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71.
A new, short, and quick method was developed for preparation of specimen for observing Actinomycetes of genus Streptomyces by scanning electron microscopy. The cultures were directly grown on stubs and coated with a film of gold without using any fixative and dehydrating procedures. Using this simple preparation procedure, surface of intact sporing structures of Streptomyces was observed over a range of magnifications. As the preparation procedure is so simple and rapid, this procedure could be most useful for the routine examination and identification of Streptomyces. 相似文献
72.
Two-photon-pumped (TPP) frequency-upconverted blue lasing of Coumarin 500 dye solution has been experimentally investigated. The shortest lasing wavelength was measured to be ~479 nm from a Coumarin 500 solution in chloroform pumped with ~800-nm laser pulses of ~5-ns duration. The spectral, temporal, and spatial structures as well as the output-input characteristics of TPP cavity lasing were measured with a 1-cm-long Coumarin 500 solution-filled quartz cuvette. The cavity lasing spectral structure and the numbers of longitudinal modes were easily controlled simply by attachment of an optical plate to the output window of the dye-solution cuvette. The net conversion efficiency from the absorbed 800-nm pump pulse energy to the blue-upconverted cavity lasing energy was ~4.8%. 相似文献
73.
A small three-wavelength (355-, 532-, and 1064-nm) lidar system at NASA Langley Research Center in Hampton, Virginia, has been used since 1992 to make measurements on stratospheric aerosols. The data have been processed to study the decay rate of the stratospheric aerosol layer formed after the eruption of Mount Pinatubo in 1991 and its modulation, the aerosol effective radius, and the column mass loading. The stratospheric aerosol decay curves show annual and biennial cycles as well as short-term changes. At 532 nm, the decay time constant was 302 days for the period from February 1992 to August 1994 and had increased to 645 days for the period from September 1994 to December 1997. By 1996 the integrated stratospheric aerosol backscatter had fallen to levels (7.7 x 10(-5) sr(-1) at 532 nm) close to those seen in 1979 and 1989-1991. This decreasing trend was still continuing in 1997, showing no evidence for any anthropogenic contribution to the stratospheric aerosol. 相似文献
74.
Local decorrelation of speckle patterns scattered by a surface is used for nondestructive evaluation of the state of conservation of wooden artifacts. Some experiments have been carried out on models with simulated internal flaws and on real, ancient, wooden panel paintings. The setup is very simple and can easily be used by nonoptically skilled operators. 相似文献
75.
High-density optical recording using a solid immersion lens 总被引:4,自引:0,他引:4
A solid immersion lens attached to a conventional objective increases the effective numerical aperture (NA(eff)) of an optical pickup and yields an areal recording density proportional to (NA(eff))(2). One version of this device, with an effective (NA(eff)) of 1.7, should be capable of very high density storage but would probably need a sealed system. Another simple configuration enables the use of this method for optical data storage in an unsealed environment and extends the spatial cutoff frequency 1.5 times. Experiments with these devices are compared with the full vector field theory of this type of imaging system. 相似文献
76.
77.
Soil samples collected from the vicinity of "Manpasand textile industry", located near Ichalkaranji, India were studied for screening and isolation of bacterial strains capable of degradation of textile dyes. A potential strain was selected on the basis of rapid dye degradation and later identified as Comamonas sp. UVS. Comamonas sp. UVS showed 100% decolorization of Direct Red 5B (DR5B) dye at 40 degrees C and pH 6.5. The maximum Direct Red 5B concentration decolorized was 1100mg/l in nutrient broth within 125h. A numerical simulation with the Michaelis-Menten kinetics model gives an optimal value of 16.01+/-0.36mgdye/gcell/h for maximum rate (V(max)) and 7.97+/-0.21mg/l for the Michaelis constant (K(m)). The induction in the activities of laccase and LiP was observed during decolorization. These enzymes were inhibited by the addition of sodium azide. The biodegradation was monitored by UV-vis, FTIR spectroscopy and HPLC. The GCMS analysis indicated the presence of 7-benzoylamino-3-diazenyl-4-hydroxy-naphthalene-2-sulfonic acid in degraded product of the dye. The germination of Triticum aestivum seeds was inhibited with DR5B treatment but not with the treatment of dye degradation products. 相似文献
78.
Asane GS Nirmal SA Rasal KB Naik AA Mahadik MS Rao YM 《Drug development and industrial pharmacy》2008,34(11):1246-1266
To overcome the relatively short gastrointestinal (GI) time and improve localization for oral controlled or sustained release drug delivery systems, bioadhesive polymers that adhere to the mucin/epithelial surface are effective and lead to significant improvement in oral drug delivery. Improvements are also expected for other mucus-covered sites of drug administration. Bioadhesive polymers find application in the eye, nose, and vaginal cavity as well as in the GI tract, including the buccal cavity and rectum. This article lays emphasis mainly on mucoadhesive polymers, their properties, and their applications in buccal, ocular, nasal, and vaginal drug delivery systems with its evaluation methods. 相似文献
79.
Tripathi S Brajpuriya R Sharma A Soni A Okram GS Chaudhari SM Shripathi T 《Journal of nanoscience and nanotechnology》2008,8(6):2955-2963
In the present paper, we have investigated structural, optical as well as electronic properties of electron beam evaporated Ge thin films having layer thicknesses ranging from ultra-thin (5 nm) to thick (200 nm). The Raman spectra show that all peaks are shifted towards lower wave number as compared to their bulk counterparts and are considered as a signature of nanostructure formation and quantum confinement effect. The Raman line exhibits transformation from nanocrystalline to microcrystalline phase with a reduction in blue shift of peak position with increase in Ge film thickness (>5 nm). Similarly, the optical absorption spectra corresponding to these films also show reduction in blue shift effect, although Ge 5 nm film shows the absorption behaviour quite different from higher thickness films. The corresponding band gap values obtained from absorption measurements are much larger than bulk Ge and are mainly attributed to the effect of quantum confinement as expected for small size particles calculated from GIXRD patterns. AFM data in each case are correlated and discussed with structural as well as optical results to support the effect of growth morphology on the above-mentioned observations. The results are further supported by photoelectron spectroscopy (PES), photoluminescence (PL) and resistivity measurements and are interpreted in terms of crystallinity and quantum confinement effect. 相似文献
80.
Distance-of-flight mass spectrometry (DOF-MS) has not yet been implemented, though it has many potential advantages in a variety of applications. Impeding the implementation of DOF-MS is the development of the required array detectors and working out the equivalents to the focusing methods now used in time-of-flight (TOF) mass analyzers. Ideally, a batch of ions composed of a variety of m/z values, despite initial distributions of space and energy, would be spatially focused at their respective flight distances at the same time. First-order energy focusing, including ion turnaround, is shown to be accomplished by the use of an ion mirror in conjunction with constant momentum acceleration of the initial ion packet. The initial spatial dispersion is maintained throughout the flight path. With zero initial spatial ion spread, energy focusing to achieve resolutions in the tens of thousands is shown to be feasible with ions from the elemental and isotope ratio mass regions through the extremely high m/z range. With moderate spatial spread taken into account, the DOF-MS approach is shown to achieve resolutions competitive with quadrupole and ion trap mass analyzers. Advantages of DOF-MS include all the advantages of TOF-MS plus simpler detector electronics and the improved signal-to-noise ratio and dynamic range afforded by array detection. 相似文献