全文获取类型
收费全文 | 296篇 |
免费 | 23篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 141篇 |
金属工艺 | 6篇 |
机械仪表 | 9篇 |
建筑科学 | 13篇 |
矿业工程 | 2篇 |
能源动力 | 4篇 |
轻工业 | 49篇 |
水利工程 | 2篇 |
石油天然气 | 1篇 |
无线电 | 3篇 |
一般工业技术 | 56篇 |
冶金工业 | 10篇 |
自动化技术 | 22篇 |
出版年
2023年 | 5篇 |
2022年 | 24篇 |
2021年 | 29篇 |
2020年 | 13篇 |
2019年 | 9篇 |
2018年 | 10篇 |
2017年 | 21篇 |
2016年 | 14篇 |
2015年 | 12篇 |
2014年 | 9篇 |
2013年 | 28篇 |
2012年 | 18篇 |
2011年 | 28篇 |
2010年 | 17篇 |
2009年 | 18篇 |
2008年 | 19篇 |
2007年 | 13篇 |
2006年 | 5篇 |
2005年 | 4篇 |
2004年 | 4篇 |
2003年 | 1篇 |
2002年 | 1篇 |
2001年 | 5篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1996年 | 1篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1991年 | 1篇 |
1986年 | 1篇 |
1981年 | 1篇 |
1978年 | 1篇 |
排序方式: 共有319条查询结果,搜索用时 12 毫秒
61.
Holger Keitel Andrea Dimmig-Osburg Lucie Vandewalle Luc Schueremans 《Materials and Structures》2012,45(10):1513-1533
The development of creep prediction models has been a field of extensive research and many different models have already been proposed. This paper presents an evaluation method of the prediction quality of creep models for specific experimental data. Within the scope of this paper, the model according to Bockhold and the model according to Heidolf are examined. First, the parameters of the models are identified with respect to existing experimental data. This is done using a sampling based approach of Bayesian updating developed by Ba?ant and Chern. In extension to the method by Ba?ant and Chern, the uncertainty coming from inaccurate measurement data is taken into account in the definition of the likelihood function within the updating algorithm. The more inaccurate the measurements are, the more uncertain the estimated model parameters and model prognoses become. The identification is performed for different short- and long-term creep tests. The intension is not to validate these models intensively, but to evaluate their prognoses for the individually tested creep behavior. The results show that the identifiability of the models?? parameters is different for both models and consequently the models prognoses differ in their uncertainties. Second, the models are evaluated using two different strategies: the stochastic model selection according to MacKay, Beck and Yuen based on the Ockham factor, and a comparison of the uncertainties taking into account parameter and model uncertainties. The results of the evaluation of the creep models differ for various experimental tests. Model Heidolf is more flexible and gives a better fit to the data, however, it fails to predict reliable long-term creep deformations using only short-term measurements compared to model Bockhold. Comparing the evaluation methods, the analysis of uncertainties of the creep prognosis proofs to be more stable than the evaluation using the stochastic model selection. 相似文献
62.
We prepared interpenetrating polymer networks (IPNs) composed of a gelatin hydrogel and a HydroThaneTM elastomer to combine the advantages of both polymers into one biomaterial. Fourier transform Infrared (FTIR) spectroscopy
and Differential Scanning Calorimetry (DSC) confirmed the co-existence of the two polymers in the IPNs. Optical light microscopy
confirmed hydrogel domains were interspaced into an elastomer network. Hydration and stability studies in aqueous solution
showed that, although the IPN biomaterials exhibited stable swelling for more than 30 days, approximately 10% and 50% loss
of the hydrogel component were confirmed at room temperature and 37 °C, respectively, using gel permeation chromatography
(GPC). The swelling study in the serum-containing medium indicated the biomaterials maintained their swelling stability for
different periods, depending on the extent of gelatin methacrylation, photoinitiator concentration and incubation temperature.
Lastly, the biomaterials exhibited higher failure stress and lower failure strain in a dry state than in a swollen state,
and showed limited changes in both stress and strain at room temperature and at 37 °C, in contrast with a decrease at 50 °C.
No significant effects of gelatin methacrylation on mechanical properties were noticed. The preparation and characterization
methods were well established and formed the basis of further developing the biomaterials. 相似文献
63.
