全文获取类型
收费全文 | 806篇 |
免费 | 21篇 |
国内免费 | 2篇 |
专业分类
化学 | 445篇 |
晶体学 | 21篇 |
力学 | 17篇 |
数学 | 48篇 |
物理学 | 298篇 |
出版年
2022年 | 7篇 |
2021年 | 11篇 |
2020年 | 11篇 |
2019年 | 13篇 |
2018年 | 6篇 |
2017年 | 3篇 |
2016年 | 14篇 |
2015年 | 11篇 |
2014年 | 11篇 |
2013年 | 27篇 |
2012年 | 37篇 |
2011年 | 26篇 |
2010年 | 25篇 |
2009年 | 18篇 |
2008年 | 51篇 |
2007年 | 44篇 |
2006年 | 52篇 |
2005年 | 40篇 |
2004年 | 42篇 |
2003年 | 28篇 |
2002年 | 37篇 |
2001年 | 21篇 |
2000年 | 17篇 |
1999年 | 12篇 |
1998年 | 11篇 |
1997年 | 6篇 |
1996年 | 9篇 |
1995年 | 13篇 |
1994年 | 8篇 |
1993年 | 9篇 |
1992年 | 9篇 |
1991年 | 11篇 |
1990年 | 16篇 |
1989年 | 12篇 |
1988年 | 16篇 |
1987年 | 12篇 |
1986年 | 17篇 |
1985年 | 8篇 |
1984年 | 10篇 |
1983年 | 10篇 |
1982年 | 4篇 |
1981年 | 13篇 |
1980年 | 12篇 |
1979年 | 18篇 |
1978年 | 8篇 |
1977年 | 7篇 |
1976年 | 4篇 |
1975年 | 9篇 |
1973年 | 3篇 |
1969年 | 3篇 |
排序方式: 共有829条查询结果,搜索用时 15 毫秒
821.
Seidl R Hasuko K Abe K Adachi I Aihara H Anipko D Asano Y Aushev T Bakich AM Balagura V Barberio E Bartel W Bay A Bitenc U Bizjak I Blyth S Bozek A Bracko M Browder TE Chang P Chen A Cheon BG Choi Y Choi YK Chuvikov A Dalseno J Danilov M Dash M Dragic J Eidelman S Fratina S Gabyshev N Gershon T Go A Gokhroo G Golob B Gorisek A Grosse Perdekamp M Ha HC Hayasaka K Hayashii H Hazumi M Hokuue T Hoshi Y Hou S Hou WS Iijima T Inami K Ishikawa A Itoh R Iwasaki M Iwasaki Y Kang JH Kapusta P Katayama N 《Physical review letters》2006,96(23):232002
The Collins effect connects transverse quark spin with a measurable azimuthal dependence in the yield of hadronic fragments around the quark's momentum vector. Using two different reconstruction methods, we find evidence of statistically significant azimuthal asymmetries for charged pion pairs in e(+)e(-) annihilation at a center-of-mass energy of 10.52 GeV, which can be attributed to a transverse polarization of the primordial quarks. The measurement was performed using a sample of 79 x 10(6) hadronic events collected with the Belle detector. 相似文献
822.
Kalmykov Y Adachi T Berg GP Fujita H Fujita K Fujita Y Hatanaka K Kamiya J Nakanishi K von Neumann-Cosel P Ponomarev VY Richter A Sakamoto N Sakemi Y Shevchenko A Shimbara Y Shimizu Y Smit FD Wakasa T Wambach J Yosoi M 《Physical review letters》2006,96(1):012502
The fine structure of the Gamow-Teller resonance in a medium-heavy nucleus is observed for the first time in a high-resolution 90Zr(3He,t)90Nb experiment at the Research Center for Nuclear Physics, Osaka. Using a novel wavelet analysis technique, it is possible to extract characteristic energy scales and to quantify their relative importance for the generation of the fine structure. This method combined with the selectivity of the reaction permits an extraction of the level density of 1+ states in 90Nb. 相似文献
823.
Somov A Schwartz AJ Abe K Abe K Adachi I Aihara H Anipko D Arinstein K Asano Y Aulchenko V Aushev T Aziz T Bahinipati S Bakich AM Balagura V Bay A Bedny I Belous K Bitenc U Bizjak I Blyth S Bondar A Bozek A Bracko M Brodzicka J Browder TE Chang MC Chang P Chao Y Chen A Chen WT Cheon BG Chistov R Choi SK Choi Y Choi YK Chuvikov A Cole S Dalseno J Dash M Dragic J Drutskoy A Eidelman S Epifanov D Gabyshev N Garmash A Gershon T Go A Gokhroo G Golob B Hara K Hara T Hastings NC Hayasaka K Hayashii H 《Physical review letters》2006,96(17):171801
We have measured the branching fraction , longitudinal polarization fraction f(L), and CP asymmetry coefficients A and S for B(0) --> rho(+) rho(-) decays with the Belle detector at the KEKB e(+) e(-) collider using 253 Fb(-1) of data. We obtain B = [22.8 +/- 3.8(stat)(+2.3)(-2.6)(syst)] x 10(-6), f(L) = 0.941 (+0.034)(-0.040)(stat) +/- 0.030(syst). A = 0.00 +/- 0.30(stat) +/- 0.09(syst) and S = 0.08 +/- 0.09(syst). These values are used to constrain the Cabibbo-Kobayashi-Maskawa phase ; the solution consistent with the standard model is phi(2) = (88 +/- 17) degrees or 59 degrees < phi(2) < 115 degrees at 90% C.L. 相似文献
824.
