全文获取类型
收费全文 | 6032篇 |
免费 | 204篇 |
国内免费 | 33篇 |
专业分类
化学 | 4151篇 |
晶体学 | 19篇 |
力学 | 210篇 |
数学 | 1040篇 |
物理学 | 849篇 |
出版年
2022年 | 35篇 |
2021年 | 59篇 |
2020年 | 65篇 |
2019年 | 81篇 |
2018年 | 85篇 |
2017年 | 81篇 |
2016年 | 154篇 |
2015年 | 141篇 |
2014年 | 169篇 |
2013年 | 259篇 |
2012年 | 327篇 |
2011年 | 368篇 |
2010年 | 235篇 |
2009年 | 232篇 |
2008年 | 331篇 |
2007年 | 325篇 |
2006年 | 332篇 |
2005年 | 303篇 |
2004年 | 262篇 |
2003年 | 241篇 |
2002年 | 288篇 |
2001年 | 106篇 |
2000年 | 102篇 |
1999年 | 56篇 |
1998年 | 59篇 |
1997年 | 65篇 |
1996年 | 77篇 |
1995年 | 53篇 |
1994年 | 64篇 |
1993年 | 52篇 |
1992年 | 49篇 |
1991年 | 57篇 |
1990年 | 47篇 |
1989年 | 44篇 |
1988年 | 39篇 |
1987年 | 44篇 |
1986年 | 39篇 |
1985年 | 84篇 |
1984年 | 83篇 |
1983年 | 51篇 |
1982年 | 87篇 |
1981年 | 56篇 |
1980年 | 77篇 |
1979年 | 56篇 |
1978年 | 74篇 |
1977年 | 56篇 |
1976年 | 56篇 |
1975年 | 42篇 |
1974年 | 44篇 |
1973年 | 33篇 |
排序方式: 共有6269条查询结果,搜索用时 46 毫秒
131.
132.
Pierre Douzou 《Nachrichten aus der Chemie》1981,29(8):540-543
133.
Mario Olivieri Gianluca Spiteri Jessica Brandi Daniela Cecconi Marina Fusi Giovanna Zanoni Corrado Rizzi 《Molecules (Basel, Switzerland)》2022,27(4)
Wheat allergens are responsible for symptoms in 60–70% of bakers with work-related allergy, and knowledge, at the molecular level, of this disorder is progressively accumulating. The aim of the present study is to investigate the panel of wheat IgE positivity in allergic Italian bakers, evaluating a possible contribution of novel wheat allergens included in the water/salt soluble fraction. The water/salt-soluble wheat flour proteins from the Italian wheat cultivar Bolero were separated by using 1-DE and 2-DE gel electrophoresis. IgE-binding proteins were detected using the pooled sera of 26 wheat allergic bakers by immunoblotting and directly recognized in Coomassie stained gel. After a preparative electrophoretic step, two enriched fractions were furtherly separated in 2-DE allowing for detection, by Coomassie, of three different proteins in the range of 21–27 kDa that were recognized by the pooled baker’s IgE. Recovered spots were analyzed by nanoHPLC Chip tandem mass spectrometry (MS/MS). The immunodetected spots in 2D were subjected to mass spectrometry (MS) analysis identifying two new allergenic proteins: a glucose/ribitol dehydrogenase and a 16.9 kDa class I heat shock protein 1. Mass spectrometer testing of flour proteins of the wheat cultivars utilized by allergic bakers improves the identification of until now unknown occupational wheat allergens. 相似文献
134.
135.
136.
Grand symmetry models in noncommutative geometry, characterized by a non-trivial action of functions on spinors, have been introduced to generate minimally (i.e. without adding new fermions) and in agreement with the first order condition an extra scalar field beyond the standard model, which both stabilizes the electroweak vacuum and makes the computation of the mass of the Higgs compatible with its experimental value. In this paper, we use a twist in the sense of Connes-Moscovici to cure a technical problem due to the non-trivial action on spinors, that is the appearance together with the extra scalar field of unbounded vectorial terms. The twist makes these terms bounded and - thanks to a twisted version of the first-order condition that we introduce here - also permits to understand the breaking to the standard model as a dynamical process induced by the spectral action, as conjectured in [24]. This is a spontaneous breaking from a pre-geometric Pati-Salam model to the almost-commutativegeometryofthestandardmodel,withtwoHiggs-likefields: scalar and vector. 相似文献
137.
Jocelyn D Laughton Philippe Bittar Yves Charnay Luc Pellerin Enikö Kovari Pierre J Magistretti Constantin Bouras 《BMC neuroscience》2007,8(1):35
Background
For a long time now, glucose has been thought to be the main, if not the sole substrate for brain energy metabolism. Recent data nevertheless suggest that other molecules, such as monocarboxylates (lactate and pyruvate mainly) could be suitable substrates. Although monocarboxylates poorly cross the blood brain barrier (BBB), such substrates could replace glucose if produced locally. 相似文献138.
Bermejo D Martínez RZ Loubignac E Boudon V Pierre G 《Journal of Molecular Spectroscopy》2000,201(1):164-171
High-resolution Raman spectra of the nu(2) band of SF(6) have been recorded at a temperature of 195 K (dry ice) and a pressure of 39 mbar. These spectra were analyzed using a new set of programs specially written for XY(6) molecules. These programs, called HTDS (highly spherical top data system) in reference to the set of programs called STDS (spherical top data system written for XY(4) molecules) can be freely accessible through ftp (user anonymous) at jupiter.u-bourgogne.fr or on the web at the URL http://www.u-bourgogne.fr/LPUB/shTDS.html. The study of nu(2) was made using a Hamiltonian developed through the third order. Four parameters were determined. The standard deviation obtained using about 559 data up to J < 61 is 0.0021 cm(-1). This result is used to refine by simultaneous analysis the nu(2) and nu(2) + nu(6) bands of SF(6). This new fit allows the determination for the first time of some nu(6) parameters. The values obtained for this band (forbidden in Raman and in infrared) will be used to study the infrared hot bands in the nu(3) and nu(4) regions. Copyright 2000 Academic Press. 相似文献
139.
Pierre Pigeaud 《Reports on Mathematical Physics》1978,14(2):261-284
The theory of Jordan-Thiry is investigated by using a five-dimensional Riemannian manifold V5 which admits a one-parameter group of isometries. The set of trajectories is supposed to represent the space-time of Relativity.The use of the induced metric in the quotient space leads to essential difficulties. It is necessary to consider a conformal metric and to modify the energy tensor in order to obtain the classical results of relativistic celestial mechanics. Moreover, the conformal metric brings out the evident interpretation of the fifteenth potential like a massless scalar field.A mass term referring to the scalar field is introduced; then the gravitational, electromagnetic, and mesonic scalar fields are unified through the metric of V5. Several results make the new theory very coherent; in particular, the exact relativistic equations of motion are obtained asymptotically when the matter density vanishes.Exact solutions are searched. The classical Schwarzschild solution and neighbouring solutions are valid in the interior of the matter. Special non-static solutions are also obtained; some of these may be interpreted locally as describing the “collapse” of neutron stars; others ones, analogous to Robertson's metric, can be used to build a cosmology of the unified field. 相似文献
140.
Electroreflectance spectra at normal incidence of (100) and (110) faces of gold and copper monocrystals are given, in the spectral range from 0.22–0.7 μm. The fractional change in reflectance is different with (110) faces when light is polarized parallel to the [001] direction and parallel to the [] direction while no anisotropy is seen on (100) faces. This shows that electroreflectance is a powerful tool to investigate metal surfaces where the optical electrons are sensitive to the distribution of the surface atoms. 相似文献