添加微量铝对TS-2合成及苯酚羟基化的影响

以硅溶胶为硅源合成分子筛TS 2时 ,在溶胶制备过程中添加微量的铝 ,可以降低模板剂氢氧化四丁基铵 (TBAOH)的用量 ,当TBAOH/SiO2 降低到 0 .1以下时 ,仍然合成了性能优良的TS 2 ,而且用于苯酚过氧化氢羟基化反应过程中催化活性也大大提高。所得催化剂用XRD ,IR ,ICP进行了表征     

A data porting tool for coupling models with different discretization needs

The presented work is part of a larger research program dealing with developing tools for coupling biogeochemical models in contaminated landscapes. The specific objective of this article is to provide researchers with a data porting tool to build hexagonal raster using information from a rectangular raster data (e.g. GIS format). This tool involves a computational algorithm and an open source software (written in C). The method of extending the reticulated functions defined on 2D networks is an essential key of this algorithm and can also be used for other purposes than data porting. The algorithm allows one to build the hexagonal raster with a cell size independent from the geometry of the rectangular raster. The extended function is a bi-cubic spline which can exactly reconstruct polynomials up to degree three in each variable. We validate the method by analyzing errors in some theoretical case studies followed by other studies with real terrain elevation data. We also introduce and briefly present an iterative water routing method and use it for validation on a case with concrete terrain data.     

Connectivity Infrastructure and Components for POCT Environments - Overall Infrastructure

Connectivity infrastructure, hardware and software components for point-of-care testing (POCT) environments at medium-to-large sized hospitals with expected number of POCT instruments in the order of hundreds or thousands are described. The instruments include both network-ready and non-network-ready devices. The latter are connected to the network by means of a hardware-based Instrument Network Adapter. Instrument messages are converted to standardized form and, depending on message content, are routed and delivered to appropriate destinations by a software-based Message Routing System consisting of a Message Router and a Delivery Agent. Target information systems consist of departmental and central information systems.     

PM 2 Tec 2003: PM industry turning the corner

Abstract

MPIF's 2003 International Conference on Powder Metallurgy and Particulate Materials in Las Vegas attracted 1100 delegates from more than 30 countries. JOSEPH M. CAPUS reviews the event, while JOHN DUNKLEY assesses developments pointing the way to higher density, higher performance PM components.     

Serrated yielding in Cu-1 wt-%Cd alloy

Abstract

The influence of grain size and temperature on the serration patterns of the Portevin-Le Chatelier (PLC) effect and on the yield and flow stresses in a Cu-1 wt-%Cd alloy was investigated in the temperature range 150 to 360 ° C. Two kinds of serration patterns were observed in this alloy. Type I occurred at lower temperatures and its yield points are moderately spaced. Type II consists of regular jerky flow observed athigher temperatures. The Hall-Petch equation is obeyed over the temperature range in which jerky flow occurs. The Hall-Petch parameter k (?) is observed to show a local maximum in the temperature range where serrated flow is first observed. The PLC effect is associated with the solute- dislocation interactions, implying that k (?) contains a component associated with grain size dependent dislocation storage.     

Effect of vapour phase hydrogen peroxide,as a decontaminant for civil aviation applications,on microstructure,tensile properties and corrosion resistance of 2024 and 7075 age hardenable aluminium alloys and 304 austenitic stainless steel

Abstract

A response to the chemical or biological contamination of aircraft requires the use of a suitable decontaminant. Among possible chemical decontaminants, vapour phase hydrogen peroxide appears to be a likely candidate in terms of a combination of efficacy, low environmental impact and potential for materials compatibility. The present paper examines the effect of hydrogen peroxide, both in the vapour phase and as a liquid concentrate on two common structural materials used in aviation, namely 2024 and 7075 age hardenable aluminium alloys and on 304 austenitic stainless steel, the latter as employed in galley and lavatory surfaces. The present paper characterises both the effects of hydrogen peroxide on the microstructure of the materials and the impact that decontamination has on the tensile properties and corrosion resistance of these materials. Microstructural effects are both relatively small in magnitude and confined to a region immediately beside the exposed surface. No systematic effect is found on either the tensile properties or the post-exposure corrosion resistance of the three alloys examined. These observations are encouraging in terms of the use of vapour phase hydrogen peroxide for decontamination applications.     

