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121.
Kirsten Bobzin Nazlim Bagcivan Arnold Gillner Claudia Hartmann Jens Holtkamp Walter Michaeli Fritz Klaiber Maximilian Sch?ngart Sebastian Thei? 《Production Engineering》2011,5(4):415-422
Molding of micro structures by injection molding leads to special requirements for the molds e.g. regarding wear resistance
and low release forces of the molded components. At the same time it is not allowed to affect the replication precision. Physical
vapor deposition (PVD) is one of the promising technologies for applying coatings with adapted properties like high hardness,
low roughness, low Young’s modulus and less adhesion to the melt of polymers. Physical vapor deposition technology allows
the deposition of thin films on micro structures. Therefore, the influence of these PVD layers on the contour accuracy of
the replicated micro structures has to be investigated. For this purpose injection mold inserts were laser structured with
micro structures of different sizes and afterwards coated with two different coatings, which were deposited by a magnetron
sputter ion plating PVD technology. After deposition, the coatings were analyzed by techniques regarding hardness, Young’s
modulus and morphology. The geometries of the micro structures were analyzed by scanning electron microscopy before and after
coating. Afterwards, the coated mold inserts were used for injection molding experiments. During the injection molding process,
a conventional and a variothermal temperature control of the molds were used. The molded parts were analyzed regarding roughness,
structure height and structure width by means of laser microscopy. 相似文献
122.
R. Kree T. Yasseri A.K. Hartmann 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2009,267(8-9):1403-1406
We present a new Monte Carlo model and a new continuum theory of surface pattern formation due to “surfactant sputtering”, i.e. erosion by ion beam sputtering including a submonolayer coverage of additional, co-sputtered surfactant atoms. This setup, which has been realized in recent experiments in a controlled way leads to a number of interesting possibilities to modify pattern forming processing conditions. We will present three simple scenarios, which illustrate some potential applications of the method. In all three cases, simple Bradley–Harper type ripples appear in the absence of surfactant, whereas new, interesting structures emerge during surfactant sputtering. 相似文献
123.
X-ray powder diffraction, microscopy, thermal analysis and electron probe microanalysis were used to characterize a ZrO2-MgO inert matrix containing CeO2 as a homolog for PuO2 and Er2O3 as a burnable poison. The synthesis was carried out using a precipitation method. A large composition range of MgO to ZrO2 was evaluated to determine phases present, phase mixing, phase composition, microstructure and thermal properties. It was found that most compositions of the material consist of two phases: MgO (periclase) and ZrO2 (cubic zirconia). The zirconia phase incorporates 5% (wt/wt) MgO and up to 14% and 12% (wt/wt) CeO2 and Er2O3, respectively. The MgO phase remains pure, which will enable it to retain its heat transfer and solubility properties and will improve the overall thermal conductivity and reprocessing component of the inert matrix fuel. The results with Ce will be used as the basis of future studies with actinides. 相似文献
124.
Ackermann T. Ancell G. Borup L.D. Eriksen P.B. Ernst B. Groome F. Lange M. Mohrlen C. Orths A.G. O'Sullivan J. de la Torre M. 《Power and Energy Magazine, IEEE》2009,7(6):65-75
The power systems in Denmark, Spain, Ireland, and New Zealand have some of the highest wind penetrations in the world (see Table 1). The management of the different power systems to date, with increasing amounts of wind energy, has been successful. There have been no incidents in which the wind has directly or indirectly been a major factor causing operational problems for the system. However, there are a number of parameters that are being monitored that indicate the need for active management in the near future (and in some cases already today). In this article, we briefly describe the situations in these four countries, giving special emphasis to the market integration of wind power, the use of wind forecasting, and curtailment experience. The final section provides an overview of the main wind forecasting methodologies and challenges. 相似文献
125.
