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821.
The interface structure of an Al2O3/Nb/Al2O3 sandwich produced by solid-state diffusion bonding was investigated in detail by various transmission electron microscopy (TEM) methods. The joint possessed at one interface a
,
, and on the other interface a
and
orientation relationship. At both interfaces, misfit dislocations formed to compensate the lattice mismatch as found by high-resolution transmission electron microscopy (HRTEM). Electron energy-loss near edge structure (ELNES) studies revealed that the interface is terminating with an Al layer resulting in Al–Nb bonds. Identical sandwiches were investigated on the meso- and macroscopic scale by performing compression tests and simultaneously monitoring the strain development at (001)Nb and crystal faces. The full-field optical strain measurements (FFOM) revealed that the strain is localized at the interfaces when observed at the (001)Nb face while it is along the maximum shear directions of 36–54° inclined to the interface when observed at the face. The strain localization along a specific maximum shear direction results in the cleavage of Al2O3, always initiating from the interface possessing the
and
orientation relationship. 相似文献
822.
Ha SY Jung MN Park SH Ko HJ Ko H Oh DC Yao T Chang JH 《Journal of nanoscience and nanotechnology》2006,6(11):3624-3627
Well-aligned ZnO nanorods have been achieved using new alloy (AuGe) catalyst. Zn powder was used as a source material and it was transported in a horizontal tube furnace onto an AuGe deposited Si substrates. The structural and optical properties of ZnO nanorods were characterized by scanning electron microscopy, high resolution X-ray diffraction, and photoluminescence. ZnO nanorods grown at 650 degrees C on 53 nm thick AuGe layer show uniform shape with the length of 8 +/- 0.5 microm and the diameter of 150 +/- 5 nm. Also, the tilting angle of ZnO nanorods (+/- 5.5 degrees) is confirmed by HRXRD. High structural quality of the nanorods is conformed by the photoluminescence measurement. All samples show strong UV emission without considerable deep level emission. However, weak deep level emission appears at high (700 degrees C) temperature due to the increase of oxygen desertion. 相似文献
823.
A self-assembled biomolecule was used to create a highly sensitive sensor surface for detecting toxic chemical species (polychlorinated biphenyls, PCBs). We fabricated the nanostructured sensor surface via the self-assembly of cytochrome c on a Au thin film. Surface plasmon resonance (SPR), an evanescent wave technique possessing maximum sensitivity on the surface and characterized by an exponential decay of sensitivity with distance from the surface, was utilized as the principle for signal transduction. When this sensor surface was used for the detection of PCB, even trace amounts of PCB (from 0.1 ppb to 8.0 ppb) in an aqueous solution were readily detectable. 相似文献
824.
In the immunoassay based on surface plasmon resonance (SPR) system, the signal enhancement was done by means of the conjugate of gold (Au) nanoparticle-antibody fragment. Antibody fragment was prepared for the improved immobilization based on Au-thiol interaction. Through the ellipsometric analysis on surface, the conjugation between Au and antibody fragment was performed in the oriented manner. The optimal fabrication conditions such as concentration and incubation time were determined for the constant size of the fabricated nanoparticle-antibody conjugate. Through the plot of SPR angle difference versus antigen concentration, the linear correlation was achieved, of which the detection limit was 100 fg/ml. 相似文献
825.
Lee SY Oh SW Chung HJ Reyes-De-Corcuera JI Powers JR Kang DH 《Journal of food protection》2006,69(3):591-595
This study was conducted to investigate the effect of steam treatment on the reduction of Salmonella enterica serovar Enteritidis on the surface of raw almonds. Two cultivars, 'Nonpareil' and 'Mission', were studied. Salmonella Enteritidis was inoculated on the surface of raw almonds, which were then treated with steam (93 degrees C +/- 1 degrees C) for 5, 15, 25, 35, 45, 55, and 65 s. After steam treatment, samples were plated on xylose lysine desoxycholate (XLD) and overlay (OV) XLD as a selective and nonselective agar for Salmonella, respectively, to investigate the extent of sublethal injury in Salmonella. Steam treatment of raw almonds effectively reduced Salmonella Enteritidis, and the effect was pronounced with increasing treatment time. After 65 s of steam treatment, reductions in Salmonella Enteritidis populations were 5.7 log and 5.8 log for 'Nonpareil' and 4.0 log and 4.1 log for 'Mission' when enumerated on XLD and OV XLD, respectively. There was no significant difference in population estimates determined with XLD and OV XLD over time (P > 0.05). The effect of the steam treatment was significantly different between two almond cultivars. Salmonella inoculated onto 'Mission' was more resistant to the steam treatment than that on 'Nonpareil', indicating that varietal differences must be considered in the application of steam for the disinfection of raw almonds. The present investigation revealed the potential usefulness of steam treatments for the control of pathogens in raw almonds. 相似文献
826.
