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排序方式: 共有278条查询结果,搜索用时 265 毫秒
81.
Mathias Lux Oge Marques Klaus Schöffmann Laszlo Böszörmenyi Georg Lajtai 《Multimedia Tools and Applications》2010,46(2-3):521-544
Arthroscopic surgery is a minimally invasive procedure that uses a small camera to generate video streams, which are recorded and subsequently archived. In this paper we present a video summarization tool and demonstrate how it can be successfully used in the domain of arthroscopic videos. The proposed tool generates a keyframe-based summary, which clusters visually similar frames based on user-selected visual features and appropriate dissimilarity metrics. We discuss how this tool can be used for arthroscopic videos, taking advantage of several domain-specific aspects, without losing its ability to work on general-purpose videos. Experimental results confirm the feasibility of the proposed approach and encourage extending it to other application domains. 相似文献
82.
Rashid Jalal Qureshi Laszlo Kovacs Balazs Harangi Brigitta Nagy Tunde Peto Andras Hajdu 《Computer Vision and Image Understanding》2012,116(1):138-145
This paper proposes an efficient combination of algorithms for the automated localization of the optic disc and macula in retinal fundus images. There is in fact no reason to assume that a single algorithm would be optimal. An ensemble of algorithms based on different principles can be more accurate than any of its individual members if the individual algorithms are doing better than random guessing. We aim to obtain an improved optic disc and macula detector by combining the prediction of multiple algorithms, benefiting from their strength and compensating their weaknesses. The location with maximum number of detectors’ outputs is formally the hotspot and is used to find the optic disc or macula center. An assessment of the performance of integrated system and detectors working separately is also presented. Our proposed combination of detectors achieved overall highest performance in detecting optic disc and fovea closest to the manually center chosen by the retinal specialist. 相似文献
83.
We present a genetic algorithm for selecting centers to seed the popular k-means method for clustering. Using a novel crossover operator that exchanges neighboring centers, our GA identifies superior partitions using both benchmark and large simulated data sets. 相似文献
84.
An adaptive multimedia proxy is presented which provides (1) caching, (2) filtering, and (3) media gateway functionalities. The proxy
can perform media adaptation on its own, either relying on layered coding or using transcoding mainly in the decompressed
domain. A cost model is presented which incorporates user requirements, terminal capabilities, and video variations in one
formula. Based on this model, the proxy acts as a general broker of different user requirements and of different video variations. This is a first step towards What You Need is What You Get (WYNIWYG) video services, which deliver videos to users in exactly the quality they need and are willing to pay for. The
MPEG-7 and MPEG-21 standards enable this in an interoperable way. A detailed evaluation based on a series of simulation runs
is provided. 相似文献
85.
A qualitative test developed by Laszlo has been adapted to the quantitative determination of BHA. The determination is based
on measurement of the specific and sensitive color resulting from reaction of BHA with diazotized sulfanilic acid in alkaline
solution. The red-purple color, which is stable for long periods, has an absorption maximum at 535 mμ. Beer’s law is obeyed,
and a concentration range of 0.0001% to 0.01% BHA may be measured. The method requires careful adjustment of antioxidant-reagent
ratios for rapid and maximum color development, The optimum ratios, the effect of alcohol, and interfering substances are
diseussed.
The method, as described, also provides for an accurate specific determination of BHA in fats and oils even when other antioxidants
are present.
Journal Pager No. 184, American Meat Institute Foundation.
Presented at 50th Anniversary Meeting, American Oil Chemists’ Society, April 20–22, 1959, New Orleans, La.
Chemist in the Division for Inspection of Animal Products (D.I.P.O.A.) of the Ministry of Agriculture (Rio de Janeiro, Brazil)
and American Association of University Women Fellow at the American Meat Institute Foundation during 1958–59. 相似文献
86.
A method of treating data acquired with the planar laser‐induced fluorescence technique has been developed to visualize the topology of two‐dimensional concentration fields and to describe the dynamics of the coherent mixing structures identified. This method is based on a conditional binary transformation of the local concentration data, combined with a joint probability calculation. The methodology has been used to investigate the mixing in a stirred tank, at two injection port locations (in the bulk and in the impeller stream region). With bulk injection, a “folding phenomenon” of the coherent mixing structure was detected. Away from this port, large‐scale spatially periodic motion was identified, with a characteristic time of oscillation of the order of 2 to 3 s. With injection in the impeller stream region, no spatial instabilities of the coherent structure were detected. Local oscillations of the coherent mixing structure were found both on short and long time‐scales (i.e., ?1 and ?80 s). 相似文献
87.
