全文获取类型
收费全文 | 391篇 |
免费 | 22篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 169篇 |
金属工艺 | 4篇 |
机械仪表 | 4篇 |
建筑科学 | 15篇 |
能源动力 | 16篇 |
轻工业 | 56篇 |
石油天然气 | 1篇 |
无线电 | 22篇 |
一般工业技术 | 76篇 |
冶金工业 | 9篇 |
原子能技术 | 3篇 |
自动化技术 | 36篇 |
出版年
2024年 | 2篇 |
2023年 | 4篇 |
2022年 | 20篇 |
2021年 | 20篇 |
2020年 | 13篇 |
2019年 | 12篇 |
2018年 | 7篇 |
2017年 | 7篇 |
2016年 | 15篇 |
2015年 | 9篇 |
2014年 | 23篇 |
2013年 | 31篇 |
2012年 | 29篇 |
2011年 | 38篇 |
2010年 | 20篇 |
2009年 | 25篇 |
2008年 | 21篇 |
2007年 | 27篇 |
2006年 | 20篇 |
2005年 | 13篇 |
2004年 | 12篇 |
2003年 | 15篇 |
2002年 | 7篇 |
2001年 | 5篇 |
2000年 | 5篇 |
1999年 | 4篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1990年 | 1篇 |
排序方式: 共有413条查询结果,搜索用时 0 毫秒
61.
Partial Sperm beta1 Integrin Subunit Deletion Proves Its Involvement in Mouse Gamete Adhesion/Fusion
Virginie Barraud-Lange Cme Ialy-Radio Cline Chalas Isabelle Holtzmann Jean-Philippe Wolf Sandrine Barbaux Ahmed Ziyyat 《International journal of molecular sciences》2020,21(22)
We have previously shown, using antibodies, that the sperm alpha6beta1 integrin is involved in mouse gamete fusion in vitro. Here we report the conditional knockdown of the sperm Itgb1 gene. It induced a drastic failure of sperm fusogenic ability with sperm accumulation in the perivitelline space of in vitro inseminated oocytes deleted or not for the Itgb1 gene. These data demonstrate that sperm, but not oocyte, beta1 integrin subunit is involved in gamete adhesion/fusion. Curiously, knockdown males were fertile in vivo probably because of the incomplete Cre-mediated deletion of the sperm Itgb1 floxed gene. Indeed, this was shown by Western blot analysis and confirmed by both the viability and litter size of pups obtained by mating partially sperm Itgb1 deleted males with females producing completely deleted Itgb1 oocytes. Because of the total peri-implantation lethality of Itgb1 deletion in mice, we assume that sperm that escaped the Itgb1 excision seemed to be preferentially used to fertilize in vivo. Here, we showed for the first time that the deletion, even partial, of the sperm Itgb1 gene makes the sperm unable to normally fertilize oocytes. However, to elucidate the question of the essentiality of its role during fertilization, further investigations using a mouse expressing a recombinase more effective in male germ cells are necessary. 相似文献
62.
Praveen Kumar Christopher L. Berhaut Diana Zapata Dominguez Eric De Vito Samuel Tardif Stphanie Pouget Sandrine Lyonnard Pierre‐Henri Jouneau 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(11)
Failure mechanisms associated with silicon‐based anodes are limiting the implementation of high‐capacity lithium‐ion batteries. Understanding the aging mechanism that deteriorates the anode performance and introducing novel‐architectured composites offer new possibilities for improving the functionality of the electrodes. Here, the characterization of nano‐architectured composite anode composed of active amorphous silicon domains (a‐Si, 20 nm) and crystalline iron disilicide (c‐FeSi2, 5–15 nm) alloyed particles dispersed in a graphite matrix is reported. This unique hierarchical architecture yields long‐term mechanical, structural, and cycling stability. Using advanced electron microscopy techniques, the nanoscale morphology and chemical evolution of the active particles upon lithiation/delithiation are investigated. Due to the volumetric variations of Si during lithiation/delithiation, the morphology of the a‐Si/c‐FeSi2 alloy evolves from a core‐shell to a tree‐branch type structure, wherein the continuous network of the active a‐Si remains intact yielding capacity retention of 70% after 700 cycles. The root cause of electrode polarization, initial capacity fading, and electrode swelling is discussed and has profound implications for the development of stable lithium‐ion batteries. 相似文献
63.
