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41.
Jesper Andersen Ebbe Elsborg Fritz Henglein Jakob Grue Simonsen Christian Stefansen 《International Journal on Software Tools for Technology Transfer (STTT)》2006,8(6):485-516
We present a declarative language for compositional specification of contracts governing the exchange of resources. It extends
Eber and Peyton Jones’s declarative language for specifying financial contracts (Jones et al. in The Fun of Programming. 2003)
to the exchange of money, goods and services amongst multiple parties and complements McCarthy’s Resources, Events and Agents
(REA) accounting model (McCarthy in Account Rev. LVII(3), 554–578, 1982) with a view- independent formal contract model that supports definition of user-defined contracts, automatic
monitoring under execution and user-definable analysis of their state before, during and after execution. We provide several
realistic examples of commercial contracts and their analyses. A variety of (real) contracts can be expressed in such a fashion
as to support their integration, management and analysis in an operational environment that registers events. The language
design is driven by both domain considerations and semantic language design methods: a contract denotes a set of traces of
events, each of which is an alternative way of concluding the contract successfully, which gives rise to a CSP-style (Brooker
et al. in J.ACM 31(3), 560–599, 1984; Hoare in Communicating Sequential Processes, 1985) denotational semantics. The denotational semantics
drives the development of a sound and complete small-step operational semantics, where a partially executed contract is represented
as a (full) contract that represents the remaining contractual commitments. This operational semantics is then systematically
refined in two stages to an instrumented operational semantics that reflects the bookkeeping practice of identifying the specific
contractual commitment a particular event matches at the time the event occurs, as opposed to delaying this matching until
the contract is concluded. 相似文献
42.
43.
Korhonen I Karhu J Mainardi L Jakob SM 《Computer methods and programs in biomedicine》2000,63(3):211-218
Measuring effects of sensory stimuli on haemodynamics could provide information about the interplay between central and autonomous nervous system (ANS). However, ANS response to sensory stimulus has received little attention. In this paper we present a signal processing scheme to extract the responses of heart rate and systemic arterial pressure on auditory stimulus in intensive care patients (N=5). In short, the effect of mechanical ventilation is rejected by optimal linear modelling. Other disturbances are attenuated by filtering and efficient rejection of outlying sweeps of data. The results show identifiable responses on three out of five cases. The response characteristics may be explained by synchronisation of spontaneous variability in systemic arterial pressure to auditory stimulus. 相似文献
44.
45.
G Vassalli P Kaufmann B Villari M Jakob H Boj W Kiowski OM Hess 《Canadian Metallurgical Quarterly》1995,91(12):2916-2923
BACKGROUND: Enlargement of the epicardial coronary arteries occurs in left ventricular (LV) hypertrophy as an adaptation to the increased coronary blood flow. METHODS AND RESULTS: Vasodilator capacity of the epicardial coronary arteries was determined in 44 patients. The dose-response relation of intracoronary nitroglycerin was assessed in 14 patients (7 control subjects and 7 patients with aortic stenosis [study A]) using quantitative coronary angiography. In a second study (B), vasodilator capacity of the epicardial coronary arteries was determined in 15 control subjects and 15 patients with valvular heart disease. In study A, a curvilinear dose-response relation with maximal vasodilation after 90 micrograms intracoronary nitroglycerin was found in both control subjects and patients with aortic stenosis. Vasodilator capacity was reduced in those with aortic stenosis, although sensitivity to nitroglycerin was similar in both groups. In study B, coronary circumferential length at baseline was larger in those with LV hypertrophy (12.2 +/- 2.2 mm) than in control subjects (8.6 +/- 1.5 mm; P < .001); after 100 micrograms intracoronary nitroglycerin, it increased to 12.9 +/- 2.2 mm (6 +/- 5%) in those with LV hypertrophy and to 10.3 +/- 1.5 mm (21 +/- 8%; P < .001) in control subjects. An inverse relation between baseline circumferential length and its percent increase after nitroglycerin was found (r = -.71, P < .001). CONCLUSIONS: Vasodilator capacity of the epicardial coronary arteries is reduced in patients with LV hypertrophy, although sensitivity to nitroglycerin is normal. This may be due to a flow-mediated decrease in coronary vasomotor tone and/or the occurrence of vascular remodeling with an enlargement of the coronary arteries. 相似文献
46.
Neuberger T Greiser A Nahrendorf M Jakob PM Faber C Webb AG 《Magma (New York, N.Y.)》2004,17(3-6):196-200
The mouse has become an important animal model for human cardiac disease, and the development of techniques for non-invasive imaging of the mouse heart in vivo is, therefore, of great potential interest. Previous magnetic resonance imaging studies have concentrated on pathologically induced changes in cardiac structure and dynamics by acquiring proton images. Further information can be gained by studying cardiac function and physiology using other nuclei, for example, sodium. Sodium imaging of such a small structure presents considerable technical challenges. In this work we show the first sodium images of the mouse heart, with an isotropic spatial resolution of 1 × 1 × 1 mm, acquired in a time of 1.5 h. The ventricles, septum and myocardium are readily distinguishable in these images, which were acquired through the combination of 3D density-weighted chemical shift imaging, optimized instrumentation, and a high magnetic field strength (17.6 T). Measurements of the myocardial:blood sodium concentration in the left and right ventricles agree well with theoretical values. 相似文献
47.
