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101.
The relationships between the alcohol yield obtainable from different malts and some readily measurable parameters have been investigated. Gel filtration studies clearly show that melanoidin-type condensation products, which were previously suggested as a cause of low fermentability, are not produced in significant amounts in highly modified malts. These studies also show important details relating to the hydrolysis of dextrins in distillers' worts and washes. Measurement of the limit dextrinase activity of a range of distillers' malts has indicated that this enzyme is not a limiting factor in determining wort fermentability and its concentration does not correlate with the overall spirit yield. There may be a relationship between the whole amylase complex, as expressed by the diastatic power and wort fermentability. From a study of the reducing sugar contents of worts, it was confirmed that the major factor controlling fermentable extract in malt is the relative amounts of starch-derived sugars in the wort. It now appears possible to determine the fermentability of distilling wort by the standard extract and the reducing power of the wort obtained by the standard I.O.B. extraction. 相似文献
102.
Billion-transistor processors will be much as they are today, just bigger, faster and wider (issuing more instructions at once). The authors describe the key problems (instruction supply, data memory supply and an implementable execution core) that prevent current superscalar computers from scaling up to 16- or 32-instructions per issue. They propose using out-of-order fetching, multi-hybrid branch predictors and trace caches to improve the instruction supply. They predict that replicated first-level caches, huge on-chip caches and data value speculation will enhance the data supply. To provide a high-speed, implementable execution core that is capable of sustaining the necessary instruction throughput, they advocate a large, out-of-order-issue instruction window (2,000 instructions), clustered (separated) banks of functional units and hierarchical scheduling of ready instructions. They contend that the current uniprocessor model can provide sufficient performance and use a billion transistors effectively without changing the programming model or discarding software compatibility 相似文献
103.
Typical audible pedestrian signals indicate when the pedestrian walk interval is in effect but provide little, or even misleading information for directional alignment. In three experiments, blind and blindfolded sighted adults crossed a simulated crossing with recorded traffic noise to approximate street sounds. This was done to investigate how characteristics of signal presentation affected usefulness of the auditory signal for guiding crossing behaviour. Crossing was more accurate when signals came only from the far end of the crossing rather than the typical practice of presenting signals simultaneously from both ends. Alternating the signal between ends of the crossing was not helpful. Also, the customary practice of signalling two parallel crossings at the same time drew participants somewhat toward the opposite crossing. Providing a locator tone at the end of the crossing during the pedestrian clearance interval improved crossing accuracy. These findings provide a basis for designing audible pedestrian signals to enhance directional guidance. The principal findings were the same for blind and sighted participants and applied across a range of specific signals (e.g. chirps, clicks, voices). 相似文献
104.
This paper demonstrates a technique to premold and transfer lead-free solder balls for microelectrocmechanical systems (MEMS)/electronics packaging applications. A reusable bulk micromachined silicon wafer is used to mold a solder paste and remove excess flux prior to transfer to a host wafer that may contain released MEMS. This technique has been used to fabricate low temperature thin film MEMS vacuum packages. Long term (>5 months) reliability of these packages at room temperature and pressure is demonstrated through integrated Pirani gauges. These packages have survived over 600 hours in an autoclave (130/spl deg/C, 85% RH, 2 atm) and more than 1300 temperature cycles (55/spl deg/C to 125/spl deg/C). 相似文献
105.
An examination of the development of α-glucosidase and maltase activities (as measured by the hydrolysis of p-nitrophenyl α-D-glucoside and maltose respectively) indicated that two genotypes of Glacier barley had the same general pattern of enzyme development. However, the development of α-glucosidase activity followed a different course from that of maltase activity suggesting that separate enzyme proteins are involved in hydrolysing these substrates. Further evidence that separate enzyme proteins were responsible for hydrolysis of maltose and p-nitrophenyl α-glucoside was obtained by column chromatography of extracts of germinated barley which indicated the presence of two maltases and two α-glucosidases. The maltases and the α-glucosidases differed in molecular weight, pH of optimum activity and in thermostability. When isomaltose was used as a substrate the optimum pH and behaviour on gel chromatography were coincident with that of maltase activity but different from the α-glucosidases. 相似文献
106.
The Hutchinson metric is a natural measure of the discrepancy between two images for use in fractal image processing. A neural network is described which can quickly calculate this metric. By combining this with the architecture previously described by the author for implementing the Markov operator of an iterated function system (IFS) on a neural network, a fast method is obtained for determining the distance between a target image and the invariant measure of a trial IFS. This has obvious applications to Barnsley's fractal image compression scheme 相似文献
107.
Hassan A.A. Stark W.E. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》1990,36(3):677-683
The correcting properties of concatenated codes with parallel decoding over an additive channel are investigated. The i th inner decoder's output is a codeword if the Euclidean distance between the received vector and some codeword is less than Δi and an erasure otherwise. The outer decoders correct errors and erasures. The error-correcting capability, which is taken to be the minimum length of any noise vector that can cause an error, is obtained for a bank of z inner and outer decoders as a function of the thresholds used. The set of thresholds that maximize the error-correcting capability is also found. It is shown that for a small number of branches, the error-correcting capability is nearly as large as any decoder 相似文献
108.
109.
Christian Saminger Michael Stark Michael Gebhart Stefan Grünberger Josef Langer 《e & i Elektrotechnik und Informationstechnik》2013,130(7):218-223
This article gives a detailed insight into the very high bit rates (VHBR) technology for the data transfer with NFC and RFID. In the first part enhancements and changes to the ISO/IEC 14443 and related standards are discussed. In the second part an analysis of different bit rates with focus on communication parameters and bit error rates are provided. 相似文献
110.
It is commonly assumed that attitudes and behaviours need to be modified to secure a sustainable energy future. This paper examines insights from the social sciences in this extensive field. Alongside instruments such as regulation and economic measures, government campaigns have sought to ‘educate’ the public. However, such ‘information deficit’ models have been criticised on theoretical and pragmatic grounds. In the area of energy consumption, there is a need to take account of the physical, social, cultural and institutional contexts that shape and constrain people's choices, and for a richer understanding of opposition to energy facility siting, which has often been (inadequately) characterised as ‘NIMBYism’. Recent work also points to the need for more deliberation and better communication between decision-makers, technical experts, other stakeholders and the public. Predicting future developments in the field is challenging but attention is likely to focus on aspects of policy learning, a more critical examination of the ‘deliberative turn’, and the need for a systemic approach to complex socio-economic and socio-technical systems. The consistency of government objectives across all policy spheres is likely to provide an important avenue for future research. 相似文献