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61.
Kishore Sinha 《Journal of research of the National Institute of Standards and Technology》1991,96(5):613-615
Group divisible designs are the most important class of partially balanced incomplete block (PBIB) designs. A list of new group divisible designs with r, k ⩽ 10 is provided. 相似文献
62.
MRI was performed on patients with miliary pulmonary tuberculosis to look for brain involvement and to study the features sequentially, during treatment. We studied seven patients with typical radiographic tuberculosis, and no symptoms or signs of central nervous system involvement. Conventional spin-echo (SE) imaging, including contrast enhanced images, was performed in all cases. All patients showed brain involvement: four patients showed lesions mainly less than 3 mm in diameter, better seen on contrast-enhanced images. These patients showed oedema around the lesions after 2 months of treatment, with subsequent regression on follow-up. The remaining three patients had multiple lesions, 3 mm or more in diameter, which showed a gradual decrease on follow-up. We conclude that the brain may commonly be involved in miliary pulmonary tuberculosis. The response to treatment depends on the stage of the granuloma and shows a definite pattern of healing on follow-up. 相似文献
63.
Kishore Kumar Sankara L.V.K.V Sarma 《International Journal of Engineering Science》1985,23(8):875-886
The steady flow of a fluid-particle suspension over an infinite rotating disk with uniform suction is considered. The equations of motion are reduced to ordinary differential equations by similarity transformations and solved numerically by using a least-squares finite-element method. Some typical results for both fluid and particle phases and density distributions of the particles are presented graphically for the suction parameter A = 3.0 in order to illustrate some interesting features of the solutions. It is observed that the radial velocity of the particle attains its maximum on the surface of the disk and the particles slip in the tangential direction on the disk. The magnitudes of the radial velocity components of both the fluid and particle phases are found to decrease rapidly as suction increases. 相似文献
64.
Arun Ravindran Eva Vidal Seoung-Jae Yoo Kishore Ramarao Mohammed Ismail 《Analog Integrated Circuits and Signal Processing》2004,38(2-3):161-174
A novel CMOS variable gain amplifier operating on current signals with a dB-linear gain control is presented. The gain control is achieved by multiplying a digitally synthesized exponentially varying control current signal by a differential input signal in the current domain. A current amplifier at the output sets the gain to the desired level. Current-mode operation allows for a reduced supply voltage by minimizing the voltage swing at the low impedance nodes of the circuit. Multiple circuit realizations for various blocks are presented allowing for designs meeting different constraints. Experimental realization of the variable gain amplifier shows the validity of the presented approach. 相似文献
65.
The representation of stress-strain curves by empirical relations can give first-hand information on the deformation behavior
of a material. Although the constants in these equations are simple numerals for smooth fitting of the curves, a theoretical
basis using dislocation interaction has been out forth bv Berastrom.[1] 相似文献
66.
Performance evaluation of a fluid temperature-compensated single sensor constant temperature anemometer 总被引:1,自引:0,他引:1
Ferreira R.P.C. Freire R.C.S. Deep G.S. 《IEEE transactions on instrumentation and measurement》2003,52(5):1554-1558
The performance of a hot-wire anemometer configuration is affected by variation in the fluid temperature. The classical temperature compensation techniques in such anemometers employ two sensors. The performance of a temperature-compensated hot-wire anemometer configuration, using a single sensor alternating between two operating temperatures, and proposed for constant fluid velocity, is investigated under conditions of time-varying fluid velocity. The measurement error introduced is quantified and can be practically eliminated using a low-pass digital filter. 相似文献
67.
68.
The microstructure of aluminum, extruded under industrial conditions at 250°C has been investigated in relation to the purity
of the billet. Electron microscopy was used to observe the substructure and Kikuchi diffraction techniques were used to measure
boundary angles and thus distinguish between recrystallization and repolygonization for samples of two different purities
(99.7 pct Al and 99.99 pct Al) extruded under identical conditions. High tensile flow stresses of about 8000 to 9000 psi (55
to 62 MN/m2) were observed in specimens taken from the first sections of the high purity extrusion. These high strength levels were attributed
to the presence of fine microstructure. When small recrystallized grains (0.5 to 2.0 μm diam) were present a yield drop was
observed. This phenomenon is associated with the condition where nearly all the dislocations are likely to be immobile. The
absence of a yield point in the 99.7 pct purity aluminum extruded under the same conditions as the 99.99 pct purity aluminum
is due to the existence of fine subgrains instead of the fine recrystallized structure. A small yield point in 99.7 pct aluminum
was induced by subsequent heat treatment resulting in the formation of small recrystallized grains of similar character to
those in the higher purity extrusion.
Formerly Research Assistant, Department of Mechanical Engineering, University of Waterloo, Waterloo, Ontario. 相似文献
69.
70.
A CMOS RF front-end for a multistandard WLAN receiver 总被引:1,自引:0,他引:1
Kishore Rama Rao Wilson J. Ismail M. 《Microwave and Wireless Components Letters, IEEE》2005,15(5):321-323
This letter describes the design and performance of a dual band tri-mode receiver front-end compliant with the IEEE 802.11a, b, and g standards. The receiver front-end was built in a 0.18-/spl mu/m CMOS process and achieves a noise figure of 4.7 dB/5.1 dB for the 2.4-GHz/5-GHz bands, respectively. The receiver front-end provides a dual gain mode of 5 dB/30 dB with an IIP3 of -1dBm for the low gain mode. The front-end draws 25 mA/27 mA from a 1.8-V supply for the 2.4-GHz/5-GHz bands, respectively. 相似文献