Comparative XPS analysis of passive layers composition formed on AISI 304 L SS after standard and high‐current density electropolishing

In the paper, there are described chemical compositions of passive surface layers formed on AISI 304 L (EN 1.4307) stainless steel after standard (EP50; i = 50 A/dm²) and high‐current density (EP1000; i = 1000 A/dm²) electropolishing. For the studies, a mixture of orthophosphoric and sulfuric acid electrolyte in proportion 1:4 was used. The survey and high‐resolution spectra of Cr 2p, Fe 2p, S 2p, P 2p, Ni 2p and C 1s are presented. On the basis of the obtained results it was noted that the chromium‐to‐iron ratio (Cr/Fe) after EP50 was about 3.5 times higher than that after EP1000 treatment. The phosphorus‐to‐sulfur ratios after EP50 and EP1000 electropolishing were 0.13 and 0.3, respectively, and nickel to the sum of chromium and iron coefficient (Ni/Cr + Fe) for both electrochemical polishing was equal to 0.04. Copyright © 2014 John Wiley & Sons, Ltd.     

Sc(Ⅲ)催化硫醇对邻亚甲基苯醌的亲核加成反应合成邻羟基苄硫醚衍生物

以2-[羟基(苯基)甲基]苯酚类化合物和简单的硫醇为原料, 1,2-二氯乙烷为溶剂, 在Sc(Ⅲ)促进下原位生成邻亚甲基苯醌, 并发生亲核加成反应构建邻羟基苄硫醚. 该反应在50 ℃下搅拌2 h即可完成, 目标产物产率82%95%. 反应可放大至克级规模.     

Immobilization of oligonucleotides onto silica nanoparticles for DNA hybridization studies

This paper describes the development of oligonucleotide-functionalized nanoparticles. We used disulfide-coupling chemistry for the immobilization of oligonucleotides onto silica nanoparticles and subsequently demonstrated the properties of the resulting DNA nanoparticles. Factors influencing the immobilization and hybridization processes were examined and optimized. The oligonucleotide-modified silica nanoparticles provide an efficient substrate for hybridization and can be used in the development of DNA biosensors and biochips.     

Synthesis, reactivity, electrochemical and crystallographic studies of diferrocenoyl diselenide and ferrocenoyl selenides

Diacyl diselenide (8), diacyl selenide (9) and acyl selenol esters (10-12) incorporating the ferrocenoyl substituent have been synthesized from ferrocene carboxylic acid (13). The new compounds (8-10) have been characterized by multinuclear NMR (¹H, ¹³C, ⁷⁷Se), IR spectroscopy and electrospray mass spectrometry. All compounds (8-13) undergo a one electron reversible oxidation at significantly more positive potential than ferrocene. The structures of the diselenide and selenide (8 and 10) have been confirmed by single crystal X-ray diffraction. The absolute structure parameter of 8 indicates that it crystallizes in an enantiomerically pure form. The peroxidase-like activities of the diselenide (8) and selenides (9-12) have been determined by the thiol assay.     

S1000D标准下数据模块发布样式的研究

【】：为了促进S1000D标准在以信息化为中心的综合保障技术中的应用,满足后勤保障信息的有效管理与使用,本文在研究了S1000D标准的基础上,重点研究了数据模块样式发布的方法。并以某一民用航空发动机的描述性信息数据模块为研究对象,研究了利用XSL-FO将XML文档到PDF文档格式的转换方法并实现了最终的展示效果。该方法对于相关标准和技术在实际工作中的应用具有重要的指导性意义。     

Electrical conduction measurement of thiol modified DNA molecules

We present a novel transport measurement of 60 base pairs of poly(dG)–poly(dC) DNA molecules. Thiol-terminated DNA molecules are chemically anchored at the surface of a Au nanoparticle and this DNA attached Au nanoparticle is self-trapped in between Au nanoelectrodes to make an electrical conduction channel. It provides an automatic electrical conduction channel consisting of electrode–DNA–nanoparticle–DNA–electrode. Due to robust bonding of thiol and Au, this transport channel is stable and reliable. The current–voltage characteristics measured from our device show a nonlinear behavior with voltage gaps comparable to previous experiment using the same molecules.     

