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排序方式: 共有213条查询结果,搜索用时 15 毫秒
61.
The technique of atomic force microscopy (AFM) has been used to obtain comparative evaluation of scratch damage in polymeric materials (low‐ and high‐crystallinity poly(propylene)s and ethylene‐propylene diblock copolymers) and examine the surface deformation processes. A comparative assessment of scratch damage is made in terms of average surface height of the plastically deformed region, and the depth, thickness, and density of the scratch tracks. The resistance to scratch deformation under identical conditions of scratch test follows the sequence: high‐crystallinity poly(propylene)s > low‐crystallinity poly(propylene)s > ethylene‐propylene diblock copolymers. Additionally, short‐chain polymers are characterized by a greater resistance to mechanical deformation than their respective long‐chain polymers. The scratch tracks in low‐ and high‐crystallinity poly(propylene)s are zig‐zag in shape, while in ethylene‐propylene diblock copolymers they are parabolic with localized plastic flow involving voids. The AFM observations suggest that higher tensile modulus and higher yield stress are key factors responsible for superior resistance to mechanically induced deformation in high‐crystallinity poly(propylene)s.
62.
Tihamer Levendovszky Daniel Balasubramanian Anantha Narayanan Feng Shi Chris van Buskirk Gabor Karsai 《Software and Systems Modeling》2014,13(2):807-823
One of the main advantages of defining a domain-specific modeling language (DSML) is the flexibility to adjust the language definition to changing requirements or in response to a deeper understanding of the domain. With the industrial applications of domain-specific modeling environments, models are valuable investments. If the modeling language evolves, these models must be seamlessly migrated to the evolved DSML. Although the changes stemming from the language evolution are not abrupt in nature, migrating existing models to a new language is still a challenging task. Our solution is the Model Change Language (MCL) tool set, which defines a DSML to describe the migration rules and then performs the model migration automatically. In this paper, we describe the precise semantics of MCL and its execution, along with the confluence of the migration. 相似文献
63.
Puneet P. Newaskar Raul Blazquez Anantha P. Chandrakasan 《Journal of Signal Processing Systems》2005,39(1-2):175-188
Ultra wideband radio (UWB) is a new wireless technology that uses narrow pulses to transmit information. Implementing an “all-digital” UWB receiver has numerous potential benefits ranging from low-cost and ease-of-design to flexibility. Digitizing an RF signal near the antenna, however, introduces its own set of challenges and has traditionally been considered infeasible. A high-speed, high-resolution analog-digital converter (ADC) is difficult to design, and is extremely power-hungry. The viability of an “all-digital” architecture, therefore, hinges upon the specifications of this block. In this paper, we demonstrate that 4 bits of resolution are sufficient for reliable detection of a typical UWB signal that is swamped in noise and interference. 相似文献
64.
Gopalan AI Lee KP Hong MH Santhosh P Manesh KM Kim SH 《Journal of nanoscience and nanotechnology》2006,6(6):1594-1601
Hollow spheres of poly(diphenylamine) (PDPA) was prepared by confining PDPA in the galleries of montmorillonite organo clay modified with organoammonium cations (MMT). At first instant, diphenylamine (DPA) was loaded into the galleries of MMT and subjected to subsequent oxidative polymerization to form PDPA. beta-naphthalene sulfonic acid (NSA) was used as medium to influence self-assembly of DPA inside the galleries of MMT. Polymerization of self assembled structure resulted hollow spheres of PDPA inside galleries of MMT. X-ray diffraction analysis (XRD), field emission transmission electron microscopy (FETEM), Fourier transform infra-red spectroscopy (FT-IR) and thermogravimetric analysis (TGA) were used to characterize the composites. Transmission emission microscopy of the composite shows the hollow spherical morphology of PDPA. FT-IR, UV-Visible spectroscopy, conductivity measurement and X-ray photoelectron spectroscopy were used to characterize the PDPA extracted from MMT galleries. PDPA extracted from MMT galleries was found to have difference in electronic property than PDPA formed by the conventional method, due to the confinement effect. 相似文献
65.