David L. Compton Joseph A. Laszlo Michael Appell Karl E. Vermillion Kervin O. Evans 《Journal of the American Oil Chemists' Society》2014,91(2):271-279
2‐Monoricinoleoylglycerol (2‐MRG) was synthesized by the Novozym 435 catalyzed alcoholysis of castor oil in excess ethanol (1:70 mol:mol) at ambient temperature. Due to the fatty acid C12‐OH group, conventional liquid–liquid extraction methods developed for less polar, non‐hydroxylated 2‐monoacylglycerols (2‐MAG) proved inadequate for 2‐MRG purification. Alternatively, 2‐MRG was purified by normal‐phase flash chromatography (FC) on silica gel using a binary acetone‐hexane gradient mobile phase. Gram quantities of 2‐MRG were isolated in 63 % yield and contained no residual diacylglycerol (DAG), which fail to separate using liquid–liquid extraction methods. The 2‐MRG was obtained at ~90 mol% relative to 1‐MRG, proving that the FC method did not appreciably catalyze acyl migration. 1H‐NMR spectroscopy was used to monitor the spontaneous acyl migration of isolated 2‐MRG from 20 to 80 °C. The relative energy of activation calculated from the Arrhenius relationship of the 2‐MRG acyl migration rate constants was 82.9 kJ/mol. This was ~two‐fold higher than the theoretical ΔG298.15 calculated from molecular modeling using density functional calculations (B3LYP/6?31 + G*) of 2‐MRG, the ketal ring transition state, and 1‐monoricinoleoylglycerol (1‐MRG). The synthesis and isolation methods reported herein provide a convenient means to access useful intermediates for functionalized structured lipids. 相似文献
88.
Anja Keskinarkaus Sami Huttunen Antti Siipo Jukka Holappa Magda Laszlo Ilkka Juuso Eero Väyrynen Janne Heikkilä Matti Lehtihalmes Tapio Seppänen Seppo Laukka 《Multimedia Tools and Applications》2016,75(11):6321-6345
The MORE system is designed for observation and machine-aided analysis of social interaction in real life situations, such as classroom teaching scenarios and business meetings. The system utilizes a multichannel approach to collect data whereby multiple streams of data in a number of different modalities are obtained from each situation. Typically the system collects a 360-degree video and audio feed from multiple microphones set up in the space. The system includes an advanced server backend component that is capable of performing video processing, feature extraction and archiving operations on behalf of the user. The feature extraction services form a key part of the system and rely on advanced signal analysis techniques, such as speech processing, motion activity detection and facial expression recognition in order to speed up the analysis of large data sets. The provided web interface weaves the multiple streams of information together, utilizes the extracted features as metadata on the audio and video data and lets the user dive into analyzing the recorded events. The objective of the system is to facilitate easy navigation of multimodal data and enable the analysis of the recorded situations for the purposes of, for example, behavioral studies, teacher training and business development. A further unique feature of the system is its low setup overhead and high portability as the lightest MORE setup only requires a laptop computer and the selected set of sensors on site. 相似文献
89.
Direct analysis in real time (DART) is a recently developed ambient ionization technique for mass spectrometry to enable rapid and sensitive analyses with little or no sample preparation. After swab-based field sampling, the organothiophosphate malathion was analyzed using DART-Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry (MS) and tandem mass spectrometry (MS/MS). Mass resolution was documented to be over 800,000 in full-scan MS mode and over 1,000,000 for an MS/MS product ion produced by collision-induced dissociation of the protonated analyte. Mass measurement accuracy below 1 ppm was obtained for all DART-generated ions that belonged to the test compound in the mass spectra acquired using only external mass calibration. This high mass measurement accuracy, achievable at present only through FTMS, was required for unequivocal identification of the corresponding molecular formulae. 相似文献
90.
Fabian G Farago N Feher LZ Nagy LI Kulin S Kitajka K Bito T Tubak V Katona RL Tiszlavicz L Puskas LG 《International journal of molecular sciences》2011,12(9):6116-6134
Toxicogenomics, based on the temporal effects of drugs on gene expression, is able to predict toxic effects earlier than traditional technologies by analyzing changes in genomic biomarkers that could precede subsequent protein translation and initiation of histological organ damage. In the present study our objective was to extend in vivo toxicogenomic screening from analyzing one or a few tissues to multiple organs, including heart, kidney, brain, liver and spleen. Nanocapillary quantitative real-time PCR (QRT-PCR) was used in the study, due to its higher throughput, sensitivity and reproducibility, and larger dynamic range compared to DNA microarray technologies. Based on previous data, 56 gene markers were selected coding for proteins with different functions, such as proteins for acute phase response, inflammation, oxidative stress, metabolic processes, heat-shock response, cell cycle/apoptosis regulation and enzymes which are involved in detoxification. Some of the marker genes are specific to certain organs, and some of them are general indicators of toxicity in multiple organs. Utility of the nanocapillary QRT-PCR platform was demonstrated by screening different references, as well as discovery of drug-like compounds for their gene expression profiles in different organs of treated mice in an acute experiment. For each compound, 896 QRT-PCR were done: four organs were used from each of the treated four animals to monitor the relative expression of 56 genes. Based on expression data of the discovery gene set of toxicology biomarkers the cardio- and nephrotoxicity of doxorubicin and sulfasalazin, the hepato- and nephrotoxicity of rotenone, dihydrocoumarin and aniline, and the liver toxicity of 2,4-diaminotoluene could be confirmed. The acute heart and kidney toxicity of the active metabolite SN-38 from its less toxic prodrug, irinotecan could be differentiated, and two novel gene markers for hormone replacement therapy were identified, namely fabp4 and pparg, which were down-regulated by estradiol treatment. 相似文献