全文获取类型
收费全文 | 289篇 |
免费 | 0篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 70篇 |
金属工艺 | 7篇 |
机械仪表 | 6篇 |
建筑科学 | 12篇 |
能源动力 | 8篇 |
轻工业 | 29篇 |
无线电 | 24篇 |
一般工业技术 | 57篇 |
冶金工业 | 15篇 |
原子能技术 | 5篇 |
自动化技术 | 54篇 |
出版年
2024年 | 1篇 |
2023年 | 3篇 |
2022年 | 9篇 |
2021年 | 16篇 |
2020年 | 6篇 |
2019年 | 6篇 |
2018年 | 6篇 |
2017年 | 8篇 |
2016年 | 7篇 |
2015年 | 7篇 |
2014年 | 5篇 |
2013年 | 25篇 |
2012年 | 17篇 |
2011年 | 26篇 |
2010年 | 13篇 |
2009年 | 17篇 |
2008年 | 8篇 |
2007年 | 12篇 |
2006年 | 13篇 |
2005年 | 11篇 |
2004年 | 7篇 |
2003年 | 7篇 |
2002年 | 9篇 |
2001年 | 3篇 |
2000年 | 9篇 |
1999年 | 4篇 |
1998年 | 7篇 |
1997年 | 5篇 |
1996年 | 4篇 |
1995年 | 3篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1990年 | 2篇 |
1988年 | 3篇 |
1983年 | 2篇 |
1981年 | 1篇 |
1977年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有289条查询结果,搜索用时 15 毫秒
41.
Cu Vinh Loc Nguyen Trac Burie Jean-Christophe Ogier Jean-Marc 《International Journal on Document Analysis and Recognition》2020,23(3):219-239
International Journal on Document Analysis and Recognition (IJDAR) - Motivated by increasing possibility of the tampering of genuine documents during a transmission over digital channels, we focus... 相似文献
42.
Dr. Mathieu Lalande Dr. Lucas Schwob Dr. Violaine Vizcaino Dr. Fabien Chirot Dr. Philippe Dugourd Dr. Thomas Schlathölter Dr. Jean-Christophe Poully 《Chembiochem : a European journal of chemical biology》2019,20(24):2972-2980
In this review, recent progress in understanding the direct effects of radiation on the structure and stability of collagen, the most abundant protein in the human body, and other proteins is surveyed. Special emphasis is placed on the triple-helical structure of collagen, as studied by means of collagen mimetic peptides. The emerging patterns are the dose dependence of radiation processes and their abundance, the crucial role of radicals in covalent-bond formation (crosslinking) or cleavage, and the influence of the radiation energy and nature. Future research should allow fundamental questions, such as charge transfer and fragmentation dynamics triggered by ionization, to be answered, as well as developing applications such as protein-based biomaterials, notably with properties controlled by irradiation. 相似文献
43.
Stefano J. Mandriota Mirna Tenan Adeline Nicolle Julia D. Jankowska Paolo Ferrari Jean-Christophe Tille Mary-Anne Durin Catherine M. Green Sebastien Tabruyn Daniela Moralli Andr-Pascal Sappino 《International journal of molecular sciences》2020,21(23)
Genomic instability is generally considered as a hallmark of tumorigenesis and a prerequisite condition for malignant transformation. Aluminium salts are suspected environmental carcinogens that transform mammary epithelial cells in vitro through unknown mechanisms. We report here that long-term culture in the presence of aluminium chloride (AlCl3) enables HC11 normal mouse mammary epithelial cells to form tumours and metastases when injected into the syngeneic and immunocompetent BALB/cByJ strain. We demonstrate that AlCl3 rapidly increases chromosomal structural abnormalities in mammary epithelial cells, while we failed to detect direct modulation of specific mRNA pathways. Our observations provide evidence that clastogenic activity—a well-recognized inducer of genomic instability—might account in part for the transforming abilities of aluminium in mammary epithelial cells. 相似文献
44.
