全文获取类型
收费全文 | 7632篇 |
免费 | 167篇 |
国内免费 | 30篇 |
专业分类
化学 | 4562篇 |
晶体学 | 89篇 |
力学 | 178篇 |
数学 | 1073篇 |
物理学 | 1927篇 |
出版年
2020年 | 73篇 |
2019年 | 67篇 |
2016年 | 142篇 |
2015年 | 127篇 |
2014年 | 135篇 |
2013年 | 290篇 |
2012年 | 275篇 |
2011年 | 277篇 |
2010年 | 163篇 |
2009年 | 176篇 |
2008年 | 256篇 |
2007年 | 269篇 |
2006年 | 251篇 |
2005年 | 248篇 |
2004年 | 201篇 |
2003年 | 193篇 |
2002年 | 184篇 |
2001年 | 168篇 |
2000年 | 153篇 |
1999年 | 110篇 |
1998年 | 109篇 |
1997年 | 113篇 |
1996年 | 127篇 |
1995年 | 127篇 |
1994年 | 104篇 |
1993年 | 114篇 |
1992年 | 107篇 |
1991年 | 96篇 |
1990年 | 72篇 |
1989年 | 97篇 |
1988年 | 106篇 |
1987年 | 97篇 |
1986年 | 104篇 |
1985年 | 147篇 |
1984年 | 116篇 |
1983年 | 91篇 |
1982年 | 114篇 |
1981年 | 114篇 |
1980年 | 85篇 |
1979年 | 107篇 |
1978年 | 95篇 |
1977年 | 92篇 |
1976年 | 92篇 |
1975年 | 98篇 |
1974年 | 80篇 |
1973年 | 93篇 |
1971年 | 65篇 |
1968年 | 97篇 |
1967年 | 100篇 |
1966年 | 99篇 |
排序方式: 共有7829条查询结果,搜索用时 78 毫秒
141.
T. C. Awes C. Barlag F. Berger M. A. Bloomer C. Blume D. Bock R. Bock E. -M. Bohne D. Bucher A. Claussen G. Clewing L. Dragon A. Eklund S. Garpman R. Glasow H. Gustafsson H. H. Gutbrod G. Hölker J. Idh P. Jacobs K. H. Kampert B. W. Kolb H. Löhner I. Lund F. E. Obenshain A. Oskarsson I. Otterlund T. Peitzmann F. Plasil A. M. Poskanzer M. Purschke B. Roters S. Saini R. Santo H. R. Schmidt S. P. Sørensen K. Steffens P. Steinhaeuser E. Stenlund D. Stüken G. R. Young 《Zeitschrift fur Physik C Particles and Fields》1995,65(2):207-213
Correlations between protons are studied in the target fragmentation region of reactions of protons and16O with C, Cu, Ag, Au and of32S with Al and Au at 200A GeV. The emitted protons were measured with the Plastic Ball detector in the WA80 experiment at the CERN SPS. The comparison of the correlation function with calculations, assuming a spherical, gaussian shaped source with a lifetime τ=0 fm/c, allows the extraction of radius parameters. The values are very close to those expected from the geometry of the target nuclei and increase with the target mass as αA Target 1/3 . Even in proton induced reactions the whole target nucleus is involved. The dependence of the radii on centrality, polar angleθ lab, and energy, and their relation to measured proton yields are presented. 相似文献
142.
Zusammenfassung Das -Isomer des Antimontribenzoats kristallisiert rhomboedrisch (hexagonale Aufstellung) in der Raumgruppe R3 mita=1944.0 pm,c=422.3 pm undZ=3. Die Moleküle sind parallel zu 001 gestapelt. Sb hat gegenüber O die Koordinationszahl 3+3 (Sb-O: 208 bzw. 256 pm).
Antimonytribenzoate
Summary The isomer of (C6H5CO2)3Sb crystallizes rhombohedrally (hexagonal axes) in the space group R3 witha=1944.0 pm,c=422.3 pm, andZ=3. The molecules are stacked parallel to 001; Sb has a coordination number of 3+3 (Sb-O: 208 and 256 pm, resp.).相似文献
143.
Within the concept of projective lattice geometry we are considering the class of stable geometries which have also been introduced in [14]. The investigation of their basic properties will result in fundamental structure theorems which especially give a lattice-geometric characterization of free left modules of rank 6 over proper right Bezout rings of stable rank 2. This yields a proper generalization of previous results of ours. 相似文献
144.
We consider the differential equation on a finite interval I, where I contains m turning points, that is here, zeros of ?. Using asymptotic estimates proved by R. E. LANGER for solutions of (*) for intervals containing only one turning point we derive asymptotic estimates (for ρ → ) for a special fundamental system of solutions of (*) in I. The results obtained are fundamental for the investigation of eigenvalue problems defined by (*) and suitable boundary conditions. 相似文献
145.
LetG(V,E) be a graph. A mappingf:E{0,1}
m
is called a (binary) coding ofG, if the induced mapping
, assigns different vectors to the vertices. For the Boolean sum,f is called aB-code, and for the mod 2 sum anM-code. Letm
B
(G) resp.m
M
(G) be the smallest lengthm for whichB-codes resp.M-codes are possible. Trivially,m
B
(G),m
M
(G) log2|V|. Improving results of Z. Tuza we showm
B
(G)log2|V| + 1,m
M
(G)log2|V|+4. 相似文献
146.
147.
148.
149.
Bockhorst M. Burbach G. Burgwinkel R. Empt J. Guse B. Guse B. Haas K. -M. Hannappel J. Heinloth K. Hey T. Hoffmann-Rothe P. Honscheid K. Jahnen T. Jakob H. P. Jöpen N. Jüngst H. Kirch U. Klein F. -J. Kostrewa D. Lindemann L. Link J. Manns J. Menze D. Merkel H. Merkel R. Neuerburg W. Paul E. Plötzke R. Schenk U. Schmidt S. Scholmann J. Schütz P. Schultz-Coulon H. -C. Schweitzer M. Schwille W. J. Tran M. -Q. Umlauf G. Vogl W. Wedemeyer R. Wehnes F. Wißkirchen J. Wolf A. 《Zeitschrift fur Physik C Particles and Fields》1994,63(1):37-47
The reactions pK
+ and pK
+ 0 have been measured with the multiparticle detector system SAPHIR at ELSA in Bonn. Besides the differential cross sections the polarization and, for the first time, the 0 polarization have been determined in a photon induced reaction. All data are presented as functions of the photon energy (from threshold up to 1.47 GeV) and of the kaon production angle (0°–180°). The polarization of both and 0 is substantial at all energies and varies strongly with the production angle.This work is supported by the Bundesminister für Forschung und Technologie (BMFT), FK 06 BN 621 I 相似文献
150.
Acosta D Athanas M Masek G Paar H Bean A Gronberg J Kutschke R Menary S Morrison RJ Nakanishi S Nelson HN Nelson TK Richman JD Ryd A Tajima H Schmidt D Sperka D Witherell MS Procario M Yang S Balest R Cho K Daoudi M Ford WT Johnson DR Lingel K Lohner M Rankin P Smith JG Alexander JP Bebek C Berkelman K Besson D Browder TE Cassel DG Cho HA Coffman DM Drell PS Ehrlich R Galik RS Garcia-Sciveres M Geiser B Gittelman B Gray SW Hartill DL Heltsley BK Jones CD Jones SL Kandaswamy J Katayama N Kim PC 《Physical review D: Particles and fields》1994,49(11):5690-5700