Kinetics of electrochemical corrosion of chalcopyrite in presence of bacteria

1　ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｉｍｐｏｒｔａｎｔｂａｃｔｅｒｉａｉｎｂｉｏｈｙｄｒｏｍｅｔａｌｌｕｒｇｙａｒｅｍａｉｎｌｙａｅｒｏｂｉｃｃｈｅｍｏｌｉｔｈｏｔｒｏｐｈｉｃｓｐｅｃｉｅｓ ,ｏｆｗｈｉｃｈｔｈｅｍｏｒｅｉｍｐｏｒｔａｎｔａｒｅＴｈｉｏｂａｃｉｌｌｕｓｆｅｒｒｏｏｘｉ ｄａｎｓａｎｄＴｈｉｏｂａｃｉｌｌｕｓｔｈｉｏｏｘｉｄａｎｓ .ＴｈｅｐｒｏｐｅｒｔｉｅｓｏｆｔｈｅｔｗｏｓｐｅｃｉｅｓａｒｅｓｈｏｗｎｉｎＴａｂｌｅ 1.Ｔｈｅｙｃａｔａｌｙｚｅｔｈｅｏｘｉｄａｔｉｏｎｏｆｓｏｍｅｏｒａ…     

Editorial Committee of Transactions of Nonferrous Metals Society of China

Chairman :KANGYi　康　义Vice Chairmen :HUANGBai yun　黄伯云NIUYin jian钮因健QIUGuan zhou　邱冠周Advisors:CHENJia yong　　陈家镛HUANGPei yun　 黄培云SHIChang xu　 师昌绪WANDian zuo　王淀佐WEIShou kun　魏寿昆Members :CAOChu nan　　　曹楚南　　　　　PENGChao qun　　彭超群　　　　　YANGXian wan　　杨显万CHENJing　 陈　景　　　　　QIUDing fan　 邱定蕃　　　　　YINEn sheng　 殷恩生CHENQi yuan　 陈启元　　　　　QIUZhu xian　邱竹贤　　　　　ZENGSu min　曾苏民CUIKun　…     

Influence of concentration of zinc ions on electrocrystallization process of zinc

Cyclic voltammetry, chronoamperometry and scanning electron microscopy were employed to study the influence of Zn^2 ion concentration in electrolyte solutions on zinc electroplating process. The results show that, at high overpotentials, the nucleation of zinc is instantaneous, and nuclear density increases with the overpotentials increasing. While at low overpotentials, the zinc may be preferentially electrodeposited on surface inhomogeneities such as emergence points of edge, screw dislocations, atomic disorder, kink sites, or monoatomic steps, and no distinguished nucleation current can be observed. The major dissolution peak in cyclic voltammogram drifts positively due to the change of the rate-determining step of zinc electroplating processes from diffusion to the electrochemical reaction with the increase of Zn^2 ion concentration.     

Optimization of parameters and study of joint microstructure of resistance spot welding of magnesium alloy

Experimental investigations on the DC spot welding of Mg alloy AZ31B are presented. Experiments are carried out to study the influence of spot welding parameters （ electrode force, welding heat input and welding time） on the tensile shear load and the diameter of nugget, based on an orthogonal test and analysis method. The optimum parameters are as follows： electrode force is 2 000 N, welding heat input is 80% and welding time is 6 cycles. The microstrueture of spot weld is single fine equiaxed crystals in the nugget, of which the structure is β-Mg17Al12 precipitated on α-Mg boundaries induced by nonequilibrium freezing. And the surface condition of the workpiece has great influence on the joint quality.     

Effect of particle size of iron on reaction velocity of combustion synthesis of Ti-C-Fe system

Four Ti-C-Fe powder mixtures, with a same molar ratio but different particle sizes of Fe and Ti, were used to measure the reaction velocity of the combustion synthesis. The results show that in the case of the finer Ti powder used, the reaction velocity of mixture with the finer Fe powder is higher than that with the coarser Fe powder. However,in the case of the coarser Ti powder used, the reaction velocity of mixture with the finer Fe powder is lower than that with the coarser Fe powder. The effect of particle size of Fe powder on reaction velocity can be explained with the previously proposed mechanisms of the combustion synthesis of Ti-C-Fe system.     