Faecal contamination of greywater and associated microbial risks 总被引:1,自引:0,他引:1
The faecal contamination of greywater in a local treatment system at Viby?sen, north of Stockholm, Sweden was quantified using faecal indicator bacteria and chemical biomarkers. Bacterial indicator densities overestimated the faecal load by 100-1000-fold when compared to chemical biomarkers. Based on measured levels of coprostanol, the faecal load was estimated to be 0.04 g person(-1) day(-1). Prevalence of pathogens in the population and the faecal load were used to form the basis of a screening-level quantitative microbial risk assessment (QMRA) that was undertaken for rotavirus, Salmonella typhimurium, Campylobacter jejuni, Giardia lamblia and Cryptosporidium parvum. The different exposure scenarios simulated--direct contact, irrigation of sport fields and groundwater recharge--gave unacceptably high rotavirus risks (0.04 < Pinf < 0.60) despite a low faecal load. The poor reduction of somatic coliphages, which were used as a virus model, in the treatment was one main reason and additional treatment of the greywater is suggested. Somatic coliphages can under extreme circumstances replicate in the wastewater treatment system and thereby underestimate the virus reduction. An alternative QMRA method based on faecal enterococci densities estimated similar risks as for rotavirus. Growth conditions for Salmonella in greywater sediments were also investigated and risk modelling based on replication in the system increased the probability of infection from Salmonella 1000-fold, but it was still lower than the risk of a rotavirus infection. 相似文献
48.
We compare Monte Carlo (MC) and discrete-ordinate radiative-transfer (DISORT) simulations of irradiances in a one-dimensional coupled atmosphere-ocean (CAO) system consisting of horizontal plane-parallel layers. The two models have precisely the same physical basis, including coupling between the atmosphere and the ocean, and we use precisely the same atmospheric and oceanic input parameters for both codes. For a plane atmosphere-ocean interface we find agreement between irradiances obtained with the two codes to within 1%, both in the atmosphere and the ocean. Our tests cover case 1 water, scattering by density fluctuations both in the atmosphere and in the ocean, and scattering by particulate matter represented by a one-parameter Henyey-Greenstein (HG) scattering phase function. The CAO-MC code has an advantage over the CAO-DISORT code in that it can handle surface waves on the atmosphere-ocean interface, but the CAO-DISORT code is computationally much faster. Therefore we use CAO-MC simulations to study the influence of ocean surface waves and propose a way to correct the results of the CAO-DISORT code so as to obtain fast and accurate underwater irradiances in the presence of surface waves. 相似文献
49.
Jakob PM Wang T Schultz G Hebestreit H Hebestreit A Elfeber M Hahn D Haase A 《Magma (New York, N.Y.)》2002,15(1-3):10-17
The unique characteristics of the human lung arising from low proton density and multiple air-tissue interfaces of the alveoli
cause difficulty in1H lung magnetic resonance imaging. In addition, the dominating signal from sources such as the thoracic muscle and subcutaneous
fat hampers the visualization of the lung parenchyma. In this contribution, an efficient tissue suppression technique is presented
which allows one to significantly enhance lung parenchyma visibility. A short inversion time inversion recovery (STIR) experiment
combined with a magnetization transfer (MT) experiment was used for magnetization preparation in order to suppress the signal
from muscle. A half-Fourier single-shot turbo spin-echo sequence was used as acquisition module. This approach was used to
perform lung anatomical imaging in eight healthy human subjects and five patients withcystic fibrosis. The results obtained demonstrate that with MT-STIR approach high quality human lung images can be obtained and that this
approach has the potential for the evaluation of lung pathologies. 相似文献
50.
Batson C. Daniel; Eklund Jakob H?kansson; Chermok Valerie L.; Hoyt Jennifer L.; Ortiz Biaggio G. 《Canadian Metallurgical Quarterly》2007,93(1):65
Two experiments examined the role of valuing the welfare of a person in need as an antecedent of empathic concern. Specifically, these experiments explored the relation of such valuing to a well-known antecedent--perspective taking. In Experiment 1, both perspective taking and valuing were manipulated, and each independently increased empathic concern, which, in turn, increased helping behavior. In Experiment 2, only valuing was manipulated. Manipulated valuing increased measured perspective taking and, in part as a result, increased empathic concern, which, in turn, increased helping. Valuing appears to be an important, largely overlooked, situational antecedent of feeling empathy for a person in need. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献