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71.
With the recent emergence of cloud computing based services on the Internet, MapReduce and distributed file systems like HDFS have emerged as the paradigm of choice for developing large scale data intensive applications. Given the scale at which these applications are deployed, minimizing power consumption of these clusters can significantly cut down operational costs and reduce their carbon footprint—thereby increasing the utility from a provider’s point of view. This paper addresses energy conservation for clusters of nodes that run MapReduce jobs. The algorithm dynamically reconfigures the cluster based on the current workload and turns cluster nodes on or off when the average cluster utilization rises above or falls below administrator specified thresholds, respectively. We evaluate our algorithm using the GridSim toolkit and our results show that the proposed algorithm achieves an energy reduction of 33% under average workloads and up to 54% under low workloads.  相似文献   
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73.
The aim of this paper was to compare nicotine concentration in 28 hospitality premises (HPs) in Florence and Belluno, Italy, where a smoking ban was introduced in 2005, and in 19 HPs in Vienna, Austria, where no anti-smoking law entered into force up to now. Airborne nicotine concentrations were measured in the same HPs in winter 2002 or 2004 (pre-ban measurements) and winter 2007 (post-ban measurements). In Florence and Belluno, medians decreased significantly (P < 0.001) from 8.86 [interquartile range (IQR): 2.41-45.07)] before the ban to 0.01 microg/m3 (IQR: 0.01-0.41) afterwards. In Austria (no smoking ban) the medians collected in winters 2004 and 2007 were, respectively, 11.00 (IQR: 2.53-30.38) and 15.76 microg/m3 (IQR: 2.22-31.93), with no significant differences. Measurements collected in winter 2007 in 28 HPs located in Naples, Turin, Milan (0.01 microg/m3; IQR: 0.01-0.16) confirmed post-ban results in Florence and Belluno. The medians of nicotine concentrations in Italy and Austria before the Italian ban translates, using the risk model of Repace and Lowery, into a lifetime excess lung cancer mortality risk for hospitality workers of 11.81 and 14.67 per 10,000, respectively. Lifetime excess lung cancer mortality risks for bar and disco-pub workers were 10-20 times higher than that calculated for restaurant workers, both in Italy and Austria. In winter 2007, it dropped to 0.01 per 10,000 in Italy, whereas in Austria it remained at the same levels. The drop of second-hand smoke exposure indicates a substantial improvement in air quality in Italian HPs even after 2 years from the ban. PRACTICAL IMPLICATIONS: The nation-wide smoking ban introduced in Italy on January 10, 2005, resulted in a drop in second-hand smoke exposure in hospitality premises, whereas in Austria, where there is no similar nation-wide smoking ban, the exposure to second-hand smoke in hospitality premises remains high. Given that second-hand smoke is considered a group 1 carcinogen according to the International Agency for Research on Cancer classification, the World Health Organization Framework Convention on Tobacco Control strongly recommends the implementation of nation-wide smoke-free policies in order to improve the indoor air quality of hospitality premises and workplaces. Results from our study strongly supports this recommendation.  相似文献   
74.
Gold nanoparticle networks were obtained by linking them with cysteine modified triethyleneglycols. The oligo-ether linker molecule initially having a linear structure probably adopts a crown ether type structure upon complexation with alkali metal ions that leads to a controlled aggregation of the network. The extent of aggregation depends on the degree of conformational change in the molecule upon complexation with the metal ion, which in turn is governed by the metal ion radius leading to a dependence of red shift of the surface plasmon resonance on the metal ion radius. Since this network is present in the organic solvent they also act as phase transferring agent for the alkali metal ions from aqueous to organic media.  相似文献   
75.
