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91.
The interaction of a living organism with external foreign agents is a central issue for its survival and adaptation to the environment. Nanosafety should be considered within this perspective, and it should be examined that how different organisms interact with engineered nanomaterials (NM) by either mounting a defensive response or by physiologically adapting to them. Herein, the interaction of NM with one of the major biological systems deputed to recognition of and response to foreign challenges, i.e., the immune system, is specifically addressed. The main focus is innate immunity, the only type of immunity in plants, invertebrates, and lower vertebrates, and that coexists with adaptive immunity in higher vertebrates. Because of their presence in the majority of eukaryotic living organisms, innate immune responses can be viewed in a comparative context. In the majority of cases, the interaction of NM with living organisms results in innate immune reactions that eliminate the possible danger with mechanisms that do not lead to damage. While in some cases such interaction may lead to pathological consequences, in some other cases beneficial effects can be identified.  相似文献   
92.
Batteries have become an integral part of everyday life—from small coin cells to batteries for mobile phones, as well as batteries for electric vehicles and an increasing number of stationary energy storage applications. There is a large variety of standardized battery sizes (e.g., the familiar AA-battery or AAA-battery). Interestingly, all these battery systems are based on a huge number of different cell chemistries depending on the application and the corresponding requirements. There is not one single battery type fulfilling all demands for all imaginable applications. One battery class that has been gaining significant interest in recent years is polymer-based batteries. These batteries utilize organic materials as the active parts within the electrodes without utilizing metals (and their compounds) as the redox-active materials. Such polymer-based batteries feature a number of interesting properties, like high power densities and flexible batteries fabrication, among many more.  相似文献   
93.
Hobert  Anne  Jahn  Najko  Mayr  Philipp  Schmidt  Birgit  Taubert  Niels 《Scientometrics》2021,126(12):9751-9777

This study investigates the development of open access (OA) to journal articles from authors affiliated with German universities and non-university research institutions in the period 2010–2018. Beyond determining the overall share of openly available articles, a systematic classification of distinct categories of OA publishing allowed us to identify different patterns of adoption of OA. Taking into account the particularities of the German research landscape, variations in terms of productivity, OA uptake and approaches to OA are examined at the meso-level and possible explanations are discussed. The development of the OA uptake is analysed for the different research sectors in Germany (universities, non-university research institutes of the Helmholtz Association, Fraunhofer Society, Max Planck Society, Leibniz Association, and government research agencies). Combining several data sources (incl. Web of Science, Unpaywall, an authority file of standardised German affiliation information, the ISSN-Gold-OA 3.0 list, and OpenDOAR), the study confirms the growth of the OA share mirroring the international trend reported in related studies. We found that 45% of all considered articles during the observed period were openly available at the time of analysis. Our findings show that subject-specific repositories are the most prevalent type of OA. However, the percentages for publication in fully OA journals and OA via institutional repositories show similarly steep increases. Enabling data-driven decision-making regarding the implementation of OA in Germany at the institutional level, the results of this study furthermore can serve as a baseline to assess the impact recent transformative agreements with major publishers will likely have on scholarly communication.

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94.
α‐Melanocyte stimulating hormone (α‐MSH) derivatives target the melanocortin‐1 receptor (MC1R) specifically and selectively. In this study, the α‐MSH‐derived peptide NAP‐NS1 (Nle‐Asp‐His‐d ‐Phe‐Arg‐Trp‐Gly‐NH2) with and without linkers was conjugated with 5‐(bis(pyridin‐2‐ylmethyl)amino)pentanoic acid (DPA‐COOH) and labeled with [99mTc]Tc‐tricarbonyl by two methods. With the one‐pot method the labeling was faster than with the two‐pot method, while obtaining similarly high yields. Negligible trans‐chelation and high stability in physiological solutions was determined for the [99mTc]Tc‐tricarbonyl–peptide conjugates. Coupling an ethylene glycol (EG)‐based linker increased the hydrophilicity. The peptide derivatives displayed high binding affinity in murine B16F10 melanoma cells as well as in human MeWo and TXM13 melanoma cell homogenates. Preliminary in vivo studies with one of the [99mTc]Tc‐tricarbonyl–peptide conjugates showed good stability in blood and both renal and hepatobiliary excretion. Biodistribution was performed on healthy rats to gain initial insight into the potential relevance of the 99mTc‐labeled peptides for in vivo imaging.  相似文献   
95.
