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691.
Calander N 《Journal of the Optical Society of America. A, Optics, image science, and vision》2007,24(9):2513-2515
A theory for focused optical beams at planar structures is described. It is an extension of a previous theory based on summation of plane waves. The focused beam is obtained by an imaginary shift in the position vector of the plane waves. It is well suited for calculations of electromagnetic fields at planar surface plasmon resonance structures excited by a focused optical beam. 相似文献
692.
Increasingly, drug-discovery processes focus on complete gene families. Tools for analyzing similarities and differences across protein families are important for the understanding of key functional features of proteins. Herein we present a method for classifying protein families on the basis of the properties of their active sites. We have developed Cavbase, a method for describing and comparing protein binding pockets, and show its application to the functional classification of the binding pockets of the protein family of protein kinases. A diverse set of kinase cavities is mutually compared and analyzed in terms of recurring functional recognition patterns in the active sites. We are able to propose a relevant classification based on the binding motifs in the active sites. The obtained classification provides a novel perspective on functional properties across protein space. The classification of the MAP and the c-Abl kinases is analyzed in detail, showing a clear separation of the respective kinase subfamilies. Remarkable cross-relations among protein kinases are detected, in contrast to sequence-based classifications, which are not able to detect these relations. Furthermore, our classification is able to highlight features important in the optimization of protein kinase inhibitors. Using small-molecule inhibition data we could rationalize cross-reactivities between unrelated kinases which become apparent in the structural comparison of their binding sites. This procedure helps in the identification of other possible kinase targets that behave similarly in "binding pocket space" to the kinase under consideration. 相似文献
693.
A three-dimensional numerical model was applied to compute uniform and nonuniform sediment transport and bed deformation in an S-shaped laboratory channel located at the University of Innsbruck, where detailed measurements of the velocity field and bed elevation changes were made. The channel had two bends, a trapezoidal cross section, and a slope of S = 0.005. Gravel with a mean diameter of 4.2?mm was used as movable bed material and for sediment feeding. Wu’s formula for multiple grain sizes was compared with van Rijn’s formula using one grain size. Fairly good agreement was found between the computed and measured bed elevations for both approaches, whereas Wu’s formula could further improve the numerical results. Looking at the physics of the erosion pattern, the computed scour areas were located slightly more downstream than what was observed in the physical model. The current study also includes several parameter tests: grid distribution in vertical, lateral, and longitudinal direction; time step; number of inner iterations/time step; active sediment layer thickness; and the Shields coefficient. The variation of those parameters gave some differences in the results, but the overall pattern of bed elevation changes remained the same. 相似文献
694.
This paper describes the standardisation process and introduction timeline of high definition television. The development of the standard is a process that goes back over 40 years, but HDTV is only today slowly finding its place in the home entertainment market. This paper explores why the European standard for analogue HDTV was not widely adopted, what Europe’s relation to HDTV means today, and proposes some general lessons that can be learned for the benefit of the development of HDTV’s successor, Ultra HDTV aka Super Hi-Vision. 相似文献
695.
Nils Ulltveit-Moe Vladimir A. Oleshchuk Geir M. Køien 《Wireless Personal Communications》2011,57(3):317-338
The paper proposes a location-aware mobile Intrusion Prevention System (mIPS) architecture with enhanced privacy that is integrated
in Managed Security Service (MSS). The solution is envisaged in a future fifth generation telecommunications (5G) context
with increased but varying bandwidth, a virtualised execution environment and infrastructure that allows threads, processes,
virtual machines and storage to be migrated to cloud computing services on demand, to dynamically scale performance and save
power. 5G mobile devices will be attractive targets for malicious software, and this threat will in some cases change with
location. Mobile devices will store more sensitive information and will also be used to a larger extent for sensitive transactions
than they typically do today. In addition, a distributed execution environment in itself gives raise to some new security
challenges. In order to handle these security challenges, we have proposed the location-aware mIPS architecture, which benefits
from a distributed execution environment where processor intensive services can be outsourced to Cloud hosting providers.
The mIPS supports querying location threat profiles in a privacy-preserving way, and ensures that mIPS alerts sent to the
the first-line MSS are anonymised. We finally perform an analysis of potential strengths and weaknesses of the proposed approach. 相似文献
696.