Standard material parameters identification strategies for constitutive equations generally use an extensive number of classical tests for collecting the required experimental data. Recently, new specimen geometries for heterogeneous tests were designed to enhance the richness of the strain field and capture supplementary strain states using full‐field measurement techniques. The butterfly specimen is an example of such a geometry, designed through a numerical optimization procedure where an indicator capable of evaluating the heterogeneity and the richness of strain information is used. The aim of this work is to experimentally validate the heterogeneous butterfly mechanical test in the parameter identification framework. Blanks of mild steel DC04 are cut with the butterfly geometry, and specific grips are designed. Tests are performed with Digital Image Correlation technique, and a Finite Element Model Update inverse strategy is used for the parameter identification, as well as the calculation of the indicator. The identification strategy is accomplished with the data obtained from the experimental tests, and the results are compared with quasi‐homogeneous tests. 相似文献
64.
This special issue collects current efforts to advance the state of the art in the science and technology of software verification, through the interaction of theory development, tool evolution, and experimental validation. 相似文献
65.
Gary Jacobs Sandrine Ricote Uschi M. Graham Patricia M. Patterson Burtron H. Davis 《Catalysis Today》2005,106(1-4):259-264
A similar degree of surface shell reduction of ceria was obtained for a series of metal/ceria catalysts. Surface formate species were generated by reaction of CO with bridging OH groups associated with the Ce3+ defects. Forward decomposition of the pseudo-stable formates was followed in flowing H2O, leading to the production of surface carbonate species. The forward formate decomposition rate was enhanced changing the promoter from Au to Pt, and by increasing the promoter loading (from 0.5 to 2.5%). Results suggest that formate CH bond breaking is not only facilitated by H2O, but it is further enhanced by type and loading of metal promoter. From earlier kinetic isotope effect and isotopic tracer studies, the rate-limiting step of the forward formate decomposition (WGS reaction) was considered to be associated with CH bond rupture of the formate. The results can explain the promotion in the WGS rates observed for these samples by changing from Au to Pt and by increasing the promoter loading. 相似文献
66.
Proton Transport in Electrospun Hybrid Organic–Inorganic Membranes: An Illuminating Paradox
下载免费PDF全文
![点击此处可从《Advanced functional materials》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Leslie Dos Santos Manuel Maréchal Armel Guillermo Sandrine Lyonnard Simona Moldovan Ovidiu Ersen Ozlem Sel Hubert Perrot Christel Laberty‐Robert 《Advanced functional materials》2016,26(4):594-604
Chemistry and processing have to be judiciously combined to structure the membranes at various length scales to achieve efficient properties for polymer electrolyte membrane fuel cell to make it competitive for transport. Characterizing the proton transport at various length and space scales and understanding the interplays between the nanostructuration, the confinement effect, the interactions, and connectivity are consequently needed. The goal here is to study the proton transport in multiscale, electrospun hybrid membranes (EHMs) at length scales ranging from molecular to macroscopic by using complementary techniques, i.e., electrochemical impedance spectroscopy, pulsed field gradient‐NMR spectroscopy, and quasielastic neutron scattering. Highly conductive hybrid membranes (EHMs) are produced and their performances are rationalized taken into account the balances existing between local interaction driven mobility and large‐scale connectivity effects. It is found that the water diffusion coefficient can be locally decreased (2 × 10?6 cm2 s?1) due to weak interactions with the silica network, but the macroscopic diffusion coefficient is still high (9.6 × 10?6 cm2 s?1). These results highlight that EHMs have slow dynamics at the local scale without being detrimental for long‐range proton transport. This is possible through the nanostructuration of the membranes, controlled via processing and chemistry. 相似文献
67.
Alves ID Sachon E Bolbach G Millstine L Lavielle S Sagan S 《Analytical chemistry》2007,79(6):2189-2198
Integral membrane proteins are among the most challenging targets for biomedical research as most important cellular functions are tied to these proteins. To analyze intrinsically their structure/function, their transduction mechanism, or both, these proteins are commonly expressed in cultured cells as recombinant proteins. However, it is not possible to check whether these recombinant proteins are homogeneously or heterogeneously expressed. Owing to difficulties in their purification, very few mass spectrometry studies have been performed with those proteins and even less with G-protein coupled receptors. Here we have set up a procedure that is highly compatible with MALDI-TOF mass spectrometry to analyze an intact histidine-tagged G-protein coupled, namely, the tachykinin NK-1 receptor expressed in CHO cells, solubilized and purified using cobalt or nickel chelating magnetic beads. The metal-chelating magnetic beads containing the receptor were directly spotted on the MALDI plate for analysis. SDS-PAGE, combined with in-gel digestion analyzed by mass spectrometry, Western blot ((His)6 and FLAG M2 tags), photoaffinity labeling with a radioactive agonist, and Edman sequencing, confirmed the identity of the purified protein as the human tachykinin NK-1 receptor. Mass spectrometry study of both the glycosylated and deglycosylated intact protein forms revealed the existence of several receptor species that is tempting to correlate with the unusual pharmacological behavior of the receptor. 相似文献
68.
