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991.
Naciye El Levent Dandik H. Ayşe Aksoy 《Journal of the American Oil Chemists' Society》1998,75(12):1207-1211
The solvent-free glycerolysis of used sunflower oil catalyzed by acetone powder of Nigella sativa seeds was investigated. The highest partial acylglycerols yield was obtained at 60°C. The glycerolysis reactions, conducted
at molar ratios of 1:1, 2:1, and 3:1 of oil to glycerol keeping the acetone powder content at 30% based on oil weight and
the temperature at 60°C, approached equilibrium after 2 h. The highest partial acylglycerol content of the products was 66%
(1:1 molar ratio) and 60% (2:1 molar ratio). 相似文献
992.
993.
Experimental Study on Deoxidization of Barium and Barium Alloy 总被引:2,自引:0,他引:2
1.Experimeotal1.1ConvectionfreebatheXPerjmentsThepurposeofconvectionfreebathexperimelltswastoacquiremoltenironsysteminwhichthedeoxi-dizationproducts(firstoriginalinclusions)wouldnotbeaffectedbytheinnercirculationflowcausedbyconvection.TheregUlarityofbariumdeoxidizationcanbestudiedbasedonthefirstoriginalinclusions.Duringtheexperimentalperiod,thedirectcurrentmolybdenum-woundfurnacewasusedinwhichtheex-ternalforcecausedbythealternatemagneticfieldwaseliminated.Themicrocomputertemperaturecolltrols… 相似文献
994.
Preciptated solid materials (PSM) from waste black liquor (WBL), at pH 8·5–9·0, produced from cooking of rice straw in paper
mill factories were thermally treated. The cooking process led to decrease in organic material and partial substitution in
silica structure. During this cooking process, three probable stages of mass loss comprise removal of moisture, volatile release,
and combustion.
The chemical analysis depicts the cooking effect on leaching either the high percentage elements (Ca, Na, and K) or some metallic
cations (Mn, Cd, Zn and Cu) in the parent rice straw. Silica hydrate, amorphous silica and crystalline silica were obtained
at <600°C, 600–700°C and at>800°C, respectively. The infrared spectra show gradual removal of the hydrocarbon bond (C–H),
molecular H2O, and sianol group (Si-OH) with temperature. TG, DTA, XRD and SEM were used in this study. 相似文献
995.
996.
Samah M S El‐Shafei Sally S Sakr Nagwa H I Abou‐Soliman 《International Journal of Dairy Technology》2020,73(1):126-133
This study investigated the impact of supplementing goats' milk with quinoa extracts, in the range of 5, 10 and 15 g/100 g on the milk fermentation. The properties of yoghurt produced from this milk, which include viscosity, microstructure and sensory acceptability, were assessed. The supplementation of goats' milk with quinoa extracts, particularly permeate extract, reduced the fermentation time and enhanced the viability of lactic acid bacteria. Supplementation of yoghurt with increased levels of quinoa extracts increased the apparent viscosity and changed the yoghurt protein matrix. Panellists highly accepted the yoghurt that contained quinoa permeate extract. 相似文献
997.
Antioxidant activities of enzymatic‐hydrolysed proteins of dromedary (Camelus dromedarius) colostrum
Olfa Oussaief Zeineb Jrad Isabelle Adt Mohamed Dbara Touhami Khorchani Halima El‐Hatmi 《International Journal of Dairy Technology》2020,73(2):333-340
This work investigated the antioxidant activities of dromedary colostrum proteins before and after hydrolysis by pepsin, trypsin, α‐chymotrypsin, pancreatin and papain. The enzymatic hydrolysis affected the degrees of hydrolysis, electrophoretic profiles, molecular weight distribution and hydrophobic/hydrophilic properties of the generated peptides. The antioxidant activities were evaluated using four antioxidant assays, including 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) and 2,2′‐azinobis(3‐ethylbenzothiazoline‐6‐sulfonic acid) (ABTS) radical‐scavenging activities, ferric reducing power and ferrous ion chelating activity. Interestingly, the antioxidant activities of dromedary colostrum proteins were enhanced after enzymatic hydrolysis. The highest antioxidant potential was obtained by pancreatic hydrolysates (P ≤ 0.05). These results suggest that dromedary colostrum protein hydrolysates are an important source of natural antioxidant peptides. 相似文献
998.