Uehara S Abe K Abe K Adachi I Aihara H Arinstein K Asano Y Aulchenko V Aushev T Bakich AM Balagura V Barberio E Bedny I Belous K Bitenc U Bizjak I Blyth S Bondar A Bozek A Bracko M Browder TE Chang MC Chen A Chen WT Cheon BG Chistov R Choi SK Choi Y Choi YK Chuvikov A Dalseno J Danilov M Dash M Dragic J Eidelman S Epifanov D Fratina S Gabyshev N Garmash A Gershon T Gokhroo G Gorisek A Ha HC Hayasaka K Hayashii H Hazumi M Hinz L Hoshi Y Hou S Iijima T Inami K Ishikawa A Itoh R Iwasaki M 《Physical review letters》2006,96(8):082003
We report on a search for new resonant states in the process gamma gamma --> DD. A candidate C-even charmonium state is observed in the vicinity of 3.93 GeV/c2. The production rate and the angular distribution in the gamma gamma center-of-mass frame suggest that this state is the previously unobserved chi(c2)', the 2(3)P2 charmonium state. 相似文献
825.
Morimoto Y Takaishi M Adachi N Okita T Yata H 《Organic & biomolecular chemistry》2006,4(17):3220-3222
The asymmetric synthesis of tetraol (+)-3, a degradation product derived from a C2 symmetric oxasqualenoid intricatetraol 1, has been achieved through the two-directional synthesis starting from diol 7, realizing the further additional assignment of the incomplete stereostructure of 1, the stereochemistry of which is difficult to determine otherwise. 相似文献
826.
Adachi H Kondo K Kojima F Umezawa Y Ishino K Hotta K Nishimura Y 《Natural product research》2006,20(4):361-370
3-Deoxy-D-manno-octulosonate cytidyltransferase (CMP-KDO synthetase) is involved in the biosynthesis of lipopolysaccharide (LPS) which is an essential component of the outer membrane of gram-negative bacteria. New CMP-KDO synthetase inhibitors, 8-substituted derivatives of 2-deoxy-beta-KDO (2) have been prepared. Compounds 8, 11, 15 and 16 in which the 8-hydroxyl group of 2 is replaced by guanidine, di(carbamoylethyl)amino, p-methoxy- or p-nitro-benzyloxycarbonylamino, respectively affect moderately the CMP-KDO synthetase activity. 相似文献
827.
Naumov P Sakurai K Asaka T Belik AA Adachi S Takahashi J Koshihara SY 《Inorganic chemistry》2006,45(13):5027-5033
The structural grounds of the decrease of point and lattice symmetries coupled with switching of the exchange interaction in single crystals of a highly strained, coordinationally unsaturated bisdiaminecopper(II) cation are described. The combined magnetic susceptibility and X-ray diffraction results indicate that the interplay between the inherent vibronic instability and ligand-field strain imposed by moderately flexible, coordinationally shielding ligands enables effective switching of the pseudo-Jahn-Teller d9 centers between states with different exchange interaction in the low-temperature regime and valence orbital orientation and coordination geometry in the high-temperature regime. Within the low-temperature hysteresis region, the phase transition can also be induced by excitation of the ligand-to-metal charge-transfer bands, resulting in overall shrinkage of the lattice. The compound is a prototype of weakly electronically coupled one-dimensional Jahn-Teller systems, which can undergo phase transitions induced by light, in addition to heating, cooling, and change of pressure, and it represents a prospective basis for the design of switching materials capable of multimode external control. 相似文献
828.
We have developed a novel method for genotyping based on free solution affinity capillary electrophoresis. We prepared DNA-nanoparticle conjugates by mixing biotin-modified DNA and NeutrAvidin-modified polystyrene nanoparticles; this mixture was then injected into a capillary. Subsequently, we injected the fluorescent-labeled sample DNAs into the capillary, applied the voltage, increased its temperature after 7 min, and detected the fluorescence at its anodic end. This novel method was applied for genotyping human c-K-ras, and the three genotypes were definitely distinguishable with high reproducibility. This method can be easily automated, and it is useful for high-throughput gene mutation analysis. 相似文献
829.
Juan J. Freire Luis A. Molina Antonio Rey Keiichiro Adachi 《Macromolecular theory and simulations》1999,8(4):321-327
A dynamic Monte Carlo algorithm is employed to investigate the dynamics of flexible linear and star chains on a cubic lattice at different concentrations. Some results for similar systems are also obtained with an off‐lattice algorithm. Diffusion coefficient, relaxation times and mean size data are combined into friction‐independent ratios in good agreement with the theoretical predictions from the Rouse theory. The relaxation times and amplitudes corresponding to the Rouse normal modes are analyzed in terms of their variation with the mode order. The end‐to‐end vector correlation times obtained from the simulations for linear chains are compared with the theoretical expression obtained from the Rouse theory. Deviations from this theory are observed for the contribution of the different modes in the non‐dilute systems. Finally, the time correlation function corresponding to a subchain's end‐to‐end vector is investigated. The results also show deviations from the Rouse theory, which are in qualitative agreement with the features observed in data from dielectric relaxation experiments of block copolymers. 相似文献