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991.
John T. Christian 《Nuclear Engineering and Design》1980,61(3):369-382
Standard response spectra for design earthquakes have recently been proposed for use in Japan. These are based on the peak particle velocity of the motion, which is computed from the magnitude and epicentral distance of the controlling event. Spectra computed according to U.S. Nuclear Regulatory Commission (NRC) Regulatory Guide 1.60 are based on the peak particle acceleration, so direct comparison of Japanese and American spectra is not simple. By assuming magnitudes and epicentral distances comparable to those used for the Japanse spectra and by using several different attenuation relations, it is possible to develop American spectra for events similar to the Japanese. Comparison indicates that the American spectra are substantially higher for frequencies below 2 to 5 Hz and are generally higher at all frequencies for intermediate and near events. For near events and frequencies above 2 to 5 Hz the two sets of spectra are similar. The effect of damping other than 5 percent of critical either is essentially the same for the two procedures or is greater in the American spectra. 相似文献
992.
Large irradiation creep strains were observed in WSA-4 mixed-oxide fuel pins at 7% burn-up and 1023 n cm?2 (E>0.1 MeV) which were exposed to temperature variations relative to pins irradiated at approximately constant temperature. A comparison of the fuel pin and pressurized tube samples exposed to gradual temperature reductions shows similar behaviour. The results show that the irradiation creep coefficient increases with increasing temperature reduction and initial irradiation temperature. The increase in irradiation creep and the previously reported increase in swelling with temperature reduction appears similar to other macroscopic strain reports of irradiation creep and swelling association. 相似文献
993.
Gregory K Miller David A Petti Dominic J Varacalle Jr. John T Maki 《Journal of Nuclear Materials》2003,317(1):69-82
The fundamental design for a gas-cooled reactor relies on the behavior of the coated particle fuel. The coating layers, termed the TRISO coating, act as a mini-pressure vessel that retains fission products. Results of US irradiation experiments show that many more fuel particles have failed than can be attributed to one-dimensional pressure vessel failures alone. Post-irradiation examinations indicate that multi-dimensional effects, such as the presence of irradiation-induced shrinkage cracks in the inner pyrolytic carbon layer, contribute to these failures. To address these effects, the methods of prior one-dimensional models are expanded to capture the stress intensification associated with multi-dimensional behavior. An approximation of the stress levels enables the treatment of statistical variations in numerous design parameters and Monte Carlo sampling over a large number of particles. The approach is shown to make reasonable predictions when used to calculate failure probabilities for irradiation experiments of the New Production - Modular High Temperature Gas Cooled Reactor Program. 相似文献
994.
An explanation is proposed for the nuclear reactions that occur in the electrolysis class of LENR processes. The proposed explanation postulates that a proton, or deuteron, dissolved in the hydrogen bearing metal cathode, absorbs its associated atomic electron to become a short lived state of the neutron with the resulting neutrino in a singular wave function centered on the neutron. The energy required to initiate this endothermic reaction is supplied either by the ion current during electrolysis type experiments, or by ion bombardment in plasma type experiments. It is the energy of this bombardment of the cathode with heavy ions that creates a coherent polyplasmon field within crystalline metallic grains that are present in the metal cathode of typical active electrolysis cells. The LENR process consists of a second order reaction mediated by a coherent plasmon field excited in the conduction electrons in a hydrogen bearing metal that is in the form of crystalline grains of the order of a few microns in dimension. The coherent plasmon field in each grain is called a polyplasmon. The metallic grains typically form during solidification of a metal, the impurities being forced to the grain surfaces. The resulting grain thus forms a resonant structure that can be filled with a number of coherent plasmons, i.e., a polyplasmon. 相似文献
995.
996.
Marc Serra Colomer Birgitte Funch Natalia Solodovnikova Timothy John Hobley Jochen Förster 《Journal of the Institute of Brewing》2020,126(3):280-288
Several hop derived compounds in wort are known to be converted by yeast during fermentation, influencing the overall perception of the beer. A deeper understanding of such metabolic processes during fermentation is needed to achieve better control of the outcome. Here, the interaction between hop derived compounds and the yeast genera Brettanomyces was studied. Several Brettanomyces strains with different genomic backgrounds were selected, focusing on two traits: beta-glucosidase activity and nitrate assimilation. The role of three beta-glucosidases present in Brettanomyces bruxellensis and Brettanomyces anomalus and their impact on the final monoterpene alcohol profile was analysed. The beta-glucosidase activity was highly strain dependent, with B. anomalus CRL-49 exhibiting the highest conversion. Such activity could not be related to the release of aglycones from hops during fermentation, as a substantial part of such activity was intracellular. Nevertheless, the reduction of geraniol to β-citronellol was remarkably efficient for all Brettanomyces strains during fermentation, and it is suggested that two oxidoreductases BbHye2 and BbHye3 may have an influence. Moreover, the transfer of nitrate from hops to wort and its further assimilation by Brettanomyces species was analysed. The amount of nitrate in wort proved to be linearly proportional to the contact time of the hops with the wort. The level of nitrate assimilation by yeast was shown to be dependent on the nitrate assimilation cluster (YNR, YNI, YNT). Hence, the desired yeast strains may be selected according to the genetic make-up. © 2020 The Authors. Journal of the Institute of Brewing published by John Wiley & Sons Ltd on behalf of The Institute of Brewing & Distilling 相似文献
997.
Bhekisisa C. Dlamini John R. N. Taylor Elna M. Buys 《International Journal of Food Science & Technology》2020,55(2):841-850
Because gluten-free type brewing with unmalted sorghum does not provide adequate nitrogen for complete fermentation, wort supplementation with ammonia (as diammonium phosphate, DAP) or lysine on yeast performance was investigated. By Phenotype Microarray, under aerobic conditions, greater yeast growth was indicated with DAP than lysine both as a single source and combined with sorghum wort amino acids. With sorghum fermentation, both DAP and lysine improved maltose and maltotriose uptake. However, DAP supplementation also maintained yeast numbers (24.0–21.3 × 106 cells mL−1), whereas there was a decline with lysine supplementation. Lysine supplementation also resulted in adverse effects on yeast cell morphology. Neither DAP nor lysine supplementation resulted in evident genetic change to the yeast, but the change in substrate from barley malt wort to unmalted sorghum wort slightly altered the yeast genetically. Therefore, ammonia as DAP has potential as a nitrogen supplement for improving yeast fermentation performance in sorghum gluten-free brewing. 相似文献
998.
999.
The exhibit 10 Short Films About Fog, which was part of the Data & Matter Exhibition at Palazzo Bembo during the Venice Architecture Biennale in 2018, documents and expands experiments into the relationship between fog, textiles, and air. The project sought to probe whether the otherwise formless phenomena of fog could be explicitly formed, and how it might assume structures and textures. By revealing the characteristics of fog that fascinate us, yet are latent, the short films also transform the phenomena through magnification, thereby amplifying inherent behaviors and qualities. 相似文献
1000.
Roja Gholamhosseini Iderlina Mateo Babiano Laurel Johnson John Minnery 《Journal of Urban Design》2019,24(2):269-289
For Middle Eastern migrants to Australia, the process of acculturation is compounded by Islamophobia, which is on the rise, with many incidents occurring in public spaces and targeting women. Through in-depth interviews, this paper examines how women migrants from the Middle East, especially Muslim ones, are affected. The study finds that Middle Eastern women migrants have a different perspective on public space compared to local populations, and this difference stems from their cultural, political and religious backgrounds. These findings can help cities create inclusive and culturally-sensitive public spaces, which catalyze a ‘sense of belonging’ and ‘sense of place’ among migrants. 相似文献