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661.
This study reports screening of 102 Iranian medicinal plant species belonging to 49 families for the biosynthesis of colloidal silver nanoparticles (AgNPs). Among tested plants, 37 species in 19 plant families are new bio‐resources in this regard. Water extracts of macerated plant parts are used in this survey. Six of the bioactive plants are selected for further analysis. They produced amorphous spherical 40–70 nm AgNPs. Biosynthesised colloidal AgNPs are characterised by UV–visible spectroscopy, transmission electron microscopy and scanning electron microscopy. Families of Lamiaceae (8 out of 12), Leguminosae (7 out of 9), Liliaceae (4 out of 7) contained most bio active species. No correlation noticed between bioactivity and pH of plant water‐extracts. The simple procedure used in this study may form a platform for mass production of environmentally safe and eco‐friendly green production of these multipurpose AgNPs in future; however, optimisation protocols need to be well documented.Inspec keywords: silver, nanoparticles, drugs, ultraviolet spectroscopy, visible spectroscopy, scanning electron microscopy, pH, agriculture, nanobiotechnologyOther keywords: folkloric medicine, screening, Iranian medicinal plant species, biosynthesis, colloidal silver nanoparticles production, bioresources, plant water extracts, macerated plant parts, bioactive plants, amorphous spherical AgNP, UV–visible spectroscopy, transmission electron microscopy, scanning electron microscopy, Lamiaceae, Leguminosae, Liliaceae, pH, mass production, environmentally safe green production, eco‐friendly green production  相似文献   
662.
In this paper, we propose an XML-based recommender system, called SPGProfile. It is a type of collaborative information filtering system. SPGProfile uses ontology-driven social networks, where nodes represent social groups. A social group is an entity that defines a group based on demographic, ethnic, cultural, religious, age, or other characteristics. In the SPGProfile framework, query results are filtered and ranked based on the preferences of the social groups to which the user belongs. If the user belongs to social group Gx, results will be filtered based on the preferences of Gx and the preferences of each ancestor social group of Gx in the social network. SPGProfile can be used for various practical applications, such as Internet or other businesses that market preference-driven products. In the ontology, the preferences of a social group are identified from either: (1) the preferences of its member users or (2) from published studies about the social group. We describe and experimentally compare these two approaches. We also experimentally evaluate the search effectiveness and efficiency of SPGProfile and compare it to two existing search engines.  相似文献   
663.
In this work, a generalized time-dependent variable coefficients combined KdV–mKdV (Gardner) equation arising in plasma physics and ocean dynamics is studied. By means of three amplitude ansatz that possess modified forms to those proposed by Wazwaz in 2007, we have obtained the bell type solitary waves, kink type solitary waves, and combined type solitary waves solutions for the considered model. Importantly, the results show that there exist combined solitary wave solutions in inhomogeneous KdV-typed systems, after proving their existence in the nonlinear Schrödinger systems. It should be noted that, the characteristics of the obtained solitary wave solutions have been expressed in terms of the time-dependent coefficients. Moreover, we give the formation conditions of the obtained solutions for the considered KdV–mKdV equation with variable coefficients.  相似文献   
664.
A novel architecture to accelerate a neocortex inspired cognitive model is presented. The architecture utilizes a collection of context switchable processing elements (PEs). This enables time multiplexing of nodes in the model onto available PEs. A streaming memory system is designed to enable high-throughput computation and efficient use of memory resources. Several scheduling algorithms were examined to efficiently assign network nodes to the PEs. Multiple parallel FPGA-accelerated implementations were evaluated on a Cray XD1. Networks of varying complexity were tested and indicate that hardware acceleration can provide an average throughput gain of 184 times over equivalent parallel software implementations.  相似文献   
665.
Development of intelligent systems with the pursuit of detecting abnormal events in real world and in real time is challenging due to difficult environmental conditions, hardware limitations, and computational algorithmic restrictions. As a result, degradation of detection performance in dynamically changing environments is often encountered. However, in the next‐generation factories, an anomaly detection system based on acoustic signals is especially required to quickly detect and interfere with the abnormal events during the industrial processes due to the increased cost of complex equipment and facilities. In this study we propose a real time Acoustic Anomaly Detection (AAD) system with the use of sequence‐to‐sequence Autoencoder (AE) models in the industrial environments. The proposed processing pipeline makes use of the audio features extracted from the streaming audio signal captured by a single‐channel microphone. The reconstruction error generated by the AE model is calculated to measure the degree of abnormality of the sound event. The performance of Convolutional Long Short‐Term Memory AE (Conv‐LSTMAE) is evaluated and compared with sequential Convolutional AE (CAE) using sounds captured from various industrial manufacturing processes. In the experiments conducted with the real time AAD system, it is shown that the Conv‐LSTMAE‐based AAD demonstrates better detection performance than CAE model‐based AAD under different signal‐to‐noise ratio conditions of sound events such as explosion, fire and glass breaking.  相似文献   
666.