Vincenzo Farano Mark Cresswell Kerstin Gritsch Phil Jackson Nina Attik Brigitte Grosgogeat Jean-Christophe Maurin 《Journal of materials science. Materials in medicine》2018,29(7):101
Phosphate-based glasses have been attracting attention due to their possible medical applications arising from unique dissolution characteristics in the human body leading to the possibility of new tissue regeneration. In this study, the leaching kinetics of a series of melt-quenched Sr-doped phosphate glasses are presented. Regardless of the presence of Sr, all the glasses have an initial linear and sustained release of the ions followed by a plateau. To guarantee proper nutritional support to the growing tissue during regeneration and to mimic the 3-dimensional architecture of tissues, organic scaffold systems have been developed. However, their poor mechanical strength has limited their application. To overcome this problem, cross-linkers can be used although this then limits the solubility of the materials. To succeed in dealing with such a limitation, in this paper, by freeze-drying, the aforementioned soluble melt-quenched phosphate glasses were combined as powders with collagen fibres from bovine achilles tendon to make degradable scaffolds. The scaffolds were characterized by SEM, EDX and BET. Changes to the dissolution behaviour of the glasses arising from the presence of collagen interacting with the ions leached were reported. Furthermore, the ability of the scaffolds to induce hydroxyapatite (HA) formation was evaluated: one the elaborated scaffold could grow an HA-like layer after a week in SBF. Based on the results obtained, a possible application in restorative dentistry is proposed for one or more materials. 相似文献
45.
Novel A-B-A triblock and star-block amphiphilic copolymers, i.e. poly(N-(2-hydroxypropyl)methacrylamide)-block-poly(D,L-lactide)-block-poly(N-(2-hydroxypropyl)metha-crylamide), poly(N-vinyl-2-pyrrolidone)-block-poly(D,L-lactide)-block-poly(N-vinyl-2-pyrrolidone), star-poly(D,L-lactide)-block-poly(N-(2-hydroxypropyl)methacrylamide) and star-poly(D,L-lactide)-block-poly(N-vinylpyrrolidone), were synthesized and characterized. These polymers were prepared by free radical polymerization of N-(2-hydroxypropyl)methacrylamide and N-vinyl-2-pyrrolidone in the presence of either poly(D,L-lactide) dithiol or star-poly(D,L-lactide) tetrakis-thiol, both biodegradable macromolecular chain-transferring agents. All copolymers self-assembled in aqueous solution to form supramolecular aggregates of 20–180 nm in size. The critical aggregation concentration of the copolymers ranged from 5 to 24 mg/L, depending on their hydrophobicity. The partition equilibrium constant of pyrene in the hydrophobic core of micelles was between 0.71×105 and 1.63×105. The triblock copolymer micelles were loaded with two model poorly water-soluble drugs, namely, indomethacin (1.5–16.4% w/w) and paclitaxel (0.4–1.5% w/w), by a dialysis procedure. These triblock and star-block copolymers could prove useful as nanocarriers for the solubilization and delivery of hydrophobic drugs. 相似文献
46.
Girard O Ginefri JC Poirier-Quinot M Darrasse L 《The Review of scientific instruments》2007,78(12):124703
A contactless method based on reflectometry to accurately characterize an inductive radio frequency (rf) resonator even in the occurrence of a strong electrical nonlinearity is presented. Nonlinear extraction of the unloaded quality factor and resonance frequency is possible by combining an initial low-level swept-frequency calibration with high-level single-frequency measurements. The extraction protocol relies on a simple intrinsic R, L, C model and does not involve a fitting procedure according to a particular nonlinearity model. It includes a correction for strong coupling conditions between the probe and the rf coil, which allows extending the analysis over a wide range of transmitted power. Electrical modeling based on the extracted intrinsic data allows predicting the coil behavior when loaded by any kind of matching network. The method will have implications in different domains such as Magnetic Resonance (MR) applications with superconducting probe heads or analysis of rf properties in nonlinear materials. The method is demonstrated here by characterizing a high temperature superconducting (HTS) coil dedicated to MR imaging at 64 MHz. The coil consists in a multiturn spiral design that is self-resonant close to the MR frequency of interest. The Q factor and the resonance frequency are determined as a function of the actual power dissipated in the HTS coil accounting for losses occurring in the measurement system. Further characteristics of the HTS coil are considered in the present paper. The relation between the transmitted power and the magnetic field generated by the coil, which is the most relevant characteristics for MR applications, is directly accessible. The equivalent impedance of the coil under test is also expressed as a function of the total current flowing in the windings. The method could be extended to assess the fundamental properties of the nonlinear material (e.g., the London penetration depth or the critical current density) by including any pertinent model. 相似文献
47.
