Highly dispersed V_2O_5/TiO_2 modified with transition metals(Cu,Fe,Mn,Co) as efficient catalysts for the selective reduction of NO with NH_3

Different transition metals were used to modify V2O5-based catalysts （M-V, M = Cu, Fe, Mn, Co） on TiO2 via impregnation, for the selective reduction of NO with NH3. The introduced metals induced high dispersion in the vanadium species and the formation of vanadates on the TiO2 support, and increased the amount of surface acid sites and the strength of these acids. The strong acid sites might be responsible for the high N2 selectivity at higher temperatures. Among these catalysts, Cu-V/TiO2 showed the highest activity and N2 selectivity at 225-375 ~C. The results of X-ray photo- electron spectroscopy, NH3-temperature-programmed desorption, and in-situ diffuse reflectance infrared Fourier transform spectroscopy suggested that the improved performance was probably due to more active surface oxygen species and increased strong surface acid sites. The outstanding activity, stability, and SO2/H2O durability of Cu-V/TiO2 make it a candidate to be a NOx removal catalyst for stationary flue gas.

Thioetherification of isoprene and butanethiol on transition metal phosphides

Thioetherification between mercaptan and diolefin is an efficient process to remove mercaptans in FCC gasoline at mild condition, during which the selective hydrogenation of diolefin to monoolefin is also expected. Here, Si O2 supported transition metal（Fe, Co, Ni, Mo and W） phosphides were tested for the thioetherification of isoprene and butanethiol on a fixed-bed reactor at 120℃ and 1.5 MPa H2, and their structure before and after reaction was characterized by means of XRD, HRTEM, N2 sorption, CO chemisorption, NH3-TPD, XPS and TG. It was found that, among different metal phosphides, Mo P/Si O2 showed the best performance, and the optimal nominal Mo P loading was 25%. Apart from the nature of metal, the density of metal and acid sites determined the catalyst performance. Metal site was mainly responsible for hydrogenation of isoprene, while acid site dominantly contributed to the thioetherification and the polymerization of olefins. Moreover, a balance between metallic and acidic functions is required to arrive at a desired performance. Excessive metal sites or acid sites led to the over-hydrogenation of isoprene or the severe polymerization of olefins, respectively. 25%Mo P/Si O2 was tested for 37 h time on stream, and butanethiol conversion maintained at 100%; although isoprene conversion remarkably decreased, the selectivity to isopentenes exceeded 80% after reaction for 11 h. We suggest that the deactivation of Mo P/Si O2 is mainly ascribed to the butanethiol poisoning and the carbonaceous deposit, especially the former.

Processing, Recovery and Analysis of Precious Metals Using Molecular Recogntion Technology

IBC Advanced Technologies' Molecular Recognition Technology(MRT) products,trade named SuperLig,selectively and rapidly bind with target metal ions to remove them from solution.The MRT process can produce a high purity separation product of maximum added value at low cost.In this paper,applications of MRT in the precious metals industry,including selective commercial separations involving Au,Pd,Pt,Rh,and Ru,are described and discussed.Application of MRT to the analytical determination of precious metals is presented.Potential use of MRT in recovering precious metals from end-of-life(EOL) products is discussed.

Abstracts of Selected Articles on metals Published in China

92A0025 Saturation of Preferential Sites forNucleation and Growth of Ferrite Phase at EarlyStages of Austenite Decomposition in Low-carbonBoron Steels The microstructural evolutionpath at early stages of austenite decomposition at620℃ in low-carbon boron steels has been investi-

Alatiacts of Selected Artleles on Metals

92A0001 Effect of Hydrogen on Debye Tempera-ture and Lattice Parameter of Ti-30MoAlloy The variations of Debye temperature andlattice parameter of Ti-30Mo alloy with differenthydrogen contents were measured by X-raydiffraction.It was found that as the hydrogen con-tent increased,the Debye temperature decreased,but the lattice parameter of the alloy increased.Theabove results experimentally support thedecohesion theory that the increase of hydrogen in

Determination of Selected Metals and Nutritional Compositions of Pigeon Pea (<i>Cajanus cajan</i>) Cultivated in Wolaita Zone, Ethiopia

