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41.
Two experiments examined possible negative transfer in nonexperts from the use of pictorial examples in a laboratory design problem-solving situation. In Experiment 1, 89 participants were instructed to "think aloud" and were assigned to 1 of 3 conditions: (a) control (standard instructions), (b) fixation (inclusion of a problematic example, describing its problematic elements), or (c) defixation (inclusion of a problematic example, with instructions to avoid using problematic elements). Negative transfer due to examples was measured both quantitatively and qualitatively through verbal protocols. Verbal protocols (N = 176) were analyzed for participants' reasons for reference to the examples. In Experiment 2, fixation to examples was evaluated in nonverbalizing participants (N = 60). Results of both experiments suggest that (a) although participants consulted the problem instructions, they tended to follow the examples even when they included inappropriate elements and (b) the fixation effects can be diminished with the use of defixating instructions. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
42.
Nikolaos Spyropoulos-Antonakakis Evangelia Sarantopoulou Goran Drazic Zoe Kollia Dimitrios Christofilos Gerasimos Kourouklis Dimitrios Palles Alkiviadis Constantinos Cefalas 《Nanoscale research letters》2013,8(1):432
Amorphous semiconducting materials have unique electrical properties that may be beneficial in nanoelectronics, such as low leakage current, charge memory effects, and hysteresis functionality. However, electrical characteristics between different or neighboring regions in the same amorphous nanostructure may differ greatly. In this work, the bulk and surface local charge carrier transport properties of a-TaNx amorphous thin films deposited in two different substrates are investigated by conductive atomic force microscopy. The nitride films are grown either on Au (100) or Si [100] substrates by pulsed laser deposition at 157 nm in nitrogen environment. For the a-TaNx films deposited on Au, it is found that they display a negligible leakage current until a high bias voltage is reached. On the contrary, a much lower threshold voltage for the leakage current and a lower total resistance is observed for the a-TaNx film deposited on the Si substrate. Furthermore, I-V characteristics of the a-TaNx film deposited on Au show significant hysteresis effects for both polarities of bias voltage, while for the film deposited on Si hysteresis, effects appear only for positive bias voltage, suggesting that with the usage of the appropriate substrate, the a-TaNx nanodomains may have potential use as charge memory devices. 相似文献
43.
The long-term (6 months) oxidization of hcp-InN (wurtzite, InN-w) nanostructures (crystalline/amorphous) synthesized on Si [100] substrates is analyzed. The densely packed layers of InN-w nanostructures (5-40 nm) are shown to be oxidized by atmospheric oxygen via the formation of an intermediate amorphous In-Ox-Ny (indium oxynitride) phase to a final bi-phase hcp-InN/bcc-In2O3 nanotexture. High-resolution transmission electron microscopy, energy-dispersive X-ray spectroscopy, electron energy loss spectroscopy and selected area electron diffraction are used to identify amorphous In-Ox-Ny oxynitride phase. When the oxidized area exceeds the critical size of 5 nm, the amorphous In-Ox-Ny phase eventually undergoes phase transition via a slow chemical reaction of atomic oxygen with the indium atoms, forming a single bcc In2O3 phase. 相似文献
44.
Fouling Analysis and Performance of Tubular Ultrafiltration on Pretreated Olive Mill Waste Water 总被引:1,自引:0,他引:1
This study deals with the performance of a tubular ultrafiltration system on sieved and centrifuged olive mill waste water.
A generalized statistical model was developed describing the impact and the relative importance of major experimental parameters
(membrane pore size, transmembrane pressure, feed flow rate, and feed temperature) on permeate flux. According to this model,
process pressure appeared to have the largest impact on permeate flux, followed by process temperature. As membrane treatment
of such a difficult material largely depends on fouling, a systematic analysis of prevailing fouling mechanisms was also run.
Despite sieving and centrifugation of the original waste, membrane fouling caused a flux decline of 60–65% within 15–20 min.
Internal fouling, pore blocking, and cake layer formation were all responsible for membrane fouling during the first 40 min
of operation. After that period, cake formation appeared to play a predominant role. Based on the proposed generalized model,
the relative importance of process parameters can be evaluated and process performance can be improved by proper interventions.
Independent of membrane size, fouling is a serious problem to be resolved. The qualitative performance of this process, including
chemical oxygen demand distribution, polyphenol profile, and antioxidant capacity, is discussed in a separate paper. 相似文献
45.
The efficiency of grape stem extracts to express antiradical activity was assessed using two different approaches and DPPH as the radical probe. In addition, the mixture effects when the extracts were combined with ascorbic acid (AA) and α-tocopherol (α-Tcp) were also evaluated. The approaches included a simple linear regression analysis between the response (antiradical activity) and concentration, but also a response surface methodology, which permitted the monitoring of the response upon simultaneous variation of both the concentration of the total polyphenols of the extracts and either of the antioxidants (AA and α-Tcp). The deployment of linear regression poses important constraints with regard to concentration ranges, whereas response surface methodology might be a valuable statistical tool for similar assessments and credible modelling of binary mixtures of antioxidants. In all combinations tested it was found that an antagonism was manifested, presumably as a result of AA and α-Tcp regeneration by the extract polyphenols, at the expense of the latter. 相似文献
46.
