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排序方式: 共有481条查询结果,搜索用时 15 毫秒
41.
Hans Erhorn Tomasz Mroz Ove Mørck Fritz Schmidt Lorenz Schoff Kirsten Engelund Thomsen 《Energy and Buildings》2008,40(4):419-428
Educational buildings such as kindergartens, schools and universities display many similar design, operation and maintenance features in most countries. The two most noteworthy similarities amongst these building types are the high energy consumption and the necessity for retrofitting many buildings within this sector. However, studies have shown that during retrofit, energy saving measures are only rarely applied, because the decision-makers lack knowledge of investments and the efficiency of potential energy saving measures. The main goal of the International Energy Agency ECBCS Annex 36 is to provide the educational building decision-makers with sufficient data, information and tools to improve their learning and teaching environments by improving the energy efficiency of their buildings. 相似文献
42.
A 27-year-old woman was admitted with an abdominal mass in the right hypochondrium. Ultrasound, intravenous urography and scintigraphy revealed a giant non-functioning hydronephrosis. Because she refused surgery, a percutaneous aspiration with instillation of doxycycline was performed. One year thereafter, the patient was still without recurrence of any symptoms or hydronephrosis. 相似文献
43.
Van Gils M. Rosenfalck A. White S. Prior P. Gade J. Senhadji L. Thomsen C. Ghosh I.R. Longford R.M. Jensen K. 《IEEE engineering in medicine and biology magazine》1997,16(6):56-63
Methods for analyzing and displaying EEG signals are discussed. The increasing availability and affordability of powerful computer equipment makes possible the use of ever more sophisticated signal processing techniques, which extract relevant (but not readily discernible) information from long-term EEG recordings and can easily identify important features in the EEG. Whether these techniques are actually taken up in clinical practice is heavily dependent on how well they match clinical requirements. This article concentrates on requirements set in the context of long-term recordings in the ICU that demand the ability to process short-term discrete events as well as long-term trend information. A huge range of potentially useful signal processing techniques exists. This article illustrates the value of some of these techniques for ICU signals using the EEG recordings collected during the IMPROVE project 相似文献
44.
We compare the performance of a digital receiver operating with both a fixed and adaptive decision threshold in response to gain transients arising from network operation of an optically gain-clamped erbium-doped fiber amplifier. An optical burst switching link, based on a recirculating transmission loop, is used to study the effect of transients accumulated across a number wavelength-routing nodes linked by amplified fiber spans where bursts are added and dropped at each node. The use of an adaptive threshold reduces the amount of optical feedback required by a factor of 6 and, in some cases, allows for unclamped operation. 相似文献
45.
A.E. Lewis J. Nathoo K. Thomsen H.J. Kramer G.J. Witkamp S.T. Reddy D.G. Randall 《Chemical Engineering Research and Design》2010
Complex, hypersaline brines originating from the mining and extractive metallurgical industries have the potential to be treated using Eutectic Freeze Crystallization (EFC). Although EFC has been shown to be effective in separating a single salt and water, it has yet to be applied to the complex hypersaline brines that are typical of reverse osmosis retentates in South Africa. This paper focuses on the application of EFC for the purification of a typical brine containing high levels of sodium, chlorine, sulphate and ammonia that cannot be achieved with other separation techniques. The presence of ammonia prevents the application of membrane technology to treat the brine, leaving only cooling or evaporation as other possible options. Evaporation produces a mixed salt that requires further treatment. Modelling tools were applied to describe the phase behaviour of the complex saline systems under different process conditions and were experimentally validated. The results showed that Eutectic Freeze Crystallization could be used to selectively recover the sodium as a sodium sulphate salt. The simulation tools were especially useful in the design and optimisation of the process. 相似文献
46.
Suraj Loomba Muhammad Waqas Khan Muhammad Haris Seyed Mahdi Mousavi Ali Zavabeti Kai Xu Anton Tadich Lars Thomsen Christopher F. McConville Yongxiang Li Sumeet Walia Nasir Mahmood 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(18):2207310
Hydrogen is emerging as an alternative clean fuel; however, its dependency on freshwater will be a threat to a sustainable environment. Seawater, an unlimited source, can be an alternative, but its salt-rich nature causes corrosion and introduces several competing reactions, hindering its use. To overcome these, a unique catalyst composed of porous sheets of nitrogen-doped NiMo3P (N-NiMo3P) having a sheet size of several microns is designed. The presence of large homogenous pores in the basal plane of these sheets makes them catalytically more active and ensures faster mass transfer. The introduction of N and Ni into MoP significantly tunes the electronic density of Mo, surface chemistry, and metal-non-metal bond lengths, optimizing surface energies, creating new active sites, and increasing electrical conductivity. The presence of metal-nitrogen bonds and surface polyanions increases the stability and improves anti-corrosive properties against chlorine chemistry. Ultimately, the N-NiMo3P sheets show remarkable performance as it only requires overpotentials of 23 and 35 mV for hydrogen evolution reaction, and it catalyzes full water splitting at 1.52 and 1.55 V to achieve 10 mA cm−2 in 1 m KOH and seawater, respectively. Hence, structural and compositional control can make catalysts effective in realizing low-cost hydrogen directly from seawater. 相似文献
47.