Douglas E. Burkes J. Rory Kennedy Thomas Hartmann Cynthia A. Papesch 《Nuclear Engineering and Design》2009,239(12):2747-2753
Metallic fuel alloys consisting of uranium, plutonium, and zirconium with minor additions of americium and neptunium are under evaluation for potential use to transmute long-lived transuranic actinide isotopes in fast reactors. The current irradiation test series design, designated AFC2, includes minor additions of rare earth elements to simulate expected fission product carry-over from the electrochemical molten salt reprocessing technique. The metal fuel alloys have been fabricated by an arc casting technique. The as-cast fuel alloys have been investigated for phase and thermal properties, specifically, enthalpies of transition, transition temperatures, and room temperature phase characteristics. Results and observations related to these characteristics for the “fresh” fuel alloys are provided. The alloy compositions are based on a U-20Pu-3Am-2Np-15Zr alloy, along with additions of 1 and 1.5 wt% RE (at the expense of U) where RE denotes rare earth alloy of cerium, lanthanum, praseodymium and neodymium. Phase behavior and associated transitions have been compared to available U-Pu-Zr ternary diagrams with acceptable agreement. Enthalpies of transition were deconvoluted from heating and cooling thermal traces for relatively reliable values. The rare earth additions to the base alloy have a minimal influence on the room temperature phases present, but the room temperature phases present slightly impacted the enthalpies of transition and transition temperatures. 相似文献
126.
Shay Artzi Adam Kieżun Jaime Quinonez Michael D. Ernst 《Automated Software Engineering》2009,16(1):145-192
Knowing which method parameters may be mutated during a method’s execution is useful for many software engineering tasks.
A parameter reference is immutable if it cannot be used to modify the state of its referent object during the method’s execution. We formally define this notion,
in a core object-oriented language. Having the formal definition enables determining correctness and accuracy of tools approximating
this definition and unbiased comparison of analyses and tools that approximate similar definitions.
We present Pidasa, a tool for classifying parameter reference immutability. Pidasa combines several lightweight, scalable
analyses in stages, with each stage refining the overall result. The resulting analysis is scalable and combines the strengths
of its component analyses. As one of the component analyses, we present a novel dynamic mutability analysis and show how its
results can be improved by random input generation. Experimental results on programs of up to 185 kLOC show that, compared
to previous approaches, Pidasa increases both run-time performance and overall accuracy of immutability inference. 相似文献
127.
Since it is known that crosslinked polythylene can be worked, it is clear that the mechanics acting in the interior of a welded joint are not adequately explained yet. There are several criteria, hypotheses and models that attempt to describe what happens in a welded joint. In this paper, two new promising hypotheses, the Mixed Crystal Hypothesis and the Nexus Hypothesis, are introduced. The Mixed Crystal Hypothesis can be proven by the help of several different examination methods. Other examinations support the Nexus Hypothesis. 相似文献
128.
129.
Andrea Kaiser Katja I. Hartmann Dietmar R. Kammerer Reinhold Carle 《European Food Research and Technology》2013,237(3):353-365
Initial heating was applied as the first processing step in the production of innovative pasty celeriac products. For this purpose, celeriac was converted into a paste and subsequently heated at 90 and 100 °C for 5–10 min. Alternatively, the fresh plant material was blanched prior to mincing. For the first time, phenolic compounds in celeriac were characterized by high-performance liquid chromatography coupled with mass spectrometry (LC–MSn). Among the 14 phenolics detected, several caffeic, ferulic and quinic acid derivatives as well as malonylated and acetylated flavonoid derivatives were newly identified. Upon thermal treatment, the antioxidant capacities (TEAC assay) and the total phenolic contents remained virtually unchanged. The antioxidant capacities of heated samples determined by the FRAP assay were even higher than those of the unheated control. The contents of the main phenolic compound apiin decreased upon heat treatment, whereas the levels of the minor compounds malonylapiin A and B increased. Only by extended steam- and water-blanching at 100 °C, respectively, complete inactivation of peroxidase and polyphenol oxidase was achieved. The obtained celeriac products were characterized by their bright white color. Consequently, blanching is recommended as the initial operation in the processing of celeriac into novel pasty products. 相似文献
130.
Linking back to D. Horton and R. Wohl (1956) , the present approach conceptualizes and empirically examines viewers' parasocial interaction experience with a TV performer. Causes and outcomes of parasocial interaction experience are examined. To this end, a new Experience of Parasocial Interaction (EPSI) scale is introduced. In a 2 (Bodily Addressing) × 2 (Verbal Addressing) between‐subjects experiment (N = 198) viewers reported a more intense parasocial experience if they were addressed by a TV performer on a bodily and verbal level. In addition, the more viewers perceived the performer to be attractive and the stronger their perspective‐taking ability, the more intense their parasocial experience. Stronger parasocial experience resulted in higher commitment to social norms and a greater enjoyment of the exposure situation. 相似文献