检索结果-南通市图书馆

Effect of coating material and lubricant on forming force and surface defects in wire drawing process

在线全文

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals society of China 2011年第A1期21卷 104-110页

作者： s.M.BYON s.J.LEE D.W.LEE Y.H.LEE Y.LEE Department of Mechanical Engineering Dong-A University Department of Mechanical Engineering Chung-Ang University Wire Rod Research Group POSCO Technical Research Laboratories

A pilot wire drawing machine as well as wire end-pointing roller was developed. Using these machines, a wire drawing test for four different coating materials and two different lubricants was performed as the reduction ratio increased from 10% to 30%. Materials used for a substrate in this study are plain carbon steel (AIsI1045) and ultra low carbon bainite steel. To compute the friction coefficient between the coating layer of wire and the surface of die for a specific lubricant, a series of finite element analyses were carried out. sEM observations were also conducted to investigate the surface defects of wire deformed. Results show that the behavior of drawing force varies with the lubricant-type at the initial stage of drawing. The powder-typed lubricant with a large particle causes the retardation of full lubrication on the entire contact surface and the local delamination of coating layer on the wire surface. As the flow stress of a substrate increases, the delamination becomes severe.

关键词：涂层材料模具表面拉丝工艺表面缺陷润滑剂成形力超低碳贝氏体钢润滑油型

Global Annual Mean surface Air Temperature Anomalies and Their Link with Indian summer Monsoon Failures

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric sciences 1990年第2期7卷 245-248页

作者： s.s.Dugam s.B.Kakade R.K.Verma Indian Institute of Tropical Meteorology Pune-411005 IndiaIndian Institute of Tropical Meteorology Pune-411005 IndiaIndian Institute of Tropical Meteorology Pune-411005 India

Analysis of the global mean annual temperature anomalies based on land and marine data for the last 88 years (1901-1988) of this century has been carried out with a view to find any relationship with failures in Indian summer monsoon rainfall. On the climatological scale (i.e. 30 years) it has been noticed that there is an abnormal increase in the frequency of drought years during epochs of global warming and cooling, while it is considerably less when global temperatures are near normal. Results are unchanged even when the data are filtered out for ENsO (El-Nino southern Oscillation) *** has also been noticed that during warm and cold epochs in global temperatures the amount of summer monsoon rainfall decreases as compared to the rainfall during a normal temperature epoch.

关键词： In Global Annual Mean surface Air Temperature Anomalies and Their Link with Indian summer Monsoon Failures ENsO Mean

Improving the Thermal Efficiency and Performance of Refrigeration systems:Numerical-Experimental Analysis of Minimization of Frost Formation

在线全文

学校读者我要写书评

暂无评论

Energy Engineering 2022年第5期119卷 1771-1788页

作者： Felipe Mercês Biglia Raquel da Cunha Ribeiro da silva Fátima deMoraes Lino Kamal Abdel Radi Ismail Thiago Antonini Alves Federal University of Technology-Parana(UTFPR) CuritibaBrazil Federal University of Technology-Parana(UTFPR) GuarapuavaBrazil University of Campinas(UNICAMP) CampinasBrazil Federal University of Technology-Parana(UTFPR) Ponta GrossaBrazil

The frost growth on cold surfaces in evaporators is an undesirable phenomenon which becomes a problem for the thermal efficiency of the refrigeration systems because the ice layer acts as a thermal insulation,drastically reducing the rate of heat transfer in the *** accumulation implies an increase in energy demand and a decrease in the performance of various components involved in the refrigeration process,reducing its efficiency and making it necessary to periodically remove the frost,resulting in expenses for the defrost *** the present work,a numerical-experimental analysis was performed in order to understand the formation process of porous ice in flat plates with different surface treatments and *** understanding is of utmost importance to minimize the formation of porous ice on cold surfaces and improve equipment efficiency and *** this context,a low-cost experimental apparatus was developed,enabling an experimental analysis of the phenomenon under *** environmental conditions evaluated are the temperature of the cold surface,roomtemperature,humidity,and air *** material of the surfaces under study are aluminum,copper,and brass with different surface finishes,designated as smooth,grooved(hydrophilic),and varnished(hydrophobic).The numerical-experimental analysis demonstrates measurements and simulations of the thickness,surface temperature,and growth rate of the porous ice layer as a function of the elapsed *** numerical results were in good agreement with the experimental results,indicating that the varnished surface,with hydrophobic characteristics,presents greater difficulty in providing the ***,the results showed that application of a coating allowed a significant reduction on the frost formation process contributing to the improvement of thermal efficiency and performance of refrigeration systems.