Struijk J.J. Thomsen M. Larsen J.O. Sinkjaer T. 《IEEE engineering in medicine and biology magazine》1999,18(3):91-98
Cuff electrodes for recording of the electro-neurogram from peripheral nerves were introduced by Hoffer [1974] and Stein, et al. [1975]. The cuffs were used to obtain higher signal amplitudes than previously possible, at least in chronic recordings, and to decrease the pick-up of noise, especially from muscles. Cuff electrodes are relatively stable in long-term recordings, but the stability has never been quantified in terms of input-output relationships; i.e., in terms of responses to repeatable stimuli over time. Moreover. The relationship between nerve damage and electrophysiological parameters has never been assessed. In this article, after reviewing the development of cuff electrodes and their applications, we present a long-term study of tactile peripheral nerve signals, electrically activated nerve signals, and impedance measurements. We show how the recordings vary over a 16-month period after implantation of nerve cuff electrodes in rabbits, and how nerve damage is reflected in the recorded signals 相似文献
48.
John A. Wert Christian Thomsen Rune Debel Jensen Mogens Arentoft 《Journal of Materials Processing Technology》2009,209(3):1570-1579
The present article considers forward extrusion, closed-die forging and backward extrusion processes for fabrication of individual microcomponents from two bulk metallic glass (BMG) compositions: Mg60Cu30Y10 and Zr44Cu40Ag8Al8. Two types of tooling were used in the present work: relatively massive die sets characteristic of cold forming operations for crystalline metals and lightweight die sets adapted to the special characteristics of BMGs. In addition to demonstrating that microcomponents of several geometries can be readily fabricated from BMGs, rheological properties are combined with crystallization kinetics to formulate a generally applicable method that can guide selection of optimal forming parameters. Finally, the use of particulate-based lubricants for BMG forming is shown to result in individual lubricant particles becoming mechanically locked into the BMG surface. 相似文献
49.
Geert Lissens Helene Klinke Willy Verstraete Birgitte Ahring Anne Belinda Thomsen 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2004,79(8):889-895
Woody yard waste with high lignin content (22% of dry matter (DM)) was subjected to wet oxidation pre‐treatment for subsequent enzymatic conversion and fermentation. The effects of temperature (185–200 °C), oxygen pressure (3–12 bar) and addition of sodium carbonate (0–3.3 g per 100 g DM biomass) on enzymatic cellulose and hemicellulose (xylan) convertibility were studied. The enzymatic cellulose conversion was highest after wet oxidation for 15 min at 185 °C with addition of 12 bars of oxygen and 3.3 g Na2CO3 per 100 g waste. At 25 FPU (filter paper unit) cellulase g?1 DM added, 58–67% and 80–83% of the cellulose and hemicellulose contained in the waste were converted into monomeric sugars. The cellulose conversion efficiency during a simultaneous saccharification and fermentation (SSF) assay at 10% DM was 79% for the highest enzyme loading (25 FPU g?1 DM) while 69% conversion efficiency was still reached at 15 FPU g?1 DM. Total carbohydrate recoveries were high (91–100% for cellulose and 72–100% for hemicellulose) and up to 49% of the original lignin and 79% of the hemicellulose could be solubilized during wet oxidation treatment and converted into carboxylic acids mainly (total carboxylic acids = 3.1–7.4% on DM basis). Copyright © 2004 Society of Chemical Industry 相似文献
50.
Merrill Lex L.; Thomsen Cynthia J.; Sinclair Barbara B.; Gold Steven R.; Milner Joel S. 《Canadian Metallurgical Quarterly》2001,69(6):992
Female Navy recruits (N=5,226) completed surveys assessing history of childhood sexual abuse (CSA), childhood strategies for coping with CSA, childhood parental support, and current psychological adjustment. Both CSA and parental support independently predicted later adjustment. In analyses examining whether CSA victims' functioning was associated with CSA severity (indexed by 5 variables), parental support (indexed by 3 variables), and coping (constructive, self-destructive, and avoidant), the negative coping variables were the strongest predictors. A structural equation model revealed that the effect of abuse severity on later functioning was partially mediated by coping strategies. However, contrary to predictions, the model revealed that childhood parental support had little direct or indirect impact on adult adjustment. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献