This study was aimed to determine the level of selected metals and nutritional composition of pigeon pea seed collected from seven districts of Wolaita zone. A wet digestion procedure involving the use of mixtures of (69% - 72%) HNO3 and (70%) HClO4 at an optimum temperature and time duration was used to determine metals by using flame atomic absorption spectrometry. Kjeldahl digestion method, Soxhlet extraction and furnace were used to determine nutritional values of pigeon pea, and physicochemical properties of soils were assessed using standard methods. The results showed that the levels of concentration of metals in mg/kg dry weight were ranged 105.17 to 144.07 for K, 8.95 to 12.67 for Mg, 7.74 to 12.27 for Ca, 0.247 to 0.543 for Fe, 0.122 to 0.313 for Zn, 0.061 to 0.432 for Mn, 0.087 to 0.134 for Cu and 0.0011 to 0.00196 for Cr. The proximate composition of pigeon pea was in the range of 19.28% to 25.79% for crude protein, 0.993% to 1.75% for crude fat, 3.75% to 5.31% for ash, 10.65% to 13.73% for moisture, 2.28% to 3.06% for fiber, 54.36% to 60.1% for carbohydrate and 326.8 to 345.23 Kcal for energy. The pH of the soil was in the range from pH 5.09 (strongly acidic) to 6.77 (slightly acidic), EC of the soil ranged from 0.047 to 0.14 dS/m (low), the soil OC level was from 1.6% to 2.42% (moderate), total Nitrogen was from 0.12% to 0.23% (low to moderate), the available Phosphorus content of the soil was from 6.82 to 13.52 mg/kg (low to moderate), CEC value of the soil was from 14.8 to 23.53 meq/100g (moderate). The textural classes of soil were sandy clay loam for all sites except Abela abaya. The study confirmed that pigeon pea was a good source of proteins, carbohydrates, and selected metals such as Mg, K, Ca, Fe, Zn, Mn, Cu, and Cr. The concentration of metals and nutritional compositions of pigeon pea seed were found at a permissible level.

Abstracts of Selected Aitieles on Metals Published in China

92A0035 Fatigue-Creep Interaction and FractureMode of Steel 12CrlMoV A fatigue-creepinteraction fracture map for steel 12Cr1MoV tubewas constructed.It shows clearly the full view ofinteraction behaviour under a wide range of com-bination of fatigue and creep stresses.All the in-formation including the macro-properties(fracturelife,strain rate and ductility)and micro-fracturemodes(FF,FCF,FCC,CFC and CC),and themain interaction mechanism could be obtainedfrom the map.For the steel 12Cr1MoV at 588℃ a

Abstracts of Selected Articles on metals Published in China

92A0040 Influence of V;（C,N）;in Fe-C-V Alloyon Distribution of Dislocation Area and FatigueStrength This paper describes the influence ofV;（C,N）;in Fe-C-V alloy on the area ofdeslocation movement and fatigue strength.The re-sults show that fine,uniform,dispersed and stableV;（C,N）;may enlarge the area of dislocation

Abstracts of Selected Articles on Metals Published in China

CONTENTSA:Physics of metal andmetallography(20-24)B:Testing and analysis(3)C:Mechanical,physical and chemicalproperties(23-27)D:Metallurgy(21-28)E:Metal working(18-22)

Abstracts of Selected Articles on Metals Published in China

90A0047 Transformation Characteristic of TwoWay Shape Memory Material Constrained byStress The snap-acting transition and two wayshape memory(TWSM)effect have been obtainedin a TWSM spring made of Ni51Ti49 alloy usingthe constrained effect of stress on driving force ofTWSM material.When the snap-acting transition

SELECTED ABSTRACTS OF ARTICLES ON RARE METALS FROM CHINESE PERIODICALS

89 1-01 Investigation of SingleMoFeSCubane-Like Cluster Compounds——Ⅲ.TheConversion of Linear Trinuclear Cluster into SingleCubane Cluster and the Structure ofMoFeS(EtNCS)CHCN Reaction ofFe(DMF)[(FeCl)MoS] and EtNCSNa in DMF re-sults in conversion of the linear trinuclear cluster into thesingle cabane—like cluster,MoFeS(EtNCS),thestructure of which has been determined.The influence ofthe ligand—related redox process and the ligation modeon the conversion reaction and the product are discussed.

SELECTED ABSTRACTS OF ARTICLES ON RARE METALS FROM CHINESE PERIODICALS

93-1-38 Chemical Dispersion of MoOand TiOat Interface of MoO/TiOThe dispersion capacity ofMoOand TiOat the interface of MoO/TiOcal-cined at 500℃ for 5h was studied by XRD and FT-IR dif-ference spectra.There is about one monolayer ofnon-crystalline phase of MoOand TiOat the interface.

Abstracts of Selected Articles on Metals Published in China

90A0026 Influence of Deformation at MartensiticState on Shape Recovery in Co-Zn-Al Memory Al-loys An investigation of the influence ofdeformation on shape recovery has been put for-ward in Cu-Zn-Al shape memory alloys.Startingat the model of the re-orientation of martensiticvariants,the principle and essentiality of the influ-ence of the amount of pre-deformations on shaperecovery rate η is elucidated.LI Bing,JIANGBohong and XU Zuyao: Acta Metall.Sin.,1989,25(4),A235-A243.

