全文获取类型
收费全文 | 194篇 |
免费 | 9篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 110篇 |
金属工艺 | 6篇 |
机械仪表 | 3篇 |
建筑科学 | 2篇 |
能源动力 | 4篇 |
轻工业 | 24篇 |
无线电 | 7篇 |
一般工业技术 | 26篇 |
冶金工业 | 7篇 |
原子能技术 | 1篇 |
自动化技术 | 11篇 |
出版年
2023年 | 3篇 |
2022年 | 16篇 |
2021年 | 18篇 |
2020年 | 9篇 |
2019年 | 7篇 |
2018年 | 3篇 |
2017年 | 6篇 |
2016年 | 9篇 |
2015年 | 4篇 |
2014年 | 12篇 |
2013年 | 10篇 |
2012年 | 16篇 |
2011年 | 10篇 |
2010年 | 11篇 |
2009年 | 16篇 |
2008年 | 11篇 |
2007年 | 12篇 |
2006年 | 5篇 |
2005年 | 8篇 |
2004年 | 3篇 |
2003年 | 2篇 |
2002年 | 5篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
排序方式: 共有203条查询结果,搜索用时 15 毫秒
11.
Robert L. Wolff Olivier Lavialle Frédérique Pédrono Elodie Pasquier Laurent G. Deluc Anne M. Marpeau Kurt Aitzetmüller 《Lipids》2001,36(5):439-451
Following our previous review on Pinus spp. seed fatty acid (FA) compositions, we recapitulate here the seed FA compositions of Larix (larch), Picea (spruce), and Pseudotsuga (Douglas fir) spp. Numerous seed FA compositions not described earlier are included. Approximately 40% of all Picea taxa and one-third of Larix taxa have been analyzed so far for their seed FA compositions. Qualitatively, the seed FA compositions in the three genera
studied here are the same as in Pinus spp., including in particular the same Δ5-olefinic acids. However, they display a considerably lower variability in Larix and Picea spp. than in Pinus spp. An assessment of geographical variations in the seed FA composition of P. abies was made, and intraspecific dissimilarities in this species were found to be of considerably smaller amplitude than interspecific
dissimilarities among other Picea species. This observation supports the use of seed FA compositions as chemotaxonomic markers, as they practically do not
depend on edaphic or climatic conditions. This also shows that Picea spp. are coherently united as a group by their seed FA compositions. This also holds for Larix spp. Despite a close resemblance between Picea and Larix spp. seed FA compositions, principal component analysis indicates that the minor differences in seed FA compositions between
the two genera are sufficient to allow a clear-cut individualization of the two genera. In both cases, the main FA is linoleic
acid (slightly less than one-half of total FA), followed by pinolenic (5,9,12-18:3) and oleic acids. A maximum of 34% of total
Δ5-olefinic acids is reached in L. sibirica seeds, which appears to be the highest value found in Pinaceae seed FA. This apparent limit is discussed in terms of regio-
and stereospecific distribution of Δ5-olefinic acids in seed triacylglycerols. Regarding the single species of Pseudotsuga analyzed so far (P. menziesii), its seed FA composition is quite distinct from that of the other two genera, and in particular, it contains 1.2% of 14-methylhexadecanoic
(anteiso-17:0) acid. In the three genera studied here, as well as in most Pinus spp., the C18Δ5-olefinic acids (5,9-18:2 and 5,9,12-18:3 acids) are present in considerably higher amounts than the C20Δ5-olefinic acids (5,11-20:2 and 5,11,14-20:3 acids). 相似文献
12.
13.
Elodie G. Rodrigues Sónia A. C. Carabineiro Xiaowei Chen Juan J. Delgado José L. Figueiredo Manuel F. R. Pereira José J. M. Órfão 《Catalysis Letters》2011,141(3):420-431
Abstract
Noble metal catalysts (Pt, Ir, Pd, Rh, Au) supported on activated carbon were assessed for glycerol oxidation. Rhodium is a highly efficient catalyst when the support has neutral or basic properties. The surface chemistry of activated carbon plays a key role in the performance. 相似文献14.
