Adhesion of sputtered copper to plasma-treated polyimide substrates

We have studied the adhesion of a sputtered copper film (thickness 5000 Angstroms) to flexible polyimide substrates between 1 mil and 5 mil thick. The polyimide types include Kapton (based on the monomers of pyromellitic dianhydride and oxydialine, i.e., PMDA-ODA) and Upilex (based on the bi-phenyl tetracarboxylic dianhydride monomer). (A. S. Wood, 1988) For each of these polyimides, a clear difference in adhesion is observed when the polymer surface has been treated with a simple AC nitrogen glow discharge. We used a tape test to estimate the strength of the adhesion bond. The difference in adhesion only becomes apparent after the film and substrate have been subjected to either boiling water or steam for 30 minutes or more; the difference becomes quite clear after two hours. After two hours, about 100% of the copper film fails the adhesion tape test for an untreated polyimide surface; for a plasma modified surface, less than 1% of the copper film fails the tape test. In this thesis, we present experimental data on the effects of moisture, cleaning procedures, and plasma surface modification in copper - polyimide adhesion. A crude model of the AC discharge plasma is discussed

Age and mass studies for young star clusters in M31 from SEDs-fit

In this paper, we present photometry for young star clusters in M31, which are selected from Caldwell et al. These star clusters have been observed as part of the Beijing--Arizona--Taiwan--Connecticut (BATC) Multicolor Sky Survey from 1995 February to 2008 March. The BATC images including these star clusters are taken with 15 intermediate-band filters covering 3000--10000 \AA. Combined with photometry in the {\sl GALEX} far- and near-ultraviolet, broad-band $UBVRI$, SDSS $ugriz$, and infrared $JHK_{\rm s}$ of Two Micron All Sky Survey, we obtain their accurate spectral energy distributions (SEDs) from 1538-20000 \AA. We derive these star clusters' ages and masses by comparing their SEDs with stellar population synthesis models. Our results are in good agreement with previous determinations. The mean value of age and mass of young clusters ($<2$ Gyr) is about 385 Myr and $2\times 10^4 {M_\odot}$, respectively. There are two distinct peaks in the age distribution, a highest peak at age $\sim$ 60 Myr and a secondary peak around 250 Myr, while the mass distribution shows a single peak around $10^4 {M_\odot}$. A few young star clusters have two-body relaxation times greater than their ages, indicating that those clusters have not been well dynamically relaxed and therefore have not established the thermal equilibrium. There are several regions showing aggregations of young star clusters around the 10 kpc ring and the outer ring, indicating that the distribution of the young star clusters is well correlated with M31's star-forming regions. The young massive star clusters (age $\leq 100$ Myr and mass $\geq 10^4 {M_\odot}$) show apparent concentration around the ring splitting region, suggesting a recent passage of a satellite galaxy (M32) through M31 disk.Comment: Accepted for Publication in AJ, 15 pages, 14 figures and 4 table

Stochastic dynamical model for stock-stock correlations

We propose a model of coupled random walks for stock-stock correlations. The walks in the model are coupled via a mechanism that the displacement (price change) of each walk (stock) is activated by the price gradients over some underlying network. We assume that the network has two underlying structures, describing the correlations among the stocks of the whole market and among those within individual groups, respectively, each with a coupling parameter controlling the degree of correlation. The model provides the interpretation of the features displayed in the distribution of the eigenvalues for the correlation matrix of real market on the level of time sequences. We verify that such modeling indeed gives good fitting for the market data of US stocks

Optimization and evaluation of an influenza A (H5) pseudotyped lentiviral particle-based serological assay

Background: Novel serological methods provide alternative options for sero-diagnosis, sero-epidemiology and for determining evidence of naturally acquired or vaccine induced immunity. Micro-neutralization tests are currently the gold standard for serological studies of highly pathogenic avian influenza in mammalian species but require handling live virus in a biosafety level (BSL) 3 environment. We previously reported the use of H5 pseudotyped lentiviral particles (H5pp) as an alternative to micro-neutralization tests in a BSL-2 setting (Nefkens et al., 2007). Objective: To optimize and evaluate this newly developed H5pp assay on relevant clinical specimens. Study design: We optimise and evaluate the performance of the H5pp assay using well-characterized sera from humans with confirmed H5N1 disease or controls. Results: The H5pp assay is a reliable serological method for the detection and quantification of neutralizing antibody to H5-viruses. Conclusion: H5pp provide a reliable and safe alternative for sero-diagnosis and sero-epidemiology of H5N1 infections in a BSL-2 setting. © 2009 Elsevier B.V. All rights reserved.postprin

