全文获取类型
收费全文 | 445篇 |
免费 | 11篇 |
专业分类
化学 | 300篇 |
晶体学 | 16篇 |
力学 | 29篇 |
数学 | 49篇 |
物理学 | 62篇 |
出版年
2022年 | 5篇 |
2021年 | 6篇 |
2020年 | 5篇 |
2019年 | 5篇 |
2018年 | 8篇 |
2017年 | 7篇 |
2016年 | 10篇 |
2015年 | 9篇 |
2014年 | 12篇 |
2013年 | 19篇 |
2012年 | 26篇 |
2011年 | 23篇 |
2010年 | 18篇 |
2009年 | 11篇 |
2008年 | 22篇 |
2007年 | 23篇 |
2006年 | 12篇 |
2005年 | 24篇 |
2004年 | 17篇 |
2003年 | 15篇 |
2002年 | 16篇 |
2001年 | 6篇 |
2000年 | 7篇 |
1999年 | 5篇 |
1998年 | 7篇 |
1997年 | 3篇 |
1996年 | 8篇 |
1995年 | 10篇 |
1994年 | 9篇 |
1993年 | 6篇 |
1992年 | 3篇 |
1991年 | 7篇 |
1990年 | 9篇 |
1989年 | 2篇 |
1987年 | 5篇 |
1985年 | 5篇 |
1984年 | 6篇 |
1983年 | 5篇 |
1982年 | 7篇 |
1981年 | 5篇 |
1980年 | 4篇 |
1979年 | 7篇 |
1978年 | 4篇 |
1977年 | 6篇 |
1976年 | 3篇 |
1975年 | 2篇 |
1974年 | 5篇 |
1972年 | 5篇 |
1968年 | 2篇 |
1966年 | 2篇 |
排序方式: 共有456条查询结果,搜索用时 31 毫秒
451.
Maria Luisa Dalla Chiara Roberto Giuntini Roberto Leporini Giuliano Toraldo di Francia 《International Journal of Theoretical Physics》2008,47(1):44-60
In quantum computational logics meanings of formulas are identified with quantum information quantities: systems of qubits or, more generally, mixtures of systems of qubits. We consider two kinds of quantum computational semantics: (1) a compositional semantics, where the meaning of a compound formula is determined by the meanings of its parts; (2) a holistic semantics, which makes essential use of the characteristic “holistic” features of the quantum-theoretic formalism. The compositional
and the holistic semantics turn out to characterize the same logic. In this framework, one can introduce the notion of quantum-classical truth table, which corresponds to the most natural way for a quantum computer to calculate classical tautologies.
Quantum computational logics can be applied to investigate different kinds of semantic phenomena where holistic, contextual and gestaltic patterns play an essential role (from natural languages to musical compositions). 相似文献
452.
We show how to realize a “protected” qubit by using a fully frustrated Josephson junction ladder (JJL) with Mobius boundary conditions. Such a system has been recently studied within a twisted conformal field theory (CFT) approach [G. Cristofano, G. Maiella, V. Marotta, Mod. Phys. Lett. A 15 (2000) 1679; G. Cristofano, G. Maiella, V. Marotta, G. Niccoli, Nucl. Phys. B 641 (2002) 547] and shown to develop the phenomenon of flux fractionalization [G. Cristofano, V. Marotta, A. Naddeo, G. Niccoli, Eur. Phys. J. B 49 (2006) 83]. The relevance of a “closed” geometry has been fully exploited in relating the topological properties of the ground state of the system to the presence of half flux quanta and the emergence of a topological order has been predicted [G. Cristofano, V. Marotta, A. Naddeo, J. Stat. Mech.: Theory Exp. (2005) P03006]. In this Letter the stability and transformation properties of the ground states under adiabatic magnetic flux change are analyzed and the deep consequences on the realization of a solid state qubit, protected from decoherence, are presented. 相似文献
453.
G. Peter Matthews Charlotte L. Levy Giuliano M. Laudone Katie L. Jones Cathy J. Ridgway Ingrid L. Hallin S. Andrea Gazze Lewis Francis W. Richard Whalley Joachim Schoelkopf Patrick A. C. Gane 《Transport in Porous Media》2018,124(2):631-653
This work addresses two continuing fallacies in the interpretation of percolation characteristics of porous solids. The first is that the first derivative (slope) of the intrusion characteristic of the non-wetting fluid or drainage characteristic of the wetting fluid corresponds to the void size distribution, and the second is that the sizes of all voids can be measured. The fallacies are illustrated with the aid of the PoreXpert® inverse modelling package. A new void analysis method is then described, which is an add-on to the inverse modelling package and addresses the second fallacy. It is applied to three widely contrasting and challenging porous media. The first comprises two fine-grain graphites for use in the next-generation nuclear reactors. Their larger void sizes were measured by mercury intrusion, and the smallest by using a grand canonical Monte Carlo interpretation of surface area measurement down to nanometre scale. The second application is to the mercury intrusion of a series of mixtures of ground calcium carbonate with powdered microporous calcium carbonate known as functionalised calcium carbonate (FCC). The third is the water retention/drainage characteristic of a soil sample which undergoes naturally occurring hydrophilic/hydrophobic transitions. The first-derivative approximation is shown to be reasonable in the interpretation of the mercury intrusion porosimetry of the two graphites, which differ only at low mercury intrusion pressures, but false for FCC and the transiently hydrophobic soil. The findings are supported by other experimental characterisations, in particular electron and atomic force microscopy. 相似文献
454.
455.
Sandro L. Barbosa David Lee Nelson Milton de S. Freitas Wallans Torres Pio dos Santos Stanlei I. Klein Giuliano C. Clososki Franco J. Caires Alexandre P. Wentz 《Molecules (Basel, Switzerland)》2022,27(15)
SiO2–SO3H, with a surface area of 115 m2/g and pore volume of 0.38 cm3g−1, and 1.32 mmol H+/g was used as a 20% w/w catalyst for the preparation of methyl salicylate (wintergreen oil or MS) from acetylsalicylic acid (ASA). A 94% conversion was achieved in a microwave reactor over 40 min at 120 °C in MeOH. The resulting crude product was purified by flash chromatography. The catalyst could be reused three times. 相似文献