15.
Christèle Bartholome Emmanuel Beyou Elodie Bourgeat-Lami Philippe Chaumont Nathalie Zydowicz 《Polymer》2005,46(23):9965-9973
Polystyrene (PS) chains with molecular weights comprised between 15,000 and 60,000 g/mol and narrow polydispersities were successfully grown from the surface of silica nanoparticles by nitroxide-mediated polymerization (NMP). Small angle X-ray scattering was used to characterize the structure of the interface layer formed around the silica particles, and at a larger scale, dynamic light scattering was used to determine the hydrodynamic diameter of the functionalized silica suspension. In a second part, blends of PS-grafted silica particles and pure polystyrene were prepared to evaluate the influence of the length of the grafted PS segments on the viscoelastic behavior of the so-produced nanocomposites in the linear viscoelasticity domain.Combination of all these techniques shows that the morphology of the nanocomposite materials is controlled by grafting. The steric hindrance generated by the grafted polymer chains enables partial destruction of the agglomerates that compose the original silica particles when the latter are dispersed either in a solvent or in a polymeric matrix. 相似文献
16.
Vasily Smirnov Olivier Grunewald Jean Muller Christina Zeitz Carolin D. Obermaier Aurore Devos Valrie Pelletier Batrice Bocquet Camille Andrieu Jean-Louis Bacquet Elodie Lebredonchel Saddek Mohand-Saïd Sabine Defoort-Dhellemmes Jos-Alain Sahel Hlne Dollfus Xavier Zanlonghi Isabelle Audo Isabelle Meunier Elise Boulanger-Scemama Claire-Marie Dhaenens 《International journal of molecular sciences》2021,22(12)
Variants of the TTLL5 gene, which encodes tubulin tyrosine ligase-like family member five, are a rare cause of cone dystrophy (COD) or cone-rod dystrophy (CORD). To date, only a few TTLL5 patients have been clinically and genetically described. In this study, we report five patients harbouring biallelic variants of TTLL5. Four adult patients presented either COD or CORD with onset in the late teenage years. The youngest patient had a phenotype of early onset severe retinal dystrophy (EOSRD). Genetic analysis was performed by targeted next generation sequencing of gene panels and assessment of copy number variants (CNV). We identified eight variants, of which six were novel, including two large multiexon deletions in patients with COD or CORD, while the EOSRD patient harboured the novel homozygous p.(Trp640*) variant and three distinct USH2A variants, which might explain the observed rod involvement. Our study highlights the role of TTLL5 in COD/CORD and the importance of large deletions. These findings suggest that COD or CORD patients lacking variants in known genes may harbour CNVs to be discovered in TTLL5, previously undetected by classical sequencing methods. In addition, variable phenotypes in TTLL5-associated patients might be due to the presence of additional gene defects. 相似文献
17.
Delphine Antoni Hélène Burckel Elodie Josset Georges Noel 《International journal of molecular sciences》2015,16(3):5517-5527
Cell culture is an important tool for biological research. Two-dimensional cell culture has been used for some time now, but growing cells in flat layers on plastic surfaces does not accurately model the in vivo state. As compared to the two-dimensional case, the three-dimensional (3D) cell culture allows biological cells to grow or interact with their surroundings in all three dimensions thanks to an artificial environment. Cells grown in a 3D model have proven to be more physiologically relevant and showed improvements in several studies of biological mechanisms like: cell number monitoring, viability, morphology, proliferation, differentiation, response to stimuli, migration and invasion of tumor cells into surrounding tissues, angiogenesis stimulation and immune system evasion, drug metabolism, gene expression and protein synthesis, general cell function and in vivo relevance. 3D culture models succeed thanks to technological advances, including materials science, cell biology and bioreactor design. 相似文献
18.
