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991.
This paper uses two large databases, one of given names and one of family names, to categorise the names of researchers from Italy, Sweden, the UK and the USA whose papers in astronomy and oncology were published in 2006–2007 and in 2011–2012 by sex (gender) and ethnicity or national origin. For all the countries, there were relatively many more females publishing papers in oncology than in astronomy, but their share of contributions was lower than the percentage of researchers. Sweden and the UK had much higher percentages of both other European and Rest of the World researchers than Italy did. US researchers with non-European names were categorised in six main country groups. The ones with the greatest presence were Chinese (mainly Mandarin) and South Asians (mainly Indians). The method could be adapted to investigate the progress of women in research in many other countries, and the role played by non-national researchers in their scientific output. 相似文献
992.
Anton Kurz Jürgen J. Schmied Kristin S. Grußmayer Phil Holzmeister Philip Tinnefeld Dirk‐Peter Herten 《Small (Weinheim an der Bergstrasse, Germany)》2013,9(23):4061-4068
Obtaining quantitative information about molecular assemblies with high spatial and temporal resolution is a challenging task in fluorescence microscopy. Single‐molecule techniques build on the ability to count molecules one by one. Here, a method is presented that extends recent approaches to analyze the statistics of coincidently emitted photons to enable reliable counting of molecules in the range of 1–20. This method does not require photochemistry such as blinking or bleaching. DNA origami structures are labeled with up to 36 dye molecules as a new evaluation tool to characterize this counting by a photon statistics approach. Labeled DNA origami has a well‐defined labeling stoichiometry and ensures equal brightness for all dyes incorporated. Bias and precision of the estimating algorithm are determined, along with the minimal acquisition time required for robust estimation. Complexes containing up to 18 molecules can be investigated non‐invasively within 150 ms. The method might become a quantifying add‐on for confocal microscopes and could be especially powerful in combination with STED/RESOLFT‐type microscopy. 相似文献
993.
In this paper we consider Runge–Kutta discontinuous Galerkin (RKDG) schemes for Vlasov–Poisson systems that model collisionless plasmas. One-dimensional systems are emphasized. The RKDG method, originally devised to solve conservation laws, is seen to have excellent conservation properties, be readily designed for arbitrary order of accuracy, and capable of being used with a positivity-preserving limiter that guarantees positivity of the distribution functions. The RKDG solver for the Vlasov equation is the main focus, while the electric field is obtained through the classical representation by Green’s function for the Poisson equation. A rigorous study of recurrence of the DG methods is presented by Fourier analysis, and the impact of different polynomial spaces and the positivity-preserving limiters on the quality of the solutions is ascertained. Several benchmark test problems, such as Landau damping, the two-stream instability, and the Kinetic Electro static Electron Nonlinear wave, are given. 相似文献
994.
Philip J. Nickel 《Minds and Machines》2013,23(4):489-502
Some of the systems used in natural language generation (NLG), a branch of applied computational linguistics, have the capacity to create or assemble somewhat original messages adapted to new contexts. In this paper, taking Bernard Williams’ account of assertion by machines as a starting point, I argue that NLG systems meet the criteria for being speech actants to a substantial degree. They are capable of authoring original messages, and can even simulate illocutionary force and speaker meaning. Background intelligence embedded in their datasets enhances these speech capacities. Although there is an open question about who is ultimately responsible for their speech, if anybody, we can settle this question by using the notion of proxy speech, in which responsibility for artificial speech acts is assigned legally or conventionally to an entity separate from the speech actant. 相似文献
995.
AbstractRecent data breaches at major retailers have created an extra awareness of information security risks within the IT internal auditors. This article focuses on top security topics which every internal auditor must consider before they finalize their audit plans 相似文献
996.
Shabana Vohra Bruck Taddese Alex C. Conner David R. Poyner Debbie L. Hay James Barwell Philip J. Reeves Graham J. G. Upton Christopher A. Reynolds 《Journal of the Royal Society Interface》2013,10(79)
Modelling class B G-protein-coupled receptors (GPCRs) using class A GPCR structural templates is difficult due to lack of homology. The plant GPCR, GCR1, has homology to both class A and class B GPCRs. We have used this to generate a class A–class B alignment, and by incorporating maximum lagged correlation of entropy and hydrophobicity into a consensus score, we have been able to align receptor transmembrane regions. We have applied this analysis to generate active and inactive homology models of the class B calcitonin gene-related peptide (CGRP) receptor, and have supported it with site-directed mutagenesis data using 122 CGRP receptor residues and 144 published mutagenesis results on other class B GPCRs. The variation of sequence variability with structure, the analysis of polarity violations, the alignment of group-conserved residues and the mutagenesis results at 27 key positions were particularly informative in distinguishing between the proposed and plausible alternative alignments. Furthermore, we have been able to associate the key molecular features of the class B GPCR signalling machinery with their class A counterparts for the first time. These include the [K/R]KLH motif in intracellular loop 1, [I/L]xxxL and KxxK at the intracellular end of TM5 and TM6, the NPXXY/VAVLY motif on TM7 and small group-conserved residues in TM1, TM2, TM3 and TM7. The equivalent of the class A DRY motif is proposed to involve Arg2.39, His2.43 and Glu3.46, which makes a polar lock with T6.37. These alignments and models provide useful tools for understanding class B GPCR function. 相似文献
997.
Umkehrwalze A was the original reflector used in the version of the Enigma machine employed by the German armed services. Its wiring was originally deduced by the Polish cryptanalyst Marian Rejewski in December 1932 or January 1933, but details of the wiring have not previously been published. Sufficient information to recover the wiring analytically is provided in a wartime document by Alan Turing, and other sources have been found to confirm the solution. This paper presents the wiring, along with alternative methods of recovering it from Turing's data. 相似文献
998.
David Harries Mark McHenry Philip Jennings Chacko Thomas 《The International journal of environmental studies》2013,70(6):803-814
The three renewable energy technologies discussed in this paper are based on water, but differ markedly in terms of the size of the available potential resource, the maturity of the associated conversion technologies, the extent to which they have been exploited to date, and the current research effort being devoted to their future development. Hydro-electricity and tidal power are both very mature technologies. The exploitation of Australia's relatively limited potential for hydro-electric development began over a century ago and the opportunities for further hydro-electric development are now very restricted. The country's significant tidal power resources, on the other hand, have not been exploited for electricity generation to date, but continual assessment of the feasibility of tidal power projects has been undertaken over the past half century. Although Australia has large ocean wave energy resources, ocean wave energy conversion technology is not yet fully commercial and no commercial wave generation plants are operating in Australia. A small number of wave energy conversion devices, however, are at the pilot testing stage. 相似文献
999.
Do-it-yourself (DIY) is a staple element of the spare time activities of many households, but little is known about the extent to which basic repair work is carried out through DIY and about the quality of this work. Through secondary analyses of UK government data (English House Condition Survey and Family Expenditure Survey), this paper examines the scale of DIY work by owner-occupiers, how work is organized, the interrelationship of DIY work, the use of unpaid help, and the use of contractors. It considers the types of work carried out, the characteristics of those who tackle DIY or use unpaid help, the dwelling types most likely to experience DIY work, and the motivations of and constraints on those home-owners who do it. The paper concludes with a discussion on the policy implications of these findings for government and the building industry. Although most DIY work is cosmetic and does not deal with basic repair and maintenance, the sheer scale of DIY ensures that it makes a contribution to improving housing conditions. The provision of more advice, information and education by government, local authorities and the private sector could ensure that more DIY work is of better quality and that home owners give priority to essential repairs whether or not they tackle these themselves. 相似文献
1000.