The influence of carbon content and porosity of lithium vanadium phosphate, Li3V2(PO4)3, on its diffusion properties and electrochemical performance was examined by GITT and galvanostatic charge/discharge experiments. The diffusion coefficient of Li3V2(PO4)3, as determined by GITT measurements, appears relatively high, thus making this material interesting also for high power application. Moreover, the results of this study clearly show that the porosity and the carbon content of the electrode materials is an important factor affecting the diffusion as well as the electrochemical performance of Li3V2(PO4)3. It was demonstrated that excessive carbon coating may lead to kinetic hindrances but may also contribute specific capacity in anode materials in voltage regions below 1.0 V versus Li/Li+. 相似文献
697.
Ilse Van Gucht Alice Krebsova Birgitte Rode Diness Steven Laga Dave Adlam Marlies Kempers Nilesh J. Samani Tom R. Webb Ania A. Baranowska Lotte Van Den Heuvel Melanie Perik Ilse Luyckx Nils Peeters Pavel Votypka Milan Macek Josephina Meester Lut Van Laer Aline Verstraeten Bart L. Loeys 《International journal of molecular sciences》2021,22(13)
Thoracic aortic aneurysm and dissection (TAAD) is a major cause of cardiovascular morbidity and mortality. Loss-of-function variants in LOX, encoding the extracellular matrix crosslinking enzyme lysyl oxidase, have been reported to cause familial TAAD. Using a next-generation TAAD gene panel, we identified five additional probands carrying LOX variants, including two missense variants affecting highly conserved amino acids in the LOX catalytic domain and three truncating variants. Connective tissue manifestations are apparent in a substantial fraction of the variant carriers. Some LOX variant carriers presented with TAAD early in life, while others had normal aortic diameters at an advanced age. Finally, we identified the first patient with spontaneous coronary artery dissection carrying a LOX variant. In conclusion, our data demonstrate that loss-of-function LOX variants cause a spectrum of aortic and arterial aneurysmal disease, often combined with connective tissue findings. 相似文献
698.
Textile fibers and yarns of high conductivity, and their integration into wearable textiles for different electronic applications, have become an important research field for many research groups throughout the world. We have produced novel electrically conductive textile yarns by vapor‐phase polymerization (VPP) of a conjugated polymer, poly(3,4‐ethylenedioxythiophene) (PEDOT), on the surface of commercially available textile yarns (viscose). In this article, we have presented a novel setup for electrical resistance measurements, which can be used not only for fibrous structures but also for woven structures of specific dimensions. We have reported a two‐point resistance‐measuring method using an already manufactured setup and also a comparison with the conventionally used method (so‐called crocodile clip method). We found that the electrical properties of PEDOT‐coated viscose fibers strongly depend on the concentration of oxidant (FeCl3) and the doping (oxidation) process of PEDOT. To evaluate the results, we used mass specific resistance values of PEDOT‐coated viscose yarns instead of normal surface resistance values. The voltage–current (V–I) characteristics support the ohmic behavior of coated fibers to some extent. Monitoring of the charging effect of the flow of current through conductive fibers for prolonged periods of time showed that conductivity remains constant. The change in electrical resistance values with increase in the length of coated fibers was also reported. The resistance‐measuring setup employed could also be used for continuous measurement of resistance in the production of conductive fibers, as well as for four‐point resistance measurement. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 相似文献
699.
The toxic effects of cadmium, cobalt, uranium and zinc to the bacterium Zoogloea ramigera have been studied. This organism, which is abundant in sewage-treatment plants, responded to media supplemented with heavy metals by showing a prolonged lag phase and by decreasing its growth rate. The length of the lag phase was proportional to the metal concentration when Z. ramigera was exposed to cadmium, cobalt and zinc. When exposed to uranium (uranyl ions) the organism altered its growth behavior by showing an extended lag phase almost independent of the metal concentration. The order of toxicity of the metals to Z. ramigera was Cd2+ = Zn2+ > Co2+ > UO22+. 相似文献
700.
Oxygen uptake by soft bottom sediments was measured in situ with an oxygen electrode in a bell jar. Values in the range 0·3-3·0 g O2 m−2 d−1 were obtained at 19 localities in fresh and brackish water. Comparative measurements were made in the laboratory on sediment cores. These gave consistently lower values than the in situ measurements. Laboratory experiments showed that the oxygen uptake depended on the oxygen concentration and that the temperature coefficient decreased with increasing temperature. There was no simple correlation between oxygen uptake and content organic matter in sediments. 相似文献