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991.
Daniele da Silva Bastos Maria do Pilar Gonçalves Cristina Tristão de Andrade Kátia Gomes de Lima Araújo Maria Helena Miguez da Rocha Leão 《Food and Bioproducts Processing》2012,90(4):683-692
The aim of this work was to obtain a new stable food product from cashew apple juice encapsulated by spray-drying technique using chitosan–whey protein isolate systems. The materials were evaluated according to their physicochemical stability during storage at different conditions and characterized with respect to their particle size distribution and structure. Encapsulated commercial and natural juices showed homogenous and unimodal particle size distribution with diameters ranging from 0.2 to 5.0 μm and from 0.2 to 40.0 μm, respectively. Both juices demonstrated higher physicochemical stability for vitamin C and color measurements than their respective non-encapsulated juices. X-ray diffractograms evidenced that the powder juices after the 140th day of storage were still in amorphous state. These results indicate that the new product was effective in protecting sensitive compounds present in the food matrix and it was also able to remain stable throughout the study period. 相似文献
992.
Alireza Hassanzadeh Fatemeh Kanaani Shában Elahi 《Expert systems with applications》2012,39(12):10959-10966
In the era of internet, universities and higher education institutions are increasingly tend to provide e-learning. For suitable planning and more enjoying the benefits of this educational approach, a model for measuring success of e-learning systems is essential. So in this paper, we try to survey and present a model for measuring success of e-learning systems in universities. For this purpose, at first, according to literature review, a conceptual model was designed. Then, based on opinions of 33 experts, and assessing their suggestions, research indicators were finalized. After that, to examine the relationships between components and finalize the proposed model, a case study was done in 5 universities: Amir Kabir University, Tehran University, Shahid Beheshti University, Iran University of Science & Technology and Khaje Nasir Toosi University of Technology. Finally, by analyzing questionnaires completed by 369 instructors, students and alumni, which were e-learning systems user, the final model (MELSS Model1). 相似文献
993.
Rosa Raybaudi-Massilia Alexandra Zambrano-Durán Jonathan Mosqueda-Melgar María Isabel Calderón-Gabaldón 《Journal für Verbraucherschutz und Lebensmittelsicherheit》2012,7(4):273-282
In this research, several plant compounds were in vitro evaluated against Salmonella enterica ser. Saintpaul and Escherichia coli O157:H7 through disc’s method. Among them Panax ginseng (PG) showed the highest antimicrobial activity in comparison to other natural antimicrobials. Combinations of PG (2?% v/v) with malic acid (MA) (0.5?% v/v) and/or potassium sorbate (PS) (0.05?% v/v) were made for evaluating their effects on S. Saintpaul and E. coli O157:H7 populations in sterile and fresh mango and orange juices stored at 5?°C. The best combination of antimicrobial compounds on native flora (during 21?days) as well as sensory attributes (0?day) of fresh juices were evaluated. The antimicrobial compounds added into mango and orange juices were more effective against S. Saintpaul than against E. coli O157:H7. The combination of PG (2?% v/v), MA (0.5?% v/v) and PS (0.05?% v/v) showed the highest antimicrobial effectiveness against both pathogenic microorganisms in both juices, in addition to a higher microbiological inhibition during storage (21?days). Sensory attributes such as aroma, color and taste were enhanced, but acidity was notably affected in both juices. In conclusion, the combination of PG, MA and PS could be an effective method in the food industry for ensuring the microbial safety and quality in mango and orange juices. 相似文献
994.
