Nonmetal-Metal Transition in Solutions of Metals in Molten Salts

Solutions of metals in molten salts present a rich phenomenology: localisatlon of electrons in disordered ionic media, activated electron transport increasing with metal concentration towards a nonmetal-metal (NM-M) transition, and liquid-liquid phase separation. A brief review of progress in the study of these systems is given in this article, with main focus on the NM-M transition. After recalling the known NM-M behaviour of the component elements in the case of expanded fluid alkali metals and mercury and of solid halogens under pressure, the article focuses on liquid metal-molten salt solutions and traces the different NM-M behaviours of the alkalis in their halides and of metals added to polyvalent metal halides.     

Behaviour of Rare Earths in Solid Solution in Steel

The contents of rare earth metals(REM) insolid solution in 16 Mn steel were determined bymeans of inductive coupling plasma (ICP)spectroscopy.The amount of REM in solid solutionis only a few ppm in the steel with MnS inclusions,which rises slightly with the increasing of REMcontent in steel.At RE/S>1.9,the MnS inclu-sions in steel disappear completely,the REM con-tent in solid solution increases rapidly with the in-creasing of REM content.The solubility of ceriumin 16 Mn steel(st 52)is less than 0.011 wt—％ atroom temperature.The results obtained indicate that REM in sol-id solution reduce the amount of pearlite and in-crease that of ferrite and its microhardness.Dis-solved REM oculd increase temperature of criticalpoints,alleviate band structnre and suppressgrowth of austenite grains.     

The Annual Meeting of IEC/CISPR of 2004 Held in Shanghai in September

The annual meeting of International Electrotech-nical Commission and International Special Committee on Radio Interference( IEC/CISPR ) 2004, which was sponsored by Standardization Administra-tion of China and China National Administration of IEC, organized by China National Technical Commit-tee for Standardization on Radio Interference as well as Shanghai Electrical Apparatus Research Institute where the Committee Secretariat is, was held in Yinghe Hotel, Shanghai from Septem…     

Three Concepts of Pressure Distribution in the Field of an Acoustic Emitter in Systems of Control of Gas–Liquid Flows

The structure of the field used in ultrasonic control of gas–liquid flows of a shortwave acoustic emitter (AE) of continuous harmonic oscillations and long pulses is considered. The formula for emission pressure in the paraxial domain of the field is verified.     

Specific Features of Structural Changes in Lanthanum–Nickel–Aluminum Alloys in the Process of Heating in Hydrogen

We study interactions in LaNi_{5 – x} Al _x –H₂ (x = 0, 0.2, 0.4, 0.6, and 0.8) systems by the methods of differential thermal and X-ray phase diffraction analyses within the temperature range from the room temperature to 920°C in hydrogen whose initial pressure can be as high as 5.7 MPa. In LaNi_{5 – x} Al _x –H₂ systems with x = 0, 0.2, and 0.4, the processes of formation and decomposition of the intermetallic hydride run without changes in its symmetry. The process of heating of LaNi_{5 – x} Al _x (x = 0, 0.2, and 0.4) alloys in hydrogen results in their homogenization. Thus, the process of heating of the LaNi_4.4Al_0.6 alloy in hydrogen to 700°C for an initial pressure of about 5.7 MPa results in a partial decomposition (disproportionation) of the original phase accompanied by the formation of lanthanum hydride and Ni₃Al. As a result of heating to 575°C in hydrogen ( 5.0 MPa), the LaNi_4.2Al_0.8 compound disproportionates into Ni₃Al and an unknown phase. After heating to 840°C followed by holding for 1.5 h, we detect the original phase, lanthanum hydride, Ni₃Al, and an unknown phase. At the same time, as a result of heating to 910°C followed by holding for 2 h, we observe the formation of a hydride of the original phase with doubled spacing c, lanthanum hydride, and Ni₃Al.     

