Expression of redesigned mussel silk-like protein in <Emphasis Type="Italic">Escherichia coli</Emphasis>

Silks have been used widely for human beings due to their several extraordinary properties. Until now, the studies on silk proteins have mainly focused on spiders and silkworms. Because silk properties are organism-dependent, novel silk protein types can be found and developed through investigation of new silk-bearing organisms. We noticed that marine mussel has silk-like domains containing many repeats with abundance of glycine and alanine. In the present work, we redesigned mussel-derived silk-like gene sequence which contains alternating repeated and nonrepeated regions with optimized codons for Escherichia coli. For successful expression of recombinant mussel silk-like protein in E. coli cells, we employed several experimental strategies, including use of strong promoter, cold shock expression, and genetic fusions. We observed significant repression on cell growths by even low expression levels of soluble mussel silk-like proteins in cold shock- and glutathione s-transferase (GST) fusion-based systems. Thus, we finally used baculoviral polyhedrin protein as a fusion partner and successfully expressed insoluble mussel silk-like protein with relatively high expression level and without cell growth repression in E. coli.     

Relationship between the crystallization behavior and the warpage of film‐insert‐molded parts

The dimensional variation of an injection‐molded, semicrystalline polymer part is larger than the variation of an amorphous polymer part because the shrinkage of a crystalline polymer is generally greater than the shrinkage of an amorphous one. We investigated the warpage of film‐insert‐molded (FIM) specimens to determine the effect of the crystallization behavior on the deformation of FIM parts. More perfect crystalline structures and higher crystallinity developed in the core region of the FIM specimens versus other regions. Relatively imperfect crystalline structures and low crystallinity developed in the adjacent regions of the inserted films, whereas a thin, amorphous skin layer developed in the adjacent regions of the metallic mold wall. The crystallizable substrate in the FIM specimens caused very large warpage because nonuniform shrinkage occurred in the thickness direction of the specimens. Therefore, the warpage of an experimentally prepared FIM poly(butylene terephthalate) specimen was greater than that predicted numerically because of its complex crystallization behavior. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

基于概率语言组合赋权与MULTIMOORA的多准则决策方法

针对传统的全乘比例多目标优化法(MULTIMOORA)存在的难以表征评价信息的模糊性和不确定性以及评价准则的权重需要从外部获取等问题,提出了一种改进的全乘比例多目标优化法,即基于概率语言组合赋权与MULTIMOORA的多准则决策方法.该方法采用概率语言(PLTS)处理决策者的评价信息,并引入改进的G1和CRITIC法构建组合优化赋权模型以计算评价准则的组合权重.实例对比实验结果表明,改进后的MULTIMOORA决策方法不仅赋权合理,而且具有更高的决策效率和鲁棒性,因此该方法对多准则决策问题具有良好的实际应用价值.     

Thermopower Enhancement of Bi2Te3 Films by Doping I Ions

The thermoelectric properties of I-doped Bi₂Te₃ films grown by metal-organic chemical vapor deposition have been studied. I-doped epitaxial (00l) Bi₂Te₃ films were successfully grown on 4° tilted GaAs (001) substrates at 360 °C. I concentration in the Bi₂Te₃ films was easily controlled by the variation in a flow rate of H₂ carrier gas for the delivery of an isopropyliodide precursor. As I ions in the as-grown Bi₂Te₃ films were not fully activated, they did not influence the carrier concentration and thermoelectric properties. However, a post-annealing process at 400 °C activated I ions as a donor, accompanied with an increase in the carrier concentration. Interestingly, the I-doped Bi₂Te₃ films after the post-annealing process also exhibited enhancement of the Seebeck coefficient at the same electron concentration compared to un-doped Bi₂Te₃ films. Through doping I ions into Bi₂Te₃, the thermopower was also enhanced in Bi₂Te₃, and a high power factor of 5 × 10^?3 W K^?2 m^?1 was achieved.     

Statistical Process Control‐Based Intrusion Detection and Monitoring

Intrusion detection systems have a vital role in protecting computer networks and information systems. In this article, we applied a statistical process control (SPC)–monitoring concept to a certain type of traffic data to detect a network intrusion. We proposed an SPC‐based intrusion detection process and described it and the source and the preparation of data used in this article. We extracted sample data sets that represent various situations, calculated event intensities for each situation, and stored these sample data sets in the data repository for use in future research. This article applies SPC charting methods for intrusion detection. In particular, it uses the basic security module host audit data from the MIT Lincoln Laboratory and applies the Shewhart chart, the cumulative sum chart, and the exponential weighted moving average chart to detect a denial of service intrusion attack. The case study shows that these SPC techniques are useful for detecting and monitoring intrusions. Copyright © 2013 John Wiley & Sons, Ltd.     

Effect of Ga doping concentrations,substrate temperatures and working pressures on the electrical and optical properties of ZnO thin films

We fabricated Ga-doped ZnO (GZO) thin films on glass substrate by RF magnetron sputtering method with different conditions of Ga₂O₃ concentration, substrate temperature and working pressure. Next we investigated the electrical, optical and structural properties of the GZO thin films. At a substrate temperature of 300 °C, a working pressure of 1 mTorr, and a Ga₂O₃ concentration of 3 wt%, the GZO thin films showed the lowest resistivity of 3.16 × 10^?4 Ω cm, a carrier concentration of 7.64 × 10²⁰ cm^?3 and a Hall mobility of 25.8 cm²/Vs. Moreover, the GZO thin films exhibited the highest (002) orientation under the same conditions and the full width at half maximum of X-ray peak was 0.34°. All GZO thin films showed the optical transmittance of more than 80 % in the visible range regardless of working conditions. The Burstein–Moss effect was observed by the change of doping concentration of Ga₂O₃. The GZO thin films were fabricated to have the good electrical and optical properties through optimizing doping concentration of Ga₂O₃, substrate temperature, working pressure. Therefore, we confirmed the possibility of application of GZO thin film as transparent conductive oxide used in flat panel display and solar cell.     

Modified physico–chemical properties and supercapacitive performance via DMSO inducement to PEDOT:PSS active layer

Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) was treated with dimethyl sulfoxide (DMSO) in order to modify it physico–chemical properties in an effort to improve its electrochemical performance. In this study, the conductivity of PEDOT:PSS was controlled through post-solvent treatment in DMSO for various dipping times. The maximum conductivity of the DMSO-treated PEDOT:PSS electrode was ∼1890 S cm⁻¹. The electrical conductivity, PEDOT to PSS ratio, chemical compositions, wettability, and surface roughness are correlated and suitably explained. The supercapacitive performance of the DMSO-treated PEDOT:PSS electrodes was studied in 1 M H₂SO₄ within an optimized potential window of 0 to −0.6 V versus Ag/AgCl. The maximum specific capacitance of the PEDOT:PSS electrode treated in DMSO for 60 min was found to be ∼153 F g⁻¹ at a 1 mA cm⁻² discharge current density (∼145 F g⁻¹ at a 10 mV s⁻¹ scan rate), along with an energy density of 93 W h kg⁻¹ and a power density of 4.6 kW kg⁻¹.