全文获取类型
收费全文 | 938篇 |
免费 | 27篇 |
国内免费 | 1篇 |
专业分类
化学 | 797篇 |
晶体学 | 12篇 |
力学 | 13篇 |
数学 | 36篇 |
物理学 | 108篇 |
出版年
2023年 | 4篇 |
2022年 | 4篇 |
2021年 | 6篇 |
2020年 | 8篇 |
2019年 | 9篇 |
2018年 | 5篇 |
2017年 | 8篇 |
2016年 | 13篇 |
2015年 | 22篇 |
2014年 | 17篇 |
2013年 | 39篇 |
2012年 | 27篇 |
2011年 | 39篇 |
2010年 | 30篇 |
2009年 | 32篇 |
2008年 | 72篇 |
2007年 | 56篇 |
2006年 | 60篇 |
2005年 | 47篇 |
2004年 | 60篇 |
2003年 | 51篇 |
2002年 | 71篇 |
2001年 | 11篇 |
2000年 | 12篇 |
1999年 | 12篇 |
1998年 | 12篇 |
1997年 | 13篇 |
1996年 | 18篇 |
1995年 | 8篇 |
1994年 | 8篇 |
1993年 | 9篇 |
1992年 | 11篇 |
1991年 | 12篇 |
1990年 | 6篇 |
1989年 | 8篇 |
1988年 | 7篇 |
1986年 | 7篇 |
1985年 | 15篇 |
1984年 | 19篇 |
1983年 | 5篇 |
1982年 | 12篇 |
1981年 | 6篇 |
1980年 | 7篇 |
1979年 | 10篇 |
1978年 | 10篇 |
1977年 | 9篇 |
1976年 | 11篇 |
1975年 | 4篇 |
1973年 | 9篇 |
1972年 | 3篇 |
排序方式: 共有966条查询结果,搜索用时 15 毫秒
861.
Hisashi Okamoto 《Journal of Mathematical Fluid Mechanics》2009,11(1):46-59
The generalized Proudman–Johnson equation, which was derived from the Navier–Stokes equations by Jinghui Zhu and the author,
are considered in the case where the viscosity is neglected and the periodic boundary condition is imposed. The equation possesses
two nonlinear terms: the convection and stretching terms. We prove that the solution exists globally in time if the stretching
term is weak in the sense to be specified below. We also discuss on blow-up solutions when the stretching term is strong.
Partly supported by the Grant-in-Aid for Scientific Research from JSPS No. 14204007. 相似文献
862.
K.B. Garg Hisashi Hayashi A. Sato T. Azumi Y. Udagawa Kenji Ishii Toshiya Inami T. Chatterji 《Journal of magnetism and magnetic materials》2008
Spin-selected polarized X-ray absorption near-edge structures (SSXANES) at the Mn K-edge from a bilayer La1.2Sr1.65Ca0.15Mn2O7 single crystal have been studied with high resolution, both in the ferromagnetic (15 K) as well as paramagnetic phase (300 K). The orientation-dependent SSXANES spectra show unmistakable temperature dependence as the system makes the ferromagnetic to paramagnetic phase transition. The pre-edge structures are too intense to be ascribed to weak quadrupole transitions and are interpreted in terms of hybridization of Mn 3d orbitals with O2p and Mn 4p orbitals over and above similar onsite hybridization. The results also indicate possible existence of a small local (time-frozen) ferromagnetic ordering in the macroscopically disordered state. Need for further experimental and theoretical work on the SSXANES spectra from the bilayer system is emphasized. 相似文献
863.
When the electron-electron interaction is explicitly considered in many-electron atoms, the average electron radius (r) splits into the inner (r<) and outer (r>) radii. It is shown that the sum and difference of these radii constitute upper and lower bounds, respectively, to the electron-pair relative distance r(12)=(/r1-r2/). An analogous result is also derived for the electron-pair center-of-mass radius (R)=(/r1+r2//2). For the 102 atoms He through Lr in their ground states, the tightness of these bounds is numerically examined at the Hartree-Fock limit level. Good linear correlations are observed between (r12) and (r>), and between (R) and (r>)/2. 相似文献
864.
865.
866.
Xie H Wang T Matsuda H Morikawa T Yoshikawa M Tani T 《Chemical & pharmaceutical bulletin》2005,53(11):1416-1422
The 80% aqueous acetone extract from the whole plant of Saussurea medusa MAXIM. was found to inhibit rat lens aldose reductase (IC50=1.4 microg/ml). From this extract, flavonoids, lignans, and quinic acid derivatives were isolated together with two new ionone glycosides, saussureosides A and B. Their absolute stereostructures were elucidated on the basis of chemical and physicochemical evidence including the application of modified Mosher's method. In addition, some isolates were found to show an inhibitory effect on aldose reductase. 相似文献
867.
Iwai Y Kita K Matsushita Y Yamauchi A Kihara M 《Chemical & pharmaceutical bulletin》2002,50(3):441-443
The new coupling reaction of phenacylamines with silylstannane and lithium diisopropylamide (LDA) is reported. The treatment of a phenacylamine iodide 1 with (trimethylsilyl)tributylstannane (Me3SiSnBu3) and cesium fluoride (CsF) gave a dimerization product 2 having no iodine atom. Reaction of 1 with LDA afforded a dimerization product 3 with an iodine atom. The products 2 and 3 were separated to the meso and racemic isomers, respectively. 相似文献
868.
Takahisa Anada Masako Ogawa Hisashi Yokomizo Yoshihisa Ozaki Tohru Takarada Yoshiki Katayama Mizuo Maeda 《Analytical sciences》2003,19(1):73-77
We describe here a method of affinity capillary electrophoresis in which oligodeoxynucleotide (ODN) was immobilized onto the inner surface of the capillary. The immobilized ODN functioned successfully as an affinity ligand for sequence-based DNA separation. Six- or 12-mer ODN with a sequence complementary to one of the c-K-ras gene was used as an immobilized ligand. When the 12-mer ODN was used, the detection peak for the complementary ODN disappeared selectively, while the single-base mutant was detected as usual. In contrast, when the 6-mer ODN was used as the affinity ligand with a mixture of the complementary ODN and its single-base mutant, it was possible to detect both as completely separate peaks. That is, the separation mode was dependent on the base number of the immobilized ODN used as an affinity ligand. 相似文献
869.
Effective and convenient syntheses of solenopsin A and B have been developed which involve the Beckman rearrangement-alkylation reaction promoted by organoaluminum reagents and a new stereoselective reduction of imino functional group. 相似文献
870.