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921.
Dr. Hubert Gojzewski Dr. Michael Kappl Gunnar Kircher Dr. Wojciech Koczorowski Prof. Dr. Hans‐Jürgen Butt Dr. Arkadiusz Ptak 《Chemphyschem》2013,14(3):543-549
Nanoadhesion on a self‐assembled monolayer of 4‐methyl‐4′‐mercaptobiphenyl is measured using a modified atomic force microscope. The dependence of the adhesion force on the loading rate is analyzed with the Dudko–Hummer–Szabo model, and the kinetic and interaction potential parameters for a single terminal group are extracted. The energy and location of the activation barrier suggest that the adhesion is dominated by van der Waals dispersion forces. The humidity effect on the nanoadhesion is also studied. The results are compared with previously measured values for methyl‐terminated alkane thiols and the influence of the thiol rigidity on the adhesion force is discussed. 相似文献
922.
A. Mianowski 《Journal of Thermal Analysis and Calorimetry》2009,96(2):507-513
It was proved on the basis of Holba-Šesták equation (1972) that the one is very interesting point of view to define the relative
rate of reaction/process. Thereby, the assumption about interconnection between three-parametric equation and thermodynamic
condition determined by equilibrium conversion degree in given temperature, is strengthened. Further considerations, still
based on analysis of the inequality, made possible proposition of thesis about maximal rate of reaction/process in dynamic
conditions in relation to modified van’t Hoff’s isobar (equation). 相似文献
923.
基于分形维数的分析信号自适应中值滤波 总被引:3,自引:0,他引:3
提出一种面向分析仪器谱图信号处理的分形维自适应中值波方法(AMeFFD)。该法延拓运用分形理论,定义了相对点盒维数概念,由此建立建立判定脉冲型噪声的特异性指标,从而可自动调节中值滤波窗口宽度,有效地滤除脉冲型噪声及其它类噪声。对仿真色谱信号及实测色谱图的处理结果表明:AMeFFD法克服了经典中值滤波算法的缺陷,无论在信号的均方根偏差还是谱峰差等指标上,均明显优于后者,能在确保谱峰不畸变的同时更有效地滤除脉冲型常见噪声,是处理化学谱图信号的有力工具。 相似文献
924.
相配合的输入轴和输入主动锥齿轮在跑车过程中均失效,经过宏观分析、化学成分分析、金相分析及硬度检测、综合分析等理化检测方法,最终分析出其原因在于输入轴错料、基体硬度低导致花键部位因被主动锥齿轮花键部位严重挤压而磨损,并使输入主动锥齿轮接触疲劳崩齿断裂. 相似文献
925.
Yi Zhuang Chuanxiong Zhang Yumei Zhang Biao Wang Jianming Jiang 《Journal of Macromolecular Science: Physics》2013,52(4):601-614
A model suitable to polymeric nanocomposites was developed for the simulation of both low‐ and high‐speed melt spinning. Considering the different content of nanoparticles, different TiO2 modifications, and different take‐up speeds, various spinning parameters along the spinline, such as velocity gradient, tension, relative crystallinity, etc., were predicted. Calculations based on the model indicated that the addition of nanoparticles has a large effect on the spinning parameters, especially relative crystallinity, apparent elongational viscosity, and tensile force 相似文献
926.
The concept of a strong difference family formally introduced in Buratti [J Combin Designs 7 (1999), 406–425] with the aim of getting group divisible designs with an automorphism group acting regularly on the points, is here extended for getting, more generally, sharply‐vertex‐transitive Γ‐decompositions of a complete multipartite graph for several kinds of graphs Γ. We show, for instance, that if Γ has e edges, then it is often possible to get a sharply‐vertex‐transitive Γ‐decomposition of Km × e for any integer m whose prime factors are not smaller than the chromatic number of Γ. This is proved to be true whenever Γ admits an α‐labeling and, also, when Γ is an odd cycle or the Petersen graph or the prism T5 or the wheel W6. We also show that sometimes strong difference families lead to regular Γ‐decompositions of a complete graph. We construct, for instance, a regular cube‐decomposition of K16m for any integer m whose prime factors are all congruent to 1 modulo 6. © 2008 Wiley Periodicals, Inc. J Combin Designs 16: 443–461, 2008 相似文献
927.
