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991.
A radix-8 wafer scale FFT processor 总被引:2,自引:0,他引:2
Earl E. Swartzlander Jr. Vijay K. Jain Hiroomi Hikawa 《The Journal of VLSI Signal Processing》1992,4(2-3):165-176
Wafer Scale Integration promises radical improvements in the performance of digital signal processing systems. This paper describes the design of a radix-8 systolic (pipeline) fast Fourier transform processor for implementation with wafer scale integration. By the use of the radix-8 FFT butterfly wafer that is currently under development, continuous data rates of 160 MSPS are anticipated for FFTs of up to 4096 points with 16-bit fixed point data. 相似文献
992.
[3H]Platelet-activating factor (PAF) binding to rabbit platelet membranes was examined before and after 20 min preincubation
at 25°C in the presence of PAF, lysoPAF, or of five different PAF receptor antagonists (L 652731, BN 52021, WEB 2086, BN 52111
and BN 52115). When platelet membranes were not washed after preincubation with PAF or PAF antagonists, no significant specific
binding of [3H]PAF was observed, which suggests full occupancy of the binding sites. When membranes were extensively washed, full recovery
of specific [3H]PAF binding was attained with L 652731 and partial recoveries (60%, 55% and 30%) were reached with BN52021, WEB 2086 and
PAF, respectively; no recovery was seen with the dioxolanes BN 52111 and BN 52115. Scatchard analysis of the binding data
indicated that no significant change in the dissociation constant (Kd) and maximum number of binding sites (Bmax) occurred after preincubation of platelet membrane with L 652731, whereas a reduction of Bmax was observed when PAF and BN 52021 were measured. When platelet membranes were preincubated with WEB 2086, Bmax and Kd significantly increased. The data suggest differing binding properties for PAF and the PAF antagonists. Some of the PAF antagonists
may tightly bind to the PAF receptor site(s) and/or irreversibly modify or downregulate PAF recognition sites. Our results
also suggest that the interaction of PAF receptor antagonists with PAF receptor can be divided into at least two components,
namely a reversible component and an irreversible one.
Based on a paper presented at the Third International Conference on Platelet-Activating Factor and Structurally Related Alkyl
Ether Lipids, Tokyo, Japan, May 1989. 相似文献
993.
Chawki M.J. Auffret R. Le Coquil E. Pottier P. Berthou L. Paciullo H. Le Bihan J. 《Lightwave Technology, Journal of》1992,10(10):1388-1397
Characteristics of a two-electrode DFB laser filter are studied both theoretically and experimentally. Using a matrix analysis of spontaneous emission, a continuous tuning range of 6.7 Å is achieved by changing both net field gains of the two electrodes. A total discontinuous tuning range of over 10 nm comprising alternating mode jumps and continuous tuning range of 4 Å are measured experimentally. The laser filter presents a FWHM bandwidth of 5 GHz which depends on the optical input power. In addition, it is demonstrated that a DFB laser filter can act as a frequency discriminator/photodetector, i.e., a narrow-band FM receiver, with a uniform bandwidth of 1.5 GHz. Using the two-electrode DFB laser for both transmitter and receiver, a two-channel FSK-WDM transmission system utilizing the discontinuous tuning range is reported. The advantage of such a device is the simplicity as compared to the heterodyne technique 相似文献
994.
The overall legal significance of multiple drafts of professional communications is discussed. In particular, some of the legal principles that govern the status of written documents, such as the applicable rules of court are reviewed, and the types of litigation in which previous drafts can figure prominently are examined. The possibility of multiple draft liability in light of the current emphasis on writing as a process, with writers encouraged to turn off the editorial sides of their brains during the early stages of composing, is considered 相似文献
995.
A polypropylene-based binder system was used to injection mould test bars containing 65 vol% aluminium powder. Specimens, 3 and 6 mm thick, made from these bars were used for pyrolytic binder removal experiments in static air and nitrogen. The development of a carefully defined experimental procedure for the determination of the heating rate at which binder removal can be carried out at a given temperature without the creation of macro defects is fully described. The use of isothermal heat treatments during pyrolysis are also considered and results are presented as temperature-heating rate diagrams for each atmosphere and thickness investigated. These diagrams show a lower and an upper boundary. Defect formation occurs if the temperature-heating rate relationship lies between the boundaries. Near optimum binder removal schedules deduced from each diagram have been experimentally verified. 相似文献
996.
It is proposed that when solving an arithmetic word problem, unsuccessful problem solvers base their solution plan on numbers and keywords that they select from the problem (the direct translation strategy), whereas successful problem solvers construct a model of the situation described in the problem and base their solution plan on this model (the problem-model strategy). Evidence for this hypothesis was obtained in 2 experiments. In Experiment 1, the eye fixations of successful and unsuccessful problem solvers on words and numbers in the problem statement were compared. In Experiment 2, the degree to which successful and unsuccessful problem solvers remember the meaning and exact wording of word problems was examined. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
997.
L. H. Yang Randolph Q. Hood J. E. Pask J. E. Klepeis 《Journal of Computer-Aided Materials Design》2007,14(3):337-347
High-Z metals constitute a particular challenge for large-scale ab initio electronic-structure calculations, as they require high resolution due to the presence of strongly localized states and require
many eigenstates to be computed due to the large number of electrons and need to accurately resolve the Fermi surface. Here,
we report recent findings on high-Z metals, using an efficient massively parallel planewave implementation on some of the largest computational architectures
currently available. We discuss the particular architectures employed and methodological advances required to harness them
effectively. We present a pair-correlation function for U, calculated using quantum molecular dynamics, and discuss relaxations
of Pu atoms in the vicinity of defects in aged and alloyed Pu. We find that the self-irradiation associated with aging has
a negligible effect on the compressibility of Pu relative to other factors such as alloying.
The US Goverment’s right to retain a non-exclusive, royalty-free license in and to any copyright is acknowledged. 相似文献
998.
Translated from Fiziko-Khimicheskaya Mekhanika Materialov, Vol. 27, No. 6, pp. 69–71, November–December, 1991. 相似文献
999.
A series of long-chain quaternary ammonium halogen esters (UKK-chemicals), quaternary dimethyl tallow epoxypropyl ammonium
halogens (EPK1), quaternary ditallow methyl epoxypropyl ammonium halogens (EPK2), and EPK2 oligomers (EPK2P) were synthesized.
At acidic, neutral, or slightly basic conditions, EPK1-, EPK2-, EPK2P-, and UKK-chemicals operate as cationic chemicals. They
can be used, for example, as stock sizings, surface sizings, or fixatives. Stock sizing, surface sizing, and fixative experiments
indicate that EPK1-, EPK2-, EPK2P-, and UKK-chemicals function at least as well as or better than the corresponding synthetic
chemicals used in papermaking. 相似文献
1000.