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31.
Wilson A. Cañas-Marín Julián D. Ortiz-Arango Uriel E. Guerrero-Aconcha 《International Journal of Thermophysics》2008,29(2):634-642
A model is proposed to predict magnetic susceptibilities in diamagnetic binary fluid mixtures. The model predictions are compared
to experimental information for nine binary systems including polar and non-polar compounds. The predictions are also compared
to the results obtained from the traditional Boyer-Donzelot equation. For all systems analyzed, the model predicted magnetic
susceptibilities closer to the experimental values than those predicted from the Boyer-Donzelot equation. The deviations from
the experimental values decrease when the binary system exhibits a positive excess magnetic susceptibility. 相似文献
32.
This paper describes the power quality analysis applied on 6?kW building-integrated photovoltaic system (BIPVS) and its economic study. A monitoring system was implemented using virtual instrumentation to measure irradiance, ambient temperature and electric variables of the photovoltaic (PV) system. The study includes a period of one year from September 2015 to August 2016 and for this the IEEE 929-2000 standard guidelines were followed. The results indicate that the power quality parameters: % THDv, frequency, nominal voltage and flicker meet the standard limits mentioned. Economic analysis of the PV system using the RETScreen? software is also presented. The results show a net present value of USD 35,157 for a period of 20 years with an annual energy saving of USD 1750. Greenhouse gas emissions avoided by the use of solar energy are 6.6 t CO2 per year. 相似文献
33.
This paper provides a spatial vector autoregressive (SpVAR) analysis of growth spillovers for the Spanish regions over the period 1965–2003. First, a spatial Granger causality analysis is performed that indicates the relevant impact of spatial spillover effects across regions in Spain. Second, the empirical research offers a contribution in the context of the SpVAR modelling estimating the push‐in (from the neighbours to the region) and push‐out (from the region to its neighbours) effects of growth spillovers within a regional economic system. Finally, the proposed methodology reveals empirical evidence about both the short‐run and long‐term regional growth adjustment processes in space and time. The results for the Spanish regional panel data suggest the existence of strong spatiotemporal regional spillovers of growth output. This has important implications for the choice of regional policy goals and regional policy instruments. 相似文献
34.
Inorganic carbon limitations on nitrification: experimental assessment and modelling 总被引:3,自引:0,他引:3
Nitrification is a two-step process that involves two different biomass populations: ammonia oxidising biomass (AOB) and nitrite oxidising biomass (NOB). Both populations are autotrophic (i.e. their carbon source is inorganic). Therefore, a deficit of this substrate should result in a decrease of the process rate. Recent technology advances such as the SHARON process have brought new scenarios in biological nitrogen removal where these limitations should be considered. Hence, this work examines the inorganic carbon limitation using respirometric and titrimetric techniques. For this aim, the nitrification rate was measured at different total inorganic carbon (TIC) concentrations. The experimental results obtained show that AOB was limited at TIC concentrations lower than 3mmol CL(-1). At the same time, no carbon source limitation for NOB was observed in spite of the low TIC concentrations attained (lower than 0.1mmol CL(-1)). The AOB limitation could be successfully modelled using Monod, Tessier and sigmoidal kinetics. The best fit was obtained with sigmoidal kinetics. However, unexpected biomass activity (oxygen consumption) was observed despite a very low TIC concentration (lower than 0.1mmol CL(-1)). 相似文献
35.
36.
Carolina Estefanía Chávez-Murillo Mónica Samantha Aceves-Flores Mariana Verástegui-Quevedo Julián de la Rosa-Millán 《International Journal of Food Science & Technology》2021,56(7):3388-3399
Recent research has shown that pulse-derived ingredients present a technological alternative to cereals, higher protein and fibre content, and differentiated starch characteristics. In this work, the partial substitution of pulse flours with and without heat moisture treatment (HMT) was evaluated in a biscuit model. The digestion residues at 20 and 120 min that correspond to rapidly, slowly and resistant starch from the Englyst methodology were analysed by DSC, X-Ray and ATR-FTIR. The use of pulse flours in biscuits improved their thermal stability (ΔH = 3.01 and 4.99 J/g for control and Lentil + HMT), preserving a fraction of particularly ling glucans, that influenced the decreasing in the rapidly available starch from 55.26 to 24.11 % (Control and Faba bean + HMT), and enhanced its protein's digestibility from 75.26 to 87.43 % for the same sources. Among pulses, there were similarities regarding their resistance to enzymatic hydrolysis that may help select those with better organoleptic attributes. 相似文献
37.
