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71.
Fourier transform infrared spectroscopy (FT-IR) has been utilized to investigate the interfacial chemical bonding at the interfaces of the aminosilanes and the nedic methyl anhydiride cured epoxy matrix in fiber-reinforced composites. It is found that the nedic methyl anhydride can react with γ-aminopropyltriethoxysilane (APS) and N-methylaminoproplytrimethoxysilane (MAPS). In comparing the relative reactivities of two coupling agents to the epoxy resin, the secondary aminosilance has a higher reactivity than the primary aminosilance. An elevated temperature is required for the copolymerization to take place between the silane and the epoxy resin. The results indicate that covalent bonds form at the coupling agents. The molecular structure of the interface in MAPS treated fiberglass reinforced composites is different from that of the APS treated fiber composites. In addition, an accelerated copolymerization initiated by the coupling agent treated surface is also found in the resin interphase which may be important in determining the mechanical properties of the composites. 相似文献
72.
Blood has traditionally been used as a high protein ingredient in both human food and animal feed, with resulting economic, environmental and nutritional benefits. However, potentially serious health and safety issues related to blood consumption, particularly the risk of pathogenic or harmful metabolic materials, the infectivity of prion diseases, and the presence of identified allergens such as bovine serum albumin (BSA), are causing many consumers to shy away from any product containing either animal blood or ingredients derived from animal blood. Thus, despite the significant volumes of blood produced by slaughterhouses, blood is currently underutilized as a food ingredient. This article reviews the use of animal blood as an ingredient in food intended for human consumption or for animal feed and discusses the related consumer concerns. 相似文献
73.
The chemical reactions at the interface between an anhydride-cured epoxy resin and an aminosilane treated fiber have been investigated using Fourier transform infrared methods (FT-IR). The results indicate that chemical bonds are formed in the interfacial region between the matrix and the coupling agents. The amount of interfacial bonding depends on the composition and the processing conditions. 相似文献
74.
Allie E. Auld Fabian Mueller Keyue Ma Smedley Scott Samuelsen Jack Brouwer 《Journal of power sources》2008
Adding distributed generation (DG) is a desirable strategy for providing highly efficient and environmentally benign services for electric power, heating, and cooling. The interface between a solid oxide fuel cell (SOFC), typical loads, and the electrical grid is simulated in Matlab/Simulink and analyzed to assess the interactions between DG and the electrical grid. A commercial building load profile is measured during both steady-state and transient conditions. The load data are combined with the following models that are designed to account for physical features: a One-Cycle Control grid-connected inverter, a One-Cycle Control active power filter, an SOFC, and capacitor storage. High penetration of DG without any power filter increases the percentage of undesirable harmonics provided by the grid, but combined use of an inverter and active power filter allows the DG system interconnection to improve the grid tie-line flow by lowering total harmonic distortion and increasing the power factor to unity. 相似文献
75.
Characterisation of CYP102A25 from Bacillus marmarensis and CYP102A26 from Pontibacillus halophilus: P450 Homologues of BM3 with Preference towards Hydroxylation of Medium‐Chain Fatty Acids 下载免费PDF全文
Dr. Joanne L. Porter Jack Manning Selina Sabatini Michele Tavanti Prof. Nicholas J. Turner Prof. Sabine L. Flitsch 《Chembiochem : a European journal of chemical biology》2018,19(5):513-520
Cytochrome P450 monooxygenases are highly desired biocatalysts owing to their ability to catalyse a wide variety of chemically challenging C?H activation reactions. The CYP102A subfamily of enzymes are natural catalytically self‐sufficient proteins consisting of a haem and FMN‐FAD reductase domain fused in a single‐component system. They catalyse the oxygenation of saturated and unsaturated fatty acids to produce primarily ω?1, ω?2 and ω?3 hydroxy acids. These monooxygenases have potential applications in biotechnology; however, their substrate range is still limited and there is a continued need to add diversity to this class of biocatalysts. Herein, we present the characterisation of two new members of this class of enzymes, CYP102A25 (BMar) from Bacillus marmarensis and CYP102A26 (PHal) from Pontibacillus halophilus, both of which express readily in a recombinant bacterial host. BMar exhibits the highest activity toward myristic acid and shows moderate activity towards unsaturated fatty acids. PHal exhibits broader activity towards mid‐chain‐saturated (C14–C18) and unsaturated fatty acids. Furthermore, PHal shows good regioselectivity for the hydroxylation of myristic acid, targeting the ω?2 position for C?H activation. 相似文献
76.
Aluminium corrosion is a significant concern in the aqueous chemical environment of the reactor containment building following a hypothetical loss-of-coolant accident (LOCA) at a nuclear power plant. Aluminium corrosion may lead to the formation of precipitates that can, in combination with insulation debris, block the recirculation sump screens. This study investigated aluminium corrosion experimentally at both bench and pilot scale under conditions representative of several types of nuclear power plants. Evidence of corrosion was determined using aqueous concentrations measured with inductively-coupled plasma (ICP) spectrometry and surface examinations using scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), X-ray photoelectron spectrometry (XPS), X-ray fluorescence (XRF), and X-ray diffraction (XRD). Corrosion proceeded slowly at pH near 7, but more rapidly at higher pH when the representative pipe insulation material was fibreglass. However, when calcium silicate pipe insulation was introduced into the system, corrosion became insignificant even at pH values near 10. Experimental evidence indicates that the calcium silicate insulation released a significant amount of silicate to the solution. Silicate formed a passivation layer composed of Al2OSiO4 with a thickness of more than 10 nm, and this layer effectively inhibited corrosion. 相似文献
77.
78.
Andrew Artzer Michael Moats Jack Bender 《JOM Journal of the Minerals, Metals and Materials Society》2018,70(12):2856-2863
Antimony and bismuth recovery from copper electrorefining electrolyte could reduce the impacts of these problem elements and produce a new primary source for them. Two proprietary phosphonic acid ester extractants were examined (REX-1 and REX-2) for the removal of antimony and bismuth from copper electrorefining electrolytes. Experimentation included shakeout and break tests to determine the basic parameters for the extractants in terms of maximum loading, break times, and extraction and stripping efficiency. Five permutations of extractant mixtures (100 wt.% REX-1 and 25 wt.%, 50 wt.%, 75 wt.% and 100 wt.% REX-2) were studied. It was determined that REX-2 was able to extract Sb and Bi from the electrolyte, but required some mixture with REX-1 to better facilitate stripping with 400 g/L sulfuric acid. The laboratory electrorefining electrolyte containing glue had faster disengagement times than a synthetic solution without glue. 相似文献
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