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121.
Saima Yasin Tanveer Iqbal Fazeel Ahmad Hamayoun Mehmood Paul F. Luckham 《高分子科学杂志,A辑:纯化学与应用化学》2019,56(7):640-647
Nano-indentation is an interesting tool for analyzing nano-scale mechanical properties. The analysis of nano-mechanical properties as a function of experimental conditions is very critical for designing engineering components. In this study, nano-indentation experiments were performed by considering different values of amplitude (1, 5, 10?nm), frequency (11.2, 22.5, 45?Hz), strain rate (0.02, 0.05, 0.1, 0.2, 1?s?1), peak load (10, 30, 100?mN) and hold time (1, 3, 5, 10, 20, 50, 100?sec) to analyze their effect on the mechanical properties of LDPE. The results showed that the effect of amplitude and frequency on the nano-mechanical properties of LDPE were negligible. Load-displacement curves displayed a shift towards higher indentation depths along with a decrease in peak load from 20.6 to 14.8?mN by having a decrease in strain rate from 1 to 0.02?s?1. Elastic modulus and hardness values exhibited a decrease with an increase in hold time. Logarithmic creep model was used to fit the experimental data of creep as a function of holding time which showed good agreement (r2 ≥ 0.97) with the experimental values. Recommended holding times are also suggested to eliminate the creep and nose problem in order to achieve high accuracy in measurements. 相似文献
122.
123.
Islam Atif Yasin Tariq Akhtar Muhammad Javed Imran Zahid Sabir Aneela Sultan Misbah Khan Shahzad M. Jamil Tahir 《Journal of Solid State Electrochemistry》2016,20(2):571-578
Journal of Solid State Electrochemistry - Polymer films were cast from aqueous solutions of chitosan (CS) and poly(vinyl alcohol) (PVA) in employing tetraethoxysilane (TEOS) as a crosslinking... 相似文献
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125.
A. S. Yasin A. N. Pavlov A. E. Hramov 《Journal of Communications Technology and Electronics》2017,62(3):236-240
The problem of refinement of the quality of filtering of noisy audio signals with the help of the methods based on a discrete wavelet transform with real bases and a dual-tree (complex) wavelet transform using analytical wavelets as basis functions is considered. Test examples and processing of experimental data have shown that, in the case of the optimum selection of the threshold level, the approach using the dual-tree wavelet transform ensures the minimum signal reconstruction error after correction of wavelet coefficients. 相似文献
126.
A. S. Yasin A. N. Pavlov A. E. Hramov 《Journal of Communications Technology and Electronics》2016,61(2):145-150
The problem of digital wavelet filtering of noisy data is considered. The results are comparatively analyzed when the threshold function is specified in different ways for wavelet transformation coefficients. The influence of the choice of the wavelet basis on the efficiency of the noise removal is studied. It is shown that the minimum filtering error is in most cases provided when the soft variant of the threshold function introduction is introduced. 相似文献
127.
Keshavarz Mohammad Hossein Abadi Yasin Hayat Esmaeilpour Karim Damiri Sajjad Oftadeh Mohsen 《Chemistry of Heterocyclic Compounds》2017,53(6-7):797-801
Chemistry of Heterocyclic Compounds - This work uses density functional theory and suitable predictive methods to assess the effect of N-oxide group in 1,2-bis(6-nitro-1,2,4,5-tetrazin-3-yl)diazene... 相似文献
128.
Terhalle B Langner A Päivänranta B Guzenko VA David C Ekinci Y 《Optics letters》2011,36(21):4143-4145
We fabricate computer generated holograms for the generation of phase singularities at extreme ultraviolet (EUV) wavelengths using electron beam lithography and demonstrate their ability to generate optical vortices in the nonzero diffraction orders. To this end, we observe the characteristic intensity distribution of the vortex beam and verify the helical phase structure interferometrically. The presented method forms the basis for further studies on singular light fields in the EUV frequency range, i.e., in EUV interference lithography. Since the method is purely achromatic, it may also find applications in various fields of x ray optics. 相似文献
129.
Using a high loading of synthetic precipitated amorphous white silica nanofiller, an acrylonitrile–butadiene rubber containing 26% by weight acrylonitrile was crosslinked and its mechanical properties were measured. The silica surfaces were pre‐treated with bis(3‐triethoxysilylpropyl)tetrasulfide (TESPT) to chemically adhere silica to the rubber. To optimize the reaction between the tetrasulfane groups of TESPT and the rubber, accelerator and activator were added. The rubber was fully crosslinked and the hardness, tensile strength, stored energy density at break, elongation at break, tearing energy, and modulus increased substantially because of the filler. The bound rubber, crosslink density, tan δ, and glass transition temperature measurements indicated a strong interaction between the filler and rubber. This new method helped to substantially reduce the use of the curing chemicals and produce a safer and more cost‐effective rubber compound without compromising the good mechanical properties of the rubber, which are essential for long service life. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
130.
Deepika Sharma Roderick Y. H. Lim Thomas Pfohl Yasin Ekinci 《Particle & Particle Systems Characterization》2021,38(2):2000275
Nanoparticle trapping in a nanofluidic device utilizing geometry-induced electrostatic (GIE) potential trap is an efficient and robust way to perform nano‑object confinement and single particle studies. The GIE‑trapping is a passive method that solely depends on the device geometry and device-particle surface interaction. Therefore, optimization of a nanofluidic device based on experimental requirements, helps to achieve stiffer single-particle trapping. The efficiency of a GIE‑trapping device is defined in terms of residence time and trapping stiffness of the nanoparticle inside a potential trap. The present study reveals all crucial parameters that affect the device efficiency, particle trapping stiffness, and particle residence time. Furthermore, the trends of particle trapping stiffness are presented as a function of crucial parameters and demonstrate two variants of simulations to estimate the particle trapping efficiency: (a) using charged particle, and (b) using point charge approximation. Simulations with charged particle give more realistic values related to particle trapping whereas simulations with point charge approximation is a faster approach which gives approximate values and a guideline for more rigorous simulations. The results demonstrate a good agreement with experimental observations and hold the key for future developments in this field, wherein a device geometry can be very precisely optimized. 相似文献