Application of Mini Mills in China

The COREX(coal reduction process),EOF(energy optimizing furnace)andRCC-DR(rotary continuous casting-directreduction)process have been operatingcommercially in south Africa,Brazil andAustria respectively.The linkage of theseprocesses,the COREX-EOF-RCC-DRprocess,will be suited to small and medium-sized local steel plants in China,whereless scrap is available,electrical poweris expensive and resources of natural gasare scarce.     

Characterization of Iron Oxide Generated in Ruthner Plant of Pickling Unit in Mobarakeh Steel Complex

Reducing the chloride content in regenerated iron oxides (RIO) from steel-pickling acid waste economically treated by Ruthner process is the most critical issue for the development of RIO as a useful raw material resource. In this paper, the results of a new method for characterization and modification of RIO produced in Mobarakeh Steel Complex were reported.     

CAS-The Prospect of Work in 2006

Mission Statement China Association for Standardization (CAS) is to act as a bridge linking nationwide specialists in standardization with social communities. To meet the needs of government, society, market and enterprises, CAS endeavors to disseminate and popularize the standardization knowledge, organize academic forums and seminars, provide technical consultation on standardization, promote domestic and international cooperation and exchanges, and push forward the standardization process in China.     

Thermodynamics of Bainitic Formation in Carbon-depleted Region in Fe-C Alloys

Thermodynamic analysis for the formation of bainitic ferrite in carbon -depleted region has been conducted. The results show that the driving force of bainitic formation increases with depleting of carbon in parent austenite and with decreasing the transformation temperature. The critical driving force (absolute value) at the Bs temperature is 600-1 200 J / mol, which increases as the mean carbon content of Fe-C alloys increases. The freshly-formed bainitic ferrite has partial supersaturation of carbon, which increases smoothly with decreasing the transformation temperature Therefore, the displacive formation of bainitic ferrite in carbon-depleted region is thermodynamically feasible in the whole temperature range of bainitic reaction.     

Effectiveness of strategic environmental assessment in Germany? – meta-review of SEA research in the light of effectiveness dimensions

SEA practice in Germany has been growing since its introduction and so has the number of SEA research projects and publications. This paper provides a meta-review of German SEA effectiveness research published between 2004 and 2018. In this context, we discuss: (1) What is the status quo of SEA application in Germany? (2) What dimensions of SEA effectiveness have been addressed in research to date? and (3) How effective is SEA in Germany? Our findings indicate that there is room and need for SEA improvement, for example, with regards to the practice of screening, transparency, and quality management. With a focus of previous SEA research on the dimension of procedural effectiveness, future research should aim at other dimensions and their interactions (substantive, transactive, knowledge and learning, legitimacy).     

Microstructures in Al-richγ-TiAl strained in the domain of temperature of flow stress anomalies

The plastic behaviour of single-phaseγ-TiAl poses a certain number of fundamental problems as to the origin of the flow stress anomaly and to how this is related to dislocation properties. Understanding these questions is of significant interest in the investigations of flow stress anomalies in intermetallics and in other materials. Also, it may reveal useful in the study of theγ-based lamellar alloys. The present contribution accounts for an investigation of mechanical properties and microstructural organization conducted in Al-richγ-TiAl single crystals oriented to activate single slip. Three separate topics are addressed.

Behaviour of Hydrogen in Nano-transition Metals

Nanocrystalline transition metals were prepared with Ar+H2 arc plasma method. The hydrogenmust be used during preparation to get a special nanrvparticles. The hydrogen plays an importantrole in the structure and state of nanocrystalline transition metals. The state of hydrogen andthe change of the nanocrystalline metal structure caused by hydrogen are called the behaviour ofhydrogen in nano-transition metals which includes the ability and function of storing hydrogenin the metals.     