Barman I Dingari NC Kang JW Horowitz GL Dasari RR Feld MS 《Analytical chemistry》2012,84(5):2474-2482
In recent years, glycated hemoglobin (HbA1c) has been increasingly accepted as a functional metric of mean blood glucose in the treatment of diabetic patients. Importantly, HbA1c provides an alternate measure of total glycemic exposure due to the representation of blood glucose throughout the day, including post-prandially. In this article, we propose and demonstrate the potential of Raman spectroscopy as a novel analytical method for quantitative detection of HbA1c, without using external dyes or reagents. Using the drop coating deposition Raman (DCDR) technique, we observe that the nonenzymatic glycosylation (glycation) of the hemoglobin molecule results in subtle but discernible and highly reproducible changes in the acquired spectra, which enable the accurate determination of glycated and nonglycated hemoglobin using standard chemometric methods. The acquired Raman spectra display excellent reproducibility of spectral characteristics at different locations in the drop and show a linear dependence of the spectral intensity on the analyte concentration. Furthermore, in hemolysate models, the developed multivariate calibration models for HbA1c show a high degree of prediction accuracy and precision--with a limit of detection that is a factor of ~15 smaller than the lowest physiological concentrations encountered in clinical practice. The excellent accuracy and reproducibility achieved in this proof-of-concept study opens substantive avenues for characterization and quantification of the glycosylation status of (therapeutic) proteins, which are widely used for biopharmaceutical development. We also envision that the proposed approach can provide a powerful tool for high-throughput HbA1c sensing in multicomponent mixtures and potentially in hemolysate and whole blood lysate samples. 相似文献
66.
Annrose J. Rufus N. Herald Anantha Rex C. R. Edwin Selva Immanuel D. Godwin 《Wireless Personal Communications》2022,122(4):2995-3017
Wireless Personal Communications - Bean which is botanically called Phaseolus vulgaris L. belongs to the Fabaceae family. Unnecessary economic losses arise during bean disease identification due to... 相似文献
67.
Ankalagiri Chinna Venkata Ramudu Kempannagari Anantha Kumar Vangala Sugunamma Naramgari Sandeep 《亚洲传热研究》2020,49(8):5020-5037
The foremost objective of the current article is to explore the impact of Brownian motion on magnetohydrodynamic Casson nanofluid flow toward a stretching sheet in the attendance of nonlinear thermal radiation. The combined heat and mass transfer characteristics are investigated. The influence of chemical reaction, nonuniform heat source/sink, Soret, and Dufour is deemed. The convective boundary condition is taken. The appropriate transformations are utilized to transform the flow regulating partial differential equations into dimensionless ordinary differential equations (coupled). The numerical outcomes of the converted nonlinear system are solved by the Runge-Kutta based Shooting procedure. Results indicate that the temperature is an increasing function of both thermophoresis and Brownian motion parameters. The concentration of the fluid and the corresponding boundary layer thickness reduces with an enhancement in Lewis number. 相似文献
68.
Ramesh Dasari Dr. James J. La Clair Prof. Alexander Kornienko 《Chembiochem : a European journal of chemical biology》2017,18(18):1792-1796
The application of new chemical reactions in a biological context has advanced bioconjugation methods for both fundamental research and commercial arenas. Recent adaptations of reactions such as Huisgen 1,3‐dipolar or Diels–Alder cycloadditions have enabled the labeling of specific residues in biomolecules by the attachment of molecules carrying azides, alkynes, or strained alkenes. Although these are fundamental tools, there is a need for the discovery of reactions that can label native proteins. We report herein the adaptation of the Paal–Knorr reaction to label lysine residues in proteins via pyrrole linkages. 相似文献
69.
Two‐Photon Luminescence and Second‐Harmonic Generation in Organic Nonlinear Surface Comprised of Self‐Assembled Frustum Shaped Organic Microlasers 下载免费PDF全文
70.
We describe experiments to measure the spatial and the temporal distribution of photons traversing a turbid medium in the early-arriving regime in which the photons are multiply scattered but are not completely randomized. The photon paths are resolved temporally by a streak camera and spatially by an adjustable absorbing screen with a small aperture. The results are compared with predictions of a theory based on path integrals (PIs) and with the standard diffusion approximation. The PI theory agrees with the data for both long and short times of flight; this agreement is in contrast to the diffusion approximation, which fails for short times. An alternative PI calculation, based on the use of an effective Lagrangian, also agrees with the experiments. PI theory succeeds because it preserves causality. The implications for optical tomography are discussed. 相似文献