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91.
E. Çadırlı U. Böyük S. Engin H. Kaya N. Maraşlı M. Arı 《Journal of Materials Science: Materials in Electronics》2010,21(5):468-474
Sn–3 wt% Cu hypereutectic alloy was directionally solidified upward with different growth rates (2.24–133.33 μm/s) at a constant
temperature gradient (4.24 K/mm) and with different temperature gradients (4.24–8.09 K/mm) at a constant growth rate (7.64 μm/s)
in the Bridgman-type growth apparatus. The measurements of microhardness of directionally solidified samples were obtained
by using a microhardness test device. The dependence of microhardness HV on the growth rate (V) and temperature gradient (G) were analyzed. According to these results, it has been found that with the increasing the values of V and G the value of HV increases. Variations of electrical resistivity (ρ) and electrical conductivity (σ) for casting samples with
the temperature in the range of 300–500 K were also measured by using a standard dc four-point probe technique. The variation
of Lorenz coefficient with the temperature for Sn–3 wt% Cu hypereutectic alloy was determined by using the measured values
of electrical and thermal conductivities. The enthalpy of fusion for same alloy was determined by means of differential scanning
calorimeter from heating trace during the transformation from eutectic liquid to eutectic solid. 相似文献
92.
93.
94.
Shahla Ataei Rosiyah Yahya Seng Neon Gan 《Journal of Coatings Technology and Research》2011,8(6):719-725
The macromer was synthesized using medium oil length oleic acid, phthalic anhydride, and glycerol. The synthesized macromer
and methyl methacrylate (MMA) were copolymerized by free radical polymerization in toluene. The ratio between the macromer
and MMA changed, and the effects on different properties of the copolymers, such as glass transition temperature (T
g) and film properties, were studied. The macromer and copolymer structures were characterized by FTIR and 1H NMR spectroscopies. The coatings prepared with the highest ratio of MMA exhibited better overall physico-chemical properties.
Alternatively, Tafel polarization curves showed that the corrosion rate value in NaCl solution decreases significantly when
the MMA content is increased. Dynamic mechanical analysis results revealed that the increasing amounts of MMA lead to increasing
T
g values of copolymers. 相似文献
95.
Ibrahim Sevim Fatih Hayat Yakup Kaya Nizamettin Kahraman Sadettin Şahin 《The International Journal of Advanced Manufacturing Technology》2013,66(9-12):1825-1834
In this article, Metal Inert Gas (MIG) weldability of commercially received and aged samples of 6061-T6 and 7075-T651 aluminum alloys was investigated. The welding joints were prepared in ten different combinations. Microstructure, microhardness, EDX, energy-dispersive spectroscopy (EDS), and X-ray diffraction (XRD) analyses were used in order to evaluate the effect of aged heat treatment on the performance of welded joints. In addition, the mechanical properties of welding joints were characterized using the tensile and microhardness tests. In conclusion, it was shown that prewelding aging heat treatment improves the mechanical properties of welding joints. 相似文献
96.
Rahim Yadollahi Yahya Hamzeh Alireza Ashori Shademan Pourmousa Mohammad Jafari Kambiz Rashedi 《Polymer Engineering and Science》2013,53(1):183-188
Papermaking sludge (PS), a waste residue from the pulp and paper processing, has brought great pressure on the environment because of large quantities that are produced in paper mills. This work was carried out to explore the possibility of making PS/cement composite products using solid waste of PS. Boards measuring 350 × 270 × 12 mm3 were manufactured using PS contents of 40, 50, and 60 wt%, adhesive dosages of 0, 10, and 15 wt%, and 0 and 5 wt% of calcium chloride as an accelerator. At least three replications were fabricated for each treatment, and some mechanical and physical properties of the boards were evaluated. Test results showed that the bending and internal strengths of the specimens decreased with an increase in the PS content, and the maximum values were obtained at PS loading of 40 wt%. The negative influence of PS content on the mechanical properties can be explained by the reduced bonding ability because of weaker PS compared with cement. Screw withdrawal values were up to 22.7 kPa. Water absorption and thickness swelling of cement mortar considerably increased with increased content of PS, with a corresponding reduction of bulk density. In general, all properties of the boards were improved when the adhesive and calcium chloride contents were increased. The results showed that an increase in board density improved the mechanical and physical properties. Finally, results showed that PS has good potential for recycling and utilization in developing value‐added building components. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers 相似文献
97.
The Constant Modulus Algorithm (CMA), although it is the most commonly used blind equalization technique, converges very slowly.
The convergence rate of the CMA is quite sensitive to the adjustment of the step size parameter used in the update equation
as in the Least Mean Squares (LMS) algorithm. A novel approach in adjusting the step size of the CMA using the fuzzy logic
based outer loop controller is presented in this paper. Inspired by successful works on the variable step size LMS algorithms,
this work considers designing a training trajectory that it overcomes hurdles of an adaptive blind training via controlling
the level of error power (LOEP) and trend of error power (TOEP) and then obtains a more robust training process for the simple
CMA algorithm. The controller design involves with optimization of training speed and convergence rate using experience based
linguistic rules that are generated as a part of FLC. The obtained results are compared with well-known versions of CMA; Conventional
CMA, Normalized-CMA [Jones, IEEE conference record of the twenty-ninth asilomar conference on signals, systems and computers (Vol. 1, pp. 694–697), 1996], Modified-CMA [Chahed, et al., Canadian conference on electrical and computer engineering (Vol. 4, pp. 2111–2114), 2004], Soft Decision Directed-CMA (Chen, IEE Proceedings of Visual Image Signal Processing, 150, 312–320, 2003) for performance measure and validation. 相似文献
98.
Downscaling alone is not sufficient to sustain the development of CMOS devices, and further paradigm shifts are necessary. In this paper, we argue such a shift is possible and show through technology computer-aided design simulations that a symmetrically operating CMOS device pair may be built under a single gate structure by a surprisingly simple choice of device layout and channel engineering parameters. As a result, we predict that another seemingly fundamental CMOS architectural requirement, the need to build two separate MOSFETs with individual gate stacks, may be eliminated. We call this new architecture a complementary orthogonal stacked MOS (COSMOS), which places the n and p MOSFETs perpendicular to one another under a single gate, integrating them vertically, as well as laterally. We demonstrate how the device may be built, operated, and optimized for symmetric operation, as well as verifying logic NOT operation via three-dimensional device simulations. The COSMOS architecture would not only mean significant savings in the active device area of a conventional digital CMOS layout, but also reductions in RC device parasitics associated with building and wiring two sets of devices for a single Boolean output function. 相似文献
99.
A. Kaya G. Ben-Hamu D. Eliezer K. S. Shin S. Kohen 《Metal Science and Heat Treatment》2006,48(11-12):518-523
The corrosion resistance of an alloy of the Mg-Y-Zr-REM system obtained by sand casting and subjected to different modes of heat treatment is studied with the use of potentiodynamic polarization, immersion tests, scanning electron microscope, and Auger electron spectroscope. The microstructure of the alloy is described. 相似文献
100.
In this study, a decomposition method for approximating the solution of the Pochhammer-Chreeequation is implemented. By using this scheme, explicit exact solution is calculated in the form of a convergent power series with easily computable components. To illustrate the application of this method numerical results are derived by using the calculated components of the decomposition series. The obtained results are found to be in good agreement with the exact solutions known for some special cases. 相似文献