Software requirements and acceptance testing

In this paper we 1) review industry acceptance testing practices and 2) present a systematic approach to scenario analysis and its application to acceptance testing with the aim to improve the current practice. It summarizes the existing practice into categories and identifies the serious weakness. Then, a new approach based on the formal scenario analysis is presented. It is systematic, and easily applicable to any software or system. A simple, yet realistic example is used to illustrate its effectiveness. Finally, its benefits and its applicability are summarized.     

Transferable belief model for decision making in thevaluation-based systems

We present a decision support system which is based on the transferable belief model (TBM), a model to represent someone's degree of belief based on belief functions. The system performs reasoning and decision making by integrating a system for belief propagation and a system for Bayesian decision analysis. The two subsystems are developed within the framework of the valuation-based systems. They are connected through the pignistic transformation as described in the context of the TBM. The system takes as inputs the user's beliefs and utilities, and suggests either the optimal decision or the optimal sequence of decisions. An example concerning a nuclear waste disposal problem is given to demonstrate the applicability of the system in a real-world domain     

Uniaxial and cubic anisotropy constants in ion-implanted Sm,Tm,Ga:YIG bubble thin films

The effects of ion implantation into (SmTmY)3(GaFe)5O12garnet thin films have been studied by ferromagnetic resonance. He+ ions were used for implantation with doses ranging from 3 to 4 × 10¹⁵He+/ cm²and implantation energy ranging from 150 to 175 Kev. The uniaxial and cubic anisotropy constants have been studied as a function of temperature from 0°C to 100°C for both as-grown and ion-implanted films. The implantation has effectively changed an easy-axis anisotropy to that of an easy plane in the implanted layers of the films. A cubic anisotropy constant K1with values varying from 4 × 10³to 6 × 10³erg/cm³at room temperature has been observed in these films. The results also indicated that to the first order, the implanted region in the film was essentially magnetically uncoupled from the bulk of the film.     

International intercomparison of absolute reflectance scales

An intercomparison of the absolute reflectance scales of NBS, Washington, D.C. (USA), NRC, Ottawa (Canada), and PTB, Braunschweig (FRG) was organized by sending two samples of Russian opal glass MS-20 to the three laboratories. An additional exchange of a Halon sample between NBS and NRC was arranged. The results of this intercomparison are presented. They show that the three different geometries used at the three laboratories yield values which agree to within ±0.1%.     

Multiple-copy-gene integration on chromosome of <Emphasis Type="Italic">Escherichia coli</Emphasis> for beta-galactosidase production

Recombinant E. coli strains with 1–3 copies of lacZ genes on their chromosomes were constructed and their β-galactosidase (β-gal) expressions were examined. Serial dilution cultures were used to analyze the long-term genetic stability of the recombinant lacZ genes of the chromosomal or plasmid expression system. The strain with a 3-copy lacZ on the chromosome has a sustainable β-gal expression through 60 hours. However, the β-gal activity of the plasmid expression system lasted less than 36 hours under a no selection condition. Obviously, the genetic stability of the chromosomal expression system demonstrated in this study is better than that of the plasmid expression system under nonselective condition, such as a medium without antibiotics. The results demonstrated that the strains with a multiple-copy-gene on the chromosome are useful for protein production in industrial repeated fed-batch fermentation. This work was presented at 13 ^th YABEC symposium held at Seoul, Korea, October 20–22, 2007.     

Development of zeptomole and attomolar detection sensitivity of biotin-peptide using a dot-blot gold nanoparticle immunoassay

An ultrasensitive, simple, and fast immunoassay for biotin-peptide detection using gold nanoparticles conjugated with antibodies has been developed. Biotin was covalently attached to a peptide and the biotin-peptide bound on a nitrocellulose membrane. Antibody-coated gold nanoparticles bound to the biotin-peptide formed red dots. With this method, 100 amol of the biotin-peptide was detected and no immunogold was bound to the membrane in the absence of biotin. The relative intensity of each dot was scored using Quantity One, a quantitative analysis software program. The linear working range of this assay was between 1 pmol and 1 micromol. The assay sensitivity was increased by silver enhancement to 100 zmol, and the linear working range was between 100 zmol and 100 fmol. This assay can be extended to detect target molecules, such as dioxin, digoxin, mercury, and so on, with matched antibodies and has potential broad applications in immunoassay.     