Ricardo Colomo-Palacios Israel González-Carrasco Jose Luis López-Cuadrado Antonio Trigo Joao Eduardo Varajao 《Information Systems Frontiers》2014,16(4):607-625
People in software development teams are crucial in order to gain and retain strategic advantage inside a highly competitive market. As a result, human factors have gained attention in the software industry. Software Project Managers are decisive to achieve project success. A competent project manager is capable of solving any problem that an organization may encounter, regardless of its complexity. This paper presents I-Competere which is a tool developed to forecast competence gaps in key management personnel by predicting planning and scheduling competence levels. Based on applied intelligence techniques, I-Competere allows the forecast and anticipation of competence needs thus articulating personnel development tools and techniques. The results of the test, using several artificial neural networks, are more than promising and show prediction accuracy. 相似文献
995.
Mónica B. Betancor Ma. José Caballero Genciana Terova Samuela Corà Reda Saleh Tibiábin Benítez-Santana J. Gordon Bell Carmen María Hernández-Cruz Marisol Izquierdo 《Lipids》2012,47(12):1193-1207
Docosahexaenoic acid (DHA) is an essential fatty acid necessary for many biochemical, cellular and physiological functions in fish. However, high dietary levels of DHA increase free radical injury in sea bass (Dicentrarchus labrax) larvae muscle, even when vitamin E (α-tocopherol, α-TOH) is increased. Therefore, the inclusion of other nutrients with complementary antioxidant functions, such as vitamin C (ascorbic acid, vitC), could further contribute to prevent these lesions. The objective of the present study was to determine the effect of vitC inclusion (3,600?mg/kg) in high DHA (5?% DW) and α-TOH (3,000?mg/kg) microdiets (diets 5/3,000 and 5/3,000?+?vitC) in comparison to a control diet (1?% DHA DW and 1,500?mg/kg of α-TOH; diet 1/1,500) on sea bass larvae growth, survival, whole body biochemical composition and thiobarbituric acid reactive substances (TBARS) content, muscle morphology, skeletal deformities and antioxidant enzymes, insulin-like growth factors (IGFs) and myosin expression (MyHC). Larvae fed diet 1/1,500 showed the best performance in terms of total length, incidence of muscular lesions and ossification degree. IGFs gene expression was elevated in 5/3,000 diet larvae, suggesting an increased muscle mitogenesis that was confirmed by the increase in the mRNA copies of MyHC. vitC effectively controlled oxidative damages in muscle, increased α-TOH larval contents and reduced TBARS content and the occurrence of skull deformities. The results of the present study showed the antioxidant synergism between vitamins E and C when high contents of DHA are included in sea bass larvae diets. 相似文献
996.
Vanessa Migliorini Urban Ana Lucia Machado Carlos Eduardo Vergani Eunice Teresinha Giampaolo Ana Cláudia Pavarina Quezia Bezerra Cass 《应用聚合物科学杂志》2012,123(2):732-739
The effect of a post‐polymerization treatment on the leaching of methacrylic acid (MA) and benzoic acid (BA) from the reline resins [Kooliner (K), New Truliner (N), Ufi Gel hard (U), and Tokuso Rebase Fast (T)] was evaluated. Specimens of each material were divided into two groups: Group C (control) – left untreated; Group WB (water‐bath) – immersion in water at 55 ± 1°C for 10 min. Specimens were placed in artificial saliva at 37 ± 1°C and, after 1‐, 3‐, 5‐, 24‐h and 3‐, 7‐, 14‐, and 30‐day intervals, aliquots were removed and analyzed using high performance liquid chromatography. Data were analyzed by using Wilcoxon, Mann–Whitney or Kruskal–Wallis tests (α = 0.05). At 1 h, the concentration of MA released from U control specimens was higher than those of the other ones, and decreased after 3 h. WB specimens released lower amounts of MA than control specimens only for material U, at the 1‐ and 3‐h periods. For all control specimens, concentrations of leached BA progressively decreased within 5 h and from 24 h to the end. WB specimens released significantly lower amounts of BA than did the control groups. The highest concentration of MA was leached from control specimens of Ufi Gel hard. Water‐bath post‐polymerization treatment caused a significant reduction in elution of BA. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献
997.