Luis TruebaJr Monica A. Torres Lucie B. Johannes Daniel Rybicki 《International Journal of Material Forming》2018,11(4):559-570
Self-reacting friction stir welding (SR-FSW), also called bobbin-tool friction stir welding (BT-FSW), is a solid state welding process similar to friction stir welding (FSW) except that the tool has two opposing shoulders instead of the shoulder and a backing plate found in FSW. The tool configuration results in greater heat input and a symmetrical weld macrostructure. A significant amount of information has been published in the literature concerning traditional FSW while little has been published about SR-FSW. An optimization experiment was performed using a factorial design to evaluate the effect of process parameters on the weld temperature, surface and internal quality, and mechanical properties of self-reacting friction stir welded aluminum alloy 6061-T6 butt joints. The parameters evaluated were tool rotational speed, traverse speed, and tool plunge force. A correlation between weld temperature, defect formation (specifically galling and void formation), and mechanical properties was found. Optimum parameters were determined for the welding of 8-mm-thick 6061-T6 plate. 相似文献
64.
Lucie Pigeon Cristine Gonçalves David Gosset Chantal Pichon Patrick Midoux 《Small (Weinheim an der Bergstrasse, Germany)》2013,9(22):3845-3851
Chemical vectors as cationic polymers and cationic lipids are promising alternatives to viral vectors for gene therapy. Beside endosome escape and nuclear import, plasmid DNA (pDNA) migration in the cytosol toward the nuclear envelope is also regarded as a limiting step for efficient DNA transfection with non‐viral vectors. Here, the interaction between E3‐14.7K and FIP‐1 to favor migration of pDNA along microtubules is exploited. E3‐14.7K is an early protein of human adenoviruses that interacts via FIP‐1 (Fourteen.7K Interacting Protein 1) protein with the light‐chain components of the human microtubule motor protein dynein (TCTEL1). This peptide is conjugated with pDNA and mediates interaction of pDNA in vitro with isolated microtubules as well as with microtubules in cellulo. Videomicroscopy and tracking treatment of images clearly demonstrate that P79‐98/pDNA conjugate exhibits a linear transport with large amplitude along microtubules upon 2 h transfection with polyplexes whereas control pDNA conjugate exhibits small non‐directional movements in the cytoplasm. Remarkably, P79‐98/peGFP polyplexes enhance by a factor 2.5 (up to 76%) the number of transfected cells. The results demonstrate, for the first time, that the transfection efficiency of polyplexes can be drastically increased when the microtubules migration of pDNA is facilitated by a peptide allowing pDNA docking to TCTEL1. This is a real breakthrough in the non viral gene delivery field that opens hope to build artificial viruses. 相似文献
65.
Wiebe Deborah J.; Alderfer Melissa A.; Palmer Steven C.; Lindsay Rob; Jarrett Lucie 《Canadian Metallurgical Quarterly》1994,62(6):1204
The hypothesis that negative affectivity (NA) is associated with accuracy of blood glucose (BG) symptom perceptions and diabetes control was assessed. After completing measures of BG symptom beliefs and NA-related constructs (i.e., attentional focus and trait anxiety), 35 adolescents with insulin-dependent diabetes monitored their physical symptoms and their actual BG levels 3 times daily for 2 weeks. Each subject's actual BG symptoms were determined by correlating symptom ratings with BG levels and were then compared with symptom beliefs. Those who were more internally focused were more able to discern which symptoms actually covaried with BG fluctuations; those with higher trait anxiety tended to misattribute non-diabetes-related symptoms to BG levels. Finally, interactions suggested that those who both attend to internal physical sensations and experience-heightened anxiety display poorer metabolic control. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
66.
67.
Hanuš Seiner Lucie Bodnárová Petr Sedlák Miloš Janeček Ondřej Srba Robert Král Michal Landa 《Acta Materialia》2010,58(1):235-247
Anisotropy of elastic properties of ultrafine-grained polycrystalline copper after one, two and four passes of equal-channel angular pressing (ECAP) is investigated by means of ultrasonic methods. For each material, Young’s and shear moduli in the principal processing directions are evaluated and the symmetry and orientation of the anisotropy are identified. The relation between the determined symmetry and the processing mechanisms is discussed. It is shown that the material after one and two passes of ECAP exhibits a measurable anisotropy, while the material after the fourth pass behaves isotropically. Within the discussion, it is shown that the origin of the observed anisotropy may be attributed to the spatial arrangement of grain boundaries rather than to the crystallographic texture. In the light of this conclusion, the obtained results correspond well with optical and transmission electron microscopy observations of the microstructures of ECAPed materials documented in the literature. 相似文献
68.