韩英波 《高校应用数学学报(A辑)》2008,23(3)
讨论了具有双不变度量的李群中超曲面的广义Gauss映照,并且给出广义Gauss映照是相对仿射的一些条件. 相似文献
928.
纳米聚硅材料在油藏注水井中降压增注的室内研究 总被引:1,自引:0,他引:1
应用聚硅纳米材料在油田注水井中降压增注的室内实验表明,纳米聚硅材料能够改变岩石润湿性、提高水相相对渗透率,一同时说明聚硅材料易吸附于岩石表面能改变界面性质,其强憎水特性能够驱替吸附在孔隙内表面的水膜,扩大孔径.所以纳米聚硅材料能降低注水压力,提高注水量,具有较好的经济效益. 相似文献
929.
Shunsuke Moriya Kaori Iwasaki Keijiro Samejima Koichi Takao Kohfuku Kohda Kyoko Hiramatsu Masao Kawakita 《Analytica chimica acta》2012
An analytical method for the determination of three polyamines (putrescine, spermidine, and spermine) and five acetylpolyamines [N1-acetylspermidine (N1AcSpd), N8-acetylspermidine (N8AcSpd), N1-acetylspermine, N1,N8-diacetylspermidine, and N1,N12-diacetylspermine] involved in the polyamine catabolic pathway has been developed using a hybrid tandem mass spectrometer. Heptafluorobutyryl (HFB) derivatives of these compounds and respective internal standards labeled with stable isotopes were analyzed simultaneously by TOF MS, based on peak areas appearing at appropriate m/z values. The isomers, N1AcSpd and N8AcSpd were determined from their fragment ions, the acetylamidopropyl and acetylamidobutyl groups, respectively, using MS/MS with 13C2-N1AcSpd and 13C2-N8AcSpd which have the 13C2-acetyl group as an internal standard. The TOF MS method was successfully applied to measure the activity of enzymes involved in polyamine catabolic pathways, namely N1-acetylpolyamine oxidase (APAO), spermine oxidase (SMO), and spermidine/spermine N1-acetyltransferase (SSAT). The following natural substrates and products labeled with stable isotopes considering the application to biological samples were identified; for APAO, [4,9,12-15N3]-N1-acetylspermine and [1,4,8-15N3]spermidine (15N3-Spd), respectively; for SMO, [1,4,8,12-15N4]spermine and 15N3-Spd, respectively; and for SSAT, 15N3-Spd and [1,4,8-15N3]-N1-acetylspermidine, respectively. 相似文献
930.
Marco Righettoni Antonio Tricoli Samuel Gass Alex Schmid Anton Amann Sotiris E. Pratsinis 《Analytica chimica acta》2012
Breath analysis has the potential for early stage detection and monitoring of illnesses to drastically reduce the corresponding medical diagnostic costs and improve the quality of life of patients suffering from chronic illnesses. In particular, the detection of acetone in the human breath is promising for non-invasive diagnosis and painless monitoring of diabetes (no finger pricking). Here, a portable acetone sensor consisting of flame-deposited and in situ annealed, Si-doped epsilon-WO3 nanostructured films was developed. The chamber volume was miniaturized while reaction-limited and transport-limited gas flow rates were identified and sensing temperatures were optimized resulting in a low detection limit of acetone (∼20 ppb) with short response (10–15 s) and recovery times (35–70 s). Furthermore, the sensor signal (response) was robust against variations of the exhaled breath flow rate facilitating application of these sensors at realistic relative humidities (80–90%) as in the human breath. The acetone content in the breath of test persons was monitored continuously and compared to that of state-of-the-art proton transfer reaction mass spectrometry (PTR-MS). Such portable devices can accurately track breath acetone concentration to become an alternative to more elaborate breath analysis techniques. 相似文献