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排序方式: 共有1212条查询结果,搜索用时 15 毫秒
1.
Martina Ziefle 《Behaviour & Information Technology》2002,21(5):303-311
The study focuses on usability, ease of use and learnability of three different mobile phones (Nokia 3210, Siemens C35i, Motorola P7389). The first independent variable refers to the complexity of the menu (depth/breadth of the menu tree) and navigation keys (number/functionality). The Nokia phone had the lowest and the Motorola the highest complexity, with the Siemens phone ranging between them. The second independent variable was user expertise: 30 novices and 30 experts solved six telephone tasks. In order to assess effects of learnability, tasks were presented twice. Differences between the mobile phones regarding effectiveness, efficiency and learnability were found: The best performance was shown by Nokia users. The remaining two phones did not differ significantly, although the most complex phone was superior to the phone of medium complexity which had the lowest performance. Moreover, an effect of expertise was confirmed, though suboptimal interfaces were identified as lessening the advantage of expertise. Specific weaknesses of the tested phones are discussed. 相似文献
2.
Martina Schwarz-Geschka 《Creativity & Innovation Management》1994,3(4):229-232
‘The Japanese are not creative, they just copy….’ This prejudice often crops up when you ask Western people about the creativity of the Japanese. However, Japanese industry is at the leading edge in many industrial sectors and one cannot adhere to this prejudice any longer. Japanese creativity is interesting from two points of view. First, Japanese industry is very competitive and the success cannot be explained by a single factor, like low wages or production costs. Secondly, there is a big difference between Japanese and western civilization and a comparison shows cultural influences on creativity in understanding and practice. However, the cultural specialities which are labelled as Japanese are mostly characteristic of other East Asian cultures as well. 相似文献
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Stephan Boden Martina Bieberle Uwe Hampel 《Chemical engineering journal (Lausanne, Switzerland : 1996)》2008,139(2):351-362
Cone-beam type X-ray computed tomography (CBCT) is a potential method to measure three-dimensional phase distributions in vessels. An example for that is the measurement of gas profiles in stirred chemical reactors. Such data are highly valuable for the assessment and evaluation of chemical processes, for optimisation of the reactor and stirrer design, and for evaluation of computational fluid dynamics codes used to model the fluid flow and heat transfer in reactive systems. However, there are considerable difficulties for accurate quantitative measurements due to beam hardening and radiation scattering effects. In a theoretical and experimental work we have investigated the non-linear effects of both physical phenomena and developed a suitable measurement setup as well as calibration and software correction methods to achieve a highly accurate measurement of void fraction profiles with CBCT. 相似文献
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Martina Mazzariol Giovanni Camussi Maria Felice Brizzi 《International journal of molecular sciences》2021,22(8)
Extracellular vesicles (EV) are microparticles released in biological fluids by different cell types, both in physiological and pathological conditions. Owing to their ability to carry and transfer biomolecules, EV are mediators of cell-to-cell communication and are involved in the pathogenesis of several diseases. The ability of EV to modulate the immune system, the coagulation cascade, the angiogenetic process, and to drive endothelial dysfunction plays a crucial role in the pathophysiology of both autoimmune and renal diseases. Recent studies have demonstrated the involvement of EV in the control of renal homeostasis by acting as intercellular signaling molecules, mediators of inflammation and tissue regeneration. Moreover, circulating EV and urinary EV secreted by renal cells have been investigated as potential early biomarkers of renal injury. In the present review, we discuss the recent findings on the involvement of EV in autoimmunity and in renal intercellular communication. We focused on EV-mediated interaction between the immune system and the kidney in autoimmune diseases displaying common renal damage, such as antiphospholipid syndrome, systemic lupus erythematosus, thrombotic microangiopathy, and vasculitis. Although further studies are needed to extend our knowledge on EV in renal pathology, a deeper investigation of the impact of EV in kidney autoimmune diseases may also provide insight into renal biological processes. Furthermore, EV may represent promising biomarkers of renal diseases with potential future applications as diagnostic and therapeutic tools. 相似文献
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The vinyl ester-type glycomonomer 6-O-vinyladipoyl-d-glucopyranose was polymerized in water and alcohol solutions. In all cases, long polymerization times were necessary to achieve reasonable conversions. Depending on the nature of the solvent, polydisperse glycopolymers were obtained possessing a molecular weight ranging between 10,000 and 122,000 Da (PS equivalent). Higher alcohols appeared to act as chain transfer agents and oligomers with DPn between 2 and 6 were indeed obtained when 2-propanol was the solvent. Also, thorough oxygen removal from the reaction mixture proved to be essential for the success of the experiment, plain nitrogen sparging being ineffective in most cases. 相似文献
9.
Large domains with platelets almost parallel to each other were obtained in bulk YBa2Cu3O7– by a single-step partial melting procedure. The mechanisms of nucleation and growth of platelets are discussed. The nucleation of peritectic material from the liquid phase is favoured by heterogeneities in the melt. Experimental evidence of spiral growth of the nuclei in the [0 0 1] direction is given. Furthermore, structures of growth, which could also be an indication of spiral growth in the [0 1 0]/[1 0 0] directions, are shown. The final morphology of the domains can be explained on the basis of the periodic bond chain (PBC) theory if the growth rates of flat (F) faces of the platelets are dominated by kinetic coefficients which differ between them. The morphology of the as-grown (0 0 1) surface is explained in the framework of the PBC theory with the shape of the steps of macrospirals governed by the transition from roughness to smoothness of the liquid-solid interface. An account of large step heights is given by the model of giant screw dislocations caused by an impurity-induced lattice-constant gradient. Even higher step heights are correlated to the presence of obstacles and lack of liquid phase. 相似文献
10.
C. Melody Carswell Cindy H. Lio Martina I. Klein Duncan Clarke Stephen Strup 《Applied ergonomics》2010,42(1):138-145