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991.
Rapid organizational change is increasing the pressure on employees to continually update their skills and adapt their behavior to new organizational realities. Goal orientation is a promising motivational construct that may explain why some individuals adapt to change better. Unfortunately, the current goal orientation literature is in a state of conceptual and methodological disarray. This presentation reviews the goal orientation literature and identifies numerous conceptual ambiguities, including definitional inconsistencies, dimensional inconsistencies, and inconsistencies in the conceptualization of stability. These conceptual ambiguities result in a confusing array of goal orientation measures and manipulations and ultimately an incoherent empirical database. A dynamic self-regulation model of goal orientation, termed motivated action theory, is presented to integrate the various conceptual perspectives and to provide guidelines for future goal orientation research. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
992.
A theoretical comparison of energy sources--microwave, ultrasound and laser--for interstitial thermal therapy 总被引:1,自引:0,他引:1
A number of heating sources are available for minimally invasive thermal therapy of tumours. The purpose of this work was to compare, theoretically, the heating characteristics of interstitial microwave, laser and ultrasound sources in three tissue sites: breast, brain and liver. Using a numerical method, the heating patterns, temperature profiles and expected volumes of thermal damage were calculated during standard treatment times with the condition that tissue temperatures were not permitted to rise above 100 degrees C (to ensure tissue vaporization did not occur). Ideal spherical and cylindrical applicators (200 microm and 800 microm radii respectively) were modelled for each energy source to demonstrate the relative importance of geometry and energy attenuation in determining heating and thermal damage profiles. The theoretical model included the effects of the collapse of perfusion due to heating. Heating patterns were less dependent on the energy source when small spherical applicators were modelled than for larger cylindrical applicators due to the very rapid geometrical decrease in energy with distance for the spherical applicators. For larger cylindrical applicators, the energy source was of greater importance. In this case, the energy source with the lowest attenuation coefficient was predicted to produce the largest volume of thermally coagulated tissue, in each tissue site. 相似文献
993.
Desert pavements can be detected through multi-spectral polarization measurements of reflected sunlight both in and out of the solar principle plane. The combination of polarization and color distinguishes desert pavements from other desert landforms and vegetation. Desert pavements linearly polarize and impart a blueness to sunlight reflected at visible wavelengths. The polarization and color of skylight reflected at high emission angles is also preserved. The polarization properties of desert pavements are dominated by Fresnel reflection at large phase angles and by multiple scattering at low phase angles, causing significant positive and small negative polarization, respectively. 相似文献
994.
MN Gomez 《Canadian Metallurgical Quarterly》1998,89(1):222-240
995.
Employing subtype-specific antisera, we measured the relative immunoreactivity of five muscarinic acetylcholine receptor (mAChR) subtype proteins (m1-m5) in the human iris. The most intensive FITC immunofluorescence was detected by the anti-m3 antibody, followed by anti-m1 and -m5 antisera, in the iris sphincter muscle cells. Only very weak fluorescence was obtained by anti-m2 and -m4 antibodies. In dilator muscle cells, weak but not consistent immunoreactivity was found by anti-m1 and -m5 antibodies. The results suggest that the m3 muscarinic receptor is the predominant subtype in sphincter muscle cells of the human iris. 相似文献
996.
G Kessie M Ettayebi AM Haddad AM Shibl FJ al-Shammary AF Tawfik MN al-Ahdal 《Canadian Metallurgical Quarterly》1998,84(3):417-422
(1) Submitochondrial particles prepared from beef liver mitochondria were immobilized on Fractosil, a porous form of silica, in order to stabilize their enzymatic activity. (2) The catalytic activity of succinate-cytochrome c reductase, an enzyme complex of the inner mitochondrial membrane, was followed in this study. Adsorption resulted in significant stabilization with a lowering of K(m) (app.) for succinate, in spite of mass transfer and diffusion limitations expected to occur in such a complex and heterogeneous system. An increase in catalytic potential was also observed upon immobilization. These observations, taken together, suggest that substantial degree of conversation of substrates to their respective products may be achieved by such immobilized preparations. (3) Positive cooperative interactions for binding of submitochondrial particles to the matrix was observed, apparently with two sets of sites, the second set indicating a much greater hill coefficient. (4) The present report indicates that adsorption with the use of a porous inorganic support such as Fractosil may provide a simple and efficient method of immobilization. Such preparations containing membrane enzymes in their native microenvironments would be useful for continuous catalytic transformations and also for construction of biosensors. 相似文献
997.
998.
Gurton K.P. Bruce C.W. Gillespie J.B. 《Antennas and Propagation, IEEE Transactions on》1998,46(11):1674-1678
The functional dependence of the electromagnetic backscatter by thin, straight, dielectric fibers with metallic coatings was measured as a function of coating thickness and conductivity at a wavelength of 0.86 cm (35 GHz). Cu and Ni coatings were applied to fibrous glass substrates (having a nominal diameter of 5.50 μm) using an evaporative process. The thicknesses of the thin films were directly measured by scanning electron microscopy (SEM) and ranged from 0.02 to 0.70 μm. Measurements were conducted using single fibers. Measured quantities agreed well with calculations based on previously developed theory 相似文献
999.
1000.
We evaluated the prevalence of pathological visually evoked potentials (VEP) before the appearance of papilledema or other signs of elevated intracranial pressure in children suffering from craniosynostosis. In 52 children (19 girls, 33 boys, median age 7.6 months, mean age 7.6 months, range from 3 to 34 months) preoperative VEP were analyzed. In 13 patients, pathological VEP were observed. In all children, both eyes were involved. Only 1 child suffered from papillar anomalies. Latency was pathological in 12 children, whereas the amplitude was suppressed in only 2 children. In all children with preoperative pathological VEP, postoperative controls (n = 4) were improved or normal. Thus, VEP may be the first test for neuronal damage in craniosynostosis. 相似文献