Fe3O4纳米封堵剂的制备、表征及封堵性能

通过热分解法制备了Fe₃O₄纳米封堵剂,利用傅里叶转换红外光谱（FT-IR）仪、X-射线衍射（XRD）仪、透射电镜对所制备的Fe₃O₄纳米粒子进行了结构表征,考察了Fe₃O₄在不同盐度NaCl溶液中稳定性及超声时间对Fe₃O₄纳米粒子在不同盐度NaCl溶液中分散稳定性的影响,并进行了人造泥饼模拟封堵实验。实验结果表明,Fe₃O₄纳米封堵剂最佳反应温度为200℃,最佳反应时间为2 h。FT-IR分析表明聚乙二醇修饰在纳米粒子表面,XRD分析表明所制备的Fe₃O₄纳米粒子属于立方晶相,TEM分析表明所制备的Fe₃O₄纳米粒子粒径在9.5 nm左右。超声0.5 h后的所制备的Fe₃O₄纳米粒子的耐盐分散性能最好。人造泥饼模拟实验结果表明,加入100 mL 质量分数为3%的Fe₃O₄纳米粒子水分散液,3.5 MPa压力下,7200 s后的滤失量只有11.3 mL,说明该纳米封堵剂堵水效果显著,是一种性能优异的纳米封堵材料。     

CO Catalytic Oxidation of Pt-Loaded Perovskite BaTiO_3 Near Ferroelectric-Phase Transition Temperature

Perovskite BaTiO_3(BTO) nanocrystals with a size of 150–200 nm have successfully been synthesized via a facile hydrothermal method by employing titanate nanowires as synthetic precursor. Tetragonality and spontaneous ferroelectric polarization of BTO nanocrystals have been determined by X-ray diffraction and transmission electron microscopy investigations. BTO nanocrystals loaded with Pt nanoparticles in a size of 2–5 nm have been explored as a catalyst towards CO oxidation to CO_2. It is interesting to find that CO catalytic conversion rate over Pt-BTO nanocrystals gradually decreased and further increased near 100 °C when the catalytic temperature keeps increasing, whereas the conversion behavior in oxides is expected to be enhanced upon the catalytic temperature grows. Using differential scanning calorimetry and first-principle calculations, the observed catalytic behavior has been discussed on the basis of the ferroelectric polarization effect and the ferroelectric–paraelectric transition of BTO nanocrystals with a Curie temperature of ~110 °C. Below Curie temperature, CO catalytic oxidation could be significantly tailored by ferroelectric polarization of BTO nanocrystals via a promoted dissociation of O_2 molecules. The findings suggest that a ferroelectric polarization in perovskite oxides could be an alternative way to modify the CO catalytic oxidation.     

Mechanical properties, deformation behaviors and interface adhesion of (AlCrTaTiZr)Nx multi-component coatings

In this study, (AlCrTaTiZr)N_x multi-component coatings with quinary metallic elements were developed as protective hard coatings for tribological application. The mechanical properties, creep behaviors, deformation mechanisms and interface adhesion of the (AlCrTaTiZr)N_x coatings with different N contents were characterized. With increasing the N₂-to-total (N₂ + Ar) flow ratio, R_N, during sputtering deposition, the (AlCrTaTiZr)N_x coatings transformed from an amorphous metallic phase to a nanocomposite and finally a crystalline nitride structure. The hardness of the coatings accordingly increased from 13 GPa to a high value of about 30 GPa, but the creep strain rate also increased from 1.3 × 10^− 4 to 7.3 × 10^− 4 1/s. The plastic deformation of the amorphous metallic coating deposited with R_N = 0% proceeded through the formation and extension of shear bands, whereas dislocation activities dominated the deformation behavior of the crystalline nitride coatings deposited with R_N = 10% and 30%. With increasing R_N, the interface adhesion energy between the coatings and the substrates was also enhanced from 6.1 to 22.9 J/m².