全文获取类型
收费全文 | 6924篇 |
免费 | 178篇 |
国内免费 | 4篇 |
专业分类
化学 | 4475篇 |
晶体学 | 35篇 |
力学 | 220篇 |
数学 | 900篇 |
物理学 | 1476篇 |
出版年
2023年 | 32篇 |
2022年 | 48篇 |
2021年 | 66篇 |
2020年 | 79篇 |
2019年 | 91篇 |
2018年 | 107篇 |
2017年 | 74篇 |
2016年 | 161篇 |
2015年 | 193篇 |
2014年 | 185篇 |
2013年 | 367篇 |
2012年 | 424篇 |
2011年 | 431篇 |
2010年 | 292篇 |
2009年 | 187篇 |
2008年 | 427篇 |
2007年 | 378篇 |
2006年 | 362篇 |
2005年 | 341篇 |
2004年 | 301篇 |
2003年 | 277篇 |
2002年 | 238篇 |
2001年 | 148篇 |
2000年 | 158篇 |
1999年 | 76篇 |
1998年 | 102篇 |
1997年 | 70篇 |
1996年 | 99篇 |
1995年 | 52篇 |
1994年 | 64篇 |
1993年 | 59篇 |
1992年 | 63篇 |
1991年 | 36篇 |
1990年 | 39篇 |
1989年 | 42篇 |
1988年 | 51篇 |
1987年 | 29篇 |
1986年 | 34篇 |
1985年 | 57篇 |
1984年 | 64篇 |
1983年 | 32篇 |
1982年 | 43篇 |
1981年 | 52篇 |
1980年 | 45篇 |
1979年 | 41篇 |
1978年 | 45篇 |
1977年 | 48篇 |
1976年 | 58篇 |
1975年 | 42篇 |
1973年 | 34篇 |
排序方式: 共有7106条查询结果,搜索用时 15 毫秒
81.
S. Franchoo F. Ibrahim F. Le Blanc M. Lebois A. Olivier C. Phan Viet B. Roussière R. Sifi D. Verney 《Hyperfine Interactions》2006,171(1-3):117-119
The availability of both a tandem deuteron beam and a linac electron beam, the latter converted into Bremsstrahlung, at the
new ALTO facility at IPN-Orsay offers a unique opportunity to compare the performance of a laser ion guide under different
regimes. The ALTO accelerator has delivered its first electron beam at the end of 2005 and a design for a gas-cell prototype
is being studied. 相似文献
82.
Glycopeptides were isolated from functional units of two molluscan hemocyanins (Hcs). They were analyzed and localized in the sequences. A comparison with potential N-glycosylation sites of two other molluscan Hcs was made. An immunological cross-reactivity was observed between the beta-Hc and the alpha-macroglobulin of Helix pomotia. ELISA experiments with glycopeptide fractions indicated a competition. 相似文献
83.
We describe innovation in terms of a generalized branching process. Each new invention pairs with any existing one to produce a number of offspring, which is Poisson distributed with mean p. Existing inventions die with probability p/τ at each generation. In contrast with mean field results, no phase transition occurs; the chance for survival is finite for all p > 0. For τ = ∞, surviving processes exhibit a bottleneck before exploding superexponentially-a growth consistent with a law of accelerating returns. This behavior persists for finite τ. We analyze, in detail, the asymptotic behavior as p→0. 相似文献
84.
Hellmann S Beye M Sohrt C Rohwer T Sorgenfrei F Redlin H Kalläne M Marczynski-Bühlow M Hennies F Bauer M Föhlisch A Kipp L Wurth W Rossnagel K 《Physical review letters》2010,105(18):187401
Femtosecond time-resolved core-level photoemission spectroscopy with a free-electron laser is used to measure the atomic-site specific charge-order dynamics of the charge-density?wave in the Mott insulator 1T-TaS2. After strong photoexcitation, a prompt loss of charge order and subsequent fast equilibration dynamics of the electron-lattice system are observed. On the time scale of electron-phonon thermalization, about 1?ps, the system is driven across a phase transition from a long-range charge ordered state to a quasiequilibrium state with domainlike short-range charge and lattice order. The experiment opens the way to study the nonequilibrium dynamics of condensed matter systems with full elemental, chemical, and atomic-site selectivity. 相似文献
85.
Gaëtan Compère Emilie Marchandise Jean-François Remacle 《Journal of computational physics》2008,227(3):1923-1942
An anisotropic adaptation process is applied to a three-dimensional incompressible two-phase flow solver. The solver uses a level set/finite element method on unstructured tetrahedral meshes. We show how the level set function can be used to build an anisotropic mesh with good properties. Some computations with a strong transient character and large densities ratios (1/1000) are presented. We show that the efficiency of the computations can be deeply enhanced by mesh adaptations. 相似文献
86.
J. Blachot J. Crançon B. de Goncourt A. Gizon A. Llères 《Zeitschrift für Physik A Hadrons and Nuclei》1985,321(4):645-651
Cross sections, recoil energy distributions for residues produced by14N,20Ne,40Ar on124Sn targets have been measured in the 10–70 MeV/u intermediate energy range. As the projectile energy increases, processes as complete fusion-evaporation, incomplete fusion-evaporation and intranuclear cascade-evaporation participate progressively in the nuclear collisions. Peculiar residues corresponding to a gain of 4, 5 or even 6 protons for the124Sn target have been observed in the 30–50 MeV energy range. 相似文献
87.
88.
Gidal G Boyer J Butler F Cords D Abrams GS Amidei D Baden AR Barklow T Boyarski AM Burchat P Burke DL Dorfan JM Feldman GJ Gladney L Gold MS Goldhaber G Golding LJ Haggerty J Hanson G Hayes K Herrup D Hollebeek RJ Innes WR Jaros JA Juricic I Kadyk JA Karlen D Klein SR Lankford AJ Larsen RR LeClaire BW Levi ME Lockyer NS Lüth V Matteuzzi C Nelson ME Ong RA Perl ML Richter B Riles K Rowson PC Schaad T Schellman H Schmidke WB Sheldon PD Trilling GH de la Vaissière C Wood DR Yelton JM Zaiser C 《Physical review letters》1987,59(18):2016-2019
89.
R. Bimbot D. Gardès H. Geissel K. H. Schmidt 《Zeitschrift für Physik A Hadrons and Nuclei》1978,286(3):327-328
The kinetic energy of86Kr ions accelerated by UNILAC (GSI-Darmstadt) was measured using the recoil proton technique. A good agreement was found with the energy values obtained by the time-of-flight technique currently used at UNILAC. 相似文献
90.
Agnès Tourin 《Numerische Mathematik》1992,62(1):75-85
Summary The reconstruction from a shaded image of a Lambertian and not self-shadowing surface illuminated by a single distant pointwise light source may be written as a first-order Hamilton-Jacobi equation.In this paper, we continue the investigation begun in E. Rouy and A. Tourin into the uniqueness of the solution of this equation; the approach is based on the viscosity solutions theory and the dynamic programming principle.More precisely, we concentrate here on the uniqueness of the viscosity solution of this equation in case the measured luminous intensity reflected by the surface is discontinuous along a smooth curve. We prove a general comparison result for a piecewise Lipschitz continuous Hamiltonian and illustrate it by numerical experiments. 相似文献