全文获取类型
收费全文 | 43017篇 |
免费 | 1283篇 |
国内免费 | 115篇 |
专业分类
化学 | 28435篇 |
晶体学 | 286篇 |
力学 | 830篇 |
综合类 | 2篇 |
数学 | 7101篇 |
物理学 | 7761篇 |
出版年
2023年 | 319篇 |
2022年 | 423篇 |
2021年 | 653篇 |
2020年 | 728篇 |
2019年 | 670篇 |
2018年 | 1216篇 |
2017年 | 1013篇 |
2016年 | 1529篇 |
2015年 | 1224篇 |
2014年 | 1267篇 |
2013年 | 2654篇 |
2012年 | 2821篇 |
2011年 | 3066篇 |
2010年 | 1829篇 |
2009年 | 1582篇 |
2008年 | 2600篇 |
2007年 | 2583篇 |
2006年 | 2285篇 |
2005年 | 2077篇 |
2004年 | 1671篇 |
2003年 | 1360篇 |
2002年 | 1169篇 |
2001年 | 876篇 |
2000年 | 825篇 |
1999年 | 580篇 |
1998年 | 427篇 |
1997年 | 355篇 |
1996年 | 475篇 |
1995年 | 339篇 |
1994年 | 333篇 |
1993年 | 369篇 |
1992年 | 334篇 |
1991年 | 247篇 |
1990年 | 241篇 |
1989年 | 208篇 |
1988年 | 193篇 |
1987年 | 193篇 |
1986年 | 191篇 |
1985年 | 260篇 |
1984年 | 249篇 |
1983年 | 196篇 |
1982年 | 194篇 |
1981年 | 186篇 |
1980年 | 144篇 |
1979年 | 142篇 |
1978年 | 151篇 |
1977年 | 131篇 |
1976年 | 134篇 |
1975年 | 120篇 |
1973年 | 118篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
121.
A hybrid method for measuring the electron distribution function in the low temperature plasma is described. The time resolution of the measurement is of the order of several sec. 相似文献
122.
123.
J. Kuriplach L. Lešták M. Rotter B. Sedlák M. Trhlík M. Finger T. Lešner J. Dupák P. Novák M. Vobecký 《Hyperfine Interactions》1987,34(1-4):339-342
First experimental results of160Tb nuclear orientation in yttrium single crystal matrix are described. The influence of external magnetic field in combination with the crystal field interaction is discussed. 相似文献
124.
125.
M. Rotter B. Sedlák J. Englich P. Čížek M. Finger P. Malinský 《Czechoslovak Journal of Physics》1986,36(11):1331-1335
The results of NMR/ON measurements on56,57,60Co isotopes in iron are presented in the paper. To avoid the uncertainties caused by local demagnetizing field inhomogeneities the measurements on two cobalt isotopes in one sample have been carried out. The values of nuclear-factors ratios
57/
60=1·805(20),
60/
56 = 0·761(20),
56/
57 = 0·726(20) and hyperfme anomalies56
60 = –0·036(10),60
57 = 0·017(10) and57
56 = 0·018(10) have been calculated from the experimental results.Dedicated to the 30th anniversary of the Joint Institute for Nuclear Research. 相似文献
126.
127.
A very special case of one of the theorems of the authors states as follows: Let 1a
1a
2... be an infinite sequence of integers for which all the sumsa
i
+a
j
, 1ij, are distinct. Then there are infinitely many integersk for which 2k can be represented in the forma
i
+a
j
but 2k+1 cannot be represented in this form. Several unsolved problems are stated.Dedicated to our friend Professor E. Hlawka on the occasion of his seventieth birthday 相似文献
128.
A. Caubet A. Labarta R. Rodríguez A. Fernandez E. Molins V. Moreno J. Tejada 《Hyperfine Interactions》1986,28(1-4):773-776
By means of57Co Mössbauer emission spectroscopy and magnetic susceptibility measurements, the local symmetries and electronic structure of the Co(II) ions in the Co-5IMO and Co-5GMP complexes in the hydrated and dehydrated forms have been determined. 相似文献
129.
Elías Molins Amílcar Labarta Javier Tejada Amparo Caubet Santiago Alvarez 《Transition Metal Chemistry》1983,8(6):377-380
Summary Magnetic moments and57Fe Mössbauer spectra at room temperature and at liquid nitrogen temperature of polynuclear ligand-bridged iron phthalocyanines, FePcL (L = pyrazine and 4,4-bipyridyl), are reported. The experimental data are in agreement with a pseudo-octahedral environment around the iron(II) cation. Partially oxidized derivatives, FePc(pz)I0.26 and FePc(bipy)I1.06 have been synthesized and their57Fe Mössbauer spectra and magnetic moments within the same temperature range obtained. Oxidation is shown to be metal centred and the iodine is found to be in I– form for FePc(pz)0.26 and as both I– and I
3
–
species for FePc(bipy)I1.06. While the magnetic moment of FePc(pz) increases upon oxidation, the opposite occurs for FePc(bipy). 相似文献
130.
A R P?s? O A Forsander 《Acta chemica Scandinavica. Series B: Organic chemistry and biochemistry》1976,(9):801-806
The effect of the ethanol oxidation rate on the interaction between the phosphorylation state (the [ATP]/[ADP] X [HPO4]2- ratio) and the redox state (the free [NAD+]/[NADH] ratio) of the liver cytosol was studied in intact fed rats. The rate of ethanol oxidation was inhibited to different degrees with pyrazole. The ethanol oxidation rate had no influence on the liver lactate level but correlated significantly with the pyruvate level. Accordingly, a significant correlation was also found between the ethanol oxidation rate and the lactate/pyruvate ratio. The rate of ethanol oxidation correlated significantly with the liver 3-phosphoglycerate level. No change in the glyceraldehyde-3-phosphate level was found. No correlation was found between the ethanol oxidation rate and the glyceraldehyde-3-phosphate/3-phosphoglycerate redox couple. Ethanol administration slightly increased the liver ATP level, but the simultaneous administration of pyrazole eliminated this effect. Other adenine nucleotides and HPO4 2- were not changed. The changes in the rate of ethanol oxidation had no effect on the phosphorylation state in the fed liver. It is assumed that in the fed liver the phosphorylation state is so well stabilized that the redox level has no influence. 相似文献