SELECTED ABSTRACTS OF ARTICLES ON RARE METALS FROM CHINESE PERIODICALS

CONTENTS1.Extractive Metallurgy(9～16)2.Metal Material and Technology(5～9)3.Semiconductor(9～17)4.Metal Physics(5～8)5.Chemical Analysis and Physical Testing(5～11)92 1-9 Determination of Trace Selenium in High-Puri-ty Copper by Polarographic Catalytic Wave after Enrichmentand Separation with Sulfhydrl-Cotton A novel procedure

Abstractsof Selected Articles on metals Published in China

90A0064 Electron Radiation Induced Void Swell-ing and Grain Boudary Segregation in anFe—Cr—Mu Austenitic Alloy The behaviour ofvoid swelling and segregation in Fe—15Cr—xMnand Fe—15Cr—15Mn—2W—2V alloys was investi-gated by electron irradiation.The compositionalanalysis in the irradiated regions including grainboundaries was performed.In the Fe—Cr—Mn alloysystems void swelling was remarkably suppressedand at the same time the radiation—induced segre-gation Was also retarded,furthermore,the segrega-tion was strongly retarded in Fe—15Cr—

SELECTED ABSTRACTS OF ARTICLES ON RARE METALS FROM CHINESE PERIODICALS

CONTENTS1.Extractive Metallurgy(40～43)2.Metal Materials and Technology(30～32)3.Semiconductors(38～40)4.Metal Physics(24～26)5.Chemical Analysis and Physical Testing(38～39)93-1-40 Study of Pt-Ga/AlOCatalysts Ⅱ.Ef-fect of Ga on the Surface Structure and Acidity of the Cata-lysts The effect of Ga on the surface structure of sup-port and the acidity of Pt-Ga/AlOcatalysts was studiedby using EPMA,XRD,IR,physical adsorption,frontaladsorption of basic gases and cumene cracking.The results

Alatiacts of Selected Aiticles on metal Published in China

89A0001 Internal Friction Associated withMartensitic Transformation of As-cast Mn-CuAlloys Internal friction of martensitictransformation of as-cast Mn-Cu alloys with90%Mn was studied. Results show that the peaktemperature of the stable peak (T=0) at lowfrequencies is independent of the measuringfrequency, but the peak height decreases withincreasing frequency. It is, therefore, notof a static hysteresis mechanism. The peakheight is dependent on T and f at a constantheating or cooling rate, but it does not showa linear relationship with T, 1/f or T/f. Thepeak height is independent of the strain amplitudein the yange (A_ε: 1× 10-5--1×10-4). Consequentlythe low frequency internal friction of martensitictransformation is not only a volume effect,but also a surface effect connected with coherentboundaries. XIE Cunyi, WEN Yiting and ZHU

Abstracts of Selected Articles on Metals Published in China

CONTENTSA:Physics of metal andmetallography(36-46)B:Testing and analysis(7)C:Mechanical,physical and chemicalproperties(58-74)D:Metallurgy(46-61)E:Metal working(31-50)90A0036 Plastic Deformation and DislocationStructure In γ′-phase of a Directionally SolidifiedNi-base Superalloy The dislocationsubstructure of directionally solidified Rene 80

Abstracts of Selected Articles on Metals Published in China

A: Physics of metal and metallography(11-26)B: Testing and analysis(8-17)C: Mechanical, physical and chemical properties(10-21)D: Metallurgy(27-37)E: Metal working(10-23)89A0011 Effect of Mo on Tempered MartensiteEmbrittlement of Medium Carbon Si-Mn SteelsAn investigation on the effect of alloying elementMo on tempered martensite embrittlement (TME)in 40Si2Mn2 steel has been made. Experimentalresults show that TME in 40Si2Mn2 steel cannot be eliminated by Mo, but Mo addition candecrease the ductile-brittle transitiontemperature (DBTT) of the steel and make theimpact test temperature for revealing TMEdecreased. On the other hand, it is found thatMo can retard TME through to a higher temperingtemperature and Mo has a deferring role on TMEin 40Si2Mn2 steel. The results obtained by meansof transmission electron microscopy indicatethat the phenomenon is associated with theretardation of Mo on the precipitation ofcementite during tempering. FU Ming and QIUYaojian: Iron Steel, 1988, 23((7), 36-41.

Abstracts of Selected Articles on Metals Published in China

A: Physics of metal and metallography(68-78)B: Testing and analysis(27-28)C: Mechanical, physical and chemical properties (64-78)D: Metallurgy(111-141)E: Metal working(50-59)89A0068 Observation of Epitaxial Overlayer ofMetals at Atomic Level Epitaxial overlayerof metals at atomic level has been successfully