The synthesis of new Schiff base-like ligands with asymmetric substituents pattern and their iron complexes with pyridine as axial ligand is described. Two of the ligands and one of the iron(II) complexes were characterized by single crystal X-ray structure analysis. One of the the iron(II) complexes shows spin crossover behavior while the others remain in the high spin state. The influence of the reduced symmetry of the ligand on the properties of the complexes is discussed.
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96.
To tackle climate change it is essential to reduce carbon dioxide emissions. To this end, it is important to reduce the energy demands of non-domestic buildings. Naturally ventilated buildings can have low energy demands but the strategy is difficult to implement in deep plan, urban locations. The Frederick Lanchester Library at Coventry University, UK, incorporates natural ventilation, daylighting and passive cooling strategies. By using lightwells and perimeter stacks to supply and exhaust air, it can be ventilated by natural means despite its deep plan form and sealed façade. This paper describes the building and presents the energy consumption and the internal temperatures and CO2 levels recorded in 2004/2005. The building's performance is compared to the original design criteria and good practice guidelines. Recommendations for the design of such buildings are made and the likely performance in other UK cities is assessed. It is concluded that the building uses under half the energy of a standard air-conditioned building and yet, in summer, can keep the interior comfortable and up to 5 °C below ambient. The design would perform equally well in the typical weather conditions experienced at 13 other UK cities, but not in London. It is concluded that deep-plan, naturally ventilated buildings with sealed facades, if well designed, could maintain thermal comfort in all but a very few UK locations, whilst consuming much less energy than even good practice standards.  相似文献   
97.
The SAFIRA-project (remediation research in regionally contaminated aquifers) focuses on innovative in situ remediation technologies to treat complex groundwater contamination. For this purpose, a model site located in Bitterfeld, Germany, was selected. The site is heavily contaminated with aliphatic and aromatic chlorinated hydrocarbons. The goal of the project is to develop, test and optimize new technologies of reactive barriers under controlled in situ conditions in a pilot plant. In order to create the necessary basis for this model project, the hydrogeological and hydrogeochemical conditions at the selected field site were investigated and various technologies for the design of the in situ pilot plant were examinated. Small-scale laboratory studies and tests in a mobile test unit (scale 1 m) were carried out in order to test the technologies prior to their application in the field. The technologies now tested in the reactive columns at the pilot plant include physico-chemical, microbial and combined techniques.  相似文献   
98.
Commercially available heat transfer fluids used in borehole heat exchangers were investigated for their composition, their biodegradability as well as their ecotoxicity. The main components of the fluids are organic compounds (often glycols) for freezing protection. Biodegradation of the fluids in laboratory studies caused high oxygen depletion as well as nitrate/iron(III) reduction under anaerobic conditions. Additives such as benzotriazoles for corrosion protection were persistent. Ecotoxicity data show that the commercially available fluids caused much higher ecotoxicity than their main organic constituents. Consequently, with regard to groundwater protection pure water as heat transfer medium is recommended. The second best choice is the usage of glycols without any additives. Effects on groundwater quality should be considered during ecological-economical cost-benefit-analyses of further geothermal energy strategies. The protection of groundwater as the most important drinking water resource must take priority over the energy gain from aquifers.  相似文献   
99.
Superparamagnetic MnFe2O4 nanocrystals of different sizes were synthesized in high-boiling ether solvent and transferred into water using three different approaches. First, we applied a ligand exchange in order to form a water soluble polymer shell. Second, the particles were embedded into an amphiphilic polymer shell. Third, the nanoparticles were embedded into large micelles formed by lipids. Although all approaches lead to effective negative contrast enhancement, we observed significant differences concerning the magnitude of this effect. The transverse relaxivity, in particular r2*, is greatly higher for the micellar system compared to the polymer-coated particles using same-sized nanoparticles. We also observed an increase in transverse relaxivities with increasing particle size for the polymer-coated nanocrystals. The results are qualitatively compared with theoretical models describing the dependence of relaxivity on the size of magnetic spheres.  相似文献   
100.
Membrane processes are able to separate liquid mixtures as well as mixtures of gases or vapours according to the sizes, solubilities, rates of diffusion or charges of the components. A separation is also possible using membranes in which the transport is coupled to a specific chemical reaction between the permeand and the membrane (facilitated or carrier mediated transport). This paper discusses aspects related to carrier‐mediated separation processes such as the transport mechanisms, the choice of appropriate carriers, the incorporation of carriers in the polymeric membrane material, the coating of porous support membranes with thin selective layers of the carrier‐polymer and, finally, the choice of appropriate parameters for the separation process. The separation of gas mixtures by carrier‐membranes appears very promising from a technical point of view. Experimental membrane samples often show excellent separation factors, but they have not met the permeability requirements for an economic use so far.  相似文献   
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