb, and La was investigated. X-ray diffraction analysis confirmed that all the samples crystallize in a single phase perovskite structure. The dielectric properties were investigated as a function of temperature and applied electric field frequency. compared with Li-substituted kNN （kLNN）, Mn-substituted kNN （kMNN） exhibited a higher dielectric constant εmax （i.e., 4840） at its critical transition temperature Tc （i.e., 421℃） along with a lower value of tangent loss at 10 kHz and greater values of saturation polarisation Ps （i.e., 20.14 μC/cm^2） and remnant polarisation Pr （i.e., 15.48 μC/cm^2）. The piezoelectric constant （d33） of kMNN was 178 pC/N, which is comparable to that of lead-based hard ceramics. The results presented herein suggest that B-site or Mn substitution at the optimum concentration results in good enhancement of different properties required for materials used in memory devices and other applications.

关键词： ceramics dielectric properties ferroelectricity piezoelectricity substitution comparative study

Influence of Non-Magnetic Substitutional Atoms on Spontaneous Moment and Curie Temperature of Ce_2co_(17) compounds

在线全文

学校读者我要写书评

暂无评论

journal of Rare Earths 2002年第4期20卷 273-277页

作者：胡社军刘正义 De Boer F R Buschow k H j Faculty of Materials and Energy Guangdong University of Technology Guangzhou 510643 China

The structure and magnetic properties of Ce 2co 17-xM x(M=Ga,Al and Si) compounds for M concentrations up to x=5 were studied by means of X-ray diffraction and magnetic measurements. The experimental results show that the Curie temperatures and co spontaneous magnetization decrease significantly with increasing the addition of non-magnetic substitutional atoms, and that Si which has a minimum solid solubility in Ce 2co 17 causes a largest reduction of Curie temperature, spontaneous magnetization and moment per co atom compared with Ga and Al.

关键词： rare earths Ce 2co 17 compounds Curie temperature spontaneous magnetization

Carbon coated sand filtration

在线全文

学校读者我要写书评

暂无评论

化工进展 2011年第S1期30卷 921-926页

作者： CHEN Ming (jiangsu Sunpower Technology co.,Ltd,Nanjing 211112,jiangsu,China)

The goal of this work is to determine the removal efficiency of pathogen by using carbon coated sand *** the bacterial research,serial dilution and agar plate methods are used,*** is used as bacterial indicator and the experiments are operated under four different conditions:different HRTs,different sand:bran ratios,different carbon sources and different sand *** a result the treatment efficiency of bacteria is too much less than the slow sand ***’s not suitable for bacteria *** its treatment efficiency is less than the advanced methods,it is a low-tech system which can be easily built up and it is very economic.

关键词： carbon coated sand E.coli

MICROWAVE PERMEABILITY SPECTRA OF SPUTTERED Fe-co-B SOFT MAGNETIC THIN FILMS

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2008年第6期21卷 419-424页

作者： j.S. Liao Z.k. Feng j. Qiu Y. Q. Tong Department of Electronic Science and Technology Huazhong University of Science and Technology Wuhan 430074 China

Permeability characteristics of sputtered soft magnetic Fe40co40B20 thin films are investigated in the range of O. 5 to 5 GHz by a shortened microstrip transmission line perturbation method. Excellent microwave permeability is achieved at 0.4 Pa argon pressure： fr is 3.32 GHz, the real and imaginary part of permeability at 0.5 GHz are 104 and 61, respectively. In addition, the thickness effect on permeability is also studied. The minimum damping can be achieved at the thinnest film. Different sources contributed to in-plane anisotropy are discussed briefly. The deviation between the peak frequency of the imaginary part and the zero-crossing frequency of the real part of permeability is also presented.

