全文获取类型
收费全文 | 988篇 |
免费 | 24篇 |
国内免费 | 6篇 |
专业分类
化学 | 508篇 |
晶体学 | 2篇 |
力学 | 67篇 |
数学 | 220篇 |
物理学 | 221篇 |
出版年
2023年 | 8篇 |
2022年 | 18篇 |
2021年 | 17篇 |
2020年 | 19篇 |
2019年 | 23篇 |
2018年 | 19篇 |
2017年 | 20篇 |
2016年 | 52篇 |
2015年 | 25篇 |
2014年 | 32篇 |
2013年 | 53篇 |
2012年 | 68篇 |
2011年 | 87篇 |
2010年 | 49篇 |
2009年 | 43篇 |
2008年 | 59篇 |
2007年 | 70篇 |
2006年 | 41篇 |
2005年 | 41篇 |
2004年 | 40篇 |
2003年 | 42篇 |
2002年 | 24篇 |
2001年 | 12篇 |
2000年 | 11篇 |
1999年 | 8篇 |
1998年 | 4篇 |
1997年 | 8篇 |
1996年 | 11篇 |
1995年 | 15篇 |
1994年 | 11篇 |
1993年 | 9篇 |
1992年 | 6篇 |
1991年 | 7篇 |
1990年 | 5篇 |
1989年 | 6篇 |
1988年 | 3篇 |
1986年 | 8篇 |
1985年 | 6篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1981年 | 4篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 7篇 |
1977年 | 5篇 |
1976年 | 1篇 |
1975年 | 2篇 |
1974年 | 4篇 |
1973年 | 1篇 |
排序方式: 共有1018条查询结果,搜索用时 421 毫秒
101.
M. Fabrizio G. Matarazzo M. Pecoraro 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2011,62(6):1013-1026
In this paper, by an extension of the Ginzburg–Landau theory, we propose a mathematical model describing hard magnets within which we are able to explore the para–ferromagnetic transition and by using the Landau–Lifshitz–Gilbert equation, to study the 3D evolution of magnetic field. Finally, the hysteresis loops are obtained and represented by numerical implementations. 相似文献
102.
103.
Badaloni E Barbarino M Cabri W D'Acquarica I Forte M Gasparrini F Giorgi F Pierini M Simone P Ursini O Villani C 《Journal of chromatography. A》2011,1218(25):3862-3875
New monolithic HPLC columns were prepared by γ-radiation-triggered polymerization of hexyl methacrylate and ethylene glycol dimethacrylate monomers in the presence of porogenic solvents. Polymerization was carried out directly within capillary (250-200 μm I.D.) and nano (100-75 μm I.D.) fused-silica tubes yielding highly efficient columns for cap(nano)-LC applications. The columns were applied in the complete separation of core (H2A, H2B, H3, and H4) and linker (H1) histones under gradient elution with UV and/or electrospray ionization (ESI) ion trap mass spectrometry (MS) detections. Large selectivity towards H1, H2A-1, H2A-2, H2B, H3-1, H3-2 and H4 histones and complete separation were obtained within 8 min time windows, using fast gradients and very high linear flow velocities, up to 11 mm/s for high throughput applications. The method developed was the basis of a simple and efficient protocol for the evaluation of post-translational modifications (PTMs) of histones from NCI-H460 human non-small-cell lung cancer (NSCLC) and HCT-116 human colorectal carcinoma cells. The study was extended to monitoring the level of histone acetylation after inhibition of Histone DeACetylase (HDAC) enzymes with suberoylanilide hydroxamic acid (SAHA), the first HDAC inhibitor approved by the FDA for cancer therapy. Attractive features of our cap(nano)-LC/MS approach are the short analysis time, the minute amount of sample required to complete the whole procedure and the stability of the polymethacrylate-based columns. A lab-made software package ClustMass was ad hoc developed and used to elaborate deconvoluted mass spectral data (aligning, averaging, clustering) and calculate the potency of HDAC inhibitors, expressed through a Relative half maximal Inhibitory Concentration parameter, namely R_IC(50) and an averaged acetylation degree. 相似文献
104.
Acid-base interaction between transition-metal hydrides: dihydrogen bonding and dihydrogen evolution
105.
A system with piecewise linear restoring forces, typical of damaged beams with a breathing crack, exhibits bifurcations characterized
by the onset of superabundant modes in internal resonance with a significantly different shape than that of modes on a fundamental
branch. A 2-DOF frame with piecewise linear stiffness is analyzed by means of an experimental investigation; the frame is
forced by an harmonic base excitation and the operative modal shapes as well as the response amplitude are directly measured;
the results are compared with numerical outcomes for different damping values. This study shows that the shapes and the frequencies
of certain nonlinear normal modes (NNMs) of the related autonomous system strongly affect the forced response, in both the
numerical and the experimental environments. Therefore, it is possible to match the NNM with the forced response of the system,
leading to the prospect of identifying the severity and position of the damage from experimental tests. 相似文献
106.
Fabrizio Caselli 《Israel Journal of Mathematics》2011,185(1):155-187
107.
We compare the two methods of deriving interaction-induced pair polarizabilities from collision-induced, depolarized spectra, namely classical line shape and moment analysis. We discuss their limitations and show that the joint use of line shape and moment analysis leads to the determination of an empirical pair polarizability anisotropy model which has maximal consistency with the available experimental results. We have applied the combined method to the pair spectrum of argon at room temperature (298 K) as an example. 相似文献
108.
109.
The development of a straightforward synthesis of 4-amino-6-benzyl-6H-pyrrolo[3,4-d]pyrimidine and 7-amino-2-benzyl-2H-pyrazolo[4,3-d]pyrimidine derivatives allowed for the preparation of a small family of potential Hsp90 inhibitors. Some of the newly synthesized compounds showed Hsp90 inhibitory activity in preliminary biological assays. 相似文献
110.
We present a moment analysis of the experimental two-body collision induced light scattering spectrum of argon which allows the determination of a three-parameter empirical form for the collision induced pair-polarizability anisotropy. The result of the calculation shows that beside the DID and the exponential short-range terms also an intermediate-range term gives an important contribution to the pair polarizability. 相似文献