ABSTRACT

Coral reefs of the United Arab Emirates (UAE) are living in the world’s hottest sea. Recently, corals harbouring Symbiodinium thermophilum, a thermotolerant microalgae, were found to be prevalent among UAE reefs and were reported to endure extreme sea-surface temperatures. Late 2015–early 2016 was marked with the strongest El Niño on record worldwide, which caused massive coral bleaching (loss of symbiotic microalgae from reef-building corals). In September 2015, the waters flanking UAE coasts were identified to be among the areas facing a thermal stress reaching its highest level liable to cause massive coral bleaching. However, the effect of this thermal stress on UAE corals remained largely unknown. Here, multi-temporal DubaiSat-2 satellite images were used to show that changes in the reef environment of Dalma Island, UAE, between 2014 and 2016, occurred in macroalgae-dominant habitats, whereas live corals remained unaltered. Furthermore, extending the study to a larger area helped in discovering a continuum of live and pristine corals, which was not reported or studied before. While sea-surface temperature anomalies of 1°C were reported to significantly damage coral reefs around the world, the live coral habitat was observed to exhibit no-change despite four consecutive months of +2°C to 3°C anomalies reported during the study period. These findings point to the tolerance of UAE live corals faced with extreme climate conditions.  相似文献   
667.
Amine and alcohol functional dendritic polymers were used as covalent coupling agents for maleic anhydride grafted polyethylene and their efficiency compared with metallic salt and zinc acetate, acting as an ionic coupling agent. The crosslinking reactions in the molten state were carried out at 150°C in an internal mixer and the resulting modified polyethylenes were characterized by dynamic mechanical analysis and Small angle X‐ray Scattering. These agents led to efficient coupling and crosslinking. The covalent coupling reactions were conducted in a heterogeneous multiphase system: The kinetics of crosslinking depends on the nature of the coupling agent: at 150°C, the reactions were completed within 5 min. with the amine hyperbranched polymer and 20 min. with the alcohol functionalized dendritic polymer. The zinc acetate forms ionic interactions with the grafted polyethylene in less than 1 min. Ionic interactions are thermo mechanically reversible; they correspond to electronic density fluctuations evidenced by SAXS. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007  相似文献   
668.
This paper focuses on a problem that is common to most watermarking-based ownership dispute resolutions and ownership assertion systems. Such systems are vulnerable to a simple but effective class of attacks that exploit the high false-positive rate of the watermarking techniques to cast doubt on the reliability of a resulting decision. To mitigate this vulnerability, we propose embedding multiple watermarks, as opposed to embedding a single watermark, and detecting a randomly selected subset of them while constraining the embedding distortion. The crux of the scheme lies in both watermark generation, which deploys a family of one-way functions and selective detection, which injects uncertainty into the detection process. The potential of this approach in reducing the false-positive probability is analyzed under various operating conditions and compared to single watermark embedding. The multiple watermark embedding and selective detection technique is incorporated analytically into the additive watermarking technique and results obtained through numerical solutions are presented to illustrate its effectiveness.  相似文献   
669.
BACKGROUND & AIMS: Gastric injury by nonsteroidal anti-inflammatory drugs (NSAIDs) is minimal in neutropenic animals. This study examined peptic ulcer development in the presence or absence of gastric neutrophils in patients requiring long-term use of NSAIDs. METHODS: Gastric histology, neutrophils, and Helicobacter pylori were assessed in 120 patients randomized to receive placebo or 20 or 40 mg famotidine twice daily as prophylaxis against NSAID-related ulcers and who underwent endoscopy at 0, 4, 12, and 24 weeks. RESULTS: In 43 patients without gastric neutrophils, ulcers developed in 1 of 14 (7.7%) taking placebo, 2 of 16 (12.5%) taking 20 mg famotidine, and none of 13 taking 40 mg famotidine. However, in 77 patients with neutrophils, ulcers developed in 13 of 28 (47. 4%) taking placebo (P < 0.001), 3 of 26 (12.6%) taking 20 mg famotidine, and 3 of 23 (13%) taking 40 mg famotidine. Eight of 46 patients (17%) without H. pylori had neutrophils compared with 69 of 74 (93%) with both H. pylori and neutrophils (P < 0.001). CONCLUSIONS: Gastric neutrophils increase the incidence of ulceration in long-term NSAID users. Because neutrophils exist with H. pylori, eradicating this infection might prevent NSAID-related peptic ulcers.  相似文献   
670.
This work describes the use of phase transfer catalyst (PTC) for the Knoevenagel condensation in the synthesis of several substituted stilbenes derived from weak acidic substrates such as p-nitro toluene (pKa = 20.4) and phenylacetonitrile (pKa = 21.9) with benzaldehyde using TBAB (tetrabutylammonium bromide) or 18-crown-6 as PTCs, respectively. Reaction of p-nitro toluene with benzaldehyde suffered from the competitive Cannizzaro reaction along with Knoevenagel condensation. Nevertheless, the problem has been solved and the novel procedure yielded >90% of isolated p-nitro stilbene. Utilizing a solid potassium carbonate as base and crown-ether as PTC proved to be the best reaction conditions for phenylacetonitrile and benzaldehyde, which showed 100% conversion of phenylacetonitrile to the corresponding stilbene (1,2-diphenyl-1′-nitrile ethene). To explore the role of PTC, we carried out a thorough kinetic investigation of these reactions. This includes modifying the catalyst nature and structure, the stirring rate, temperature effect and varying the concentration of the reactants and catalysts. Here, we prove for the first time that the PTC extraction mechanism taking place in a solid–liquid system for the carbonate anion. We conclude that it behaves as a typical second order reaction.  相似文献   
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