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In a pneumatic tire, the contained air carries the load of the vehicle and also augments performance for other functional requirements, such as, rolling resistance, ride and handling, durability, and so on. The inner liner of the tire is responsible to ensure air retention by virtue of its high air impermeability. The present study focused on developing inner-liner compounds of improved air impermeability by utilizing platelet filler (layered silicate). The obtained organoclay was subjected to a pre-treatment process called exfoliation to increase the d spacing between the clay layers that further improved the morphological aspect of the compound. The inner-liner compound has been modified by partial replacement of carbon black with organically modified bentonite clay in 1:1 and 2.5:1 ratio. Air impermeability of rubber compounds was tested in a gas permeability tester. Field emission scanning electron microscope, transmission electron microscope, atomic force microscope, and x-ray diffraction were utilized to understand the distribution and dispersion of clay in the rubber compounds. Fatigue crack growth analysis was carried out to measure the fatigue life of the materials. The modified compounds exhibited air impermeability improvement from 7% to 30% vs the reference carbon-black filled compound with improved mechanical properties and filler dispersion.  相似文献   
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With increasing faults and attacks on the Internet infrastructure, there is an impending need to provide automatic techniques to detect and mitigate the impact of attacks on network services. Denial-of-service attacks have been successful in denying legitimate traffic access to its required resources because existing routing protocols treat the attacking traffic equally as any normal traffic. This paper presents a proactive network defense framework that can be integrated with existing quality-of-service (QoS) protocols to provide differentiated services to network traffic flows based on their distance from the normal behavior. We introduce a new metric that we refer to as abnormality distance (AD) metric that can be used to classify traffic into normal, probable normal, probable abnormal (suspicious traffic), and abnormal (attacking traffic). The AD metric can then be used in conjunction with any QoS protocol to give high priority to normal traffic and lower priority to abnormal traffic. We demonstrate through several examples, how our approach can dynamically detect attacks, quantify their impact, and how to reduce the impacts and recover from them.  相似文献   
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In the search for effective multifunctional agents for the treatment of Alzheimer’s disease (AD), a series of novel hybrids incorporating benzofuran and chalcone fragments were designed and synthesized. These hybrids were screened by using a transgenic Caenorhabditis elegans model that expresses the human β‐amyloid (Aβ) peptide. Among the hybrids investigated, (E)‐3‐(7‐methyl‐2‐(4‐methylbenzoyl)benzofuran‐5‐yl)‐1‐phenylprop‐2‐en‐1‐one ( 4 f ), (E)‐3‐(2‐benzoyl‐7‐methylbenzofuran‐5‐yl)‐1‐phenylprop‐2‐en‐1‐one ( 4 i ), and (E)‐3‐(2‐benzoyl‐7‐methylbenzofuran‐5‐yl)‐1‐(thiophen‐2‐yl)prop‐2‐en‐1‐one ( 4 m ) significantly decreased Aβ aggregation and increased acetylcholine (ACh) levels along with the overall availability of ACh at the synaptic junction. These compounds were also found to decrease acetylcholinesterase (AChE) levels, reduce oxidative stress in the worms, lower lipid content, and to provide protection against chemically induced cholinergic neurodegeneration. Overall, the multifunctional effects of these hybrids qualify them as potential drug leads for further development in AD therapy.  相似文献   
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The VHDL design code and its implementation using 0.25 μm technology have been demonstrated for the real time video applications. The processing time of a frame running at 400 MHz was estimated to be 8.1 ms for QCIF and CIF Sequences, which accommodates more than 120 frames per second, and this warrant real time video codec. The design was validated and simulated using ModelSim from Mentor Graphics tools, and then verified using both the VHDL testbench and the Matlab® Image processing toolbox. Various alternate search algorithms have been proposed and simulated using Matlab for their real time processing. Skipping “every other column” (SC), and skipping “every other row and column” (SRC) algorithm, “optimal local neighborhood search” (OLNS), and limited-optimal neighborhood search (L-OLNS) have been demonstrated. The microprocessor as a controller is based on RISC processor and it uses pipelining to gain clocking efficiency.  相似文献   
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This work describes the VHDL design and implementation of block-based motion estimation in order to make it feasible for real-time video applications. The design was functionally tested and simulated using ModelSim from Mentor Graphics tools, and then verified using both a VHDL testbench and the Matlab? Image processing tools. The design was tested for different image sizes at different clock frequencies with varying block sizes and search areas. With a clock frequency of 400 MHz, the estimated time for motion estimation for QCIF and CIF sequences shows the feasibility for real-time video-codec.
Maher E. RizkallaEmail:
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Today's distributed and high-performance applications require high computational power and high communication performance. Recently, the computational power of commodity PCs has doubled about every 18 months. At the same time, network interconnects that provide very low latency and very high bandwidth are also emerging. This is a promising trend in building high-performance computing environments by clustering - combining the computational power of commodity PCs with the communication performance of high-speed network interconnects. There are several network interconnects that provide low latency and high bandwidth. Traditionally, researchers have used simple microbenchmarks, such as latency and bandwidth tests, to characterize a network interconnects communication performance. Later, they proposed more sophisticated models such as LogP. However, these tests and models focus on general parallel computing systems and do not address many features present in these emerging commercial interconnects. Another way to evaluate different network interconnects is to use real-world applications. However, real applications usually run on top of a middleware layer such as the message passing interface (MPI). Our results show that to gain more insight into the performance characteristics of these interconnects, it is important to go beyond simple tests such as those for latency and bandwidth. In future, we plan to expand our microbenchmark suite to include more tests and more interconnects.  相似文献   
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At present, there is a vital need for river water purification by developing new approaches to eliminate bacterial biofilms, textile dyes, and Low-Density Polyethylene (LDPE) plastics that pose severe threats to human and environmental health. The current work put forward the construction of an eco-friendly green strategy to synthesize zinc oxide nanoparticles (ZnO NPs) using areca nut (Areca catechu) extract and their application to tackle the challenges in water purification. Prepared biogenic NPs were characterized by X-ray diffraction analysis (XRD), Fourier Transform Infra-Red (FT-IR), Energy Diffraction Spectroscopy (EDS), Scanning Electronic Microscopy (SEM), Transmission Electron Microscopy (TEM) analysis, confirmed the spherical shape in 20 nm and UV–vis spectroscopy. The characteristic absorption band exhibited at 326 nm confirmed the formation of ZnO NPs using UV–vis spectroscopy. Among all the tested bacterial pathogens, the E. coli at 50 µg/mL concentration showed the highest inhibition of biofilm activity, followed by the highest growth curve, cellular leakage, and potassium ion efflux. The ZnO NPs observed with photo-degradation of Rhodamine-B (Rh-B), Methylene Blue (MB), and Nigrosine dyes under sunlight irradiation at different time intervals. Finally, the photocatalytic activity of LDPE-ZnO NPs nanocomposite film showed the highest degradation under solar light irradiation were confirmed through photo-induced weight loss, SEM, FTIR, and MALDI-TOF analysis. This study demonstrates ZnO NPs exhibit efficacy against biofilm formation, degradation of photocatalytic textile dyes, and low-density LDPE film under solar light irradiation, which can be a step forward in water purification.

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