Comparing the input, output, and validation maps for several models of land change 总被引:31,自引:0,他引:31
Robert Gilmore Pontius Jr Wideke Boersma Jean-Christophe Castella Keith Clarke Ton de Nijs Charles Dietzel Zengqiang Duan Eric Fotsing Noah Goldstein Kasper Kok Eric Koomen Christopher D. Lippitt William McConnell Alias Mohd Sood Bryan Pijanowski Snehal Pithadia Sean Sweeney Tran Ngoc Trung A. Tom Veldkamp Peter H. Verburg 《The Annals of Regional Science》2008,42(1):11-37
This paper applies methods of multiple resolution map comparison to quantify characteristics for 13 applications of 9 different
popular peer-reviewed land change models. Each modeling application simulates change of land categories in raster maps from
an initial time to a subsequent time. For each modeling application, the statistical methods compare: (1) a reference map
of the initial time, (2) a reference map of the subsequent time, and (3) a prediction map of the subsequent time. The three
possible two-map comparisons for each application characterize: (1) the dynamics of the landscape, (2) the behavior of the
model, and (3) the accuracy of the prediction. The three-map comparison for each application specifies the amount of the prediction’s
accuracy that is attributable to land persistence versus land change. Results show that the amount of error is larger than
the amount of correctly predicted change for 12 of the 13 applications at the resolution of the raw data. The applications
are summarized and compared using two statistics: the null resolution and the figure of merit. According to the figure of
merit, the more accurate applications are the ones where the amount of observed net change in the reference maps is larger.
This paper facilitates communication among land change modelers, because it illustrates the range of results for a variety
of models using scientifically rigorous, generally applicable, and intellectually accessible statistical techniques. 相似文献
48.
Claire Duménil David Woud Francesco Pinto Jeroen T. Alkema Ilse Jansen Anne M. Van Der Geest Sanne Roessingh Jean-Christophe Billeter 《Journal of chemical ecology》2016,42(3):259-269
Individuals can make choices based on information learned from others, a phenomenon called social learning. How observers differentiate between which individual they should or should not learn from is, however, poorly understood. Here, we showed that Drosophila melanogaster females can influence the choice of egg-laying site of other females through pheromonal marking. Mated females mark territories of high quality food by ejecting surplus male sperm containing the aggregation pheromone cis-11-vaccenyl acetate (cVA) and, in addition, deposit several sex- and species-specific cuticular hydrocarbon (CHC) pheromones. These pheromonal cues affect the choices of other females, which respond by preferentially laying eggs on the marked food. This system benefits both senders and responders, as communal egg laying increases offspring survival. Virgin females, however, do not elicit a change in the egg-laying decision of mated females, even when food has been supplemented with ejected sperm from mated females, thus indicating the necessity for additional cues. Genetic ablation of either a female’s CHC pheromones or those of their mate results in loss of ability of mated females to attract other females. We conclude that mated females use a pheromonal marking system, comprising cVA acquired from male ejaculate with sex- and species-specific CHCs produced by both mates, to indicate egg-laying sites. This system ensures information reliability because mated, but not virgin, females have both the ability to generate the pheromone blend that attracts other flies to those sites and a direct interest in egg-laying site quality. 相似文献
49.
The development of a novel, chemoselective, and catalytic deprotection methodology that proceeds under mild and neutral conditions is described, and its mechanism of action is analyzed in some detail. The scope, limitations, and advantages of this protocol are discussed. Selected applications in synthesis are also highlighted. 相似文献
50.
Tchernycheva M Cirlin GE Patriarche G Travers L Zwiller V Perinetti U Harmand JC 《Nano letters》2007,7(6):1500-1504
We report on the fabrication by Au-assisted molecular beam epitaxy of InP nanowires with embedded InAsP insertions. The growth temperature affects the nucleation on the nanowire lateral surface. It is therefore possible to grow the wires in two steps: to fabricate an axial heterostructure (at 420 degrees C), and then cover it by a shell (at 390 degrees C). The InAsP alloy composition could be varied between InAs0.35P0.65 and InAs0.5P0.5 by changing the As to P flux ratio. When a shell is present, the InAsP segments show strong room-temperature photoluminescence with a peak wavelength tunable from 1.2 to 1.55 mum by adjusting the As content. If the axial heterostructure has no shell, luminescence intensity is drastically reduced. Low-temperature microphotoluminescence performed on isolated single wires shows narrow peaks with a line width as small as 120 microeV. 相似文献