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41.
42.
Caroline Weidemann Sebastian Stahl Hermann Nirschl 《Food and Bioproducts Processing》2013,91(4):515-524
In this paper a new method for cleaning of filter media is presented, and the cleanability with different textures and surface finishes is compared. With the method described, it is possible to evaluate the quality of the cleaning process. According to the German VDMA standard cleaning test, riboflavin and malt extract are applied as model contaminants for evaluation of the cleaning results. To compare the cleanability of filter media with different properties and geometries the results are adapted to the law of mass transfer and to the Sherwood number, a dimensionless parameter describing the quality of a cleaning process. 相似文献
43.
Franky Ruslim Bernhard Hoffner Hermann Nirschl Werner Stahl 《Chemical Engineering Research and Design》2009,87(8):1075-1084
Filter cake washing is a purification method for particulate products in liquids. This process is mostly one step of a sequence in a solid–liquid separation process. For soluble products not only the mechanical transport mechanisms in washing but also the dissolution process of the product must be considered in order to describe the washing process appropriately. An unconsidered dissolution may cause problems and often severe product loss depending on the material properties. This paper presents several methods of soluble solids washing including filter cake washing by pressure and centrifugal forces as well as moving bed washing. The advantages and drawbacks of each method are discussed to evaluate the suitability of its technical application. 相似文献
44.
S. M. Olsen L. T. Pedersen M. H. Hermann S. Kiil K. Dam-Johansen 《Journal of Coatings Technology and Research》2009,6(2):187-199
Modern antifouling coatings are generally based on cuprous oxide (Cu2O) and organic biocides as active ingredients. Cu2O is prone to bioaccumulation, and should therefore be replaced by more environmentally benign compounds when technically
possible. However, cuprous oxide does not only provide antifouling properties, it is also a vital ingredient for the antifouling
coating to obtain its polishing and leaching mechanism. In this paper, peroxides of strontium, calcium, magnesium, and zinc
are tested as pigments in antifouling coatings. The peroxides react with seawater to create hydrogen peroxide and highly seawater-soluble
ions of the metal. The goals have been to establish the antifouling potency of an antifouling coating that releases hydrogen
peroxide as biocide, and to investigate the potential use of peroxides as water-soluble polishing and leaching pigments. The
investigations have shown that it is possible to identify particulates that, when applied as pigments in antifouling coatings,
will provide polishing and leaching rates comparable to those of Cu2O-based coatings. Furthermore, the combination of polishing and hydrogen peroxide leaching by a coating based on zinc peroxide
in a suitable binder matrix provides antifouling properties exceeding those of a similar coating based entirely on zinc oxide. 相似文献
45.
A process model of dual fluidized bed gasification is presented based on mass- and energy balances. The model further covers the evaluation of thermodynamic equilibrium states. The gasification is investigated for the special case that CaO/CaCO3 is used as bed material allowing selective transport of CO2 from the gasification reactor to the combustion reactor by repeated carbonation and calcination. Experimental data are used to determine the model parameters. An empirical approach towards the kinetics of fuel conversion allows prediction of process behaviour at varied fuel water content. The selective transport of CO2 results in high H2 contents in the produced syngas. The lower operating temperatures in the gasification reactor increase the efficiency of energy conversion. The results are in agreement with experimental data and show the thermodynamic limitations of the technology. 相似文献
46.
The unique properties of gold nanoparticles have stimulated the increasing interest in the application of GNPs in interfacing biological recognition events with signal transduction and in designing biosensing devices exhibiting novel functions. The optical properties of GNPs provide wide range opportunities for construction optical biosensors. The excellent biocompatibility, conductivity, catalytic properties and high surface-to-volume ratio and high density of GNPs facilitate extensive application of GNPs in construction of electrochemical and piezoelectric biosensors with enhanced analytical performance with respect to other biosensor designs. In this article, the recent advances in construction of GNP-based optical, electrochemical and piezoelectric biosensors are reviewed, and some illustrative examples given, with a focus on the roles GNPs play in the biosensing process and the mechanism of GNPs for improving the analytical performances. Finally, the review concludes with an outline of present and future research for the real-world applications. 相似文献
47.
