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81.
In this study, the erosion–corrosion performance of carbon steel was investigated in crude oil, reservoir water, and a mixture of both solutions at a range of applied potentials, velocities and impact angle. The application of such work is to upstream and downstream oilfield conditions, where the proportions of hydrocarbon and water may vary during the extraction process over time. Following exposure of the carbon steel in the crude oil, the extent of erosion was greater than that of corrosion, whilst in the reservoir water, the erosion and corrosion contributions were similar. Regimes of erosion–corrosion were proposed based on the variation in erosion behaviour at various impact angles and applied potentials in the environments studied. Mechanistic changes were identified on erosion–corrosion maps as a function of velocity and applied potential at various impact angles, indicating important transitions in erosion–corrosion processes in the oil/water environments.  相似文献   
82.
Populations of Bifidobacterium longum BB536, Salmonella choleraesuis JCM 6977, Escherichia coli ATCC 35922 and B. pseudocatenulatum G4 were monitored over 24 and 48 h. The digestibility of Mangifera pajang fibrous (MPF) and its polysaccharides by human gastric juice and human α-amylase were also determined. MPF and its polysaccharides increased the number of bifidobacteria but did not affect the growth of S. choleraesuis JCM 6977 or E. coli ATCC 35922; moreover, their effects were comparable to those of the commercial prebiotic inulin. M. pajang fibrous polysaccharides showed the highest non-digestibility by human gastric juice and human α-amylase compared to MPF and inulin; MPF showed a higher non-digestibility than inulin. MPF and its polysaccharides showed strong fermentation and non-digestibility properties, and thus it might be a prospective prebiotic that could be incorporated into food products.  相似文献   
83.
The mechanism by which small molecules assemble into microscale tubular structures in aqueous solution remains poorly understood, particularly when the initial building blocks are non‐amphiphilic molecules and no surfactant is used. It is here shown how a subnanometric molecule, namely p‐aminothiophenol (p‐ATP), prepared in normal water with a small amount of ethanol, spontaneously assembles into a new class of nanovesicle. Due to Brownian motion, these nanostructures rapidly grow into micrometric vesicles and start budding to yield macroscale tubular branches with a remarkable growth rate of ~20 μm s?1. A real‐time visualization by optical microscopy reveals that tubular growth proceeds by vesicle walk and fusion on the apex (growth cone) and sides of the branches and ultimately leads to the generation of centimeter‐long microtubes. This unprecedented growth mechanism is triggered by a pH‐activated proton switch and maintained by hydrogen bonding. The vesicle fusion‐mediated synthesis suggests that functional microtubes with biological properties can be efficiently prepared with a mixture of appropriate diaminophenyl blocks and the desired macromolecule. The reversibility, timescale, and very high yield (90%) of this synthetic approach make it a valuable model for the investigation of hierarchical and structural transition between organized assemblies with different size scales and morphologies.  相似文献   
84.
This letter discusses the effect of antenna losses due to rain on a 26 GHz microwave link and the technique of extracting the losses from the measured rain attenuation. A 2-feet parabolic dish antenna with horizontal polarization has been used in the study. The measurement results have been compared with those obtained from other locations in Malaysia and some other Published Research works. The study will provide useful information in the microwave link planning and design in tropical regions; and it can also be adapted to satellite communication operating at ka-band.  相似文献   
85.
This study aimed to determine the angiotensin converting enzyme‐inhibitory activity and antimicrobial effect of fermented camel milk. Samples were prepared either using Lactobacillus acidophilus and Streptococcus thermophilus or Lactobacillus helveticus and Str. thermophilus and labelled as S1 and S2, respectively. The IC50 values of S1 and S2 samples ranged between 113–200 and 70–133 μg/mL, respectively. The antimicrobial effects of S1 and S2 samples against Bacillus cereus, Salmonella Typhimurium and Staphylococcus aureus were apparent after 12 h of incubation and continued until 15 days of storage, whereas unfermented camel milk exhibited no antimicrobial effects against any of the tested pathogens.  相似文献   
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88.
A function-based automatic test pattern generation (ATPG) tool for embedded core testing is presented that reduces test cost and considers test power dissipation of system-on-chip (SoC). Cores are tested concurrently with the use of test functions, as opposed to simple patterns, and by I/O pin allocation on the test access mechanism (TAM) during a compact ATPG process. Turnaround time benefits from pre-existing test vectors, or test functions supplied by the provider of each core. The presented method also targets low-power dissipation by considering the switching activity on the SoC inputs. Experimental results show a significant reduction in the test application time due to the achieved level of concurrency.  相似文献   
89.
Nitrile Butadiene Rubber (NBR) nanocomposites are prepared with different contents ranging from 5 to 20 phr (part per hundred parts of rubber) of Sinai sand nanoparticles and fumed silica micro particles (SiO2) and mixed with other additives to improve its properties. The nanocomposites were irradiated with gamma irradiation from 25 to 150 kGy. The effect of the silica content and irradiation dose on the morphology, the mechanical and the physical properties of nanocomposites was investigated. The scanning electron microscope (SEM) showed that there is a fine dispersion of nanoparticles into NBR matrix, also some aggregates were observed and their size depends on the SiO2 content. The results indicated that there was an improvement in tensile strength by increasing irradiation doses up to 50 kGy and by increasing silica loading up to 15 phr. Enhancement of volume fraction by increasing irradiation doses and also by increasing silica loading was observed. The thermal gravimetric analysis (TGA) indicated that the thermal stability of NBR increases by increasing silica contents and the increase in irradiated samples is higher than that in un-irradiated. Finally, it is found that the presence of silica in the nanocomposites enhances the electrical insulating properties of the NBR.  相似文献   
90.
Zeolite membranes offer superior thermal, chemical, and mechanical stability compared to polymeric membranes. However, it is still a challenge to prepare completely defect‐free membranes without any intercrystalline voids, which is necessary for gas separation processes. In this study zeolite beta (*BEA) membranes on stainless‐steel supports were prepared by applying the multiple in situ crystallization technique. The membranes were used as a model system to systematically study the decomposition of the organic structure directing agent tetraethylammoniumhydroxide (TEA‐OH). It was evaluated if the organic decomposition products of TEA‐OH can be used for enhancing the membranes selectivity. Post‐treatment experiments have been carried out to adjust surface properties and pore size dimensions in the zeolitic membrane layer. The results show that membranes calcined at lower temperatures exhibit a higher gas selectivity.  相似文献   
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