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21.
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Translated from Izmeritel'naya Tekhnika, No. 8, pp. 16–17, August, 1992.  相似文献   
23.
The multimedia security is becoming more and more important as the data being exchanged on the Internet is increasing exponentially. Though cryptography is one of the methods which is used to secure the data during transit, but the camouflaged appearance of the scrambled data alerts the adversary about some critical information being shared. In such a scenario, steganography has been used as an alternate solution to secure the secret information. In this paper a color image steganographic algorithm based on hybrid edge detection is proposed. The color image is partitioned into constituent Red (R), Green (G) and Blue (B) planes. Hybrid edge detection is used for finding the edge and non-edge pixels of Green and Blue planes of cover image. The Green and Blue planes are used for hiding the data while Red plane holds the pixel status (whether edge or non-edge) of these planes. The RC4 encryption algorithm is used to encrypt secret message before embedding it in the cover image to enhance security of the secret data. A fragile watermark/logo (whose size is less than 1% of total secret data) has been embedded, besides secret data in the cover image, to facilitate content authentication and early tamper detection. At the receiver, firstly logo is extracted. If it is same as one embedded at transmitter, indicating that secret data has not been altered during transit, secret data is extracted. Otherwise (if extracted logo is not same as used at input) the receiver does not waste critical time to extract compromised data but sends an automatic retransmission request. Experimental investigations reveal that the proposed scheme is capable of providing high quality of stego-images for a fairly high pay load. A comparison of the proposed technique with some state of art schemes substantiates the above arguments.  相似文献   
24.
ABSTRACT

Ensuring consistency of knowledge systems is always one of the essential requirements because, without it, most of these systems become useless. Because of the importance, many studies have involved the restoration of consistency in knowledge systems. However, these approaches are only implemented on knowledge systems that are represented by logic or probabilistic logic, thus when we apply them to probabilistic knowledge systems, there are many inadequacies. To overcome these drawbacks, in this paper, we put forward a new model for restoring the consistency of a probabilistic knowledge base by focusing on changing the probabilities in this knowledge base via several inconsistency measures. To this end, a set of inconsistency measures is presented and a family of consistency restoring operators for probabilistic knowledge bases is introduced. Next, an axiomatic model consists of a set of axioms is built to characterize the desirable properties of the consistency restoring operators. Finally, the properties of each consistency restoring operator in the introduced family are investigated and discussed.  相似文献   
25.
Sn-substituted yttrium iron garnet samples, Y3Fe5-xSnxO12 (x = 0–0.1, step 0.02) were prepared using a citrate sol–gel method and followed by a sintering process. Synchrotron X-ray diffraction (SXRD), X-ray absorption near edge structure (XANES), scanning electron microscope (SEM) and Fourier infrared spectroscopy (FTIR) measurements were used to investigate the structure parameters, valence state of Fe, oxygen vacancies and lattice distortion in the samples. The magnetic properties of the samples were measured with the SQUID and VSM equipments. The Sn substitution and oxygen vacancies cause the transformation of Fe3+ to Fe2+ which leads to the decrease of Curie temperature and slight increase of saturation magnetization. Temperature dependence of the resistivity in the range of 300–573 K was investigated to elucidate the conduction mechanism in the samples. The resistivity of the sol-gel derived samples was found to be nine orders of magnitudes lower than the value for the bulk sample prepared by flux-grown method. The effects of Fe2+ centers, lattice dislocation, porosity and grain boundary on the resistivity are discussed. This study indicates that Sn-substituted yttrium iron garnets are good candidates for sensor elements which operate based on electrical signals.  相似文献   
26.
Ashita  Loan  Sajad A.  Alkhammash  Hend I.  Rafat  Mohammad 《SILICON》2022,14(5):2165-2174
Silicon - In this work, we propose a Germanium Fin Buried Oxide (FinBOX) Fin Electron-Hole Bilayer Tunnel FET (FBF-EHBTFET) structure. The proposed structure eliminates the gated underlaps and...  相似文献   
27.
