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31.
Atorod Azizinamini Karl Barth Robert Dexter Camille Rubeiz 《Canadian Metallurgical Quarterly》2004,9(3):212-217
This paper provides a summary of the major research studies conducted or being conducted in the U.S., to address design issues related to use of high performance steel (HPS) in bridge construction. Emphasis of the paper is on the work related to HPS-485W steel, which has specified minimum yield strength of 485 MPa (70 ksi). Design issues that are addressed in this paper include (1) flexural capacity of compact and noncompact HPS sections in negative bending; (2) issues related to ductility of HPS composite girders in the positive sections (this section presents a simplified ductility check for composite plate girders); (3) tensile ductility of HPS plates; (4) shear capacity of the hybrid steel plate girders; (5) live load deflections; and (6) brief overview of the work that is underway to develop innovative bridge configurations capable of incorporating the advantages of HPS. 相似文献
32.
In 3 studies, the authors explored the relation between threatening upward social comparisons and performance. In an initial study, participants were exposed to comparison targets who either threatened or boosted self-evaluations and then completed a performance task. Participants exposed to the threatening target performed better than those in a control group, whereas those exposed to the nonthreatening target performed worse. In Study 2, self-affirmation prior to comparison with threatening targets eliminated performance improvements. In Study 3, performance improvements were found only when the performance domain was different from the domain of success of the comparison target. These boundary conditions suggest that increases in performance following social comparison arise from individuals' motivations to maintain and repair self-evaluations. Implications for the study of the behavioral consequences of social comparison are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
33.
Galvin Katherine E.; King Camille T.; King Michael S. 《Canadian Metallurgical Quarterly》2004,118(1):163
The "waist" area and external subnuclei of the parabrachial nucleus (PBN) have been implicated in the processing of gustatory information, yet their behavioral roles are not clearly defined. In the current study, areas within and surrounding the PBN were stimulated while oromotor behaviors were monitored in conscious rats. Electrical and chemical (100 mM glutamate) stimulation of the waist area increased ingestive oromotor behaviors over baseline (p 相似文献
34.
Is an attributional analysis of the learned helplessness phenomenon viable? A critique of the Abramson-Seligman-Teasdale reformulation. 总被引:1,自引:0,他引:1
Considers that the reformulation of the learned helplessness model by L. Y. Abramson et al (see record 1979-00305-001) overcomes many of the shortcomings inherent in the original model and raises questions for future research on helplessness and depression. A critique is made of the various components of the reformulated model: (a) Some questions are raised about the importance of attributions in predicting reactions to uncontrollable outcomes, including whether people make attributions and whether there is a relationship between attributions and behavior. (b) It is questioned whether the dimensions of attribution selected by Abramson et al are the most significant ones in predicting the nature and magnitude of behavioral deficits. (c) The possibility is raised that factors other than attributions and expectations for future control may influence reactions to uncontrollable outcomes. Certain characteristics of the outcome, such as whether it is expected and whether people are able to find meaning in it, may be important. (d) The account of the cognitive, motivational, and affective responses to lack of control is examined. The present authors feel that 2 basic questions are left unanswered: What is the relationship between the various deficits that are proposed, and when does exposure to lack of control result in deficits, and when does it result in facilitated performance? (e) The reformulated learned helplessness model of depression is examined. The model is seen to raise questions about the direction of causality between attributions, expectations, and depression. (53 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
35.
Distinguishing optimism from pessimism: Relations to fundamental dimensions of mood and personality.
Marshall Grant N.; Wortman Camille B.; Kusulas Jeffrey W.; Hervig Linda K.; Vickers Ross R. Jr. 《Canadian Metallurgical Quarterly》1992,62(6):1067
Contrary to unidimensional conceptions of optimism and pessimism, factor analysis of 2 widely used instruments revealed that optimism and pessimism are empirically differentiable, but related, constructs. Moreover, consistent with expectations, optimism and pessimism were differentially linked with fundamental dimensions of mood and personality. Pessimism was principally associated with neuroticism and negative affect. Optimism was primarily associated with extraversion an positive affect. Findings are discussed with reference to current conceptual and measurement models of optimism and pessimism and their relations to broad dimensions of mood and personality. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
36.
Gómez-Laberge C Adler A Cameron I Nguyen TB Hogan MJ 《IEEE transactions on bio-medical engineering》2008,55(10):2372-2380
Functional MRI (fMRI) may be possible without a priori models of the cerebral hemodynamic response. First, such data-driven fMRI requires that all cerebral territories with distinct patterns be identified. Second, a systematic selection method is necessary to prevent the subjective interpretation of the identified territories. This paper addresses the second point by proposing a novel method for the automated interpretation of identified territories in data-driven fMRI. Selection criteria are formulated using: 1) the temporal cross-correlation between each identified territory and the paradigm and 2) the spatial contiguity of the corresponding voxel map. Ten event-design fMRI data sets are analyzed with one prominent algorithm, fuzzy c-means clustering, before applying the selection criteria. For comparison, these data are also analyzed with an established, model-based method: statistical parametric mapping. Both methods produced similar results and identified potential activation in the expected territory of the sensorimotor cortex in all ten data sets. Moreover, the proposed method classified distinct territories in separate clusters. Selected clusters have a mean temporal correlation coefficient of 0.39+/-0.07 (n=19) with a mean 2.7+/-1.4 second response delay. At most, four separate contiguous territories were observed in 87% of these clusters. These results suggest that the proposed method may be effective for exploratory fMRI studies where the hemodynamic response is perturbed during cerebrovascular disease. 相似文献
37.