Bestimmung von Epoxyendgruppen in modifizierten chromatographischen Sorbentien und Gelen

Zusammenfassung Zur Bestimmung der auf Silicagel oder Ethylenglykolmethacrylat-Gel Spheron chemisch gebundenen Epoxygruppen wurden die Methoden der Addition von Chlorwasserstoff aus einer Lösung von Pyridiniumchlorid in Pyridin, einer Lösung von Chlorwasserstoff in Dioxan oder Methylcellosolve, sowie die Addition von Thiosulfat und die direkte Titration mit Perchlorsäure in nichtwäßrigem Milieu in Anwesenheit von Tetraethylammoniumbromid untersucht und angewendet. Die besten Resultate mit einer guten Reproduzierbarkeit liefert die direkte Titration der in einer Tetraethylammoniumbromidlösung in Eisessig suspendierten Probe mit einer Perchlorsäurelösung in Eisessig. Die relative Standardabweichung in einem Bereich von 0,6–0,8 mmol Epoxygruppe/g ist nicht höher als 1%.

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Determination of epoxy end-groups in modified chromatographic sorbents and gels

Summary The addition of hydrogen chloride from solutions of pyridinium chloride in pyridine, or from solutions of hydrogen chloride in dioxan or in methylcellosolve, as well as the addition of thiosulphate and the direct non-aqueous titration with perchloric acid in the presence of tetraethylammonium bromide were studied and applied for the determination of bound epoxy groups in epoxidized silicagels and the ethyleneglycol methacrylate gels Spheron. Best results with high reproducibility were obtained by direct titration with perchloric acid of a sample suspended in a solution of tetraethylammonium bromide in acetic acid. The relative standard deviation in the range of 0.6–0.8 mmol epoxy group/g does not exceed 1%.

     

Biological efficacy of antisense oligonucleotides complementary to overlapping regions of the mRNA target

Phosphorothioate oligonucleotides complementary to target mRNA are stable in biological milieu and are capable of decreasing levels of this mRNA and the protein encoded by this mRNA (antisense knockdown). The results of our study are compared with the data published in the literature on the efficacy of three antisense 18—21-mer oligonucleotides, which are targeted to the start codon or nearby sequences of _2A-adrenoceptor mRNA, on receptor expression, and functions regulated by these receptors. The highest biological efficacy was shown by the oligonucleotide, which is complementary to the mRNA region and contains the largest number of unpaired bases in the theoretically calculated conformation corresponding to the free energy minimum. Targeting of both ends of the antisense on unpaired bases of the target also leads to the enhancement of its biological efficacy.     

AP1000屏蔽厂房在接触爆炸荷载作用下的非线性动力分析

屏蔽厂房是AP1000核岛厂房的第一层外部防线,确保屏蔽厂房在服役期间遭受爆炸冲击荷载作用下的安全性和完整性,十分重要。本文中,采用欧拉-拉格朗日算法(coupled Euler-Lagrange, CEL),对炸药在屏蔽厂房20种不同起爆部位作用下的动态破坏特征进行了研究,以结构贯穿破坏的损伤质量作为损伤程度的判别依据,着重探讨在不同起爆位置作用下结构的压力和损伤演化特性。研究表明：在接触爆炸荷载作用下,厂房在起爆点附近发生局部破坏;在相同高度下,环向不同角度起爆所引起的损伤程度差异较小,不同高度起爆的损伤程度差异较大。通过压力和损伤的演化分析,确定了屏蔽厂房最不利抗爆部位,对厂房不同部位的配筋策略提出建议。结论可为制定屏蔽厂房在爆炸冲击荷载作用下的安全防护措施提供参考依据。