Jenny Faucheu Author Vitae Catherine Gauthier Author Vitae Author Vitae Jean-Yves Cavaillé Author Vitae Author Vitae Elodie Bourgeat Lami Author Vitae 《Polymer》2010,51(1):6-5269
This review intends to present different aspects concerning clay/polymer nanocomposites produced by heterophase polymerization in aqueous media. This paper highlights the ability of miniemulsion polymerization to produce clay/polymer nanoparticles with tailored nanostructures. Indeed, this polymerization route enables the synthesis of composite nanoparticles with the clay platelets located either on the surface of the polymer particle or embedded inside the polymer particle. A focus is given on the influence of these nanostructures on the properties of the final material through a direct comparison of the composites obtained after water evaporation from these structured nanoparticles. Indeed, the film obtained from the film forming process of these nanoparticles present significantly different nanostructures and exhibit totally different mechanical behaviours and water uptakes. By comparing experimental results and modeling approaches, it is demonstrated that their properties are clearly related to the clay dispersion and contacts. It is also evidenced that the main drawback of miniemulsion from the coating application point of view, is the large water uptake promoted by the surfactant presence whose localization is strongly influenced by nanostructuration. This stresses the need for the further development of surfactant free miniemulsion polymerization using advantageously the clay presence to stabilize the emulsion. 相似文献
19.
New dimer acid-based-polyamides were synthesized with rapeseed oil-based dimer acid (DA) and 1,2-diaminoethane, 1,6-diaminohexane or 1,8-diaminooctane to form DAPAe, DAPAh and DAPAo, respectively. Effects of diamine chain lengths on kinetics evolution as well as on the thermal, physical and mechanical properties of the different polyamides synthesized were investigated. DAPAo was found to be the most reactive diamine because of its higher nucleophilic character. Differential scanning calorimetry (DSC) combined with X-ray diffraction revealed a low-order semi-crystalline structure for all polyamides. A tentative schema for the structural organization of these DAPA is proposed and shows a specific organization with local semi-crystalline segregation domains. DAPAe was found to possess the higher melting temperature likely due to higher crystal cohesion, which was confirmed by higher Young modulus in stress-strain experiments. Rheological data showed an increase of the glass transition temperature concomitantly with the increase of diamine chain length. They also revealed an increase of complex viscosity with the diamine chain length. Investigation of thermal stability showed that DAPAe degrades before DAPAh and DAPAo in connection with the number of methylene units per diamine. 相似文献
20.
Thierry Kientega Emmanuelle Conil Abdelhamid Hadjem Elodie Richalot Azzedine Gati Man Fai Wong Odile Picon Joe Wiart 《电信纪事》2011,66(7-8):419-428
The assessment of the exposure to electromagnetic waves is nowadays a key question. Dealing with the relationship between exposure and incident field, most of previous investigations have been performed with a single plane wave. Realistic exposure in the far field can be modeled as multiple plane waves with random direction of arrival, random amplitude, and random phase. This paper, based on numerical investigations, studies the whole body specific absorption rate (SAR) linked to the exposure induced by five random plane waves having uniformly distributed angles of arrival in the horizontal plane, log-normal distributed amplitudes, and uniformly distributed phases. A first result shows that this random heterogeneous exposure generates maximal variations of ??25% for the whole body specific absorption. An important observation is that the exposure to a single plane wave arriving face to the body, used for the guidelines, does not constitute the worst case. We propose a surrogate model to assess the distribution of the whole body SAR in the case of an exposure to multiple plane waves. For a sample of 30 values of whole body SAR induced by five plane waves at 2.4?GHz, this simple approach, considering the resulting SAR as the sum of the SAR induced by each isolated plane wave, leads to an estimated distribution of whole body SAR following the real distribution with a p value of 76% according to the Kolmogorov statistical test. 相似文献