In the current context of climate change and ecological awareness, designing sustainable environments is definitely understood as a shared responsibility. With the construction sector consuming half of the world׳s energy, the role of some key stakeholders such as architects becomes even more critical when providing responsible and relevant design for the built environment. Thus, improving the way our environments are being designed challenges some cultural systems that show evident limits, such as the training of future architects and engineers.In this research, the focus is on architecture students and aims to demonstrate how the use of a new sustainable performance simulation tool, called Easy Approach for Sustainable and Environmental Design (EASED) could contribute to educate them about innovatively sustainable design. This was assessed through the evaluation of student engagement, their use of the tool and its appropriation. Results show that individual work was not convincing, whereas success was met during group work. Limits and improvement possibilities were found in the interface of EASED as well as in the educational set up of the tool. 相似文献
38.
The Rubus genus produces numerous species that are known for their medicinal properties. Rubus rosifolius, called the red raspberry, grows wild in elevated regions in Jamaica. Phytochemical examination of the ethyl acetate extract of the fruit yielded eight compounds of the 19-α-hydroxyursane type: euscaphic acid (1), 1-β-hydroxyeuscaphic acid (2), hyptatic acid B (3), 19α-hydroxyasiatic acid (4), trachelosperogenin (5), 4-epi-nigaichigoside F1 (6), nigaichigoside F1 (7), and trachelosperoside B-1 (8), as confirmed by NMR spectroscopy. Inhibition of cell proliferation by these compounds were determined by using MCF-7 (breast), SF-268 (CNS), NCI H460 (lung), HCT-116 (colon) and AGS (gastric) human tumour cells. Among the human tumour cell lines assayed, only compounds 3 and 6 displayed significant growth inhibition and was specific to colon tumour cells by 56% and 40%, respectively. These ursolic acid analogues were also tested for anti-inflammatory activity using in vitro cycloxegenase-1 (COX-1) and cycloxegenase-2 (COX-2) enzyme inhibitory assays. Compounds 1, 2 and 3 showed selective COX-1 enzyme inhibitory activity (13%, 25% and 35%) at 25 μg/ml. In the lipid peroxidation (LPO) inhibitory assays, compounds 2, 4, 7 and 6 inhibited LPO by 62%, 60%, 53% and 68%, respectively, at 25 μg/ml. 相似文献
39.
Yang Hu Stephanie M. Sjoberg Chunpen Chen Amber L. Hauvermale Craig F. Morris Stephen R. Delwiche Ashley E. Cannon Camille M. Steber Zhiwu Zhang 《Comprehensive Reviews in Food Science and Food Safety》2022,21(3):2105-2117
This review examines the application, limitations, and potential alternatives to the Hagberg–Perten falling number (FN) method used in the global wheat industry for detecting the risk of poor end-product quality mainly due to starch degradation by the enzyme α-amylase. By viscometry, the FN test indirectly detects the presence of α-amylase, the primary enzyme that digests starch. Elevated α-amylase results in low FN and damages wheat product quality resulting in cakes that fall, and sticky bread and noodles. Low FN can occur from preharvest sprouting (PHS) and late maturity α-amylase (LMA). Moist or rainy conditions before harvest cause PHS on the mother plant. Continuously cool or fluctuating temperatures during the grain filling stage cause LMA. Due to the expression of additional hydrolytic enzymes, PHS has a stronger negative impact than LMA. Wheat grain with low FN/high α-amylase results in serious losses for farmers, traders, millers, and bakers worldwide. Although blending of low FN grain with sound wheat may be used as a means of moving affected grain through the marketplace, care must be taken to avoid grain lots from falling below contract-specified FN. A large amount of sound wheat can be ruined if mixed with a small amount of sprouted wheat. The FN method is widely employed to detect α-amylase after harvest. However, it has several limitations, including sampling variability, high cost, labor intensiveness, the destructive nature of the test, and an inability to differentiate between LMA and PHS. Faster, cheaper, and more accurate alternatives could improve breeding for resistance to PHS and LMA and could preserve the value of wheat grain by avoiding inadvertent mixing of high- and low-FN grain by enabling testing at more stages of the value stream including at harvest, delivery, transport, storage, and milling. Alternatives to the FN method explored here include the Rapid Visco Analyzer, enzyme assays, immunoassays, near-infrared spectroscopy, and hyperspectral imaging. 相似文献