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131.
Ljerka Kratofil Krehula Zvonimir Katančić Anita Ptiček Siročić Zlata Hrnjak-Murgić 《木材化学与工艺学杂志》2014,34(1):39-54
Due to the widespread use of wood-plastic composites (WPCs), high-density polyethylene-wood flour composites (HDPE/WF) were studied in order to determine their stability in different application conditions. UV degradation and periodic absorption/desorption of moisture cause damaging changes to material during WPCs’ exterior application, so it is necessary to ensure WPCs’ durability against atmospheric influences. Samples were characterized by FTIR spectroscopy and scanning electron microscopy (SEM) in order to study the degradation after simulated weathering. The degree of water absorption was also determined. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) were used for the determination of composites’ thermal properties. Results show that the stability of the HDPE/WF composites to UV treatment highly depends on stabilizer content and its dispersion in the polymer matrix. Incompatibility of HDPE and wood particles is a major problem that should be solved to achieve good durability and satisfying properties in use. 相似文献
132.
The effect of replacing fat with oat bran on fatty acid composition and physicochemical properties of meatballs 总被引:1,自引:0,他引:1
Oat bran was used as a fat substitute in the production of meatballs. The effect of oat bran addition on the fatty acid composition, trans fatty acids, total fat, some physicochemical and sensory properties of the samples was studied. Meatballs were produced with four different formulations; the addition of 5, 10, 15 and 20% oat bran. Control samples were formulated with 25% fat addition as in commercial production. The major fatty acids were cis-oleic, palmitic and stearic acid in all the meatball samples, those with oat bran added as well as the control. Meatballs containing oat bran had lower concentrations of total fat and total trans fatty acids than the control samples. Meatballs made with 20% oat bran had the highest protein, salt and ash contents, L value (lightness), b value (yellowness), and the lowest moisture content and a value (redness). There was no significant difference among the meatball samples with respect to sensory properties, and all samples had high acceptability. 相似文献
133.
The present study describes the phytochemical profile and antimicrobial activity of Satureja subspicata Vis. essential oils, collected in Dalmatia (Croatia). Three samples of essential oils were obtained from the aerial parts of the plant by hydrodistillation and analyzed by GC–MS. From the 24 compounds representing 97.47% of the oils, carvacrol (16.76%), α-pinene (13.58), p-cymene (10.76%), γ-terpinene (9.54%) and thymol methyl ether (8.83%) appear as the main components. The oils also contained smaller percentages of myrcene, linalool, β-caryophyllene, limonene, geranyl acetate, 1-Octen-3-ol, nerol, thymol and borneol. Furthermore, antimicrobial activity of the oil was evaluated using agar diffusion and broth microdilution methods. The antimicrobial test results showed that the oils had a great potential antimicrobial activity against all 13 bacteria and 9 fungal strains. Gram-positive bacteria are more sensitive to the investigated oil, with a range of 0.09 to 6.25 μl/ml than Gram-negative bacteria in the range which is significantly higher from 1.56 to 25.00 μl/ml. Results presented here may suggest that the essential oil of S. subspicata possesses antimicrobial properties, and is therefore a potential source of antimicrobial ingredients for the food and pharmaceutical industry. 相似文献
134.
Marina M. Radišić Tatjana M. Vasiljević Nikolina N. Dujaković Mila D. Laušević 《Food Analytical Methods》2013,6(2):648-657
This study presents an application of rapid and sensitive multiresidue method for the analysis of acephate, acetamipride, atrazine, carbendazim, carbaryl, carbofuran, dimethoate, imidacloprid, linuron, malathion, monocrotophos, monuron, propazine, simazine, and tebufenozide in fruits. The method involves an extraction procedure based on matrix solid-phase dispersion using diatomaceous earth as a dispersant and dichloromethane as the eluent. The target pesticides were determined using liquid chromatography–ion trap mass spectrometry. Quantification of the analytes was carried out using the most sensitive ion transition. Ion trap parameters, like activation q and time, were found to have a prominent influence on method sensitivity for some pesticides and they were optimized accordingly. The confirmation of residues detected in real samples was performed by repeated injection and acquiring additional ion transitions besides the ones used for quantification. The method was validated for accuracy, linearity, reproducibility, and sensitivity. Mean values for recoveries were in the range of 70–120 % for all tested matrices. Repeatability of the method, expressed as the relative standard deviation, was in general lower than 20 %. The applicability of the method to routine analysis was tested in real fruit samples with good performance. 相似文献
135.
