稀土对6063铝合金导电性的影响

通过实验研究了稀土对6063铝合金导电性的影响。发现添加微量稀土对6063铝合金的导电性有好的影响；而人工时效时间对导电性也有影响，时效时间过长会降低导电性。     

Reduction property of rare earth oxide doped molybdenum oxide

Rare earth oxide doped molybdenum powders were prepared by the reduction of rare earth nitrites doped MoO3. The effect of rare earth oxide on the reduction behavior of molybdenum oxide had been studied by means of Temperature Programmed Reduction (TPR), thermal analysis, X-ray diffraction. Doping rare earth oxide in the powder could lower the reduction temperature of molybdenum oxide and decrease the particle size of molybdenum. The mechanism for the effects had been discussed in this paper.     

稀土金属真空提纯炉的研制

介绍了一种用于稀土金属提纯的单晶炉,根据区熔法提纯单晶的特殊工艺要求,分析了其主要结构及特点。该设备也适用于多种激光晶体的生长和激光晶体的真空退火。     

The Syntheses,Characterization and Crystal Structure of Extraction Complexes of Rare Earths

The syntheses,characterization and crystal structure of rare earth coordination compounds of five typicalextraction systems commonly used in the separation technology were reported.They are:(1)carboxylic acidsystem,(2)organophosphorous acid system,(3)quarternary ammonium salt system,(4)neutralorganophosphonate system and(5)synergistic system.     

Study on Differential Rate Kinetics Analysis Based on the Substitution Reaction of Rare Earth-PHA with CyDTA

The kinetic behaviours of the substitution reaction of rare earth-PHA with CyDTA were studied systemati-cally.The relationship between the rate constant and atomic number was discussed.The rate differentiation val-ue R_d(R_d=lgk_(z n)-lgk_z)was proposed to evaluate the possibility of differential kinetic analysis.The R_d valuebetween the neighbouring lanthanide ions first increases and then decreases along with increasing atomic number,so that the middle and heavy rare earth mixture(such as Sm-Gd and Gd-Y)are ideal systems for thedifferential rate kinetic analysis.     

把握稀土市场,发展湖南稀土工业

在叙述国内外稀土市场基本情况的基础上，指出我国稀土行业目前存在的问题，并提出了发展湖南稀土工业的建议。     

Organic Metallogeny of Weathering Crust RE Deposit

ＯｒｇａｎｉｃＭｅｔａｌｏｇｅｎｙｏｆＷｅａｔｈｅｒｉｎｇＣｒｕｓｔＲＥＤｅｐｏｓｉｔＣｈｅｎＺｈｉｃｈｅｎｇ（陈志澄）（ＧｕａｎｇｄｏｎｇＣｏｌｅｇｅｏｆＰｈａｒｍａｃｙ，Ｇｕａｎｇｚｈｏｕ５１０２２４，Ｃｈｉｎａ）ＹｕＳｈｏｕｊｕｎ（俞受均金）...     

ISRE: immersive scenario-based requirements engineering with virtual prototypes

Virtual prototyping is a useful approach for refining requirements for complex designs. However, the use of virtual reality (VR) technology can cause usability problems that can be interpreted as false positive requirements errors. The immersive scenario-based requirements engineering (ISRE) method guides the analysis of problems encountered during the testing of virtual prototypes and helps assign causes to either genuine requirements defects or to usability issues with VR technology. The method consists of techniques for walkthrough testing, testing with users, causal analysis of observed problems and the design of scenario-based analysis sessions. The method is described and its use illustrated with a case study of validating requirements for an aircraft maintenance application.     

Defining a Requirements Process Improvement Model

Both software organisations and the academic community are aware that the requirements phase of software development is in need of further support. We address this problem by creating a specialised Requirements Capability Maturity Model (R-CMM¹). The model focuses on the requirements engineering process as defined within the established Software Engineering Institute’s (SEI’s) software process improvement framework. Our empirical work with software practitioners is a primary motivation for creating this requirements engineering process improvement model. Although all organisations in our study were involved in software process improvement (SPI), they all showed a lack of control over many requirement engineering activities.This paper describes how the requirements engineering (RE) process is decomposed and prioritised in accordance with maturity goals set by the SEI’s Software Capability Maturity Model (SW CMM). Our R-CMM builds on the SEI’s framework by identifying and defining recommended RE sub-processes that meet maturity goals. This new focus will help practitioners to define their RE process with a view to setting realistic goals for improvement.Sarah Beecham is a research fellow in the Department of Maths and Computing in The Open University in the UK. She is currently working on the EPSRC funded CRESTES project () looking into modelling resource estimation for long-lived software. She has recently completed her PhD for a program of work entitled “A Requirements-based Software Process Maturity Model”. Current research interests are in estimation for software evolution and maintenance and in the general areas of software process improvement. Her particular research interests are in empirical methods in software engineering and requirements engineering.Tracy Hall leads the Systems & Software Research Group in the Department of Computer Science at the University of Hertfordshire. She specialises in the empirical investigation of technical and non-technical issues within software engineering. During the past ten years Tracy has successfully collaborated with many companies on a variety of research projects. She is very active in the Empirical Software Engineering community and is regularly invited to talk about empirical methods both in the UK and abroad. Tracy is an accomplished researcher having published over twenty high quality journal papers.Austen Rainer Austen Rainer is a senior lecturer at the University of Hertfordshire. He studied for his PhD at Bournemouth University, in conjunction with IBM Hursley Park. His current research interests include open source software development, longitudinal case study research, and the credibility of empirical evidence for researchers and software practitioners.     

微量RE和Al对Sn-9Zn焊料组织与性能的影响

采用正交试验研究了微量RE和Al对Sn-9Zn无铅焊料电导率、硬度、润湿性及微观组织的影响,并与传统锡铅焊料进行了对比。Sn-9Zn焊料的电性能及力学性能优于传统锡铅焊料,但润湿性较差。添加微量RE和Al可以显著提高Sn-9Zn合金铺展率、细化组织,且不降低焊料电导率和力学性能,最佳w(RE)和w(Al)分别为0.05%和0.10%,铺展率达到61.98%,与Sn-9Zn相比提高了13.40%,硬度为20.90HB,电导率为8.15×106S/m。