全文获取类型
收费全文 | 226篇 |
免费 | 6篇 |
国内免费 | 2篇 |
专业分类
化学 | 181篇 |
力学 | 4篇 |
数学 | 23篇 |
物理学 | 26篇 |
出版年
2022年 | 6篇 |
2021年 | 13篇 |
2020年 | 4篇 |
2019年 | 4篇 |
2018年 | 3篇 |
2017年 | 3篇 |
2016年 | 3篇 |
2015年 | 7篇 |
2014年 | 6篇 |
2013年 | 25篇 |
2012年 | 10篇 |
2011年 | 14篇 |
2010年 | 7篇 |
2009年 | 3篇 |
2008年 | 7篇 |
2007年 | 14篇 |
2006年 | 21篇 |
2005年 | 8篇 |
2004年 | 13篇 |
2003年 | 5篇 |
2002年 | 9篇 |
2001年 | 4篇 |
2000年 | 3篇 |
1999年 | 7篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 5篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1990年 | 3篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1981年 | 2篇 |
1979年 | 3篇 |
1977年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有234条查询结果,搜索用时 15 毫秒
81.
Chiantia S Kahya N Schwille P 《Langmuir : the ACS journal of surfaces and colloids》2005,21(14):6317-6323
Atomic force microscopy (AFM) has been applied to characterize hydrated sphingomyelin/dioleoylphosphatidylcholine/cholesterol supported bilayers, after dehydration either in the absence or in the presence of several stabilizing substances. Such a study provides information about the effect of extreme environmental conditions on biological membranes and, in particular, on lipidic microdomains. Dehydration stress, indeed, is thought to cause both macroscopical damage and alterations of microdomains in biomembranes, leading to deleterious effects. These phenomena can be avoided if disaccharides are added during dehydration. In this work, we apply AFM imaging to directly visualize damage caused to supported lipid bilayers by water removal. We compare the efficiency of sucrose, trehalose, dextran, dimethyl sulfoxide, and glucose in preserving the structural integrity of domain-exhibiting model membranes. Finally, in addition to confirming previous findings, our results provide further insight into damage and alteration of microdomains in membranes as a consequence of stressful drying conditions. 相似文献
82.
Nematic liquid crystal droplets dispersed in a thermoplastic matrix with a built-in d.c. electric field exhibit a quasi-linear response to an electric field. In this work we show a device characterized by a large light modulation. The device can store fields up to several V µm -1 and operates well from d.c. to several kHz. In addition, we found that the experimental results are in agreement with a simple theoretical model for light scattering by a dispersion of liquid crystal droplets. This device allows us to overcome possible drawbacks, due to a reduced light modulation, in applications where polarity detection is required. 相似文献
83.
Rovere Pierpaolo Nicoletta Squarcina Secondo Gola Luca Sandei Stefania Iametti Giuseppe Carpi 《高压研究》2013,33(1-6):99-107
Abstract It is known that pressure alone is not able to make shelf-stable any food stored in room conditions. Acid products are normally spoiled by enzymes, and low acid products are spoiled even by spore-forming micro-organisms. To overcome the problem the role of heat in the process has been re-evaluated and the possibility of destroying at the same time spores and enzymes has been found. This work compares the effect of sterilisation by High Pressure Processing (HPP) with one of the conventional retort processing techniques. Two batches of meat sauce were kept in room conditions over a year and their quality was evaluated periodically during the shelf life simulation. The physico-chemical characteristics of the retorted ones showed a progressive appearance of the typical thermal damage. The High Pressure Sterilised samples on the contrary showed limited damage, related to the unavoidable pre-heating. Their quality markers were constant over the shelf life evaluated period. 相似文献
84.
85.
