全文获取类型
收费全文 | 3110篇 |
免费 | 43篇 |
国内免费 | 12篇 |
专业分类
化学 | 2356篇 |
晶体学 | 20篇 |
力学 | 37篇 |
数学 | 292篇 |
物理学 | 460篇 |
出版年
2016年 | 28篇 |
2015年 | 30篇 |
2014年 | 34篇 |
2013年 | 58篇 |
2012年 | 68篇 |
2011年 | 85篇 |
2010年 | 46篇 |
2009年 | 52篇 |
2008年 | 71篇 |
2007年 | 73篇 |
2006年 | 96篇 |
2005年 | 89篇 |
2004年 | 76篇 |
2003年 | 65篇 |
2002年 | 76篇 |
2001年 | 51篇 |
2000年 | 61篇 |
1999年 | 41篇 |
1998年 | 32篇 |
1997年 | 37篇 |
1996年 | 51篇 |
1995年 | 33篇 |
1994年 | 53篇 |
1993年 | 55篇 |
1992年 | 71篇 |
1991年 | 44篇 |
1990年 | 36篇 |
1989年 | 43篇 |
1988年 | 51篇 |
1987年 | 74篇 |
1986年 | 49篇 |
1985年 | 57篇 |
1984年 | 71篇 |
1983年 | 46篇 |
1982年 | 58篇 |
1981年 | 52篇 |
1980年 | 48篇 |
1979年 | 49篇 |
1978年 | 53篇 |
1977年 | 64篇 |
1976年 | 63篇 |
1975年 | 41篇 |
1974年 | 44篇 |
1973年 | 32篇 |
1972年 | 32篇 |
1971年 | 25篇 |
1970年 | 34篇 |
1967年 | 22篇 |
1966年 | 18篇 |
1909年 | 24篇 |
排序方式: 共有3165条查询结果,搜索用时 15 毫秒
1.
Pan Huang Dawen Xu Robert M. Reich Felix Kaiser Boping Liu Fritz E. Kühn 《Tetrahedron letters》2019,60(24):1574-1577
A first example of an Et2Zn mediated silylation of 1-aklynes is reported. A series of functional groups are tolerated in this reaction. Mechanistic studies support Zn alkynilides as intermediates in the reaction. This reaction protocol provides a practical method for the preparation of alkynylsilanes and expands the application of organometallic zinc in organic synthesis. 相似文献
2.
3.
H. William Bosch Sre
o D. kapin Egon Matijevi 《Colloids and surfaces. A, Physicochemical and engineering aspects》2004,250(1-3):43-50
Controlled precipitation of the diagnostic imaging agent ethyl 3,5-di(acetylamino)-2,4,6-triiodobenzoate has been used to produce fine particles of various sizes, morphologies, and degrees of crystallinity, which depended on experimental conditions. In addition, two distinct polymorphic forms of the drug have been fully characterized by single crystal X-ray diffraction studies, and evidence for a third polymorph was also observed. Some of the so prepared dry particles were coated with a thin layer of silica. 相似文献
4.
5.
Journal of Statistical Physics - Let V 0be a real-valued function on [0,∞) and V∈L 1([0,R]) for all R&;gt;0 so that H(V 0)=? $\frac{{d^2 }}{{dx^2 }}$ +V 0in L 2([0,∞))... 相似文献
6.
Cordula Grüttner Knut Müller Joachim Teller Fritz Westphal Allan Foreman Robert Ivkov 《Journal of magnetism and magnetic materials》2007
Bionized nanoferrite (BNF) particles with high specific power absorption rates were synthesized in the size range of 20–100 nm by high-pressure homogenization for targeted cancer therapy with alternating magnetic fields. Several strategies were used to conjugate antibodies to the BNF particles. These strategies were compared using an immunoassay to find optimal conditions to reach a high immunoreactivity of the final antibody–particle conjugate. 相似文献
7.
B. Sun Yu. A. Litvinov P. M. Walker K. Beckert P. Beller F. Bosch D. Boutin C. Brandau L. Chen C. Dimopoulou H. Geissel R. Knöbel C. Kozhuharov J. Kurcewicz S. A. Litvinov M. Mazzocco J. Meng C. Nociforo F. Nolden W. R. Plass C. Scheidenberger M. Steck H. Weick M. Winkler 《The European Physical Journal A - Hadrons and Nuclei》2007,31(3):393-394
A new long-lived isomeric state in the near proton dripline nucleus 125Ce has been identified with Schottky mass spectrometry at GSI. The excitation energy E
* = 103(12)keV and the decay time of 193(1)s have been obtained from a single stored fully ionized 125m
Ce58+ ion. The data implies an E3 transition and a 1/2+ assignment for the spin of the isomer. 相似文献
8.
H. Tsertos E. Berdermann F. Bosch M. Clemente S. Huchler P. Kienle W. Koenig C. Kozhuharov 《Zeitschrift für Physik A Hadrons and Nuclei》1992,342(1):79-94
We present the results obtained from systematic studies of positron creation for a series of heavy-collision systems, with united chargeZ u =Z 1 +Z 2 ranging fromZ u =164 (Pb + Pb) toZ u =184 (U+U) at bombarding energies close to the Coulomb barrier, using the Orangeβ-spectrometer at GSI. For each collision system studied, the dominating continuous distributions due to quasiatomic and nuclear positron emission are determined accurately. This is essential in obtaining the characteristics of the still unexplained monoenergetic positron lines which appear in the energy range between 200 keV and 400 keV. Our results are compared with coupled-channels calculations for quasi-atomic positron creation. The latter describe quite well the global features of the measured spectra, but overestimate systematically their absolute values. From the comparison, a common normalization factor of about 0.75 can be established for the calculated spectra. In particular, the dependence onZ u of the measured emission probabilities was found to follow a power law (∝Z u 195±1), in fair agreement with the theoretical prediction. 相似文献
9.
10.
Brandau C. Bartsch T. Böhm S. Böhme C. Hoffknecht A. Kieslich S. Knopp H. Schippers S. Shi W. Müller A. Grün N. Scheid W. Steih T. Bosch F. Franzke B. Kozhuharov C. Krämer A. Mokler P. H. Nolden F. Steck M. Stöhlker T. Stachura Z. 《Hyperfine Interactions》2003,146(1-4):41-45
Hyperfine Interactions - An overview of measurements of dielectronic recombination (DR) with the heaviest lithiumlike ions is presented. The experiments have been carried out at the heavy ion... 相似文献