关键词： Frost layer growth frost thickness minimization of frost hydrophobic surface refrigeration systems

Carbon dioxide reforming of methane on monolithic Ni/Al_2O_3-based catalysts

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

Journal of Natural Gas Chemistry 2011年第2期20卷 184-190页

作者： s. O. soloviev A. Yu. Kapran s. N. Orlyk E. V. Gubareni L. V. Pisarzhevskii Institute of Physical Chemistry National Academy of Sciences of Ukraine

Nickel-alumina catalysts supported on cordierite monoliths of honeycomb structure surpass essentially the conventional granulated ones with respect to the output in carbon dioxide reforming of methane. Adjusting the surface acid-base properties of catalysts by introduction of alkali metal （Na, K） oxides inhibits the carbonization and as a result, improves the operational stability of these catalysts. An effect of promotion of nickel-alumina based composite doped by lanthanum oxide is found. This effect, caused by an additional route for the CO2 activation on Ni-La2O3/Al2O3/cordierite catalyst, is displayed in increase of methane conversion under conditions of an oxidant excess.

关键词： methane carbon dioxide reforming hydrogen syngas Ni/Al2O3 catalysts cordierite monolithic supports honeycomb structure sodium and potassium lanthanum oxide modifying additives

Plasma electrolytic oxidation of the magnesium alloy MA8 in electrolytes containing TiN nanoparticles

在线全文

学校读者我要写书评

暂无评论

Journal of Materials science & Technology 2017年第5期33卷 461-468页

作者： D.V.Mashtalyar s.V.Gnedenkov s.L.sinebryukhov I.M.Imshinetskiy A.V.Puz Institute of Chemistty Far Eastern BranchRussian Academy of Sciences 159Prosp.100-1etya VladivostokaVladivostok 690022Russia Far Eastern Federal University 8 Sukhanova St.Vladivostok690950Russia

The formation of protective multifunctional coatings on magnesium alloy MA8 using plasma electrolyt- ic oxidation （PEO） in an electrolytic system containing nanosized particles of titanium nitride was investigated. Electrochemical and mechanical properties of the obtained layers were examined. It was established that microhardness of the coating with the nanoparticle concentration of 3 gl-1 increased twofold （4.2 ± 0.5 GPa）, while wear resistance decreased （4.97 × 10-6 mm3 N-1 m-1）, as compared to re- spective values for the PEO-coating formed in the electrolyte without nanoparticles （2.1 ± 0.3 GPa, 1.12 × 10.5 mm3 N-1 m-1）.

关键词： Magnesium alloys Protective coatings Plasma electrolytic oxidation Corrosion titanium nitride Nanoparticles

Effect of imidazole based polymer blend electrolytes for dye-sensitized solar cells in energy harvesting window glass applications

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2019年第11期27卷 2807-2814页

作者： K.M.Manikandan A.Yelilarasi s.s.saravanakumar P.senthamaraikannan Anish Khan Abdullah M.Asiri Department of Physics Kamaraj College of Engineering and TechnologyK.VellakulamVirudhunagar625701 MaduraiTamil NaduIndia Department of Mechanical Engineering Kamaraj College of Engineering and TechnologyK.VellakulamVirudhunagar625701 MaduraiTamil NaduIndia Chemistry Department Faculty of ScienceKing Abdulaziz UniversityJeddah 21589Saudi Arabia Center of Excellence for Advanced Materials Research King Abdulaziz UniversityJeddah 21589P.O.Box 80203Saudi Arabia

The exploration of polymer electrolyte in the field of dye sensitized solar cell(DssC) can contribute to increase the invention of renewable energy applications. In the present work, the influence of imidazole on the poly(vinylidene fluoride)(PVDF)–poly(methyl methacrylate)(PMMA)–Ethylene carbonate(EC)–KI–I2 polymer blend electrolytes has been evaluated. The different weight percentages of imidazole added into polymer blend electrolytes have been prepared by solution casting. The prepared films were characterized by Fourier transform infrared spectroscopy(FTIR), X-ray diffraction(XRD), thermogravimetric analysis(TGA), UV–visible spectra, photoluminescence spectra and impedance spectroscopy. The surface roughness texture of the film was analyzed by atomic force microscopy(AFM). The ionic conductivity of the optimized polymer blend electrolyte was determined by impedance measurement, which is 1.95 × 10-3 s·cm-1 at room temperature. The polymer electrolyte containing 40 wt% of imidazole content exhibits the highest photo-conversion efficiency of 3.04%under the illumination of 100 m W·cm-2. Moreover, a considerable enhancement in the stability of the DssC device was demonstrated.

