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61.
Geraldo Lúcio Tiago Filho Camila Rocha Galhardo Adriana de Cássia Barbosa Regina Mambeli Barros Fernando das Graças Braga da Silva 《Energy Policy》2011
This article presents the main regulatory changes that occurred in the Brazilian power sector in 2009, along with the impacts these changes caused on the market, especially related to small hydropower (<30 MW). This study addresses regulatory issues based on inventory studies and records of basic projects, changes related to the compensation of the assured energy of SHPs in the Brazilian energy reallocation market, the socio-economic impact resulting from the construction of SHPs, SHPs in alternative resource auctions and finally the general outlook for the growth scenario for SHPs in Brazil according to the ten-year plan (2010–2019). The overall conclusions of this investigation were that the 2008/2009 biennium was a period of great changes in the regulation of small hydropower plants in Brazil, and the SHP market has shown maturity. Additionally, despite SHP being a type of technology that is completely dominated by domestic industry, in recent years, they have experienced policy disincentives caused by changes to rules that inhibit their growth. 相似文献
62.
Analysis and mathematical modelling of the behaviour of Escherichia coli in the mascarpone cheese during cold storage 下载免费PDF全文
Jaroslaw Kowalik Adriana Lobacz Justyna Zulewska Bogdan Dec 《International Journal of Food Science & Technology》2018,53(6):1541-1548
The aim of this work was to study the behaviour of E. coli in mascarpone cheese during storage at the temperatures ranging from 3 to 15 °C, as well as application of predictive microbiology to describe the experimental data. The Baranyi, Gompertz and logistic models were fitted at the stage of primary modelling. Although all applied primary models described the growth of micro‐organisms accurately, the most accurate goodness of fit was obtained for the Gompertz model and the growth rates generated by this model were used for secondary modelling. The polynomial model predicted accurately the influence of temperature on the growth rate of E. coli, reaching the adjusted coefficient of linear regression 0.99. Generated predictive model that describes the growth of E. coli in mascarpone cheese constitutes a valuable tool in assessing the microbiological stability of the food product with similar physicochemical properties. 相似文献
63.
Leonardo S. Lopes Filipe S. Q. Silva Adriana S. Silva Isabella F. Delgado 《Journal of surfactants and detergents》2013,16(3):445-448
Enzymatic detergents are widely used in health services. These products should be controlled to ensure their activity. In this paper, a UV spectrophotometric method for the determination of proteolytic activity in enzymatic detergents was validated. An artificial substrate (azocasein) was used to quantify the enzyme activity at 340 nm. The results showed that the method was satisfactory in respect to its specificity, linearity, precision, accuracy and robustness. This method fulfills both ICH’s and Brazilian criteria, demonstrating its suitability for routine analysis as well as its potential application for regulatory purposes. 相似文献
64.
Fábio M. DaMatta Adriana Grandis Bruna C. Arenque Marcos S. Buckeridge 《Food research international (Ottawa, Ont.)》2010,43(7):1814-1823
Carbon emissions related to human activities have been significantly contributing to the elevation of atmospheric [CO2] and temperature. More recently, carbon emissions have greatly accelerated, thus much stronger effects on crops are expected. Here, we revise literature data concerning the physiological effects of CO2 enrichment and temperature rise on crop species. We discuss the main advantages and limitations of the most used CO2-enrichment technologies, the Open-Top Chambers (OTCs) and the Free-Air Carbon Enrichment (FACE). Within the conditions expected for the next few years, the physiological responses of crops suggest that they will grow faster, with slight changes in development, such as flowering and fruiting, depending on the species. There is growing evidence suggesting that C3 crops are likely to produce more harvestable products and that both C3 and C4 crops are likely to use less water with rising atmospheric [CO2] in the absence of stressful conditions. However, the beneficial direct impact of elevated [CO2] on crop yield can be offset by other effects of climate change, such as elevated temperatures and altered patterns of precipitation. Changes in food quality in a warmer, high-CO2 world are to be expected, e.g., decreased protein and mineral nutrient concentrations, as well as altered lipid composition. We point out that studies related to changes in crop yield and food quality as a consequence of global climatic changes should be priority areas for further studies, particularly because they will be increasingly associated with food security. 相似文献
65.
Ma Soledad Crdova‐Aguilar Adriana Snchez Leobardo Serrano‐Carren Enrique Galindo 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2001,76(11):1101-1106
The production of γ‐decalactone by the filamentous fungus Trichoderma harzianum involves four phases (oil–water–air–mycelium) and its dispersion is crucial during fermentation. Oil and biomass (when present) dispersion, as a function of the volumetric power drawn (P/V), was characterized, in two; three‐ and four‐phase systems agitated with Rushton turbines. Trichoderma harzianum mycelium was used as the solid phase in the four‐phase system. Two stages of the fermentation were simulated: the beginning (15% oil and 1.4 kgm?3 of mycelium) and the end (2% oil and 10.6 kg m?3 of mycelium). In the two‐phase system, the use of exhausted broth achieved higher oil dispersions at low P/V values as compared with distilled water. Aeration decreased the oil dispersion for the high‐oil system, but enhanced oil dispersion for the low‐oil system. Compared with the P/V used in the actual fermentation (0.2 kW m?3), a high segregation of the system was observed for the high‐oil/low‐biomass system, due to the difficulty of mixing the thick oil–air emulsion present at the top of the tank. The system simulating the end of the fermentation reached almost complete homogeneity of oil and biomass, a phenomenon due to the high biomass/oil ratio and the biomass acting as an oil carrier. © 2001 Society of Chemical Industry 相似文献
66.