IhnSung Cho IlHyun Beak JaeCheon Jo JuMi Park SeokHyung Oh JaeYoun Jung 《Journal of Mechanical Science and Technology》2010,24(6):1363-1368
The bent-axis type of piston pump driven by the piston rod works by the piston rod driving the cylinder block; because of
this the taper angle of the piston rod and the swivel angle between the cylinder block and the shaft are important design
factors. If these factors cannot satisfy the conditions for optimum design, the friction loss between the cylinder bore and
the piston increases, and the pump can fail to work under conditions of severe friction and wear. Since the piston reciprocates
in the cylinder bore with high velocity, at the same time rotating on its own axis and revolving on the center of the cylinder
block, a decrease of the volume efficiency is generated because of the leakage between the cylinder bore and the piston. Therefore,
to prevent this, the piston ring is designed to be at the end of the piston, and the friction characteristics between the
piston ring and the cylinder bore require further research due to their great influence on the performance of the piston pump.
Thus, in this paper, the elastohydrodynamic lubrication (EHL) analysis of the film thickness, the pressure distribution, and
the friction force, have been studied between the piston ring and the cylinder bore in the bent-axis type of piston pump.
The analyzed results show that the friction force is influenced by the rotating speed and the discharge pressure. 相似文献
827.
Proton-transport-membrane water gas shift (WGS) reactors, based on thin dense SrCe0.7Zr0.2Eu0.1O3−δ membranes on tubular Ni–SrCe0.8Zr0.2O3−δ supports, were developed to increase H2 yields relative to thermodynamic limitations. Pure H2 permeate, total H2 production, and reactor side CO conversion and H2/CO effluent ratio were measured as a function of temperature, flow rate, CO concentration and H2O/CO feed ratios. CO conversion, total H2 production and yield, and the H2/CO in the reactor side effluent increased with increasing temperature and H2O/CO feed ratios. CO conversions of 84% and 90% were achieved at 900 °C with H2O/CO feed ratios of 1/1 and 2/1, respectively. These respective 77% and 44% increases in CO conversion compared to feed gas condition thermodynamics resulted in 73% and 42% increases in H2 production. Permeated H2 and total H2 production increased with increasing flow rate and CO concentration. Finally, membrane stability under WGS conditions was significantly improved by Zr substitution. 相似文献
828.
829.
Pin Pin Oh Harrison Lik Nang Lau Junghui Chen Mei Fong Chong Yuen May Choo 《Renewable & Sustainable Energy Reviews》2012,16(7):5131-5145
Biodiesel is commonly produced from lipid feedstock, animal fats and waste cooking oil by transesterification reaction. Considering the depletion of fossil fuel, biodiesel is gaining more attention as a renewable and environmental friendly fuel. The rapid growth of biodiesel industry thereafter has raised concerns to many existing commercial biodiesel enterprises. The major issues like feedstock flexibility, yield productivity and environmental impact are always the challenges to the continuous growth of conventional biodiesel processing technology. The processing of biodiesel is greatly hinged on the rich scientific background and technology development for better process advancement. The present paper reviews various concerns raised from the commercial biodiesel processing technology. It also addresses some innovative process intensification (PI) technologies, which likely bring appropriate technological improvement for biodiesel production. 相似文献
830.
Soo-Haeng Cho Seung-Chul Oh Seong-Bin Park Kwang-Mo Ku Jong-Hyeon Lee Jin-Mok Hur Han-Soo Lee 《Metals and Materials International》2012,18(6):939-949
The high temperature corrosion behavior of N07263, N06600, and N06625 in LiCl-Li2O molten salt was investigated at temperatures ranging from 650 to 850 °C in a glove box. The high temperature corrosion behavior was observed using measurements of the oxide morphology and thickness, the extent of internal corrosion, and the compositional changes in the scale and in the substrate. Corrosion tests were performed, and these demonstrated that the main corrosion products were Fe(Ni,Co)3, FeNi3, and LiCrO2. The internal corrosion of N07263 was localized, while that of N06600 maintained intergranular corrosion throughout the test temperature range. N06625 exhibited uniform intergranular corrosion behaviors at low and high temperatures. N07263 exhibited superior corrosion resistance, as evidenced by its corrosion layer which was more continuous, dense, and adherent when compared with those of N06600 and N06625. 相似文献