Giovanni De Filpo Marialuigia MacChione Fiore P. Nicoletta Daniela Cupelli Roberta Cassano Giuseppe Chidichimo 《Liquid crystals》2013,40(8):1025-1029
In this work we present a new technique for obtaining large diffraction gratings (some cm) by means of a simple filling of cells having a planar treatment of their inner surfaces. A homogeneous mixture, composed of a cholesteric liquid crystal and a nematic liquid crystal monomer, was used. During the filling process, the flow induces a phase separation between the cholesteric liquid crystal and the liquid crystal monomer and, at the same time, the latter is oriented planar to the surfaces of the cell. Phase separation produces alternate arrays constituted by the cholesteric liquid crystal and the nematic liquid crystal monomer. Successive UV polymerization of these films yields a permanent grating. We have investigated the transmitted and first order diffracted beam efficiency for films obtained at different temperatures. The morphology of the films was studied by using an optical microscope equipped with crossed polarizers and by electron microscopy in order to control the shape of the arrays and the alignment of the oriented polymer. 相似文献
86.
Rosa Pilolli Nicoletta Ditaranto Nicola Cioffi Luigia Sabbatini 《Analytical and bioanalytical chemistry》2013,405(2-3):713-724
In the present, contribution angle-resolved X-ray photoelectron spectroscopy (AR-XPS) was proposed as a useful tool to address the challenge of probing the near-surface region of bio-active sensor surfaces. A model bio-functionalised surface was characterised by parallel AR-XPS and commercially available Thermo Avantage-ARProcess software was used to generate non-destructive concentration depth profiles of protein-functionalised silicon oxide substrates. At each step of the functionalisation procedure, the surface composition, the overlayer thickness, the in-depth organisation and the in-plane homogeneity were evaluated. The critical discussion of the generated profiles highlighted the relevance of the information provided by PAR-XPS technique. Figure
Schematic representation of the functionalization procedure along with the generated profiles 相似文献
87.
Martina Vizza Walter Giurlani Lorenzo Cerri Nicola Calisi Antonio Alessio Leonardi Maria Jos Lo Faro Alessia Irrera Enrico Berretti Juan Víctor Perales-Rondn Alvaro Colina Elena Bujedo Saiz Massimo Innocenti 《Molecules (Basel, Switzerland)》2022,27(17)
Molybdenum disulfide (MoS2) has attracted great attention for its unique chemical and physical properties. The applications of this transition metal dichalcogenide (TMDC) range from supercapacitors to dye-sensitized solar cells, Li-ion batteries and catalysis. This work opens new routes toward the use of electrodeposition as an easy, scalable and cost-effective technique to perform the coupling of Si with molybdenum disulfide. MoS2 deposits were obtained on n-Si (100) electrodes by electrochemical deposition protocols working at room temperature and pressure, as opposed to the traditional vacuum-based techniques. The samples were characterized by X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and Rutherford Back Scattering (RBS). 相似文献
88.
G. Torquati O. Francescangeli M. Ghedini S. Armentano F. P. Nicoletta R. Bartolino 《Il Nuovo Cimento D》1990,12(9):1363-1376
Summary The results arising from a systematic X-ray analysis carried out on a homologous series ofN-(4-alkoxysalicylidene)-4′-alkyl-aniline, either as uncomplexed ligands or as copper (II) complexes, are reported. Such an
investigation, performed in order to elucidate the role played by both the metal centre and the length of the aliphatic chain,
suggests a molecular packing which accounts for the increased order induced by the metallic core, the strong interdigitation
of the molecules, the solid-phase features and the structural properties of the smectic mesophases.
Work presented at the second USSR-Italy Bilateral Meeting on Liquid Crystals held in Moscow, September 15–21, 1988. 相似文献
89.
90.
Paola Mannucci Claudio Marchi Nicoletta Tchou 《NoDEA : Nonlinear Differential Equations and Applications》2016,23(4):47
We study existence and uniqueness of the invariant measure for stochastic processes with degenerate diffusion, whose infinitesimal generators are linear subelliptic operators in the whole space \({{\mathbb{R}}^N}\) with possibly unbounded coefficients. Such a measure together with a Liouville-type theorem will play a crucial role in two applications: the ergodic problem studied through stationary problems with vanishing discount and the long time behavior of the solution to a parabolic Cauchy problem. In both cases, the constants will be characterized in terms of the invariant measure. 相似文献