Diego Fernández-Francos David Martínez-Rego Oscar Fontenla-Romero Amparo Alonso-Betanzos 《Computers & Industrial Engineering》2013,64(1):357-365
Rolling-element bearings are among the most used elements in industrial machinery, thus an early detection of a defect in these components is necessary to avoid major machine failures. Vibration analysis is a widely used condition monitoring technique for high-speed rotating machinery. Using the information contained in the vibration signals, an automatic method for bearing fault detection and diagnosis is presented in this work. Initially, a one-class ν-SVM is used to discriminate between normal and faulty conditions. In order to build a model of normal operation regime, only data extracted under normal conditions is used. Band-pass filters and Hilbert Transform are then used sequentially to obtain the envelope spectrum of the original raw signal that will finally be used to identify the location of the problem. In order to check the performance of the method, two different data sets are used: (a) real data from a laboratory test-to-failure experiment and (b) data obtained from a fault-seeded bearing test. The results showed that the method was able not only to detect the failure in an incipient stage but also to identify the location of the defect and qualitatively assess its evolution over time. 相似文献
998.
999.
Márcio Carocho Amilcar L. Antonio João C. M. Barreira Andrzej Rafalski Albino Bento Isabel C. F. R. Ferreira 《Food and Bioprocess Technology》2014,7(7):1917-1927
Chestnuts are widely consumed around the world, especially in China, which is the major producer. Portugal is the fifth biggest producer, reaching an income of 17 M €, with particular relevance for Trás-os-Montes region, which is responsible for 81 % of Portuguese production. During postharvest storage, a number of pests tend to attack chestnuts, contributing to high economic losses. Since 2010, the most effective postharvest treatment, i.e., fumigation with methyl bromide, was banned in the European Union, urging producers to seek effective and reasonable alternatives. One alternative could be irradiation with gamma rays or electron beam, which is used in food commodities, legally regulated and allows outstanding results. Our research group has tested both irradiation types in chestnuts and studied the nutritional, antioxidant, and other chemical parameters, obtaining promising results. Herein, we extended these studies to selected cultivars from Portugal and Italy in order to validate this technique as a viable alternative to fumigation. The selected irradiation dose (1 kGy) was chosen following previous results where it proved to be effective without causing remarkable changes in chemical or antioxidant profiles. To obtain a global knowledge about how each cultivar reacts to irradiation, principal component analysis was performed using all the measured parameters. Despite the detected differences among cultivars, which differentiated particularly Palummina and Cota, it was verified that irradiation did not cause changes in chemical and antioxidant parameters that could enable defining distinctive features among irradiated and non-irradiated chestnuts. Hence, the results herein reported might be seen as a new step toward the completion of irradiation as feasible conservation technology, independently of chestnuts origin. 相似文献
1000.
N. A. Usov S. A. Gudoshnikov O. N. Serebryakova M. L. Fdez-Gubieda A. Muela J. M. Barandiarán 《Journal of Superconductivity and Novel Magnetism》2013,26(4):1079-1083
Chemically synthesized iron oxide nanoparticles and magnetosomes produced by magnetotactic bacteria are of great importance for application in biomedicine. In this paper, we discuss the complicated magnetic anisotropy of the nanoparticles, the influence of the magnetostatic interactions, and thermal fluctuations on the behavior of these assemblies. Numerical simulation for dilute assemblies of iron oxide nanoparticles with combined magnetic anisotropy show that the uniaxial shape anisotropy dominates even for small aspect ratios of the particle, L/D≥1.1–1.2. The quasistatic hysteresis loops are calculated for various clusters of bacterial magnetosomes with diameters D=40–60 nm to understand the influence of magnetostatic interactions. The specific absorption rate (SAR) is calculated for assemblies of magnetic nanoparticles dispersed in solid and liquid media. A new electrodynamic method of measurement is used to obtain the SAR of the assembly of bacterial magnetosomes with average diameter D=48 nm. 相似文献