全文获取类型
收费全文 | 2402篇 |
免费 | 33篇 |
国内免费 | 13篇 |
专业分类
化学 | 1427篇 |
晶体学 | 28篇 |
力学 | 86篇 |
数学 | 426篇 |
物理学 | 481篇 |
出版年
2020年 | 18篇 |
2019年 | 18篇 |
2018年 | 19篇 |
2017年 | 24篇 |
2016年 | 33篇 |
2015年 | 28篇 |
2014年 | 24篇 |
2013年 | 116篇 |
2012年 | 86篇 |
2011年 | 97篇 |
2010年 | 58篇 |
2009年 | 66篇 |
2008年 | 100篇 |
2007年 | 109篇 |
2006年 | 103篇 |
2005年 | 105篇 |
2004年 | 111篇 |
2003年 | 79篇 |
2002年 | 99篇 |
2001年 | 54篇 |
2000年 | 45篇 |
1999年 | 56篇 |
1998年 | 28篇 |
1997年 | 32篇 |
1996年 | 33篇 |
1995年 | 23篇 |
1994年 | 27篇 |
1993年 | 22篇 |
1992年 | 34篇 |
1991年 | 21篇 |
1990年 | 25篇 |
1989年 | 36篇 |
1988年 | 15篇 |
1987年 | 24篇 |
1986年 | 29篇 |
1985年 | 44篇 |
1984年 | 51篇 |
1983年 | 36篇 |
1982年 | 38篇 |
1981年 | 58篇 |
1980年 | 38篇 |
1979年 | 44篇 |
1978年 | 38篇 |
1977年 | 44篇 |
1976年 | 25篇 |
1975年 | 33篇 |
1974年 | 35篇 |
1973年 | 37篇 |
1972年 | 26篇 |
1970年 | 18篇 |
排序方式: 共有2448条查询结果,搜索用时 31 毫秒
1.
Howard Robinson 《Acta Analytica》2005,20(3):7-10
Nicholas Nathan tries to resist the current version of the causal argument for sense-data in two ways. First he suggests that,
on what he considers to be the correct re-construction of the argument, it equivocates on the sense of proximate cause. Second
he defends a form of disjunctivism, by claiming that there might be an extra mechanism involved in producing veridical hallucination,
that is not present in perception. I argue that Nathan’s reconstruction of the argument is not the appropriate one, and that,
properly interpreted, the argument does not equivocate on proximate cause. Furthermore, I claim that his postulation of a
modified mechanism for hallucinations is implausibly ad hoc. 相似文献
2.
3.
Emily S. Tepe Ellen S. Deutsch MD Quiana Sampson Stephen Lawless James S. Reilly Robert Thayer Sataloff 《Journal of voice》2002,16(2):244-250
The objective of this study was to determine the incidence of vocal problems in young choir singers and to correlate vocal problems with demographic and behavioral information. A questionnaire addressing vocal habits and hygiene was offered to 571 young choir singers, up to 25 years of age, who sing at least weekly; 129 (22.6%) responded. More than one-half of the respondents had experienced vocal difficulty, particularly older adolescents. Detrimental behaviors and circumstances surveyed were not reflective of the incidence of vocal difficulty, except for morning hoarseness, chronic fatigue, insomnia, and female gender after puberty. Voice care professionals should be aware that self-reported voice difficulties are common among young choral singers, especially postpubescent girls, and children with symptoms consistent with reflux (morning hoarseness) and emotional stress (insomnia). Laryngologists should communicate with choral conductors and singing teachers to enhance early identification and treatment of children with voice complaints, and to develop choral educational strategies that help decrease their incidence. 相似文献
4.
5.
Howard Jacobowitz Gerardo Mendoza 《Transactions of the American Mathematical Society》2003,355(10):4201-4222
We study embeddings of complex vector bundles, especially line bundles, in the complexification of the tangent bundle of a manifold. The aim is to understand implications of properties of interest in partial differential equations.
6.
7.
Paul Howard 《Mathematical Logic Quarterly》2007,53(3):247-254
Two theorems are proved: First that the statement “there exists a field F such that for every vector space over F, every generating set contains a basis” implies the axiom of choice. This generalizes theorems of Halpern, Blass, and Keremedis. Secondly, we prove that the assertion that every vector space over ?2 has a basis implies that every well‐ordered collection of two‐element sets has a choice function. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
8.
9.
Summary. We examine the convergence characteristics of iterative methods based on a new preconditioning operator for solving the linear
systems arising from discretization and linearization of the steady-state Navier-Stokes equations. With a combination of analytic
and empirical results, we study the effects of fundamental parameters on convergence. We demonstrate that the preconditioned
problem has an eigenvalue distribution consisting of a tightly clustered set together with a small number of outliers. The
structure of these distributions is independent of the discretization mesh size, but the cardinality of the set of outliers
increases slowly as the viscosity becomes smaller. These characteristics are directly correlated with the convergence properties
of iterative solvers.
Received August 5, 2000 / Published online June 20, 2001 相似文献
10.