关键词： Fe-co-B In-plane anisotropy Magnetic thin films Permeability

Biogas recovery from microwave heated sludge by anaerobic digestion

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2010年第1期53卷 144-149页

作者： QIAO Wei1,WANG Wei2,ZHU CuiPing3 & ZHANG ZhongZhi1 1 college of Chemical Science and Engineering,China University of Petroleum,Beijing 102249,China 2 Department of Environmental Science and Engineering,Tsinghua University,Beijing 10084,China 3 j & k China Cleaning Energy Technology co.Ltd.,Beijing 100085,China 1. college of Chemical Science and Engineering China University of Petroleum Beijing 102249 China2. Department of Environmental Science and Engineering Tsinghua University Beijing 10084 China3. J & K China Cleaning Energy Technology Co. Ltd. Beijing 100085 China

Biogas generated from sewage sludge,livestock waste,and food waste by anaerobic digestion is a valuable renewable energy ***,conventional anaerobic digestion is not an efficient process.A long hydraulic retention time and low biogas recovery rate hinder the applications of those *** effective pretreatment method to destroy sludge microbial cells has been one of the major concerns regarding improvement of the biogas *** article focuses on the effects of microwave heating on sludge anaerobic *** suspended solid(VSS) and chemical organic demand solubilization of heated sludge were *** heating was found to be a rapid and efficient process for releasing organic substrates from *** increase of organic dissolution ratio was not obvious when holding time was over 5 min with microwave *** effect of the VSS solubilization was primarily dependent on heating *** highest value of VSS dissolving ratio,36.4%,was obtained at 170°C for 30 *** coD dissolving ratio was about 25% at 170°*** organic carbon of treated sludge liquor was 1.98 and 2.73 g/L at 150°C and 170°C for 5 min,respectively.A biochemical methane potential(BMP) test of excess sludge and a mixture of primary and excess sludge demonstrated an increase in biogas *** total biogas from microwave treated mixture sludge increased by 12.9% to 20.2% over control after 30 days of *** production was 11.1% to 25.9% higher for excess sludge than for untreated *** VS removal ratios of mixture sludge and excess sludge were 12% and 11% higher,respectively,compared to the untreated sludge.

关键词： biogas recovery microwave heating sludge anaerobic digestion

Enhanced thermoelectric performance of spark plasma sintered p-type Ca_(3-x)Y_(x)co_(4)O_(9+δ)systems

在线全文

学校读者我要写书评

暂无评论

journal of Materials Science & Technology 2020年第20期52卷 212-222页

作者： j.S.Cha D.H.kim H.Y.Hong k.Park Faculty of Nanotechnology and Advanced Materials Engineering Sejong UniversitySeoul05006Republic of Korea

Highly textured dense Ca3-xYxco4 O9+δ(0≤x≤0.3)samples were fabricated by combining sol-gel process with spark plasma sintering(SPS).Y^3+substitution for Ca^2+simultaneously increased the Seebeck coefficient and reduced the thermal *** latter was attributed to the increase in lattice anharmonicity,structural distortion,and grain boundary area,which enhanced the phonon ***2.7Y0.3co4 O9+δshowed the largest dimensionless figure-of-merit(ZT=0.194)at 1073 k because it had the largest Seebeck coefficient and the lowest thermal *** ZT value was 55%larger than that of undoped Ca3 co4 O9(0.125 at 1073 k).Therefore,Y^3+substitution,sol-gel powder synthesis,and SPS are highly effective for enhancing the thermoelectric prope rties of Ca_(3)co_(4)O_(9).

关键词： Electrical conductivity Ca_(3)co_(4)O_(9) Thermoelectric properties Seebeck coefficient Thermal conductivity Spark plasma sintering

Technical Study on Ultra-Low Sulfur Steel Production in Ansteel

在线全文

学校读者我要写书评

暂无评论

journal of Iron and Steel Research International 2011年第S1期18卷 567-571页

作者： XU Xiang-yang (No.1 Steelmaking Plant of Angang Steel co Ltd.,Anshan 114031,China) 1 Steelmaking Plant Angang Steel co Ltd Anshan 114031 Peoples R China

Based on the fact of long period deep desulfurization treatment in LF,the relationships among top slag constituent in LF,molten steel constituent,stirring ability of blowing argon,molten steel temperature and desulphurization rate were *** the experiments,the parameters about treatment technology of top slag in LF,the [Als] content in molten steel,slag charge match,molten steel temperature and the argon flow for stirring have been *** desulphurization treatment period in LF can be shortened by 5～8 *** target sulfur content in molten steel can be controlled below 30 ppm within one LF treatment period which is only 36 *** LF treatment period of ultra-low sulfur steel can primarily match with the continuous casting period,multi-heat continuous casting can be ensured.

关键词： ultra-low sulfur steel LF deep desulphurization treatment