Juli��n Luengo Alberto Fern��ndez Salvador Garc��a Francisco Herrera 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2011,15(10):1909-1936
In the classification framework there are problems in which the number of examples per class is not equitably distributed,
formerly known as imbalanced data sets. This situation is a handicap when trying to identify the minority classes, as the
learning algorithms are not usually adapted to such characteristics. An usual approach to deal with the problem of imbalanced
data sets is the use of a preprocessing step. In this paper we analyze the usefulness of the data complexity measures in order
to evaluate the behavior of undersampling and oversampling methods. Two classical learning methods, C4.5 and PART, are considered
over a wide range of imbalanced data sets built from real data. Specifically, oversampling techniques and an evolutionary
undersampling one have been selected for the study. We extract behavior patterns from the results in the data complexity space
defined by the measures, coding them as intervals. Then, we derive rules from the intervals that describe both good or bad
behaviors of C4.5 and PART for the different preprocessing approaches, thus obtaining a complete characterization of the data
sets and the differences between the oversampling and undersampling results. 相似文献
38.
Martin Di Federico Tomaso Poggi Pedro Julián Marco Storace 《Digital Signal Processing》2010,20(6):1723-1732
In this paper we present an integrated circuit implementing piecewise-linear (PWL) functions with three inputs, where each input can be either analog or digital. The PWL function to be implemented can be chosen by properly storing a set of coefficients in a 4 kB external memory. Experimental results are shown that demonstrate the circuit working up to 50 MHz with a maximum power consumption of 3.7 mW. Measurements corresponding to both static and time-varying inputs are provided and discussed. 相似文献
39.
A commercially available dot immunoassay that employs the lipoarabinomannan antigen was evaluated for the serologic diagnosis of tuberculosis. The test showed a high specificity (100%); however, its sensitivity was low (18.5%). Antibodies to lipoarabinomannan were detected in the sera of 7 of 71 patients with newly acquired tuberculosis and in sera of 10 of 21 patients with relapse tuberculosis. It has been shown by others that sera from patients with relapse tuberculosis had a higher concentration of antibodies and reacted with a greater variety of antigens (native culture filtrates of Mycobacterium tuberculosis H37Rv) than did sera from patients with newly acquired tuberculosis. Our data confirm the results of these previous studies as far as lipoarabinomannan is concerned. We conclude that the differences in the production of antibodies shown by the two groups of tuberculous patients (new and relapse) must be taken into account when assessing the usefulness of serologic tests for the diagnosis of tuberculosis. 相似文献
40.
P Ferrer Salvans R Ravella Mateu R Peyra Juliá T Saura Campo R Solá Herrera 《Canadian Metallurgical Quarterly》1997,108(8):286-292
BACKGROUND: The methods and characteristics of clinical data gathered at the initial steps of development of a computerized system to aid medical diagnosis are reported. The objectives of the study were as follows: to describe the overall method and to set a framework for developing an intellectual model of the medical diagnosis procedure. MATERIAL AND METHODS: A structured medical interview and physical examination using an informatic program on PC compatible portable computers were completed in a sample 1,238 patients attending the outpatient clinics of our institution. Data obtained were compared with information in the patient's medical record taking as reference pattern the record of physicians in charge of the patients. Diagnosis were codified according to WHO International Classification of Diseases (ICD-9-CM). RESULTS: The distribution of symptoms and signs corresponding to the different organs and systems was analyzed. Each subdivision afforded a range of 1.3 to 3.9 abnormal findings per patient. A total of 3,571 diagnoses were codified for the whole group 1,238 patients with a mean (standard deviation) of 3 (2) diagnoses per patient (range 0-12). The distribution of diagnostic groups varied depending on the consideration of the main diagnosis or the concomitant diagnoses that defined the patient's clinical context. The most frequent main diagnoses included tumors, cardiovascular diseases, gastrointestinal disorders, and genitourinary tract diseases. CONCLUSIONS: As shown by results obtained in a sample of 1,238 patients, there is a very complex situation in clinical practice due to the simultaneous occurrence of several clinical patterns. This finding should be taken into account when developing clinical decision making support systems. The use of a structured medical interview or a structured and standard medical visit may be an adequate tool to clarify this matter and to contribute to standardization of clinical concepts and situations. 相似文献