Ultrafine fluorescent fibers were prepared by electrospinning of a phenyleneethynylene oligomer mixed in DMF with a poly(styrene-co-maleimide) (PSM). The microscopic characterization by SEM reveals that the fibers are smooth and entangled one to the others forming a non-woven mat with an average diameter of 490 nm. By TEM, a core-sheath type structure is observed which derives from phase segregation between the PSM interacting with the oligomer and the excess of PSM that acts as matrix, as supported by XRD and DSC analysis. The membranes are fluorescent emitting at 420 nm, in the blue region, a high energy light, opening the possibility of their application in optoelectronic devices such as fluorescent sensors. Preliminary assays have been performed for the detection of sodium ions. 相似文献
67.
The traditional regression analysis is usually applied to homogeneous observations. However, there are several real situations where the observations are not homogeneous. In these cases, by utilizing the traditional regression, we have a loss of performance in fitting terms. Then, for improving the goodness of fit, it is more suitable to apply the so-called clusterwise regression analysis. The aim of clusterwise linear regression analysis is to embed the techniques of clustering into regression analysis. In this way, the clustering methods are utilized for overcoming the heterogeneity problem in regression analysis. Furthermore, by integrating cluster analysis into the regression framework, the regression parameters (regression analysis) and membership degrees (cluster analysis) can be estimated simultaneously by optimizing one single objective function. In this paper the clusterwise linear regression has been analyzed in a fuzzy framework. In particular, a fuzzy clusterwise linear regression model (FCWLR model) with symmetrical fuzzy output and crisp input variables for performing fuzzy cluster analysis within a fuzzy linear regression framework is suggested. For measuring the goodness of fit of the suggested FCWLR model with fuzzy output, a fitting index is proposed. In order to illustrate the usefulness of FCWLR model in practice, several applications to artificial and real datasets are shown. 相似文献
68.
This paper proposes and experimentally evaluates a method to determine the stressed syllable of a word in the framework of speech synthesis in Romanian. In order to produce high quality speech, a speech synthesis system needs information about the position of the stress for each word of a sentence to be generated. Otherwise, incorrect positioning of stress (or, in the worst case, completely ignoring it) translates into poor quality synthesized speech. Since Romanian is a free-stressed language (as is English, for example), the position of the stressed syllable within a word is not clearly defined. Consequently, a set of explicit rules that can determine the exact position of the stress is difficult to generate. In order to solve this problem, we propose an original method to find stressing rules for the Romanian language as well as an algorithm to implement this method. According to this algorithm, the position of the stressed syllable is computed according to a number of word parameters encompassing morphologic, phonetic, and lexical characteristics of the word. The experimental results show that the errors of the automatic stress assignment using our method do not exceed 6%. 相似文献
69.
Adriana Giordana R. Glosser Keith Joyner Gordon Pollack 《Journal of Electronic Materials》1991,20(11):949-958
Photoreflectance (PR) was used to study SIMOX materials produced under various fabrication conditions. The position, amplitude
and shape of the 3.4 eV PR response were monitored for three different sets of samples which provided information about the
crystalline quality of the top silicon layer. Each sample of the first set underwent different annealing conditions. A second
set of six samples was arranged such that one sample was removed at a different step of the process involving three implantation-anneal
cycles. A third set of four samples was implanted with different doses of oxygen. In the first case the PR signal improved
with longer annealing times and higher temperatures; in the second case the PR signal appeared to deteriorate with each cycle
undergone by the samples, while in the third case the degradation of the structure increased with the increased implantation
dosage. Transmission electron microscopy (TEM) was also performed in the last two cases, and its results supported the PR
conclusions. 相似文献
70.
Blanco-Metzler A Tovar J Fernández-Piedra M 《Archivos latinoamericanos de nutrición》2004,54(3):322-327
Tropical roots and tubers (TRT) are important staple foods in the tropics. TRT are produced by small farmers and have received only limited attention. The objective of this paper was to evaluate nutritionally important carbohydrate fractions and proximal composition of cooked cassava (Manihot esculenta), cocoyam- or tannia- (Xantosoma sp) and yam (Dioscorea alata) grown in Costa Rica. Twenty boiled samples of each TRT were analyzed for proximal composition, following AOAC protocols. Carbohydrate fractions (dietary fiber, available and resistant starch) and alpha-amylolysis rate were assessed by enzymatic methods. All TRT analyzed consisted mainly of water and carbohydrates, representing moderate dietary fiber and energy sources. They show a low protein level and contain no fat. Moisture, protein, ashes and dietary fiber contents vary significantly (p<0.01) among the three species. In terms of their proximal composition, these locally grown TRT differ from TRTs cultivated in the South Pacific area, but appear similar to other Latin American varieties. In all samples most of the dietary fiber (84-88%) is insoluble; available starch ranges between 74 and 84% of the dry matter, whereas resistant starch content varied between 0.7 and 1.7%. Amylolysis rate was similar for cassava and cocoyam, whereas a significantly slower digestion (p<0.01) was recorded for yam. Compared to values reported in the literature for other starchy foods and to gelatinized potato starch, used as reference sample, the studied TRT showed intermediate amylolysis rates. It is concluded that consumption of these TRT may be promoted in Costa Rica and other countries with a similar nutritional situation. 相似文献