Samuel Dorey Fanny Gaston Nina Girard-Perier Nathalie Dupuy Sylvain R.A. Marque Lucie Delaunay 《应用聚合物科学杂志》2020,137(44):49361
The potential changes of single-use plastic materials (EVA/EVOH/EVA multilayer film in this study) used in biopharmaceutical and food-packaging industries are investigated after several gamma irradiation doses: 30, 50, 115, and 270 kGy, and for nonsterilized samples (0 kGy) from a point of view of mechanical properties, thermal properties and permeability properties. Tensile tests, differential scanning calorimetry (DSC), oxygen transmission rate (OTR) and water vapor transmission rate (WVTR) are performed on the multilayer film. For irradiation doses below 50 kGy, thermal and water vapor barrier properties are not altered. For higher doses (50 to 270 kGy), mechanical, thermal and water vapor barrier properties are slightly altered whereas oxygen barrier property decreases from 13 to 27 cm3.m−2.day−1. This slight change is shown not to happen due to chain entanglement or chain mobility loss in the amorphous phase of the different polymers. It rather comes from a change of the chemical environment of the EVOH layer. 相似文献
69.
Anne Virsolvy Aurlie Fort Lucie Erceau Azzouz Charrabi Maurice Hayot Franck Aimond Sylvain Richard 《International journal of molecular sciences》2021,22(5)
Arterial smooth muscle exhibits rhythmic oscillatory contractions called vasomotion and believed to be a protective mechanism against tissue hypoperfusion or hypoxia. Oscillations of vascular tone depend on voltage and follow oscillations of the membrane potential. Voltage-gated sodium channels (Nav), responsible for the initiation and propagation of action potentials in excitable cells, have also been evidenced both in animal and human vascular smooth muscle cells (SMCs). For example, they contribute to arterial contraction in rats, but their physiopathological relevance has not been established in human vessels. In the present study, we investigated the functional role of Nav in the human artery. Experiments were performed on human uterine arteries obtained after hysterectomy and on SMCs dissociated from these arteries. In SMCs, we recorded a tetrodotoxin (TTX)-sensitive and fast inactivating voltage-dependent INa current. Various Nav genes, encoding α-subunit isoforms sensitive (Nav 1.2; 1.3; 1.7) and resistant (Nav 1.5) to TTX, were detected both in arterial tissue and in SMCs. Nav channels immunostaining showed uniform distribution in SMCs and endothelial cells. On arterial tissue, we recorded variations of isometric tension, ex vivo, in response to various agonists and antagonists. In arterial rings placed under hypoxic conditions, the depolarizing agent KCl and veratridine, a specific Nav channels agonist, both induced a sustained contraction overlaid with rhythmic oscillations of tension. After suppression of sympathetic control either by blocking the release of catecholamine or by antagonizing the target adrenergic response, rhythmic activity persisted while the sustained contraction was abolished. This rhythmic activity of the arteries was suppressed by TTX but, in contrast, only attenuated by antagonists of calcium channels, Na+/Ca2+ exchanger, Na+/K+-ATPase and the cardiac Nav channel. These results highlight the role of Nav as a novel key element in the vasomotion of human arteries. Hypoxia promotes activation of Nav channels involved in the initiation of rhythmic oscillatory contractile activity. 相似文献
70.
David Cluet Blandine Vergier Nicolas-Pierre Levy Lucie Dehau Alexandre Thurman Ikram Amri Martin Spichty 《Chembiochem : a European journal of chemical biology》2022,23(4):e202100640
A genetic assay permits simultaneous quantification of two interacting proteins and their bound fraction at the single-cell level using flow cytometry. Apparent in-cellula affinities of protein-protein interactions can be extracted from the acquired data through a titration-like analysis. The applicability of this approach is demonstrated on a diverse set of interactions with proteins from different families and organisms and with in-vitro dissociation constants ranging from picomolar to micromolar. 相似文献