Homoisoflavonoids (3-benzylidene-4-chromanones) are considered as an infrequent flavonoid class, possessing multi-beneficial bioactivities. The present study gives an overview on phytochemical aspects of homoisoflavonoids, including utilized plant species, parts, extracts, and separation techniques. Overall, these compounds have mainly been isolated and identified from bulbs and rhizomes of the plants belonging to Asparagaceae and Fabaceae families, particularly the genera of Ophiopogon, Dracaena, Scilla, Polygonatum, and Caesalpinia. 相似文献
48.
Anna Kutschenko Selma Staege Karen Grütz Hannes Glaß Norman Kalmbach Thomas Gschwendtberger Lisa M. Henkel Johanne Heine Anne Grünewald Andreas Hermann Philip Seibler Florian Wegner 《International journal of molecular sciences》2021,22(7)
Myoclonus-dystonia (DYT-SGCE, formerly DYT11) is characterized by alcohol-sensitive, myoclonic-like appearance of fast dystonic movements. It is caused by mutations in the SGCE gene encoding ε-sarcoglycan leading to a dysfunction of this transmembrane protein, alterations in the cerebello-thalamic pathway and impaired striatal plasticity. To elucidate underlying pathogenic mechanisms, we investigated induced pluripotent stem cell (iPSC)-derived striatal medium spiny neurons (MSNs) from two myoclonus-dystonia patients carrying a heterozygous mutation in the SGCE gene (c.298T>G and c.304C>T with protein changes W100G and R102X) in comparison to two matched healthy control lines. Calcium imaging showed significantly elevated basal intracellular Ca2+ content and lower frequency of spontaneous Ca2+ signals in SGCE MSNs. Blocking of voltage-gated Ca2+ channels by verapamil was less efficient in suppressing KCl-induced Ca2+ peaks of SGCE MSNs. Ca2+ amplitudes upon glycine and acetylcholine applications were increased in SGCE MSNs, but not after GABA or glutamate applications. Expression of voltage-gated Ca2+ channels and most ionotropic receptor subunits was not altered. SGCE MSNs showed significantly reduced GABAergic synaptic density. Whole-cell patch-clamp recordings displayed elevated amplitudes of miniature postsynaptic currents and action potentials in SGCE MSNs. Our data contribute to a better understanding of the pathophysiology and the development of novel therapeutic strategies for myoclonus-dystonia. 相似文献
49.
Hermann G. Hauthal Peter Jürges Lothar Möhle Udo Ohlerich 《Journal of surfactants and detergents》1999,2(2):175-180
It has been shown that ternary surfactant synergism can be predicted on the basis of nonideality parameters of binary subsystems
derived from advancing contact angles. Studies with appropriate surfactant mixtures of glucamides, ether sulfates, secondary
alkane sulfonates, and alkylamidopropyl betaines were performed on substrates of different polarity. 相似文献
50.
The electronic structure and bonding at different oxygen sites of MoO3(0 1 0) and (1 0 0) surfaces is reviewed on the basis of ab initio density functional theory (DFT-LCGTO) cluster calculations. The clusters are chosen as finite sections of the ideal MoO3 surface where cluster embedding is achieved by bond saturation with hydrogen terminator atoms yielding clusters up to Mo7O30H18. Resulting charge density distributions and binding properties are analyzed by populations, bond orders, and electrostatic potential maps. Interatomic binding at the surface is determined by both ionic and covalent contributions with a clear distinction between terminal oxygens and different bridging surface oxygens. Electronic differences between the MoO3 (0 1 0) and (1 0 0) surfaces are found to be mainly due to the different atom arrangement while local atom charging and binding properties seem surface independent. The electronic surface parameters influence the behavior and reactions of adsorbed molecules as will be shown for H, OH, and C3H5 adsorbates. 相似文献