Isoflavones are plant-derived chemicals that are potential endocrine disruptors. Although some recent studies have detected isoflavones in natural waters, little is known about their aquatic fates. The photochemical behaviors of the isoflavones daidzein, formononetin, biochanin A, genistein, and equol were studied under simulated solar light and natural sunlight. All of these phytoestrogens were found to be photolabile under certain conditions. Daidzein and formononetin degraded primarily by direct photolysis. Their expected near-surface summer half-lives in pH 7 water at 47° latitude are expected to be 10 and 4.6 h, respectively. Biochanin A, genistein, and equol degraded relatively slowly by direct photolysis at environmentally realistic pH values, though they showed significant degradation rate enhancements in the presence of natural organic matter (NOM). The indirect photolysis rates for these compounds scaled with NOM concentration, and NOM from microbial origin was found to be a more potent photosensitizer than NOM from terrestrial sources. Mechanistic studies were performed to determine the indirect photolysis pathways responsible for the rate enhancements. Results of these studies implicate reaction with both singlet oxygen and excited state triplet NOM. Environmental half-lives for biochanin A, genistein, and equol are expected to vary on the basis of pH as well as NOM source and concentration.  相似文献   
28.
Fish assemblages in rivers of the Midwestern United States are an important component of the region's natural resources and biodiversity. We characterized the physical environment and presence of dams in a series of reaches in three eastern Iowa rivers tributary to the Mississippi River and related these characteristics to the fish assemblages present. Some physical characteristics were similar among the 12 study reaches, whereas others differed substantially. We found a total of 68 species across the 12 study reaches; 56 in the Turkey River, 51 in the Maquoketa River and 50 in the Wapsipinicon River. Seventeen species could be described as ‘downstream‐distributed’; 15 being found only in the lowest reach of one or more rivers and the other two being found only in the lowest reaches or two or more contiguous reaches including the lowest reach. Two species could be described as ‘upstream‐distributed’, being found only in an uppermost reach. Non‐metric multidimensional scaling ordination illustrated similarities among reaches, and five physical variables were significantly correlated with assemblage similarities. Catchment area and number of dams between reaches and the Mississippi River were strongly correlated with assemblage similarities, but the directions of their effects were opposite. Catchment area and number of dams were confounded. The collective evidence to date suggests that the pervasiveness of dams on rivers significantly alters fish assemblages, making underlying patterns of species change and relationships with naturally varying and human‐influenced physical characteristics along a river's course difficult to discern. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.  相似文献   
29.
For human-machine communication to be as effective as human-to-human communication, research on speech emotion recognition is essential. Among the models and the classifiers used to recognize emotions, neural networks appear to be promising due to the network’s ability to learn and the diversity in configuration. Following the convolutional neural network, a capsule neural network (CapsNet) with inputs and outputs that are not scalar quantities but vectors allows the network to determine the part-whole relationships that are specific 6 for an object. This paper performs speech emotion recognition based on CapsNet. The corpora for speech emotion recognition have been augmented by adding white noise and changing voices. The feature parameters of the recognition system input are mel spectrum images along with the characteristics of the sound source, vocal tract and prosody. For the German emotional corpus EMO-DB, the average accuracy score for 4 emotions, neutral, boredom, anger and happiness, is 99.69%. For Vietnamese emotional corpus BKEmo, this score is 94.23% for 4 emotions, neutral, sadness, anger and happiness. The accuracy score is highest when combining all the above feature parameters, and this score increases significantly when combining mel spectrum images with the features directly related to the fundamental frequency.  相似文献   
30.
In this study, we analyze the rheological properties of epoxy/polypyrrole/carbon black coating and its performance as electromagnetic interference shielding efficiency (EMI SE). For this purpose, a commercial epoxy coating was mixed with a conductive polymer, namely polypyrrole. Rheological tests were performed to obtain the flow curve, the storage and loss moduli, the cure time and thixotropic characteristics. Thermal analysis of DSC (cure behavior) and EMI SE were also performed. Epoxy coating showed non‐Newtonian (shear thinning) behavior. The addition of PPy.DBSA reduced the coating fluidity by the increase in consistency index and viscosity. The stress oscillatory amplitude sweep test was performed to determine the linear viscoelastic range. The results of the LVR stress and strain frequency sweep tests were compared to the PPy.DBSA. The results show that LVR and critical crossover change with the percent of Polypyrrole. The cure times obtained by the rheometer and DSC were in good agreement: the addition of polypyrrole reduced the cure time, probably due to the presence of amino groups in the PPy.DBSA, which can react with the oxirane ring in the epoxy resin. The EMI SE attenuation by absorption and reflection mechanism was observed by adding 10 phr of PPy.DBSA. For practical applications, it is necessary to combine polypyrrole with conducting carbon black. The formulation with 1.5 phr of carbon black improves the EMI SE performance to 72%. J. VINYL ADDIT. TECHNOL., 26:348–353, 2020. © 2019 Society of Plastics Engineers  相似文献   
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