H. H. Abou El Naga E. S. H. El Ashry M. A. Khattab A. E. Salem Y. M. Boghdady 《Lubrication Science》2001,13(3):251-271
This paper describes work aimed at producing a high‐quality transformer oil from local Egyptian paraffinic base stock by hydrogenation, or hydrogenation plus sulphonation. Analysis showed that the neutral base oil 70N was suitable for producing transformer oil. This neutral base oil was chemically treated by hydrogenation under various conditions of temperature, pressure, and time, using two different catalysts, and by hydrogenation followed by sulphonation using optimum conditions. Optimum hydrogenation conditions were achieved by using a Ni/Mo (10 wt. %) catalyst, at 275°C and 100 psi pressure for 60 min, while optimum sulphonation conditions were achieved in previous work by using oleum or SO3 gas at a concentration of 6 wt. % at 35°C for 60 min. Laboratory results and field trials indicated that the neutral paraffinic base oil when so treated meets the IEC 296 international specification for transformer oil, with the exception of the pour point (−18°C). However, this pour point is not relevant in certain hot climatic conditions. Evaluation of the treated oil with commercial transformer oil has shown its potential for use. 相似文献
999.
G
M Abd El‐Moniem J Honke A Bednarska 《Journal of the science of food and agriculture》2000,80(1):57-62
The effects of optimum conditions of frying soybean, broad bean and Polish pea on proximate analysis and amino acid composition were investigated. Maximum water absorption of 192.93, 129.05 and 148.68% for soybean, broad bean and Polish pea was reached after soaking periods of 16.41, 17.84 and 16.45 h respectively. Sensory evaluation of different temperatures (150, 170 and 190 °C) and frying times (5, 10 and 15 min) for preparing soybean, broad bean and Polish pea indicated that there was a significant difference (P < 0.01) between treatments. The most acceptable fried soybean, broad bean or Polish pea was obtained after frying at 190 °C for 5 min. All the processed legumes under investigation had higher protein digestibility as measured in vitro and minimum reduction in total amino acid composition. The optimum frying process is an effective method for lowering phytate content (myo‐inositol hexaphosphate) by 89.77, 67.70 and 82.88% respectively as well as causing considerable loss of total oligosaccharides by 64.35, 16.16 and 49.44%. © 2000 Society of Chemical Industry 相似文献
1000.
Systematic electrical and mechanical studies were carried out on natural rubber (NR) blended with different types of synthetic rubber such as styrene‐butadiene rubber (SBR), polybutadiene rubber (BR), and ethylene‐propylene‐diene monomer (EPDM) as nonpolar rubbers and nitrile‐butadiene rubber (NBR) and chloroprene rubber (CR) as polar rubbers. The NR/SBR, NR/BR, NR/EPDM, NR/NBR, and NR/CR blends were prepared with different ratios (100/0, 75/25, 50/50, 25/75, and 0/100). The permittivity (ε′) and dielectric loss (ε″) of these blends were measured over a wide range of frequencies (100 Hz–100 kHz) and at room temperature (∼ 27°C). The compatibility results obtained from the dielectric measurements were comparable with those obtained from the calculation of the heat of mixing. These results were confirmed by scanning electron microscopy and showed that NR/SBR and NR/BR blends were compatible while NR/EPDM, NR/NBR, and NR/CR blends were incompatible. To overcome the problem of phase separation (incompatibility) between NR and EPDM, NBR, or CR, a third component such as SBR or poly(vinyl chloride) (PVC) was added as a compatibilizing agent to these blends. The experimental data of dielectric and mechanical measurements showed that the addition of either SBR or PVC could improve the compatibility of such blends to some extent. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 60–71, 2001 相似文献