International Working Group for Sabotage Concerns of Transport and Storage Casks

Abstract

The International Working Group for Sabotage Concerns of Transport and Storage Casks (IWGSTSC), gathers multiple organisations from different countries (for US party Department of Energy, Nuclear Regulatory Commission, and Sandia National Laboratories; for German party Gesellschaft für Anlagen- und Reaktorsicherheit and Fraunhofer Institut; for the French party Institut de Radioprotection et de Sûreté Nucléaire). The goal of the IWGSTSC is to continue cooperation to improve the analytic capabilities, through information sharing and collaborative research and development plus modelling, to understand the potential adverse public health effects and environmental impacts of radiological sabotage directed at or associated with the transport and storage of civilian nuclear material or other civilian radioactive materials. The Parties may also undertake collaborative research and development in other areas of the physical protection of civilian nuclear materials or other radioactive materials. Since 2000, the IWGSTSC has conducted an extensive test programme for the assessment of the aerosol source term produced in the case of spent fuel transport sabotage by a high energy density device, after having examined several scenarios. The major goal of this programme is to produce an accurate estimate of the so called spent fuel ratio in the domain of respirable, aerosol particles produced. All the reports prepared by Sandia National Laboratories have precisely emphasised the important efforts they have made from the beginning and the amount of work already accomplished. In parallel, the International Atomic Energy Agency (IAEA), assisted by technical experts from different countries, has provided a draft document promised to become guidance for the security of radioactive or nuclear materials during transport. The IAEA document contains general guidance addressed to anyone who intends to implement or improve the security of material transports, but the text is, as of today, limited to rather general recommendations. Based on all the knowledge accumulated from past experiments and also based on the work carried out in Vienna at the IAEA, the IWGSTSC members have decided to work on the development of a method for the evaluation of the vulnerability and the source term. So for doing that, joint projects for the research, development, testing and evaluation of the consequences of the malevolent actions during transport are being pursued and are described in this paper.     

Transport of large nuclear power plant components: experiences in mechanical design assessment

Abstract

In the course of decommissioning of power plants in Germany large nuclear components (steam generator, reactor pressure vessel) must be transported over public traffic routes to interim storage facilities, where they are dismantled or stored temporarily. Since it concerns surface contaminated objects or low specific activity materials, a safety evaluation considering the IAEA transport regulations mainly for industrial packages (type IP-2) is necessary. For these types of industrial packages the requirements from normal transport conditions are to be covered for the mechanical proof. For example, a free drop of the package from a defined height, in dependence of its mass, onto an unyielding target, and a stacking test are required. Since physical drop tests are impossible generally due to the singularity of such 'packages', a calculation has to be performed, preferably by a complex numerical analysis. The assessment of the loads takes place on the basis of local stress distributions, also with consideration of radiation induced brittleness of the material and with consideration of recent scientific investigation results. Large nuclear components have typically been transported in an unpackaged manner, so that the external shell of the component provides the packaging wall. The investigation must consider the entire component including all penetration areas such as manholes or nozzles. According to the present IAEA regulations the drop position is to be examined, which causes the maximum damage to the package. In the case of a transport under special arrangement a drop only in an attitude representing the usual handling position (administratively controlled) is necessary. If dose rate values of the package are higher than maximum allowable values for a public transport, then it is necessary that additional shielding construction units are attached to the large component.     

Tensile and fatigue properties of cold and warm compacted Alumix 431 alloy

Abstract

In this experimental study, tensile and fatigue properties of the Alumix 431 alloy (Al, Zn, Mg and Cu alloys) produced using the conventional press and sinter processes in different pressures and temperatures are investigated. The results clearly showed that the warm compacted specimens can reach the mechanical properties of the cold compacted ones under less pressure. In the fatigue tests it was observed that fracture started from large pores as shown in all scanning electron microscope (SEM) examinations and ductile fracture occurred. 85% of the 180 MPa/80°C and 77% of the 230 MPa/RT specimens fractured at the machined surface. Tensile and fatigue properties of warm compacted (180 MPa/80°C) and cold (230 MPa/RT) compacted specimens are almost equal at these same densities. This result indicates the economic benefit of warm compaction by the much lower applied compaction pressure.     

Tensile creep behaviour of NiAl-Cr(Zr) multiphase intermetallic alloy

Abstract

The microstructure of a multiphase NiAl-33.5Cr-0.5Zr intermetallic alloy was examined by SEM with energy dispersive spectroscopy and TEM. The tensile creep behaviour of the hot isostatically pressed NiAl-33.5Cr-0.5Zr alloy was studied. The results of the creep test indicated that all of the creep curves under the present test have similar characteristics: a short primary creep stage, a dominant tertiary creep stage, and nearly identical creep strains (~45%). The apparent stress exponent and the apparent activation energy were analysed and discussed. The mechanism of the creep deformation was also analysed by the observation of TEM.