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21.
Citation analyses were performed for Australian social science journals to determine the differences between data drawn from
Web of Science and Scopus. These data were compared with the tier rankings assigned by disciplinary groups to the journals
for the purposes of a new research assessment model, Excellence in Research for Australia (ERA), due to be implemented in
2010. In addition, citation-based indicators including an extended journal impact factor, the h-index, and a modified journal diffusion factor, were calculated to assess whether subsequent analyses influence the ranking
of journals. The findings suggest that the Scopus database provides higher number of citations for more of the journals. However,
there appears to be very little association between the assigned tier ranking of journals and their rank derived from citations
data. The implications for Australian social science researchers are discussed in relation to the use of citation analysis
in the ERA. 相似文献
22.
Tjeenk Marjjke Leuveling; Bulsink Yvonne B. M.; Slotboom Arend J.; Verheij Hubertus M.; Haas Gerard H.de; Demleitner Gaby; Gotz Friedrich 《Protein engineering, design & selection : PEDS》1994,7(4):579-583
The Staphylococcus hyicus lipase is an acyl hydrolase with broadsubstrate specificity including neutral glycerides and phospholipids.To obtain further insight into the mechanism of action of thisenzyme, we tested several sulfonyl fluorides as active site-directedinhibitors. The enzyme is resistant to the well-known serineprotease/esterase inhibitor phenylmethanesulfonyl fluoride (PMSF),but is rapidly inactivated by hexadecylsulfonyl fluoride. Thekinetics of inactivation were studied in Triton X-100 micelles.Inactivation is fast and the rate of inactivation is constantover the pH range where this lipase is active. Metal ions likeCa2+ and Sr2+ do not appreciably influence the rate of inactivation,although the enzymatic activity is significantly increased,suggesting a structural role for these ions. The S.hyicus lipasecontains a consensus sequence G-H/Y-S-X-G. Substitution by site-directedmutagenesis of this serine (Ser369) by a cysteine resulted ina mutant with only 0.2% residual activity. The activity of thismutant could not be inhibited with water-soluble sulfhydrylreagents either in the presence or absence of Triton X-100 micelles.In the presence of Triton X-100 micelles, inactivation of themutant occurred with 4-nitrophenylhexadecyl disulfide (t1/2= 125 min) while the wild-type enzyme does not react at all.We conclude that Ser369 is the active site residue and thatin water this residue is inaccessible. Only after interfacialactivation Ser369 (or Cys369) becomes exposed and reacts withirreversible inhibitors. 相似文献
23.
A.M. Al-Saie M. Bououdina A. Jaffar S. Arekat John M. Melnyczuk Ynhi T. Thai Christopher S. Brazel 《Journal of Alloys and Compounds》2011
Single and nanosized spinel CoFe2O4 phase has been prepared successfully by a simple combination of mechanical milling from a mixture of Fe2O3 and Co3O4 powder precursors followed by a subsequent annealing. X-ray diffraction analysis reveals that the estimated crystallite size of CoFe2O4 increases with increasing temperature but remains at the nanoscale, i.e. 85 nm at 900 °C. Moreover, magnetic measurements show that a great enhancement in the saturation magnetization was achieved whereas a large hysteresis loop was observed (i.e.72 emu/g at 900 °C). Evaluation and applicability of CoFe2O4 nanoparticles under high frequency AC magnetic field for heating in biomedical applications were examined. It was found that under fixed amplitude (516 Oe) and frequency (229 kHz), the prepared nanoparticles generate significant heat: after 5 s the temperature was around 97 °C for the as-milled powder and reached almost 178 °C for the powder annealed at 900 °C. 相似文献
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26.
Steve Schneider Thai Son Hoang Ken Robinson Helen Treharne 《Electronic Notes in Theoretical Computer Science》2005,137(2):183
The introduction of probabilistic behaviour into the B-Method is a recent development. In addition to allowing probabilistic behaviour to be modelled, the relationship between expected values of the machine state can be expressed and verified. This paper explores the application of probabilistic B to a simple case study: tracking the volume of liquid held in a tank by measuring the flow of liquid into it. The flow can change as time progresses, and sensors are used to measure the flow with some degree of accuracy and reliability, modelled as non-deterministic and probabilistic behaviour respectively. At the specification level, the analysis is concerned with the expectation clause in the probabilistic B machine and its consistency with machine operations. At the refinement level, refinement and equivalence laws on probabilistic GSL are used to establish that a particular design of sensors delivers the required level of reliability. 相似文献
27.
Gas Sensors: High Performance Three‐Dimensional Chemical Sensor Platform Using Reduced Graphene Oxide Formed on High Aspect‐Ratio Micro‐Pillars (Adv. Funct. Mater. 6/2015) 下载免费PDF全文
28.
Chin-Chen Chang Thai Son Nguyen Chia-Chen Lin 《Journal of Visual Communication and Image Representation》2011,22(7):664-672
Data hiding is designed to solve the problem of secure information exchange through public networks such as Internet. In this paper, we present an improved reversible data hiding scheme that can recover original VQ indices after data extraction. As with Chang et al.’s scheme, our proposed scheme also depends on the locally adaptive coding scheme. However, experimental results confirm that the hiding capacity of our proposed scheme is around 1.36 bpi in most digital images, which is typically higher than that of Chang et al.’s [17]. Moreover, the average compression rate that can be achieved with our proposed scheme is 0.49 bpp, which outperforms both Lin and Chang’s scheme (0.50 bpp), Tsai (0.50 bpp), Chang et al.’s scheme (0.53 bpp), and Yang and Lin’s scheme (0.53 bpp). 相似文献
29.
提出一种精确的计算方法,用于地震作用下悬索桥的非线性时程分析。该方法考虑了几何非线性和材料非线性。利用稳定函数分析桥塔和主梁的几何非线性,而用弹性悬链线的精确解析方程分析索杆的几何非线性。利用切线模量概念和精细塑性铰模型按构件长度和截面划分屈服等级。给出一种基于Newton-Raphson法的Newmark平均加速算法。计算结果与商业软件SAP2000的分析结果吻合,说明该计算程序准确有效。 相似文献
30.
This paper presents closed-form solution for buckling analysis of orthotropic plates using two variable refined plate theory. The theory accounts for a quadratic variation of the transverse shear strains across the thickness, and satisfies the zero traction boundary conditions on the top and bottom surfaces of the plate without using shear correction factors. Governing equations are derived from the principle of minimum total potential energy. The closed-form solutions of rectangular plates with two opposite edges simply supported and the other two edges having arbitrary boundary conditions are obtained by applying the state space approach to the Levy-type solution. Comparison studies are performed to verify the validity of the present results. The effects of boundary condition, loading condition, and variations of modulus ratio, aspect ratio, and thickness ratio on the critical buckling load of orthotropic plates are investigated and discussed in detail. 相似文献