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991.
Anna Haliaková Anna Prnová Róbert Klement Dušan Galusek Wei-Hsing Tuan 《Ceramics International》2012,38(7):5543-5549
The paper deals with the synthesis and characterisation of binary aluminate glasses in the La2O3–Al2O3 system with Al2O3 contents changing between 74.6 and 86.9 mol% (48–65 wt.%), and of ternary glasses with 75.7 mol% Al2O3 doped with 1 mol% of Nd2O3 or Er2O3. Six binary and two ternary compositions were prepared. Flame synthesis facilitated the preparation of X-ray amorphous microspheres in the systems with 58 wt.% Al2O3, and with eutectic composition in the pseudobinary LaAlO3–LaAl11O18 system doped with Er. Other systems contained low fractions of crystalline LaAlO3 perovskite, regardless of the composition. The diameter of prepared microspheres ranged between 2 and 10 μm. They were transparent for visible light, as well as in the IR wavenumber range from 1300 to 4000 cm?1. 相似文献
992.
Esther Hontañón Marcel Rouenhoff Alfredo Azabal Emilio Ramiro Frank Einar Kruis 《Aerosol science and technology》2014,48(3):333-339
An existing differential mobility analyzer (DMA) of cylindrical electrodes and a novel DMA of rectangular plate electrodes are demonstrated for size fractionation of nanoparticles at high-aerosol flow rates in this work. The two DMAs are capable of delivering monodisperse size selected nanoparticles (SMPS σg < 1.1) at gas flow rates ranging from 200 slm to 500 slm. At an aerosol flow rate of 200 slm, the maximum attainable particle mean size is of about 20 nm for the cylindrical DMA and of nearly 50 nm for the rectangular plate DMA. The number concentration of the monodisperse nanoparticles delivered by the high-flow DMAs spans from 104 cm?3 to 106 cm?3 depending upon the particle mean size and particle size dispersion.
Copyright 2014 American Association for Aerosol Research 相似文献
993.
López Antonio Montaño Alfredo Garrido Antonio 《Journal of the American Oil Chemists' Society》2005,82(2):129-133
A survey of vitamin E levels in a wide variety of olive-based foodstuffs was conducted. Vitamin E was determined by normal-phase
HPLC. The only form of vitamin E found in all commercial presentations of table olives was α-tocopherol, with an average content
of 3.1 mg/100 g edible portion. A very low content (<0.4 mg/100 g edible portion) of γ-tocopherol was found in most of the
samples analyzed. The main sources of variation of vitamin E were olive cultivars and commercial presentations. Processing
type (Spanish style green olives, directly brined olives, ripe olives) had a limited influence. Irrespective of the elaboration
style, the Gordal cultivar was the poorest with respect to the vitamin E content. On the other hand, all commercial presentations
based on the Hojiblanca cultivar had high contents of vitamin E. The results of this study may be used by the industry for
requirements of nutritional labeling or by nutritionists to estimate vitamin E intakes in diets that include table olives. 相似文献
994.
G.?A.?Garzón K.?Warner F.?C.?FelkerEmail author D.?E.?Palmquist F.?Eller 《Journal of the American Oil Chemists' Society》2004,81(9):861-866
The oxidative deterioration of dry starch-oil composites was investigated by chemical and sensory methods. The composites
were stored at 37°C for 63 d, and changes in the hexanal content and odor attributes were monitored. Analysis of the extracted
oil showed that the first run through the drum dryer presented higher hexanal concentrations than the subsequent runs. Starch-oil
composites from the first run though the drum dryer showed higher metal concentrations and higher odor ratings during storage
time than the subsequent runs. There was a significant correlation between odor attributes and hexanal concentration in the
first run. Since both the oxidation and the metal content were higher in the first run and decreased in further runs, we concluded
that oxidation might have been induced by the presence of metal in the drum dryer. It is likely that during drum drying, the
metal drum and knife surfaces became coated with soy oil, reducing both abrasion and metal contact with the product. Since
many applications of the starch-oil composite technology require drum drying, it will be necessary to take measures to minimize
metal contamination of the product, perhaps by discarding the initial portion of product, which contains the most metal. 相似文献
995.
M. J. Abad A. Ares L. Barral J. Cano F. J. Díez S. García‐Garabal J. Lpez C. Ramírez 《应用聚合物科学杂志》2004,94(4):1763-1770
The effect of a sodium ionomer (ion.Na+) on the compatibility of polypropylene (PP)/high‐barrier ethylene–vinyl alcohol copolymer (EVOH) blends was studied in terms of the thermal, mechanical, and optical properties and morphology. The rheological behavior, tensile tests, and morphology of the binary blends showed that the miscibility of EVOH with PP was very poor. The miscibility of the polymers improved with the ionomer addition. In general, the ion.Na+ concentration did not alter the thermal behavior of the blends, but it did improve the ductility of the injection‐molded specimens. Scanning electron micrographs displayed better adhesion between the PP and EVOH phases in the samples with the ionomer. The mechanical improvement was better in the film samples than in the injection‐molded samples. A 90/10 (w/w) PP/EVOH film with 5% ion.Na+ and an 80/20 (w/w) PP/EVOH film with 10% ion.Na+ presented better global properties than the other blends studied. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1763–1770, 2004 相似文献
996.