Computer Simulation of IT-diagrams of Steel

PHASE transformation modeling is one of the mainchallenges in modeling of heat treatment[1].The mechanism of phase transformations is not fullyunderstood and interactive influence of differentelements,austenitizing temperature,etc.usually arenot taken in account.The mistakes in phase transformation calculationcould be extremely great if a model is based only ongrain size of prior austenite,austenitizing temperatureand elemental composition of steel.Phase transformation kinetic depends also o…     

Editorial Committee of Transactions of the Nonferrous Metals Society of China

ＥｄｉｔｏｒｉａｌＣｏｍｍｉｔｔｅｅｏｆＴｒａｎｓａｃｔｉｏｎｓｏｆｔｈｅＮｏｎｆｅｒｒｏｕｓＭｅｔａｌｓＳｏｃｉｅｔｙｏｆＣｈｉｎａ￥／／Ｃｈａｉｒｍａｎ：ＨｅＢｏｑｕａｎＰｒｏｆｅｓｓｏｒＶｉｃｅ－Ｃｈａｉｒｍａｎ：ＣｈｅｎＪｉａｙｏｎｇＲｅｓｅ...     

‘Road map’ of the development of the technological component of the strategy of national security

This article is devoted to the development of guidelines for road mapping in planning the development of the technological component of structures of national security. Making the ‘road map’ is reduced to the method of conventional optimization i.e. achievement of the target in conditions of severe limitations of existing resources taking into account the effect of controlled and uncontrolled factors. Such a result can be regarded as a scientific novelty.     

Dalian University of Technology Key Laboratory of Special Processing of Raw Materials

1. Introduction The province Key Laboratory of Special Processing of Raw Mate- rials was founded in October 2001 by uniting the Materials Elec- tromagnetic Processing & Solidification Control Institute, and Macromolecule Materials Institute. The laboratory is located at Dalian University of Technology (DUT), Dalian, China. The School of Materials Science and Engineering is the main or- ganization supporting the laboratory. It has first-class authorization spot of material science a…     

Meeting Summary of Composites Committee of FICMES

The working meeting of Composites Committee of Foundry Institution of Chinese Mechanical Engineering Society (FICMES) was held on July 25th, 2004 in Kunming, Yunnan Province. The newly elected committee members attended the meeting. The committee consists of 27 members from universities, research institutions and enterprises. The meeting was presided over by deputy-director of Composites Committee of FICMES, Prof. Ye PAN from Southeast University. He also briefly introduced the Composites Committee development amt academic activities. Prof. Shifang SU, the     

Measurement of elastic modulus and evaluation of viscoelasticity of foundry green sand

Elastic modulus is an important physical parameter of molding sand; it is closely connected with molding sand's properties. Based on theories of rheology and molding sand microdeformation, elastic modulus of molding sand was measured and investigated using the intelligent molding sand multi-property tester developed by ourselves. The measuring principle was introduced. Effects of bentonite percentage and compactibility of the molding sand were experimentally studied. Furthermore, the essential viscoelastic nature of green sand was analyzed. It is considered that viscoelastic deformation of molding sand consists mainly of that of Kelvin Body of clay membrane, and elastic modulus of molding sand depends mainly on that of Kelvin Body which is the elastic component of clay membrane between sands. Elastic modulus can be adopted as one of the property parameters, and can be employed to evaluate the viscoelastic properties of molding sand.     

Transactions of Nonferrous Metals Society of China

<正>Chief editor: HUANG Bai-yun, member of the Chinese Academy of EngineeringThe Transactions of Nonferrous Metals Society of China, mainly publishes original research andreview articles in the field of nonferrous     

Shandong University Key Lab of Liquid Structure and Heredity of Materials, Ministry of Education of China

In 1995, the Key Lab of Liquid Structure andHeredity of Metals was set up by the approval ofShandong province, but the research work on theliquid structure and heredity of materials startedin the last three decades. In 2000, combining thelab of engineering ceramic and the institute ofjoining technology in Shandong University, thelab was established as Key Lab of LiquidStructure and Heredity of Materials, by theapproval of the Ministry of Education.Currently, prof. Zhuangqi HU, prominen…     

Evaluation of glass forming ability of alloys

Key step of exploiting a new type BMG (Bulk Metallic Glass) is quickly judging GFA (Glass Forming Ability) of the alloys. The mole melting heats of BMGs are calculated using the weighted averages principle. The reliability and limitation of Trg criterion for CFA are discussed. The reason why Trg of BMGs is larger than 0.5 is discussed. Two new criteria for GFA, △Hmg and △Gg, are proposed. GFA sequence of BMGs is calculated using the △Hmg criterion, the result agrees with that of A. Inoue and the Rc criterion. Furthermore, as an example, the Rc of the alloys developed by Chuang DONG et al is calculated using the △Hmg and △Gg. The ascending sequence of these alloys calculated with the △Hmg criterion agrees with that of Chuang DONG et al. On the contrary, the result by the △Gg criterion is in contrary with Chuang DONG et al, indicating that the △Hmg criterion is better and more convenient than the △Gg criterion. Calculation showed that the optimum △Hmg iS -15.16 k J/mol.