The Internet of Things (IoT) has become widely used in applications such as smart homes, industrial automation, and transportation due to its affordable hardware and fast internet connectivity. However, the increase in IoT-enabled gadgets, particularly those running on batteries or connected to other sources, is putting strain on the world's energy requirements. Therefore, this study focuses on a green routing solution for battery-powered IoT-enabled Software-defined Wireless Sensor Networks (IoT-SDWSN). Finding green solutions for IoT-based networks to address this energy challenge has become crucial. This study focuses on developing a green routing solution for battery-powered IoT-SDWSN. Energy efficiency in IoT-SDWSN is attained by the process of clustering nodes. The network is partitioned into small clusters, and a Control Node (CN) is set up by a Control Server (CS) to transmit the data packets sent by sensor nodes. Choosing a CN in these networks is a critical concern due to the substantial energy consumption involved in delivering data to the CS. This research focuses on the problem of energy-efficient cluster routing in IoT-based SD-WSN. It introduces the Energy-optimized Artificial Hummingbird Algorithm (EOAHA) as a green routing technique. EOAHA aims to extend the lifespan of IoT-based SD-WSNs by intelligently selecting (based on a new fitness function) CNs to distribute the network load and increase its overall longevity. To evaluate the performance of EOAHA, a comparative analysis is conducted against other state-of-the-art algorithms. The results demonstrate that EOAHA outperforms these algorithms by a minimum of 13.5% in terms of network longevity.  相似文献   
76.
International Journal on Document Analysis and Recognition (IJDAR) - Script recognition has many real-life applications like optical character recognition, document archiving, writer...  相似文献   
77.
Bulletin of Engineering Geology and the Environment - This study aims to investigate the effectiveness of fly ash (FA) in stabilising a kaolin soil through laboratory tests. Kaolin is an example of...  相似文献   
78.
Drug resistance mechanisms in human pathogenic Candida species are continually evolving. Over the time, Candida species have acquired diverse strategies to vanquish the effects of various classes of drugs thereby, emanating as a serious life threat. Apart from the repertoire of well-established strategies, which predominantly comprise alteration, overexpression of drug targets, and chromosome duplication, Candida species have evolved a number of permeability constraints for antifungal drugs, via compromised drug import or increased drug efflux. For the latter, genome of Candida species harbour battery of exporters designated as Candida drug resistance genes. These genes predominantly encode membrane efflux transporters, which expel the incoming drugs and thus prevent toxic intracellular accumulation of drugs to manifest multidrug resistance. Such a phenomenon is restricted not only to Candida species but has been observed among many other pathogenic fungal species as well. Notably, the existence of large number of drug exporters in genomes of Candida species posits other pivotal roles for these efflux transporter proteins. The brief review discusses as to how the whole gamut of antifungal research has since been changed to include these new observations wherein reduced permeability of azoles across cell membrane of Candida cells is being implicated as one of the major determinants of antifungal susceptibilities, which all began with the identification of the first multidrug resistance gene CDR1, in Andre Goffeau's laboratory back in 1995.  相似文献   
79.
The third section of closed loop Iodine Sulphur (IS) thermochemical cycle, dealing with HIx processing, suffers from low equilibrium decomposition of HI to hydrogen with a conversion value of only ~22% at 700 K. Here, we report a significant enhancement in conversion of HI into hydrogen (up to ~95%) using a zeolite membrane reactor for the first time. The all silica DDR (deca dodecasil rhombohedral) zeolite membrane with dense, interlocked structure was synthesized on the seeded clay alumina substrate by sonication mediated hydrothermal process. The synthesized membranes along with seed crystals were characterized by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) and energy dispersive X-ray spectroscopy (EDX). Corrosion studies were carried out by exposing the membrane samples to simulated HI decomposition reaction environment (at 450 °C) for different durations of time upto 200 h. The FESEM, EDX and XRD analyses indicated that no significant changes occurred in the morphology, composition and structure of the membranes. Iodine adsorption on to the membrane surface was observed which got increased with the exposure duration as confirmed by secondary ion mass spectrometry studies. A packed bed membrane reactor (PBMR) assembly was fabricated with integration of in-house synthesized zeolite membrane and Pt-alumina catalyst for carrying out HI decomposition studies. The tube side was chosen as reaction zone and the shell side as the permeation zone. The HI decomposition experiments were carried out for different values of temperature and feed flow rates. DDR zeolite based PBMR was found to enhance the single-pass conversion of HI up to ~95%. The results indicate that for achieving optimal performance of PBMR, it should be operated with space velocities of 0.2–0.3 s?1 and temperature in the range of 650 K–700 K with permeate side vacuum of 0.12 kg/cm2. It is believed that the in-house developed zeolite PBMR shall be a potential technology augmentation in making the IS thermochemical cycle energy efficient.  相似文献   
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