Carballa M Omil F Lema JM Llompart M García-Jares C Rodríguez I Gómez M Ternes T 《Water research》2004,38(12):2918-2926
Two cosmetic ingredients (galaxolide, tonalide), eight pharmaceuticals (carbamazepine, diazepam, diclofenac, ibuprofen, naproxen, roxithromycin, sulfamethoxazole and iopromide) and three hormones (estrone, 17beta-estradiol and 17alpha-ethinylestradiol) have been surveyed along the different units of a municipal Sewage Treatment Plant (STP) in Galicia, NW Spain. Among all the substances considered, significant concentrations in the influent were only found for the two musks (galaxolide and tonalide), two anti-inflammatories (ibuprofen and naproxen), two natural estrogens (estrone, 17beta-estradiol), one antibiotic (sulfamethoxazole) and the X-ray contrast medium (iopromide), where the other compounds studied were below the limit of quantification. In the primary treatment, only the fragrances (30-50%) and 17beta-estradiol (20%) were partially removed. On the other hand, the aerobic treatment (activated sludges) caused an important reduction in all compounds detected, between 35% and 75%, with the exception of iopromide, which remained in the aqueous phase. The overall removal efficiencies within the STP ranged between 70-90% for the fragrances, 40-65% for the anti-inflammatories, around 65% for 17beta-estradiol and 60% for sulfamethoxazole. However, the concentration of estrone increased along the treatment due to the partial oxidation of 17beta-estradiol in the aeration tank. 相似文献
997.
Persistent, bioaccumulative and toxic substances in fish: human health considerations 总被引:3,自引:0,他引:3
Dórea JG 《The Science of the total environment》2008,400(1-3):93-114
Fish are important dietary items that provide essential nutrients. Fish however, bioaccumulate monomethyl mercury (MMHg) and organo-halogenated pollutants (OHP) that are persistent bioaccumulative and toxic substances (PBTS). Unlike man-made OHP, MMHg is mainly of natural origin but background concentrations of aquatic systems are determined by the environmental Hg-methylating potential. Industrial activities can modulate environmental discharges and fish bioaccumulation of PBTS. Fish and seafood consumption are associated with human body load of PBTS, but farming practices that utilize fishmeal increase the terrestrial food chain resulting in farm-animal accumulation of PBTS. These substances are neurotoxic and endocrine active that can impact humans and wild life, but chemical characteristics of MMHg and OHP modulate interactions with animal tissues. MMHg is protein reactive with a faster metabolism (months) than OHP that are stored and slowly (years) metabolized in fat tissues. Except for brain-Hg, neither Hg nor OHP in tissues are markers of toxic effects; however, deficits in neurobehavioral test-scores of children have been shown in some fish-eating populations. These deficits are transient and within normal range, and are not prodromes of neurological diseases. Although population studies show that consumption of fish at current levels of contamination do not explain neurological disorders, endocrine activity remains controversial. Understanding risk of hazard caused by fish-PBTS consumption requires a wide range of expertise. We discuss chemical, toxic, metabolic, and ecological characteristics associated with PBTS in fish. There are proven health outcome derived from fish consumption, while risk of exposure to avoidable PBTS is a chance that can be minimized by societal actions. 相似文献
998.
999.
Removal of dichloromethane from waste gases in one- and two-liquid-phase stirred tank bioreactors and biotrickling filters 总被引:3,自引:0,他引:3
The removal of dichloromethane (DCM) from polluted air was studied both in biotrickling filters and in continuous stirred tank bioreactors, using either a single-liquid aqueous phase or a combination of an aqueous-organic liquid phase. The presence of the organic phase, i.e. silicone oil, at a volume ratio of 10% of the liquid phase, increased the maximum EC by about 25% in the BTF, reaching 200 g m3/h, and by as much as 300% in the CSTB, reaching 350 g m3/h. Based on data of chloride release in the aqueous phase and carbon dioxide production in the gas phase, complete dechlorination and mineralization of the pollutant could be confirmed. When applying shock loads, a more stable behaviour was observed in the presence of the organic phase. Generally, the completely mixed reactors were also more stable than the plug-flow biotrickling filters, irrespective of the presence of the organic phase. The use of molecular techniques allowed showing that the originally inoculated DCM-degrading Hyphomicrobium strains remained present, although not dominant, after long-term bioreactor operation. Different new bacterial populations did also appear in the systems, some of which were unable to degrade DCM. 相似文献
1000.
ABSTRACT This article revolves around the naming of streets in Dakar-Plateau. This was borne in mind as analysis considered the system of urban nomenclature applied in the colonial era, when the city was founded and shaped by France’s colonial administration; as well as the (re)naming process ongoing after Senegal’s independence. The approach thus applied quantitative verification methods to a thesis oft-repeated in the subject literature, that a French glossary of toponyms dominates the system by which streets in Dakar are named. Quantitative analysis here shows unequivocally that there is only a slight numerical prevalence of colonial-era names of streets over new names. Beyond that, clear evidence is offered for the idea that, in both colonial days and today, the symbolic urban landscape expressed with the aid of urbanonyms was shaped by authorities in a conscious manner, being pressed into the service of political objectives. To indicate the strength of this kind of linkage, the article engages in the detailed discussion of each change of name that certain streets have been through; the bases for this approach being reference to the historical town/city plans present in the Archives Nationales du Sénégal, as well as fieldwork carried out in the Senegalese capital. 相似文献