关键词： Polymer blend electrolyte Imidazole Dye-sensitized solar cell surface roughness Ionic conductivity

Influence of zone formation on stability of continuous fluidized bed layering granulation with external product classification

在线全文

学校读者我要写书评

暂无评论

Particuology 2015年第6期13卷 1-7页

作者： C. Dreyschultze C. Neugebauer s. Palis A. Buck E. Tsotsas s. Heinrich A. Kienle Otto yon Guericke University Universit~tsplatz 2 D-39106 Magdeburg Germany Max Planck Institute for Dynamics of Complex Technical systems Sandtorstraabe 1 D-39106 Magdeburg Germanyc Hamburg University of Technology Denickestrae 15 D-21073 Hamburg Germany

Continuous fluidized bed layering granulation with external product classification and a sieve-mill cycle can show instability in the form of self-sustained nonlinear oscillations of the particle size distribution. In the present study, the stability and bifurcation analysis of this process is presented. The underlying process models explicitly account for compartmentalization of the fluidized bed into a granulation and a drying zone, which is an important feature of many technical processes. Implications for plant operations are discussed with the help of stability diagrams as a function of zone size, residence time within different zones, the addition of external seeds and particular properties of the sieve-mill cycle.

关键词： Fluidized bed Granulation Population balance stability Bifurcation

Egyptian heavy vacuum gas oil hydrotreating over Co-Mo/CNT and Co-Mo/γ-Al2O3 catalysts

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

燃料化学学报 2016年第7期44卷 853-861页

作者： W.Ahmed Hoda,s.Ahmed H.s.El-sheshtawy Nadia,A.Mohamed Asmaa,I.Zahran Egyptian Petroleum Research Institute 1Aahmed El-Zomor st.Naser city 11727CairoEgypt Ain-shams University for Girls Roqqsy SquireCairoEgypt

The catalytic activity of CoMos /CNT towards the Egyptian heavy vacuum gas oil hydrotreating was studied. The delivered CNT was functionalized with 6 mol /L HNO_3. The CNT were loaded with 12% MoO_3( by weight) and 0.7 Co /Mo atomic ratio with impregnation methods. The γ-Al_2O_3 catalyst was also prepared by impregnation method to compare both catalysts *** analysis tools such XRD,Raman spectroscopy,TEM,and BET were used to characterize the catalysts. The autoclave reactor was used to operate the hydrotreating experiments. The hydrotreating reactions were tested at various operating conditions of temperature 325-375 ℃,pressure 2-6 MPa,time 2-6 h,and catalyst /oil ratio( by weight) of 1 ∶75,1 ∶33 and 1 ∶10. The results revealed that the CoMos /CNT was highly efficient for the hydrotreating more than the CoMos /γ-Al_2O_3. Also, the hydrodesulfurization( HDs) increased with increasing catalyst /oil ratio. Additionally,results showed that the optimum condition was temperature 350℃,pressure 4 MPa,catalyst /oil ratio of 1 ∶75 for 2 h. Furthermore,even at low CoMos /CNT catalyst /oil ratio of 1 ∶75,an acceptable HDs of 77.1% was achieved.

关键词： hydrotreatment hydrodesulfurization carbon nanotube heavy vacuum gas oil(HVGO)

spin—Other—Orbit Effect in Two—Mode Multiphoton Ionization

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2002年第1期19卷 36-39页

作者：李晓峰 D.s.Guo 等 LaboratoryofOpticalPhysics InstituteofPhysicsChineseAcademyofSciencesBeijing100080 DepartmentofAppliedscience UniversityofCalifornia-DavisDavisCalifornia95616USA

A previously unknown ``spin-other-orbit'' effect of photon modes is predicted by solving a schrödinger-like equation for a non-relativistic electron interacting with a two-mode intense photon field propagating in two perpendicular directions. A multiphoton ionization experiment to test this effect is suggested. Transition rates which manifest this effect to be measured in the experiment are calculated and presented graphically. A detailed comparison between this effect and the well-known spin-other-orbit effect of electrons is included.

关键词： Photons