Photoluminescence of ZnS Clusters in Zeolite-Y

Two obvious emissions are observed from the ZnS clusters encapsulated in zeolite-Y. The emissionaround 355 nm is sharp and weak, locating at the onset of the absorption edge. The bandaround 535 nm is broad. Strong and Stokes-shifted. Both the two emissions shift to blue andtheir intensities firstly increase then decrease as the loading of ZnS in zeolite-Y or clusters sizedecreases. Through investigation, the former is attributed to the excitonic fluorescence, andthe latter to the trapped luminescence from surface States. The cluster size-dependence of theluminescence may be explained qualitatively by considering both the carrier recombination andthe nonradiative recombination rates. Four peaks appearing in the excitation spectra are assignedto the transitions of 1S-1S, 1S-1P, 1S-1D and sudsce state, respectively. The excitation spectraof the clusters do not coincide with their absorption spectra. The states splitted by quantum-sizeconfinement are detected in the excitation spectra, but could not be differentiated in the opticalabsorption spectra due to inhomogeneous broadening. The size-dependence of the excitationspectra is similar to that of the absorption spectra. Both the excitation spectra of excitonicand of trapped emissions are similar, but change in relative intensity and shift in position areobserved.     

Management of the Recall of Defective Motor Vehicles in China

The A dm inistrative Regulation on the RecallofD efective M otorV ehicles has officially entered into force on ctober1st,2004,w hich m eans the m anagem enton defective products has m ade a substantive progress.The enact- entand enforcem entofthe A dm inistrative Regulation has generated active responses in our society and draw n uch attention from the autom obile industry.U p to M arch 2005,there have been 15 dom estic and foreign auto m an-facturersinitiating voluntary recallssince the A…     

Reconfirmation of the existence of δ2 in dental amalgams

The 90°C endotherm peak in the thermogram of a conventional dental amalgam is due to two overlapping peritectic transitions involving SnHg-2 and HgAgSn-1, respectively. The aim of the present study is to separate these two events and thus confirm that the 2 phase is indeed a part of an amalgam microstructure. The materials used in this study were: sample 1, 1+1 wt% Sn; sample 2, 1+2 wt% Sn; sample 3, 1+3 wt% Sn; and sample 4, a commercial conventional amalgam with 48 wt% Hg. In powder form, they were exposed to 1 wt% NaCl solution at 37 °C for up to 45 days. At 15 day intervals, samples were withdrawn from the solution, washed, dried and then characterized by the differential scanning calorimetry (DSC) technique. Corrosion of Sn from ternary 1 matrix and intergranular 2 in respective materials during their exposure to the NaCl solution led to the following: (a) a progressive increase in 11 transition temperature in samples 1 and 2; (b) a gradual decrease in 2 peak and its disappearance in sample 2; and (c) in samples 3 and 4, initial splitting of the 90°C peak into two distinct endotherms associated with 2 and 1, respectively. Continued corrosion of the last two materials produced further changes in 2 and 1 in a manner similar to that seen in samples 1 and 2. On the basis of these observations, we have concluded that the 90°C endotherm is a valid indicator of the existence of the 2 phase in dental amalgams.     

Progress in Numerical Simulation of Solidification Process of Shaped Casting

Solidification simulation of manufacturing shaped casting which plays an important role in asSuring the soundness and quality of castings, in minimizing the trial production time and in reducing the manufacturing cost becomes one of the hottest topics of the new research frontiers of foundry technology at home and abroad. Practical three dimensional computer numerical simulation system for temperature distribution during solidification as well as shrinkage cavity and porosity prediction has already been put into application all over the world. Further fundamental researche5 on fluid flow, thermal stress and micro-modeling as well as practical approaches of numerical simulation of solidification process of shaped castings for routine analysis of foundry industry are still underway.     

Role of Pits in Corrosion Fatigue of Offshore Structural Steel

From the corrosion fatigue test under intermit-tent wetting condition for offshore structural steelof A537 cl.l and data analysis,some results associ-ated with the role of pits in fatigue process havebeen discussed.