Sandrine Marinhas Anthony Delahaye Laurence Fournaison 《International Journal of Refrigeration》2007,30(5):758-766
In the present paper, the suitability of hydrate slurries in secondary refrigeration was investigated by the means of a new hydrate solid-fraction model. Considering the high melting enthalpy of CO2-containing hydrates, slurries presenting high hydrate solid fractions can carry sufficient latent heat to be useful for a two-phase secondary-refrigerant application. The model presented in this paper allowed to calculate the solid fraction of CO2 and CO2–THF hydrate from thermodynamic conditions of pressure and temperature. Contrary to a previous work on single CO2 hydrates in a closed system, the present model can take into account hydrate mixture and is well adapted to additional CO2 injections (opened system). By relying on the hydrate-conversion model results, the study of hydrates in suspension in a carrying liquid was also studied in an experimental loop and was based on a formation process by CO2 injection in a cooled aqueous solution. 相似文献
69.
Elizabeth Dufourcq-Sekatcheff Stephan Cuin Yonghua Li-Beisson Loïc Quevarec Myriam Richaud Simon Galas Sandrine Frelon 《International journal of molecular sciences》2021,22(19)
Wildlife is chronically exposed to various sources of ionizing radiations, both environmental or anthropic, due to nuclear energy use, which can induce several defects in organisms. In invertebrates, reproduction, which directly impacts population dynamics, has been found to be the most radiosensitive endpoint. Understanding the underlying molecular pathways inducing this reproduction decrease can help in predicting the effects at larger scales (i.e., population). In this study, we used a life stage dependent approach in order to better understand the molecular determinants of reproduction decrease in the roundworm C. elegans. Worms were chronically exposed to 50 mGy·h−1 external gamma ionizing radiations throughout different developmental periods (namely embryogenesis, gametogenesis, and full development). Then, in addition to reproduction parameters, we performed a wide analysis of lipids (different class and fatty acid via FAMES), which are both important signaling molecules for reproduction and molecular targets of oxidative stress. Our results showed that reproductive defects are life stage dependent, that lipids are differently misregulated according to the considered exposure (e.g., upon embryogenesis and full development) and do not fully explain radiation induced reproductive defects. Finally, our results enable us to propose a conceptual model of lipid signaling after radiation stress in which both the soma and the germline participate. 相似文献
70.
We have previously reported that vision decline was not associated with amyloidogenesis processing in aging C57BL/6J wild-type (WT) mice and in a mouse model of Alzheimer’s disease, the APPswe/PS1ΔE9 transgenic mouse model (APP/PS1). This conclusion was drawn using middle-aged (10–13 months old) mice. Here, we hypothesized that compared with hippocampal and cortical neurons, the weak amyloidogenic activity of retinal neurons may result in a detectable release of amyloid β (Aβ) only in aged mice, i.e., between 14 and 24 months of age. The aim of the present study was thus to follow potential activity changes in the amyloidogenic and nonamyloidogenic pathways of young (4 months) and old (20–24 months) WT and APP/PS1 mice. Our results showed that in spite of retinal activity loss reported by electroretinogram (ERG) recordings, the level of amyloid beta precursor protein (APP) and its derivatives did not significantly vary in the eyes of old vs. young mice. Strikingly, the ectopic expression of human APPswe in APP/PS1 mice did not allow us to detect Aβ monomers at 23 months. In contrast, Aβ was observed in hippocampal and cortical tissues at this age but not at 4 months of life. In contrast, optic nerve transection-induced retinal ganglion cell injury significantly affected the level of retinal APP and the secretion of soluble APP alpha in the vitreous. Collectively, these results suggest that the amyloidogenic and nonamyloidogenic pathways are not involved in visual function decline in aging mice. In WT and APP/PS1 mice, it is proposed that retinal neurons do not have the capacity to secrete Aβ in contrast with other cortical and hippocampal neurons. 相似文献