Zacharaki EI Hogea CS Biros G Davatzikos C 《IEEE transactions on bio-medical engineering》2008,55(3):1233-1236
Simulating the brain tissue deformation caused by tumor growth has been found to aid the deformable registration of brain tumor images. In this paper, we evaluate the impact that different biomechanical simulators have on the accuracy of deformable registration. We use two alternative frameworks for biomechanical simulations of mass effect in 3-D magnetic resonance (MR) brain images. The first one is based on a finite-element model of nonlinear elasticity and unstructured meshes using the commercial software package ABAQUS. The second one employs incremental linear elasticity and regular grids in a fictitious domain method. In practice, biomechanical simulations via the second approach may be at least ten times faster. Landmarks error and visual examination of the coregistered images indicate that the two alternative frameworks for biomechanical simulations lead to comparable results of deformable registration. Thus, the computationally less expensive biomechanical simulator offers a practical alternative for registration purposes. 相似文献
47.
Marvin Droste Tobias Tertel Stefanie Jeruschke Robin Dittrich Evangelia Kontopoulou Bernd Walkenfort Verena Brger Peter F. Hoyer Anja K. Büscher Basant K. Thakur Bernd Giebel 《International journal of molecular sciences》2021,22(22)
Small extracellular vesicles isolated from urine (uEVs) are increasingly recognized as potential biomarkers. Meanwhile, different uEV preparation strategies exist. Conventionally, the performance of EV preparation methods is evaluated by single particle quantification, Western blot, and electron microscopy. Recently, we introduced imaging flow cytometry (IFCM) as a next-generation single EV analysis technology. Here, we analyzed uEV samples obtained with different preparation procedures using nanoparticle tracking analysis (NTA), semiquantitative Western blot, and IFCM. IFCM analyses demonstrated that urine contains a predominant CD9+ sEV population, which exceeds CD63+ and CD81+ sEV populations. Furthermore, we demonstrated that the storage temperature of urine samples negatively affects the recovery of CD9+ sEVs. Although overall reduced, the highest CD9+ sEV recovery was obtained from urine samples stored at −80 °C and the lowest from those stored at −20 °C. Upon comparing the yield of the different uEV preparations, incongruencies between NTA and IFCM data became apparent. Results obtained by both NTA and IFCM were consistent with Western blot analyses for EV marker proteins; however, NTA results correlated with the amount of the impurity marker uromodulin. Despite demonstrating that the combination of ultrafiltration and size exclusion chromatography appears as a reliable uEV preparation technique, our data challenge the soundness of traditional NTA for the evaluation of different EV preparation methods. 相似文献
48.
Bakker Arnold B.; Hakanen Jari J.; Demerouti Evangelia; Xanthopoulou Despoina 《Canadian Metallurgical Quarterly》2007,99(2):274
This study of 805 Finnish teachers working in elementary, secondary, and vocational schools tested 2 interaction hypotheses. On the basis of the job demands-resources model, the authors predicted that job resources act as buffers and diminish the negative relationship between pupil misbehavior and work engagement. In addition, using conservation of resources theory, the authors hypothesized that job resources particularly influence work engagement when teachers are confronted with high levels of pupil misconduct. In line with these hypotheses, moderated structural equation modeling analyses resulted in 14 out of 18 possible 2-way interaction effects. In particular, supervisor support, innovativeness, appreciation, and organizational climate were important job resources that helped teachers cope with demanding interactions with students. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
49.
Bakker Arnold B.; Demerouti Evangelia; Dollard Maureen F. 《Canadian Metallurgical Quarterly》2008,93(4):901
This study among 168 couples of dual-earner parents uses insights from previous work-family conflict and crossover research to propose an integrative model delineating how job demands experienced by men and women carry over to the home domain. The authors hypothesized that for both men and women, job demands foster their own work-family conflict (WFC), which in turn contributes to their partners' home demands, family-work conflict (FWC), and exhaustion. In addition, they hypothesized that social undermining mediates the relationship between individuals' WFC and their partners' home demands. The results of structural equation modeling analyses provided strong support for the proposed model. The hypothesis that gender would moderate the model relationships was rejected. These findings integrate previous findings on work-family conflict and crossover theories and suggest fluid boundaries between the work and home domains. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
50.
Ksinopoulou Evangelia Dragatogiannis Dimitrios Bakolas Asterios Charitidis Constantinos Moropoulou Antonia 《Journal of Polymer Research》2022,29(5):1-15
Journal of Polymer Research - Sodium 2,2′-methylene-bis(4,6-di-tertbutylphenyl)-phosphate (NA11) is an α-type nucleating agent for improving the mechanical and crystallization... 相似文献