全文获取类型
收费全文 | 9991篇 |
免费 | 217篇 |
国内免费 | 31篇 |
专业分类
化学 | 5706篇 |
晶体学 | 199篇 |
力学 | 209篇 |
数学 | 1696篇 |
物理学 | 2429篇 |
出版年
2022年 | 203篇 |
2021年 | 214篇 |
2020年 | 127篇 |
2019年 | 181篇 |
2018年 | 188篇 |
2017年 | 177篇 |
2016年 | 312篇 |
2015年 | 245篇 |
2014年 | 337篇 |
2013年 | 754篇 |
2012年 | 516篇 |
2011年 | 582篇 |
2010年 | 454篇 |
2009年 | 414篇 |
2008年 | 477篇 |
2007年 | 480篇 |
2006年 | 427篇 |
2005年 | 388篇 |
2004年 | 341篇 |
2003年 | 313篇 |
2002年 | 235篇 |
2001年 | 181篇 |
2000年 | 159篇 |
1999年 | 130篇 |
1998年 | 134篇 |
1997年 | 113篇 |
1996年 | 104篇 |
1995年 | 138篇 |
1994年 | 84篇 |
1993年 | 76篇 |
1992年 | 89篇 |
1991年 | 66篇 |
1990年 | 79篇 |
1989年 | 72篇 |
1988年 | 72篇 |
1987年 | 63篇 |
1986年 | 75篇 |
1985年 | 121篇 |
1984年 | 129篇 |
1983年 | 80篇 |
1982年 | 82篇 |
1981年 | 84篇 |
1980年 | 91篇 |
1979年 | 63篇 |
1978年 | 71篇 |
1977年 | 77篇 |
1976年 | 67篇 |
1975年 | 61篇 |
1974年 | 51篇 |
1973年 | 44篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Joanna Tarasińska 《Applications of Mathematics》2003,48(1):67-72
Two estimates of the regression coefficient in bivariate normal distribution are considered: the usual one based on a sample and a new one making use of additional observations of one of the variables. They are compared with respect to variance. The same is done for two regression lines. The conclusion is that the additional observations are worth using only when the sample is very small. 相似文献
62.
Piotr Bogusaw Mucha Witold Sadowski 《Mathematical Methods in the Applied Sciences》2005,28(15):1867-1880
The paper analyses long time behaviour of solutions of the Navier–Stokes equations in a two‐dimensional pipe‐like domain. The system is studied with perfect slip boundary conditions with arbitrary inflow conditions at infinity. The main results show the existence of global in time solutions and of an attractor for the dynamical system generated by the model. The paper also establishes an upper bound for the Hausdorff dimension of the attractor. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
63.
64.
Grzegorz M. Salamończyk 《Tetrahedron letters》2003,44(40):7449-7453
An efficient synthesis of antiviral dendritic prodrug candidates, water-soluble, polyanionic conjugates of 1st and 2nd generation thiophosphate dendrimers with acyclovir, is described. 相似文献
65.
Hubert Grudzński 《Reports on Mathematical Physics》2004,53(3):331-338
New elements of the dual cone of the set of fermion N-representable 2-density operators are proposed. So far, the explicit form of the corresponding necessary conditions for N-representability is obtained for N = 3. In this case the new condition is stronger than the known B- and C-conditions for 3-representability. The results provide evidence that in the spectral decomposition of the N-representable 2-density operator there exists an intrinsic relation between the eigenvalue and the corresponding eigenfunction. 相似文献
66.
Orewczyk J. Jasieńska S. Iwanczenko S. 《Journal of Thermal Analysis and Calorimetry》1998,54(1):79-84
This paper presents applications of thermal analysis to observe the course of reduction of acidic pellets, metallurgical substances
whose reducibility and strength are basic parameters of use in blast furnace processes. Both parameters depend on the mineral
composition of the samples. The investigations included determination of the chemical and phase compositions of the initial
samples and reduction products.
Research was conducted on acidic pellets from Połtawa (Poland), applied in the T. Sendzimir Steelworks (Poland), in comparison
with pellets from Brazil, Canada and Lebedyn (Russia).
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
67.
68.
Zbigniew Peradzyński Bogdan Kazmierczak 《Archive of Applied Mechanics (Ingenieur Archiv)》2005,74(11-12):827-833
The influence of mechano-chemical coupling on calcium concentration waves is considered. The propagation of calcium waves is described by a reaction–diffusion equation with the reaction term dependent on the mechanical stress responsible for the release of calcium. Similarly the balance of mechanical forces is influenced by the calcium concentration through the so-called traction force. 相似文献
69.
Dealing with infinite iterated function systems we introduce and develop the ergodic theory of Hölder systems of functions similarly as in [HU] and [HMU]. In the context of conformal infinite iterated function systems we prove the volume lemma for the Hausdorff dimension of the projection onto the limit set of a shift invariant measure. This can be considered as a Billingsley type result. Our cenral goal is to demonstrate the appearance of the "singularity-absolute continuity" dichotomy for equilibrium states of Hölder systems of functions which has been observed in [PUZ,I] and [PUZ,II] (see also [DU1] and [DU2]) in the setting of rational functions of the Riemann sphere. 相似文献
70.
Leszek Wachowski Antoni Grodzicki Piotr Piszczek Monika Richert Magdalena Hofman 《Reaction Kinetics and Catalysis Letters》2007,91(1):93-99
Hydrogenation of styrene has been applied as a test reaction to study the catalytic activity of TiO2 deposited by the CVD (chemical vapour deposition) method on the surface of a carbonaceous material enriched in nitrogen (CN). 相似文献