Fatma Tosun Çiğdem Akyüz Kızılay Kevser Erol Fatma Sultan Kılıç Mine Kürkçüoğlu Kemal Hüsnü Can Başer 《Food chemistry》2008
The anticonvulsant activity of furanocoumarins, coumarin mixture and the essential oil obtained from the fruits of Heracleum crenatifolium was examined against maximal electroshock (MES)-induced seizures in mice. Bergapten showed significant anticonvulsant activity. The furanocoumarins isolated from the fruits of the plant were identified using thin-layer chromatography, melting points and spectroscopic methods (IR, MS, 1H NMR) as isobergapten (1), pimpinellin (2), bergapten (3), isopimpinellin (4), sphondin (5) and byak-angelicol (6). The essential oil content of the fruits were found as 5.5%. Twenty-two compounds representing 99.3% of the essential oil obtained from the fruits of H. crenatifolium were determined and the major components were identified as octanol and octyl acetate (3.1% and 88.4% respectively) by GC and GC–MS. 相似文献
136.
Antioxidant (polyphenols and carotenoids) and nonantioxidant (phytosterols) bioactive compounds and dietary fiber may have a significant role in health. The intake of these compounds is strongly linked with the high consumption of fruits, vegetables, and unrefined cereals. A whole-diet approach to these food constituents is intended to render the current definition of Mediterranean diet based on food consumption more comprehensive. The Mediterranean dietary pattern can be characterized by the following four essential dietary indicators: 1) Monounsaturated to saturated fatty acid ratio (range: 1.6 to 2.0); 2) Intake of dietary fiber (41 to 62 g/person/day); 3) Antioxidant capacity of the whole diet (3500 to 5300 trolox equivalent/person/day); 4) Phytosterols intake (370 to 555 mg/person/day). The contribution of foods and beverages to these parameters is described. Spanish National Food Consumption Data for the years 2000 and 1964 were used to quantify the lowest and highest range values. The occurrence of these indicators in the Mediterranean diet has specific characteristics and there is sufficient scientific evidence to support the beneficial health effects. 相似文献
137.
Internalization and Accumulation in Dendritic Cells of a Small pH‐Activatable Glycomimetic Fluorescent Probe as Revealed by Spectral Detection 下载免费PDF全文
Prof. Zoran Arsov Prof. Urban Švajger Prof. Janez Mravljak Prof. Stane Pajk Anita Kotar Dr. Iztok Urbančič Prof. Janez Štrancar Prof. Marko Anderluh 《Chembiochem : a European journal of chemical biology》2015,16(18):2660-2667
DC‐SIGN, an antigen‐uptake receptor in dendritic cells (DCs), has a clear role in the immune response but, conversely, can also facilitate infection by providing entry of pathogens into DCs. The key action in both processes is internalization into acidic endosomes and lysosomes. Molecular probes that bind to DC‐SIGN could thus provide a useful tool to study internalization and constitute potential antagonists against pathogens. So far, only large molecules have been used to directly observe DC‐SIGN‐mediated internalization into DCs by fluorescence visualization. We designed and synthesized an appropriate small glycomimetic probe. Two particular properties of the probe were exploited: activation in a low‐pH environment and an aggregation‐induced spectral shift. Our results indicate that small glycomimetic molecules could compete with antigen/pathogen for binding not only outside but also inside the DC, thus preventing the harmful action of pathogens that are able to intrude into DCs, for example, HIV‐1. 相似文献
138.
Changes in polyphenolic content and antioxidant activity after thermal treatments of grape seed extract and grape pomace 总被引:1,自引:0,他引:1
Susana?Chamorro Isabel?Go?i Agustín?Viveros Deysy?Hervert-Hernández Agustín?BrenesEmail author 《European Food Research and Technology》2012,234(1):147-155
This study was undertaken to investigate the effect of heat treatment on polyphenolic content and antioxidant activity in
grape pomace (GP) and grape seed extract (GSE). GP and GSE were heat treated in a furnace or autoclaved at 100 °C for 15,
30 and 60 min. Structural modifications of the polyphenols during thermal processes were determined by HPLC–MS, and the antioxidant
activity was determined by ABTS, DPPH and photochemiluminescence methods. In general, furnace thermal treatment of GSE and
GP did not affect the total extractable polyphenols content, tannin content, procyanidin components and the antioxidant activity.
Autoclave treatment caused an extensive hydrolysis of gallocatechin (70%), catechin (61%), epicatechin (65%), procyanidin
B1 (75%) and procyanidin B2 (73%) in GSE, and an increase in gallic acid (71%), gallocatechin (100%) and epicatechin gallate
(129%) in GP. Autoclave treatment did not affect the antioxidant activity of GSE or GP. It can be concluded that the effect
of autoclave was more severe than furnace heat treatment modifying the phenolic profile in a different manner depending on
the grape seed product used. These modifications were not related with changes in antioxidant activity. 相似文献
139.
140.