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991.
Grzegorz Mikusiński Malgorzata Blicharska Hans Antonson Marianne Henningsson Görgen Göransson Per Angelstam 《Landscape Research》2013,38(3):384-393
Implementation of the European Landscape Convention requires new tools that link ecological, social and cultural dimensions in practical planning. Here, we propose connectivity as a conceptual tool to include different dimensions into landscape and spatial planning. We present a short review of the connectivity concept in relation to ecological, social and cultural dimensions and illustrate it by examples from a real landscape planning case. 相似文献
992.
Hans Voordijk 《Construction Management & Economics》2013,31(8):713-720
Research in the field of construction management and economics (CME) can be characterized as a multidisciplinary design science. Results from the sciences and humanities are necessary inputs for this field of research that deals with design, production and operation of the built environment. The output of CME research as multidisciplinary design science consists of three types of solution concepts: empirical generalizations based on statistical data analysis (technological laws), concepts that specify what to do, if a certain result is to be attained under given circumstances (functional rules), and insights in the interrelationship between design, production and operation of the built environment and social practice (socio‐technological understanding). Scientific justification of these solution concepts is obtained through testing them in the specific context of the built environment. 相似文献
993.
Hans Blumenfeld 《Journal of the American Planning Association. American Planning Association》2013,79(2):61-76
To provide a background for the other articles in this issue the author summarizes some of the studies that have identified key variables affecting urban growth patterns. The most consistent factor related to land use distribution is sheer distance, and especially distance from the CBD. In Philadelphia and Toronto urban density patterns have followed almost identical patterns over the past half-century, giving support to the “crest of the wave” theory of urban growth. Both residential and employment densities exhibit a consistently regular pattern that follows concentric rings out from the CBD. The observations reveal strong regularities of metropolitan land use patterns and hence raise the intriguing question posed in the title of this article. 相似文献
994.
The objective of this study is to show that the core competence approach has validity when applied to construction. The focus is on the analysis of the fit between market strategies of firms in the building industry and their core capabilities. Certain strategies require specific core capabilities and key external and internal conditions supporting these capabilities. The resource-based approach focuses on the conditions in a firm, the internal capabilities, and supports a core capability that is demanded. The network literature will be related to external conditions that support a core capability of a firm active in a certain market. In a multiple case study, firms are analysed that are involved in different stages of the building process. The case studies demonstrate firms with consistent patterns of market strategies, core capabilities, and supporting internal and external conditions. The specific core capability of the firm under investigation determines the types of external and internal conditions that are critical. 相似文献
995.
Many architecture, engineering and construction (AEC) professionals would like to use real option (RO) and decision analysis (DA) to evaluate alternatives in investment in the face of uncertainty. However, they have difficulty deciding which one to use and many are not aware of the subtle differences in assumptions and techniques between the two methodologies. We explain how DA and RO can be applied in complete and incomplete markets and what implicit assumptions we need to be aware of in each scenario. Through a toll road example, it is shown that, in a complete market, DA and RO give the same valuation regardless of the choice of the utility function. A formula is provided for pricing any investment in a complete market. The paper also discusses why the values calculated using DA and RO differ in an incomplete market and when DA is more appropriate than RO and vice versa. 相似文献
996.
Design and construction of a new bridge for the Berlin underground to replace an old structure under high time pressure. This paper is about the design and construction of a new bridge for the underground in Berlin. A new structure was necessary due to insufficient stability and serviceability of the old one. The project had to be carried out under high time pressure to avoid a decommissioning of the underground traffic. As a result of this the planning and execution phases were significantly reduced. Besides, the client provided the construction firm with the structural steel to be used for the superstructure, a potential for conflict that would need to be tackled. The project will be described from the design point of view. 相似文献
997.
998.
Alessandro Leonardi Falk K. Wittel Miller Mendoza Roman Vetter Hans J. Herrmann 《Computer-Aided Civil and Infrastructure Engineering》2016,31(5):323-333
Flexible barriers are increasingly used for the protection from debris flow in mountainous terrain due to their low cost and environmental impact. However, the development of a numerical tool for the rational design of such structures is still a challenge. In this work, a hybrid computational framework is presented, using a total Lagrangian formulation of the finite element method to represent a flexible barrier. The actions exerted on the structure by a debris flow are obtained from simultaneous simulations of the flow of a fluid‐grain mixture, using two conveniently coupled solvers: the discrete element method governs the motion of the grains, while the free‐surface non‐Newtonian fluid phase is solved using the lattice Boltzmann method. Simulations on realistic geometries show the dependence of the momentum transfer on the barrier on the composition of the debris flow, challenging typical assumptions made during the design process today. In particular, we demonstrate that both grains and fluid contribute in a nonnegligible way to the momentum transfer. Moreover, we show how the flexibility of the barrier reduces its vulnerability to structural collapse, and how the stress is distributed on its fabric, highlighting potential weak points. 相似文献
999.
1000.
Gtz Hüsken Stephan Pirskawetz Dietmar Meinel Veronika Babski Hans‐Carsten Kühne 《Bautechnik》2016,93(10):711-716
Methods for analyzing the fracture behavior of high‐strength steel fiber‐reinforced concretes High‐strength and ultra‐high strength fiber‐reinforced concretes are most suitable for applications with extreme mechanical loads. These extreme conditions require a ductile behavior under tensile loading, which is obtained solely by the addition of steel fibers and their working mechanism. Profound know ledge on the working mechanism of the steel fibers is necessary for optimizing this material. Usually, this knowledge is obtained by means of classical measuring techniques of destructive tests. Adopting measuring techniques from non‐destructive material testing helps to analyze and to identify the different stages of the fracture mechanism of high‐strength and ultra‐high strength fiber‐reinforced concretes in detail. The application of different non‐destructive measuring techniques is shown exemplary on tensile tests conducted on an ultra‐high strength fiber‐reinforced concrete and its applicability for analyzing the fracture behavior is discussed. The main focus is on the characterization of the relevant failure modes under tensile loading by the different measuring techniques and the comparison with classical measuring techniques (e. g. extensometer). The tensile tests have been analyzed by optical deformation measurements using digital image correlation (DIC), acoustic emission analysis (AE), and 3D computed tomography (CT). 相似文献