Effective DBHF Method for Asymmetric Nuclear Matter and Finite Nuclei

A new decomposition of the Dirac structure of nucleon self-energies in the Dirac Brueckner-Hartree-Fock (DBHF) approach is adopted to investigate the equation of state for asymmetric nuclear matter. The effective coupling constants of $\sigma$, $\omega$, $\delta$ and $\rho$ mesons with a density dependence in the relativistic mean field approach are deduced by reproducing the nucleon self-energy resulting from the DBHF at each density for symmetric and asymmetric nuclear matter. With these couplings the properties of finite nuclei are investigated. The agreement of charge radii and binding energies of finite nuclei with the experimental data are improved simultaneously in comparison with the projection method. It seems that the properties of finite nuclei are sensitive to the scheme used for the DBHF self-energy extraction. We may conclude that the properties of the asymmetric nuclear matter and finite nuclei could be well described by the new decomposition approach of the G matrix.Comment: 16 pages, 5 figure

Fermi level pinning on Si0.83Ge0.17 surface by inductively coupled plasma treatment

Effects of inductively coupled plasma (ICP) treatment on Fermi level pinning on the surface of Si0.83 Ge0.17 was studied by current-voltage and x-ray photoemission spectroscopy measurements. ICP treatment induced the growth of silicon oxide, suggesting that Si vacancies are generated under the oxide. From linear fitting of Schottky barrier heights with metal work functions, it was found that surface state density increased from 6.60?? 1012 to 1.13?? 1013 cm2 eV by the ICP treatment, leading to the pinning of surface Fermi level about EC ???0.53 eV. From this, it is suggested that the Si vacancies are the main surface states in pinning Fermi level on the ICP-treated surface.open1

Perverse incentives and invisible tradeoffs in subway construction in China: a case study of Hangzhou subway collapse

Abstract—Hangzhou subway collapse is the most serious subway construction disaster to date in China. In this article, the management and regulatory questions the collapse raised are focused and a case study of Hangzhou subway collapse is given. By regarding the contractual arrangement as an outcome of a power game of principal-agent, the social causes and the perverse incentives to strategic behaviors of the key players are investigated to explain the particular project outcomes. In the end, some policy suggestions are given for improving the safety performance of subway construction

BioDiVinE: A Framework for Parallel Analysis of Biological Models

In this paper a novel tool BioDiVinEfor parallel analysis of biological models is presented. The tool allows analysis of biological models specified in terms of a set of chemical reactions. Chemical reactions are transformed into a system of multi-affine differential equations. BioDiVinE employs techniques for finite discrete abstraction of the continuous state space. At that level, parallel analysis algorithms based on model checking are provided. In the paper, the key tool features are described and their application is demonstrated by means of a case study

Nouveauté or Cliché? Assessment on island ecological vulnerability to Tourism: Application to Zhoushan, China

In comparison with coastal zones, islands are even more vulnerable to anthropogenic disturbance, especially to tourism and tourism-induced activities. Despite a great number of studies on either island tourism or island vulnerability reviewed in this paper, knowledge and practice of the impact from tourism upon island ecological vulnerability (IEV) still needs to be expanded. In this contribution, the IEV of four administrative regions in Zhoushan, China is assessed between 2012 and 2017 based on an “exposure (E)-sensitivity (S)-adaptive capacity (A)” framework and by means of coupling coordination degree modeling (CCDM) for determination of the overall development level of E-S-A subsystems in each region. The assessment results show that: (1) An index system consisting of 1 objective, 3 sub-objectives, 7 elements, and 20 indicators can be established and tested to reflect the IEV to tourism; (2) As the most attractive tourist destinations, Shengsi and Putuo inevitably have the highest IEV values; (3) Dinghai's moderate low level of IEV comes as a surprise, due to its direct connectivity to its neighboring coastal city of Ningbo; (4) The more balanced the coupling coordination degree (CCD) values among E-S-A subsystems are, the higher the IEV values in the four tourist destinations of Zhoushan. In conclusion, tourism can be a double-edged sword for islands, the overall benefits of which outweigh the negative impacts upon island ecological conditions